929 resultados para phlebotomine sand fly larvae
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INTRODUCTION: A study on the phlebotomine sandfly fauna was carried out in an endemic area for American tegumentary leishmaniasis in the municipality of Governador Valadares, in the State of Minas Gerais, Brazil. METHODS: Captures were undertaken using HP light traps in four districts, on three nights per month, for one year (from January to December 2008). Correlations between climatic factors (temperature, relative air humidity and rainfall) and the numbers of sandflies collected was observed. RESULTS: 5,413 phlebotomine specimens were caught and were identified as belonging to 12 species. Of these specimens, 2,851 (52%) were females and 2,562 (48%) were males. CONCLUSIONS: Lutzomyia intermedia predominated (29.9% of the species caught), thus suggesting that they were responsible for transmission of American tegumentary leishmaniasis, together with L. whitmani, which was also found in the area (4.3%). The presence of L. longipalpis (11.9%), the main vector for visceral leishmaniasis in Brazil, is an important finding, which makes rigorous entomological surveillance of the area necessary.
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INTRODUCTION: In the last decades, a considerable geographic expansion of the leishmaniases in all regions of Brazil has been observed. The present study was carried out to identify the composition of the phlebotomine sandfly fauna and verify the seasonal variation of the main species after environmental changes occurred in São Vicente Férrer Municipality, State of Pernambuco, Brazil. METHODS: Captures were carried out during four consecutive nights of each month using Centers for Disease Control and Prevention light traps from September 2009 to September 2010. The correlation between the number of phlebotomine sandflies captured and climatic factors (temperature and rainfall) was evaluated. RESULTS: A total of 13,872 specimens belonging to 20 species were captured, of which, 6,247 (45%) were females, and 7,625 (55%) were males. Lutzomyia migonei was the most abundant species with 9,964 (71.8%) specimens, being predominant in the intradomicile and peridomicile areas with 108 (86.4%) and 9,746 (97%), respectively. In the forest remnants, Lutzomyia complexa 2,395 (65%) and Lutzomyia sordellii 770 (20.8%) predominated. The correlation analysis between the total number of sandflies captured and climatic factors did not show a significant influence on population density. CONCLUSIONS: The high abundance of Lutzomyia migonei and Lutzomyia complexa indicates the possibility of new cases of cutaneous leishmaniasis (CL).
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INTRODUCTION: Leishmaniasis is expanding across Brazil, including the State of Mato Grosso (MT). The aim of this study was to characterize the phlebotomine sandfly fauna at threerural settlements located in the municipality of Cáceres, MT, from August 2010 to July 2011. METHODS: Sandfly captures were conducted at the forest border and in intra and peridomicile areas with automatic light traps, biweekly, from 5pm to 6am. RESULTS: Of the 630 sandflies collected, 348 were female, and 282 were male. Captured specimens were distributed across 11 genera - Brumptomyia, Evandromyia, Expapillata, Lutzomyia, Martinsmyia, Micropygomyia, Nyssomyia, Pintomyia, Psathyromyia, Psychodopygus, and Sciopemyia - and 28 species. Among these, six species had not been marked yet in MT (Brumptomyia avellari, Br. mangabeirai, Evandromyia aldafalcaoae, Micropygomyia echinatopharynx, Micropygomyia peresi, and Pa. campograndensis). Nyssomyia whitmani was the most abundant species across ecotopes at all settlements. Interestingly, Lutzomyia longipalpis and Lutzomyia cruzi were found in sympatry. CONCLUSIONS: The disorganized occupation of the environment that is happening at the rural settlements of Mata Comprida, Laranjeira I and II could provide opportunities for the domiciliation of wild populations of phlebotomine, including vectors of leishmaniasis. Therefore, more studies are needed to understand the epidemiology of the disease in these areas and its impact on the human population.
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Introduction: This work was carried out on the purpose of identifying the species of phlebotomine sandflies in the municipality of Monte Negro, state of Rondonia, Brazil, that may have been transmitting the American cutaneous leishmaniasis (ACL), and concisely describe epidemiological aspects of disease. METHODS: The epidemiologic and socioeconomical indicators were obtained from government institutions and the local Municipal Secretary of Health. Phlebotomine sandflies were captured using CDC light traps between July 2006 to July 2008. The total of 1,240 of female sandflies were examined by PCR method directed to k-DNA. RESULTS: There has been a significant decrease in the incidence of ACL of about 50% over the last ten years in the municipality. A total of 1,935 specimens of 53 sandfly species were captured, three of the genus Brumptomyia genus and 50 of the genus Lutzomyia. The predominant species was Lutzomyia acanthopharynx, Lutzomyia whitmani, Lutzomyia geniculata and Lutzomyia davisi. None were positive for Leishmania sp. CONCLUSIONS: Four sandflies species were found in the State of Rondonia for the first time: Brumptomyia brumpti, Lutzomyia tarapacaensis, Lutzomyia melloi and Lutzomyia lenti. The presence of Lutzomyia longipalpis, was also captured. Socioeconomical improvement of Brazilian economy and the increase of environmental surveillance in the last 15 years collaborated in the decrease of people exposed to vectors, reducing the incidence of ACL.
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INTRODUCTION: Angiostrongylus vasorum is a nematode that parasitizes molluscs, dogs, and even man. METHODS: The objective was to evaluate the predatory activity of the conidia of two fungal isolates of Duddingtonia flagrans (AC001 and CG722) on first-stage larvae (L1) of A. vasorum in laboratory conditions. RESULTS: At the end of the experiment, there were significant reductions (p<0.01) of 74.5% and 63.2%, on average, in the A. vasorum L1 recovered in the AC001 and CG722 treatment conditions, respectively. CONCLUSIONS: The two isolates of fungi were efficient in the capture and destruction of A. vasorum L1.
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Introduction American cutaneous leishmaniasis (ACL) has been reported in every municipality of the State of Mato Grosso, Brazil, but the transmission epidemiology remains poorly understood. Our study was developed in a rural area of the Nova Mutum municipality where four autochthonous cases of ACL were reported in 2009. Our aims were to describe the local phlebotomine sandfly fauna and to investigate the infection rates and infecting Leishmania species in the captured sandflies. Methods Entomological captures were performed bimonthly at 10 fixed sites close to the edge of a forested area between June 2011 and April 2012. Results A total of 3,743 phlebotomine sandflies belonging to 31 distinct species were captured. Approximately 75% of the specimens were females. The most abundant species (45.4%) was Lutzomyia antunesi, which was consistently captured at every site. Species that are epidemiologically important for ACL, such as L. flaviscutellata, L. whitmani and L. umbratilis, were also captured. L. antunesi and L. ubiquitalis were naturally infected by Leishmania braziliensis or Le. guyanensis, with minimum infection rates of 0.88% and 6.67%, respectively. Surprisingly, L. antunesi was infected by Le. infantum (synonym chagasi). Conclusions The natural infection of L. antunesi and L. ubiquitalis by Leishmania sp. suggests that these species might play a role in the zoonotic cycle of ACL in Nova Mutum. The presence of Le. infantum in L. antunesi suggests that there may be a risk of an outbreak of visceral leishmaniasis (VL) in Nova Mutum.
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Introduction In vitro bioassays were performed to access the larvicidal activity of crude extracts from the endophytic fungus Pestalotiopsis virgulata (Melanconiales, Amphisphaeriaceae) and the saprophytic fungus Pycnoporus sanguineus (Basidiomycetes, Polyporaceae) against the mosquitoes Aedes aegypti and Anopheles nuneztovari. Methods The extracts were tested at concentrations of 100, 200, 300, 400 and 500ppm. Ethyl acetate mycelia (EAM) extracts and liquid culture media (LCM) from Pe. virgulata and Py. sanguineus were tested against third instar larvae of Ae. aegypti and An. nuneztovari. Results The larvicidal activity of the EAM extracts from Pe. virgulata against Ae. aegypti had an LC50=101.8ppm, and the extract from the basidiomycete fungus Py. sanguineus had an LC50=156.8ppm against the Ae. aegypti larvae. The Pe. virgulata extract had an LC50=16.3ppm against the An. nuneztovari larvae, and the Py. sanguineus extract had an LC50=87.2ppm against these larvae. Conclusions These results highlight the larvicidal effect of EAM extracts from the endophyte Pe. virgulata against the two larval mosquitoes tested. Thus, Pe. virgulata and Py. sanguineus have the potential for the production of bioactive substances against larvae of these two tropical disease vectors, with An. nuneztovari being more susceptible to these extracts.
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Little is known regarding the swimming ability of the larvae of European plaice (Pleuronectes platessa) in relation to changes in total length (TL), dry weight (DW) and developmental stage, which is surprising given the importance of transport processes to the recruitment dynamics of this species in the North Sea and elsewhere. We investigated ontogenetic changes in the critical swimming speed (Ucrit) of plaice from hatching to the onset of metamorphosis (50 days post-hatch, dph) at 8 °C. The mean (±SD) TL and DW growth rates were 1.59 ± 0.81 and 7.7 ± 0.35 % d−1, respectively. Larvae were unable to swim at against a minimum current speed of <0.5 cm s−1 until 10 dph (7 mm TL), after which Ucrit significantly increased with increasing TL until the onset of metamorphosis and subsequent settlement. Mean (±SD) Ucrit was 0.38(0.35), 1.59(0.54), 2.27(0.49) and 2.99(0.37) cm s−1 for stage I (6.61 ± 2.64 mm TL), stage II (7.75 ± 0.60 mm TL), stage III (9.10 ± 1.00 mm TL) and stage IV (11.59 ± 0.85 mm TL) larvae, respectively. Larval TL, DW, DNA content, RNA content and Ucrit significantly increased, whereas sRD significantly declined as larvae developed from stage I to V. Although inter-individual differences in Ucrit (coefficient of variation, CV = 33 %) were as large as those in biochemical and morphological condition (CV’s of 21–42 %), differences in Ucrit were not significantly related to those in nutritional condition and larvae with lower DNA/DW had also better swimming abilities. These estimates should be useful to ongoing efforts to create individual- based models of the transport, foraging and growth of plaice larvae in the North Sea.
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IntroductionWe compared feces culturing in charcoal or vermiculite to obtain Strongyloides venezuelensis larvae.MethodsFeces (5g) from infected rats was mixed with vermiculite (10g) or coal (10g) in plastic cups and incubated at 28°C for 48h. Larvae were recovered using Baermann-Moraes method.ResultsSignificantly higher number of positive larval cultures were recovered from vermiculite than from charcoal (15/17 and 4/17, respectively; p < 0.001; 990.6 ± 307.5 and 215 ± 78.1 larvae, p = 0.027).ConclusionsVermiculite yields more larvae and provides cleaner pellets, improving larvae identification and facilitating their use for other purposes.
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Several studies have demonstrated that although the structure of the adult and larval zebrafish caudal fin is different, there are similarities at the cellular and molecular level that turn larval zebrafish fin fold a useful model to study the basic principles of regeneration. In this process, while the essential role for Hedgehog (Hh) signaling is well established in the adult zebrafish caudal fin system, its involvement in juvenile tissue regeneration is still unknown. The aim of this Master thesis was therefore to evaluate the contribution of the Hh signaling pathway to the larval zebrafish fin fold regeneration process. Accordingly, we analyzed the expression of several Hh signaling components through in situ hybridization. Here, we showed that several of these genes are effectively expressed in the larval regenerating fin tissue, suggesting a role for Hh signaling also during larval regeneration. However, divergence in the regulation of few Hh signaling components appears to exist between the adult and larval zebrafish fin regeneration processes. Nevertheless, similarly to adult caudal fin regeneration, when Hh signaling was blocked, by using cyclopamine, the larval fin fold regenerative outgrowth is severely impaired. Since larval zebrafish fin fold is ciliated, and primary cilia are closely related to Hh signaling regulation in vertebrate systems, we further addressed the role of primary cilia during larval fin fold regeneration process. To this end, we used the zebrafish iguana mutant, in which primary cilia are not formed, to study the modulation of Hh signaling expression during larval fin fold regeneration in the absence of primary cilia. Here, we found that several genes were expressed with a delay, coincident with the delay in the mutant fin fold regeneration observed in previous work. We show that Hh signaling in the fin fold is crucial to promote cell proliferation. When Hh signaling is blocked using cyclopamine there is a strong blockage of cell proliferation and regeneration is also blocked. Surprisingly, in iguana mutants where Hh signaling is impaired but not totally blocked, cell proliferation is not detected but regeneration still occurs. This raises the question about the requirement of cell proliferation in larvae fin fold regeneration. By blocking the cell cycle using aphidicolin we demonstrate that cell proliferation is not necessary for zebrafish larvae fin fold regeneration.
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The geographical distribution of the African Tilapia Oreochromis mossambicusin Suriname is restricted to a narrow strip of land along the Atlantic coast. Within the coastal plain, O. mossambicusoccurs in brackish lagoons, oligohaline canals, and shell-sand pit lakes. Physico-chemical characteristics and phytoplankton composition of representative Tilapia water bodies are described. Blue-green algae and fine flocculent detritus are dominant food items in the diet of the Tilapia, while Rotifera and microcrustacea are also important in the diet of larvae and juveniles. Intraspecific diet overlap among ontogenetic stages of the Tilapia did not differ significantly from 1, which means that these diets showed complete overlap. Interspecific diet overlap between the Tilapia and the indigenous armoured catfish Hoplosternum littoralewere moderate or low. The results are discussed in relation to recent developments in the Surinamese fisheries and aquaculture sector.
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Over a seven year period from 1991 to 1997, 22 species of tiger beetles, representing nine genera, were recorded near Manaus, Brazil. In the Whitewaterfloodplains along the Rio Solimões-Amazonas (Ilha de Marchantaria), three diurnal species inhabit inundation forests and six species (two diurnal, four nocturnal) live in open areas. Data on their natural history and adaptation to living conditions in floodplains are presented. Fifteen species were located on non-flooded uplands (Reserva Florestal A. Ducke). Five diurnal species inhabit the forest floor, two species are canopy dwellers, and eight species (seven diurnal, one nocturnal) live in open areas on whitesand or laterite. Only one species, Pentacomia lacordairei, was found in both floodplain and upland forests. A key to the larvae of tiger beetle genera located near Manaus is presented.
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The construction industry is responsible for high energy and raw materials consumption. Thus, it is important to minimize the high energy consumption by taking advantage of renewable energy sources and reusing industrial waste, decreasing the extraction of natural materials. The mortars with incorporation of phase change materials (PCM) have the ability to regulate the temperature inside buildings, contributing to the thermal comfort and reduction of the use of heating and cooling equipment, using only the energy supplied by the sun. The simultaneous incorporation of PCM and fly ash (FA) can reduce the energy consumption and the amount of materials landfilled. However, the addition of these materials in mortars modifies its characteristics. The main purpose of this study was the production and characterization in the fresh and hardened state of mortars with incorporation of different contents of PCM and FA. The binders studied were aerial lime, hydraulic lime, gypsum and cement. The proportion of PCM studied was 0%, 20%, 40% and 60% of the mass of the sand. The content of fly ash added to the mortars was 0%, 20%, 40% and 60% of the mass of the binder. It was possible to observe that the incorporation of PCM and fly ash in mortars caused differences in properties such as workability, microstructure, water absorption, compressive strength, flexural strength and adhesion.
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Premature degradation of ordinary Portland cement (OPC) concrete infrastructures is a current and serious problem with overwhelming costs amounting to several trillion dollars. The use of concrete surface treatments with waterproofing materials to prevent the access of aggressive substances is an important way of enhancing concrete durability. The most common surface treatments use polymeric resins based on epoxy, silicone (siloxane), acrylics, polyurethanes or polymethacrylate. However, epoxy resins have low resistance to ultraviolet radiation while polyurethanes are sensitive to high alkalinity environments. Geopolymers constitute a group of materials with high resistance to chemical attack that could also be used for coating of concrete infrastructures exposed to harsh chemical environments. This article presents results of an experimental investigation on the resistance to chemical attack (by sulfuric and nitric acid) of several materials: OPC concrete, high performance concrete (HPC), epoxy resin, acrylic painting and a fly ash based geopolymeric mortar. Three types of acids, each with high concentrations of 10%, 20% and 30%, were used to simulate long term degradation by chemical attack. The results show that the epoxy resin had the best resistance to chemical attack, irrespective of the acid type and acid concentration.
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This study deals with the characterization of masonry mortars produced with different binders and sands. Several properties of the mortars were determined, like consistence, compressive and flexural strengths, shrinkage and fracture energy. By varying the type of binder (Portland cement, hydrated lime and hydraulic lime) and the type of sand (natural or artificial), it was possible to draw some conclusions about the influence of the composition on mortars properties. The results showed that the use of Portland cement makes the achievement of high strength classes easier. This was due to the slower hardening of lime compared with cement. The results of fracture energy tests showed much higher values for artificial sand mortars when compared with natural sand ones. This is due to the higher roughness of artificial sand particles which provided better adhesion between sand and binder.