Effects of Resistance Exercise with and without Blood Flow Restriction on Acute Hemodynamic Responses: A Systematic Review and Meta-Analysis.

Low-load intensity resistance exercise with blood flow restriction (BFR) is an alternative method for enhancing strength and muscle mass. However, acute cardiovascular responses to a complete training session remain uncertain compared to high-load intensity resistance exercise (HI). Therefore, the objective of this study to examine acute and post-exercise hemodynamic responses to low-load BFR and HI protocols. This systematic review and meta-analysis (RD42022308697) followed PRISMA guidelines to investigate whether the responses of heart rate (HR), blood systolic (SBP), blood diastolic pressure (DBP), and rate pressure product (RPP) immediately after and up to 60 min post-exercise from BFR were consistent with those reported after resistance exercises performed at HI in healthy individuals. Searches using PICO descriptors were conducted in databases from January 2011 to December 2023, and effect sizes were determined by Hedge's g. The selected studies involved 160 participants in nine articles, for which the responses immediately after BFR and HI exercises showed no differences in HR (p = 0.23) or SBP (p = 0.57), but significantly higher DBP (p < 0.01) and lower RPP (p < 0.01) responses were found when comparing BFR to HI. Furthermore, the BFR and HI protocols showed no differences regarding SBP (p = 0.21) or DBP (p = 0.68) responses during a 15 to 60 min post-exercise period. Thus, these results indicated that hemodynamic responses are similar between BFR and HI, with a similar hypotensive effect up to 60 min following exercise.

Towards discovery: an end-to-end system for uncovering novel biomedical relations.

Biomedical relation extraction is an ongoing challenge within the natural language processing community. Its application is important for understanding scientific biomedical literature, with many use cases, such as drug discovery, precision medicine, disease diagnosis, treatment optimization and biomedical knowledge graph construction. Therefore, the development of a tool capable of effectively addressing this task holds the potential to improve knowledge discovery by automating the extraction of relations from research manuscripts. The first track in the BioCreative VIII competition extended the scope of this challenge by introducing the detection of novel relations within the literature. This paper describes that our participation system initially focused on jointly extracting and classifying novel relations between biomedical entities. We then describe our subsequent advancement to an end-to-end model. Specifically, we enhanced our initial system by incorporating it into a cascading pipeline that includes a tagger and linker module. This integration enables the comprehensive extraction of relations and classification of their novelty directly from raw text. Our experiments yielded promising results, and our tagger module managed to attain state-of-the-art named entity recognition performance, with a micro F1-score of 90.24, while our end-to-end system achieved a competitive novelty F1-score of 24.59. The code to run our system is publicly available at https://github.com/ieeta-pt/BioNExt. Database URL: https://github.com/ieeta-pt/BioNExt.

Multi-head CRF classifier for biomedical multi-class named entity recognition on Spanish clinical notes.

The identification of medical concepts from clinical narratives has a large interest in the biomedical scientific community due to its importance in treatment improvements or drug development research. Biomedical named entity recognition (NER) in clinical texts is crucial for automated information extraction, facilitating patient record analysis, drug development, and medical research. Traditional approaches often focus on single-class NER tasks, yet recent advancements emphasize the necessity of addressing multi-class scenarios, particularly in complex biomedical domains. This paper proposes a strategy to integrate a multi-head conditional random field (CRF) classifier for multi-class NER in Spanish clinical documents. Our methodology overcomes overlapping entity instances of different types, a common challenge in traditional NER methodologies, by using a multi-head CRF model. This architecture enhances computational efficiency and ensures scalability for multi-class NER tasks, maintaining high performance. By combining four diverse datasets, SympTEMIST, MedProcNER, DisTEMIST, and PharmaCoNER, we expand the scope of NER to encompass five classes: symptoms, procedures, diseases, chemicals, and proteins. To the best of our knowledge, these datasets combined create the largest Spanish multi-class dataset focusing on biomedical entity recognition and linking for clinical notes, which is important to train a biomedical model in Spanish. We also provide entity linking to the multi-lingual Systematized Nomenclature of Medicine Clinical Terms (SNOMED CT) vocabulary, with the eventual goal of performing biomedical relation extraction. Through experimentation and evaluation of Spanish clinical documents, our strategy provides competitive results against single-class NER models. For NER, our system achieves a combined micro-averaged F1-score of 78.73, with clinical mentions normalized to SNOMED CT with an end-to-end F1-score of 54.51. The code to run our system is publicly available at https://github.com/ieeta-pt/Multi-Head-CRF. Database URL: https://github.com/ieeta-pt/Multi-Head-CRF.

Optimizing time-in-target-range assessment for blood pressure: insights from a large-scale study with continual cuffless monitoring.

Introduction: Blood pressure (BP) time-in-target-range (TTR) is an emerging predictor of cardiovascular risk. Conventional BP methods are fundamentally unable to provide an optimal assessment of TTR, using irregular measurements separated by lengthy intervals. We investigated the optimal duration and frequency for reliable, practical TTR assessment in clinical settings using continual monitoring. Methods: This retrospective study analyzed 2.3 million BP readings from 5,189 European home users (55 ± 11 years, 82% male, BMI 28.0 ± 5.8) using a cuffless BP monitor (Aktiia SA). Systolic BP (SBP) data over 15 consecutive days were assessed (29 ± 11 readings/subject/24-h; 434 + 132 readings/subject/15-day). Subjects were classified into risk-related TTR groups based on 15-day SBP data (24-h, target 90-125 mmHg; ≥6 daytime readings). Various measurement frequencies and durations (1-14 days; 24-h/daytime; 2, 4 or ≥ 6 readings/day) were compared to this reference. Two specific configurations paralleling ambulatory ("One-Day-24 h") and home ("One-Week-Daytime") BP monitoring were selected for detailed analysis. Results: The reference TTR classified 63.0% of the subjects as high risk, 19.0% intermediate, and 18.0% low. "One-Day-24 h" schedule inaccurately classified 26% of subjects compared to the reference TTR, and "One-Week-Daytime" schedule inaccurately classified 45%. Classification accuracy with both schedules was high for subjects with very low or very high reference TTR, but poor otherwise. Accuracy of ≥90% in TTR classification only occurred with 7 days of continual 24-h monitoring. Discussion: For the first time, with the benefit of a cuffless device that measures BP with sufficient frequency and duration, practical use of TTR is enabled as a potentially enhanced metric to manage hypertension.

Relationship between Femur Mineral Content and Local Muscle Strength and Mass.

Among the stimuli able to prevent early decreases in bone mineralization, exercise has a noticeable role per se as the source of mechanical stimulus or through lean tissue enlargement by its increasing of tensional stimulus. However, prevention strategies, including exercise, generally do not establish the moment in life when attention should begin to be paid to bone integrity, according to age group- and sex-related differences. Thus, this study analyzed the relationship between variables from the diagnosis of total and regional body composition, muscle strength, and bone mineral content (BMC) of femurs in young adult males. Thirty-four young Caucasian men (24.9 ± 8.6 years) had their body composition and bone density assessed by dual X-ray absorptiometry. The subjects performed a one-repetition maximum test (1-RM) in a bench press, front pulley, seated-row, push press, arm curl, triceps pulley, leg flexion, leg extension, and 45° leg press for the assessment of muscle strength in upper and lower limbs in single- and multi-joint exercises. Lean tissue mass in the trunk and upper and lower limbs were related to femoral BMC (Pearson coefficient ranging from 0.55 to 0.72, p < 0.01), and 1-RM values for different exercises involving both upper and lower limbs also correlated with femoral BMC (Pearson coefficients ranging from 0.34 to 0.46, p < 0.05). Taken together, these correlations suggest that muscle mass and strength are positively linked with the magnitude of femoral mass in men, even in early adulthood. Hence, the importance of an enhanced muscle mass and strength to the health of femoral bones in young adults was highlighted.

A decision support system to recommend appropriate therapy protocol for AML patients.

Introduction: Acute Myeloid Leukemia (AML) is one of the most aggressive hematological neoplasms, emphasizing the critical need for early detection and strategic treatment planning. The association between prompt intervention and enhanced patient survival rates underscores the pivotal role of therapy decisions. To determine the treatment protocol, specialists heavily rely on prognostic predictions that consider the response to treatment and clinical outcomes. The existing risk classification system categorizes patients into favorable, intermediate, and adverse groups, forming the basis for personalized therapeutic choices. However, accurately assessing the intermediate-risk group poses significant challenges, potentially resulting in treatment delays and deterioration of patient conditions. Methods: This study introduces a decision support system leveraging cutting-edge machine learning techniques to address these issues. The system automatically recommends tailored oncology therapy protocols based on outcome predictions. Results: The proposed approach achieved a high performance close to 0.9 in F1-Score and AUC. The model generated with gene expression data exhibited superior performance. Discussion: Our system can effectively support specialists in making well-informed decisions regarding the most suitable and safe therapy for individual patients. The proposed decision support system has the potential to not only streamline treatment initiation but also contribute to prolonged survival and improved quality of life for individuals diagnosed with AML. This marks a significant stride toward optimizing therapeutic interventions and patient outcomes.

Comparing Video Analysis to Computerized Detection of Limb Position for the Diagnosis of Movement Control during Back Squat Exercise with Overload.

Incorrect limb position while lifting heavy weights might compromise athlete success during weightlifting performance, similar to the way that it increases the risk of muscle injuries during resistance exercises, regardless of the individual's level of experience. However, practitioners might not have the necessary background knowledge for self-supervision of limb position and adjustment of the lifting position when improper movement occurs. Therefore, the computerized analysis of movement patterns might assist people in detecting changes in limb position during exercises with different loads or enhance the analysis of an observer with expertise in weightlifting exercises. In this study, hidden Markov models (HMMs) were employed to automate the detection of joint position and barbell trajectory during back squat exercises. Ten volunteers performed three lift movements each with a 0, 50, and 75% load based on body weight. A smartphone was used to record the movements in the sagittal plane, providing information for the analysis of variance and identifying significant position changes by video analysis (p < 0.05). Data from individuals performing the same movements with no added weight load were used to train the HMMs to identify changes in the pattern. A comparison of HMMs and human experts revealed between 40% and 90% agreement, indicating the reliability of HMMs for identifying changes in the control of movements with added weight load. In addition, the results highlighted that HMMs can detect changes imperceptible to the human visual analysis.

In silico analysis of the biodiversity of endophytic fungi isolated from the Brazilian Cerrado / Análise in silico da biodiversidade de fungos endofíticos isolados do Cerrado brasileiro

Abstract Endophytic microorganisms are those that inhabit the interior of plant tissues and organs without causing damage to the plant, triggering a mutualistic interaction. These endophytes are known to produce compounds with various applications in the areas of biotechnology, pharmaceutical industry and agriculture; therefore, molecular methods are used to investigate the phylogeny of these organisms. The Brazilian Cerrado is the second largest biome in Brazil and is considered a hotspot, with a high diversity of endemic fauna and flora. The objective of this work was to analyze, through in silico analysis, the phylogeny of cultivable endophytic fungi isolated from plants found in the Brazilian Cerrado biome. A search was carried out for articles that worked with endophytes in the period between 2012 and 2022. The dendrogram was generated using the Neighbor-joining method based on the ITS1-5.8S-ITS2 conserved region obtained by GenBank codes of isolated endophytes. The genera Xylaria, Diaporthe, and Colletotrichum were isolated in more than three plants in the seven articles found. Most of the articles found related to the biodiversity of endophytic fungi from the Brazilian Cerrado aim at the bioprospecting of bioactive compounds, through culture-dependent methods; as such, a part of endophytic diversity may be lost due to the inability of certain endophytes to grow in artificial media. In silico analysis can assist in the investigation of phylogenetic relationships between endophytic fungi and has the potential to guide future work aimed at prospecting for bioactive compounds, phylogenetic identification, or biodiversity of this group of endophytes.

Resumo Microrganismos endofíticos são aqueles que vivem no interior de tecidos e órgãos vegetais sem causar dano à planta, desencadeando uma interação mutualística. Esses endófitos são conhecidos por produzir compostos com diversas aplicações nas áreas de biotecnologia, indústria farmacêutica e agricultura; logo, métodos moleculares são utilizados para investigar a filogenia destes organismos. O Cerrado brasileiro é o segundo maior bioma do Brasil e é considerado um hotspot, com uma alta diversidade de fauna e flora endêmica. O objetivo deste trabalho foi analisar, por meio da análise in silico, a filogenia de fungos endofíticos cultiváveis isolados de plantas encontradas no bioma Cerrado brasileiro. Foi realizada uma busca por artigos que trabalharam com endófitos no período entre 2012 e 2022. O dendrograma foi gerado usando o método Neighbor-joining baseado na região conservada ITS1-5.8S-ITS2 obtida pelos códigos GenBank de endófitos isolados. Os gêneros Xylaria, Diaporthe e Colletotrichum foram isolados em mais de três plantas nos sete artigos encontrados. A maior parte dos artigos encontrados relacionados à biodiversidade de fungos endofíticos do Cerrado brasileiro visam à bioprospecção de compostos bioativos, através de métodos dependentes de cultura; como tal, uma parte da diversidade endofítica pode ser perdida devido à incapacidade de certos endófitos crescerem em meios artificiais. A análise in silico pode auxiliar na investigação das relações filogenéticas entre fungos endofíticos e tem potencial para orientar trabalhos futuros voltados à prospecção de compostos bioativos, identificação filogenética ou biodiversidade deste grupo de endófitos.

Microglial Rac1 is essential for experience-dependent brain plasticity and cognitive performance.

Microglia, the largest population of brain immune cells, continuously interact with synapses to maintain brain homeostasis. In this study, we use conditional cell-specific gene targeting in mice with multi-omics approaches and demonstrate that the RhoGTPase Rac1 is an essential requirement for microglia to sense and interpret the brain microenvironment. This is crucial for microglia-synapse crosstalk that drives experience-dependent plasticity, a fundamental brain property impaired in several neuropsychiatric disorders. Phosphoproteomics profiling detects a large modulation of RhoGTPase signaling, predominantly of Rac1, in microglia of mice exposed to an environmental enrichment protocol known to induce experience-dependent brain plasticity and cognitive performance. Ablation of microglial Rac1 affects pathways involved in microglia-synapse communication, disrupts experience-dependent synaptic remodeling, and blocks the gains in learning, memory, and sociability induced by environmental enrichment. Our results reveal microglial Rac1 as a central regulator of pathways involved in the microglia-synapse crosstalk required for experience-dependent synaptic plasticity and cognitive performance.

Performance of the Aktiia optical blood pressure measurement device in the elderly: a comparison with double blinded auscultation in different body positions.

BACKGROUND: Accurate blood pressure (BP) measurement is essential for the correct diagnosis and management of hypertension (HTN) especially in the elderly population. As with of all BP devices, the accuracy of cuffless devices must be verified. This study (NCT04027777) aimed to evaluate the performance of a wrist cuffless optical BP device in an elderly population cohort in different body positions with auscultation as the reference measurement. DESIGN AND METHODS: Patients aged 65-85 years with different BP categories but without diabetes were recruited. After an initial calibration based on auscultatory measurements, BP estimation from the Aktiia Bracelet (Aktiia SA, Switzerland) were compared to reference double-blinded auscultatory measurements in sitting, standing and lying positions on four separate visits distributed over one month. In the absence of a universal standard for cuffless BP device at the time of the study, modified ISO81060-2 criteria were used for performance analysis. RESULTS: Thirty-five participants were included in the analysis fulfilling the inclusion requirements of ISO 81060-2. A total of 469 paired measurements were obtained with overall 83% acceptance rate. Differences (mean ± SD)   between Aktiia Bracelet and auscultation for systolic BP were -0.26 ± 9.96 mmHg for all body positions aggregated (sitting 1.23 ± 7.88 mmHg, standing -1.81 ± 11.11 mmHg, lying -1.8 ± 9.96 mmHg). Similarly, differences for diastolic BP were -0.75 ± 7.0 mmHg (0.2 ± 5.55 mmHg, -5.35 ± 7.75 mmHg and -0.94 ± 7.47 mmHg, respectively). Standard deviation of the averaged differences per subject for systolic/diastolic BP was 3.8/2.5 mmHg in sitting and 4.4/3.7 mmHg for all body positions aggregated. CONCLUSIONS: Overall, this study demonstrates a similar performance of the Aktiia Bracelet compared to auscultation in an elderly population in body positions representative of daily activities. The use of more comfortable, non-invasive, and non-occlusive BP monitors during long periods may facilitate e-health and may contribute to better management of HTN, including diagnosis and treatment of HTN, in the elderly.

Accuracy of blood pressure measurements is essential in the diagnosis and the follow-up of patients with high blood pressure. As with any blood pressure measuring device, a validation is necessary. In this study including a elderly population, we compared values obtained by the cuffless Aktiia Bracelet (Aktiia SA, Switzerland) after an initial calibration with the reference auscultatory method during four separate study days distributed over one month. We show that the accuracy of the Aktiia Bracelet is similar to auscultation. The accuracy varies depending on the position in which the measurement is performed. Overall, the accuracy is not modified by a higher age category. The use of a cuffless device in the elderly population characterized by high prevalence of hypertension may facilitate the follow-up of blood pressure with more comfort and minimal constraints.

RhoA balances microglial reactivity and survival during neuroinflammation.

Microglia are the largest myeloid cell population in the brain. During injury, disease, or inflammation, microglia adopt different functional states primarily involved in restoring brain homeostasis. However, sustained or exacerbated microglia inflammatory reactivity can lead to brain damage. Dynamic cytoskeleton reorganization correlates with alterations of microglial reactivity driven by external cues, and proteins controlling cytoskeletal reorganization, such as the Rho GTPase RhoA, are well positioned to refine or adjust the functional state of the microglia during injury, disease, or inflammation. Here, we use multi-biosensor-based live-cell imaging approaches and tissue-specific conditional gene ablation in mice to understand the role of RhoA in microglial response to inflammation. We found that a decrease in RhoA activity is an absolute requirement for microglial metabolic reprogramming and reactivity to inflammation. However, without RhoA, inflammation disrupts Ca2+ and pH homeostasis, dampening mitochondrial function, worsening microglial necrosis, and triggering microglial apoptosis. Our results suggest that a minimum level of RhoA activity is obligatory to concatenate microglia inflammatory reactivity and survival during neuroinflammation.

Spontaneously growing fungi on the surface and processing areas of matured sheep ham and volatile compounds produced.

Raw ham is a dried and matured product traditionally made from pork leg, but other animals, such as sheep, can be used. The natural presence of bacteria and fungi in this product influences its characteristics throughout the process. This study analysed the fungal populations present during raw sheep hams' processing. Two types of products were developed: without and with the addition of seasonings. Mycological analyses were carried out from the ingredients, seasonings, facilities air, as well as on the surfaces of the hams and the air in the chamber throughout the maturation period (0, 45, 90, and 180 days) using 18 % dichloran glycerol agar and the data were submitted to Principal Component Analysis. Volatile compounds were evaluated at the end of the sheep ham manufacturing process through a gas chromatograph coupled to a mass spectrometer. At 45 days of aging, a more remarkable similarity was observed between the fungi present on the non-seasoned hams and those in the ripening chamber's air, while the seasoned hams showed a more evident relation with those fungi present in the spices. With time, the fungi in the air of the ripening chamber started to be influenced by Aspergillus ser. Aspergillus and Aspergillus ser. Rubri already installed in the seasoned hams at 45 days, and then it probably dispersed the non-seasoned ones due to the airborne spores, becoming the most prevalent in both treatments at 90 days. At the end of ripening, the mycobiota of both raw hams was composed mainly by xerophilic species of Aspergillus section Aspergillus. The total fungal count was 5.78 log CFU/cm2 for the non-seasoned and 7.19 log CFU/cm2 for the seasoned ones. A potentially ochratoxigenic Aspergillus ser. Circumdati was detected at the end of aging in raw, unseasoned hams. In conclusion, seasoning directly influences the species developing on the surface of seasoned hams throughout the ripening process, and indirectly affects the mycobiota of the non-seasoned hams when sharing the same ripening chamber. The presence of fungi in the matured sheep ham seems to contribute to the formation of volatile compounds, which are related to the sensory quality of these products.

Body Composition Relationship to Performance, Cardiorespiratory Profile, and Tether Force in Youth Trained Swimmers.

This study sought to analyze the relationship between regional body composition, swimming performance, and aerobic and force profile determined through tethered swimming in well-trained swimmers. Eleven male and five female swimmers were involved in the study and underwent the following evaluations: (1) body composition, assessed by the dual-energy X-ray absorptiometry method (DXA); (2) swimming performance, determined for 200, 400, 800, and 1.500 m front-crawl swimming; (3) a tethered swimming force test to determine maximum and mean force (Fmax and Fmean); and (4) an incremental tethered swimming test for the aerobic profile determination of the swimmers. Oxygen uptake (VO2) was directly measured by an automatic and portable system (K4b2 Cosmed, Italy). The fat-free mass (lean mass + bone mineral content, LM+BMC) in lower and upper limbs (UL_LM+BMC: 6.74 ± 1.57 kg and LL_LM+BMC: 20.15 ± 3.84 kg) positively correlated with all indexes of aerobic conditioning level, showing higher coefficients to the indexes representing the ability to perform at high aerobic intensities (VO2max: 49.2 ± 5.9 mL·kg-1·min-1 and respiratory compensation point (RCP): 43.8 ± 6.0 mL·kg-1·min-1), which attained 0.82 and 0.81 (with VO2max), 0.81 and 0.80 (with RCP). The S200 (1.48 ± 0.13 m·s-1) was significantly correlated to Trunk_LM+BMC (r = 0.74), UL_LM+BMC (r = 0.72), Total_LM+BMC (r = 0.71), and LL_LM+BMC (r = 0.64). This study highlights that regional body composition plays an important role in swimming, and body segment analysis should be considered instead of the total body. Tethered swimming may represent a useful method for force and aerobic assessment, aiming at training control and performance enhancement.

Effects of Exercise and Sports Intervention and the Involvement Level on the Mineral Health of Different Bone Sites in the Leg, Hip, and Spine: A Systematic Review and Meta-Analysis.

The current study analysed whether the osteogenic stimuli of exercises and sports have an independent effect on bone mineral density (BMD). Studies with a design having two different cohorts were searched and selected to distinguish the effect due to long-term involvement (i.e., athletes vs. non-active young with good bone health) and due to the planning of intervention (i.e., pre- vs. post-training) with exercises and sports. Moreover, only studies investigating the bone sites with a body-weight support function (i.e., lower limb, hip, and spine regions) were reviewed, since the osteogenic effects have incongruous results. A meta-analysis was performed following the recommendations of PRISMA. Heterogeneity (I2) was determined by combining Cochran's Q test with the Higgins test, with a significance level of α = 0.05. The studies reporting the effect of involvement in exercise and sports showed high heterogeneity for the lower limb, total hip, and spine (I2 = 90.200%, 93.334%, and 95.168%, respectively, with p < 0.01) and the effect size on sports modalities (Hedge's g = 1.529, 1.652, and 0.417, respectively, with p < 0.05) ranging from moderate to high. In turn, the studies reporting the effect of the intervention planning showed that there was no heterogeneity for the lower limb (I2 = 0.000%, p = 0.999) and spine (I2 = 77.863%, p = 0.000); however, for the hip, it was moderate (I2 = 49.432%, p = 0.054), with a low effect between the pre- and post-training moments presented only for the hip and spine (Hedge's g = 0.313 and 0.353, respectively, with p < 0.05). The current analysis supported the effect of involvement in exercise and sports by evidencing the effect of either weight-bearing or non-weight-bearing movements on BMD at the femoral, pelvic, and lumbar bones sites of the athletes when comparing to non-athletes or non-active peers with healthy bones. Moreover, the effect of different exercise and sports interventions highlighted the alterations in the BMD in the spine bone sites, mainly with long-term protocols (~12 months) planned with a stimulus with high muscle tension. Therefore, exercise and sport (mainly systematic long-term practice) have the potential to increase the BMD of bones with body-weight support beyond the healthy values reached during life phases of youth and adulthood.

Stroke and physiological relationships during the incremental front crawl test: outcomes for planning and pacing aerobic training.

Purpose: This study aimed to evaluate the physiological responses associated with the stroke length (SL) and stroke rate (SR) changes as swimming velocity increases during an incremental step-test. Moreover, this study also aimed to verify if SL and SR relationships toward maximal oxygen uptake (V̇O2max), gas respiratory compensation point (RCP), exchange threshold (GET), and swimming cost can be applied to the management of endurance training and control aerobic pace. Methods: A total of 19 swimmers performed the incremental test until volitional exhaustion, with each stage being designed by percentages of the 400 m (%v400) maximal front crawl velocity. V̇O2max, GET, RCP, and the respective swimming velocities (v) were examined. Also, the stroke parameters, SL, SR, the corresponding slopes (SLslope and SRslope), and the crossing point (Cp) between them were determined. Results: GET and RCP corresponded to 70.6% and 82.4% of V̇O2max (4185.3 ± 686.1 mL min-1), and V̇O2 at Cp, SLslope, and SRslope were observed at 129.7%, 75.3%, and 61.7% of V̇O2max, respectively. The swimming cost from the expected V̇O2 at vSLslope (0.85 ± 0.18 kJ m-1), vSRslope (0.77 ± 0.17 kJ m-1), and vCp (1.09 ± 0.19 kJ m-1) showed correlations with GET (r = 0.73, 0.57, and 0.59, respectively), but only the cost at vSLslope and vCp correlated to RCP (0.62 and 0.69) and V̇O2max (0.70 and 0.79). Conclusion: SL and SR exhibited a distinctive pattern for the V̇O2 response as swimming velocity increased. Furthermore, the influence of SL on GET, RCP, and V̇O2max suggests that SLslope serves as the metabolic reference of heavy exercise intensity, beyond which the stroke profile defines an exercise zone with high cost, which is recommended for an anaerobic threshold and aerobic power training. In turn, the observed difference between V̇O2 at SRslope and GET suggests that the range of velocities between SL and SR slopes ensures an economical pace, which might be recommended to develop long-term endurance. The results also highlighted that the swimming intensity paced at Cp would impose a high anaerobic demand, as it is located above the maximal aerobic velocity. Therefore, SLslope and SRslope are suitable indexes of submaximal to maximal aerobic paces, while Cp's meaning still requires further evidence.

Oxygen Uptake Kinetics and Time Limit at Maximal Aerobic Workload in Tethered Swimming.

This study aimed to apply an incremental tethered swimming test (ITT) with workloads (WL) based on individual rates of front crawl mean tethered force (Fmean) for the identification of the upper boundary of heavy exercise (by means of respiratory compensation point, RCP), and therefore to describe oxygen uptake kinetics (VO2k) and time limit (tLim) responses to WL corresponding to peak oxygen uptake (WLVO2peak). Sixteen swimmers of both sexes (17.6 ± 3.8 years old, 175.8 ± 9.2 cm, and 68.5 ± 10.6 kg) performed the ITT until exhaustion, attached to a weight-bearing pulley-rope system for the measurements of gas exchange threshold (GET), RCP, and VO2peak. The WL was increased by 5% from 30 to 70% of Fmean at every minute, with Fmean being measured by a load cell attached to the swimmers during an all-out 30 s front crawl bout. The pulmonary gas exchange was sampled breath by breath, and the mathematical description of VO2k used a first-order exponential with time delay (TD) on the average of two rest-to-work transitions at WLVO2peak. The mean VO2peak approached 50.2 ± 6.2 mL·kg-1·min-1 and GET and RCP attained (respectively) 67.4 ± 7.3% and 87.4 ± 3.4% VO2peak. The average tLim was 329.5 ± 63.6 s for both sexes, and all swimmers attained VO2peak (100.4 ± 3.8%) when considering the primary response of VO2 (A1' = 91.8 ± 6.7%VO2peak) associated with the VO2 slow component (SC) of 10.7 ± 6.7% of end-exercise VO2, with time constants of 24.4 ± 9.8 s for A1' and 149.3 ± 29.1 s for SC. Negative correlations were observed for tLim to VO2peak, WLVO2peak, GET, RCP, and EEVO2 (r = -0.55, -0.59, -0.58, -0.53, and -0.50). Thus, the VO2k during tethered swimming at WLVO2peak reproduced the physiological responses corresponding to a severe domain. The findings also demonstrated that tLim was inversely related to aerobic conditioning indexes and to the ability to adjust oxidative metabolism to match target VO2 demand during exercise.

Mechanisms of Mucor sp. CM3 isolated from the aquatic macrophyte Eichhornia crassipes (Mart.) Solms to increase cadmium bioremediation.

Bioremediation of toxic metals is a feasible and low-cost remediation tool to reduce metal contamination. Plant-fungus interactions can improve this technique. Eichhornia crassipes (Mart.) Solms is a macrophyte reported to bioremediate contaminated water. Thus, the present study aimed to isolate endophytic fungi from E. crassipes, select a highly cadmium (Cd) tolerant isolate and evaluate its bioremediation potential. This was evaluated by (1) the fungus tolerance and capacity to accumulate Cd; (2) Cd effects on cell morphology (using SEM and TEM) and on the fungal antioxidant defense system, as well as (3) the effect on model plant Solanum lycopersicum L. cultivar Calabash Rouge, inoculated with the endophyte fungus and exposed to Cd. Our results selected the endophyte Mucor sp. CM3, which was able to tolerate up to 1000 g/L of Cd and to accumulate 900 mg of Cd/g of biomass. Significant changes in Mucor sp. CM3 morphology were observed when exposed to high Cd concentrations, retaining this metal both in its cytoplasm and in its cell wall, which may be linked to detoxification and metal sequestration mechanisms related to the formation of Cd-GSH complexes. In addition, Cd stress induced the activation of all tested antioxidant enzymes - superoxide dismutase (SOD), catalase (CAT), and glutathione reductase (GR) - in this endophytic fungus. Moreover, when inoculated in tomato plants, this fungus promoted plant growth (in treatments without Cd) and induced an increased metal translocation to plant shoot, showing its potential to increase metal bioremediation. Therefore, this study indicates that the isolated endophyte Mucor sp. CM3 can be applied as a tool in different plant conditions, improving plant bioremediation and reducing the environmental damage caused by Cd, while also promoting plant growth in the absence of contaminants.