Disorder effects at low temperatures in La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3} manganites

With the aim of probing the effect of magnetic disorder in the low-temperature excitations of manganites, specific-heat measurements were performed in zero field, and in magnetic fields up to 9 T in polycrystalline samples of La_{0.7-x}Y_{x}Ca_{0.3}MnO_{3}, with Y concentrations x=0, 0.10, and 0.15. Yttrium doping yielded the appearance of a cluster-glass state, giving rise to unusual low-temperature behavior of the specific-heat. The main feature observed in the results is a strong enhancement of the specific-heat linear term, which is interpreted as a direct consequence of magnetic disorder. The analysis was further corroborated by resistivity measurements in the same compounds.Comment: 9 pages, 2 figure

Inquéritos Policiais de Homicídio no Espírito Santo: Uma Análise

Resumo: O presente trabalho buscou analisar em profundidade um determinado número de casos de homicídio consumados no estado do Espírito Santo no ano de 2012, na região metropolitana da Grande Vitória. O recorte temporal se deu pela possibilidade de acesso aos inquéritos policiais provenientes da Polícia Civil deste ano. É apresentado um panorama geral dos inquéritos no Brasil e dos específicos de homicídio no Espírito Santo, seguido de análise detalhada de oito deles, escolhidos de forma aleatória, buscando destacar nuances e particularidades a fim de determinar hipóteses, especialmente em relação às dificuldades enfrentadas pelos policiais ao trabalhar com esse tipo de crime. Além disso são discutidos conceitos como biopolítica, criminalização da pobreza, sujeição criminal, dentre outros, a fim de dialogar os dados encontrados com as teorias dos autores destes conceitos. A pesquisa teve apoio da Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) através da concessão de bolsa de mestrado e está vinculada às pesquisas Estudo da dinâmica dos padrões de homicídio no Espírito Santo em áreas de atuação do Programa Estado Presente: Serra e Cariacica; e Estudo da dinâmica dos padrões do homicídio no Espírito Santo em áreas de atuação do Programa Estado Presente: Vitória e Vila Velha, coordenadas pela professora doutora Márcia Barros Rodrigues Ferreira, que tiveram auxílio financeiro da Fundação de Amparo à Pesquisa do Espírito Santo (FAPES). Palavras-chaves: Inquérito, Homicídio, Espírito Santo, Biopolític

Map-aided navigation for emergency searches

This is the author accepted manuscript. The final version is available from the publisher via the DOI in this recordReal-time positioning of emergency personnel has been an active research topic for many years. However, studies on how to improve navigation accuracy by using prior information on the idiosyncratic motion characteristics of firefighters are scarce. This paper presents an algorithm for generating pseudo observations of position and orientation based on standard search patterns used by firefighters. The iterative closest point algorithm is used to compare walking trajectories estimated from inertial odometry with search patterns generated from digital maps. The resulting fitting errors are then used to integrate the pseudo observations into a map-aided navigation filter. Specifically, we present a sequential Monte Carlo solution where the pattern comparison is used to both update particle weights and create new particle samples. Experimental results involving professional firefighters demonstrate that the proposed pseudo observations can achieve a stable localization error of about one meter, and offer increased robustness in the presence of map errors

Magnetic behavior of the NixFe1-xNb2O6 quasi-one-dimensional system: Isolation of Ising chains by frustration

International audiencePhysical properties of the NixFe1-xNb2O6 compounds are investigated combining x-ray and neutron powder diffraction with magnetic and calorimetry measurements as well as 57Fe Mössbauer spectroscopy. This system is known to present quasi-one-dimensional magnetism with the magnetic moments arranged along weakly interacting Ising chains. Partial substitution of the magnetic ion tends to suppress the magnetic ordering observed in the end members of the series. When this happens, the low-temperature magnetic specific heat agrees well with what is expected for isolated Ising chains. The lowest temperature powder neutron-diffraction patterns exhibit evidence for the occurrence of short-range order, and analysis of these diffuse neutron-scattering patterns allow us to obtain information on the magnetic correlations. The suppression of magnetism is consistently interpreted as resulting from the magnetic-cation disorder induced by substitution, which enhances the system's tendency for frustration of geometrical origin

Two pairs of proven monozygotic twins discordant for familial amyloid neuropathy (FAP) TTR Met 30.

J Med Genet. 1999 Aug;36(8):629-32. Two pairs of proven monozygotic twins discordant for familial amyloid neuropathy (FAP) TTR Met 30. Munar-Qués M, Pedrosa JL, Coelho T, Gusmão L, Seruca R, Amorim A, Sequeiros J. Grupo de Estudio de la PAF, Palma de Mallorca, Spain. Abstract Twin studies are an important tool in medical genetics for the evaluation of the relative roles of genetic and non-genetic factors in several diseases. Familial amyloidotic polyneuropathy type I (FAP-I), TTR Met 30, was present in two sets of proven monozygotic (MZ) twins, one from Majorca and the other from Portugal. Monozygosity was established by analysis of DNA polymorphisms. Both pairs were discordant for age at onset and some clinical manifestations of FAP-I. We reviewed the differences in age at onset and clinical features in both sets and in two other pairs of presumed MZ twins with FAP-I and compared them with those in MZ twin pairs with other Mendelian disorders, such as neurofibromatosis type 1, Huntington's disease, facioscapulohumeral muscular dystrophy, and myotonic dystrophy. We conclude that, in addition to the postulated modifying genes, there must be a significant contribution from non-genetic factors to the phenotypic variability of FAP-I (age at onset and clinical expression), either because of environmental differences or stochastic events during (or after) the twinning process. PMID: 10465115 [PubMed - indexed for MEDLINE]PMCID: PMC176297