Pruebas no paramétricas para procesos poisson no homogéneos

El análisis de varios tipos de fenómenos aleatorios que ocurren en el tiempo, en ocasiones se realiza bajo el supuesto de un proceso estocástico Poisson no homogéneo (PPNH), sin la validación previa de este supuesto. Esta investigación propone un método estadístico para probar este supuesto, método que se basa en una caracterización de los PPNH. El método considera la utilización de las estadísticas de Cramér-von Mises (CVM), como una prueba de bondad de ajuste para la distribución Poisson, y la prueba de Kruskal-Wallis (KW). Las pruebas basadas en las estadísticas de CVM presentan mayor potencia que otras pruebas de bondad de ajuste comúnmente empleadas para la distribución Poisson. Aquí se presenta un estudio por simulación, el cual muestra que la prueba de KW tiene mayor potencia que la de Cramér-von Mises para evaluar si dos o más muestras provienen de una misma distribución, contra algunas alternativas de interés

Fluid Overload in Peritoneal Dialysis

The prevalence of end-stage renal disease (ESRD) has increased globally to 10% due to diabetes mellitus, hypertension, and stroke. When chronic kidney disease (CKD) maintenance therapy fails, patients require renal replacement therapy (RRT) to survive, such as peritoneal dialysis (PD), hemodialysis, and renal transplantation. The most common therapy in Mexico is PD because it is a feasible, low-cost, and easy-to-perform procedure; however, fluid overload is a frequent condition in patients with this RRT modality. The usual adverse comorbidities in patients with PD are cardiovascular diseases (CVD) associated to atherosclerosis, uremia, inflammation, and oxidative stress. Fluid overload is intimately associated to hypertension, left ventricular hypertrophy, heart failure, and worsening of kidney failure, leading to increased hospital admissions, higher cardiovascular mortality, and reduced life expectancy. Two main pathologies are involved in the deterioration of both heart and kidney functions, namely, cardiorenal syndrome and uremic cardiomyopathy. Along with these phenomena, patients in PD with rapid peritoneal transport have reduced ultrafiltration, increased glucose absorption, and albumin loss in the dialysate, which lead to overhydration, hypertension, dyslipidemia, and malnutrition. This review focuses on the clinical, physiological, and biochemical mechanisms involved in fluid overload of patients with CKD undergoing PD

The contribution of the seismic component of Topo-Iberia to the imaging of the deep structure of the Iberian Peninsula and North Morocco

Topo-Iberia has been a large-scale Spanish project running from 2007 to 2013 that integrated more than 150 researchers on Earth Sciences. One of its key assets was the management of an observatory platform, named IberArray, aimed to provide new geophysical datasets (seismic, GPS, MT) to constrain the structure of Iberia with unprecedented resolution. The IberArray seismic pool was composed by 70+ BB stations, covering the study area in 3 deployments with a site-density of 60km x 60km. The data base holds ~300 sites, including the permanent networks in the area. Hence it forms a unique seismic database in Europe that allows for multiple analyses to constrain the complex geodinamics of the Western Mediterranean. A summary of new results coming from different techniques is presented here. The SKS splitting analysis has provided a spectacular image of the rotation of the fast velocity direction along the Gibraltar Arc. In central and northern Iberia, the fast polarization directions are close to EW, consistently with global mantle flow models considering contributions of surface plate motion, density variations and net lithosphere rotation. Those results suggest an asthenospheric origin of the observed anisotropy related to present-day mantle flow. Receiver functions have revealed the crustal thickness variations beneath the Atlas, Rif and southern Iberia, evidencing a relevant crustal root beneath the Rif, in agreement with recent, high- density active seismic experiments. The Variscan Iberian massif shows a flat Moho discontinuity, while the areas reworked in the Alpine orogeny show a slightly thicker crust. Beneath N Iberia, the imbrication of the Iberian and Eurasian crusts results in complex receiver functions. Depths exceeding 45 km are observed along the Pyrenean range, while the crust thins to values of 26-28 km close to the Atlantic coasts. The geometry of the 410-km and 660-km discontinuities has been investigated using novel cross-correlation/stacking techniques. Ambient noise tomography allows to identify the main sedimentary basins and to discriminate between the Variscan and the Alpine reworked areas. Local body-wave tomography in North Morocco has improved the location of the small magnitude events on the area and the details of the crustal structure. Teleseismic tomography has confirmed, using an independent data set, the presence of a high-velocity slab beneath the Gibraltar Arc.Peer Reviewe

Increase of Oxidants and Antioxidant Consumption in Patients with Type 2 Diabetes Mellitus in Peritoneal Dialysis

Oxidative stress (OS) is implicated as a unifying factor between chronic kidney diseases and cardiovascular diseases. The objective of the study was to compare the oxidant and antioxidant status in patients with PD according to the state of DM. Lipoperoxides (LPO), 8-isoprostanes (8-IP) and nitric oxide (NO) were determined as oxidants and the activity of superoxide dismutase (SOD) and total antioxidant capacity (TAC) as antioxidants in patients with DM and without DM (No-DM). We included 35 patients with DM, 42 No-DM patients and 10 healthy people as a control group (HC). Patients with DM were older (p<0.0001), had higher BMI (p<0.0001), high glucose levels (p<0.0001) and more hypertension (p<0.0001). It was found that LPO levels increased in patients with DM and No-DM vs. HC (p<0.0001). There was a decrease in the levels of 8-IP in DM and No-DM compared to HC (p<0.0001). The levels of NO in patients with DM and No-DM decreased significantly compared to the HC group with 197.97±34.20 μM (p<0.0001). The activity of the SOD enzyme in patients with DM and No-DM was found to be increased compared to the HC group (p<0.0001). The levels of TAC in HC were 2.62±0.17 mM and decreased in patients with DM and No-DM (p<0.0001)

Detailed black hole state counting in loop quantum gravity

We give a complete and detailed description of the computation of black hole entropy in loop quantum gravity by employing the most recently introduced number-theoretic and combinatorial methods. The use of these techniques allows us to perform a detailed analysis of the precise structure of the entropy spectrum for small black holes, showing some relevant features that were not discernible in previous computations. The ability to manipulate and understand the spectrum up to the level of detail that we describe in the paper is a crucial step towards obtaining the behavior of entropy in the asymptotic (large horizon area) regime

From the North-Iberian Margin to the Alboran Basin: A lithosphere geo-transect across the Iberian Plate

A ~ 1000-km-long lithospheric transect running from the North-Iberian Margin to the Alboran Basin (W-Mediterranean) is investigated. The main goal is to image the changes in the crustal and upper mantle structure occurring in: i) the North-Iberian margin, whose deformation in Alpine times gave rise to the uplift of the Cantabrian Mountains related to Iberia-Eurasia incipient subduction; ii) the Spanish Meseta, characterized by the presence of Cenozoic basins on top of a Variscan basement with weak Alpine deformation in the Central System, and localized Neogene-Quaternary deep volcanism; and iii) the Betic-Alboran system related to Africa-Iberia collision and the roll-back of the Ligurian-Tethyan domain. The modeling approach, combines potential fields, elevation, thermal, seismic, and petrological data under a self-consistent scheme. The crustal structure is mainly constrained by seismic data whereas the upper mantle is constrained by tomographic models. The results highlight the lateral variations in the topography of the lithosphere-asthenosphere boundary (LAB), suggesting a strong lithospheric mantle strain below the Cantabrian and Betic mountain belts. The LAB depth ranges from 180 km beneath the Cantabrian Mountains to 135-110. km beneath Iberia Meseta deepening again to values of 160. km beneath the Betic Cordillera. The Central System, with a mean elevation of 1300. m, has a negligible signature on the LAB depth. We have considered four lithospheric mantle compositions: a predominantly average Phanerozoic in the continental mainland, two more fertile compositions in the Alboran Sea and in the Calatrava Volcanic Province, and a hydrated uppermost mantle in the North-Iberian Margin. These compositional differences allowed us to reproduce the main trends of the geophysical observables as well as the inferred P- and S-wave seismic velocities from tomography models and seismic experiments available in the study transect. The high mean topography of Iberia can be partly consistent with a low-velocity/high-temperature/low-density layer in the sublithospheric mantle.The presented work has been supported by Topo-Iberia Consolider-IngenioCSD2006-0004, GASAM/TopoMed (CGL2008-03474-E/BTE/07-TOPO-EUROPE-FP-006), TECLA (CGL2011-26670) funded by the Spanish Government, and PYRTEC-IP2 (SV-PA-10-03, funded by the Government of Asturias/ESF TOPO-EUROPE Programme) projects. AC benefitted from a JAE-PreCP grant from CSIC. JCA acknowledges the support from ARC GrantDP120102372.Peer Reviewe

Altered Gene Expression by Low-Dose Arsenic Exposure in Humans and Cultured Cardiomyocytes: Assessment by Real-Time PCR Arrays

Chronic arsenic exposure results in higher risk of skin, lung, and bladder cancer, as well as cardiovascular disease and diabetes. The purpose of this study was to investigate the effects on expression of selected genes in the blood lymphocytes from 159 people exposed chronically to arsenic in their drinking water using a novel RT-PCR TaqMan low-density array (TLDA). We found that expression of tumor necrosis factor-α (TNF-α), which activates both inflammation and NF-κB-dependent survival pathways, was strongly associated with water and urinary arsenic levels. Expression of KCNA5, which encodes a potassium ion channel protein, was positively associated with water and toe nail arsenic levels. Expression of 2 and 11 genes were positively associated with nail and urinary arsenic, respectively. Because arsenic exposure has been reported to be associated with long QT intervals and vascular disease in humans, we also used this TLDA for analysis of gene expression in human cardiomyocytes exposed to arsenic in vitro. Expression of the ion-channel genes CACNA1, KCNH2, KCNQ1 and KCNE1 were down-regulated by 1-μM arsenic. Alteration of some common pathways, including those involved in oxidative stress, inflammatory signaling, and ion-channel function, may underlay the seemingly disparate array of arsenic-associated diseases, such as cancer, cardiovascular disease, and diabetes

High-resolution imaging of the Pyrenees and Massif Central from the data of the PYROPE and IBERARRAY portable array deployments

International audienceThe lithospheric structures beneath the Pyrenees, which holds the key to settle long-standing controversies regarding the opening of the Bay of Biscay and the formation of the Pyrenees, are still poorly known. The temporary PYROPE and IBERARRAY experiments have recently filled a strong deficit of seismological stations in this part of western Europe, offering a new and unique opportunity to image crustal and mantle structures with unprecedented resolution. Here we report the results of the first tomographic study of the Pyrenees relying on this rich data set. The important aspects of our tomographic study are the precision of both absolute and relative traveltime measurements obtained by a nonlinear simulated annealing waveform fit and the detailed crustal model that has been constructed to compute accurate crustal corrections. Beneath the Massif Central, the most prominent feature is a widespread slow anomaly that reflects a strong thermal anomaly resulting from the thinning of the lithosphere and upwelling of the asthenosphere. Our tomographic images clearly exclude scenarios involving subduction of oceanic lithosphere beneath the Pyrenees. In contrast, they reveal the segmentation of lithospheric structures, mainly by two major lithospheric faults, the Toulouse fault in the central Pyrenees and the Pamplona fault in the western Pyrenees. These inherited Hercynian faults were reactivated during the Cretaceous rifting of the Aquitaine and Iberian margins and during the Cenozoic Alpine convergence. Therefore, the Pyrenees can be seen as resulting from the tectonic inversion of a segmented continental rift that was buried by subduction beneath the European plate

A classical modelling of abandoned mine tailings' bioleaching by an autochthonous microbial culture

The aim of this study was to study and model the bioleaching of abandoned mine tailings at different pulp densities 1–20% w/v by using an autochthonous mesophilic microbial culture. Because of the importance of the ferrous-iron oxidation as sub-process on the bioleaching of sulphide mineral ores, the ferrous-iron oxidation process by the autochthonous microbial culture was studied at different ferrous-iron concentrations. A mathematical model fitted to the experimental results and the main kinetic and stoichiometric parameters were determined, being the most relevant the maximum ferrous-iron oxidation rate 5.1 (mmol Fe2+/mmol C·h) and the biomass yield, 0.01 mmol C/mmol Fe2+, values very similar to that of mixed cultured dominated by Leptospirillum strains. This autochthonous culture was used in the bioleaching experiment carried out at different pulp densities, obtaining a maximum metal recovery in the tests carried out at 1% w/v, recovering a 90% of Cd, 60% of Zn, 30% of Cu, 25% Fe and 6% of Pb. Finally, the different leaching mechanisms were modelled by using the pyrite as ore model obtaining a bioleaching rate of 0.316 mmol Fe2+/(L·h) for the direct mechanisms and a bioleaching rate for the indirect and cooperative leaching mechanisms of 0.055 Fe2+/(L·h).El objetivo de este estudio fue estudiar y modelar la biolixiviación de relaves mineros abandonados a diferentes densidades de pulpa de 1 a 20 % p/v mediante el uso de un cultivo microbiano mesófilo autóctono. Debido a la importancia de la oxidación del hierro ferroso como subproceso en la biolixiviación de minerales sulfurados , se estudió el proceso de oxidación del hierro ferroso por parte del cultivo microbiano autóctono a diferentes concentraciones de hierro ferroso. Se ajustó un modelo matemático a los resultados experimentales y se determinaron los principales parámetros cinéticos y estequiométricos, siendo los más relevantes la velocidad máxima de oxidación del hierro ferroso 5,1 (mmol Fe 2+ /mmol C·h) y el rendimiento de biomasa , 0,01 mmol C/ mmolFe 2+, valores muy similares a los de cultivos mixtos dominados por cepas de Leptospirillum . Este cultivo autóctono se utilizó en el experimento de biolixiviación realizado a diferentes densidades de pulpa, obteniendo una máxima recuperación de metales en los ensayos realizados al 1% p/v, recuperando un 90% de Cd, 60% de Zn, 30% de Cu, 25% Fe y 6% de Pb. Finalmente, se modelaron los diferentes mecanismos de lixiviación utilizando el modelo pirita como mineral obteniendo una tasa de biolixiviación de 0.316 mmol Fe 2+ /(L·h) para los mecanismos directos y una tasa de biolixiviación para los mecanismos de lixiviación indirecta y cooperativa de 0.055 Fe 2 + /(L·h)

VAMOS: a Pathfinder for the HAWC Gamma-Ray Observatory

VAMOS was a prototype detector built in 2011 at an altitude of 4100m a.s.l. in the state of Puebla, Mexico. The aim of VAMOS was to finalize the design, construction techniques and data acquisition system of the HAWC observatory. HAWC is an air-shower array currently under construction at the same site of VAMOS with the purpose to study the TeV sky. The VAMOS setup included six water Cherenkov detectors and two different data acquisition systems. It was in operation between October 2011 and May 2012 with an average live time of 30%. Besides the scientific verification purposes, the eight months of data were used to obtain the results presented in this paper: the detector response to the Forbush decrease of March 2012, and the analysis of possible emission, at energies above 30 GeV, for long gamma-ray bursts GRB111016B and GRB120328B.Comment: Accepted for pubblication in Astroparticle Physics Journal (20 pages, 10 figures). Corresponding authors: A.Marinelli and D.Zaboro