974 resultados para Bennett, Jane


Relevância:

10.00% 10.00%

Publicador:

Resumo:

Foi feito um estudo sobre a resistência ao jejum em todas as fases evolutivas e pesagens em diferentes situações nutricionais de Triatoma lecticularia (alimentado; não alimentado; na morte após o jejum) com temperatura e umidade registradas. Observou-se que os períodos de resistência das fases ninfais apresentaram médias (dias) crescentes: 1º: 45,84; 2º: 61; 3º: 88,74; 4º: 123,47; 5º 162,30. Na fase adulta as médias foram aproximadas à do 3º estádio (para os machos 88,94 e para as fêmeas 83,66). O procedimento de pesagens permitiu registrar a quantidade de sangue ingerido, a perda de peso durante o jejum e o respectivo percentual em relação ao peso inicial. Esta espécie tem assinalada sua distribuição geográfica na região Neártica, onde tem sido encontrda infectada com Trypanosoma cruzi associada a Neotoma micropus Baird e Spermophilus variagatus (Erxeleben).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The blood parasites of 15,574 birds representing 266 species of 43 families from primarily three areas in São Paulo State, Brazil were examined for haematozoa. Only 1240 (8.0% of 121 species fo 32 families were infected with blood parasites. This prevalence was similar to that reported in a previous study. Species of Haemoproteus were the most commonly encountered haematozoans (38.9%), followed by microfilaria (30.7%), Trypanosoma (13.7%), Plasmodium (7.5%) and Leucocytozoon (0.8%). Prevalence of parasitism was significantly different between the three major areas sampled. It was shown that this was due in part to differences in the avifaunas at both the familial and species levels. Prevalence varied markedly in only one of the 10 years of the study. Monthly fluctuations in prevalence were largely due to changes in relative proportions of highlytion of both. Prevalences of both microfilaria and Trypanosoma were higher than reported for any other similar survey in the world.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In order to widen the present knowledge on the biology of this species, a study on the resistance to starvation was carried out among all nymphal stages and the adult stage (male and female). All evolutive stages were weighed on precision scale in three different nutritional situations: fed, non-fed and death registered after starvation. This procedure has allowed us to calculate the amount of blood taken in each stage and during the whole cycle, the average loss of weight during starvation and its relations with the initial weight. The insects were fed on mice and after eclosion or ecdisis they were isolated for observation of the starving period. Throuhout the whole experiment they were kept in a B. O. D./DOB incubator (28ºC and 90%R.U.). The resistance to starvation of the insects has grown from the first stage on (average of 15.5 days) to the fifth stage (average of 75.64 days); on the adult stage, the resistance period was equal to the third stage with an average of 41.76 for the males and 44.82 for the females. The amount of ingested blood was greater at the fifth stage worth 34.14 mg, corresponding to 2,04 times its initial weight. The average weight loss during the starvation was greater at the adult stage (23.95 mg), corresponding to 61.52% of the total weight.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In the biological study, the development of the biological cycle of the insect under different feeding conditions was evaluated. The insects were fed on either mouse blood (c) or pigeon blood (p) using two types of rearing techniques (individual or group) at 28(graus) C and 90% relative humidity (which is equivalent to their natural environment). A fifth cycle studied, was fed on mouse blood reared on group, and mantained at laboratory environmental temperature. In the five cycles analyzed, it was found that groups on mouse blood at near natural conditions developed more rapidly (between 60 and 73 days) and had a lower rate of mortality (16.66%). The daily handling and changes in environment, of the individually reared insects, for observation of biological characteristics (no. and duration of bloodmeal, defecation and first fed of each stage) had a negative influence. None of the individuals fed on mouse or pigeon blood reached adult hood. It was found that the longevity and the fertility rate were significantly superior on couples maintained individually on mouse blood. These males had an average lifespan of 110,26 days and the females had an average lifespan of 104,46 days. The average number of eggs laid by each female was 21,26. Four couples kept in groups (five couples in each group) under the same condition, the longevity for males was 51,86 days and for females was 81,06 days. An average of 10,5 eggs were laid by each female. However, the percentage of fertile eggs was higher in couples kept in groups (72.15%) than in the individual couples (57.68%).

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The RuvA and RuvB proteins of Escherichia coli, which are induced in response to DNA damage, are important in the formation of heteroduplex DNA during genetic recombination and related recombinational repair processes. In vitro studies show that RuvA binds Holiday junctions and acts as a specificity factor that targets the RuvB ATPase, a hexameric ring protein, to the junction. Together, RuvA and RuvB promote branch migration, an ATP-dependent reaction that increases the length of the heteroduplex DNA. Electron microscopic visualization of RuvAB now provides a new insight into the mechanism of this process. We observe the formation of a tripartite protein complex in which RuvA binds the crossover and is sandwiched between two hexameric rings of RuvB. The Holliday junction within this complex adopts a square-planar structure. We propose a molecular model for branch migration, a unique feature of which is the role played by the two oppositely oriented RuvB ring motors.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In order to widen the present knowledge of this species, was done a detailed description of eggs and all nymphal stages as well as the external genitalia of the males and females using light and scanning electron microscopy. The characteristics were compared with another species of the same genus C. pilosa Barber, 1937. Observations on the male internal genitalia were also done.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Waist-hip ratio (WHR) is a measure of body fat distribution and a predictor of metabolic consequences independent of overall adiposity. WHR is heritable, but few genetic variants influencing this trait have been identified. We conducted a meta-analysis of 32 genome-wide association studies for WHR adjusted for body mass index (comprising up to 77,167 participants), following up 16 loci in an additional 29 studies (comprising up to 113,636 subjects). We identified 13 new loci in or near RSPO3, VEGFA, TBX15-WARS2, NFE2L3, GRB14, DNM3-PIGC, ITPR2-SSPN, LY86, HOXC13, ADAMTS9, ZNRF3-KREMEN1, NISCH-STAB1 and CPEB4 (P = 1.9 × 10⁻⁹ to P = 1.8 × 10⁻⁴⁰) and the known signal at LYPLAL1. Seven of these loci exhibited marked sexual dimorphism, all with a stronger effect on WHR in women than men (P for sex difference = 1.9 × 10⁻³ to P = 1.2 × 10⁻&supl;³). These findings provide evidence for multiple loci that modulate body fat distribution independent of overall adiposity and reveal strong gene-by-sex interactions.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A population dynamics study of D. maximus was caried out under laboratory condictions (28-C e 65% ñ 5% U.R.) and the methodology was the same that have been used for hearing this insects. In order to evaluate the population growth rate of this species, during a 24 months period, five colonies started with a couple recently emerged were observed. Each couple (a male and a female) was mantained in a glass container measuring 20 cm of diameter and 20 cm in height with filter paper on the botton. The insects were monthly feeding with normal mice blood, and at this day the number of eggs, nymphal stages and adults was registered. All graphical representations of the populations growth rate showed the same shape. It was found that the average of nymphal stage represented 64.31% of the hole population whereas the oviposition curved showed to be inverse to this one (28.57%) a small percentage of adults was found: males 3.85% and females 3.12%. In this study observations on the biologycal cycle, longevity and fertility rates were also carried out.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Body fat distribution is a heritable trait and a well-established predictor of adverse metabolic outcomes, independent of overall adiposity. To increase our understanding of the genetic basis of body fat distribution and its molecular links to cardiometabolic traits, here we conduct genome-wide association meta-analyses of traits related to waist and hip circumferences in up to 224,459 individuals. We identify 49 loci (33 new) associated with waist-to-hip ratio adjusted for body mass index (BMI), and an additional 19 loci newly associated with related waist and hip circumference measures (P < 5 × 10(-8)). In total, 20 of the 49 waist-to-hip ratio adjusted for BMI loci show significant sexual dimorphism, 19 of which display a stronger effect in women. The identified loci were enriched for genes expressed in adipose tissue and for putative regulatory elements in adipocytes. Pathway analyses implicated adipogenesis, angiogenesis, transcriptional regulation and insulin resistance as processes affecting fat distribution, providing insight into potential pathophysiological mechanisms.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Cytokines are important in the cell-mediated response to Schistosoma mansoni eggs. We have found that Th2 cytokine responses (e.G. IL-4 and IL-5) are argumented after egg laying begins while the response (IL-2 and IFN-*) are down regulated in S. mansoni infected mice. Treatment of mice with anti-IL-5 monoclonal antibodies (Mab) suppressed the eosinophil response almost completley but did not affect granuloma size and slightly increased hepatic fibrosis. Anti-IL-4 treatment abolished IgE responses in infected mice and decreased hepatic fibrosis slightly. Anti-IFN-* treatment had no effect on hepatic pathology. Anti-IL-2 treatment decreased granuloma size significantly and decreased hepatic fibrosis markedly. Anti-IL-2 treatment dramatically decreased IL-5 secretion by splenic cells in vitro and decreased peripheral blood and tissue eosinophilia. In contrast IL-4 secretion was unaffected and serum IgE was normal or increased. IL-2 and IFN-* secretion by splenic cells of treated mice were slightly but not significantly increased suggesting that anti-IL-2 treatment affecting Th2 rather than Th1 responses.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

The trypomastigote, epimastigote and amastigote stages of Trypanosoma corvi Stephens and Christophers, 1908 emend. Baker, 1976 from the peripheral blood, heart and bone marrow are described herein. Other trypanosomes described from the Corvidae are compared to T. corvi and their status is discussed.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

In a complete study in 25 patients with American cutaneous leishmaniasis, caused by Leishmania braziliensis complex, immunotherapeutic efficacy of parasite derived antigen (94-67 KD) has been compared to antimonial therapy. Additionally, to delineate the mechanism of therapeutic success, microscopical features of immune response in active lesions and healed or non-healed lesions following therapy were analyzed. The results showed that cure rates in immunotherapy and chemoterapy were equal (>83 por cento). The immunohistochemical changes in two therapeutic groups were also largely similar. The analysis of humoral and cellular immune response suggest that appropriate stimulation of T helper cells in the lesion site, in association with one or more cytokines, play a key role in the healing process.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

Linear measurements and derived indices of trypanosomes from species of Fennoscandian birds were compared to those reported form Trypanosoma avium, T. everetti, T. ontarioensis and T. paddae. The trypanosomes encountered in the Fennoscandian birds were identified as T. avium from Tengmalm's owl Aegolius funereus and the pied flycatcher Ficedula hypoleuca, T. everetti from the great tit Parus major and collared flycatcher F. albicollis and T. ontarioensis from the collared flycatcher; T. paddae was not seen.

Relevância:

10.00% 10.00%

Publicador:

Resumo:

A list of type specimens of 100 mosquito species deposited in the Entomological collection of the Instituto Oswaldo Cruz is presented. It includes five holotypes belonging to the subfamily Anophelinae; 56 holotypes of Culicinae and two of Toxorhynchitinae. A lectotype is designated for Toxorhynchites fluminensis. The holotypes of six nominal species - Psorophora chiquitana, Psorophora circunflava, Psorophora melanota, Psorophora lanei, Wyeomyia brucei and Uranotaenia noctivaga - previously considered non existent or of unknown location were found in the collection.