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1
Nishikawa, Masanori, Tetsuya Hiyama, Kazuhisa Tsuboki, and Yoshihiro Fukushima. "Numerical Simulations of Local Circulation and Cumulus Generation over the Loess Plateau, China." Journal of Applied Meteorology and Climatology 48, no. 4 (April 1, 2009): 849–62. http://dx.doi.org/10.1175/2008jamc2041.1.
Анотація:
Abstract The Loess Plateau of China consists of dissected flat tablelands with steep gullies. To evaluate the effect of topography on local circulation and cumulus generation over the Loess Plateau, numerical simulations of atmospheric boundary layer (ABL) development were conducted using a cloud-resolving nonhydrostatic model. Two types of numerical simulation were carried out under two sets of bottom boundary conditions: real terrain and flat terrain. The differences in ABL development and cumulus generation between the flat- and real-terrain conditions are described and the local circulation structures induced by ABL development are illustrated. More cumulus clouds were generated over the real terrain than over the flat terrain. In the real-terrain case, large amounts of cumulus cloud were generated on the windward slopes and on the edge of the tableland, with updrafts caused by thermal generation and a local circulation developing with horizontal and vertical scales of several kilometers. Cumulus clouds clearly developed at the top of the ABL because the water vapor is nonhomogeneously lifted by the local circulation on windward slopes and on edge of the tableland. Thus, the topography of the Loess Plateau plays an important role in cumulus generation.
2
AL.Rubaei, Hashm M., and Hyder M. Abd Ali. "Efficacy of Different Oocytes Harvesting Methods on Retrieval and Quality of Oocyte from Ovaries of Local Cows." JOURNAL OF UNIVERSITY OF BABYLON for Pure and Applied Sciences 26, no. 10 (December 24, 2018): 242–48. http://dx.doi.org/10.29196/jubpas.v26i10.1878.
Анотація:
The aim of this study was to investigate the effect of different oocytes harvesting methods on retrieval and quality of oocyte from ovarian of local cows. The ovaries (n = 600) were collected from 300 non-pregnant cows their ages ranged between (3-10 years old), slaughtered at the abattoir of Babylon province during the period between September 2017 to March 2018. The oocytes were collected by slicing method, puncture method and aspiration of follicle method and classified according to layers of cumulus cells and the homogenous of cytoplasm into three groups , first group : good quality oocytes with more than 3 layers of cumulus cells and homogeneous of cytoplasm, second group : fair quality oocytes with less than 3 layers of cumulus cells and homogeneous of cytoplasm , third group : poor quality oocytes , denuded oocyte from cumulus cells with heterogeneous cytoplasm . The results showed that the total number of oocytes recovered and the number of oocytes recovered per ovary was significantly higher (P<0.05) by using slicing method (1639 and 8.195 ± 1.03 respectively) compared with the Puncture (923 and 4.610 ± 0.86 respectively ) and aspiration of follicle method (776 and 3.880 ± 0.34 respectively). The results of study also indicated that the total number of oocytes recovered , the average number of oocyte per ovary and the percentage of well recovered by slicing method (751,3.750 ± 0.95 and 45.90 % respectively) and puncture technique (399,1.99 ± 0.03 and 43.30 % respectively) were significantly higher ( P<0.05) compared with aspiration of follicle (299 , 1.14 ± 0.01 and 29.60 % respectively). We conclude from this study that slicing method is the appropriate and good method for oocyte recovering with ideal morphological aspect and quality.
3
Gristey, Jake J., Graham Feingold, Ian B. Glenn, K. Sebastian Schmidt, and Hong Chen. "Surface Solar Irradiance in Continental Shallow Cumulus Fields: Observations and Large-Eddy Simulation." Journal of the Atmospheric Sciences 77, no. 3 (March 1, 2019): 1065–80. http://dx.doi.org/10.1175/jas-d-19-0261.1.
Анотація:
Abstract This study examines shallow cumulus cloud fields and their surface shortwave radiative effects using large-eddy simulation (LES) along with observations across multiple days at the Atmospheric Radiation Measurement Southern Great Plains atmospheric observatory. Pronounced differences are found between probability density functions (PDFs) of downwelling surface solar irradiance derived from observations and LES one-dimensional (1D) online radiation calculations. The shape of the observed PDF is bimodal, which is only reproduced by offline three-dimensional (3D) radiative transfer calculations, demonstrating PDF bimodality as a 3D radiative signature of continental shallow cumuli. Local differences between 3D and 1D radiative transfer calculations of downwelling surface solar irradiance are, on average, larger than 150 W m−2 on one afternoon. The differences are substantially reduced when spatially averaged over the LES domain and temporally averaged over the diurnal cycle, but systematic 3D biases ranging from 2 to 8 W m−2 persist across different days. Covariations between the domain-averaged surface irradiance, framed as a surface cloud radiative effect, and the simulated cloud fraction are found to follow a consistent diurnal relationship, often exhibiting hysteresis. In contrast, observations show highly variable behavior. By subsampling the LES domain, it is shown that this is due to the limited sampling density of inherently 3D observations. These findings help to define observational requirements for detecting such relationships, provide valuable insight for evaluating weather and climate models against surface observations as they push to ever higher resolutions, and have important implications for future assessments of solar renewable energy potential.
4
Lehmann, Katrin, Holger Siebert, and Raymond A. Shaw. "Homogeneous and Inhomogeneous Mixing in Cumulus Clouds: Dependence on Local Turbulence Structure." Journal of the Atmospheric Sciences 66, no. 12 (December 1, 2009): 3641–59. http://dx.doi.org/10.1175/2009jas3012.1.
Анотація:
Abstract The helicopter-borne instrument payload known as the Airborne Cloud Turbulence Observation System (ACTOS) was used to study the entrainment and mixing processes in shallow warm cumulus clouds. The characteristics of the mixing process are determined by the Damköhler number, defined as the ratio of the mixing and a thermodynamic reaction time scale. The definition of the reaction time scale is refined by investigating the relationship between the droplet evaporation time and the phase relaxation time. Following arguments of classical turbulence theory, it is concluded that the description of the mixing process through a single Damköhler number is not sufficient and instead the concept of a transition length scale is introduced. The transition length scale separates the inertial subrange into a range of length scales for which mixing between ambient dry and cloudy air is inhomogeneous, and a range for which the mixing is homogeneous. The new concept is tested on the ACTOS dataset. The effect of entrained subsaturated air on the droplet number size distribution is analyzed using mixing diagrams correlating droplet number concentration and droplet size. The data suggest that homogeneous mixing is more likely to occur in the vicinity of the cloud core, whereas inhomogeneous mixing dominates in more diluted cloud regions. Paluch diagrams are used to support this hypothesis. The observations suggest that homogeneous mixing is favored when the transition length scale exceeds approximately 10 cm. Evidence was found that suggests that under certain conditions mixing can lead to enhanced droplet growth such that the largest droplets are found in the most diluted cloud regions.
5
Klinger, Carolin, Bernhard Mayer, Fabian Jakub, Tobias Zinner, Seung-Bu Park, and Pierre Gentine. "Effects of 3-D thermal radiation on the development of a shallow cumulus cloud field." Atmospheric Chemistry and Physics 17, no. 8 (April 28, 2017): 5477–500. http://dx.doi.org/10.5194/acp-17-5477-2017.
Анотація:
Abstract. We investigate the effects of thermal radiation on cloud development in large-eddy simulations (LESs) with the UCLA-LES model. We investigate single convective clouds (driven by a warm bubble) at 50 m horizontal resolution and a large cumulus cloud field at 50 and 100 m horizontal resolutions. We compare the newly developed 3-D Neighboring Column Approximation with the independent column approximation and a simulation without radiation and their respective impact on clouds. Thermal radiation causes strong local cooling at cloud tops accompanied by a modest warming at the cloud bottom and, in the case of the 3-D scheme, also cloud side cooling. 3-D thermal radiation causes systematically larger cooling when averaged over the model domain. In order to investigate the effects of local cooling on the clouds and to separate these local effects from a systematically larger cooling effect in the modeling domain, we apply the radiative transfer solutions in different ways. The direct effect of heating and cooling at the clouds is applied (local thermal radiation) in a first simulation. Furthermore, a horizontal average of the 1-D and 3-D radiation in each layer is used to study the effect of local cloud radiation as opposed to the domain-averaged effect. These averaged radiation simulations exhibit a cooling profile with stronger cooling in the cloudy layers. In a final setup, we replace the radiation simulation by a uniform cooling of 2.6 K day−1. To focus on the radiation effects themselves and to avoid possible feedbacks, we fixed surface fluxes of latent and sensible heat and omitted the formation of rain in our simulations. Local thermal radiation changes cloud circulation in the single cloud simulations, as well as in the shallow cumulus cloud field, by causing stronger updrafts and stronger subsiding shells. In our cumulus cloud field simulation, we find that local radiation enhances the circulation compared to the averaged radiation applications. In addition, we find that thermal radiation triggers the organization of clouds in two different ways. First, local interactive radiation leads to the formation of cell structures; later on, larger clouds develop. Comparing the effects of 3-D and 1-D thermal radiation, we find that organization effects of 3-D local thermal radiation are usually stronger than the 1-D counterpart. Horizontally averaged radiation causes more clouds and deeper clouds than a no radiation simulation but, in general less-organized clouds than in the local radiation simulations. Applying a constant cooling to the simulations leads to a similar development of the cloud field as in the case of averaged radiation, but less water condenses overall in the simulation. Generally, clouds contain more liquid water if radiation is accounted for. Furthermore, thermal radiation enhances turbulence and mixing as well as the size and lifetime of clouds. Local thermal radiation produces larger clouds with longer lifetimes. The cloud fields in the 100 and 50 m resolution simulations develop similarly; however, 3-D local effects are stronger in the 100 m simulations which might indicate a limit of our 3-D radiation parameterization.
6
Gomez, Ma Ninia L., Jung Taek Kang, Ok Jae Koo, Su Jin Kim, Dae Kee Kwon, Sol Ji Park, Mohammad Atikuzzaman, So Gun Hong, Goo Jang, and Byeong Chun Lee. "Effect of oocyte-secreted factors on porcine in vitro maturation, cumulus expansion and developmental competence of parthenotes." Zygote 20, no. 2 (July 27, 2011): 135–45. http://dx.doi.org/10.1017/s0967199411000256.
Анотація:
SummaryThe oocyte is known from recent studies in the mouse, cow, sheep and human to be a central regulator of follicular cell function. However, in the pig, little information is known about the regulation of cumulus expansion by oocyte-secreted factors and oocyte quality. We investigated the possible effects of oocyte-secreted factors during in vitro maturation on cumulus expansion and on porcine oocytes as judged by subsequent embryonic development after parthenogenetic activation. Cumulus–oocyte complexes (COC) from antral follicles of pig ovaries collected from a local abattoir were divided into control and treatment groups and were cultured in tissue culture medium 199 supplemented with follicle-stimulating hormone. Treatment groups consisted of increasing numbers of denuded oocytes (DO) co-cultured with COC (at ratios of COC to DO of 1:1, 1:2, 1:3, 1:4 and 1:5). After incubation for 44 h, cumulus expansion and maturation rates were assessed and oocytes were activated parthenogenetically. Cumulus expansion in the 1 COC:4 DO and 1 COC:5 DO groups was low and altered because full dispersion of the outer layer did not occur. Cell viability was not affected, as measured by the automated cell counter, but scanning electron microscopy revealed only a scanty extracellular matrix. Blastocyst rate was significantly higher in the 1 COC:4 DO (34.4%) and in the 1 COC:5 DO (34.9%) groups (p < 0.05) when compared with other groups. Maturation rate, cleavage rate and total cell number showed no significant difference between control and treatment groups. Amplification by reverse transcription polymerase chain reaction (RT-PCR) showed up-regulation of growth differentiation factor 9 (GDF9) in the cumulus cells in the 1 COC:4 DO group at 44 h. We conclude that denuded porcine oocytes could improve the maturation of COC as evidenced by increased blastocyst development in the 1 COC:4 DO, even though cumulus expansion was poor. This improvement could be a result of the GDF9 up-regulation.
7
Nguyen, B. X., T. Nagai, K. Kukuchi, N. T. Uoc, M. Ozawa, N. V. Linh, N. H. Duc, D. N. Q. Thanh, N. V. Hanh, and Q. X. Huu. "308 EFFECT OF GONADOTROPIN TREATMENT ON OOCYTE COLLECTION AND IN VITRO FERTILIZATION IN THE BAN MINIPIG." Reproduction, Fertility and Development 19, no. 1 (2007): 269. http://dx.doi.org/10.1071/rdv19n1ab308.
Анотація:
The Ban minipig is a local breed characterized by small ovaries with a scant number of follicles available for in vitro maturation (IVM). The combination of eCG and hCG has been used successfully to control estrus in pig breeding programs. In this paper we present the first results of IVF in this breed in comparison with 2 types of oocyte preparation: (1) from animals not receiving gonatotropin treatment (group 1, n = 9); and (2) from animals receiving an injection of mixed pregnant mare serum gonadotropin and hCG, 300 IU/animal, for 3 days before oocyte collection (group 2, n = 4). All animals were 1 to 3 years old and with body weights that varied from 8 to 12 kg. At the time of collection, the ovaries were observed for follicle development; the cumulus–oocyte complexes (COCs) were aspirated using a 18-gauge needle. COCs of categories A (with more than 4 layers of cumulus cells) and B (with 2 to 4 layers of cumulus cells) were collected and matured in vitro as described previously (Kikuchi et al. 2002 Biol. Reprod. 66, 1033–1041) at 39�C under 5% CO2 in air. Matured oocytes with expanding cumulus cells were inseminated using male Ban minipig epididymal semen frozen by the methods reported by Kikuchi et al. (1998 Theriogenology 50, 615–623). The frozen–thawed spermatozoa were pre-incubated for 1 h in modified medium-199 adjusted to pH 7.8 in the incubator at 37�C. The capacitated spermatozoa were diluted and added to drops of fertilization medium (Fig-FM; Suzuki et al. 2002 Int. J. Androl. 123, 135–142) containing oocytes; the final concentration of sperm was 106/mL. After 3 h of co-incubation, attached spermatozoa and cumulus cells were removed from oocytes and the oocytes were the cultured in vitro as described previously (Kikuchi et al. 2002). The results obtained from 4 replicates showed that the number of follicles with a diameter larger than 2 mm and the rates of oocytes categorized as A and B were significantly lower (P < 0.05; ANOVA test) in the nontreated animals (0.0 and 67.5%, respectively) than in the treated group (25.5 and 87.1%, respectively). The rates of oocytes with a clearly expanding cumulus obtained after IVM were 78.6 (n = 136) and 88.1% (n = 101) for groups 1 and 2, respectively. The rates of cleaved embryos and embryos developed to the compact morula stage were 47.2 and 9.1% (n = 39), respectively, for group 1; and 89.1 and 18.8% (n = 101), respectively, for group 2. In conclusion, gonadotropin treatment before the collection of oocytes is recommended for application of IVM–IVF to local Ban minipigs. This work was supported by a grant from the VAST-Japan Society for the Promotion of Science Project.
8
Tchein, Gnon, Tounou Agbéko Kodjo, Agboka Komi, and Tchegueni Matotiloa. "Evaluation d’utilités attendues des attributs de cultivars de l’igname: base d’une gestion locale de l’agrobiodiversité de Dioscorea spp au Sud-ouest des Savanes Sèches au Togo (Afrique de l’Ouest)." Journal of Applied Biosciences 153 (September 30, 2020): 15756–79. http://dx.doi.org/10.35759/jabs.153.4.
Анотація:
Objectif : La présente étude vise à évaluer et à prioriser le niveau de satisfaction des utilités attendues des cultivars d’igname auprès 1032 acteurs locaux de la filière igname au Sud-ouest des Savanes Sèches au Togo. Méthodologie et résultats: Le brainstorming, le scoring et les avis d’experts, ont permis la définition de quinze descripteurs d’utilités des cultivars, dont les notes d’appréciation ont révélé une corrélation positive significative entre attributs. L’ensemble des attributs a été priorisé en trois classes selon la loi 80/20 (la loi de Pareto). Valeur marchande, nom de cultivar à connotation d’image et gros et longs tubercules ont constitué la principale classe d’attributs avec des notes moyennes d’utilités significatives et respectivement de 9,52 ; 7,28 et 2,28. Ils ont satisfait à 63,91% des utilités cumulées attendues des attributs de tous les cultivars. De tous, le lieu de production à image de qualité (0,80) et la résilience aux divers stresseurs, (0,34) ont été faiblement apprécié. Les effets de l’âge et du sexe des participants sur les notes d’appréciation de l’utilité n‘ont pas été perçus. Conclusion et application des résultats: Les utilités cumulées attendues ont été satisfaites à 63,91% par 20% des attributs en culture d’igname et une faible atteinte d’utilité cumulée de 36,07% par 80% du reste des attributs. De futurs programmes d’amélioration variétale pourront prendre en compte la satisfaction des utilités attendues des ignames. Une piste de production labélisée des tubercules et de leurs transformations élargies aux potentialités de tous les cultivars peuvent constituer une application à envisager sur la base des présents résultats et limiter ainsi l’érosion génétique de la culture d’igname. Mots clés : ignames, attributs, priorisation, utilités attendues, Savanes Sèches, Togo. Gnon et al., J. Appl. Biosci. 2020 Evaluation d’utilités attendues des attributs de cultivars de l’igname : base d’une gestion locale de l’agrobiodiversité de Dioscorea spp au Sud-ouest des Savanes Sèches au Togo (Afrique de l’Ouest) 15765 Evaluation of expected utilities of yam cultivar attributes : a local base for agrobiodiversty management of Dioscorea spp in Southwest Dry Savannahs in Togo (West Africa) ABSTRACT Objectives: The present study aims to evaluate and prioritize the level of satisfaction of the expected utilities of yam cultivars by local actors of the yam sector in the South-West of Dry Savannah in Togo. Methodology and results: The scoring and the expert opinions, allowed the definition of fifteen cultivar attribute descriptors by 1032 actors of the yam sector followed by their prioritization in three distinct classes by the law 80/20. The average utilities of the main attributes: market value, cultivar name with image connotation and large and long tubers were respectively 9.52; 7.28 and 2.28. They represented 63.91% of the expected cumulative utilities of all attributes. The effects of age and sex on expected utility ratings were not seen in this study. Conclusion and application of the findings: 20% of the attributes fulfilled 63.91% of cumulative utilities expected in yam culture and posing the problem of the low cumulative utility of 36.07% by 80% of the attributes. Thus, future research to improve a satisfaction of utilities of the 80% of attributes is necessary. Future varietal improvement programs, may take into account the satisfaction of the expected utilities of yams. A path of labeled production of tubers and their transformations extended to the potential of all cultivars may constitute an application to be considered on the basis of the present results and thus limit the genetic erosion of the yam crop. Keywords: yams, attributes, prioritization, expected utilities, Dry Savannahs, Togo.
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Abdel-Halim, B. R., and Nermeen A. Helmy. "Effect of nano-selenium and nano-zinc particles during in vitro maturation on the developmental competence of bovine oocytes." Animal Production Science 58, no. 11 (2018): 2021. http://dx.doi.org/10.1071/an17057.
Анотація:
The objectives of the current study were to evaluate the effects of supplemental nano-selenium (NSe) and nano-zinc oxide (NZn-O) particles during in vitro maturation (IVM) on DNA damage of cumulus cells, glutathione (GSH) concentration in bovine oocytes, subsequent embryo development and re-expansion rate of vitrified warmed blastocysts. The current study was conducted on bovine ovaries obtained from a local abattoir and transported to the laboratory in sterile phosphate buffer saline with antibiotics at 37°C, within 1 h after slaughter. Ovaries were pooled, regardless of stage of the oestrous cycle of the donor. Only cumulus-intact complexes with evenly granulated cytoplasm were selected for IVM. Experimental design included the following: Experiment 1 studied the effect of addition of 1.0 µg/mL NSe or NZn-O to IVM medium on DNA damage of cumulus cells; Experiment 2 evaluated the effects of NSe or NZn-O on intracellular glutathione in oocytes and cumulus cells; in Experiment 3, the development of oocytes matured in IVM medium supplemented with 1.0 µg/mL NSe or NZn-O was investigated; and in Experiment 4, the effects of adding 1.0 µg/mL NSe and NZn-O to in vitro fertilisation media on vitrified oocytes and embryos were investigated. The DNA damage in cumulus cells decreased with supplemental NSe and NZn-O at concentration of 1 µg/mL in the IVM medium (180.2 ± 21.4, 55.8 ± 4.3 and 56.6 ± 3.9 for the control and NSe and NZn-O groups respectively). Total GSH concentrations increased following supplementation with 1 µg/mL NSe and 1 µg/mL NZn-O, compared with the control group. Re-expansion rate of vitrified warmed blastocysts in experimental media containing NSe and NZn-O with ethylene glycol was higher than that of the control. In conclusion, providing NSe and NZn-O during oocyte maturation significantly increased both intracellular GSH concentration and DNA integrity of cumulus cells. Optimal embryo development was partially dependent on the presence of NSe and NZn-O during IVM. NSe and NZn-O during oocyte maturation act as a good cryoprotective agents of vitrified, warmed blastocysts.
10
Widyastuti, Rini, Mas Rizky A. A. Syamsunarno, Takdir Saili, and Arief Boediono. "Oocyte Quality and Subsequent In Vitro Maturation of Sheep Oocyte-Cumulus Complex from Ovary with Presence and Absence of Corpus Luteum." KnE Life Sciences 3, no. 6 (December 3, 2017): 166. http://dx.doi.org/10.18502/kls.v3i6.1125.
Анотація:
In vitro maturation is the crucial step for in vitro embryo production. It needs a large number of oocytes as source gamet cells recovered. The present study is aimed to assess the influence of corpus luteum on the average number oocytes harvested, COCs quality and subsequent maturation of immature oocytes recovered from sheep ovaries. Sheep ovaries were collected from local slaughterhouse and COCs were collected by using slicing method. Collected COCs were graded into three categories dependent upon cumulus cells surrounding them and the homogenous of cytoplasm. COCs were maturated in maturation media at 5% CO2 for 24 hours. Maturation of oocytes evaluated base on the expansion of cumulus cells and extrusion of the first polar body. There was significantly higher on average of COCs harvested from ovaries with corpus luteum compared without corpus luteum. The presence of Corpus luteum did not affect the COCs quality and ability to reach the maturation stage. However, there was a dramatic effect of cultured COCs quality on maturation rate both groups. Collectively, these results indicate that COCs quality is the main factor affecting the subsequent of oocytes matured in vitro. Keywords: Corpus luteum; cumulus oocyte complex; in vitro maturation; maturation rate; ovaries
11
Kang, J. K., O. J. Koo, D. K. Kwon, G. Jang, S. K. Kang, D. Y. Kim, and B. C. Lee. "245 EFFECTS OF MELATONIN ON THE IN VITRO OOCYTE MATURATION OF PORCINE CUMULUS - OOCYTE COMPLEXES." Reproduction, Fertility and Development 20, no. 1 (2008): 202. http://dx.doi.org/10.1071/rdv20n1ab245.
Анотація:
In mammalian species, melatonin is a multifunctional hormone that mediates several circadian and seasonal processes, including reproduction. In addition to its hormonal actions, melatonin has a strong antioxidant effect and acts as a powerful free radical scavenger. Accordingly, the objective of this study was to investigate the local expression of the melatonin-receptor I (Mel-RI) gene and the effect of melatonin as an antioxidant on the in vitro maturation of porcine cumulus–oocyte complexes. Oocytes were obtained from aspiration of slaughterhouse ovaries and then matured in tissue culture medium 199 (TCM199) supplemented with 0.1% polyvinyl alcohol (PVA), 20 ng mL–1 epidermal growth factor (EGF), and 4 IU mL–1 pregnant mare serum gonadotropin (PMSG)/hCG. Expression of Mel-RI gene in cumulus cells, granulosa cells, or oocytes was evaluated by RT-PCR (Exp 1). The effect of various concentrations (0, 10, 50, and 100 ng mL–1) of melatonin on the in vitro maturation in terms of nuclear maturation (polar body extrusion) (Exp 2) and measurement of reactive oxygen species (ROS) by dichlorohydrofluorescein diacetate (Yang et al. 1998 Hum. Reprod. 13, 998–1002) (Exp 3) were investigated. Each experiment was replicated at least four times, and each replication included more than thirty oocytes. For statistical analysis, one-way anova in the Prizm software program (GraphPad, San Diego, CA, USA) was used. The Mel-RI gene was locally expressed in cumulus and granulosa cells but not in oocytes. Melatonin at 10 ng mL–1 had a beneficial effect on in vitro maturation (84.6%) compared to 0 ng mL–1 (75.6%), 50 ng mL–1 (80.9%), and 100 ng mL–1 (76.5%). Levels of ROS were also significantly decreased by melatonin treatment at 10 (14.07), 50 (14.42), and 100 ng mL–1 (13.03) of melatonin (P < 0.001) compared to that of the control group (28.21). The presence of melatonin receptor in cumulus cells and granulosa cells indicates a potentially important role for this hormone in regulating porcine ovarian and reproduction function. In conclusion, the present study demonstrated that melatonin had a beneficial effect on in vitro maturation of porcine cumulus–oocyte complexes, probably through binding a receptor and decreased ROS production. Further studies are required to elucidate the relationship between the appearance of melatonin receptor and mechanisms of melatonin function in the embryo.
12
Deetz, Konrad, Heike Vogel, Peter Knippertz, Bianca Adler, Jonathan Taylor, Hugh Coe, Keith Bower, et al. "Numerical simulations of aerosol radiative effects and their impact on clouds and atmospheric dynamics over southern West Africa." Atmospheric Chemistry and Physics 18, no. 13 (July 11, 2018): 9767–88. http://dx.doi.org/10.5194/acp-18-9767-2018.
Анотація:
Abstract. Southern West Africa (SWA) is undergoing rapid and significant socioeconomic changes associated with a massive increase in air pollution. Still, the impact of atmospheric pollutants, in particular that of aerosol particles, on weather and climate in this region is virtually unexplored. In this study, the regional-scale model framework COSMO-ART is applied to SWA for a summer monsoon process study on 2–3 July 2016 to assess the aerosol direct and indirect effect on clouds and atmospheric dynamics. The modeling study is supported by observational data obtained during the extensive field campaign of the project DACCIWA (Dynamics–Aerosol–Chemistry–Cloud Interactions in West Africa) in June–July 2016. As indicated in previous studies, a coastal front is observed that develops during daytime and propagates inland in the evening (Atlantic inflow). Increasing the aerosol amount in COSMO-ART leads to reduced propagation velocities with frontal displacements of 10–30 km and a weakening of the nocturnal low-level jet. This is related to a subtle balance of processes related to the decrease in near-surface heating: (1) flow deceleration due to reduced land–sea temperature contrast and thus local pressure gradient, (2) reduced turbulence favoring frontal advance inland and (3) delayed stratus-to-cumulus transition of 1–2 h via a later onset of the convective boundary layer. The spatial shift of the Atlantic inflow and the temporal shift of the stratus-to-cumulus transition are synergized in a new conceptual model. We hypothesize a negative feedback of the stratus-to-cumulus transition on the Atlantic inflow with increased aerosol. The results exhibit radiation as the key player governing the aerosol affects on SWA atmospheric dynamics via the aerosol direct effect and the Twomey effect, whereas impacts on precipitation are small.
13
Wang, Guang Bin, Xue Jun Li, and Ke Wang. "Signal Denoise Method Based on the Higher Order Cumulant and Local Tangent Space Mean Reconstruction." Advanced Engineering Forum 2-3 (December 2011): 188–92. http://dx.doi.org/10.4028/www.scientific.net/aef.2-3.188.
Анотація:
In signal denoise method to nonlinear time series based on principle manifold learning, reduction target dimension is chosen at random, which cause low efficiency. Local low dimensional manifold is obtained by the eigenvalue decomposition to the covariance matrix, but covariance belongs to the second order statistics and cannot reflect the nonlinear essential structure of signal, these reduce denoise efficiency and effect. In order to solve these problem, a new denoise algorithm based on the higher order cumulant and local tangent space mean reconstruction is proposed in this reserch. First, the signal's intrinsic dimension is obtained as dimension of reduction targets by maximum likelihood estimation. And then making use of restraining character to colored noise of high order cumulan,covariance matrix is constructed by high order cumulant function instead of second order moment function. The data outside intrinsic dimension space will be regarded as noise signal to be eliminated. Finanly the process of global array by affine transformation will be replaced by mean reconstruction,the data after denoise may be obtained in the inverse process of the phase space reconstruction. The effectiveness of the algorithm is verified through the denoise experiment in fan vibration signal with noise.
14
Abma, Dick, Thijs Heus, and Juan Pedro Mellado. "Direct Numerical Simulation of Evaporative Cooling at the Lateral Boundary of Shallow Cumulus Clouds." Journal of the Atmospheric Sciences 70, no. 7 (July 1, 2013): 2088–102. http://dx.doi.org/10.1175/jas-d-12-0230.1.
Анотація:
Abstract This study investigates the dynamics of the subsiding shell at the lateral boundary of cumulus clouds, focusing on the role of evaporative cooling. Since the size of this shell is well below what large-eddy simulations can resolve, the authors have performed direct numerical simulations of an idealized subsiding shell. The system develops a self-similar, Reynolds number–independent flow that allows for the determination of explicit scaling laws relating the characteristic length, time, and velocity scales of the shell. It is found that the shell width grows quadratically in time, linearly with the traveled distance. The magnitude of these growth rates shows that evaporative cooling, in its most idealized form, is capable of producing a fast-growing shell with numbers that are consistent with observations of the subsiding shell around real shallow cumulus clouds: for typical thermodynamic conditions in cumulus clouds, a velocity on the order of 1 m s−1 and a thickness on the order of 10 m are established in about 2 min. This fits well within the typical cloud lifetime, suggesting that this idealization is an adequate framework for the analysis of relevant aspects in the subsiding shell associated with buoyancy reversal. It also indicates that the scaling laws derived here can be used to estimate the potential strength of a subsiding shell and the mean lateral entrainment associated with it, once an estimate of the local thermodynamical state of the cloud boundary is provided. It is shown that the dominant parameter of this system is the saturation buoyancy, whereas the effect of the saturation mixing fraction is minor.
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Jin, J. X., S. Lee, A. Taweechaipaisankul, G. A. Kim, and B. C. Lee. "71 MELATONIN IMPROVES PORCINE IN VITRO MATURATION VIA SONIC HEDGEHOG SIGNALLING." Reproduction, Fertility and Development 29, no. 1 (2017): 143. http://dx.doi.org/10.1071/rdv29n1ab71.
Анотація:
Melatonin (N-acetyl-5-methoxytryptamine) is the hormone synthesised from the mammalian pineal gland, which has an antioxidant property and regulates physiological processes such as cellular metabolism. It is well known that melatonin affects in vitro maturation of oocytes and embryonic development in many species. However, limited information is available on the underlying beneficial effects of melatonin. Sonic Hedgehog (Shh) signalling is important for follicular development, oocyte maturation, and embryo development. To elucidate the relationship between melatonin and Shh signalling, we designed an experiment with the following three groups: (1) control, (2) melatonin, and (3) melatonin with cyclopamine (smoothened inhibitor) during porcine in vitro maturation. Porcine ovaries were collected from prepubertal gilts at a local slaughterhouse and transported to the laboratory at 28 to 32°C. The contents of follicles 3 to 6 mm in diameter were recovered by aspiration with an 18 G needle. Cumulus–oocyte complexes were pooled and cultured in TCM-199 medium for 44 h. The aim of this study was to evaluate the effects of melatonin (10−9 M) with or without cyclopamine (2 μM) on cumulus cell expansion (a total of 432 cumulus–oocyte complexes were used in 3 replicates), embryo development after parthenogenetic activation (a total of 432 oocytes were used in 4 replicates). Moreover, we detected gene expression related to cumulus expansion, oocyte maturation, and hedgehog signalling in cumulus cells and oocyte. Results indicated that melatonin treatment significantly increased cumulus expansion index (3.75 ± 0.02 v. 3.51 ± 0.03 and 3.59 ± 0.05, respectively; P < 0.05) and blastocyst formation rates (30.4 ± 2.4 v. 21.9 ± 2.2 and 20.0 ± 2.2, respectively; P < 0.05) compared with control and melatonin with cyclopamine. In addition, the expression of cumulus expansion-related genes (Ptgs1, Ptgs2, Has2, Ptx-3, and Tnfaip6) and hedgehog signalling-related genes (Shh, Pthc1, Smo, and Gli-1) in cumulus cells were up-regulated in melatonin treatment compared with control and melatonin with cyclopamine. Similarly, the expressions of oocyte maturation-related genes (GDF9 and BMP15) in porcine oocytes were up-regulated in melatonin treatment compared with control and melatonin with cyclopamine. In conclusion, Shh signalling mediated melatonin to improve porcine cumulus cell expansion, oocyte maturation, and subsequent embryo development. Further studies are needed to evaluate the effect of melatonin on protein levels of Shh signalling. Statistical analyses were performed using SPSS 22.0 (SPSS Inc., Chicago, IL, USA). All data were tested for normality and homoscedasticity and then subjected to one-way ANOVA, followed by Duncan’s multiple range test (when the variances were assumed to be equal) or Dunnet’s T3 test (when the variances were assumed to be unequal) to determine differences among experimental groups. All results are expressed as means ± SEM; P-values < 0.05 were considered to be statistically significant. This study was supported by Ministry of Trade, Industry and Energy (#10048948), Korea Institute of Planning and Evaluation for Technology in Food, Agriculture, Forestry, and Fisheries (#311011–05–4-SB010, #114059–03–2-SB010), National Research Foundation (2016M3A9B6903410), China Scholarship Council (CSC, No. 2015–3022), Research Institute for Veterinary Science, TS Corporation, and the BK21 plus program.
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Widayati, Diah Tri, and Mulyoto Pangestu. "Effect of follicle-stimulating hormone on Bligon goat oocyte maturation and embryonic development post in vitro fertilization." November-2020 13, no. 11 (2020): 2443–46. http://dx.doi.org/10.14202/vetworld.2020.2443-2446.
Анотація:
Background and Aim: Bligon goat is a crossbreed between Etawah and Kacang goat. This crossbreed goat is mostly reared by small farmers. In vitro maturation allows female goat (does) contributes toward reproduction despite the fact that the animal has been slaughtered. The aim of this study was to determine the in vitro maturation rate of Bligon goat oocytes supplemented with follicle-stimulating hormone (FSH), and their ability for further embryonic development after in vitro fertilization. Materials and Methods: Experiment was conducted at the Laboratory of Animal Physiology and Reproduction, Faculty of Animal Science, Universitas Gadjah Mada, Yogyakarta, using Bligon goat ovaries obtained from local slaughterhouse around Yogyakarta. One thousand five hundred cumulus-oocyte complexes were matured for 24 h in tissue culture medium 199 supplemented with 50 IU/L FSH or without FSH (control). First, matured oocytes were evaluated its morphology based on the expansion of cumulus cells and PB1 extrusion. Next, 600 oocytes were then stained with 1% aceto-orcein to examine maturation based on changes in the configuration of chromosomes and nuclear membrane breakdown. Oocytes were considered mature when they reached metaphase II. To prove the ability of mature oocytes to develop into embryos, 900 oocytes were processed for fertilization in vitro. The data were analyzed using analysis of variance. Results: The results indicated that FSH supplementation significantly increased oocyte maturation rate (65.21±7.26 vs. 43.25±6.23%) as indicated by extrusion of PB1 and homologous chromosome pairing and lined in the equator. The rate of degeneration was lower in the FSH-supplemented medium (3.21±0.25 vs. 10.17±3.15%). The blastocyst stage of oocyte developed embryos was reached by 12.43±2.15% and 22.28±4.86% of the control and treatment groups, respectively. Conclusion: FSH supplementation significantly improves oocyte maturation and yields mature oocytes for future embryo development in vitro.
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Pedruzo-Bagazgoitia, Xabier, Stephan R. de Roode, Bianca Adler, Karmen Babić, Cheikh Dione, Norbert Kalthoff, Fabienne Lohou, Marie Lothon, and Jordi Vilà-Guerau de Arellano. "The diurnal stratocumulus-to-cumulus transition over land in southern West Africa." Atmospheric Chemistry and Physics 20, no. 5 (March 5, 2020): 2735–54. http://dx.doi.org/10.5194/acp-20-2735-2020.
Анотація:
Abstract. The misrepresentation of the diurnal cycle of boundary layer clouds by large-scale models strongly impacts the modeled regional energy balance in southern West Africa. In particular, recognizing the processes involved in the maintenance and transition of the nighttime stratocumulus to diurnal shallow cumulus over land remains a challenge. This is due to the fact that over vegetation, surface fluxes exhibit a much larger magnitude and variability than on the more researched marine stratocumulus transitions. An improved understanding of the interactions between surface and atmosphere is thus necessary to improve its representation. To this end, the Dynamics-aerosol-chemistry-cloud interactions in West Africa (DACCIWA) measurement campaign gathered a unique dataset of observations of the frequent stratocumulus-to-cumulus transition in southern West Africa. Inspired and constrained by these observations, we perform a series of numerical experiments using large eddy simulation. The experiments include interactive radiation and surface schemes where we explicitly resolve, quantify and describe the physical processes driving such transition. Focusing on the local processes, we quantify the transition in terms of dynamics, radiation, cloud properties, surface processes and the evolution of dynamically relevant layers such as subcloud layer, cloud layer and inversion layer. We further quantify the processes driving the stratocumulus thinning and the subsequent transition initiation by using a liquid water path budget. Finally, we study the impact of mean wind and wind shear at the cloud top through two additional numerical experiments. We find that the sequence starts with a nighttime well-mixed layer from the surface to the cloud top, in terms of temperature and humidity, and transitions to a prototypical convective boundary layer by the afternoon. We identify radiative cooling as the largest factor for the maintenance leading to a net thickening of the cloud layer of about 18 g m−2 h−1 before sunrise. Four hours after sunrise, the cloud layer decouples from the surface through a growing negative buoyancy flux at the cloud base. After sunrise, the increasing impact of entrainment leads to a progressive thinning of the cloud layer. While the effect of wind on the stratocumulus layer during nighttime is limited, after sunrise we find shear at the cloud top to have the largest impact: the local turbulence generated by shear enhances the boundary layer growth and entrainment aided by the increased surface fluxes. As a consequence, wind shear at the cloud top accelerates the breakup and transition by about 2 h. The quantification of the transition and its driving factors presented here sets the path for an improved representation by larger-scale models.
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Richey, Kendall D., Culler Hannah, Matt J. Hersom, William C. Bridges, and Celina M. Checura. "PSIII-4 Effect of Photobiomodulation Treatment on Atp Concentrations in Bovine Oocytes During Maturation." Journal of Animal Science 101, Supplement_3 (November 6, 2023): 389–90. http://dx.doi.org/10.1093/jas/skad281.461.
Анотація:
Abstract Oocyte cytoplasmic maturation is critical in determining the success of subsequent embryo development. It has been proposed that light in the red-to-near infrared optical region (~600–1000 nm) enhances cellular metabolic activity through activation of the mitochondrial respiratory chain, increasing intracellular ATP concentrations, and has the potential to modify the oocyte metabolome. Previous research indicated a greater cleavage rate and similar blastocyst rates for bovine oocytes treated with photobiomodulation at hours 16 and 20 from the start of maturation compared with control. For the present study, two separate experiments were conducted to determine ATP concentration in oocytes during maturation after photobiomodulation treatment. A standardized in vitro maturation (IVM) protocol and commercial media (IVF Bioscience) were used. Briefly, bovine ovaries were obtained at a local slaughterhouse, cumulus oocyte complexes (COCs) were collected by aspiration of small (2 to 6 mm) follicles. For experiment 1, compact COCs were cultured in in vitro maturation media (n = 30/well) and treated with no light (control); light (660-665nm) for 10 minutes at hour 16 from start of maturation (L-16) and light for 10 minutes at hour 20 from the start of maturation (L-20). At hour 24 of in vitro maturation, COCs were vortexed to remove cumulus, stained with BioTracker ATP-Red Live Cell Dye (Sigma-Aldrich SCT045), imaged with Cytation-1 (Agilent Technologies Inc.) in 6 replicates. For experiment 2, COCs were cultured in in vitro maturation media (n = 40/well) and treated with no light (control) and light (660-665nm) for 10 minutes at hour 16 from start of maturation (L-16). At hours 18, 20, 22 and 24 of in vitro maturation, COCs were vortexed to remove cumulus, stained with BioTracker ATP-Red Live Cell Dye, and imaged with Cytation-1 in 4 replicates. For experiment 1, one-way ANOVA and Student’s T-Test were performed (JMP software 16.0); in experiment 2, each well was considered as an experimental unit in a model of repeated measures, main effects of time and treatment, blocked by replicate (Mixed procedure, SAS Institute Inc.). In experiment 1, there was a significant (P < 0.05) effect of treatment; ATP concentrations were greater in L-16 than control, and L-20 was intermediate. ATP concentrations were 19,579.3a ± 596.5, 21,652.0b ± 602.7 and 19,710.9ab ± 570.6 relative fluorescence units (RFU) for control, L-16, and L-20 respectively. In experiment 2, there was a significant (P < 0.05) effect of treatment and no significant effect of time. Overall ATP concentrations were 25,668 ± 894.6 and 28,332 ± 894.6 RFU for control and L-16 respectively. In conclusion, photobiomodulation treatment with LED 660-665nm for 10 minutes at hour 16 from start of oocyte maturation increases intracellular ATP concentrations from hour 18 to 24 of maturation.
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Lee, S. H., H. J. Oh, M. J. Kim, G. A. Kim, E. M. N. Setyawan, Y. B. Choi, S. Lee, J. X. Jin, A. Taweechaipaisankul, and B. C. Lee. "174 EFFECT OF HUMAN ENDOTHELIAL PROGENITOR CELLS ON IN VITRO MATURATION OF PORCINE OOCYTES AND PARTHENOGENETIC EMBRYO DEVELOPMENT COMPETENCE." Reproduction, Fertility and Development 29, no. 1 (2017): 195. http://dx.doi.org/10.1071/rdv29n1ab174.
Анотація:
In oocyte maturation, hepatocyte growth factor and vascular endothelial growth factor (VEGF) contribute to promote granulosa cell proliferation and cumulus cell expansion. It is well known that human endothelial progenitor cells (hEPC), which are isolated from monocytes and macrophages, secrete a variety of growth factors, such as hepatocyte growth factor and VEGF, and improve the process of angiogenesis. Therefore, the aim of this study was to investigate the effects of hEPC on in vitro oocyte maturation and subsequent embryo development in pigs. To isolate and culture hEPC, human peripheral blood sample was collected from a healthy donor and peripheral blood mononuclear cells were separated. The peripheral blood mononuclear cells were seeded into flask with defined Keratinocyte-SFM-based medium and incubated at 37°C, 5% CO2. The hEPC were cultured and cryopreserved until use for co-culturing with porcine oocytes obtained from a local slaughterhouse ovaries. Cumulus-oocyte complexes were randomly cultured in 2 groups; 1) co-culturing with hEPC and 2) culturing without hEPC. Cumulus-oocyte complexes were cultured in the in vitro maturation (IVM) medium containing TCM-199 supplemented with 0.57 mM cysteine, 0.91 mM sodium pyruvate, 5 μL mL−1 of insulin-transferrin-selenium solution 100X (Invitrogen, Seoul, South Korea), 10% porcine follicular fluid, 10 IU mL−1 of eCG, and 10 IU mL−1 of hCG. After IVM, the first polar body extrusion was observed under the microscope. To evaluate embryo development competence, the matured oocytes were activated with electrical stimulus and cultured in porcine zygote medium-5 for 7 days. The cleavage and blastocyst formation rates were observed on Day 2 and 7, respectively. Also, blastocysts were stained with Hoechst 33342 and total blastocyst cell numbers were evaluated under a fluorescence microscope. As a result, the oocyte maturation rate or first polar body extrusion rate of the hEPC co-culture group (90.06 ± 0.75) was significantly higher than the control group (90.06 ± 0.75 v. 85.79 ± 0.59; P < 0.05). There was no significant difference between the hEPC co-cultured and the control groups in cleavage rate. However, a significant difference in blastocyst formation rate was observed between the hEPC co-cultured and the control groups (28.45 ± 4.92 v. 15.87 ± 2.27; P < 0.05), whereas total blastocyst cell numbers did not show significant difference between the 2 groups. The all data were analysed by unpaired t-test using GraphPad Prism 5.0 (GraphPad Software Inc., La Jolla, CA, USA). Values are means ± standard error of mean. In conclusion, the results in the present study demonstrated that co-culturing with hEPC improved the in vitro oocyte maturation and blastocyst formation rate. Also, we are underway in analysing the concentration of VEGF families in the hEPC co-culture medium after IVM. For further study, we will analyse the genes of the VEGF signaling pathway in the cumulus cells and matured oocytes derived from the 2 groups. This research was supported by Nature Cell (#550-20150030), global PH.D Fellowship Program through NRF funded by the Ministry of Education (NRF-20142A1021187), and Research Institute for Veterinary Science, the BK21 plus program.
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Neggers, Roel A. J., J. David Neelin, and Bjorn Stevens. "Impact Mechanisms of Shallow Cumulus Convection on Tropical Climate Dynamics*." Journal of Climate 20, no. 11 (June 1, 2007): 2623–42. http://dx.doi.org/10.1175/jcli4079.1.
Анотація:
Abstract Subtropical shallow cumulus convection is shown to play an important role in tropical climate dynamics, in which convective mixing between the atmospheric boundary layer and the free troposphere initiates a chain of large-scale feedbacks. It is found that the presence of shallow convection in the subtropics helps set the width and intensity of oceanic ITCZs, a mechanism here termed the shallow cumulus humidity throttle because of the control exerted on the moisture supply to the deep convection zones. These conclusions are reached after investigations based on a tropical climate model of intermediate complexity, with sufficient vertical degrees of freedom to capture (i) the effects of shallow convection on the boundary layer moisture budget and (ii) the dependency of deep convection on the free-tropospheric humidity. An explicit shallow cumulus mixing time scale in this simple parameterization is varied to assess sensitivity, with moist static energy budget analysis aiding to identify how the local effect of shallow convection is balanced globally. A reduction in the mixing efficiency of shallow convection leads to a more humid atmospheric mixed layer, and less surface evaporation, with a drier free troposphere outside of the convecting zones. Advection of drier free-tropospheric air from the subtropics by transients such as dry intrusions, as well as by mean inflow, causes a substantial narrowing of the convection zones by inhibition of deep convection at their margins. In the tropical mean, the reduction of convection by this narrowing more than compensates for the reduction in surface evaporation. Balance is established via a substantial decrease in tropospheric temperatures throughout the Tropics, associated with the reduction in convective heating. The temperature response—and associated radiative contribution to the net flux into the column—have broad spatial scales, while the reduction of surface evaporation is concentrated outside of the convecting zones. This results in differential net flux across the convecting zone, in a sense that acts to destabilize those areas that do convect. This results in stronger large-scale convergence and more intense convection within a narrower area. Finally, mixed layer ocean experiments show that in a coupled ocean–atmosphere system this indirect feedback mechanism can lead to SST differences up to +2 K between cases with different shallow cumulus mixing time, tending to counteract the direct radiative impact of low subtropical clouds on SST.
21
Pedruzo-Bagazgoitia, X., H. G. Ouwersloot, M. Sikma, C. C. van Heerwaarden, C. M. J. Jacobs, and J. Vilà-Guerau de Arellano. "Direct and Diffuse Radiation in the Shallow Cumulus–Vegetation System: Enhanced and Decreased Evapotranspiration Regimes." Journal of Hydrometeorology 18, no. 6 (June 1, 2017): 1731–48. http://dx.doi.org/10.1175/jhm-d-16-0279.1.
Анотація:
Abstract Guided by a holistic approach, the combined effects of direct and diffuse radiation on the atmospheric boundary layer dynamics over vegetated land are investigated on a daily scale. Three numerical experiments are designed that are aimed at disentangling the role of diffuse and direct radiation below shallow cumulus at the surface and on boundary layer dynamics. A large-eddy simulation (LES) model coupled to a land surface model is used, including a mechanistically immediate response of plants to radiation, temperature, and water vapor deficit changes. The partitioning in direct and diffuse radiation created by clouds and farther inside the canopy is explicitly accounted for. LES results are conditionally averaged as a function of the cloud optical depth. The findings show larger photosynthesis under thin clouds than under clear sky, due to an increase in diffuse radiation and a slight decrease in direct radiation. The reduced canopy resistance is the main driver for the enhanced carbon uptake by vegetation, while the carbon gradient and aerodynamic effects at the surface are secondary. Because of the coupling of CO2 and water vapor exchange through plant stomata, evapotranspiration is also enhanced under thin clouds, albeit to a lesser extent. This effect of diffuse radiation increases the water use efficiency and evaporative fraction under clouds. The dynamic perturbations of the surface fluxes by clouds do not affect general boundary layer or cloud characteristics because of the limited time and space where these perturbations occur. It is concluded that an accurate radiation partitioning calculation is necessary to obtain reliable estimations on local surface processes.
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Contreras Huamani, Mijail, Mary Naveros, and Cesar Olaguivel. "EFFECT OF THE USE OF TWO SPERM SELECTION TECHNIQUES FOR IN VITRO PRODUCTION OF ALPACA EMBRYOS." SPERMOVA 11, no. 1 (August 13, 2021): 67–72. http://dx.doi.org/10.18548/aspe/0009.10.
Анотація:
The objective of this research was to evaluate the effect of the use of two sperm selection techniques for in vitro production of alpaca embryos. The ovaries and testis were collected from the local slaughterhouse and transport to 37 ° C in saline solution (0.9%) supplemented with gentamicin. Quality I, II and II oocytes were incubated in a maturation medium for 32 h at 38.5 ° C and 5% O2 and 5% CO2. For in vitro fertilization, sperm from the epididymis were selected using the Percoll gradient and Swim up technique. 18h after the oocytes were incubated with the sperm, these were denuded from the cumulus cells and cultured in SOFaa culture medium for 7 days. Morula and blastocyst rate and their morphological quality are evaluated at day 7 of culture. From a total of 370 ovaries, 1,137 oocytes were recovered, making an average of 3.6 oocytes / ovary. After the maturation and fertilization process and in vitro culture, the blastocyst rate was 8.43 ± 6.04% and 3.89 ± 1.75%, for oocytes fertilized with sperm selected with Percoll gradient and Swim up, respectively, not finding significant statistical differences (p> 0.05), between the groups. In conclusion, the in vitro fertilization of alpaca oocytes with spermatozoa selected with two selection techniques (percoll and swim up) did not significantly influence the quantity and quality of morulae and blastocysts at day 7 of embryo culture.
23
Adachi, A., T. Kobayashi, H. Yamauchi, and S. Onogi. "Detection of potentially hazardous convective clouds with a dual-polarized C-band radar." Atmospheric Measurement Techniques 6, no. 10 (October 21, 2013): 2741–60. http://dx.doi.org/10.5194/amt-6-2741-2013.
Анотація:
Abstract. A method for forecasting very short-term rainfall to detect potentially hazardous convective cloud that produces heavy local rainfall was developed using actual volumetric C-band polarimetric radar data. Because the rainfall estimation algorithm used in this method removed the effect of ice particles based on polarimetric measurements, it was immune to the high reflectivity associated with hail. The reliability of the algorithm was confirmed by comparing the rainfall rate estimated from the polarimetric radar measurements at the lowest elevation angle with that obtained from optical disdrometers on the ground. The rainfall rate estimated from polarimetric data agreed well with the results obtained from the disdrometers, and was much more reliable than results derived from reflectivity alone. Two small cumulus cells were analyzed, one of which developed and later produced heavy rainfall, whereas the other did not. Observations made by polarimetric radar with a volumetric scan revealed that a high vertical maximum intensity of rainfall rate and a vertical area of enhanced differential reflectivity extending above the freezing level, often termed a high ZDR column, were clearly formed about 10 min prior to the onset of heavy rainfall on the ground. The onset time of the heavy rainfall could be estimated in advance from the polarimetric data, which agreed fairly well with observations. These polarimetric characteristics were not observed for the cumulus cell that did not produce heavy rainfall. The results suggest that both the vertical maximum intensity of the rainfall rate and a high ZDR column, estimated from polarimetric measurements, can be used to identify potentially hazardous clouds. Furthermore, this study shows that polarimetric radar measurements with high spatial and temporal resolutions are invaluable for disaster reduction.
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Liu, Si-Jie, Ming Wang, Xiang Yi, Shuai-Bing Shao, Yi-Qun Zheng, and Xin-Min Zeng. "Assessing the Impact of Cumulus Parameterization Schemes on Simulated Summer Wind Speed over Mainland China." Atmosphere 13, no. 4 (April 12, 2022): 617. http://dx.doi.org/10.3390/atmos13040617.
Анотація:
Wind speed is an important meteorological parameter, whose simulation is influenced by various physical process parameterizations. However, the impact of cumulus parameterization schemes (CPSs) on wind speed simulation at the climate scale has not been sufficiently investigated in previous studies. Using the Advanced Research version of the Weather Research and Forecasting model (ARWv3) and hydrostatic wind speed change equation, we assessed the effects of four CPSs on a 10 m wind speed simulation over mainland China in the summer of 2003. In general, different CPSs can reproduce the wind speed distribution. Meanwhile, the sensitivity of wind speed simulation to CPSs was found to be the highest in East and southern China, followed by the Tibetan Plateau, and then Northwest China. We found that the main physical processes influencing wind speed (i.e., the pressure gradient (PRE), diffusion (DFN), and convection (CON) terms) vary greatly with sub-regions. CPSs mainly affect the secondary CON that regulates the balance between the dominant terms PRE and DFN, and also has a significant effect on PRE. For example, for CON, the difference index (DIF) between the Kain–Fritsch (KF) and previous KF (pKF) CPSs is larger than 20%, corresponding to a PRE DIF of about 14%. The term of local wind speed change (Vt) is significantly more sensitive to the CPSs than the other terms with a DIF of 283% over the Tibetan Plateau, suggesting high CPS sensitivity of the simulated wind speed. In addition, we explained the causes of the CPS-induced sensitivities. This work helps understand the Weather Research and Forecasting model (WRF) performance and emphasizes the importance of the CPS choice in simulating/forecasting wind speed.
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Richey, Kendall, Matt Hersom, William Bridges, and Celina M. Checura. "17 Using Photobiomodulation to Improve Bovine Oocyte Maturation." Journal of Animal Science 101, Supplement_1 (May 1, 2023): 24–25. http://dx.doi.org/10.1093/jas/skad068.027.
Анотація:
Abstract Oocyte cytoplasmic maturation is critical in determining the success of subsequent embryo development. Bovine oocytes matured in vitro yield less embryonic development rates than in vivo matured oocytes and new strategies are needed to improve the culture system. It has been proposed that light in the red-to-near infrared optical region (~600-1000 nm) enhances cellular metabolic activity through activation of the mitochondrial respiratory chain and has the potential to modify the oocyte metabolome. The objective of this work was to affect the cumulus-oocyte-complex metabolic state using photobiomodulation, aiming to enhance cytoplasmic maturation and subsequent embryonic development. A standardized in vitro fertilization (IVF) protocol and commercial media (IVF Bioscience) were used. Briefly, bovine ovaries were obtained at a local slaughterhouse, cumulus oocyte complexes (COCs) were collected by aspiration of small (2-6 mm) follicles. Compacted COCs were cultured in in vitro maturation media (n = 50/well) and treated with no light (control); light (660-665nm) for 10 minutes at hour 16 from start of maturation (L-16), and light for 10 minutes at hour 20 from start of maturation (L-20). At hour 22 from start of maturation, COCs were fertilized by co-culture with bull spermatozoa (1x106 motile sperm/mL) for 18 hours, then subjected to cumulus cell removal. Presumptive zygotes were placed in in vitro culture media (IVC) for 48 hours when cleavage rate was assessed. Embryos with ≥ 8 cells were selected and placed in fresh IVC until evaluation of blastocyst rate at 168 and 192 hours from start of fertilization. The experiment was replicated 6 times. Blastocysts present at 168 hours from start of fertilization were fixed in 5% formalin, stained with Hoechst 33342, imaged with Cytation 1 (Agilent Technologies Inc.), and blastocyst cell number was counted using ImageJ software (ImageJ2 2.9.0) in 4 replicates. For statistical analysis, each well was considered as experimental unit in a model of repeated measures, main effects of time and treatment, blocked by replicate (Mixed procedure, SAS Institute Inc.). One-way ANOVA test was used to analyze the average cell number per well by group, blocked by replicate (JMP Pro 16.1.0). There was a significant (P < 0.05) effect of treatment, replicate, and time for embryo development and there was a tendency (P = 0.6) for treatment effect on blastocyst cell number. Cleavage rates were 81.3 ± 2.5; 88.5 ± 2.5; 87.3 ± 2.5 % (LSM ± SEM), blastocyst rates were 49.1± 2.5; 49.3 ± 2.5; 51.6 ± 2.5 % and cell numbers were 159.9 ± 3.5; 149.3 ± 3.5; 164.0 ±3.5 for groups control, L-16, and L-20 respectively. The positive effect of photobiomodulation treatment on cleavage rate and blastocyst cell number suggests there is a window of sensitivity to 660-665nm light between 16 and 20 hours from start of maturation.
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Saleem, M., Z. Sarwar, M. Saad, I. Zahoor, N. Ahmad, and A. Riaz. "193 Effect of clinical metritis on oocyte recovery, oocyte quality, and early invitro developmental competence of embryos in Bos indicus dairy cattle." Reproduction, Fertility and Development 32, no. 2 (2020): 225. http://dx.doi.org/10.1071/rdv32n2ab193.
Анотація:
Unhygienic practices at the time of parturition or AI lead to uterine infections. The uterine infections ultimately result in genetic drain by culling the elite animals. The invivo developmental competence of embryos is compromised in clinically metritic animals. The genetic potential of problematic females could be harvested by invitro embryo production (IVEP). Therefore, the objective of the present study was to evaluate the effect of clinical metritis on oocyte recovery, oocyte quality, and early invitro developmental competence of embryos in Bos indicus dairy cattle. This experiment was carried out from December 2017 to April 2018. Ovaries were collected from a local abattoir (Bos indicus; 5- to 8-year-old dairy cattle, body condition score 2.75±0.25, mixed parity). These ovaries (n=982) were divided into two groups: (1) clinically metritic (n=184), and (2) healthy (n=798), based upon the presence or absence of pus in the uterine lumen. Oocytes were aspirated from follicles using an 18G needle attached to a 10-mL syringe. Cumulus-oocyte complexes (COCs) were categorized into A, B, C, and D grades based on the number of layers of cumulus cells and integrity of ooplasm. The oocytes of grades A and B were subsequently transferred in groups (10/group) in four-well plates containing 100-μL droplets. The droplets with oocytes were covered with prewarmed mineral oil and incubated for 24h at 38.5°C, 5% CO2, and 95% relative humidity. The oocytes were evaluated for IVM on the basis of cumulus expansion. Frozen semen was thawed and prepared using the sperm swim-up procedure for each group. Spermatozoa and oocytes were incubated together for a period of 18h. The presumptive zygotes were invitro cultured for 4 days in a CO2 incubator under similar culture conditions. The cleavage rate, 4-cell, and 8-cell stages were recorded on Days 2, 3, and 4 after the day of insemination, respectively. Data on oocyte recovery, oocyte quality, IVM, cleavage rate, and 4-cell and 8-cell stages were analysed by Chi-squared test using SPSS software (version 20; IBM Corp.) for Windows. Results demonstrated that recovery rate was lower (63.8% vs. 71.7%; P<0.05) in clinically metritic compared with healthy cattle. Similarly, oocytes of grade A and B quality were lower (41.0% vs. 51.1%; P<0.05), whereas those of C and D quality were higher (59.0% vs. 48.9%; P<0.05) in clinically metritic compared with the healthy group. Moreover, 4-cell (38.2% vs. 54.8%) and 8-cell stage embryos (11.3% vs. 29.1%), were lower (P<0.05) in the clinically metritic compared with the healthy group, respectively. However, maturation rate and cleavage rate did not differ (P>0.05) between groups. In conclusion, metritis in slaughterhouse ovaries negatively affects oocyte recovery rate, oocyte quality, and early invitro developmental competence of embryos in Bos indicus dairy cattle.
27
Adachi, A., T. Kobayashi, H. Yamauchi, and S. Onogi. "Detection of potentially hazardous convective clouds with a dual-polarized C-band radar." Atmospheric Measurement Techniques Discussions 6, no. 2 (April 15, 2013): 3675–722. http://dx.doi.org/10.5194/amtd-6-3675-2013.
Анотація:
Abstract. A method for forecasting very short-term rainfall to detect potentially hazardous convective cloud that produces heavy local rainfall was developed using actual volumetric C-band polarimetric radar data. Because the rainfall estimation algorithm used in this method removed the effect of ice particles based on polarimetric measurements, it was immune to the high reflectivity associated with hail. The reliability of the algorithm was confirmed by comparing the rainfall rate estimated from the polarimetric radar measurements at the lowest elevation angle with that obtained from an optical disdrometer on the ground. The rainfall rate estimated from polarimetric data agreed well with the results obtained from the disdrometer, and was much more reliable than results derived from reflectivity alone. Two small cumulus cells were analyzed, one of which developed and later produced heavy rainfall, whereas the other did not. Observations made by polarimetric radar with a volumetric scan revealed that a high vertical maximum intensity of rainfall rate and a vertical area of enhanced differential reflectivity extending above the freezing level, often termed a high ZDR column, were clearly formed about 10 min prior to the onset of heavy rainfall on the ground. The onset time of the heavy rainfall could be estimated in advance from the polarimetric data, which agreed fairly well with observations. These polarimetric characteristics were not observed for the cumulus cell that did not produce heavy rainfall. The results suggest that both the vertical maximum intensity of the rainfall rate and a high ZDR column, estimated from polarimetric measurements, can be used to identify potentially hazardous clouds. Furthermore, this study shows that polarimetric radar measurements with high spatial and temporal resolutions are invaluable for disaster reduction.
28
Grupen, C. G., T. S. Hussein, S. J. Schulz, and D. T. Armstrong. "342 DISTINCT EFFECTS OF FOLLICULAR FLUID ON CUMULUS CELL APOPTOSIS AND PORCINE OOCYTE DEVELOPMENTAL COMPETENCE." Reproduction, Fertility and Development 19, no. 1 (2007): 286. http://dx.doi.org/10.1071/rdv19n1ab342.
Анотація:
Supplementing medium with follicular fluid (FF) during in vitro maturation (IVM) enhances the developmental competence of porcine oocytes, indicating that factors present in FF are beneficial to cytoplasmic maturation. Previous findings suggest that porcine FF contains high levels of superoxide dismutase activity and exerts a beneficial effect on cytoplasmic maturation by protecting oocytes from oxidative stress (Tatemoto et al. 2004 Biol. Reprod. 71, 1150–1157). Since oxidative stress is a potent inducer of apoptosis, the aim of the present study was to examine the temporal effects of FF during IVM on cumulus cell apoptosis and oocyte developmental competence. Ovaries of prepubertal pigs were collected from a local abattoir and antral follicles, 3 to 7 mm in diameter, were aspirated. Cumulus–oocyte complexes (COCs) with at least 3 uniform layers of compact cumulus cells (CCs) were recovered, washed, and transferred to maturation medium (MM) with or without 25% FF. At 22 h of IVM, COCs from each group were washed and transferred to fresh MM with or without 25% FF, forming 4 groups: -FF/-FF, -FF/+FF, +FF/-FF, and +FF/+FF. Cohorts of COCs were TUNEL stained at 22 and 44 h of IVM using the In Situ Cell Death Detection kit (Roche Diagnostics, Castle Hill, NSW, Australia) according to the manufacturer's instructions, and apoptotic CCs were visualized using confocal microscopy. Oocytes denuded at 44 h, that had a polar body, were treated with ionomycin and 6-dimethylaminopurine to induce parthenogenetic development, and were cultured for 7 days in NCSU-23 medium at 38.5°C in 5% O2, 5% CO2, and 90% N2. Data were subjected to ANOVA and Tukey's post-hoc test. At 22 h of IVM, the presence of FF reduced the proportion of apoptotic CCs in COCs (2.1% vs. 4.6%). COCs matured with FF from 22 to 44 h of IVM had much lower proportions of apoptotic CCs (+FF/+FF: 0.9%; −FF/+FF: 2.6%) compared with those matured without FF (+FF/−FF: 10.3%; −FF/−FF: 17.8%). The rate of maturation to the metaphase-II stage was greater when oocytes were matured with FF from 0 to 22 h of IVM (−FF/−FF: 68.6%; −FF/+FF: 72.8%; +FF/−FF: 89.2%; +FF/+FF: 86.2%). Maturation without FF for the entire IVM interval reduced the proportion of activated oocytes that formed blastocysts compared with the other groups (−FF/−FF: 25.1%; −FF/+FF: 44.6%; +FF/−FF: 46.6%; +FF/+FF: 47.3%). Despite a 4-fold difference in the proportion of apoptotic CCs between COCs of the +FF/−FF and −FF/+FF groups, exposure to FF for the first or second half of IVM was as beneficial to oocyte developmental competence as exposure to FF for the entire IVM interval. This suggests that the protective effect of FF in reducing oxidative stress on oocytes during IVM is distinct from the effect on oocyte developmental competence.
29
Hayashi, Michiya, and Hisanori Itoh. "The Importance of the Nontraditional Coriolis Terms in Large-Scale Motions in the Tropics Forced by Prescribed Cumulus Heating." Journal of the Atmospheric Sciences 69, no. 9 (September 1, 2012): 2699–716. http://dx.doi.org/10.1175/jas-d-11-0334.1.
Анотація:
Abstract In meteorological dynamics, the shallow-atmosphere approximation is generally used in the momentum equation, together with the “traditional approximation.” In the traditional approximation, two cosine Coriolis terms [hereafter called nontraditional Coriolis terms (NCTs)] and some metric terms are omitted. However, some studies have suggested that the omission of the NCTs may not be appropriate for conditions near the equator. Therefore, this paper investigates the effect of the NCTs on large-scale motions forced by local positive-only heating mimicking cumulus convection. The authors use the linearized quasihydrostatic equation system on an equatorial β plane. Prescribed heating is assumed to move eastward with the slow phase speed of an intraseasonal period. Results of scale analysis and numerical calculations show that differences with and without the NCTs (hereafter, contributions) exhibit the following four features. (i) Whereas contributions to horizontal divergence and vertical velocity are small, the NCTs have large effects on horizontal velocity (vertical vorticity) and perturbations of pressure, potential temperature, and density. (ii) Contributions to horizontal velocity and pressure perturbation have equivalent barotropic structure. (iii) Contributions show east–west asymmetric patterns, with large contributions appearing at the western side of the forcing. (iv) Contributions to vertical vorticity and pressure perturbation are extremely large when the meridional gradient of heating is large. These features can be comprehensively explained by the tilting of the meridional component of the planetary vorticity, which is caused by the meridional gradient of heating.
30
Veshkini, A., A. A. Khadem, M. Soleimani, R. Jahanbin, M. Salehi, A. A. Alamouti, A. Salehi, K. Schellander, M. Hoelker, and A. Mohammadi-Sangcheshmeh. "Erratum to: 264 EXOGENOUS LINOLENIC ACID IN OOCYTE MATURATION MEDIA PROMOTES NUCLEAR MATURATION AND PARTHENOGENETIC PREIMPLANTATION EMBRYONIC DEVELOPMENT IN THE GOAT." Reproduction, Fertility and Development 25, no. 1 (2013): 280. http://dx.doi.org/10.1071/rdv25n1ab264.
Анотація:
Dietary intakes of polyunsaturated fatty acids are thought to mediate a wide range of actions in reproductive tissues. This includes the effects on ovarian follicle and corpus luteum functions via improved energy efficiency as well as providing precursors for the synthesis of signalling molecules such as steroids and prostaglandins. An appropriate level of α-linolenic acid (ALA) in the oocyte maturation medium has been shown to induce molecular changes associated with oocyte maturation and embryo developmental competence. In that light, we hypothesised that supplementation of exogenous ALA to maturation media could enhance nuclear maturation and embryonic development in the goat. A preliminary experiment was executed to measure the level of ALA in antral follicles by gas chromatography/mass spectrometry analysis. Our results revealed that the concentration of ALA in follicular fluids ranged from 0.006 to 0.02 mg mL–1 (21.5 to 71.8 µM, with a mean of ~50 µM). To test the effect of ALA on the competence of goat oocytes to complete meiotic maturation to metaphase II and sustain embryonic development, ovaries were obtained from a local abattoir. Cumulus–oocyte complexes were recovered by the slicing method followed by selection of oocytes with a homogenous cytoplasm and at least three layers of compact cumulus cells. The cumulus–oocyte complexes were placed in maturation media supplemented with 50 µM ALA. Oocytes in the control group were incubated in the same maturation medium without ALA. In vitro maturation (IVM) was performed in a humidified atmosphere containing 5% CO2, 5% O2, and 90% N2 at 38.5°C for 24 h. After IVM, several oocytes from the treatment (n = 170) and control (n = 166) groups were stained with Hoechst and were evaluated in relation to their metaphase-II rate. Other groups of oocytes from both the treatment (n = 70) and control (n = 61) groups were subjected to parthenogenetic activation by applying 1 min of exposure to 2.5 µM ionomycin followed by 2 mM 6-DMAP treatment for 3 h. After activation, oocytes were cultured in CR1aa medium for 7 days under the conditions stated above. Four replications were performed. Differences in developmental rates were analysed for significance by one-way ANOVA using SAS version 8.0 (SAS Institute Inc., Cary, NC, USA), considering P < 0.05 to be significant. As a result, supplementation of the maturation media with ALA did not appear to affect cumulus expansion. In contrast, IVM of goat oocytes in the presence of ALA resulted in a significantly higher maturation rate compared with maturation without ALA supplementation (66.4% v. 57.9%). Likewise, addition of ALA to the IVM medium significantly increased the rate of cleavage (60.1% v. 52.4%) and blastocyst formation (22.6% v. 14.9%), calculated from the activated oocytes. Collectively, the results of our study show that supplementation of IVM media with 50 µM ALA promotes nuclear maturation, increases cleavage rate, and results in higher blastocyst rate in goat oocytes after parthenogenetic activation. Thus, providing appropriate levels of ALA in maturation media could have beneficial effects on embryo development and reproductive efficiency in the goat.
31
Veshkini, A., A. A. Khadem, M. Soleimani, R. Jahanbin, M. Salehi, A. A. Alamouti, A. Salehi, K. Schellander, M. Hoelker, and A. Mohammadi-Sangcheshmeh. "Erratum to: 264 EXOGENOUS LINOLENIC ACID IN OOCYTE MATURATION MEDIA PROMOTES NUCLEAR MATURATION AND PARTHENOGENETIC PREIMPLANTATION EMBRYONIC DEVELOPMENT IN THE GOAT." Reproduction, Fertility and Development 25, no. 3 (2013): 587. http://dx.doi.org/10.1071/rdv25n1ab264_er.
Анотація:
Dietary intakes of polyunsaturated fatty acids are thought to mediate a wide range of actions in reproductive tissues. This includes the effects on ovarian follicle and corpus luteum functions via improved energy efficiency as well as providing precursors for the synthesis of signalling molecules such as steroids and prostaglandins. An appropriate level of α-linolenic acid (ALA) in the oocyte maturation medium has been shown to induce molecular changes associated with oocyte maturation and embryo developmental competence. In that light, we hypothesised that supplementation of exogenous ALA to maturation media could enhance nuclear maturation and embryonic development in the goat. A preliminary experiment was executed to measure the level of ALA in antral follicles by gas chromatography/mass spectrometry analysis. Our results revealed that the concentration of ALA in follicular fluids ranged from 0.006 to 0.02mgmL–1 (21.5 to 71.8µM, with a mean of ~50µM). To test the effect of ALA on the competence of goat oocytes to complete meiotic maturation to metaphase II and sustain embryonic development, ovaries were obtained from a local abattoir. Cumulus–oocyte complexes were recovered by the slicing method followed by selection of oocytes with a homogenous cytoplasm and at least three layers of compact cumulus cells. The cumulus–oocyte complexes were placed in maturation media supplemented with 50µM ALA. Oocytes in the control group were incubated in the same maturation medium without ALA. In vitro maturation (IVM) was performed in a humidified atmosphere containing 5% CO2, 5% O2, and 90% N2 at 38.5°C for 24h. After IVM, several oocytes from the treatment (n=170) and control (n=166) groups were stained with Hoechst and were evaluated in relation to their metaphase-II rate. Other groups of oocytes from both the treatment (n=70) and control (n=61) groups were subjected to parthenogenetic activation by applying 1min of exposure to 2.5µM ionomycin followed by 2mM 6-DMAP treatment for 3h. After activation, oocytes were cultured in CR1aa medium for 7 days under the conditions stated above. Four replications were performed. Differences in developmental rates were analysed for significance by one-way ANOVA using SAS version 8.0 (SAS Institute Inc., Cary, NC, USA), considering P<0.05 to be significant. As a result, supplementation of the maturation media with ALA did not appear to affect cumulus expansion. In contrast, IVM of goat oocytes in the presence of ALA resulted in a significantly higher maturation rate compared with maturation without ALA supplementation (66.4% v. 57.9%). Likewise, addition of ALA to the IVM medium significantly increased the rate of cleavage (60.1% v. 52.4%) and blastocyst formation (22.6% v. 14.9%), calculated from the activated oocytes. Collectively, the results of our study show that supplementation of IVM media with 50µM ALA promotes nuclear maturation, increases cleavage rate, and results in higher blastocyst rate in goat oocytes after parthenogenetic activation. Thus, providing appropriate levels of ALA in maturation media could have beneficial effects on embryo development and reproductive efficiency in the goat.
32
Pascottini, O. B., M. Catteeuw, A. Van Soom, and G. Opsomer. "167 Effect of Storage Time and Temperature of a Commercial Embryo Holding Medium on the Maturation Kinetics of Immature Bovine Oocytes." Reproduction, Fertility and Development 30, no. 1 (2018): 223. http://dx.doi.org/10.1071/rdv30n1ab167.
Анотація:
The effect of holding time and temperature during storage of immature bovine oocytes in a commercial embryo holding medium (EHM; Syngro® Ltd., Livingston, United Kingdom) was evaluated. Ovaries were collected at the local slaughterhouse and processed within 2 h. Cumulus-oocyte complexes (COC) were collected and allocated to groups of 60. The COC were held in 1-mL sterile glass osmometer tubes, filled to the top with the EHM to limit the amount of air. Vials were capped and covered with parafilm to ensure a tight seal and prevent leakage. Tubes were stored for 6 h at 4°C, room temperature (RT), or 38.5°C; for 10 h at 4°C and RT; and for 14 h at RT. Next, oocytes were fixed after storage in EHM (immature holding) or fixed after being held in EHM and subsequent 22-h maturation at 38.5°C in 5% CO2 in humidified air (mature holding). Maturation medium consisted of modified bicarbonate-buffered TCM-199 supplemented with gentamycin and epidermal growth factor. During all experiments, a control group was included each time. The control consisted of groups of 60 COC immediately fixed after collection or transferred to maturation medium for 22 h and subsequently fixed. Nuclear maturation of oocytes was assessed after Hoechst 33342 staining, using a 400× magnification fluorescence microscope. A total of 3043 COC were evaluated in 3 replicates. Oocytes maturation stages were classified as (1) oocytes in germinal vesicle stage, (2) oocytes in meiotic progression (diakinesis, metaphase I, or anaphase), (3) matured (telophase I or metaphase II), and (4) degenerated (degraded chromatin). Oocytes remained at the germinal vesicle stage when held in EHM (without subsequent maturation) regardless of holding time and temperature (P > 0.05). When oocytes were held for 6 h and subsequently matured (Table 1), the number of matured oocytes was significantly lower for oocytes held at 38.5°C compared with the other groups (control, RT, and 4°C). When held for 10 h, the oocyte maturation rate was similar between the control and RT groups (P > 0.05), but it was significantly lower in oocytes held at 4°C. Last, when compared with oocytes held at RT for 14 h, the maturation rate was higher in the control group (P < 0.05). To conclude, immature bovine oocytes can be successfully held in EHM at RT for up to 10 h. Storing immature oocytes in EHM can delay oocyte maturation and concomitantly synchronize maturation. Table 1.Kinetics of cumulus-oocyte complex nuclear status after storage in embryo holding medium for different times and temperatures and subsequent 22-h maturation
33
Xu, Haiming, Mimi Xu, Shang-Ping Xie, and Yuqing Wang. "Deep Atmospheric Response to the Spring Kuroshio over the East China Sea*." Journal of Climate 24, no. 18 (September 15, 2011): 4959–72. http://dx.doi.org/10.1175/jcli-d-10-05034.1.
Анотація:
Abstract The atmospheric response to the spring Kuroshio Front over the East China Sea is investigated using a suite of high-resolution satellite data and a regional atmospheric model. The atmospheric response appears to extend beyond the marine atmospheric boundary layer, with frequent occurrence of cumulus convection. In spring, Quick Scatterometer (QuikSCAT) wind speed shows a clear effect of sea surface temperature (SST), with high (low) wind speed observed over the warm (cold) tongue. This in-phase relationship between SST and surface wind speed is indicative of SST influence on the atmosphere. Wind convergence is found on the warmer flank of the Kuroshio Front, accompanied by a narrow rainband. The analysis of satellite-borne radar measurements indicates that deep convection appears over the Kuroshio warm tongue in the spring season, with enhanced convective precipitation, frequent occurrence of cumulus convection, and increased precipitation (cloud) tops in altitude. These deep convective activities along the Kuroshio warm tongue are further supported by enhanced lightning flash rate observed by satellite and atmospheric heating estimated by a Japanese reanalysis. The Weather Research and Forecasting (WRF) model is used to investigate the precipitation response to the spring Kuroshio SST front over the East China Sea. Forced by observed SST [control (CTL)], the model well simulates a narrow band of precipitation, high wind speed, and surface wind convergence that closely follows the Kuroshio warm current, consistent with satellite observations. This narrow rainband completely disappears in the model when the SST front is removed by horizontally smoothed SST (SmSST). The results show that it is convective precipitation that is sensitive to the Kuroshio SST front. A case study for an eastward-moving extratropical cyclone indicates that convective precipitation increases its intensity and duration in the CTL run compared to the SmSST run. Local enhancement of upward sensible and latent heat fluxes and convective instability in the lower atmosphere are the key to anchoring the narrow band of convective precipitation that closely follows the Kuroshio.
34
Hasler, J. F., and J. E. Stokes. "222 EFFECT OF THE PRESENCE OR ABSENCE OF PERCOLL CENTRIFUGATION; PENICILLAMINE, HYPOTAURINE, AND EPINEPHRINE; AND HEPARIN ON IN VITRO PRODUCTION OF BOVINE EMBRYOS." Reproduction, Fertility and Development 25, no. 1 (2013): 259. http://dx.doi.org/10.1071/rdv25n1ab222.
Анотація:
Protocols for the production of bovine embryos in vitro routinely include Percoll centrifugation of semen, usually include heparin, and often include penicillamine, hypotaurine, and epinephrine (PHE) in the fertilization media. This study examined the contribution of each of these components to the success of in vitro fertilization of bovine oocytes and subsequent blastocyst development. Bovine oocytes were aspirated from 2- to 10-mm follicles within 5 h after slaughter of cattle at a local abattoir. Groups of 30 to 40 cumulus–oocyte complexes (COC) were matured in 0.5 mL of TCM-199 with 10% FCS, 4 µg mL–1 of FSH, and 6 µg mL–1 of LH (NOBL Laboratories, Sioux Center, IA, USA) for 24 h (39°C, 4% CO2 in air). The COC were then washed and placed in 0.5 mL of modified Tyrode-lactate medium for IVF with various combinations of 2 µg mL–1 of heparin, 20 µM penicillamine, 10 µM hypotaurine, and 1 µM epinephrine. Each group of COC was inseminated with 0.25 × 106 frozen–thawed sperm from a single bull after 30 min of centrifugation with (Exp. 1) or without (Exp. 2) a 45/90% Percoll gradient with sperm TALP. Oocytes were vortexed to remove the cumulus after 18 h and placed in co-culture wells containing a monolayer of buffalo rat liver cells and 0.5 mL of Menezo’s B2 medium supplemented with 10% FCS. On the fourth day of in vitro culture, cleavage was defined as 2 cells or greater and embryos were transferred to fresh co-culture wells. There were 4 replicates in the first experiment and 6 in the second. Data were analysed by ANOVA. In the first experiment, the use of a Percoll gradient during centrifugation for separation of viable sperm from seminal plasma and cryprotectants resulted in significantly higher cleavage and Day 8 blastocyst rates than did the absence of Percoll when PHE and heparin were used together, and both cleavage and blastocyst rates were lower when only PHE or heparin was used separately compared with when both were used together (Table 1). The absence of Percoll, PHE, and heparin resulted in the lowest rates of cleavage and development. In the second experiment, the absence of either PHE or heparin resulted in lower cleavage rates, but not blastocyst rates, compared with the use of both, and the absence of both resulted in the lowest cleavage and blastocyst rates in spite of the use of Percoll. Table 1.Effects of Percoll; penicillamine, hypotaurine, and epinephrine (PHE); and heparin on cleavage and subsequent embryo development per oocyte
35
Diamond, Michael S., Pablo E. Saide, Paquita Zuidema, Andrew S. Ackerman, Sarah J. Doherty, Ann M. Fridlind, Hamish Gordon, et al. "Cloud adjustments from large-scale smoke–circulation interactions strongly modulate the southeastern Atlantic stratocumulus-to-cumulus transition." Atmospheric Chemistry and Physics 22, no. 18 (September 19, 2022): 12113–51. http://dx.doi.org/10.5194/acp-22-12113-2022.
Анотація:
Abstract. Smoke from southern Africa blankets the southeastern Atlantic Ocean from June to October, producing strong and competing aerosol radiative effects. Smoke effects on the transition between overcast stratocumulus and scattered cumulus clouds are investigated along a Lagrangian (air-mass-following) trajectory in regional climate and large eddy simulation models. Results are compared with observations from three recent field campaigns that took place in August 2017: ObseRvations of Aerosols above CLouds and their intEractionS (ORACLES), CLouds and Aerosol Radiative Impacts and Forcing: Year 2017 (CLARIFY), and Layered Atlantic Smoke Interactions with Clouds (LASIC). The case study is set up around the joint ORACLES–CLARIFY flight that took place near Ascension Island on 18 August 2017. Smoke sampled upstream on an ORACLES flight on 15 August 2017 likely entrained into the marine boundary layer later sampled during the joint flight. The case is first simulated with the WRF-CAM5 regional climate model in three distinct setups: (1) FireOn, in which smoke emissions and any resulting smoke–cloud–radiation interactions are included; (2) FireOff, in which no smoke emissions are included; (3) RadOff, in which smoke emissions and their microphysical effects are included but aerosol does not interact directly with radiation. Over the course of the Lagrangian trajectory, differences in free tropospheric thermodynamic properties between FireOn and FireOff are nearly identical to those between FireOn and RadOff, showing that aerosol–radiation interactions are primarily responsible for the free tropospheric effects. These effects are non-intuitive: in addition to the expected heating within the core of the smoke plume, there is also a “banding” effect of cooler temperature (∼1–2 K) and greatly enhanced moisture (>2 g kg−1) at the plume top. This banding effect is caused by a vertical displacement of the former continental boundary layer in the free troposphere in the FireOn simulation resulting from anomalous diabatic heating due to smoke absorption of sunlight that manifests primarily as a few hundred meters per day reduction in large-scale subsidence over the ocean. A large eddy simulation (LES) is then forced with free tropospheric fields taken from the outputs for the WRF-CAM5 FireOn and FireOff runs. Cases are run by selectively perturbing one variable (e.g., aerosol number concentration, temperature, moisture, vertical velocity) at a time to better understand the contributions from different indirect (microphysical), “large-scale” semi-direct (above-cloud thermodynamic and subsidence changes), and “local” semi-direct (below-cloud smoke absorption) effects. Despite a more than 5-fold increase in cloud droplet number concentration when including smoke aerosol concentrations, minimal differences in cloud fraction evolution are simulated by the LES when comparing the base case with a perturbed aerosol case with identical thermodynamic and dynamic forcings. A factor of 2 decrease in background free tropospheric aerosol concentrations from the FireOff simulation shifts the cloud evolution from a classical entrainment-driven “deepening–warming” transition to trade cumulus to a precipitation-driven “drizzle-depletion” transition to open cells, however. The thermodynamic and dynamic changes caused by the WRF-simulated large-scale adjustments to smoke diabatic heating strongly influence cloud evolution in terms of both the rate of deepening (especially for changes in the inversion temperature jump and in subsidence) and in cloud fraction on the final day of the simulation (especially for the moisture “banding” effect). Such large-scale semi-direct effects would not have been possible to simulate using a small-domain LES model alone.
36
Giroto, A. B., F. F. Franchi, P. K. Fontes, M. A. Maioli, G. P. Nogueira, M. F. G. Nogueira, and A. C. S. Castilho. "128 Evidence that Pregnancy-Associated Serum Protein A (PAPP-A) Plays Role on Bovine In Vitro Embryo Production." Reproduction, Fertility and Development 30, no. 1 (2018): 204. http://dx.doi.org/10.1071/rdv30n1ab128.
Анотація:
The aim of present work was to assess the effects of pregnancy-associated serum protein A (PAPP-A) during oocyte in vitro maturation (IVM) on meiosis progression, DNA fragmentation, IGF-1 free bioavailability, as well as effects on embryo yield and transcriptional profile of matured cumulus–oocyte complexes (COC). First, the COC from a local abattoir were submitted to IVM for 24 h with TCM-199 serum-free medium supplemented with PAPP-A (100 ng mL−1: P100 group) or not (control group). The matured oocytes were submitted to evaluation of DNA fragmentation (TUNEL assay) and meiosis progression (Hoechst 33342; n = 5 replicates; 20 COC/replicate per group), and maturation medium was collected to measure levels of free IGF-1. Then, the oocytes were separated from their respective cumulus cells and followed for the transcriptional profile of 96 genes (3 reference genes; ACTH, GAPDH, PPIA) by RT-qPCR using Taqman® assays in the HD-Biomark System® (Fluidigm Corp., South San Francisco, CA, USA). Further, the matured oocytes were submitted to in vitro fertilization followed by in vitro culture for 7 days. On Days 3 and 7, the cleavage and blastocyst (BL) rates were verified. On Day 7, BL (3 BL/pool; control: n = 4 pools; P100: n = 5 pools) were collected to analyse the transcriptional pattern of 96 genes (4 reference genes; ACTH, GAPDH, PPIA, and SDHA) as described above for COC. The DNA fragmentation, meiosis progression, cleavage, and BL rates were calculated as percentages and transformed to arcsine. The mRNA abundance of target genes was normalized by geometric mean of reference genes and data were transformed to fold change. The free IGF-I concentration also was transformed to fold change. All data were tested by ANOVA and means were compared with t-test or Wilcoxon tests using JMP software (SAS Institute Inc., Cary, NC, USA). Differences were considered significant when P ≤ 0.05. The addition of PAPP-A increased free IGF-I concentration 1.27-fold in IVM medium. There were no alterations in the percentage of oocytes in metaphase II or oocyte DNA fragmentation. In cumulus cells, the genes BCL2, GPX1, RPLP0, and RPS25 (anti-apoptotic and anti-oxidative stress) was higher in the P100 group, whereas DICER, GREM1, GUCY1B3, and FOXO3 (cell proliferation, cumulus expansion, cGMP regulator, and apoptotic initiator, respectively) were higher in the control group. In oocytes, the mRNA relative abundance of ACACA, BCL2, H1FOO, TXNRD1, and VCAN (related with fatty acid synthesis, anti-apoptotic effect, chromatin regulation, oxidative stress processes, and cell proliferation, respectively) was higher in the P100 group. There was no difference in cleavage rate or embryo yield. The mRNA abundance of genes related to cellular stress (ATF4, GPX4, and HIF1A) and lipid metabolism (FASN and SREBF1) was lower in embryos of the P100 group. On the other hand, genes involved in cellular proliferation/differentiation (MAPK1) and pluripotency (POU5F1) were up-regulated in embryos of the P100 group. In conclusion, the addition of PAPP-A during the IVM increased free IGF-I and modulates the gene expression in COC and blastocysts, which could modify oocyte competence and embryo development.
37
Guan, H., R. B. Chatfield, S. R. Freitas, R. W. Bergstrom, and K. M. Longo. "Modeling the effect of plume-rise on the transport of carbon monoxide over Africa with NCAR CAM." Atmospheric Chemistry and Physics 8, no. 22 (November 27, 2008): 6801–12. http://dx.doi.org/10.5194/acp-8-6801-2008.
Анотація:
Abstract. We investigated the effects of fire-induced plume-rise on the simulation of carbon monoxide (CO) over Africa and its export during SAFARI 2000 using the NCAR Community Atmosphere Model (CAM) with a CO tracer and a plume-rise parameterization scheme. The plume-rise parameterization scheme simulates the consequences of strong buoyancy of hot gases emitted from biomass burning, including both dry and cloud-associated (pyro-cumulus) lofting. The current implementation of the plume-rise parameterization scheme into the global model provides an opportunity to examine the effect of plume-rise on long-range transport. The CAM simulation with the plume-rise parameterization scheme seems to show a substantial improvement of the agreements between the modeled and aircraft-measured vertical distribution of CO over Southern Africa biomass-burning area. The plume-rise mechanism plays a crucial role in lofting biomass-burning pollutants to the middle troposphere. In the presence of deep convection we found that the plume-rise mechanism results in a decrease of CO concentration in the upper troposphere. The plume-rise depletes the boundary layer, and thus leaves lower concentrations of CO to be lofted by the deep convection process. The effect of the plume-rise on free troposphere CO concentration is more important for the source area (short-distance transport) than for remote areas (long-distance transport). A budget analysis of CO burden over Southern Africa reveals the plume-rise process to have a similar impact as the chemical production of CO by OH and CH4. In addition, the plume-rise process has an minor impact on the regional export. These results further confirm and extend previous findings in a regional model study. Effective lofting of large concentration of CO by the plume-rise mechanism also has implications for local air quality forecasting in areas affected by other fire-related pollutants.
38
Zhang, Yunyan, Stephen A. Klein, Jiwen Fan, Arunchandra S. Chandra, Pavlos Kollias, Shaocheng Xie, and Shuaiqi Tang. "Large-Eddy Simulation of Shallow Cumulus over Land: A Composite Case Based on ARM Long-Term Observations at Its Southern Great Plains Site." Journal of the Atmospheric Sciences 74, no. 10 (September 19, 2017): 3229–51. http://dx.doi.org/10.1175/jas-d-16-0317.1.
Анотація:
Abstract Based on long-term observations by the Atmospheric Radiation Measurement program at its Southern Great Plains site, a new composite case of continental shallow cumulus (ShCu) convection is constructed for large-eddy simulations (LES) and single-column models. The case represents a typical daytime nonprecipitating ShCu whose formation and dissipation are driven by the local atmospheric conditions and land surface forcing and are not influenced by synoptic weather events. The case includes early morning initial profiles of temperature and moisture with a residual layer; diurnally varying sensible and latent heat fluxes, which represent a domain average over different land surface types; simplified large-scale horizontal advective tendencies and subsidence; and horizontal winds with prevailing direction and average speed. Observed composite cloud statistics are provided for model evaluation. The observed diurnal cycle is well reproduced by LES; however, the cloud amount, liquid water path, and shortwave radiative effect are generally underestimated. LES are compared between simulations with an all-or-nothing bulk microphysics and a spectral bin microphysics. The latter shows improved agreement with observations in the total cloud cover and the amount of clouds with depths greater than 300 m. When compared with radar retrievals of in-cloud air motion, LES produce comparable downdraft vertical velocities, but a larger updraft area, velocity, and updraft mass flux. Both observations and LES show a significantly larger in-cloud downdraft fraction and downdraft mass flux than marine ShCu.
39
Kobayashi, Yasuhiro, Fermin Jimenez-Krassel, Qinglei Li, Jianbo Yao, Ruiping Huang, James J. Ireland, Paul M. Coussens, and George W. Smith. "Evidence that Cocaine- and Amphetamine-Regulated Transcript Is a Novel Intraovarian Regulator of Follicular Atresia." Endocrinology 145, no. 11 (November 1, 2004): 5373–83. http://dx.doi.org/10.1210/en.2004-0283.
Анотація:
Abstract We recently obtained evidence that cocaine- and amphetamine-regulated transcript (CART), a potent anorectic neuropeptide, is expressed in the bovine ovary. The objectives of this study were to characterize bovine ovarian CART and determine its localization, regulation, and regulatory role during follicular development. CART mRNA was detected in stroma of adult ovaries and in large follicles, but was undetectable in several peripheral tissues, fetal ovaries, and corpora lutea. Within the ovary, CART mRNA and peptide were localized to the granulosal layer of some, but not all, antral follicles, with low, but detectable, expression in oocytes and cumulus cells. CART mRNA was undetectable in granulosal cells of dominant ovulatory follicles collected before and after the preovulatory gonadotropin surge, but was detected in the granulosal layer of adjacent subordinate follicles. In addition, amounts of CART mRNA and follicular fluid concentrations of CART peptide were greater in subordinate follicles vs. dominant follicles of the first follicular wave. Furthermore, CART treatment inhibited basal estradiol production, but not progesterone production, by granulosal cells in a dose-dependent fashion, and the effect was dependent on stage of cell differentiation. We conclude that granulosal cell CART expression is temporally regulated and potentially associated with follicle health status, and CART can inhibit granulosal cell estradiol production. Thus, CART may be a novel local regulator of follicular atresia in the bovine ovary.
40
Lee, K. B., A. Bettegowda, J. J. Ireland, and G. W. Smith. "148 EFFECT OF FOLLISTATIN TREATMENT POST-FERTILIZATION ON TIME TO FIRST CLEAVAGE, DEVELOPMENT TO THE BLASTOCYST STAGE, AND CELL ALLOCATION OF IN VITRO-PRODUCED BOVINE EMBRYOS." Reproduction, Fertility and Development 19, no. 1 (2007): 191. http://dx.doi.org/10.1071/rdv19n1ab148.
Анотація:
Previous studies from our laboratory have demonstrated a positive association of follistatin mRNA abundance with oocyte competence. Follistatin mRNA is greater in germinal vesicle stage oocytes collected from prepubertal (model of poor oocyte competence) vs. adult animals. Furthermore, follistatin mRNA abundance is also greater in early-cleaving 2-cell bovine embryos (collected prior to the maternal zygotic transition and initiation of significant transcription from the embryonic genome) than their late-cleaving counterparts. Given these results and the fact that early-cleaving embryos develop to the blastocyst stage at a greater rate, we hypothesized that follistatin has a stimulatory role in early embryonic development. To begin to test this hypothesis, we determined the effects of follistatin treatment of in vitro-produced bovine embryos (during the initial 72 h post-fertilization) on time to first cleavage, development to the blastocyst stage (Day 7), and blastocyst cell allocation (quality). Cumulus–oocyte complexes (COCs) were harvested from ovaries obtained from a local abattoir, matured, and fertilized in vitro. After 20 h of co-incubation with spermatozoa, presumptive zygotes were stripped of cumulus cells and cultured in KSOM medium supplemented with 0.3% BSA containing 0, 1, 10, or 100 ng mL-1 follistatin (n = 25 presumptive zygotes per treatment; n = 6 replicates). Proportions of embryos reaching the 2-cell stage within 30 h (early-cleaving), 30–36 h (late-cleaving), and within 48 h post-fertilization (total cleavage rate) were recorded. Embryos at the 8–16-cell stage were separated 72 h after fertilization and cultured in fresh KSOM medium supplemented with 0.3% BSA and 10% FBS until Day 7. The proportion of embryos reaching the blastocyst stage at Day 7 post-fertilization was recorded and the numbers of inner cell mass (ICM) and trophectoderm (TE) cells determined by differential staining. Follistatin treatment did not increase the rate of total cleavage and the proportion of late-cleaving embryos when compared to control. However, supplementation with 1 and 10, but not 100, ng mL-1 follistatin increased the proportion of early-cleaving embryos (26.3 and 35.3% vs. 9.5%) and development to the blastocyst stage (28.6 and 31.7% vs. 18.4%) relative to controls (P < 0.05). Treatment with 10 ng mL-1 follistatin increased total cell numbers (130.1 vs. 110.9) and proportion of trophectoderm cells (61.6% vs. 48.4%) and decreased the ICM/total cell ratio (38.4% vs. 51.5%) in Day 7 blastocysts relative to controls (P < 0.05). The results indicate that exogenous follistatin treatment during the early stages of in vitro bovine embryo development can enhance time to first cleavage, development to the blastocyst stage, and cell allocation in favor of increased trophectoderm cells, and can support a potential functional role for follistatin in early embryogenesis.
41
Palazzi, E. G., D. Hansen, M. F. Alves, A. H. C. Nogueira, R. A. Ogata, J. G. Bersano, L. P. Pacheco, et al. "172 ANTIVIRAL ACTION OF PROPOLIS AQUEOUS EXTRACT DURING MATURATION OF INFECTED BOVINE OOCYTES." Reproduction, Fertility and Development 28, no. 2 (2016): 216. http://dx.doi.org/10.1071/rdv28n2ab172.
Анотація:
The objective of this study was to evaluate the decrease of virus replication in BoHV-1 (Colorado strain, 106.5 TCID50/mL) after the treatment using propolis aqueous extract (PAE) during in vitro maturation of infected bovine oocytes (24 h). Cow ovaries were obtained from a local slaughterhouse (Nelore breed) and transported to the laboratory. Cumulus-oocyte complexes (COC) were aspirated from follicles and separated into 4 groups (number of replicates for all groups = 6), which were exposed to 20 μL of sterile physiological solution (SPS), 100 μL of the in vitro maturation (IVM) medium [G1 (control), n = 609]; 10 μL of BoHV-1 (106.5 TCID50/mL) virus, 100 μL IVM medium, and 10 μL of SPS (G2, n = 786); 10 μL of PAE in 0.001% in SPS, 100 μL IVM medium, and 10 μL of SPS (G3, n = 819); 10 μL of PAE extract in 0.001% in SPS, 10 μL of BoHV-1 (106.5 TCID50/mL) virus and 100 μL of the IVM medium (G4, n = 734). All groups were kept for 24 h at 38.5°C, 5% CO2 in air. After the IVM, we analysed COC expansion and the presence of a polar body by optical microscope as well as viral replication by titration (Reed and Muench test) after 72 h of co-culture with Madin-Darby bovine kidney (MDBK) cells. The G1, G3, and G4 showed steady expansion of the cumulus cells and ooplasm with uniform appearance. The G2 did not have expansion of the cumulus cells. In contrast, the cytoplasm showed degenerative appearance and an absence of maturity in numerous oocytes. The maturation rates were as follows: G1 = 79% (482/609), G2 = 51% (407/786), G3 = 80% (662/819), and G4 = 76% (565/734). The differences among groups in maturation rates were compared using the chi-squared test (α = 5%) and the average titrations using the Mann–Whitney test (α = 5%). There was a significant difference (P < 0.01) among G1 and G2 evincing the interference of the virus maturation. The extract did not affect maturation as there was no difference among G1 and G3 (P = 0.43). The main step was finding no significant difference between the groups G1 and G4, (P = 17) proving that the extract interferes with viral replication. The titration after co-culturing the oocytes in MDBK demonstrated that G4 (average titrations = 1.63 × 103 titration) showed a lower rate of viral replication, the Mann-Whitney test, when compared to group G2 (average titrations = 6.04 × 107) which has not been subjected to treatment with PAE (P = 0.02). These results indicate that the propolis aqueous extract reduces the rate of viral replication without interfering with the maturation of oocytes and, therefore, it can be a conclusion that the analysis of the action of the molecules of this extract (by proteomics, for example) and future studies should be directed towards identifying the effect of extract on antiviral activity during the assessment of oocyte competence and embryo development.
42
Baró Pérez, Alejandro, Michael S. Diamond, Frida A. M. Bender, Abhay Devasthale, Matthias Schwarz, Julien Savre, Juha Tonttila, et al. "Comparing the simulated influence of biomass burning plumes on low-level clouds over the southeastern Atlantic under varying smoke conditions." Atmospheric Chemistry and Physics 24, no. 8 (April 18, 2024): 4591–610. http://dx.doi.org/10.5194/acp-24-4591-2024.
Анотація:
Abstract. Biomass burning plumes are frequently transported over the southeast Atlantic (SEA) stratocumulus deck during the southern African fire season (June–October). The plumes bring large amounts of absorbing aerosols and enhanced moisture, which can trigger a rich set of aerosol–cloud–radiation interactions with climatic consequences that are still poorly understood. We use large-eddy simulation (LES) to explore and disentangle the individual impacts of aerosols and moisture on the underlying stratocumulus clouds, the marine boundary layer (MBL) evolution, and the stratocumulus-to-cumulus transition (SCT) for three different meteorological situations over the southeast Atlantic during August 2017. For all three cases, our LES shows that the SCT is driven by increased sea surface temperatures and cloud-top entrainment as the air is advected towards the Equator. In the LES model, aerosol indirect effects, including impacts on drizzle production, have a small influence on the modeled cloud evolution and SCT, even when aerosol concentrations are lowered to background concentrations. In contrast, local semi-direct effects, i.e., aerosol absorption of solar radiation in the MBL, cause a reduction in cloud cover that can lead to a speed-up of the SCT, in particular during the daytime and during broken cloud conditions, especially in highly polluted situations. The largest impact on the radiative budget comes from aerosol impacts on cloud albedo: the plume with absorbing aerosols produces a total average 3 d of simulations. We find that the moisture accompanying the aerosol plume produces an additional cooling effect that is about as large as the total aerosol radiative effect. Overall, there is still a large uncertainty associated with the radiative and cloud evolution effects of biomass burning aerosols. A comparison between different models in a common framework, combined with constraints from in situ observations, could help to reduce the uncertainty.
43
Harlow, Christopher R., Angela C. Bradshaw, Michael T. Rae, Kirsty D. Shearer, and Stephen G. Hillier. "Oestrogen formation and connective tissue growth factor expression in rat granulosa cells." Journal of Endocrinology 192, no. 1 (January 2007): 41–52. http://dx.doi.org/10.1677/joe.1.06689.
Анотація:
Ovarian follicular development involves continual remodelling of the extracellular matrix (ECM) forming the basement membrane and intercellular framework that support granulosa cell (GC) growth and differentiation. Insight into the molecular regulation of ovarian ECM remodelling is potentially translatable to tissue remodelling elsewhere in the body. We therefore studied the link between a gene marker of ECM remodelling (connective tissue growth factor (CTGF)) and oestrogen biosynthesis (cytochrome P450aromatase (P450arom)) in rat granulosa cells. To determine if a cause–effect interaction exists, we used semi-quantitative in situ hybridisation to analyse patterns of CTGF and P450arom mRNA expression and immunohistochemistry to detect CTGF protein localisation throughout follicular development, and tested the actions of CTGF on oestrogen biosynthesis and oestradiol on CTGF mRNA expression in isolated GC in vitro. CTGF mRNA levels in GC rose gradually through small preantral (SP) and small antral (SA) stages of development to a maximum (fivefold higher) in large antral (LA) follicles. In preovulatory (PO) follicles, the CTGF mRNA level fell to 30% of that in SP follicles. P450arom mRNA also increased (threefold in LA relative to SP) throughout antral development follicles, but in contrast to CTGF continued to increase (12-fold) in PO follicles. In the cumulus oophorus of PO follicles, the residual GC CTGF mRNA expression increased with proximity to the oocyte, being inversely related to P450arom. Elsewhere in the follicle wall, there was a mural-to-antral gradient of CTGF mRNA expression, again inversely related to P450arom. Immunohistochemistry showed CTGF protein localisation broadly followed mRNA expression during follicular development, although the protein was also present in the theca interna and ovarian surface epithelium. Gradients in CTGF expression across the cumulus oophorus and follicle wall were similar to those observed for mRNA with CTGF protein expression being greatest in proximity to the oocyte. Treatment of isolated GC from preantral and SA follicles with recombinant human CTGF (1–100 ng/ml) did not affect basal or FSH-stimulated GC aromatase activity. However, in the absence of FSH, oestradiol (10−7–10−5 M) stimulated CTGF mRNA expression up to twofold. Conversely, FSH (10 ng/ml) alone reduced CTGF mRNA expression by 40% and combined treatment with FSH and oestradiol further suppressed CTGF to 10% of the control value. The oestrogen receptor (ER) antagonist, ICI 182 780 blocked the stimulatory and inhibitory effects of oestradiol, suggesting a specific ER-mediated mode of action on CTGF. Therefore, CTGF gene expression in GC is under local control by oestrogen whose effect (positive or negative) is modulated by FSH. This helps explain why gene expression of CTGF and P450arom diverge in FSH-induced PO follicles and has implications for oestrogenic regulation of CTGF formation elsewhere in the body.
44
Moser, Daniel H., and Sonia Lasher-Trapp. "Cloud-Spacing Effects upon Entrainment and Rainfall along a Convective Line." Journal of Applied Meteorology and Climatology 57, no. 8 (August 2018): 1865–82. http://dx.doi.org/10.1175/jamc-d-17-0363.1.
Анотація:
AbstractCumulus clouds modify their immediate surroundings by detraining their warm, humid updrafts. When clouds are closely spaced, this conditioning of the local environment may alter the properties of the air entrained by neighboring clouds and slow their dilution. This effect has not been quantified, nor has its importance been determined for influencing the amount of convective rainfall from a system of neighboring clouds. Here, a series of idealized numerical simulations, which are based on an observed line of precipitating cumulus congestus clouds, is performed using increasingly smaller cloud spacing to investigate how cloud proximity may alter entrainment, cloud development, and convective rainfall. For clouds of radius R, which is approximately 1 km in these simulations, distances between updraft centers from 4R through 9R are tested. Over this range, the initial clouds all exhibit negligible differences in the directly calculated entrainment rates and in the thermodynamic characteristics of the entrained air. Instead, for cloud separation distances of less than 6R, the subcloud inflow is increasingly disturbed, limiting initial cloud depths and slowing updraft speeds and precipitation onset. Ultimately, however, these same cases produce a new generation of clouds that are stronger and produce more rainfall than for all other cases. The smaller cloud separation distance allows precipitation outflows from the initial clouds to meet and force new, stronger cloud updrafts. For this second generation of clouds, their entrained air is slightly more humid, but the stronger updrafts and ingestion of residual ice and precipitation from earlier clouds appear to be most important for enhancing their rainfall.
45
Hoffmann, Fabian, Takanobu Yamaguchi, and Graham Feingold. "Inhomogeneous Mixing in Lagrangian Cloud Models: Effects on the Production of Precipitation Embryos." Journal of the Atmospheric Sciences 76, no. 1 (December 26, 2018): 113–33. http://dx.doi.org/10.1175/jas-d-18-0087.1.
Анотація:
Abstract Although small-scale turbulent mixing at cloud edge has substantial effects on the microphysics of clouds, most models do not represent these processes explicitly, or parameterize them rather crudely. This study presents a first use of the linear eddy model (LEM) to represent unresolved turbulent mixing at the subgrid scale (SGS) of large-eddy simulations (LESs) with a coupled Lagrangian cloud model (LCM). The method utilizes Lagrangian particles to provide the trajectory of air masses within LES grid boxes, while the LEM is used to redistribute these air masses among the Lagrangian particles based on the local features of turbulence, allowing for the appropriate representation of inhomogeneous to homogeneous SGS mixing. The new approach has the salutary effect of mitigating spurious supersaturations. At low turbulence intensities, as found in the early stages of an idealized bubble cloud simulation, cloud-edge SGS mixing tends to be inhomogeneous and the new approach is shown to be essential for the production of raindrop embryos. At higher turbulence intensities, as found in a field of shallow cumulus, SGS mixing tends to be more homogeneous and the new approach does not significantly alter the results, indicating that a grid spacing of 20 m may be sufficient to resolve all relevant scales of inhomogeneous mixing. In both cases, droplet in-cloud residence times are important for the production of precipitation embryos in the absence of small-scale inhomogeneous mixing, either naturally due to strong turbulence or artificially as a result of coarse resolution or by not using the LEM as an SGS model.
46
Saadeldin, Islam M., Ok Jae Koo, Jung Taek Kang, Dae Kee Kwon, Sol Ji Park, Su Jin Kim, Joon Ho Moon, Hyun Ju Oh, Goo Jang, and Byeong Chun Lee. "Paradoxical effects of kisspeptin: it enhances oocyte in vitro maturation but has an adverse impact on hatched blastocysts during in vitro culture." Reproduction, Fertility and Development 24, no. 5 (2012): 656. http://dx.doi.org/10.1071/rd11118.
Анотація:
Kisspeptin (Kp) is best known as a multifunctional peptide with roles in reproduction, the cardiovascular system and cancer. In the present study the expression of kisspeptin hierarchy elements (KISS1, GNRH1 and LHB) and their receptors (KISS1R, GNRHR and LHCGR, respectively) in porcine ovary and in cumulus–oocyte complexes (COCs) were investigated, as were its effects on the in vitro maturation (IVM) of oocytes and their subsequent ability to sustain preimplantation embryo competence after parthenogenetic electrical activation. Kp system elements were expressed and affected IVM of oocytes when maturation medium was supplemented with 10–6 M Kp. Oocyte maturation, maternal gene expression (MOS, GDF9 and BMP15), blastocyst formation rate, blastocyst hatching and blastocyst total cell count were all significantly increased when oocytes were matured in medium containing Kp compared with the control group (without Kp). A Kp antagonist (p234) at 4 × 10–6 M interfered with this hierarchy but did not influence the threshold effect of gonadotrophins on oocyte maturation. FSH was critical and permissive to Kp action on COCs by increasing the relative expression of KISS1R. In contrast, Kp significantly increased apoptosis, the expression of pro-apoptotic gene, BAK1, and suppressed trophoblast outgrowths from hatched blastocysts cultured on feeder cells. The present study provides the first functional evidence of the Kp hierarchy in porcine COCs and its role in enhancing oocyte maturation and subsequent developmental competence in an autocrine–paracrine manner. However, Kp supplementation may have a harmful impact on cultured hatched blastocysts reflecting systemic or local regulation during the critical early period of embryonic development.
47
Dochi, O., M. Tanisawa, S. Goda, and H. Koyama. "188 EFFECT OF TRANSFER OF FROZEN-THAWED IVF EMBRYOS ON PREGNANCY IN REPEAT-BREEDER INSEMINATED OR NON-INSEMINATED HOLSTEIN CATTLE." Reproduction, Fertility and Development 18, no. 2 (2006): 202. http://dx.doi.org/10.1071/rdv18n2ab188.
Анотація:
Repeat-breeding is one of the important factors that affect dairy management. The objective of this study was to investigate the effect of transfer of frozen–thawed IVF embryos on pregnancy in repeat-breeder Holstein cattle. Cumulus–oocyte complexes (COCs) were collected by aspiration of 2–1-mm follicles from ovaries obtained at a local abattoir. COCs were matured for 20 h in TCM-199 supplemented with 5% calf serum (CS) and 0.02 mg/mL of FSH at 38.5°C under a 5% CO2 atmosphere in air. Matured oocytes were inseminated with spermatozoa of 5 × 106/mL in BO solution (Brackett and Oliphant 1975 Biol. Reprod. 12, 260–274) containing 10 mM hypotaurine and 4 units/mL heparin. After 18 h of gamete co-culture, presumptive zygotes were cultured in CR1aa (Rosenkrans et al. 1991 Theriogenology 35, 266) supplemented with 5% CS for 8 days at 38.5°C under 5% CO2, 5% O2, 90% N2 atmosphere in air. After in vitro fertilization, Day 7 and Day 8 blastocysts were frozen in 1.5 M ethylene glycol (EG) in Dulbecco's PBS (DPBS) supplemented with 0.1 M sucrose and 20% CS. Embryos were transferred into a freezing medium, loaded into 0.25-mL straws, and allowed to stand for 15–20 min for equilibration. The straws were then plunged into a −7°C methanol bath of a programmable freezer for 1 min, seeded at −7°C, maintained at −7°C for 15 min, cooled to −30°C at the rate of −0.3°C/min, and then plunged into liquid nitrogen. Recipient animals (43 heifers, 131 cows) included those that did not conceive after being artificially inseminated (AI) 3 to 15 times. The frozen–thawed IVF embryos were directly transferred to the recipient animals 7 days after estrus or AI. Pregnancy rates were analyzed by chi-square test. The results are presented in Table 1. There were no significant differences in the pregnancy rates between treatments. However, a slightly higher pregnancy rate was achieved by embryo transfer after AI. These results suggest that embryo transfer may increase the pregnancy rate in repeat-breeder Holstein cattle. Table 1. Pregnancy rates after transfer of IVF frozen–thawed embryos in repeat-breeder Holstein cattle
48
Hotta, Daisuke, and Hisashi Nakamura. "On the Significance of the Sensible Heat Supply from the Ocean in the Maintenance of the Mean Baroclinicity along Storm Tracks." Journal of Climate 24, no. 13 (July 1, 2011): 3377–401. http://dx.doi.org/10.1175/2010jcli3910.1.
Анотація:
Abstract The relative importance between the sensible heat supply from the ocean and latent heating is assessed for the maintenance of near-surface mean baroclinicity in the major storm-track regions, by analyzing steady linear responses of a planetary wave model to individual components of zonally asymmetric thermal forcing taken from a global reanalysis dataset. The model experiments carried out separately for the North Atlantic, North Pacific, and south Indian Oceans indicate that distinct local maxima of near-surface baroclinicity observed along the storm tracks can be reinforced most efficiently as a response to the near-surface sensible heating. The result suggests the particular importance of the differential sensible heat supply from the ocean across an oceanic frontal zone for the efficient restoration of surface baroclinicity, which acts against the relaxing effect by poleward eddy heat transport, setting up conditions favorable for the recurrent development of transient eddies to anchor a storm track. Unlike what has been suggested, the corresponding reinforcement of the near-surface baroclinicity along a storm track as the response to the latent heating due either to cumulus convection or large-scale condensation is found less efficient. As is well known, poleward eddy heat flux convergence acts as the primary contributor to the reinforcement of the surface westerlies, especially in the core of a storm track. In its exit region, a substantial contribution to the reinforcement arises also from a planetary wave response to the sensible heat supply from the ocean. In contrast, the surface wind acceleration as a planetary wave response to the latent heating is found to contribute negatively to the maintenance of the surface westerlies along any of the major storm tracks.
49
Park, Y. M., S. S. Kim, J. H. Lee, Y. S. Park, and H. D. Park. "292 MATURATION IN A STRAW IS EFFECTIVE ON THE DEVELOPMENT OF BOVINE OOCYTES IN VITRO." Reproduction, Fertility and Development 17, no. 2 (2005): 296. http://dx.doi.org/10.1071/rdv17n2ab292.
Анотація:
In vitro embryo development is strongly influenced by oocyte maturation environments. Maturation of bovine oocytes is processed in a culture dish. However, the development rate to the transferable blastocyst stage was 10 to 30%. This experiment was to examine the effect of the size of straw and the medium exchange on the development of Korean Native Cow (KNC) oocytes. Ovaries of KNC were obtained from a local slaughterhouse and cumulus oocyte complexes (COCs) were aspirated from 2- to 8-mm follicles. Groups of 15 COCs were matured in TCM-199 supplemented with 10% fetal calf serum (FCS), 1 μg/mL FSH, 10 μg/mL LH, and 1 μg/mL estradiol-17β for 18 h. In vitro-matured oocytes were fertilized using frozen-thawed percoll-separated spermatozoa (Day 0) in fer-TALP medium for 20 h and cultured in CR1aa medium supplemented with 0.3% BSA (before Day 3) or 10% FBS (after Day 3). All cultures were maintained in an incubator at 39°C, 5% CO2 in air with maximum humidity. Data from three replicates were analyzed by chi-square test. In Experiment 1, we examined the effect of the instrument of maturation (dish or 0.25-mL and 0.5-mL straws) on embryo development. There were no difference in the cleavage (2-cell) among treatment groups. However, the development rate to the 8-cell and blastocyst stage was significantly higher in the 0.5-mL straw (38.5 and 17.0%) than in the 0.25 mL-straw (26.6 and 7.4%, all respectively). In Experiment 2, the KNC oocytes were matured in 0.5-mL straws based on the results of Experiment 1, and we examined the effect of the conditions such as circulation and exchange of maturation medium at 9 h after the start of IVM on embryo development. The development rates to the 2-cell, 8-cell, and blastocyst stage were significantly higher in the circulation group (83.3, 58.0 and 31.3%) than in the control (72.0, 44.7 and 19.3%) and exchange groups (71.3, 40.0, and 18.0%, all respectively). The results of this study suggest that the maturation of KNC oocytes in 0.5-mL straws accompanied by circulation of medium at 9 h is effective in the development to the blastocyst stage.
50
Ihara, Y., K. Tatakura, Y. Wada, H. Kawahara, and K. Yamanaka. "34 Effect of polysaccharide from Flammulina velutipes on the vitrification of bovine oocytes." Reproduction, Fertility and Development 32, no. 2 (2020): 143. http://dx.doi.org/10.1071/rdv32n2ab34.
Анотація:
The developmental competence of oocytes after cryopreservation is compromised by the physical injury due to the ice crystallisation. Recent studies have reported that polysaccharide (xylomannan) derived from the mycelium and fruit body of the basidiomycete Flammulina velutipes inhibits the ice recrystallisation in the cryopreserved Chinese hamster ovary cells. In this study, we aimed to clarify the effect of xylomannan from Flammulina velutipes on the developmental competence of bovine vitrified oocytes. Bovine ovaries were obtained from a local abattoir, and cumulus-oocyte complexes (COCs) were aspirated from follicles (2-6mm in diameter) using a 19-gauge needle attached to a syringe. The COCs were matured for 22h in tissue culture medium-199 supplemented with 5% fetal bovine serum (FBS), 0.02IUmL−1 FSH, and 10μgmL−1 gentamycin. After maturation, COCs were incubated in base solution (BS: 10% FBS-tissue culture medium-199, control group; n=149) or BS supplemented with 100μgmL−1 xylomannan (xylomannan group; n=175) for 1h before vitrification. All vitrification procedures were performed at room temperature. The COCs were equilibrated in BS with 3% ethylene glycol for 12min and then in vitrification solution (BS with 30% ethylene glycol, 1.0M sucrose) for 1min. The COCs were loaded on a Cryotop (Kitazato) and transferred into liquid nitrogen. The warming procedure was performed on a warm plate (42°C). The COCs were placed into BS supplemented with 0.5, 0.25, 0.125, and 0M sucrose for 5min each. After washing with IVF100 solution (Research Institute for the Functional Peptide), COCs were applied for IVF. The viability of putative zygotes was morphologically evaluated following IVF, and ones that survived were cultured in CR1aa supplemented with 5% FBS. The cleavage pattern was evaluated at 28h after IVF as follows: embryos with blastomeres of the same size without fragmentation were classified as normal cleavage; embryos with 2 blastomeres and several small fragments, direct cleavage from the 1-cell stage to 3 or 4 blastomeres, or 2 blastomeres of different size were classified as abnormal cleavage. The rates of cleavage and blastocyst formation were calculated on 2 and 8 days after culture, respectively. Total cell number and apoptosis of blastocysts were measured by terminal deoxynucleotidyl transferase dUTP nick end labelling assay. All data were obtained from more than four replicates. Viability and invitro development data were analysed using the chi-squared test. Total cell number and apoptosis data were analysed by a Student's t-test. Although no significant differences in viability, cleavage pattern, and cleavage rate (85.8 vs. 80.3%, 17.2 vs. 14.8%, and 35.4 vs. 36.7%, respectively) were observed, the developmental rate to blastocysts in the xylomannan group was significantly higher than that in the control group (68.6 vs. 42.2%; P<0.01). The present results suggest that co-incubation with xylomannan before vitrification is an effective method to improve the vitrification outcome in bovine oocytes.