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1.
Eur J Sport Sci ; 24(6): 788-803, 2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38874933

RESUMO

Individuals are recommended to lead active lifestyles throughout the life course. The model of physical activity-related health competence (PAHCO) adopts a competence approach by integrating physical, cognitive, and motivational determinants for health-enhancing PA (movement competence, control competence, self-regulation competence). Drawing on a comprehensive dataset pooling, the goal of the present study was to model the idiosyncratic courses of 10 PAHCO indicators over the life span. We identified studies that empirically operationalized PAHCO, combining data of 7134 individuals (age range: 15-97 years; 61% female) from 18 different populations (prevention and rehabilitation sectors). We applied a stepwise multilevel analysis approach with disjunct sub-samples (n = 48) to examine linear and quadratic associations between age and PAHCO. Indicators of movement competence (i.e., manageability of endurance, strength, and balance demands; task-specific self-efficacy) congruently showed negative associations with age (0.054 ≤  R marg 2 ${R}_{\text{marg}}^{2}$  ≤ 0.211). However, parameters of control competence remained stable across the life span (-0.066 ≤ ß ≤ 0.028). The three indicators of self-regulation competence revealed an inconsistent relationship with age, though uncovering positive associations for self-control (ß = 0.106) and emotional attitude toward PA (ß = 0.088). The associations of some indicators varied significantly across sub-samples. The results suggest differential analyses for associations between PAHCO and age. While the physically determined PAHCO indicators (movement competence) probably decline across the life span, the ability to ensure regularity of PA (self-regulation competence) or align PAs with an individual's health (control competence) appear to remain constant or improve with increasing age. The findings reinforce a de-stigmatizing approach for PA promotion practices with considerable space for aligning activities with health also in the elderly.


Assuntos
Exercício Físico , Estilo de Vida Saudável , Autoeficácia , Autocontrole , Humanos , Idoso , Pessoa de Meia-Idade , Adulto , Adolescente , Idoso de 80 Anos ou mais , Adulto Jovem , Feminino , Masculino , Motivação , Fatores Etários , Comportamentos Relacionados com a Saúde
2.
Ger J Exerc Sport Res ; 54(2): 192-200, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-38812659

RESUMO

Considering the positive health effects of leisure-time physical activity (LTPA), youth is an important life stage to promote lifelong LTPA. However, the stability of LTPA over the life course is low, and specific predictors of LTPA in youth for lifelong activity have some shortcomings, e.g. neglecting the interacting factors of LTPA within individuals. Therefore, from a person-oriented approach, patterns of LTPA behaviour in youth considering time- and context-related aspects and their relationships with lifelong LTPA were investigated. Life course data from n = 1519 Swiss inhabitants aged between 25 and 76 years were recorded retrospectively using a validated questionnaire (CATI method). Latent profile analyses were used to find the optimal profile solution and for the association with lifelong LTPA auxiliary conditional effect models (controlled for age) were applied. Six distinct patterns emerged. Overall, mostly inactive youth are also the least active in adulthood, whereas several other patterns are associated with a mainly continuous LTPA throughout adulthood. More precisely, multiple constellations in youth occurred to be physically active in at least 80% of the years in adulthood: (1) early starters regarding LTPA in a rather self-organised setting but not with many different LTPAs; (2) late entrants with a variety of different activities and organisational settings; or (3) a high expression in every variable investigated. Consequently, there is not just one type of LTPA behaviour in youth linked to lifelong activity, which indicates that certain aspects of LTPA in youth can be compensated by each other. Implications for LTPA promotion can be derived. Supplementary Information: The online version of this article (10.1007/s12662-023-00884-9) contains supplementary material, which is available to authorized users.

3.
Elife ; 122024 Mar 05.
Artigo em Inglês | MEDLINE | ID: mdl-38441122

RESUMO

Root gravitropic bending represents a fundamental aspect of terrestrial plant physiology. Gravity is perceived by sedimentation of starch-rich plastids (statoliths) to the bottom of the central root cap cells. Following gravity perception, intercellular auxin transport is redirected downwards leading to an asymmetric auxin accumulation at the lower root side causing inhibition of cell expansion, ultimately resulting in downwards bending. How gravity-induced statoliths repositioning is translated into asymmetric auxin distribution remains unclear despite PIN auxin efflux carriers and the Negative Gravitropic Response of roots (NGR) proteins polarize along statolith sedimentation, thus providing a plausible mechanism for auxin flow redirection. In this study, using a functional NGR1-GFP construct, we visualized the NGR1 localization on the statolith surface and plasma membrane (PM) domains in close proximity to the statoliths, correlating with their movements. We determined that NGR1 binding to these PM domains is indispensable for NGR1 functionality and relies on cysteine acylation and adjacent polybasic regions as well as on lipid and sterol PM composition. Detailed timing of the early events following graviperception suggested that both NGR1 repolarization and initial auxin asymmetry precede the visible PIN3 polarization. This discrepancy motivated us to unveil a rapid, NGR-dependent translocation of PIN-activating AGCVIII kinase D6PK towards lower PMs of gravity-perceiving cells, thus providing an attractive model for rapid redirection of auxin fluxes following gravistimulation.


Assuntos
Gravitropismo , Proteínas Quinases , Acilação , Transporte Biológico , Ácidos Indolacéticos
4.
Psychol Sport Exerc ; 72: 102606, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38341163

RESUMO

Previous research has demonstrated that psychosocial resources are associated with elite athletes' perceived stress. However, these resources have mainly been studied separately. Using a person-oriented approach, this study aimed to identify meaningful profiles of athletes' psychosocial resources, their stability over time, and their relationship with perceived stress during the COVID-19 pandemic. To identify such patterns, separate latent profile analyses (LPA) at two measurement points T1 (June 2020) and T2 (March 2021) and a subsequent latent transition analysis (LTA) were conducted with athletic identity, resilience, perceived social support, and self-esteem for a sample of 373 Swiss elite athletes. Perceived stress was analyzed at and between T1 and T2 with a mixed-design ANOVA. For LPA, theoretical considerations and statistical criteria led to a solution of four profiles: (1) Athletic Identifiers With Above-Average Resources (nT1 = 235; nT2 = 240), (2) Below-Average Athletic Identifiers With Below-Average Resources (nT1 = 84; nT2 = 90), (3) Variable Athletic Identifiers With Below-Average Internal and Clearly Below-Average External Resources (nT1 = 14; nT2 = 7), and (4) Athletic Identifiers With Below-Average Internal and Above-Average External Resources (nT1 = 40; nT2 = 36). For LTA, both structural and individual stability was demonstrated. A large and significant main effect of perceived stress was observed for resource profiles, while there was no significant main effect for measurement point nor interaction effect. Direct comparisons revealed that Athletic Identifiers With Above-Average Resources perceived significantly less stress than the other profiles at both time points. In conclusion, regardless of psychosocial resource profile, the perceived stress of elite athletes was stable during the COVID-19 pandemic, but exhibiting a pattern with high psychosocial resources seems to buffer against stress compared to a lack of specific resources. Therefore, sport federations and practitioners should provide tailored support programs to help athletes build all these resources.


Assuntos
COVID-19 , Esportes , Humanos , Pandemias , COVID-19/epidemiologia , Atletas/psicologia , Esportes/psicologia , Estresse Psicológico/epidemiologia
5.
Genes Dev ; 37(5-6): 171-190, 2023 03 01.
Artigo em Inglês | MEDLINE | ID: mdl-36859339

RESUMO

Both the presence of an abnormal complement of chromosomes (aneuploidy) and an increased frequency of chromosome missegregation (chromosomal instability) are hallmarks of cancer. Analyses of cancer genome data have identified certain aneuploidy patterns in tumors; however, the bases behind their selection are largely unexplored. By establishing time-resolved long-term adaptation protocols, we found that human cells adapt to persistent spindle assembly checkpoint (SAC) inhibition by acquiring specific chromosome arm gains and losses. Independently adapted populations converge on complex karyotypes, which over time are refined to contain ever smaller chromosomal changes. Of note, the frequencies of chromosome arm gains in adapted cells correlate with those detected in cancers, suggesting that our cellular adaptation approach recapitulates selective traits that dictate the selection of aneuploidies frequently observed across many cancer types. We further engineered specific aneuploidies to determine the genetic basis behind the observed karyotype patterns. These experiments demonstrated that the adapted and engineered aneuploid cell lines limit CIN by extending mitotic duration. Heterozygous deletions of key SAC and APC/C genes recapitulated the rescue phenotypes of the monosomic chromosomes. We conclude that aneuploidy-induced gene dosage imbalances of individual mitotic regulators are sufficient for altering mitotic timing to reduce CIN.


Assuntos
Pontos de Checagem da Fase M do Ciclo Celular , Neoplasias , Humanos , Pontos de Checagem da Fase M do Ciclo Celular/genética , Aneuploidia , Neoplasias/genética , Instabilidade Cromossômica/genética , Cariótipo , Fuso Acromático/genética , Mitose
6.
J Behav Med ; 46(5): 709-719, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-36862249

RESUMO

Regular physical activity (PA) supports the long-term success of bariatric surgery. However, integrating health-enhancing physical activity in daily life requires specific competences. In this study, we evaluated a multimodal exercise programme to build these competences.Forty adults who underwent bariatric surgery were randomised to a multimodal exercise programme or control group. Primary outcomes were the facets of PA-related health competences, namely the control competence for physical training, PA-specific affect regulation, motivational competence and PA-specific self-control. Secondary outcomes were PA behaviour and subjective vitality. Outcomes were assessed before, directly after the intervention and at 3 months follow-up.Significant treatment effects were found for control competence for physical training and PA-specific self-control but not for PA-specific affect regulation and motivational competence. Significant treatment effects were further observed for self-reported exercise and subjective vitality, all in favour of the intervention group. In contrast, no treatment effect was found for device-based PA. Overall, this study provides a foundation for future research to optimise long-term post bariatric surgery outcomes.


Assuntos
Cirurgia Bariátrica , Exercício Físico , Adulto , Humanos , Atividade Motora , Motivação , Terapia por Exercício
7.
Swiss Med Wkly ; (19-20)2022 05 09.
Artigo em Inglês | MEDLINE | ID: mdl-35633635

RESUMO

BACKGROUND: Exercise is an effective therapy for breast cancer patients to reduce fatigue and to improve health-related quality of life and physical function. Yet breast cancer patients often do not meet the recommended physical activity guidelines. To better understand why recommendations are not met and to improve long-term physical activity maintenance, this study aimed at identifying facilitators and barriers of breast cancer survivors to supervised, centre-based exercise within a cardio-oncological rehabilitation programme and to unsupervised, home-based exercise both during and after the completion of the programme, as well as strategies used to manage these barriers. METHODS: Breast cancer patients who had previously completed a structured centre-based exercise programme at a Swiss tertiary centre were recruited by mailed invitation letter. Semi-structured telephone interviews were conducted with consenting patients and subsequent thematic analysis was performed to identify common themes. RESULTS: Of the 37 eligible breast cancer patients, 19 patients (51%, mean age 48.9 ± 9.7 years) responded to our invitation. Baseline characteristics did not differ from the total eligible population. General facilitators for exercise were anticipated and experienced benefits on physical and mental health and enjoyment of exercise. Facilitators specific for supervised centre-based exercise were social support, accountability and the provision of structured exercise by the programme. Centre-based exercise barriers included physical, psychological and environmental barriers, whereby psychological barriers were reported predominantly in the context of home-based exercise. Strategies to manage these barriers were diverse and included the adaptation of training circumstances, behaviour change strategies and strategies to deal with side effects. CONCLUSIONS: This first study on facilitators of and barriers to exercise in breast cancer patients in Switzerland identified more barriers, particularly psychological barriers, for unsupervised home-based exercise than for supervised centre-based exercise. These findings support the importance of providing structured supervised exercise programmes for breast cancer patients and suggest that a special focus should be directed at the transition from supervised to self-organized exercise in order to enhance and maintain long-term exercise participation.


Assuntos
Neoplasias da Mama , Sobreviventes de Câncer , Terapia por Exercício , Adulto , Neoplasias da Mama/psicologia , Neoplasias da Mama/terapia , Feminino , Humanos , Pessoa de Meia-Idade , Qualidade de Vida , Suíça
8.
Front Psychiatry ; 13: 780498, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35401258

RESUMO

Objective: The present study aimed to assess the frequency of trauma exposure, the prevalence of possible post-traumatic stress disorder (PTSD), the extent of resilience, and sense of coherence among personnel of the Swiss alpine rescue association (ARS). Methods: Using a trilingual online survey approach, 465 mountain rescuers of the ARS were surveyed using the Posttraumatic Diagnostic Scale (PDS), the PTSD Checklist 5 (PCL-5), the Resilience Scale 13 and 14 (RS-13/-14), the Perceived Stress Scale 10 (PSS-10), the General Health Questionnaire 12 (GHQ-12), the Pittsburg Sleep Quality Index (PSQI), the Sense of Coherence Scale 13 (SOC-13), and the Berlin Social Support Scales (BSSS). Results: Although the rate of mountain rescuers having witnessed or experienced a traumatic event was high (71%), the prevalence of possible PTSD was low (0.9%). The sample showed high resilience and high sense of coherence. Resilience was positively correlated with work experience. Low perceived stress and high sense of coherence predicted resilience. The severity of PTSD symptoms was mainly predicted by low sense of coherence. Sense of coherence mediated the interaction between resilience and severity of PTSD symptoms. Conclusion: The findings suggest that resilience and sense of coherence are indicative for the low prevalence of possible PTSD among mountain rescuers, and may therefore represent valuable screening and training parameters for mountain rescue personnel.

9.
J Sport Exerc Psychol ; 44(2): 103-115, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35213816

RESUMO

This study tested the effectiveness of individual exercise and sport counseling in a nonclinical setting. The COunseling based on Motives and goals in Exercise and sporT (COMET) approach focuses on individual motives and goals and aims to identify suitable activities. Participants experience different exercise and sport activities and reflect on them with a counselor, who applies motivational interviewing. A stratified randomized controlled design with 129 people was used. The intervention group took part in a counseling event, which included feedback on motives and goals, trial exercise and sport sessions, and structured reflection. Four weeks later, members of the group got a telephone booster. The control group received minimal intervention as written information. Results show that the counseling promoted motivational competence (η2 = .16), physical activity-specific self-control (η2 = .08), and the weekly volume of exercise and sport (η2 = .15), whereas it did not influence self-concordance. Further studies can investigate whether the COMET approach is also effective in other settings.


Assuntos
Entrevista Motivacional , Esportes , Aconselhamento , Exercício Físico/psicologia , Humanos , Motivação
10.
BMC Public Health ; 22(1): 152, 2022 01 21.
Artigo em Inglês | MEDLINE | ID: mdl-35062941

RESUMO

BACKGROUND: The present study firstly aimed to identify context patterns in sport and exercise among adolescents at lower and upper secondary education. The organisational, social and competitive contexts of leisure-time sport and exercise were included as pattern indicators. The second aim was to examine the stability of these patterns across educational transition. The last aim was to investigate whether a subjective evaluation of the transition influences whether people stay in the same pattern across time. METHODS: One-year longitudinal data of 392 adolescents were analysed. RESULTS: Both before and after the educational transition, four context patterns were identified: the traditional competitive club athletes with friends, the self-organised individualists, the non-club-organised sportspersons and the mostly inactives. More than half of the individuals stayed in the same pattern across time. When individuals changed pattern, their change was most often from the self-organised individualists and the non-club-organised to the mostly inactives. A subjective evaluation of the transition influenced the stability of only the traditional competitive club athletes with friends. The chance of these people staying in the same pattern decreased with increased transitional stress. CONCLUSIONS: Knowledge about the stability and change of context patterns can be used to make recommendations for policy strategies and to develop more individually-tailored promotion programs.


Assuntos
Esportes , Adolescente , Exercício Físico , Humanos , Atividades de Lazer , Organizações , Comportamento Sedentário
11.
J Sports Sci ; 40(5): 571-582, 2022 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-34844515

RESUMO

In sport and exercise promotion, it is important to consider goals because achieving these goals leads to a sense of well-being and behaviour adherence. Individuals often pursue multiple goals simultaneously. Therefore, it is also important to not only consider each individual's combination of goals but also to identify so-called "goal profiles". Taking a developmental-psychological perspective, the goal profiles of adolescents may differ from those of young adults. Furthermore, goal profiles might differ concerning the self-determined motivation, sport and exercise behaviour, and gender. Therefore, both age groups, 966 adolescents and 636 young adults, were questioned by self-report on their goals in sport and exercise, self-determined motivation, sport and exercise behaviour, and gender. A multiple-group-analysis for latent-profile-solutions was conducted resulting in six goal profiles for both age groups. As expected, the shape of these profiles differed qualitatively for the majority of adolescents and young adults: In adolescents, goals such as contact and the perception of challenge were more prominent, whereas in young adults, health, figure/appearance, and distraction/catharsis were dominant. Validation analyses support the profiles identified as they differ in self-determined motivation, sport and exercise behaviour, and gender. To more efficiently tailor interventions, an age-specific focus on goal profiles seems promising.


Assuntos
Motivação , Esportes , Adolescente , Exercício Físico/psicologia , Objetivos , Humanos , Autonomia Pessoal , Esportes/psicologia , Adulto Jovem
12.
Elife ; 102021 10 13.
Artigo em Inglês | MEDLINE | ID: mdl-34643181

RESUMO

Stem cell homeostasis in plant shoot meristems requires tight coordination between stem cell proliferation and cell differentiation. In Arabidopsis, stem cells express the secreted dodecapeptide CLAVATA3 (CLV3), which signals through the leucine-rich repeat (LRR)-receptor kinase CLAVATA1 (CLV1) and related CLV1-family members to downregulate expression of the homeodomain transcription factor WUSCHEL (WUS). WUS protein moves from cells below the stem cell domain to the meristem tip and promotes stem cell identity, together with CLV3 expression, generating a negative feedback loop. How stem cell activity in the meristem centre is coordinated with organ initiation and cell differentiation at the periphery is unknown. We show here that the CLE40 gene, encoding a secreted peptide closely related to CLV3, is expressed in the SAM in differentiating cells in a pattern complementary to that of CLV3. CLE40 promotes WUS expression via BAM1, a CLV1-family receptor, and CLE40 expression is in turn repressed in a WUS-dependent manner. Together, CLE40-BAM1-WUS establish a second negative feedback loop. We propose that stem cell homeostasis is achieved through two intertwined pathways that adjust WUS activity and incorporate information on the size of the stem cell domain, via CLV3-CLV1, and on cell differentiation via CLE40-BAM1.


Plants are sessile lifeforms that have evolved many ways to overcome this challenge. For example, they can quickly adapt to their environment, and they can grow new organs, such as leaves and flowers, throughout their lifetime. Stem cells are important precursor cells in plants (and animals) that can divide and specialize into other types of cells to help regrow leaves and flowers. A region in the plant called meristem, which can be found in the roots and shoots, continuously produces new organs in the peripheral zone of the meristem by maintaining a small group of stem cells in the central zone of the meristem. This is regulated by a signalling pathway called CLV and a molecule produced by the stem cells in the central zone, called CLV3. Together, they keep a protein called WUS (found in the deeper meristem known as the organizing zone) at low levels. WUS, in turn, increases the production of stem cells that generate CLV3. However, so far it was unclear how the number of stem cells is coordinated with the rate of organ production in the peripheral zone. To find out more, Schlegel et al. studied cells in the shoot meristems from the thale cress Arabidopsis thaliana. The researchers found that cells in the peripheral zone produce a molecule called CLE40, which is similar to CLV3. Unlike CLV3, however, CLE40 boosts the levels of WUS, thereby increasing the number of stem cells. In return, WUS reduces the production of CLE40 in the central zone and the organizing centre. This system allows meristems to adapt to growing at different speeds. These results help reveal how the activity of plant meristems is regulated to enable plants to grow new structures throughout their life. Together, CLV3 and CLE40 signalling in meristems regulate stem cells to maintain a small population that is able to respond to changing growth rates. This understanding of stem cell control could be further developed to improve the productivity of crops.


Assuntos
Proteínas de Arabidopsis/genética , Arabidopsis/fisiologia , Proteínas de Homeodomínio/genética , Brotos de Planta/fisiologia , Proteínas Serina-Treonina Quinases/genética , Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Diferenciação Celular , Regulação da Expressão Gênica de Plantas , Proteínas de Homeodomínio/metabolismo , Homeostase , Células Vegetais/fisiologia , Brotos de Planta/genética , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de Sinais/genética , Células-Tronco/fisiologia
13.
Front Sports Act Living ; 3: 706467, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-34485903

RESUMO

Objective: The purpose of this study was to investigate a potential psychological mechanism of green exercise on perceived stress. More precisely, it was analyzed whether the relationship between the natural environment of physical activity and perceived stress was mediated by recovery experiences, namely by psychological detachment and relaxation. An ecological momentary assessment approach was used, meaning that specific recovery experiences were assessed directly in real-life situations and multiple times. Materials and methods: Thirty five women and 27 men took part in the ecological momentary assessment study over seven days (M age = 32.30 years, SD = 10.23, 53% had a degree from a university or a university of applied science). If participants were involved in PA lasting at least 10 min on a given day, they had to answer questionnaires on the smartphone both prior to the activity and immediately afterwards. Perceived naturalness, psychological detachment and relaxation were assessed after physical activity events, whereas perceived stress was measured before and after each physical activity event. A two-level mediation analysis was conducted. The direct and indirect effect of perceived naturalness on perceived stress after engagement in physical activity was analyzed on the within- and between-person levels. Results and conclusion: Results showed that the relaxation as a recovery experience served as mediator between perceived naturalness and perceived stress after engagement in physical activity, but only on a within-person level. This means that the more natural a given individual appraised the physical activity environment, the more relaxed he or she felt during physical activity (ß = 0.322, p < 0.0005). Furthermore the more relaxed the individual was, the less stress he or she perceived after exercising (ß = -0.221, p < 0.0005). The psychological detachment as a recovery experience in contrast, did not serve as mediator, neither at the within- and the between-person level. Considering the indirect effect of perceived naturalness on perceived stress and the importance of relaxation experiences, current findings suggest that research should put greater emphasis on examining the specific psychological mechanisms of green exercise to make even better use of its beneficial effects in the future.

14.
Artigo em Inglês | MEDLINE | ID: mdl-33440746

RESUMO

Affective well-being is positively linked to regular exercise. Therefore, it is important to identify the factors that influence intra-individual variability of affective well-being. This study investigated (1) whether affective responses vary within an individual and (2) how affective responses are associated with a motive-incentive fit and a skill-task fit. A total of 107 adults (66% females, Mage = 41.79 years old, 58% doing no exercise) took part in three exercise sessions in a random order. Each session lasted 30 min with a break of 10 min between. The sessions were similarly structured but covered diverse activity incentives (e.g., figure vs. social contact vs. aesthetic movements). Intraclass correlation coefficients showed a very high within-person variation of affective valence and enjoyment across the exercise sessions. The results of multi-level regression analyses revealed that associations between perceived competence, considered to be an indicator of the skill-task fit, and affective well-being were moderate to high, whereas those between motive-incentive fit and affective well-being were low to moderate.


Assuntos
Variação Biológica Individual , Exercício Físico , Adulto , Afeto , Emoções , Feminino , Humanos , Masculino , Motivação , Prazer
15.
Sci Rep ; 10(1): 13198, 2020 08 06.
Artigo em Inglês | MEDLINE | ID: mdl-32764650

RESUMO

Network analysis is an important tool to analyze the structure of complex systems such as tropical forests. Here, we infer spatial proximity networks in tropical forests by using network science. First, we focus on tree neighborhoods to derive spatial tree networks from forest inventory data. In a second step, we construct species networks to describe the potential for interactions between species. We find remarkably similar tree and species networks among tropical forests in Panama, Sri Lanka and Taiwan. Across these sites only 32 to 51% of all possible connections between species pairs were realized in the species networks. The species networks show the common small-world property and constant node degree distributions not yet described and explained by network science. Our application of network analysis to forest ecology provides a new approach in biodiversity research to quantify spatial neighborhood structures for better understanding interactions between tree species. Our analyses show that details of tree positions and sizes have no important influence on the detected network structures. This suggests existence of simple principles underlying the complex interactions in tropical forests.

16.
PLoS One ; 15(7): e0236546, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32722690

RESUMO

Grasslands contribute to global biogeochemical cycles and can host a high number of plant species. Both-species dynamics and biogeochemical fluxes-are influenced by abiotic and biotic environmental factors, management and natural disturbances. In order to understand and project grassland dynamics under global change, vegetation models which explicitly capture all relevant processes and drivers are required. However, the parameterization of such models is often challenging. Here, we report on testing an individual- and process-based model for simulating the dynamics and structure of a grassland experiment in temperate Europe. We parameterized the model for three species and confront simulated grassland dynamics with empirical observations of their monocultures and one two-species mixture. The model reproduces general trends of vegetation patterns (vegetation cover and height, aboveground biomass and leaf area index) for the monocultures and two-species community. For example, the model simulates well an average annual grassland cover of 70% in the species mixture (observed cover of 77%), but also shows mismatches with specific observation values (e.g. for aboveground biomass). By a sensitivity analysis of the applied inverse model parameterization method, we demonstrate that multiple vegetation attributes are important for a successful parameterization while leaf area index revealed to be of highest relevance. Results of our study pinpoint to the need of improved grassland measurements (esp. of temporally higher resolution) in close combination with advanced modelling approaches.


Assuntos
Pradaria , Modelos Estatísticos , Características de Residência , Dinâmica Populacional
17.
BMC Public Health ; 20(1): 570, 2020 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-32345245

RESUMO

BACKGROUND: In order to generate more effective interventions to promote exercise and sport in adolescence, a better understanding of the interaction of influencing factors across different levels is needed. In particular, motivation and volition for exercise and sport, as well as the context in which adolescents are doing exercise and sport, have been identified as important factors. Behavioral context refers to both the organizational setting, e.g., doing exercise and sport in a club, and the social setting, e.g., doing exercise and sport with friends. Extending previous research, the present study applies a person-oriented approach and aims to identify typical behavioral context patterns and motivational-volitional patterns. To validate the patterns, it was examined whether they differ concerning the exercise and sport activity level. Furthermore, the study investigated how behavioral context patterns and motivational-volitional patterns interact. METHOD: A cross-sectional design with 1155 adolescents (Mage = 15.29; 53% female) was applied. A latent profile analysis was used twice to identify typical patterns: once with eight organizational and social setting factors to examine behavioral context patterns, and once with five motivational-volitional factors to examine motivational-volitional patterns. To validate the patterns identified, the exercise and sport activity level were compared across the patterns using Wald-tests. Finally, transition probabilities and odds ratios were calculated in order to investigate the interaction of the behavioral context and motivational-volitional patterns. RESULTS: Four behavioral context patterns - differing in activity level - were identified: Mostly inactive, non-club-organized individualists, self-organized individualists and family sportspersons, and traditional competitive club athletes with friends. Furthermore, five motivational-volitional patterns emerged with differing activity levels: three level patterns with overall low, moderate or high motivation and volition, and two shape patterns called the intention- and plan-less and the plan-less motivated. Regarding interaction, the results indicate that one behavioral context pattern is not solely responsible for moderate to high motivation and volition in adolescents. CONCLUSION: Applying a person-oriented approach allows a more differentiated view of how behavioral context and motivational-volitional factors interact within homogenous subgroups. This, in turn, provides a basis to design tailored multilevel interventions which account for the interaction of influencing factors across different levels.


Assuntos
Comportamento do Adolescente/psicologia , Exercício Físico/psicologia , Motivação , Esportes/psicologia , Volição , Adolescente , Estudos Transversais , Feminino , Comportamentos Relacionados com a Saúde , Humanos , Intenção , Masculino , Adulto Jovem
18.
Appl Psychol Health Well Being ; 12(2): 312-334, 2020 07.
Artigo em Inglês | MEDLINE | ID: mdl-31600037

RESUMO

BACKGROUND: The first aim of the present study was to identify psychosocial patterns among adolescents at lower secondary school. Employing the motivation and volition process model and a socioecological framework, self-concordance, action planning, social support, and club-related exercise and sport activities were included as indicators. The second aim was to examine how these patterns are associated with the maintenance of exercise and sport during students' transition to upper secondary education. The last aim was to investigate whether the associations were moderated by individuals' subjective evaluation of the transition. METHODS: One-year longitudinal data of 392 adolescents were analysed. All variables were measured via online self-report. RESULTS: Based on latent profile analysis, four patterns were found: "averages", "club enthusiasts", "club engaged planners", and "less motivated and social uncommits". Regression analyses showed that the club engaged planners were more likely to adopt and maintain exercise and sport than to drop out. Additionally, moderation analyses revealed that the averages were less likely to be maintainers/adopters when they evaluated the transition more negatively. CONCLUSION: People with relatively high action planning and a high number of club-related activities were less vulnerable to decreasing their activity time during the transition to upper secondary education. Furthermore, transitional stress bore no negative association with students' exercise and sport behaviour.


Assuntos
Comportamento do Adolescente/fisiologia , Desenvolvimento do Adolescente/fisiologia , Exercício Físico/fisiologia , Esportes , Estresse Psicológico/fisiopatologia , Pensamento/fisiologia , Adolescente , Feminino , Humanos , Estudos Longitudinais , Masculino , Autorrelato
19.
Eur J Pain ; 23(2): 272-284, 2019 02.
Artigo em Inglês | MEDLINE | ID: mdl-30098104

RESUMO

BACKGROUND: Chronic pelvic pain, in particular dysmenorrhoea, is a significant yet unresolved healthcare problem in gynaecology. As interoceptive sensitivity and underlying neural mechanisms remain incompletely understood, this functional magnetic resonance imaging (fMRI) study assessed behavioural and neural responses to visceral stimuli in primary dysmenorrhoea (PMD). METHODS: Women with PMD (N = 19) without psychological comorbidity and healthy women (N = 20) were compared with respect to visceral sensory and pain thresholds, and to neural responses to individually calibrated mildly painful and painful rectal distensions implemented during scanning. Trial-by-trial ratings of perceived intensity were accomplished with visual analogue scales (VAS). RESULTS: Although women with dysmenorrhoea reported significantly higher chronic pain intensity and pain interference with daily life activities (p < 0.01, assessed with the West Haven-Yale Multidimensional Pain Inventory), there were no differences between groups in visceral sensitivity and mean trial-by-trial VAS ratings were virtually identical. Analysis of neural responses revealed activation in brain regions previously shown to be involved in the processing of visceral stimuli with differences between painful and mildly painful stimulation, but no group differences were found even when using a liberal statistical threshold. CONCLUSIONS: Dysmenorrhoea patients show unaltered perceptual and neural responses to experimental interoceptive stimuli. Despite limited sample size, these negative results argue against a generalized sensitization towards interoceptive stimuli in patients without psychological comorbidities. Future studies should clarify the role of psychosocial factors in central sensitization using more pain region-specific models in larger and clinically more heterogeneous samples. SIGNIFICANCE: Despite higher chronic pain and pain interference with daily life activities, women with primary dysmenorrhoea do not differ from healthy women with respect to visceral sensitivity or neural processing of aversive interoceptive stimuli induced by rectal distensions. Generalized sensitization may be present only in subgroups with pronounced psychosocial or psychiatric disturbances.


Assuntos
Dismenorreia/fisiopatologia , Dismenorreia/psicologia , Dor Visceral/fisiopatologia , Dor Visceral/psicologia , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Estudos de Casos e Controles , Sensibilização do Sistema Nervoso Central , Dismenorreia/diagnóstico por imagem , Feminino , Humanos , Imageamento por Ressonância Magnética , Medição da Dor , Percepção da Dor , Limiar da Dor , Dor Visceral/diagnóstico por imagem , Adulto Jovem
20.
Transpl Int ; 31(11): 1207-1215, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30091268

RESUMO

Liver transplantation (LT) is the first-line therapy in patients with transthyretin (TTR) amyloidosis and progressive familial amyloid polyneuropathy (FAP). Explanted organs from these patients can be used for domino liver transplantation (DLT). After DLT, de novo amyloidosis may develop in domino recipients (DR). Data were collected prospectively in a transplant database. Electroneurography by nerve conduction velocity (NCV), quantitative sensory testing, heart rate variability (HRV), sympathetic skin response, orthostatic reaction (tilt table test), transthoracic echocardiography, cardiac MRI and organ biopsy results were evaluated. The cohort included 24 FAP- (11 Val30Met, 13 nonVal30Met) and 23 DR-patients. DR symptoms referred to post-DLT only, while those of FAP patients were both pre- and post-transplantation. Symptoms of TTR-amyloidosis in Val30Met and Non-Val30Met patients pre- and post-LT were similarly distributed. Biopsy-proven de novo amyloidosis occurred in 4/23 DR after a mean observation of 10 years. Analysis for manifestations of amyloidosis only included patients with available 5-year follow-up data (n = 13 FAP, n = 12 DR). Compared to Val30Met FAP patients pre-LT, Val30Met DR patients had better NCV (P = 0.04) and HRV (P = 0.015). In the Non-Val30Met group no differences were found between DR and FAP patients pre-LT. TTR-amyloidosis symptoms showed no differences in FAP patients pre- and 5 years post-LT, irrespective of Val30Met status. In DR patients, de novo amyloidosis occurred earlier than expected. Therefore, recipients for DLT need to be carefully selected and followed.


Assuntos
Neuropatias Amiloides Familiares/cirurgia , Progressão da Doença , Falência Hepática/cirurgia , Transplante de Fígado/efeitos adversos , Doadores Vivos , Adulto , Idoso , Neuropatias Amiloides Familiares/diagnóstico , Biópsia , Criança , Bases de Dados Factuais , Ecocardiografia , Feminino , Frequência Cardíaca , Humanos , Transplante de Fígado/métodos , Masculino , Metionina/química , Pessoa de Meia-Idade , Estudos Prospectivos , Fatores de Tempo , Resultado do Tratamento , Valina/química
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