Journal articles on the topic 'Degree Discipline: Reproductive Biology'
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1
Dubynin, Alexander. "Conservation Biology as an Academic Discipline: Novosibirsk State University’s Master’s Degree Program Experience." BIO Web of Conferences 38 (2021): 00027. http://dx.doi.org/10.1051/bioconf/20213800027.
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A reduction in the planet’s biodiversity requires an active response by politicians, environmental activists, and scientists. Modern biological education should provide an opportunity to acquire the knowledge and skills necessary to solve complex tasks targeted at preserving and restoring vulnerable species habitats and ecosystems. Students study conservation biology at many universities around the world with this as their goal. For the first time in Russia, a Master’s Conservation Biology course for biology students was developed and tested at Novosibirsk State University. This primer course (108 hours) includes lectures, discussions, excursions, elements of gamification, combines auditorium and online classes, uses social networks for additional communication with students, and experienced practitioners. The course has been highly rated by students and can be expanded to include a larger audience.
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Krafsur, E. S., R. D. Moon, and T. J. Lysyk. "ADULT AGE AND REPRODUCTIVE SUCCESS IN STABLE FLY POPULATIONS (DIPTERA: MUSCIDAE)." Canadian Entomologist 126, no. 2 (April 1994): 239–49. http://dx.doi.org/10.4039/ent126239-2.
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AbstractThe pterin age-grading method was applied to natural populations of stable flies sampled for 3 years from diverse locations in Minnesota and Iowa. Significant differences were detected among years in mean degree-day ages per fly. Fly ages, in degree-day units, were exponentially distributed. A two-parameter Weibull distribution closely fit the fly survival distributions. Mean expectations of life did not differ significantly between males and females and were estimated to be 86.6 degree-days above a 6.5 °C threshold. Conventional age-grading techniques based on ovarian morphology applied to Iowa females showed that large fractions of the populations experienced delays in vitellogenesis. The reproductive rate, in terms of lifetime ovipositions, was less than the maximum sustainable rate suggested by ambient temperatures.
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Vágási, Csongor I., Orsolya Vincze, Jean-François Lemaître, Péter L. Pap, Victor Ronget, and Jean-Michel Gaillard. "Is degree of sociality associated with reproductive senescence? A comparative analysis across birds and mammals." Philosophical Transactions of the Royal Society B: Biological Sciences 376, no. 1823 (March 8, 2021): 20190744. http://dx.doi.org/10.1098/rstb.2019.0744.
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Our understanding on how widespread reproductive senescence is in the wild and how the onset and rate of reproductive senescence vary among species in relation to life histories and lifestyles is currently limited. More specifically, whether the species-specific degree of sociality is linked to the occurrence, onset and rate of reproductive senescence remains unknown. Here, we investigate these questions using phylogenetic comparative analyses across 36 bird and 101 mammal species encompassing a wide array of life histories, lifestyles and social traits. We found that female reproductive senescence: (i) is widespread and occurs with similar frequency (about two-thirds) in birds and mammals; (ii) occurs later in life and is slower in birds than in similar-sized mammals; (iii) occurs later in life and is slower with an increasingly slower pace of life in both vertebrate classes; and (iv) is only weakly associated, if any, with the degree of sociality in both classes after accounting for the effect of body size and pace of life. However, when removing the effect of species differences in pace of life, a higher degree of sociality was associated with later and weaker reproductive senescence in females, which suggests that the degree of sociality is either indirectly related to reproductive senescence via the pace of life or simply a direct outcome of the pace of life. This article is part of the theme issue ‘Ageing and sociality: why, when and how does sociality change ageing patterns?’
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Mann, Danny, and Jason Morrison. "Are there curricular differences between biology-based and application-based "bio" engineering disciplines?" Canadian Biosystems Engineering 63, no. 1 (December 31, 2021): 9.19–9.29. http://dx.doi.org/10.7451/cbe.2021.63.9.19.
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Several authors have previously promoted the transformation of the application-based agricultural engineering discipline into a biology-based biological engineering discipline. A systematic analysis of titles for courses being taught by ASABE-umbrella programs across North America was undertaken to identify curricular differences between biology-based and application-based “bio” engineering disciplines. Based on 44 ASABE-umbrella programs analyzed, the four most commonly used program names were biological engineering (25%), biosystems engineering (20%), biological systems engineering (15.9%) and agricultural engineering (13.6%). Definitions of these four program names were reviewed; biosystems, biological systems and agricultural engineering are typically defined such that they are best described as application-based “bio” engineering disciplines while biological engineering is best described as a biology-based engineering discipline. Based on statistical analysis of the frequency of words in course titles, there was a significant increase in the usage of the word “food” and a lack of the word “project” in the course titles within biological engineering programs. Over half of the unique options were found in biological engineering programs suggesting that they do offer unique course content compared with biosystems, biological systems and agricultural engineering degree programs, however, it is noteworthy that four options appear across all four degrees. It is concluded that there are curricular differences between biology-based and application-based “bio” engineering disciplines, however, the curricular differences are not as substantive as one might conclude from the philosophical discussions in the literature. Alternatively, it may simply not be possible to detect curricular differences solely from an analysis of the course titles
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Singh, B. N., and Sujata Chatterjee. "No character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana." Genome 34, no. 6 (December 1, 1991): 849–52. http://dx.doi.org/10.1139/g91-131.
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To test whether character displacement for reproductive isolation between Drosophila bipectinata and Drosophila malerkotliana exists, the degree of sexual isolation was measured between their sympatric and allopatric populations. Although the isolation indices vary in different crosses, the average isolation index for sympatric populations is very close to that for allopatric populations. This shows no difference in the degree of sexual isolation between sympatric and allopatric populations of D. bipectinata and D. malerkotliana. Thus there is no evidence for the existence of character displacement for sexual isolation between these two closely related sympatric species.Key words: Drosophila bipectinata, Drosophila malerkotliana, sexual isolation, sympatric and allopatric populations.
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Bentley, R. Alexander, William A. Brock, Camila C. S. Caiado, and Michael J. O'Brien. "Evaluating reproductive decisions as discrete choices under social influence." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1692 (April 19, 2016): 20150154. http://dx.doi.org/10.1098/rstb.2015.0154.
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Discrete choice, coupled with social influence, plays a significant role in evolutionary studies of human fertility, as investigators explore how and why reproductive decisions are made. We have previously proposed that the relative magnitude of social influence can be compared against the transparency of pay-off, also known as the transparency of a decision, through a heuristic diagram that maps decision-making along two axes. The horizontal axis represents the degree to which an agent makes a decision individually versus one that is socially influenced, and the vertical axis represents the degree to which there is transparency in the pay-offs and risks associated with the decision the agent makes. Having previously parametrized the functions that underlie the diagram, we detail here how our estimation methods can be applied to real-world datasets concerning sexual health and contraception.
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Calvo, Jorge, Elba Morriconi, and Gustavo A. Rae. "Reproductive biology of the icefish Champsocephalus esox (Günther, 1861) (Channichthyidae)." Antarctic Science 11, no. 2 (June 1999): 140–49. http://dx.doi.org/10.1017/s0954102099000206.
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Champsocephalus esox is the only icefish species found outside Antarctica. In a population from the Beagle Channel, the complete annual reproductive cycle has been determined. Gonad maturity stages have been established for males and females by histological analysis. Males are sexually mature from January–September with a maximum gonadosomatic index (GSI) of 3.63%. Histologically, testes are very homogeneous and the degree of maturation of the testicular cysts is similar among different tubules at the same maturation stage. Running ripe testes have mature sperm and a few spermatogoniae arranged near the blind end of the tubules. In sexually active females that are found from February–November, ovaries contain only ripe oocytes or postovulatory follicles, together with a batch of previtellogenic oocytes. During hydration, oocyte diameter reaches 2.7 mm, and oocyte dry weight increases due to material intake, the maximum GSI in ovulated ovaries is 21.89 and hepatosomatic index (HSI) decreases. These facts suggest a transfer of matter from liver to the gonads. Absolute fecundity ranges from 3303–8600 oocytes. Relative fecundity ranges from 22.5–43.5 oocytes per gram total weight. In C. esox, relative fecundity has a similar range to those quoted for the different C. gunnari populations, whilst mature oocyte diameter is small and reproductive season extended compared to the same parameters in other Channichthyidae.
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Arheden, Håkan. "Clinical physiology: a successful academic and clinical discipline is threatened in Sweden." Advances in Physiology Education 33, no. 4 (December 2009): 265–67. http://dx.doi.org/10.1152/advan.00072.2009.
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Clinical physiologists in Sweden are physicians (the majority with a PhD degree) with thorough training in system physiology and pathophysiology. They investigate patients in a functional approach and are engaged in basic and applied physiology teaching and research. In 1954, clinical physiology was founded as an independent academic and clinical discipline by the Swedish government to ensure “contact between routine clinical work and the scientific progression.” Up until 2008, clinical physiology was an independent clinical discipline but was then made a subdiscipline to radiology, a fundamentally different discipline. Individuals wishing to become clinical physiologists are required to be trained and certified as European radiologists, after which training and certification as clinical physiologists may be pursued. This means that radiologists without training in clinical physiology have become gatekeepers for future clinical physiologists. Unfortunately, this development takes place at a time when research and education in preclinical integrative physiology have diminished in favor of other organizational levels, such as cellular and molecular biology. The responsibilities for education and research in integrative human physiology have therefore mainly been transferred to clinical physiologists. Clinical physiology has been a successful independent clinical discipline in Sweden for the past 55 years and could serve as a model for other countries. Unless clinical physiologists regain control over their own discipline, systems physiology as a knowledge base and resource for patient care, education, and research will be severely impaired.
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Borna, Fatemeh, Nabil M. Ahmad, Shuming Luo, and Richard Trethowan. "Reproductive biology of a medicinally important plant Leonurus cardiaca (Lamiaceae)." Australian Journal of Botany 64, no. 4 (2016): 342. http://dx.doi.org/10.1071/bt15186.
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Motherwort (Leonurus cardiaca L.) is an annual species indigenous to central Europe and Scandinavia and has been used in traditional medicine because of its health benefits. The reproductive biology of L. cardiaca was investigated to provide a basis for the genetic improvement of secondary metabolites or extracts that could have human health benefits. L. cardiaca is self-compatible but bears protandrous flowers, which promote cross-pollination. The stigma becomes receptive 2 or 3 days after anthesis and anther dehiscence. Phenological observations revealed that the mean flowering duration was approximately 2 weeks within each inflorescence and 2 months within a plant. The timing of anthesis of flowers within each inflorescence and flowers of different inflorescences is usually synchronous, leading to the possibility of geitonogamous pollination. A high degree of synchronisation in flowering was observed among the plants within each of the populations studied. Among the populations, Khansar was the first to flower, whereas Dargaz was the last. A modified Brewbaker and Kwack (BK) medium optimised for in vitro germination of L. cardiaca pollen was used to establish a rapid and simple test that generally correlated with seed set. The optimised medium comprised 15% sucrose and 2.5% polyethylene glycol 4000. Data from staining with iodine–potassium iodide solution (IKI) and Alexander’s stain were positively correlated with in vitro germination and, therefore, could be used in rapid pollen-viability assays for L. cardiaca.
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van Wichelen, Sonja, and Marc de Leeuw. "Biolegality: How Biology and Law Redefine Sociality." Annual Review of Anthropology 51, no. 1 (October 24, 2022): 383–99. http://dx.doi.org/10.1146/annurev-anthro-041520-102305.
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As an empirical concept, biolegality emerged at the height of biotechnological advances in Euro-American societies when rapid changes in the life sciences (including molecular biology, immunology, and the neurosciences) and their attendant techniques (including reproductive technologies and gene editing) started to challenge ethical norms, legal decisions, and legal forms. As a theoretical concept, biolegality deepens the Foucauldian notion of biopolitics with an operation of legality that emphasizes how biology and its attendant technologies alter legal form, knowledge, practice, and experience. These empirical and theoretical developments affect how we understand sociality. While public discourse remains preoccupied with the call for more regulation—thereby underscoring law's lag in its dealings with technology—the social science scholarship describes instead how bioscience and biotechnology are fragmenting and rearranging legal knowledge about property, personhood, parenthood, and collective identity. As it opens broader anthropological debates around exchange, self, kinship, and community, the study of biolegality brings a novel currency to the discipline, addressing how biology and law inform new ways of relating and knowing.
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Hunter, Darren C., Josephine M. Pemberton, Jill G. Pilkington, and Michael B. Morrissey. "Pedigree-Based Estimation of Reproductive Value." Journal of Heredity 110, no. 4 (June 2019): 433–44. http://dx.doi.org/10.1093/jhered/esz033.
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AbstractHow successful an individual or cohort is, in terms of their genetic contribution to the future population, is encapsulated in the concept of reproductive value, and is crucial for understanding selection and evolution. Long-term studies of pedigreed populations offer the opportunity to estimate reproductive values directly. However, the degree to which genetic contributions, as defined by a pedigree, may converge on their long-run values within the time frames of available data sets, such that they may be interpreted as estimates of reproductive value, is unclear. We develop a system for pedigree-based calculation of the expected genetic representation that both individuals and cohorts make to the population in the years following their birth. We apply this system to inference of individual and cohort reproductive values in Soay sheep (Ovis aries) from St Kilda, Outer Hebrides. We observe that these genetic contributions appear to become relatively stable within modest time frames. As such, it may be reasonable to consider pedigree-based calculations of genetic contributions to future generations as estimates of reproductive value. This approach and the knowledge that the estimates can stabilize within decades should offer new opportunities to analyze data from pedigreed wild populations, which will be of value to many fields within evolutionary biology and demography.
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Nerio, Ron, Althea Webber, Effie MacLachlan, David Lopatto, and Avrom J. Caplan. "One-Year Research Experience for Associate’s Degree Students Impacts Graduation, STEM Retention, and Transfer Patterns." CBE—Life Sciences Education 18, no. 2 (June 2019): ar25. http://dx.doi.org/10.1187/cbe.19-02-0042.
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The CUNY Research Scholars Program (CRSP) provides a yearlong faculty-mentored research experience to associate’s degree students. The program takes place at all 10 associate’s degree–granting colleges within the City University of New York system. We report on a mixed-methods study of 500 students who participated in the program during its initial 3 years. Quantitative longitudinal assessments revealed that students who engaged in CRSP were more likely to be retained in a science, technology, engineering, and mathematics (STEM) discipline or to graduate with a STEM degree than their counterparts in a matched comparison group. Furthermore, students who participated in CRSP demonstrated an increased likelihood of transferring to the more research-intensive 4-year schools within the CUNY system and to R1 universities outside the CUNY system. CRSP students reported an increased sense of belonging in college based on survey data, and focus groups with their mentors provided insight into the factors that led to the gains listed above. These combined results—of student data analysis, student surveys, and mentor focus groups—provide evidence that early research experiences for associate’s degree students contribute to their academic success.
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Veen, Thor, Joseph Faulks, Rolando Rodríguez-Muñoz, and Tom Tregenza. "Premating Reproductive Barriers between Hybridising Cricket Species Differing in Their Degree of Polyandry." PLoS ONE 6, no. 5 (May 5, 2011): e19531. http://dx.doi.org/10.1371/journal.pone.0019531.
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Parker, Brian R., and William G. Franzin. "Reproductive biology of the quillback, Carpiodes cyprinus, in a small prairie river." Canadian Journal of Zoology 69, no. 8 (August 1, 1991): 2133–39. http://dx.doi.org/10.1139/z91-298.
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Quillback (Carpiodes cyprinus (Lesueur)) spawning migrations were monitored in 1984 and 1985 in the Ochre River, Manitoba. Quillback migrations were limited by both water temperature and discharge. Upstream spawning migrations began after water temperatures reached 5 °C but only when discharges were high. Quillback migrated up to 32 km upstream from Dauphin Lake during periods of high discharge but only 2–3 km upstream if discharges were low. Quillback probably are annual spawners and spawned from mid-April to mid-June at water temperatures between 7 and 18 °C. Fecundity ranged from 46 600 to 360 000 ova in females of 912–3410 g wet weight. Fecundity had a linear relationship to quillback wet weight. Relative gonad weight, ova diameter, and dry weight of ova all increased with increasing female weight. Fertilized ova hatched after 13–17 calendar days or 220.7–229.8 degree-days. The mean total length of newly hatched larvae was 7.95 mm. Tubercle distributions were similar to previously described patterns except that, in addition, Dauphin Lake quillback bore tubercles on the dorsal surface of the head, the anal and caudal fins, and the cornea of the eye.
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Piza-Roca, Carmen, David Schoeman, and Celine Frere. "Fitness benefits of male dominance behaviours depend on the degree of individual inbreeding in a polyandrous lizard." Proceedings of the Royal Society B: Biological Sciences 287, no. 1927 (May 20, 2020): 20200097. http://dx.doi.org/10.1098/rspb.2020.0097.
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In polyandrous species, sexual selection extends beyond mating competition to selection for egg fertilization. As a result, the degree to which factors influencing mating success impact overall reproductive success becomes variable. Here, we used a longitudinal behavioural and genetic dataset for a population of eastern water dragons ( Intellagama lesueurii ) to investigate the degree to which male dominance, a pre-mating selection trait, influences overall reproductive success, measured as the number of surviving offspring. Moreover, we examine the interactive effects with a genetic trait, individual inbreeding, known to influence the reproductive success of males in this species. We found fitness benefits of male dominance, measured as body size and frequency of dominance behaviours displayed. However, individuals' propensity to display dominance behaviours had mixed effects, depending on the degree of inbreeding. While inbred males benefited from frequent displays, highly outbred males exhibited better reproductive outputs when displaying to a lesser extent. Given that outbred males have enhanced reproductive success in this species, the costs of displaying dominance behaviours may outweigh the benefits. Overall, our results demonstrate the fitness benefits of dominance in a polyandrous lizard, and suggest that these are modulated by an independent genetic trait. Our results may contribute to explaining the presence of alternative mating tactics in this species, owing to the variability in net fitness benefits of dominance. Our findings also reveal the challenges associated with investigating fitness traits in isolation, which may undermine the validity of results when important interactions are ignored.
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Nunes, N. A. S., A. V. Leite, and C. C. Castro. "Phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca, Vitaceae) cultivated in northeastern Brazil." Brazilian Journal of Biology 76, no. 4 (May 17, 2016): 975–82. http://dx.doi.org/10.1590/1519-6984.05315.
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Abstract Phenology and reproductive biology of cultivated species are important for the comprehension of the requirements for fruit and seed production and the management of pollinators. This study aimed to characterise the phenology, reproductive biology and growing degree days of the grapevine ‘Isabel’ (Vitis labrusca) in northeastern Brazil during January 2011 (P1), Augst 2011 (P2), April 2012 (P3) and August 2012 (P4). We recorded the duration (days) of the phenological stages, pruning (P), woolly bud (W), budburst (B), inflorescence development (ID), flowering (F), ripening (R) and harvest (H). We analysed the floral biology, the sexual system and the breeding system. We measured the growing degree days (GDD) required to reach the subperiods P-B, B-F and F-H. The periods P1, P2, P3 and P4 lasted for 116, 125, 117 and 130 days, respectively. The number of days of harvest were similar in the same dry (P1 and P3) and rainy (P2 and P4) periods. All the periods that we recorded were shorter than those observed in other regions of Brazil, which may be attributable to the mean temperature and carbohydrate metabolism. The flowers are green, hermaphroditic, with an odour of mignonette, low pollen viability and autogamous. The base temperature of 10°C was considered the most adequate for the subperiods as has been documented for other grape varieties in Brazil. Thus, temperature was also the most adequate for the cycles, presenting a smaller standard deviation (0.119, 0.147, 0.156 and 0.153 to P1, P2, P3 and P4, respectively) when compared to a base temperature of 12°C (0.122, 0.158, 0.165 and 0.160 to P1, P2, P3 and P4, respectively). The higher and the lower observed GDD were 1972.17 and 1870.05, respectively, both above the values recorded in other parts of Brazil for same variety. The phonological results, including knowledge of growing degree days, are important to the planning of cultures at the study site and in other regions that have similar climatic conditions and make it possible to pre-determine the harvest.
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Garrido, Alejandro, María Fernández-González, Rosa A. Vázquez-Ruiz, F. Javier Rodríguez-Rajo, and María J. Aira. "Reproductive Biology of Olive Trees (Arbequina cultivar) at the Northern Limit of Their Distribution Areas." Forests 12, no. 2 (February 10, 2021): 204. http://dx.doi.org/10.3390/f12020204.
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In recent years, North-western Spain has experienced an increase in the cultivated area of olive trees. The main propitious areas for olive groves are the Miño and Sil basins, as a consequence of their Oceanic climate with Mediterranean influence. The objective of this study is to determine the characteristics of reproductive biology, phenological and aerobiological behaviour of olive trees in the most northerly new plantation areas of the Iberian Peninsula. The study was carried out in an olive grove growing Olea europaea L. cv. ‘Arbequina’ located in Quiroga (Lugo) from 2016 to 2018. The phenological observations were based upon the main growth stages following the Biologische Bundesanstalt Bundessortenamt and Chemical industry (BBCH) scale. To predict the onset of flowering, a thermal time model was used in order to quantify the chill requirements, and growing degree-days were applied to determine the heat requirement. The production, viability and germination rates of Olea pollen were evaluated from samples selected in nine individual trees for the phenological survey. The aerobiological study was conducted by means of a Hirst-type pollen trap located in the centre of the olive grove. The vegetative period of the olive tree in the study area lasted an average of 259 days. The important phenological stage 6 (flowering) was the shortest stage. An average of 704 Chilling Hours (CH) with a threshold of 2.5 °C was required to overcome the chilling period, 1139 Growing Degree Days (GDD) for the beginning of flowering, and 4463 GDD for harvest. The pollen production per anther was 82589 grains (± 14084 pollen grains), with a rate of 81% viability and 12% pollen tube germination. The main pollen season started on average on May 20th and ended on June 16th with an average duration of 27 days and an annual pollen integral of 833 pollen grains. The low pollen concentrations could be a consequence of the Northern location of the forest, in a bioclimatic transition zone between the Eurosiberian and the Mediterranean areas, at the limit of olive tree distribution.
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Teng, Mingming, Yuan Luo, Chan Wang, and Anmin Lei. "Effect of Disulfiram on the Reproductive Capacity of Female Mice." International Journal of Molecular Sciences 24, no. 3 (January 25, 2023): 2371. http://dx.doi.org/10.3390/ijms24032371.
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In the process of assisted reproduction, the high-oxygen in vitro environment can easily cause oxidative damage to oocytes. Disulfiram (DSF) can play an anti-oxidant or pro-oxidant role in different cells, and the effect of DSF on oocytes remains unclear. Moreover, it remains unclear whether the use of DSF in the early stages of pregnancy has a negative impact on the fetus. In this study, we found that DSF increased serum FSH levels and increased the ovulation rate in mice. Moreover, DSF enhanced the antioxidant capacity of oocytes and contributed to the success rate of in vitro fertilization. Moreover, the use of DSF in early pregnancy in mice increased the uterine horn volume and the degree of vascularization, which contributed to a successful pregnancy. In addition, it was found that DSF regulated the mRNA expression of angiogenesis-related genes (VEGF), follicular development-related genes (C1QTNF3, mTOR and PI3K), ovulation-related genes (MAPK1, MAPK3 and p38 MAPK) and antioxidant-related genes (GPX4 and CAT). These results indicate that DSF is helpful for increasing the antioxidant capacity of oocytes and the ovulation rate. In early pregnancy in mice, DSF promotes pregnancy by increasing the degree and volume of uterine vascularization.
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Dyer, Michael G. "Toward Synthesizing Artificial Neural Networks that Exhibit Cooperative Intelligent Behavior: Some Open Issues in Artificial Life." Artificial Life 1, no. 1_2 (October 1993): 111–34. http://dx.doi.org/10.1162/artl.1993.1.1_2.111.
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The tasks that animals perform require a high degree of intelligence. Animals forage for food, migrate, navigate, court mates, rear offspring, defend against predators, construct nests, and so on. These tasks commonly require social interaction/cooperation and are accomplished by animal nervous systems, which are the result of billions of years of evolution and complex developmental/learning processes. The Artificial Life (AL) approach to synthesizing intelligent behavior is guided by this biological perspective. In this article we examine some of the numerous open problems in synthesizing intelligent animal behavior (especially cooperative behavior involving communication) that face the field of AL, a discipline still in its infancy.
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Ronca, April E., Joshua S. Alwood, Ruth K. Globus, and Kenneth A. Souza. "Mammalian Reproduction and Development on the International Space Station (ISS): Proceedings of the Rodent Mark III Habitat Workshop." Gravitational and Space Research 1, no. 1 (July 1, 2013): 107–23. http://dx.doi.org/10.2478/gsr-2013-0009.
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ABSTRACT The Mark III Rodent Habitat Workshop was held at NASA Ames Research Center on March 21-22, 2013 to prepare top-level science requirements for developing a habitat to support studies of mammalian reproduction and development on the International Space Station (ISS). This timely workshop assembled a diverse team with expertise in reproductive and developmental biology, behavior, space biosciences, habitat development, physiology, mouse genetics, veterinary medicine, rodent husbandry, flight hardware development (rodent), and spaceflight operations. Participants received overview presentations from each discipline, discussed concerns, potential risks, and risk mitigations corresponding to distinctive reproductive and developmental phases, and reviewed specific examples of research within the major space bioscience disciplines requiring a Mark III habitat1 to achieve their objectives. In this review, we present the workshop materials and products, and summarize major recommendations for defining the requirements envelope for the NASA Rodent Habitat (RH) Mark III. Development of this habitat will permit the first long duration studies of mammalian reproduction and development in space, within and across generations.
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Muis, Khoirul Fatah. "Reproductive Biology of Carp (Cyprinus carpio) in Batu Bulan Reservoir, Sumbawa, West Nusa Tenggara." Journal of Global Sustainable Agriculture 1, no. 2 (July 25, 2021): 56. http://dx.doi.org/10.32502/jgsa.v1i2.3246.
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Research about carp (Cyprinus carpio) reproductive biology in Batu Bulan Reservoir was conducted in April, May, July, and October 2016. This study aims to determine some biological aspects include the degree of gonad maturity, fecundity, spawning frequency and season, and length of the first gonad maturity. The results showed the sex ratio between male and female fish in April (1:5), May (1:3), July (1:3), and October (1:3), with an average of 1:3.5 with the Chi-Square test on the confidence interval. 95%, it turns out that the sex ratio does not follow the 1:1 pattern, or the sex ratio of the fish is not balanced. TKG II carp occurred every month of observation, while the ripe fish of TKG IV gonads were founded only in April, July, and October. The highest percentage of female fish ripe for TKG IV gonads was 45.32%, and males 67.40% were found in October. The size of the ripening female carp size in Batu Bulan Reservoir is 20.16 cm. Carp fecundity ranges from 1,439 to 40,281.
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Tyagi, Anand P. "Cytogenetics and Reproductive Biology of some BELE (Abelmoschus manihot Linn., Medic Sub-Species manihot) Cultivars." South Pacific Journal of Natural and Applied Sciences 20, no. 1 (2002): 4. http://dx.doi.org/10.1071/sp02002.
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Four locally grown (from Fiji Islands) and three imported (from Papua New Guinea), a total of seven BELE (Abelmoschus manihot Linn., Medic sub-species manihot) cultivars were investigated for their cytogenetics and reproductive biology. Chromosome counting from flower buds and root tips showed that chromosome number in all the seven cultivars does not exceed 2n=66. Pollen viability in all the seven cultivars was high, exceeding 85% from pollen staining technique and 78% from pollen germination technique. All the seven Bele cultivars were fully self-compatible. Cross-compatibility among four local cultivars and three cultivars from Papua New Guinea was very high. However cross compatibility between local (Fijian) cultivars and cultivars from Papua New Guinea was partial indicating some degree of genetic difference between cultivars from two countries. This could be due to differences in compatibility alleles between cultivars from Fiji and Papua New Guinea. Procedures such as cutting the style shorter and placing pollen grains to enhance and affect fertilisation to get cross seed were suggested.
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Helenurm, Kaius, and Spencer C. H. Barrett. "The reproductive biology of boreal forest herbs. II. Phenology of flowering and fruiting." Canadian Journal of Botany 65, no. 10 (October 1, 1987): 2047–56. http://dx.doi.org/10.1139/b87-279.
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The flowering and fruiting phenologies of 12 boreal forest herbs were recorded during 1979 (flowering and fruiting) and 1980 (flowering only) in spruce–fir forests of central New Brunswick. The species studied were Aralia nudicaulis, Chimaphila umbellata, Clintonia borealis, Cornus canadensis, Cypripedium acaule, Linnaea borealis, Maianthemum canadense, Medeola virginiana, Oxalis montana, Pyrola secunda, Trientalis borealis, and Trillium undulatum. Flowering in the community occurred from mid-May to the end of July. The order of flowering was maintained in the 2 years, but the degree of synchronization of inflorescences differed in several species. Fruiting in the community began in mid-July and extended beyond the end of September. The percentage of buds that ultimately bore fruit ranged from 0 (Cypripedium acaule) to 61% (Aralia nudicaulis). With the exception of Cypripedium acaule, which received little pollinator service, the self-incompatible species, Cornus canadensis, Maianthemum canadense, and Medeola virginiana, experienced the lowest levels of fruit-set. Pollen limitation and predation of developing fruit appear to be the major factors limiting percentage fruit-set in boreal forest herbs. Fruit production varied with time of flowering of inflorescences in several species, with periods of low fruit-set tending to coincide with lower densities of flowering inflorescences. Significant rates of fruit removal by herbivores occurred in all sarocochorous species. Disappearance of fruits from infructescences ranged from 31 (Medeola virginiana) to 95% (Aralia nudicaulis), with highest removal rates occurring during periods of greatest fruit availability.
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Judd, Stephen J. "Disturbance of the reproductive axis induced by negative energy balance." Reproduction, Fertility and Development 10, no. 1 (1998): 65. http://dx.doi.org/10.1071/r98024.
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Animal reproduction is impaired when intake of energy is so restricted that activities essential to life are threatened; this is seen as a homeostatic adjustment that restricts wasteful energy expenditure. Fasting or exercising to a degree requiring considerable energy expenditure has major effects on the hypothalamus, including activation of corticotrophin-releasing factor (CRF) neurons, suppression of thyrotrophin-releasing hormone synthesis, and increased growth hormone secretion; these are associated with increased concentrations of hypothalamic neuropeptide Y mRNA and are corrected by administration of leptin, an adipose-tissue protein with a tertiary structure similar to the cytokine interleukin-2. This response to fasting results from a disordered pattern of activity in the gonadotrophin-releasing hormone (GnRH) pacemaker, characterized by reduced luteinizing hormone pulsatility, particularly during daytime. Animal studies have suggested that the response depends on an intact afferent vagal system from the stomach and the presence of oestrogen. Noradrenergic neurons forming the A2 group increase the activity of CRF neurons that, in turn, inhibit GnRH pulsatility. Reproductive impairment due to fasting is reversed by leptin, and abnormalities of leptin are described in individuals who fast or who develop exercise-induced amenorrhoea. This paper discusses these changes induced by negative energy balance and speculates on the involvement of leptin as a contributor to these abnormalities.
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Günther, Veronika, Leila Allahqoli, Georgios Gitas, Nicolai Maass, Karolin Tesch, Johannes Ackermann, Paula Rosam, Liselotte Mettler, Sören von Otte, and Ibrahim Alkatout. "Impact of Adenomyosis on Infertile Patients—Therapy Options and Reproductive Outcomes." Biomedicines 10, no. 12 (December 13, 2022): 3245. http://dx.doi.org/10.3390/biomedicines10123245.
Full textAbstract:
Adenomyosis is associated with a negative impact on reproductive outcomes. Although adenomyosis is detected more frequently in women of late reproductive age, its impact on pregnancy rates is important because, in today’s world, family planning has shifted towards the late reproductive phase of life for many women. Although the diagnostic indications for imaging studies are well-known, we lack strict diagnostic criteria and classification systems concerning the extent of the disease. Selecting the optimal evidence-based treatment option for adenomyosis is difficult because of the paucity of evidence concerning the association between fertility and the degree and composition of adenomyosis. Furthermore, the treatment of infertility might interfere with the treatment of adenomyosis due to the presence of pain. The aim of this review is to analyze the association between adenomyosis and infertility, and describe treatment options to enhance reproductive outcomes. The following aspects will be addressed in detail: (a) prevalence and causes of adenomyosis, (b) diagnostic tools with imaging techniques, (c) clinical symptoms, (d) proposed pathomechanism of adenomyosis and infertility, and (e) different treatment approaches (pharmacological, surgical, others) and their impact on reproductive outcomes.
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Hale, M. L., A. M. Borland, and K. Wolff. "High degree of conservation of nuclear microsatellite loci in the genus Clusia." Genome 48, no. 5 (October 1, 2005): 946–50. http://dx.doi.org/10.1139/g05-048.
Full textAbstract:
In plants, microsatellites and their flanking DNA are rarely conserved across a whole genus, let alone other genera in the same family. Therefore, the possibility of using microsatellite primers developed for a species across a large number of plant species in the same genus is often limited. Remarkably, dinucleotide nuclear microsatellites developed for Clusia minor and for Clusia nemorosa amplified homologous microsatellites in species across the whole genus Clusia. In this present study, we report on the DNA sequence variation across the genus of 3 microsatellite loci with varying levels of variation. Compared over the species, there was a correlation between the lengths of the microsatellite loci. Interrupts occurred multiple times and did not seem to lead to the death of the microsatellite. These highly conserved markers will be useful for studying the variable reproductive systems in the genus Clusia.Key words: microsatellite, Clusia, cross-species amplification, microsatellite evolution.
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Obrien, SP, and DM Calder. "Reproductive Biology and Floral Phenologies of the Sympatric Species Leptospermum myrsinoides and L. continentale (Myrtaceae)." Australian Journal of Botany 41, no. 5 (1993): 527. http://dx.doi.org/10.1071/bt9930527.
Full textAbstract:
The reproductive biology and floral phenologies of co-occurring Leptospermum myrsinoides and L. continentale were investigated. Both species have similar floral structure and both are protandrous. Anther dehiscence is staggered over approximately 6 days and pollen viability remains high for at least 3 days. The styles of both species are short at anthesis but extend during the next 6 days to approximately the same height as the anthers. The stigmas of these species do not achieve maximum receptivity until at least 4 days after anthesis. Both species are self-compatible. At the three sites studied, L. myrsinoides and L. continentale have separate flowering times with L. myrsinoides always flowering first. Within populations of each species, plants reached first flower and peak flower in the same order in 1989 and 1990, implying genetic control over flowering time. It is suggested that protandry in these species enhances the likelihood of outcrossing and the staggered release of pollen coupled with the degree of overlap within flowering populations increases the number of potential mates available to each flower.
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Drinkwater, Michael J., Kelly E. Matthews, and Jacob Seiler. "How Is Science Being Taught? Measuring Evidence-Based Teaching Practices across Undergraduate Science Departments." CBE—Life Sciences Education 16, no. 1 (March 2017): ar18. http://dx.doi.org/10.1187/cbe.15-12-0261.
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While there is a wealth of research evidencing the benefits of active-learning approaches, the extent to which these teaching practices are adopted in the sciences is not well known. The aim of this study is to establish an evidential baseline of teaching practices across a bachelor of science degree program at a large research-intensive Australian university. Our purpose is to contribute to knowledge on the adoption levels of evidence-based teaching practices by faculty within a science degree program and inform our science curriculum review in practical terms. We used the Teaching Practices Inventory (TPI) to measure the use of evidence-based teaching approaches in 129 courses (units of study) across 13 departments. We compared the results with those from a Canadian institution to identify areas in need of improvement at our institution. We applied a regression analysis to the data and found that the adoption of evidence-based teaching practices differs by discipline and is higher in first-year classes at our institution. The study demonstrates that the TPI can be used in different institutional contexts and provides data that can inform practice and policy.
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Evans, G. "Application of reproductive technology to the Australian livestock industries." Reproduction, Fertility and Development 3, no. 6 (1991): 627. http://dx.doi.org/10.1071/rd9910627.
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Current use of reproductive technology in the Australian livestock industries is limited, though it increased in line with higher prices for beef and wool through the 1980s. The required techniques, many of which were developed in Australia, are available and the level of expertise is comparable to the best in the world. However, the extensive pastoral industries do not readily lend themselves to these procedures. Only in the dairy industry is artificial insemination used to a significant degree. On the other hand, application of the technology in the pastoral industries is confined largely to studs and breeding cooperatives which provide breeding animals for producer flocks and herds. Hence the impact of applied technology may be more widespread than first appears. Until recently, little regard was paid to application of the technology along sound breeding principles. Artificial insemination and multiple ovulation and embryo transfer (MOET) have not been used so much in planned breeding programmes aimed at local improvement of stock, but more to proliferate genes of reputedly superior stock, imported either from overseas or elsewhere in Australia. This is particularly true of MOET, where the incentive to use it is commonly a short term cash gain made from proliferating breeding stock of a particularly valuable and usually novel strain or breed. Recent technological improvements which render the use of reproductive technology cheaper and more effective will lead to its more widespread use in commercial practice. Techniques for embryo freezing and splitting have been greatly simplified and quickly put into practice. The novel livestock technologies of in vitro oocyte maturation and fertilization have already found commercial application overseas. Fecundity-enhancing products have also been adopted by the livestock industries. There is potential value for greater use of reproductive technology in the livestock industries provided it is implemented according to sound breeding principles and provided associated management practices are applied simultaneously.
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Rose, Steven. "Précis of Lifelines: Biology, freedom, determinism." Behavioral and Brain Sciences 22, no. 5 (October 1999): 871–85. http://dx.doi.org/10.1017/s0140525x99002204.
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There are many ways of describing and explaining the properties of living systems; causal, functional, and reductive accounts are necessary but no one account has primacy. The history of biology as a discipline has given excessive authority to reductionism, which collapses higher level accounts, such as social or behavioural ones, into molecular ones. Such reductionism becomes crudely ideological when applied to the human condition, with its claims for genes “for” everything from sexual orientation to compulsive shopping. The current enthusiasm for genetics and ultra-Darwinist accounts, with their selfish-gene metaphors for living processes, misunderstand both the phenomena of development and the interactive role that DNA and the fluid genome play in the cellular orchestra. DNA is not a blueprint, and the four dimensions of life (three of space, one of time) cannot be read off from its one-dimensional strand. Both developmental and evolutionary processes are more than merely instructive or selective; the organism constructs itself, a process known as autopoiesis, through a lifeline trajectory. Because organisms are thermodynamically open systems, living processes are homeodynamic, not homeostatic. The self-organising membrane-bound and energy-utilising metabolic web of the cell must have evolved prior to so-called naked replicators. Evolution is constrained by physics, chemistry, and structure; not all change is powered by natural selection, and not all phenotypes are adaptive. Finally, therefore, living processes are radically indeterminate; like all other living organisms, but to an even greater degree, we make our own future, though in circumstances not of our own choosing.
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Frewin, Andrew J., Kevin Scaife, Hannah Fraser, and Cynthia D. Scott-Dupree. "Survey of the reproductive development of field-caught Halyomorpha halys (Hemiptera: Pentatomidae) in the Niagara Region of Ontario, Canada." Canadian Entomologist 151, no. 3 (March 18, 2019): 406–9. http://dx.doi.org/10.4039/tce.2019.9.
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AbstractHalyomorpha halys (Stål) (Hemiptera: Pentatomidae), also known as the brown marmorated stink bug, is an invasive agricultural and nuisance pest. Knowledge of the life history of insect pests is important for informing pest management activities. Some North American populations of H. halys have two generations per year, and it is suspected that H. halys may have a partial second generation in the Niagara Region of Ontario, Canada. We determined the number of H. halys generations in Ontario by examining the reproductive development of field-caught adult females. The pattern of reproductive development we observed supports the conclusion that H. halys complete one generation per year in the Niagara Region of Ontario. Reproductively active H. halys were captured as early as May and continued until early September, and the peak of reproductively active individuals occurred between 250 and 550 degree days calculated with a sine-wave function and a lower threshold set to 14.17 °C.
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Webster, M. M., and K. N. Laland. "Reproductive state affects reliance on public information in sticklebacks." Proceedings of the Royal Society B: Biological Sciences 278, no. 1705 (September 8, 2010): 619–27. http://dx.doi.org/10.1098/rspb.2010.1562.
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The degree to which animals use public and private sources of information has important implications for research in both evolutionary ecology and cultural evolution. While researchers are increasingly interested in the factors that lead individuals to vary in the manner in which they use different sources of information, to date little is known about how an animal's reproductive state might affect its reliance on social learning. Here, we provide experimental evidence that in foraging ninespine sticklebacks ( Pungitius pungitius ), gravid females increase their reliance on public information generated by feeding demonstrators in choosing the richer of two prey patches than non-reproductive fish, while, in contrast, reproductive males stop using public information. Subsequent experiments revealed reproductive males to be more efficient asocial foragers, less risk-averse and generally less social than both reproductive females and non-reproductives. These findings are suggestive of adaptive switches in reliance on social and asocial sources of information with reproductive condition, and we discuss the differing costs of reproduction and the proximate mechanisms that may underlie these differences in information use. Our findings have important implications for our understanding of adaptive foraging strategies in animals and for understanding the way information diffuses through populations.
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Collett, Rachael A., Andrew M. Baker, and Diana O. Fisher. "Prey productivity and predictability drive different axes of life-history variation in carnivorous marsupials." Proceedings of the Royal Society B: Biological Sciences 285, no. 1890 (October 31, 2018): 20181291. http://dx.doi.org/10.1098/rspb.2018.1291.
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Variation in life-history strategies has usually been characterized as a single fast–slow continuum of life-history variation, in which mean lifespan increases with age at maturity as reproductive output at each breeding event declines. Analyses of plants and animals suggest that strategies of reproductive timing can vary on an independent axis, with iteroparous species at one extreme and semelparous species at the other. Insectivorous marsupials in the Family Dasyuridae have an unusually wide range of life-history strategies on both purported axes. We test and confirm that reproductive output and degree of iteroparity are independent in females across species. Variation in reproductive output per episode is associated with mean annual rainfall, which predicts food availability. Position on the iteroparity-semelparity axis is not associated with annual rainfall, but species in regions of unpredictable rainfall have longer maximum lifespans, more potential reproductive events per year, and longer breeding seasons. We suggest that these two axes of life-history variation arise because reproductive output is limited by overall food availability, and selection for high offspring survival favours concentrated breeding in seasonal environments. Longer lifespans are favoured when reproductive opportunities are dispersed over longer periods in environments with less predictable food schedules.
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Richards, JoAnne S. "WOMEN IN REPRODUCTIVE SCIENCE: Discovering science and the ovary: a career of joy." Reproduction 158, no. 6 (December 2019): F69—F80. http://dx.doi.org/10.1530/rep-18-0513.
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My career has been about discovering science and learning the joys of the discovery process itself. It has been a challenging but rewarding process filled with many exciting moments and wonderful colleagues and students. Although I went to college to become a French major, I ultimately stumbled into research while pursuing a Masters Degree in teaching. Thus, my research career began in graduate school where I was studying NAD kinase in the ovary as a possible regulator of steroidogenesis, a big issue in the late 1960s. After a short excursion of teaching in North Dakota, I became a postdoctoral fellow at the University of Michigan, where radio-immuno assays and radio receptor assays had just come on the scene and were transforming endocrinology from laborious bioassays to quantitative science and of course these assays related to the ovary. From there I went to Baylor College of Medicine, a mecca of molecular biology, cloning genes and generating mouse models. It has been a fascinating and joyous journey.
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Ehmcke, Jens, and Stefan Schlatt. "Animal models for fertility preservation in the male." REPRODUCTION 136, no. 6 (December 2008): 717–23. http://dx.doi.org/10.1530/rep-08-0093.
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Fertility preservation in the male is routinely focused on sperm. In clinical and veterinary settings, cryopreservation of sperm is a widely used tool. However, the goals for male fertility preservation differ between experimental models, maintenance of livestock, conservation of rare species, and fertility protection in men. Therefore very different approaches exist, which are adapted to the specialized needs for each discipline. Novel tools for male fertility preservation are explored targeting immature germ cells in embryonic or immature testes. Many options might be developed to combine germline preservation and generation of sperm ex vivo leading to interesting new perspectives. This review highlights current and future options for male fertility preservation with a special focus on animal models and a consideration of the various disciplines in need of novel tools.
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Shi, Luye, Xiujuan Li, Zhihong Ji, Zishi Wang, Yuhua Shi, Xiangyu Tian, and Zhenlong Wang. "The reproductive inhibitory effects of levonorgestrel, quinestrol, and EP-1 in Brandt’s vole (Lasiopodomys brandtii)." PeerJ 8 (June 11, 2020): e9140. http://dx.doi.org/10.7717/peerj.9140.
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Background Rodent pests can inflict devastating impacts on agriculture and the environment, leading to significant economic damage associated with their high species diversity, reproductive rates and adaptability. Fertility control methods could indirectly control rodent pest populations as well as limit ecological consequences and environmental concerns caused by lethal chemical poisons. Brandt’s voles, which are common rodent pests found in the grasslands of middle-eastern Inner Mongolia, eastern regions of Mongolia, and some regions of southern Russia, were assessed in the present study. Methods We evaluated the effects of a 2-mg/kg dose of levonorgestrel and quinestrol and a 1:1 mixture of the two (EP-1) on reproductive behavior as well as changes in the reproductive system, reproductive hormone levels, and toxicity in Brandt’s voles. Results Our results revealed that all three fertility control agents can cause reproductive inhibition at a dosage of 2 mg/kg. However, quinestrol caused a greater degree of toxicity, as determined by visible liver damage and reduced expression of the detoxifying molecule CYP1A2. Of the remaining two fertility control agents, EP-1 was superior to levonorgestrel in inhibiting the secretion of follicle-stimulating hormone and causing reproductive inhibition. We believe that these findings could help promote the use of these fertility control agents and, in turn, reduce the use of chemical poisons and limit their detrimental ecological and environmental impacts.
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Oliveira, Cicero Diogo, Rosangela Lessa, Zafira Almeida, and Francisco Marcante Santana. "Biology and fishery of Acoupa Weakfish Cynoscion acoupa (Lacepède, 1801): a review." Neotropical Biology and Conservation 15, no. 3 (August 14, 2020): 333–49. http://dx.doi.org/10.3897/neotropical.15.e55563.
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The present study describes the fishery and biology of Acoupa Weakfish Cynoscion acoupa, an important fishery resource in South America. We found and analyzed 31 articles and 10 publications about the species. Cynoscion acoupa is an estuarine marine species, which has a feeding habit with preference for fish and crustaceans. Its spawning occurs during two periods of the year and the size at maturity of females is 40 to 50 cm, while males mature earlier, with 38–40 cm. Their growth is considered slow to moderate, with growth coefficient k ranging from 0.13 to 0.28, and the species can reach up to 15 years of age. C. acoupa is target of commercial and recreational fisheries in estuarine and marine coastal environments, mainly in the northern region of South America. The fisheries occur throughout the year, with different fishing gear, being more frequent with gillnets. In addition, fishing is more frequent on juveniles, which may compromise the stock. This species is categorized as of Least Concern by the International Union for Conservation of Nature, although it has a high degree of vulnerability to fishing, which, combined with overexploitation, shows that C. acoupa should be listed as under threat of extinction to some degree. The lack of studies on the species makes it difficult to establish management measures. Therefore, further studies should be prioritized, especially on reproductive biology, growth and fishing exploitation.
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Marshall, Lindsay J., William T. White, and Ian C. Potter. "Reproductive biology and diet of the southern fiddler ray, Trygonorrhina fasciata (Batoidea:Rhinobatidae), an important trawl bycatch species." Marine and Freshwater Research 58, no. 1 (2007): 104. http://dx.doi.org/10.1071/mf05165.
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The reproductive cycle of Trygonorrhina fasciata females in south-western Australian waters is shown to include a protracted period of embryonic diapause or delayed development. This characteristic is typically regarded as enabling young to be born when conditions are optimal. The birth of T. fasciata occurs in April/May, when water temperatures are still high and conducive to rapid growth. Furthermore, because gut fullness in this and subsequent months was similar to other times of the year, the prey of neonates, i.e. mysids, carids, pinnotherids, amphipods and isopods, were presumably abundant in that period. Ovulation occurs in April/May and embryos grow rapidly between December and birth in April/May. Females grew to greater lengths than males, i.e. 1460 v. 890 mm, and matured (L50) at larger lengths, i.e. 892 v. 678 mm respectively. As body size increased, teleosts, pilumnid and portunid crabs and molluscs became important dietary components. Overall, the diet consisted predominantly of crustaceans, fish, polychaetes and molluscs, with volumetric contributions of 73.4, 17.2, 5.3 and 2.8% respectively. Dietary composition underwent a cyclical seasonal change and differed among locations, indicating some degree of opportunistic feeding. Interspecific comparisons indicate that benthic food resources are partitioned among and within the main batoid species in south-western Australian waters.
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Oliveira, Elton Celton de, Alexandre Augusto Auache-Filho, Denis Damasio, Nédia de Castilhos Ghisi, and Maria Antônia Michels-Souza. "Reproductive indicators of the endemic species Astyanax bifasciatus (Teleostei: Characidae) in a tributary of the Lower Iguaçu River Basin, Brazil." Acta Scientiarum. Biological Sciences 41 (December 18, 2019): e47720. http://dx.doi.org/10.4025/actascibiolsci.v41i1.47720.
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The reproductive process promotes morphophysiological and behavioral changes in fish species throughout their life cycle. Its success is vital to define their resilience in the environment. This study aimed to evaluate the reproductive biology of the endemic fish species Astyanax bifasciatus in a tributary of the Lower Iguaçu River Basin, Paraná, Brazil. Fish were collected monthly at four sites along the Jirau Alto River in the city of Dois Vizinhos from October 2015 to September 2016. A standardized catch effort with gill nets and fish traps was used. In the laboratory, standard length and total weight were recorded. After anesthesia, the animals were sectioned to macroscopically determine the sex, sexual maturity stage, and presence of celomatic fat. The gonads and liver were removed to determine the gonadosomatic and hepatosomatic indexes, respectively. A total of 160 individuals (104 females and 56 males) were used. The gonadosomatic index, frequency of the gonadal maturation stages, and condition factor showed a long reproductive period with two investment cycles for both sex. Length at first sexual maturity was 4.57 cm for females and 3.56 cm for males. The reproductive data corroborate the generalist profile of the species and demonstrate a high degree of adaptive capacity, even in smaller tributaries.
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Burton, Graham J., Tereza Cindrova-Davies, Hong wa Yung, and Eric Jauniaux. "HYPOXIA AND REPRODUCTIVE HEALTH: Oxygen and development of the human placenta." Reproduction 161, no. 1 (January 2021): F53—F65. http://dx.doi.org/10.1530/rep-20-0153.
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Development of the human placenta takes place in contrasting oxygen concentrations at different stages of gestation, from ~20 mmHg during the first trimester rising to ~60 mmHg at the start of the second trimester before gradually declining to ~40 mmHg at term. In view of these changes, the early placenta has been described as ‘hypoxic’. However, placental metabolism is heavily glycolytic, supported by the rich supply of glucose from the endometrial glands, and there is no evidence of energy compromise. On the contrary, the trophoblast is highly proliferative, with the physiological low-oxygen environment promoting maintenance of stemness in progenitor populations. These conditions favour the formation of the cytotrophoblastic shell that encapsulates the conceptus and interfaces with the endometrium. Extravillous trophoblast cells on the outer surface of the shell undergo an epithelial-mesenchymal transition and acquire invasive potential. Experimental evidence suggests that these changes may be mediated by the higher oxygen concentration present within the placental bed. Interpreting in vitro data is often difficult, however, due to the use of non-physiological oxygen concentrations and trophoblast-like cell lines or explant models. Trophoblast is more vulnerable to hyperoxia or fluctuating levels of oxygen than to hypoxia, and some degree of placental oxidative stress likely occurs in all pregnancies towards term. In complications of pregnancy, such as early-onset pre-eclampsia, malperfusion generates high levels of oxidative stress, causing release of factors that precipitate the maternal syndrome. Further experiments are required using genuine trophoblast progenitor cells and physiological concentrations to fully elucidate the pathways by which oxygen regulates placental development.
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Żeber-Dzikowska, Ilona. "Czym jest edukacja biologiczna w wychowaniu człowieka?" Studia Ecologiae et Bioethicae 7, no. 2 (December 31, 2009): 105–18. http://dx.doi.org/10.21697/seb.2009.7.2.09.
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Schools allow to develop and extend the approaches and attitudes in the social, moral, ideological, and religious spheres. The realization of these matters is possible due to the fulfillment of three basic school functions, i.e. didactic, educational, and protective. No one should forget that human education starts already in the period of childhood. Initially, parents introduce the children to the indispensable problems and matters in their future lives. It takes place in the form of games. They satisfy their growing need of gaining the knowledge, by answering numerous questions. They develop the knowledge through practical activities to let them gain experience, that is, organize walks, educational games, and so forth. Then young people begin school education, which influences, to a large degree, their lives. Then, in the educational process, the subject of Biology appears, almost certainly already known thanks to the parents’ education. The scientific discipline called Biology is a very important element in the education of people, which is helpful in understanding their own personalities and the surrounding reality. The wide range of biological contents as well as the short reflection on the subject of gaining the knowledge in the range of Biology allows us to notice, that this discipline, similarly to other disciplines shapes the personality of young, growing up people. All things considered, however, it differs from disciplines such as history, or mathematics, because it is closely and directly related to the human being and functioning, as the basis of human life. Biology, more considerably and effectively, than different disciplines, makes the students sensible towards human needs as well as the needs of nature and its protection.
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Radael, Marcella Costa, Leonardo Demier Cardoso, Dalcio Ricardo Andrade, Douglas Mattos, Jonas Henrique Motta, João Vitor Manhães, and Manuel Vazquez Vidal. "Morphophysiological characterization of the embryonic development of Melanotaenia praecox (Weber & de Beaufort, 1922)." Zygote 22, no. 4 (May 9, 2013): 533–39. http://dx.doi.org/10.1017/s096719941300018x.
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SummaryDwarf rainbowfish (Melanotaenia praecox) are an ornamental fish with a high added value and considerable commercial interest. However, little information is known about the organism's reproductive biology, especially the early stages of embryonic development (initial ontogeny). Melanotaenia praecox embryos were examined throughout development to describe the dwarf rainbowfish initial ontogeny. Eggs were incubated at 28°C, and observations were recorded at pre-determined times. Development stages were identified and classified according to morphophysiological characteristics. The initial size of the eggs ranged between 0.99 and 1.04 mm. Oil droplets were observed in the eggs, and fixing filaments for adhesion were observed in the corium. Embryonic development was similar to that of other species in the genus Melanotaenia, in which hatching begins 119.50 h post-fertilisation or 3405.75 degree-h post-fertilisation. The main features of the newly hatched larvae were excellent swimming activity, a reduced yolk sac, mouth movement and an apparently functional digestive system.
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Kretova, Irina G., Olga V. Belyaeva, Olga A. Vedyasova, and Snezhanna I. Pavlenko. "The analysis of students' attitude to healthy lifestyle and reproductive health care." Hygiene and sanitation 101, no. 9 (September 30, 2022): 1080–85. http://dx.doi.org/10.47470/0016-9900-2022-101-9-1080-1085.
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Introduction. In connection with low competency of young people in the issue of life safety it is relevant to analyze entirely the students` attitude to healthy lifestyle. Also it is important to assess the students` knowledge about reproductive health and ways of keeping it well. Materials and methods. The authors undertook questionnaire method and asked anonymously seven hundred sixty three students of Samara National Research University. Survey consists of 38 questions regarding students` age, leisure time, academic performance and influence of the process of education on health, family social status, attitude to sport, psychoactive substances. Also students were asked about their knowledge of healthy lifestyle components, sexually transmitted infections, possibility of prevention and contraception. Results. The authors found out that young men do sports more often than girls. Also boys use more often cold training and eat regularly. Every tenth girl has a lack sleep, sleep duration is less than 5-6 hours. 30% of boys and girls drink alcohol two or three times a month, 35% of students smoke. 12.45% of young people (men and women) experimented with drugs. Peculiarities of students`sexual behaviour are early beginning of sexual intercourse and frequent changing of sexual partners. The authors revealed low level of students` knowledge about contraception, sexually transmitted infections and its sequela, preventive measures. Limitations. Only students of Samara National Research University were involved into this investigation except students of Biology Faculty (because they are more informed in the field of healthy life style and reproductive health) and students who do sports professionally or who have chronic diseases. Conclusion. The problem of reproductive health care and primary prevention of sexually transmitted infections can`t be solved only by medical staff. Correction of risky behaviour is an interdisciplinary challenge that demands comprehensive approach focused on group and social norm changing. Universities must play an important role in this issue making it possible for professors to have classes of academic discipline such as «Family health», « Fundamentals of Medicine» where qualified professors with higher medical education can discuss with students the issue of reproductive behavior.
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Soderstrom, Mark. "Family Trees and Timber Rights: Albert E. Jenks, Americanization, and the Rise of Anthropology at the University of Minnesota." Journal of the Gilded Age and Progressive Era 3, no. 2 (April 2004): 176–204. http://dx.doi.org/10.1017/s1537781400003339.
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Hindsight allows present-day scholars to view the development of academic disciplines in a light that contemporaries would never have seen. Hence, from our perspective, Mary Furner's assertion that anthropology developed as a profession reacting against biology and the physical sciences makes sense, for we tend to celebrate the triumph of cultural anthropology as the coming of age of the discipline. However, this trajectory of professional development was not a necessary or predestined development. Rather, the eventual (if occasionally still embattled) predominance of culture over the categories of race, nation, and biology was only one of many possible outcomes. This paper investigates a different trajectory, one that most current scholars would hope has been relegated to the dustbin of history. It is still a cautionary tale, though, in that while the racial anthropology followed in this narrative did not survive World War II, its practitioners did enjoy a degree of prominence and influence that was much greater and longer than has been generally acknowledged by current accounts.
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Li, Jia, Zhu Xianglei, and Xu Guoliang. "Research status and development trend of altruism in the biological field - knowledge graph analysis based on CiteSpace." Journal of Biology and Medicine 6, no. 1 (December 1, 2022): 042–47. http://dx.doi.org/10.17352/jbm.000034.
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Based on the visualization analysis of foreign literature on altruistic behavior in recent ten years (2012-2022) by CiteSpace, it is found that the research on altruistic behavior in the field of biology abroad has experienced the initial exploratory stage, the outbreak stage, and now enters the stable and deepening stage. The discipline distribution is mainly behavioral ecology, supplemented by evolutionary biology, biomathematics, and genetics. The author has three main cooperative groups, and a relatively tight cooperative network has been formed locally in related fields. From the perspective of cooperation degree, the cooperation density of major research institutions is high, and relevant research has been relatively mature. Judging from the period calculated in the software, altruism, cooperation, kin Selection, reciprocity, and inclusive fitness emerged earlier. In recent years, constitutive theory, density dependence, and Habitat construction have emerged, which may become a new direction for future research. Therefore, future research can expand the scope of disciplines, strengthen the cooperation between authors and units, and explore other research hotspots.
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Li, R., and A. Trounson. "Rapid freezing of the mouse blastocyst: effects of cryoprotectants and of time and temperature of exposure to cryoprotectant before direct plunging into liquid nitrogen." Reproduction, Fertility and Development 3, no. 2 (1991): 175. http://dx.doi.org/10.1071/rd9910175.
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This study investigates the effects of time and temperature of exposure to a high concentration (4.5 M) of dimethyl sulfoxide (DMSO), glycerol, 1,2-propanediol (PROH), or a mixture of DMSO and glycerol (DG) in a solution containing 0.25 M sucrose, on the survival and development of rapidly frozen mouse blastocysts. Embryos had significantly (P less than 0.01) higher rates of survival and development when exposed to cryoprotectant at 0 degree C compared with room temperature. The time of exposure to cryoprotectant at either 0 degree C or room temperature before being plunged into liquid nitrogen significantly (P less than 0.01) affected the survival and development of frozen-thawed embryos. Survival and development of blastocysts in vitro and in vivo was significantly (P less than 0.05) higher when exposed at 0 degree C for 10 min to DG, DMSO and glycerol than to PROH. It is concluded that, unlike early-cleavage stage embryos, blastocysts need to be equilibrated at a low temperature (0 degree C) with high concentrations of cryoprotectant before rapid freezing. Exposure of blastocysts to 4.5 M cryoprotectant and 0.25 M sucrose at room temperature either was toxic or else markedly reduced their viability after freezing and thawing, depending on the duration of the initial exposure.
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Green, Delbert A., and Cassandra G. Extavour. "Insulin signalling underlies both plasticity and divergence of a reproductive trait in Drosophila." Proceedings of the Royal Society B: Biological Sciences 281, no. 1779 (March 22, 2014): 20132673. http://dx.doi.org/10.1098/rspb.2013.2673.
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Phenotypic plasticity is the ability of a single genotype to yield distinct phenotypes in different environments. The molecular mechanisms linking phenotypic plasticity to the evolution of heritable diversification, however, are largely unknown. Here, we show that insulin/insulin-like growth factor signalling (IIS) underlies both phenotypic plasticity and evolutionary diversification of ovariole number, a quantitative reproductive trait, in Drosophila . IIS activity levels and sensitivity have diverged between species, leading to both species-specific ovariole number and species-specific nutritional plasticity in ovariole number. Plastic range of ovariole number correlates with ecological niche, suggesting that the degree of nutritional plasticity may be an adaptive trait. This demonstrates that a plastic response conserved across animals can underlie the evolution of morphological diversity, underscoring the potential pervasiveness of plasticity as an evolutionary mechanism.
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Williams, Cory T., Marcel Klaassen, Brian M. Barnes, C. Loren Buck, Walter Arnold, Sylvain Giroud, Sebastian G. Vetter, and Thomas Ruf. "Seasonal reproductive tactics: annual timing and the capital-to-income breeder continuum." Philosophical Transactions of the Royal Society B: Biological Sciences 372, no. 1734 (October 9, 2017): 20160250. http://dx.doi.org/10.1098/rstb.2016.0250.
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Tactics of resource use for reproduction are an important feature of life-history strategies. A distinction is made between ‘capital’ breeders, which finance reproduction using stored energy, and ‘income’ breeders, which pay for reproduction using concurrent energy intake. In reality, vertebrates use a continuum of capital-to-income tactics, and, for many species, the allocation of capital towards reproduction is a plastic trait. Here, we review how trophic interactions and the timing of life-history events are influenced by tactics of resource use in birds and mammals. We first examine how plasticity in the allocation of capital towards reproduction is linked to phenological flexibility via interactions between endocrine/neuroendocrine control systems and the sensory circuits that detect changes in endogenous state, and environmental cues. We then describe the ecological drivers of reproductive timing in species that vary in the degree to which they finance reproduction using capital. Capital can be used either as a mechanism to facilitate temporal synchrony between energy supply and demand or as a means of lessening the need for synchrony. Within many species, an individual's ability to cope with environmental change may be more tightly linked to plasticity in resource allocation than to absolute position on the capital-to-income breeder continuum. This article is part of the themed issue ‘Wild clocks: integrating chronobiology and ecology to understand timekeeping in free-living animals’.
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Nurullayeva, Nodira, Khislat Haydarov, Zebiniso Umurzakova, and Dilfuza Safarova. "Growth and development of Lycium barbarum L. in the environment of Samarkand in Uzbekistan." Plant Science Today 8, no. 2 (April 1, 2021): 278–82. http://dx.doi.org/10.14719/pst.2021.8.2.919.
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Shrub Lycium barbarum belongs of the family Solanaceae, is introduced and does not occur naturally in Uzbekistan. Despite its numerous medicinal characteristics, in Uzbekistan, its growth and development have not been studied. Therefore, our primary goal was to study the germination of seeds, stages of ontogenesis and some morphological signs of fruits. The highest seed germination rate of 74±0,12% as at the 20 degree C. When studying ontogenesis, plant development was divided into ten stages and four periods. The pre-reproductive period lasted 1-2 years. The reproductive period was determined for 2-3 years from the beginning of the growing season. For several months, an analysis of the changes in the morphological characteristics of the fruits of L. barbarum was carried out and in May, relatively large ripened fruits were determined (length 2.18 ± 0.09, width 1.14 ± 0.11).
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Guerrero, Pablo C., Claudia A. Antinao, Beatriz Vergara-Meriño, Cristian A. Villagra, and Gastón O. Carvallo. "Bees may drive the reproduction of four sympatric cacti in a vanishing coastal mediterranean-type ecosystem." PeerJ 7 (October 7, 2019): e7865. http://dx.doi.org/10.7717/peerj.7865.
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Background Sympatric congeneric plants might share pollinators, or each species might avoid competition by evolving specialized traits that generate partitions in pollinator assemblages. In both cases, pollen limitation (a decrease in the quality and quantity of compatible reproductive pollen) can occur, driving the plant mating system to autogamy as a mechanism of reproductive assurance. We assessed the relationships between pollinator assemblages and mating systems in a group of sympatric congeneric plants. We attempted to answer the following questions: (i) How similar are pollinator assemblages among sympatric cactus species? (ii) Which mating systems do sympatric cactus species use? Methods We studied sympatric Eriosyce taxa that inhabit a threatened coastal strip in a mediterranean-type ecosystem in central Chile. We performed field observations on four taxa and characterized pollinators during the years 2016 and 2017. We estimated differences in the pollinator assemblages using the Bray–Curtis index. To elucidate the mating systems, we conducted hand-pollination experiments using three treatments: manual cross-pollination, automatic self-pollination, and control (unmanipulated individuals). We tested differences in seed production for statistical significance using Kruskal–Wallis analysis. Results Eriosyce subgibbosa showed a distinctive pollinator assemblage among the sympatric species that we studied (similarity ranged from 0% to 8%); it was visited by small bees and was the only species that was visited by the giant hummingbird Patagona gigas. Pollinator assemblages were similar between E. chilensis (year 2016 = 4 species; 2017 = 8) and E. chilensis var. albidiflora (2016 = 7; 2017 = 4); however, those of E. curvispina var. mutabilis (2016 = 7; 2017 = 6) were less similar to those of the aforementioned species. E. curvispina var. mutabilis showed the highest interannual variation in its pollinator assemblage (18% similarity). Reproduction in E. subgibbosa largely depends on pollinators, although it showed some degree of autogamy. Autonomous pollination was unfeasible in E. chilensis, which depended on flower visitors for its reproductive success. Both E. chilensis var. albidiflora and E. curvispina var. mutabilis showed some degree of autogamy. Discussion We observed differences in pollinator assemblages between E. subgibbosa and the remaining Eriosyce taxa, which depend on hymenopterans for pollen transfer. Pollinator assemblages showed considerable interannual variation, especially those of E. subgibbosa (ornithophilous syndrome) and E. curvispina var. mutabilis (melitophilous syndrome). Autogamous reproduction in these taxa may act as a reproductive assurance mechanism when pollinator availability is unpredictable. Our study contributes to improving our understanding of the reproductive systems of ecological interactions between threatened species in a Chilean mediterranean-type ecosystem.