Objective: Motivation seems to be a fundamental indicator of long-term physical exercise adherence. Self-Determination Theory (SDT) argues that social environment plays a central role in the satisfaction of basic psychological needs, which might directly affect the quality of one's motivation. Individuals who appear to be more self-determined tend to persist longer at certain behaviors. Therefore, this body of work intends to analyze the relationship between motivational variables and behavioral outcomes in the exercise context, having as theoretical background the Self-Determination Theory.Methods: This systematic review was conducted through an electronic search on Web of Science, PubMed, SPORTDiscus, and PsycINFO. Data such as instruments, main predictors and results were collected from studies published between 1985 and 2018. A total of 35 empirical studies were considered for a detailed analysis.Results: Results showed the relevance of autonomy support performed by exercise professionals, as well as the major contribution that these behaviors have toward the satisfaction of basic psychological needs, besides the inherent benefits of developing more autonomous regulations. According to the literature, few studies have analyzed interpersonal thwarting behavior and the way this relates to basic psychological needs' frustration. Nether less, there seems to be a negative relationship between less self-determined regulations and exercise practice.Conclusion: Despite the existence of numerous cross-sectional studies that demonstrate positive correlations between SDT and behavioral outcomes in the exercise context, longitudinal research that analyzes all six dimensions of interpersonal behaviors and their relationship with persistence and adherence to exercise proves to be crucial. However, according to this review, interventions based on SDT appear to be fundamental when it comes to promote the maintenance of a long-term exercise practice.

Health literacy, a more complex concept than knowledge, is a required capacity to obtain, understand, integrate and act on health information [1], in order to enhance individual and community health, which is defined by different levels, according to the autonomy and personal capacitation in decision making [2]. Medium levels of Health literacy in an adolescent population were found in a study conducted in 2013/2014, being higher in sexual and reproductive health and lower in substance use. It was also noticed that the higher levels of health literacy were in the area adolescents refer to have receipt more health information. The health literacy competence with higher scores was communication skills, and the lower scores were in the capacity to analyze factors that influence health. Higher levels were also found in younger teenagers, but in a higher school level, confirming the importance of health education in these age and development stage. Adolescents seek more information in health professionals and parents, being friends more valued as a source information in older adolescents, which enhance the importance of peer education mainly in older adolescents [3]. As a set of competences based on knowledge, health literacy should be developed through education interventions, encompassing the cultural and social context of individuals, since the society, culture and education system where the individual is inserted can define the way the development and enforcement of the health literacy competences [4]. The valued sources of information should be taken into account, as well as needs of information in some topics referred by adolescents in an efficient health education. Schizophrenia is a serious and chronic mental illness which has a profound effect on the health and well-being related with the well-known nature of psychotic symptoms. The exercise has the potential to improve the life of people with schizophrenia improving physical health and alleviating psychiatric symptoms. However, most people with schizophrenia remains sedentary and lack of access to exercise programs are barriers to achieve health benefits. The aim of this study is to evaluate the effect of exercise on I) the type of intervention in mental health, II) in salivary levels of alpha-amylase and cortisol and serum levels of S100B and BDNF, and on III) the quality of life and selfperception of the physical domain of people with schizophrenia. The sample consisted of 31 females in long-term institutions in the Casa de Saúde Rainha Santa Isabel, with age between 25 and 63, and with diagnosis of schizophrenia according to the Diagnostic and Statistical Manual of Mental Disorders (DSM-IV-TR). Physical fitness was assessed by the six-minute walk distance test (6MWD). Biological variables were determined by ELISA (Enzyme-Linked Immunosorbent Assay). Psychological variables were assessed using SF-36, PSPP-SCV, RSES and SWLS tests. Walking exercise has a positive impact on physical fitness (6MWD -p = 0.001) and physical components of the psychological test...

Haematopoiesis is a developmental cascade that generates all blood cell lineages in health and disease. This process relies on quiescent haematopoietic stem cells capable of differentiating, self renewing and expanding upon physiological demand. However, the mechanisms that regulate haematopoietic stem cell homeostasis and function remain largely unknown. Here we show that the neurotrophic factor receptor RET (rearranged during transfection) drives haematopoietic stem cell survival, expansion and function. We find that haematopoietic stem cells express RET and that its neurotrophic factor partners are produced in the haematopoietic stem cell environment. Ablation of Ret leads to impaired survival and reduced numbers of haematopoietic stem cells with normal differentiation potential, but loss of cell-autonomous stress response and reconstitution potential. Strikingly, RET signals provide haematopoietic stem cells with critical Bcl2 and Bcl2l1 surviving cues, downstream of p38 mitogen-activated protein (MAP) kinase and cyclic-AMP-response element binding protein (CREB) activation. Accordingly, enforced expression of RET downstream targets, Bcl2 or Bcl2l1, is sufficient to restore the activity of Ret null progenitors in vivo. Activation of RET results in improved haematopoietic stem cell survival, expansion and in vivo transplantation efficiency. Remarkably, human cord-blood progenitor expansion and transplantation is also improved by neurotrophic factors, opening the way for exploration of RET agonists in human haematopoietic stem cell transplantation. Our work shows that neurotrophic factors are novel components of the haematopoietic stem cell microenvironment, revealing that haematopoietic stem cells and neurons are regulated by similar signals.

Age-related DNA damage is regarded as one of the possible explanations of aging. Although a generalized idea about the accumulation of DNA damage with age exists, results found in the literature are inconsistent. To better understand the question of age-related DNA damage in humans and to identify possible moderator variables, a meta-analysis was conducted.Electronic databases and bibliographies for studies published since 2004 were searched. Summary odds ratios (ORs) and 95% confidence intervals (CIs) for age-related DNA damage were calculated in a random-effects model.A total of 76 correlations from 36 studies with 4676 participants were included. Based on our analysis, a correlation between age and DNA damage was found (r = 0.230, p = 0.000; 95% confidence interval = 0.111 - 0.342). The test for heterogeneity of variance indicates that the study´s results are significantly high (Q (75) = 1754.831, p = 0.000). Moderator variables such as smoking habits, technique used, and the tissue/sample analyzed, are shown to influence age-related DNA damage (p=0.026; p=0.000; p=0.000, respectively). Nevertheless, sex did not show any influence on this relation (p=0.114).In conclusion, this meta-analysis showed an association between age and DNA damage in humans. It was also found that smoking habits, the technique used, and tissue/sample analyzed, are important moderator variables in age-related DNA damage.

ARTIGO DE REVISÃO | REVIEW ARTICLE RESUMOSumários da evidência disponível que sejam credíveis são fundamentais para o apoio à tomada de decisão de investigadores e profissionais no desempenho do seu trabalho. Por esta razão, a qualidade do trabalho final deve depender e refletir o rigor aplicado em todas as etapas de elaboração dos trabalhos de revisão. O objetivo do presente trabalho é compilar orientações e recomendações para o planeamento, elaboração e redação de revisões sistemáticas, que sirvam de apoio à melhor consecução do trabalho de investigadores e revisores. Inicialmente situam-se os trabalhos de revisão sistemática no âmbito de outros trabalhos de síntese da literatura, identificando as suas características distintivas. Posteriormente, apresentam-se as etapas de desenvolvimento de trabalhos de revisão sistemática, destacando-se as principais preocupações e cuidados no cumprimento de cada uma. Finalmente, será apresentada uma versão comentada de uma checklist de redação de estudos, que facilite a redação de futuros trabalhos desta natureza. Pretende-se descrever as principais tarefas e preocupações em cada fase de elaboração de revisões sistemáticas no sentido de contribuir para a uniformização da estrutura dos trabalhos bem como da qualidade dos mesmos, de modo a que o conhecimento disponível em sínteses da literatura constitua uma fonte fiável de fundamento para a tomada de decisão. Palavras-chave: revisão sistemática, recomendações, metodologia da investigação, síntese ABSTRACT Reliable summaries of the available evidence are essential to help researchers and practitioners make well-informed decisions. For this reason, the quality of the final result depends on the accuracy in each stage of the development of a systematic review. The aim of the present study is to draw guidelines and recommendations for planning, conducting, reporting and evaluating systematic reviews that support the work of researchers and reviewers. Initially, we address the main characteristics and differences of a systematic review compared to other literature reviews. Then, we describe the main procedures and concerns to be considered in each phase of developing a systematic review. Finally, we present a commented version of a checklist for reporting systematic reviews and guide the reader. We intend to contribute to the set of standards for the structure and quality of knowledge published in review papers, in the fields of Sport and Health, which support more informed decisions.