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931.
932.
Pessôa Marina Gabriel Paulino Bruno Nicolau Mano Mario Cezar Rodrigues Neri-Numa Iramaia Angélica Molina Gustavo Pastore Glaucia Maria 《Applied microbiology and biotechnology》2017,101(9):3493-3511
Applied Microbiology and Biotechnology - Global demand for biotechnological products has increased steadily over the years. Thus, need for optimized processes and reduced costs appear as a key... 相似文献
933.
Figueiredo Douglas B. Carvalho Eneas Santos Mauricio P. Kraschowetz Stefanie Zanardo Rafaela T. Campani Gilson Silva Gabriel G. Sargo Cíntia R. Horta Antonio Carlos L. de C. Giordano Roberto Miyaji Eliane N. Zangirolami Teresa C. Cabrera-Crespo Joaquin Gonçalves Viviane Maimoni 《Applied microbiology and biotechnology》2017,101(6):2305-2317
Applied Microbiology and Biotechnology - Streptococcus pneumoniae is the main cause of pneumonia, meningitis, and other conditions that kill thousands of children every year worldwide. The... 相似文献
934.
Exposure to Bordetella pertussis adenylate cyclase toxin affects integrin‐mediated adhesion and mechanics in alveolar epithelial cells
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935.
James?E.?PatersonEmail authorView authors OrcID profile Gabriel?Blouin-Demers 《Oecologia》2017,183(2):337-345
Partitioning of the niche space is a mechanism used to explain the coexistence of similar species. Ectotherms have variable body temperatures and their body temperatures influence performance and, ultimately, fitness. Therefore, many ectotherms use behavioral thermoregulation to avoid reduced capacities associated with body temperatures far from the optimal temperature for performance. Several authors have proposed that thermal niche partitioning in response to interspecific competition is a mechanism that allows the coexistence of similar species of ectotherms. We reviewed studies on thermal resource partitioning to evaluate the evidence for this hypothesis. In almost all studies, there was insufficient evidence to conclude unequivocally that thermal resource partitioning allowed species coexistence. Future studies should include sites where species are sympatric and sites where they are allopatric to rule out alternative mechanisms that cause differences in thermal traits between coexisting species. There is evidence of conservatism in the evolution of most thermal traits across a wide range of taxa, but thermal performance curves and preferred temperatures do respond to strong selection under laboratory conditions. Thus, there is potential for selection to act on thermal traits in response to interspecific competition. Nevertheless, more stringent tests of the thermal resource partitioning hypothesis are required before we can assess whether it is widespread in communities of ectotherms in nature. 相似文献
936.
Júnia Rafael Mendonça Figueiredo Patrícia Duarte de Oliveira Paiva Michele Valquíria dos Reis Fernanda Carlota Nery Samantha de Menezes Campos Diogo Pedrosa Corrêa da Silva Renato Paiva 《Acta Physiologiae Plantarum》2017,39(7):147
Soil salinity is mainly caused by excessive use of fertilizers and the use of poor quality water, and adversely affected crop growth especially when grown in protected environments. Soil salinity causes salt stress in plants, which inhibits plant growth, leading to morphological, metabolic and physiological changes. Though it is a major problem occurs more frequently, there is less information on the behavior of calla lily (Zantedeschia aethiopica) under these conditions, and most studies are conducted with other species of the genus Zantesdeschia. Therefore, this study aimed to evaluate ecophysiological, biochemical and anatomical growth responses of calla lily plants to salt stress. Rhizomes were grown in trays containing coconut fiber as a substrate and treated with 0, 25, 50, 75 and 100 mM NaCl to induce stress. A decrease in plant height was observed, as well as in the number of tillers and leaves, main root length, fresh and dry matter of the shoot and root system. A reduction in photosynthetic rate, stomatal conductance and transpiration rate was observed at 60 days. However, after 90 days, the photosynthetic rate was unchanged, with increased stomatal conductance and transpiration rate for plants exposed to 75 mM NaCl. Salt stress caused a higher accumulation of carbohydrates in shoots and roots. Thus, high concentrations of NaCl affect the development of calla lily, indicating that this species is susceptible to salt stress. 相似文献
937.
Martina Trokter Catarina Felisberto‐Rodrigues Adam Cryar Konstantinos Thalassinos Richard D Hayward Elena V Orlova Gabriel Waksman 《The EMBO journal》2017,36(20):3080-3095
Type IV secretion (T4S) systems are versatile bacterial secretion systems mediating transport of protein and/or DNA. T4S systems are generally composed of 11 VirB proteins and 1 VirD protein (VirD4). The VirB1‐11 proteins assemble to form a secretion machinery and a pilus while the VirD4 protein is responsible for substrate recruitment. The structure of VirD4 in isolation is known; however, its structure bound to the VirB1‐11 apparatus has not been determined. Here, we purify a T4S system with VirD4 bound, define the biochemical requirements for complex formation and describe the protein–protein interaction network in which VirD4 is involved. We also solve the structure of this complex by negative stain electron microscopy, demonstrating that two copies of VirD4 dimers locate on both sides of the apparatus, in between the VirB4 ATPases. Given the central role of VirD4 in type IV secretion, our study provides mechanistic insights on a process that mediates the dangerous spread of antibiotic resistance genes among bacterial populations. 相似文献
938.
María Angélica Pérez-Mayorga Lilian Casatti Fabrício Barreto Teresa Gabriel Lourenço Brejão 《Environmental Biology of Fishes》2017,100(12):1527-1541
Environmental and spatial variables can distinctly influence the occupancy frequency distributions in stream fish. From a metacommunity context, we tested the following hypothesis, intermediate species are governed by dispersal and niche-based processes; in contrast, satellite species are governed by niche-based processes. To test this, we separately analyzed three data sets, the entire metacommunity, the intermediate species and the satellite species, using a forward selection of explanatory variables, and a partial Redundancy Distance Analysis. The fish and 31 variables of 52 stream reaches of a Brazilian river basin in the Western Amazon were collected during the dry period of 2012. The results for all of the data set revealed two different patterns: on one side, satellite species revealed that niche and dispersal-based processes were the most important; on the other side, for intermediate species and for all of the species set, only dispersal-based processes were the most important. For the data set including all of the species and the intermediate species, the variance was explained mainly by landscape scale variables. By contrast, the variance within the satellite species set was explained by local scale variables. Management efforts for intermediate species should be taking at larger scale, but they are usually less critical for the maintenance of aquatic biodiversity; on the other hand, management efforts for satellite species should be taken at smaller scale and based on specific biological and ecological information for the focal species. 相似文献
939.
940.
Gabriel Yarmush Lucas Santos Joshua Yarmush Srivathsan Koundinyan Mubasher Saleem Nir I. Nativ Martin L. Yarmush Francois Berthiaume Timothy J. Maguire Chris Guaghan 《Biomechanics and modeling in mechanobiology》2017,16(4):1095-1102
Donor livers available to transplant for patients with end-stage liver disease are in severe shortage. One possible avenue to expand the donor pool is to recondition livers that would be otherwise discarded due to excessive fat content. Severely steatotic livers (also known as fatty livers) are highly susceptible to ischemia-reperfusion injury and as a result, primary liver non-function post-transplantation. Prior studies in isolated perfused rat livers suggest that “defatting” may be possible in a timeframe of a few hours; thus, it is conceivable that fatty liver grafts could be recovered by machine perfusion to clear stored fat from the organ prior to transplantation. However, studies using hepatoma cells and adult hepatocytes made fatty in culture report that defatting may take several days. Because cell culture studies were done in static conditions, we hypothesized that the defatting kinetics are highly sensitive to flow-mediated transport of metabolites. To investigate this question, we experimentally evaluated the effect of increasing flow rate on the defatting kinetics of cultured HepG2 cells and developed an in silico combined reaction-transport model to identify possible rate-limiting steps in the defatting process. We found that in cultured fatty HepG2 cells, the time required to clear stored fat down to lean control cells can be reduced from 48 to 4–6 h by switching from static to flow conditions. The flow required resulted in a fluid shear of .008 Pa, which did not adversely affect hepatic function. The reaction-transport model suggests that the transport of l-carnitine, which is the carrier responsible for taking free fatty acids into the mitochondria, is the key rate-limiting process in defatting that was modulated by flow. Therefore, we can ensure higher levels of l-carnitine uptake by the cells by choosing flow rates that minimize the limiting mass transport while minimizing shear stress. 相似文献