Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 159
Filtrar
1.
J Sports Sci ; : 1-9, 2024 Oct 02.
Artigo em Inglês | MEDLINE | ID: mdl-39356873

RESUMO

The prediction of one-repetition maximum (1RM) using the submaximal load-velocity relationship (LVR) is highly relevant for the field of strength and conditioning. The optimal minimum velocity threshold (MVT) was recently proposed to increase the accuracy of 1RM predictions. However, using the average optimal MVT would allow for more practical estimations. LVRs of the free-weight back squat were obtained in 53 participants, throughout 2 sessions. LVRs were obtained using the multi- and two-point methods. Estimations of 1RM were made based on the average actual MVT (1RM velocity) and the average optimal MVT. The accuracy of 1RM predictions was examined using absolute-percent error and Bland-Altman plots. Cross-validation was performed using a leave-one-out approach. The number of selected loads did not affect the slope, y-intercept, optimal MVT or the accuracy of 1RM predictions. Predictions based on the average optimal MVT displayed greater accuracy than those obtained with the average actual MVT (~6% vs. ~8% absolute-percent error, respectively). However, wide 95% limits of agreement (LoA) were found between actual and estimated 1RM using both approaches (~13%1RM). The average optimal MVT offers more accurate 1RM estimations than the average actual MVT. However, errors prove substantial, making it challenging to precisely track minor changes in 1RM.

2.
Phys Rev E ; 110(2-1): 024109, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-39295010

RESUMO

Entropy production is the crucial quantity characterizing irreversible phenomena and the second law of thermodynamics. Yet, a ubiquitous definition eludes consensus. Given that entropy production arises from incomplete access to information, in this work we use Jaynes' maximum entropy principle to establish a framework that brings together prominent and apparently conflicting definitions. More generally, our definition of entropy production addresses any tomographically incomplete quantum measurement and/or the action of a quantum channel on a system.

3.
Phys Rev Lett ; 133(6): 060401, 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39178447

RESUMO

With the control of increasingly complex quantum systems, the relevant degrees of freedom we are interested in may not be those traditionally addressed by statistical quantum mechanics. Here, we employ quantum channels to define generalized subsystems, capturing the pertinent degrees of freedom, and obtain their associated canonical state. We show that the generalized subsystem description from almost any microscopic pure state of the whole system will behave similarly to its corresponding canonical state. Such canonical typicality behavior depends on the entropy of the channel used to define the generalized subsystem.

4.
Int J Sports Med ; 2024 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-39068935

RESUMO

The prediction of one-repetition maximum (1RM) is highly relevant for strength and conditioning. The optimal minimum-velocity threshold (MVT) was recently proposed to increase the accuracy of 1RM predictions. Individual load-velocity profiles (LVP) were obtained in 18 athletes enrolled in recreational soccer. Reliability analyses were computed for all LVP-derived variables. Estimations of 1RM were made based on general (0.3 m.s- 1), pre-individual (mean velocity at 1RM obtained in a preliminary session) and optimal MVT (velocity that eliminates the difference between actual and predicted 1RM, determined in a preliminary session). The accuracy of 1RM predictions was examined using absolute-percent error and Bland-Altman plots. Between-day reliability of the LVP and 1RM was good (intraclass-correlation coefficients - ICCs>0.9 and coefficients of variation - CVs<5%). The individual and optimal MVT reached moderate-to-good reliability (ICCs>0.9 and CVs<10%, respectively). The predictions based on the optimal MVT displayed greater accuracy than those obtained with the individual and general MVT (absolute percent error: 2.8 vs. 5.5 vs. 4.9%, respectively). However, wide limits of agreement (LoA) were found between actual and estimated 1RM using this approach (~15 kg). Data indicate that the optimal MVT provides better estimations of 1RM for the free-weight back squat than the general and the individual MVT.

5.
J Pain ; 25(10): 104602, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-38866123

RESUMO

Numerous cultural adaptations of the Tampa Scale of Kinesiophobia 11-item version (TSK-11) scale have emerged since the original version was introduced. We conducted a (COnsensus-based Standards for the selection of health Measurement INstruments) COSMIN-informed systematic review of measurement properties to identify the cross-cultural adaptation of the TSK-11 and report, critically appraise, and systematize its measurement properties. Six databases were searched for studies published since 2005. Studies reporting on the measurement properties of culturally adapted versions of the TSK-11, published in English, Portuguese, and Spanish, were considered for inclusion. The results were synthesized by measurement properties and rated against the COSMIN criteria for good measurement properties. The quality of the evidence was assessed using the Grading of Recommendations, Assessment, Development, and Evaluation approach and presented in a summary of findings table. Twenty-three studies were included, and cultural adaptations for 15 languages were identified: English, Chinese, Cantonese, Swedish, German, Dutch, Arabic, Turkish, Danish, Spanish, Japanese, Brazilian Portuguese, Marathi, Thai, and Persian. There is "high" certainty in the evidence for "sufficient" criterion validity (TSK-17, r = .84) and "insufficient" measurement error (small detectable change range 5.6-6.16). "Moderate" certainty in the evidence for "sufficient" construct validity (87.8% of hypotheses confirmed), test-retest reliability (intraclass correlation coefficient2,1 = .747-.87), and "low" certainty in evidence for "sufficient" responsiveness. The numerous sources of heterogeneity prevent conclusions from being drawn regarding structural validity. Measurement error, responsiveness, and structural validity of the TSK-11 require further investigation. Clinicians should complement the use of TSK-11 with other instruments. Future studies on the structural validity of the questionnaire should standardize the data analysis methods. PERSPECTIVE: This article presents the measurement properties of the cross-cultural adaptations of the TSK-11. Clinicians should be aware that cultural and clinical aspects may influence the structural validity of the questionnaire. Using the TSK-11 as a stand-alone instrument may omit relevant clinical progression in the patient's condition.


Assuntos
Comparação Transcultural , Transtornos Fóbicos , Psicometria , Humanos , Transtornos Fóbicos/diagnóstico , Transtornos Fóbicos/etnologia , Reprodutibilidade dos Testes , Psicometria/normas , Psicometria/instrumentação , Inquéritos e Questionários/normas , Cinesiofobia
6.
eNeuro ; 11(6)2024 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-38839305

RESUMO

Social behavior is important for our well-being, and its dysfunctions impact several pathological conditions. Although the involvement of glutamate is undeniable, the relevance of vesicular glutamate transporter type 3 (VGluT3), a specific vesicular transporter, in the control of social behavior is not sufficiently explored. Since midbrain median raphe region (MRR) is implicated in social behavior and the nucleus contains high amount of VGluT3+ neurons, we compared the behavior of male VGluT3 knock-out (KO) and VGluT3-Cre mice, the latter after chemogenetic MRR-VGluT3 manipulation. Appropriate control groups were included. Behavioral test battery was used for social behavior (sociability, social discrimination, social interaction, resident intruder test) and possible confounding factors (open field, elevated plus maze, Y-maze tests). Neuronal activation was studied by c-Fos immunohistochemistry. Human relevance was confirmed by VGluT3 gene expression in relevant human brainstem areas. VGluT3 KO mice exhibited increased anxiety, social interest, but also aggressive behavior in anxiogenic environment and impaired social memory. For KO animals, social interaction induced lower cell activation in the anterior cingulate, infralimbic cortex, and medial septum. In turn, excitation of MRR-VGluT3+ neurons was anxiolytic. Inhibition increased social interest 24 h later but decreased mobility and social behavior in aggressive context. Chemogenetic activation increased the number of c-Fos+ neurons only in the MRR. We confirmed the increased anxiety-like behavior and impaired memory of VGluT3 KO strain and revealed increased, but inadequate, social behavior. MRR-VGluT3 neurons regulated mobility and social and anxiety-like behavior in a context-dependent manner. The presence of VGluT3 mRNA on corresponding human brain areas suggests clinical relevance.


Assuntos
Ansiedade , Camundongos Knockout , Comportamento Social , Animais , Masculino , Humanos , Ansiedade/metabolismo , Núcleos da Rafe/metabolismo , Camundongos , Neurônios/metabolismo , Camundongos Endogâmicos C57BL , Comportamento Animal/fisiologia , Camundongos Transgênicos , Sistemas de Transporte de Aminoácidos Acídicos/metabolismo , Sistemas de Transporte de Aminoácidos Acídicos/genética , Proteínas Proto-Oncogênicas c-fos/metabolismo , Agressão/fisiologia
7.
Eur J Appl Physiol ; 2024 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-38730035

RESUMO

PURPOSE: To explore if mean concentric velocity (MCV) of the last repetition before set failure differs between free-weight back squat protocols with greater emphasis on metabolic accumulation vs. mechanical loading. The between-set and between-day reliability of terminal MCV obtained with these different loading schemes was also determined. METHODS: Fifteen healthy male participants (18-30 years) were included. They all were required to exhibit a relative strength ≥ 1.5 times their body mass. MCVs were obtained at one-repetition maximum (1RM) and with two submaximal protocols (metabolic emphasis: three sets of 40%1RM with blood-flow restriction vs. mechanical emphasis: three sets 80%1RM without blood-flow restriction). Participants were instructed to reach maximal intended concentric velocity in each repetition up to failure. RESULTS: Set failure was achieved at a faster MCV with the metabolic protocol (p < 0.05). The reliability of MCV at failure reached higher values for the metabolic loading scheme. However, while the MCV achieved at failure during the metabolic protocol was systematically higher than the MCV at 1RM (p < 0.05), this was not entirely the case for the mechanical protocol (similar to 1RM MCV during the last sets in both testing days). Finally, the absolute error derived from estimating the MCV at 1RM based on the MCV obtained at set failure with the mechanical protocol was considerably high (≥ 0.05 m/s). CONCLUSION: This study indicates that MCV obtained at set failure is dependent on the specificity of the physiological demands of exercise. Thus, MCVs obtained at failure with submaximal loads should not be used to estimate 1RM MCV.

8.
Plants (Basel) ; 13(9)2024 Apr 25.
Artigo em Inglês | MEDLINE | ID: mdl-38732403

RESUMO

For centuries, the carob tree (Ceratonia siliqua L.) has contributed to the economy of the Mediterranean basin, mainly as food for livestock. Nowadays, the value of the carob tree extends far beyond its traditional uses, encompassing a wide range of industries and applications that take advantage of its unique properties and nutritional benefits. Despite its high industrial demand and European indications, there has been a 65% reduction in the area cultivated throughout the Mediterranean area in the 21st century. Given the threats posed by climate change, including reduced water availability and nutrient-depleted soils, there is a growing need to focus on this crop, which is well placed to cope with unpredictable weather. In this review, we use a bibliographic search approach to emphasise the prioritisation of research needs for effective carob tree exploitation. We found enormous gaps in the scientific knowledge of this under-utilised crop species with fruit pulp and seeds of high industrial value. Insufficient understanding of the biology of the species, as well as inadequate agronomic practices, compromise the quantity and the quality of fruits available to the industry. In addition to industrial applications, carob can also be used in reforestation or restoration programmes, providing a valuable crop while promoting biodiversity conservation and soil restoration. The carbon sequestration potential of the trees should be taken into account as a promising alternative in fighting climate change. This bibliographic search has highlighted clusters with different knowledge gaps that require further research and investment. The carob tree has untapped potential for innovation, economic development, and environmental sustainability.

9.
Heliyon ; 10(10): e30922, 2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38799736

RESUMO

In the last two decades, important advances have been made in the chemical analysis of the fruit of carob tree. After harvesting, the fruits (also known as dry pods) are ground. The seeds can then be separated from the pulp, which represents 80-90 % of a pod's weight. The health benefits of carob pulp derivatives are well-recognized, and carob pulp-based food products are becoming increasingly available to consumers. The major carob-producing countries are in southern Europe and northern Africa, including the Mediterranean islands, and carob pulp products are normally prepared and consumed regionally. In this review, we compare the sugar and phenol profiles of carob pods harvested from different countries in the Mediterranean basin while accounting for the different cultivars and soil conditions in each sample area. We conclude that pod nutritional composition varies widely among countries, making it necessary for future, multi-year studies to more closely evaluate how climate and soil properties affect the phenol and sugar contents of fruits from the same trees or cultivars.

10.
Int J Mol Sci ; 25(8)2024 Apr 13.
Artigo em Inglês | MEDLINE | ID: mdl-38673899

RESUMO

According to previous studies, the median raphe region (MRR) is known to contribute significantly to social behavior. Besides serotonin, there have also been reports of a small population of dopaminergic neurons in this region. Dopamine is linked to reward and locomotion, but very little is known about its role in the MRR. To address that, we first confirmed the presence of dopaminergic cells in the MRR of mice (immunohistochemistry, RT-PCR), and then also in humans (RT-PCR) using healthy donor samples to prove translational relevance. Next, we used chemogenetic technology in mice containing the Cre enzyme under the promoter of the dopamine transporter. With the help of an adeno-associated virus, designer receptors exclusively activated by designer drugs (DREADDs) were expressed in the dopaminergic cells of the MRR to manipulate their activity. Four weeks later, we performed an extensive behavioral characterization 30 min after the injection of the artificial ligand (Clozapine-N-Oxide). Stimulation of the dopaminergic cells in the MRR decreased social interest without influencing aggression and with an increase in social discrimination. Additionally, inhibition of the same cells increased the friendly social behavior during social interaction test. No behavioral changes were detected in anxiety, memory or locomotion. All in all, dopaminergic cells were present in both the mouse and human samples from the MRR, and the manipulation of the dopaminergic neurons in the MRR elicited a specific social response.


Assuntos
Clozapina/análogos & derivados , Neurônios Dopaminérgicos , Comportamento Social , Animais , Neurônios Dopaminérgicos/metabolismo , Masculino , Camundongos , Humanos , Clozapina/farmacologia , Núcleos da Rafe/metabolismo , Comportamento Animal , Dopamina/metabolismo , Camundongos Endogâmicos C57BL
11.
Trends Plant Sci ; 29(9): 962-970, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38637173

RESUMO

Most high-yielding crops are susceptible to abiotic and biotic stresses, making them particularly vulnerable to the potential effects of climate change. A possible alternative is to accelerate the domestication of wild plants that are already tolerant to harsh conditions and to increase their yields by methods such as gene editing. We foresee that crops' wild progenitors could potentially compete with the resulting de novo domesticated plants, reducing yields. To improve the recognition of weeds, we propose using gene editing techniques to introduce traits into de novo domesticated crops that will allow for visual recognition of the crops by weeding robots that have been trained by machine learning.


Assuntos
Produtos Agrícolas , Domesticação , Plantas Daninhas , Produtos Agrícolas/genética , Plantas Daninhas/genética , Plantas Daninhas/fisiologia , Edição de Genes/métodos , Mudança Climática
12.
J Bodyw Mov Ther ; 37: 209-219, 2024 01.
Artigo em Inglês | MEDLINE | ID: mdl-38432808

RESUMO

OBJECTIVE: This study aimed investigate the effect of auriculotherapy on exercise-induced muscle fatigue, isometric torque production, and surface electromyographic activity (EMG). METHODS: Design: Randomized Crossover Trial. The sample consisted of 18 males' volunteers who exercised at least twice a week. THE SAMPLE WAS RANDOMLY ASSIGNED TO TWO GROUPS: Placebo Group (n = 9) and Treated Group (n = 9), and after seven days, the groups were crossed. The data analysis included 18 participants in each group. MAIN OUTCOME MEASURE: The muscle fatigue index, force production rate, and EMG of the quadriceps were used for evaluation. The evaluation moments included baseline pre-fatigue, baseline post-fatigue, 48 h post-intervention pre-fatigue, and 48 h post-intervention post-fatigue. Mixed two-way test ANOVA was used to compare times and groups. RESULTS: The fatigue index for peak torque and work showed no significant effect on time, groups, or interaction (p > 0.05). However, for isometric torque, force production rate, and EMG median frequency and average, the results indicate a positive change in values over time (p < 0.05) (with little practical relevance), with no differences observed between the groups or interaction (p > 0.05). CONCLUSIONS: In conclusion, auriculotherapy had no effect on exercise-induced muscle fatigue, isometric torque production, and surface electromyographic activity.


Assuntos
Auriculoterapia , Fadiga Muscular , Masculino , Humanos , Estudos Cross-Over , Análise de Variância , Músculo Quadríceps
13.
Exp Brain Res ; 242(5): 1037-1046, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38451319

RESUMO

The regularity of the fluctuations present in torque signals represent the adaptability of the motor control. While previous research showed how it is affected by neuromuscular fatigue and ageing, the underlying mechanisms remain unclear. It is currently under debate whether these changes are explained by central or peripheral neuromuscular mechanisms. Here, we experimentally manipulated the sleep of thirteen young adults through a supervised 24 h-sleep deprivation protocol. This study aimed to investigate the effect of sleep deprivation on the regularity of torque fluctuations, and other standard torque-related outcomes (Peak Torque - PT - and Rate of Torque Development - RTD). The participants were asked to perform knee extension maximal voluntary contractions (MVC) and submaximal knee extensions at 40% of MVC for 30 s. PT and RTD were calculated from the MVC and the regularity of the torque fluctuations was determined on the submaximal task through Sample Entropy (SampEn). In addition, rate of perceived effort (RPE) was collected. We found no significant changes in PT and RTD. The regularity of torque fluctuations significantly increased (i.e., a decrease in SampEn) after 24 h-sleep deprivation (PRE = 1.76 ± 0.268, POS24 = 1.71 ± 0.306; p = 0.044). Importantly, we found a negative correlation between RPE and SampEn relative changes after sleep deprivation. This study brings new insights towards the understanding of the underlying mechanisms that explain changes in torque fluctuations, demonstrating that these changes are not limited to neuromuscular processes but are also likely to be affected by other domains, such as psychological profile, which can indirectly affect the neural drive to the muscles.


Assuntos
Contração Isométrica , Músculo Esquelético , Privação do Sono , Torque , Humanos , Masculino , Privação do Sono/fisiopatologia , Adulto Jovem , Adulto , Feminino , Músculo Esquelético/fisiologia , Contração Isométrica/fisiologia , Fadiga Muscular/fisiologia , Eletromiografia
14.
J Strength Cond Res ; 38(6): 1013-1018, 2024 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-38373076

RESUMO

ABSTRACT: Gomes, M, Fitas, A, Santos, P, Pezarat-Correia, P, and Mendonca, GV. Validation of a single session protocol to determine the load-velocity profile and one-repetition maximum for the back squat exercise. J Strength Cond Res 38(6): 1013-1018, 2024-We investigated whether a single session of absolute incremental loading is valid to obtain the individual load-velocity profile (LVP) and 1 repetition maximum (1RM) for the free-weight parallel back squat. Twenty strength-trained male subjects completed 3 testing sessions, including a baseline 1RM session and 2 LVP sessions (LVP rel based on incremental relative loads and LVP abs based on absolute load increments until 1RM). The 1RM load was compared between the baseline and LVP abs . The load at zero velocity (load-axis intercept [L 0 ]), maximal velocity capacity (velocity-axis intercept [V 0 ]), slope, and area under the load-velocity relationship line (A line ) were compared between the LVP rel and LVP abs using equivalence testing through 2 one-sided t -tests. Measurement accuracy was calculated using the absolute percent error. The 1RM measured at baseline and LVP abs was equivalent and presented a low absolute percent error (1.2%). The following LVP parameters were equivalent between LVP rel and LVP abs : 1RM, L 0 , and A line because the mean difference between sessions was close to zero and the Bland-Altman limits of agreement (1RM:5.3 kg; L 0 :6.8 kg; A line : 9.5 kg·m -1 ·s -1 ) were contained within the a priori defined ± equivalent margins (5% for 1RM and L 0 and 10% for A line ). The aforementioned variables presented a low absolute percent error. However, slope and V 0 were not equivalent between sessions. In conclusion, a single session of absolute incremental loading is a valid approach to obtain the L 0 and A line of the individual LVP and 1RM, and can be used to efficiently track the magnitude of neuromuscular adaptations throughout the training cycles for the free-weight back squat.


Assuntos
Força Muscular , Treinamento Resistido , Humanos , Masculino , Treinamento Resistido/métodos , Adulto Jovem , Força Muscular/fisiologia , Adulto , Levantamento de Peso/fisiologia , Reprodutibilidade dos Testes , Músculo Esquelético/fisiologia , Suporte de Carga/fisiologia
15.
J Acad Nutr Diet ; 124(8): 1041-1050, 2024 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-38242204

RESUMO

BACKGROUND: Optimal nutrition is highly valuable for athletes aiming at maintaining or improving body composition and sports performance. When combined with structured exercise, time-restricted energy intake may represent an effective nonpharmacological approach to achieving these results. OBJECTIVE: The aim of this study was to investigate the effects of 4 weeks of time-restricted eating (TRE) vs 4 weeks of habitual diet on aerobic capacity, body composition, and metabolic health in 18- to 30-year-old men accustomed to endurance running. DESIGN: This trial used a randomized-crossover study design. Participants completed graded exercise tests, body composition scans, and fasting blood samples before and after each intervention condition. PARTICIPANTS/SETTING: Sixteen male physical education students were recruited and enrolled in the study from the Faculty of Human Kinetics-University of Lisbon in September 2020, in Lisbon, Portugal. One participant was excluded after 1 week because of a lack of adherence to the study protocol. Therefore, 15 participants completed the study and were involved in the final analysis. INTERVENTION: During the TRE condition, participants consumed two to three meals within an 8-hour eating window (between 1:00 and 9:00 pm). Only water, tea, and coffee (without caloric additives) were permitted to be consumed in the remaining 16 hours per 24-hour period. During the non-TRE condition, participants consumed their habitual diet without any timing restrictions. The order of the TRE intervention and the habitual diet condition was randomized and counterbalanced, and participants served as their own controls. The participants followed a structured training routine during each dietary condition. MAIN OUTCOME MEASURES: Body composition variables, indices of running aerobic capacity, and markers of metabolic health were assessed. STATISTICAL ANALYSES PERFORMED: One-way repeated-measures analysis of variance and covariance were performed to analyze differences between conditions and time with each intervention. RESULTS: Neither condition elicited observed changes in total body mass, fat mass, or fat-free mass between time points. Moreover, no significant changes were observed for markers of metabolic health. Significant improvements were obtained with both conditions for the first ventilatory threshold, maximum oxygen uptake (VO2max), and velocity at VO2max (P < 0.05). CONCLUSIONS: Four weeks of endurance running and TRE, compared with 4 weeks of endurance running and a habitual diet, in healthy trained 18- to 30-year-old male recreational runners did not result in observed differences in total body mass, fat mass, or fat-free mass. In addition, TRE did not offer any additional benefit for improving submaximal or peak exercise capacity in this population.


Assuntos
Composição Corporal , Estudos Cross-Over , Corrida , Humanos , Masculino , Corrida/fisiologia , Adulto , Adulto Jovem , Biomarcadores/sangue , Adolescente , Jejum , Ingestão de Energia , Dieta/métodos , Portugal , Resistência Física/fisiologia
16.
J Fungi (Basel) ; 10(1)2024 Jan 04.
Artigo em Inglês | MEDLINE | ID: mdl-38248986

RESUMO

This correction refers to two new genera (Corollosporella and Corollosporopsis) and three new species combinations published in Journal of Fungi [...].

17.
Sci Rep ; 14(1): 1175, 2024 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-38216718

RESUMO

Learning and memory are important in everyday life as well as in pathological conditions. The median raphe region (MRR) contributes to memory formation; however, its precise role and the neurotransmitters involved have yet to be elucidated. To address this issue, we stimulated the MRR neurons of mice by chemogenetic technique and studied them in the operant conditioning and active avoidance tests. The virus carrier infected a variety of neuron types including both GABAergic and glutamatergic ones. Behavior was not influenced by stimulation. We hypothesize that the lack of effect was due to opposing effects exerted via GABAergic and glutamatergic neurons. Therefore, next we used VGAT-Cre mice that allowed the specific manipulation of MRR-GABAergic neurons. The stimulation did not affect behavior in the learning phase of the operant conditioning task, but increased reward preference and total responses when operant contingencies were reversed. The enhanced responsiveness might be a proclivity to impulsive behavior. Stimulation facilitated learning in the active avoidance test but did not affect reversal learning in this paradigm. Our findings suggest that MRR-GABAergic neurons are involved in both learning and reversal learning, but the type of learning that is affected depends on the task.


Assuntos
Condicionamento Operante , Reforço Psicológico , Camundongos , Animais , Aprendizagem , Neurônios GABAérgicos/fisiologia , Recompensa
18.
J Strength Cond Res ; 38(2): 228-235, 2024 Feb 01.
Artigo em Inglês | MEDLINE | ID: mdl-38088936

RESUMO

ABSTRACT: Fitas, A, Santos, P, Gomes, M, Pezarat-Correia, P, Schoenfeld, BJ, and Mendonca, GV. Prediction of one repetition maximum in free-weight back squat using a mixed approach: the combination of the individual load-velocity profile and generalized equations. J Strength Cond Res 38(2): 228-235, 2024-We aimed to develop a mixed methods approach for 1 repetition maximum (1RM) prediction based on the development of generalized equations and the individual load-velocity profile (LVP), and to explore the validity of such equations for 1RM prediction. Fifty-seven young men volunteered to participate. The submaximal load-velocity relationship was obtained for the free-weight parallel back squat. The estimated load at 0 velocity (LD0) was used as a single predictor, and in combination with the slope of the individual LVP, to develop equations predictive of 1RM. Prediction accuracy was determined through the mean absolute percent error and Bland-Altman plots. LD0 was predictive of 1RM ( p < 0.0001), explaining 70.2% of its variance. Adding the slope of the LVP to the model increased the prediction power of 1RM to 84.4% ( p < 0.0001). The absolute percent error between actual and predicted 1RM was lower for the predictions combining LD0 and slope (6.9 vs. 9.6%). The mean difference between actual and estimated 1RM was nearly zero and showed heteroscedasticity for the LD0 model, but not for the combined model. The limits of agreement error were of 31.9 and 23.5 kg for LD0 and LD0 combined with slope, respectively. In conclusion, the slope of the individual LVP adds predictive value to LD0 in 1RM estimation on a group level and avoids error trends in the estimation of 1RM over the entire spectrum of muscle strength. However, the use of mixed methods does not reach acceptable accuracy for 1RM prediction of the free-weight back squat on an individual basis.


Assuntos
Treinamento Resistido , Levantamento de Peso , Masculino , Humanos , Levantamento de Peso/fisiologia , Postura , Força Muscular/fisiologia
19.
Int J Gynaecol Obstet ; 164(3): 830-834, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-37537869

RESUMO

Postpartum femoral neuropathy has a reported incidence of less than 1% and its total recovery time extends up to 6 months to a year. A multidisciplinary approach is vital to rule out permanent disability and to assure a correct diagnosis and earlier rehabilitation. We report a case of a 37-year-old puerperal woman with a history of intrapartum epidural analgesia, who presented post-labor unilateral lower-limb motor weakness and sensory loss, with functional compromise on independent gait. A multidisciplinary team consisting of an anesthesiologist, a physiatrist, a neurologist, and an obstetrician was then established. In the initial physiatry and neurology assessment, the patient reported pain (numerical rating scale 7/10) over the inguinal ligament, lower limb hypoesthesia, and muscle weakness. Femoral neuropathy was suspected. Magnetic resonance imaging ruled out potential complications related to the anesthetic procedure. The patient was then enrolled in a supervised rehabilitation program and, 3 weeks later, electrodiagnostic studies confirmed the initial suspicion. Two months later, the patient had regained lower-limb active range of motion and no pain nor paresthesia was reported. Our case report describes how an early multimodal rehabilitation program within a multidisciplinary framework allows for sooner neuromotor function improvement and activities of daily living independence.


Assuntos
Neuropatia Femoral , Reabilitação Neurológica , Gravidez , Feminino , Humanos , Adulto , Atividades Cotidianas , Período Pós-Parto , Imageamento por Ressonância Magnética
20.
Sci Rep ; 13(1): 20721, 2023 11 25.
Artigo em Inglês | MEDLINE | ID: mdl-38007498

RESUMO

It has been found that fractal-like patterns are present in the temporal structure of the variability of healthy biological rhythms, while pathology and disease lead to their deterioration. Interestingly, it has recently been suggested that these patterns in biological rhythms are related with each other, reflecting overall health or lack of it, due to their interaction. However, the underlying neurophysiological mechanisms responsible for such dependency remain unknown. In addition, this relationship between different elements needs to be first verified before we even pursue understanding their interaction. This study aimed to investigate the relationship between two elements of the neuromuscular system, gait and muscle activity variability patterns in older adults. Twenty-one older adults walked at their preferred walking speed on a treadmill. Inter-stride intervals were obtained through an accelerometer placed on the lateral malleoli to assess the temporal structure of variability of stride-to-stride fluctuations. Inter muscle peak intervals were obtained through the electromyographic signal of the gastrocnemius to assess the temporal structure of the variability of the simultaneous muscle activity. The temporal structure of variability from both signals was evaluated through the detrended fluctuation analysis, while their magnitude of variability was evaluated using the coefficient of variation. The Pearson's Correlation coefficient was used to identify the relationship between the two dependent variables. A significant strong positive correlation was found between the temporal structure of gait and muscle activity patterns. This result suggests that there is an interdependency between biological rhythms that compose the human neuromuscular system.


Assuntos
Marcha , Caminhada , Humanos , Idoso , Caminhada/fisiologia , Marcha/fisiologia , Velocidade de Caminhada/fisiologia , Teste de Esforço , Fractais
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA