363 research outputs found

    <i>Baltorussus</i> total makeover:rejuvenation and sex change in an ancient parasitoid wasp lineage

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    The Orussidae is a small and rare but phylogenetically important family of parasitoid wasps. The fossil record of the family is also very poor. Baltorussus velteni was described from Baltic amber from an allegedly female specimen. This and another recently discovered specimen are examined with microCT scanning and standard microscopy. We reveal that both the holotype and the new specimen are actually males. Furthermore, the results of the microCT scanning allow us to integrate the fossils in a morphological data set assembled for extant Orussidae. Phylogenetic analyses consistently retrieve Baltorussus as a separate basal lineage within the crown group, whereas two Cretaceous fossils are placed as stem group orussids and a Dominican amber fossil in an extant genus. Based on the positions of the fossils, we estimate that the extant Orussidae radiated in the mid-Cretaceous (approx. 100 Ma ago). This is considerably younger than a previously suggested Early Jurassic date (180 Ma ago), which was primarily based on biogeographic evidence

    The european project NURISP for nuclear reactor simulation

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    The NURISP project aims at developing the European NURESIM reference simulation platform [1] for nuclear reactor. A first version of NURESIM was delivered in 2008. 22 organizations from 14 European countries contribute to the further development of this platform. NURISP also includes a User’s Group (UG) whose members are not NURISP partners and come from the industrial nuclear sector or European and non-European R&D labs. Users can benefit from the use of the NURESIM platform, methods, results and modules and they provide concrete input and feedback on the use of these elements

    Le radio-tracking des vertébrés : conseils et techniques d’utilisation

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    Recent advances in radio- tracking small vertebrates are reviewed. Practical suggestions are made on how to build cheap transmitters which can be used in tropical as well as temperate habitats

    8. Palpação e ultrassom em éguas: ultrassonografia

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    Neste recurso educacional estão contidos 08 vídeos sobre exames e biotécnicas de reprodução de equinos. Vídeo 1: demonstra os materiais utilizados no exame ginecológico da égua. Vídeo 2: demonstra a preparação e montagem dos materiais utilizados no exame ginecológico da égua. Vídeo 3: demonstra a realização do exame ginecológico da égua. Vídeo 4: demonstra o exame do garanhão, genital externo em seus aspectos básicos, porém importantes. São procedimentos realizados em todos exames andrológicos no Reprolab/UFRGS. Vídeo 5: demonstra a preparação da Vagina Artificial (VA) para a coleta de sêmen do garanhão. Vídeo 6: demonstra a coleta de sêmen do garanhão e aspectos básicos, porém importantes, da análise do sêmen no laboratório. Vídeo 7: demonstra a Inseminação Artificial na égua, aspectos básicos porém importantes. Vídeo 8: demonstra a palpação retal e a ultrassonografia na égua. Alguns exemplos dos achados à ultrassonografia são demonstrados.Vídeo: Não é possível instalar um arquivo de vídeo. Apenas transfira-o para seu computador e abra como um arquivo comum. Arquivos de vídeo não podem ser editados, mas podem ser visualizados em players como o VLC Media Player (que é gratuito), o Windows Media Player ou o QuickTime. Os formatos mais comuns de vídeo serão executados normalmente por estes players (avi, mpeg e mp4). PDF: Estes arquivos não podem ser editados, pois é um formato fechado. Este formato permite que sejam feitas edições — como marcação de texto e comentários, além de preenchimento de formulários — caso o autor permita. Este arquivo pode ser visualizado em leitores de PDF como o Adobe Acrobat Reader ou em navegadores da web.VídeoEspera-se que a série de vídeos auxilie nas seguintes atividades: acompanhar se o aluno conhece todos os materiais utilizados em um exame ginecológico da égua; acompanhar se o aluno conhece todos os materiais utilizados e sua correta preparação para realizar o exame ginecológico da égua; verificar se o aluno entende a preparação para o exame, as etapas do exame ginecológico da égua, e o processamento das amostras coletadas; discutir a necessidade e a eficiência de uma vaginoscopia na égua. Conhecer os diferentes métodos de vaginoscopia; verificar se o aluno conheceu os diferentes modelos de VA, o funcionamento e a sua preparação e utilização; verificar se o aluno entende o método de coleta de sêmen do garanhão bem como os principais aspectos da análise laboratorial; verificar se o aluno entende os métodos de conservação do sêmen, suas aplicações, sua preparação e utilização; Vídeo 8: Verificar se o aluno entende os métodos de a palpação retal e a ultrassonografia na égua, bem como demonstrar os achados de ultrassonografias

    Birkhoff type decompositions and the Baker-Campbell-Hausdorff recursion

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    We describe a unification of several apparently unrelated factorizations arisen from quantum field theory, vertex operator algebras, combinatorics and numerical methods in differential equations. The unification is given by a Birkhoff type decomposition that was obtained from the Baker-Campbell-Hausdorff formula in our study of the Hopf algebra approach of Connes and Kreimer to renormalization in perturbative quantum field theory. There we showed that the Birkhoff decomposition of Connes and Kreimer can be obtained from a certain Baker-Campbell-Hausdorff recursion formula in the presence of a Rota-Baxter operator. We will explain how the same decomposition generalizes the factorization of formal exponentials and uniformization for Lie algebras that arose in vertex operator algebra and conformal field theory, and the even-odd decomposition of combinatorial Hopf algebra characters as well as to the Lie algebra polar decomposition as used in the context of the approximation of matrix exponentials in ordinary differential equations.Comment: accepted for publication in Comm. in Math. Phy

    Homodimerization of the Death-Associated Protein Kinase Catalytic Domain: Development of a New Small Molecule Fluorescent Reporter

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    Agence Nationale de Recherche (ANR); Centre National de la Recherche Scientifique (CNRS); University of StrasbourgBackground: Death-Associated Protein Kinase (DAPK) is a member of the Ca(2+)/calmodulin regulated serine/threonine protein kinases. Its biological function has been associated with induced cell death, and in vivo use of selective small molecule inhibitors of DAPK catalytic activity has demonstrated that it is a potential therapeutic target for treatment of brain injuries and neurodegenerative diseases. Methodology/Principal Findings: In the in vitro study presented here, we describe the homodimerization of DAPK catalytic domain and the crucial role played by its basic loop structure that is part of the molecular fingerprint of death protein kinases. Nanoelectrospray ionization mass spectrometry of DAPK catalytic domain and a basic loop mutant DAPK protein performed under a variety of conditions was used to detect the monomer-dimer interchange. A chemical biological approach was used to find a fluorescent probe that allowed us to follow the oligomerization state of the protein in solution. Conclusions/Significance: The use of this combined biophysical and chemical biology approach facilitated the elucidation of a monomer-dimer equilibrium in which the basic loop plays a key role, as well as an apparent allosteric conformational change reported by the fluorescent probe that is independent of the basic loop structure

    Origin and Manipulation of Stable Vortex Ground States in Permalloy Nanotubes

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    We present a detailed study on the static magnetic properties of individual permalloy nanotubes (NTs) with hexagonal cross-sections. Anisotropic magnetoresistance (AMR) measurements and scanning transmission X-ray microscopy (STXM) are used to investigate their magnetic ground states and its stability. We find that the magnetization in zero applied magnetic field is in a very stable vortex state. Its origin is attributed to a strong growth-induced anisotropy with easy axis perpendicular to the long axis of the tubes. AMR measurements of individual NTs in combination with micromagnetic simulations allow the determination of the magnitude of the growth-induced anisotropy for different types of NT coatings. We show that the strength of the anisotropy can be controlled by introducing a buffer layer underneath the magnetic layer. The magnetic ground states depend on the external magnetic field history and are directly imaged using STXM. Stable vortex domains can be introduced by external magnetic fields and can be erased by radio-frequency magnetic fields applied at the center of the tubes via a strip line antenna

    Hepatic Stem-like Phenotype and Interplay of Wnt/β-Catenin and Myc Signaling in Aggressive Childhood Liver Cancer

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    SummaryHepatoblastoma, the most common pediatric liver cancer, is tightly linked to excessive Wnt/β-catenin signaling. Here, we used microarray analysis to identify two tumor subclasses resembling distinct phases of liver development and a discriminating 16-gene signature. β-catenin activated different transcriptional programs in the two tumor types, with distinctive expression of hepatic stem/progenitor markers in immature tumors. This highly proliferating subclass was typified by gains of chromosomes 8q and 2p and upregulated Myc signaling. Myc-induced hepatoblastoma-like tumors in mice strikingly resembled the human immature subtype, and Myc downregulation in hepatoblastoma cells impaired tumorigenesis in vivo. Remarkably, the 16-gene signature discriminated invasive and metastatic hepatoblastomas and predicted prognosis with high accuracy

    Staphylococcus aureus synthesizes adenosine to escape host immune responses

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    Staphylococcus aureus infects hospitalized or healthy individuals and represents the most frequent cause of bacteremia, treatment of which is complicated by the emergence of methicillin-resistant S. aureus. We examined the ability of S. aureus to escape phagocytic clearance in blood and identified adenosine synthase A (AdsA), a cell wall–anchored enzyme that converts adenosine monophosphate to adenosine, as a critical virulence factor. Staphylococcal synthesis of adenosine in blood, escape from phagocytic clearance, and subsequent formation of organ abscesses were all dependent on adsA and could be rescued by an exogenous supply of adenosine. An AdsA homologue was identified in the anthrax pathogen, and adenosine synthesis also enabled escape of Bacillus anthracis from phagocytic clearance. Collectively, these results suggest that staphylococci and other bacterial pathogens exploit the immunomodulatory attributes of adenosine to escape host immune responses
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