Size distribution and sex ratio in the spider crab Epialtus brasiliensis (Dana 1852) associated with seaweed on a rocky shore in southeastern Brazil (Crustacea, Decapoda, Brachyura, Majoidea, Epialtidae).

This study analyzed a population of the spider crab Epialtus brasiliensis, in regard to its size distribution, sex ratio and Sexual maturity. The study was conducted on a rocky shore in the Ubatuba region, state of Silo Paulo, Brazil, where a wide strip of algae covers the intertidal zone. A total of 378 specimens were obtained: 200 males (128 juvenile and 72 adult crabs) and 178 females (46 juveniles and 132 adults). Their Sizes ranged from 3.4 to 16.7 mm carapace length (CL). Taking into account that the pubertal and terminal molts are coincident in majid crabs, the maximum sizes attained by males and females are especially dependent on the factors that influence sexual maturity, mainly food resources, temperature and intraspecific competition. Males of E. brasiliensis occurred in all size classes, whereas females occurred only as far the 10th size class (12-13 min CL). file total sex ratio did not differ statistically from 1 : 1, but when the juvenile and adult specimens were analyzed separately the differences between sexes were significantly different, with higher proportions of immature males and mature females. The CL50 calculated for males and females was 10.4, and 6.9 min CL, respectively. Thus, males reach their sexual maturity at a larger size than females. This feature may be important for the reproductive strategy of this species, because larger males probably have greater reproductive Success.

Population biology and reproduction of the hermit crab Clibanarius vittatus (Decapoda: Anomura) in an estuarine region of southern Brazil

The population dynamics and reproduction of the hermit crab Clibanarius vittatus were evaluated on Pescadores Beach, located on the estuarine channel of Sao Vicente (São Paulo), Brazil. The hermit crabs were captured by hand during low tide,from May 2001 to April 2003. A total of 2554 hermit crabs were captured, of which 701 were males, 1741 non-ovigerous females, 48 ovigerous females and 64 intersex individuals. The size-frequency distribution of the males was represented by a platykurtic bell-shaped curve, which differed from the leptokurtic bell-shaped curve of the females. The smaller and intermediate classes were composed mainly of females (modal size 6.5-7.5 mm carapace shield length (CSL)), and the larger classes only by males (modal size 9.5-10.5 mm CSL). The overall sex-ratio was skewed toward females (0.39:1/M:F), differing significantly from the expected 1:1. A seasonal reproductive pattern was recorded for C. vittatus in this location, with more intensive reproductive activity in the warmer months. The absence of juveniles suggests that their recruitment area is different than the area inhabited by adults, possibly another area with more protection and specialized or different resources for young.

Distribution and abundance of four caiman species (Crocodylia: Alligatoridae) in Jaú National Park, Amazonas, Brazil

Jaú National Park is a large rain forest reserve that contains small populations of four caiman species. We sampled crocodilian populations during 30 surveys over a period of four years in five study areas. We found the mean abundance of caiman species to be very low (1.0 ± 0.5 caiman/km of shoreline), independent of habitat type (river, stream or lake) and season. While abundance was almost equal, the species' composition varied in different waterbody and study areas. We analysed the structure similarity of this assemblage. Lake and river habitats were the most similar habitats, and inhabited by at least two species, mainly Caiman crocodilus and Melanosuchus niger. However, those species can also inhabit streams. Streams were the most dissimilar habitats studied and also had two other species: Paleosuchus trigonalus and P. palpebrosus. The structure of these assemblage does not suggest a pattern of species associated and separated by habitat. Trends in species relationships had a negative correlation with species of similar size, C. crocodilus and P. trigonatus, and an apparent complete exclusion of M. niger and P. trigonatus. Microhabitat analysis suggests a slender habitat partitioning: P. trigonatus was absent from river and lake lgapo (flooded forest), but frequent in stream Igapó. This species was the most terrestrial and found in microhabitats similar to C crocodilus (shallow waters, slow current). Melanosuchus niger inhabits deep, fast moving waters in different study areas Despite inhabiting the same waterbodies in many surveys, M. niger and C. crocodilus did not share the same microhabitats. Paleosuchus palpebrosus was observed only in running waters and never in stagnant lake habitats. Cluster analysis revealed three survey groups: two constitute a mosaic in floodplains. (a) a cluster with both M. niger and C crocodilus, and another (b) with only C. crocodilus. A third cluster (c) included more species, and the presence of Paleosuchus species. There was no significant difference among wariness of caimans between disturbed and undisturbed localities. However, there was a clear trend to increase wariness during the course of consecutive surveys at four localities, suggesting that we, more than local inhabitants, had disturbed caimans. The factors that are limiting caiman populations can be independent of human exploitation. Currently in Amazonia, increased the pressure of hunting, habitat loss and habitat alteration, and there is no evidence of widespread recovery of caiman populations. In large reserves as Jaú without many disturbance, most caiman populations can be low density, suggesting that in blackwater environments their recovery from exploitation should be very slow.

Systematics and distribution of Thorea (Thoreaceae, Rhodophyta) from central Mexico and south-eastern Brazil

Thirteen populations of Thorea were analyzed from central Mexico and south-eastern Brazil. All populations were considered as belonging to a single species [Thorea hispida (Thore) Desvaux], with wide variation of morphological features. Secondary branches varying in frequency were observed in several populations with an overlapping in the range of branch density for Thorea violacea Bory and T. hispida (0-9 and 11-41 per 30 mm, respectively). As this is the most distinguishing character and on the basis of the overlapping (within a same population or even a single plant), we regarded T. violacea as a synonym of T. hispida. 'Chantransia' stage in culture, as well as gametophyte and carposporophyte were described in detail. We confirmed the coexistence of asexual monosporangia with sexual reproductive structures (carpogonia and spermatangia) and carposporangia. Size, content, arrangement and chromosome number were the most distinctive characteristics among spermatangia, carposporangia and monosporangia. Monosporangia can be promptly differentiated from spermatangia by their granulated content and larger size but they are similar to carposporangia in shape and size; however, monosporangia are not arranged in fascicles. Structures resembling bisporangia were observed in female plants of some populations. Chromosome numbers were n = 4 for spermatangia and fascicle cells, and 2n ca8 for gonimoblast filaments, carpospores and the 'Chantransia' stage cells. The populations of Thorea from central Mexico and south-eastern Brazil corroborated the known world distribution for T. hispida, consisting dominantly of tropical to subtropical rainforests, sometimes extending into warm temperate areas. Thorea hispida occurred in warm (temperature 17.6-28.0°C), neutral to alkaline (pH 7.0-8.0), high ion content (specific conductance 59-2140 μS cm-1), moderate flowing (current velocity 17-43 cm/s) and shallow waters (depth <50 cm); these data are essentially similar to previous reports.

Ehrlichiosis in anemic, thrombocytopenic, or tick-infested dogs from a hospital population in South Brazil

Ehrlichia canis has a worldwide distribution, but clinical manifestations may vary geographically. We selected 129 dogs to determine prevalence of ehrlichiosis in dogs with anemia, thrombocytopenia, or ticks presented to a Veterinary Teaching Hospital in South Brazil. Of the 129 dogs, 68 carried the brown dog tick (Rhipicephalus sanguineus), 61 had thrombocytopenia (platelet count <150,000/μl), and 19 had anemia (PCV < 22%). Twenty dogs fulfilled more than one inclusion criteria. Ehrlichiosis was diagnosed by positive amplification of ehrlichial DNA by PCR using primers ECC and ECB that amplify a sequence of the 16S rRNA gene. Presence of E. canis was confirmed by cleavage of the amplified DNA using endonucleases HaeIII and AvaI. Fourteen of 68 (21%) dogs with ticks had ehrlichiosis, whereas 12 of 61 (20%) dogs presented with thrombocytopenia and 4 of 19 (21%) anemic dogs had ehrlichiosis. Similar results were obtained in dogs with thrombocytopenia and anemia (one of eight positive) and in dogs with thrombocytopenia and ticks (two of seven positive). All four dogs with anemia and ticks, and the dog that fulfilled all inclusion criteria yield no amplification of ehrlichial DNA by PCR. Based on our results, one in each five dogs infested by the brown dog tick, with anemia or thrombocytopenia had ehrlichosis. Contrary to widespread believe, ehrlichiosis was not the main cause for thrombocytopenia in our region. © 2003 Elsevier B.V. All rights reserved.

Longitudinal distribution of Copepoda populations in the transition zone of Paranapanema River and Jurumirim Reservoir (São Paulo, Brazil) and interchange with two lateral lakes.

Longitudinal changes in composition, abundance, and distribution of copepods were studied at the transition zone of Paranapanema River-Jurumirim Reservoir (SP, Brazil). The interchange of biotic material between marginal lakes and the river system was also examined. Water samples were obtained from 6 stations along a stretch of 13 km of the Paranapanema River, from an upstream reach with high water velocity up to the river mouth into Jurumirim Reservoir. Two other sites in lateral lakes were also sampled. Nine copepod taxa were identified: 3 calanoids (Argyrodiaptomus furcatus Sars, Notodiaptomus iheringi Wright, and N. conifer Sars) and 6 cyclopoids (Eucyclops Claus, Microcyclops Claus, Mesocyclops longisetus Thiébaud, Thermocyclops decipiens Fischer, T. minutus Lowndes, and Paracyclops Claus). Harpacticoids were also collected. Calanoid and cyclopoid nauplii and copepodids, and harpacticoids were the most abundant organisms. In general, there was a longitudinal decrease in copepod abundance, whereas an increase was detected near the lakes. The abundance of most copepods was inversely correlated with current velocity and suspended solids. Higher abundance was observed in the river main course during the rainy season, during which there is a higher connectivity between the lakes and the main river. This promotes exportation of biologic material from marginal lakes to the river system, a biotic exchange reflecting the importance of marginal lakes to the river community structure.

Temporal-spatial distribution of the hermit crab Loxopagurus loxochelis (Decapoda: Diogenidae) from Ubatuba Bay, São Paulo State, Brazil

The present work was conducted to determine the distribution of Loxopagurus loxochelis collected monthly, over a period of one year, in Ubatuba Bay (from September/95 to August/96). A total of 179 specimens were collected (138 males, 30 females and 11 ovigerous females). The greatest depth, predominance of very fine sand and highest mean value of organic matter contents of sediment, in combination with the low temperatures registered in winter (July and August), determined the presence of L. loxochelis in the subarea located at the Ubatuba Bay mouth, exposed to the open sea with high water current energy, important because this position insures that spawned larvae will enter into the oceanic circulation.

GSTT1, GSTM1 and CYP2E1 genetic polymorphisms in gastric cancer and chronic gastritis in a Brazilian population

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Spatial distribution of characidiin fishes (Teleostei, Crenuchidae) in the Ribeirão Grande system, a tributary of Paraíba do Sul river basin, Brazil

This study analyses the spatial distribution of characidiin fishes Characidium lauroi and Characidium alipioi (Crenuchidae) in a forest stream system located in southeastern Brazil. Fish were sampled from Jury 2001 to April 2002. Collections were made with an electro-fishing device in five stream reaches of the Ribeirão Grande system. Conductivity, pH, water temperature and dissolved oxygen were measured at each site. The species have different distributions in Ribeirão Grande system. Characidium lauroi is abundant in montane-piedmont zones and Characidium alipioi occurs mainly in piedmont-plain zones. Streams' different features contribute to these species' distribution in the system.

Population dynamics of Ectatomma brunneum (Hymenoptera, Formicidae) under laboratory conditions

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Evaluation of a multiobjective performance index for distribution systems with distributed generation

Here a multiobjective performance index for distribution systems with distributed generation based on a steady-state analysis of the network is proposed. This index quantifies the distributed generation impact on total losses, voltage profile and short circuit currents, and will be used as objective function in an evolutionary algorithm aimed at searching the best points for connecting distributed generators. Moreover, a loss allocation technique, based on the Zbus method, is applied on the original configuration of the network to obtain a good quality initial population. An IEEE medium voltage distribution network is analysed and results are presented and discussed.

Atlantic forest fragmentation and genetic diversity of an isolated population of the Blue-manakin, Chiroxiphia caudata (Pipridae), assessed by microsatellite analyses

Habitat fragmentation is predicted to restrict gene flow, which can result in the loss of genetic variation and inbreeding depression. The Brazilian Atlantic forest has experienced extensive loss of habitats since European settlement five centuries ago, and many bird populations and species are vanishing. Genetic variability analysis in fragmented populations could be important in determining their long-term viability and for guiding management plans. Here we analyzed genetic diversity of a small understory bird, the Blue-manakins Chiroxiphia caudata (Pipridae), from an Atlantic forest fragment (112 ha) isolated 73 years ago, and from a 10,000 ha continuous forest tract (control), using orthologous microsatellite loci. Three of the nine loci tested were polymorphic. No statistically significant heterozygote loss was detected for the fragment population. Although genetic diversity, which was estimated by expected heterozygosity and allelic richness, has been lower in the fragment population in relation to the control, it was not statistically significant, suggesting that this 112 ha fragment can be sufficient to maintain a blue-manakin population large enough to avoid stochastic effects, such as inbreeding and/or genetic drift. Alternatively, it is possible that 73 years of isolation did not accumulate sufficient generations for these effects to be detected. However, some alleles have been likely lost, specially the rare ones, what is expected from genetic drift for such a small and isolated population. A high genetic differentiation was detected between populations by comparing both allelic and genotypic distributions. Only future studies in continuous areas are likely to answer if such a structure was caused by the isolation resulted from the forest fragmentation or by natural population structure.

Relief influence on the spatial distribution of the Atlantic Forest cover on the Ibiúna Plateau, SP

Several studies suggest that, on a large scale, relief conditions influence the Atlantic Forest cover. The aim of this work was to explore these relationships on a local scale, in Caucaia do Alto, on the Ibiúna Plateau. Within an area of about 78 km2, the distribution of forest cover, divided into two successional stages, was associated with relief attribute data (slope, slope orientation and altitude). The mapping of the vegetation was based on the interpretation of stereoscopic pairs of aerial photographs, from April 2000, on a scale of 1:10,000, while the relief attributes were obtained by geoprocessing from digitalized topographic maps on a scale of 1:10,000. Statistical analyses, based on qui-square tests, revealed that there was a more extensive forest cover, irrespective of the successional stage, in steeper areas (>10 degrees) located at higher altitudes (>923 m), but no influence of the slope orientation. There was no sign of direct influence of relief on the forest cover through environmental gradients that might have contributed to the forest regeneration. Likewise, there was no evidence that these results could have been influenced by the distance from roads or urban areas or with respect to permanent preservation areas. Relief seems to influence the forest cover indirectly, since agricultural land use is preferably made in flatter and lower areas. These results suggest a general distribution pattern of the forest remnants, independent of the scale of study, on which relief indirectly has a strong influence, since it determines human occupation.

Autoimmunity does not contribute to the highly prevalent glucose metabolism disturbances in a Japanese Brazilian population

The Japanese Brazilian population has one of the highest prevalences of diabetes worldwide. Despite being non-obese according to standard definitions, their body fat distribution is typically central. We investigated whether a subset of these subjects had autoantibodies that would suggest a slowly progressive form of type 1 diabetes. A total of 721 Japanese Brazilians (386 men) in the 30- to 60-year age group underwent clinical examination and laboratory procedures, including a 75-g oral glucose tolerance test and determinations of serum autoantibodies. Antibodies to glutamic acid decarboxylase (GADab) were determined by radioimmunoassay and to thyroglobulin (TGab) and thyroperoxidase (TPOab) by flow-cytometry assays. Mean body mass index was 25.2 ± 3.8 kg/m2, but waist circumference was elevated according to the Asian standards. Diabetes, impaired glucose tolerance, and impaired fasting glycemia were found in 31%, 22%, and 22%, respectively, and 53% of the subjects had metabolic syndrome. Glutamic acid decarboxylase (GADab) was positive in 4.72%, TGab in 9.6%, and TPOab in 10% of the whole sample. When participants were stratified according to the presence of thyroid antibodies, similar frequencies of GADab were found in positive and negative groups. The prevalence rates of glucose metabolism disturbances did not differ between GADab positive and negative groups. Our data did not support the view that autoimmune injury could contribute to the high prevalence of diabetes seen in Japanese Brazilians, and the presence of co-morbidities included in the spectrum of metabolic syndrome favors the classification as type 2 diabetes.

Distribution of carabid beetles in agroecosystems across spatial scales - A review

The review focuses on the questions (1) how does the spatial heterogeneity of landscape influences carabid biodiversity, and (2) what are the main factors causing this biodiversity across nested spatial scales (study point - plant association - landscape level). The analysis of recent literature indicates that the spatial distribution of carabids differs at various spatial scales, and the factors responsible for the distribution are different. At the study point level most of the communities exhibit high variability of population density and diversity, which has no correlations with soil, and sometimes, vegetation, parameters. Most of the factors that contribute to formation of the communities are stochastic, simply because patches of a factor are much smaller than the size of a distinct carabid community. At the level of plant association, soil factors begin to play the role in driving the communities. At this level, litter depth, micro-climate and vegetation composition are the main factors. At the landscape level, geological factors, such as topography, landscape geochemistry, and history are playing important roles. As a conservation measure, spatial heterogeneity should be kept at all spatial scales at the same time to maintain carabid biodiversity in agricultural areas.