PRACTICE FREQUENCY AND REASONS FOR PARTICIPATION IN PHYSICAL ACTIVITIES IN GENDER AND AGE FUNCTION OF 13-14 YEARS OLD SCHOOLCHILDREN FROM MELILLA

El presente artículo expone los resultados de un estudio dirigido a conocer la influencia del género y el curso en la frecuencia semanal y diaria de práctica de actividad física (AF), así como en los motivos de práctica de AF que manifiestan escolares de 13-14 años de Melilla. Los participantes han sido 548 escolares (267 chicos y 281 chicas) de los cursos, 1º y 2º (13 - 14 años) de cuatro centros de Educación Secundaria Obligatoria de  Melilla.  Los  datos  se  han  recogido  a  través  del  cuestionario  de  “Hábitos  de participación  en  Actividades  Físicas”.  Los  resultados  muestran  la  existencia  de diferencias significativas en función del género tanto en los niveles de participación como en la importancia que conceden a los motivos que le llevan a participar en AF y en virtud de la variable curso, siendo los alumnos de 2º los que presentan niveles más bajos  de  participación  y  menor  valoración  de  los  motivos  principales  para  la participación en AF, resultados similares a los hallados en estudios anteriores en otros contextos nacionales e internacionales.This paper presents the results of a study to determine the influence of gender and grade on weekly and daily physical activity, as well as the reasons for physical activity to show students 13-14 years of Melilla. Participants were 548 students (267 boys and 281 girls) in grade 1st and 2nd (13 - 14 years) from four secondary schools in Melilla. Data were  collected  through  the  questionnaire  of  "Habits  of  participation  in  Physical Activity." The results show the significant differences by gender in both participation levels and the importance of the reasons that made you take part in physical and sports activities. Also found significant differences under variable grade, with the 2nd grade students who have lower levels of participation and lower valuation of the main reasons for participation in physical activities, results similar to those found in previous studies other national and international contexts

Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements