Resumo A infecção de hospedeiro por parasitos é influenciada por uma série de fatores, incluindo características do hospedeiro e ambientais. Nós investigamos a relação entre sexo do hospedeiro, tamanho corporal e idade, bem como sazonalidade nos padrões de infecção por acantocéfalos em coatis (Procyonidae: Nasua nasua) e em cachorro-do-mato (Canidae: Cerdocyon thous ) do Pantanal brasileiro e quais fatores explicaram melhor a prevalência e a intensidade desses parasitos. Entre 2006 e 2009, coletamos amostras fecais desses hospedeiros e analisamos a presença de ovos de acantocéfalos. Prevalência, abundância e intensidade de ovos de acantócefálios foram calculados. A abundância de ovos foi analisada utilizando modelos lineares generalizados (GLM) com distribuição binomial negativa e os modelos foram comparados pelo critério de Akaike para verificar o efeito de fatores bióticos e abióticos. A prevalência de acantocéfalos foi maior na estação úmida em ambas as espécies de hospedeiros, mas não diferiu entre os sexos do hospedeiro; no entanto, os cachorros-do-mato adultos apresentaram maior prevalência de ovos de acantocéfalos do que em juvenis. Em contraste, a prevalência de ovos de acantocéfalos encontrados em coatis foi maior em juvenis do que em adultos. A idade do hospedeiro, a estação e a temperatura máxima foram os preditores de abundância de ovos de acantocéfalos em cachorro-do-mato, enquanto a estação e o sexo do hospedeiro foram preditores da abundância dos ovos do parasito em coatis. A importância da sazonalidade para a abundância do acantocéfalo foi clara para ambas as espécies hospedeiras. A influência dos atributos relacionados ao hospedeiro, no entanto, variou entre as espécies de hospedeiros, sendo o sexo e idade do hospedeiro fatores importantes associados à prevalência e às cargas parasitárias.

Abstract Host infection by parasites is influenced by an array of factors, including host and environmental features. We investigated the relationship between host sex, body size and age, as well as seasonality on infection patterns by acanthocephalan in coatis (Procyonidae: Nasua nasua) and in crab-eating foxes (Canidae: Cerdocyon thous ) from the Brazilian Pantanal wetlands. Between 2006 and 2009, we collected faecal samples from these hosts and analyzed for the presence of acanthocephalan eggs. Prevalence, abundance and intensity of eggs of acanthocephalans were calculated. Egg abundance was analyzed using generalized linear models (GLM) with a negative binomial distribution and models were compared by Akaike criteria to verify the effect of biotic and abiotic factors. Prevalence of acanthocephalans was higher in the wet season in both host species but did not differ between host sexes; however, adult crab-eating foxes showed higher prevalence of acanthocephalan eggs than juveniles. In contrast, prevalence of acanthocephalan eggs found in coatis was higher in coati juveniles than in adults. Host age, season and maximum temperature were the top predictors of abundance of acanthocephalan eggs in crab-eating foxes whereas season and host sex were predictors of egg abundance in coatis. The importance of seasonality for abundance of acanthocephalan was clear for both host species. The influence of host-related attributes, however, varied by host species, with host gender and host age being important factors associated with prevalence and parasite loads.

O presente trabalho objetivou realizar um estudo retrospectivo sobre os prolapsos vaginal e uterino em ovelhas atendidas no Serviço de Clínica de Bovinos e Pequenos Ruminantes (CBPR) da FMVZ/USP no período compreendido entre 2000 a 2010, no qual, foram atendidas 56 ovinos com problemas inerentes ao sistema reprodutivo, dessas, 25 apresentaram prolapso vaginal ou uterino (44,6%). O prolapso vaginal total foi o de maior frequência (72%). As ovelhas acometidas, em sua maioria, possuíam idade superior a quatro anos (64%), eram sem raça definida (44%) ou da raça Ile de France (40%). As manifestações clínicas observadas durante a maioria dos atendimentos foram: taquipnéia, taquicardia, mucosas oculares avermelhadas indicando estado de toxemia, decúbito esternal ou lateral, apatia e anorexia. O tratamento instituído para todos os casos foi a limpeza, desinfecção e reintrodução do órgão prolapsado. A sutura de Bühner foi feita em 84% dos casos e a histeropexia em um caso (4%). A evolução foi satisfatória em 80% dos casos atendidos, nos demais casos (20%) observou-se óbito da fêmea acometida. Do total de óbitos, os prolapsos vaginais foram responsáveis por 60% (3/5) e os prolapsos uterinos por 40% (2/5). A etiologia dos prolapsos não foi definida nos casos atendidos, sendo esses associados com o período pós-parto em sua maioria (56%), provavelmente associados com quadros de hipocalcemia, altas concentrações séricas de estrógeno e hipertonia uterina. Além disso, a predisposição genética não pode ser descartada.

This study aimed to conduct a retrospective study on vaginal and uterine prolapse in sheep seen at the Clinic and Surgery on Cattle and Small Ruminants (CBPR) at University of São Paulo, from 2000 to 2010. During this period, 56 sheep were treated with problems of the reproductive system. Of these, 25 ewes had vaginal or uterine prolapse (44.6%). The total vaginal prolapse was the most frequently (72%). The majority of sheep that was affected were 4 years old (64%); most were mixed breed (44%) and 40% were Ile de France. Main clinical signs were increased cardiac and respiratory rates, congested ocular mucosa, sternal or lateral recumbence, apathy and anorexia, suggesting toxemia. The treatment of all cases was the cleaning and disinfection of the prolapsed organ and its reintroduction. The Bühner suture was made in 84% of the cases. The uterus fixation was made in one case (4%). Recovered was observed in 80% of the cases and 20% of the patients died. Vaginal prolapse corresponded to 60% of the deaths and uterine prolapse to 40%. The etiology of the prolapses had not been defined, but most cases (56%) occurred during the postpartum period, probably associated with hypocalcaemia, high serum concentrations of estrogen or uterine hypertonia. Furthermore, a genetic predisposition on affected sheep cannot be discharged.

Aim. To establish a correlation between medical student learning styles (LS) and the geographical context, the curricular context and different academic levels. Subjects and methods. The study was performed in 490 undergraduate students from Medical Schools of the Universities of Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San Francisco Xavier (Sucre, Bolivia), Zaragoza and País Vasco (Spain). The instrument used was the Honey-Alonso learning style questionnaire that assesses the student preference for one of four LS: active, reflexive, theoretic and pragmatic. In addition, LS according to the Kolb inventory were also assessed. Results. Using the Kolb inventory, significant differences were found when the LS were correlated with the geographical context. While Spanish students showed a high preference for the assimilator style of learning, Chilean students resulted to be mainly accommodators, and Bolivian students were both assimilators and divergent. Comparing the LS distribution during the third course in two universities with different curricula (problem and lecture based learning), there were no significant differences. LS of medical students from a Medical School with a lecture based curriculum (University of Chile) were not significantly different during the first, the third and the fifth level of their undergraduate students. They showed a significant preference for reflexive and theoretic styles of learning. Conclusions. The present study allowed demonstrating that significant differences among the styles of learning of medical students correlated with the geographical context more than with the different curricula, or along the different courses of the career.

Objetivo. Determinar si los estilos de aprendizaje (EA) de los estudiantes de medicina se correlacionan con el contexto geográfico, con el contexto curricular o con el nivel de la carrera. Sujetos y métodos. El estudio se realizó en 490 estudiantes de las Escuelas de Medicina de las Universidades de Chile (Santiago, Chile), Nacional de Cuyo (Mendoza, Argentina), San Francisco Xavier (Sucre, Bolivia), Zaragoza y País Vasco (España). Se aplicó el cuestionario Honey-Alonso, que valora la preferencia por cada uno de cuatro EA: activo, reflexivo, teórico y pragmático. También se evaluó el EA de acuerdo al modelo de Kolb. Resultados. Al relacionar el EA con el contexto geográfico se observó que mientras los estudiantes de universidades españolas muestran un estilo preferentemente asimilador, siguiendo la denominación de Kolb, para Chile fue el acomodador y para Bolivia los estudiantes se distribuyen entre los estilos asimilador y divergente. Al comparar la distribución de los EA durante el tercer curso de medicina en dos facultades que poseen diferente currículo, no se observaron diferencias significativas. Los EA en una Facultad de Medicina con un currículo basado en asignaturas (Chile) no mostraron diferencias en los tres cursos del estudio (1.º, 3.º y 5.º), siendo preferentes los estilos reflexivo y teórico. Conclusiones. El estudio permitió establecer diferencias significativas entre los estilos de aprendizaje de los estudiantes de Medicina en relación con el contexto geográfico, más que con los diferentes currículos, o a lo largo de los distintos cursos de la carrera.

Complex conductance, sigma*(f) = <FONT FACE=Symbol>s¢</FONT>(f)+isigma"(f), measurements of polyaniline/carnauba wax composites were carried out at room temperature in samples containing different amounts of PAni. While sigma"(f) ever grows as a function of the frequency f; <FONT FACE=Symbol>s¢</FONT>(f) was observed to vary as f n(n <FONT FACE=Symbol>»</FONT> 1) in the high frequency domain, and to be frequency-independent for lower frequencies. This is the quasi-universal behavior characteristic of conduction in a disordered medium. Superposed on this, another signal was observed to occur, and the whole impedance response was then analysed in an Argand Diagram, disclosing an electrode process in series with the bulk one. An equivalent conductance expression was used to explain such electrical behavior, in which the bulk properties of the composite were represented through the Random Free Energy Barrier model, while the composite-electrode interface by a simple parallel combination of a capacitor and a resistor. From the theoretical fittings it was concluded that the increase of PAni concentration acts in the sense of increasing not only the sample conductance, but also the bulk capacitance. The separation of the bulk and the interface contributions was then achieved.

The Ca2+-modulated, dimeric proteins of the EF-hand (helix-loop-helix) type, S100A1 and S100B, that have been shown to inhibit microtubule (MT) protein assembly and to promote MT disassembly, interact with the type III intermediate filament (IF) subunits, desmin and glial fibrillary acidic protein (GFAP), with a stoichiometry of 2 mol of IF subunit/mol of S100A1 or S100B dimer and an affinity of 0.5-1.0 µM in the presence of a few micromolar concentrations of Ca2+. Binding of S100A1 and S100B results in inhibition of desmin and GFAP assemblies into IFs and stimulation of the disassembly of preformed desmin and GFAP IFs. S100A1 and S100B interact with a stretch of residues in the N-terminal (head) domain of desmin and GFAP, thereby blocking the head-to-tail process of IF elongation. The C-terminal extension of S100A1 (and, likely, S100B) represents a critical part of the site that recognizes desmin and GFAP. S100B is localized to IFs within cells, suggesting that it might have a role in remodeling IFs upon elevation of cytosolic Ca2+ concentration by avoiding excess IF assembly and/or promoting IF disassembly in vivo. S100A1, that is not localized to IFs, might also play a role in the regulation of IF dynamics by binding to and sequestering unassembled IF subunits. Together, these observations suggest that S100A1 and S100B may be regarded as Ca2+-dependent regulators of the state of assembly of two important elements of the cytoskeleton, IFs and MTs, and, potentially, of MT- and IF-based activities.