291 research outputs found

    Contribution of water-limited ecoregions to their own supply of rainfall

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    The occurrence of wet and dry growing seasons in water-limited regions remains poorly understood, partly due to the complex role that these regions play in the genesis of their own rainfall. This limits the predictability of global carbon and water budgets, and hinders the regional management of naturalresources. Using novel satellite observations and atmospheric trajectory modelling, we unravel the origin and immediate drivers of growing-season precipitation, and the extent to which ecoregions themselves contribute to their own supply of rainfall. Results show that persistent anomalies in growing-season precipitation—and subsequent biomass anomalies—are caused by a complex interplay of land and ocean evaporation, air circulation and local atmospheric stability changes. For regions such as the Kalahari and Australia, the volumes of moisture recycling decline in dry years, providing a positive feedback that intensifies dry conditions. However, recycling ratios increase up to40%, pointing to the crucial role of these regions in generating their own supply of rainfall; transpiration in periods of water stress allows vegetation to partly offset the decrease in regional precipitation. Findings highlight the need to adequately represent vegetation–atmosphere feedbacks in models to predict biomass changes and to simulate the fate of water-limited regions in our warming climate

    Criterios de aplicación para el reconocimiento de derechos existenciales, cuando se presenta colisión entre éstos, en las decisiones del Tribunal Superior de Distrito Judicial de Manizales, Sala Laboral, entre los años 2010 y 2016, en relación con el Bloque de Constitucionalidad referente a los convenios 87 y 98 de la OIT

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    Maestría en Derecho, Facultad de Ciencias Jurídicas.El operador jurídico, más concretamente el Tribunal Superior Sala laboral, tiene una confusión. Cuando se trata de reconocer derechos existenciales y se encuentran en un mismo paralelo de importancia, no se identifica el criterio para identificarlos, es por eso que se requiere establecer a partir del año 2010 (última década), ad portas de la justicia transicional y el posconflicto, cómo opera el restablecimiento del derecho de libertad y asociación sindical, ratificados por medio del Bloque de Constitucionalidad con los Convenios 87 y 98 de la Organización Internacional de Trabajo (OIT)

    Partition Quantitative Assessment (PQA): A quantitative methodology to assess the embedded noise in clustered omics and systems biology data

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    Identifying groups that share common features among datasets through clustering analysis is a typical problem in many fields of science, particularly in post-omics and systems biology research. In respect of this, quantifying how a measure can cluster or organize intrinsic groups is important since currently there is no statistical evaluation of how ordered is, or how much noise is embedded in the resulting clustered vector. Many of the literature focuses on how well the clustering algorithm orders the data, with several measures regarding external and internal statistical measures; but none measure has been developed to statistically quantify the noise in an arranged vector posterior a clustering algorithm, i.e., how much of the clustering is due to randomness. Here, we present a quantitative methodology, based on autocorrelation, to assess this problem.Comment: 9 pages, 6 figure

    Expression of Novel Opsins and Intrinsic Light Responses in the Mammalian Retinal Ganglion Cell Line RGC-5. Presence of OPN5 in the Rat Retina

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    The vertebrate retina is known to contain three classes of photoreceptor cells: cones and rods responsible for vision, and intrinsically photoresponsive retinal ganglion cells (RGCs) involved in diverse non-visual functions such as photic entrainment of daily rhythms and pupillary light responses. In this paper we investigated the potential intrinsic photoresponsiveness of the rat RGC line, RGC-5, by testing for the presence of visual and non-visual opsins and assessing expression of the immediate-early gene protein c-Fos and changes in intracellular Ca2+mobilization in response to brief light pulses. Cultured RGC-5 cells express a number of photopigment mRNAs such as retinal G protein coupled receptor (RGR), encephalopsin/panopsin (Opn3), neuropsin (Opn5) and cone opsin (Opn1mw) but not melanopsin (Opn4) or rhodopsin. Opn5 immunoreactivity was observed in RGC-5 cells and in the inner retina of rat, mainly localized in the ganglion cell layer (GCL). Furthermore, white light pulses of different intensities and durations elicited changes both in intracellular Ca2+ levels and in the induction of c-Fos protein in RGC-5 cell cultures. The results demonstrate that RGC-5 cells expressing diverse putative functional photopigments display intrinsic photosensitivity which accounts for the photic induction of c-Fos protein and changes in intracellular Ca2+ mobilization. The presence of Opn5 in the GCL of the rat retina suggests the existence of a novel type of photoreceptor cell

    Clinical Correlation Between Computerized Tomography Findings and Pathologic Diagnosis in Patients Surgically Treated for Complex Renal Cysts in a Colombian Tertiary Center

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    IntroductionRecent data have reexamined the historical rates of malignancy observed in Bosniak IIF and III cystic lesions, and this has led to an endorsement of the use of active surveillance as the standard of care for Bosniak III renal cysts by affirming that overtreatment rates for this subgroup are close to 50%. In light of this, the present study describes the correlation between imaging studies and pathologic diagnosis in patients surgically treated for complex renal cysts in Colombia.Materials and methodsThis is a retrospective, descriptive, and observational study. We analyzed the medical histories of patients who had been surgically treated for complex renal cysts between 2010 and 2018 in the urology department of a tertiary center in Bogota, Colombia. The exclusion criteria were incomplete clinical histories and absent diagnostic images or their official interpretation.ResultsOut of the 235 urological procedures performed, nine were excluded. And 6.19% (n = 14) were cases of surgically treated complex renal cysts; 38.46% were compatible with Bosniak 46.15% were Bosniak III, and 15.38% were Bosniak IV. The percentage of renal cancer as revealed by the histopathological study was 60, 66.7 and 100 for renal cysts Bosniak IIF, III, and IV, respectively; 77.7% of these confirmed oncological cases had received a diagnosis of clear cell renal carcinoma.ConclusionsIn our study, the percentage of malignancy in patients with renal cysts Bosniak IIF and III was found to be greater compared to the findings in the recent medical literature. We believe that the management offered to the population with complex renal cysts in Colombia should be tailored to the individual risk characteristics of each patient

    Prevalencia de sarcopenia en adultos mayores de dos hogares geriátricos de Pereira, Colombia: Prevalence of sarcopenia in older adults in two retirement homes in Pereira, Colombia

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    Introduction: Is a risk factor for morbidity, mortality and disability in older adults, so its management is a priority in geriatrics. The aim of this article is to characterize a population of older adults from two geriatric homes and to establish the prevalence of sarcopenia and the degree of dependence. Methods: Cross-sectional study developed in the city of Pereira-Colombia. A population of 72 adults from 65 to 98 years of age was included, using probability sampling. Sarcopenia was determined by means of the Criteria of the European Consensus on Definition and Diagnosis of Sarcopenia, evaluating grip strength, skeletal muscle mass index, in case of sarcopenia, the severity of sarcopenia together with walking speed, and the degree of dependence according to the Barthel scale.  Results: 57 people participated. A total of 68.4% (n=39) were women. The median age was 83 years. Two percent had no sarcopenia, 9% had suspected sarcopenia, 28% had confirmed sarcopenia and 61% had severe sarcopenia. According to the Barthel scale, 31.5% were independent, 45.6% had mild, 15.8% moderate, 5.3% severe and 1.8% total dependence. Conclusions: The prevalence of sarcopenia in nursing homes in Pereira is higher compared to that reported in the literature. Similarly, being in a private nursing home does not guarantee a better physical condition and/or quality of lifeIntroducción: La sarcopenia es un factor de riesgo para morbilidad, mortalidad y discapacidad en adultos mayores, por lo que su manejo es prioridad en geriatría. El objetivo de este artículo, consiste en caracterizar una población de adultos mayores de dos hogares geriátricos y establecer la prevalencia de sarcopenia y el grado de dependencia. Métodos: Estudio de corte transversal desarrollado en la ciudad de Pereira-Colombia. Se incluyó a una población de 72 adultos desde los 65 hasta los 98 años, usando muestreo probabilístico. Se determinó la sarcopenia por medio de los Criterios del Consenso Europeo sobre Definición y Diagnóstico de Sarcopenia; evaluándose la fuerza de prensión, índice de masa muscular esquelética, en caso de presentarse sarcopenia, la severidad de esta junto a la velocidad de marcha, y el grado de dependencia según la escala de Barthel. Resultados: Participaron finalmente 57 personas. El 68,4% (n=39) eran mujeres. La mediana de la edad fue de 83 años. El 2% no presentó sarcopenia, 9% presentaban sospecha de sarcopenia, 28% tenían sarcopenia confirmada y 61% sarcopenia grave. Según la escala de Barthel, el 31,5% eran independientes, 45,6% tenían dependencia leve, 15,8% moderada, 5,3% severa y 1,8% total. Conclusiones: La prevalencia de sarcopenia en los hogares geriátricos de Pereira es mayor en comparación a la reportada en la literatura. Del mismo modo, encontrarse en un hogar geriátrico privado no garantiza una mejor condición física y/o calidad de vida

    Carga de entrenamiento y variabilidad de la frecuencia cardiaca en una exposición aguda a la hipoxia hipobárica: Estudio de caso

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    Objetivo: Analizar el control de la carga de entrenamiento en la estrategia de aclimatación empleada por dos atletas amateur (mujer y hombre) antes de una ascensión exitosa a 5460 metros. Metodología: Durante 195 días consecutivos se realizaron mediciones basales de variabilidad de la frecuencia cardiaca (VFC). Se obtuvieron cuatro muestras de sangre durante la semana previa al evento principal (Pre), inmediatamente antes de la ascensión (Pre A), después (Post A) y una semana de recuperación (Post C). Resultados: Los registros diarios de VFC matutinos parecen ser una forma útil para monitorizar el estado de equilibrio simpático-parasimpático en montañistas antes de abordar las sesiones de entrenamiento. Se observó que ambos sujetos aumentaron sus niveles de leucocitos y neutrófilos exhibiendo variaciones sobre 60% entre las condiciones pre A y post B. Eritrocitos, hematocrito y hemoglobina presentaron tras la exposición aguda a 5460 m disminuciones, lo que coincide con las diferencias porcentuales en plaquetas entre ambos sujetos (-3% y -51%). Conclusiones: Los registros diarios de VFC matutinos y de 5 minutos de duración parecen ser una forma útil para monitorizar el estado de equilibrio simpático-parasimpático. Se observaron cambios significativos en algunas células de la serie blanca

    Training load and heart rate variability in acute exposure to hypobaric hypoxia: A case study

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    Objetivo: Analizar el control de la carga de entrenamientoen la estrategia de aclimatación empleada por dos atletas amateur (mujer y hombre) antes de una ascensión exitosa a 5460 metros. Metodología: Durante 195 días consecutivos se realizaron mediciones basales de variabilidad de la frecuencia cardiaca (VFC). Se obtuvieron cuatro muestras de sangre durante la semana previa al evento principal (Pre), inmediatamente antes de la ascensión (Pre A), después (Post A) y una semana de recuperación (Post C). Resultados:Los registros diarios de VFC matutinos parecen ser una forma útil para monitorizar el estado de equilibrio simpático-parasimpático en montañistas antes de abordar las sesiones de entrenamiento. Se observó que ambos sujetos aumentaron sus niveles de leucocitos y neutrófilos exhibiendo variaciones sobre 60% entre las condiciones pre A y post B. Eritrocitos, hematocrito y hemoglobina presentaron tras la exposición aguda a 5460 m disminuciones, lo que coincide conlas diferencias porcentuales en plaquetas entre ambos sujetos (-3% y -51%). Conclusiones: Los registros diarios de VFC matutinos y de 5 minutos de duración parecen ser una forma útil para monitorizar el estado de equilibrio simpático-parasimpático. Se observaron cambios significativos en algunas células de la serie blanca.Aim: To analyzethe control of training load for an acclimatization strategy employed by two amateur athletes (female and male) prior to a successful ascent to 5460 meters. Methodology:Baseline heart rate variability (HRV) measurements were taken for 195 consecutive days. Four blood samples were taken the week before the main event (Pre), pre-ascent (Pre A), post-ascent (Post A), and one-week post-ascent (Post C). Results:Daily morning HRV recordings were useful for monitoring the state of sympathetic-parasympathetic balance in mountaineers prior to tackling training sessions. Both subjects had increased leukocytes and neutrophil levels, exhibiting variations over 60% between pre-A and post-B conditions. Erythrocytes, hematocrit, and haemoglobin decreased after acute exposure to 5460 m, coinciding with changes in platelet levels between both subjects (-3% and -51%). Conclusions:Daily morning and 5-min HRV recordings are a useful way for monitoring the state of sympathetic-parasympathetic balance. Significant changes were observed in some white blood cells

    Percutaneous Closure of Paravalvular Leaks: A Systematic Review

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    [EN] Paravalvular leak (PVL) is an uncommon yet serious complication associated with the implantation of mechanical or bioprosthetic surgical valves and more recently recognized with transcatheter aortic valves implantation (TAVI). A significant number of patients will present with symptoms of congestive heart failure or haemolytic anaemia due to PVL and need further surgical or percutaneous treatment. Until recently, surgery has been the only available therapy for the treatment of clinically significant PVLs despite the significant morbidity and mortality associated with re-operation. Percutaneous treatment of PVLs has emerged as a safe and less invasive alternative, with low complication rates and high technical and clinical success rates. However, it is a complex procedure, which needs to be performed by an experienced team of interventional cardiologists and echocardiographers. This review discusses the current understanding of PVLs, including the utility of imaging techniques in PVL diagnosis and treatment, and the principles, outcomes and complications of transcatheter therapy of PVLs. (J Interven Cardiol 2016;29:382–392

    Dispersive interactions between atoms and non planar surfaces

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    We calculate the dispersive force between a ground state atom and a non planar surface. We present explicit results for a corrugated surface, derived from the scattering approach at first order in the corrugation amplitude. A variety of analytical results are derived in different limiting cases, including the van der Waals and Casimir-Polder regimes. We compute numerically the exact first-order dispersive potential for arbitrary separation distances and corrugation wavelengths, for a Rubidium atom on top of a silicon or gold corrugated surface. We discuss in detail the inadequacy of the proximity force approximation, and present a simple but adequate approximation for computing the potential.Comment: 10 pages, 4 figure
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