56 resultados para SPECIES DISTRIBUTION MODELS


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Brazilian studies involving entomological succession patterns in carcasses have been used to describe the necrophagous entomofauna of a determined municipality or region with forensic objectives. Following the same objectives, an ecological study with 10 calyptrate dipterans was carried out during the winter of 2007 and the summer of 2008 in the metropolitan region of the municipality of Rio de Janeiro. The aim of this study was to describe several aspects of the phenology of these species in three neighbouring areas. Carcasses of three domestic pigs (Sus scrofa L.) were used in each season as models for forensic and legal medicine investigations in the region. Temperature, relative humidity and rainfall were measured daily and their relations with population abundance of the colonising species and the decomposition stages were analysed. Ten fly species were recorded to be colonising the carcasses, five of which belonged to the Calliphoridae family, three to the Muscidae, one to the Fanniidae and one to the Sarcophagidae family. Data show preferences of these species for climatic season and decomposition stage, as well as for the studied area and suggest that short distances can significantly influence the abundance of some species.

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This study updates the geographic distributions of phlebotomine species in Central-West Brazil and analyses the climatic factors associated with their occurrence. The data were obtained from the entomology services of the state departments of health in Central-West Brazil, scientific collections and a literature review of articles from 1962-2014. Ecological niche models were produced for sandfly species with more than 20 occurrences using the Maxent algorithm and eight climate variables. In all, 2,803 phlebotomine records for 127 species were analysed. Nyssomyia whitmani,Evandromyia lenti and Lutzomyia longipalpiswere the species with the greatest number of records and were present in all the biomes in Central-West Brazil. The models, which were produced for 34 species, indicated that the Cerrado areas in the central and western regions of Central-West Brazil were climatically more suitable to sandflies. The variables with the greatest influence on the models were the temperature in the coldest months and the temperature seasonality. The results show that phlebotomine species in Central-West Brazil have different geographical distribution patterns and that climate conditions in essentially the entire region favour the occurrence of at least one Leishmania vector species, highlighting the need to maintain or intensify vector control and surveillance strategies.

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The prevalence of thermotolerant Campylobacters in mammals and birds from Southern Chile was determined. Campylobacters were isolated from 46.3% of the animals studied being C. jejuni biotipe 1 the most frequent (25.7%) followed by C. coli (17.4%) and C. jejuni biotipe 2 (3.2%).

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Introduction: In past decades, leishmaniasis burden has been low across Egypt; however, changing environment and land use has placed several parts of the country at risk. As a consequence, leishmaniasis has become a particularly difficult health problem, both for local inhabitants and for multinational military personnel. Methods: To evaluate coarse-resolution aspects of the ecology of leishmaniasis transmission, collection records for sandflies and Leishmania species were obtained from diverse sources. To characterize environmental variation across the country, we used multitemporal Land Surface Temperature (LST) and Normalized Difference Vegetation Index (NDVI) data from the Moderate Resolution Imaging Spectroradiometer (MODIS) for 2005-2011. Ecological niche models were generated using MaxEnt, and results were analyzed using background similarity tests to assess whether associations among vectors and parasites (i.e., niche similarity) can be detected across broad geographic regions. Results: We found niche similarity only between one vector species and its corresponding parasite species (i.e., Phlebotomus papatasi with Leishmania major), suggesting that geographic ranges of zoonotic cutaneous leishmaniasis and its potential vector may overlap, but under distinct environmental associations. Other associations (e.g., P. sergenti with L. major) were not supported. Mapping suitable areas for each species suggested that northeastern Egypt is particularly at risk because both parasites have potential to circulate. Conclusions: Ecological niche modeling approaches can be used as a first-pass assessment of vector-parasite interactions, offering useful insights into constraints on the geography of transmission patterns of leishmaniasis.

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Introduction The diverse and complex environmental conditions of the Amazon Basin favor the breeding and development of Anopheles species. This study aimed to describe the composition, abundance and temporal frequency of Anopheles species and to correlate these factors with precipitation, temperature and relative humidity. Methods The study was conducted in the District of Coração, State of Amapá, Brazil. Samples were collected monthly during three consecutive nights, from 6:00 PM to 10:00 PM, from December 2010 to November 2011. In addition, four 12-hour collections (i.e., 6:00 PM to 6:00 AM) were performed during this period. Results A total of 1,230 Anopheles specimens were collected. In the monthly collections, Anopheles darlingi was the predominant species, followed by An. braziliensis and An. albitarsis s.l., whereas An. darlingi, An. peryassui and An. braziliensis were the most frequent species collected in the 12-hour collections. The greatest number of anophelines was collected in September (the dry season). The highest frequency of anophelines was observed for An. darlingi during September, when there were the least rainfalls of the year, along with lower relative humidity and higher temperatures. There was little variation in the abundance of this species in other months, with the exception of slight increases in February, July and August. Conclusions The major malaria vectors, An. darlingi and An. albitarsis s.l. (likely An. marajoara), were the most abundant species collected in the study area. Consequently, prevention and control measures should be taken to prevent malaria outbreaks in the District of Coração.

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One hundred and fourteen hectares of a "terra-fiirme" rain forest 70 km north of Manaus, Amazonas, Brazil, were surveyed for leaf-cutting ant colonies (Atta spp). One half of this area was in isolated forest fragments (surrounded by pastures or second growth) of two sizes: 1 and 10 ha. The other half was in non-isolated fragments (connected to a large parch of forest) of the same sizes. Only two species occured in this forest: Atta sexdens sexdens L. and A. cepfhalotes L. The first was the most abundant species with a mean density of 0.35 colonies per ha. The mean density of A. cephalotes colonies was 0.03 per ha. The density of colonies was not significantly different between the isolated fragments and the continuous forest. Furthermore, the species composition did not change with isolation. However, pre-isolation data and long term monitoring are necessary to conclude that the isolation of a forest fragment has no effect upon Atta colonies. The non-uniform spatial distribution of Atta colonics within the "terra-firme" forest must be taken into account when selecting conservation areas in the Amazon, in order to preserve this important group of ants together with their native habitat.

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Stomata are turgor-operated valves that control water loss and CO2 uptake during photosynthesis, and thereby water relation and plant biomass accumulation is closely related to stomatal functioning. The aims of this work were to document how stomata are distributed on the leaf surface and to determine if there is any significant variation in stomatal characteristics among Amazonian tree species, and finally to study the relationship between stomatal density (S D) and tree height. Thirty five trees (>17 m tall) of different species were selected. Stomatal type, density (S D), size (S S) and stomatal distribution on the leaf surface were determined using nail polish imprints taken from both leaf surfaces. Irrespective of tree species, stomata were located only on the abaxial surface (hypostomaty), with large variation in both S D and S S among species. S D ranged from 110 mm-2 in Neea altissima to 846 mm-2 in Qualea acuminata. However, in most species S D ranges between 271 and 543 mm-2, with a negative relationship between S D and S S. We also found a positive relationship between S D and tree height (r² = 0.14, p < 0.01), but no correlation was found between S D and leaf thickness. The most common stomatal type was anomocytic (37%), followed by paracytic (26%) and anisocytic (11%). We conclude that in Amazonian tree species, stomatal distribution on the leaf surface is a response most likely dependent on the genetic background of every species, rather than a reaction to environmental changes, and that somehow S D is influenced by environmental factors dependent on tree height.

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Glandular trichomes play a major role in the morphological characterization of the Bignoniaceae. Due to their great diversity of forms and functions, this study aimed to inventory the glandular trichomes present in the aerial vegetative axis of Amphilophium magnoliifolium, Martinella obovata and Stizophyllum riparium, analyze their structure and register the participation of ants in these plants. Fresh samples from the nodal region, petiole and from medium to apical regions of the leaflet blade were fixed and processed according to usual methods in light and scanning electron microscopies. The glandular trichomes found were: peltate, capitate, stipitate, and patelliform/cupular. Peltate trichomes are the most abundant ones and present the most uniform distribution. Patelliform/cupular trichomes occur at specific regions, such as prophylls, leaflet blade and nodal regions. Martinella obovata is the only species that presents capitate and stipitate trichomes, which are widely distributed along the entire aerial vegetative axis. Ants were found in all species, mainly at nodal regions. The occurrence of the capitate-type trichome is reported for the first time to the genus.

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Distribution records of poorly-known species are currently the most explored theme in the Brazilian seabird literature. If properly evaluated, this kind of information can improve our knowledge on distribution, migration and status of occurrence of these species. In this note we present new records for six species of poorly-known seabirds in the Brazilian coast, reviewing distribution records and defining their status of occurrence in the country. We consider Chionis albus (Gmelin, 1789) a pseudo-vagrant in Brazil and define its status as a scarce seasonal visitor from southern South America. We present the first records of Leucophaeus atricilla (Linnaeus, 1758) for Trindade Island, and of Leucophaeus pipixcan (Wagler, 1831) for the state of Rio Grande do Sul, and determined that the former is a vagrant in eastern Brazil and the latter a vagrant across the country. Anous stolidus (Linnaeus, 1758) is a vagrant in southernmost Brazil. We were unable to determine if records of Chlidonias niger (Linnaeus, 1758) for Brazil and southern South America refer to vagrancy or pseudo-vagrancy. Additionally, we verified the occurrence of breeding individuals of Anous minutus Boie, 1844 on Martin Vaz Island and confirmed that there is no evidence of breeding on neighboring Trindade Island.

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We studied life history traits of females of the lizard Eurolophosaurus nanuzae (Rodrigues, 1981), an endemic species of rock outcrop habitats in southeastern Brazil. During October 2002 and 2003 we sampled three populations in sites that encompass the meridional portion of the geographic range of the species. Clutch size varied from one to three eggs, with most females carrying two eggs. Clutch size did not vary among populations, but was correlated to female body size. Only larger females produced clutches of three eggs. Females of the small-sized E. nanuzae produce eggs as large as those of medium-sized tropidurids, thus investing a considerable amount of energy to produce clutches resulting in high values of relative clutch mass.

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Species of sandflies in the oswaldoi-group of the genus Lutzomyia occuring in Venezuela are reviewed. A new species, Lutzomyia saccai n. sp. is described. A distribution map and pictorial keys for males and females are provided with notes on biological and ecological data collected in Venezuela.

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O gênero neotropical Thecomyia (Sciomyzidae) consiste de quatro espécies descritas e onze ainda não descritas (Steyskal & Knutson em preparação), sendo a maioria não muito comum. As espécies são muito próximas e grande número delas somente pode ser separado com base na genitália do macho. Somente é conhecida a biologia e uma espécie, T. limbata (Wiedermann), que, preferentemente, preda moluscos aquáticos (Abercrombie & Berg, 1975). A análise de registros de coletas de espécies relativamente raras e relativamente comuns de Thecomyia (172 especimens do Museu Goeldi coletados em Mocambo, Belém, Pará, Brasil) proporcionam informações sobre a distribuição sazonal de espécies tropicais e sua relativa abundância. Deste material 160 especimens pertencem à T. longicornis Perty e 12 à Thecomyia sp. n. A primeira foi registrada durante todos os meses do ano, mas a espécie nova somente durante junho e dezembro, sugerindo esta última uma população de adultos anual bimodal.

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An anopheline survey was carried out in two simian malaria areas in the Brazilian Amazon, Balbina and Samuel, to determine the potential vectors of Plasmodium brasilianum. The most abundant and/or acrodendrophilic anophelines in the forest and the most likely vector were Anopheles mediopunctatus, An. nuneztovari, An. oswaldoi, An. triannulatus and An. shannoni. An. darlingi and An. marajoara were captured essentially in anthropic habitats outside the forest and are unlikely to be involved in the transmission of P. brasilianum among monkeys within the forests and from monkeys to man in their surroundings in the Amazon.

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Literature from 1928 through 2004 was compiled from different document sources published in Mexico or elsewhere. From these 907 publications, we found 19 different topics of Chagas disease study in Mexico. The publications were arranged by decade and also by state. This information was used to construct maps describing the distribution of Chagas disease according to different criteria: the disease, vectors, reservoirs, and strains. One of the major problems confronting study of this zoonotic disease is the great biodiversity of the vector species; there are 30 different species, with at least 10 playing a major role in human infection. The high variability of climates and biogeographic regions further complicate study and understanding of the dynamics of this disease in each region of the country. We used a desktop Genetic Algorithm for Rule-Set Prediction procedure to provide ecological models of organism niches, offering improved flexibility for choosing predictive environmental and ecological data. This approach may help to identify regions at risk of disease, plan vector-control programs, and explore parasitic reservoir association. With this collected information, we have constructed a data base: CHAGMEX, available online in html format.