A numerical study of cell merger over Cuba ? Part II: sensitivity to environmental conditions

International audienceIn the first part of this study, an external 3-D ambient field (3d-field) was used to initiate a simulation (Sim1). In this paper, the influence of the 3-D field in the occurrence of the cloud merger simulated in Sim1 is studied. The surface convergence was very important to supply the lifting necessary for the development of new the convection. The interaction of the gust front from an old cloud with the environmental wind, as well as the interaction between the two gust fronts, were the main factors that enhanced the surface convergence. A favorable perturbation pressure gradient was also found to intensify this mechanism. The formation and development of a new cloud from the cloud bridge was the main feature for the occurrence of the cloud merger. The influence of the wind shear components and the relative humidity (RH) in the occurrence of the cloud merger was also analyzed. The parallel wind shear component and the large RH present in the zone of study had a positive contribution to the occurrence of the cloud merger. However, the perpendicular wind shear component did not provide the main forced lifting which would be capable of generating the new convection along the direction between interacting clouds. A high resolution simulation corroborated that the cloud merger was correctly simulated and it was not obtained by unrealistic effects due to the coarse resolution employed. It evidenced that when the horizontal resolution is improved, the life cycle of each cloud and the different processes related to their interactions are better described

A numerical study of cell merger over Cuba ? Part I: implementation of the ARPS/MM5 models

International audienceOn 21 July 2001 a number of severe storms developed over the region of Camaguey, Cuba, which were observed by radar. A numerical simulation was performed in order to realistically reproduce the development of the storms observed that day. The mesoscale model MM5 was used to determine the initial, boundary and update conditions for the storm-scale simulation with the model ARPS. Changes to the source code of ARPS were made in order to assimilate the output from the MM5 as input data and a new land-use file with a 1-km horizontal resolution for the Cuban territory was created. A case representing the merger between cells at different stages of development was correctly reproduced by the simulation and is in good agreement with radar observations. The state of development of each cell, the time when the merger occurred, starting from the formation of clouds, the propagation motion of the cells and the increase in precipitation, due to the growth of the area after the merger, were correctly reproduced. Simulated clouds matched the main characteristics of the observed radar echoes, though in some cases, reflectivity tops and horizontal areas were overestimated. Maximum reflectivity values and the heights where these maximum values were located were in good agreement with radar data, particularly when the model reflectivity was calculated without including the snow. The MM5/ARPS configuration introduced in this study, improved sensibly the ability to simulate convective systems, thereby enhancing the local forecasting of convection in the region

Evaluación de la calidad de los diagnósticos premortem de causas de muerte en las autopsias del Hospital Clínico Universitario de Valencia (1985-1992)

Se estudiaron 998 autopsias realizadas en el Servicio de Anatomía Patológica del Hospital Clínico Universitario de Valencia entre 1985 y 1992, introducidas y procesadas en el Sistema Automatizado de Registro y Control de Anatomía Patológica (SARCAP) en el Hospital «Hermanos Ameijeiras» de La Habana, Cuba. Los principales resultados fueron: predominio del sexo masculino y las edades avanzadas; las principales causas básicas de muerte fueron los tumores malignos, la ateromatosis coronaria, la cirrosis hepática y el SIDA, y las principales causas directas de muerte fueron la bronconeumonía, la extensión del cáncer y el tromboembolismo pulmonar. Hubo 10,6% de discrepancias diagnósticas premortem y postmortem en la Causa Básica de Muerte (CBM) y 30,7% en la Causa Directa de Muerte (CDM). Se destaca la importancia del estudio multicausal de la muerte y la utilidad del SARCAP para la creación de una base de datos de todas autopsias realizadas en el Hospital Universitario de Valencia y que forme parte de una base de datos de todas las autopsias Iberoamericana.998 necropsies carried out in the Department of Pathology of the University Hospital of Valencia between 1985 and 1992 were evaluated and the data obtained was analyzed by the Pathology Registry and Automated Control System (PRACS) at the «Hermanos Ameijeiras» Hospital in La Habana (Cuba). The results showed a predominance of elderly males and that the principal, basic causes of death (BCD) were malignant tumours, coronary atheromatosis, hepatic cirrhosis and AIDS. The major direct causes of death (DCD) were broncopneumonia, tumour progression and thromboembolism in the lung. A 10.6% discrepancy was found between the pre- and post-mortem results of BCD and a 30.7% discrepancy in the results of DCD. It was concluded that a multicausal study of death is important and that the PRACS is a useful tool for creating a common database of all the necropsies performed in the University Hospital of Valencia within an Iberoamerican network.Llombart Bosch, Antonio, [email protected] ; Ferrandez Izquierdo, Antonio, [email protected]

A novel presenilin 1 mutation (L174M) in a large Cuban family with early onset Alzheimer disease.

We studied a Cuban family with presenile dementia (autosomal dominant) consisting of 281 members within six generations, the proband descended from a Spanish founder. Mean age at onset was 59 years of age. Memory impairment was the main symptom in all patients, additionally, ischemic episodes were described in 4 (n = 18) patients. Neuropathological examination of brain material (1 patient) revealed neuronal loss, amyloid plaques, and neurofibrillary tangles. Thirty DNA samples were genotyped (regions on chromosome 1, 3, 10, 12, 14, 17, 19, 20, and 21). A maximum Lod score of 3.79 at theta = 0 was obtained for marker D14S43, located in a 9-cM interval in which all patients shared the same haplotype. Sequencing of the PSEN1 gene revealed a heterozygous base substitution, C520A (exon 6), which is predicted to cause an amino acid change from leucine to methionine in the TMIII of the presenilin 1 protein. The mutation was found to co-segregate with the disease phenotype and the associated disease haplotype. The C --> A change was not observed in 80 control chromosomes from the Cuban population. Leucine at position 174 is highly conserved among species and is identical in prese

Biophysical insights into the regulatory and DNA-binding mechanisms of the eukaryotic transcription factors Pax5 and Ets1

Transcription factors are proteins that bind at promoter and enhancer sites to regulate gene expression. In this thesis, I used NMR spectroscopy and other methods to investigate the structural and biophysical basis of DNA binding by two eukaryotic transcription factors that are crucial in the development of lymphocytes, Pax5 and Ets1. In chapter 2, I describe how the two subdomains comprising the bipartite DNA-binding Paired domain of Pax5 cooperate to mediate transcriptional regulation. The N-terminal subdomain recognizes DNA sequences in a highly specific manner, whereas the C-terminal subdomain shows little sequence discrimination. The more rigid C-terminal subdomain binds DNA primarily though non-specific electrostatic interactions. In contrast, association with specific DNAs by the dynamic N-terminal subdomain involves relatively large and compensating changes in enthalpy and entropy that point to structural rearrangements upon binding. I propose that the distinct behaviors of the subdomains allow the Pax5 protein to rapidly scan non-specific genomic DNA while retaining specificity for functional regulatory sites. In chapter 3, I expand our understanding of the structural and thermodynamic basis of Ets1 autoinhibition. Previously it was reported that an intrinsically disordered serine-rich region (SRR) interacts transiently with the adjacent ETS domain to attenuate DNA binding. Although forming a dynamic fuzzy complex, I was able to use NMR spectroscopy and X-ray crystallography to provide a detailed mechanism for this inhibitory interaction. In particular, I exploited a trans peptide system to show that the SRR uses a combination of electrostatic and hydrophobic-driven interactions to sterically block the ETS domain DNA-binding interface. I also show how phosphorylation of the SRR strengthens its association with the ETS domain. Altogether, these results explain how the activity of Ets1 is regulated at the level of DNA binding through post-translational modifications that impinge upon the SRR.Science, Faculty ofGraduat

Relación entre el crecimiento de tormentas y la temperatura para algunas estaciones con información adecuada para su gestión

Los estudios a nivel mundial han constatado un aumento de la actividad de descargas eléctricas atmosféricas y su relación con el aumento de la temperatura ambiente, la temperatura de la superficie marina y la densidad de aerosoles en la atmósfera. El presente trabajo tiene como objetivo analizar la relación entre la marcha interanual de la ocurrencia de tormentas y la temperatura del aire en superficie para series suficientemente completas y sin sesgos, de las observaciones de las estaciones meteorológicas de Cuba, en el periodo 1989 – 2016. Para el estudio se utilizan los registros trihorarios de código de estado de tiempo presente y pasado para caracterizar las tormentas y los registros trihorarios de temperatura del aire en superficie de 14 estaciones cubanas en el periodo 1989 – 2016. Las series son sometidas a pruebas no paramétricas de análisis de homogeneidad y se relacionan las variables con ayuda del coeficiente de correlación de Pearson. La relación entre el por ciento de ocurrencia de observaciones con tormenta y las variables asociadas a la temperaturas no explica el crecimiento de la actividad del fenómeno