Neutrino Masses and Lepton Flavour Violation in Thick Brane Scenarios

We address the issue of lepton flavour violation and neutrino masses in the ``fat-brane'' paradigm, where flavour changing processes are suppressed by localising different fermion field wave-functions at different positions (in the extra dimensions) in a thick brane. We study the consequences of suppressing lepton number violating charged lepton decays within this scenario for lepton masses and mixing angles. In particular, we find that charged lepton mass matrices are constrained to be quasi-diagonal. We further consider whether the same paradigm can be used to naturally explain small Dirac neutrino masses by considering the existence of three right-handed neutrinos in the brane, and discuss the requirements to obtain phenomenologically viable neutrino masses and mixing angles. Finally, we examine models where neutrinos obtain a small Majorana mass by breaking lepton number in a far away brane and show that, if the fat-brane paradigm is the solution to the absence of lepton number violating charged lepton decays, such models predict, in the absence of flavour symmetries, that charged lepton flavour violation will be observed in the next round of rare muon/tau decay experiments.Comment: 33 pages, 9 eps figure

A 14-year experience with kidney transplantation.

Between November, 1962 and August, 1975, 668 kidney transplants were done in 556 consecutive patients at Denver, Colorado. The Denver experience has been divided into 7 periods of time, according to the conditions of care during each period. The results in related transplantation have changed little during the decade beginning in 1966. The results in unrelated transplantation have not materially changed since 1968. The long-term patient survival after related transplantation has been better than after cadaver transplantation. The results of transplantation in 57 children ages 3 to 18 years have been slightly better than the results of adult transplantation. The outcome of kidney transplantation and the feasibility of improving this therapy with present techniques are limited by our inability to accurately match each patient with the immunologically best donor and by our inability to precisely control the immune system of the recipient. Rejection is still the main reason for graft loss, and sepsis remains the main cause of patient mortality. More specific and less toxic means of achieving graft acceptance are needed before a higher level of patient service can be realized. However, even with the tools now available, thousands of recipients throughout the world have been returned to useful lives

Preferência por estratos florestais e por substâncias odoríferas em abelhas Euglossinae (Hymenoptera, Apidae) Stratification and scents baits preferences in Euglossinae bees (Hymenoptera, Apidae)

<abstract language="eng">Euglossinae bees of two areas of Terra Firme forest, near Manaus, Amazonas, Brazil were studied. During one year the collections were done fortnightly, using traps with eight kinds of scent baits. The traps were placed in the understory and in tree crowns. Some species showed a very clear vertical stratification in the forest. The comparison between the strata studied showed that the fauna of one understory is more similar to other than fauna of crowns and the similarity between fauna of understory and fauna of crown of the the two areaswas low. Some species were specialists while most were generalists in their choice of scent baits. Some species varied its preferences during the year

The “Football is Medicine” platform—scientific evidence, large-scale implementation of evidence-based concepts and future perspectives

[No abstract available

Epidemiological and ecological aspects related to malaria in the area of influence of the lake at Porto Primavera dam, in western São Paulo State, Brazil Aspectos epidemiológicos e ecológicos relacionados à malária na área de influência do lago da Represa de Porto Primavera, região oeste do Estado de São Paulo, Brasil

A study was carried out in the area of influence of the Porto Primavera Hydroelectric Power Station, in western São Paulo State, to investigate ecological and epidemiological aspects of malaria in the area and monitor the profile of the anopheline populations following the environmental changes brought about by the construction of the lake. Mosquitoes captured were analyzed by standardized indicator species analysis (ISA) before and during different flooding phases (253 m and 257 m elevations). The local human population was studied by means of parasitological (thin/thick blood smears), molecular (PCR) and serological tests. Serological tests consisted of Enzyme Linked Immunosorbent Assay (ELISA) with synthetic peptides of the circumsporozoite protein (CSP) from classic Plasmodium vivax, P. vivax variants (VK247 and "vivax-like"), P. malariae and P. falciparum and Indirect Immunofluorescence Assay (IFA) with asexual forms of P. vivax, P. malariae and P. falciparum. The results of the entomological survey indicated that, although the Anopheles darlingi population increased after the flooding, the population density remained very low. No malaria, parasite infection or DNA was detected in the inhabitants of the study area. However, there was a low frequency of antibodies against asexual forms and a significant prevalence of antibodies against P. vivax, P. vivax variants, P. falciparum and P. malariae; the presence of these antibodies may result from recent or less recent contact with human or simian Plasmodium (a parallel study in the same area revealed the existence of a sylvatic cycle). Nevertheless, these results suggest that, as in other places where malaria is present and potential vectors circulate, the local epidemiological conditions observed could potentially support the transmission of malaria in Porto Primavera Lake if infected individuals are introduced in sufficient numbers. Further studies are required to elucidate the phenomena described in this paper.<br>Foi realizada pesquisa na área de influência do lago da Usina Hidrelétrica de Porto Primavera, região oeste do Estado de São Paulo, para estudar aspectos ecológicos e epidemiológicos da malária na localidade e acompanhar o perfil das populações de anofelinos frente às mudanças decorrentes do impacto ambiental pela formação do lago. Mosquitos capturados foram analisados pelo Índice de Abundância de Espécies Padronizado (IAEP), antes e durante o enchimento do reservatório (cotas 253 e 257 m). A população humana local foi estudada por meio de teste parasitológico (gota espessa e esfregaço sangüíneo), testes moleculares (PCR) e testes sorológicos. A sorologia consistiu na reação de ELISA com peptídeos sintéticos correspondentes à porção repetitiva da proteína circumsporozoíta (CSP) de Plasmodium vivax clássico, e suas variantes VK247 e "vivax-like", P. malariae e P. falciparum; e reação de Imunofluorescência Indireta (RIFI) com formas assexuadas de P. vivax, P. malariae e P. falciparum. Os resultados do estudo entomológico indicaram que, embora a população de Anopheles darlingi tenha aumentando após o enchimento, permaneceu em baixa densidade. Não foi detectada malária nem a presença de parasitos ou de DNA parasitário nos habitantes estudados. No entanto, foi observada baixa freqüência de anticorpos contra formas assexuadas e significativa prevalência de anticorpos contra esporozoítos de P. vivax e suas variantes, P. falciparum e P. malariae, que poderiam decorrer de contatos prévios, recentes ou não, com plasmódios humanos ou símios (o ciclo silvestre foi evidenciado em estudo paralelo realizado na mesma área). Por outro lado, estes resultados sugerem que, como em outros lugares onde existem vetores potenciais da malária, as condições epidemiológicas poderiam potencialmente permitir a transmissão da malária na área de influência do lago de Porto Primavera, se indivíduos infectados fossem introduzidos em número suficiente. Estudos adicionais deverão ser realizados para elucidar os fenômenos relatados neste artigo