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2.
Sports Health ; 16(2): 285-294, 2024.
Article in English | MEDLINE | ID: mdl-37994044

ABSTRACT

CONTEXT: Physical exercise (PE) is an effective treatment for depression, alone or as an adjunct. OBJECTIVE: There is a lack of indicators regarding the frequency, intensity, duration, and type of physical exercise (PE). This study aims to synthesize and analyze the dose-effect of different PE protocols in adult subjects in the treatment of depression, based on the analysis of randomized controlled trials (RCTs). DATA SOURCES: The search was conducted using Web of Science, PubMed, and Cochrane Library electronic databases. STUDY SELECTION: Studies with an exercise-based intervention published by December 31, 2021 were identified. RCTs and meta-analyses involving adults with depression were also included; 10 studies were selected, including a total of 956 subjects. STUDY DESIGN: Systematic review and meta-analysis. LEVEL OF EVIDENCE: Level 1. RESULTS: Effect sizes were summarized using standardized mean differences (95% confidence interval) by effected randomized models. The results reinforce that exercise appears to be beneficial in improving depression among adults aged 18 to 65 years. Interventions lasting above 150 minutes per week of moderate intensity and group interventions seem to have a more significant effect on reducing depression. Studies have revealed that aerobic exercise, compared with resistance or flexibility, has a more positive effect on depression. CONCLUSION: PE can be a way to reduce depression and can be used as a possible adjunctive tool for pharmacological and/or alternative treatments. Considering the findings of this study, it is important that health professionals (eg, exercise physiologists, physicians, nurses, psychologists) promote the practice of PE as a complementary alternative and act early to prevent the worsening of depression. PROSPERO REGISTRATION NUMBER: CRD42020188909.


Subject(s)
Depression , Exercise , Adult , Humans , Depression/therapy , Randomized Controlled Trials as Topic , Treatment Outcome
3.
Healthcare (Basel) ; 11(23)2023 Nov 22.
Article in English | MEDLINE | ID: mdl-38063587

ABSTRACT

This study aims to explore data on objectively measured physical activity from a sample of adults and older adults and to investigate the achievement of the minimum physical activity required for health benefits. Participants, 257 women (age 58.99 ± 18.93 years, BMI 26.75 ± 4.57 kg·m-2) and 178 men (age 49.22 ± 20.39 years, BMI 26.81 ± 3.51 kg·m-2), wore an accelerometer for 4 to 7 days. Approximately 40% of the time was spent daily in sedentary behaviors during waking hours. Our results do not sustain the suggestion that adult men are more physically active than women. The results indicated a decrease in intensity of physical activity with age, in men and women, but not in successive age groups. Around 75% of adults and 30% of older adults accumulated the minimum daily physical activity for health benefits, in periods shorter than 10 min, above moderate intensity. The number of steps taken per day revealed that most men and women (except the oldest) attained or exceeded the lower threshold for deriving health benefits. To obtain relevant health benefits, future physical activity interventions should aim at reversing the amount of sedentary behaviors, emphasizing increments in, at least, the lower levels of PA, and maintaining walking habits.

4.
Front Microbiol ; 14: 1251602, 2023.
Article in English | MEDLINE | ID: mdl-37954249

ABSTRACT

Introduction: This work investigates whether rhizosphere microorganisms that colonize halophyte plants thriving in saline habitats can tolerate salinity and provide beneficial effects to their hosts, protecting them from environmental stresses, such as aromatic compound (AC) pollution. Methods: To address this question, we conducted a series of experiments. First, we evaluated the effects of phenol, tyrosine, 4-hydroxybenzoic acid, and 2,4-dichlorophenoxyacetic (2,4-D) acids on the soil rhizosphere microbial community associated with the halophyte Allenrolfea vaginata. We then determined the ability of bacterial isolates from these microbial communities to utilize these ACs as carbon sources. Finally, we assessed their ability to promote plant growth under saline conditions. Results: Our study revealed that each AC had a different impact on the structure and alpha and beta diversity of the halophyte bacterial (but not archaeal) communities. Notably, 2,4-D and phenol, to a lesser degree, had the most substantial decreasing effects. The removal of ACs by the rhizosphere community varied from 15% (2,4-D) to 100% (the other three ACs), depending on the concentration. Halomonas isolates were the most abundant and diverse strains capable of degrading the ACs, with strains of Marinobacter, Alkalihalobacillus, Thalassobacillus, Oceanobacillus, and the archaea Haladaptatus also exhibiting catabolic properties. Moreover, our study found that halophile strains Halomonas sp. LV-8T and Marinobacter sp. LV-48T enhanced the growth and protection of Arabidopsis thaliana plants by 30% to 55% under salt-stress conditions. Discussion: These results suggest that moderate halophile microbial communities may protect halophytes from salinity and potential adverse effects of aromatic compounds through depurative processes.

5.
Healthcare (Basel) ; 11(18)2023 Sep 20.
Article in English | MEDLINE | ID: mdl-37761787

ABSTRACT

The purpose of this study was to examine and compare the psychometric properties (internal consistency and factorial validity) of different versions of the Body Shape Questionnaire (BSQ) in a sample of female aesthetic patients. The sample included 296 women attending aesthetic clinics, with ages ranging between 18 and 70 years (M = 32.23, SD = 11.35) and body mass index between 17.10 and 45.00 kg/m2 (M = 24.70, SD = 4.07). Nine different length versions of the BSQ (BSQ-34, BSQ-32, BSQ-16A, BSQ-16B, BSQ-14, BSQ-8A, BSQ-8B, BSQ-8C and BSQ-8D) were subjected to confirmatory factor analyses, using a robust maximum likelihood estimator. Robust fit indices indicated that the BSQ-8D version was the better-fitting and more parsimonious model (S-Bχ2/df = 1.81, CFI = 0.963, RMSEA = 0.052, SRMR = 0.043). This short version also showed appropriate reliability (McDonald's omega and composite reliability = 0.87) and a very high correlation with the original BSQ-34 version (r = 0.95). In sum, these findings suggest that the BSQ-8D is the most valid, reliable and suitable BSQ version for measuring body shape concerns in female aesthetic patients.

6.
Sports (Basel) ; 11(8)2023 Aug 09.
Article in English | MEDLINE | ID: mdl-37624129

ABSTRACT

Alzheimer's disease is a type of dementia that progressively affects memory, thinking, and behavior. It can interfere with daily activities and lead to a decline in cognitive abilities over time. Exercise-based interventions can complement Alzheimer's disease treatment. Exercise is a valuable tool in all healthcare settings and has shown promise as an effective cognitive improvement intervention for people with cognitive impairments. This systematic review and meta-analysis aimed to analyze the effect of physical exercise on the QoL of subjects with Alzheimer's disease. A search was performed with the help of the electronic databases PubMed and Web of Science. Randomized controlled trials with exercise-based interventions were selected. Four studies met the inclusion criteria, which included interventions based on exercise. The effects were summarized using standardized mean differences (95% confidence intervals) using random-effect models. The results showed that exercise had no significant effect on the QoL of subjects with Alzheimer. Thus, the effect of exercise interventions on the QoL of patients with Alzheimer's disease is not conclusive. More research is needed about this topic and the way in which the QoL is assessed; the necessity to conduct an objective way to assess the QoL in this population is mandatory.

7.
Healthcare (Basel) ; 11(10)2023 May 16.
Article in English | MEDLINE | ID: mdl-37239735

ABSTRACT

BACKGROUND: Chronic obstructive pulmonary disease (COPD) is a heterogeneous lung condition, the main symptoms of which are dyspnoea and fatigue. Though exercise has been recommended for subjects with COPD, its benefits remain unclear. The aim of this study was to summarise, through a systematic review and meta-analysis, the available evidence on the effects of aerobic, resistance, stretching, and combined exercise on the main symptoms of COPD. METHODS: Search was performed using the electronic databases PubMed and Web of Science. Randomised controlled trials (RCTs) with interventions based on aerobic, resistance and/or combined exercise published until July 2022 were identified. The effects were summarised based on standardised mean differences (95% confidence intervals) using random and fixed effect models. RESULTS: Eight studies were selected, including a total of 375 subjects. The results obtained showed that resistance exercise, aerobic exercise and combined exercise seem to improve dyspnoea and fatigue symptoms in COPD subjects. CONCLUSIONS: In general, we can conclude that exercise-based interventions appear to improve the main COPD symptoms and may benefit quality of life in this population.

8.
Life (Basel) ; 13(2)2023 Jan 20.
Article in English | MEDLINE | ID: mdl-36836655

ABSTRACT

Physical activity and diet are two predominant determinants of population health status that may influence each other. Physical activity has been identified as a behavior that may lead to a healthier diet and regulates eating behaviors. This research aimed to investigate how the level of physical activity is associated with the motivation related to eating behaviors and, consequently, the eating style individuals have on a daily basis. This was a cross-sectional study in which participants completed an online questionnaire that assessed the following variables: the level of physical activity, the motivation toward eating behavior, and the type of eating behavior. In total, 440 individuals (180 men and 260 women) who regularly exercised in gyms and fitness centers aged between 19 and 64 years (M = 33.84; SD = 10.09) took part in the study. The data were collected following the Declaration of Helsinki and with the approval of the Ethics Committee of the Polytechnic of Leiria. For the statistical analysis, mean and standard deviations were first calculated, as well as bivariate correlations between all the variables of interest. Then, structural equation model analyses were performed considering the levels of physical activity as the independent variable, motivations toward eating behavior as the mediators, and eating styles as the dependent variables. It was concluded that a greater level of physical activity leads to a more self-determined type of eating regulation, which in turn results in less constricted eating behaviors that are influenced by external factors and emotional factors.

10.
Front Psychol ; 13: 987149, 2022.
Article in English | MEDLINE | ID: mdl-36092047

ABSTRACT

Competitive sports involve physiological, technical and psychological skills, which influence directly on individuals' performance. This study aims to investigate the levels of perceived stress and Heart Rate Variability (HRV) before and after matches with victory and defeat in professional eSports athletes. Our hypothesis was that the winners would have better autonomic and stress responses after match, thus corroborating the literature on neurocardiac connections. Fifty male eSport players were selected players from 10 different Brazilian teams. The experiment was carried out in 2 sessions. Firstly, after signing the informed consent form, 24 h before the game, anthropometric, physical activity levels and time of expertise data were recorded only for sample characterization and the players were familiarized with the perceived stress scale-10 (PSS-10) and the HRV measurements. Secondly, players performed the PSS-10 and HRV recording at rest by 10 min 60 and 30 min before the game (i.e., baseline time) and 10 min after the end of the game. Overall, concerning PSS-10 our findings show that VG had significant reduced scores in post-game time compared to baseline (BL) and pre-game times, while DG had significant increased scores in post-game time compared to BL and pre-game times. Regarding HRV, our results demonstrate that VG had significant increase in RR, SDNN, rMSSD, pNN50 and HF, and significant decrease in LF and LF/HF, while DG had a significant decrease in RR, SDNN, rMSSD and HF, and significant increase in LF and LF/HF. It was observed that VG had better HRV responses (greater parasympathetic activation) as well as lower levels of perceived stress, while DG had worst HRV responses (greater sympathetic activation) and higher levels of perceived stress.

11.
Scand J Med Sci Sports ; 32(12): 1710-1723, 2022 Dec.
Article in English | MEDLINE | ID: mdl-35920056

ABSTRACT

Grounded in hedonic assumptions, evidence suggests that people tend to engage in activities they consider pleasurable and enjoyable, while trying to avoid pain and displeasure. This suggests that the dynamic between positive and negative affect can influence current behavior and the intentions to continue performing. Regarding resistance training (RT), research focusing on how to promote a better affective response is still scarce and much needed. Given existing limitations and theoretical suggestions, a RT program was developed and applied to recreational exercisers in a quasi-experimental design aiming to (1) explore the affective response dynamic through an assessment after the last set of each exercise; and (2) analyze possible differences of preference and tolerance profiles in affective variables (core affect and enjoyment). For that purpose, 43 participants (21 male and 22 female; Mage  = 34.69 ± 6.71 years; Mexperience  = 8.32 ± 4.54 years; MBMI  = 24.26 ± 2.64 kg/m2 ) accepted to participate in this study. Descriptive statistics, correlational, and group comparisons analyses were performed to provide evidence for proposed objectives. The present study showed that measures of affective valence/arousal applied immediately after a set represents a feasible and ecologically valid approach to tap core affect. Results presented evidence that recreationally trained exercisers in a common RT program would need a minimum of one measurement to assess the affective response. However, additional assessments could refine the understanding of exercise pleasurable experience. Results also suggest that exercisers with distinct profiles of preference/tolerance depicted differentiated patterns for the affective response, possibly justifying a distinct approach when promoting affective regulation.


Subject(s)
Resistance Training , Humans , Male , Female , Adult , Affect/physiology , Pleasure/physiology , Exercise/physiology , Muscles
12.
Medicina (Kaunas) ; 58(8)2022 Aug 14.
Article in English | MEDLINE | ID: mdl-36013564

ABSTRACT

Background and Objectives: Fibromyalgia are heterogeneous and differ from patient to patient; however, the most reported are general myalgia and at specific points associated with fatigue and certain psychological adversities. Physical activity can mitigate the effects of the symptoms. However, the associations between fibromyalgia-related fatigue, self-esteem, anxiety, depression, satisfaction with life and physical activity are unclear. Therefore, the aim of the present study was to understand the associations between these symptoms and whether there are differences between these associations across two distinct cultures. Materials and Methods: A total of 473 women aged between 28 and 75 years (M = 49.27; SD ± 8.28) completed five questionnaires about fibromyalgia-related fatigue, physical activity, anxiety, depression, self-esteem, and satisfaction with life. Results: Fibromyalgia-related fatigue was positively associated with depression and anxiety, depression and anxiety were negatively associated with self-esteem, self-esteem was positively associated with satisfaction with life, satisfaction with life was positively associated with physical activity and there were no differences in terms of the perceptions and associations of these variables between Portuguese and Brazilian patients. Conclusions: Our results showed the significant role of associations between these variables and a similarity in the perception and relationship of the variables between the two cultures.


Subject(s)
Fibromyalgia , Adult , Aged , Anxiety/complications , Anxiety/psychology , Brazil/epidemiology , Depression/complications , Depression/psychology , Exercise , Fatigue/complications , Female , Fibromyalgia/complications , Fibromyalgia/psychology , Humans , Latent Class Analysis , Middle Aged , Patient Satisfaction , Personal Satisfaction , Portugal , Quality of Life/psychology , Self Concept , Surveys and Questionnaires
13.
ASN Neuro ; 14: 17590914221116574, 2022.
Article in English | MEDLINE | ID: mdl-35903937

ABSTRACT

SUMMARY STATEMENT: EAAT1/GLAST down-regulates its expression and function at the transcriptional level by activating a signaling pathway that includes PI3K, PKC and NF-κB, favoring the notion of an activity-dependent fine-tuning of glutamate recycling and its synaptic transactions through glial cells.


Subject(s)
Excitatory Amino Acid Transporter 1 , Gene Expression Regulation , Cells, Cultured , Excitatory Amino Acid Transporter 1/genetics , Excitatory Amino Acid Transporter 1/metabolism , Gene Expression Regulation/genetics , Glutamic Acid/metabolism , Neuroglia/metabolism
14.
Sci Rep ; 12(1): 10391, 2022 06 20.
Article in English | MEDLINE | ID: mdl-35725780

ABSTRACT

Exercise has been recommended for fibromyalgia treatment. However, doubts related to exercise benefits remain unclear. The objective of this study was to summarise, through a systematic review with meta-analysis, the available evidence on the effects of aerobic, resistance and stretching exercise on pain, depression, and quality of life. Search was performed using electronic databases Pubmed and Cochrane Library. Studies with interventions based on aerobic exercise, resistance exercise and stretching exercise published until July 2020 and updated in December 2021, were identified. Randomized controlled trials and meta-analyses involving adults with fibromyalgia were also included. Eighteen studies were selected, including a total of 1184 subjects. The effects were summarised using standardised mean differences (95% confidence intervals) by random effect models. In general, aerobic exercise seems to reduce pain perception, depression and improves quality of life; it also improves mental and physical health-related quality of life. Resistance exercise decreases pain perception and improves quality of life and moreover improves the physical dimension of health-related quality of life. It was also observed that resistance exercise appears to have a non-significant positive effect on depression and the mental dimension of health-related quality of life. Studies revealed that stretching exercise reduces the perception and additionally improves quality of life and health-related quality of life. However, a non-significant effect was observed on depression. We conclude that exercise may be a way to reduce depression, and pain and improve the quality of life in adult subjects with fibromyalgia and should be part of the treatment for this pathology.


Subject(s)
Fibromyalgia , Adult , Exercise , Exercise Therapy/methods , Fibromyalgia/therapy , Humans , Pain , Quality of Life , Randomized Controlled Trials as Topic
15.
Article in English | MEDLINE | ID: mdl-35457737

ABSTRACT

The symptoms of fibromyalgia are varied, including general muscle pain and pain at specific points (also called tender points), excessive fatigue, anxiety, depression, and some psychological problems that can have a negative impact on quality of life. Physical activity is a widely used option by health professionals to alleviate the effects of this syndrome. However, there is no clear information on the possible mediating role of physical activity in the relationship between fibromyalgia-related fatigue and quality of life. Therefore, this study aims to evaluate the relationship between fibromyalgia-related fatigue and quality of life, and to investigate the mediating role of physical activity in patients with this syndrome. METHODS: In a cross-sectional study, 237 Portuguese women aged 28 to 75 years (M = 49.12; SD ± 8.87) and 117 Brazilian women aged 20 to 69 years (M = 46.72; SD ± 8.38) were recruited to participate in this study. These patients completed three valid and reliable questionnaires related to the assessment of fibromyalgia-related fatigue (MDF-Fibro-17), physical activity (IPAQ), and quality of life (SF-36). RESULTS: Both samples had scores above the midpoint for all dimensions of fibromyalgia-related fatigue and scores below the midpoint for quality of life. Physical activity had no mediating effect in either sample, as the total indirect effect was not significant. CONCLUSIONS: Physical activity does not mediate the relationship between fatigue and quality of life. However, the results also show that the fatigue dimensions associated with fibromyalgia had a negative and significant association with physical and mental health indicators in both samples. Thus, patients with FM with higher scores on fatigue-related symptoms might suffer more from physical and mental health, both of which are related to quality of life.


Subject(s)
Fibromyalgia , Cross-Sectional Studies , Exercise , Fatigue/complications , Female , Fibromyalgia/psychology , Humans , Pain/complications , Quality of Life/psychology , Surveys and Questionnaires
16.
Front Psychol ; 13: 806176, 2022.
Article in English | MEDLINE | ID: mdl-35360588

ABSTRACT

Translating and validating measurement instruments in sport and exercise psychology is not an easy task. Rather, it is a task that requires effort and time, for the process is not limited to a simple translation to translate words from one language to another, just in order to make valid and reliable measure. All researchers should be aware that the only proper way is to adopt rigorous and robust methodologies to conduct the process from the preliminary stage of translation to reaching the validation stage of the psychological variable. Only so is it possible to avoid creating fragile and inadequate psychological assessment instruments that can jeopardize the entire investigation to be held with its use. Thus, the main objective of this work is to promote reflection and discussion on the subject by presenting some considerations and recommendations about translation and validation of questionnaires for psychological assessment applied to sport and exercise domain.

17.
Front Psychol ; 13: 780059, 2022.
Article in English | MEDLINE | ID: mdl-35250719

ABSTRACT

Given the need to explore the factors that can account for a better understanding of the intention-behavior gap in exercise practice in health club settings, and considering the emergence of hedonic assumptions related to exercise adherence, this cross-sectional study aimed to test the moderation effect of the intensity traits agreement/disagreement in three relevant outcomes of exercise enjoyment: exercise habit, intention to continue exercising, and exercise frequency. A sample consisted of 273 exercisers (male = 127; M age = 36.21; SD = 11.29) enrolled in nine health clubs who voluntarily fulfilled a battery of questionnaires. All analyses were performed using SPSS v. 23.0/PROCESS v. 3.5. The results of the study presented a moderation effect of exercise intensity traits agreement on three relevant enjoyment outcomes: exercise habit, intention to continue exercising, and exercise frequency. No relevant results emerged from intensity traits disagreement. The results suggest that assessing and tailoring exercise prescription and supervision in order to customize exercise intensity may influence future exercise participation.

18.
Cien Saude Colet ; 26(suppl 3): 5303-5313, 2021.
Article in Portuguese | MEDLINE | ID: mdl-34787221

ABSTRACT

The scope of this paper was to analyze the impact of motivational determinants in enjoyment and persistence in physical exercise among practitioners of physical exercise. In total, 967 gym and health club exercise practitioners aged between 18 and 65 (M=45.08; SD=13.76) were recruited for analysis. All participants had more than six months of regular exercise practice. Participants completed and validated scales in the exercise context duly translated into Portuguese, assessing interpersonal behaviors, basic psychological needs, and behavioral regulation. Persistence was measured using computerized records considering persistent exercisers as being those who were exercising at similar frequencies as those self-reported at the initial assessment. Results showed that the measurement and structural model fit the data. Several significant effects were found supporting previous literature. Indirect effects showed enjoyment to play a crucial role on exercise persistence, both by the significant effect via autonomous and controlled motivation. In essence, activities that give pleasure that gym and health club exercisers experience during the practice of physical exercise can be the key variable of long-term persistence.


Como objetivo deste trabalho, definiu-se analisar os efeitos indiretos de determinantes motivacionais no divertimento e na persistência em praticantes de exercício físico regular. Participaram ao todo 967 praticantes de exercício em ginásio e health clubs, com idades compreendidas entre 18 e 65 anos (M=45,08; DP=13,76). Todos os participantes tinham mais de 6 meses de experiência regular em exercício físico. Os participantes preencheram ao todo questionários traduzidos e validados para a língua portuguesa no contexto do exercício físico, que examinavam a perceção dos comportamentos interpessoais, as necessidades psicológicas básicas, a regulação da motivação e o divertimento. A persistência foi medida através de registos eletrónicos, considerando um praticante persistente aquele que tivesse uma frequência semanal similar aquela auto-reportada no momento inicial. A maioria das regressões são significativas, confirmado os pressupostos da literatura existente. Os efeitos indiretos mostram que o divertimento desempenha um papel crucial na persistência, tanto por via motivação autónoma, como por via motivação controlada. Em suma, atividades promotoras do prazer que os praticantes de ginásio e health club experienciam durante a prática de exercício físico poderão ser a variável chave na persistência a longo prazo.


Subject(s)
Motivation , Pleasure , Adolescent , Adult , Aged , Exercise , Health Behavior , Humans , Middle Aged , Personal Autonomy , Young Adult
19.
Ciênc. Saúde Colet. (Impr.) ; 26(supl.3): 5303-5313, Oct. 2021. tab, graf
Article in Portuguese | LILACS | ID: biblio-1345739

ABSTRACT

Resumo Como objetivo deste trabalho, definiu-se analisar os efeitos indiretos de determinantes motivacionais no divertimento e na persistência em praticantes de exercício físico regular. Participaram ao todo 967 praticantes de exercício em ginásio e health clubs, com idades compreendidas entre 18 e 65 anos (M=45,08; DP=13,76). Todos os participantes tinham mais de 6 meses de experiência regular em exercício físico. Os participantes preencheram ao todo questionários traduzidos e validados para a língua portuguesa no contexto do exercício físico, que examinavam a perceção dos comportamentos interpessoais, as necessidades psicológicas básicas, a regulação da motivação e o divertimento. A persistência foi medida através de registos eletrónicos, considerando um praticante persistente aquele que tivesse uma frequência semanal similar aquela auto-reportada no momento inicial. A maioria das regressões são significativas, confirmado os pressupostos da literatura existente. Os efeitos indiretos mostram que o divertimento desempenha um papel crucial na persistência, tanto por via motivação autónoma, como por via motivação controlada. Em suma, atividades promotoras do prazer que os praticantes de ginásio e health club experienciam durante a prática de exercício físico poderão ser a variável chave na persistência a longo prazo.


Abstract The scope of this paper was to analyze the impact of motivational determinants in enjoyment and persistence in physical exercise among practitioners of physical exercise. In total, 967 gym and health club exercise practitioners aged between 18 and 65 (M=45.08; SD=13.76) were recruited for analysis. All participants had more than six months of regular exercise practice. Participants completed and validated scales in the exercise context duly translated into Portuguese, assessing interpersonal behaviors, basic psychological needs, and behavioral regulation. Persistence was measured using computerized records considering persistent exercisers as being those who were exercising at similar frequencies as those self-reported at the initial assessment. Results showed that the measurement and structural model fit the data. Several significant effects were found supporting previous literature. Indirect effects showed enjoyment to play a crucial role on exercise persistence, both by the significant effect via autonomous and controlled motivation. In essence, activities that give pleasure that gym and health club exercisers experience during the practice of physical exercise can be the key variable of long-term persistence.


Subject(s)
Humans , Adolescent , Adult , Aged , Young Adult , Pleasure , Motivation , Exercise , Health Behavior , Personal Autonomy , Middle Aged
20.
Front Microbiol ; 12: 723874, 2021.
Article in English | MEDLINE | ID: mdl-34367123

ABSTRACT

Perchlorate is an oxidative pollutant toxic to most of terrestrial life by promoting denaturation of macromolecules, oxidative stress, and DNA damage. However, several microorganisms, especially hyperhalophiles, are able to tolerate high levels of this compound. Furthermore, relatively high quantities of perchlorate salts were detected on the Martian surface, and due to its strong hygroscopicity and its ability to substantially decrease the freezing point of water, perchlorate is thought to increase the availability of liquid brine water in hyper-arid and cold environments, such as the Martian regolith. Therefore, perchlorate has been proposed as a compound worth studying to better understanding the habitability of the Martian surface. In the present work, to study the molecular mechanisms of perchlorate resistance, a functional metagenomic approach was used, and for that, a small-insert library was constructed with DNA isolated from microorganisms exposed to perchlorate in sediments of a hypersaline pond in the Atacama Desert, Chile (Salar de Maricunga), one of the regions with the highest levels of perchlorate on Earth. The metagenomic library was hosted in Escherichia coli DH10B strain and exposed to sodium perchlorate. This technique allowed the identification of nine perchlorate-resistant clones and their environmental DNA fragments were sequenced. A total of seventeen ORFs were predicted, individually cloned, and nine of them increased perchlorate resistance when expressed in E. coli DH10B cells. These genes encoded hypothetical conserved proteins of unknown functions and proteins similar to other not previously reported to be involved in perchlorate resistance that were related to different cellular processes such as RNA processing, tRNA modification, DNA protection and repair, metabolism, and protein degradation. Furthermore, these genes also conferred resistance to UV-radiation, 4-nitroquinoline-N-oxide (4-NQO) and/or hydrogen peroxide (H2O2), other stress conditions that induce oxidative stress, and damage in proteins and nucleic acids. Therefore, the novel genes identified will help us to better understand the molecular strategies of microorganisms to survive in the presence of perchlorate and may be used in Mars exploration for creating perchlorate-resistance strains interesting for developing Bioregenerative Life Support Systems (BLSS) based on in situ resource utilization (ISRU).

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