615 research outputs found

    ACTIVIDAD CELULOLITICA DE CEPAS DE Aspergillus niger y A. flavus AISLADAS DE SUELOS CON CULTIVO DE TRIGO Y TRATAMIENTO HERBICIDA

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    Se estudia la actividad celulolítica de cepas de Aspergillus niger y A. flavus aisladas de suelo del sur de la provincia de Santa Fe, sembrado con trigo y tratado con Metsulfurón-metil+Dicamba. Dichas cepas fueron las más frecuentes en un muestreo que abarcó distintas etapas del cultivo de trigo en 1994 y mostraron a su vez, variaciones en su frecuencia a lo largo del mismo.Nuestro objetivo fue conocer si dichas variaciones de frecuencia se correlacionan con cambios en la actividad celulolítica de las mismas. Se trabajó con 3 cepas deA. niger y 2 de A. flavus. En los filtrados de los cultivos, se determinó: peso seco, proteínas solubles, producción de exoglucanasas frente a la celulosa cristalina, endoglucanasas frente a carboximetilcelulosa y celobiasas extracelulares.En A. niger, no hubo una correlación clara entre frecuencia y actividad  enzimática, sólo se observó que las cepas de A. niger de mayor frecuencia (superior al 50%) tuvieron también mayor actividad. En A. flavus, encambio, se observó una correlación inversa

    Are you suffering from a large arterial occlusion? Please raise your arm!

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    Background and purpose: Triage tools to identify candidates for thrombectomy are of utmost importance in acute stroke. No prognostic tool has yet gained any widespread use. We compared the predictive value of various models based on National Institutes of Health Stroke Scale (NIHSS) subitems, ranging from simple to more complex models, for predicting large artery occlusion (LAO) in anterior circulation stroke. Methods: Patients registered in the SITS international Stroke Register with available NIHSS and radiological arterial occlusion data were analysed. We compared 2042 patients harbouring an LAO with 2881 patients having no/distal occlusions. Using binary logistic regression, we developed models ranging from simple 1 NIHSS-subitem to full NIHSS-subitems models. Sensitivities and specificities of the models for predicting LAO were examined. Results: The model with highest predictive value included all NIHSS subitems for predicting LAO (area under the curve (AUC) 0.77), yielding a sensitivity and specificity of 69% and 76%, respectively. The second most predictive model (AUC 0.76) included 4-NIHSS-subitems (level of consciousness commands, gaze, facial and arm motor function) yielding a sensitivity and specificity of 67% and 75%, respectively. The simplest model included only deficits in arm motor-function (AUC 0.72) for predicting LAO, yielding a sensitivity and specificity of 67% and 72%, respectively. Conclusions: Although increasingly more complex models yield a higher discriminative performance for predicting LAO, differences between models are not large. Assessing grade of arm dysfunction along with an established stroke-diagnosis model may serve as a surrogate measure of arterial occlusion-status, thereby assisting in triage decisions

    Efficacy of a specific rehabilitation protocol in postural control of a young woman with multiple fragility vertebral fractures: a case report

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    The fragility vertebral fractures have a considerable impact on an individual's health-related quality of life due to pain, limitations in activity, social participation, altered mood and balance impairment. Physiotherapy interventions may have an important role in improving quality of life, balance and reducing the fracture risk in people with osteoporotic vertebral fractures. In literature there are only a few studies that examine exercise interventions in osteoporotic populations with vertebral fracture and few studies that examine the effects on balance with instrumental measurements. In this paper we present a case of a woman with fragility vertebral fractures and a related balance impairment and the effects of a specific rehabilitation program using both clinical evaluations that instrumental measurement

    Underdiagnosis of osteoporotic vertebral fractures in patients with fragility fractures: retrospective analysis of over 300 patients

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    Osteoporosis (OP) is a silent disease unless a fracture occurs; it is a major health problem, mainly due to fragility fractures, that occur at vertebral and peripheral sites. Vertebral fractures (VF) are probably the most common fragility fractures, but they go often unrecognized. The main clinical symptoms of VF are acute and chronic back pain, spinal deformity, reduced mobility and impaired quality of life. They are frequently associated with other fragility fractures. We examined 478 patients at our outpatient clinic, who were referred for fragility fracture occurrence. The most common fragility fractures was hip fractures. However, after execution of spine X-rays in patients who had sustained hip fracture, we found that a large proportion of them had VF, which had not been reported in their medical history

    A separation of electrons and protons in the GAMMA-400 gamma-ray telescope

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    The GAMMA-400 gamma-ray telescope is intended to measure the fluxes of gamma rays and cosmic-ray electrons and positrons in the energy range from 100 MeV to several TeV. Such measurements concern with the following scientific goals: search for signatures of dark matter, investigation of gamma-ray point and extended sources, studies of the energy spectra of Galactic and extragalactic diffuse emission, studies of gamma-ray bursts and gamma-ray emission from the active Sun, as well as high-precision measurements of spectra of high-energy electrons and positrons, protons, and nuclei up to the knee. The main components of cosmic rays are protons and helium nuclei, whereas the part of lepton component in the total flux is ~10E-3 for high energies. In present paper, the capability of the GAMMA-400 gamma-ray telescope to distinguish electrons and positrons from protons in cosmic rays is investigated. The individual contribution to the proton rejection is studied for each detector system of the GAMMA-400 gamma-ray telescope. Using combined information from all detector systems allow us to provide the proton rejection from electrons with a factor of ~4x10E5 for vertical incident particles and ~3x10E5 for particles with initial inclination of 30 degrees. The calculations were performed for the electron energy range from 50 GeV to 1 TeV.Comment: 19 pages, 10 figures, submitted to Advances and Space Researc

    The GAMMA-400 space observatory: status and perspectives

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    The present design of the new space observatory GAMMA-400 is presented in this paper. The instrument has been designed for the optimal detection of gamma rays in a broad energy range (from ~100 MeV up to 3 TeV), with excellent angular and energy resolution. The observatory will also allow precise and high statistic studies of the electron component in the cosmic rays up to the multi TeV region, as well as protons and nuclei spectra up to the knee region. The GAMMA-400 observatory will allow to address a broad range of science topics, like search for signatures of dark matter, studies of Galactic and extragalactic gamma-ray sources, Galactic and extragalactic diffuse emission, gamma-ray bursts and charged cosmic rays acceleration and diffusion mechanism up to the knee

    Time dependence of the e^- flux measured by PAMELA during the July 2006 - December 2009 solar minimum

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    Precision measurements of the electron component in the cosmic radiation provide important information about the origin and propagation of cosmic rays in the Galaxy not accessible from the study of the cosmic-ray nuclear components due to their differing diffusion and energy-loss processes. However, when measured near Earth, the effects of propagation and modulation of galactic cosmic rays in the heliosphere, particularly significant for energies up to at least 30 GeV, must be properly taken into account. In this paper the electron (e^-) spectra measured by PAMELA down to 70 MeV from July 2006 to December 2009 over six-months time intervals are presented. Fluxes are compared with a state-of-the-art three-dimensional model of solar modulation that reproduces the observations remarkably well.Comment: 40 pages, 18 figures, 1 tabl

    Search for anisotropies in cosmic-ray positrons detected by the PAMELA experiment

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    The PAMELA detector was launched on board of the Russian Resurs-DK1 satellite on June 15, 2006. Data collected during the first four years have been used to search for large-scale anisotropies in the arrival directions of cosmic-ray positrons. The PAMELA experiment allows for a full sky investigation, with sensitivity to global anisotropies in any angular window of the celestial sphere. Data samples of positrons in the rigidity range 10 GV \leq R \leq 200 GV were analyzed. This article discusses the method and the results of the search for possible local sources through analysis of anisotropy in positron data compared to the proton background. The resulting distributions of arrival directions are found to be isotropic. Starting from the angular power spectrum, a dipole anisotropy upper limit \delta = 0.166 at 95% C.L. is determined. Additional search is carried out around the Sun. No evidence of an excess correlated with that direction was found.Comment: The value of the dipole anisotropy upper limit has been changed. The method is correct but there was a miscalculation in the relative formul
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