Sobre uma nova esp��cie neotr��pica do g��nero Tanypus Meigen, 1803 (Diptera: Chironomidae, Tanypodinae)

A new neotropical species of the genus Tanypus Meigen, 1803, misidentified by Oliveira (1944) as Tanypus stellatus Coquillett, 1902, is described.

In vivo differentiation of Trypanosoma cruzi - 1. Experimental evidence of the influence of vector species on metacyclogenesis

Vector species has not hitherto been studied as influencing metacyclogenesis of Trypanosoma cruzi, while the role of the parasite strain has been frequently stressed as of dominant importance in this process. In order to fill this gap in our knowledge, metacyclogenesis was monitored in nine triatomine species. The first part of this paper presents photographs of the main and intermediate parasite stages in each vector species studied. In the second part of the study the proportional distribution of all these forms, as seen in Giemsa stained smears is summarized, thus providing an opportunity to analyze both: the length of time between the ingestion of the blood trypomastigotes and the appearance of metacyclic forms and the rates of developmental stages leading to these latter. The most remarkable observation was that metacyclogenesis rates in vivo appear to be vector dependent, reaching 50 in Rhodnius neglectus, 37 in its congener R. prolixus and being dramatically lower in the majority of Triatoma species (5 in T. sordida, 3 in T. brasiliensis and 0 in T. pseudomaculata) at the 120th day of infection. These observations suggest that through screening of different vector species it is possible to find some that are capable of minimizing or maximizing metacyclic production.

Dynamics of evolution and resistance to starvation of Triatoma vitticeps (Stal 1859) (Reduviidae: Triatominae), submitted to two different regimens of food deprivation

The resistance to starvation of Triatoma vitticeps has been analyzed comparatively, according to different regimens of food deprivation under laboratory conditions. One cohort, composed of 100 specimens of each evolutionary nymphal stage, was submitted to continuous fasting until death; the second group, arranged in the same way, was fed once on chicken. Through this work, it was possible not only to compare the results obtained from the first group with other authors' results but, also, to analyze the dynamics of evolution, molting, longevity and the increase in insect longevity, in the second group. The average values recorded for survival time revealed statistical differences between the two groups. Among the important results detected, there is one that deserves to be emphasized: the incredible increase in longevity among insects that received only one feed - an average increase in survival time that reached 2.95 to 3.30 times in nymphs of 3rd and 4th stages, respectively. One 5th stage nymph survived for up to 350 days and the females may triplicate their survival rate, what represents an important epidemiological factor. The knowledge about this type of biological characteristic of T. vitticeps may contribute to prevent the domiciliation of this species, what seems to be incipient in some municipal districts, in Brazil.

Alteration in the endogenous intestinal flora of swiss webster mice by experimental Angiostrongylus costaricensis infection

The association between worm infections and bacterial diseases has only recently been emphasized. This study examined the effect of experimental Angiostrongylus costaricensis infection on endogenous intestinal flora of Swiss Webster mice. Eight mice aging six weeks were selected for this experiment. Four were infected with A. costaricensis and the other four were used as controls. Twenty eight days after the worm infection, all mice in both groups were sacrificed and samples of the contents of the ileum and colon were obtained and cultured for aerobic and anaerobic bacteria. In the mice infected with A. costaricensis there was a significant increase in the number of bacteria of the endogenous intestinal flora, accompanied by a decrease in the number of Peptostreptococcus spp. This alteration in the intestinal flora of mice infected by the nematode may help to understand some bacterial infections described in humans.

Morphobiological aspects of Rhodnius brethesi Matta, 1919 (Hemiptera:Reduviidae) from the Upper and Middle Negro River, Amazon region of Brazil: I - scanning electron microscopy

The occurrence of autochthonous cases of Chagas disease in the Amazon region of Brazil over recent decades has motivated an intensification of studies in this area. Different species of triatomines have been identified, and ten of these have be proven to be carriers of the parasite Trypanosoma cruzi or " cruzi-like " parasites. Studies conducted in the municipalities of Santa Isabel do Rio Negro and Barcelos, located on the Upper and Middle of the Negro River, microregion of Negro River, state of Amazonas have confirmed not only that Rhodnius brethesi is present in the palm tree Leopoldinia piassaba, but also that this insect was recognized by palm fiber collectors. A morphological study of eyes, inter-ocular and inter-ocellar regions, antennae, buccula, labrum, rostrum, stridulatory sulcus and feet, including the apex of the tibia, spongy fossette and ctenidium was conducted by scanning electron microscopy. The buccula and the stridulatory sulcus presented notable differences in specimens of different genera and also of different species. These data make it possible to suggest that the details presented in these structures can be included as diagnostic characteristics to be used in new dichotomous keys, thereby contributing towards studies of taxonomy and systematics and furnishing backing for comparative analysis of specimens collected from different localities.

Detection of Wuchereria bancrofti DNA in paired serum and urine samples using polymerase chain reaction-based systems

The Global Program for the Elimination of Lymphatic Filariasis (GPELF) aims to eliminate this disease by the year 2020. However, the development of more specific and sensitive tests is important for the success of the GPELF. The present study aimed to standardise polymerase chain reaction (PCR)-based systems for the diagnosis of filariasis in serum and urine. Twenty paired biological urine and serum samples from individuals already known to be positive for Wuchereria bancrofti were collected during the day. Conventional PCR and semi-nested PCR assays were optimised. The detection limit of the technique for purified W. bancrofti DNA extracted from adult worms was 10 fg for the internal systems (WbF/Wb2) and 0.1 fg by using semi-nested PCR. The specificity of the primers was confirmed experimentally by amplification of 1 ng of purified genomic DNA from other species of parasites. Evaluation of the paired urine and serum samples by the semi-nested PCR technique indicated only two of the 20 tested individuals were positive, whereas the simple internal PCR system (WbF/Wb2), which has highly promising performance, revealed that all the patients were positive using both samples. This study successfully demonstrated the possibility of using the PCR technique on urine for the diagnosis of W. bancrofti infection.

A rela����o entre a satisfa����o dos funcion��rios e a satisfa����o dos clientes: estudo nas empresas de software do munic��pio de Belo Horizonte

A ind��stria de software tem apresentado crescimento vigoroso nos ��ltimos anos, n��o s�� em termos mundiais, como tamb��m no Brasil. O segmento �� composto basicamente por empresas de pequeno porte, com utiliza����o intensiva de m��o de obra especializada. No entanto, estudos indicam que o setor pouco se preocupa com a qualifica����o de funcion��rios, talvez porque, normalmente, a demanda supere a oferta, o que relega a um plano secund��rio as preocupa����es com a gest��o de pessoas, ficando as aten����es voltadas para o desenvolvimento e a formata����o do servi��o propriamente dito. Segundo os modelos te��ricos, a participa����o dos funcion��rios �� de vital import��ncia para o fornecimento de um servi��o de qualidade, podendo acarretar a satisfa����o dos clientes, sua lealdade e, consequentemente, incrementar a rentabilidade da organiza����o. A satisfa����o dos funcion��rios pode ser alcan��ada pela introdu����o de pr��ticas adequadas de gerenciamento de recursos humanos, incluindo boa comunica����o, treinamento e desenvolvimento, trabalho em equipe, incentivo �� participa����o e poder de decis��o. Diversos modelos foram propostos para avaliar a satisfa����o dos clientes, a qual �� fruto da qualidade percebida do servi��o, de suas expectativas e do valor percebido, de acordo com um dos modelos em quest��o. Alguns estudos relatam a exist��ncia de rela����o positiva e significativa entre satisfa����o de clientes e de funcion��rios. Nesse contexto, procurou-se avaliar qual o impacto da satisfa����o dos funcion��rios diretamente sobre a satisfa����o dos clientes, com base em um modelo te��rico que integrasse pr��ticas de Recursos Humanos e antecedentes da satisfa����o dos clientes. Por meio de pesquisa quantitativa, foram entrevistados clientes e funcion��rios de 50 empresas da ind��stria de software de Belo Horizonte (Minas Gerais, Brasil), totalizando uma amostra v��lida de 147 respondentes para cada grupo. Os dados foram avaliados com o recurso da modelagem de equa����es estruturais, pelo m��todo dos m��nimos quadrados parciais. Com base nos resultados obtidos, infere-se que as melhores pr��ticas de Recursos Humanos realmente influenciam a satisfa����o dos funcion��rios e que a qualidade percebida do servi��o influencia positivamente a satisfa����o dos clientes. Contudo, n��o se constatou rela����o significativa entre a satisfa����o dos funcion��rios e a satisfa����o dos clientes.

Himen��pteros parasit��ides (Insecta, Hymenoptera) coletados em cultura de algod��o (Gossypium hirsutum L.) (Malvaceae), no munic��pio de Ribeir��o Preto, SP, Brasil

Parasitoid Hymenoptera (Insecta, Hymenoptera) collected in a cotton (Gossypium hirsutum L.) (Malvaceae) plantation at the municipal district of Ribeir��o Preto, SP, Brazil. Parasitoid Hymenoptera were collected by using Moericke trap placed in a cotton plantation (Gossypium hirsutum L.) of the variety Delta Pine 90, during the period of February 23rd to April 3rd, 2001. A total of 16,166 specimens of parasitoids, belonging to eight superfamilies and 22 families, were collected. Encyrtidae, Trichogrammatidae, Mymaridae and Scelionidae were the most common families, being responsible for 45.14%, 19.11%, 14.33% and 6.57% of the total number of parasitoids collected, respectively. Other eigthteen families showed the relative frequency lower than 5%.

Himen��pteros parasit��ides (Insecta, Hymenoptera) coletados em cultura de soja (Glycine max (L.)) Merril (Fabaceae), no munic��pio de Nuporanga, SP, Brasil

Parasitoid Hymenoptera collected in a soybean plantation (Glycine max (L.)) Merril (Fabaceae) at the municipal district of Nuporanga, SP, Brazil. Parasitoid Hymenoptera were collected by using Moericke trap placed in a soybean plantation (Glycine max (L.) Merril) (Fabaceae) of the variety Conquista, during the period of March 24th to April 7th, 2000. A total of 4,969 specimens of parasitoids, belonging to seven superfamilies and 15 families, were collected. Scelionidae, Encyrtidae, Aphelinidae and Trichogrammatidae were the most common families, being responsible for 41.66%, 19.42%, 11.19% and 7.35% of the total number of parasitoids collected, respectively. Other eleven families showed the relative frequency lower than 5%.

Bilateral anomaly in the style of Micropygomyia schreiberi (Martins, Falc��o & Silva) (Diptera, Psychodidae)

This paper presents a specimen of phlebotomine sand fly with a bilateral anomaly in the style. Although such anomaly be rare in this group of insects, it may cause confusion in taxonomic identification and even lead to description of new species, increasing the number of synonymies. The specimen was measured and compared with the holotype and four paratypes of Micropygomyia schreiberi (Martins, Falc��o & Silva, 1975) and confirmed that it belongs, in fact, to this species.

Micorriza arbuscular e nutri����o fosf��tica na toxidez de zinco para a trema [Trema micrantha (L.) Blum.]

O objetivo deste trabalho foi avaliar os efeitos de micorriza arbuscular, do estado nutricional de P da planta e de concentra����es crescentes de P em solu����o nutritiva na toxidez de Zn para Trema micrantha (L.) Blum. Em um primeiro experimento, mudas de trema foram formadas em substrato que continha doses crescentes de P [0, 100, 200 e 400 mg dm-3 na forma de Ca(H2PO4)2] e um tratamento de inocula����o com Glomus etunicatum (Ge). Ap��s crescimento por 60 dias, as mudas foram transferidas para vasos com solu����o nutritiva de Clark, que continha 2, 75, 150 e 225 µmol L-1 de Zn, e mantidas por mais 40 dias, quando foram colhidas e avaliadas. Os efeitos do P na ameniza����o da fitotoxidez de Zn foram avaliados em outro experimento, aplicando-se, simultaneamente e de forma combinada em solu����o, doses de P (0,07; 0,5; 1 e 2 mmol L-1 fornecido por diferentes fontes) e de Zn (2, 75, 150 e 225 µmol L-1 na forma de ZnSO4.7H2O), nas quais foram cultivadas mudas de trema por 40 dias. Houve acentuada inibi����o no crescimento e na coloniza����o micorr��zica da trema em doses elevadas de Zn em solu����o (150 e 225 µmol L-1). Constatou-se que a melhoria da nutri����o fosf��tica reduziu a transloca����o do Zn das ra��zes para a parte a��rea, mas isto, assim como a coloniza����o micorr��zica, n��o resultou em favorecimento do crescimento da planta em condi����es de excesso deste metal em solu����o. No segundo experimento, verificou-se que a eleva����o na concentra����o de P em solu����o nutritiva promoveu melhoria no estado nutricional de P, conferindo prote����o �� planta do excesso de Zn. Como a especia����o qu��mica da solu����o indicou que a aplica����o de P n��o interferiu, de modo significativo, nas formas de Zn em solu����o, os resultados indicam que a a����o amenizante do P ocorre na planta, possivelmente reduzindo a transloca����o do Zn das ra��zes para a parte a��rea.

Adsor����o de c��dmio em Latossolos sob vegeta����o de mata nativa e cultivados��

Os metais pesados podem ser encontrados naturalmente em solos, em baixas concentra����es, podendo ter seus teores intensificados por meio de a����es antr��picas, tornando-se um dos entraves no manejo de solos tropicais. Esses elementos qu��micos podem ser encontrados na constitui����o de adubos org��nicos e inorg��nicos, inseticidas, fungicidas, rejeito de minera����o e lixo urbano, podendo causar s��rios danos ao ambiente e �� sa��de humana. Nesse sentido, estudos de adsor����o s��o imprescind��veis na avalia����o do comportamento de metais pesados no solo. O objetivo deste trabalho foi avaliar a influ��ncia dos atributos qu��micos, granulom��tricos e mineral��gicos sobre a adsor����o de Cd, avaliados pelos modelos de Langmuir e de Freundlich, em Latossolos que sofreram ou n��o a����o antr��pica. As amostras de solo foram coletadas da camada superficial, 0,00-0,20 m, sendo realizadas an��lises qu��micas, granulom��tricas e mineral��gicas. No estudo de adsor����o, foram usadas as concentra����es 0, 5, 25, 50, 100, 200, 300 e 400 ��g L-1 de Cd na forma de Cd(NO3)2. Para a constru����o das isotermas de adsor����o, utilizaram-se os modelos matem��ticos emp��ricos de Langmuir e Freundlich. Os dados obtidos foram analisados por meio de t��cnicas estat��sticas multivariadas, An��lise de Agrupamento e An��lise de Componentes Principais; no experimento de adsor����o os dados ajustaram-se aos modelos de Langmuir e Freundlich. Os solos com menor rela����o goethita/hematita e maior capacidade de troca de c��tions e pH apresentaram maior capacidade m��xima de adsor����o de Cd.

Characterization for plant height and flowering date in the biological species oat

The use of wild oat races in artificial hybridization with cultivated oat (Avena sativa L.) has been used as a way of increasing the variability. This work aimed to identify the variability for plant height and flowering date of groups of cultivated oat genotypes, wild introductions of A. fatua L. and segregating populations of natural crosses between A. sativa and A. fatua. Wide genetic variability was observed for both traits in the groups and between them. The wild group of A. fatua L. showed high plants with early maturity, but in the segregating group there was reduced plant height and early maturity. The wild introductions of A. fatua L. studied in this work can be used in oat breeding programs to increase genetic variability by transferring specific characters into the cultivated germ plasm.

Heran��a de caracteres do trigo relacionados �� qualidade de panifica����o

A qualidade de panifica����o possui grande import��ncia para a ind��stria e produtores de trigo, e possibilita a agrega����o de valor de mercado ao produto. O melhoramento voltado para a qualidade, por��m, tem sido dificultado pela complexidade do car��ter e pela necessidade de testes adequados para a sele����o em gera����es segregantes. O objetivo deste trabalho foi analisar a heran��a dos caracteres volume de sedimenta����o, ��ndice de sedimenta����o e teor de prote��na, em dez cruzamentos envolvendo cinco cultivares de trigo classificadas distintamente quanto �� qualidade de panifica����o. As m��dias dos genitores diferiram entre si em rela����o a todos os caracteres. Atrav��s das vari��ncias e dos par��metros gen��ticos estimados, foi detectada variabilidade nos cruzamentos, no tocante aos caracteres avaliados, o que sugere a exist��ncia de genes complementares relativos a esses caracteres. A cultivar CEP 24-Industrial contribuiu com o maior n��mero de genes para o incremento da qualidade no conjunto de cruzamentos analisados, e possui alelos favor��veis tamb��m para o teor de prote��na. Os caracteres volume e ��ndice de sedimenta����o foram fortemente associados e apresentaram herdabilidade semelhante. O teor de prote��nas influenciou as medidas de qualidade obtidas pelo teste de sedimenta����o.