Sexting and Mental Health: A School-based Longitudinal Study Among Youth in Texas

Background: Sexting has emerged as a common socio-cultural problem in our society today. Few studies have estimated the prevalence of sexting among younger middle school youth and even fewer have assessed the relationship between sexting and mental health outcomes like anxiety and depression symptoms among middle school youth. Objectives: To estimate the prevalence of sexting among sixth and seventh-grade middle school students in a large urban school district in Southeast Texas and to assess its relationship with mental health outcomes (both anxiety and depression) among these youth. Methods: A retrospective analysis of an existing three-year randomized, two-arm, nested longitudinal study was conducted. Associations between sexting and depression symptoms; and sexting and anxiety symptoms were assessed via univariate and multivariate logistic analysis. Results: The prevalence of sexting among sixth graders was found to be 12%. Compared to youth who were not engaged in sexting, engagement in sexting was associated with significantly increased odds of depression and anxiety symptoms. Conclusion: Sexting is common among youth and is associated with poorer mental health outcomes such as anxiety and depression among these youth, but further validation of these findings is needed

Sexual health education for behavior change: How much is enough?

Purpose: Successful implementation of sexual health curricula in school settings is often compromised by competing academic priorities. This study explores the association between exposure to sexual health lessons (time-on-task in hours and lesson content topics) and delayed sexual initiation of middle school students at long term follow-up. Methods: Post hoc data analysis was conducted from a RCT (n=15 middle schools) in the south-central U.S. in which grade 7 students demonstrated delayed sexual initiation (adjusted odds ratio [AOR]: 1.54, 95% CI: 1.20 to 1.99) by grade 9 follow-up after using It’s Your Game (IYG), a 24 lesson sexual health curriculum. Logistic regression was conducted on a sub-sample of 314 grade 7 and 8 students who received IYG and who were sexually inexperienced at baseline, adjusting for covariates of age, gender, and race/ethnicity to address the impact of lesson exposure variables (time-on-task in hours and type of sexual health content) on initiation of any sex by grade 9. Results: The greatest impact of exposure on delayed sexual initiation was a duration of 13 or more lesson hours (OR = 8.40; p\u3c0.05) and exposure to lesson content on HIV/STI and pregnancy consequences (OR = 4.93; p\u3c0.05). Conclusions: Results support previous exposure studies and provide guidance on how effective sexual health curricula can meet the challenges of delivery in a reduced and competitive academic environment

Use of linear discriminant function analysis in seed morphotype relationship study in 31 Lima bean (Phaseolus lunatus L.) accessions in Ghana

Variation in seed morphology of the Lima bean in 31 accessions was studied. Data were collected on 100-seed weight, seed length and seed width. The differences among the accessions were significant, based on the three seed characteristics. K-means cluster analysis grouped the 31 accessions into four distinct groups, representing four different morphotypes. Mahalanobis distances (D2) among the groups were highly significant. The four different morphotypes were attributed to the Mesoamerican gene pool, comprising the cultigroups Sieva-Big Lima, Potato-Sieva and Potato. Sub-cultigroups of the Sieva-Big Lima and Potato cultigroups due to differences in seed weight were suggested.Variation en morphologie de graine du haricot de Lima en trente accessions était étudiée. Des données étaient collectées sur poids de 100 graines, longueur de graine et largeur de graine. Il y avait des différences considérables parmi les accessions basées sur les trois caractéristiques de graine. Analyse du régime par K-moyens groupait les 31 accessions en quatre groupes distincts, représentant quatre morphotypes différents. Les distances (D2) Mahalanobis parmi les groupes étaient hautement considérables. Les quatre morphotypes différents étaient attribués au bagage héréditaire de Mesoaméricain, comprenant les groupes de cultures: Sieva-Grand Lima, Patate-Sieva et Patate. Les groupes de sous-cultures de Sieva-Grand Lima et Patate groupes de culture dû aux différences en poids de graine étaient suggérées. Ghana Journal of Agricultural Science Vol. 39 (1) 2006: pp. 87-9

Phenotypic and seed protein analysis in 31 Lima bean (Phaseolus lunatus) accessions in Ghana

Phenotypic and seed protein analyses were performed on 31 accessions of Lima bean assembled in Ghana. Data on 16 phenotypic characters consisting of eight quantitative and eight qualitative were analysed. There were significant differences among the accessions based on the eight quantitative characters. Seed protein analysis showed 17 bands with relative mobility of bands, which ranged from 0.01 to 0.86. An ordinal logistic regression analysis showed significant evidence for seed coat, pod beak shape and seed size association. Cluster analysis based on both phenotypic and protein data provided evidence for differences among the accessions. Quantitative characters were associated with some specific clusters

Evaluating student learning in large introductory biology courses: predictors of student success and lessons for course redesign

In 2009, the University of Calgary began an extensive redesign of its first-year biology courses based on survey feedback from both students and faculty, as well as the extensive literature showing the effectiveness of student-centered pedagogies in enhancing student learning, engagement and retention in large classes. The two newly designed courses, Energy Flow in Biological Systems and DNA, Inheritance and Evolution are concept-based courses that emphasize the integration of key concepts from biomolecules to the biosphere within a student-centered learning environment; these courses begin in Fall 2011. In order to understand the factors influencing student success in first-year biology, we have initiated a three-year mixed-methods investigation of students’ a priori knowledge, motivations, and approaches to learning. In our current first-year courses, we collected data related to changes in both student motivation and learning over the entire first year for 750 students. The strongest predictors of student success, based on grades earned in the lecture component of the course, were multiple-choice pre-test scores (

Less Traditional – More Conceptual: Enhancing Student Learning in First-Year Biology

Over the last two decades, a number of influential reports have called for fundamental changes to undergraduate science education. Most importantly, these reports advocate a shift from traditional lecture-based teaching formats to ones that use student-focused pedagogies to encourage deep student learning about key conceptual ideas in science. Based on these reports, and the underlying research, the University of Calgary completed an extensive redesign of its first-year biology courses in 2011, resulting in two courses: Energy Flow in Biological Systems and DNA, Inheritance and Evolution. These courses focus student learning on two foundational concepts and use student-centered pedagogies to encourage the development of critical-thinking and problem-solving skills. Pre/post data collected from one year of the previous introductory courses and two years of the redesigned courses were used to determine the impact of the transition to a conceptual-based curriculum and the incorporation of active learning strategies including clickers and in-class group assignments on student learning gains measured via normalized change using questions from Biological Concept Inventory, Respiration and Photosynthesis Diagnostic Question Clusters and the Conceptual Inventory of Natural Selection. Student motivations and approaches for learning (e.g. deep versus surface approaches) using the published Approaches and Study Skills Inventory for Students (ASSIST) survey and the Experiences of Teaching and Learning Questionnaire (ETLQ). Data show significantly higher learning gains during the two consecutive years of implementation of the redesigned courses than those achieved in the previous format. Additionally, students reported that lecture activities allowed them being more engaged with course content. We are currently analyzing student written responses, which will provide further insight into the impact of course redesign on content knowledge and critical reasoning skills on student success

Particle motion and stain removal during simulated abrasive tooth cleaning

Stain removal from teeth is important both to prevent decay and for appearance. This is usually achieved using a filament-based toothbrush with a toothpaste consisting of abrasive particles in a carrier fluid. This work has been carried out to examine how these abrasive particles interact with the filaments and cause material removal from a stain layer on the surface of a tooth. It is important to understand this mechanism as while maximum cleaning efficiency is required, this must not be accompanied by damage to the enamel or dentine substrate. In this work simple abrasive scratch tests were used to investigate stain removal mechanism of two abrasive particles commonly used in tooth cleaning, silica and perlite. Silica particles are granular in shape and very different to perlite particles, which are flat and have thicknesses many times smaller than their width. Initially visualisation studies were carried out with perlite particles to study how they are entrained into a filament/counterface contact. Results were compared with previous studies using silica. Reciprocating scratch tests were then run to study how many filaments have a particle trapped at one moment and are involved in the cleaning process. Stain removal tests were then carried out in a similar manner to establish cleaning rates with the two particle types. Perlite particles were found to be less abrasive than silica. This was because of their shape and how they were entrained into the filament contacts and loaded against a counterface. With both particles subsurface damage during stain removal was found to be minimal. A simple model was built to predict stain removal rates with silica particles, which gave results that correlated well with the experimental data

Assessing the Need and Receptivity for an Integrated Healthy Sexual and Dating Relationships Intervention for Community College Students

Background: In emerging adulthood, youth often become involved in more serious romantic relationships. However, many lack the skills to avoid an unplanned pregnancy or sexually transmitted infection (STI), and to ensure a healthy dating relationship. Community college students serve nearly half of all undergraduate students in the United States; yet, community colleges typically lack resources for sexual health promotion. Purpose: To assess the need and receptivity for a web-based integrated healthy sexual and dating relationships intervention among community college students. Methods: In summer 2016, we partnered with three community colleges in South Central Texas to conduct an online survey of students’ sexual behaviors and dating relationships, and usability testing of activities from an integrated, web-based healthy sexual and dating relationship intervention. Results: Online survey participants (n=271) were 70% female, 38% Hispanic, 24% White, 17% Black, and 16% Asian; 20% self-identified as sexual minority; mean age was 20.8 years (SD = 2.05). Participants reported high rates of sexual risk behavior including sex without a condom or an effective birth control method, low use of long-acting reversible contraception, frequent use of emergency contraception, and low use of dual protection to prevent pregnancy and sexually transmitted infections. Two-thirds reported experiencing any type of dating violence perpetration or victimization in the past year. Usability testing participants (n=14) were 86% female, 42% Hispanic, 50% Asian/Pacific Islander, 14% Black, and 7% White; 71% were sexually experienced; mean age was 20.7 years (SD = 1.64). The web-based activities were highly rated in terms of usability parameters, and positively impacted short-term psychosocial outcomes related to condom use, accessing contraceptive health services, and constructive interpersonal conflict resolution. Conclusion: Findings underscore the high need and receptivity for an integrated healthy sexual and dating relationship web-based intervention among community college students, an understudied subgroup of youth in emerging adulthood

A Study of Large Droplet Ice Accretions in the NASA-Lewis IRT at Near-Freezing Conditions

This report documents the results of an experimental study on large droplet ice accretions which was conducted in the NASA-Lewis Icing Research Tunnel (IRT) with a full-scale 77.25 inch chord Twin-Otter wing section. This study was intended to: (1) document the existing capability of the IRT to produce a large droplet icing cloud, and (2) study the effect of various parameters on large droplet ice accretions. Results are presented from a study of the IRT's capability to produce large droplets with MVD of 99 and 160 microns. The effect of the initial water droplet temperature on the resultant ice accretion was studied for different initial spray bar air and water temperatures. The initial spray bar water temperature was found to have no discernible effect upon the large droplet ice accretions. Also, analytical and experimental results suggest that the water droplet temperature is very nearly the same as the tunnel ambient temperature, thus providing a realistic simulation of the large droplet natural icing condition. The effect of temperature, droplet size, airspeed, angle-of attack, flap setting and de-icer boot cycling time on ice accretion was studied, and will be discussed in this report. It was found that, in almost all of the cases studied, an ice ridge formed immediately aft of the active portion of the de-icer boot. This ridge was irregular in shape, varied in location, and was in some cases discontinuous due to aerodynamic shedding

A Study of Large Droplet Ice Accretion in the NASA Lewis IRT at Near-Freezing Conditions

Results of experiments designed to determine the effects of large droplet ice accretion on a NACA 23012 wing section are presented. Using primarily an icing condition with a median volumetric diameter droplet size of 160 micron and a liquid water content of 0.82 grams per cubic meter, the effects of various air temperatures, angles of attack, and de-icer boot cycle interval times on ice accretion were studied. Measurements of aerodynamic performance penalties due to the ice accretions were made. Results were also compared with similar tests conducted with a Twin Otter wing section in Part 1 of this study. The form of the ice from the large droplet cloud varied as a function of air total temperature; particularly at the near-freezing temperatures of 28 F to 34 F. Changing boot cycle interval time did not prevent formation of an ice ridge. The most detrimental aerodynamic effects occurred at an air total temperature of 28 F