908 research outputs found
A data relocation approach for terrain surface analysis on multi-GPU systems: a case study on the total viewshed problem
Digital Elevation Models (DEMs) are important datasets for modelling the line
of sight, such as radio signals, sound waves and human vision. These are
commonly analyzed using rotational sweep algorithms. However, such algorithms
require large numbers of memory accesses to 2D arrays which, despite being
regular, result in poor data locality in memory. Here, we propose a new
methodology called skewed Digital Elevation Model (sDEM), which substantially
improves the locality of memory accesses and increases the inherent parallelism
involved in the computation of rotational sweep-based algorithms. In
particular, sDEM applies a data restructuring technique before accessing the
memory and performing the computation. To demonstrate the high efficiency of
sDEM, we use the problem of total viewshed computation as a case study
considering different implementations for single-core, multi-core, single-GPU
and multi-GPU platforms. We conducted two experiments to compare sDEM with (i)
the most commonly used geographic information systems (GIS) software and (ii)
the state-of-the-art algorithm. In the first experiment, sDEM is on average
8.8x faster than current GIS software despite being able to consider only few
points because of their limitations. In the second experiment, sDEM is 827.3x
faster than the state-of-the-art algorithm in the best case
Exercise-induced mitral regurgitation and right ventricle to pulmonary circulation uncoupling across the heart failure phenotypes
Exercise-induced mitral regurgitation (Ex-MR) is one of the mechanisms that contribute to reduced functional capacity in heart failure (HF). Its prevalence is not well defined across different HF subtypes. The aim of the present study was to describe functional phenotypes and cardiac response to exercise in HFrEF, HFmrEF, and HFpEF, according to Ex-MR prevalence. A total of 218 patients with HF [146 men, 68 (59–78) yr], 137 HFrEF, 41 HFmrEF, 40 HFpEF, and 23 controls were tested with cardiopulmonary exercise test combined with exercise echocardiography. Ex-MR was defined as development of at least moderate (≥2+/4+) regurgitation during exercise. Ex-MR was highly prevalent in the overall population (52%) although differed in the subgroups as follows: 82/137 (60%) in HFrEF, 17/41 (41%) in HFmrEF, and 14/40 (35%) in HFpEF (P < 0.05). Ex-MR was associated with a high rate of ventilation (VE) to carbon dioxide production (VCO2) in all HF subtypes [31.2 (26.6–35.6) vs. 33.4 (29.6–40.5), P = 0.004; 28.1 (24.5–31.9) vs. 34.4 (28.2–36.7), P = 0.01; 28.8 (26.6–32.4) vs. 32.2 (29.2–36.7), P = 0.01] and with lower peak VO2 in HFrEF and HFmrEF. Exercise right ventricle to pulmonary circulation (RV-PC) uncoupling was observed in HFrEF and HFpEF patients with Ex-MR [peak TAPSE/SPAP: HFrEF 0.40 (0.30–0.57) vs. 0.29 (0.23–0.39), P = 0.006; HFpEF 0.44 (0.28–0.62) vs. 0.31 (0.27–0.33), P = 0.05]. HFpEF with Ex-MR showed a distinct phenotype characterized by better chronotropic reserve and peripheral O2 extraction
Use of anakinra in severe COVID-19: a case report
Coronavirus Disease 19 is a global healthcare emergency with high lethality rate. Relevant inflammatory cytokine storm is associated with severity of disease and IL1 inhibition is a cornerstone treatment for hyperinflammatory diseases. We present here the case of a patient with critical COVID-19 successfully treated with IL-1 receptor antagonist (anakinra)
On the Effect of Correlation on the Capacity of Backscatter Communication Systems
We analyse the effect of correlation between the forward and backward links
on the capacity of backscatter communication systems. To that aim, we obtain an
analytical expression for the average capacity under a correlated Rayleigh
product fading channel, as well as closed-form asymptotic expressions for the
high and low signal-to-noise ratio (SNR) regimes. Our results show that
correlation is indeed detrimental for a fixed target SNR; contrarily to the
common belief, we also see that correlation can be actually beneficial in some
instances when a fixed power budget is considered.Comment: This work has been submitted for publication. Copyright may be
transferred without notice, after which this version may no longer be
accessibl
El índice de riesgo nutricional en el Estado de México
Introducción: La información actual que existe en México sobre problemas nutricionales generalmente es a nivel nacional, lo cual diluye los datos a nivel municipal y local, situa- ción que conlleva a la nula detección de zonas más afectadas nutricionalmente.Objetivo: Describir la situación nutricional a nivel municipal en el Estado de México en 2005 a través del Índice de Riesgo Nutricional (IRN).Métodos y materiales: Se realizó un estudio descriptivo, transversal, observacional y re- trospectivo en los 125 municipios del Estado de México durante agosto 2012 y julio 2013. El IRN 2005 está integrado por 14 variables que se dividen en 3 categorías: estadísticas vitales, estadísticas sociales y variable antropométrica. Para el análisis estadístico se usó el programa SPSS y EXCEL.Resultados: En el Estado de México entre 2000 y 2005 empeoró la situación nutricional pasando de un IRN de bajo a moderado; los municipios más afectados en 2005 fueron: San José del Rincón, Donato Guerra, Villa Victoria, San Felipe del Progreso y Sultepec; 3 municipios mejoraron (18.25%) y 13 (81.25%) empeoraron su situación nutricional.Conclusiones: Un alto número de municipios del Estado de México se encuentran en una categoría de riesgo nutricional moderado, por ello es importante no minimizar el pro- blema y emprender esfuerzos para disminuir los problemas nutricionales
Challenges in the Diagnosis and Management of Bacterial Lung Infections in Solid Organ Recipients: A Narrative Review
Respiratory infections pose a significant threat to the success of solid organ transplantation, and the diagnosis and management of these infections are challenging. The current narrative review addressed some of these challenges, based on evidence from the literature published in the last 20 years. Specifically, we focused our attention on (i) the obstacles to an etiologic diagnosis of respiratory infections among solid organ transplant recipients, (ii) the management of bacterial respiratory infections in an era characterized by increased antimicrobial resistance, and (iii) the development of antimicrobial stewardship programs dedicated to solid organ transplant recipient
Correlative study on impaired prostaglandin E2 regulation in EAT and maladaptive cardiac remodeling via EPAC2 and ST2 signaling in overweight CVD subjects
There is recent evidence that the dysfunctional responses of a peculiar visceral fat deposit known as epicardial adipose tissue (EAT) can directly promote cardiac enlargement in the case of obesity. Here, we observed a newer molecular pattern associated with LV dysfunction mediated by prostaglandin E2 (PGE(2)) deregulation in EAT in a cardiovascular disease (CVD) population. A series of 33 overweight CVD males were enrolled and their EAT thickness, LV mass, and volumes were measured by echocardiography. Blood, plasma, EAT, and SAT biopsies were collected for molecular and proteomic assays. Our data show that PGE(2) biosynthetic enzyme (PTGES-2) correlates with echocardiographic parameters of LV enlargement: LV diameters, LV end diastolic volume, and LV masses. Moreover, PTGES-2 is directly associated with EPAC2 gene (r = 0.70, p < 0.0001), known as a molecular inducer of ST2/IL-33 mediators involved in maladaptive heart remodelling. Furthermore, PGE(2) receptor 3 (PTEGER3) results are downregulated and its expression is inversely associated with ST2/IL-33 expression. Contrarily, PGE(2) receptor 4 (PTGER4) is upregulated in EAT and directly correlates with ST2 molecular expression. Our data suggest that excessive body fatness can shift the EAT transcriptome to a pro-tissue remodelling profile, may be driven by PGE(2) deregulation, with consequent promotion of EPAC2 and ST2 signalling
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