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1.
Philos Trans R Soc Lond B Biol Sci ; 375(1798): 20190243, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32200741

RESUMO

Much of Earth's biodiversity has the capacity to engage in dormancy, a reversible state of reduced metabolic activity. By increasing resilience to unfavourable conditions, dormancy leads to the accumulation of 'seed banks'. These reservoirs of genetic and phenotypic diversity should diminish the strength of environmental filtering and increase rates of dispersal. Although prevalent among single-celled organisms, evidence that dormancy influences patterns of microbial biogeography is lacking. We constructed geographical and environmental distance-decay relationships (DDRs) for the total (DNA) and active (RNA) portions of bacterial communities in a regional-scale 16S rRNA survey of forested ponds in Indiana, USA. As predicted, total communities harboured greater diversity and exhibited weaker DDRs than active communities. These observations were robust to random resampling and different community metrics. To evaluate the processes underlying the biogeographic patterns, we developed a platform of mechanistic models that used the geographical coordinates and environmental characteristics of our study system. Based on more than 106 simulations, our models approximated the empirical DDRs when there was strong environmental filtering along with the presence of long-lived seed banks. By contrast, the inclusion of dispersal generally decreased model performance. Together, our findings support recent theoretical predictions that seed banks can influence the biogeographic patterns of microbial communities. This article is part of the theme issue 'Conceptual challenges in microbial community ecology'.


Assuntos
Bactérias/isolamento & purificação , Florestas , Microbiota , Lagoas/microbiologia , Bactérias/classificação , Meio Ambiente , Geografia , Indiana , RNA Bacteriano/análise , RNA Ribossômico 16S/análise , Áreas Alagadas
2.
Spinal Cord ; 46(3): 216-21, 2008 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-17646838

RESUMO

STUDY DESIGN: Prospective, observational cohort study. OBJECTIVES: This paper describes the rationale and methodology for the Study of Health and Activity in People with Spinal Cord Injury (SHAPE SCI). The study aims to (1) describe physical activity levels of people with different injury levels and completeness, (2) examine the relationship between physical activity, risk and/or presence of secondary health complications and risk of chronic disease, and (3) identify determinants of physical activity in the SCI population. SETTING: Ontario, Canada. METHODS: Seven hundred and twenty men and women who have incurred a traumatic SCI complete self-report measures of physical activity, physical activity determinants, secondary health problems and subjective well-being during a telephone interview. A representative subsample (n=81) participate in chronic disease risk factor testing for obesity, insulin resistance and coronary heart disease. Measures are taken at baseline, 6 and 18 months. CONCLUSION: SHAPE SCI will provide much-needed epidemiological information on physical activity patterns, determinants and health in people with SCI. This information will provide a foundation for the establishment of evidence-based physical activity guidelines and interventions tailored to the SCI community.


Assuntos
Medicina Baseada em Evidências/métodos , Guias como Assunto , Atividade Motora/fisiologia , Traumatismos da Medula Espinal/fisiopatologia , Estudos de Coortes , Doença das Coronárias/etiologia , Doença das Coronárias/fisiopatologia , Feminino , Humanos , Resistência à Insulina/fisiologia , Entrevistas como Assunto , Masculino , Obesidade/etiologia , Obesidade/fisiopatologia , Ontário , Estudos Prospectivos , Fatores de Risco , Traumatismos da Medula Espinal/complicações
3.
Percept Mot Skills ; 93(2): 359-62, 2001 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-11769890

RESUMO

One potential contributing factor to the commonly observed home advantage in competitive sport is that officials may be biased in favour of the home team as a result of pressure from spectators. The present study examined officiating behaviour and home advantage, defined as home teams winning over 50% of decided games in English Club Cricket, a sport virtually devoid of spectator influence. Records of game outcomes, as well as dismissals requiring a decision by the umpire, were analysed. The relative frequency of umpiring decisions did not favour either home or away teams. However, a home advantage was found, with the home teams winning 57.1% of decided games (n = 1.449). Considered together, the results suggest that in sports with little or no spectator influence teams may win more often at home for reasons other than biased umpiring decisions, such as familiarity with their home ground or a visiting team's fatigue following travel.


Assuntos
Comportamento Competitivo , Preconceito , Meio Social , Esportes , Tomada de Decisões , Inglaterra , Humanos , Viagem
4.
J Health Psychol ; 6(4): 425-34, 2001 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-22049390

RESUMO

The purpose of the study was to examine the relationship between perceptions of self-efficacy, proxy efficacy, and exercise class attendance of participants involved in a 10-week structured group fitness program. At week 3, 127 females completed measures of self-efficacy and proxy efficacy and their class attendance was monitored for the subsequent four weeks. Self-efficacy was assessed through measures of exercise, scheduling, and barrier self-efficacy. Proxy efficacy was assessed through a measure of fitness instructor efficacy defined as participants' confidence in their fitness instructors' communication, teaching, and motivating capabilities. Results revealed positive correlations between self-efficacy variables and proxy efficacy. Hierarchical multiple regression analyses indicated that among those who were classified as exercise initiates (n = 33), self-efficacy and proxy efficacy accounted for 34 percent of the variance in exercise class attendance with the latter variable explaining a unique 12 percent. Consistent with theorizing, these preliminary findings indicate that for instructor-led, group physical activities such as aerobics classes, proxy efficacy perceptions are related to self-efficacy and may also be an important predictor of exercise behavior.

5.
J Sports Sci ; 18(5): 353-61, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10855681

RESUMO

Thirty-four youth competitive skiers (mean age = 13.74 years) completed measures of social evaluative concern and competitive anxiety. Consistent with past research, regression analyses showed that cognitive anxiety was related to performance-specific evaluative concerns. However, contrary to current conceptualizations of sport competition anxiety, somatic anxiety was correlated with concerns about evaluation of other non-performance aspects of ski racing. Competitive skiers were most concerned about parents' and friends' evaluations of their performance, and other competitors' and friends' evaluations of their skiing in general. These findings are discussed in relation to the theory and management of sport competition state anxiety.


Assuntos
Ansiedade/psicologia , Comportamento Competitivo , Esqui/psicologia , Adolescente , Análise de Variância , Cognição , Relações Familiares , Feminino , Objetivos , Humanos , Masculino , Escala de Ansiedade Manifesta , Grupo Associado , Valor Preditivo dos Testes , Autoimagem , Estatísticas não Paramétricas , Inquéritos e Questionários
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