Percolation and cluster Monte Carlo dynamics for spin models

A general scheme for devising efficient cluster dynamics proposed in a previous letter [Phys.Rev.Lett. 72, 1541 (1994)] is extensively discussed. In particular the strong connection among equilibrium properties of clusters and dynamic properties as the correlation time for magnetization is emphasized. The general scheme is applied to a number of frustrated spin model and the results discussed.Comment: 17 pages LaTeX + 16 figures; will appear in Phys. Rev.

On the link between rotation, chromospheric activity and Li abundance in subgiant stars

The connection rotation-CaII emission flux-lithium abundance is analyzed for a sample of bona fide subgiant stars, with evolutionary status determined from HIPPARCOS trigonometric parallax measurements and from the Toulouse-Geneva code.Comment: 9 pages, 8 figure

Nuclear structures: Twinning and modulation in crystals

Crystal structure analysis is a standard technique routinely applied to single crystals as well as powders. However the process is not so straightforward if the crystal sample is affected by twinning or if the structure is modulated. In such cases the standard procedures are not directly applicable. The main purpose of this contribution is to show how to solve and refine such difficult structures. While for twinned structures the basic property of crystal – translation symmetry in three dimensional space–remains valid, for modulated crystals a special superspace theory must be exploited in order to describe the atomic structure with crystallographic methods generalized for superspace

Potential of Macrostomum lignano to recover from γ-ray irradiation

Stem cells are the only proliferating cells in flatworms and can be eliminated by irradiation with no damage to differentiated cells. We investigated the effect of fractionated irradiation schemes on Macrostomum lignano, namely, on survival, gene expression, morphology and regeneration. Proliferating cells were almost undetectable during the first week post-treatment. Cell proliferation and gene expression were restored within 1 month in a dose-dependent manner following exposure to up to 150 Gy irradiation. During recovery, stem cells did not cross the midline but were restricted within lateral compartments. An accumulated dose of 210 Gy resulted in a lethal phenotype. Our findings demonstrate that M. lignano represents a suitable model system for elucidating the effect of irradiation on the stem cell system in flatworms and for improving our understanding of the recovery potential of severely damaged stem-cell systems

Lead isotopic analysis of infant bone tissue dating from the Roman era via multicollector ICP-mass spectrometry

Archaeological samples originating from a cemetery of a Roman settlement, Pretorium Agrippinae (1st-3rd century A.D.), excavated near Valkenburg (The Netherlands) have been subjected to Pb isotopic analysis. The set of samples analysed consisted of infant bone tissue and possible sources of bone lead, such as the surrounding soil, garum, and lead objects (e.g., water pipes). After sample digestion with quantitative Pb recovery and subsequent quantitative and pure isolation of lead, the Pb isotopic composition was determined via multicollector ICP-mass spectrometry. The Pb isotope ratio results allowed distinction of three groups: bone, soil, and lead objects + garum. The Pb-208/Pb-206 ratio ranges were between 2.059 and 2.081 for the soils, between 2.067 and 2.085 for the bones, and between 2.087 and 2.088 for the lead objects. The garum sample is characterised by a Pb-208/Pb-206 ratio of 2.085. The bone group is situated on the mixing line between the soil and lead object groups, allowing the statement that diagenesis is not the main cause of the Pb found in the bones

Estudo da influência do glúten sobre parâmetros comportamentais e bioquímicos em animais submetidos a modelos de doenças neuropsiquiátricas: Glúten e parâmetros comportamentais e bioquímicos em animais submetidos a modelos de doenças neuropsiquiátricas

Objectives: The presence of gluten in the diet can trigger several pathophysiological processes that culminate in neuropsychiatric diseases in addition to gastrointestinal problems. In the so-called “non-celiac gluten-sensitive”, the literature data are divergent. Therefore, the objective of the present work was to evaluate the effect of treatments of different diets related to gluten content, on behavioral and biochemical parameters. Methods: C56bl/6j mice (female, N:7-10) were subjected to behavioral tests for neuropsychiatric disorders. The animals were divided into groups: G1/food enriched with 75% gluten (DEG), G2/normal diet (Nuvilab®-DNN) and G3/gluten-free diet (DIG). For the depression and anxiety tests, two additional groups were introduced (controls - positive) that received respectively Fluoxetine (20mg/kg mg), Diazepam (0.75mg/kg and galanthamine (4mg kg/kg). The animals were submitted to behavioral tests: Open field, Suspension by the tail (TSC), Elevated plus maze (LCE) and Inhibitory Avoidance (TEI). ALT, AST, fasting glucose, total cholesterol, HDL, TG) Results: The results showed that DEG triggered anxiety and depression behaviors in animals, in addition to memory deficits, it also promoted hyperglycemia,   increase in body weight,  decreased HDL and increased LDL. may lead to a malfunction of liver functions (AST and ALT) Conclusions: The results together confirm the deleterious effects caused by gluten.A presença de glúten na dieta pode ser desencadeante de vários processos fisiopatológicos que culminam em doenças neuropsiquiátricas além dos problemas gastrointestinais.  Nos chamados “sensíveis ao glúten não celíacos”, os dados da literatura são divergentes. Objetivo: avaliar o efeito dos tratamentos de diferentes dietas relacionadas ao teor de glúten, sobre parâmetros comportamentais e bioquímicos. Métodos: camundongos C56bl/6j (fêmeas, N:7-10) foram submetidos a testes comportamentais de doenças neuropsiquiátricas. Os animais foram divididos em grupos: G1/ ração enriquecida 75% de glúten (DEG), G2/dieta normal (Nuvilab®- DNN) e G3/dieta isenta de glúten (DIG). Para os testes de depressão e ansiedade, foram introduzidos dois grupos adicionais (controles – positivos) que receberam respectivamente Fluoxetina (20mg/kg mg), Diazepam (0.75mg/kg e galantamina (4mg kg/kg).  Após o período de tratamento os animais foram submetidos aos testes comportamentais: Open field (Campo aberto), Suspensão pela cauda (TSC), labirinto em cruz elevada (LCE) e esquiva inibitória (TEI). Foram realizados ensaios bioquímicos para verificar a influência da DEG sobre os parâmetros bioquímicos (ALT, AST, glicose de jejum, colesterol total, HDL, TG). Resultados: Os resultados demonstraram que DEG desencadeou comportamentos de ansiedade e depressão nos animais, além de déficits de memória. Promoveu também hiperglicemia, aumento do peso corporal, diminuição do HDL e aumento do LDL. Podendo levar à um mau funcionamento das funções hepáticas (AST e ALT). Conclusão: Os resultados em conjunto  confirmam  os efeitos deletérios causado pelo glúten. Palavras-chave: Glúten. Depressão. Ansiedade. Memória. Ensaios pré-clinicos. Camundongos