Search Results (1,686)

Background/Objectives: Frailty is a multidimensional syndrome characterized by diminished physiological reserves, reduced mobility, and increased fall risk. While clinical assessments are commonly used to screen for frailty, they may not capture minor deficits in postural control. Center-of-pressure (CoP) metrics from force plates provide objective markers of postural control, yet their role in frailty screening remains underexplored. This study aimed to investigate the associations between functional performance measures and CoP-based metrics to identify predictors of frailty among older adults. Methods: Eighty-three adults aged ≥ 55 years with a history of falls were classified as frail or pre-frail based on modified Fried criteria. Functional assessments (Timed Up and Go (TUG), grip strength, Berg Balance Scale [BBS], Falls Efficacy Scale [FES]) and CoP metrics (mean velocity, sway path; eyes open/closed) were evaluated. Both unadjusted and age-adjusted logistic regression models were used to identify independent predictors of frailty. Results: Increased TUG time and number of falls were the strongest risk factors for frailty, while increased sway path and CoP velocity were protective. In particular, sway path under eyes-closed conditions showed the strongest protective association (OR = 0.323, p < 0.001). Additionally, fear of falling (OR = 1.078, p = 0.013) emerged as a significant psychological factor, consistently associated with increased frailty risk regardless of physical performance. Correlation analysis supported these findings, showing that better functional performance was linked to lower frailty risk. Conclusions: CoP sway path and mean velocity independently predict frailty status and offer added value beyond traditional clinical tools. These findings highlight the importance of incorporating instrumented balance assessments into frailty screening to capture nuanced postural control deficits and guide early intervention strategies. Full article

In the context of mounting climate impacts and growing urgency to meet the Paris Agreement goals, the ocean is now increasingly being recognised not just as a victim of climate change, but as an indispensable part of the solution. Research has demonstrated that readily actionable ocean-based climate solutions can help close the emissions gap (the difference between the greenhouse gas emission reductions needed to limit global warming to 1.5 °C, and projected global emissions considering current national pledges and policies) by providing approximately a third of the mitigation needed to keep the Paris Agreement’s 1.5 °C goal within reach. This mitigation potential (of fully actioning these solutions) is unequally divided across seven key ocean-based action areas (listed in decreasing order of magnitude): phasing out offshore oil and gas; deploying offshore renewable energy infrastructure; decarbonising maritime transport and associated infrastructure; decarbonising ocean and aquatic food value chains; carbon capture and storage; marine and coastal conservation and restoration; and decarbonising coastal tourism. We argue that achieving the full potential of ocean climate solutions will require smart governance, drastically increased financial investment, and international cooperation. Accomplishing this, however, will bring strong co-benefits for biodiversity, food systems, and coastal resilience. The Third United Nations Ocean Conference and 30th United Nations Climate Change Conference of the Parties (COP 30) present rare opportunities to mainstream the ocean into global climate strategies. Full article

Vacuum membrane-based air dehumidification (MAD) is potentially more efficient than refrigeration cycles. Air permeance through a membrane is inevitable, especially when there is a large pressure difference between the supply and permeate sides. Given the high specific gas volume under vacuum conditions, removing the permeating air from the dehumidifier is crucial for the stable operation of the vacuum compressor. Energy-efficient air removal techniques are still lacking, thereby hindering the development of MAD technology. This paper proposes a novel MAD approach using a vacuum mixing condenser. The cooling water directly condenses moisture from the vacuum compressor without any heat exchanger. The permeating air and water mixture in the condenser then experiences a quasi-isothermal pressurization process through a multiphase pump, enabling continuous dehumidification and air removal with low power consumption. The fundamentals of the proposed approach are illustrated, and mathematical models are built. Influences of air permeance rate, cooling water flow rate, condenser pressure, membrane area, and gravitational work are investigated. The results show that a COP of 8~12 is achievable to dehumidify air to 50%RH, 25 °C. The vacuum compressor consumes about 80% of the power. A low air permeance rate, low condenser pressure, large membrane area, and high gravitational work positively impact the COP, while the cooling water flow rate has a more complex effect. The proposed dehumidifier can use less selective membranes for higher permeability and cost-effectiveness. Full article

Mathematics teacher educators (MTEs) play a significant role in supporting prospective teachers (PTs) to develop the mathematical content and pedagogical knowledge they need for teaching. We examined how four novice prospective MTEs learn within a Community of Practice (CoP) and develop Mathematical Knowledge for Teaching Teachers (MKTT) and MTE identities when they are serving as interns in a mathematics content course for PTs taught through problem solving. We collected data through weekly reflections written by the novice prospective MTEs, researcher memos, and interviews with each participant at three points in the semester. We found that within the CoP, the novice prospective MTEs exhibited their growth predominately through learning as experience and learning as doing. We found that they indicated their development of MKTT most notably by noting new insights into pedagogical practices and enacting new pedagogical practices. We contribute (a) a model of how prospective MTEs can experience and learn how to teach PTs mathematics through problem solving, and (b) evidence of how this learning occurred and how their MTE identities developed through this experience. Full article

Objective: Head-to-head evidence comparing closed-kinetic-chain (CKC) and open-kinetic-chain (OKC) training on balance in middle-aged women with knee osteoarthritis (KOA) is limited. Purpose: To compare 10-week hip abduction/external rotation-focused CKC versus OKC on static and dynamic balance. Methods: Twenty-two women with KOA were randomized to CKC (n = 11) or OKC (n = 11) and trained twice weekly for 10 weeks. The primary outcome was the center of pressure (COP) during single-leg stance (AP/ML range, excursion, velocity, and RMS); the secondary outcome was the Y-Balance Test (YBT) composite score. Results: CKC produced significant within-group reductions across all COP variables and significant YBT increases for both affected and unaffected limbs (p < 0.05). OKC showed only small changes in select COP indices and no meaningful change in YBT. Post-intervention between-group comparisons consistently favored CKC for AP/ML and total COP excursion/velocity and for the YBT composite score (p < 0.05). Conclusions: Under weight-bearing conditions, a hip-focused CKC program that promotes multi-joint coordination and co-contraction yields broader and more consistent improvements in postural stability and dynamic balance than OKC in middle-aged women with KOA. These findings support prioritizing CKC when rehabilitation aims include gait and functional stability. Full article

This study investigated the performance of a hybrid desiccant dehumidification system integrated with a post-cooling mechanism, focusing on its application to energy-efficient indoor climate control. A liquid desiccant system using magnesium chloride (MgCl₂) was tested in its pure form and in combination with silica gel at 10% and 20% concentrations to enhance its moisture removal capabilities. The key parameters, including the air velocity (3–6 m/s), desiccant flow rate (1–3 LPM), and desiccant composition, were varied to analyze their effects on the dehumidification efficiency, moisture removal rate (MRR), temperature reduction after post-cooling, and coefficient of performance (COP). The results show that post-cooling using a crossflow heat exchanger effectively lowered the exit air temperature, ensuring thermal comfort. Addition of silica gel significantly improved system performance. The MgCl₂ + 20% silica gel mixture achieved the highest dehumidification efficiency of 0.86, the greatest temperature drop of 1.95 °C, and the maximum COP of 2.36 at optimal flow conditions. While the dehumidification efficiency declined with increasing air velocity due to reduced contact time, the COP increased owing to the higher thermal processing of the air stream. This study highlights the potential of optimized hybrid desiccant systems as sustainable solutions for building air conditioning, aligning with the key Sustainable Development Goals (SDGs) related to clean energy, climate action, and sustainable infrastructure. Full article

Background: Inline skating has rapidly grown in popularity. Early research primarily focused on injury patterns and protective measures. However, its biomechanical similarity to other skating modalities enables the synthesis of existing evidence, emphasizing key physical attributes essential for performance, namely, balance and the strength of the hip adductor and abductor muscles. The interaction between these muscle groups in relation to balance has not yet been examined in inline skaters. This study aimed to investigate the relationship between single-leg static balance and the isometric strength of the hip adductors and abductors, including their strength ratio. Methods: A total of 191 amateur inline skaters (aged 18 to 59 years) were evaluated. Balance was assessed through center of pressure displacement using the Footscan^® 9 platform, and the maximal isometric strength of the hip adductors and abductors was measured using a handheld dynamometer. A linear regression on the center of pressure (CoP) displacement was performed. Results: Age, sex, and skating frequency were the most influential predictors (p < 0.001), although strength variables also significantly predicted the CoP (p <0.05). Conclusions: Superior balance performance was observed in younger individuals, women, and those practicing five or more days a week. Furthermore, single-leg static balance was associated with an equilibrium between adductor/abductor strength, particularly when a low ratio was accompanied by high levels of hip adductor strength. Full article

Background: Chagas disease, caused by the protozoan parasite Trypanosoma cruzi (T. cruzi), remains a major public health concern in Latin America. No licensed vaccine exists to prevent or treat T. cruzi infection. Identifying correlates of protection (CoPs) could provide substitute endpoints to guide and accelerate vaccine development. Although most CoPs established to date are antibody-based, their utility has not been demonstrated in T. cruzi vaccine reports. Thus, this study aimed to explore alternative strategies considering the use of immune cells as potential CoPs. Methods: Mice were immunized with a vaccine candidate based on the T. cruzi trans-sialidase protein (TSf) and potentiated with 5-fluorouracil (5FU) to deplete myeloid-derived suppressor cells (MDSCs). Percentages of CD4⁺, CD8⁺, and CD11b⁺Gr-1⁺ cellular biomarkers were assessed by flow cytometry from the peripheral blood of immunized mice, which were subsequently challenged with a high dose of T. cruzi. A machine-learning (ML) model based on decision trees was applied to identify potential CoPs to predict survival by day 25 post-infection. Results: Individual biomarkers obtained from flow cytometry did not show strong predictive performance. In contrast, biomarker engineering led to a combination that integrated biomarkers rationally: summing the percentages of CD8⁺ and CD4⁺ cells and subtracting the percentage of CD11b⁺Gr-1⁺ MDSC-like cells (REB), enhanced the predictive capacity. Subsequent computational analysis and ML application led to the identification of a better and even improved potential Integrative CoP: $2 \ast \%CD{8}^{+}+ {\%CD4}^{+} - {\%CD11b}^{+}{ Gr1}^{+}$(pICoP), which significantly improved the performance of a simple one-level decision-tree model, achieving an average accuracy of 0.86 and an average AUC-ROC of 0.87 for predicting survival in immunized and infected mice. Conclusions: Results presented herein provide evidence that integrating cellular immune biomarkers through rational biomarker engineering, together with ML analysis, could lead to the identification of potential CoPs for a T. cruzi vaccine. Full article

This work mainly focuses on the energy and exergy analysis of a single-effect absorption cooling system operating with the couple H₂O-LiBr, under different climatic conditions in Senegal and France. A simulation model was developed, using the Engineering Equation Solver V10 (EES) software. Results indicate that the system can achieve a maximum COP of 0.76 and an exergy efficiency of 56%, which decreases as the generator temperature increases. Increasing the generator temperature from 87 to 95 °C significantly improves COP, but gains become marginal beyond 100 °C. The highest exergy destruction occurs in the generator, followed by the absorber, condenser, and evaporator. A temperature difference above 44 °C between the generator and the absorber is required to maintain H₂O-LiBr solution stability. Optimal temperatures for hot climates like Senegal are 90 °C (generator), 42 °C (absorber/condenser), and 7 °C (evaporator), while maximum exergy efficiency (56%) is reached at 81 °C, typical of moderate climates (France). Evaporator exergy efficiency increases from 16 to 52% with rising ambient temperature, while absorber and condenser efficiencies drop. Increasing the cooling water flow rate from 0.2 to 1.4 kg/s reduces exergy losses in the absorber and the condenser by up to 36%. The solution heat exchanger (SHE) optimal effectiveness of 0.75 reduces exergy consumption in the absorber and the generator. Full article

The growing need for cooling, combined with the environmental concerns surrounding conventional mechanical vapour compression (MVC) systems, has accelerated research for sustainable cooling solutions driven by low-grade heat. Single-stage dual-bed adsorption chillers (ADCs) using silica gel and water provide a promising approach due to their continuous cooling output, lower complexity, and the use of environmentally safe working fluids. However, limitations in their performance, specifically in the coefficient of performance (COP), cooling capacity (${\mathrm{Q}}_{\mathrm{c}\mathrm{c}}$), and waste heat recovery efficiency (${\mathsf{\eta }}_{\mathrm{e}}$), necessitate improvement through optimization. This study employs statistically validated regression-based objective functions to optimize ten decision variables using the single Grey Wolf Optimizer (GWO) and its multi-objective variant, Muilti-Objective Grey Wolf Optimization (MOGWO), for a silica gel–water single-stage dual-bed ADC. The results from the single-objective optimization showed a maximum coefficient of performance (COP) of 0.697, cooling capacity (${\mathrm{Q}}_{\mathrm{c}\mathrm{c}}$) of 20.76 kW, and waste heat recovery efficiency (ηe) of 0.125. The values from the Pareto-optimal solutions for the MOGWO ranged from 0.5123 to 0.6859 for COP, 12.45 to 20.73 kW for ${\mathrm{Q}}_{\mathrm{c}\mathrm{c}}$ and 8.24% to 12.48% for ${\mathsf{\eta }}_{\mathrm{e}}$, demonstrating superior performance compared to existing benchmarks. A one-at-a-time sensitivity analysis revealed non-linear and non-monotonic impacts of variables, confirming the robustness and physical realism of the MOGWO model. The developed MOGWO framework effectively enhances the performance of the single-stage dual-bed ADC and improves low-grade heat utilization, offering a robust decision-support tool for system design and optimization. Full article

Background: Accurate differentiation of Parkinson’s disease (PD) from healthy aging is crucial for timely intervention and effective management. Postural sway abnormalities are prominent motor features of PD. Quantitative stabilometry and machine learning (ML) offer a promising avenue for developing objective markers to support the diagnostic process. This study aimed to develop and validate high-performance ML models to classify individuals with PD and age-matched healthy older adults (HOAs) using a comprehensive set of stabilometric parameters. Methods: Thirty-seven HOAs (mean age 70 ± 6.8 years) and 26 individuals with idiopathic PD (Hoehn and Yahr stages 2–3, on medication; mean age 66 years ± 2.9 years), all aged 60–80 years, participated. Stabilometric data were collected using a force platform during quiet stance under eyes-open (EO) and eyes-closed (EC) conditions, from which 34 parameters reflecting the time- and frequency-domain characteristics of center-of-pressure (COP) sway were extracted. After data preprocessing, including mean imputation for missing values and feature scaling, three ML classifiers (Random Forest, Gradient Boosting, and Support Vector Machine) were hyperparameter-tuned using GridSearchCV with three-fold cross-validation. An ensemble voting classifier (soft voting) was constructed from these tuned models. Model performance was rigorously evaluated using 15 iterations of stratified train–test splits (70% train and 30% test) and an additional bootstrap procedure of 1000 iterations to derive reliable 95% confidence intervals (CIs). Results: Our optimized ensemble voting classifier achieved excellent discriminative power, distinguishing PD from HOAs with a mean accuracy of 0.91 (95% CI: 0.81–1.00) and a mean Area Under the ROC Curve (AUC ROC) of 0.97 (95% CI: 0.92–1.00). Importantly, feature analysis revealed that anteroposterior sway velocity with eyes open (V-AP) and total sway path with eyes closed (TOD_EC, calculated using COP displacement vectors from its mean position) are the most robust and non-invasive biomarkers for differentiating the groups. Conclusions: An ensemble ML approach leveraging stabilometric features provides a highly accurate, non-invasive method to distinguish PD from healthy aging and may augment clinical assessment and monitoring. Full article

Copper ions serve as essential cofactors for many enzymes but exhibit toxicity at elevated concentrations. In Gram-negative bacteria, the Cop system, typically encoded by copABCD, plays a crucial role in maintaining copper homeostasis and detoxification. The chromosome of Pseudomonas putida harbors two copAB clusters but lacks copCD, along with two copR-copS clusters that encode the cognate two-component system. Here, the roles of these Cop components in countering copper toxicity were studied. We found that copAB2 was essential for full resistance to Cu²⁺ in P. putida, while copAB1 made only a minor contribution, partially due to its low expression. The two-component systems CopRS1 and CopRS2 both played significant regulatory roles in copper resistance. Although they could compensate for the absence of each other to mediate copper resistance, they exhibited distinct regulatory effects. CopR1 bound to all four cop promoters and activated their transcription under copper stress. In contrast, though CopR2 bound to the same sites as CopR1 in each cop promoter, it significantly activated only copAB2 and copRS2 expression. Its competitive binding at the copAB1 and copRS1 promoters likely impeded CopR1-mediated activation of these genes. Overall, this study reveals the distinct contributions of the two Cop systems to copper resistance and their regulatory interplay in P. putida. Full article

Resource maps for open-loop ground source heat pump (GSHP) systems were developed based on heating and cooling experiments to identify areas with potential for reduced operational costs. Experiments conducted at a public hall, where groundwater temperatures fluctuate seasonally, clarified the relationships between the coefficient of performance (COP) of a heat pump and three key parameters: groundwater temperature, flow rate, and energy consumption. Multiple regression analysis produced equations for estimating the energy consumption of both the heat pump and the water pump. Results indicate that groundwater temperature influences the COP, increasing it by 0.07969 per °C during heating and decreasing it by 0.1721 per °C during cooling. These equations enable the estimation of energy consumption in open-loop systems from groundwater temperature, groundwater depth, and building type. Resource maps developed for the Nobi Plain in central Japan reveal that annual energy consumption is lower in the northwestern region, where groundwater temperatures are generally lower, except in marginal zones for hospitals and offices. Full article

This review focuses on the advancements of CO₂ transcritical cycle technology in building indoor environmental regulation, particularly in combined heating and cooling applications. The paper highlights the energy efficiency and environmental benefits of CO₂ as a natural refrigerant, which has zero ozone depletion potential (ODP) and very low global warming potential (GWP). It provides a comprehensive overview of recent optimization strategies, including distributed compression, the integration of ejectors and expanders, and the design improvements of key components such as gas coolers, compressors, and throttling valves. Through optimization strategies such as dual-system cycles, this technology can achieve a COP improvement of 15.3–46.96% in heating scenarios; meanwhile, with the help of distributed compression technology, its cooling capacity can be enhanced by up to 26.5%. The review also examines various operating conditions such as discharge pressure and subcooling, which significantly affect system performance. The paper concludes by identifying the current challenges in the application of CO₂ systems, such as high initial costs and system stability under extreme conditions, and suggests future research directions to overcome these limitations and improve the practical application of CO₂ transcritical cycles in the building industry. Overall, it is concluded that the development of expander-compressors holds great potential for achieving better performance and represents a promising direction for future advancements in this field. Full article

Background/Objectives: Community-acquired pneumonia (CAP) remains a major cause of hospitalisation and death, particularly among older and frail adults. Although treatment guidelines exist, adherence to empiric antibiotic recommendations is variable. This study examined whether receiving guideline-concordant antibiotics for CAP was associated with better short- and long-term clinical outcomes. Methods: We conducted a retrospective cohort study of adults admitted with radiologically confirmed CAP to a tertiary hospital in Australia from 1 January to 31 December 2023. Patients with hospital-acquired pneumonia or COVID-19 were excluded. Antibiotic concordance was assessed against local guidelines. Propensity score matching (PSM) accounted for 16 covariates including age, comorbidities (Charlson Index), frailty (Hospital Frailty Risk Score), and pneumonia severity (SMART-COP). Primary outcomes were in-hospital, 30-day, and one-year mortality. Secondary outcomes included ICU admission, invasive ventilation, vasopressor use, hospital length of stay, and 30-day readmissions. Results: Of 241 patients, 51.4% received guideline-concordant antibiotics. Mean age was 73.5 years; 50.2% were male; 42.2% had severe pneumonia (SMART-COP ≥ 5); 36.5% were frail. In unadjusted analysis, in-hospital mortality was higher in the concordant group (5.6% vs. 0.9%, p = 0.038). After PSM (n = 105 matched pairs), concordant treatment was associated with significantly lower 30-day mortality (coefficient = –0.12; 95% CI: –0.23 to –0.02; p = 0.018) and there was a non-significant trend towards reduced 1-year mortality (p = 0.058). Other outcomes, including in-hospital mortality, were not significantly different. Conclusions: Guideline-concordant antibiotics were associated with reduced 30-day mortality in CAP. These results support adherence to evidence-based treatment guidelines to improve patient outcomes. Full article