Power Deficit Research Articles

Hopping kinetic differences in masters runners with and without Achilles tendinopathy

ABSTRACT Achilles tendinopathy (AT) is the most common running-related pathology among masters runners. Previous evidence suggests there are no differences in submaximal running biomechanics between masters runners with and without AT. Evidence suggests lower extremity power deficits are common among ageing individuals and those with AT. The single-leg horizontal hop (SLHH) test is a valid and reliable lower extremity power test. The purpose of this study was to investigate differences in SLHH biomechanics between masters runners with and without AT. 32 masters runners age 50 and older with AT (60.31 ± 8.37, n = 16) and without (59.94 ± 4.95 n = 16) were included. 3D motion capture and force plates were used to assess hopping biomechanics. Masters runners with AT had significantly lower peak ankle plantarflexion positive power peak hip extensor positive power and peak hip extension moments compared to healthy controls. No differences in peak ankle plantarflexion moments and knee kinetics were observed between groups. Masters runners with AT demonstrate altered lower extremity biomechanics during the propulsive phase of the SLHH, suggesting they may not be able to appropriately generate forces and release stored energy from the Achilles tendon during maximal efforts.

Resting-State EEG Oscillations in Amyotrophic Lateral Sclerosis (ALS): Toward Mechanistic Insights and Clinical Markers

Introduction: Amyotrophic lateral sclerosis (ALS) is a complex, progressive neurodegenerative disorder characterized by the degeneration of motor neurons in the brain, brainstem, and spinal cord. Several neuroimaging techniques can help reveal the pathophysiology of ALS. One of these is the electroencephalogram (EEG), a noninvasive and relatively inexpensive tool for examining electrical activity of the brain with excellent temporal precision. Methods: This mechanistic review examines the pattern of resting-state EEG activity. With a focus on publications published between January 1995 and October 2024, we carried out a comprehensive search in October 2024 across a number of databases, including PubMed/Medline, Research Gate, Google Scholar, and Cochrane. Results: The literature search yielded 17 studies included in this review. The studies varied significantly in their methodology and patient characteristics. Despite this, a common biomarker typical of ALS was found—reduced alpha power. Regarding other oscillations, the findings are less consistent and sometimes contradictory. As this is a mechanistic review, three possible explanations for this biomarker are provided. The main and most important one is increased cortical excitability. In addition, due to the limitations of the studies, recommendations for future research on this topic are outlined to enable a further and better understanding of EEG patterns in ALS. Conclusions: Most studies included in this review showed alpha power deficits in ALS patients, reflecting pathological hyperexcitability of the cerebral cortex. Future studies should address the methodological limitations identified in this review, including small sample sizes, inconsistent frequency-band definitions, and insufficient functional outcome measures, to solidify and extend current findings.

Local climate action from the middle-out: the social potential of craft guilds to facilitate low-carbon installations in Germany

Shortages of skilled workers and special expertise in the crafts and trades hamper the implementation of low-carbon transitions in many countries. However, research on effective governance arrangements targeting this ‘installation bottleneck’ is limited. To fill this gap, we adopt a Middle-Out Perspective (MOP) and use rich qualitative data including in-depth interviews to study the role of craft guilds within Germany's low-carbon transition, particularly in rooftop photovoltaic and heat pump installation. Our analysis demonstrates that guilds occupy pivotal ‘upper middle actor’ positions to resolve the ‘installation bottleneck’ from the middle-out. Situated between policymaking and on-the-ground installation, guilds have unique agency and capacity qualities deriving from preferential access to the local implementers of low-carbon transitions and legal commissions with critical tasks including training, informing, and associating installers. However, we find that guilds suffer from resource constraints, membership declines, and a lack of deliberate activation. Informal power structures and deficits of change makers exacerbate guilds’ propensity for inertia while unstable framework conditions and the dearth of strategic engagements leave guilds inactivated. Our extended MOP framework of agency, capacity, and propensity allows researchers and policymakers to attend to potentials and trade-offs between these qualities. By recognising the contextual social sphere of installation as potential, policymakers can design more effective implementation strategies that gain people’s support by ‘meeting them where they are’.

Multi‐source PV‐battery DC microgrid operation mode and power allocation strategy based on two layer fuzzy controller

AbstractThe conventional DC bus signaling (DBS) coordination control strategy for islanded DC microgrids (IDCMGs) faces challenges in coordinating multiple distributed generators (DGs) and fails to effectively incorporate the state of charge (SOC) information of the energy storage system, reducing system flexibility. In this article, a two‐layer fuzzy control‐based coordination strategy is proposed for multi‐PV islanded DC microgrids. The first layer fuzzy logic controller (FLC) quantifies and selects the optimal system operating mode, adaptively adjusting the number of PV units operating in maximum power point tracking (MPPT) mode to manage system power surplus or deficit, thereby simplifying system design and enhancing flexibility. The second layer FLC adaptively adjusts the output of distributed energy sources based on SOC and current system conditions to better align the energy storage system's output with overall system operation, resulting in at least a 4% improvement in SOC level and effectively preventing overcharging or over‐discharging issues seen in traditional control. Additionally, for PV units operating in droop mode, the droop coefficient is recalculated based on their maximum generation capacity under changing external conditions, thereby achieving more efficient power distribution and preventing system instability caused by power exceeding the limits of individual PV units. Finally, the effectiveness of the proposed control strategy is validated through RT‐lab hardware‐in‐the‐loop (HIL) simulations.

Effect of antipsychotic on mismatch negativity amplitude and evoked theta power in drug-naïve patients with schizophrenia

BackgroundRecurrent observations have indicated the presence of deficits in mismatch negativity (MMN) among schizophrenia. There is evidence suggesting a correlation between increased dopaminergic activity and reduced MMN amplitude, but there is no consensus on whether antipsychotic medications can improve MMN deficit in schizophrenia.MethodsWe conducted clinical assessments, cognitive function tests, and EEG data collection and analysis on 31 drug-naïve patients with schizophrenia. Comprehensive evaluation tools such as PANSS and MCCB. MMN amplitude was analyzed by event-related potential (ERP) approaches, evoked theta power was analyzed by event-related spectral perturbation (ERSP) approaches.ResultsOur findings indicate that antipsychotic treatment significantly improved clinical symptoms, as evidenced by reductions in PANSS positive, negative, general symptoms, and total scores (all p < 0.001). Cognitive function improvements were observed in language learning, working memory, and overall MCCB scores (p < 0.05), although other cognitive domains showed no significant changes. However, no significant improvements were noted in MMN amplitude and evoke theta power after four weeks of antipsychotic treatment (p > 0.05).ConclusionThese results suggest that while antipsychotic medications effectively alleviate clinical symptoms, their impact on MMN amplitude and evoke theta power deficit is limited in the short term. Moreover, the amelioration of cognitive impairment in individuals with schizophrenia is not readily discernible, and it cannot be discounted that the enhancement observed in language acquisition and working memory may be attributed to a learning effect. These findings underscore the complexity of the neurobiological mechanisms involved and highlight the need for further research to optimize individualized treatment strategies for schizophrenia.Trial RegistrationChiCTR2000038961, October 10, 2020.

Gradient Descent Algorithm with Greedy Repositioning Using Power Deficit Aggregation of Wakes to Accelerate the Offshore Wind Farm Layout Optimization Problem in Irregular Concession Areas

Wind farm layout optimization is essential to maximize the energy production of renewable energy systems. A new layout optimization method for offshore wind farms is proposed to minimize power deficits due to the wake effect without limitation on the number of turbines, the shape, or the extension of the concession area. The main engine of the algorithm is a gradient-descent method in which throughout the optimization process, new turbines are progressively and randomly included within the concession area and quickly expand outward, looking for areas with less perturbation, in turn, pushing the previous ones. When the optimization process ends, to avoid local maxima, it enters into a process of suppression of the set of locations that cause the greatest potential (power deficit). Then, a map of potential for the entire area is created, and a greedy algorithm places new turbines to complete the layout with the final number of turbines. The overall process is completed in 25 s. To drastically speed up the search process and the creation of the potential map, a simplification has been validated and added: for turbines affected by multiple wakes, the resulting power has been calculated by using a linear aggregation of power deficits, instead of the usual linear (or quadratic) aggregation of speed deficits. Owing to this type of aggregation, an analogy is established between power deficit and repulsive non-isotropic electrostatic potential energy, which allows using the properties of conservative fields. Thanks to this, the process is 20 times faster than any other layout optimization algorithm found in the revised literature. Irregular concession areas are easily treated using Stokes’ theorem to detect outer points.

Open EFT treatment of inflation with thermal initial conditions

Investigating the thermal inflationary model, we introduce stochastic effects, incorporating a cutoff parameter σ which distinguishes between quantum and classical modes. Testing the model against Planck 2018 data, we observe a preference for a non-zero σ at least at 68% C.L., suggesting the classicalization of most modes and providing a theoretical foundation for the quantum to classical transition. As a result of introducing the stochastic effects, we find that the solution to the large-scale power deficit requires a lower comoving temperature of inflaton.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision - 2024

The Academy of Orthopaedic Physical Therapy (AOPT) has an ongoing effort to create evidence-based clinical practice guidelines (CPG) for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The 2024 Achilles Pain, Stiffness, and Muscle Power Deficit: Midportion Achilles Tendinopathy Clinical Practice Guideline (CPG) is a revision of the 2018 CPG and represents the third CPG from AOPT on this topic. The goals of the revision were to provide a concise summary of the contemporary evidence and to develop new recommendations or revise previously published recommendations to support evidence-based practice. This current CPG covers prevalence, pathoanatomical features, risk factors, clinical course, diagnosis, examination, imaging, and physical therapy interventions for the management of midportion Achilles tendinopathy. J Orthop Sports Phys Ther 2024;54(12):CPG1-CPG32. Epub 27 November 2024. doi:10.2519/jospt.2024.0302.

A novel algorithmic multi-attribute decision-making framework for the evaluation of energy systems using rough approximations of hypersoft sets

Selecting the best power source that is legal, affordable, environmentally friendly, and able to ensure long-term viability is a difficult but vital task. Existing frameworks based on traditional fuzzy and soft sets are unable to adequately capture the complexity of the optimal energy system selection (ESS). These decision models may also be complex, especially when rough data and integrity need to be taken into account. In this study, the imperative concepts of rough set and hypersoft set are integrated into a novel theoretical framework called hypersoft rough set (HSRS). The former provides a broad theoretical framework to address information-based ambiguities and uncertainties, while the latter can be thought of as a trustworthy aid for incomplete data analysis using approximate methods. Elementary notions of HSRS, its relevant approximation space, lower and upper approximations, and operations are characterized along with essential properties and results. A rigorous algorithmic strategy for assessing the feasibility of ESS based on the operations of HSRS is suggested to assist decision-makers in identifying appropriate strategies to address the electric power deficit. Potential benefits of the newly suggested approach include improved versatility in modeling complex decision-making scenarios, better discriminating ability, suitability for handling abnormalities in data, and parametrization. The algorithm's adaptability is evaluated through a practical application to a real-world problem about the identification of the best ESS in Pakistan. The outcomes show that the suggested approach effectively ascertains the ideal ESS. Compared to the methods currently in use, the analytical framework that has been suggested seems to be more robust.

Achilles Pain, Stiffness, and Muscle Power Deficits: Midportion Achilles Tendinopathy Revision – 2024

The Academy of Orthopaedic Physical Therapy (AOPT) has an ongoing effort to create evidence-based clinical practice guidelines (CPG) for orthopaedic physical therapy management of patients with musculoskeletal impairments described in the World Health Organization's International Classification of Functioning, Disability, and Health (ICF). The 2024 Achilles Pain, Stiffness, and Muscle Power Deficit: Midportion Achilles Tendinopathy Clinical Practice Guideline (CPG) is a revision of the 2018 CPG and represents the third CPG from AOPT on this topic. The goals of the revision were to provide a concise summary of the contemporary evidence and to develop new recommendations or revise previously published recommendations to support evidence-based practice. This current CPG covers prevalence, pathoanatomical features, risk factors, clinical course, diagnosis, examination, imaging and physical therapy interventions for the management of midportion Achilles tendinopathy.

Integrating model-driven and data-driven methods for under-frequency load shedding control

With the access of a high percentage of new energy sources, power system frequency stability is challenged. Under-frequency load shedding (UFLS) is one of the primary measures to maintain frequency stability. Due to the mismatch between the amount of load shed by the traditional UFLS methods and the actual active power deficit, a new UFLS method needs to be designed. An approach utilizing a deep deterministic policy gradient (DDPG) algorithm for the problem is proposed. First, the DDPG algorithm is modified to adapt to the UFLS problem. Then, the idea of model-driven is introduced to improve the validity of the model. Thus, a novel UFLS method is proposed, which integrates data-driven and model-driven ideas. Furthermore, a structure called the dual experience pool is designed to accelerate training speed and improve stability. Based on the proposed method, a UFLS control framework is designed. Finally, the suggested methodology is validated using the IEEE-39 bus system and the Fujian power grid as test cases.

МОДЕЛИРОВАНИЕ ПРОЦЕССА ПРОГНОЗИРОВАНИЯ ДЕФИЦИТА ВЫЧИСЛИТЕЛЬНЫХ МОЩНОСТЕЙ НА ЗНАЧИМОМ ОБЪЕКТЕ КРИТИЧЕСКОЙ ИНФОРМАЦИОННОЙ ИНФРАСТРУКТУРЫ

The aim of the study is to formalize the process of forecasting the computing power deficit at significant objects of critical information infrastructure using a functional model. The task is to create a correct functional model for forecasting the computing power deficit. To solve this problem, the BPwin software product and functional modelling methods are used. The novelty of the work lies in using the analytical alignment of dynamic series to forecast the computing power deficit at significant objects of critical information infrastructure. As the study result, the authors build a functional model of the process of forecasting the computing power deficit at significant objects of critical information infrastructure. Thus, the resulting functional model reflects the technological features of the process of forecasting the computing power deficit and can be automated and applied to significant objects of critical information infrastructure in the future.

Glimpse on Spot and Derivative Market of Electricity and Nepal’s Hydropower

Energy plays a vital role in a country’s economic development. Nepal abundantly blessed with various renewable resources like hydropower, solar energy, biogas, and biomass can achieve prosperity both economically and socially. Further, with a significant opportunities for the regional electricity market as the country has been surrounded by big powerhouses like China and India. It has huge possibilities for regional trading of renewable energy. The present total Installed capacity of power is 3157 MW in Nepal. With 95% hydropower generation, the energy mix in the Integrated Nepal Power System makes the country a surplus of electricity during the wet season when the water in the river is very high and a shortage during the dry season when the discharge in the river is minimal. Hence, to address the surplus generation during the wet season and shortage of power during the dry season, trading in the region plays a very vital role in balancing the demand and supply of the country. Nepal has been importing power during the dry season power deficit in the market during the dry season when the demand is high leaving NEA at risk of interrupting the supply to its customers. Likewise, uncertainty about clearing a bid during the wet season when the power production is high and Nepal is in the position to export the power in the regional market, as the Hydropower plant has to compete with the cheap coal power plant resulting in financial loss and uncertainty of return on investment. Hence, to tackle the mentioned financial risks, the Electricity Derivative market can be one of the best options as derivatives markets can be used to hedge against price fluctuations in electricity spot markets. Similarly, the uncertainty of power sale can be avoided by selling or buying the electricity through a derivative market for the future time period that secures the price and the amount that can be sold in the market in the future. In a nutshell, the Electricity Derivative market can be a useful mechanism for the development of hydropower in Nepal in the future.

Effects of Droop Based Fast Frequency Response on Rotor Angle Stability During System Wide Active Power Deficits

Effects of Droop Based Fast Frequency Response on Rotor Angle Stability During System Wide Active Power Deficits

Climate Youth to Power: Coalition Strategy as Social Movement Response to Youth Power Deficits

Climate Youth to Power: Coalition Strategy as Social Movement Response to Youth Power Deficits

Power Deficit Analysis of Multiple Hydrokinetic Power Plants in an Open-Channel System

Power Deficit Analysis of Multiple Hydrokinetic Power Plants in an Open-Channel System

Numerical analysis on hydrodynamic performance and wake recovery of helical-bladed hydrokinetic turbine: Impact of section inclination angle

In the context of exploiting renewable sources, cross-flow helical hydrokinetic turbine is conceded as one of the promising choices to unlock the potential in free-flowing water bodies. This study examines the impact of blade section inclination angle (−10° to +8°) and operational parameters, namely, tip speed ratio (0.6–1.4) and inflow velocity (1.0–2.5 m/s) on the performance as well as wake recovery of a 4-bladed rotor. The coefficients of power and section-averaged mean streamwise velocity deficit values are computed by solving the unsteady Reynolds-Averaged Navier-Stokes equations coupled with k-ε RNG turbulence model using numerical simulations to assess the performance and velocity recovery, respectively. The power coefficients are seen to be improved with an increase in negative section inclination angle and are found optimum in the range from −6° to −10° at a tip speed ratio of 1.0. The simulation results also reveal that the section inclination angle and tip speed ratio parameters significantly influence the velocity recovery. Furthermore, the performance decreases as the inflow velocity increases; however, the wake recovery is unaffected, with an identical wake length of 13 times the rotor diameter along the streamwise direction at a tip speed ratio of 1.0.

A Systems Perspective on the Public Perception of Wind Power in Norway

AbstractThe Sustainable Development Goals, a set of ambitious targets embraced by United Nations member states, are designed to meet global challenges head‐on while shaping a sustainable future. Of these, Goal 7, in particular, focuses on the critical need for affordable, reliable, sustainable, and modern energy for all. Wind energy holds a significant potential in fulfilling Goal 7 of the sustainable development goals. In Norway, there exists a unique scenario, where nearly 98% of electricity is generated from renewable resources. However, without a subsequent increase in power production, a deficit in power is projected by 2027 according to a short‐term market analysis by Statnett. To prevent this, it is imperative to increase the production of electricity from wind. However, in recent years, there has been a significant rise in opposition towards wind power projects in Norway. Some of the wind power projects have even been put on hold because of the increase in protests. In light of this, we apply systems thinking methodologies to improve our understanding of this complex problem. Initially, we identify the stakeholders in our system of interest and categorize them through stakeholder salience analysis framework. Then, we developed a systemigram to graphically represent the system of interest. Finally, we carry out causal loop analysis to find causal loops in our system of interest. Our primary focus with this work is to better understand the factors shaping public perception of wind power projects in Norway. By gaining a deeper understanding about the factors influencing public perception of wind power projects in Norway, we aim to find better solutions to improve the social acceptance of these initiatives in Norway in future works.

Multilevel interlaminar fenestration with soft tissue decompression in lumbar canal stenosis

Introduction: Lumbar Canal Stenosis is the narrowing of the Spinal Canal and/or the intervertebral foramina, which causes compression of the thecal sac and/or caudal roots at a single vertebral level. Stenosis may be local, segmental, or generalised; bone or soft tissue can cause it. Stenosis can involve the bony canal, dural sac or both.[9] Aim: Assessment of outcomes of multilevel fenestration with soft tissue decompression in lumbar canal stenosis. Material and method: A prospective study comprised patients with two or more lumbar canal stenosis levels. The Study eliminated patients with infective pathology or recurrent surgery on identical levels. The surgical technique of canal decompression via multilevel fenestrations was used in this study, which enables the decompression of the neural structures while preserving as much of the bony and ligamentous structures as possible. Post-op clinical measures such as motor, sensory, post-op complications, and VAS score improvement assessed study outcomes. Result: Studies showed improvement in symptoms of pain, motor power and sensory deficit, post-operative improvement in VAS score for pain, and improved quality of life in almost all the patients from day 7 to day 60 after surgery. Conclusion: The study shows that “Multilevel interlaminar fenestration with Soft Tissue Decompression in Lumbar Canal Stenosis” is a feasible, safe, and effective approach to lumbar canal stenosis and is associated with minimal complications and minimal perioperative morbidity.

Single Nuclear Analyses Reveal Compromised Integrity of Neuromuscular Junction Myonuclei Following Joint Injury

The neuromuscular junction is an essential structure that links electrical signals from the nervous system to contraction of skeletal muscle. The post synaptic region of a muscle cell is maintained by a subset of specialized myonuclei responsible for clustering of post synaptic structural proteins and acetylcholine receptors. Disruptions in the transcriptional program of these myonuclei may result in ineffective myofiber recruitment, slowed force generation, and muscle weakness. We have shown that traumatic joint injury results in protracted deficits in muscle strength and power, but the peripheral mechanistic underpinnings remain unclear. Phenotypically, muscle pathology occurring after traumatic joint injury resembles that of neuromuscular destabilization, yet molecularly, this remains uninvestigated. Therefore, we hypothesize that disruption of neuromuscular regulatory gene programs and destabilization of the neuromuscular junction following joint injury will result in rapid muscle functional deficits. Human muscle biopsies were obtained from the vastus lateralis of anterior cruciate ligament (ACL) injured and healthy limbs of 26 participants. Injured biopsies were taken before and 7 days following reconstruction surgery. Bulk tissue RNA-seq analysis was performed on all participants and single-nucleus RNAseq (snRNAseq) was performed on a subset of participants. Briefly, for snRNAseq, muscle was dounce homogenized, filtered, and nuclei isolated via fluorescent activated cell sorting. Following sequencing, CellRanger output files containing count matrices were filtered, and analyzed using Partek Flow and Seurat. Biopsy sections were processed for histochemistry to analyze fiber size and motor end plate innervation. All participants underwent strength testing on a biodex to assess isometric quadriceps torque and rate of torque development. RNA sequencing displayed &gt;3 fold upregulation of CHRNA1 (P&lt; 0.001) after injury alone and &gt;18 fold upregulation 7 days following reconstruction surgery (P&lt; 0.001). This was accompanied by a host of other neuromuscular regulatory genes including HDAC4 (P&lt; 0.001), GDNF (P&lt; 0.001), and RUNX1 (P&lt; 0.001). Single nucleus sequencing revealed a complete disappearance of neuromuscular junction regulatory myonuclei following reconstruction surgery coupled with delocalization of acetylcholine receptor expression. These findings were confirmed with fluorescent in situ hybridization of CHRNA1 RNA on biopsy sections. Functionally, CHRNA1 RNA expression strongly correlates with deficits in rate of torque development following injury (R^2 = 0.85, P&lt; 0.001). Our results display rapid remodeling of the postsynaptic neuromuscular junction following joint injury that underscores sustained deficits in strength and power. Interventions targeting the preservation of peripheral innervation may be warranted to enhance outcomes following joint injury. R01AR072061. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.