Cyclic Strain Research Articles

Acute Responses to Repeated-SprintTraining in Hypoxia Combined With Whole-Body Cryotherapy: A Preliminary Study.

This study aimed to investigate acute psychophysiological responses to repeated-sprint training in hypoxia (RSH) combined with whole-body cryotherapy (WBC). Sixteen trained cyclists performed 3 sessions in randomized order: RSH, WBC-RSH (WBC pre-RSH), and RSH-WBC (WBC post-RSH). RSH consisted of 3 sets of 5 × 10-second sprints with 20-second recovery at a simulated altitude of 3000m. Power output, muscle oxygenation (tissue saturation index), heart-rate variability, and recovery perception were analyzed. Sleep quality was assessed on the nights following test sessions and compared with a control night using nocturnal ActiGraphy and heart-rate variability. Power output did not differ between the conditions (P = .27), while the decrease in tissue saturation index was reduced for WBC-RSH compared to RSH-WBC in the last set. In both conditions with WBC, the recovery perception was higher compared to RSH (WBC-RSH: +15.4%, and RSH-WBC: +21.9%, P < .05). The number of movements during the RSH-WBC night was significantly lower than for the control night (-18.7%, P < .01) and WBC-RSH (-14.9%, P < .05). RSH led to a higher root mean square of the successive differences of R-R intervals and high-frequency band during the first hour of sleep compared to the control night (P < .05) and RSH-WBC (P < .01). Inclusion of WBC in an RSH session did not modify the power output but could improve prolonged performance in hypoxia by maintaining muscle oxygenation. A single RSH session did not deteriorate sleep quality. WBC, particularly when performed after RSH, positively influenced recovery perception and sleep.

Pkm at the Indonesian Community Organization (Permai) Pulau Pinang in the Implementation of the Accounting Cycle

The partner in this PKM is the Indonesian Community Organization (PERMAI) located at Jalan Kuantan 66, George Town, 10150 George Town, Pulau Pinang, Malaysia. PERMAI members consist of Indonesians who live in Malaysia, including entrepreneurs, workers, lecturers, teachers, students and university students who live in Malaysia. PERMAI also seeks to collaborate with parties who are willing to synergize knowledge in the fields of eCommerce, Fintech, Digital Technology and other special skills that are appropriate to establish socio-cultural cooperative relations between the people of Indonesia and Malaysia. Business actors certainly have business units, so they need accounting for the business units they run. Accounting, which starts from recording transactions to financial reports, is a basic science that business people must know. Problem: a). Business people still need accounting knowledge; b) They have not implemented accounting in their business units. Solution: a) Provide knowledge transfer to PERMAI business actors about what accounting is and what its cycles are; b) Providing training on the accounting cycle starting from recording transactions to preparing financial reports for PERMAI business actors. Target: a) Provide knowledge transfer to PERMAI business actors about accounting and its cycles, b) Provide accounting cycle training to PERMAI business actors, starting from recording transactions to preparing financial reports. Evaluation and monitoring will be carried out to ensure the success of the program so that the continuity of the implementation of accounting for business actors at PERMAI will continue and be beneficial, especially for PERMAI business actors in Pulau Pinang, Malaysia.

Functional state of team sports athletes in the annual training cycle

Determination of the dynamics of the functional state of the musculoskeletal system of team sports athletes in the annual training cycle. The achievement of this goal will allow for providing scientifically-based management of training and competitive processes in the annual training cycle and contribute to the normalization of the functional state of the athlete's musculoskeletal system. The authors assessed the functional state of the musculoskeletal system of athletes involved in football, handball, and field hockey, using goniometry, and stabilometry, as well as testing physical abilities, associated with the flexibility of the joints (forward bend from a standing position (on the bench), bridge, transverse and longitudinal (best of 2 possible), splits). Testing was conducted during the annual training cycle, after the competitive period, and at the beginning and at the end of the preparatory period. Assessment of the functional state of the musculoskeletal system of athletes at the end of the competition period showed the low and below average flexibility levels. Static support ability (stabilometry) and joint mobility (goniometry) were below average and average levels. Decrease in static support ability testified to violations of the vestibular apparatus and proprioceptive sensitivity, which have a significant impact on balance. The low results of joint flexibility and mobility indicated the lack of elasticity of the musculoskeletal apparatus, which indicated the presence of overstrain. Diagnosed positive changes in the state of the musculoskeletal system of athletes at the beginning and at the end of the preparatory period, regardless of the team sport, indicated a partial restoration of the functional state of the musculoskeletal system during the transition period. According to the results of the study, recommendations were given for including in the training process, along with prestretching, corrective and preventive exercises based on the use of the myofascial relaxation technique, which contribute to the restoration of the functional state of the musculoskeletal system of team sports athletes. Keywords: football players, handball players, hockey players, functional state, musculoskeletal system, flexibility, stabilometry, goniometry.

Experience in managing the process of continuing medical education of medical workers in public health and health care

Introduction. The problem of continuous professional development of medical specialists with higher and secondary medical education is especially relevant at the present stage, when medical knowledge, technologies, and drugs are being improved every day. &#x0D; Purpose. Analysis of the forms of conducting cycles of continuous medical education in the field of health care management and public health at the Pirogov Russian National Research Medical University of the Ministry of Health of the Russian Federation for the development of the most popular and perfect form of its implementation.&#x0D; Materials and methods. An analysis of the main directions of the mnagement of the process of continuous medical education of medical workers in general and in public health and health care in the Federal State Autonomous Educational Institution of Higher Education of the Russian National Research Medical University named after N.I. Pirogov of the Ministry of Health of the Russian Federation. &#x0D; Results. Since 1977 a continuous medical education was started in the USSR. A course for advanced training of doctors in social hygiene was opened at the Department of Social Hygiene and Health Organization of the 2nd Medical Institute. Within the framework of the specialty “Organization of Health Care and Public Health”, the department conducted cycles of professional retraining (PP-504 hours), advanced training: 144 hours (PC-144), 72 hours and 36 hours. Continuing medical education is aimed at obtaining the competencies necessary to perform a new type of professional activity. The plans for further improvement of continuing medical education by the department provide for the renewal of work programs, the creation of distance and new relevant cycles.&#x0D; Limitations of the study. An analysis of professional retraining cycles of students of various durations for the acquisition of new qualifications, qualitative expansion of the field of knowledge, skills and abilities in the period 2017–2022 was carried out. &#x0D; Conclusion. The presented data indicate the expediency of managing advanced training within the framework of the specialty “Organization of Health Care and Public Health” using short cycles of advanced training of full-time and distant forms of training of students.

Biofeedback Endurance Training for Gait Rehabilitation in Parkinson’s Disease: a Non-Randomized Controlled Study

INTRODUCTION. Parkinson’s disease is a disease with the highest rates of disability growth in the neurodegenerative pathology group, with the leading motor symptom — impaired walking and an increased risk of falling. There is evidence that Parkinson’s disease preserves stability for cycling. The issue of extending the effects of cycling training to daily activity, including walking, remains unclear.&#x0D; AIM. To evaluate the effect of a course of endurance training on a cycle ergometer with biofeedback (BFB) on a walking ability of a patient with Parkinson’s disease.&#x0D; MATERIALS AND METHODS. A total of 69 patients with stages 2–3 Parkinson’s disease according to the Hoehn and Yahr Rating Scale were included in the study, group 1: 34 people (60.05 ± 7.07 years) and group 2: 35 patients (61.75 ± 7.53 years). The patients were examined — anamnesis collection: duration of Parkinson disease, presence of arterial hypertension (AH), sports history, medication, assessment of systolic and diastolic blood pressure (SBP and DBP), body mass index (BMI), “6-minute walk” test (6MWT), motor function according to the MDS UPDRS scale — part III. The patients of group 1 had daily exercises on a digital bicycle ergometer with BOS for 10 days, the patients of group 2 — therapeutic gymnastics. The therapy was assessed by repeated 6MWT.&#x0D; RESULTS AND DISCUSSION. The Parkinson’s disease duration was longer in the patients of group 1. Concomitant hypertension was in 20 (57 %) patients of group 1 and 16 (47 %) patients of group 2 (p 0.05). 11 people of group 1 and 5 of group 2 had a sports history (p = 0.07). The indicators of SBP and DBP of groups 1 and 2 had normal values during the examination. BMI in both groups corresponded to excess body weight. Patients had risk factors of the modern world: hypertension and overweight. Motor disorders according to the MDS UPDRS — Part III scale were greater in group 1. Despite having serious motor impairments in group 1, after the therapy, the patients demonstrated an increase in the distance traveled in 6 minutes (392.18 ± 96.3 m vs. 476.43 ± 108.08 m; p 0.05), while no changes were found in group 2.&#x0D; CONCLUSION. BOS endurance training on a cycle ergometer is effective for walking rehabilitation of Parkinson’s disease patients.

Silicone-based highly stretchable multifunctional fiber pumps

Recent advancements on electrohydrodynamic (EHD) soft pumps demonstrate their applicability to various fluid-driven systems such as soft robots, wearable devices, and stretchable electronics. In particular, fiber type EHD pumps reported more recently is a promising pumping element thanks to their versatile fibrous structure. Yet existing EHD fiber pumps are less stretchable and require sophisticated, complex fabrication equipment, implying opportunity for technology advancement. This paper presents a simplified method to create highly stretchable multifunctional fiber EHD pumps. The method employs highly compliant silicone elastomers for the fiber structure that is formed by simple dipping fabrication process. The fabricated pumps (length of 100 mm, inner diameter 4 mm, and mass 5.3 g) exhibit a high stretchability (up to 40% strain) and flow rate and pressure of 167.4 ± 7.6 mL/min (31.6 mL/min/g) and 4.1 ± 0.6 kPa (0.8 kPa/g), respectively. These performances are comparable or even higher than those of previously reported EHD pumps including fiber types. The output performance of the fabricated pumps remain constant for repeated strain cycles (0–25%, up to 2000 cycles) and bending angle up to 180° (corresponding to curvature of 0–30/m). Moreover, the pumps demonstrate unprecedented functionality as a sensor to distinguish the type of fluid inside the tube and to detect strains by reading the capacitance between the electrodes. The characterization result reveals the sensing ability of the pumps as high repeatability up to 30% strain with negligible hysteresis, which is consistent for 5000 cycles.

Labor Market Information System: A Review of Some Practices

Accurate and up-to-date labor market information system, which is conducted with the involvement of public decision markers, technical and vocational education and training (TVET) practitioners, employers and their associations, employee associations, training providers and learners, is an essential feature of a successful TVET system. Similarly, engagement of multiple TVET stakeholders is an important component of overall skills development system which leads to developing responsive labor market skill needs, supporting prioritized economic sectors to foster dialogue among the stakeholders to maintain balance demand and supply of labor right. It enhances integration of labor market requirements in the overall training and skills development cycle and ensures that trainees acquire market-relevant skills for their employability and self-employment. In the context of changing labor market conditions, collecting, compiling, analyzing, and disseminating current and future needs from the TVET customers can support better matching for training and employment. As labor markets are constantly evolving and changing, labor market analysis therefore needs to be conducted on a regular basis so that real time labor market information can be obtained. But the active and regular labor market information process is underexplored in a developing country like Nepal. The main objective of the article is to explore the common practices of Nepali labor market information system and the problems faced by the TVET system. Thus, the article addresses the information gap by diving deep into the clear understanding of labor market, practices of labor market information processes in some South Asian countries, including Nepal and issues and challenges facing the Nepali labor market information process.

Development of an Artificial Intelligence-Based Image Recognition System for Time-Sequence Analysis of Tracheal Intubation.

Total intubation time (TIT) is an objective indicator of tracheal intubation (TI) difficulties. However, large variations in TIT because of diverse initial and end targets make it difficult to compare studies. A video laryngoscope (VLS) can capture images during the TI process. By using artificial intelligence (AI) to detect airway structures, the start and end points can be freely selected, thus eliminating the inconsistencies. Further deconstructing the process and establishing time-sequence analysis may aid in gaining further understanding of the TI process. We developed a time-sequencing system for analyzing TI performed using a #3 Macintosh VLS. This system was established and validated on 30 easy TIs performed by specialists and validated using TI videos performed by a postgraduate-year (PGY) physician. Thirty easy intubation videos were selected from a cohort approved by our institutional review board (B-ER-107-088), and 6 targets were labeled: the lip, epiglottis, laryngopharynx, glottic opening, tube tip, and a black line on the endotracheal tube. We used 887 captured images to develop an AI model trained using You Only Look Once, Version 3 (YOLOv3). Seven cut points were selected for phase division. Seven experts selected the cut points. The expert cut points were used to validate the AI-identified cut points and time-sequence data. After the removal of the tube tip and laryngopharynx images, the durations between 5 identical cut points and sequentially identified the durations of 4 intubation phases, as well as TIT. The average and total losses approached 0 within 150 cycles of model training for target identification. The identification rate for all cut points was 92.4% (194 of 210), which increased to 99.4% (179 of 180) after the removal of the tube tip target. The 4 phase durations and TIT calculated by the AI model and those from the expert exhibited strong Pearson correlation (phase I, r = 0.914; phase II, r = 0.868; phase III, r = 0.964; and phase IV, r = 0.949; TIT, r = 0.99; all P < .001). Similar findings were obtained for the PGY's observations (r > 0.95; P < .01). YOLOv3 is a powerful tool for analyzing images recorded by VLS. By using AI to detect the airway structures, the start and end points can be freely selected, resolving the heterogeneity resulting from the inconsistencies in the TIT cut points across studies. Time-sequence analysis involving the deconstruction of VLS-recorded TI images into several phases should be conducted in further TI research.

Proteomics of appetite-regulating system influenced by menstrual cycle and intensive exercise in female athletes: a pilot study

Female athletes who endure intense training are at risk of developing the 'female athlete triad,' making energy intake management crucial. However, the fluctuations in estradiol and progesterone levels throughout the menstrual cycle present a challenge in maintaining consistent energy intake. This study aimed to uncover the underlying factors associated with appetite regulation linked to menstrual phases and exercise using proteomic approach. Five female athletes engaged in 60 min of bicycle exercise, followed by 90 min of rest, during both the follicular and luteal phases. Serum samples were collected before, during, and after exercise, and the serum proteome was analyzed using 2D-gel electrophoresis. A total of 511 spots were detected in the subjects' serum profiles, with significant decreases observed in haptoglobin during the luteal phase and complement component 3 during bicycle training. Unsupervised learning with a generalized estimating equation analysis showed that serum peptide YY (PYY), an appetite suppressor, significantly influenced the fluctuations of serum proteins induced by exercise (p < 0.05). Regression analysis demonstrated a positive correlation between PYY and serum IgM (R = 0.87), implying that the intestinal environment and the immune response in female athletes may contribute to appetite regulation.

Effect of stage amplitude ratio on dynamic behaviors of sand under wind turbine loading

Offshore wind turbines are subjected to more significant wave and wind environmental loads at extreme weather conditions, making subsoil experience various loading stages with different amplitudes. To investigate the coupling effect of both cyclic shear stress ratio (CSR) and stage amplitude ratio (Ar) between normal and extreme weather conditions, a series of bi-directional simple shear tests with five different Ar and three CSR values were conducted on marine sand using the variable-direction dynamic cyclic simple shear (VDDCSS) apparatus. In the tests, soil samples were compacted under vertical stress and then sheared in undrained conditions by applying two shear stresses acting in different horizontal directions. Test results indicated that the cyclic strain, pore water pressure ratio, and cyclic strength were significantly determined by the value of stage amplitude ratios and the CSRs: at the same CSR, cyclic strains, and pore water pressure increased while cyclic strength decreased with the Ar. Comparing the test data between various cyclic stress ratios found that the CSRs can accelerate shear strains, pore pressure accumulation, and cyclic strength attenuation.

Reliability and Validity of Cycling Sprint Performance at Isolinear Mode Without Torque Factor: A Preliminary Study in Well-Trained Male Cyclists

ABSTRACT Purpose: This study aimed to compare the performance-derived parameters utilizing isolinear (ISOLIN) and isovelocity (ISOVEL) sprint cycling modes. Method: For that, 20 male trained cyclists performed 2 sprints of 7 s on an electromagnetically braked cycle ergometer in ISOLIN and six sprints in ISOVEL mode with cadences between 90 and 180 rpm, each separated by 3-min. A linear function modeled the sprints within each mode to extrapolate maximal cadence (CMAX) and torque (TMAX), and a quadratic function was used to extrapolate the apex defined as optimal cadence power (OPTCAD) and peak power output (PMAX). Fifteen subjects performed another 4 sprints at ISOLIN mode on different days to verify the reliability. Results: The measures from the power-cadence relationship were not different between the ISOLIN and ISOVEL modes. Although significant differences were detected in the T-C relationship, TMAX was greater at ISOLIN than ISOVEL (p = .006). On the other hand, CMAX was higher at ISOVEL than ISOLIN (p < .001). The correlation between parameters was large to very large (r = 0.51 to 0.89). However, high limits of agreement were verified. The ISOLIN presented consistency during the trials, and the random errors were acceptable (CV = 5.3% to 11.5%). Conclusion: Using the power-cadence relationship, PMAX and OPTCAD could be detected similarly between the two sprint modes (ISOLIN and ISOVEL). Thus, the findings demonstrated that a single ISOLIN sprint test could be a suitable tool for quantifying the time course of muscle fatigue during and after cycling exercises in well-trained male cyclists.

Hypoxic, blood flow restriction, or eccentric cycling: Which training intervention is the most effective in elderly individuals?

Introduction&#x0D; The global rise in the elderly population is accompanied by an increased incidence of non-communicable diseases, including cancers, cardiovascular conditions, or sarcopenia. Therefore, it becomes crucial to find effective strategies to delay the onset or slow down the progression of these diseases. Hypoxic (HYP), blood flow restriction (BFR), and eccentric (ECC) training are promising modalities to mitigate the effects of aging. However, these training strategies have never been compared. Thus, this study aimed to evaluate whether moderate-intensity intermittent training (MIIT) combined with HYP, BFR, or ECC can induce similar or greater effects in strength and muscle mass in the elderly, compared to traditional cycling training (CON).&#x0D; Methods&#x0D; Fifty-five elderly participants completed a four-week MIIT protocol on cycle ergometers, divided into HYP, BFR, ECC, and CON groups. The HYP group trained under hypoxic conditions (inspired oxygen fraction ~14%), BFR group used occlusion cuffs applied proximally on thighs (~350 mmHg occlusion pressure), ECC group trained with an eccentric cycle-ergometer, and the CON group underwent standard cycling training. The first week consisted of 3 sets of 5 min exercise followed by 5 min rest and an additional set was added each week. All groups maintained a 60-rpm cadence, with intensity set at a 14-perceived exertion level on the 6-20 Borg scale.&#x0D; Strength parameters were assessed via isokinetic tests at angular velocities of 30°/s, 90°/s, and 180°/s, as well as isometric and endurance tests. Endurance strength was calculated as a percentage decrement score during 30 repetitions at 180°/s and the rate of force development was calculated on the isometric test.&#x0D; Muscle-bone cross-sectional area (CSA) was measured by integrating thigh circumference measured using a measuring tape, and anterior and posterior adipose tissue thickness assessed with a B-mode ultrasound.&#x0D; Results&#x0D; Post-training, all groups showed increased isometric quadriceps strength (14 ± 15%, p &lt; 0.001) and strength at all angular velocities: 18 ± 17% and 15 ± 21% (30°/s), 17 ± 20% and 20 ± 26% (90°/s), 10 ± 14% and 10 ± 16% (180°/s) for quadriceps and hamstrings respectively, all P &lt; 0.001. No significant group interaction effects were noted, except for hamstring strength at 30°/s (P = 0.038), with no improvements in the ECC group. No changes in the rate of force development or dynamic endurance post-training were noted. Thigh circumference increased (1 ± 2%, p = 0.008), without difference between training modalities.&#x0D; No significant variations in adipose tissue thickness or muscle-bone CSA occurred. The ECC group had higher training intensity (173.2 ± 7.5 W) than HYP (169.6 ± 9.8 W), BFR (169.9 ± 11.6 W), and CON (169.6 ± 8.4 W) groups (p &lt; 0.001). Training heart rate was lower in ECC (104.5 ± 6.6 bpm) compared to BFR (117.5 ± 10.5 bpm; p = 0.007) and CON (122.2 ± 12.3 bpm; p = 0.001), but similar to HYP (112.2 ± 9.4 bpm).&#x0D; Discussion/Conclusion&#x0D; MIIT, regardless of modality, effectively improves muscle strength in the elderly. Unexpectedly, no single training method was superior. Power output reduction has been proposed as an advantage of HYP and BFR modalities but was not observed in the present study. These results advocate for a personalized approach to training prescriptions, considering individual preferences and health conditions. Future research should explore longer training durations and impacts on other health outcomes such as cardiovascular and respiratory health.

Percolation behavior and sensing performance of polypropylene‐based conductive polymer composites under compressive strains and temperature

AbstractPercolation behavior is highly significant for mechanical, thermal, and electrical properties, as well as manufacturing processes of conductive polymer composites (CPCs). It has been reported that temperature and external loads are important parameters directly affecting the percolation threshold. Herein, carbon black/polypropylene (CB/PP) and carbon black/multiwalled carbon nanotubes/polypropylene (CB/MWCNTs/PP) composites are prepared via the melt blending method. After the synthesis of composites, the rheological properties, the filler distribution, crystallization, and conductive network formation within the composite are evaluated. The effect of conductive network structure on conductive percolation behavior is studied under various compressive strains and temperatures. Finally, the sensing performance under compressive strain and temperature cycling is discussed. Obtained results reveal that MWCNTs work as “bridges” between segregated CB particles leading to a synergic effect on the conducting properties. The volume resistivity of PP‐based CPCs exhibits a critical strain and a positive temperature coefficient (PTC), resulting in altered percolation. PP‐based CPCs with the addition of MWCNTs have greater PTC intensity, demonstrating sensing stability and sensitivity to compressive strain under temperature cycling. This study underscores the essential contribution of MWCNTs in building conductive networks and elucidates the potential application of PP‐based CPCs with superior sensing performance under compressive strain and varying temperatures.

Contemporary development of educators in the context of digitalisation of education

Relevance. The relevance of the article research is determined by the problem of improving the quality of the educational environment through the wide implementation of various modern innovative means of information and communication technologies, which will expand the capabilities of the educational process. Purpose. The aim of the article is to develop a model of professional information and communication competence formation among educators. Methodology. Leading methods for studying this problem included diagnostic testing “Determination of the style of interpersonal interaction” developed by S. V. Maximov, Y. A. Lobeiko, and “Self-assessment of professional and pedagogical motivation” adapted by N. P. Fetiskin, which allow determining the personal interest of educators to acquire new information and communication technologies and use them in their work in terms of manifestation of educational creative communication within the effective enhancement of the level of informative, accessibility of the teaching and educational process. Results. The article presents a model of development of information and communication competence of educators within the framework of using modern technologies in pedagogical activity, which includes a timely study of information and communication developments and the creation of several schemes of their successful use in conditions of preserving health saving learning environment, for the solution of pedagogical issues and improvement of the educational process which was proposed within the framework of creation and introduction of the training cycle “Pedagogical methods with the use of ICT” with the same name into the sphere of practical education. Conclusions. There, in the factor of obtaining a pedagogical speciality or upgrading this professional qualification educators will acquire knowledge and practical skills in the use in the practice of verification of domestic work, conducting classes, strengthening information and communication contacts through the exploitation of existing developments in the area of information and communication technology, which will have practical significance in the training of highly qualified personnel in the educational sphere.

Fatigue Characteristics of Steel–Concrete Composite Beams

Fatigue in steel–concrete composite beams can result from cyclic loading, causing stress fluctuations that may lead to cumulative damage and eventual failure over an extended period. In this paper, the experimental findings from fatigue loading tests on composite beams with various arrangements are presented. Fatigue tests were performed up to 1,000,000 cycles using four-point loading, encompassing various ranges of shear stress at a consistent amplitude. Additionally, the effects of external post-tensioning and the strength of the shear connection were investigated. Static tests were run until failure to assess the enduring strength of the specimens subjected to fatigue. The cyclic mid-span deflections, slippages, and strains were measured during the testing. Based on the experimental findings, it was found that the damage region that the shear studs caused in the concrete slab, which resulted in a reduction in stiffness within the shear connection, grew as the loading cycles increased, leading to an increase in residual deflections and plastic slippages. Controlling the longitudinal fatigue cracks in the concrete slab was largely dependent on the strength of the shear connection between the steel beams and concrete slabs. Moreover, the applied fatigue loading range affected the propagation and distribution of fatigue cracks in the concrete slab. The strains in different parts of the composite specimens were significantly reduced by applying the external post-tensioning. With no signs of distress at the anchors, the tendons displayed excellent fatigue performance.

Regulation of YAP Promotor Accessibility in Endothelial Mechanotransduction.

Endothelial cells are constantly exposed to mechanical forces in the form of fluid shear stress, extracellular stiffness, and cyclic strain. The mechanoresponsive activity of YAP (Yes-associated protein) and its role in vascular development are well described; however, whether changes to transcription or epigenetic regulation of YAP are involved in these processes remains unanswered. Furthermore, how mechanical forces are transduced to the nucleus to drive transcriptional reprogramming in endothelial cells is poorly understood. The YAP target gene, AmotL2 (angiomotin-like 2), is a junctional mechanotransducer that connects cell-cell junctions to the nuclear membrane via the actin cytoskeleton. We applied mechanical manipulations including shear flow, stretching, and substrate stiffness to endothelial cells to investigate the role of mechanical forces in modulating YAP transcription. Using in vitro and in vivo endothelial depletion of AmotL2, we assess nuclear morphology, chromatin organization (using transposase-accessible chromatin sequencing), and whole-mount immunofluorescent staining of the aorta to determine the regulation and functionality of YAP. Finally, we use genetic and chemical inhibition to uncouple the nuclear-cytoskeletal connection to investigate the role of this pathway on YAP transcription. Our results reveal that mechanical forces sensed at cell-cell junctions by the YAP target gene AmotL2 are directly involved in changes in global chromatin accessibility and activity of the histone methyltransferase EZH2, leading to modulation of YAP promotor activity. Functionally, shear stress-induced proliferation of endothelial cells in vivo was reliant on AmotL2 and YAP/TAZ (transcriptional coactivator with PDZ-binding motif) expression. Mechanistically, uncoupling of the nuclear-cytoskeletal connection from junctions and focal adhesions led to altered nuclear morphology, chromatin accessibility, and YAP promotor activity. Our findings reveal a role for AmotL2 and nuclear-cytoskeletal force transmission in modulating the epigenetic and transcriptional regulation of YAP to maintain a mechano-enforced positive feedback loop of vascular homeostasis. These findings may offer an explanation as to the proinflammatory phenotype that leads to aneurysm formation observed in AmotL2 endothelial deletion models.

The impact of a training cycle on statistics and probability for future primary schoolteachers with a gender-focused approach within the framework of education for sustainable development

This study explores a training cycle in statistics and probability for future primary school teachers, aimed at fostering gender equality and education in sustainable development. By implementing methodologies such as lesson study and didactic-mathematical knowledge and competencies model, an intervention was conducted with two groups of future teachers: the first group comprised 16 participants, while the second had nine, with the latter receiving an enhanced version of the training cycle. The assessment was carried out using content analysis and tests before and after the cycle, in addition to focus groups with the second group. The findings indicate improvements in pedagogical skills, gender equality, and knowledge in statistics and probability, underscoring the effectiveness of the training cycle. It is concluded that, despite the lack of notable differences between the two versions of the training cycle, it is effective in its educational aim and in raising awareness on sustainability issues.

Effects of concentric and eccentric cycling training on muscular hemodynamic and erythrocyte rheological responses to exercise in sedentary males

AbstractErythrocyte rheological properties contribute to the dynamic regulation of vascular resistance to flow shear force, facilitating blood delivery from the heart to peripheral tissues. Despite improved physical performance, the effects of eccentric cycling training (ECT) on erythrocyte rheological characteristics remain unclear. This study investigates the distinct effects of ECT and concentric cycling training (CCT) on muscular hemodynamic and erythrocyte rheological responses to exercise. Thirty‐nine sedentary healthy males were randomly assigned to either ECT (n = 13) or CCT (n = 13) at 45%–70% of the maximal workload for 30 min/day, 5 days/week for 6 weeks, or to a control group (n = 13) that did not receive any exercise intervention. A graded exercise test (GXT) was performed before and after the intervention. Muscular hemodynamic and erythrocyte rheological responses to the GXT were determined by near‐infrared spectroscopy and ektacytometry, respectively. Both ECT and CCT significantly enhanced perfusion (Δ[THb]VL) and O2 extraction (Δ[HHb]VL) in vastus lateralis during GXT. Before training, an acute GXT significantly reduced erythrocyte deformability and increased aggregability, whereas after 6 weeks of either ECT or CCT, the extent of erythrocyte rheological changes caused by GXT was diminished. Moreover, CCT elicited higher improvements in cardiac output (CO), VO2, and work‐rate at peak performance than ECT. In hierarchical regression, the change of maximal CO was the most influential factor affecting VO2max following CCT. In contrast, enhanced VO2max was significantly associated with Δ[HHb]VL and erythrocyte aggregability/deformability in ECT. Although CCT is superior to ECT for increasing aerobic capacity, either ECT or CCT effectively enhances aerobic efficiency by improving muscular hemodynamic and erythrocyte rheological responses to exercise.

Experimental study of the damage characteristics of rocks containing non-penetrating cracks under cyclic loading

The damage evolution process of non-penetrating cracks often causes some unexpected engineering disasters. Gypsum specimens containing non-penetrating crack(s) are used to study the damage evolution and characteristics under cyclic loading. The results show that under cyclic loading, the relationship between the number of non-penetrating crack(s) and the characteristic parameters (cyclic number, peak stress, peak strain, failure stress, and failure strain) of the pre-cracked specimens can be represented by a decreasing linear function. The damage evolution equation is fitted by calibrating the accumulative plastic strain for each cycle, and the damage constitutive equation is proposed by the concept of effective stress. Additionally, non-penetrating cracks are more likely to cause uneven stress distribution, damage accumulation, and local failure of specimen. The local failure can change the stress distribution and relieve the inhibition of non-penetrating crack extension and eventually cause a dramatic destruction of the specimen. Therefore, the evolution process caused by non-penetrating cracks can be regarded as one of the important reasons for inducing rockburst. These results are expected to improve the understanding of the process of spalling formation and rockburst and can be used to analyze the stability of rocks or rock structures.

Rapid Self-Healing Hydrogel with Ultralow Electrical Hysteresis for Wearable Sensing.

Self-healing hydrogels are in high demand for wearable sensing applications due to their remarkable deformability, high ionic and electrical conductivity, self-adhesiveness to human skin, as well as resilience to both mechanical and electrical damage. However, these hydrogels face challenges such as delayed healing times and unavoidable electrical hysteresis, which limit their practical effectiveness. Here, we introduce a self-healing hydrogel that exhibits exceptionally rapid healing with a recovery time of less than 0.12 s and an ultralow electrical hysteresis of less than 0.64% under cyclic strains of up to 500%. This hydrogel strikes an ideal balance, without notable trade-offs, between properties such as softness, deformability, ionic and electrical conductivity, self-adhesiveness, response and recovery times, durability, overshoot behavior, and resistance to nonaxial deformations such as twisting, bending, and pressing. Owing to this unique combination of features, the hydrogel is highly suitable for long-term, durable use in wearable sensing applications, including monitoring body movements and electrophysiological activities on the skin.