Resumo Embora a distribuição e a riqueza em espécies arbóreas nas fitofisionomias do Cerrado venham sendo bastante estudadas, a transição entre savanas e florestas deciduais ainda não foi abordada. Investigamos o efeito de características físico-químicas do solo sobre a distribuição de espécies arbóreas em região de contato entre cerrado sentido restrito e floresta estacional decidual (FED). As espécies arbóreas foram amostradas sistematicamente, e variáveis de topografia e características do solo foram medidas em 30 parcelas de 10×40 m, sendo 15 parcelas em cada fisionomia. A distribuição das espécies arbóreas foi espacialmente estruturada, e as características do solo diferiram entre as áreas de cerrado sentido restrito e FED, principalmente relacionadas à saturação de alumínio, saturação de bases e teores de fósforo. A saturação de alumínio aumentou em direção ao cerrado sentido restrito, enquanto a saturação de bases aumentou em direção à FED. A maioria das espécies arbóreas predominou em uma das fisionomias, como Callisthene major em cerrado sentido restrito e Anadenanthera colubrina em FED. Apenas 20% das espécies foram amplamente distribuídas em ambas as fisionomias ou, em poucos casos, restritas aos valores intermediários do gradiente de solo. Os resultados indicam um forte contraste de características do solo entre o cerrado sentido restrito e a FED, assim como uma transição acentuada e espacialmente organizada quanto à distribuição de espécies arbóreas.

Abstract Although richness and distribution of woody species in the Cerrado physiognomies have been extensively studied, the shifts of woody species from savanna physiognomies to dry forests have not yet been addressed. Here, we investigate the effect of soil physical-chemical traits on the woody species turnover between adjacent cerrado stricto sensu and dry forest physiognomies. Woody species were surveyed, and soil and topographic variables measured, in 30 10×40 m plots systematically distributed, with 15 plots in each physiognomy. We found a spatially structured distribution of woody species, and differences of soil traits between cerrado stricto sensu and dry forest areas, mainly related to the aluminum saturation, base saturation, and available phosphorus. Aluminum saturation increased toward the savanna area, while base saturation increased toward the dry forest. Most woody species predominated in one physiognomy, such as Callisthene major in the cerrado stricto sensu and Anadenanthera colubrina in the dry forest. Only 20% of the species were widely distributed across both physiognomies or, not often, restricted to the intermediary values of the soil gradient. General results indicate that contrasting soil traits between cerrado stricto sensu and dry forest produce a strongly spatially organized and sharp transition in terms of species distribution between these physiognomies.

Resumo Agricultura urbana é muito comum nas cidades, como Rio de Janeiro e adjacências, sendo uma importante atividade econômica de subsistência. No entanto, esta prática pode criar condições adequadas para o estabelecimento e manutenção do ciclo de vida de muitos parasitos. Os moluscos limneídeos podem atuar como hospedeiros intermédios de muitas espécies de trematódeos, incluindo aqueles que infectam humanos e animais selvagens e domésticos. No presente estudo, o molusco Lymnaea columella foi coletado de plantações urbanas de agrião e a morfologia das cercárias liberadas por eles foi analisada por microscopia eletrônica de varredura leve e de varredura. As larvas foram identificadas como xifidiocercárias, pertencentes ao grupo das Cercariae Ornatae, Ordem Plagiorchiiformes. Análises histológicas da glândula digestiva dos moluscos infectados evidenciaram esporocistos, com formação de granuloma e metaplasia do tecido epitelial.

Abstract Urban agriculture is very common in the cities, as Rio de Janeiro and adjacencies, being important as economic activity. However, this practice can create appropriate conditions for establishment and maintenance of life cycle of many parasites. Lymneid snails can act as intermediate hosts of many trematodes species, including those that infect humans and wild and domestic. In the present study, the snail Lymnaea columella was collected from an urban watercress plantations and the morphology of cercariae released by them was analyzed by light and scanning electron microscopy. The specimens were identified as xiphidiocercariae, belonging to the Cercariae Ornatae group, of the order Plagiorchiiformes. Histological examination of the digestive gland of the infected snails revealed the presence of developing sporocysts, with hemocitary infiltration and metaplasia in the epithelial tissue.

A alimentação de ninhêgos de Pitangus sulphuratus (Tyrannidae) tem sido pouco estudada. Descrevemos, neste estudo, o comportamento de forrageamento de um casal de P. sulphuratus e o tempo para busca e oferta de itens aos ninhêgos, no Pantanal, Brasil. A coleta de dados foi realizada durante 25 dias nas proximidades do prédio da Base de Estudos do Pantanal, habitada por morcegos insetívoros. Os registros foram baseados em observações diretas com auxílio de binóculo. O casal demandou pouco tempo de busca para a captura de pequenos insetos e frutos, porém esses itens representaram pouca quantidade de alimento por evento de captura. Algumas presas grandes demandaram mais tempo para busca, mas o longo período que esses itens foram oferecidos aos ninhêgos sobrecompensou o tempo de busca. Considerando-se o tempo de alimentação dos ninhêgos (benefício) em relação ao tempo de busca pelos pais (custo), morcegos e caramujos são itens mais vantajosos para os pais de P. sulphuratus alimentar ninhêgos no local de estudo.

Feeding of Pitangus sulphuratus (Tyrannidae) nestlings have been poorly studied. Here we describe the foraging behavior of a P. sulphuratus pair and the searching and offering time of food items to nestlings in the Pantanal, Brazil. Data collection was carried out over 25 days on the outskirts of the Base de Estudos do Pantanal building, inhabited by insectivorous bats. Records were based on direct observations with the help of binocular. The pair required little time for searching for small insects and fruits, but these items comprised a little amount of food per event of capture. Some large prey was more time-costly for searching, but the long period that these food items were offered to nestlings overcompensated the searching time. Considering the time of feeding nestlings (benefit) in relation to the searching time by the parents (cost), bats and snails are the most advantageous items for P. sulphuratus parents feeding nestlings at the study site.

Diversos trabalhos têm registrado o número de espécies de mamíferos nos diferentes hábitats naturais do Pantanal, com base nos registros do conhecimento corrente, com a riqueza de espécies variando de 89 a 152 ocorrências anotadas. Nossa lista atual soma 174 espécies. Contudo pelo menos três fatores devem ser enfatizados quando se lida com os números encontrados: 1) o limite exato do ecótono entre a bacia de inundação (que é o Pantanal) e os domínios vizinhos, como o Cerrado, apesar da existência de mapas recentes; 2) a falta de levantamentos intensivos, particularmente sobre pequenos mamíferos, roedores e marsupiais; e 3) a revisão taxonômica constante de morcegos, roedores e marsupiais. Algumas espécies são abundantes, como a capivara Hydrochoerus hydrochaeris, e o lobinho Cerdocyon thous, outras são raras e outras ainda são intrinsecamente raras, como o cachorro-vinagre Speothos venaticus. Assume-se que a abundância de espécies reflete os recursos ecológicos contidos nos hábitats. A diversidade local e o número de indivíduos de roedores silvestres e marsupiais também dependem da oferta ecológica de recursos e da especialização de comportamento para explorar componentes de micro-hábitats. Grande número de espécies interage com os tipos de vegetação do hábitat, por meio de seleção de hábitat com padrões ativos de comportamento ecológico, que resultam na dependência dos mamíferos de hábitats arbóreos e florestados do Pantanal. Além disso, os mamíferos respondem ao encolhimento e expansão dos hábitats devido à inundação sazonal do Pantanal, com abundância de espécies mais altas na estação seca, quando há considerável expansão de hábitats terrestres, principalmente campos inundáveis. As ameaças mais importantes para os mamíferos são a perda e alteração de hábitats devido à intervenção humana, particularmente o desmatamento, práticas de agricultura e pecuária insustentáveis, com conversão da vegetação natural em pastos. O Pantanal ainda abriga cerca de uma dúzia de espécies oficialmente ameaçadas de extinção.

Different works have registered the number of mammal species within the natural habitats of the Pantanal based on currently known records, with species richness ranging from 89 to 152 of annotated occurrences. Our present list sums 174 species. However, at least three factors have to be emphasised to deal with recorded numbers: 1) to establish the ecotone limit between the floodplain (which is the Pantanal) and its neighbouring domain like the Cerrado, besides the existence of maps recently produced; 2) the lack of intensive surveys, especially on small mammals, rodents and marsupials; and 3) the constant taxonomic revision on bats, rodents and marsupials. Some species are very abundant - for example the capybara Hydrochoerus hydrochaeris and the crab-eating fox Cerdocyon thous, and some are rare, and others are still intrinsically rare - for example, the bush dog Speothos venaticus. Abundance of species is assumed to reflect ecological resources of the habitat. Local diversity and number of individuals of wild rodents and marsupials also rely on the offering of ecological resources and behavioural specialisation to microhabitat components. A large number of species interact with the type of the vegetation of the habitat, by means of habitat selection through active patterns of ecological behaviour, resulting on dependency on arboreal and forested habitats of the Pantanal. In addition, mammals respond to seasonal shrinking-and-expansion of habitats due to flooding regime of the Pantanal. The highest number of species is observed during the dry season, when there is a considerable expansion of terrestrial habitats, mainly seasonally flooded grassland. Major threats to mammal species are the loss and alteration of habitats due to human intervention, mainly deforestation, unsustainable agricultural and cattle-ranching practices, which convert the natural vegetation into pastures. The Pantanal still harbours about a dozen of species officially listened as in danger.

Estudamos a fauna de morcegos na planície do Pantanal e nos planaltos de entorno no Mato Grosso do Sul, Brasil, com base na coleção científica da Universidade Anhanguera - Uniderp e no banco de dados do Projeto Morcegos do Pantanal, UFMS, incluindo 9.037 capturas de 56 espécies, entre 1994 e 2007. Amostragens no Pantanal foram feitas nas sub-regiões da Nhecolândia, Aquidauana, Miranda e Paraguai; no planalto as amostragens foram realizadas nas formações de Maracaju, Bodoquena e Urucum. Espécies de morcegos foram registradas ao longo de 376 noites em 35 sítios, predominantemente com o uso de redes de neblina próximas a árvores frutíferas, abrigos e florestas. Na planície, foram registradas 46 espécies (n = 6.292 indivíduos) e no planalto 44 espécies (n = 2.745 indivíduos). Seis famílias foram encontradas: Phyllostomidae (30 espécies), Molossidae (12 espécies), Verpertilionidae (nove espécies), Noctilionidae (duas espécies), Emballorunidae (duas espécies) e Mormoopidae (uma espécie). A fauna de morcegos foi predominantemente composta de espécies insetívoras (32) e frugívoras (15). O frugívoro Artibeus planirostris (n = 3.101) foi a espécie mais comum na planície e no planalto. Outras espécies comuns foram Myotis nigricans (n = 762), Molossus molossus (n = 692), Noctilio albiventris (n = 681), Platyrrhinus lineatus (n = 633), Sturnira lilium (n = 461), Carollia perspicillata (n = 451), Glossophaga soricina (n = 436), Artibeus lituratus (n = 320) e Desmodus rotundus (n = 281). Na planície, ocorreram três espécies de morcegos insetívoros dentre as espécies mais comuns, contrastando com o planalto, onde houve dominância de frugívoros. A diversidade para os 35 sítios reunidos (H' = 2,5) é comparável à encontrada em florestas tropicais. A fauna de morcegos apresentada aqui representa 34% das espécies brasileiras, e 62% das espécies já reportadas para a Bacia do Alto Paraguai. Adicionalmente, cinco espécies são reportadas pela primeira vez no Mato Grosso do Sul.

We studied the bat fauna of the Pantanal floodplain and its surrounding plateaus in Mato Grosso do Sul, Brazil, based on the scientific collection at Universidade Anhanguera - Uniderp and on the Projeto Morcegos do Pantanal data bank at UFMS, comprising 9,037 captures of 56 species recorded from 1994 to 2007. The Pantanal surveys were carried out in the Nhecolândia, Aquidauana, Miranda, and Paraguai sub-regions; the uplands surveys took place in the Maracaju, Bodoquena, and Urucum formations. Bat specimens were mist-netted over 376 nights in 35 sites, predominantly near fruiting trees, bat shelters, and forest patches. In the floodplain 46 species were recorded (n = 6,292 individuals), and 44 species were found in the uplands (n = 2,745 individuals). Six families were recorded: Phyllostomidae (30 species), Molossidae (12 species), Verpertilionidae (nine species) Noctilionidae (two species), Emballorunidae (two species) and Mormoopidae (one species). The bat fauna was predominantly composed of insectivore (32) and frugivore (15) species. The frugivorous Artibeus planirostris (n = 3,101 individuals) was the commonest species in floodplain and uplands. Other common species were Myotis nigricans (n = 762), Molossus molossus (n = 692), Noctilio albiventris (n = 681), Platyrrhinus lineatus (n = 633), Sturnira lilium (n = 461), Carollia perspicillata (n = 451), Glossophaga soricina (n = 436), Artibeus lituratus (n = 320), and Desmodus rotundus (n = 281). In the floodplain there were three insectivores among the most common species, contrasting with the uplands dominated by the frugivores. The diversity for the 35 sites assembled (H' = 2.5) is comparable to that recorded for tropical forests. The bat fauna presented here represents 34% of the Brazilian bat species, and 62% of species reported for the Upper Paraguay River Basin. Additionally, five species are reported for the first time in Mato Grosso do Sul.

Long-term vascular accesses are usually performed in patients submitted to renal replacement therapy using autologous vessels. When arterio-venous fistula creation is impossible, animal conduits have been used in order to obtain high patency rates. Bovine vessel heterograft has been introduced as a substitute for the construction of arterio-venous fistulas. However, when experimental research of graft failure is focused to vascular wall properties, the ovine model is one of the more frequently utilized instead of the study of bovine vessels. Biomechanical vessel wall properties study is very important, since the viscoelastic mismatch among the fistulae conduits has been pointed out as a determinant of intimal hyperplasia, a cause of access dysfunction. In this work we have analyzed viscoelastic properties of arteries and veins harvested from human donors in brain death condition and healthy sheep. The elastic mismatch calculus revealed that the human brachial artery and the ovine jugular veins exhibit the best coupling accompanied by an optimal viscous matching.

Intimal hyperplasia development is largely the most important cause of vascular access failure in patients submitted to hemodialysis. Differences in the biomechanical properties between the vascular substitutes and the native vessels have been related to the development of intimal hyperplasia. This work aim was to characterize the biomechanical behavior of arteries, veins, cryopreserved arteries and ePTFE prostheses. Fresh and cryopreserved human arteries and veins and ePTFE conduits were in-vitro studied in order to analyze their viscoelastic properties. Our results show that ePTFE has an elastic index, which is significantly different from that of the other conduits. This determines a high elastic mismatch that has been involved as a cause of intimal hyperplasia development. We conclude that the biomechanical study of tubular segments to be used as vascular accesses demonstrate viscoelastic differences that could be an important determinant of access viability.

Estudamos a polinização de Passiflora coccinea por beija-flores Phaethornis superciliosus na Amazônia Central, Brasil. Nossa hipótese é que maiores taxas de secreção de néctar (TSN) aumentam o sucesso da polinização de flores individuais através do comportamento de visitas de Ph. superciliosus. Para flores controladas, a TSN foi uma função positiva do diâmetro da base da flor (DBF). O número total de visitas de Ph. superciliosus por flor foi uma função positiva do DBF. Adicionalmente, a deposição de pólen sobre os estigmas aumentou com o aumento do número acumulado de visitas de Ph. superciliosus. Nossos resultados indicam que flores maiores de P. coccinea secretam néctar em taxas mais altas, são visitadas mais vezes pelos beija-flores, e apresentam maior sucesso de polinização. Este parece ser o primeiro estudo não-manipulativo que descreve este efeito da TSN sobre o sucesso de polinização de flores individuais na natureza.

The pollination of Passiflora coccinea by the hummingbird Phaethornis superciliosus was studied in Central Amazon, Brazil. We hypothesized that a greater nectar secretion rate (NSR) increases the pollination success of single flowers through Ph. superciliosus visiting behavior. For control flowers, NSR was an increasing function of flower base diameter (FBD). The total number of Ph. superciliosus probes per flower was an increasing function of FBD. Additionally, deposition of pollen on stigmas increased with the cumulative number of Ph. superciliosus probes. Our results show that larger P. coccinea flowers secrete nectar at higher rates, are probed more times during each hummingbird visit and are more successful at pollination. This seems to be the first non-manipulative study describing such an effect of NSR on the pollination of single flowers in nature.

Usually vascular surgeons consider the use of vein grafts as the materials of first choice for bypass or reconstruction of small arteries, while synthetic prosthesis (i.e. polytetrafluoroethylene, ePTFE) plays a secondary role in this matter. However, the causes for the superior performance of vein grafts respect ePTFE remain unclear. Our aim was to compare the conduit (CF) and buffering function (BF) of arteries, with those of vein grafts and ePTFE. In vitro pressure (Konigsberg) and diameter (Sonomicrometry) were measured in ovine arteries and veins, and ePTFE prosthesis, under isobaric and physiological pressures levels. From stress-strain relationship the Kelvin-Voigt time constant was calculated to quantify the BF. The CF was evaluated as 1/Z C, where Z C is the characteristic impedance. Vein graft CF and BF were more similar to native arteries than those of ePTFE prosthesis. Consequently, the higher performance of vein grafts could be related with their superior matching with arteries.

This work describes the biophysical basis of blood vessels' wall dynamics and reports a methodology developed in our laboratory to characterize mechanical vessels' wall properties and those of vascular prostheses. Our study includes in vitro measurements of arteries, veins and ePTFE conduits placed in a circulating loop. Segments are allowed to equilibrate for a period of 15 minutes under a steady state of flow (150 ml/min) and a mean pressure of 93 mmHg, at a stretching rate of 110 beats/min. Data analysis consisted in obtaining pressure-diameter loop in order to calculate: Incremental elastic modulus, wall viscosity, Peterson modulus, pulse wave velocity, characteristic impedance, stiffness index, cross sectional compliance and distensibility. Incremental elastic modulus of ePTFE (48.56±0.82 10(7)dyn/cm²) was significantly higher than that of the veins (26.19±19.90 10(7)dyn/cm²) and that of the arteries (4.06±2.55 10(7)dyn/cm²). This is an important approach, since mechanical wall dynamics plays a major role in vascular disease.