Search results for "Multivariate Analysi"
showing 10 items of 1084 documents
Factors related to the relative survival of patients with diffuse large B-cell lymphoma in a population-based study in France: does socio-economic st…
2017
IF 7.702; International audience; The survival of patients with diffuse large B-cell lymphoma has increased during the last decade as a result of addition of anti-CD20 to anthracycline-based chemotherapy. Although the trend is encouraging, there are persistent differences in survival within and between the USA and European countries suggesting that non-biological factors play a role. Our aim was to investigate the influence of such factors on relative survival of patients with diffuse large B-cell lymphoma. We conducted a retrospective, multicenter, registry-based study in France on 1165 incident cases of diffuse large B-cell lymphoma between 2002 and 2008. Relative survival analyses were p…
Archéophytes et néophytes.Pour une nouvelle détermination des marqueurs polliniques de l'anthropisation. Le cas des milieux cultivés et rudéraux de F…
2007
297p. de synthèse, annexes p.299-414, 15 articles en soumission Diplôme : Dr. d'Universite
Bienestar Subjetivo de los Adolescentes: Un Estudio Comparativo entre Argentina y Brasil
2012
ResumenEl objetivo del presente estudio es conocer y comparar los niveles de bienestar subjetivo de adolescentes argentinos y brasileños. La muestra está compuesta por 640 adolescentes de ambos sexos con edades entre los 12 y 16 años, siendo el 46.3% argentinos y el 53.7% brasileños. Se han utilizado tres escalas: el Personal Wellbeing Index (PWI), la Satisfaction with Life Scale (SWLS) y la Brief Multidimensional Students’ Life Satisfaction Scale (BMSLSS). El PWI y la BMSLSS mostraron puntuaciones más altas en los adolescentes argentinos (MPWI=82.42y MBMSLSS=41.19) que en los brasileños (MPWI=80.88y MBMSLSS=40.09), y mientras que la SWLS mostró resultados semejantes (MSWLS-Arg=31.50y MSWLS…
Real-time Patterns of Behavior Following Nociceptive Stimulation in Rats
2016
The hot-plate test is employed, in rodents, to assess the analgesic properties of drugs. The surface where the animal is placed is normally maintained at a constant temperature around 50°C or 55°C. For this reason rat’s behavior, once placed on the heated surface, can be observed only for few seconds, and a necessary interruption occurs following an a priori-established cut-off to avoid tissue injuries. Such a narrow time window dampened the assessment of fine behavioral characteristics such as the temporal structure of behavior. In the present paper we demonstrate the possibility to apply a refined multivariate approach, known as T-pattern analysis (TPA), to describe the temporal character…
Comportamiento de las correlaciones producto-momento y tetracórica-policórica en escalas ordinales: un estudio de simulación
2017
El análisis estadístico multivariante de escalas de respuesta tipo Likert, dado su empleo generalizado, resulta un tema controvertido en la comunidad científica, principalmente desde la especificación del problema de la medida. Este trabajo tiene como objeto estudiar cómo afectan diversas condiciones de estas escalas ordinales al cálculo de los coeficientes de correlación producto-momento y tetracórico-policórico. Para ello, se aplica un estudio de simulación en el que se generaron 90 bases de datos con 10 ítems cada una, controlando las siguientes variables: número de categorías de respuesta, distribución simétrica o asimétrica de los datos, tamaño de la muestra y nivel de relación entre l…
Sign and rank covariance matrices with applications to multivariate analysis
2002
A Cross-Cultural Exploratory Study of Health Behaviors and Wellbeing During COVID-19
2021
This study explored the influence of the COVID-19 pandemic on perceived health behaviors; physical activity, sleep, and diet behaviors, alongside associations with wellbeing. Participants were 1,140 individuals residing in the United Kingdom (n = 230), South Korea (n = 204), Finland (n = 171), Philippines (n = 132), Latin America (n = 124), Spain (n = 112), North America (n = 87), and Italy (n = 80). They completed an online survey reporting possible changes in the targeted behaviors as well as perceived changes in their physical and mental health. Multivariate analyses of covariance (MANCOVA) on the final sample (n = 1,131) revealed significant mean differences regarding perceived physical…
Microstructural assessment of rodent behavior in the hole-board experimental assay
2010
The aim of the present methodological article was to assess whether a microstructure of hole-exploratory activity can be demonstrated in rats tested in the hole-board, an experimental assay widely used to study anxiety-related behaviors in rodents. Six never properly described hole exploratory behavioral components were identified: active-dip, static-dip, rapid-dip, circular-sniff, point-sniff and central-sniff. Results, assessed by means of descriptive and multivariate approaches, reveal a complex microstructural organization of these behavioral elements. The hypothesis of an important role of the relationships between point-sniff and head dipping activities, in anxiety-related hole explor…
Prevalence of endodontic infection in patients with Crohn ́s disease and ulcerative colitis
2021
[Background] Previous studies have linked apical periodontitis (AP) to inflammatory bowel disease (IBD). The aim of this study was to compare the prevalence of AP and root canal treatment (RCT) in patients with ulcerative colitis (UC) and Crohn ́s disease (CD).
On the calculation of derived variables in the analysis of multivariate responses
1992
AbstractThe multivariate regression of a p × 1 vector Y of random variables on a q × 1 vector X of explanatory variables is considered. It is assumed that linear transformations of the components of Y can be the basis for useful interpretation whereas the components of X have strong individual identity. When p ≥ q a transformation is found to a new q × 1 vector of responses Y∗ such that in the multiple regression of, say, Y1∗ on X, only the coefficient of X1 is nonzero, i.e. such that Y1∗ is conditionally independent of X2, …, Xq, given X1. Some associated inferential procedures are sketched. An illustrative example is described in which the resulting transformation has aided interpretation.