Sexting Prevalence and Socio-Demographic Correlates in Spanish Secondary School Students

Introduction This research analyzes the prevalence of sexting and socio-demographic correlates in a sample of 647 adolescents administered a questionnaire at secondary schools in Valencia (Spain). Methods The questionnaire results indicate that 61% of respondents reported being involved in at least one case of sexting, with 24, 58, and 18% reporting having sent a sext, received a sext, and forwarded a sext, respectively. Results More males and older adolescents reported having received and forwarded sexts than female and younger adolescents. Conclusions Furthermore, time spent using Information and Communications Technology (ICT) devices, use and frequency of use of social media, grade repetition, low academic performance expectations in Math, and a single-parent family situation appear to correlate with an increase in the prevalence of sexting experiences. Policy Implications Our study also provides results that can support new lines of inquiry into analyzing the relationship between sexting and certain socio-demographic, family situation, and educational variables in relation to adolescents

Prevalence os sending, receiving and forwarding sexts among youths: A three-level meta-analysis.

By systematic review with a three-level, mixed-effects meta-analysis, this paper examines the prevalence of sexting experiences among youths aimed at analyzing conceptual and methodological moderators that might explain its heterogeneity. A search was conducted of five bibliographic databases and grey literature up until February 2020. The risk of bias in primary studies was assessed. A total of seventy-nine articles met the set inclusion criteria. Mean prevalences for sending, receiving and forwarding sexts were .14 (95% CI: .12, .17), .31 (95% CI: .26, .36) and .07 (95% CI: .05, .09), respectively, expressed as fractions over one. Moderator analyses showed that all sexting experiences increased with age (e.g., the mean prevalence for sending sexts at the age of 12 was .04, whereas, at the age of 16, it was .21) and year of data collection (e.g., the mean prevalence for sending sexts in studies collecting data in 2009 was .07, whereas, in studies collecting data in 2018, it was .33). Subgroup analysis revealed that studies with probabilistic samples led to significantly lower mean prevalences for the sexting experiences of sending (.08, 95% CI: .06, .11), receiving (.19, 95% CI: .15, .24) and forwarding sexts (.04, 95% CI: .03, .07). Self-reported administration procedures also led to more homogeneous prevalence estimates than interviews. Prevalence estimates also varied according to the type of media content (e.g., the mean prevalence for sending sexual text messages was .22, whereas, for sending sexual images or videos, it was .12). Overall, our meta-analysis results suggest high and increasing prevalences of sending and receiving sexts among youths

Implications of Message Length and Delay in Undergraduate Online Discussions

This study aimed at verifying the association of message length and delay in university online discussions with academic achievement and students' influence on their classmates. Forums in Moodle were designed, and asynchronous online discussions with first-year undergraduate students of Educational Sciences were conducted. We gained word count from the learning management system, the weekly delay in posting a message to the forum was regarded, and we assumed the students' grades to know their academic success. To obtain an indicator of influence, we conducted a social network analysis from the interactions that emerged from the online discussions. Then, we calculated the eigenvector centrality of each student once the debate had been completed. Results showed a low monotonic association between grades and the message words or the delay in posting. There was a slight trend to achieve more eigenvector centrality since students took more time to send a message and when messages were more synthetic. However, we did not obtain values in the coefficients that would allow us to infer a relevant association. The level of correlation detected for the grades was significant and, above all, regarding eigenvector centrality. We discussed the limitations of this study, the need for more research, and the implications for educational practice.El objetivo de este estudio fue comprobar la relación de la extensión y la demora de los mensajes en discusiones en línea con la influencia entre estudiantes y el rendimiento académico en la universidad. Se diseñaron foros en Moodle y se llevaron a cabo discusiones asíncronas en línea con estudiantes de primer año de Ciencias de la Educación. Obtuvimos el recuento de palabras desde el sistema de gestión del aprendizaje, consideramos el retraso semanal para publicar mensajes en el foro y tomamos las calificaciones de los estudiantes para conocer su éxito académico. Para obtener un indicador de influencia, llevamos a cabo un análisis de redes sociales a partir de las interacciones en los debates. Después calculamos la centralidad de vector propio para cada estudiante, una vez finalizado el debate. Los resultados mostraron una correlación monotónica baja entre las notas y la extensión de los mensajes o el retraso en publicarlos. Hubo una ligera tendencia a conseguir más centralidad de vector propio a medida que se tardaba más en enviar un mensaje y cuando los mensajes eran más sintéticos. Sin embargo, no hubo valores en los coeficientes que permitieran inferir una asociación sustantiva. El nivel de correlación detectado para las calificaciones fue significativo, sobre todo para la centralidad del vector propio. Discutimos las limitaciones del estudio, la necesidad de más investigación y las implicaciones para la práctica educativa

Procedencia del material pétreo de los molinos de los yacimientos Cogotas I (Bronce Medio y Tardío) de la Cuenca del Duero y modelos consecuentes de flujo

The source provenance of twelve hand grindstones of Cogotian sites from the sedimentary Duero Basin was characterized using petrographic, mineralogical and geochemical criteria, according to an operational process previously proposed. Many of the provenances were determined after trace-element normalized diagrams and comparative diagrams with respect to available data from potential source areas. This methodology confirms that the geochemical signature can be seen as an archaeological fingerprint which allows the identification of facies or rock sub-types from the established source areas. Granite sources are the commonest provenance, although granodiorite, orthogneisses and sandstone are also involved, all of them belonging to the Variscan Basement. One of these source areas includes copper minerals, which could have been used for metallurgical purposes. Probably, since the early phase of Cogotas I, the principle of least effort no longer was a guiding force to boost the supply of material. The archaeological sites experienced a long-distance raw material supply in crossed directions, according to the established sources areas, indicating a dense network of connections between the commnunities of the region at a hecto-kilometric scale.Se ha estudiado la procedencia del material pétreo de doce molinos de diferentes yacimientos cogotenses de la Cuenca del Duero. Utilizando una marcha metodológica previa, se alcanza una caracterización petrográfica, mineralógica y geoquímica del material, incluyendo el tratamiento de elementos traza mediante diagramas de normalización y comparación con datos disponibles de áreas fuente potenciales. Esto ha permitido, en muchos casos, la identificación de áreas fuente locales ya que la signatura geoquímica representa una huella arqueológica fidedigna de las facies o subtipos de rocas implicadas. La mayoría de las áreas fuente identificadas son graníticas, existiendo también granodioritas, gneises y areniscas, todas ellas pertenecientes al basamento varisco. Una de estas áreas incluye minerales de cobre, eventualmente aprovechables para metalurgia. Probablemente, ya desde la fase inicial de Cogotas I dejó de regir el principio del mínimo esfuerzo en el aprovisionamiento del material. El suministro de materias primas a los yacimientos arqueológicos es de carácter lejano y en direcciones cruzadas, de acuerdo con las áreas fuente establecidas, indicando una densa red de conexiones entre las comunidades de la región a escala hectokilométric

Effect of the electrophoretic deposition of Au NPs in the performance CdS QDs sensitized solar cells

Solution-processed mesoscopic oxide semiconductor-based materials offer potentially low-cost and high stability alternative for next generation of solar cells, and metallic nanoparticles had shown to be a good alternative to improve specific parameters in such kind of devices. In the present work, it is showed the systematic study of the effect of electrophoretic gold nanospheres (Au NPs) with cadmium sulfide Quantum Dots (CdS QDs) sensitized TiO2 solar cells. Au NPs were added by electrophoretic deposition at several times (0.5, 2.5 and 7.5 minutes) and CdS QDs were deposited by a Successive Ionic Layer Absorption and Reaction (SILAR) method. Electrophoretic deposition allowed to significantly decrease the Au NPs deposition times respect previously reported methods. The results show that Au NPs reduce the photocurrent (from 9.85 to 9.44 mA/cm2) at the same time that increase the open circuit voltage (Voc) (from 575 to 618 mV) and the Fill Factor (FF) (from 46 to 51%) which result in a final increase of the photoconversion efficiency (η) (from 2.63 to 2.96% for 0.5 min of deposit). A systematic characterization permitted to identify the origin of the variations observed in the solar cell parameters with and without Au NPs. Incident Photon to Current conversion efficiency (IPCE) demonstrate that the Au NPs reduces the amount of light that reach the CdS QDs and Impedance Spectroscopy (IS) analysis, indicates a downshift in the TiO2 conduction band (CB) and decreases the recombination processes, resulting in the observed increase in the FF and Voc.We acknowledge financial support from CONACYT through grant 134111, the UC-MEXUS program grant 00007, the European Community Seven Framework Program (FP7- 428 NMP-2010-EU-MEXICO), CIO-UGTO 2013–2015 and the CEMIE-Solar (04002) consortium. D. Esparza, and A. Ceja acknowledge scholarship from CONACYT and thanks to Maria Christian Albor for SEM and EDS analysis. Isaac Zarazúa thanks to CONACYT for the postdoctoral fellow

Efecto de la temperatura de calcinación sobre la concentración de grupos silanoles en superficies de SiO2 (SBA–15)

The preparation of SBA-15 materials involves both, calcination and activation processes. The effects of the temperatures of these stages on the silanol superficial concentration are studied experimentally. The characterization techniques employed were: nitrogen adsorption, infrared spectroscopy, nuclear magnetic resonance, and X-ray diffraction. To improve the concentration of silanols groups on the solid surface, the obtained results indicate that the best temperatures of calcination and activation are 623K and 373K, respectively

Central venous-catheter related bacteremia: incidence and risk factors in a hospital in western Mexico

AbstractBackgroundCentral venous catheters (CVC) are needed for monitoring and treatment of critically ill patients; however, their use increases the risk of bacteremia. The aim of the study was to quantify the incidence of central venous catheter-related bacteremia (CVCRB) and to identify factors associated with this infection.MethodsA prospective cohort study was conducted in a concentration hospital of western Mexico. The association of CVCRB and study variables was investigated using multivariate Cox regression analysis.ResultsTwo hundred and four patients with CVC were studied. The mean age was 4.6 years; 66.2% were male. Insertion sites of the catheters were subclavian vein 72.5% (n = 148), jugular vein 20.1% (n = 41) and femoral vein 7.4% (n = 15). CVCRB incidence was 6.5 events/1,000 catheter-days; microorganisms identified were gram-positive cocci 37.5% (n = 6), gram-negative bacilli 37.5% (n = 6) and Candida albicans 25% (n = 4). It was observed that the increase in catheter manipulations per day was associated with bacteremia (HR 1.14, 95% CI 1.06–1.23), whereas the use of intravenous antibiotics showed a protective effect (HR 0.84, 95% CI 0.76–0.92).ConclusionsIn addition to the strategies of maximum caution when placing or manipulating the catheter, we recommend decreasing, as much as possible, disconnects between the CVC and the infusion line. Antibiotics showed a protective effect, but the outcome is uncertain and the promotion of antimicrobial resistance should be considered

Operating Mechanisms of Mesoscopic Perovskite Solar Cells through Impedance Spectroscopy and J-V Modeling

The performance of perovskite solar cell (PSC) is highly sensitive to deposition conditions, the substrate, humidity, and the efficiency of solvent extraction. However, the physical mechanism involved in the observed changes of efficiency with different deposition conditions has not been elucidated yet. In this work, PSCs were fabricated by the antisolvent deposition (AD) and recently proposed air-extraction antisolvent (AAD) process. Impedance analysis and J–V curve fitting were used to analyze the photogeneration, charge transportation, recombination, and leakage properties of PSCs. It can be elucidated that the improvement in morphology of perovskite film promoted by AAD method leads to increase in light absorption, reduction in recombination sites, and interstitial defects, thus enhancing the short-circuit current density, open-circuit voltage, and fill factor. This study will open up doors for further improvement of device and help in understanding its physical mechanism and its relation to the deposition methods

Effect of multi-component school-based program on body mass index, cardiovascular and diabetes risks in a multi-ethnic study

Background: Mexico occupies one of the first places worldwide in childhood obesity. Its Mestizo and Indigenous communities present different levels of westernization which have triggered different epidemiological diseases. We assessed the effects of a multi-component school-based intervention program on obesity, cardiovascular and diabetes risk factors. Methods: A physical activity, health education and parent involvement (PAHEPI) program was developed and applied in six urban (Mestizo ethnic group) and indigenous (Seri and Yaqui ethnic groups) primary schools for 12 weeks. A total of 320 children aged 4–12 years participated in intervention program; 203 under Treatment 1 (PAHEPI program) and 117, only from Mestizo groups, under Treatment 2 (PAHEPI+ school meals). For Body Mass Index (BMI), cardiovascular and diabetes factors, pairwise comparisons of values at baseline and after treatments were done using Wilcoxon signed rank test. Generalized linear models were applied to assess the intervention effect by age, sex and nutritional status in relation to ethnicity and treatment. Results: We observed improvements on BMI in children with overweight-obesity and in triglycerides in the three ethnic groups. The Mestizo ethnic group showed the largest improvements under Treatment 2. While Seris showed improvements only in cardiovascular risk factors, Yaquis also showed improvements in diabetes risk factors, though not in BMI. Conclusions: This study showed that the same intervention may have positive but different effects in different ethnic groups depending on their lifestyle and their emerging epidemiological disease. Including this type of intervention as part of the school curriculum would allow to adapt to ethnic group in order to contribute more efficiently to child welfare