Population Structure in The Brown Tube Sponge (agelas Conifera) in The Florida Reef Tract And Caribbean

Sponges are broadly distributed, occur in a wide range of habitats, and comprise a substantial amount of the biomass and macro-biodiversity on coral reefs. Despite their ubiquity in reef ecosystems, their dispersal dynamics are largely unknown. Here we report on gene flow and population structure for the common brown tube sponge, Agelas conifera (Demospongiae, Poecilosclerida) in the Florida reef tract and Caribbean. Over 300 samples collected from ten geographically distinct locations throughout Florida and the Caribbean are being analyzed for variation at eight microsatellite loci. Preliminary results from screening four loci in 295 individuals from eight locations indicated significant population structure overall (FST = 0.072; P = 0.0018) with a significant heterozygosity deficit (FIS = 0.310; P = 0.001). Lower FST values occurred within the Florida reef tract sites compared to those between Caribbean island locations suggesting relatively greater gene flow within the Florida reef system. Significant isolation by distance was not found to occur Caribbean-wide (r = 0.25; P = 0.14), nor within the Florida reef tract (r = 0.39; P = 0.10). Fine scale population structure occurred among sites separated by \u3c1 km around the islands of Utila (Honduras) and St. Croix (USVI) suggesting A. conifera recruitment in these areas is highly local source dependant. In contrast, no structure was observed among sites around Grand Cayman (Cayman Islands). Only populations within St. Croix showed a significant isolation by distance pattern (r = 0.74; P \u3c 0.001). The strong overall and in some instances even highly localized genetic structure observed is consistent with the typically short larval durations known for sponges generally; suggesting recruitment in these important reef biomass components may be driven mainly from local sources

Social Withdrawal and Romantic Relationships:A Longitudinal Study in Early Adulthood

Involvement in romantic relationships is a salient developmental task in late adolescence and early adulthood, and deviations from normative romantic development are linked to adverse outcomes. This study investigated to what extent social withdrawal contributed to deviations from normative romantic development, and vice versa, and the interplay between withdrawal and couples’ relationship perceptions. The sample included 1710 young adults (55–61% female) from the Tracking Adolescents’ Individual Lives Survey cohort and their romantic partners. Data were collected across 4 waves, covering romantic relationships from ages 17 to 29 years. The results showed that higher withdrawal predicted a higher likelihood of romantic non-involvement by adulthood, consistently being single at subsequent waves, and entering one’s first relationship when older. Withdrawal moderately decreased when youth entered their first relationship. Male’s withdrawal in particular affected romantic relationship qualities and dynamics. These results provide new insights into the developmental sequelae of withdrawn young adults’ romantic relationship development

The social withdrawal and social anxiety feedback loop and the role of peer victimization and acceptance in the pathways

Social withdrawal and social anxiety are believed to have a bidirectional influence on one another, but it is unknown if their relationship is bidirectional, especially within person, and if peer experiences influence this relationship. We investigated temporal sequencing and the strength of effects between social withdrawal and social anxiety, and the roles of peer victimization and acceptance in the pathways. Participants were 2,772 adolescents from the population-based and clinically referred cohorts of the Tracking Adolescents' Individual Lives Survey. Self- and parent-reported withdrawal, and self-reported social anxiety, peer victimization, and perceived peer acceptance were assessed at 11, 13, and 16 years. Random-intercept cross-lagged panel models were used to investigate within-person associations between these variables. There was no feedback loop between withdrawal and social anxiety. Social withdrawal did not predict social anxiety at any age. Social anxiety at 11 years predicted increased self-reported withdrawal at 13 years. Negative peer experiences predicted increased self- and parent-reported withdrawal at 13 years and increased parent-reported withdrawal at 16 years. In turn, self-reported withdrawal at 13 years predicted negative peer experiences at 16 years. In conclusion, adolescents became more withdrawn when they became more socially anxious or experienced greater peer problems, and increasing withdrawal predicted greater victimization and lower acceptance

Muscle Contraction Duration and Fibre Recruitment Influence Blood Flow and VO2 Independent of Contractile Work during Steady-State Exercise in Humans

We tested the hypothesis that, among conditions of matched contractile work, shorter contraction durations and greater muscle fibre recruitment result in augmented skeletal muscle blood flow and oxygen consumption (O2) during steady-state exercise in humans. To do so, we measured forearm blood flow (FBF; Doppler ultrasound) during 4 minutes of rhythmic handgrip exercise in 24 healthy young adults and calculated forearm O2 via blood samples obtained from a catheter placed in retrograde fashion into a deep vein draining the forearm muscle. In Protocol 1 (n = 11), subjects performed rhythmic isometric handgrip exercise at mild and moderate intensities under conditions in which tension time index (TTI; isometric analog of work) was held constant but contraction duration was manipulated. In this protocol, shorter contraction durations led to greater FBF (184 ± 25 vs. 164 ± 25 ml·min-1) and O2 (23 ± 3 vs. 17 ± 2 ml·min-1; both PPper se during steady-state exercise in humans

Quality over quantity:A transactional model of social withdrawal and friendship development in late adolescence

The aim of this study was to test a longitudinal, transactional model that describes how social withdrawal and friendship development are interrelated in late adolescence, and to investigate if post-secondary transitions are catalysts of change for highly withdrawn adolescents' friendships. Unilateral friendship data of 1,019 adolescents (61.3% female, 91% Dutch-origin) from the Tracking Adolescents' Individual Lives Survey (TRAILS) cohort were collected five times from ages 17 to 18 years. Social withdrawal was assessed at 16 and 19 years. The transactional model was tested within a Structural Equation Modeling framework, with intercepts and slopes of friendship quantity, quality, and stability as mediators and residential transitions, education transitions, and sex as moderators. The results confirmed the presence of a transactional relation between withdrawal and friendship quality. Whereas higher age 16 withdrawal predicted having fewer, lower-quality, and less-stable friendships, only having lower-quality friendships, in turn, predicted higher age 19 withdrawal, especially in girls. Residential transitions were catalysts of change for highly withdrawn youth's number of friends: higher withdrawal predicted a moderate increase in number of friends for adolescents who relocated, and no change for those who made an educational transition or did not transition. Taken together, these results indicate that the quality of friendships-over and above number of friends and the stability of those friendships-is particularly important for entrenching or diminishing withdrawal in late adolescence, and that relocating provides an opportunity for withdrawn late adolescents to expand their friendship networks

A Cross-Training Program Does Not Alter Self-Reported Physical Activity Levels in Elementary School Children

The purpose of the study was to examine the effects of a school-based cross-training program on body mass index (BMI), attitudes toward physical activity (ATPA), and physical activity (PA) levels of children in the 4th and 5th grades. Children (N = 118) were divided into control (n = 60) and experimental (n = 58) groups based on class availability. While the control group continued academic classes as usual, the experimental group participated in cross-training involving resistance training (RT), calisthenics, and stretching twice a week for 10 weeks. Pre- and post-intervention measures included height, mass, ATPA, and PA. BMI was calculated and ATPA and PA levels were assessed via questionnaire. The groups did not differ significantly (p \u3e .05) for either pre- or post-intervention regarding BMI, ATPA, and PA. However, BMI and PA levels significantly increased over time for both groups (p ≤ .05). Overall, cross-training in a school setting may be a safe and enjoyable option for physical activity participation. BMI and PA increases were likely the result of the natural growth process and seasonal weather pattern changes, respectively. Nevertheless, the cross-training did not detract from PA levels and may have led to an overall increase in PA levels. As subdomain analyses revealed decreased attitude toward health and fitness in the experimental group, shorter programs involving RT with various protocols are recommended

Practical Considerations for Using Exploratory Factor Analysis in Educational Research

The uses and methodology of factor analysis are widely debated and discussed, especially the issues of rotational use, methods of confirmatory factor analysis, and adequate sample size. The variety of perspectives and often conflicting opinions can lead to confusion among researchers about best practices for using factor analysis. The focus of the present review is to clarify terminology, identify key issues, and clarify areas of debate regarding best practices and functions of factor analytic procedures., The conclusions and implications drawn should be useful to researchers in education, psychology, and cognate social fields who employ factor analytic procedures or evaluate research using factor analytic methods. Accessed 27,993 times on https://pareonline.net from March 05, 2013 to December 31, 2019. For downloads from January 1, 2020 forward, please click on the PlumX Metrics link to the right

Differences in reef fish assemblages between populated and remote reefs spanning multiple archipelagos across the central and western Pacific

Comparable information on the status of natural resources across large geographic and human impact scales provides invaluable context to ecosystem-based management and insights into processes driving differences among areas. Data on fish assemblages at 39 US flag coral reef-areas distributed across the Pacific are presented. Total reef fish biomass varied by more than an order of magnitude: lowest at densely-populated islands and highest on reefs distant from human populations. Remote reefs (<50 people within 100 km) averaged ~4 times the biomass of “all fishes” and 15 times the biomass of piscivores compared to reefs near populated areas. Greatest within-archipelagic differences were found in Hawaiian and Mariana Archipelagos, where differences were consistent with, but likely not exclusively driven by, higher fishing pressure around populated areas. Results highlight the importance of the extremely remote reefs now contained within the system of Pacific Marine National Monuments as ecological reference areas

Surgical ward rounds in England: a trainee-led multi-centre study of current practice

BACKGROUND: Recent guidance advocates daily consultant-led ward rounds, conducted in the morning with the presence of senior nursing staff and minimising patients on outlying wards. These recommendations aim to improve patient management through timely investigations, treatment and discharge. This study sought to evaluate the current surgical ward round practices in England. METHODS: Information regarding timing and staffing levels of surgical ward rounds was collected prospectively over a one-week period. The location of each patient was also documented. Two surgical trainee research collaboratives coordinated data collection from 19 hospitals and 13 surgical subspecialties. RESULTS: Data from 471 ward rounds involving 5622 patient encounters was obtained. 367 (77.9%) ward rounds commenced before 9am. Of 422 weekday rounds, 190 (45%) were consultant-led compared with 33 of the 49 (67%) weekend rounds. 2474 (44%) patients were seen with a nurse present. 1518 patients (27%) were classified as outliers, with 361 ward rounds (67%) reporting at least one outlying patient. CONCLUSION: Recommendations for daily consultant-led multi disciplinary ward rounds are poorly implemented in surgical practice, and patients continue to be managed on outlying wards. Although strategies may be employed to improve nursing attendance on ward rounds, substantial changes to workforce planning would be required to deliver daily consultant-led care. An increasing political focus on patient outcomes at weekends may prompt changes in these areas