220 research outputs found

    FÉRAL, Josette, Mise en scène et jeu de l’acteur : entretiens, Montréal/Carnières (Belgique), Éditions Jeu/Éditions Lansman, t. 2, 1998

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    Frugivorous birds are important seed dispersers and influence the recruitment of many plant species in the rainforest. The efficiency of this dispersal generally depends on environment quality, bird species, richness and diversity of resources, and low levels of anthropogenic disturbance. In this study, we compared the sighting number of dusky-legged guans (Penelope obscura) by km and their movement in two areas of Serra do Japi, one around the administrative base (Base) where birds received anthropogenic food and a pristine area (DAE) with no anthropogenic resource. We also compared the richness of native seeds in feces of birds living in these two areas. Although the abundance of P. obscura was higher in the Base, these individuals moved less, dispersed 80% fewer species of plants and consumed 30% fewer seeds than individuals from DAE. The rarefaction indicated a low richness in the frugivorous diet of birds from the Base when compared to the populations from DAE. We conclude that human food supply can interfere in the behavior of these birds and in the richness of native seeds dispersed.Frugivorous birds are important seed dispersers and influence the recruitment of many plant species in the rainforest. The efficiency of this dispersal generally depends on environment quality, bird species, richness and diversity of resources, and low le75410081017sem informaçãosem informaçãoAves frugívoras são importantes dispersoras de sementes e influenciam no recrutamento de muitas espécies na floresta tropical. A eficiência dessa dispersão geralmente depende da qualidade do meio ambiente, das espécies de aves envolvidas, da riqueza e divWe thank the Graduate Program in Ecology of Unicampfor financial support through the discipline Topics in Field Ecology. The Research Base of Serra do Japi for lodging and authorizing research in the study area. We also thank E. Pereira for contributions

    Influence of collective feeding on weight gain and size variability of Anelosimus jabaquara Levi 1956 (Araneae : Theridiidae)

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    Differences in the size and weight of spiders within colonies may be an important factor for determining dispersion and food distribution among nestmates. In this study we report on the variation in size of spiders from 27 colonies of A. jabaquara, collected during one year. We also conducted an experiment under laboratory conditions to test if prey size, and consequently, collective or individual capture behaviours, influence the establishment of weight differences. Female size variation within colonies was high, increasing slightly from March to September. However, from November to January the variation was much lower, probably as a consequence of the emigration of large spiders during the reproductive period. Spiders that fed on large flies in the laboratory experiment grew more and collective feeding seemed to induce a larger variation in weight among individuals. These results indicate that collective feeding promotes an unequal distribution of food in A. jabaquara colonies.139419841431144

    First Record Of Egg Sac Predation On A Wall Crab Spider Selenopidae (araneae) By The Wasp Camera Lunavenatrix Sp. N. (ichneumonidae, Cryptinae)

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    We report the first record of egg sac predation on the wall crab spider Selenops cocheleti by wasps of the genus Camera (Ichneumonidae: Cryptinae) with the description of a new species, as well as biological information on the wasp and the spider host. The rearing record and information presented herein are the first biological data for the genus.496579AMNH, American Museum of Natural History1501802, NSF, National Science FoundationSSB, Society of Systematic Biologist

    Niche partitioning and coexistence of two spiders of the genus peucetia (araneae, oxyopidae) inhabiting trichogoniopsis adenantha plants (asterales, asteraceae)

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    Niche theory suggests that the coexistence of ecologically similar species in the same site requires some form of resource partitioning that reduces or avoids interspecific competition. Here, from July 2013 to December 2015, we investigated spatial niche differentiation at three different scales of two sympatric congeneric spiders, Peucetia rubrolineata and P. flava, along an altitudinal gradient in shaded and open areas in an Atlantic forest in Serra do Japi, SP, Brazil. These spiders are peculiar in that they present an exclusive association with the plant Trichogoniopsis adenantha (Asteraceae). In theory, the coexistence of two Peucetia species could be explained by: (1) microhabitat segregation with individuals from different species occupying different parts of the same plants; (2) mesohabitat segregation with different species using plant in different environments; (3) macrohabitat segregation, where different species would not co-occur along the altitudinal gradient. With respect to micro-habitat use, in both species, different instars used different plant parts, while the same instars of both species used the same type of substrate. However, the two Peucetia species segregated by meso-habitat type, with P. rubrolineata preferring T. adenantha plants in shaded areas and P. flava preferring those in open areas. Our results support the hypothesis of niche partitioning begetting diversity, and highlight the importance of analyzing habitat use at multiple scales to understand mechanisms related to coexistence1410CONSELHO NACIONAL DE DESENVOLVIMENTO CIENTÍFICO E TECNOLÓGICO - CNPQCOORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESFUNDAÇÃO DE AMPARO À PESQUISA DO ESTADO DE SÃO PAULO - FAPESPnão temnão temnão te

    Acúmulo e distribuição de macronutrientes em dois híbridos duplos de milho, em função da disponibilidade de água no solo.

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    A quantidade de nutrientes presente nos tecidos vegetais de uma determinada espécie, em um dado momento, é função da interação das condições ambientais com o genótipo e é de importância ecológica e econômica, pois permite a otimização do uso dos insumos e de diferentes manejos importantes na sustentabilidade do sistema produtivo. Neste trabalho, foram quantificados os macronutrientes nos diferentes órgãos de plantas de dois híbridos duplos de milho (BRS 2121 e BR 205) cultivados em campo, submetidos a quatro épocas (dez dias antes ou 15, 30 e 50 dias após a floração) de supressão da irrigação e três tipos de parcelamento da adubação de cobertura de N e K (10 kg de N ha-1 + 90 kg de K2O ha-1 no plantio e 120 kg de N ha-1 no estádio V8; 10 kg de N ha-1 + 45 kg de K2O ha-1 no plantio e 45 kg ha-1 de K2O + 120 kg de N ha-1 no estádio V8; 10 kg de N ha-1 + 30 kg de K2O ha-1 no plantio, 30 kg ha-1 de K2O + 60 kg de N ha-1 no estádio V8 e 30 kg ha-1 de K2O + 60 kg de N ha-1 no estádio V12), bem como em plantas jovens dos mesmos híbridos, cultivadas em casa-de-vegetação, sob quatro regimes hídricos: irrigação diária ou a cada três, cinco ou sete dias. Os resultados mostraram que, em campo, a resposta ao deficit hídrico variou de acordo com o nutriente e o órgão analisado. Em casa-de-vegetação houve tendência de concentração dos nutrientes nos tecidos em resposta ao déficit hídrico

    Serological survey of toxoplasmosis and leptospirosis in neotropical wild mammals from Aracaju Zoo, Sergipe, Brazil

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    Os zoológicos modernos são instituições destinadas à manutenção da fauna selvagem com o objetivo de promover a conservação, pesquisa científica, lazer, recreação e educação ambiental. A ampla variedade de espécies selvagens, vivendo em condições diferentes do seu habitat natural, representa um ambiente propício à disseminação de doenças, muitas delas zoonóticas. Devido à escassez de dados e à relevância dos mamíferos selvagens neste contexto epidemiológico, tanto na toxoplasmose, quanto na leptospirose, foi efetuado o inquérito sorológico para toxoplasmose e leptospirose em mamíferos selvagens neotropicais do Zoológico de Aracaju, Sergipe, Brasil. Para tanto foram colhidas amostras sanguíneas de 32 animais, adultos, de ambos os sexos incluindo: 14 macacos-prego (Cebus libidinosus), quatro macacos-prego-do-peito-amarelo (Cebus xanthosternus), três onças-suçuaranas (Puma concolor), uma onça-pintada (Pantheraonca), uma raposa (Cerdocyon thous), seis guaxinins (Procyon cancrivorus), dois quatis (Nasua nasua) e um papa-mel (Eira barbara). Para a pesquisa de anticorpos anti-Toxoplasma gondii foi utilizado o Teste de Aglutinação Modificada (MAT ³"1:25) e para pesquisa de anticorpos anti-Leptospira spp. foi utilizado o teste de Soroaglutinação Microscópica (ponto de corte ³1:100) com uma coleção de antígenos vivos que incluiu 24 variantes sorológicas de leptospiras patogênicas e duas leptospiras saprófitas. Dentre os 32 mamíferos, 17 (53,1%) apresentaram anticorpos anti-T. gondii e quatro (12,5%) foram positivos para anticorpos anti-Leptospira spp. De acordo com o sexo, 60% (9/15) dos machos e 47,1% (8/17) das fêmeas foram soropositivos para T. gondii e 26,7% (4/15) dos machos apresentaram anticorpos anti-Leptospira spp. Dos mamíferos que apresentaram anticorpos anti-T. gondii, 47% (8/17) nasceram no zoológico, 41,2% (7/17) foram oriundos de outras instituições e dois (11,8%) foram ) provenientes da natureza. Em relação aos quatro mamíferos soropositivos para Leptospira spp., três (75%) foram procedentes da natureza e um (25%) nasceu no zoológico. Este foi o primeiro inquérito sorológico de anticorpos anti-Leptospira spp. em primatas e carnívoros neotropicais em um zoológico do Nordeste do Brasil e descreveu pela primeira vez a ocorrência de anticorpos anti-T. gondii e anti-Leptospira spp. com sorovar mais provável Copenhageni no primata ameaçado de extinção macaco-prego-de-peito-amarelo (C. xanthosternus) em Aracaju, SEModern zoological gardens are institutions to wildlife maintenance, aiming its conservation, the performance of scientific research and leisure, recreation and environ-mental education activities. The variety of wild species living in conditions different from the one found in its natural habitats represents a propitious environment for diseases spread, specially the zoonotic ones. Due to data shortage and wild mammals' epidemio-logical relevance both for toxoplasmosis as for leptospirosis, this study aimed to determine the serological survey of toxoplasmosis and leptospirosis in Neotropical wild mammals, from Zoo of Aracaju, Sergipe, Brazil. Blood samples were collected from 32 wild mammals, adults and from both sexes: 14 wild bearded capuchins (Cebus libidinosus), four golden-bellied capuchins (Cebus xanthosternus), three pumas (Puma concolor), one jaguar (Pantheraonca), one crab-eating fox (Cerdocyon thous), six crab-eating raccoons (Procyon cancrivorus), two South American coatis (Nasua nasua), and one tayra (Eira barbara). Sera were tested to Toxoplasma gondii antibodies by the modified agglutination test (MAT e"1:25), and by the microscopic seroaglutination test (cut-off e"1:100) using 24 serovar of pathogenic leptospiras and two serovar of saprophyte leptospiras. Antibodies to T. gondii were found in 17 of 32 (53.1%) wild mammals, and antibodies to Leptospira spp. were found in 4 of 32 (12.5%) wild mammals. In relation to gender, 9 of 15 (60%) males, and 8 of 17 (47.1%) females had antibodies to Toxoplasma gondii, and 4 of 15 (26.7%) males had antibodies to Leptospira spp. Considering the origin of the seropositive animals to T. gondii, 8 of 17 (47%) were born in the zoo, 7 of 17 (41.2%) were from other zoos, and 2 (11.8%) were from the wild. Three of 4 (75%) mammals seropositive to Leptospira spp. were born in zoo, and 1 of 4 (25%) was from the wild. This is the first serological survey of Leptospira spp. in Neotropical and carnivores from Northeast zoo of Brazil, and the first time that antibodies to T. gondii and Leptospira spp. (serovar Copenhageni) were observed in the threaten specie of primate golden-bellied capuchins (Cebus xanthosternus) in Aracaju, S

    Could petroleum biodegradation be a joint achievement of aerobic and anaerobic microrganisms in deep sea reservoirs?

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    Several studies suggest that petroleum biodegradation can be achieved by either aerobic or anaerobic microorganisms, depending on oxygen input or other electron acceptors and appropriate nutrients. Evidence from in vitro experiments with samples of petroleum formation water and oils from Pampo Field indicate that petroleum biodegradation is more likely to be a joint achievement of both aerobic and anaerobic bacterial consortium, refining our previous observations of aerobic degradation. The aerobic consortium depleted, in decreasing order, hydrocarbons > hopanes > steranes > tricyclic terpanes while the anaerobic consortium depleted hydrocarbons > steranes > hopanes > tricyclic terpanes. The oxygen content of the mixed consortia was measured from time to time revealing alternating periods of microaerobicity (O2 ~0.8 mg.L-1) and of aerobicity (O2~6.0 mg.L-1). In this experiment, the petroleum biodegradation changed from time to time, alternating periods of biodegradation similar to the aerobic process and periods of biodegradation similar to the anaerobic process. The consortia showed preferences for metabolizing hydrocarbons > hopanes > steranes > tricyclic terpanes during a 90-day period, after which this trend changed and steranes were more biodegraded than hopanes. The analysis of aerobic oil degrading microbiota by the 16S rRNA gene clone library detected the presence of Bacillus, Brevibacterium, Mesorhizobium and Achromobacter, and the analysis of the anaerobic oil degrading microbiota using the same technique detected the presence of Bacillus and Acinetobacter (facultative strains). In the mixed consortia Stenotrophomonas, Brevibacterium, Bacillus, Rhizobium, Achromobacter and 5% uncultured bacteria were detected. This is certainly a new contribution to the study of reservoir biodegradation processes, combining two of the more important accepted hypotheses

    Polarimetric SAR Image Segmentation with B-Splines and a New Statistical Model

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    We present an approach for polarimetric Synthetic Aperture Radar (SAR) image region boundary detection based on the use of B-Spline active contours and a new model for polarimetric SAR data: the GHP distribution. In order to detect the boundary of a region, initial B-Spline curves are specified, either automatically or manually, and the proposed algorithm uses a deformable contours technique to find the boundary. In doing this, the parameters of the polarimetric GHP model for the data are estimated, in order to find the transition points between the region being segmented and the surrounding area. This is a local algorithm since it works only on the region to be segmented. Results of its performance are presented
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