Search results for "Linear Model"
showing 10 items of 598 documents
Linguistic diversity and assessment in multilingual schools
2018
En un entorno en el que la diversidad lingüística es natural, la metodología de evaluación afronta nuevos retos. La equidad en el proceso evaluativo aconseja la consideración de aspectos relacionados con las características psicométricas de las pruebas, el desarrollo de la competencia lingüística, o el contexto sociolingüístico, a través de modelos explicativos sobre las variables contextuales de naturaleza lingüística que inciden en el rendimiento. Utilizando datos poblacionales de centros educativos de segundo curso de enseñanza secundaria obligatoria que ofertan más de un modelo lingüístico en la Comunidad Autónoma del País Vasco (N=45), este trabajo analiza las respuestas de 2783 estudi…
Refugees’ perception of their new life in Germany
2021
Since 2015, Germany has been hosting noticeable incoming flows of refugees and asylum seekers and despite the quality of life of refugees is expected to be improved in the aftermath of their arrival to Germany, refugees are still facing several problems of integration and economic deprivation. Using a sample of individuals from the first wave of the German IAB-BAMF-SOEP Survey of Refugees, we present some preliminary analyses on their life satisfaction (LS). A gamma glm was estimated to focus on the association among levels of LS and main socio-demographic characteristics as well as post-migration factors. Greater stability (both in the legal and personal sphere) in refugees’ lives is posit…
Insights into the derivative-based method for nonlinear mediation models
2022
Associational mediation analysis has generally relied on the linearity of models to estimate the indirect effect as a product of regression coefficients. Very few examples of generalisations to nonlinear settings have been proposed, including a derivative-based method that, however, is far from being widely spread among scholars. In this paper, we clarify some aspects of such an approach to nonlinear mediation models, which have not been addressed by the previous literature. In addition, we run a simulation study to compare confidence intervals for the indirect effect obtained through different approaches.
Four color-measuring devices compared with a spectrophotometric reference system
2009
Abstract Objectives The objective of this study was to compare the L*C*h° color coordinates of dental color-measuring devices with those of a spectrophotometric reference system. Methods The International Commission on Illumination (CIE) L*C*h° color coordinates of ceramic samples, matching the colors of the VITA Linearguide, were recorded using four color-measuring devices (VITA Easyshade (A), VITA Easyshade compact (B), Degudent Shadepilot (C), X-Rite Shadevision (D)) and a spectrophotometric reference system under standardized test conditions. The intraclass correlation coefficients, regression lines with coefficients of determination, and mean deviations of the dental color-measuring de…
Comparison of frequency domain measures based on spectral decomposition for spontaneous baroreflex sensitivity assessment after Acute Myocardial Infa…
2021
Abstract The objective of this study is to present a new method to assess in the frequency domain the directed interactions between the spontaneous variability of systolic arterial pressure (SAP) and heart period (HP) from their linear model representation, and to apply it for studying the baroreflex control of arterial pressure in healthy physiological states and after acute myocardial infarction (AMI). The method is based on pole decomposition of the model transfer function and on the following evaluation of causal measures of coupling and gain from the poles associated to low frequency (0.04−0.15 Hz) oscillatory components. It is compared with traditional non-causal approaches for the sp…
Differential effects of sex hormones on peri- and endocortical bone surfaces in pubertal girls.
2005
Context: The role of sex steroids in bone growth in pubertal girls is not yet clear. Bone biomarkers are indicators of bone metabolic activity, but their value in predicting bone quality has not been studied in growing girls. Objective: This study examines the association of sex hormones and bone markers with bone geometry and density in pubertal girls. Design: The study was designed as a 2-yr longitudinal study in pubertal girls. Measurements were performed at baseline and at 1and 2-yr follow-ups. Setting: The study was conducted in a university laboratory. Participants: A total of 258 10- to 13-yr-old healthy girls at the baseline participated. Methods:Peripheralquantitativecomputedtomogr…
Size and subclasses of low-density lipoproteins in patients with obstructive sleep apnea.
2012
Patients with obstructive sleep apnea (OSA) have proatherogenic dyslipidemia. We analyzed predictors of low-density lipoproteins' (LDLs) size in patients with OSA. In a cross-sectional study including 58 participants with OSA (30 without the metabolic syndrome [MetS] and 28 with MetS), we evaluated the size of LDL by gradient gel electrophoresis. Compared with patients without the MetS, those with MetS showed lower LDL size ( P = .007), due to a reduction in large LDL-I particles ( P = .002) and an increase in small, dense LDL-IIIA ( P = .048) and LDL-IIIB ( P = .037). The size of LDL correlated inversely with age ( r = −.268, P = .042) and serum triglycerides ( r = −.364, P = .005), and p…
Evaluating the neurotoxic effects of lactational exposure to persistent organic pollutants (POPs) in Spanish children.
2012
Although the brain continues developing in the postnatal period, epidemiological studies on the effects of postnatal exposure to neurotoxic POPs through breast-feeding remain mostly inconclusive. Failure to detect associations between postnatal exposure and health outcomes may stem from the limitations of commonly employed approaches to assess lactational exposure. The aim of the present study was to assess whether lactational exposure to polychlorinated biphenyl-153 (PCB-153), dichlorodiphenyldichloroethylene (DDE), or hexachlorobenzene (HCB) as estimated with a physiologically based pharmacokinetic (PBPK) model, is associated with decrements in mental and psychomotor development scores of…
Estrogen receptor alpha polymorphism modifies the association between childhood exercise and bone mass: follow-up study.
2007
This follow-up study confirms our previous findings that the ER-α PvuII polymorphism (Pp) modulates the association between exercise and bone mass. The differences in bone properties of girls with consistently low physical activity (LLPA) and consistently high physical activity (HHPA) were evident only in those bearing the heterozygote ER-α genotype (Pp). In particular, areal bone mineral density of the total femur, bone mineral content and areal bone mineral density of the femoral neck, and bone mineral content and cortical thickness of the tibia shaft were significantly (p < .05) lower in the Pp girls with LLPA than in their HHPA counterparts. These findings might partly explain the ge…
Contrasting patterns of temperature related mortality and hospitalization by cardiovascular and respiratory diseases in 52 Spanish cities.
2020
Climate change is a severe public health challenge. Understanding to what extent fatal and non-fatal consequences of specific diseases are associated with temperature may help to improve the effectiveness of preventive public health efforts. This study examines the effects of temperature on deaths and hospital admissions by cardiovascular and respiratory diseases, empathizing the difference between mortality and morbidity.