Transovarial passage of Leishmania infantum kDNA in artificially infected Rhipicephalus sanguineus

Phlebotomine sand flies are the only proven biological vectors of Leishmania parasites. However, Rhipicephalus sanguineus ticks have long been suspected to transmit Leishmania infantum in studies carried out in laboratory and natural conditions. In the present study, 5 mu l of L. infantum promastigotes (1 x 10(6) cells per ml) was injected into the hemocel through the coxa 1 of four engorged females (F1, F2, F3 and F4). Control ticks (F5 and F6) were injected with sterile phosphate-buffered saline (PBS) using the same procedure. Then, these females, their eggs, and the originated larvae were tested by real time polymerase chain reaction (real-time PCR) for the presence of L. infantum kinetoplast DNA (kDNA). Females and eggs were tested after the end of the oviposition period (about 5 weeks post-inoculation) whereas larvae were tested about 4 months after the inoculation of females. All artificially infected females were positive for L. infantum kDNA. In addition, two pools of eggs (one from F2 and other from F4) and four pools of larvae (one from each F1 and F4 and two from F2) were positive for L infantum kDNA. These results showed, for the first time, the transovarial passage of L. infantum kDNA in R. sanguineus ticks, thus suggesting that the transovarial transmission of L. infantum protozoa in ticks is worth to be investigated. (C) 2010 Elsevier Inc. All rights reserved.

Carbon hydroxylation of alkyltetrahydropyranols: A paradigm for spiroacetal biosynthesis in Bactrocera sp.

[GRAPHICS] In a number of Bactrocera species the penultimate step in the biosynthesis of spiroacetals is shown to be the hydroxylation of an alkyltetrahydropyranol followed by cyclization, The monooxygenases that catalyze this side chain hydroxylation show a strong preference for oxidation four carbons from the hemiketal center, to produce the spiroacetal, The hydroxy spiroacetals observed in Bactrocera appear to derive from direct oxidation of the parent spiroacetals and not from alternate precursors.

Host preference and host suitability in an egg-pupal fruit fly parasitoid, Fopius arisanus (Sonan) (Hym., Braconidae)

The relative oviposition rate of the parasitoid Fopius arisanus (Sonan) was investigated across three frugivorous tephritid species, Bactrocera tryoni Froggart, Bactrocera jarvisi (Tryon) and Bactrocera cucumis French. Choice and no-choice tests were both used. The suitability of these three species for sustaining larval development and survival to the adult stage was also assessed. Fopius arisanus parasitized all three tephritid species. regardless of the method of exposure, but showed stronger preference for B. tryoni and B. jarvisi over B. cucumis. Superparasitism was extremely rare. Successful development of F. arisanus varied across host species. Bactrocera tryoni yielded significantly more parasitoids than B. jarvisi, but no wasps emerged from B. cucumis puparia. Tests were set up in replicated trials. but results were not homogeneous across trials. We discuss the host relationships of F. arisanus with reference to this variation and in relation to host suitability for larval development.

Wolbachia-mediated sperm modification is dependent on the host genotype in Drosophila

Estimates of Wolbachia density in the eggs, testes and whole flies of drosophilid hosts have been unable to predict the lack of cytoplasmic incompatibility (CI) expression in so-called mod(-) variants. Consequently, the working hypothesis has been that CI expression, although related to Wolbachia density, is also governed by unknown factors that are influenced by both host and bacterial genomes. Here, we compare the behaviour of the mod(-) over-replicating Wolbachia popcorn strain in its native Drosophila melanogaster host to the same strain transinfected into a novel host, namely Drosophila simulans. We report that (i) the popcorn strain is a close relative of other D. melanogaster infections, (ii) the mod(-) status of popcorn in D. melanogaster appears to result from its inability to colonize sperm bundles, (iii) popcorn is present in the bundles in D. simulans and induces strong CI expression, which demonstrates that the bacterial strain does not lack the genetic machinery for inducing CI and that there is host-species-specific control over Wolbachia tissue tropism, and (iv) infection of sperm bundles by the mod(-) D. simulans wCof strain indicates that there are several independent routes by which a strain can be a CI non-expressor.

Olfaction in the Queensland fruit fly, Bactrocera tryoni. I: Identification of olfactory receptor neuron types responding to environmental odors

The electroantennogram method was used to investigate the number of distinct olfactory receptor neuron types responding to a range of behaviorally active volatile chemicals in gravid Queensland fruit flies, Bactrocera tryoni. Three receptor neuron types were identified. One type responds to methyl butyrate, 2-butanone, farnesene, and carbon dioxide; a second to ethanol; and a third to n-butyric acid and ammonia. The receptor neuron type responding to methyl butyrate, 2-butanone, farnesene, and carbon dioxide consists of three subtypes. The presence of a limited number of receptor neuron types responding to a diverse set of chemicals and the reception of carbon dioxide by a receptor neuron type that responds to other odorants are novel aspects of the peripheral olfactory discrimination process.

Olfaction in the Queensland fruit fly, Bactrocera tryoni. II: Response spectra and temporal encoding characteristics of the carbon dioxide receptors

Single-unit electrophysiology was used to record the nerve impulses from the carbon dioxide receptors of female Queensland fruit flies, Bactrocera tryoni. The receptors responded to stimulation in a phasic-tonic manner and also had a period of inhibition of the nerve impulses after the end of stimulation, at high stimulus intensities. The cell responding to carbon dioxide was presented with a range of environmental odorants and found to respond to methyl butyrate and 2-butanone. The coding characteristics of the carbon dioxide cell and the ability to detect other odorants are discussed, with particular reference to the known behavior of the fly.

[18O]-Oxygen incorporation reveals novel pathways in spiroacetal biosynthesis by Bactrocera cacuminata and B. cucumis

The origins of the oxygen atoms in 1,7-dioxaspiro[5.5]undecane (1) and hydroxyspiroacetal (2) from Bactrocera cacuminata, and in 2,8-dimethyl-1,7-dioxaspiro[5.5]undecane (3) and hydroxyspiroacetal (4) from B. cucumis, have been investigated by incorporation studies from both [18O2]-dioxygen and [18O]-water. Combined GC-MS examination and high-field NMR analysis have demonstrated that all oxygen atoms in 1 and 2 from B. cacuminata are dioxygen derived, but in contrast, the spiroacetals 3 and 4 from B. cucumis incorporate one ring oxygen from water and one ring oxygen (and the hydroxyl oxygen in 4) from [18O2]-dioxygen. These results reveal not only the generality of monoxygenase mediation of spiroacetal formation in Bactrocera sp., but also an unexpected complexity in their biosynthesis. A general paradigm accommodating these and other observations is presented.

Monooxygenase stereoselectivity in the biosynthesis of stereoisomeric spiroacetals in the cucumber fly, Bactrocera cucumis

The stereoselectivity of hydroxylation of alkyltetrahydropyran-2-ols (or their biological equivalents) in the formation of stereoisomers of 2,8-dimethyl-1,7-dioxaspiro[5.5]undecanes in male Bactrocera cucumis has been investigated. Racemic, (6R)-, and (6S)-6-methyl-2-[5-H-2(1)]-n-pentyltetrahydropyran-2-ol was administered under an [O-18(2)]-enriched atmosphere. The stereochemistry and isotopic composition of generated spiroacetals were monitored by combined enantioselective GC-MS. The monooxygenase(s) strongly prefers the (6S)-substrate and furnishes predominantly the (S)-alcohol and then the (2S,6R,8S)-2,8-dimethyl-1,7-dioxaspiro[5.5]undecane. The (2S,6S,8R) and (2R,6S,8S) (E,Z)-isomers appear to be derived in vivo predominantly from (R)-hydroxylation of the (6S)-tetrahydropyranol.

Role of the domestic chicken (Gallus gallus) in the epidemiology of urban visceral leishmaniasis in Brazil

Zoonotic visceral leishmaniasis (ZVL) is a serious public health problem in several Brazilian cities. Although the proximity of chicken houses is often cited as a risk factor in studies of urban ZVL, the role chickens play in the epidemiology of the disease has not been defined. Chickens attract both male and female sand flies (Lutzomyia longripalpis) but are unable to sustain Leishmania infections, and their presence may exert a zooprophylactic effect. We discuss environmental, physiologic, socioeconomic, and cultural factors related to chicken raising that could influence Le. infantum transmission in Brazilian cities and evaluate whether this practice significantly affects the risk of acquiring ZVL.

The ultrastructure and function of the silk-producing basitarsus in the Hilarini (Diptera : Ernpididae)

The tribe Hilarini (Diptera: Empididae), commonly known as dance flies, can be recognised by their swollen silk-producing prothoracic basitarsus, a male secondary sexual characteristic. The ultrastructure and function of the silk-producing basitarsus from one undescribed morphospecies of Hilarini, 'Hilarempis 20', is presented. Male H. 20 collect small parcels of diatomaceous algae from the surface of freshwater creeks that they bind with silk produced by the gland in the basitarsus. The gift is then presented to females in a nearby swarm, composed predominately of females. The basitarsus houses approximately 12 pairs of class III dermal glandular units that congregate on the ventral side of the cavity. Each gland cell has a large extracellular lumen where secretion accumulates. The lumen drains to the outside via a conducting canal encompassed by a canal cell and a duct extending through the shaft of a specialised secretory spine. The secretory spines lie in pairs in a ventral groove that runs the length of the basitarsus. A comparison of the basitarsal secretory spines with sensilla on the basitarsi of non gland-bearing legs of males, and with non gland-bearing prothoracic. basitarsi of females, suggests that the glandular units are derived from contact chemosensory sensilla. (C) 2003 Elsevier Ltd. All rights reserved.

Análise de fatores geográficos e climáticos relacionados à distribuição de Phlebotominae (Diptera: Psychodidae) em área de transmissão de leishmaniose tegumentar americana no estado do Espírito Santo, Brasil

A leishmaniose tegumentar americana (LTA) é uma doença que acomete pele e mucosas causada por parasitos dermotrópicos do gênero Leishmania Ross, 1903. Os parasitos são transmitidos através da picada de pequenos dípteros da família Psychodidae, os flebotomíneos. O município de Cariacica, Espírito Santo, Brasil, esteve nos últimos cinco anos (2009 a 2013) entre os cinco que apresentaram maior número de casos notificados no estado, segundo a Secretaria de Estado de Saúde (SESA-ES, 2014). A localidade de Roda D’Água demonstra grande importância, por concentrar elevado número de casos, contribuindo com grande parte das notificações do município. Avaliando os casos da doença na região, registrados nos prontuários médicos do serviço de referência, na Unidade de Medicina Tropical da Universidade Federal do Espírito Santo, observou-se que estes ocorriam a até 550 m de altitude, numa área que vai de 20 a 718 m. A hipótese mais provável seria a de que o fenômeno fosse relacionado aos vetores, já que o homem e os animais estariam presentes em todas as altitudes. De fevereiro de 2002 a janeiro de 2004 foram realizadas coletas mensais de flebotomíneos em Roda D’Água, que aconteciam simultaneamente em três níveis de altitude, sendo: nível 1 - até 250 m; nível 2 - entre 250 e 500m e nível 3 - acima de 500m. Em cada nível as coletas aconteciam em dois ambientes: mata e peridomicílio. As capturas eram feitas em armadilhas de Shannon modificadas e por busca ativa em repouso, com capturador de Castro. Avaliou-se o comportamento das espécies quanto à pluviosidade (períodos seco e chuvoso) e às estações do ano. Analisaram-se estatisticamente as principais espécies antropofílicas de importância epidemiológica (Falqueto, 1995). Foram calculados os índices ecológicos abundância, riqueza, diversidade, equitabilidade e dominância. Coletou-se um total de 13233 flebotomíneos, com identificação de 23 espécies. A espécie predominante foi Nyssomyia intermedia (61,12%), seguida por Pintomyia fischeri (18,20%) e Migonemyia migonei (8,68%), todas antropofílicas. Somou-se a estas a espécie Pintomyia monticola, que representou 1,67% do total de espécimes coletados e também é altamente antropofílica. As demais espécies somaram 10,10% do total de flebotomineos. A altitude influenciou a distribuição das quatro espécies analisadas, tendo Ny. intermedia e Pi. fischeri sido mais abundantes no nível 2, Mg. migonei mais abundante no nível 1 e Pi. monticola no nível 3. Em relação ao ambiente, as espécies Ny. intermedia e Mg. migonei foram estatisticamente mais abundantes no peridomicílio e Pi. monticola na mata. A distribuição de Pi. fisheri não apresentou diferença significativa entre os dois ambientes, porém foi a única afetada pelas chuvas e estações do ano, sendo a espécie mais encontrada no período seco e no inverno. Nyssomyia intermedia parece ser a principal espécie vetora da LTA em Roda D’Água, com Mg. migonei provavelmente tendo papel secundário. Pi. fisheri não parece estar envolvido localmente na transmissão da doença para humanos, apesar de já ter sido incriminado em outras regiões. A distribuição de Pi. monticola em relação à altitude e ao ambiente indica ser improvável sua participação na transmissão da LTA naquela região.

Diptera of sanitary importance associated with composting of biosolids in Argentina

OBJECTIVE: Odorous compounds produced at the biosolids composting plant in Bariloche (NW Patagonia) attract a variety of insects, mainly belonging to the order Diptera. In order to characterize these flies, collected specimens were taxonomically identified, their community characteristics were described and their sanitary and synanthropic importance and autochthonous or introduced character were determined. METHODS: Sampling was performed from October 1999 until March 2000. Adults were collected using an entomological net, and larvae and puparia were obtained from the composting material and incubated to obtain adults. Richness, abundance and sex ratio were calculated. RESULTS: A total of 9 taxa of Diptera were identified: Sarconesia chlorogaster, Phaenicia sericata, Calliphora vicina, Cochliomya macellaria, Ophyra sp, Muscina stabulans, Musca domestica, Sarcophaga sp and Fannia sp. Specimens of Anthomyiidae, Acaliptratae and one larva of Eristalis tenax were also found. Ophyra sp. was the most abundant taxa. All the captured Diptera belonged to introduced taxa. Most of them are considered to be eusynanthropic and/or hemisynanthropic and have sanitary importance as they may cause myiasis and pseudomyiasis. The high number of females registered and the finding of immature stages indicated that flies can develop their complete life cycle on biosolid composting windrows. CONCLUSIONS: The characterization of flies obtained in this study may be useful for defining locations of urban or semi-urban composting facilities. It also highlights the importance of sanitary precautions at such plants.

Análise técnica e económico-financeira de um sistema de abastecimento de veículos zero emissões integrando um sistema fotovoltaico

Com o aumento da população mundial registado nos últimos anos surgiu também uma maior procura energética. Esse aumento foi inicialmente colmatado recorrendo essencialmente a fontes de origem fóssil, pelo facto destas serem mais baratas. No entanto, essa tendência de preços baixos sofreu o primeiro abalo nos anos 70 do século passado, altura em que o preço do petróleo disparou, devido a questões políticas. Nessa altura ficou visível para os países ocidentais o quanto estes eram dependentes dos países produtores de petróleo que, em geral, são instáveis politicamente. Começou então a procura de fontes energéticas alternativas. Além da questão económica do aumento do preço dos combustíveis, existe também o problema ambiental. Os maiores responsáveis pela emissão de gases efeito estufa (GEE) são os combustíveis fósseis. Os GEE contribuem para o aquecimento global, o que origina fenómenos ambientais severos que poderão levar a mudanças climáticas significativas. As energias renováveis apresentam-se como a solução mais viável ao problema energético e ambiental que se verifica actualmente, porque permitem colmatar o aumento da procura energética de uma forma limpa e sustentável. Na sequência destes problemas surgiram nos últimos anos veículos que permitem reduzir ou mesmo eliminar o consumo de combustíveis fósseis, como os veículos híbridos eléctricos, eléctricos e a hidrogénio. Nesta dissertação analisa-se um sistema que foi pensado para ser implementado em áreas de serviço, que permite efectuar o carregamento de electric vehicles (EV) utilizando energia eléctrica de origem fotovoltaica e a produção de hidrogénio para os fuels cell electric vehicles (FCEV). É efectuada uma análise económica do sistema, uma análise ambiental e analisou-se também o impacto na redução da dependência do país em relação ao exterior, sendo ainda efectuada uma pequena análise ao sistema MOBIE. No caso dos veículos a hidrogénio, foi determinada qual seria a melhor opção em termos económicos, para a produção de hidrogénio considerando três regimes de produção: recorrendo apenas à energia eléctrica proveniente do sistema fotovoltaico, apenas à energia eléctrica da rede, ou uma combinação dos dois regimes. O sistema estudado nesta dissertação apresenta um enorme potencial a nível energético e ambiental, surgindo como alternativa para abastecer os veículos que irão permitir, no futuro, eliminar a dependência energética em relação às fontes fósseis e ao mesmo tempo diminuir a quantidade de gases efeito estufa emitidos para a atmosfera.

Les Hipparion du Portugal

This paper is concerned with Hipparion from Ribatejo, Portugal, and with the stratigraphy of the Neogene series of this region. The first two chapters are an introduction and an historical review. Paleontological study includes both a revision of the specimens accounted by ROMAN (1907) and the description of new material. Two forms were recognized, an early H. cf. primigenium, lower Vallesian in age, NM 9 mammal unit (from Archino, Vila Nova da Rainha, Aveiras de Cima), and a more advanced H. primigenium cf. melendezi. Upper Vallesian, NM 10 (possibly lowermost Turolian, NM 11) (at Azambujeira and Marmeleira). A synthesis of Middle and Upper Miocene from Ribatejo is also presented. Levels with H. p. cf. melendezi are somewhat older than «Upper Pontian», as it was previously acknowledged, they attain at the best the lowermost Turolian (approximately corresponding to «Upper Pontian»). Even higher levels may be Turolian in age, though they are not yet accurately dated. Almost all the localities are shown (tableau 11) according to its stratigraphical position; age, correspondance to mammal units from NM 5 to NM 10 (and may be also from NM 11 to NM 12), and correlation with marine formations near Lisbon are also taken in account. The stratigraphical position of localities such as Póvoa de Santarém, Quinta do Marmelal, Pero Filho, Azambujeira (lower levels), and Fonte do Pinheiro was revised; the stratigraphical position of Marmeleira was ascertained. The localities so far known correspond to NM 5 (?), NM 6, NM 8, NM 9, NM 10 and possibly to NM II and NM 12. A new interpretation (M. T. ANTUNES) of localities with oysters from Ribatejo allows a better correlation with vertebrate localities. Relationships with Serravallian transgression seem well established. Only two localities, Vila Nova da Rainha and Foz do Alviela, may possibly be correlated to V-b division of Lisbon (Langhian) with «Hispanotherium fauna». All the other localities are younger than Serravallian oyster beds. Undirect correlation shows that NM 6 localities are somewhat younger than the apogee ef Serravallian transgression (corresponding approximately to Blow's N 11 to N 13 zones based on planctonic foraminifera).