ResumenAlthough network usage is a generalized and beneficial phenomenon in a lot of ways, there are an increasing number of studies which warn off the psychological and

Adolescents' use of the Internet is becoming a matter of great concern for different sectors of society. The psychological and behavioural consequences of problematic Internet use in young people demands quick and effective answers. One of the major challenges in this context is the development of empirically validated tools, which would facilitate early detection and screening for potential risk cases. This is precisely the aim of this paper. Based on a sample of 1,709 secondaryschool students from Galicia (a region in northern Spain) aged 11 to 17 (M = 13.74, SD = 1.43), the analysis carried out permitted us to present a brief and simple tool (with just 11 items). It has substantial theoretical support, since both the existing background information and the views of experts from the academic and professional spheres were taken into account in the course of its development. The scale is adapted to the Spanish cultural context and to the language of young people. It has satisfactory psychometric properties in terms of reliability of the scores (α = .82), evidence of its internal structure (tested via a Confirmatory Factorial Analysis), sensitivity (81%), and specificity (82.6%). Moreover, its use enables the gradation of adolescents on a risk or problematic Internet use continuum. In our view, all of this lends it enormous applied potential in both the educational and clinical contexts. [INE], 2014), in Spain 92% of minors aged 10 to 15 are Internet users. The Web provides access to multiple sources of information, learning, leisure and personal, academic and professional development, as well as to innovative forms of communication, relation and expression. Without questioning its benefits, we should not overlook the fact that its use also involves certain associated risks and dangers (loss of privacy, contact with strangers, isolation), in addition to disconcerting practices such as cyberbullying, grooming or sexting, which are affecting increasing numbers of adolescents, considered one of the most vulnerable groups in this new environment (Castellana, Sánchez-Carbonell, Graner, & Beranuy, 2007;Echeburúa & Corral, 2010;Yang & Tung, 2007).The use that teenagers make or are able to make of Internet is a topic of concern in Spain and elsewhere (Oliva et al., 2012;Puerta-Cortés & Carbonell, 2014;Ruiz-Olivares, Lucena, Pino, & Herruzo, 2010;Smahel et al., 2012; Tsitsika, Tzavela, Mavromati and EU consortium NET ADB, 2012; Valedor do Pobo, 2011). This general concern has been heightened in recent years by the sometimes sensationalist way in which the subject is treated in the media. This has helped to create some degree of social alarm and no little scepticism among researchers and professionals, who do not consider it appropriate to speak of Internet addiction per se (Estallo, 2001;Grohol, 1999;Matute, 2001). However, others have indeed taken this step, attempting to scientific credibility to the use of this term (Cao & Su, 2007;Young, 1998). Various studies have tried to provide evidence that the behaviour of som...

The consolidation of materials concept, which consists of introducing a chemical substance (consolidant) into degraded stone, has been applied to architectural conservation. Silicon compounds such as tetraethoxysilane (TEOS) are frequently used as a base for commercial consolidant formulations due to their ability to form a siloxane polymer such as SiO 2 . However, the silica xerogels deposited into the stone show poor performance and the gels obtained are non-porous and tend to crack during the drying stage. In order to avoid the fractures and to improve gel properties, we propose the synthesis of a hybrid consolidant based on TEOS and fillers such as colloidal silica (200 nm in diameter) and hydroxy-terminated polydimethylsiloxane (PDMS-OH). Both additives enhance gel properties such as porosity and elasticity, leading to the formation of non-fractured and permeable gels. Characterization of the hybrid xerogel was carried out by nitrogen adsorption and 29 Si MAS-NMR. The properties of the hybrid xerogels were compared with those prepared from a formulation based on TEOS (T-ME) with a composition similar to a commercial product. In order to evaluate the effectiveness of the hybrid consolidant, it was applied to tuff-stone of historical monuments in the city of Guanajuato, Mexico. The tuff-stone was also treated with the formulation T-ME. Both treatments were studied by determining the percentage of consolidant deposited, evaluating changes in porosity and hardness of the treated stone. The applicability of the hybrid consolidant for the decayed tuff-stone is under study.

Más allá de los innumerables beneficios que ha supuesto la expansión de Internet y las Tecnologías de la Información y la Comunicación (TIC), cada vez son más los estudios que recalcan también los problemas y riesgos que suele conllevar, especialmente en el caso de los adolescentes. El aumento del sedentarismo y el aislamiento, la distorsión de la socialización, de las pautas de sueño y alimentación y, en general, el uso problemático de Internet, están suscitando una creciente preocupación social a la que expertos e investigadores siguen intentando dar respuesta. Sin embargo, el desarrollo de estrategias educativas o preventivas realmente eficaces es todavía una cuenta pendiente. El fomento de la práctica deportiva de manera regular puede deparar beneficios importantes también en este contexto. El objetivo de este trabajo ha sido precisamente aportar evidencias al respecto, intentando comprobar si efectivamente el hecho de que los adolescentes realicen deporte de forma regular, e incluso vinculados a un club y con licencia federativa, implica tasas de uso problemático de Internet significativamente menores. Los resultados obtenidos a partir de una muestra de 509 estudiantes de entre 10 y 17 años evidencian que realmente así es. Como consecuencia, más allá de las limitaciones muestrales del trabajo empírico y de su carácter exploratorio, lo que se pone sobre la mesa es la importancia que posee a estos niveles la supervisión del tiempo de ocio de nuestros hijos/as y la promoción de la actividad física y deportiva de forma regular. El potencial que a nivel preventivo tienen los programas encaminados a fomentar el deporte entre los adolescentes está, a nuestro modo de ver, aun por aprovechar.Abstract. Despite the countless benefits that the expansion of Internet and New Communication Technologies has brought, every time more studies emphasize problems and risks that they often imply, especially in the case of adolescents. The increase of physical inactivity and isolation, the distortion of socialization, sleeping and eating patterns, as well as problematic Internet use, have provoked rising social concerns that experts and researchers are still trying to respond to. In fact, the development of truly effective educational and preventive strategies is still an unresolved matter. Encouraging regular practice of sport can bring significant benefits even in this context. The aim of this study was to provide evidence that adolescents practicing sport regularly, including those having federal license and belonging to sports clubs, show lower rates of problematic Internet use. Results obtained from a sample of 509 students aged between 10 to 17 years confirm our hypothesis. Consequently, despite sampling limitations of this empirical work and its exploratory character, it is clear that we need to monitor children’s leisure time, as well as to promote regular practice of physical activity and sport. In our view, the preventive potential of programs focused on encouraging adolescents to be active is still unexpressed.

La práctica físico-deportiva es un elemento valioso en la salud integral de los individuos. Sin embargo, el abandono deportivo es un fenómeno que prolifera y se acentúa en las etapas de formación sobre todo en las practicantes femeninas. Los motivos del abandono son múltiples y diversos, estando muy marcados por las características de la modalidad deportiva y de sus practicantes. El piragüismo en una modalidad muy exigente y competitiva que en el último lustro en nuestro país ha mostrado una tasa de abandono muy elevada (del 32,9% al 49,7%) entre las deportistas femeninas federadas. El presente estudio pretende reconocer los motivos por los cuales las piragüistas han abandonado la práctica contribuyendo a establecer medidas y recomendaciones que atenúen esta realidad en el futuro. Para ello se ha recurrido a una estrategia mixta, combinando un enfoque cualitativo y cuantitativo. El estudio cualitativo se basó en dos Grupos Focales, uno con ex-palistas (n=6) y otro con entrenadoras/es (n=8), mientras que el estudio cuantitativo consistió en un cuestionario ad hoc realizado telefónicamente entre deportistas que abandonaron la modalidad en los tres último años (n=160). Los resultados obtenidos permiten afirmar que el abandono femenino tiene un carácter multifactorial pero está muy determinado por los roles de género vigentes que infravaloran a la mujer palista, la excesiva presión competitiva, la dificultad para conciliar el piragüismo y los estudios, así como la carencia de categorías de menor nivel competitivo. Las Federaciones y Administraciones deberían realizar un mayor esfuerzo en labores de promoción del piragüismo femenino.Abstract: The physical-sports practice is valuable for any individual’s overall health. However, dropout from sports is an increasing  phenomenon accentuated in the formative stages, especially in female practitioners. Reasons for withdrawing are diverse and highly dependent on the characteristics of each sport and its practitioners. Canoeing in a very demanding and competitive discipline that has shown a very high dropout rate (32.9% to 49.7%) among federated female athletes from our country in the last five years. This study aims to recognize the reasons why canoeists abandon the practice so to help establishing measures and recommendations to mitigate this occurrence in the future. A mixed strategy, combining qualitative and quantitative approach, was employed for the study purposes. The qualitative study was based on two focus groups, one composed by ex-paddlers (n = 6) and one with coaches/s (n = 8), while the quantitative study consisted of an ad-hoc questionnaire conducted by telephone with athletes who withdrew from that sport within the last three years (n = 160). The results confirm that women's dropout has a multifactorial nature, yet it is largely determined by gender biases commonly underestimating paddler women, excessive competitive pressure, difficulty in pairing canoeing and education, and lack of categories with lower competitive level. Federations and authorities should make greater efforts in promoting women's canoeing modality.