Journal articles on the topic 'Transporteur de Si'

To see the other types of publications on this topic, follow the link: Transporteur de Si.

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles

Select a source type:

Consult the top 50 journal articles for your research on the topic 'Transporteur de Si.'

Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.

You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.

Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.

1

Cissé, Yacouba. "L’identification du transporteur maritime à l’épreuve de la qualification juridique." Revue générale de droit 34, no. 1 (November 7, 2014): 5–49. http://dx.doi.org/10.7202/1027234ar.

Full text
Abstract:
Comment identifier le transporteur maritime responsable d’un préjudice causé aux tiers ? Telle est la question posée de manière récurrente et à laquelle le droit international du transport maritime n’a pas encore apporté de solutions satisfaisantes. Les phénomènes suivants contribuent, dans une large mesure à renforcer l’opacité du droit du commerce maritime qui se réalise grâce au transport par voie de mer : il s’agit des pavillons de complaisance, des navires fantômes, des navires apparentés, des sociétés-écrans, des affrètements, des fraudes à l’assurance maritime, de l’ambiguïté des clauses ou des mentions insérées dans les chartes-parties et les connaissements, de la complaisance des sociétés de classification, etc. Bref les pratiques commerciales maritimes sont devenues si obscures qu’elles n’apportent pas suffisamment d’éclairage quant à l’identité des acteurs du transport maritime et plus particulièrement sur celle du transporteur maritime. Ce manque de transparence pose toute la question de l’identification du transporteur maritime responsable. Cet essai présente l’état du droit en la matière et les solutions susceptibles de répondre le mieux aux problèmes soulevés.
APA, Harvard, Vancouver, ISO, and other styles
2

Bozec, Yves, and Claude Laurin. "L’impact de l’annonce de la privatisation sur la performance." Articles 76, no. 2 (February 5, 2009): 265–98. http://dx.doi.org/10.7202/602324ar.

Full text
Abstract:
RÉSUMÉ Cet article vise à analyser si le statut juridique de l’entreprise et la nature des objectifs qu’elle poursuit influent sur l’efficience de ses opérations. Pour ce faire, nous avons choisi de comparer la productivité des deux principaux transporteurs ferroviaires canadiens, soit le Canadien National (CN), transporteur du secteur public, avec son plus proche rival du secteur privé, le Canadien Pacifique (CP), durant les périodes précédant et suivant l’annonce de la privatisation du CN. L’efficience interne des deux transporteurs est comparée à l’aide de la productivité totale des facteurs (PTF) sur une période de quinze ans, soit de 1981 à 1995. Les résultats tendent à démontrer que bien qu’étant moins efficientes durant la période 1981-1991, les opérations du CN sont devenues aussi efficientes que celles du CP durant la période de préprivatisation, soit de 1992 à 1995. Ces résultats nous portent à conclure qu’un changement dans la nature des objectifs poursuivis par le CN a eu un impact significatif sur son efficience interne.
APA, Harvard, Vancouver, ISO, and other styles
3

Laîné, Philippe, Raphaël Coquerel, Mustapha Arkoun, Jacques Trouverie, and Philippe Etienne. "Assessing the Effect of Silicon Supply on Root Sulfur Uptake in S-Fed and S-Deprived Brassica napus L." Plants 11, no. 12 (June 18, 2022): 1606. http://dx.doi.org/10.3390/plants11121606.

Full text
Abstract:
Silicon (Si) is known to alleviate many nutritional stresses. However, in Brassica napus, which is a highly S-demanding species, the Si effect on S deficiency remains undocumented. The aim of this study was to assess whether Si alleviates the negative effects of S deficiency on Brassica napus and modulates root sulfate uptake capacity and S accumulation. For this, Brassica napus plants were cultivated with or without S and supplied or not supplied with Si. The effects of Si on S content, growth, expression of sulfate transporter genes (BnaSultr1.1; BnaSultr1.2) and sulfate transporters activity in roots were monitored. Si supply did not mitigate growth or S status alterations due to S deprivation but moderated the expression of BnaSultr1.1 in S-deprived plants without affecting the activity of root sulfate transporters. The effects of Si on the amount of S taken-up and on S transporter gene expression were also evaluated after 72 h of S resupply. In S-deprived plants, S re-feeding led to a strong decrease in the expression of both S transporter genes as expected, except in Si-treated plants where BnaSultr1.1 expression was maintained over time. This result is discussed in relation to the similar amount of S accumulated regardless of the Si treatment.
APA, Harvard, Vancouver, ISO, and other styles
4

Rodríguez, Lorenzo. "La Aviación comercial y los transportes de superficie." Revista de Estudios Turísticos, no. 40 (September 11, 2023): 151–58. http://dx.doi.org/10.61520/et.401973.242.

Full text
Abstract:
En el artículo se pretende analizar de una manera somera la Aviación Comercial, tanto de línea regular como la demanda y su correlación con otros medios que han pasado a ser complementarios de ésta, si bien bajo algunas circunstancias mantienen y aun aumentan su potencial como medios de transporte turísticos. Dentro de esta idea se analizan los: Transportes por carretera: Autobús, coche privado; transporte por ferrocarril y transportes marítimos
APA, Harvard, Vancouver, ISO, and other styles
5

Luz, Fabio dos Santos Corrêa da, and Nilson Rosa Faria. "MODAL RODOVIÁRIO PARANAENSE." Revista (RE)DEFINIÇÕES DAS FRONTEIRAS 1, no. 2 (May 10, 2023): 371–84. http://dx.doi.org/10.59731/vol1iss2pp371-384.

Full text
Abstract:
O presente trabalho visa a abordar aspectos do modal rodoviário paranaense, destacando os desafios do escoamento da produção. Nas pegadas desse processo, ocupa-se de estudar e refletir acerca da origem dos transportes e estradas na humanidade. Trata-se de compreender o esforço humano em se atingir alternativas para transportar suas mercadorias e a si próprio, indo desde a tração animal aos mais recentes automóveis e aeronaves. Igualmente, busca-se situar a economia do estado do Paraná, seu histórico, seus ciclos produtivos, anseios e necessidades, para, assim, analisar seu processo de consolidação rodoviária. O estado do Paraná, a despeito de seus desafios e problemas, tem-se mostrado um referencial para a República Federativa do Brasil. Isso porquanto se encontra na lista dos cinco maiores IDHs, dentre os estados-membros, e sua monocultura traz inúmeros benefícios ao mercado nacional. Isso tudo robustece a importância de se estudar e se aprimorar o transporte e modal rodoviário regional.
APA, Harvard, Vancouver, ISO, and other styles
6

Hu, Jiangtao, Yali Li, and Byoung Ryong Jeong. "Putative Silicon Transporters and Effect of Temperature Stresses and Silicon Supplementation on Their Expressions and Tissue Silicon Content in Poinsettia." Plants 9, no. 5 (April 29, 2020): 569. http://dx.doi.org/10.3390/plants9050569.

Full text
Abstract:
Silicon (Si) is a beneficial element for plants. To understand Si uptake and accumulation in poinsettia, the Si transporters and their expression patterns were investigated. Nodulin 26-like intrinsic membrane proteins (NIPs) act as transporters of water and small solutes, including silicic acid. In this study, one NIP member, designated EpLsi1, was identified. Additionally, a protein from the citrate transporter family, designated EpLsi2, was identified. Sequence analyses indicated that EpLsi1 belonged to the NIP-I subgroup, which has a low Si uptake capacity. Consistently, the measured tissue Si content in the poinsettia was less than 1.73 ± 0.17 mg·g−1 dry weight, which was very low when compared to that in high Si accumulators. The expressions of EpLsi1 and EpLsi2 in poinsettia cuttings treated with 0 mg·L−1 Si decreased under temperature stresses. A short-term Si supplementation decreased the expressions of both EpLsi1 and EpLsi2 in the roots and leaves, while a long-term Si supplementation increased the expression of EpLsi1 in the leaves, bracts, and cyathia, and increased the expression of EpLsi2 in the roots and leaves. Tissue Si content increased in the roots of cuttings treated with 75 mg·L−1 Si at both 4 and 40 °C, indicating that the transport activities of the EpLsi1 were enhanced under temperature stresses. A long-term Si supplementation increased the tissue Si content in the roots of poinsettia treated with 75 mg·L−1 Si. Overall, poinsettia was a low Si accumulator, the expressions of Si transporters were down-regulated, and the tissue Si content increased with temperature stresses and Si supplementation. These results may help the breeding and commercial production of poinsettia.
APA, Harvard, Vancouver, ISO, and other styles
7

Nawaz, Muhammad Amjad, Farrukh Azeem, Alexander Mikhailovich Zakharenko, Xiao Lin, Rana Muhammad Atif, Faheem Shehzad Baloch, Ting-Fung Chan, et al. "In-silico Exploration of Channel Type and Efflux Silicon Transporters and Silicification Proteins in 80 Sequenced Viridiplantae Genomes." Plants 9, no. 11 (November 20, 2020): 1612. http://dx.doi.org/10.3390/plants9111612.

Full text
Abstract:
Silicon (Si) accumulation protects plants from biotic and abiotic stresses. It is transported and distributed within the plant body through a cooperative system of channel type (e.g., OsLsi1) and efflux (Lsi2s e.g., OsLsi2) Si transporters (SITs) that belong to Noduline-26 like intrinsic protein family of aquaporins and an uncharacterized anion transporter family, respectively. Si is deposited in plant tissues as phytoliths and the process is known as biosilicification but the knowledge about the proteins involved in this process is limited. In the present study, we explored channel type SITs and Lsi2s, and siliplant1 protein (Slp1) in 80 green plant species. We found 80 channel type SITs and 133 Lsi2s. The channel type SITs characterized by the presence of two NPA motifs, GSGR or STAR selectivity filter, and 108 amino acids between two NPA motifs were absent from Chlorophytes, while Streptophytes evolved two different types of channel type SITs with different selectivity filters. Both channel type SITs and Lsi2s evolved two types of gene structures each, however, Lsi2s are ancient and were also found in Chlorophyta. Homologs of Slp1 (225) were present in almost all Streptophytes regardless of their Si accumulation capacity. In Si accumulator plant species, the Slp1s were characterized by the presence of H, D-rich domain, P, K, E-rich domain, and P, T, Y-rich domain, while moderate Si accumulators lacked H, D-rich domain and P, T, Y-rich domains. The digital expression analysis and coexpression networks highlighted the role of channel type and Lsi2s, and how Slp1 homologs were ameliorating plants’ ability to withstand different stresses by co-expressing with genes related to structural integrity and signaling. Together, the in-silico exploration made in this study increases our knowledge of the process of biosilicification in plants.
APA, Harvard, Vancouver, ISO, and other styles
8

Moiseeva, Natalia I., Lidia A. Laletina, Timur I. Fetisov, Leyla F. Makhmudova, Angelika E. Manikaylo, Liliya Y. Fomina, Denis A. Burov, et al. "Analysis of Multiple Drug Resistance Mechanism in Different Types of Soft Tissue Sarcomas: Assessment of the Expression of ABC-Transporters, MVP, YB-1, and Analysis of Their Correlation with Chemosensitivity of Cancer Cells." International Journal of Molecular Sciences 23, no. 6 (March 16, 2022): 3183. http://dx.doi.org/10.3390/ijms23063183.

Full text
Abstract:
Chemotherapy of soft tissue sarcomas (STS) is restricted by low chemosensitivity and multiple drug resistance (MDR). The purpose of our study was the analysis of MDR mechanism in different types of STS. We assessed the expression of ABC-transporters, MVP, YB-1, and analyzed their correlation with chemosensitivity of cancer cells. STS specimens were obtained from 70 patients without metastatic disease (2018–2020). Expression level of MDR-associated genes was estimated by qRT-PCR and cytofluorimetry. Mutations in ABC-transporter genes were captured by exome sequencing. Chemosensitivity (SI) of STS to doxorubicin (Dox), ifosfamide (Ifo), gemcitabine (Gem), and docetaxel (Doc) was analyzed in vitro. We found strong correlation in ABCB1, ABCC1, and ABCG2 expression. We demonstrated strong negative correlations in ABCB1 and ABCG2 expression with SI (Doc) and SI (Doc + Gem), and positive correlation of MVP expression with SI (Doc) and SI (Doc + Gem) in undifferentiated pleomorphic sarcoma. Pgp expression was shown in 5 out of 44 STS samples with prevalence of synovial sarcoma relapses and it is strongly correlated with SI (Gem). Mutations in MDR-associated genes were rarely found. Overall, STS demonstrated high heterogeneity in chemosensitivity that makes reasonable in vitro chemosensitivity testing to improve personalized STS therapy, and classic ABC-transporters are not obviously involved in MDR appearance.
APA, Harvard, Vancouver, ISO, and other styles
9

Ashokan, Akhila, S. Anand, B. Aparna, and V. Mini. "Silicon Uptake Mechanism and its Multidimensional Influences on Stress Mitigation in Rice (Oryza sativa L.)." International Journal of Plant & Soil Science 35, no. 4 (March 4, 2023): 16–24. http://dx.doi.org/10.9734/ijpss/2023/v35i42793.

Full text
Abstract:
Silicon (Si) is the second most abundant element in the earth crust constituting 27.7 per cent. The beneficial effects of Si includes mitigation of various forms of abiotic and biotic stresses. Rice (Oryza sativa), a typical Si accumulator, takes up Si actively in the form of silicic acid. There are three transporters involved in the uptake of Si viz, LSi1, LSi2 and LSi3. Influx transporter (LSi1) takes up silicic acid from soil solution and mediates its transport upto the exodermal layer of root system, followed by the efflux transporter (LSi2), which transports it across the aerenchyma. Further movement of Si to the aerial parts of the plant is mediated by another influx transporter, LSi6 and finally gets deposited as silica in the plant parts. Silicon present in soil solution as well as its deposition in plants helps in mitigating various stresses in rice. Si application during drought stress prevents compression of xylem vessels and thereby resulting in reduction of transpiration rate. Sufficient supply of Si stabilises the culms and serves to decrease the risk of lodging. Rice is sensitive to metal toxicities like Iron (Fe), Manganese (Mn) and Aluminium (Al). Si complexation with these metal ions decreases their translocation rate and reduces the toxic effects. Heavy metal toxicity due to accumulation of cadmium (Cd) and arsenic (As) can be alleviated through supplementation of Si. Si also ameliorates salt stress by decreasing Na uptake and its root-to-shoot translocation. Silicon deposition in plant parts provides a mechanical barrier against pathogens and pests. The plants supplied with Si produce phenolics and phytoalexins in response to fungal infection and cuticle-Si double layer act as a defence mechanism preventing pests. The key mechanisms of Si-mediated alleviation of stresses in rice include stimulation of antioxidants, complexation of toxic metal ions with Si, immobilization of toxic metal ions and compartmentation of metal ions within plants.
APA, Harvard, Vancouver, ISO, and other styles
10

Wild, G. E., L. E. Searles, K. G. Koski, L. A. Drozdowski, J. Begum-Hasan, and A. B. R. Thomson. "Oral polyamine administration modifies the ontogeny of hexose transporter gene expression in the postnatal rat intestine." American Journal of Physiology-Gastrointestinal and Liver Physiology 293, no. 2 (August 2007): G453—G460. http://dx.doi.org/10.1152/ajpgi.00077.2006.

Full text
Abstract:
Gastrointestinal mucosal polyamines influence enterocyte proliferation and differentiation during small intestinal maturation in the rat. Studies in postnatal rats have shown that ornithine decarboxylase (ODC) protein and mRNA peak before the maximal expression of brush-border membrane (BBM) sucrase-isomaltase (SI) and the sugar transporters sodium-dependent glucose transporter 1 (SGLT1) and glucose transporter 2 (GLUT2). This study was undertaken to test the hypothesis that the oral administration of spermidine in postnatal rats upregulates the expression of ODC, thereby enhancing the expression of SI and SGLT1 in the brush-border membrane as well as basolateral membrane-facilitative GLUT2 and Na+-K+-ATPase. Northern and Western blot analyses were performed with antibodies and cDNA probes specific for SI, SGLT1, GLUT2, α1- and β1-subunits of Na+-K+-ATPase, and ODC. Postnatal rats fed 6 μmol spermidine daily for 3 days from days 7 to 9 were killed either on postnatal day 10 (Sp10) or day 13 following a 3-day washout period (Sp13). Sp10 rats showed a precocious increase in the abundance of mRNAs for SI, SGLT1, and GLUT2 and Na+-K+-ATPase activity and α1- and β1-isoform gene expression compared with controls. ODC activity and protein and mRNA abundance were also increased in Sp10 animals. The increased expression of these genes was not sustained in Sp13 rats, suggesting that these effects were transient. Thus, 3 days of oral polyamine administration induces the precocious maturation of glucose transporters in the postnatal rat small intestine, which may be mediated by alterations in ODC expression. 1 1 Supplemental material for this article is available online at the American Journal of Physiology-Gastrointestinal and Liver Physiology website.
APA, Harvard, Vancouver, ISO, and other styles
11

Zalewska-Bochenko, Agnieszka. "Digitising the public transport services based on the example of Bialystok City Card." Zeszyty Naukowe Uniwersytetu Szczecińskiego. Studia Informatica 37 (2015): 155–65. http://dx.doi.org/10.18276/si.2015.37-12.

Full text
APA, Harvard, Vancouver, ISO, and other styles
12

Pineda Jaramillo, Juan Diego, and Iván Sarmiento. "Variables influyentes en la elección entre carretera y ferrocarril para carga general de comercio exterior." Ingeniería Solidaria 10, no. 17 (December 1, 2014): 29–37. http://dx.doi.org/10.16925/in.v9i17.792.

Full text
Abstract:
Aunque el transporte de carga por carretera presenta muchos inconvenientes en Colombia, no existe un estudio que demuestre cuáles son las variables que influyen en la elección de un modo para transportar carga, para saber si realmente sería útil un ferrocarril para una determinada región. En este estudio se realiza una investigación cualitativa a través de las técnicas de grupo focal con las empresas importantes de una región, ilustrándose la metodología con el caso de Antioquia; de esta manera, se logran conocer las variables que influyen en la elección de un modo de transporte por parte de las empresas que exportan e importan mercancías. Estas variables serán importantes para futuros trabajos de estimación de la demanda.
APA, Harvard, Vancouver, ISO, and other styles
13

Cadiz, Fabian, Alistair C. H. Rowe, and Daniel Paget. "Le spin des électrons se transporte-t-il comme leur charge ?" Reflets de la physique, no. 65 (April 2020): 6–11. http://dx.doi.org/10.1051/refdp/202065006.

Full text
Abstract:
Pour répondre aux besoins croissants de la microélectronique, il a été proposé de transmettre l’information par le spin de l’électron, cette variable quantique dont l’analogue classique est la rotation sur lui-même. Il serait naturel de penser que la charge de l’électron et son spin se transportent de manière identique, si l’on excepte la tendance de toute orientation de spin à disparaitre par relaxation. Et pourtant, plusieurs études fondamentales montrent que le spin peut se transporter de façon indépendante de l’électron qui le porte, et donc « vivre sa vie » comme une particule autonome. Cet article est consacré à ces résultats fortement contre-intuitifs.
APA, Harvard, Vancouver, ISO, and other styles
14

Vomhof-DeKrey, Emilie E., Allie D. Stover, Mary Labuhn, Marcus R. Osman, and Marc D. Basson. "Vil-Cre specific Schlafen 3 knockout mice exhibit sex-specific differences in intestinal differentiation markers and Schlafen family members expression levels." PLOS ONE 16, no. 10 (October 28, 2021): e0259195. http://dx.doi.org/10.1371/journal.pone.0259195.

Full text
Abstract:
The intestinal epithelium requires self-renewal and differentiation in order to function and adapt to pathological diseases such as inflammatory bowel disease, short gut syndrome, and ulcers. The rodent Slfn3 protein and the human Slfn12 analog are known to regulate intestinal epithelial differentiation. Previous work utilizing a pan-Slfn3 knockout (KO) mouse model revealed sex-dependent gene expression disturbances in intestinal differentiation markers, metabolic pathways, Slfn family member mRNA expression, adaptive immune cell proliferation/functioning genes, and phenotypically less weight gain and sex-dependent changes in villus length and crypt depth. We have now created a Vil-Cre specific Slfn3KO (VC-Slfn3KO) mouse to further evaluate its role in intestinal differentiation. There were increases in Slfn1, Slfn2, Slfn4, and Slfn8 and decreases in Slfn5 and Slfn9 mRNA expression that were intestinal region and sex-specific. Differentiation markers, sucrase isomaltase (SI), villin 1, and dipeptidyl peptidase 4 and glucose transporters, glucose transporter 1 (Glut1), Glut2, and sodium glucose transporter 1 (SGLT1), were increased in expression in VC-Slfn3KO mice based on intestinal region and were also highly female sex-biased, except for SI in the ileum was also increased for male VC-Slfn3KO mice and SGLT1 was decreased for both sexes. Overall, the variations that we observed in these VC-Slfn3KO mice indicate a complex regulation of intestinal gene expression that is sex-dependent.
APA, Harvard, Vancouver, ISO, and other styles
15

Ratcliffe, Sarah, Ravin Jugdaohsingh, Julien Vivancos, Alan Marron, Rupesh Deshmukh, Jian Feng Ma, Namiki Mitani-Ueno, et al. "Identification of a mammalian silicon transporter." American Journal of Physiology-Cell Physiology 312, no. 5 (May 1, 2017): C550—C561. http://dx.doi.org/10.1152/ajpcell.00219.2015.

Full text
Abstract:
Silicon (Si) has long been known to play a major physiological and structural role in certain organisms, including diatoms, sponges, and many higher plants, leading to the recent identification of multiple proteins responsible for Si transport in a range of algal and plant species. In mammals, despite several convincing studies suggesting that silicon is an important factor in bone development and connective tissue health, there is a critical lack of understanding about the biochemical pathways that enable Si homeostasis. Here we report the identification of a mammalian efflux Si transporter, namely Slc34a2 (also termed NaPiIIb), a known sodium-phosphate cotransporter, which was upregulated in rat kidney following chronic dietary Si deprivation. Normal rat renal epithelium demonstrated punctate expression of Slc34a2, and when the protein was heterologously expressed in Xenopus laevis oocytes, Si efflux activity (i.e., movement of Si out of cells) was induced and was quantitatively similar to that induced by the known plant Si transporter OsLsi2 in the same expression system. Interestingly, Si efflux appeared saturable over time, but it did not vary as a function of extracellular [Formula: see text] or Na+ concentration, suggesting that Slc34a2 harbors a functionally independent transport site for Si operating in the reverse direction to the site for phosphate. Indeed, in rats with dietary Si depletion-induced upregulation of transporter expression, there was increased urinary phosphate excretion. This is the first evidence of an active Si transport protein in mammals and points towards an important role for Si in vertebrates and explains interactions between dietary phosphate and silicon.
APA, Harvard, Vancouver, ISO, and other styles
16

Kato, Tomoko, Norio Harada, Eri Ikeguchi-Ogura, Akiko Sankoda, Tomonobu Hatoko, Xuejing Lu, Takuma Yasuda, Shunsuke Yamane, and Nobuya Inagaki. "Gene expression of nutrient-sensing molecules in I cells of CCK reporter male mice." Journal of Molecular Endocrinology 66, no. 1 (January 2021): 11–22. http://dx.doi.org/10.1530/jme-20-0134.

Full text
Abstract:
Cholecystokinin (CCK) is secreted from enteroendocrine I cells in response to fat, carbohydrate, and protein ingestion. Gene expression of nutrient-sensing molecules in I cells remains unclear, primarily due to the difficulty in distinguishing I cells from intestinal epithelial cells in vivo. In this study, we generated CCK reporter male mice in which the red fluorescence protein tdTomato (Tomato) is produced by activation of the native murine Cck promoter. Fluorescence microscopy revealed the presence of Tomato-positive cells in upper small intestine (SI), lower SI, and colon. Flow cytometer analysis revealed that Tomato-positive cells among epithelial cells of upper SI, lower SI, and colon occurred at the rate of 0.95, 0.54, and 0.06%, respectively. In upper SI and lower SI, expression levels of Cck mRNA were higher in Tomato-positive cells than those in Tomato-negative cells. The fatty acid receptors Gpr120, Gpr40, and Gpr43 and the oleoylethanolamide receptor Gpr119 were highly expressed in Tomato-positive cells isolated from SI, but were not found in Tomato-positive cells from colon. The glucose and fructose transporters Sglt1, Glut2, and Glut5 were expressed in both Tomato-positive cells and -negative cells, but these expression levels tended to be decreased in Tomato-positive cells from upper SI to colon. The peptide transporter Pept1 and receptor Gpr93 were expressed in both Tomato-positive cells and -negative cells, whereas Casr was expressed only in Tomato-positive cells isolated from SI. Thus, this transgenic mouse reveals that I cell number and gene expression in I cells vary according to region in the gastrointestinal tract.
APA, Harvard, Vancouver, ISO, and other styles
17

Coskun, Devrim, Rupesh Deshmukh, S. M. Shivaraj, Paul Isenring, and Richard R. Bélanger. "Lsi2: A black box in plant silicon transport." Plant and Soil 466, no. 1-2 (July 10, 2021): 1–20. http://dx.doi.org/10.1007/s11104-021-05061-1.

Full text
Abstract:
Abstract Background Silicon (Si) is widely considered a non-essential but beneficial element for higher plants, providing broad protection against various environmental stresses (both biotic and abiotic), particularly in species that can readily absorb the element. Two plasma-membrane proteins are known to coordinate the radial transport of Si (in the form of Si(OH)4) from soil to xylem within roots: the influx channel Lsi1 and the efflux transporter Lsi2. From a structural and mechanistic perspective, much more is known about Lsi1 (a member of the NIP-III subgroup of the Major Intrinsic Proteins) compared to Lsi2 (a putative Si(OH)4/H+ antiporter, with some homology to bacterial anion transporters). Scope Here, we critically review the current state of understanding regarding the physiological role and molecular characteristics of Lsi2. We demonstrate that the structure–function relationship of Lsi2 is largely uncharted and that the standing transport model requires much better supportive evidence. We also provide (to our knowledge) the most current and extensive phylogenetic analysis of Lsi2 from all fully sequenced higher-plant genomes. We end by suggesting research directions and hypotheses to elucidate the properties of Lsi2. Conclusions Given that Lsi2 is proposed to mediate xylem Si loading and thus root-to-shoot translocation and biosilicification, it is imperative that the field of Si transport focus its efforts on a better understanding of this important topic. With this review, we aim to stimulate and advance research in the field of Si transport and thus better exploit Si to improve crop resilience and agricultural output.
APA, Harvard, Vancouver, ISO, and other styles
18

Garrefa, Fernando, Flávia Fernandes Carvalho, Júlia Tavares de Sousa Elias, and Isabella Denadae de Campos Pinto. "PADRÕES DE VIAGENS INTRAURBANAS PARA O TRABALHO E ESTABELECIMENTOS EDUCACIONAIS: EVIDÊNCIAS A PARTIR DO ESTUDO DE CASO DE UBERLÂNDIA - MG." Caminhos de Geografia 21, no. 78 (December 4, 2020): 303–24. http://dx.doi.org/10.14393/rcg217857702.

Full text
Abstract:
O presente artigo busca analisar os padrões de viagem considerando-se, a partir da habitação, os deslocamentos para o trabalho e estabelecimentos educacionais. Busca-se analisar as distâncias percorridas, e os modais de transporte na cidade de Uberlândia, MG. Para tal, recorreu-se à aplicação de questionários, posterior inserção em banco de dados georreferenciado para cálculo das distâncias e uso de software estatístico para análise de dados. Os resultados demonstraram que a medida em que aumenta a renda familiar e o nível de escolaridade, maior é a escolha pelo automóvel individual. Os dados também evidenciam uma ampliação constante e generalizada dos transportes motorizados individuais por meio de aplicativos, principalmente em faixas etárias de 19 a 29 anos. O trabalho mostra ainda que carros ou motos o meio de transporte mais utilizado para as viagens ao trabalho e para as viagens à escola pelo gênero masculino. Para as viagens à escola pelo gênero feminino, os meios de transporte são mais diversificados e combinados entre si. A partir das análises desenvolvidas espera-se contribuir com as decisões de planejamento urbano e formulação de políticas públicas de transporte. Também espera-se contribuir para a mitigação dos impactos causados pelos deslocamentos diários, derivados das viagens para trabalho e educação.
APA, Harvard, Vancouver, ISO, and other styles
19

Valadez Noriega, Marcela, and Genaro Cvabodni Miranda de la Lama. "Implicaciones, tendencias y perspectivas del transporte de larga distancia en el ganado bovino. Revisión." Revista Mexicana de Ciencias Pecuarias 11, no. 2 (June 2, 2020): 517–38. http://dx.doi.org/10.22319/rmcp.v11i2.4767.

Full text
Abstract:
El creciente comercio internacional, el crecimiento poblacional y su consecuente demanda de proteínas de origen animal en los países en vías de desarrollo y emergentes, han dado lugar a un considerable aumento en el número de animales criados, transportados y procesados en todo el mundo. Esto ha derivado en un aumento de la distancia recorrida y el tiempo de viaje, estimulando ciertas mejoras en la infraestructura ganadera; camiones con mayor autonomía; capacidad de carga y adaptados a las necesidades biológicas de los animales; reducción de costos de operación; y liberalización de restricciones zoosanitarias que facilitan el comercio internacional. La presente revisión hace un análisis pormenorizado y actualizado del transporte de larga distancia con una visión de conjunto. Si se toma en cuenta que la tendencia actual es aumentar el tiempo del transporte, escalas logísticas y transportes mixtos, es necesario desarrollar sistemas de evaluación y toma de decisiones con herramientas y protocolos que minimicen el coste biológico en el ganado bovino.
APA, Harvard, Vancouver, ISO, and other styles
20

Kaur, Harmanjit, and Maria Greger. "A Review on Si Uptake and Transport System." Plants 8, no. 4 (March 29, 2019): 81. http://dx.doi.org/10.3390/plants8040081.

Full text
Abstract:
Silicon (Si) was long listed as a non-essential component for plant growth and development because of its universal availability. However, there has been a resurgence of interest in studying the underlying uptake and transport mechanism of silicon in plants because of the reported dynamic role of silicon in plants under stressed environmental conditions. This uptake and transport mechanism is greatly dependent upon the uptake ability of the plant’s roots. Plant roots absorb Si in the form of silicic acid from the soil solution, and it is moved through different parts of the plant using various influx and efflux transporters. Both these influx and efflux transporters are mostly found in the plasma membrane; however, their location and pattern of expression varies among different plants. The assessment of these features provides a new understanding of different species-dependent Si accumulations, which have been studied in monocots but are poorly understood in other plant groups. Therefore, the present review provides insight into the most recent research exploring the use of Si transporters in angiosperms and cryptogams. This paper presents an extensive representation of data from different families of angiosperms, including monocots and eudicots. Eudicots (previously referred to as dicots) have often been neglected in the literature, because they are categorized as low/intermediate Si accumulators. However, in this review, we attempt to highlight the accumulating species of different plant groups in which Si uptake is mediated through transporters.
APA, Harvard, Vancouver, ISO, and other styles
21

Lu, Yi, Fangyuan Peng, Yingyang Wang, Haipu Li, and Zhaoguang Yang. "Effects of Transporter Inhibitors and Chemical Analogs on the Uptake of Antimonite and Antimonate by Boehmeria nivea L." Toxics 11, no. 10 (October 14, 2023): 860. http://dx.doi.org/10.3390/toxics11100860.

Full text
Abstract:
Antimony (Sb) is a non-essential metalloid that can be taken up by plants from contaminated soils and thus enter the food chain and threaten human health. Boehmeria nivea L. (ramie) is a promising phytoremediation plant for Sb-polluted soils. However, the mechanisms of antimonite (SbIII) and antimonate (SbV) uptake by ramie remain unclear. In this study, a hydroponic system was established to investigate how different substances affect the uptake of SbIII or SbV by ramie, including an energy inhibitor (malonic acid), an aquaglyceroporin inhibitor (silver nitrate), an SbV analog (phosphate—PV), and SbIII analogs (arsenite—AsIII, glycerol, silicic acid—Si, and glucose). The results indicated that ramie primarily transported Sb by increasing the Sb concentration in the bleeding sap, rather than increasing the weight of the bleeding sap. After 16 h of Sb exposure, the absolute amount of transported Sb from the roots to the aboveground parts was 1.90 times higher under SbIII than under SbV. The addition of malonic acid significantly inhibited the uptake of SbV but had limited effects on SbIII, indicating that SbV uptake was energy dependent. PV addition significantly reduced SbV uptake, while the addition of AsIII, glycerol, and Si obviously inhibited SbIII uptake. This suggested that the uptake of SbV might be via low-affinity P transporters and SbIII might use aquaglyceroporins. These findings deepen the understanding of Sb uptake pathways in ramie, contribute to a better comprehension of Sb toxicity mechanisms in ramie, and establish a foundation for identifying the most effective Sb uptake pathways, which could further improve the efficiency of phytoremediation of Sb-polluted soils.
APA, Harvard, Vancouver, ISO, and other styles
22

Chaiwong, Nanthana, Tonapha Pusadee, Sansanee Jamjod, and Chanakan Prom-u-thai. "Silicon Application Promotes Productivity, Silicon Accumulation and Upregulates Silicon Transporter Gene Expression in Rice." Plants 11, no. 7 (April 5, 2022): 989. http://dx.doi.org/10.3390/plants11070989.

Full text
Abstract:
Rice has been shown to respond positively to Si fertilizer in terms of growth and productivity. The objective of this study was to evaluate the effect of a series of Si application rates on grain yield, Si concentration, and the expression of the OsLsi6 gene among three Thai rice varieties. The varieties CNT1, PTT1, and KDML105 were grown in a pot experiment under six levels of Si (0, 100, 150, 200, 250, and 300 kg Si/ha). Grain yield was the highest at 300 kg Si/ha, being increased by 35%, 53%, and 69% in CNT1, PTT1, and KDML105, respectively, compared with the plants grown without added Si. For Si concentrations in rice plants, rising Si fertilizer application up to 150 kg/ha significantly increased the Si concentration in straw, flag leaf, and husk in all varieties. The Si concentration in all tissues was higher under high Si (300 kg Si/ha). Applying Si fertilizer also increased the expression level of OsLsi6 in both CNT1 and PTT1 varieties. The highest expression level of OsLsi6 was associated with 300 kg Si/ha, being increased by 548% in CNT1 and 326% in PTT1 compared with untreated plants. These results indicate that Si application is an effective way to improve rice yield as well as Si concentration, and that the effect is related to the higher expression of the OsLsi6 gene.
APA, Harvard, Vancouver, ISO, and other styles
23

Li, Ruonan, Yihan Sun, Hongzhen Wang, and Huasen Wang. "Advances in Understanding Silicon Transporters and the Benefits to Silicon-Associated Disease Resistance in Plants." Applied Sciences 12, no. 7 (March 23, 2022): 3282. http://dx.doi.org/10.3390/app12073282.

Full text
Abstract:
Silicon (Si) is the second most abundant element after oxygen in the earth’s crust and soil. It is available for plant growth and development, and it is considered as quasi-essential for plant growth. The uptake and transport of Si is mediated by Si transporters. With the study of the molecular mechanism of Si uptake and transport in higher plants, different proteins and coding genes with different characteristics have been identified in numerous plants. Therefore, the accumulation, uptake and transport mechanisms of Si in various plants appear to be quite different. Many studies have reported that Si is beneficial for plant survival when challenged by disease, and it can also enhance plant resistance to pathogens, even at low Si accumulation levels. In this review, we discuss the distribution of Si in plants, as well as Si uptake, transport and accumulation, with a focus on recent advances in the study of Si transporters in different plants and the beneficial roles of Si in disease resistance. Finally, the application prospects are reviewed, leading to an exploration of the benefits of Si uptake for plant resistance against pathogens.
APA, Harvard, Vancouver, ISO, and other styles
24

Lezcano, Fernando, Celine Quintero, Pedro De la Torre, and Victoria Serrano. "Diseño y control de un robot de cuatro patas." Revista de Iniciación Científica 6, no. 1 (June 30, 2020): 15–19. http://dx.doi.org/10.33412/rev-ric.v6.1.2606.

Full text
Abstract:
Se ha propuesto resolver la problemática del transporte de objetos a nivel doméstico utilizando un robot de cuatro patas,y en este caso se trabajó con una tarjeta Arduino. Se ha planteado si es posible crear un robot de cuatro patas que funcione a niveldoméstico, para lo cual se busca que camine y que pueda ser controlado. En esta investigación se describen los enfoques de cómodebe ser la estructura en términos de mecánica, y la programación de la placa Arduino para que el robot cumpla su misión. Tambiénse plantean los problemas que surgieron sobre el robot como la estabilidad y su control, y esto ha dado diferentes giros a lainvestigación, lo que lleva a incluir también factores como el ángulo al que se moverán los motores y el material para la estructurafinal de las patas, para que tenga la resistencia suficiente para cargar o transportar diferentes objetos. Además, se presentan loscomponentes que se deberán incluir tanto, a la estructura, como a los softwares con los que trabajamos.
APA, Harvard, Vancouver, ISO, and other styles
25

Li, Jie, Scott M. Leisner, and Jonathan Frantz. "Alleviation of Copper Toxicity in Arabidopsis thaliana by Silicon Addition to Hydroponic Solutions." Journal of the American Society for Horticultural Science 133, no. 5 (September 2008): 670–77. http://dx.doi.org/10.21273/jashs.133.5.670.

Full text
Abstract:
Copper (Cu) is an essential micronutrient for plants and is the a.i. in pesticides for some pathogens and algae. Elevated doses of Cu can cause toxicity in plants. While silicon (Si) is reported to alleviate the toxicity of some heavy metals, its role in reducing the symptoms induced by excess Cu is unclear. Therefore, the role of Si in plant response to Cu stress was investigated in arabidopsis [Arabidopsis thaliana (L.) Heyn.]. Based on plant symptoms (a reduction of leaf chlorosis as well as increased shoot and root biomass) and a reduction of phenylalanine ammonia lyase [PAL (EC 4.3.1.5), a stress-induced enzyme] activity in the shoot, Si was found to alleviate copper stress. Real-time reverse transcriptase-polymerase chain reaction analyses indicated that the RNA levels of two arabidopsis copper transporter genes, copper transporter 1 (COPT1) and heavy metal ATPase subunit 5 (HMA5) were induced by high levels of Cu, but were significantly decreased when Si levels were also elevated. Taken together, our findings indicate that Si addition can improve the resistance of arabidopsis to Cu stress, and this improvement operates on multiple levels, ranging from physiological changes to alterations of gene expression.
APA, Harvard, Vancouver, ISO, and other styles
26

Frick, Daniel A., Rainer Remus, Michael Sommer, Jürgen Augustin, Danuta Kaczorek, and Friedhelm von Blanckenburg. "Silicon uptake and isotope fractionation dynamics by crop species." Biogeosciences 17, no. 24 (December 22, 2020): 6475–90. http://dx.doi.org/10.5194/bg-17-6475-2020.

Full text
Abstract:
Abstract. That silicon is an important element in global biogeochemical cycles is widely recognised. Recently, its relevance for global crop production has gained increasing attention in light of possible deficits in plant-available Si in soil. Silicon is beneficial for plant growth and is taken up in considerable amounts by crops like rice or wheat. However, plants differ in the way they take up silicic acid from soil solution, with some species rejecting silicic acid while others actively incorporate it. Yet because the processes governing Si uptake and regulation are not fully understood, these classifications are subject to intense debate. To gain a new perspective on the processes involved, we investigated the dependence of silicon stable isotope fractionation on silicon uptake strategy, transpiration, water use, and Si transfer efficiency. Crop plants with rejective (tomato, Solanum lycopersicum, and mustard, Sinapis alba) and active (spring wheat, Triticum aestivum) Si uptake were hydroponically grown for 6 weeks. Using inductively coupled plasma mass spectrometry, the silicon concentration and isotopic composition of the nutrient solution, the roots, and the shoots were determined. We found that measured Si uptake does not correlate with the amount of transpired water and is thus distinct from Si incorporation expected for unspecific passive uptake. We interpret this lack of correlation to indicate a highly selective Si uptake mechanism. All three species preferentially incorporated light 28Si, with a fractionation factor 1000×ln (α) of −0.33 ‰ (tomato), −0.55 ‰ (mustard), and −0.43 ‰ (wheat) between growth medium and bulk plant. Thus, even though the rates of active and passive Si root uptake differ, the physico-chemical processes governing Si uptake and stable isotope fractionation do not. We suggest that isotope fractionation during root uptake is governed by a diffusion process. In contrast, the transport of silicic acid from the roots to the shoots depends on the amount of silicon previously precipitated in the roots and the presence of active transporters in the root endodermis, facilitating Si transport into the shoots. Plants with significant biogenic silica precipitation in roots (mustard and wheat) preferentially transport silicon depleted in 28Si into their shoots. If biogenic silica is not precipitated in the roots, Si transport is dominated by a diffusion process, and hence light silicon 28Si is preferentially transported into the tomato shoots. This stable Si isotope fingerprinting of the processes that transfer biogenic silica between the roots and shoots has the potential to track Si availability and recycling in soils and to provide a monitor for efficient use of plant-available Si in agricultural production.
APA, Harvard, Vancouver, ISO, and other styles
27

Gonzalez-Espinosa, Juan F. "La educación gratuita: transporte." Logos Boletín Científico de la Escuela Preparatoria No. 2 10, no. 20 (July 5, 2023): 10–12. http://dx.doi.org/10.29057/prepa2.v10i20.11370.

Full text
Abstract:
El presente ensayo presenta una visión del derecho a la educación en su vertiente gratuita y como esta debe ser y es garantizado por el Estado, en específico por lo que hace el transporte y el costo que representa para los estudiantes trasladarse a sus centros educativos y si ello es una violación al principio de gratuidad del derecho a la educación.
APA, Harvard, Vancouver, ISO, and other styles
28

Guo, Yongping, Qian Jiang, Dingkun Gui, and Niansong Wang. "Chinese Herbal Formulas Si-Wu-Tang and Er-Miao-San Synergistically Ameliorated Hyperuricemia and Renal Impairment in Rats Induced by Adenine and Potassium Oxonate." Cellular Physiology and Biochemistry 37, no. 4 (2015): 1491–502. http://dx.doi.org/10.1159/000438517.

Full text
Abstract:
Background/Aims: Hyperuricemia is an independent risk factor for chronic kidney disease and cardiovascular disease. Here, we examined the combined protective effects of Chinese herbal formula Si-Wu-Tang and Er-Miao-San on hyperuricemia and renal impairment in rats. Methods: Rats were randomly divided into normal rats, hyperuricemic rats, and hyperuricemic rats orally administrated with benzbromarone (4.5 mg·kg-1·d-1), Si-Wu-Tang (3.78 g·kg-1·d-1) and Si-Wu-Tang plus Er-Miao-San (6.48 g·kg-1·d-1) for 4 weeks. Hyperuricemic rats were orally gavaged with adenine (0.1 g·kg-1·d-1) and potassium oxonate (1.5 g·kg-1·d-1) daily for 4 weeks. Serum uric acid, creatinine, total cholesterol (TCH), triglyceride and blood urea nitrogen (BUN) concentrations, as well as urinary uric acid and microalbuminuria were measured weekly. Serum xanthine oxidase (XOD) activity and renal histopathology were also evaluated. The renal expression of organic anion transporter 1 (OAT1) and organic anion transporter 3 (OAT3) was detected by western blot. Results: Si-Wu-Tang plus Er-Miao-San lowered serum uric acid, creatinine, triglyceride and BUN levels to a greater degree than did Si-Wu-Tang alone. Si-Wu-Tang plus Er-Miao-San ameliorated microalbuminuria and renal histopathology, as well as decreased serum TCH concentration and XOD activity in hyperuricemic rats. Combination of Si-Wu-Tang and Er-Miao-San also led to a greater increase in OAT1 and OAT3 expression than did Siwutang alone. Conclusion: Si-Wu-Tang and Er-Miao-San synergistically ameliorated hyperuricemia and renal impairment in rats through upregulation of OAT1 and OAT3.
APA, Harvard, Vancouver, ISO, and other styles
29

Réthoré, Elise, Nusrat Ali, Jean-Claude Yvin, and Seyed Abdollah Hosseini. "Silicon Regulates Source to Sink Metabolic Homeostasis and Promotes Growth of Rice Plants under Sulfur Deficiency." International Journal of Molecular Sciences 21, no. 10 (May 23, 2020): 3677. http://dx.doi.org/10.3390/ijms21103677.

Full text
Abstract:
Being an essential macroelement, sulfur (S) is pivotal for plant growth and development, and acute deficiency in this element leads to yield penalty. Since the last decade, strong evidence has reported the regulatory function of silicon (Si) in mitigating plant nutrient deficiency due to its significant diverse benefits on plant growth. However, the role of Si application in alleviating the negative impact of S deficiency is still obscure. In the present study, an attempt was undertaken to decipher the role of Si application on the metabolism of rice plants under S deficiency. The results showed a distinct transcriptomic and metabolic regulation in rice plants treated with Si under both short and long-term S deficiencies. The expression of Si transporters OsLsi1 and OsLsi2 was reduced under long-term deficiency, and the decrease was more pronounced when Si was provided. The expression of OsLsi6, which is involved in xylem loading of Si to shoots, was decreased under short-term S stress and remained unchanged in response to long-term stress. Moreover, the expression of S transporters OsSULTR tended to decrease by Si supply under short-term S deficiency but not under prolonged S stress. Si supply also reduced the level of almost all the metabolites in shoots of S-deficient plants, while it increased their level in the roots. The levels of stress-responsive hormones ABA, SA, and JA-lle were also decreased in shoots by Si application. Overall, our finding reveals the regulatory role of Si in modulating the metabolic homeostasis under S-deficient condition.
APA, Harvard, Vancouver, ISO, and other styles
30

Ferraris, R. P., S. Yasharpour, K. C. Lloyd, R. Mirzayan, and J. M. Diamond. "Luminal glucose concentrations in the gut under normal conditions." American Journal of Physiology-Gastrointestinal and Liver Physiology 259, no. 5 (November 1, 1990): G822—G837. http://dx.doi.org/10.1152/ajpgi.1990.259.5.g822.

Full text
Abstract:
Luminal glucose (Glc) concentrations in the small intestine (SI) are widely assumed to be 50-500 mM. These values have posed problems for interpreting SI luminal osmolality and absorptive capacity, Glc transporter Michaelis-Menten constants (Km), and the physiological role of active Glc transport and its regulation. Hence we measured luminal contents, osmolality, and Glc, Na+, and K+ concentrations in normally feeding rats, rabbits, and dogs. Measured Glc concentrations were compatible with the portion of measured osmolality not accounted for by Na+ and K+ salts, amino acids, and peptides. Mean SI luminal osmolalities were less than or equal to 100 mosmol/kg hypertonic. For animals on the most nearly physiological diets, SI Glc concentrations averaged 0.4-24 mM and ranged with time and SI region from 0.2 to a maximum of 48 mM. The older published very high values are artifacts of direct infusion of concentrated Glc solutions into the gut, nonspecific Glc assays, and failure to test for quantitative recovery or to centrifuge samples in the cold. By storing food after meals and releasing it between meals, rat stomach greatly damps diurnal fluctuations in quantity and osmolality of food reaching the SI and hence also damps fluctuations in absorption rates. These new values for luminal Glc have five important physiological implications: the problem of accounting for apparently very hypertonic SI contents in the face of high osmotic water permeability disappears; the effective Km of the SI Glc transporter is now comparable to prevailing Glc concentrations; the SI no longer appears to have enormous excess absorptive capacity for Glc; regulation of Glc transport by dietary intake now makes functional sense; and the claim that high luminal Glc concentrations permit solvent drag to become the major mode of Glc absorption under normal conditions is undermined.
APA, Harvard, Vancouver, ISO, and other styles
31

Wang, Fuzhou, and Xiaofeng Shen. "Albumin versus Saline in Mortality in Critically Ill Children." Science Insights 5, no. 2 (December 20, 2013): 92–93. http://dx.doi.org/10.15354/si.13.op010.

Full text
Abstract:
High mortality in critically ill patients is a challenge for the intensive care medicine. While different reasons were figured out and corresponding therapeutic protocols were recommended, the actual mortality is still high and it is hard to conquer it and make a big improvement of the overall outcomes. Albumin, the most abundant protein in human blood plasma, plays an essential role in maintaining oncotic pressure, in participating in as an important protein transporter, and in possessing many physiological functions. In the context of critical care medicine, administration of albumin was found benefit patients in increasing their survival rate. However, a more recent study reported that bolus injection of albumin in critically ill pediatric patients increased the mortality. Of this report, we analyzed carefully and commented their methodology in performing the study. Some issues were not that clear, and it is difficult to determine the real effect of albumin administration on the mortality in children. It is a challenge to answer one question precisely and in overall, and we herein raise our concerns on this topic to discuss them with other researchers.
APA, Harvard, Vancouver, ISO, and other styles
32

Yamaji, Naoki, Gen Sakurai, Namiki Mitani-Ueno, and Jian Feng Ma. "Orchestration of three transporters and distinct vascular structures in node for intervascular transfer of silicon in rice." Proceedings of the National Academy of Sciences 112, no. 36 (August 17, 2015): 11401–6. http://dx.doi.org/10.1073/pnas.1508987112.

Full text
Abstract:
Requirement of mineral elements in different plant tissues is not often consistent with their transpiration rate; therefore, plants have developed systems for preferential distribution of mineral elements to the developing tissues with low transpiration. Here we took silicon (Si) as an example and revealed an efficient system for preferential distribution of Si in the node of rice (Oryza sativa). Rice is able to accumulate more than 10% Si of the dry weight in the husk, which is required for protecting the grains from water loss and pathogen infection. However, it has been unknown for a long time how this hyperaccumulation is achieved. We found that three transporters (Lsi2, Lsi3, and Lsi6) located at the node are involved in the intervascular transfer, which is required for the preferential distribution of Si. Lsi2 was polarly localized to the bundle sheath cell layer around the enlarged vascular bundles, which is next to the xylem transfer cell layer where Lsi6 is localized. Lsi3 was located in the parenchyma tissues between enlarged vascular bundles and diffuse vascular bundles. Similar to Lsi6, knockout of Lsi2 and Lsi3 also resulted in decreased distribution of Si to the panicles but increased Si to the flag leaf. Furthermore, we constructed a mathematical model for Si distribution and revealed that in addition to cooperation of three transporters, an apoplastic barrier localized at the bundle sheath cells and development of the enlarged vascular bundles in node are also required for the hyperaccumulation of Si in rice husk.
APA, Harvard, Vancouver, ISO, and other styles
33

Premkumar, Albert, Muhammad Tariq Javed, Katharina Pawlowski, and Sylvia M. Lindberg. "Silicate Inhibits the Cytosolic Influx of Chloride in Protoplasts of Wheat and Affects the Chloride Transporters, TaCLC1 and TaNPF2.4/2.5." Plants 11, no. 9 (April 26, 2022): 1162. http://dx.doi.org/10.3390/plants11091162.

Full text
Abstract:
Chloride is an essential nutrient for plants, but high concentrations can be harmful. Silicon ameliorates both abiotic and biotic stresses in plants, but it is unknown if it can prevent cellular increase of chloride. Therefore, we investigated the influx of Cl− ions in two wheat cultivars different in salt sensitivity, by epifluorescence microscopy and a highly Cl−-sensitive dye, MQAE, N-[ethoxycarbonylmethyl]-6-methoxy-quinolinium bromide, in absence and presence of potassium silicate, K2SiO3. The Cl−-influx was higher in the salt-sensitive cv. Vinjett, than in the salt-tolerant cv. S-24, and silicate pre-treatment of protoplasts inhibited the Cl−-influx in both cultivars, but more in the sensitive cv. Vinjett. To investigate if the Cl−-transporters TaCLC1 and TaNPF2.4/2.5 are affected by silicate, expression analyses by RT-qPCR were undertaken of TaCLC1 and TaNPF 2.4/2.5 transcripts in the absence and presence of 100 mM NaCl, with and without the presence of K2SiO3. The results show that both transporter genes were expressed in roots and shoots of wheat seedlings, but their expressions were differently affected by silicate. The TaNPF2.4/2.5 expression in leaves was markedly depressed by silicate. These findings demonstrate that less chloride accumulates in the cytosol of leaf mesophyll by Si treatment and increases salt tolerance.
APA, Harvard, Vancouver, ISO, and other styles
34

Husein, Diab M., Sandra Rizk, and Hassan Y. Naim. "Differential Effects of Sucrase-Isomaltase Mutants on Its Trafficking and Function in Irritable Bowel Syndrome: Similarities to Congenital Sucrase-Isomaltase Deficiency." Nutrients 13, no. 1 (December 22, 2020): 9. http://dx.doi.org/10.3390/nu13010009.

Full text
Abstract:
Congenital sucrase-isomaltase deficiency (CSID) is a rare metabolic intestinal disorder with reduced or absent activity levels of sucrase-isomaltase (SI). Interestingly, the main symptoms of CSID overlap with those in irritable bowel syndrome (IBS), a common functional gastrointestinal disorder with unknown etiology. Recent advances in genetic screening of IBS patients have revealed rare SI gene variants that are associated with IBS. Here, we investigated the biochemical, cellular and functional phenotypes of several of these variants. The data demonstrate that the SI mutants can be categorized into three groups including immature, mature but slowly transported, and finally mature and properly transported but with reduced enzymatic activity. We also identified SI mutant phenotypes that are deficient but generally not as severe as those characterized in CSID patients. The variable effects on the trafficking and function of the mutations analyzed in this study support the view that both CSID and IBS are heterogeneous disorders, the severity of which is likely related to the biochemical phenotypes of the SI mutants as well as the environment and diet of patients. Our study underlines the necessity to screen for SI mutations in IBS patients and to consider enzyme replacement therapy as an appropriate therapy as in CSID.
APA, Harvard, Vancouver, ISO, and other styles
35

Belintxon Martin, Unai. "Derechos humanos y responsabilidad social corporativa en las empresas de transporte. Un apunte de Derecho europeo." Cuadernos Europeos de Deusto, no. 63 (September 30, 2020): 269–94. http://dx.doi.org/10.18543/ced-63-2020pp269-294.

Full text
Abstract:
Este estudio tiene por objeto el análisis y la valoración crítica de la evolución jurídico-normativa experimentada en el ámbito de los Derechos Humanos y la responsabilidad social corporativa en las empresas de transporte en la UE. En particular el análisis centrará su atención en el sector del transporte internacional por carretera y en el sector del transporte aéreo internacional. Se estudiará y valorará si la UE de los derechos humanos del siglo xxi debe actuar de forma mucho más activa con el fin de evitar la fragmentación del proyecto europeo y el mercado interior, o si por el contrario debe mantener una actitud de inacción legislativa que permita a los Estados miembros de la UE seguir vulnerando el derecho europeo e incluso los derechos humanos en el sector del transporte.Recibido: 06 abril 2020Aceptado: 30 abril 2020Publicación en línea: 30 septiembre 2020
APA, Harvard, Vancouver, ISO, and other styles
36

Lee, Jeon Lo. "A Comparison of Genetic versus Non-Genetic Contribution of Serotonin to Suicide." Science Insights 43, no. 1 (July 31, 2023): 995–1002. http://dx.doi.org/10.15354/si.23.re611.

Full text
Abstract:
Suicide is a complex and multifaceted public health issue that has been intensively studied to identify its contributing factors. Serotonin, a neurotransmitter essential for affective regulation and mood control, has been linked to suicidal propensity. Understanding the relative contribution of serotonin’s genetic versus non-genetic influences is essential for the development of effective preventive measures, given that the etiology of suicide involves both genetic and non-genetic factors. This review seeks to compare the influence of genetic and non-genetic factors on the association between serotonin and suicide risk. Examining serotonin-related gene polymorphisms, with a focus on the serotonin transporter gene, the serotonin receptor 1A, and the serotonin receptor 2A, genetic contributions are investigated. This review emphasizes the complex interplay between genetic and non-genetic contributions to serotonin’s role in suicide by synthesizing existing literature. Understanding these complex interactions can provide a comprehensive framework for targeted interventions and individualized methods of suicide prevention and mental health promotion. Future research should incorporate large-scale genetic studies, genetic and non-genetic interaction analyses, and longitudinal designs in order to further elucidate the complex relationship between serotonin and suicide risk.
APA, Harvard, Vancouver, ISO, and other styles
37

Asai, Guilherme, Carlos Alberto Piacenti, and Angelo Costa Gurgel. "Impactos no Comportamento do Frete: Uma Aplicação de Equilíbrio Geral Computável para os Produtos Agropecuários do Brasil." Internext 15, no. 3 (June 16, 2020): 17. http://dx.doi.org/10.18568/internext.v15i3.556.

Full text
Abstract:
Objetivo: este trabalho teve como objetivo investigar o impacto da oscilação do custo do frete para os produtos agropecuários brasileiros.Método: trata-se de uma pesquisa descritiva de natureza quantitativa, focado na análise de cenário por meio da modelagem em equilíbrio geral computável para as cinco macrorregiões brasileiras.Principais resultados: como resultado da pesquisa indica-se: (i) a importação e a exportação sofreram impacto causado pela variação do preço do frete, aumentando em todas as macrorregiões brasileiras; (ii) o aumento das importações e exportações é um indicativo no movimento dos fluxos comerciais e traz benefícios para a economia do país, favorecendo a troca e a economia regional e (iii) as regiões com menor custo de frete, apresentam ganhos de competitividade para produtos agropecuários.Relevância/originalidade: trabalho contribui com uma agenda de pesquisa que envolve setores importantes da economia brasileira – agropecuária e transportes – e como estão relacionados entre si, fornecendo uma visão de como o custo de frete influência no comércio dos produtos agropecuários no Brasil.Contribuições teóricas/metodológicas: o trabalho apresenta uma abordagem diferente de métodos mais tradicionais, por ECG, criando uma alternativa para análise de como o custo de transporte impacta no comércio inter-regional.
APA, Harvard, Vancouver, ISO, and other styles
38

SCHRÖDER, Heinz-C., Sanja PEROVIĆ-OTTSTADT, Matthias ROTHENBERGER, Matthias WIENS, Heiko SCHWERTNER, Renato BATEL, Michael KORZHEV, Isabel M. MÜLLER, and Werner E. G. MÜLLER. "Silica transport in the demosponge Suberites domuncula: fluorescence emission analysis using the PDMPO probe and cloning of a potential transporter." Biochemical Journal 381, no. 3 (July 27, 2004): 665–73. http://dx.doi.org/10.1042/bj20040463.

Full text
Abstract:
Silicon is, besides oxygen, the most abundant element on earth. Only two taxa use this element as a major constituent of their skeleton, namely sponges (phylum Porifera) and unicellular diatoms. Results from combined cytobiological and molecularbiological techniques suggest that, in the demosponge Suberites domuncula, silicic acid is taken up by a transporter. Incubation of cells with the fluorescent silica tracer PDMPO [2-(4-pyridyl)-5-{[4-(2-dimethylaminoethylaminocarbamoyl)methoxy]phenyl}-oxazole] showed a response to silicic acid by an increase in fluorescence; this process is temperature-dependent and can be blocked by DIDS (4,4-di-isothiocyanatostilbene-2,2-disulphonic acid). The putative NBC (Na+/HCO3−) transporter was identified, cloned and analysed. The deduced protein comprises all signatures characteristic of those molecules, and phylogenetic analysis also classifies it to the NBC transporter family. This cDNA was used to demonstrate that the expression of the gene is strongly up-regulated after treatment of cells with silicic acid. In situ hybridization demonstrated that the expression of the sponge transporter occurs in those cells that are located adjacent to the spicules (the skeletal element of the animal) or in areas in which spicule formation occurs. We conclude that this transporter is involved in silica uptake and have therefore termed it the NBCSA {Na+/HCO3−[Si(OH)4]} co-transporter.
APA, Harvard, Vancouver, ISO, and other styles
39

Davis, J., R. Clark, and J. Giuliani. "Ultrashort pulse laser-produced Al/Si plasma." Laser and Particle Beams 13, no. 1 (March 1995): 3–18. http://dx.doi.org/10.1017/s0263034600008818.

Full text
Abstract:
The X-ray emission from an ultrashort-pulse laser incident on a solid aluminum and a layered aluminum /silicon slab is investigated with a non-LTE radiation-hydrodynamics model coupled to a Helmholtz wave equation for P-wave polarization. A fraction of the absorbed energy is expended in the production of fast electrons, which are transported and deposited in the cold material. These electrons create K-shell vacancies that produce characteristic Kα line radiation. A time history of the emission spectra, including the Kα lines and continuum radiation, is presented for a laser intensity of 1017 W/cm2.
APA, Harvard, Vancouver, ISO, and other styles
40

Sánchez Abril, Héctor Mauricio. "Las empresas de transporte público colectivo urbano en Colombia y la calidad de su servicio." Revista Estrategia Organizacional 1, no. 1 (December 15, 2012): 47. http://dx.doi.org/10.22490/25392786.1211.

Full text
Abstract:
El transporte sostenible surgió de la necesidad de asegurar la movilidad, disminuir la contaminación por emisiones atmosféricas y ruido y lograr ciudades amables para sus habitantes. Con esta perspectiva el transporte público colectivo urbano (TPCU) tiene una alta importancia y la manera como se lo presta en calidad de servicio es esencial, pues si ésta es adecuada por parte de las empresas se incentivará su uso. Por lo anterior, en el presente artículo se plasman los antecedentes, las definiciones y los enfoques existentes acerca de la calidad del servicio en empresas de TPCU, así como algunos resultados de investigación sobre transporte sostenible concernientes a la calidad de servicio de algunas empresas prestadoras en ciudades colombianas intermedias y específicamente en Tunja. El transporte sostenible surgió de la necesidad de asegurar la movilidad, disminuir la contaminación por emisiones atmosféricas y ruido y lograr ciudades amables para sus habitantes. Con esta perspectiva el transporte público colectivo urbano (TPCU) tiene una alta importancia y la manera como se lo presta en calidad de servicio es esencial, pues si ésta es adecuada por parte de las empresas se incentivará su uso. Por lo anterior, en el presente artículo se plasman los antecedentes, las definiciones y los enfoques existentes acerca de la calidad del servicio en empresas de TPCU, así como algunos resultados de investigación sobre transporte sostenible concernientes a la calidad de servicio de algunas empresas prestadoras en ciudades colombianas intermedias y específicamente en Tunja.
APA, Harvard, Vancouver, ISO, and other styles
41

Hu, Cai, and Jeong. "Silicon Affects Root Development, Tissue Mineral Content, and Expression of Silicon Transporter Genes in Poinsettia (Euphorbia pulcherrima Willd.) Cultivars." Plants 8, no. 6 (June 17, 2019): 180. http://dx.doi.org/10.3390/plants8060180.

Full text
Abstract:
The effects of silicon (Si) on root development, mineral content, and expression of Si transporter genes in Euphorbia pulcherrima Willd. ‘Flame’, ‘Mable Bell’, ‘Green Star’, ‘Pink Bell’, and ‘Peach Bowl’ cultivars were investigated in this study. Stem cuttings in a propagation bench were drenched regularly with a solution containing either 0 (control) or 50 ppm of silicon (Si treatment) from potassium silicate (K2SiO3), with a 25 °C mean air temperature and 80% relative humidity (RH) under 70% shading. The results showed that the ‘Flame’ treated with Si had a significantly higher survival ratio as compared with that of the control (P ≤ 0.05) and that the Si treatment improved number of roots, length of longest root, fresh root weight, and dry root weight in all cultivars except ‘Mable Bell’. Supplementary Si increased the content of magnesium (Mg) and decreased the content of boron (B) and zinc (Zn) in the roots. The content of sulfur (S) in the shoots was increased by supplementary Si. The relative expression of Lsi1 and Lsi2 was higher in ‘Peach Bowl’, while it was lower in ‘Mable Bell’ and ‘Green Star’, which may be caused by the differing accumulation of Si in the shoot. Overall, supplementary Si had beneficial effects during cutting propagation of poinsettia cultivars, although these effects were cultivar-dependent.
APA, Harvard, Vancouver, ISO, and other styles
42

Karczewski, J., T. Miruszewski, B. Bochentyn, and B. Kusz. "Determination of ionic conductivity in the Bi-Si-O and Pb-Si-O glasses." Materials Science-Poland 35, no. 4 (March 20, 2018): 681–86. http://dx.doi.org/10.1515/msp-2017-0102.

Full text
Abstract:
Abstract Impedance spectroscopy measurements in various gas atmospheres were carried out in order to explain the doubts about the type of carriers and the mechanism of electrical conductivity in Bi-Si-O and Pb-Si-O glasses. In bismuth silicate glass, a typical ionic conductivity with oxygen ions as charge carriers was observed. The level of electrical conductivity of the glass at 400 °C was 5 × 10-8 S·cm-1, with the activation energy of 1.3 eV and was independent of measuring atmosphere. In the case of lead silicate glasses, the conductivity changed with measuring atmosphere. Two types of charge carriers: oxygen ions and proton ions were postulated. Proton conductivity measured in wet argon at temperature 400 °C was estimated at the level of 4 × 10-8 S·cm-1 while the oxygen ions conductivity in such conditions was 78 × 10-8 S·cm-1. We suggest that both types of charge carriers are transported along the same conduction paths using oxygen defects in the glass structure.
APA, Harvard, Vancouver, ISO, and other styles
43

Marinucci, Elsa. "Logística y transporte internacional:." Revista Integración y Cooperación Internacional, no. 32 (December 15, 2020): 6–21. http://dx.doi.org/10.35305/revistamici.v0i32.71.

Full text
Abstract:
Este trabajo describe la disrupción que la pandemia por COVID-19 causó a uno de los pilares de la logística internacional: el transporte. La respuesta inmediata a la pandemia fue el cierre de fronteras, afectando con ello al transporte internacional y, como consecuencia, a todo el movimiento, el almacenamiento y el flujo de mercancías entre países. Si bien el impacto del COVID-19 en la logística internacional se sintió por primera vez en China -debido al papel que este país desempeña en la fabricación mundial-, se extendió rápidamente por todo el mundo. Estas perturbaciones de la cadena de suministros generaron importantes aumentos de costos logísticos que afectaron aún más las ya debilitadas exportaciones de Argentina
APA, Harvard, Vancouver, ISO, and other styles
44

Sklan, David, Asaf Geyra, Elad Tako, Orit Gal-Gerber, and Zehava Uni. "Ontogeny of brush border carbohydrate digestion and uptake in the chick." British Journal of Nutrition 89, no. 6 (June 2003): 747–53. http://dx.doi.org/10.1079/bjn2003853.

Full text
Abstract:
Ingestion of carbohydrates from the small intestine is the major route of energy supply in animals. In mammals these functions develop both pre- and postnatally and are coordinated for the sucking period. In birds, the physiological requirements are different and hatchlings ingest diets rich in complex carbohydrates soon after hatching. The present study examined the ontogeny of intestinal carbohydrate uptake in the chicken. The expression of mRNA for a brush border enzyme, sucrase–isomaltase (SI), which is critical in disaccharide digestion, was determined, together with that of the Na–glucose transporter (SGLT)-1, which is the major apical glucose transporter, In addition, the homeobox gene cdx, which is involved in inducing SI expression in mammals was examined. It was found that the expression of cdxA mRNA and cdxA protein increased from day 15 of incubation until hatch, after which further changes were small. CdxA protein was shown to bind to the promoter region of SI in the chick indicating that cdxA is similar to the mammalian cdx2. The mRNA of SI was observed at 15 d incubation, increased from 17 d of incubation to a peak on day 19, decreased at hatch and had a further peak of expression 2 d post-hatch. In contrast, the mRNA of SGLT-1 was not detected until 19 d of incubation when a major peak of expression was observed followed by a decrease to low levels at hatch and small increases post-hatch. It appears that both SI and SGLT-1 mRNA are expressed before hatch in the chick, but the ontogeny of expression is controlled by different mechanisms.
APA, Harvard, Vancouver, ISO, and other styles
45

Al Murad, Musa, and Sowbiya Muneer. "Physiological and Molecular Analysis Revealed the Role of Silicon in Modulating Salinity Stress in Mung Bean." Agriculture 13, no. 8 (July 27, 2023): 1493. http://dx.doi.org/10.3390/agriculture13081493.

Full text
Abstract:
Salinity stress acts as a significant deterrent in the course of optimal plant growth and productivity, and mung bean, being a relay crop in the cereal cropping system, is severely affected by salinity. Silicon (Si), on the other hand, has exhibited promising outcomes with regards to alleviating salinity stress. In order to understand the critical mechanisms underlying mung bean (Vigna radiata L.) tolerance towards salt stress, this study examined the effects of different salinity concentrations on antioxidant capacity, proteome level alterations, and influence on Si-transporter and salt-responsive genes. Salinity stress was seen to effect the gaseous exchange machinery, decrease the soluble protein and phenolic content and NR activity, and increase the accumulation of reactive oxygen species. An efficient regulation of stomatal opening upon Si application hints towards proficient stomatal conductance and CO2 fixation, resulting in efficient photosynthesis leading to proficient plant growth. The soluble protein and phenolic content showed improved levels upon Si supplementation, which indicates an optimal solute transport system from source to sink. The content of superoxide radicals showed a surge under salinity stress treatment, but efficient scavenging of superoxide radicles was noted under Si supplementation. Salinity stress exhibited more damaging effects on root NR activity, which was notably enhanced upon Si supplementation. Moreover, the beneficial role of Si was further substantiated as there was notable Si accumulation in the leaves and roots of salinity-stressed mung bean plants. Furthermore, Si stimulated competent ROS scavenging by reinforcing the antioxidant enzyme activity, as well coordinating with their isozyme activity, as expressed by the varying band intensities. Similarly, the Si-mediated increase in peroxidase activity may reveal changes in the mechanical characteristics of the cell wall, which are in turn associated with salinity stress adaptation. Proteomic investigations revealed the upregulation or downregulation of several proteins, which were thereafter identified by LC−MS/MS. About 45 proteins were identified and were functionally classified into photosynthesis (24%), metabolic process (19%), redox homeostasis (12%), transmembrane transport (10%), stress response (7%), and transcription regulation (4%). The gene expression analysis of the silicon transporter genes (Lsi1, Lsi2, and Lsi3) and SOS pathway genes (SOS1, SOS2, and SOS3) indicated the role of silicon in mitigating salinity stress. Hence, the findings of this study can facilitate a profound understanding of the potential mechanisms adopted by mung bean due to exogenous Si application during salinity stress.
APA, Harvard, Vancouver, ISO, and other styles
46

Flórez Guzmán, María Victoria, Sandy Yulieht Gómez Fernández, Lizzette Viviana González Cuadros, Sandra Rodríguez Naranjo, and Juan Ernesto Almeira Ospina. "Determinación del método más eficiente en la migración del catión potasio en caolinita analítica sometido a un campo eléctrico uniforme." Innovando En La U, no. 11 (July 10, 2023): 6–13. http://dx.doi.org/10.18041/2216-1236/innovando.11.2019.10439.

Full text
Abstract:
Debido a la gran contaminación presente en el suelo por acció n antró pica, se realizó la evaluació n para la remoción de contaminantes del suelo como lo son los metales, a través del sistema de electromigración, el cual consiste en someter iones a diferencial de potencial constante para que estos se transporten al electrodo de carga opuesta. Lo anterior consiste en que los iones de carga positiva (cationes) como el potasio, se transportan hacia el electrodo de carga negativa, y los iones de carga negativa (aniones) se transportan al electrodo de carga positiva. La evaluación de transporte constó de dos métodos, se construyeron dos celdas en acrı́lico iguales que consta cada una de tres cámaras: la primera catiónica, una solución de potasio de 100ppm, en la cámara central caolinita analı́tica y finalmente en la tercera cámara anódica agua desionizada. El primer método se adaptó un sistema de vibración a través de un parlante y el segundo sin vibración. El objetivo de la investigación fue determinar si el método con vibración es más eficiente que el método sin vibración para la migración del catión potasio en caolinita sometido a un debido a que es el que menos energı́a migrar mayor concentración de este.
APA, Harvard, Vancouver, ISO, and other styles
47

Escobar-Olguín, Héctor Enrique, Maricruz Covarrubias-Solís, and Julio César Villarreal-Lira. "El impacto de la Rotación de Personal en una Empresa Transportista: Un estudio de caso." Vinculatégica EFAN 9, no. 6 (November 30, 2023): 79–92. http://dx.doi.org/10.29105/vtga9.6-447.

Full text
Abstract:
El presente estudio analiza las causas de la rotación de personal en una empresa de transporte de carga. Es una investigación cuantitativa, descriptiva e interpretativa, que pretende conocer las principales causas de la deserción de personal en la empresa Transportes Logísticos. Cuenta con una flotilla de 15 operadores de carga pesada. Se generó y se aplicó un instrumento de diez preguntas con escala del Likert. Se realizó un análisis en el programa SPSS (donde se hizo la verificación del alfa de Cronbach: 0.78) y a la vez realizando la correlación en Excel. La información obtenida arrojó los siguientes factores: las unidades en buen estado, el mantenimiento que se les brindan, la mala organización en la empresa, las actitudes del jefe de tráfico, viáticos adecuados y si consideran redituable que se ocupe doble operador en los viajes largos. En conclusión, los factores de mayor impacto entre los operadores son: baja remuneración en función del kilómetro recorrido (sueldo), la medición de combustible en relación al buen rendimiento, la empresa procede a rebajar el faltante, las horas de descanso entre los viajes que no son respetados sus tiempos y la importancia de ellos hacia la empresa que no les hacen sentir como operadores.
APA, Harvard, Vancouver, ISO, and other styles
48

Quintero González, Julián Rodrigo, and Laura Estefanía Quintero González. "El transporte sostenible y su papel en el desarrollo del medio ambiente urbano." Ingeniería y Región 14, no. 2 (March 1, 2016): 87. http://dx.doi.org/10.25054/22161325.696.

Full text
Abstract:
Este artículo presenta un análisis acerca de la problemática actual de la movilidad urbana representada en dificultades puntuales como la congestión, falta de accesibilidad al servicio de transporte, ocupación del espacio público e impactos en el medio ambiente, entre otros; problemas que son originados por algunos de los sistemas de transporte más utilizados en las grandes ciudades. Son mencionados además los modelos de transporte actuales como el metro y el Bus Rapid Transit (BRT), que si bien colaboran en el desarrollo del medio ambiente urbano, existen sistemas de transporte alternativo que maximizan dicha labor. Por esto mismo, el objetivo de este documento es mostrar algunas de las tendencias de sistemas de transporte alternativo y su papel en la solución de las problemáticas anteriormente mencionadas; sus principales características y sus ventajas a nivel de movilidad, a nivel social y ambiental. Así mismo, las directrices bajo las cuales es ideal la planeación e implementación de mecanismos de transporte para el desarrollo sostenible urbano son descritas de manera general.
APA, Harvard, Vancouver, ISO, and other styles
49

Rahman, Md Atikur, Sang-Hoon Lee, Yowook Song, Hyung Soo Park, Jae Hoon Woo, Bo Ram Choi, and Ki-Won Lee. "Molecular Characterization of Silicon (Si) Transporter Genes, Insights into Si-acquisition Status, Plant Growth, Development, and Yield in Alfalfa." Journal of The Korean Society of Grassland and Forage Science 43, no. 3 (September 30, 2023): 168–76. http://dx.doi.org/10.5333/kgfs.2023.43.3.168.

Full text
APA, Harvard, Vancouver, ISO, and other styles
50

Pooja, Vikram, Jyoti Sharma, Shivani Verma, and Asha Sharma. "Importance of silicon in combating a variety of stresses in plants: A review." Journal of Applied and Natural Science 14, no. 2 (June 18, 2022): 607–30. http://dx.doi.org/10.31018/jans.v14i2.3426.

Full text
Abstract:
The abundance of silicon (Si) in the earth's crust is found as silicon dioxide (SiO2). But this abundance of Si is not a sign that the plants take up an adequate amount of Si. This review article incorporates research based on Si to understand the importance of Si in plants under various stress conditions and its role in sustainable agricultural production. Si's application is considered a better approach to providing stress tolerance to plants under stress conditions. The review describes the different phases of Si, its absorption, transport in plants, and its various mechanisms of action to tolerate specific stresses. The uptake and transport of Si through various Si transporters have also been reported. This review also discusses the various mechanisms of Si under biotic or abiotic stress in different plants. The application of Si improves soil quality and soil health and enhances the soil microbial population. In addition, the role of Si in the upregulation and down-regulation of proteins under stressful conditions has also been reported. The information can help to better understand the importance and mechanism of Si in plants and its application in agriculture.
APA, Harvard, Vancouver, ISO, and other styles
We offer discounts on all premium plans for authors whose works are included in thematic literature selections. Contact us to get a unique promo code!

To the bibliography