1,316 research outputs found

    Efficacy Beliefs are Related to Task Cohesion: Communication is a Mediator

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    Efficacy beliefs and communication are key constructs which have been targeted to develop task cohesion. This study’s purpose was to: (1) examine whether collective efficacy, team-focused other-efficacy, and team-focused relation-inferred self-efficacy (RISE) are predictive of task cohesion, and (2) evaluate the possibility that communication mediates efficacy-task cohesion relationships. British university team-sport athletes (n = 250) completed questionnaires assessing efficacy beliefs, communication (i.e., positive conflict, negative conflict, and acceptance communication), and task cohesion (i.e., attractions to group; ATG-T, group integration; GI-T). Data were subjected to a multi-group path analysis to test mediation hypotheses while also addressing potential differences across males and females. Across all athletes, collective efficacy and team-focused other-efficacy significantly predicted ATG-T and GI-T directly. Positive conflict and acceptance communication significantly mediated relationships between efficacy (team-focused other-efficacy, collective efficacy) and cohesion (ATG-T, GI-T). Findings suggest enhancing athletes’ collective efficacy and team-focused efficacy beliefs will encourage communication factors affecting task cohesion

    The Effect of Oral Contraceptive Pill Use on Knee Joint Laxity in Women

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    Schultz et al. (2004) demonstrated that 63% of the change in knee joint laxity (KJL) during a menstrual cycle was due to associated fluctuations in sex hormone levels. Use of oral contraceptives modulates the fluctuation of sex hormone levels during the menstrual cycle and thus may reduce fluctuation in KJL PURPOSE: Given that increased KJL is a known risk factor for sustaining knee injuries, the purpose of this study was to examine the effect of oral contraceptive use on KJL during the follicular, ovulation, and luteal phases of the menstrual cycle. METHODS: Sixty college-age women were screened for participation and fourteen (20.07±1.21 years, 163.05± 9.70, and 66.81± 12.32 kg) met the inclusion criteria, provided informed consent, and participated in the study. Based on screening questionnaires, participants were sorted into groups, oral contraceptive users (OC) and non-users (NOC). Each participant’s KJL was measured on six occasions, five days apart. KJL was measured using a KT-1000 Knee Arthrometer at 133 N. Measurements on days 1-7, 11-14, and 19-22 were used for data analysis to correspond with the three phases of the menstrual cycle. A 2x3 (group x phase) mixed model ANOVA was used to compare KJL between groups and across the three phases of the menstrual cycle. RESULTS: KJL are reported in Table 1. Group and phase did not interact to affect KJL (F(2,24)=1.92, p=0.17). KJL did not differ between OC and NOC users across the menstrual cycle (F(1,12)=0.07, p=0.80), and was not different between any phase of the menstrual cycle (F(2,24)=0.14, p=0.87). However, given that the spike in estradiol associated with the ovulation phase has been suggested to affect ligament laxity, a comparison between groups during this phase was conducted. Though KJL was larger for NOC than OC, the results of a one-tailed independent t-test suggest that this difference was not statistically significantly (t(12)= 1.72, p = 0.06). However, this difference was characterized by a large effect size (Cohen d= 0.92) suggesting that NOC users experience more KJL during the ovulation phase than OC users. CONCLUSION: The results of the study indicate that OC may play a role in KJL. However, with limited statistical power of these analyses, additional data are needed to fully assess this effect

    Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus.

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    Idiopathic congenital nystagmus is characterized by involuntary, periodic, predominantly horizontal oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 singleton cases of idiopathic congenital nystagmus (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina, suggesting a specific role in the control of eye movement and gaze stability

    Investigating the effects of age-related spatial structuring on the transmission of a tick-borne virus in a colonially breeding host

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    Higher pathogen and parasite transmission is considered a universal cost of colonial breeding due to the physical proximity of colony members. However, this has rarely been tested in natural colonies, which are structured entities, whose members interact with a subset of individuals and differ in their infection histories. We use a population of common guillemots, Uria aalge, infected by a tick-borne virus, Great Island virus, to explore how age-related spatial structuring can influence the infection costs borne by different members of a breeding colony. Previous work has shown that the per-susceptible risk of infection (force of infection) is different for prebreeding (immature) and breeding (adult) guillemots which occupy different areas of the colony. We developed a mathematical model which showed that this difference in infection risk can only be maintained if mixing between these age groups is low. To estimate mixing between age groups, we recorded the movements of 63 individually recognizable, prebreeding guillemots in four different parts of a major colony in the North Sea during the breeding season. Prebreeding guillemots infrequently entered breeding areas (in only 26% of watches), though with marked differences in frequency of entry among individuals and more entries toward the end of the breeding season. Once entered, the proportion of time spent in breeding areas by prebreeding guillemots also varied between different parts of the colony. Our data and model predictions indicate low levels of age-group mixing, limiting exposure of breeding guillemots to infection. However, they also suggest that prebreeding guillemots have the potential to play an important role in driving infection dynamics. This highlights the sensitivity of breeding colonies to changes in the behavior of their members—a subject of particular importance in the context of global environmental change

    DNM1 encephalopathy: A new disease of vesicle fission.

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    ObjectiveTo evaluate the phenotypic spectrum caused by mutations in dynamin 1 (DNM1), encoding the presynaptic protein DNM1, and to investigate possible genotype-phenotype correlations and predicted functional consequences based on structural modeling.MethodsWe reviewed phenotypic data of 21 patients (7 previously published) with DNM1 mutations. We compared mutation data to known functional data and undertook biomolecular modeling to assess the effect of the mutations on protein function.ResultsWe identified 19 patients with de novo mutations in DNM1 and a sibling pair who had an inherited mutation from a mosaic parent. Seven patients (33.3%) carried the recurrent p.Arg237Trp mutation. A common phenotype emerged that included severe to profound intellectual disability and muscular hypotonia in all patients and an epilepsy characterized by infantile spasms in 16 of 21 patients, frequently evolving into Lennox-Gastaut syndrome. Two patients had profound global developmental delay without seizures. In addition, we describe a single patient with normal development before the onset of a catastrophic epilepsy, consistent with febrile infection-related epilepsy syndrome at 4 years. All mutations cluster within the GTPase or middle domains, and structural modeling and existing functional data suggest a dominant-negative effect on DMN1 function.ConclusionsThe phenotypic spectrum of DNM1-related encephalopathy is relatively homogeneous, in contrast to many other genetic epilepsies. Up to one-third of patients carry the recurrent p.Arg237Trp variant, which is now one of the most common recurrent variants in epileptic encephalopathies identified to date. Given the predicted dominant-negative mechanism of this mutation, this variant presents a prime target for therapeutic intervention

    Acceptability of Carraguard Vaginal Microbicide Gel among HIV-Infected Women in Chiang Rai, Thailand

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    Background: Few studies of microbicide acceptability among HIV-infected women have been done. We assessed CarraguardH vaginal gel acceptability among participants in a randomized, controlled, crossover safety trial in HIV-infected women in Thailand. Methodology/Principal Findings: Participants used each of 3 treatments (Carraguard gel, methylcellulose placebo gel, and no product) for 7 days, were randomized to one of six treatment sequences, and were blinded to the type of gel they received in the two gel-use periods. After both gel-use periods, acceptability was assessed by face-to-face interview. Responses were compared to those of women participating in two previous Carraguard safety studies at the same study site. Sixty women enrolled with a median age of 34 years; 25 % were sexually active. Self-reported adherence (98%) and overall satisfaction rating of the gels (87% liked ‘‘somewhat’ ’ or ‘‘very much’’) were high, and most (77%) considered the volume of gel ‘‘just right.’ ’ For most characteristics, crossover trial participants evaluated the gels more favorably than women in the other two trials, but there were few differences in the desired characteristics of a hypothetical microbicide. Almost half (48%) of crossover trial participants noticed a difference between Carraguard and placebo gels; 33 % preferred Carraguard while 12 % preferred placebo (p=0.01). Conclusions/Significance: Daily Carraguard vaginal gel use was highly acceptable in this population of HIV-infecte

    Transformation of the rodent malaria parasite Plasmodium chabaudi and generation of a stable fluorescent line PcGFPCON

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    <p>Abstract</p> <p>Background</p> <p>The rodent malaria parasite <it>Plasmodium chabaudi </it>has proven of great value in the analysis of fundamental aspects of host-parasite-vector interactions implicated in disease pathology and parasite evolutionary ecology. However, the lack of gene modification technologies for this model has precluded more direct functional studies.</p> <p>Methods</p> <p>The development of <it>in vitro </it>culture methods to yield <it>P. chabaudi </it>schizonts for transfection and conditions for genetic modification of this rodent malaria model are reported.</p> <p>Results</p> <p>Independent <it>P. chabaudi </it>gene-integrant lines that constitutively express high levels of green fluorescent protein throughout their life cycle have been generated.</p> <p>Conclusion</p> <p>Genetic modification of <it>P. chabaudi </it>is now possible. The production of genetically distinct reference lines offers substantial advances to our understanding of malaria parasite biology, especially interactions with the immune system during chronic infection.</p

    Mutations in FRMD7, a newly identified member of the FERM family, cause X-linked idiopathic congenital nystagmus

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    Idiopathic congenital nystagmus (ICN) is characterised by involuntary, periodic, predominantly horizontal, oscillations of both eyes. We identified 22 mutations in FRMD7 in 26 families with X-linked idiopathic congenital nystagmus. Screening of 42 ICN singleton cases (28 male, 14 females) yielded three mutations (7%). We found restricted expression of FRMD7 in human embryonic brain and developing neural retina suggesting a specific role in the control of eye movement and gaze stability
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