1,491 research outputs found

    Quasinormal modes of massive charged flavor branes

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    We present an analysis and classification of vector and scalar fluctuations in a D3/D7 brane setup at finite termperature and baryon density. The system is dual to an N=2 supersymmetric Yang-Mills theory with SU(N_c) gauge group and N_f hypermultiplets in the fundamental representation in the quenched approximation. We improve significantly over previous results on the quasinormal mode spectrum of D7 branes and stress their novel physical interpretation. Amongst our findings is a new purely imaginary scalar mode that becomes tachyonic at sufficiently low temperature and baryon density. We establish the existence of a critical density above which the scalar mode stays in the stable regime for all temperatures. In the vector sector we study the crossover from the hydrodynamic to the quasiparticle regime and find that it moves to shorter wavelengths for lower temperatures. At zero baryon density the quasinormal modes move toward distinct discrete attractor frequencies that depend on the momentum as we increase the temperature. At finite baryon density, however, the trajectories show a turning behavior such that for low temperature the quasinormal mode spectrum approaches the spectrum of the supersymmetric zero temperature normal modes. We interpret this as resolution of the singular quasinormal mode spectrum that appears at the limiting D7 brane embedding at vanishing baryon density.Comment: 56 pages, 40 figure

    A prospective, multi centre, randomized clinical study to compare the efficacy and safety of Ertapenem 3 days versus Ampicillin - Sulbactam 3 days in the treatment of localized community acquired intra-abdominal infection. (T.E.A. Study: Three days Ertapenem vs three days Ampicillin-sulbactam)

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    <p>Abstract</p> <p>Background</p> <p>The recommendations outlined in the latest guidelines published by the Surgical Infection Society (SIS) and the Infectious Disease Society of America (IDSA) regarding the proper duration of antibiotic therapy in patients with intra-abdominal infections are limited and non-specific. This ambiguity is due mainly to the lack of clinical trials on the topic of optimal duration of therapy. It is well known that the overuse of antibiotics has several important consequences such as increased treatment costs, reduced clinical efficacy, and above all, the increased emergence of antibiotic-resistant pathogens. Ampicillin-Sulbactam is a commonly used "first line" antibiotic for intra-abdominal infections. Ertapenem and Ampicillin-sulbactam are recommended as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines.</p> <p>Methods/Design</p> <p>This study is a prospective multi-center randomized investigation. The study will be performed in the Departments of General, Emergency, and Transplant Surgery of Sant'Orsola-Malpighi University Hospital in Bologna, Italy, in the General Surgery Department of the Ospedali Riuniti of Bergamo, Italy, and in the Trauma and Emergency Surgery Department of Maggiore Hospital in Bologna, Italy, and will be conducted by all surgeons willing to participate in the study. The inclusion period of the study will take approximately two years before the planned number of 142 enrolled patients is reached.</p> <p>Discussion</p> <p>Ertapenem and Ampicillin-sulbactam are recommended both as primary treatment agents for localized peritonitis by both the SIS and IDSA guidelines. As one of the discussed topic is the optimal duration of the antibiotic therapy and this ambiguity is due mainly to the lack of clinical trials on the topic, the present study aims for obtain precise data.</p> <p>Trial Registration</p> <p>ClinicalTrials.gov: <a href="http://www.clinicaltrials.gov/ct2/show/NCT00630513">NCT00630513</a></p

    International variation in prescribing antihypertensive drugs: Its extent and possible explanations

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    BACKGROUND: Inexpensive antihypertensive drugs are at least as effective and safe as more expensive drugs. Overuse of newer, more expensive antihypertensive drugs is a poor use of resources. The potential savings are substantial, but vary across countries, in large part due to differences in prescribing patterns. We wanted to describe prescribing patterns of antihypertensive drugs in ten countries and explore possible reasons for inter-country variation. METHODS: National prescribing profiles were determined based on information on sales and indications for prescribing. We sent a questionnaire to academics and drug regulatory agencies in Canada, France, Germany, UK, US and the Nordic countries, asking about explanations for differences in prescribing patterns in their country compared with the other countries. We also conducted telephone interviews with medical directors of drug companies in the UK and Norway, the countries with the largest differences in prescribing patterns. RESULTS: There is considerable variation in prescribing patterns. In the UK thiazides account for 25% of consumption, while the corresponding figure for Norway is 6%. In Norway alpha-blocking agents account for 8% of consumption, which is more than twice the percentage found in any of the other countries. Suggested factors to explain inter-country variation included reimbursement policies, traditions, opinion leaders with conflicts of interests, domestic pharmaceutical production, and clinical practice guidelines. The medical directors also suggested hypotheses that: Norwegian physicians are early adopters of new interventions while the British are more conservative; there are many clinical trials conducted in Norway involving many general practitioners; there is higher cost-awareness among physicians in the UK, in part due to fund holding; and there are publicly funded pharmaceutical advisors in the UK. CONCLUSION: Two compelling explanations the variation in prescribing that warrant further investigation are the promotion of less-expensive drugs by pharmaceutical advisors in UK and the promotion of more expensive drugs through "seeding trials" in Norway

    Influence of motor practices on university students’ emotional state [Influencia de las prácticas motrices sobre el estado emocional de estudiantes universitarios]

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    The emotional experience is a key aspect when promoting student’s well-being from the physical education. This study analyzed the effects of three kinds of motor practices without teammates or adversaries (games, body expression and introjections) on women and men’s emotional state. 358 students took part in this study (98 women, 27.37%, and 260 men, 72.63%) from four different Spanish universities. After each activity students filled out a questionnaire to validate the Games and Emotions Scale (GES), indicating the experienced intensity in positive, negative and ambiguous emotions. Data were analyzed by generalized estimating equations. It was confirmed that the three kinds of practices work as specific subdomains in the emotional experience. Men showed more intense emotions than women (p <.001), although both genders had a similar emotional behavior in motor expression and motor introjections practices. Women registered lower values in motor games. La vivencia emocional es un aspecto clave para promover el bienestar del alumnado desde la educación física. Este trabajo examinó los efectos de tres tipos de prácticas psicomotrices sin presencia de compañeros y de adversarios (juegos, expresión e introyección) sobre el estado emocional de mujeres y hombres. Participaron 358 estudiantes (98 mujeres, 27,37% y 260 hombres, 72,63%) de 4 universidades españolas. Tras cada actividad los estudiantes cumplimentaron el cuestionario validado de juegos y emociones (GES), indicando la intensidad experimentada en emociones positivas, negativas y ambiguas. Los datos se analizaron mediante ecuaciones de estimación generalizadas. Se confirmó que los tres tipos de prácticas funcionan como subdominios específicos en la vivencia emocional. Los hombres expresaron emociones más intensas (p < ,001) que las mujeres, aunque ambos sexos tuvieron un comportamiento emocional similar en la expresión e introyección. Las mujeres registraron valores inferiores en los juegos motores

    Early apoptosis of porcine alveolar macrophages limits avian influenza virus replication and proinflammatory dysregulation

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    Pigs are evidently more resistant to avian than swine influenza A viruses, mediated in part through frontline epithelial cells and alveolar macrophages (AM). Although porcine AM (PAM) are crucial in influenza virus control, their mode of control is unclear. To gain insight into the possible role of PAM in the mediation of avian influenza virus resistance, we compared the host effects and replication of two avian (H2N3 and H6N1) and three mammalian (swine H1N1, human H1N1 and pandemic H1N1) influenza viruses in PAM. We found that PAM were readily susceptible to initial infection with all five avian and mammalian influenza viruses but only avian viruses caused early and extensive apoptosis (by 6 h of infection) resulting in reduced virus progeny and moderated pro- inflammation. Full length viral PB1-F2 present only in avian influenza viruses is a virulence factor that targets AM for mitochondrial associated apoptotic cell death. With the use of reverse genetics on an avian H5N1 virus, we found that full length PB1-F2 contributed to increased apoptosis and pro-inflammation but not to reduced virus replication. Taken together, we propose that early apoptosis of PAM limits the spread of avian influenza viruses and that PB1-F2 could play a contributory role in the process

    Imaging of acute appendicitis in children: EU versus US ... or US versus CT? A European perspective

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    There is substantial evidence that imaging may reduce the negative appendectomy rate, also in children. However, controversy exists about the preferred method: US or CT, and the choice appears to be determined by the side of the Atlantic Ocean. This review brings forth several arguments in favour of U

    BLISS: an artificial language for learnability studies

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    To explore neurocognitive mechanisms underlying the human language faculty, cognitive scientists use artificial languages to control more precisely the language learning environment and to study selected aspects of natural languages. Artificial languages applied in cognitive studies are usually designed ad hoc, to only probe a specific hypothesis, and they include a miniature grammar and a very small vocabulary. The aim of the present study is the construction of an artificial language incorporating both syntax and semantics, BLISS. Of intermediate complexity, BLISS mimics natural languages by having a vocabulary, syntax, and some semantics, as defined by a degree of non-syntactic statistical dependence between words. We quantify, using information theoretical measures, dependencies between words in BLISS sentences as well as differences between the distinct models we introduce for semantics. While modeling English syntax in its basic version, BLISS can be easily varied in its internal parametric structure, thus allowing studies of the relative learnability of different parameter sets

    Epigenome Microarray Platform for Proteome-Wide Dissection of Chromatin-Signaling Networks

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    Knowledge of protein domains that function as the biological effectors for diverse post-translational modifications of histones is critical for understanding how nuclear and epigenetic programs are established. Indeed, mutations of chromatin effector domains found within several proteins are associated with multiple human pathologies, including cancer and immunodeficiency syndromes. To date, relatively few effector domains have been identified in comparison to the number of modifications present on histone and non-histone proteins. Here we describe the generation and application of human modified peptide microarrays as a platform for high-throughput discovery of chromatin effectors and for epitope-specificity analysis of antibodies commonly utilized in chromatin research. Screening with a library containing a majority of the Royal Family domains present in the human proteome led to the discovery of TDRD7, JMJ2C, and MPP8 as three new modified histone-binding proteins. Thus, we propose that peptide microarray methodologies are a powerful new tool for elucidating molecular interactions at chromatin

    A hippocampal circuit linking dorsal CA2 to ventral CA1 critical for social memory dynamics

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    Recent results suggest that social memory requires the dorsal hippocampal CA2 region as well as a subset of ventral CA1 neurons. However, it is unclear whether dorsal CA2 and ventral CA1 represent parallel or sequential circuits. Moreover, because evidence implicating CA2 in social memory comes largely from long-term inactivation experiments, the dynamic role of CA2 in social memory remains unclear. Here, we use pharmacogenetics and optogenetics in mice to acutely and reversibly silence dorsal CA2 and its projections to ventral hippocampus. We show that dorsal CA2 activity is critical for encoding, consolidation, and recall phases of social memory. Moreover, dorsal CA2 contributes to social memory by providing strong excitatory input to the same subregion of ventral CA1 that contains the subset of neurons implicated in social memory. Thus, our studies provide new insights into a dorsal CA2 to ventral CA1 circuit whose dynamic activity is necessary for social memory.We thank David H. Brann and the other members of the Siegelbaum laboratory for helpful discussions and João Cerqueira for critical input. This work was supported by R01 MH104602 and R01 MH106629 from the NIH (S.A.S.), by PD/BD/113700/2015 from the Portuguese Foundation for Science and Technology (T.M.) and by the European Molecular Biology Organization (A.O.)
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