ABSTRACT
This paper presents a polarization calibration method applied to a microwave polarimeter demonstrator based on a near-infrared (NIR) frequency up-conversion stage that allows both optical correlation and signal detection at a wavelength of 1550 nm. The instrument was designed to measure the polarization of cosmic microwave background (CMB) radiation from the sky, obtaining the Stokes parameters of the incoming signal simultaneously, in a frequency range from 10 to 20 GHz. A linearly polarized input signal with a variable polarization angle is used as excitation in the polarimeter calibration setup mounted in the laboratory. The polarimeter systematic errors can be corrected with the proposed calibration procedure, achieving high levels of polarization efficiency (low polarization percentage errors) and low polarization angle errors. The calibration method is based on the fitting of polarization errors by means of sinusoidal functions composed of additive or multiplicative terms. The accuracy of the fitting increases with the number of terms in such a way that the typical error levels required in low-frequency CMB experiments can be achieved with only a few terms in the fitting functions. On the other hand, assuming that the calibration signal is known with the required accuracy, additional terms can be calculated to reach the error levels needed in ultrasensitive B-mode polarization CMB experiments.
ABSTRACT
In this work, the use of a calibration satellite (L2-CalSat) flying in formation with a Cosmic Microwave Background (CMB) polarization mission in an orbit located at the second Lagrange point, is proposed. The new generation of CMB telescopes are expected to reach unprecedented levels of sensitivity to allow a very precise measurement of the B-mode of polarization, the curl-like polarization component expected from gravitational waves coming from Starobinski inflationary models. Due to the CMB polarized signal weakness, the instruments must be subjected to very precise calibration processes before and after launching. Celestial sources are often used as external references for calibration after launch, but these sources are not perfectly characterized. As a baseline option, L2-CalSat is based on the CubeSat standard and serves as a perfectly known source of a reference signal to reduce polarization measurements uncertainty. A preliminary design of L2-CalSat is described and, according to the scanning strategy followed by the telescope, the influence of the relative position between the spacecrafts in the calibration process is studied. This new calibration element will have a huge impact on the performance of CMB space missions, providing a significant improvement in the measurements accuracy without requiring new and costly technological developments.
ABSTRACT
BACKGROUND: Traumatic brain injury (TBI) is one of the most frequent and severe neurological diseases. In the last few decades, significant advances have been made in TBI pathophysiology and monitoring, however new treatments have not emerged. Although the central nervous system (CNS) has been historically defined as an immunologically privileged organ, recent studies show the increasingly predominant role of inflammatory and apoptotic phenomena in the pathogenesis of TBI. Inflammatory response mediators can be eliminated with continuous renal replacement therapies (CRRT). Our aim was to investigate whether hemofiltration protects the brain after head trauma in an experimental study in animals. METHODS AND RESULTS: A model of TBI and CVVH was performed in anesthetized New Zealand white rabbits without acute renal failure. The experimental group TBI ( +)-CVVH ( +) was compared with a TBI ( +)-CVVH (-) and a TBI (-)-CVVH ( +) control groups. Rabbits were assessed immediately (NES1) and 24 h hours after (NES2) TBI and/or CVVH using a functional Neurological Evaluation Score (NES) and histology of the brains after sacrifice. There was evidence to support a difference of NES1 comparing with the TBI (-)-CVVH ( +), but not with TBI ( +)-CVVH (-) with only 15% of the rabbits treated with CVVH and TBI showing a favorable neurological course. The final neurological outcome (mortality at 24 h) was 0%, 22% and 53% in the TBI(-) + CVVH( +), TBI( +)-CVVH(-) and TBI( +)-CVVH( +) groups respectively. The use of hemofiltration before or after TBI did not make a difference in regards the outcome of the rabbits. There was evidence in the histology to support an increase of mild ischemia, hemorrhage and edema in the experimental group compared with the other two groups. CONCLUSIONS: CVVH in rabbits without renal failure used with the intention to protect the brain may worsen the prognosis in TBI.
ABSTRACT
In this data article, we provide a dataset of 8,982,694 Twitter posts around the coronavirus health global crisis. The data were collected through the Twitter REST API search. We used the rtweet R package to download raw data. The term searched was "Coronavirus" which included the word itself and its hashtag version. We collected the data over 23 days, from January 21 to February 12, 2020. The dataset is multilingual, prevailing English, Spanish, and Portuguese. We include a new variable created from other four variables; it is called "type" of tweets, which is useful for showing the diversity of tweets and the dynamics of users on Twitter. The dataset comprises seven databases which can be analysed separately. On the other hand, they can be crossed to set other researches, among them, trends and relevance of different topics, types of tweets, the embeddedness of users and their profiles, the retweets dynamics, hashtag analysis, as well as to perform social network analysis. This dataset can attract the attention of researchers related to different fields on knowledge, such as data science, social science, network science, health informatics, tourism, infodemiology, and others.
ABSTRACT
Introducción: la familia constituye el espacio por excelencia para el desarrollo del hombre, en el contexto es necesario angolano la existencia de pruebas validadas que permitan su evaluación. Objetivo: validar la Prueba de Percepción del Funcionamiento Familiar para la población angolana. Método: se efectuó un estudio instrumental, bajo un paradigma cuantitativo, con una muestra de 326 sujetos seleccionados aleatoriamente. El procesamiento de datos se llevó a cabo mediante el paquete estadístico SPSS/Windows 21.0, aplicándose el coeficiente Alpha de Crombach y el Análisis Factorial Exploratorio. Resultados: se reveló el ajuste a un solo factor de la prueba que explicó el 36,52 por5 ciento de la varianza acumulada, además de excelentes comunalidades y una elevada consistencia interna. Conclusiones: puede afirmarse que la prueba posee adecuadas propiedades psicométricas, permitiendo la evaluación del constructo funcionamiento familiar en la población angolana(AU)
Introduction: The family constitutes the space per excellence for the man's development; in the Angolan context, the existence is necessary of validated tests that permit its assessment. Objective: Validate the perception test of family functioning for the Angolan population. Methods: An instrumental study with a qualitative paradigm was carried out on a sample of 326 individuals randomly chosen. Data processing was performed using the statistical package SPSS in Windows 21.0, applying the Cronbach's Alpha and exploratory factor analysis. Results: An adjustment to one factor only was shown for the test, which explained the 36.52 percent of accumulated variance, as well as excellent communalities and a high internal consistency. Conclusions: We can affirm that the test has adequate psychometric properties, which permits assessing the family functioning construct in the Angolan population(AU)
Subject(s)
Humans , Male , Female , Adult , Social Perception , Reproducibility of Results , Factor Analysis, Statistical , Family Relations , AngolaABSTRACT
Introducción: la familia constituye el espacio por excelencia para el desarrollo del hombre, en el contexto es necesario angolano la existencia de pruebas validadas que permitan su evaluación. Objetivo: validar la Prueba de Percepción del Funcionamiento Familiar para la población angolana. Método: se efectuó un estudio instrumental, bajo un paradigma cuantitativo, con una muestra de 326 sujetos seleccionados aleatoriamente. El procesamiento de datos se llevó a cabo mediante el paquete estadístico SPSS/Windows 21.0, aplicándose el coeficiente Alpha de Crombach y el Análisis Factorial Exploratorio. Resultados: se reveló el ajuste a un solo factor de la prueba que explicó el 36,52 porciento de la varianza acumulada, además de excelentes comunalidades y una elevada consistencia interna. Conclusiones: puede afirmarse que la prueba posee adecuadas propiedades psicométricas, permitiendo la evaluación del constructo funcionamiento familiar en la población angolana(AU)
Introduction: The family constitutes the space per excellence for the man's development; in the Angolan context, the existence is necessary of validated tests that permit its assessment. Objective: Validate the perception test of family functioning for the Angolan population. Methods: An instrumental study with a qualitative paradigm was carried out on a sample of 326 individuals randomly chosen. Data processing was performed using the statistical package SPSS in Windows 21.0, applying the Cronbach's Alpha and exploratory factor analysis.Results: An adjustment to one factor only was shown for the test, which explained the 36.52 percent of accumulated variance, as well as excellent communalities and a high internal consistency. Conclusions: We can affirm that the test has adequate psychometric properties, which permits assessing the family functioning construct in the Angolan population(AU)
Subject(s)
Humans , Male , Female , Adult , Social Perception , Reproducibility of Results , Factor Analysis, Statistical , Family Relations , AngolaABSTRACT
El objetivo fue evaluar la bondad de ajuste de 16 ecuaciones para ajustar curvas de lactancia en seis genotipos bovinos. Se analizaron registros semanales o mensuales de producción de leche de vacas Pardo Suizo Americano (n=826 lactancias), Bos indicus (BI, n=52), ¾BI»Bos taurus (BT, n=507), ½BI½BT (n=462), 3/8 BI 5/8 BT (n=167) y »BI¾BT (n=62). Los parámetros de las ecuaciones se estimaron, para cada lactancia individual, por regresión lineal y no lineal, y las comparaciones se realizaron con base en los cuadrados medios de residuales, mediante la jerarquización dentro de genotipo utilizando la prueba de Suma de Rangos de Friedman. Otros criterios adicionales fueron la proporción de casos con producción de leche diaria anormal y los casos con autocorrelación positiva. Existieron diferencias (P<0,05) en la bondad de ajuste de las ecuaciones a través de genotipos. Sin embargo, para todos los genotipos la ecuación de mejor ajuste (P<0,05) fue una reparametrización de la ecuación de Wood, la cual considera la primera fecha de muestreo como el tiempo cero.
The objective was to evaluate the goodness of fit of 16 equations to estimate lactation curves of six cattle genotypes. Monthly or weekly milk production records of Brown Swiss (n=826 lactations), Bos indicus (BI, n=52), ¾BI»Bos taurus (BT, n=507), ½BI½BT (n=462), BIBT (n=167) and »BI¾BT (n=62) cows were analyzed. Fitting of equations to individual lactations was performed by linear or non-linear regression. The residual mean squares obtained after fitting of the equations were ranked within genotype and compared by Friedmans test. Additional criteria to compare the equations were the proportion of cases of abnormal daily milk production, and cases with positive autocorrelation. Equations differed (P<0.05) on their suitability to properly describe lactation curves across genotypes. However, for all genotypes the equation of best fit (P<0.05) was a reparameterization of Woods equation in which the first test date is considered as time zero. The use of this equation is recommended to fit lactation curves of cattle genotypes such as the ones evaluated in this study.
Subject(s)
Cattle , Animals , Animals, Suckling , Cattle/metabolism , Lactation , Milk , Veterinary MedicineABSTRACT
Se hace un informe preliminar sobre los resultados de una propuesta grupal interventiva de corte psicoeducativo en 40 pacientes portadores de trastornos distímicos, seleccionados entre los pacientes atendidos en la consulta de Depresión del Hospital Psiquiátrico Provincial Docente Villa Clara durante el año 2004 y que reunieron los criterios de inclusión requerida. La intervención consto de las tres etapas y una duración de 12 semanas al cabo de los cuales fue evaluada su efectividad en términos de mejoría clínica, nivel de información sobre el tema, mejoría de las relaciones intrafamiliares y condiciones para el enfrentamiento de una crisis suicida mostrando en todos los casos resultados favorables. Se hacen recomendaciones al respecto(AU)
Subject(s)
Humans , Depressive Disorder/therapy , Psychotherapy, Group/methodsABSTRACT
Se ofrece una breve información de la proteinosis alveolar pulmonar, se señala su poca frecuencia y origen desconocido, así como la edad y el sexo en que es más propicia su aparición. Se da una definición conceptual de la misma, sus métodos diagnósticos, principales manifestaciones y evolución clínica de esta enfermedad. En la presentación del caso clínico motivo de este trabajo, se dan a conocer los síntomas, signos y exámenes complementarios realizados. Se analizan las hipótesis actuales del mecanismo de producción de la sustancia proteica intraalveolar. Finalmente se destaca el hecho de no encontrarse ningún otro caso publicado en nuestro país
Subject(s)
Middle Aged , Humans , Female , Pulmonary Alveolar ProteinosisABSTRACT
Se ofrece una breve información de la proteinosis alveolar pulmonar, se señala su poca frecuencia y origen desconocido, así como la edad y el sexo en que es más propicia su aparición. Se da una definición conceptual de la misma, sus métodos diagnósticos, principales manifestaciones y evolución clínica de esta enfermedad. En la presentación del caso clínico motivo de este trabajo, se dan a conocer los síntomas, signos y exámenes complementarios realizados. Se analizan las hipótesis actuales del mecanismo de producción de la sustancia proteica intraalveolar. Finalmente se destaca el hecho de no encontrarse ningún otro caso publicado en nuestro país
