286 research outputs found

    Stromal cell-derived factor 1 polymorphism in patients infected with HIV and implications for AIDS progression in Tunisia

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    Sameh Amara1, Jorge Domenech2, Faouzi Jenhani31Cellular Immunology and Cytometry, National Blood Transfusion Center, Tunis, Tunisia; 2Hematopoiesis Laboratory, Faculty of Medicine, University of Tours, Tours, France; 3Faculty of Pharmacy, Unit Research in Immunology, Tunis, TunisiaBackground: An interesting finding in the epidemiology of human immunodeficiency virus (HIV) infection is that certain mutations in genes coding for chemokines, and their receptors and ligands, may confer resistance or susceptibility to HIV-1 infection and acquired immunodeficiency syndrome (AIDS) progression. The mutation most frequently studied is stromal cell-derived factor (SDF)1-3'A, a single nucleotide polymorphism in the 3' untranslated region at the 801 position of the SDF1 gene, which seems to be associated with susceptibility or resistance to diseases, including AIDS. We examined the frequency of the above polymorphisms in the Tunisian population, and evaluated their contribution to a protective genetic background against HIV infection and progression.Methods and materials: One hundred forty blood samples from HIV-infected patients from the Cellular Immunology Research Laboratory at the National Blood Transfusion Center were compared with those of 164 random blood donors from the same center. Genotyping was initially performed by polymerase chain reaction (PCR) analysis. SDF1 PCR product genomic regions were further subjected to restriction fragment length polymorphism analysis for genotype determination. Screening for the SDF1 polymorphism in the HIV-infected population yielded 56 heterozygous (40%), 52 mutation homozygous (37.1%), and 32 wild-type homozygous (22.8%) subjects. In contrast, in our healthy population, we found 70/164 heterozygous (42.6%), nine mutation homozygous (5.4%), and 85 wild-type homozygous (51.8%) subjects. The allele frequencies in the HIV-infected and healthy populations were f(SD1 3'A) = 57.1%, f(SDF1) = 42.8%, f(SDF1 3'A) = 26.8%, and f(SDF1) = 73.1%, respectively. The allelic and genotypic frequencies of the SDF1 3'A in our population show significantly higher distribution profiles compared with those observed in other Caucasian, European, and African American populations. Our results were examined by X2 test and appear to confirm an association between polymorphism and AIDS progression. A higher odds ratio (>1) was found for the SDF1-3'A allele than for the wild-type allele (<1).Conclusion: This result seems to confirm that the SDF1-3'A allele is associated with acceleration and progression from HIV infection to AIDS in the Tunisian population.Keywords: human immunodeficiency virus, SDF1 polymorphism, Tunisi

    Mobile exergaming in adolescents’ everyday life—contextual design of where, when, with whom, and how: the SmartLife case

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    Exergames, more specifically console-based exergames, are generally enjoyed by adolescents and known to increase physical activity. Nevertheless, they have a reduced usage over time and demonstrate little effectiveness over the long term. In order to increase playing time, mobile exergames may increase potential playing time, but need to be engaging and integrated in everyday life. The goal of the present study was to examine the context of gameplay for mobile exergaming in adolescents’ everyday life to inform game design and the integration of gameplay into everyday life. Eight focus groups were conducted with 49 Flemish adolescents (11 to 17 years of age). The focus groups were audiotaped, transcribed, and analyzed by means of thematic analysis via Nvivo 11 software (QSR International Pty Ltd., Victoria, Australia). The adolescents indicated leisure time and travel time to and from school as suitable timeframes for playing a mobile exergame. Outdoor gameplay should be restricted to the personal living environment of adolescents. Besides outdoor locations, the game should also be adaptable to at-home activities. Activities could vary from running outside to fitness exercises inside. Furthermore, the social context of the game was important, e.g., playing in teams or meeting at (virtual) meeting points. Physical activity tracking via smart clothing was identified as a motivator for gameplay. By means of this study, game developers may be better equipped to develop mobile exergames that embed gameplay in adolescents’ everyday life

    Multiobjective optimization of large scale photovoltaic (PV) systems design: Technico-economic and life-cycle assessment considerations

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    Solar energy systems are a source of "clean" energy. Yet, if power generation from photovoltaic (PV) systems is free from fossil fuel use and greenhouse gas (GHG) emissions, a considerable amount of energy is consumed in the manufacturing and transport of the elements of the system. Silicon is currently the most widely used material for solar cell design. In this context, life cycle assessment (LCA) studies play a major role to compare and analyze the environmental impacts of products and services along their life cycle. This work aims at determining a general methodology for designing large scale photovoltaic systems, taking into account both technico-economic and environmental considerations. In this paper, only the environmental issue tackled by Life Cycle Assessment has been implemented to quantify the environmental impacts related to three technology of crystalline silicon for photovoltaic modules (PV) that are monocrystalline, multicrystalline and ribbon silico

    Búsqueda de modelos QSAR para la actividad repelente de sesquiterpenos naturales frente al mosquito de la Fiebre Amarilla, Aedes aegypti

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    El objetivo de este trabajo ha sido desarrollar modelos QSAR aplicando la topología molecular y el análisis de regresión multilineal para la predicción de la repelencia espacial frente al mosquito de la Fiebre Amarilla,  Aedesa egypti  de un grupo de sesquiterpenos naturales. Validados los modelos, se realiza un cribado molecular y se seleccionan nuevos sesquiterpenos potencialmente activos

    Flipping Game Development

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    [EN] This work describes the implementation of a flip teaching alternative in an introductory game development course, using resources from a massive open online course. The results proved to achieve better grades and higher satisfaction to previous and similar lecture-based coursesLinares-Pellicer, J.; Orta-López Jorge; Izquierdo-Doménech, JJ. (2018). Flipping Game Development. IEEE Computer Graphics and Applications. 38(6):118-124. https://doi.org/10.1109/MCG.2018.2876487S11812438

    Correlation between the dioptric power, astigmatism and surface shape of the anterior and posterior corneal surfaces

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    A knowledge of the shape of the cornea is of major importance for the planning and monitoring of surgery, and for the correct diagnosis of corneal diseases. Many authors have studied the geometry of the second corneal surface in the central region and it has been stated that there is a high correlation between the central radii of curvature and asphericities of the two corneal surfaces. In this work we extend this study to a larger, central, 6 mm diameter of the cornea. Surface height data, obtained with an Oculus Pentacam from 42 eyes of 21 subjects, were analysed to yield surface power vectors. Corneal heights of both surfaces were also decomposed into low order Zernike polynomials and the correlations between each of the power vectors and low-order Zernike coefficients for the two surfaces were studied. There was not only a strong correlation between spherical powers and Zernike defocus coefficients, but also between the astigmatic components. The correspondence between the astigmatism in both surfaces found here can be of the utmost importance in planning optical surgery, since perfect spherical ablation of the first surface does not assure total correction of corneal astigmatism.This work has been partially supported by the Spanish Ministry of Education and Science through the project nr. FIS2005-05053. Julian Espinosa and Jorge Perez acknowledge financial support from the University of Alicante through the project GRE07-7P. Henryk Kasprzak acknowledges the University of Alicante for its economical support through the project Senior 08/07

    Aplicación de la topología molecular para la predicción de biodegradación anaerobia de clorofenoles

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    Se ha aplicado la topología molecular y el análisis de regresión multilineal en la búsqueda de un modelo de relación cuantitativa estructura-actividad (QSAR) capaz de predecir la capacidad de biodegradación anaerobia de un grupo de clorofenoles. Tomando el valor de la constante de velocidad de desaparición del derivado clorofenólico ,log k, como variable dependiente y los descriptores topológicos como variables independientes, se obtuvo una ecuación con tres variables y coeficientes de correlación y de predicción , R2=0.9291 y Q2=0.870. El modelo fue validado a través de una validación interna y un test de aleatoriedad. Los resultados obtenidos muestran una alta capacidad de predicción para la biodegradación de los compuestos analizados

    Internet- and mobile-based interventions for the treatment of specific phobia: A systematic review and preliminary meta-analysis

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    Internet- and mobile-based interventions (IMIs) are being developed for a wide range of psychological disorders and they showed their effectiveness in multiple studies. Specific phobia (SP) is one of the most common anxiety disorders, and research about IMIs for their treatment has also been conducted in recent years. The aim of this paper was to conduct a systematic review and preliminary meta-analysis exploring IMIs for the treatment of SP. A comprehensive search conducted in five different databases identified 9 studies (4 pre-post studies, 5 randomized controlled trials) with 7 Internet-based interventions and 2 mobile-based interventions. Results showed that exposure was the main component of all interventions, and that animal phobia was the most common subtype. Samples included children, adolescents, and adults. A preliminary meta-analysis of the included studies showed that participants receiving IMIs experienced a significant reduction of SP symptoms from pre- to post-treatment (g = 1.15). This systematic review found that there is already some evidence in the literature supporting the potential benefits of IMIs for SP. However, the number of studies included is small and more research should be carried out in the field

    On-line quizzes to evaluate comprehension and integration skills

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    This work demonstrates the use of a 2.0 tool, namely, Socrative, to evaluate one of the cross-curricular competences indicated by the Universitat Politècnica de València, specifically, comprehension and integration. It has been applied to the courses in different areas: sciences, engineering and languages. As part of its implementation, activities were proposed that could be done at the beginning, during or at the end of the class to, on the one hand, help students acquire the knowledge associated with the course(s), and on the other, gather evidence that demonstrates acquisition of said competence. The results show a high level of satisfaction by the students with the use of the Socrative tool as an element to promote active participation and the acquisition of the cross-curricular competence of comprehension and integration; therefore, its extension to other courses has been suggested
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