Ikaros has a crucial role in regulation of B cell receptor signaling

transcription factor Ikaros, a key regulator of hematopoiesis, has an essential role in lymphocyte development. In mice, fetal lymphoid differentiation is blocked in the absence of Ikaros, and whereas T cells develop postnatally, B cells are totally absent. The significance of Ikaros in the B cell development is evident, but how Ikaros regulates B cell function has neither been established nor previously been studied with B cells that lack Ikaros expression. Here we show that disruption of Ikaros in the chicken B cell line DT40 induces a B cell receptor (BCR) signaling defect with reduced phospholipase C gamma 2 phosphorylation and impaired intracellular calcium mobilization, which is restored by Ikaros reintroduction. Furthermore, we show that lack of Ikaros induces hyperphosphorylation of Casitas B lymphoma protein subsequent to BCR activation. These results indicate that the absolute need of Ikaros for development, cell fate decisions and maintenance of B cells is due to the enhancement of BCR signaling

The effects of meson mixing on dilepton spectra

The effect of scalar and vector meson mixing on the dilepton radiation from hot and dense hadronic matter is estimated in different isospin channels. In particular, we study the effect of $\sigma$-$\omega$ and $\rho-a_0$ mixing and calculate the corresponding rates. Effects are found to be significant compared to standard $\pi$-$\pi$ and $K$-${\bar K}$ annihilations. While the mixing in the isoscalar channel mostly gives a contribution in the invariant mass range between the two-pion threshold and the $\omega$ peak, the isovector channel mixing induces an additional peak just below that of the $\phi$. Experimentally, the dilepton signals from $\rho$-$a_0$ mixing seem to be more tractable than those from $\sigma$-$\omega$ mixing.Comment: 10 pages, 9 figure

tau-->eta(eta')2pi nu, 3pi nu and WZW anomaly

The effects of the anomalous contact terms are taken into account in tau to eta(eta')2pi nu decay. tau to 3pi nu is computed. Theoretical result agrees with data. It is the first time the anomalous vertex eta aa is tested. An a_{1} resonance is predicted in the final state. The decay rate of tau to eta'3pi nu is predicted.Comment: 15 pages, one latex file for the paper and one p-script file for the figur

Humanização no contexto da formação em obstetrícia Humanization in the context of obstetric training

O artigo propõe uma reflexão acerca do tema da humanização do parto no contexto da formação em obstetrícia, fundamentalmente instigada pela contribuição de uma etnografia do processo de ensino-aprendizagem em medicina nessa área. As técnicas de pesquisa utilizadas foram observação participante, entrevistas semi-estruturadas e pesquisa documental. Apresenta-se o material etnográfico produzido no acompanhamento de um curso oferecido pelo Departamento de Obstetrícia e Ginecologia de conceituada faculdade de medicina em São Paulo e de visitas de seus alunos a serviços públicos de "assistência humanizada" e suas repercussões no ensino da atenção ao parto. Chama atenção que os embates em torno da noção de humanização contrapõem modelos de atenção apresentados nas visitas àqueles serviços ao existente no Hospital-Escola e, ainda, a modelos ideais propostos por seus professores. A discussão também põe em pauta o próprio ideal de profissão e seu campo de competências. Neste sentido, as visitas e suas repercussões constituíram também uma oportunidade de consolidação de uma identidade coletiva em formação. A dificuldade de lidar com o pluralismo de propostas de conduta, objetivo da disciplina em pauta, impede, da perspectiva do ensino, a formação do pensamento crítico e a maior autoconfiança na tomada de decisão.<br>The article discusses humanization in the context of Obstetric training, instigated by contributions from ethnography on the process of learning medicine in this field. Research techniques utilized include participant observation, primary source analysis, and in-depth interviews. Ethnographic material was produced while accompanying a course offered by the Department of Gynecology and Obstetrics of a renown São Paulo medical school and visits by students to public services offering "humanized care" in birth, as part of its curricular activities. Repercussions of these visits in class are also presented. Conflicting views on the notion of humanization contrast the models of care presented by the hospitals visited and by the Medical School Hospital, as well as ideal models of obstetric care upheld by its professors. The ensuing discussion also highlights the ideal of the medical profession and its field of competence. Thus, the visit and its repercussions were also an opportunity for further consolidating a collective identity: that of physician in training. The difficulty in dealing with pluralisms as to conducts, proposed by different schools of thought within Medicine is brought to attention. As a consequence, difficulties arise in developing a critical outlook and in gaining self-confidence in decision-making