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Search Results: 1 - 10 of 602842 matches for " María C. Valverde "
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Extreme Rainfall Indices in the Hydrographic Basins of Brazil  [PDF]
María C. Valverde, José A. Marengo
Open Journal of Modern Hydrology (OJMH) , 2014, DOI: 10.4236/ojmh.2014.41002
Abstract: The authors analyze climate extremes indices (CEI) of rainfall over the largest basins of the Brazilian territory: Amazon (AMA), S?o Francisco (SF), Tocantins (TO) and Paraná (PAR) rivers. The CEI represent the frequency of heavy precipitation events (R30mm and R95p) and short duration extreme rainfall (RX5day and RX1day). Droughts (CDDd) are identified based on two indicators: The longest dry period (CDD) and the annual cycle. The results demonstrate that CDDd, RX1day and RX5day occurred with more frequency and intensity in SF basin during El Ni?o events. CDDd was of greater magnitude in the TO basin during La Ni?a events, while an increase of RX1day occurred in El Ni?o. The strong El Ni?o events (1983 and 1997) caused more intense and frequent RX1day and R30mm over the PAR basin. Amazon droughts occurred in two out of the six El Ni?o events. Moreover, the relationship between the positive (negative) sea superficial temperatures anomalies in North (South) Tropical Atlantic and drought in AMA basin was corroborated. A gradual warming of SST was observed at the start of 2003 until it achieved a maximum in 2005 associated with the southwestern Amazon drought. The second highest anomaly of SST was in 2010 linked with drought that was more spatially extensive than the 2005 drought. The spatial distribution of annual trends showed a significant increase of CDD in south-eastern AMA, Upper SF, northern PAR and throughout the TO basins. R20mm, RX1day and RX5day tend to increase significantly in southwestern (northeast) PAR (AMA) and northwestern TO basins. Comparisons between CEI derived from daily precipitation data from Climate Prediction Center (CPCp) and of the ETA_HadCM3 model showed that the model overestimated RX1day, RX5day and CDD, in the four basins. Future scenarios show that dry periods will occur with greatest magnitude in all the basins until 2071-2099 time slice, while RX1day will be more intense in the TO and SF basins.
Mudan?as na circula??o atmosférica sobre a América do Sul para cenários futuros de clima projetados pelos modelos globais do IPCC AR4
Valverde, María C;Marengo, José A;
Revista Brasileira de Meteorologia , 2010, DOI: 10.1590/S0102-77862010000100011
Abstract: in this paper changes in the atmospheric circulation that may occur in the south america (sa) as a consequence of climate change were studied for various emission scenarios. five global models from ipcc ar4 (cccma, gfdl, hadcm3, miroc and giss) are used, for 1961-1990 (present climate) from the 20c3m model run, and for 2011-2100 for the sres a2 high emission scenario. for the future, (2011-2040, 2041-2070 and 2071-2100 time periods), in most of the models (except the miroc), the thermal continental low (chaco low) is shifted to the southwest while the bolivian high is northwest shifted during in the summer and spring. all the models show, for present climate simulation a weak subtropical southeast pacific anticyclone (spa), which would induce a reduction atmospheric subsidence. when the anticyclone is shifted southward, it would be linked with a stronger and more southward pacific itcz. for the future climate, only two models (hadcm3 and giss) showaweakerspaascomparedtothepresent. ontheotherhand,thesubtropicalsouthwestatlantic anticyclone (saa) seems to be more intense during fall and winter in almost all models (with the exception of the giss model). among the different models, the hadcm3 simulates the summer and spring circulation close to ncep reanalysis. this model does exhibit a relatively well simulated sacz, contributing with a decrease of precipitation over amazon. moreover, for the future scenarios the hadcm3 model shows changes in rainfall patterns, with positive anomalies over the west coast of peru and equator and negative anomalies over northeast of brazil, and eastern of amazon, linked to weaker and southward shifted south pacific high, enforcing the itcz over 5os, as a consequence of a decrease of the moisture convergence over amazon.
A longitudinal study of two species of Belostoma Latreille (Heteroptera: Belostomatidae): allometry and ontogeny
Iglesias, Mónica S.;Gaspe, María S.;Valverde, Alejandra C.;
Neotropical Entomology , 2008, DOI: 10.1590/S1519-566X2008000600006
Abstract: the multivariate allometric growth patterns from longitudinal data of leg and rostral segments of all instars of belostoma elegans (mayr) and b. cummingsi de carlo are presented for the first time, and the allometric coefficients are compared. the segments of the middle and hind legs present allometric coefficients with opposite polarity to those of forelegs. this discrepancy in the ontogenetic trajectories may be due to the different functions of the legs. the foreleg main function is to capture of the prey, while the middle and hind legs are adapted to swimming. the relative size of rostral segments is an important taxonomic character in belostoma. in b. cummingsi, the proximal segment is longer than the middle one, while in b. elegans they are subequal. our purpose is to explain these differences through the analysis of their ontogenetic trajectories in an attempt to illuminate the morphological differences among species from a developmental perspective.
Perforación intestinal secundaria a tuberculosis intestinal Bowel perforation secondary to intestinal tuberculosis
M. Ruiz Marín,F. M. González Valverde,J. A. Benavides Buleje,C. Escamilla Segade
Revista Espa?ola de Enfermedades Digestivas , 2009,
Abstract:
Pensar y hablar
Valverde, José María
Isegoría , 1995,
Abstract: Not available. José María Valverde, al repasar su relación personal con la filosofía recuerda como experiencia decisiva para toda su vida intelectual la toma de conciencia de que el pensar y el hablar son una sola cosa. Esto le parece la gran cuestión para la filosofía del siglo XX pero, aunque algunos pensadores la hayan asumido, mejor o peor. no son pocos los que la eluden, quizá porque desde tal perspectiva hay riesgo de ver la filosofía como algo imposible o como abuso del lenguaje , Nietzsche, el poeta-pensador Valéry, Wittgenstein y Heidegger, entre otros, ilustran este tema, que emplaza hoy no sólo a la filosofía. sino también a toda producción mental organizada sea teología, ciencia, literatura o pensamiento moral y político.
Factores predictores de riesgo de morbimortalidad en hipertensos esenciales seguidos 25 a?os
Román A,Oscar; Cuevas,Gerardo; Badilla S,Marta; Valenzuela C,María Angélica; Cumsille G,Francisco; Valverde F,Luis; González M,Alejandra; Pulgar SM,María; Pino V,Claudia;
Revista médica de Chile , 2001, DOI: 10.4067/S0034-98872001001100004
Abstract: background: among hypertensive patients, other risk factors for mortality and morbidity, besides blood pressure, must be considered when therapeutic decisions are done. aim: to assess the incidence and relevance of cardiovascular risk factors in a cohort of patients with essential hypertension. material and methods: a cohort of 1.072 treated patients with essential hypertension was followed for a period up to 25 years. four hundred eighty six were men and 586 were women, age ranged from 31 to 70 years. at entry, 56% of subjects did not have any organic complications associated to hypertension (stage i who criteria), 30% had mild alterations (stage ii) and 14% had major complications (myocardial infarction, stroke, heart failure or renal failure). likewise, 43.8% had mild, 14.5%, moderate and 41.7%, severe hypertension. patients were treated with monotherapy or combined therapy based on diuretics, beta blockers, calcium antagonists and angiotensin converting enzyme inhibitors. goal of therapy was 140/90 mm hg. risk factors associated diseases and complications were registered carefully. causes of death were obtained from hospital records and death certificates. mortality was analyzed using life tables (intention to treat method included). results: blood pressure dropped significantly during follow up from a mean of 182/110 to 154/92 mm hg. during follow up, 143 patients died and 429 complications (lethal or non lethal) were recorded. twenty four percent of patients smoked, 24% reported alcohol intake, 56% had hypercholesterolemia, 11% were obese, 13% had diabetes and 3% had gout. the proportional hazard model showed that the existence of previous complications, the presence of more than 3 risk factors, and age over 60 and mean systolic and diastolic pressure during therapy, were independent and significant risk factors for mortality. conclusions: the incidence of risk factors among our hypertensive patients is very similar to that of other national or international c
Rese a de "Madre Terrible. La diosa en la religión del México antiguo" de Blanca Solares
María del Carmen Valverde Valdés
Contribuciones desde Coatepec , 2008,
Abstract:
Tres citas nuevas del género Ischnoptera Burmeister, 1838 (Blattellinae, Blattellidae, Blattaria) para Uruguay
del C. Valverde, Alejandra;Crespo, Francisco A.;
Entomología y Vectores , 2005, DOI: 10.1590/S0328-03812005000100014
Abstract: the number of species of the genus ischnoptera reported from uruguay is doubled, increasing its number to 6. ischnoptera argentina hebard, 1921; i. bilunata saussure, 1869; and i. litostylata hebard, 1921 are reported for the first time. the available information on the species distribution is mapped.
Controlling Excitations Inversion of a Cooper Pair Box Interacting with a Nanomechanical Resonator
C. Valverde,A. T. Avelar,B. Baseia
Physics , 2011, DOI: 10.1088/0256-307X/29/8/080303
Abstract: We investigate the action of time dependent detunings upon the excitation inversion of a Cooper pair box interacting with a nanomechanical resonator. The method employs the Jaynes-Cummings model with damping, assuming different decay rates of the Cooper pair box and various fixed and t-dependent detunings. It is shown that while the presence of damping plus constant detunings destroy the collapse/revival effects, convenient choices of time dependent detunings allow one to reconstruct such events in a perfect way. It is also shown that the mean excitation of the nanomechanical resonator is more robust against damping of the Cooper pair box for convenient values of t-dependent detunings.
Hole burning in a nanomechanical resonator coupled to a Cooper pair box
C. Valverde,A. T. Avelar,B. Baseia
Physics , 2011, DOI: 10.1088/1674-1056/21/3/030308
Abstract: We propose a scheme to create holes in the statistical distribution of excitations of a nanomechanical resonator. It employs a controllable coupling between this system and a Cooper pair box. The success probability and the fidelity are calculated and compared with those obtained in the atom-field system via distinct schemes. As an application we show how to use the hole-burning scheme to prepare (low excited) Fock states.
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