1,386 research outputs found
The Berry phase and the pump flux in stochastic chemical kinetics
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
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
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
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
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
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
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
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
Influence of the NAO on the northwestern Mediterranean wave climate
RESUMEN. Influencia de la nao en el clima marĂtimo del MediterrĂĄneo noroccidental. â El presente trabajo estudia las teleconexiones entre la OscilaciĂłn del AtlĂĄntico Norte (NAO ) y el clima marĂtimo en el MediterrĂĄneo noroccidental, definido por la media mensual de la altura significante (SWH) y la media mensual de la altura significante correspondiente al percentil 95 (percentil 95 SWH), en el perĂodo comprendido entre 1958 y 2001. Los datos analizados corresponden al retroanĂĄlisis de 44 años de datos atmosfĂ©ricos, dentro del marco del proyecto HIPOCAS . Estos datos han sido codificados en forma de EOF s para obtener la variabilidad espacio-temporal asociada a la NAO . Los datos utilizados han sido previamente blanqueados para evitar correlaciones ficticias entre las series, mediante el ajuste a un modelo autorregresivo de orden p. Los resultados muestran como el clima marĂtimo del MediterrĂĄneo noroccidental estĂĄ influenciado a escala mensual por las distintas fases de la NAO . Cuando la NAO estĂĄ en su fase positiva, podemos observar anomalĂas positivas en la altura significante media mensual, asĂ como en la altura de ola correspondiente al percentil 95, estas anomalĂas aparecen en la zona comprendida entre las Islas Baleares, el Golfo de LeĂłn y la costa catalana.ABSTRACT. This study examines teleconnections between the North Atlantic Oscillation (NAO ) and the wave climate of the northwestern Mediterranean Sea (NWM), defined by the monthly mean significant wave height (SWH) and the 95th percentile significant wave height (95th percentile SWH), in the period ranging from 1958 to 2001. The data analyzed comes from the multidecadal hindcast over Europe carried out during the HIPOCAS project. In order to avoid fictitious cross-correlations, data were prewhitened by fitting a p-order autoregressive model. To split the temporal and spatial variability, an EOF encoding technique was applied to residuals before searching for teleconnections. We found the northwestern Mediterranean wave climate to be influenced by the North Atlantic Oscillation (NAO ) with an instantaneous response. When the NAO is in its positive phase, positive anomalies in the SWH and the 95th percentile SWH appear in the area between the Balearic Islands, the Gulf of Lions and the Catalonian coast
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