5,630 research outputs found

    Increased levels of RNA oxidation enhance the reversion frequency in aging pro-apoptotic yeast mutants

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    Despite recent advances in understanding the complexity of RNA processes, regulation of the metabolism of oxidized cellular RNAs and the mechanisms through which oxidized ribonucleotides affect mRNA translation, and consequently cell viability, are not well characterized. We show here that the level of oxidized RNAs is markedly increased in a yeast decapping Kllsm4Δ1 mutant, which accumulates mRNAs, ages much faster that the wild type strain and undergoes regulated-cell-death. We also found that in Kllsm4Δ1 cells the mutation rate increases during chronological life span indicating that the capacity to han- dle oxidized RNAs in yeast declines with aging. Lowering intracellular ROS levels by antioxidants recovers the wild- type phenotype of mutant cells, including reduced amount of oxidized RNAs and lower mutation rate. Since mRNA oxidation was reported to occur in different neurodegen- erative diseases, decapping-deficient cells may represent a useful tool for deciphering molecular mechanisms of cell response to such conditions, providing new insights into RNA modification-based pathogenesis

    Test of Einstein Equivalence Principle for 0-spin and half-integer-spin atoms: Search for spin-gravity coupling effects

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    We report on a conceptually new test of the equivalence principle performed by measuring the acceleration in Earth's gravity field of two isotopes of strontium atoms, namely, the bosonic 88^{88}Sr isotope which has no spin vs the fermionic 87^{87}Sr isotope which has a half-integer spin. The effect of gravity upon the two atomic species has been probed by means of a precision differential measurement of the Bloch frequency for the two atomic matter waves in a vertical optical lattice. We obtain the values η=(0.2±1.6)×10−7\eta = (0.2\pm 1.6)\times10^{-7} for the E\"otv\"os parameter and k=(0.5±1.1)×10−7k=(0.5\pm1.1)\times10^{-7} for the coupling between nuclear spin and gravity. This is the first reported experimental test of the equivalence principle for bosonic and fermionic particles and opens a new way to the search for the predicted spin-gravity coupling effects.Comment: 5 pages, 4 figures. New spin-gravtity coupling analysis on the data added to the manuscrip

    Structural aspects of the female sexual differentiation of the pirarucu (Arapaima gigas, SCHINZ, 1822).

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    The pirarucu (Arapaima gigas) are the biggest scale Amazonian fish and their farming potential is enormous. However, there are few studies involving the reproductive physiology of pirarucu. Raising fish in confined environments still encounters several adversities, being necessary basic studies for the development of the productive chain, mainly at the early stages of development. Thus, studies related to the gonadal development are essential for the understanding of the reproductive biology of the species

    A device to characterize optical fibres

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    ATLAS is a general purpose experiment approved for the LHC collider at CERN. An important component of the detector is the central hadronic calorimeter; for its construction more than 600,000 Wave Length Shifting (WLS) fibres (corresponding to a total length of 1,120 Km) have been used. We have built and put into operation a dedicated instrument for the measurement of light yield and attenuation length over groups of 20 fibres at a time. The overall accuracy achieved in the measurement of light yield (attenuation length) is 1.5% (3%). We also report the results obtained using this method in the quality control of a large sample of fibres.Comment: 17 pages 20 figeres submitted to NIM journa

    Creating Non-Believed Memories for Recent Autobiographical Events

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    A recent study showed that many people spontaneously report vivid memories of events that they do not believe to have occurred [1]. In the present experiment we tested for the first time whether, after powerful false memories have been created, debriefing might leave behind nonbelieved memories for the fake events. In Session 1 participants imitated simple actions, and in Session 2 they saw doctored video-recordings containing clips that falsely suggested they had performed additional (fake) actions. As in earlier studies, this procedure created powerful false memories. In Session 3, participants were debriefed and told that specific actions in the video were not truly performed. Beliefs and memories for all critical actions were tested before and after the debriefing. Results showed that debriefing undermined participants' beliefs in fake actions, but left behind residual memory-like content. These results indicate that debriefing can leave behind vivid false memories which are no longer believed, and thus we demonstrate for the first time that the memory of an event can be experimentally dissociated from the belief in the event's occurrence. These results also confirm that belief in and memory for an event can be independently-occurring constructs

    Multiple exophytic osteomas of craniofacial bones not associated with Gardner s Syndrome: a case report

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    Exophytic osteomas are mature bone protuberances required to be carefully differentiated from other lesions. The authors present a male, 44 year-old patient s report presenting multiple exophytic osteomas located in both sides of the vestibulomaxillary, premolar and molar regions not-associated with Gardner s Syndrome.Osteomas exofĂ­ticos sĂŁo protuberĂąncias de osso maduro que necessitam ser cuidadosamente diferenciados de outras lesĂ”es. Os autores apresentam relato de paciente do sexo masculino, com 44 anos de idade, apresentando osteomas exofĂ­ticos mĂșltiplos localizados na regiĂŁo vestĂ­bulo-maxilar em ambos os lados, regiĂŁo de prĂ©-molares e molares nĂŁo associados Ă  SĂ­ndrome de Gardner.UNIFESP-EPMUNIFESP, EPMSciEL

    Analytical and Numerical Characterization of Cherenkov Diffraction Radiation as a Longitudinal Electron Bunch Profile Monitor for AWAKE Run 2

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    In this paper, CST simulations of the coherent Cherenkov Diffraction Radiation with a range of parameters for different dielectric target materials and geometries are discussed and compared with the theoretical investigation of the Polarization Current Approach to design a prototype of a radiator for the bunch length/profile monitor for AWAKE Run 2. It was found that the result of PCA theory and CST simulation are consistent with each other regarding the shape of the emitted ChDR cone

    Optimization Study of Beam Position and Angular Jitter Independent Bunch Length Monitor for Awake Run 2

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    In this paper, a study using the Polarization Current Approach (PCA) model is performed to optimize the design of a short bunch length monitor using two dielectric radiators that produce coherent Cherenkov Diffraction Radiation (ChDR). The electromagnetic power emitted from each radiator is measuring a different part of the bunch spectrum using Schottky diodes. For various bunch lengths, the coherent ChDR spectrums are calculated to find the most suitable frequency bands for the detection system. ChDR intensities measured by each detector are estimated for different impact parameters to explore the dependence of bunch length monitor on beam position and angular jitter. It is found that, in the present configuration, the effects of beam position and angular jitter are negligibly small for bunch length measurement

    Model-based meta-analysis of salbutamol pharmacokinetics and practical implications for doping control.

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    Salbutamol was included in the prohibited list of the World Anti-Doping Agency (WADA) in 2004. Although systemic intake is banned, inhalation for asthma is permitted but with dosage restrictions. The WADA established a urinary concentration threshold to distinguish accordingly prohibited systemic self-administration from therapeutic prescription by inhalation. This study aimed at evaluating the ability of the WADA threshold to differentiate salbutamol therapeutic use from violation of antidoping rules. Concentration-time profile of salbutamol in plasma and its excretion in urine was characterized through a model-based meta-analysis of individual and aggregate data collected after administration of a large range of doses following different modes of administration and under a variety of conditions. The developed model adequately fitted salbutamol plasma and urine concentration-time profiles of the 13 selected studies. Model-based simulations confirmed that a wide range of salbutamol urine concentrations might be measured after drug intake. Although violation of the WADA Code can be strongly suspected in individuals showing very high salbutamol urine concentrations, uncertainty remains for values close to the WADA threshold as they can be compatible with both permitted therapeutic use and violation. Although not entirely discriminant, the current WADA rule is globally supported by our appraisal. It could be further improved by a slight and reasonable adjustment of inhaled daily dosages allowed for therapeutic use. Our model might help antidoping experts in the evaluation of suspected doping cases through confronting the athlete's urine measurements with their allegations about salbutamol treatment
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