940 resultados para Methods: Data Analysis


Relevância:

90.00% 90.00%

Publicador:

Resumo:

Extreme value models are widely used in different areas. The Birnbaum–Saunders distribution is receiving considerable attention due to its physical arguments and its good properties. We propose a methodology based on extreme value Birnbaum–Saunders regression models, which includes model formulation, estimation, inference and checking. We further conduct a simulation study for evaluating its performance. A statistical analysis with real-world extreme value environmental data using the methodology is provided as illustration.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Dissertação de mestrado em Engenharia Industrial

Relevância:

90.00% 90.00%

Publicador:

Resumo:

This data article is referred to the research article entitled The role of ascorbate peroxidase, guaiacol peroxidase, and polysaccharides in cassava (Manihot esculenta Crantz) roots under postharvest physiological deterioration by Uarrota et al. (2015). Food Chemistry 197, Part A, 737746. The stress duo to PPD of cassava roots leads to the formation of ROS which are extremely harmful and accelerates cassava spoiling. To prevent or alleviate injuries from ROS, plants have evolved antioxidant systems that include non-enzymatic and enzymatic defence systems such as ascorbate peroxidase, guaiacol peroxidase and polysaccharides. In this data article can be found a dataset called newdata, in RData format, with 60 observations and 06 variables. The first 02 variables (Samples and Cultivars) and the last 04, spectrophotometric data of ascorbate peroxidase, guaiacol peroxidase, tocopherol, total proteins and arcsined data of cassava PPD scoring. For further interpretation and analysis in R software, a report is also provided. Means of all variables and standard deviations are also provided in the Supplementary tables (data.long3.RData, data.long4.RData and meansEnzymes.RData), raw data of PPD scoring without transformation (PPDmeans.RData) and days of storage (days.RData) are also provided for data analysis reproducibility in R software.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

The chemical composition of propolis is affected by environmental factors and harvest season, making it difficult to standardize its extracts for medicinal usage. By detecting a typical chemical profile associated with propolis from a specific production region or season, certain types of propolis may be used to obtain a specific pharmacological activity. In this study, propolis from three agroecological regions (plain, plateau, and highlands) from southern Brazil, collected over the four seasons of 2010, were investigated through a novel NMR-based metabolomics data analysis workflow. Chemometrics and machine learning algorithms (PLS-DA and RF), including methods to estimate variable importance in classification, were used in this study. The machine learning and feature selection methods permitted construction of models for propolis sample classification with high accuracy (>75%, reaching 90% in the best case), better discriminating samples regarding their collection seasons comparatively to the harvest regions. PLS-DA and RF allowed the identification of biomarkers for sample discrimination, expanding the set of discriminating features and adding relevant information for the identification of the class-determining metabolites. The NMR-based metabolomics analytical platform, coupled to bioinformatic tools, allowed characterization and classification of Brazilian propolis samples regarding the metabolite signature of important compounds, i.e., chemical fingerprint, harvest seasons, and production regions.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Dissertação de mestrado integrado em Engenharia e Gestão de Sistemas de Informação

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Tese de Doutoramento em Biologia Ambiental e Molecular

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Inspired by the relational algebra of data processing, this paper addresses the foundations of data analytical processing from a linear algebra perspective. The paper investigates, in particular, how aggregation operations such as cross tabulations and data cubes essential to quantitative analysis of data can be expressed solely in terms of matrix multiplication, transposition and the Khatri–Rao variant of the Kronecker product. The approach offers a basis for deriving an algebraic theory of data consolidation, handling the quantitative as well as qualitative sides of data science in a natural, elegant and typed way. It also shows potential for parallel analytical processing, as the parallelization theory of such matrix operations is well acknowledged.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

OBJECTIVE: To report the authors' experience with the anomalous origin of the left coronary artery (AOLCA) from the pulmonary trunk, emphasizing preoperative data, surgical aspects and midterm results of the follow-up. METHODS: Retrospective analysis of 11 patients operated upon at the Royal Brompton Hospital from October, 84 to April, 97. RESULTS: Nine infants had heart failure (HF) and two other children presented with dyspnea and chest pain. All had ECG changes. The echocardiogram identified the anomalous origin of the coronary artery in 7 (64%) patients and hemodynamic studies were performed in 7 patients. All infants were operated upon between the 2nd and 10th month of life. Six patients were treated with aortic reimplantation of the left coronary artery, whereas five were operated upon according to the Takeuchi technique. All patients are alive, with clear improvement of the ECG changes and ventricular function, as evaluated by echocardiography. Two patients operated upon according to the Takeuchi technique required additional surgery due to severe supravalvular pulmonary stenosis. CONCLUSION: AOLCA is a rare disease. Most patients show early signs of severe HF associated with ECG findings. Surgical therapy must be instituted early in the disease, preferentially through aortic implantation of the anomalous coronary artery, with a high possibility of success. Shortly after surgery, clinical and ECG improvement, as well as normalization of left ventricular function, should be expected.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

OBJECTIVE: To evaluate the frequency of oral antihypertensive medication preceding the increase in blood pressure in patients in a university hospital, the drug of choice, and the maintained use of antihypertensive medication. METHODS: Data from January to June 1997 from the University Hospital Professor Edgard Santos Pharmacy concerning the prescriptions of all inpatients were used. Variables included in the analysis were: antihypertensive medication prescription preceding increase in blood pressure, type of antihypertensive medication, gender, clinical or surgical wards, and the presence of maintained antihypertensive medication. RESULTS: The hospital admitted 2,532 patients, 1,468 in surgical wards and 818 in medical wards. Antihypertensive medication prescription preceding pressure increase was observed in 578 patients (22.8%). Nifedipine was used in 553 (95.7%) and captopril in 25 (4.3%). In 50.7% of patients, prescription of antihypertensive medication was not associated with maintained antihypertensive medication. Prescription of antihypertensive drugs preceding elevation of blood pressure was significantly (p<0.001) more frequent on the surgical floor (27.5%; 405/1468) than on the medical floor (14.3%; 117/818). The frequency of prescription of antihypertensive drugs preceding elevation of blood pressure without maintained antihypertensive drugs and the ratio between the number of prescriptions of nifedipine and captopril were greater in surgical wards. CONCLUSION: The use of antihypertensive medication, preceding elevation of blood pressure (22.8%) observed in admitted patients is not supported by scientific evidence. The high frequency of this practice may be even greater in nonuniversity hospitals.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Objective: To test the potential mediation effect of psychosomatic symptoms on the relationship between parents' history of childhood physical victimization and current risk for child physical maltreatment. Methods: Data from the Portuguese National Representative Study of Psychosocial Context of Child Abuse and Neglect were used. Nine-hundred and twenty-four parents completed the Childhood History Questionnaire, the Psychosomatic Scale of the Brief Symptom Inventory, and the Child Abuse Potential Inventory. Results: Mediation analysis revealed that the total effect of the childhood physical victimization on child maltreatment risk was significant. The results showed that the direct effect from the parents' history of childhood physical victimization to their current maltreatment risk was still significant once parents' psychosomatic symptoms were added to the model, indicating that the increase in psychosomatic symptomatology mediated in part the increase of parents' current child maltreatment risk. Discussion: The mediation analysis showed parents' psychosomatic symptomatology as a causal pathway through which parents' childhood history of physical victimization exerts its effect on increased of child maltreatment risk. Somatization-related alterations in stress and emotional regulation are discussed as potential theoretical explanation of our findings. A cumulative risk perspective is also discussed in order to elucidate about the mechanisms that contribute for the intergenerational continuity of child physical maltreatment.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

OBJECTIVE - To analyze the trends in risk of death due to cardiovascular diseases in the northern, northeastern, southern, southeastern, and central western Brazilian geographic regions from 1979 to 1996. METHODS - Data on mortality due to cardiovascular, cardiac ischemic, and cerebrovascular diseases in 5 Brazilian geographic regions were obtained from the Ministry of Health. Population estimates for the time period from 1978 to 1996 in the 5 Brazilian geographic regions were calculated by interpolation with the Lagrange method, based on the census data from 1970, 1980, 1991, and the population count of 1996, for each age bracket and sex. Trends were analyzed with the multiple linear regression model. RESULTS - Cardiovascular diseases showed a declining trend in the southern, southeastern, and northern Brazilian geographic regions in all age brackets and for both sexes. In the northeastern and central western regions, an increasing trend in the risk of death due to cardiovascular diseases occurred, except for the age bracket from 30 to 39 years, which showed a slight reduction. This resulted from the trends of cardiac ischemic and cerebrovascular diseases. The analysis of the trend in the northeastern and northern regions was impaired by the great proportion of poorly defined causes of death. CONCLUSION - The risk of death due to cardiovascular, cerebrovascular, and cardiac ischemic diseases decreased in the southern and southeastern regions, which are the most developed regions in the country, and increased in the least developed regions, mainly in the central western region.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

A partir de las últimas décadas se ha impulsado el desarrollo y la utilización de los Sistemas de Información Geográficos (SIG) y los Sistemas de Posicionamiento Satelital (GPS) orientados a mejorar la eficiencia productiva de distintos sistemas de cultivos extensivos en términos agronómicos, económicos y ambientales. Estas nuevas tecnologías permiten medir variabilidad espacial de propiedades del sitio como conductividad eléctrica aparente y otros atributos del terreno así como el efecto de las mismas sobre la distribución espacial de los rendimientos. Luego, es posible aplicar el manejo sitio-específico en los lotes para mejorar la eficiencia en el uso de los insumos agroquímicos, la protección del medio ambiente y la sustentabilidad de la vida rural. En la actualidad, existe una oferta amplia de recursos tecnológicos propios de la agricultura de precisión para capturar variación espacial a través de los sitios dentro del terreno. El óptimo uso del gran volumen de datos derivado de maquinarias de agricultura de precisión depende fuertemente de las capacidades para explorar la información relativa a las complejas interacciones que subyacen los resultados productivos. La covariación espacial de las propiedades del sitio y el rendimiento de los cultivos ha sido estudiada a través de modelos geoestadísticos clásicos que se basan en la teoría de variables regionalizadas. Nuevos desarrollos de modelos estadísticos contemporáneos, entre los que se destacan los modelos lineales mixtos, constituyen herramientas prometedoras para el tratamiento de datos correlacionados espacialmente. Más aún, debido a la naturaleza multivariada de las múltiples variables registradas en cada sitio, las técnicas de análisis multivariado podrían aportar valiosa información para la visualización y explotación de datos georreferenciados. La comprensión de las bases agronómicas de las complejas interacciones que se producen a la escala de lotes en producción, es hoy posible con el uso de éstas nuevas tecnologías. Los objetivos del presente proyecto son: (l) desarrollar estrategias metodológicas basadas en la complementación de técnicas de análisis multivariados y geoestadísticas, para la clasificación de sitios intralotes y el estudio de interdependencias entre variables de sitio y rendimiento; (ll) proponer modelos mixtos alternativos, basados en funciones de correlación espacial de los términos de error que permitan explorar patrones de correlación espacial de los rendimientos intralotes y las propiedades del suelo en los sitios delimitados. From the last decades the use and development of Geographical Information Systems (GIS) and Satellite Positioning Systems (GPS) is highly promoted in cropping systems. Such technologies allow measuring spatial variability of site properties including electrical conductivity and others soil features as well as their impact on the spatial variability of yields. Therefore, site-specific management could be applied to improve the efficiency in the use of agrochemicals, the environmental protection, and the sustainability of the rural life. Currently, there is a wide offer of technological resources to capture spatial variation across sites within field. However, the optimum use of data coming from the precision agriculture machineries strongly depends on the capabilities to explore the information about the complex interactions underlying the productive outputs. The covariation between spatial soil properties and yields from georeferenced data has been treated in a graphical manner or with standard geostatistical approaches. New statistical modeling capabilities from the Mixed Linear Model framework are promising to deal with correlated data such those produced by the precision agriculture. Moreover, rescuing the multivariate nature of the multiple data collected at each site, several multivariate statistical approaches could be crucial tools for data analysis with georeferenced data. Understanding the basis of complex interactions at the scale of production field is now within reach the use of these new techniques. Our main objectives are: (1) to develop new statistical strategies, based on the complementarities of geostatistics and multivariate methods, useful to classify sites within field grown with grain crops and analyze the interrelationships of several soil and yield variables, (2) to propose mixed linear models to predict yield according spatial soil variability and to build contour maps to promote a more sustainable agriculture.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Esta investigación propone aproximarse al conocimiento y comprensión de los diversos mecanismos de movilidad social en Villa La Tela barrios adyacentes (ciudad de Córdoba). Si bien las poblaciones objetivo poseen diferentes niveles de vida, este proyecto no se propone la comparación entre ambos sectores urbanos, sino la identificación de diversos patrones de movilidad social vigentes. Se intenta también aproximarse indirectamente al esquema de estratificación social vigente en la ciudad de Córdoba. El equipo se propone avanzar en la definición de una estrategia metodológica que permita comprender de una manera integral los diversos mecanismos de movilidad social. Se propone articular una triangulación de métodos cuantitativos y cualitativos que aproveche las fortalezas de cada enfoque para efectuar una mirada multidisciplinaria de las condiciones de vida de la población en estudio. Se intenta también aprovechar la inserción que ya tienen algunos de los investigadores del equipo en los barrios, a fin de aportar conocimientos útiles a las organizaciones que realizan actividades de intervención social. El trabajo se propone en tres fases constituidas por tres instancias que no necesariamente se corresponden con tiempos cronológicos: análisis de información secundaria (censos de población, relevamientos de organismos gubernamentales y civiles) y de resultados de investigaciones previas; en otra fase se generará un espacio recreativo en la comunidad que permita identificar las percepciones subjetivas de los actores locales en relación a las condiciones de vida y la experiencia de movilidad social (etnodrama, etnografía fotográfica); finalmente se realizará una fase de trabajo de encuestas y entrevistas en profundidad a partir de los insumos producidos en las dos fases antes mencionadas. Se tomará para ello, como unidad de análisis socio-económica a los hogares, considerados como el espacio físico y social desde el cual se diseñan e implementan las estrategias familiares de vida de sus miembros. Se considera que el proyecto puede transferir los resultados -parciales y finales- alcanzados a las instituciones intervinientes en los barrios considerados. Esta transferencia constituye una actividad de extensión concreta, dado que las intervenciones en marcha están destinadas a mejorar las condiciones de vida de la población en términos materiales y culturales. La acción sinérgica entre las diversas instituciones que intervienen o investigan sobre estas comunidades es un compromiso, ya que de ello depende la calidad del impacto en las propias comunidades. En este sentido, la descripción de las experiencias intergeneracionales de movilidad social de los hogares y su significación subjetiva, puede considerarse de interés tanto para las instituciones como para la comunidad misma. De esta manera se espera devolver a las comunidades lo que éstas le ofrezcan al equipo de investigación, como flujo de intercambio recíproco de conocimiento y desarrollo humano. Desde el punto de vista metodológico, el equipo espera realizar una evaluación de los distintos abordajes cuantitativos y cualitativos a escala microsocial, a fin de realizar propuestas válidas para nuevas investigaciones en ámbitos locales. This research proposes to approach the knowledge and understanding of the various mechanisms of social mobility in adjacent neighborhoods of Villa La Tela (Cordoba, Argentina). Although the target populations have different levels of life, this project does not intend to compare urban areas, but the identification of different patterns of social mobility nowadays. Indirect approach is also intended to outline the existing social stratification in Cordoba city. We plan to define a methodological approach based on triangulation of quantitative and qualitative methods, exploiting the strengths of each approach to make a multidisciplinary vision of the population living conditions. Project proposes phases consisting of three instances, that do not necessarily correspond with chronological time: 1) secondary data analysis (population censuses, surveys of government agencies and civilian organizations) and previous research results; 2) promotion of a recreation space in the community to identify the subjective perceptions of local actors in relation to living conditions and experience of social mobility; 3) finally there will be a phase of survey work and deep interviews from inputs produced in the two phases mentioned above. Households will be taken as socio-economic unit, also considered as social and physical space where family strategies of life are designed and implemented by its members. We considere this project can transfer the obtained results to the institutions involved in the concerned districts. This transfer is a specific outreach activity, since the interventions in place are aimed to improving the living conditions of population in material and cultural terms.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

In Ireland the average energy cost for a household in 2006 was estimated to be €1,767, an increase of 4% on 2005 figures. With the state o f the current economic climate, home owners are beginning to realise the potential of energy efficient construction methods. The Passive House Standard offers a cost efficient and sustainable construction solution compared to the Traditional Irish construction methods. This report focuses on the Cost comparison between Passive House construction and traditional construction methods. The report also focuses on barriers that are slowing market penetration of the Passive House standard in the Irish Market. It also identifies potential energy savings that passive house occupants would benefit from. The report also highlights professional opinions on the future development o f the Passive House Standard in Ireland. The conclusions of this report are that the Passive House Standard is a more financially suitable construction solution compared to that o f a traditional dwelling complying with the Irish Building Regulations. The report also concludes that the Passive House Standard won’t be introduced as an Irish Building Regulation in the future but that it will have a big impact on future building regulations. The hypothesis o f this report is supported by data obtained from a literature review, qualitative data analysis and a case study. The report recommends that in order for the Passive House Standard to penetrate further into the Irish construction market, various barriers must be rectified. Local manufactures must start producing suitable components that suit the Passive House specification. The Building Energy Rating system must be altered in order for the Passive House to achieve its potential BER rating.

Relevância:

90.00% 90.00%

Publicador:

Resumo:

Background:Overweight is one of the major public health problems in Brazil; it is associated with dyslipidemia, which is an important risk factor for cardiovascular diseases.Objective:To evaluate the lipid profile of residents of the municipality of São Paulo, state of São Paulo, according to the nutritional status.Methods:Data from the population-based cross-sectional study ISA-Capital 2008 on a sample of residents of São Paulo were used. Participants were categorized into groups according to body mass index and age range. The levels of total cholesterol, HDL-cholesterol, LDL-cholesterol, triglycerides, and non-HDL cholesterol were measured. The association between lipid profile, nutricional status, and waist circumference was investigated. The data were processed using the survey mode of the Stata 11.0 software.Results:The prevalence of any type of dyslipidemia in the population was 59.74%, with low HDL-cholesterol dyslipidemia being the most common type. Not overweight individuals had higher mean levels of HDL-cholesterol and lower levels of LDL-cholesterol, total cholesterol, triglycerides, and non-HDL cholesterol when compared with the overweight group. The rate of inadequacy of these variables was higher in the overweight individuals, regardless of the age group, to the exception of LDL-cholesterol in the adults and elderly. A higher prevalence of isolated hypertriglyceridemia was observed in individuals with higher waist circumference among the adults and the total population.Conclusion:The results indicate an association between dyslipidemia and overweight in the population of the city of São Paulo. The most prevalent dyslipidemia in this population was low HDL-cholesterol.