894 resultados para datos panel


Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anàlisi estadístic de dades composicionals dels planetes

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this work was to study the influence of cyanogenesis on the onset of irreversible tapping panel dryness (TPD) and the physiological and histological aspects of secondary phloem in the trunk (tapping panel) of rubber trees (Hevea spp.). Two cyanogenic compounds, linamarin and KCN, were applied separately on the trunk bark of healthy mature trees belonging to two Brazilian clones (Fx 4098 and Fx 3899). Changes in histology, latex pressure potential (ΨP) and cyanogenic potential (HCNp) were followed in the trunk inner barks. In addition, the HCNp levels were determined in TPD-affected plants of both clones. The applications of linamarin or KCN in healthy plants decreased latex ΨP, and formed tylosoids associated with in situ coagulation of latex. The clone Fx 4098 had the higher HCNp and showed the quicker and stronger responses to the cyanogenic compounds. Plants with TPD syntoms had a higher HCNp than the untreated healthy ones. Since histological changes are also structural markers of early TPD, it can be inferred that excessive release of cyanide can induce it in sensitive rubber clones

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The discussion about setting up a program for lung cancer screening was launched with the publication of the results of the National Lung Screening Trial, which suggested reduced mortality in high-risk subjects undergoing CT screening. However, important questions about the benefit-harm balance and the details of a screening program and its cost-effectiveness remain unanswered. A panel of specialists in chest radiology, respiratory medicine, epidemiology, and thoracic surgery representing all Swiss university hospitals prepared this joint statement following several meetings. The panel argues that premature and uncontrolled introduction of a lung cancer screening program may cause substantial harm that may remain undetected without rigorous quality control. This position paper focuses on the requirements of running such a program with the objective of harmonizing efforts across the involved specialties and institutions and defining quality standards. The underlying statement includes information on current evidence for a reduction in mortality with lung cancer screening and the potential epidemiologic implications of such a program in Switzerland. Furthermore, requirements for lung cancer screening centers are defined, and recommendations for both the CT technique and the algorithm for lung nodule assessment are provided. In addition, related issues such as patient management, registry, and funding are addressed. Based on the current state of the knowledge, the panel concludes that lung cancer screening in Switzerland should be undertaken exclusively within a national observational study in order to provide answers to several critical questions before considering broad population-based screening for lung cancer.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El objetivo principal del TFC es la construcción y explotación de un almacén de datos. El proceso de trabajo se basa en la ejecución de un caso práctico, en el cual se presenta un escenario en el que se necesita desarrollar un almacén de datos para la Fundació d'Estudis per a la Conducció Responsable, la cual desea estudiar la evolución del número de desplazamientos en vehículo de motor en Cataluña así como analizar las posibles correlaciones entre medios de locomoción, perfiles de conductores y algunas variables de seguridad vial.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Este trabajo consiste en la creación de un almacén de datos y su explotación por medio de un conjunto de informes. El almacén de datos registra información relativa al tránsito de vehículos, número de licencias, conductores, etc., la cual está organizada por municipios y años.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Construcción y explotación de un almacén de datos para el análisis de información sobre el tránsito de vehículos.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

El caso práctico de este trabajo consiste, en esencia, en la creación de un almacén de datos para nuestro cliente ficticio ¿FECRES¿, así como la realización de varios informes. Algunos de estos informes serán estáticos y otros dinámicos (cubos OLAP).

Relevância:

20.00% 20.00%

Publicador:

Resumo:

La forma en que adolescentes y jóvenes utilizan las tecnologías de la información y la comunicación es diferente a la de la población adulta. Las prácticas son más intensivas y extensivas entre l@s más jóvenes, tal y como muestran las estadísticas disponibles. Este resultado, ampliamente conocido, nos lleva a preguntarnos ¿qué implicaciones tienen estas prácticas comunicativas de las generaciones más jóvenes?Tomando como punto de partida algunos estudios que analizan la situación, tanto en España como en otros países, revisaremos los cambios que ya se están produciendo en ámbitos que van desde el aprendizaje a la socialización. Revisaremos, asimismo, algunas propuestas que intentan dar una explicación teórica global de las prácticas y las actitudes comunicativas de jóvenes y adolescentes. En el análisis tendremos en cuenta el creciente proceso de individualización de nuestras sociedades y la presencia habitual de comunidades de práctica permanentemente conectadas que caracterizan a estas generaciones.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Abordamos el Informe del Grupo de Alto Nivel sobre la Coherencia en todo el Sistema de las Naciones Unidas («Informe del Grupo») y el proceso de reforma de las Naciones Unidas del que forma parte como grupos de la sociedad civil que tienen una larga experiencia por lo que se refiere a propugnar reformas del sistema de las Naciones Unidas.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

T helper cell (Th) functions are crucial for proper immune defence against various intra- and extracellular pathogens. According to the specific immune responses, Th cells can be classified into subtypes, Th1 and Th2 cells being the most frequently characterized classes. Th1 and Th2 cells interact with other immune cells by regulating their functions with specific cytokine production. IFN, IL-2 and TNF- are the cytokines predominantly produced by Th1 cells whereas Th2 cells produce Th2-type cytokines, such as IL-4, IL-5 and IL-13. Upon TCR activation and in the presence of polarizing cytokines, Th cells differentiate into effector subtypes from a common precursor cell. IFN and IL-12 are the predominant Th1 polarizing cytokines whereas IL-4 directs Th2 polarization. The cytokines mediate their effects through specific receptor signalling. The differentiation process is complex, involving various signalling molecules and routes, as well as functions of the specific transcription factors. The functions of the Th1/Th2 cells are tightly regulated; however, knowledge on human Th cell differentiation is, as yet, fairly poor. The susceptibility for many immune-mediated disorders often originates from disturbed Th cell responses. Thus, research is needed for defining the molecular mechanisms involved in the differentiation and balanced functions of the Th cells. Importantly, the new information obtained will be crucial for a better understanding of the pathogenesis of immune-mediated disorders, such as asthma or autoimmune diseases. In the first subproject of this thesis, the role of genetic polymorphisms in the human STAT6, GATA3 and STAT4 genes were investigated for asthma or atopy susceptibility in Finnish asthma families by association analysis. These genes code for key transcription factors regulating Th cell differentiation. The study resulted in the identification of a GATA3 haplotype that associated with asthma and related traits (high serum IgE level). In the second subproject, an optimized method for human primary T cell transfection and enrichment was established. The method can be utilized for functional studies for the selected genes of interest. The method was also utilized in the third subproject, which aimed at the identification of novel genes involved in early human Th cell polarization (0-48h) using genome-wide oligonucleotide arrays. As a result, numerous genes and ESTs with known or unknown functions were identified in the study. Using an shRNA knockdown approach, a panel of novel IL-4/STAT6 regulated genes were identified in the functional studies of the genes. Moreover, one of the genes, NDFIP2, with a previously uncharacterized role in the human Th differentiation, was observed to promote IFN production of the differentiated Th1 cells. Taken together, the results obtained have revealed potential new relevant candidate genes serving as a basis for further studies characterizing the detailed networks involved in the human Th cell differentiation as well as in the genetic susceptibility of Th-mediated immune disorders.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Panel data can be arranged into a matrix in two ways, called 'long' and 'wide' formats (LFand WF). The two formats suggest two alternative model approaches for analyzing paneldata: (i) univariate regression with varying intercept; and (ii) multivariate regression withlatent variables (a particular case of structural equation model, SEM). The present papercompares the two approaches showing in which circumstances they yield equivalent?insome cases, even numerically equal?results. We show that the univariate approach givesresults equivalent to the multivariate approach when restrictions of time invariance (inthe paper, the TI assumption) are imposed on the parameters of the multivariate model.It is shown that the restrictions implicit in the univariate approach can be assessed bychi-square difference testing of two nested multivariate models. In addition, commontests encountered in the econometric analysis of panel data, such as the Hausman test, areshown to have an equivalent representation as chi-square difference tests. Commonalitiesand differences between the univariate and multivariate approaches are illustrated usingan empirical panel data set of firms' profitability as well as a simulated panel data.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The objective of this paper is to examine whether informal labor markets affect the flows of Foreign Direct Investment (FDI), and also whether this effect is similar in developed and developing countries. With this aim, different public data sources, such as the World Bank (WB), and the United Nations Conference on Trade and Development (UNCTAD) are used, and panel econometric models are estimated for a sample of 65 countries over a 14 year period (1996-2009). In addition, this paper uses a dynamic model as an extension of the analysis to establish whether such an effect exists and what its indicators and significance may be.