717 resultados para Vampire bats


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The diagnosis of rabies in bats is usually performed using the brain of suspected animals. The main hypothesis tested by the present study was whether the aspiration method using a plastic pipette (Pasteur type) was effective in the collection of bat brain sample for rabies diagnosis when compared to the skull-opening method. A total of 200 bats of 4 species were studied: Molossus rufus E. Geoffroy, 1805, Molossus molossus (Pallas, 1766), Artibeus lituratus (Olfers, 1818) and Myotis nigricans (Schinz, 1821). The proportion of brain weight compared to body weight was statistically higher when using the traditional method, although the brain mass collected by the aspiration method was enough for rabies diagnosis and did not damage any skull biometric characteristics. The results demonstrate that both collection methods detected positive samples, while the aspiration method has the advantage of skull preservation, permitting the identification of the species.

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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

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P>In developing countries such as Brazil, where canine rabies is still a considerable problem, samples from wildlife species are infrequently collected and submitted for screening for rabies. A collaborative study was established involving environmental biologists and veterinarians for rabies epidemiological research in a specific ecological area located at the São Paulo State, Brazil. The wild animals' brains are required to be collected without skull damage because the skull's measurements are important in the identification of the captured animal species. For this purpose, samples from bats and small mammals were collected using an aspiration method by inserting a plastic pipette into the brain through the magnum foramen. While there is a progressive increase in the use of the plastic pipette technique in various studies undertaken, it is also appreciated that this method could foster collaborative research between wildlife scientists and rabies epidemiologists thus improving rabies surveillance.

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The testicular stroma of the vampire bat including the testicular capsula and the lamina propria of the seminiferous tubuli, was strongly PAS-positive. This observation was a possible indication of great amounts of structural glycogen and other glycoconjugates at the level of smooth muscle cells; elongated contractile cells and/or collagen frameworks of the tunica albuginea and tubular lamina propria. In the last the basement membranes of the seminiferous tubules were particularly strongly PAS positive, as an indication of their neutral mucosubstances structural composition, previously described (Malmi et al., 1987). The epithelium lining from the cavitary and surface rete testis complex showed low reactivities to mucosubstances; total proteins and lipids and oxidative enzymes studied. Although the apical granulation at the rete testis epithelium showed an intense PAS reactivity with hypothesis of glycoprotein secretion, through the rete. The PAS, Sudan Black B, NADH, MDH and LDH reactions of the testicular interstitium seem correlate to steroid metabolism (biosynthesis and secretion), at the Leydig cells level. The seminiferous epithelium generally had low reactions to all the histochemical studies realized. Particularly in the adbasal compartment the histochemical localizations of NADH diaphorase and LDH were possible related to glycolytic activities and general carbohydrates metabolism, both enzymes, and hydrogen transport, the NADH. The strong PAS, diastase and PAS, and alcian blue pH 2.5 and PAS reactions observed in the adluminal seminiferous epithelium compartment were directly related to the spermatids acrosomal glycoconjugates structuration. Also the SDH localization at this level seems to be related to the mitochondrial activities at the middle piece level in the late spermatids.

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This paper deals with the ultrastructural study of mature vampire bat Sertoli cells and their relationships with the different stages of testicular germ cells. In vampire bat seminiferous epithelium there are different types of junctional specializations among Sertoli cells and among Sertoli cells and different germ cells, with special emphasis to tight junctions and to junctions like as desmosomes. Ectoplasmic junctions through the Sertoli cells, including the smooth ER, are observed. These cellular interactions and their cytophysiological roles are discussed. Also are related some ultrastructural peculiarities of the Sertoli cell nucleus, nucleolus, cytoplasmic organelles and lipidic inclusions.

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A cave bat community from a semiarid region in eastern Brazil was studied during the dry season. A high diversity was observed, with thirteen species recorded. Except for Micronycteris minuta and Lionycteris spurrelli, these bats were also found in other Brazilian karstic areas. The commonest species were the hematophague Desmodus rotundus, the omnivore Carollia perspicillata, and the insectivore Natalus stramineus. The bats formed itinerant colonies, moving frequently inside the cave. L. spurrelli was previously known from Amazonia, usually associated with evergreen forests. The present record extends its range 1600 km to the south. A disjunct distribution explains some morphological differentiation between Amazonia and Olhos d'Agua cave populations. The latter may be a relict of former continuous forest vegetation, which has been fragmented after the climatic optimum. Dispersion through the Cerrado forest gallery is also possible.

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The location of chromosomal telomeric repeats (TTAGGG)(n) was investigated in two species of the Molossidae family, Eumops glaucinus and Eumops perotis. The diploid chromosome number (2n) is 40 in E. glaucinus and 48 in E. perotis and the fundamental numbers (FN) are 64 and 58, respectively. It has been suggested that the E. glaucinus karyotype has evolved from the E. perotis karyotype through Robertsonian fusion events. In the present study, the telomeric sequences were detected at the termini of chromosomes in both species. In addition, E. glaucinus also displayed telomeric repeats in centromeric and pericentromeric regions in almost all biarmed chromosomes. Conversely, in E. perotis pericentromeric signals were only observed in two biarmed chromosomes. In both E. glaucinus and E. perotis, such telomeric sequences were observed as part of the heterochromatin. The interstitial sites of telomeric sequences suggest that they are remnants of telomeres of ancestral chromosomes that participated in the fusion event.

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The pariparoba (Piper cernuum Vell.), a native plant from the Atlantic Tropical Forest (ATF), has been commonly used in folk medicine. Works seeking the exploitation of P. cernuum natural populations need to be accomplished, seeking compatibility in obtaining income rates and preservation of ATF. The present work aimed to study the reproductive phenology and seed dispersal in P. cernuum natural population in the counties of Sete Barras/SP (Parque Estadual Intervales - PEI). The population of P. cernuum studied in PEI presented continuously bud-inflorescences, green-infrutescences and bud-inflorescence emission, with variation among individuals. Fruit-set average was of 9.1%, varying among individuals. Shading and foliar damage presented negative effect on the fruit-set. Three species of bats were identified as potential dispersors of the P. cernuum seeds: Carollia perspicillata, Anoura geoffroyi and Artibeus sp. The foragement strategy observed was the withdrawal of some seeds per infrutescence per flight. This strategy increases the potential in establishing new plants as well as in increase the potential of gene flow in comparison with the entire infrutescence plant eaten at the night perches. In consequence, the results of reproductive phenology and seed dispersal ecology presented in this work can help to establish management and conservation strategies of P. cernuum natural populations in the ATF.

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We present the results of the first bat inventory at the 'Serra das Araras' Ecological Station, MT, in the northwestern portion of the Cerrado domain. We captured bats using the traditional ground-level mist netting and, occasionally, high nets placed 3 m above the ground, and hand nets for hoosting bats. We recorded 23 species distributed in six families (Emballonuridae, Noctilionidae, Mormoopidae, Phyllostomidae, Molossidae, and Vespertilionidae), including Artibeus gnomus and A. anderseni, which had never been recorded in the Cerrado domain. © 2004 Instituto de Ciências Biológicas - UFMG.

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Objective: To describe the normal bony orbital structure of the large fruit-eating bat (Artibeus lituratus) with emphasis on a unique intraorbital bony structure previously not described in the literature. Procedures: The bony anatomy of the orbital cavity was studied on dissected skulls of large fruit-eating bats. The anatomic description of a unique intraorbital spine was made while studying the bony orbit of macerated skulls. Additional observations were made on dissected formalin-fixed whole heads. Both procedures were performed under a stereo dissecting microscope, using ×2-4-magnification. A histologic analysis of soft tissues surrounding this cylindrical bony structure was performed using cross and longitudinal oblique sections from decalcified whole heads, which had been fixed in formalin. Additionally, biometric measurements and a histomorphometric analysis were performed. Results and conclusions: An intraorbital cylindrical osseous structure measuring 3.96 ± 0.68 mm in length and 155.62 ± 14.03 μm in diameter was observed in the large fruit-eating bat (A. lituratus), creating a unique orbital structural design among mammals. We suggest the name optic spine of the alisphenoid bone. The anatomic, biometric and histologic characterization of this element might contribute to a further understanding of the dynamics of bat vision and the sort of factors that influenced evolution of the visual system of microbats. The authors hope that the documentation of this distinctive anatomic feature will also expand the debate about the phylogenetic analysis of the relationship among bat species in the near future. © 2007 American College of Veterinary Ophthalmologists.

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A PCR-RFLP analysis of the restriction pattern in nuclear (RAG2) and mitochondrial (12S/16S) gene sequences of bat species from the Molossidae, Phyllostomidae, Vespertilionidae, and Emballonuridae families produced a large number of fragments: 107 for RAG2 and 155 for 12S/16S combined in 139 and 402 haplotypes, respectively. The values detected for gene variation were low for both sequences (0.13 for RAG2 and 0.15 for 12S/16S) and reflected their conservative feature, reinforced by high values of inter- and intraspecies genetic identity (70-100%). The species with a high gene divergence were variable in the analyses of RAG2 (Eumops perotis, Artibeus lituratus, and Carollia perspicillata) and of 12S/16S (Nyctinomops laticaudatus, C. perspicillata, and Cynomops abrasus), and furthermore, one of them, C. perspicillata, also showed the highest intraspecific variation. The species that exhibited the lowest variation for both genes was Molossus rufus. In the families, the highest variation was observed in the Molossidae and this can be attributed to variation exhibited by Eumops and Nyctinomops species. The variations observed were interpreted as a natural variability within the species and genus that exhibited a conserved pattern in the two gene sequences in different species and family analyzed. Our data reinforce the idea that the analyses of mitochondrial and nuclear genes contribute to our knowledge of the diversity of New World bats. The genetic variability found in different taxa suggests that an additional diversity, unnoticed by other methods, can be revealed with the use of different molecular strategies. ©FUNPEC-RP.

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Feature selection aims to find the most important information from a given set of features. As this task can be seen as an optimization problem, the combinatorial growth of the possible solutions may be in-viable for a exhaustive search. In this paper we propose a new nature-inspired feature selection technique based on the bats behaviour, which has never been applied to this context so far. The wrapper approach combines the power of exploration of the bats together with the speed of the Optimum-Path Forest classifier to find the set of features that maximizes the accuracy in a validating set. Experiments conducted in five public datasets have demonstrated that the proposed approach can outperform some well-known swarm-based techniques. © 2012 IEEE.

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Bats are hosts of a rich diversity of microorganisms. Many studies indicate a close link between bats and fungi with pathogenic potential, especially for living in environments such as caves, caverns and hollow trees, favorable to the maintenance and spread of fungi. The objective was to study the gastrointestinal mycoflora of bats. Of the 98 samples belonging to 11 species of bats coming from 15 studied cities, 20% of the species were Carollia perspicillata, 19% Artibeus lituratus, 17% Molossus rufus, 13% Glossophaga soricina, 9% Nyctinomops macrotis, 8% Molossus molossus, 7% Desmodus rotundus, 2% Lasiurus ega and 1% Eptesicus furinalis, Myotis nigricans and Tadarida brasiliensis. The genus Aspergillus sp. was isolated from 29% of the samples, followed by 6% Microsporum sp. and Penicillium sp. 4% Trichophyton sp. and zygomycetes and 2% Fusarium sp. Of yeast species, 14% were from Rhodotorula sp., 10% Candida sp. and 2% Cryptococcus sp., 22% of isolates remained unidentified. All 82 cultures of organs were negative for Histoplasma capsulatum. There was a statistically significant association between the results of microbiological culture and bat species (p < 0.05). We conclude that the bats can act as disperser agents of fungi with pathogenic potential, although other studies should be performed to establish strategies to identify the main factors correlated with the growth and spread of microorganisms in nature and implication of bats in the epidemiological cycle.

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The MAT1-1 and MAT1-2 idiomorphs associated with the MAT1 locus of Histoplasma capsulatum were identified by PCR. A total of 28 fungal isolates, 6 isolates from human clinical samples and 22 isolates from environmental (infected bat and contaminated soil) samples, were studied. Among the 14 isolates from Mexico, 71.4% (95% confidence interval [95% CI], 48.3% to 94.5%) were of the MAT1-2 genotype, whereas 100% of the isolates from Brazil were of the MAT1-1 genotype. Each MAT1 idiomorphic region was sequenced and aligned, using the sequences of the G-217B (+mating type) and G-186AR (-mating type) strains as references. BLASTn analyses of the MAT1-1 and MAT1-2 sequences studied correlated with their respective+ and-mating type genotypes. Trees were generated by the maximum likelihood (ML) method to search for similarity among isolates of each MAT1 idiomorph. All MAT1-1 isolates originated from Brazilian bats formed a well-defined group; three isolates from Mexico, the G-217B strain, and a subgroup encompassing all soil-derived isolates and two clinical isolates from Brazil formed a second group; last, one isolate (EH-696P) from a migratory bat captured in Mexico formed a third group of the MAT1-1 genotype. The MAT1-2 idiomorph formed two groups, one of which included two H. capsulatum isolates from infected bats that were closely related to the G-186AR strain. The other group was formed by two human isolates and six isolates from infected bats. Concatenated ML trees, with internal transcribed spacer 1 (ITS1) -5.8S-ITS2 and MAT1-1 or MAT1-2 sequences, support the relatedness of MAT1-1 or MAT1-2 isolates. H. capsulatum mating types were associated with the geographical origin of the isolates, and all isolates from Brazil correlated with their environmental sources. © 2013, American Society for Microbiology. All Rights Reserved.

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Feature selection aims to find the most important information to save computational efforts and data storage. We formulated this task as a combinatorial optimization problem since the exponential growth of possible solutions makes an exhaustive search infeasible. In this work, we propose a new nature-inspired feature selection technique based on bats behavior, namely, binary bat algorithm The wrapper approach combines the power of exploration of the bats together with the speed of the optimum-path forest classifier to find a better data representation. Experiments in public datasets have shown that the proposed technique can indeed improve the effectiveness of the optimum-path forest and outperform some well-known swarm-based techniques. © 2013 Copyright © 2013 Elsevier Inc. All rights reserved.