Trypanosoma Cruzi Strains From Triatomine Collected In Bahia And Rio Grande Do Sul, Brazil.

Collection of triatomines in domestic, peridomestic and sylvatic environments in states of Bahia and Rio Grande do Sul, Northeastern and Southern Brazil respectively, and isolation of Trypanosoma cruzi strains. First, the captured triatomines were identified using insect identification keys, then their intestinal content was examined by abdominal compression, and the samples containing trypanosomatid forms were inoculated in LIT medium and Swiss mice. Six triatomine species were collected in cities in Bahia, namely Panstrongylus geniculatus (01), Triatoma melanocephala (11), T. lenti (94), T. pseudomaculata (02), T. sherlocki (26) and T. sordida (460), and two in cities in Rio Grande do Sul, namely T. circummaculata (11) and T. rubrovaria (115). Out of the specimens examined, T. cruzi was isolated from 28 triatomine divided into four different species: T. melanocephala (one), T. lenti (one), T. rubrovaria (16) and T. sordida (10). Their index of natural infection by T. cruzi was 6.4%. The isolation of T. cruzi strains from triatomines found in domestic and peridomestic areas shows the potential risk of transmission of Chagas disease in the studied cities. The maintenance of those T. cruzi strains in laboratory is intended to promote studies that facilitate the understanding of the parasite-vector-host relationship.

Chitosan Nanoparticles Loaded The Herbicide Paraquat: The Influence Of The Aquatic Humic Substances On The Colloidal Stability And Toxicity.

Polymeric nanoparticles have been developed for several applications, among them as carrier system of pesticides. However, few studies have investigated the fate of these materials in the environment in relation to colloidal stability and toxicity. In nature, humic substances are the main agents responsible for complexation with metals and organic compounds, as well as responsible for the dynamics of these nanoparticles in aquatic and terrestrial environments. In this context, the evaluation of the influence of aquatic humic substances (AHS) on the colloidal stability and toxicity of polymeric nanoparticles of chitosan/tripolyphosphate with or without paraquat was performed. In this study, the nanoparticles were prepared by the ionic gelation method and characterized by size distribution measurements (DLS and NTA), zeta potential, infrared and fluorescence spectroscopy. Allium cepa genotoxicity studies and ecotoxicity assays with the alga Pseudokirchneriella subcapitata were used to investigate the effect of aquatic humic substances (AHS) on the toxicity of this delivery system. No changes were observed in the physical-chemical stability of the nanoparticles due to the presence of AHS using DLS and NTA techniques. However some evidence of interaction between the nanoparticles and AHS was observed by infrared and fluorescence spectroscopies. The ecotoxicity and genotoxicity assays showed that humic substances can decrease the toxic effects of nanoparticles containing paraquat. These results are interesting because they are important for understanding the interaction of these nanostructured carrier systems with species present in aquatic ecosystems such as humic substances, and in this way, opening new perspectives for studies on the dynamics of these carrier systems in the ecosystem.

Engineered Nanoparticles And Organic Matter: A Review Of The State-of-the-art.

Growth in the development and production of engineered nanoparticles (ENPs) in recent years has increased the potential for interactions of these nanomaterials with aquatic and terrestrial environments. Carefully designed studies are therefore required in order to understand the fate, transport, stability, and toxicity of nanoparticles. Natural organic matter (NOM), such as the humic substances found in water, sediment, and soil, is one of the substances capable of interacting with ENPs. This review presents the findings of studies of the interaction of ENPs and NOM, and the possible effects on nanoparticle stability and the toxicity of these materials in the environment. In addition, ENPs and NOM are utilized for many different purposes, including the removal of metals and organic compounds from effluents, and the development of new electronic sensors and other devices for the detection of active substances. Discussion is therefore provided of some of the ways in which NOM can be used in the production of nanoparticles. Although there has been an increase in the number of studies in this area, further progress is needed to improve understanding of the dynamic interactions between ENPs and NOM.

Wing diagnostic characters for Culex quinquefasciatus and Culex nigripalpus (Diptera, Culicidae)

Wing diagnostic characters for Culex quinquefasciatus and Culex nigripalpus (Diptera, Culicidae). Culex quinquefasciatus and Culex nigripalpus are mosquitoes of public health interest, which can occur sympatrically in urban and semi-urban localities. Morphological identification of these species may be difficult when specimens are not perfectly preserved. In order to suggest an alternative taxonomical diagnosis, wings of these species were comparatively characterized using geometric morphometrics. Both species could be distinguished by wing shape with accuracy rates ranging from 85-100%. Present results indicate that one can identify these species relying only on wing characters when traditional taxonomical characters are not visible.

Encontro de imaturos de Anopheles cruzii em bromélias de área urbana, litoral de São Paulo

Primeiro relato da ocorrência de larvas de Anopheles (Kerteszia) cruzii, mosquito essencialmente silvestre, em bromélias de solo em área urbana do município de Ilhabela, litoral norte do estado de São Paulo. De março de 1998 a julho de 1999 foram capturadas 312 formas imaturas de An. cruzii, sendo 8,6% em bromélias do ambiente urbano, 40,1% em bromélias do periurbano e 51,3% na mata. O número médio de bromélias com An. cruzii foi de 4,0% dentre o total de pesquisadas, com valores próximos de positividade para ambiente periurbano e mata. A presença de An. cruzii no ambiente urbano provavelmente é resultante da sua ocorrência prévia na mata, aliada à elevada presença desse criadouro na área urbana, de fonte alimentar e abrigos disponíveis. Alerta-se para a possibilidade de transferência de infecções entre esses ambientes

The finding of Lutzomyia almerioi and Lutzomyia longipalpis naturally infected by Leishmania spp. in a cutaneous and canine visceral leishmaniases focus in Serra da Bodoquena, Brazil

To identify natural infections by Leishmania spp. in insect vectors of cutaneous and visceral leishmaniasis, we performed field studies in natural and anthropic environments in the Guaicurus Settlement (Bodoquena Range) of the Bonito municipality, Mato Grosso do Sul state, Brazil. From October 2002 to October 2003, a total of 1395 sandfly females were captured with Shannon and light traps and dissected in search of flagellates. The sample is composed of a total of 13 species, with Lutzomyia almerioi (59.9%) and Lutzomyia longipalpis (31.4%) predominant. Infections by flagellates were directly observed in three of the dissected of Lu. almerioi females (0.36%). To increase the sensitivity of detection, DNA extracted from pools of the 1220 dissected females (Lu. almerioi 808, Lu. longipalpis 399 and Nyssomyia whitmani 13) was subjected to small subunit rRNA-based polymerase chain reactions (SSU-PCR). DNA from Leishmania (L.) infantum chagasi was detected in at least 0.37% of Lu. almerioi females and in 0.25% of Lu. longipalpis females. The DNA of the Leishmania (Viannia) sp. was detected in 0.12% of Lu. almerioi and in 0.70% of Lu. longipalpis. Leishmania (L.) amazonensis was found in 1.25% of Lu. longipalpis. Mixed infections of L. (Leishmania) sp. and L. (Viannia) sp. were found in 0.50% of Lu. longipalpis. When considering that each positive pool contained at least a single infected specimen, we found a 1.23% rate of Leishmania spp. infection among the total population of dissected female sand flies as determined by PCR. This is the first report of natural infection by L. (L.) infantum chagasi and L. (Viannia) sp. in Lu. almerioi. It is also the first report of infection by L. (Viannia) sp. in Lu. longipalpis. The observation that Lu. longipalpis and Lu. almerioi are naturally infected by agents of both cutaneous and visceral leishmaniases suggests that these two species play a role in the transmission (continua) (continuação) of these diseases within the study area. Furthermore, the finding that Lu. longipalpis has been naturally infected by L. (L.) amazonensis and L. (Viannia) sp., and Lu. almerioi by L. (L.) infantum chagasi and L. (Viannia), suggests their participation as permissive vectors

Frozen Chicken for Wild Fish: Nutritional Transition in the Brazilian Amazon Region Determined by Carbon and Nitrogen Stable Isotope Ratios in Fingernails

Objectives: Amazonian populations are experiencing dietary changes characteristic of the nutrition transition. However, the degree of change appears to vary between urban and rural settings. To investigate this process, we determined carbon and nitrogen stable isotope ratios in fingernails and dietary intake of Amazonian populations living along a rural to urban continuum along the Solimoes River in Brazil. Methods: Carbon and nitrogen stable isotope ratios were analyzed from the fingernails of 431 volunteer subjects living in different settings ranging from rural villages, small towns to urban centers along the Solimoes River. Data from 200 dietary intake surveys were also collected using food frequency questionnaires and 24-h recall interviews in an effort to determine qualitative aspects of diet composition. Results: Fingernail delta(13)C values (mean standard deviation) were -23.2 +/- 1.3, 20.2 +/- 1.5, and 17.4 +/- 1.3 parts per thousand and delta(15)N values were 11.8 +/- 0.6, 10.4 +/- 0.8, and 10.8 +/- 0.7 parts per thousand for those living in rural villages, small towns, and major cities, respectively. We found a gradual increase in the number of food items derived from C(4) plant types (meat and sugar) and the replacement of food items derived from C(3) plant types (fish and manioc flour) with increasing size of urban centers. Conclusion: Increasing urbanization in the Brazilian Amazon is associated with a significant change in food habits with processed and industrialized products playing an increasingly important role in the diet and contributing to the nutrition transition in the region. Am. J. Hum. Biol. 23:642-650, 2011. (C) 2011 Wiley-Liss, Inc.

Impact of Commercial Search Engines and International Databases on Engineering Teaching and Research

For the last three decades, the engineering higher education and professional environments have been completely transformed by the "electronic/digital information revolution" that has included the introduction of personal computer, the development of email and world wide web, and broadband Internet connections at home. Herein the writer compares the performances of several digital tools with traditional library resources. While new specialised search engines and open access digital repositories may fill a gap between conventional search engines and traditional references, these should be not be confused with real libraries and international scientific databases that encompass textbooks and peer-reviewed scholarly works. An absence of listing in some Internet search listings, databases and repositories is not an indication of standing. Researchers, engineers and academics should remember these key differences in assessing the quality of bibliographic "research" based solely upon Internet searches.

Food habits of young and middle-aged women living outside the capital cities of Australia

Young (18-22 years) and middle-aged (45-49 years) women living in urban and rural areas of New South Wales completed a brief food frequency questionnaire as part of a wider health survey. Urban women in both age groups consumed meat less frequently than women in rural areas; and women in the less populated rural areas were more likely to eat green and yellow vegetables and least likely to eat dried beans. There were few other geographic differences in food habits. Middle-aged women consumed reduced-fat milk, fruit, vegetables, fish, biscuits and cakes significantly more frequently, and rice, pasta, full-cream milk, fried food and take-away food less frequently than younger women. Smokers in both age groups consumed fresh fruit, vegetables and breakfast cereals significantly less frequently than non-smokers, and women with low levels of habitual physical activity consumed fresh fruit and cereals less frequently than more active women. The findings suggest that strategies aimed at changing eating behaviours should be age-group-specific and targeted specifically to smokers and less active women.