Children and adolescents with attention deficit hyperactivity disorder (ADHD) often struggle with motor skill performance, which can reduce their participation in sports and physical activities. This may be due to a lack of personal relevance and a sensitivity to controlling environments that reduce motivation. Since autonomy support has been shown to enhance motor performance across different motor tasks and populations, this study aimed to investigate its effects on the immediate motor performance of adolescents with ADHD during a maximum force production task. Twenty-six adolescents aged 13 to 15 (mean age=14.1years, 20 boys and 6 girls) participated in a within-subjects experimental design, where each performed six maximum force attempts (three attempts each hand) using a dynamometer under two conditions: choice and no-choice. In the choice condition, participants selected the order in which they used their preferred and non-preferred hands, while in the no-choice condition, they completed six attempts in an order that matched the sequence chosen by the previous participant. A 20-s rest was given between each attempt. Once participants had finished six attempts in each condition, they were asked to fill out the Intrinsic Motivation Inventory. The results showed that maximum force production, as well as self-reported interest/enjoyment, and perceived competence, were all higher in the choice condition compared to the no-choice condition. No significant differences were found in the perception of choice or pressure/tension. These findings suggest that even small opportunities for autonomy-support can improve motor performance and positively influence factors that predict intrinsic motivation specifically, interest/enjoyment and perceived competence, in adolescents with ADHD.

Unleashing new-quality productive forces: Reconsidering the impact of data-factor marketization

The mechanism and effects of new quality productive forces driving the improvement of employment quality

Ageing induces structural and functional changes in the neuromuscular systems that impair voluntary force production, compromising daily function and wellbeing. We examined whether older adults preserve the capacity for motor unit adaptations to a short-term strength training intervention previously shown to enhance neural drive to muscle in young adults. Twenty‑three older adults were assigned to a training group (INT, n=13, 71 ± 4 years of age) or a control group (CON, n=10, 69 ± 2 years of age) and completed pre- and postintervention assessments of ankle dorsiflexor maximal voluntary force (MVF). Motor unit behaviour was analysed from high‑density surface EMG recorded from tibialis anterior during submaximal trapezoidal contractions. The INT group performed a 4week supervised isometric strength training programme, whereas the CON group maintained habitual activity. High‑density surface EMG signals were decomposed into individual motor units, tracked longitudinally across sessions. Training increased MVF by 17.6% and enhanced motor unit discharge rate at recruitment (+8.2%, P=0.031) and constant force (+11.3%, P < 0.001), without changes in recruitment or derecruitment thresholds. Estimates of persistent inward currents (delta frequency) increased (+1.0pulses per second) and were positively correlated with changes in discharge rate, which, in turn, were correlated with gains in MVF (rrm=0.54-0.57, P < 0.05). This pattern suggests that enhanced intrinsic excitability and synaptic input to motor neurons contributed to improvements in strength. These results demonstrate that, despite age-related motor unit remodelling, the ageing nervous system remains responsive to targeted strength training, preserving the capacity for meaningful neural adaptations. KEY POINTS: We assessed whether a short-term intensive strength training intervention, previously shown to increase spinal motor output to the muscle significantly in young adults, would also be effective in older adults. High-density surface EMG was used to identify and longitudinally track the same motor units before and after a 4week isometric strength training intervention. We found significant strength gains in older adults, with the increase in muscle force output being positively associated with higher motor unit discharge rate and persistent inward currents, indicating that neural drive enhancement was a key contributor to the observed improvements in force. Despite age-related motor neuron remodelling, the older nervous system remains highly responsive to strength training, exhibiting qualitatively similar but attenuated motor unit adaptations compared with young adults.

The digital age has stimulated innovation momentum and brought about new types of digital risks. Legislative guarantee for scientific and technological innovation is the key to driving the new productive forces and supporting the high-quality development of the digital economy. At present, the national-level legislation on scientific and technological innovation in China presents a pattern of "strategic guidance - legislative strengthening - reform guarantee". However, in legislative practice, Anhui is faced with three dilemmas: the lack of digital justice in the legislative mechanism, the ineffective connection between legislative content and the development needs of new productive forces, and the insufficient integration and absorption of digital governance practice in the legislative process. To this end, with the allocation of rights and obligations as the basic category and liability regulation clauses as the normative carrier, an institutional framework should be constructed from three dimensions: comprehensive value guidance, innovation-oriented encouragement, and prudent and inclusive supervision. This will realize the in-depth integration of legal norms for scientific and technological innovation and local governance practice, and provide a solid legal guarantee for Anhui to build a source of scientific and technological innovation.

ABSTRACT The development of comprehensive demonstration cities for energy conservation and emission reduction fiscal policies, as a targeted green policy instrument, serves as a critical measure in advancing China’s ‘dual carbon’ goals. Based on data from Chinese A-share listed companies spanning 2006 to 2022, this study employs the establishment of such demonstration cities as a quasi-natural experiment and constructs a staggered difference-in-differences model to systematically examine the impact of these fiscal policies on environmental investment by heavily polluting enterprises. The findings indicate that the policies significantly promote environmental investment by heavily polluting firms, and this conclusion remains robust after addressing endogeneity through methods Mechanism analysis reveals that the policies primarily operate by alleviating corporate financing constraints and enhancing green innovation capabilities. Heterogeneity analysis further shows that the policy effects are more pronounced among non-state-owned enterprises, firms with higher ownership concentration, those located in non-resource-based cities, and enterprises in eastern regions, thereby confirming the differential marginal effects of the policies. This study highlights the positive role of energy conservation and emission reduction fiscal policies in stimulating corporate green investment and fostering value creation, providing valuable empirical evidence to cultivate new green productive forces.

This study examined whether differences in countermovement jump (CMJ) and isometric mid-thigh pull (IMTP) force-time metrics exist between starters and non-starters in professional female basketball players. Twenty-two athletes (7 starters, 15 non-starters) competing in the first Spanish basketball league completed CMJ and IMTP testing using dual force plate system. CMJ variables included jump height, peak and mean braking and propulsive force, time-to-takeoff, and net impulse. IMTP variables included peak force and rate of force development (RFD) at 0-100 and 0-250 ms. Independent t-tests and Hedges' g effect sizes were used to assess between-group differences. No statistically significant differences were observed between starters and non-starters for any CMJ or IMTP force-time metrics of interest (p > 0.05). Both groups displayed similar values in jump height, force production, and RFD, with effect sizes ranging from small to moderate (g = 0.04-0.49). However, starters were significantly older than non-starters (p = 0.018), while no differences were found in body mass and height (p > 0.05). Overall, the findings of the present study indicate that, at the professional level of play, CMJ and IMTP performance characteristics are not capable of distinguishing starters from non-starters in women's basketball. Starting status may be shaped more by competitive experience, technical proficiency, and tactical awareness. Although monitoring neuromuscular performance remains valuable, player selection and role differentiation appear to depend more on skill execution and contextual game demands than on strength characteristics alone.

New quality productive forces, as a new type of productive forces centered on technological innovation, exert a significant influence on rural revitalization. Based on panel data from 31 provinces in China during 2012–2022, this study thoroughly investigates the impact of new quality productive forces on rural revitalization and its underlying mechanism. The findings reveal that the development of new quality productive forces significantly promotes rural revitalization. Mediation effect analysis demonstrates that new quality productive forces can further advance rural revitalization by fostering education equity. Drawing on these conclusions, it is recommended to strengthen the driving role of new quality productive forces to consolidate the technological foundation for rural revitalization, deepen the “technology education revitalization” mediation pathway, and amplify empowerment effectiveness through education equity.

The dissemination and application of modern technologies represented by electronic information technology and other advanced new productive forces are constantly deepening in various fields. How to effectively leverage these forces to achieve digital supply of public services has become a highly concerned issue. Currently, the digital supply of public services is confronted with challenges such as value fragmentation, technological rigidity, and social disruptions caused by inconsistent information. This study adopts case analysis and comparative methods, and proposes that in the process of providing public services digitally, attention should be paid to balancing the multi-dimensional values of technology and humanism.

High-G flight presents extreme neuromuscular and cardiovascular challenges, particularly for fighter pilots exposed to repeated accelerative stress. While traditional training emphasizes aerobic capacity and dynamic strength, these paradigms often fail to reflect the static, posture-bound demands of flight operations. The constrained cockpit environment, combined with helmet and night vision goggle (NVG) load, creates persistent axial stress on the cervical and lumbar spine, while G-onset imposes lower limb and lumbar tensing requirements to preserve cerebral perfusion. These realities position isometric strength training (IST), characterized by force production without joint movement, as a biomechanically superior approach for enhancing G-tolerance, posture stability, and injury resilience. This narrative review integrates current evidence on task-specific muscular demands in tactical aviation and presents isometric strategies as a low-cost, high-transfer training modality. It emphasizes the distinction between yielding (HIMA) and overcoming (PIMA) isometrics, maps these to specific flight tasks (e.g., cervical holding under load, Anti-G straining maneuver tensing), and outlines pragmatic assessment protocols using field-accessible tools such as handheld dynamometry and endurance hold benchmarks. The review further proposes region-specific programming (neck, trunk, lower limb) and embeds these within realistic operational schedules through micro-sessions and warm-up integration. Adopting IST across the pilot training continuum offers three major operational advantages: improved G performance via muscular tensing and vascular compression, reduced in-flight fatigue through enhanced isometric endurance, and fewer musculoskeletal injuries by reinforcing high-risk anatomical regions under strain. This work advocates for formalized implementation of isometric protocols as a foundational element in aircrew conditioning, supported by targeted research into normative data, dose-response, and performance outcomes.

Introduction: Muscle function is influenced by hydroelectrolytic mechanisms that regulate cellular volume beyond isolated plasma electrolyte concentrations. However, the role of integrated hydration and electrolyte regulation profiles in muscle function among older adults remains insufficiently understood. Objective: To identify which physiological domains of hydroelectrolytic regulation are most strongly associated with muscle strength and functional performance in community-dwelling older adults. Methods: A cross-sectional study was conducted in 96 community-dwelling individuals aged ≥ 70 years. Markers of cellular hydration and membrane integrity were assessed using bioelectrical impedance analysis, together with first-morning fasting plasma and urinary sodium and chloride concentrations. Principal component analysis (PCA) was applied as a data-driven approach to identify latent domains of coordinated hydroelectrolytic regulation. Associations between component scores and handgrip strength and Timed Up and Go (TUG) were examined using two sequential multivariable regression models: Model 1 adjusted for sex and fat-free mass index (FFMI); Model 2 additionally adjusted for age, hypertension, and diuretic use. Results: Three principal components were retained, explaining 77.5% of total variance: PC1 (renal-cellular domain), PC2 (plasma electrolyte domain), and PC3 (cellular volume domain). For handgrip strength, Model 1 showed significant associations for PC3 (β = 0.152; p = 0.025) and PC1 (β = 0.180; p = 0.050). In Model 2, only PC3 remained independently associated (β = 0.146; p = 0.036). For TUG, Model 1 showed associations for PC1 (β = -0.262; p = 0.049) and PC3 (β = -0.238; p = 0.015). In Model 2, PC1 (β = -0.308; p = 0.019) and PC2 (β = -0.190; p = 0.046) remained independently associated, whereas PC3 was not. Conclusions: Maximal force production appears primarily associated with cellular volume regulation, whereas functional performance reflects broader multi-compartmental hydroelectrolytic integration involving renal and plasma domains. These findings suggest that multidimensional hydration profiling may complement isolated biochemical markers in the functional assessment of older adults, warranting validation in longitudinal studies.

Many invertebrates have obliquely striated muscles, in which neighboring thin and thick filaments are staggered and aligned obliquely. This type of muscle allows force production over a wide range of lengths and is beneficial for soft-bodied animals. Unlike vertebrate cross-striated muscles, most of obliquely striated muscles lack distinct Z-lines and, instead, have dense bodies. Because the dense bodies are located in the middle of the I-bands and contain α-actinin, the dogma is that dense bodies are equivalent to the Z-lines anchoring the actin barbed ends. However, we show that the barbed ends of sarcomeric actin filaments in the nematode Caenorhabditis elegans body wall muscle are aligned linearly without converging at the dense bodies. Colocalization of F-actin and ATN-1/α-actinin was negatively correlated. CAP-1, an α-subunit of capping protein/CapZ, was linearly aligned without concentration at the dense bodies independently of ATN-1. Depletion of the capping protein subunit, CAP-1 or CAP-2, caused embryonic or larval lethality with severe actin disorganization in muscle, indicating that barbed-end regulation by capping protein is essential for sarcomere assembly. These results contradict the current view of the sarcomere organization in C. elegans muscle and suggest a new model of a linear Z-line-like arrangement of actin barbed ends.

Measures of hemiparetic ankle dorsiflexor muscle strength and rate of force development (RFD) are often used to determine the efficacy of rehabilitation interventions after stroke. However, evidence supporting the reliability of these measures is limited. This brief report provides a secondary analysis investigating the between-session reliability of isometric ankle dorsiflexor muscle strength, rate of force development (RFD), and tibialis anterior electromyography (TA EMG), in people with chronic stroke. Participants (n=15) completed three maximal isometric contractions of the ankle dorsiflexor muscles as fast as possible using a rigid dynamometer. Tests were repeated seven days later. Outcomes included ankle dorsiflexor isometric maximal voluntary contraction (MVC), RFD in the first 200ms (RFD200ms), time to reach 90% MVC, and peak TA EMG. Data were analysed for 13 participants using intra-class correlation coefficients (ICC) and standard error of the measure percentage (SEM%). Reliability was higher when analysing the mean of three trials rather than the best of three trials. There was excellent reliability for isometric dorsiflexor MVC (ICC 0.97 [95% CI 0.92, 0.99], SEM% 7%). However, for other outcomes, while the ICC indicated good reliability, the lower bound of the 95% confidence interval of the ICC fell in the moderate range for TA EMG (ICC 0.86 [95% CI 0.60, 0.96], SEM% 25%) and time to reach 90% MVC (ICC 0.80 [95% CI 0.53, 0.93], SEM% 23%) and in the poor range for dorsiflexor RFD200ms (ICC 0.79 [95% CI 0.48, 0.92], SEM% 24%). The findings raise concerns about the reliability of measures of rapid force production in the dorsiflexor muscles after stroke. Given the functional significance of the ankle dorsiflexors, larger studies should be conducted to further investigate these concerns and explore reliable methods for measuring rapid force production in the hemiparetic dorsiflexor muscles.

ABSTRACT This paper provides a critical discourse analysis of core elements of Xi Jinping’s views on science, technology and innovation. The theoretical framework focuses on the political ideologies shaping Xi’s approaches, and relates these to governance models for scientific research and innovation. The paper traces Xi Jinping’s grounding in Marxist ideology as revealed in his promotion of the concept of new quality productive forces. Moreover, it identifies a scientistic approach that underpins Xi’s discursive embrace of a linear model of innovation and compares this to emerging eco-innovation models. Finally, it identifies how patriotism shapes Xi’s emphasis on self-reliance and self-strengthening for high-tech innovation in China. A key contribution of the paper is to offer a new theoretical interpretation of key ideologies and theories that have shaped China’s governance of science, technology and innovation in more than two decades.

Since the discovery of the cardiac isoform of myosin-binding protein-C (cMyBP-C), there has been continued interest in how cMyBP-C impacts cardiac function in both health and disease. cMyBP-C is a regulatory protein in the sarcomere that controls beat-to-beat changes in contractility in response to dynamic environmental demands placed upon the heart. Changes in force production during the contractile cycle are modulated through interactions of cMyBP-C with myosin and actin. Post-translational modifications (PTMs) of cMyBP-C, of which phosphorylation has received the most attention, are critical to the function of cMyBP-C in the healthy heart and is affected in many disease states. While each of the PTMs that will be discussed in this review have known and often widespread effects on important cellular processes spanning transcriptional regulation, cell signaling, and metabolism, their impact on cMyBP-C function remains poorly understood and in some cases unverified. This Review focuses on the current understanding of cMyBP-C PTMs, namely phosphorylation, S-glutathionylation, S-nitrosylation, acetylation, citrullination, carbonylation, and O-GlcNAcylation. The potential for PTMs to exert wide ranging and likely nuanced effects may influence the range of cMyBP-C's response to varied conditions and may offer opportunities to identify novel therapeutic paradigms in the setting of disease.

Animal models and human 2D culture models have been instrumental for investigating skeletal muscle diseases and the development of therapeutics. However in vivo models and 2D cultures are limited in their translation to clinical application. These limitations are most evident through the success of myostatin inhibitors for improving mass and function in mice studies followed by unsuccessful clinical trials in patients with sarcopenia and Duchenne Muscular Dystrophy (DMD) (3-4). Although clinical trials of myostatin inhibitors have often reported increases in lean muscle mass, efficacy endpoints of improved muscle function are typically not achieved (3-4). Additionally, studies of age-related muscle atrophy, sarcopenia, have unique barriers to translation such as age-related gene expression changes and sex related muscle aging that is not conserved between species (1-2). Due to these challenges, our team developed a donor-derived 3D skeletal muscle platform housed in standard 24-well imaging plates. This platform was then utilized to investigate retention of sex- specific characteristics in 3D muscle cultures and the effectiveness of astaxanthin (ASTX) to improve contractile signaling and function in healthy and clinically sarcopenic 3D cultures. Initial characterization and validation were carried out in samples from healthy male and female donors. Contractile function recorded through digital image correlation (DIC) analysis during electrical stimulation was similar between male and female 3D muscles, but females displayed elevated type 1 fiber proportions compared to males. Female muscle also displayed elevated levels of OPA1 and TFAM protein levels along with decreased Akt signaling. Overall, female muscle exhibited a greater reliance on mitochondrial energy utilization and reduced protein synthesis indicating retention of sex-specific characteristics in 3D culture. Samples from young female and clinically sarcopenic female donors were studied in this platform for functional differences in force production, fatigue susceptibility, and contractile protein signaling following fatigue with or without astaxanthin antioxidant therapy. Astaxanthin was assessed at 1μM, 10μM, and 25μM in young cultures and only 10μM in sarcopenic cultures due to limitations in cell quantity for 7 days. Although there were no significant effects on force outputs or fatiguability for either group, 10μM rescued P38 and Akt signaling in the sarcopenic samples restoring levels to those exhibited by young DMSO- treated controls. Additionally, 10μM and 25μM in the young cohort suppressed Akt signaling indicating astaxanthin may negatively impact this critical pathway for exercise adaptation in healthy muscle. Although astaxanthin did not improve functional performance in the clinically sarcopenic or young female 3D muscle samples, clenbuterol was evaluated as a positive control for improving performance in young muscle and showed a nearly two-fold increase in both twitch and tetanic force response in 1μM treated samples compared to DMSO controls. These findings support the utilization of this muscle platform for assessing functional differences among drug treatments and untreated donor groups.

Finger flexor and extensor muscles load sharing: Effect of the climbing grip technique.

Maximal force production capacities are essential for skiing performance. Despite the evidence of dynamic demands and fatigue during racing, the relative importance of maximal, explosive, and endurance strength capacities remains unclear. The aim of this study was to investigate the specific association between lower-limb isometric maximal, rate of force development, and critical force to event-specific skiing performance. Fifty-nine skiers were recruited from national (NAT, n = 24) and regional (REG, n = 35) levels. Skiers had their isometric maximal force (Fmax), maximal rate of force development (RFDmax), and critical force (CF) assessed on a leg press ergometer. NAT skiing performance in each skiing event (Slalom, Giant-Slalom, Super-G, Downhill) was defined as FIS points. For REG skiers, performance was represented in their total time to complete a controlled giant-slalom race. Force production capacities were compared between NAT and REG using independent t-tests, with the contribution of each force production capacity to performance (event-specific FIS points for NAT and experimental race time for REG) assessed via stepwise linear regression models. The alpha value was set at 0.05. NAT presented higher Fmax (Hedges'g = 1.21, p < 0.001), RFDmax (g = 1.01, p < 0.001), and CF (g = 1.88, p < 0.001) than REG. For NAT, performance in Slalom was associated with RFDmax (R2 = 0.213) while CF was the sole predictor for Giant-Slalom (R2 = 0.256), Super-G (R2 = 0.209), and Downhill (R2 = 0.488). For REG, variance in race time was substantially explained by CF (model R2 = 0.683). This study provides evidence of an event-specific relationship between performance and force production capacities and notably the importance of isometric critical force.

Multi-dimensional integrated development strategy for urban rail transit optimized via a carbon emission model driven by new quality productive forces

How new quality productive forces affect income disparities within enterprises: a work tasks perspective