1,275 research outputs found

    The Berry phase and the pump flux in stochastic chemical kinetics

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    We study a classical two-state stochastic system in a sea of substrates and products (absorbing states), which can be interpreted as a single Michaelis-Menten catalyzing enzyme or as a channel on a cell surface. We introduce a novel general method and use it to derive the expression for the full counting statistics of transitions among the absorbing states. For the evolution of the system under a periodic perturbation of the kinetic rates, the latter contains a term with a purely geometrical (the Berry phase) interpretation. This term gives rise to a pump current between the absorbing states, which is due entirely to the stochastic nature of the system. We calculate the first two cumulants of this current, and we argue that it is observable experimentally

    Multi-Slot BLE Raw Database for Accurate Positioning in Mixed Indoor/Outdoor Environments

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    The technologies and sensors embedded in smartphones have contributed to the spread of disruptive applications built on top of Location Based Services (LBSs). Among them, Bluetooth Low Energy (BLE) has been widely adopted for proximity and localization, as it is a simple but efficient positioning technology. This article presents a database of received signal strength measurements (RSSIs) on BLE signals in a real positioning system. The system was deployed on two buildings belonging to the campus of the University of Extremadura in Badajoz. the database is divided into three different deployments, changing in each of them the number of measurement points and the configuration of the BLE beacons. the beacons used in this work can broadcast up to six emission slots simultaneously. Fingerprinting positioning experiments are presented in this work using multiple slots, improving positioning accuracy when compared with the traditional single slot approach

    Herpes Zoster After Liver Transplantation: Incidence, Risk Factors, and Complications

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    Herpes zoster is the consequence of the reactivation of latent varicella-zoster infection. Immunosuppression may be a predisposing factor for herpes zoster. We have retrospectively assessed the risk of herpes zoster, the risk factors for its occurrence, and its evolution in a population of 209 consecutive liver transplant recipients. Herpes zoster developed in 25 (12%) of patients. One-, 3-, 5-, and 10-year actuarial rates of herpes zoster were 3%, 10%, 14%, and 18%, respectively. In a case-control study, patients developing herpes zoster were younger, received a higher number of immunosuppressive drugs, and were more frequently receiving mycophenolate mofetil or azathioprine. In multivariate analysis, the only factor related to herpes zoster occurrence was treatment with mycophenolate mofetil or azathioprine. Eight patients (31%) developed postherpetic neuralgia. In conclusion, herpes zoster is a relatively common complication after liver transplantation. It is related to immunosuppressive therapy. Postherpetic neuralgia develops in one third of patients with posttransplant herpes zoster

    Conversion From Calcineurin Inhibitors to Mycophenolate Mofetil in Liver Transplant Recipients With Diabetes Mellitus

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    Diabetes mellitus, a frequent metabolic complication in liver transplant recipients, may be produced by the diabetogenic effect of calcineurin inhibitors cyclosporine and tacrolimus. The aim of this study was to investigate the safety and metabolic effects of a gradual switch from cyclosporine or tacrolimus to mycophenolate mofetil among 12 diabetic liver transplant recipients. One patient was withdrawn from the study due to gastrointestinal side effects. Of the 11 remaining patients, cyclosporine or tacrolimus was completely withdrawn in five patients. Two patients developed suspected acute rejection episodes that were controlled by increasing the tacrolimus dosage. Glycosylated hemoglobin A1C and C-peptide levels were significantly lower at 3 and 6 months after the initiation of mycophenolate mofetil (P<.03 in all cases). Furthermore, urea and uric acid levels were significantly reduced after the change of treatment. In conclusion, a switch from cyclosporine/tacrolimus to mycophenolate mofetil may produce beneficial metabolic effects in diabetic liver transplant recipients, but poses a risk of graft rejection

    Metabolic channeling of phe for lignin biosynthesis in maritime pine

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    Phenylalanine (Phe) is the main precursor of phenylpropanoids biosynthesis in plants. This vast family of Phe-derived compounds can represent more than 30% of captured photosynthetic carbon, playing essential roles in plants such as cell wall components, defense molecules, pigments and flavors. In addition to its physiological importance, phenylpropanoids and particularly lignin, a component of wood, are targets in plant biotechnology. The arogenate pathway has been proposed as the main pathway for Phe biosynthesis in plants (Maeda et al., 2010). The final step in Phe biosynthesis, catalyzed by the enzyme arogenate dehydratase (ADT), has been considered as a key regulatory point in Phe biosynthesis, due to its key branch position in the pathway, the multiple isoenzymes identified in plants and the existence of a feedback inhibition mechanism by Phe. So far, the regulatory mechanisms underlying ADT genes expression have been poorly characterized, although a strong regulation of the Phe metabolic flux should be expected depending on its alternative use for protein biosynthesis versus phenylpropanoid biosynthesis. This second fate involves a massive carbon flux compared to the first one. Here we report our current research activities in the transcriptional regulation of ADT genes by MYB transcription factors in Pinus pinaster. The conifers channels massive amounts of photosynthetic carbon for phenylpropanoid biosynthesis during wood formation. We have identified the complete ADT gene family in maritime pine (El-Azaz et al., 2016) and a set of ADT isoforms specifically related with the lignification process. The potential control of transcription factors previously reported as key regulators in pine wood formation (Craven-Bartle et al., 2013) will be presented.Universidad de MĂĄlaga. Campus de Excelencia Internacional AndalucĂ­a Tech

    Trasplante pancreĂĄtico

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    Diabetes mellitus is a health concern of the first order, given the high level of associated morbidity and mortality. The objective, in order to slow down the advance of its complications before they become irreversible, is based on correct metabolic control. The high rate of morbidity associated with the surgery of the vascularized pancreas transplant and the high index of rejection have for three decades formed an obstacle to this being considered a valid alternative in the treatment of these patients. Nowadays the pancreas transplant has come to occupy a key position, thanks to the new regimes of immunosuppression and to the perfection of surgical techniques. In this article we review the evolution of the pancreas transplant from its beginnings to its present state

    Sticky prices in the euro area: a summary of new micro evidence

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    This paper presents original evidence on price setting in the euro area at the individual level. We use micro data on consumer (CPI) and producer (PPI) prices, as well as survey information. Our main findings are: (i) prices in the euro area are sticky and more so than in the US; (ii) there is evidence of heterogeneity and of asymmetries in price setting behaviour; (iii) downward price rigidity is only slightly more marked than upward price rigidity and (iv) implicit or explicit contracts and coordination failure theories are important, whereas menu or information costs are judged much less relevant by firms. --Price setting,Price stickiness,Consumer prices,Producer prices,survey data

    Spectral calibration of the fluorescence telescopes of the Pierre Auger Observatory

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    We present a novel method to measure precisely the relative spectral response of the fluorescence telescopes of the Pierre Auger Observatory. We used a portable light source based on a xenon flasher and a monochromator to measure the relative spectral efficiencies of eight telescopes in steps of 5 nm from 280 nm to 440nm. Each point in a scan had approximately 2nm FWHM out of the monochromator. Different sets of telescopes in the observatory have different optical components, and the eight telescopes measured represent two each of the four combinations of components represented in the observatory. We made an end-to-end measurement of the response from different combinations of optical components, and the monochromator setup allowed for more precise and complete measurements than our previous multi-wavelength calibrations. We find an overall uncertainty in the calibration of the spectral response of most of the telescopes of 1.5% for all wavelengths; the six oldest telescopes have larger overall uncertainties of about 2.2%. We also report changes in physics measurables due to the change in calibration, which are generally small

    Sticky Prices in The Euro Area: a Summary of New Micro Evidence

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    This paper presents original evidence on price setting in the euro area at the individual level. We use micro data on consumer (CPI) and producer (PPI) prices, as well as survey information. Our main findings are: (i) prices in the euro area are sticky and more so than in the US; (ii) there is evidence of heterogeneity and of asymmetries in price setting behaviour; (iii) downward price rigidity is only slightly more marked than upward price rigidity and (iv) implicit or explicit contracts and coordination failure theories are important, whereas menu or information costs are judged much less relevant by firms.
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