Algunos ejemplos de relación entre agregación, capacidad de infiltración y erosión en suelos mediterráneos

[Resumen] Este trabajo tiene por objeto evaluar la influencia de la agregación sobre la capacidad de infiltración y la tendencia a la erosión de suelos mediterráneos sobre litología caliza. Se identifican algunas variables de agregación que influyen de una manera importante en la infiltración y la erosión, aunque es en combinación con otras características del suelo cuando estas variables explican mejor dichos parámetros. Se consiguen una serie de modelos de ecuaciones de regresión múltiple basadas en variables indicadoras de la agregación de los suelos y otras características (cobertura vegetal, materia orgánica, pedregosidad y humedad del suelo) que explican bastante bien la capacidad de infiltración, la concentración de sedimentos y la erosión de los suelos en las zonas de estudio.[Abstract] The objective of this work is to evaluate the influence of soil aggregation on soil infiltration capacity and erosion in mediterranean soils developed on limestones. Sorne key-variables related to soil aggregation which play an important role on soil infiltration capacity and erosion are identified. Especially the combination of these variables with other soil characterisitics give the most satisfactory results explaining soil infiltration and erosiono Sorne models of multiple regression equations based in variables related to aggregation and other soil characteristics (vegetation cover, organic matter, stoniness and soil moisture) are obtained. They explain quite well the infiltration capacity, the sediment concentration and the erosion in the study zones

Influencia de la estructura y usos del suelo en las características de retención hídrica de suelos mediterráneos sobre litología caliza

[Resumen] Se investigan las diferencias entre la capacidad de retención hídrica de suelos mediterráneos sobre litología caliza sometidos a diferentes usos: incendiados y bajo pastoreo intensivo. En estos mismos suelos se valoran las relaciones entre estructura del suelo y capacidad de retención hídrica a diversos puntos de la curva de retención. Agregados de pequeño tamaño y materia orgánica influyen positivamente y de manera considerable en la capacidad de retención en casi todos los puntos de la curva de retención determinados. Agregados de gran tamaño y microagregados estables en agua influyen negativamente. La combinación de agregados de tamaño 1-0,105 mm y el contenido en materia orgánica predicen bastante bien la capacidad de retención a niveles bajos de succión (pF 0,4 YpF 1).[Abstract] The differences between the water holding capacity of Mediterranean soils developed on limestones and under different land uses (burnt and overgrazed soils) are investigated. The relationships between soil structure and soil moisture characteristic at different levels of the water retention curve in these same soils are evaluated. Organic matter and small sized aggregates are positively related to the water holding capacity. Large sized aggregates and waterstable microaggregates are negatively related to the water holding capacity of the soils. The combination of aggregates at 1-0,105 mm and organic matter content predict quite well the water retention capacity at lower suction levels (pF 0,4 and pF 1)

Simulation Approach for Timing Analysis of Genetic Logic Circuits

Constructing genetic logic circuits is an application of synthetic biology in which parts of the DNA of a living cell are engineered to perform a dedicated Boolean function triggered by an appropriate concentration of certain proteins or by different genetic components. These logic circuits work in a manner similar to electronic logic circuits, but they are much more stochastic and hence much harder to characterize. In this article, we introduce an approach to analyze the threshold value and timing of genetic logic circuits. We show how this approach can be used to analyze the timing behavior of single and cascaded genetic logic circuits. We further analyze the timing sensitivity of circuits by varying the degradation rates and concentrations. Our approach can be used not only to characterize the timing behavior but also to analyze the timing constraints of cascaded genetic logic circuits, a capability that we believe will be important for design automation in synthetic biology

Morfología de vertientes y neotectónica en el Macizo de Javalambre (provincia de Teruel)

[Resumen] El modelado actual de las vertientes del macizo de Javalambre es consecuencia de tres tipos principales de procesos que actúan a partir de su elevación a comienzos del Plioceno -superior: (a) la dinámica periglaciar, (b) una etapa de activida~ tect6nica ocurrida hacia el Pleistoceno medio-superior, y (c) deslizamientos gravitacionales, translacionales y rotacionales producidos a favor de un sustrato plástico en las áreas de mayor incisión de la red -fluvial.Abstract] The present slope form in Javalambre area results from three principal types of processes which are active after its elevation in the early Upper Pliocene: (a) periglacial dynamics, (b) a tectonic phase in Middle-Upper Pleistocene, and (c) gravitational, translational and rotational landslides generated over plastic rocks in zones with a intensive fluvial incisio

Evaluation of clinical and antidiabetic treatment characteristics of different sub-groups of patients with type 2 diabetes : Data from a Mediterranean population database

Altres ajuts: Institut Universitari d'Investigació en Atenció Primària Jordi GolAltres ajuts: MSD Spain 4R16/062-1Aims: To describe the characteristics and antidiabetic treatment among type 2 diabetes patients according to the clinical conditions prioritized in the Spanish 2020 RedGDPS (Primary Care Diabetes Study Groups Network) therapeutic algorithm: obesity, older than 75 years, chronic kidney disease, cardiovascular disease, and heart failure. Methods: Retrospective, cross-sectional study. Clinical characteristics, the use of antidiabetic drugs and the KDIGO renal risk categories at 31.12.2016 were retrieved from the SIDIAP (Information System for Research in Primary Care) database (Catalonia, Spain). Results: From a total of 373,185 type 2 diabetes patients, 37% were older than 75 years, 45% obese, 33% had chronic kidney disease, 23.2% cardiovascular disease and 6.9% heart failure. Insulin was more frequently prescribed in chronic kidney disease, cardiovascular disease and heart failure whereas Sodium-Glucose cotransporter 2 inhibitors and Glucagon Like Peptide 1 receptor agonists were scarcely prescribed (2.6% and 1.4%, respectively). Among patients with severe renal failure, contraindicated drugs like metformin (16%) and sulfonylureas (6.1%) were still in use. The 2012 KDIGO renal risk categories distribution was: Low: 60.9%, Moderate: 21.6%, High: 9.8% and Very high: 7.7%. Conclusions: Almost 80% of our T2DM patients meet one of the five clinical conditions that should be considered for treatment individualization. Importantly, a relevant number of patients with severe renal failure were found to use contraindicated drugs

NFkB in the development of endothelial activation and damage in uremia: an in vitro approach

Impaired hemostasis coexists with accelerated atherosclerosis in patients with chronic kidney disease (CKD). The elevated frequency of atherothrombotic events has been associated with endothelial dysfunction. The relative contribution of the uremic state and the impact of the renal replacement therapies have been often disregarded. Plasma markers of endothelial activation and damage were evaluated in three groups of patients with CKD: under conservative treatment (predialysis), on hemodialysis, and on peritoneal dialysis. Activation of p38 MAPK and the transcription factor NFκB was assessed in endothelial cell (EC) cultures exposed to pooled sera from each group of patients. Most of the markers evaluated (VCAM-1, ICAM-1, VWF, circulating endothelial cells) were significantly higher in CDK patients than in controls, being significantly more increased in the group of peritoneal dialysis patients. These results correlated with the activation of both p38 MAPK and NFκB in EC cells exposed to the same sera samples, and also to the peritoneal dialysis fluids. Hemodialysis did not further contribute to the endothelial damage induced by the uremic state observed in predialysis patients, probably due to the improved biocompatibility of the hemodialysis technique in recent years, resulting in lower cellular activation. However, peritoneal dialysis seemed to exert a significant proinflammatory effect on the endothelium that could be related to the high glucose concentrations and glucose degradation products present in the dialysis fluid. Although peritoneal dialysis has been traditionally considered a more physiological technique, our results raise some doubts with respect to inflammation and EC damage

Endothelial damage, inflammation and immunity in chronic kidney disease

Chronic kidney disease (CKD) patients have an accelerated atherosclerosis, increased risk of thrombotic-ischemic complications, and excessive mortality rates when compared with the general population. There is also evidence of an endothelial damage in which the proinflammatory state, the enhanced oxidative stress, or the accumulation of toxins due to their reduced renal clearance in uremia play a role. Further, there is evidence that uremic endothelial cells are both involved in and victims of the activation of the innate immunity. Uremic endothelial cells produce danger associated molecular patterns (DAMPS), which by binding to specific pattern recognition receptors expressed in multiple cells, including endothelial cells, induce the expression of adhesion molecules, the production of proinflammatory cytokines and an enhanced production of reactive oxygen species in endothelial cells, which constitute a link between immunity and inflammation. The connection between endothelial damage, inflammation and defective immunity in uremia will be reviewed here

Threshold Corrections and Gauge Symmetry in Twisted Superstring Models

Threshold corrections to the running of gauge couplings are calculated for superstring models with free complex world sheet fermions. For two N=1 $SU(2)\times U(1)^5$ models, the threshold corrections lead to a small increase in the unification scale. Examples are given to illustrate how a given particle spectrum can be described by models with different boundary conditions on the internal fermions. We also discuss how complex twisted fermions can enhance the symmetry group of an N=4 $SU(3)\times U(1)\times U(1)$ model to the gauge group $SU(3)\times SU(2)\times U(1)$. It is then shown how a mixing angle analogous to the Weinberg angle depends on the boundary conditions of the internal fermions.Comment: easier to Tex version, figures to be sent separatel

¿Adelantan el diagnóstico de la diabetes tipo 2 los nuevos criterios de la Asociación Americana de Diabetes?

ObjetivoAnalizar el intervalo temporal entre la primera hiperglucemia basal ocasional (HBO) y el diagnóstico de diabetes mellitus tipo 2 (DM2) al aplicar los criterios de la OMS y de la Asociación Americana de Diabetes (ADA).DiseñoEstudio observacional, retrospectivo. Ámbito del estudio. Centro de atención primaria urbano.SujetosUn total de 104 pacientes con DM2, diagnosticados entre 1991 y 1995, con antecedentes de HBO.Mediciones o intervencionesEdad, género y otros factores de riesgo, fechas de la primera HBO (glucemia basal 3 110 mg/dl), del diagnóstico según criterios OMS (2 glucemias basales 3 140 mg/dl o 3 200 mg/dl a las 2 horas de la sobrecarga oral de glucosa [SOG]) y aplicando criterios ADA (2 glucemias basales 3 126 mg/dl) y los intervalos en meses entre ellas.ResultadosDe los 222 pacientes diagnosticados, 104 (47%) presentaban antecedentes de HBO. La edad en el momento del diagnóstico fue 60,8 años (DE, 10,1), siendo un 53% mujeres. En 51 casos (49%) se realizó SOG. La mediana (rango) del intervalo entre la primera HBO y el diagnóstico fue de 16 meses (0–101) en los que se realizó la SOG y de 45 (1–104) en los que no se practicó (p = 0,003). En estos últimos, los criterios ADA lo redujeron a 31 meses (0–97) (p < 0,001) y en 27 de ellos que no cumplían ambos criterios a la vez el intervalo fue de sólo 10 meses (0–93) (p < 0,001). Conclusiones. La no realización de la SOG comporta un retraso en el diagnóstico que puede ser contrarrestado con la aplicación de los criterios de la ADA.ObjectiveTo analyze the period of time between the first occasional fasting hyperglycaemia (OFH) and the diagnosis of type 2 diabetes mellitus (DM2), using the World Health Organization (WHO) criteria or the American Diabetes Association (ADA) criteria.DesignRetrospective, observational study.SettingUrban primary care centre.Subjects104 patients with DM2 diagnosed between 1991 and 1995 who had a previous OFH.MeasurementsAge, gender and other risk factors, dates of the first OFH (fasting plasma glucose 3 110 mg/dl), the diagnosis according to WHO criteria (2 fasting plasma glucose 3 140 mg/dl or 3 200 mg/dl two hours after the oral glucose test tolerance (OGTT)) or with the ADA criteria (2 fasting plasma glucose 3 126 mg/dl), and the intervals in months between them.ResultsOf the 222 diagnosed patients, 104 (47%) had previous OFH. Age at diagnosis was 60.8 (SD 10.1) and 53% were women. OGTT was performed in 51 cases (49%). The median (range) of the interval between the first OFH and diagnosis was 16 months (0–101) for those who were undertaken an OGTT, and 45 months (1–104) for those who were not (p = 0.003). In these last ones, ADA criteria reduced the interval to 31 months (0–97) (p < 0.001). In 27 of these patients who did not satisfy both criteria at the same time, ADA criteria reduced the interval to 10 months (0–93) (p < 0.001).ConclusionsNot performing the OGTT means a delay in diagnosis which can be countered by applying the ADA criteria

Effect of comorbidities on survival in patients > 80 years of age at onset of renal replacement therapy: data from the ERA-EDTA Registry

Background. The number of elderly patients on renal replacement therapy (RRT) is increasing. The survival and quality of life of these patients may be lower if they have multiple comorbidities at the onset of RRT. The aim of this study was to explore whether the effect of comorbidities on survival is similar in elderly RRT patients compared with younger ones. Methods. Included were 9333 patients >= 80years of age and 48352 patients 20-79 years of age starting RRT between 2010 and 2015 from 15 national or regional registries submitting data to the European Renal Association-European Dialysis and Transplantation Association Registry. Patients were followed until death or the end of 2016. Survival was assessed by Kaplan-Meier curves and the relative risk of death associated with comorbidities was assessed by Cox regression analysis. Results. Patients >= 80years of age had a greater comorbidity burden than younger patients. However, relative risks of death associated with all studied comorbidities (diabetes, ischaemic heart disease, chronic heart failure, cerebrovascular disease, peripheral vascular disease and malignancy) were significantly lower in elderly patients compared with younger patients. Also, the increase in absolute mortality rates associated with an increasing number of comorbidities was smaller in elderly patients. Conclusions. Comorbidities are common in elderly patients who enter RRT, but the risk of death associated with comorbidities is less than in younger patients. This should be taken into account when assessing the prognosis of elderly RRT patients.Peer reviewe