Infecção natural por tripanosomatídeos (Kinetoplastida: Trypanosomatidae) em Lutzomyia umbratilis (Diptera: Psychodidae) em áreas de leishmaniose tegumentar americana no Amazonas, Brasil

Durante o período de 2002 a 2003 foram realizadas coletas de flebotomíneos em duas áreas do estado do Amazonas (Base de treinamento militar - BI1 e Tarumã Mirim). Nessas coletas foram capturadas um total de 1.440 fêmeas de Lutzomyia (Nyssomyia) umbratilis. Lu.umbratilis é a principal responsável pela transmissão da Leishmaniose Tegumentar Americana (LTA) ao norte do Rio Amazonas. Do total coletado apenas 15 espécimens (ou 1,04%) apresentaram infecção natural por tripanosomatídeos, sendo 12 na BI1 e 3 em Tarumã-Mirim. Isso representou uma taxa de infecção de 1,66% (12 dos 720 capturados em BI1) e 0,42% (3 dos 720 em Tarumã-Mirim). Estes resultados confirmam as informações prévias por outros autores de reduzidos valores de infecção natural por tripanosomatídeos em flebotomíneos, mesmo em áreas altamente endêmicas para leishmaniose.

Estrutura fitossociológica de um fragmento natural de floresta inundável em área de Campo Sujo, Lagoa da Confusão, Tocantins

Fragmentos de florestas inundáveis localizam-se naturalmente na Planície do Araguaia entre os estados de Tocantins e Mato Grosso nas áreas de Cerrado. Ocorrem sob a forma de depressões naturais, que no estado do Tocantins estão situados nas áreas de planícies de inundação, que favorecem seu alagamento, conseqüentemente, o maior tempo de retenção da água em épocas de elevada precipitação. Este estudo teve como objetivo caracterizar a estrutura de um fragmento de floresta inundável de aproximadamente um hectare, inserido em área de Campo Sujo, no município de Lagoa da Confusão, TO. Foram amostrados todos os indivíduos arbustivo-arbóreos com circunferência 1,30m do solo (CAP) > 15 cm. Ao todo, foram encontrados 665 indivíduos, 34 famílias e 49 espécies. As espécies com maior valor de cobertura, em ordem decrescente, foram Sclerolobium paniculatum var. rubiginosum (Mart. ex Tul.) Benth., Calophyllum brasiliense Cambess. e Licania apetala (E. Mey.) Fritsch. As famílias mais ricas foram Fabaceae (8), Arecaceae, Chrysobalanaceae e Vochysiaceae (3). O índice de diversidade de Shannon (H') foi de 2,97nats/ind. A distribuição de classes de diâmetro apresentou curva na forma de "J" invertido estando a maioria dos indivíduos nas sete primeiras classes.

Geographic pattern of genetic diversity in natural populations of Rosewood (Aniba rosaeodora), in the Central Amazonia

Rosewood (Aniba rosaeodora Ducke, Lauraceae) is an Amazonian evergreen tree and a source of the purest linalool, the main component of its essential oil, which is very valuable in the international perfumery market. After decades of over-exploitation it is currently considered as threatened. We evaluated the genetic diversity and its distribution in four populations in Central Amazonia. Thirty-five reliable RAPD markers were generated, of which 32 were polymorphic (91.4%). Variation was higher within the populations (76.5%; p < 0.0001) and geographic distribution contributed to population differentiation (23.4%; p < 0.0001). The Amazon River had a small influence on gene flow (3.3%; p < 0.0001), but we identified evidence of gene flow across the river. There were significant differences in marker frequencies (p < 0.05), in agreement with the low gene flow (Nm = 2.02). The correlation between genetic distance and gene flow was - 0.95 (p = 0.06) and between geographic distance and gene flow was -0.78 (p = 0.12). There was a geographic cline of variability across an East-West axis, influenced as well by the Amazon River, suggesting the river could be a barrier to gene flow. Although threatened, these Rosewood populations retain high diversity, with the highest levels in the Manaus population, which has been protected for over 42 years in a Reserve.

Mechanical performance of natural fiber-reinforced composites for the strengthening of masonry

The growing concerns regarding the environmental impact generated by the use of inorganic materials in different fields of application increased the interest towards products based on materials with low environmental impact. In recent years, researchers have turned their attention towards the development of materials obtained from renewable sources, easily recoverable or biodegradable at the end of use. In the field of civil structures, a few attempts have been done to replace the most common composites (e.g. carbon and glass fibers) by materials less harmful to the environment, as natural fibers. This work presents a comprehensive experimental research on the mechanical performance of natural fibers for the strengthening of masonry constructions. Flax, hemp, jute, sisal and coir fibers have been investigated both from physical and mechanical points of view. The fibers with better performance were tested together with three different matrices (two of organic nature) in order to produce composites. These experimental results represent a useful database for understanding the potentialities of natural fibers as strengthening systems.

Different module placements in a modular façade system for natural ventilation

Nowadays natural ventilation has gained prominence because its correct use can reduce energy consumption for cooling systems and improve thermal comfort among users. In this paper, we report on the modelling initiative, based on the wind tunnel tests that were carried out for the determination of the influence of natural ventilation in buildings. Indeed, the renewal of air in a closed environment without using an air conditioning system with mechanical elements can lead to energy savings and, in addition, provide air quality.The wind tunnel tests were carried out by varying the positioning of six ventilation modules in the façade system configuration. The modules were positioned below the window-sill (ventilated window-sill) as well as separately above and below the façade. The wind speed measurements were taken inside and outside the model for the different façades configurations to evaluate the best performance in relation to natural ventilation. The results supported the positioning of the six ventilation modules below the window-sill, forming a â ventilated window-sillâ as the most effective natural ventilation solution.

Study of natural ventilation for a modular façade system in wind tunnel tests

Wind tunnel tests are a reliable tool to determine the effect of natural ventilation on buildings. This paper presents results of wind tunnel tests conducted to evaluate the influence of ventilation modules positioning on a façade system. Modules positioning was modified, resulting in different façade configurations. The tests were carried out with the use of a model, varying the position of the ventilation modules in the façade configuration. The cases tested were six ventilation modules positioned below the window-sill (ventilated window-sill), and three ventilation modules positioned above and below the façade. The façade system proposed was movable and interchangeable so that the same basic model could be used to test the possibilities for ventilation. Wind speed measurements were taken inside and outside the model for the different façades configurations to evaluate the best performance in relation to natural ventilation. Singleâ sided and Cross ventilation were considered for wind speed measurements. Results show the use of six ventilation modules positioned below the window-sill, forming "a ventilated window-sill" is the best solution in terms of natural ventilation.

Efeito de duas intensidades de colheita de madeira na estrutura de uma floresta natural na região de Paragominas, Pará

Foram estudadas as mudanças na estrutura de 108ha de uma floresta primária submetida a duas intensidades de colheita de madeira, na Fazenda Rio Capim, pertencente à Cikel Brasil Verde Madeiras Ltda., no município de Paragominas, Pará. Os dados foram coletados, em dois períodos (2003, antes da exploração, e 2004, após a exploração) em 36 parcelas permanentes quadradas de 0,25ha, estabelecidas aleatoriamente na área, sendo12 em floresta não-explorada: Testemunha - T0; 12 em floresta explorada com colheita apenas do fuste comercial das árvores: Tratamento - T1; e 12 em floresta explorada com colheita do fuste e dos resíduos lenhosos: Tratamento - T2. Em 2003 foram registrados 4469 indivíduos com DAP > 10cm, nas 36 parcelas amostradas (9ha). Sete meses após a exploração (2004), foram observados na área 4531 indivíduos com DAP > 10cm, sendo 4330 vivos. Lecythis idatimon, Poecilanthe effusa, Rinorea flavescens, Eschweilera grandiflora, Eschweilera pedicellata, Inga sp., Protium spp., Vouacapoua americana, Guatteria poeppigiana e Eschweilera coriacea foram as dez espécies mais importantes, tanto antes como após a exploração. A estrutura da floresta, tanto no T1 como no T2, sofreu alterações significantes devido à exploração a que foi submetida. Entretanto, não foram verificadas diferenças significativas entre os três tratamentos, sugerindo que com a intensidade de exploração aplicada, mais a retirada adicional dos resíduos, a floresta manteve as características semelhantes à floresta original, apesar do menor estoque de árvores adultas de espécies comerciais. Recomendam-se estudos sobre a regeneração natural (DAP < 10cm), silvicultura pós-colheita e crescimento da floresta.

A structured inventory of spiders (Arachnida, Araneae) in natural and artificial forest gaps at Porto Urucu, Western Brazilian Amazonia

A preliminary survey of the spider fauna in natural and artificial forest gap formations at “Porto Urucu”, a petroleum/natural gas production facility in the Urucu river basin, Coari, Amazonas, Brazil is presented. Sampling was conducted both occasionally and using a protocol composed of a suite of techniques: beating trays (32 samples), nocturnal manual samplings (48), sweeping nets (16), Winkler extractors (24), and pitfall traps (120). A total of 4201 spiders, belonging to 43 families and 393 morphospecies, were collected during the dry season, in July, 2003. Excluding the occasional samples, the observed richness was 357 species. In a performance test of seven species richness estimators, the Incidence Based Coverage Estimator (ICE) was the best fit estimator, with 639 estimated species. To evaluate differences in species richness associated with natural and artificial gaps, samples from between the center of the gaps up to 300 meters inside the adjacent forest matrix were compared through the inspection of the confidence intervals of individual-based rarefaction curves for each treatment. The observed species richness was significantly higher in natural gaps combined with adjacent forest than in the artificial gaps combined with adjacent forest. Moreover, a community similarity analysis between the fauna collected under both treatments demonstrated that there were considerable differences in species composition. The significantly higher abundance of Lycosidae in artificial gap forest is explained by the presence of herbaceous vegetation in the gaps themselves. Ctenidae was significantly more abundant in the natural gap forest, probable due to the increase of shelter availability provided by the fallen trees in the gaps themselves. Both families are identified as potential indicators of environmental change related to the establishment or recovery of artificial gaps in the study area.

Regeneración natural de nueve especies maderables en un bosque intervenido de la Amazonia Boliviana

Un aspecto fundamental del manejo forestal sostenible, es el mantenimiento de la regeneración natural en los bosques aprovechados. A corto y largo plazo, el aprovechamiento forestal tiene varias consecuencias, sobre la regeneración natural de las especies forestales. Esta investigación, compara la abundancia de la regeneración natural y la distribución espacial de plántulas de nueve especies maderables, entre un bosque aprovechado y un testigo. La abundancia y estructura espacial, fue determinada mediante 55 parcelas de muestreo anidadas (20 x 20 m, 10 x 10 m), estas fueron distribuidas en 180 hectáreas en cada condición de bosque evaluado. Dentro de las parcelas de 10 x 10 m, se registraron las categorías: plántula, brinzal y latizal. En las parcelas de 20 x 20, se midieron los árboles semilleros con DAP > 20 cm. En bosque aprovechado C. racemosa, T. altissima y A. lecointei mostraron mayor abundancia total. Según categorías de regeneración, la abundancia de P. corymbosum resultó mayor en bosque aprovechado; pero en las especies C. racemosa, T. altissima, D. odorata y C. micrantha fue mayor en el bosque testigo. La abundancia de A. lecointei, P. heterophylla y Virola sp. no difirió entre sitios. Espacialmente, solo A. lecointei y Virola sp mostraron patrones diferentes entre condiciones de bosque estudiados. Estos resultados, permiten concluir que el aprovechamiento forestal, no modifica significativamente la abundancia y estructura espacial de la regeneración de todas las especies forestales, por lo que, las intensidades de extracción moderada no comprometería el potencial de la regeneración natural en bosques manejados.

Avaliação da diversidade alfa de Passalidae (Coleoptera: Scarabaeoidea) na Amazônia Colombiana (Parque Nacional Natural La Paya, Putumayo)

Este trabalho apresenta um inventário da fauna de Passalidae da região sudeste do Parque Nacional Natural La Paya, sendo a primeira coleta deste grupo de insetos para o Estado colombiano de Putumayo. As coletas, de indivíduos adultos, foram feitas durante os dias 9 a 16 de fevereiro de 2008, em percursos livres, nos quais foram revisados 80 troncos em decomposição. A porcentagem de troncos colonizados por passalídeos foi de 40%, nos quais foram coletados 225 indivíduos pertencentes a duas tribos, quatro gêneros e 16 espécies, representando entre 73-96% da riqueza estimada por curvas de acumulação de espécies. A tribo com maior riqueza foi Passalini, enquanto o gênero com maior diversidade foi Passalus Fabricius, 1792 com 12 espécies. A diversidade local do grupo estudado é alta, em comparação a outros registros obtidos na região neotropical.

Brazil nuts: determination of natural elements and aflatoxin

A study was carried out to evaluate the association of levels of radioactivity, selenium and aflatoxin in shelled Brazil nuts, which were classified in different sizes, for export. The selenium determinations were performed by inductively coupled plasma optical emission spectrometry (LOQ = 3.0 µg g-1), and aflatoxins were detected by Liquid chromatography-mass spectrometry (LOQ = 0.85 µg kg-1), recovery rates were between 92 and 100%. Radioactivity was measured by high-resolution gamma spectrometry. The selenium mean concentration was (22.7 ± 7.4) µg g-1. (n = 30). Mean activities determined for the following radium isotopes were: 15.77 Bq kg-1 for 224Ra, 104.8 Bq kg-1 for 226Ra and 99.48 Bq kg-1 for 228Ra. For 226Ra, the levels did not vary significantly with nut sizes, although such differences were observed for 224Ra and 228Ra. There was no statistically significant association between the level of selenium and the activity of radionuclides, however, there was correlation between the radionuclides. Aflatoxins above the quantification limit were not found.

Occurrence of Aelurostrongylus abstrusus (Railliet, 1898) larvae (Nematoda: Metastrongylidae) infecting Achatina (Lissachatina) fulica Bowdich, 1822 (Mollusca: Gastropoda) in the Amazon region

Achatina fulica or "giant African snail" is an exotic species, considered to be one of the world's hundred most invasive species, causing serious environmental damages. In the present study we report, for the first time, the occurrence of Aelurostrongylus abstrusus infecting A.fulica in the Amazon region. This nematode is described parasitizing mainly the pulmonary system of felines, which causes "aelurostrongilose", also known as feline cardio-pulmonary strongyloidosis. New morphometric data of third stage larvae are presented herein. The present study demonstrated that 40% of all the snails were infected by A. abstrusus. Achatina fulica specimens were collected from three different areas in Manaus namely: rural; east and west areas. The east area presents the highest prevalence of 80%. The large number of A.fulica found in inhabited areas increases the chances of emergent zoonoses, which highlights the need of further studies so as to better control this disease.

Record of the freshwater stingrays Potamotrygon brachyura and P. motoro (Chondrichthyes, Potamotrygonidae) in the lower Uruguay river, South America

Freshwater stingrays, or potamotrygonids, are restricted to Neotropical river drainages. These elasmobranchs are well adapted to freshwater environments and the number of described species gradually increases as further research is carried out. Some of the first studies on their systematics and natural history were carried out in the 1960s and 1970s in southern South America. However, there is no new published data on potamotrygonids from Uruguayan waters since then (except for local journal reports from sportive fishermen and specimens deposited in Uruguayan collections). The present study aims to record the recent occurrence of two species of potamotrygonids caught by sport fishermen, with comments on other published historical records for the same area. As many other elasmobranchs, these species have an important, but not always well understood, role in the Uruguayan rivers ecosystems.

Eficiência do nim (Azadirachta indica A. Juss) como barreira natural ao ataque de Hypsipyla grandella (Zeller) (Lepidoptera: Pyralidae) sobre o mogno (Swietenia macrophylla King)

A eficiência da espécie Azadirachta indica como barreira natural ao ataque da Hypsipyla grandella sobre o mogno em diferentes arranjos e densidades de plantio foi, avaliada. O estudo foi realizado numa área de pastagem degradada em Vigia, PA. O delineamento experimental utilizado foi em blocos ao acaso em esquema de parcelas subdivididas no tempo, com cinco repetições, sendo as formas de cultivo do mogno as parcelas, e as épocas de avaliação (meses) as subparcelas. A barreira natural formada pelo nim não evitou o ataque de H. grandella sobre o mogno, mas retardou e minimizou o ataque em plantios mistos. Para o maior controle do ataque de H. grandella, o mogno não deve ser plantado simultaneamente com o nim, mas um ano após o plantio do nim, quando este apresenta mais de três metros de altura, formando uma barreira natural mais eficaz ao ataque desta praga.

O Sinclinal de ferro de Torre de Moncorvo: um recurso mineral como catalisador de um Tempolntermitente

Dissertação de mestrado integrado em Arquitectura