Synthetic Aperture Radar Signal Processing using GPGPU

In this work an effcient parallel implementation of the Chirp Scaling Algorithm (CSA) for Synthetic Aperture Radar (SAR) processing is presented. The architecture selected for the implementation is General Purpose Graphic Processing Unit (GPGPU), as it is well suited for scientific applications and real time implementation of algorithms. The analysis of a first implementation led to several improvements which resulted in an important final speedup. Details of the issues found are explained, and the performance improvement of their correction explicitly shown

Titanium single electron transistor fabricated by electron-beam lithography

A new method to fabricate non-superconducting mesoscopic tunnel junctions by oxidation of Ti is presented. The fabrication process uses conventional electron beam lithography and shadow deposition through an organic resist mask. Superconductivity in Ti is suppressed by performing the deposition under a suitable background pressure. We demonstrate the method by making a single electron transistor which operated at $T < 0.4$ K and had a moderate charge noise of $2.5 \times 10^{-3}$ e/$\sqrt{\mathrm{Hz}}$ at 10 Hz. Based on nonlinearities in the current-voltage characteristics at higher voltages, we deduce the oxide barrier height of approximately 110 mV.Comment: 6 pages, 4 figure

Procesamiento de señales SAR: algoritmo RDA para GP-GPU

En este trabajo se presenta una solución secuencial y una paralela del algoritmo RDA (Range Doppler Algorithm) para el procesamiento de señales de radares SAR (Synthetic Aperture Radar). La solución paralela se desarrollo en C CUDA para GP-GPU (General Purpose Graphic Processing Units). Se describe la solución desarrollada, se muestran los primeros resultados y se describen las futuras optimizaciones para dicho algoritmo.WPDP- XIII Workshop procesamiento distribuido y paraleloRed de Universidades con Carreras en Informática (RedUNCI

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Background: Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. // Methods: We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung's disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. // Findings: We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung's disease) from 264 hospitals (89 in high-income countries, 166 in middle-income countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in low-income countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. // Interpretation: Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between low-income, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Mortality from gastrointestinal congenital anomalies at 264 hospitals in 74 low-income, middle-income, and high-income countries: a multicentre, international, prospective cohort study

Summary Background Congenital anomalies are the fifth leading cause of mortality in children younger than 5 years globally. Many gastrointestinal congenital anomalies are fatal without timely access to neonatal surgical care, but few studies have been done on these conditions in low-income and middle-income countries (LMICs). We compared outcomes of the seven most common gastrointestinal congenital anomalies in low-income, middle-income, and high-income countries globally, and identified factors associated with mortality. Methods We did a multicentre, international prospective cohort study of patients younger than 16 years, presenting to hospital for the first time with oesophageal atresia, congenital diaphragmatic hernia, intestinal atresia, gastroschisis, exomphalos, anorectal malformation, and Hirschsprung’s disease. Recruitment was of consecutive patients for a minimum of 1 month between October, 2018, and April, 2019. We collected data on patient demographics, clinical status, interventions, and outcomes using the REDCap platform. Patients were followed up for 30 days after primary intervention, or 30 days after admission if they did not receive an intervention. The primary outcome was all-cause, in-hospital mortality for all conditions combined and each condition individually, stratified by country income status. We did a complete case analysis. Findings We included 3849 patients with 3975 study conditions (560 with oesophageal atresia, 448 with congenital diaphragmatic hernia, 681 with intestinal atresia, 453 with gastroschisis, 325 with exomphalos, 991 with anorectal malformation, and 517 with Hirschsprung’s disease) from 264 hospitals (89 in high-income countries, 166 in middleincome countries, and nine in low-income countries) in 74 countries. Of the 3849 patients, 2231 (58·0%) were male. Median gestational age at birth was 38 weeks (IQR 36–39) and median bodyweight at presentation was 2·8 kg (2·3–3·3). Mortality among all patients was 37 (39·8%) of 93 in low-income countries, 583 (20·4%) of 2860 in middle-income countries, and 50 (5·6%) of 896 in high-income countries (p<0·0001 between all country income groups). Gastroschisis had the greatest difference in mortality between country income strata (nine [90·0%] of ten in lowincome countries, 97 [31·9%] of 304 in middle-income countries, and two [1·4%] of 139 in high-income countries; p≤0·0001 between all country income groups). Factors significantly associated with higher mortality for all patients combined included country income status (low-income vs high-income countries, risk ratio 2·78 [95% CI 1·88–4·11], p<0·0001; middle-income vs high-income countries, 2·11 [1·59–2·79], p<0·0001), sepsis at presentation (1·20 [1·04–1·40], p=0·016), higher American Society of Anesthesiologists (ASA) score at primary intervention (ASA 4–5 vs ASA 1–2, 1·82 [1·40–2·35], p<0·0001; ASA 3 vs ASA 1–2, 1·58, [1·30–1·92], p<0·0001]), surgical safety checklist not used (1·39 [1·02–1·90], p=0·035), and ventilation or parenteral nutrition unavailable when needed (ventilation 1·96, [1·41–2·71], p=0·0001; parenteral nutrition 1·35, [1·05–1·74], p=0·018). Administration of parenteral nutrition (0·61, [0·47–0·79], p=0·0002) and use of a peripherally inserted central catheter (0·65 [0·50–0·86], p=0·0024) or percutaneous central line (0·69 [0·48–1·00], p=0·049) were associated with lower mortality. Interpretation Unacceptable differences in mortality exist for gastrointestinal congenital anomalies between lowincome, middle-income, and high-income countries. Improving access to quality neonatal surgical care in LMICs will be vital to achieve Sustainable Development Goal 3.2 of ending preventable deaths in neonates and children younger than 5 years by 2030

Estudio de películas de TiO₂ decapadas por bombardeo iónico

El propósito de este trabajo es el estudio del cambio químico inducido por el bombardeo iónico de películas de TiO₂ crecidas sobre Ti policristalino de alta pureza. Los cambios químicos en la superficie bombardeada fueron seguidos mediante AES y los espectros fueron analizados mediante la técnica de análisis de Factores aplicada en forma secuencial. El estudio permitió encontrar la secuencia que sigue la reducción del TiO₂ por bombardeo iónico: TiO₂ → Ti₂O₃ → TiO →→ TiChemical changes induced by ion-bombardment on TIO₂, films grown over high purity polycristalline Ti has been followed by the use of Auger Electron Spectroscopy and analyzed through Factor Analysis technique applied in sequential mode. Our results indicate that TiO₂, is reduced by ion-bombardment followin the sequency: TiO₂ → Ti₂ O₃ → TiO → Ti.Fil: Vaquila, I.. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. ArgentinaFil: Barco, J. L. del. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. Argentin

Estructura electrónica del As₂O₅ en sus variedades cristalinas puras e hidratadas

Hemos estudiado la estructura electrónica del As₂O₅, en sus variedades cristalinas ortorrómbica y tetragonal y sus compuestos cristalinos hidratados As₂O₅ • 5/3H₂O y As̟20₅ • 4H₂O, mediante el uso de cálculos de la densidad de estados obtenidas con el método tight-binding. Se reconocen las contribuciones atómicas al espectro experimental XPS de banda de valencia. La presencia de As en entornos tetraédricos produce un pico característico, no ocurriendo lo mismo con As en entornos octaédricos. Los óxidos hidratados tienen un menor ancho de la banda de valencia.By using calculated tight-binding density of states, we have studied the electronic structure of the orthorhombic and tetragonal phases of pure As₂O₅, as well as its hydrated crystalline compounds As₂O₅ 5/3H₂O and As₂O₅ 4H₂O. We give the contribution of the atomic states to the valence band XPS spectrum. From the tetrahedral enviroments we have identified a characteristic peak but this was not possible for the octahedral enviroments. In the case of hydrates oxides we found a valence band width lesser than the pure oxides.Fil: Vaquila, I.. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. ArgentinaFil: Passeggi, Mario César Guillermo. Universidad Nacional del Litoral - CONICET. Instituto de Desarrollo Tecnológico para la Industria Química (INTEC). Santa Fe. Argentin