Exploring the structure of relative age effects research using citation network analysis.

Since the 1980s, research on relative age effects (RAEs) consistently shows that relatively older individuals are advantaged in sport and other contexts. With the recent proliferation of studies on RAEs, periodic knowledge synthesis becomes imperative. Our purpose was to conduct a cross-disciplinary citation network analysis of RAEs literature to enhance our knowledge of RAEs citation structures and the interconnectivity of RAEs studies. We analysed 484 RAEs articles found in Web of Science that were published before 2022. Descriptive results revealed a 12.6% annual growth rate for total RAEs articles published since 1980. The articles appeared in 151 journals, had 1,180 unique authors, and averaged 23.9 citations received. Three theoretical/review papers had the most substantial influence on the field. For the conceptual structure of the field, it was apparent that RAEs research focused mainly on sport performance, maturity, and competition. Regarding intellectual structure, three distinct clusters of articles were cited together, and 13 authorship clusters were detected with few between-cluster connections. The results describe a field with productivity but little interconnectivity among authors and papers. We offer insights into this trend and the role that influential authors/articles have in the field.

Measuring leadership in sport: Development and validation of the Identity Leadership Inventory - Youth (ILI-Y).

The social identity approach to leadership posits that leaders' effectiveness depends on their ability to represent, advance, create, and embed a shared sense of social identity among their followers. Although significant progress has been made in investigating the benefits of identity leadership in adult sports, research in youth sports is still in its infancy. One reason is the lack of a youth-centric inventory that adequately measures identity leadership in this population. To bridge this gap, we developed and validated a long (16 items) and short (5 items) version of the Identity Leadership Inventory for Youth Sport (ILI-Y or ILI-Y-Short-Form) through five studies conducted in three phases of research. Data were primarily collected in football in the United Kingdom, involving a total of 1096 participants. Results of Phase I of this study provided little to no evidence that the ILI - originally developed for adults - was understandable (Study 1) and had factor validity and internal consistency (Study 2) in a sample of youth athletes. Therefore, in Phase II, the ILI was revised, leading to the development of the ILI-Y, which was understandable for youth athletes (Study 3). Results from Phase II (Study 4) also indicated that the ILI-Y exhibited a unidimensional factor structure, which was subsequently confirmed in Phase III (Study 5). This last phase offered additional evidence for the discriminant, criterion, and incremental validity of the ILI-Y and its short form, along with their measurement invariance across genders and age groups, and internal consistency. This study provides sports psychology researchers and practitioners with a valid measure to assess identity leadership in youth sports.

The Psychometric Properties of Two Brief Measures of Teamwork in Sport.

In the current study, the structural and external validity of data derived from two shorter versions of the Multidimensional Assessment of Teamwork in Sport (MATS) were examined using multilevel analyses. Evidence of model-data fit was shown for both a 5-factor model comprising 19 items (with subscales assessing teamwork preparation, execution, evaluation, adjustments, and management of team maintenance) and a single-factor model comprising five items (providing a global estimate of teamwork). In general, data from both versions were positively and significantly correlated with (and distinct from) athletes' perceptions of team cohesion, collective efficacy, performance satisfaction, enjoyment in their sport, and commitment to their team and their coaches' transformational leadership. The measures appear well suited to detect between-teams differences, as evidenced by intraclass correlation coefficients and acceptable reliability estimates of team-level scores. In summary, the 19-item Multidimensional Assessment of Teamwork in Sport-Short and five-item Multidimensional Assessment of Teamwork in Sport-Global provide conceptually and psychometrically sound questionnaires to briefly measure teamwork in sport.

Unlocking the power of 'us': Longitudinal evidence that identity leadership predicts team functioning and athlete well-being.

The social identity approach has become an important framework for understanding effective leadership. The present study is the first to longitudinally examine the relative impact of coaches' and athlete leaders' identity leadership on athletes' identification with their team, as well as the subsequent relationships with key team and individual outcomes. To investigate these research questions, 18 sport teams (N = 279) completed a questionnaire early and late in their season competition. To analyse these data, we conducted structural equation modelling and controlled both for baseline values and the nested structure of our data. Results revealed that it was mainly the identity leadership of athlete leaders (and not of the coach) early in the season that predicted athletes' team identification later in the season. This increased team identification in turn fed into both team outcomes (i.e., task climate, team resilience, team performance) and individual outcomes (i.e., well-being, burnout, and individual performance). The mediating role of team identification suggests that by building a shared sense of 'we', athlete leaders can improve the team's effectiveness and enhance athletes' well-being. Accordingly, we conclude that empowering athlete leaders and strengthening their identity leadership skills is an important way to unlock sport teams' full potential.

"Beyond the Rink": A Multilevel Analysis of Social Identity Behaviors Captured Using the Electronically Activated Recorder.

This study used ecological sampling methods to examine associations between youth athletes' experiences receiving and engaging in behaviors indicative of in-group ties, cognitive centrality, and in-group affect (i.e., social identity) during a 3-day competitive ice hockey tournament. Forty-five youth (Mage = 12.39 years; SDage = 1.14 years; 94% male) from nine teams wore an electronically activated recorder that captured brief (50-s) audio observations throughout the tournament. Participants also completed daily diary questionnaires for each day of competition. Multilevel structural equation modeling demonstrated that athletes were more likely to engage in behaviors indicative of in-group affect and cognitive centrality on days when they received as higher-than-average frequency of behaviors indicative of cognitive centrality from teammates, coaches, and parents. The findings suggest that when team members interact in ways that demonstrate they are thinking about their team, they influence fellow members to behave in ways that promote a sense of "us."

Exploring the Relations Between Social Support and Social Identity in Adolescent Male Athletes.

Purpose: Social identity (i.e., the strength with which individuals identify with a group) is a key mechanism through which youth sport participants derive developmental benefits. However, despite the importance of one's social identity in promoting these benefits, our understanding of the correlates of social identity within the sport context is limited by the absence of evidence. To address this gap, this study investigated the relations between perceived social support from coaches, family, and friends and social identification. Method: Male adolescent athletes (N = 344) completed measures of social support and social identity as part of a cross-sectional design. Latent profile analysis was used to identify distinct social support profiles. Results: Four latent profiles were identified: higher support, average support, diminished support, and lower support. ANCOVA results indicated that profile membership corresponded to significant differences in social identity perceptions, p < .001, partial η2 = .26. Participants in the higher social support profile perceived significantly higher social identity when compared with profiles of average, diminished, and lower support (ps < .05, Cohen's d ≥.67). Conclusion: Results highlight the association between support from different social agents and social identity in youth sport. Better understanding the correlates of social identity may be critical in enhancing the developmental benefits of participation in organized team sports given the relationship with social identity.

96-week comparison of once-daily atazanavir/ritonavir and twice-daily lopinavir/ritonavir in patients with multiple virologic failures.

BACKGROUND: In BMS Study 045, once-daily (QD) atazanavir/ritonavir (ATV/RTV) demonstrated comparable efficacy and safety to twice-daily (BID) lopinavir/ritonavir (LPV/RTV) over 48 weeks in treatment-experienced patients. Results of extended follow-up to 96 weeks are presented. METHODS: BMS Study 045 was an open-label, randomized, multi-national trial of HIV-infected patients with virologic failure on two or more prior HAART regimens designed to evaluate the efficacy and safety of ATV/RTV (300/100 mg) QD and LPV/RTV (400/100 mg) BID, each with tenofovir (300 mg) QD and one nucleoside reverse transcriptase inhibitor. The primary efficacy measure was the time-averaged difference (TAD) in reduction in HIV RNA from baseline. Secondary objectives included evaluation of safety and plasma lipid levels through week 96. RESULTS: Over 96 weeks, the ATV/RTV regimen demonstrated similar virologic efficacy to the LPV/RTV regimen. Mean reductions from baseline in HIV RNA were -2.29 and -2.08 log10 copies/ml, respectively [TAD (97.5% confidence interval): 0.14 log10 copies/ml (-0.13, 0.41)]. The LPV/RTV regimen resulted in significant increases in total cholesterol (+9%) and fasting triglycerides (+30%) in comparison with the ATV/RTV regimen, which demonstrated decreases in these parameters [-7 and -2%, respectively, (P < 0.0001)]. Grade 2-4 diarrhoea occurred less frequently in ATV/RTV patients (3%) in comparison with LPV/RTV patients (13%) (P < 0.01). Grade 3-4 elevations in bilirubin were more common in ATV/RTV patients (53%) than LPV/RTV patients (< 1%) (P < 0.0001), with no resulting discontinuations. CONCLUSIONS: Regimens containing once-daily ATV/RTV demonstrated comparable efficacy and safety, with significant reductions in total cholesterol and fasting triglycerides and improved gastrointestinal-tolerability in comparison with twice-daily regimens containing LPV/RTV over 96 weeks in treatment-experienced patients.

Identification of I50L as the signature atazanavir (ATV)-resistance mutation in treatment-naive HIV-1-infected patients receiving ATV-containing regimens.

Atazanavir (ATV) is a once-daily human immunodeficiency virus (HIV) protease inhibitor (PI) shown to be effective and well tolerated. ATV has a distinct resistance profile relative to other PIs, with susceptibility maintained against 86% of isolates resistant to 1-2 PIs. Clinical isolates obtained from PI-naive patients designated as experiencing virologic failure while receiving ATV-containing regimens contained a unique isoleucine-to-leucine substitution at amino acid residue 50 (I50L) of the HIV-1 protease. The I50L substitution, observed in all isolates exhibiting phenotypic resistance to ATV, emerged in a variety of different backgrounds and was most frequently accompanied by A71V, K45R, and/or G73S. Viruses containing an I50L substitution were growth impaired, displayed ATV-specific resistance, and had increased susceptibilities (

Antiviral activity of enteric-coated didanosine, stavudine, and nelfinavir versus zidovudine plus lamivudine and nelfinavir.

OBJECTIVE: To assess and compare the activity and safety of capsules containing enteric-coated beadlets of didanosine given once daily with stavudine and nelfinavir with that of a standard reference triple drug regimen of zidovudine plus lamivudine and nelfinavir. DESIGN: Multinational, 49-site, prospective, open-label, randomized, two-arm comparison study. PARTICIPANTS: HIV-infected subjects with limited or no previous antiretroviral therapy who had plasma HIV RNA levels of >or=2000 copies/mL and CD4 cell counts of >or=200/mm3 (511 were randomized to treatment groups, and 352 completed the study). INTERVENTIONS: Triple antiretroviral therapy for 48 weeks: didanosine EC (400 mg once daily), stavudine (40 mg twice daily), and nelfinavir (750 mg three times daily) or a twice-daily coformulation of zidovudine (300 mg) plus lamivudine (150 mg) and nelfinavir (750 mg three times daily). MAIN OUTCOME MEASURE: Proportion of subjects with HIV RNA levels of <400 copies/mL at week 48 based on an "intent-to-treat, missing = treatment failure" analysis. RESULTS: The two treatment groups were similar in the proportion of treatment responders (i.e., HIV RNA level of <400 copies/mL), with 54% of subjects in the didanosine EC and zidovudine plus lamivudine treatment groups responding at week 48. Results of other analyses supported those of the primary analysis. The two study regimens were associated with similar numbers of adverse events. CONCLUSIONS: The antiviral efficacy of a triple combination regimen containing once-daily didanosine EC is similar to that of a reference triple combination regimen.