546 research outputs found

    Efectividad de una intervención motivacional breve para procesos de cambio en jóvenes colombianos consumidores de marihuana

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    Estudio de casoEste trabajo establece la efectividad de una intervención motivacional breve para procesos de cambio frente al consumo de marihuana en jóvenes colombianos. El programa de prevención selectiva fue implementado mediante la estrategia de taller y los parámetros del modelo transteórico. La intervención motivacional breve afectó los procesos de cambio asociados al consumo de marihuana, siendo efectiva para la muestra seleccionada.1. ANTECEDENTES TEÓRICOS Y EMPÍRICOS 2. JUSTIFICACIÓN Y PLANTEAMIENTO DEL PROBLEMA 3. OBJETIVOS 4. VARIABLES 5. HIPÓTESIS 6. MÉTODO 7. RESULTADOS 8. DISCUSIÓN REFERENCIAS APÉNDICESMaestríaMagister en Psicologí

    Determining emotional profile based on microblogging analysis

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    First Online 30 August 2019In general, groups of people are formed because of the similarities and affinities that members have with each other. Musical preferences, soccer teams or even similar behaviours are examples of similarities and affinities that motivate group formation. In social media, identifying these affinities is a difficult task because personal information is not easily identified. In this paper we present an alternative to identifying similarities between authors and their most frequent audience in Twitter, using emotional and grammatical writing style analysis. Through this study it is possible to define the creation of an emotional profile entirely based on the interactions of people, thus allowing software like chatbots to “learn emotions” and provide emotionally acceptable responses.This work has been supported by FCT – Fundação para a Ciéncia e Tecnologia within the Project Scope: UID/CEC/00319/2019

    The structure of oppositionality: Response disposition and situational aspects

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    Background: The Amsterdam Scale of Oppositionality (ASO) is a recently developed self-report instrument to measure the full range of oppositionality. It was used to test the assumption that oppositionality can best be conceptualized as a combination of emotions and behaviors varying across contexts, i.e., with parents, peers and authority figures. Method: The sample consisted of 560 boys and 598 girls, aged 8 to 12 years. The thirty items of the ASO, grouped in item parcels, were analyzed using confirmatory factor analyses. Results: Results confirmed the main hypothesis. The best fitting models contained strongly related emotional and behavioral factors and three mutually related situational factors. Oppositionality appeared to be to a large extent situation-specific. Girls are more affected by the situation than boys and show less oppositionality only outside the family context. Conclusions: Results are discussed with respect to the concept of oppositionality, varying expectations for interpersonal consequences, and implications for clinical assessment and studies of inter-informant reliability

    Comparison of I-131 Radioimmunotherapy Tumor Dosimetry: Unit Density Sphere Model Versus Patient-Specific Monte Carlo Calculations

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    High computational requirements restrict the use of Monte Carlo algorithms for dose estimation in a clinical setting, despite the fact that they are considered more accurate than traditional methods. The goal of this study was to compare mean tumor absorbed dose estimates using the unit density sphere model incorporated in OLINDA with previously reported dose estimates from Monte Carlo simulations using the dose planning method (DPMMC) particle transport algorithm. The dataset (57 tumors, 19 lymphoma patients who underwent SPECT/CT imaging during I-131 radioimmunotherapy) included tumors of varying size, shape, and contrast. OLINDA calculations were first carried out using the baseline tumor volume and residence time from SPECT/CT imaging during 6 days post-tracer and 8 days post-therapy. Next, the OLINDA calculation was split over multiple time periods and summed to get the total dose, which accounted for the changes in tumor size. Results from the second calculation were compared with results determined by coupling SPECT/CT images with DPM Monte Carlo algorithms. Results from the OLINDA calculation accounting for changes in tumor size were almost always higher (median 22%, range -1%-68%) than the results from OLINDA using the baseline tumor volume because of tumor shrinkage. There was good agreement (median -5%, range -13%-2%) between the OLINDA results and the self-dose component from Monte Carlo calculations, indicating that tumor shape effects are a minor source of error when using the sphere model. However, because the sphere model ignores cross-irradiation, the OLINDA calculation significantly underestimated (median 14%, range 2%-31%) the total tumor absorbed dose compared with Monte Carlo. These results show that when the quantity of interest is the mean tumor absorbed dose, the unit density sphere model is a practical alternative to Monte Carlo for some applications. For applications requiring higher accuracy, computer-intensive Monte Carlo calculation is needed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/90433/1/cbr-2E2011-2E0965.pd

    Internal dose assessment of 210Po using biokinetic modeling and urinary excretion measurement

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    The mysterious death of Mr. Alexander Litvinenko who was most possibly poisoned by Polonium-210 (210Po) in November 2006 in London attracted the attention of the public to the kinetics, dosimetry and the risk of this high radiotoxic isotope in the human body. In the present paper, the urinary excretion of seven persons who were possibly exposed to traces of 210Po was monitored. The values measured in the GSF Radioanalytical Laboratory are in the range of natural background concentration. To assess the effective dose received by those persons, the time-dependence of the organ equivalent dose and the effective dose after acute ingestion and inhalation of 210Po were calculated using the biokinetic model for polonium (Po) recommended by the International Commission on Radiological Protection (ICRP) and the one recently published by Leggett and Eckerman (L&E). The daily urinary excretion to effective dose conversion factors for ingestion and inhalation were evaluated based on the ICRP and L&E models for members of the public. The ingestion (inhalation) effective dose per unit intake integrated over one day is 1.7 × 10−8 (1.4 × 10−7) Sv Bq−1, 2.0 × 10−7 (9.6 × 10−7) Sv Bq−1 over 10 days, 5.2 × 10−7 (2.0 × 10−6) Sv Bq−1 over 30 days and 1.0 × 10−6 (3.0 × 10−6) Sv Bq−1 over 100 days. The daily urinary excretions after acute ingestion (inhalation) of 1 Bq of 210Po are 1.1 × 10−3 (1.0 × 10−4) on day 1, 2.0 × 10−3 (1.9 × 10−4) on day 10, 1.3 × 10−3 (1.7 × 10−4) on day 30 and 3.6 × 10−4 (8.3 × 10−5) Bq d−1 on day 100, respectively. The resulting committed effective doses range from 2.1 × 10−3 to 1.7 × 10−2 mSv by an assumption of ingestion and from 5.5 × 10−2 to 4.5 × 10−1 mSv by inhalation. For the case of Mr. Litvinenko, the mean organ absorbed dose as a function of time was calculated using both the above stated models. The red bone marrow, the kidneys and the liver were considered as the critical organs. Assuming a value of lethal absorbed dose of 5 Gy to the bone marrow, 6 Gy to the kidneys and 8 Gy to the liver, the amount of 210Po which Mr. Litvinenko might have ingested is therefore estimated to range from 27 to 1,408 MBq, i.e 0.2–8.5 μg, depending on the modality of intake and on different assumptions about blood absorption

    A novel nonparametric item response theory approach to measuring socioeconomic position: a comparison using household expenditure data from a Vietnam health survey, 2003

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    BACKGROUND: Measures of household socio-economic position (SEP) are widely used in health research. There exist a number of approaches to their measurement, with Principal Components Analysis (PCA) applied to a basket of household assets being one of the most common. PCA, however, carries a number of assumptions about the distribution of the data which may be untenable, and alternative, non-parametric, approaches may be preferred. Mokken scale analysis is a non-parametric, item response theory approach to scale development which appears never to have been applied to household asset data. A Mokken scale can be used to rank order items (measures of wealth) as well as households. Using data on household asset ownership from a national sample of 4,154 consenting households in the World Health Survey from Vietnam, 2003, we construct two measures of household SEP. Seventeen items asking about assets, and utility and infrastructure use were used. Mokken Scaling and PCA were applied to the data. A single item measure of total household expenditure is used as a point of contrast. RESULTS: An 11 item scale, out of the 17 items, was identified that conformed to the assumptions of a Mokken Scale. All the items in the scale were identified as strong items (Hi > .5). Two PCA measures of SEP were developed as a point of contrast. One PCA measure was developed using all 17 available asset items, the other used the reduced set of 11 items identified in the Mokken scale analaysis. The Mokken Scale measure of SEP and the 17 item PCA measure had a very high correlation (r = .98), and they both correlated moderately with total household expenditure: r = .59 and r = .57 respectively. In contrast the 11 item PCA measure correlated moderately with the Mokken scale (r = .68), and weakly with the total household expenditure (r = .18). CONCLUSION: The Mokken scale measure of household SEP performed at least as well as PCA, and outperformed the PCA measure developed with the 11 items used in the Mokken scale. Unlike PCA, Mokken scaling carries no assumptions about the underlying shape of the distribution of the data, and can be used simultaneous to order household SEP and items. The approach, however, has not been tested with data from other countries and remains an interesting, but under researched approach

    A longitudinal study of the self-concepts and experiential components of self-worth and affect across adolescence

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    Classic theories depict adolescence as a period of emotional "storm and stress". Empirical evidence, mostly from cross-sectional studies, suggests that emotional development presents a mixture of continuity, swings, and resilience. We examined longitudinally the average grade trends in components of self-concept and experiential components of self-worth and affect across adolescence. We followed 1,165 6th through 12th graders for 4 years using a 3-wave, accelerated longitudinal design. Participants completed self-concept scales (global self-esteem and locus of control), and the Experience Sampling Method, which provided daily self- reports on self-worth (living up to one’s own expectations, to the expectations of others, feeling successful, and feeling in control of the situation) and affect (feeling good about oneself and feeling happy). Multilevel modeling indicated that both self-esteem and locus of control grow linearly over time. Self-worth components of experience showed a concave-up trend bottoming around Grade 10, suggesting a pubertal swing and partial readjustment by the end of adolescence. Affect declined quadratically across adolescence. Compared to White students, less positive grade trends were found for Hispanics, Asian Americans, and adolescents from nontraditional families. A mixed pattern emerged for African Americans. Behind the stable growth of components of self-concept, adolescents experience a certain degree of discontinuity as to how they evaluate their capability to meet everyday life demands and their affect declines. The modifications in grade trends due to ethnicity and family structure call for studies on the possible influence exercised by family processes and school environments
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