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941.
942.
Thaís Queiroz Morcatty Hani Rocha El Bizri Hellem Cristina Silva Carneiro Rodrigo Ludolf Biasizzo Cândida Radicchi de Oliveira Alméri Ericson Sousa da Silva Flávio Henrique Guimarães Rodrigues José Eugênio Côrtes Figueira 《Ecological Research》2013,28(6):935-947
Habitat loss is considered to be the principal cause of the local extinction of mammals worldwide. We assessed the extinction pattern of medium- and large-sized mammals caused by the effects of habitat loss in reserves in the Quadrilátero Ferrífero, southeastern Brazil, and discussed the effectiveness of these natural remnants for conserving mammals. A literature review and field collections were conducted from 2006 to 2011 to estimate the composition and richness of mammals in nine remnants of different sizes, including reserves and non-protected areas. A species–area relation and a nested subset analysis were performed, and a degree of sensitivity to habitat loss was obtained for each species according to its frequency of occurrence. Forty-five species of mammals were recorded. There was a strong species–area relation involving the legal size of reserves. High species richness was associated with large reserves, and the z value was within the range of very isolated continental remnants. The mammalian community exhibited a nested occurrence pattern, suggesting that most species were part of a more continuous ecosystem and that non-random extinction caused by habitat loss occurred in southeastern Brazil. The negative relation found between species frequencies and body weights suggested that selective species loss is associated with decreases in the size of the reserves. The estimated viable size required to conserve all of the sensitive species is greater than the size of the largest reserve inventoried. We recommend the aggregation of neighboring natural remnants and the creation of new reserves to reduce extinction risks. 相似文献
943.
Micael Reis Inês Páscoa Helder Rocha Bruno Aguiar Cristina P. Vieira Jorge Vieira 《PloS one》2014,9(1)
Even within a single genus, such as Drosophila, cases of lineage-specific adaptive evolution have been found. Therefore, the molecular basis of phenotypic variation must be addressed in more than one species group, in order to infer general patterns. In this work, we used D. americana, a species distantly-related to D. melanogaster, to perform an F2 association study for developmental time (DT), chill-coma recovery time (CRT), abdominal size (AS) and lifespan (LS) involving the two strains (H5 and W11) whose genomes have been previously sequenced. Significant associations were found between the 43 large indel markers developed here and DT, AS and LS but not with CRT. Significant correlations are also found between DT and LS, and between AS and LS, that might be explained by variation at genes belonging to the insulin and ecdysone signaling pathways. Since, in this F2 association study a single marker, located close to the Ecdysone receptor (EcR) gene, explained as much as 32.6% of the total variation in DT, we performed a second F2 association study, to determine whether large differences in DT are always due to variation in this genome region. No overlapping signal was observed between the two F2 association studies. Overall, these results illustrate that, in D. americana, pleiotropic genes involved in the highly-conserved insulin and ecdysone signaling pathways are likely responsible for variation observed in ecologically relevant phenotypic traits, although other genes are also involved. 相似文献
944.
Filipe Vieira Santos de Abreu Edmilson dos Santos Marcelo Quintela Gomes Waldemir Paixo Vargas Pedro Henrique de Oliveira Passos Charles Nunes e Silva Pollyanna Cardoso Araújo Jeferson Rocha Pires Alessandro Pecego Martins Romano Danilo Simonini Teixeira Ricardo Loureno‐de‐Oliveira 《American journal of primatology》2019,81(6)
Howler monkey capture is an arduous and expensive task requiring trained and specialized professionals. We compared strategies and methods to most efficiently capture Alouatta guariba clamitans in remnants of the Atlantic Forest in Rio de Janeiro and its bordering states of Minas Gerais and São Paulo. We tested whether or not the success of expeditions in the forest with anesthetic darts, nets, and baited traps differed with and without the support of an information network, a contact chain built with key institutions and inhabitants to continuously monitor howler monkey presence. The influence of forest conditions (vegetation type and fragment size) upon darting success was also evaluated. We captured 24 free‐living A. guariba clamitans. No howler monkey was caught with traps, probably due to the predominantly folivore feeding to high local plant diversity providing a great variety of food options. Captures based on an information network were significantly more efficient in terms of numbers of caught monkeys than without it. Captures with darts were considerably more efficient when performed in semideciduous forests and small forest fragments as opposed to ombrophilous forests or large woods. Although we walked great distances within the forest searching for howler monkeys, all but one animal were captured at the forest fringes. Hindrances to search and the darting method in the Atlantic Forest, for example, the steep terrain, high tree canopies, hunt pressure, and low A. guariba clamitans population density, were mitigated with the use of the information network in this monkey capture. Moreover, the information network enhanced the surveillance of zoonotic diseases, which howler monkeys and other nonhuman primates are reservoirs in Brazil, such as malaria and yellow fever. 相似文献
945.
We examined the stomach contents of 21 specimens of Mabuya agilis (Sauria; Scincidae) collected during February 2001 at the restinga habitat of Praia do Sul, in Ilha Grande, RJ, Brazil. Diet was composed of various types of small arthropods, with no plant material being eaten. Spiders were the most important items in the diet, followed by orthopterans. Apart from the absence of isopterans, the diet of Mabuya agilis from this insular area was similar to those of other conspecific mainland populations. This suggests that factors such as insularity and the absence of other small sympatric lizards may not have a significant effect on the feeding habits of the Praia do Sul population. 相似文献
946.
Amedea Barozzi Seabra Gabriela Freitas Pereira de Souza Lilian Lúcia da Rocha Marcos Nogueira Eberlin Marcelo Ganzarolli de Oliveira 《Nitric oxide》2004,11(3):263-272
Incorporation of nitric oxide (NO) donors in non-toxic polymeric matrices can be a useful strategy for allowing topical NO delivery. We have incorporated the NO-donor S-nitrosoglutathione (GSNO) into a liquid poly(ethylene glycol) (PEG)/H2O matrix through the S-nitrosation of GSH by a NO/O2 gas mixture. Kinetic measurements of GSNO decomposition associated with NO release were performed at 25, 35, and 45 degrees C in the dark and under irradiation with UV/Vis light, lambda>480 nm and lambda=333 nm. NO release from the liquid matrix to the gas phase was confirmed by mass spectrometry. The PEG/H2O matrix stabilizes GSNO leading to expressive reductions in the initial rates of thermal and photochemical NO release, compared to aqueous GSNO solution. This matrix effect is assigned to diffusional constrains imposed on the escape of the NO and GS radicals formed in the solvent cage. This effect allows the storage of PEG-GSNO formulations for extended periods (more than 65 days at freezer) with negligible decomposition. PEG-GSNO formulation seems therefore to be applicable in topical NO delivery and GSNO displays potential as a percutaneous absorption enhancer. Moreover, the rate of NO release can be locally increased by irradiation with visible light. 相似文献
947.
C F D Rocha M Van Sluys F H Hatano L Boquimpani-Freitas R V Marra R V Marques 《Revista brasleira de biologia》2004,64(4):879-884
Studies on anurans in restinga habitats are few and, as a result, there is little information on which methods are more efficient for sampling them in this environment. Ten methods are usually used for sampling anuran communities in tropical and sub-tropical areas. In this study we evaluate which methods are more appropriate for this purpose in the restinga environment of Parque Nacional da Restinga de Jurubatiba. We analyzed six methods among those usually used for anuran samplings. For each method, we recorded the total amount of time spent (in min.), the number of researchers involved, and the number of species captured. We calculated a capture efficiency index (time necessary for a researcher to capture an individual frog) in order to make comparable the data obtained. Of the methods analyzed, the species inventory (9.7 min/searcher /ind.- MSI; richness = 6; abundance = 23) and the breeding site survey (9.5 MSI; richness = 4; abundance = 22) were the most efficient. The visual encounter inventory (45.0 MSI) and patch sampling (65.0 MSI) methods were of comparatively lower efficiency restinga, whereas the plot sampling and the pit-fall traps with drift-fence methods resulted in no frog capture. We conclude that there is a considerable difference in efficiency of methods used in the restinga environment and that the complete species inventory method is highly efficient for sampling frogs in the restinga studied and may be so in other restinga environments. Methods that are usually efficient in forested areas seem to be of little value in open restinga habitats. 相似文献
948.
A. D. Resende ¶ E. Rocha † R. A. F. Monteiro † P. Rodrigues ‡§ 《Journal of fish biology》2002,60(6):1381-1390
Pale-grey cells appeared in the livers of healthy and non-stressed brown trout Salmo trutta 3 weeks post-hatching whereas interhepatocytic macrophages appeared at 5 months. Cells with intermediate morphological characteristics between those of pale-grey cells and macrophages were identified in all ages studies. Cell ultrastructure supported the idea that pale-grey cells probably belonged to the macrophage lineage, being eventual precursors of the active phagocytes residing amongst hepatocytes. 相似文献
949.
Guerra A.; Gonzalez A. F.; Rocha F. J.; Sagarminaga R.; Canadas A. 《Journal of plankton research》2002,24(4):333-338
Eight planktonic egg masses of the diamond-shaped Thysanoteuthisrhombus observed from 1995 to 2000 are described. Four werefound in the western Mediterranean and the others were foundoff the Canary Islands. The egg masses from the Canary Islandsare the first records for the eastern Atlantic. All were foundnear the surface at the end of summer and the beginning of autumn.The planktonic egg masses were dense, resilient oblong cylinderswith rounded tips ranging from 80 to 130 cm in length and between15 and 20 cm in diameter. Egg capsule dimensions ranged from2.8 to 3.4 mm and total length of the newly hatched paralarvaewas between 2.5 and 2.8 mm. Each egg mass contained an estimated24 10043 800 eggs. Some new characters that should helpidentification of the paralarvae, such as arm formulae, presenceof an incipient keel-shaped membrane on some arms, and the typeand chromatophore pattern are given. Ecological factors influencingthe presence and distribution of these egg masses are discussed. 相似文献
950.
M Malissen A Gillet B Rocha J Trucy E Vivier C Boyer F Kntgen N Brun G Mazza E Spanopoulou et al. 《The EMBO journal》1993,12(11):4347-4355
The CD3-zeta and CD3-eta polypeptides are two of the components of the T cell antigen receptor (TCR) which contribute to its efficient cell surface expression and account for part of its transducing capability. CD3-zeta and CD3-eta result from the alternative splicing of a single gene designated CD3-zeta/eta. To evaluate the role of these subunits during T cell development, we have produced mice with a disrupted CD3-zeta/eta gene. The analysis of thymocyte populations from the CD3-zeta/eta-/- homozygous mutant mice revealed that they have a profound reduction in the surface levels of TCR complexes and that the products of the CD3-zeta/eta gene appear to be needed for the efficient generation and/or survival of CD4+CD8+ thymocytes. Despite the almost total absence of mature single positive thymocytes, the lymph nodes from zeta/eta-/- mice were found to contain unusual CD4+CD8- and CD4-CD8+ single positive cells which were CD3-. In contrast to the situation observed in the thymus, the thymus-independent gut intraepithelial lymphocytes present in zeta/eta-/- mice do express TCR complexes on their surface and these are associated with Fc epsilon RI gamma homodimers. These results establish an essential role for the CD3-zeta/eta gene products during intrathymic T cell differentiation and further emphasize the difference between conventional T cells and thymus-independent gut intraepithelial lymphocytes. 相似文献