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101.
Mogens Trolle
rew J. Noss José Luis Passos Cordeiro Luiz Flamarion B. Oliveira 《Biotropica》2008,40(2):211-217
rew J. Noss José Luis Passos Cordeiro Luiz Flamarion B. Oliveira 《Biotropica》2008,40(2):211-217
The density of Brazilian tapirs ( Tapirus terrestris) was studied in the northeastern part of the Pantanal wetlands of Brazil using two simultaneous and independent methods: (1) systematic camera trapping combined with capture–recapture analysis, with camera traps spaced 1 km apart and distributed over 54 km2 ; and (2) line-transect sampling using an array of 12 linear transects, from 3.8 to 7.2 km long, covering the principal open and forest habitat types across the entire 1063 km2 SESC Pantanal Reserve. The two methods yielded conservative density estimates of 0.58 ± 0.11 tapirs/km2 (camera trapping) and 0.55 (95% CI 0.30–1.01) tapirs/km2 (line transects). The study suggests that certain Pantanal habitats and sites can sustain relatively high population densities of tapirs when these animals are protected from hunting. Further testing of the camera-trapping methodology as applied to tapirs is required, particularly focusing on extending the survey period. As it represents a relatively rapid method for estimating population density, in comparison to line-transect surveys, and as it generates information simultaneously on multiple species that are conservation priorities, we recommend that camera-trapping surveys be applied more widely across a variety of Pantanal habitats and land-use categories in order to confirm the value of the vast 140,000 km2 wilderness region for this vulnerable species. 相似文献
102.
Ricardo A. S. Cerboncini Talita V. Braga James J. Roper Fernando C. Passos 《Ibis》2020,162(1):227-231
Cooperative breeding is rare in shorebirds, and when found it is thought to be due to polygamous mating (cooperative polygamy). Here we describe the social structure of cooperatively breeding groups in Southern Lapwing Vanellus chilensis and test the prediction that offspring sex ratio is skewed towards the sex that helps. The social groups consisted of a breeding pair with one or two young (mostly males, 68%) from the previous breeding season, and offspring sex ratio was not skewed. Cooperative breeding in the Southern Lapwing is not the consequence of cooperative polygamy, but rather groups were formed by a mated pair and some of their offspring from previous nests as helpers. 相似文献
103.
Carlos Passos Federico Reyes Bettina Tassino Gil G. Rosenthal Andrés González 《Ethology : formerly Zeitschrift fur Tierpsychologie》2013,119(10):891-897
Chemical communication is an important mediator of social interactions in fish, including mate recognition, mate choice and intrasexual competition. We used a simultaneous‐choice design to test the response of adult females of the annual killifish, Austrolebias reicherti, towards male‐conditioned water, both crude and fractionated into its polar and non‐polar components. Females preferred male‐conditioned water when tested both against control water and female‐conditioned water. The polar and non‐polar fractions of the male‐conditioned water were not significantly attractive, although a tendency was observed towards the non‐polar fraction. Our study shows that annual fish respond to the chemical cues of potential mates. The chemical channel is likely to be particularly important in the muddy ephemeral ponds in which they occur. 相似文献
104.
P. A. Sanchez Podlech M. Furia Luna Paulo R. Jerke Carlos A. C. de Souza Neto Rogério F. dos Passos Ozair Souza Walter Borzani 《Biotechnology letters》1990,12(7):531-534
Summary A Monod-like equation correlates the lactic acid productivity and the volume fraction of inoculum in semicontinuous fermentation of whey byLactobacillus bulgaricus. The volume of the inoculum varied from 10% to 80% of the reactor working volume.Nomenclature N
number of fermentation cycles after the first fermentation
- P
lactic acid productivity
- Sw
average total sugars concentration of the whey as lactose (the standard deviation is indicated)
- T
average fermentation time (the standard deviation is indicated)
- Va
average total consumption of NH4OH solution (the standard deviation is indicated)
- Vi
volume of recently fermented medium used as inoculum of the next fermentation cycle
- Vw
volume of whey added to the reactor at the beginning of each fer mentation cycle
-
volume fraction of inoculum=Vi/(Vi+Vw) 相似文献
105.
Gadelha CA Moreno FB Santi-Gadelha T Cajazeiras JB Rocha BA Assreuy AM Lima Mota MR Pinto NV Passos Meireles AV Borges JC Freitas BT Canduri F Souza EP Delatorre P Criddle DN de Azevedo WF Cavada BS 《Journal of structural biology》2005,152(3):185-194
Here, we report the crystallographic study of a lectin from Canavalia maritima seeds (ConM) and its relaxant activity on vascular smooth muscle, to provide new insights into the understanding of structure/function relationships of this class of proteins. ConM was crystallized and its structure determined by standard molecular replacement techniques. The amino acid residues, previously suggested incorrectly by manual sequencing, have now been determined as I17, I53, S129, S134, G144, S164, P165, S187, V190, S169, T196, and S202. Analysis of the structure indicated a dimer in the asymmetric unit, two metal binding sites per monomer, and loops involved in the molecular oligomerization. These confer 98% similarity between ConM and other previously described lectins, derived from Canavalia ensiformis and Canavalia brasiliensis. Our functional data indicate that ConM exerts a concentration-dependent relaxant action on isolated aortic rings that probably occurs via an interaction with a specific lectin-binding site on the endothelium, resulting in a release of nitric oxide. 相似文献
106.
Espanhol AR Cardoso RS Junta CM Victorero G Loriod B Nguyen C Passos GA 《Molecular and cellular biochemistry》2004,260(1-2):65-68
The CBA/J inbred mouse strain constitutes an interesting in vivo model-system for studies on molecular genetics of thymus ontogeny. Using RT-PCR method we have found previously that several immune system related genes as interleukins and MHC are differentially expressed. During this period the onset of T-cell receptor beta rearrangements also occur. To know which other genes are modulated during the ontogeny of the thymus, the mRNA expression levels of fetal thymus (15 and 16 days gestation) of CBA/J mouse strain were measured by hybridization with a set of four macroarrays containing a panel of 6,144 IMAGE cDNA clones from MTB thymus library. We found 145 differentially expressed sequences; 44 were up- and 101 down-regulated in the thymus at 15-16 days gestation. Among these sequences, only 20 are identified as genes whose functions are known and 125 are still unknown. Our data demonstrated that, despite intense research on maturation of the immune system focusing on the activity of several well-characterized genes, the large scale expression profile during thymus ontogeny is still an open matter. The use of cDNA-array technology is an affordable method to identify new genes that may play a role in this phenomenon. 相似文献
107.
Programming is an epigenetic phenomena by which nutritional, hormonal, physical psychological and other stressful events acting
in a critical period of life, such as gestation and lactation, modifies in a prolonged way certain physiological functions.
This process was preserved by natural selection as an important adaptive tool for survival of organisms living in nutritional
impaired areas. So, malnutrition during gestation and lactation turns on different genes that provide the organism with a
thrifty phenotype. In the case of an abundant supply of nutrients after this period, those organisms that were adapted to
a low metabolic waste and higher energy utilization will be in a higher risk of developing metabolic diseases, such as obesity,
hyperlipidemia, diabetes mellitus and hypertension. The kind of malnutrition, duration and intensity are important for the
type of programming obtained. We discuss some of the hormonal and metabolic changes that occur in gestation or lactation,
when malnutrition is applied to the mothers and their offspring. Some of these changes, such as an increase of maternal triiodothyronine
(T3), leptin and glucocorticoids (GC) and decrease in prolactin are by itself potential programming factors. Most of these hormones
can be transfer through the milk that has other important macronutrients composition changes in malnourished dams. We discuss
the programming effects of some of these hormones upon body weight and composition, leptin, thyroid and adrenal functions,
and their effects on liver, muscle and adipose tissue metabolism and the consequences on thermogenesis. 相似文献
108.
Silaghi C Scheuerle MC Friche Passos LM Thiel C Pfister K 《Parasite (Paris, France)》2011,18(1):57-62
Central Switzerland is a highly endemic region for tick-borne fever (TBF) in cattle, however, little is known about A. phagocytophilum in goats. In the present study, 72 animals from six goat flocks (373 EDTA blood-samples) in Central Switzerland were analysed for A. phagocytophilum DNA. A real-time PCR targeting the msp2 gene of A. phagocytophilum was performed and in positive samples the partial 165 rRNA, groEL and msp4 gene were amplified for sequence analysis. Four DNA extracts were positive. Different sequence types on basis of the amplified genes were found. For comparison, sequences of A. phagocytophilum from 12 cattle (originating from Switzerland and Southern Germany) were analysed. The 165 rRNA gene sequences from cattle were all identical amongst each other, but the groEL and msp4 gene differed depending on the origin of the cattle samples and differed from the variants from goats. This study clearly provides molecular evidence for the presence of different types of A. phagocytophilum in goat flocks in Switzerland, a fact which deserves more thorough attention in clinical studies. 相似文献
109.
110.