Search Results (35)

Quercus faginea Lam., a winter-deciduous oak native to the Iberian Peninsula, typically grows under a Mediterranean climate. To identify the main drivers influencing radial wood increment, we analyzed the climatic signals in tree-ring width and wood anatomical traits using increment cores. Winter conditions influenced both latewood width and earlywood vessel size in the first row. Latewood was positively correlated with precipitation and temperature, with the long-term positive effect of winter water supply supported by SPEI. In contrast, vessel size showed negative correlations, also reflecting a long-term negative effect of winter precipitation. Consequently, conditions that enhanced latewood width and overall tree-ring growth appear to be associated with the formation of smaller earlywood vessels. Although ample winter precipitation replenishes soil water reserves and supports prolonged wood formation, it may also induce anaerobic soil conditions that promote root fermentation, depleting carbohydrates needed for cell turgor and expansion, and ultimately regulating earlywood vessel size. This physiological decoupling may help explain the lack of a significant correlation between latewood width and earlywood vessel size, underscoring their independent responses to environmental influences. Our findings highlighted the complex interplay between various climatic conditions affecting Q. faginea, with implications for understanding its adaptive capacity in changing climates. Full article

Physiological characteristics such as VO_2max, running economy (RE), maximal aerobic speed (MAS), maximal sprinting speed (MSS), anaerobic speed reserve (ASR), and player profiling (based on MSS and MAS) have been proven to be important for training prescriptions in football. However, previous studies on player profiling have neglected the absolute values of MSS and MAS. The objectives of this study were to compare the aforementioned physiological variables among player roles, create benchmarks, and provide normative data to help coaches categorize players, ultimately proposing a new player profiling method. We analyzed 195 male professional football players (50 forwards, 59 midfielders, 44 full-backs, and 42 center-backs). Multivariate analysis of variance with Tukey’s post hoc tests revealed positional differences. Center-backs exhibited lower VO_2max than midfielders and full-backs. Both center-backs and forwards showed poorer RE and MAS compared to midfielders and full-backs. Full-backs achieved higher MSS than midfielders and center-backs, and forwards outperformed center-backs. Finally, midfielders demonstrated lower ASR than all other positions. Benchmarks based on T-scores for all variables were provided. Finally, in the new profiling method proposed—also based on T-scores—players were classified as “speed”, “endurance”, or “hybrid” if their MAS and/or MSS T-score exceeded 60, “in development” if both were below 45, and “average” if both scores were between 45 and 60 without any value above 60. The normative data provided can assist coaches in identifying specific areas for improvement in players’ physical conditioning—particularly valuable for youth athletes or those returning from injury. Additionally, the new profiling method offers insights into individual player characteristics, enabling more tailored and effective training interventions. Full article

With the global emphasis on sustainable growth and development, the depletion of natural energy reserves due to reliance on fossil fuels and non-renewable sources remains a critical concern. Despite strides in transitioning to electrical mobility, rural and agricultural communities depend heavily on liquefied petroleum gas and firewood for cooking, lacking viable, sustainable alternatives. This study focuses on community-led efforts to advance biogas adoption, providing an eco-friendly and reliable energy alternative for rural and farming households. By designing and developing balloon-type anaerobic biodigesters, this initiative provides a robust, cost-effective, and scalable method to convert farm waste into biogas for household cooking. This approach reduces reliance on traditional fuels, mitigating deforestation and improving air quality, and generates organic biofertilizer as a byproduct, enhancing agricultural productivity through organic farming. The study focuses on optimizing critical parameters, including the input feed rate, gas production patterns, holding time, biodigester health, gas quality, and liquid manure yield. Statistical tools, such as descriptive analysis, regression analysis, and ANOVA, were employed to validate and predict biogas output data based on experimental and industrial-scale data. Artificial neural networks (ANNs) were also utilized to model and predict outputs, inspired by the information processing mechanisms of biological neural systems. A comprehensive database was developed from experimental and literary data to enhance model accuracy. The results demonstrate significant improvements in cooking practices, health outcomes, economic stability, and solid waste management among beneficiaries. The integration of statistical analysis and ANN modeling validated the biodigester system’s effectiveness and scalability. This research highlights the potential to harness renewable energy to address socio-economic challenges in rural areas, paving the way for a sustainable, equitable future by fostering environmentally conscious practices, clean energy access, and enhanced agricultural productivity. Full article

Wastewater treatment plants (WWTPs) consume a considerable amount of energy. They also generate energy in combined heat and power (CHP) units, which utilise biogas from the anaerobic digestion of sewage sludge to produce renewable electricity. Different prices apply to electricity generated on site in CHP units, to the purchase of electricity from the grid, to the sale of surplus electricity to the grid and energy tariffs, which motivates the optimisation of energy costs. This paper presents a strategy for optimising electricity costs by adapting on-site electricity generation in CHP units to the demand of the WWTP. The approach is designed for a CHP system that generates electricity in multiple internal combustion gas engines. It is implemented as a two-level control system, where the lower control level dynamically adjusts the power of the individual gas engines, and the upper control level optimises the desired total power, taking into account the current energy consumption of the WWTP, biogas reserves and electricity tariffs. The proposed concept was implemented at the Domžale-Kamnik WWTP. A six-month evaluation showed that electricity purchased from the grid could be reduced from 8.7% to 3.3% of the WWTP’s electricity consumption. This reduction affects the system economically, as electricity purchased from the grid at low and high tariffs is 35% and 76% more expensive than electricity generated on site (excluding the grid fee). This approach can be extended to balance dispatchable electricity generation at the WWTP to respond to short-term grid demand. Full article

Objective: To investigate the cut-off value of the breathing reserve for predicting a decline in cardiorespiratory fitness (CRF) among healthy middle-aged Chinese individuals. Methods: Healthy middle-aged individuals who underwent cardiopulmonary exercise testing (CPET) at the Peking University Third Hospital from May to October 2021 were selected. The study included 321 participants, with an average age of 48.8 ± 5.7 years. They were divided into two groups based on the peak oxygen uptake (VO₂peak): the adequate CRF group and the CRF decline group. Multivariate logistic regression analysis was used to explore the factors influencing CRF. Results: In the male CRF decline group, heart rate, alanine aminotransferase, end-tidal partial pressure of carbon dioxide (PETCO₂), and breathing reserve (BR%) were significantly higher, while the oxygen uptake at the anaerobic threshold (VO₂@AT) was lower. An elevated BR% was independently associated with CRF decline (OR = 1.111, 95% CI: 1.068–1.156). The female CRF decline group had significantly higher FEV1/FVC and BR% and significantly lower age, fasting glucose, hemoglobin, and VO₂@AT compared to the adequate CRF group. Elevated BR% was independently associated with CRF decline (OR = 1.086, 95% CI: 1.038–1.137). The receiver operating characteristic (ROC) curve for the males showed an area under the curve (AUC) of 0.769 (95% CI: 0.703–0.827) with an appropriate BR% cut-off value of 49.9%, sensitivity of 59.9%, and specificity of 77.8%. For the females, the ROC curve displayed an AUC of 0.694 (95% CI: 0.607–0.773) with an appropriate BR% cut-off value of 57.0%, sensitivity of 58.7%, and specificity of 86.0%. Conclusions: The breathing reserve was independently associated with CRF. The appropriate cut-off values for BR% to predict CRF decline were 49.9% for the males and 57.0% for the females. Full article

Cooking with firewood in inefficient stoves primarily affects the rural population in poor and developing countries, usually lacking access to clean and modern energy sources. La Guajira, Colombia, is especially affected, with 40% to 60% of the departmental households relying on firewood, which increases to 80% in rural areas. In the department, only 40.4% of the population have access to natural gas, which drops to 6% in the indigenous reservations, while 68.4% have access to electricity, which reduces to 22% in indigenous reservations. Rural areas with agricultural production in the department can benefit from biomass wastes to address firewood consumption. This study quantified the agricultural biomass waste inventory in La Guajira to assess their availability for energy valorization as cooking fuel or, when possible, for electricity generation. The geolocalization of biomass wastes and rural communities was developed to overlap biomass production with the demand for firewood. Moreover, briquetting, anaerobic digestion, and direct combustion were considered small- and medium-scale options for the energy valorization of biomass wastes. Results highlighted the department’s yearly production of 292,760 to 522,696 t of agricultural biomass wastes between 2010 and 2023. These wastes could yield an estimated 381 to 521 TJ/year of electricity using direct combustion, coinciding with some 21% to 28% of the electricity demand in 2022 in La Guajira. Furthermore, this electricity potential could replace 57% to 78% of the demand for firewood in the department using electric stoves. Moreover, anaerobic digestion could produce from 8.6 to 10 million m³/year, enough to replace between 16% and 18% of the demand for firewood using biogas stoves. Finally, briquettes could replace between 28% and 49% of the firewood demand, considering the adoption of improved biomass stoves. Considering that direct combustion and anaerobic digestion technologies would be efficient on the medium scale, briquettes surfaced as the most viable approach at the small scale to take advantage of agricultural wastes to replace firewood in households in rural areas. Full article

Background/Objectives: The purpose of this study was to investigate the effect of a short-term passive post-exercise heat acclimation (HA) protocol on anaerobic performance in college students. Methods: In total, 28 participants (age 22.3 ± 2.1 years, height 168 ± 9.1 cm, mass 71.5 ± 16.6 kg) volunteered and were randomly divided into either an intervention (INT) or control (CON) group. Both groups followed a consecutive two-day protocol, consisting of a 25 min submaximal cycle @ 50–60% heart rate reserve (HRR), followed by a 25 min hot water immersion (INT) or nothing (CON). All participants performed a 30 s Wingate Anaerobic Test (WAnT) on four separate occasions—familiarization, pre-intervention, acutely post-intervention, and 24 h post intervention. The WAnT measured their peak power (W), relative peak power (W/kg), mean power (W), fatigue index (%), and total work (kJ). Results: From the results of the Factorial ANOVA, it was found that there were no significant differences, with no main effect for group (INT vs. CON) or time (Trials 1–4) and no significant interaction across all measured variables (p > 0.05). Conclusions: A two-day post-exercise passive HA protocol utilizing hot water immersion had no significant effect on the measurement of anaerobic performance in college students. Full article

A variable pacing profile is common in different endurance events. In these races, several factors, such as changes in elevation or race dynamics, lead participants to perform numerous surges in intensity. These surges are so frequent that certain events, such as cross-country (XC) skiing, mountain biking (MTB), triathlon, and road cycling, have been termed “intermittent endurance events”. The characteristics of these surges vary depending on the sport: MTB and triathlon require athletes to perform numerous short (<10 s) bouts; XC skiing require periods of short- and moderate-(30 s to 2 min) duration efforts, while road cycling is comprised of a mix of short-, moderate-, and long-duration (>2 min) bouts. These bouts occur at intensities above the maximal metabolic steady state (MMSS), with many efforts performed at intensities above the athletes’ maximal aerobic power or speed (MAP/MAS) (i.e., supramaximal intensities). Given the factors that influence the requirement to perform surges in these events, athletes must be prepared to always engage in a race with a highly stochastic pace. The aim of this review is to characterize the variable pacing profile seen in endurance events and to discuss how the performance of multiple maximal and supramaximal surges in intensity can affect how athletes fatigue during a race and influence training strategies that can lead to success in these races. Full article

Background: In patients with prior Takotsubo syndrome (TTS), long-lasting functional cardiac limitations were described as compared with normal subjects. Emotion-triggered Takotsubo syndrome (E-TTS) has more favorable outcomes than TTS preceded by a physical trigger or by no identifiable factors. The aim of the present study was to assess long-term cardiac functional limitations in a cohort of asymptomatic E-TTS patients. Methods: We enrolled n = 40 asymptomatic patients with a diagnosis of E-TTS. Cardiopulmonary exercise tests (CPET) were performed at 30 (12–40) months median follow-up from the acute event. A cohort of n = 40 individuals matched for age, sex, body mass index and comorbidities served as control. Results: Despite recovery of left ventricular ejection fraction, patients with prior E-TTS had lower peak VO₂ and percentage of predicted peak VO₂ (17.8 ± 3.6 vs. 22.1 ± 6.5; p < 0.001 and 75.2 ± 14.1% vs. 100.6 ± 17.1%, p < 0.001), VO₂ at anaerobic threshold (AT) (11.5 [10.1–12.9] vs. 14.4 [12.5–18.7]; p < 0.001), peak O₂ pulse (9.8 ± 2.5 vs. 12.9 ± 3.5; p < 0.001) and higher VE/VCO2 slope (30.5 ± 3.7 vs. 27.3 ± 3.5; p < 0.001) compared with matched controls. We found no statistically significant differences in heart rate reserve (HRR), respiratory equivalent ratio (RER), mean blood pressure and peak PetCO₂ between patients and controls. Conclusions: Despite its favorable outcome, patients with E-TTS in our population were found to have subclinical long-term functional cardiac limitations as compared with a control cohort. Full article

Background and Aims: As there is growing interest in the application of cardiopulmonary exercise test (CPX) in chronic kidney disease (CKD), it is important to understand the utility of conventional exercise test parameters in quantifying the cardiopulmonary fitness of patients with CKD. Merely extrapolating information from heart failure (HF) patients would not suffice. In the present study, we evaluated the utility of CPX parameters such as the peak O₂-pulse and the estimated stroke volume (SV) in assessing the peak SV by comparing with the actual measured values. Furthermore, we compared the anaerobic threshold (AT), peak circulatory power, and ventilatory power with that of the measured values of the peak cardiac power (CPO_peak) in representing the cardiac functional reserve in CKD. We also performed such analyses in patients with HF for comparison. Method: A cross sectional study of 70 asymptomatic male CKD patients [CKD stages 2–5 (pre-dialysis)] without primary cardiac disease or diabetes mellitus and 25 HF patients. A specialized CPX with a CO₂ rebreathing technique was utilized to measure the peak cardiac output and peak cardiac power output. The peak O₂ consumption (VO_2peak) and AT were also measured during the test. Parameters such as the O₂-pulse, stroke volume, arteriovenous difference in O₂ concentration [C(a-v)O₂], peak circulatory power, and peak ventilatory power were all calculated. Pearson’s correlation, univariate, and multivariate analyses were applied. Results: Whereas there was a strong correlation between the peak O₂-pulse and measured peak SV in HF, the correlation was less robust in CKD. Similarly, the correlation between the estimated SV and the measured SV was less robust in CKD compared to HF. The AT only showed a modest correlation with the CPO_peak in HF and only a weak correlation in CKD. A stronger correlation was demonstrated between the peak circulatory power and CPO_peak, and the ventilatory power and CPO_peak. In HF, the central cardiac factor was the predominant determinant of the standard CPX-derived surrogate indices of cardiac performance. By contrast, in CKD both central and peripheral factors played an equally important role, making such indices less reliable markers of cardiac performance per se in CKD. Conclusion: The results highlight that the standard CPX-derived surrogate markers of cardiac performance may be less reliable in CKD, and that further prospective studies comparing such surrogate markers with directly measured cardiac hemodynamics are required before adopting such markers into clinical practice or research in CKD. Full article

(1) Background: Understanding the physicians’ knowledge, attitudes, and antimicrobial prescribing behavior is a crucial step towards designing strategies for the optimal use of these agents. (2) Methods: A cross-sectional online survey was conducted among clinicians across India between May and July 2022 using a self-administered questionnaire in English comprising 35 questions pertaining to demographic characteristics, knowledge, attitude, and practices domains. (3) Results: A total of 544 responses were received from 710 physicians contacted. Sixty percent of participants were males, with mean age of 34.7 years. Mean ± Standard Deviation scores for knowledge, attitude, and practices domains were 8 ± 1.6, 20.2 ± 3.5, and 15.3 ± 2.1, respectively. Higher scores were associated with basic [odds ratio (95% Confidence Interval), p value: 2.95 (1.21, 7.2), 0.02], medical and allied sciences [2.71 (1.09, 6.67), 0.03], and central zone [3.75 (1.39, 10.12), 0.009]. A substantial proportion of dissatisfactory responses were found regarding hospital antibiograms, antibiotics effective against anaerobes, WHO AWaRe (access, watch, and reserve) classification of antibiotics, and the role of infection prevention and control (IPC) measures in the containment of antimicrobial resistance (AMR). (4) Conclusions: There is a need to sensitize and educate clinicians on various issues related to antimicrobial use, such as antibiograms, double anaerobic cover, IPC practices, and guideline-based recommendations, to curb the AMR pandemic. Full article

As clean energy, methane has huge reserves and great development potential in the future. Copper zeolites are efficient in the oxidation of methane to methanol. Water has been confirmed as a source of oxygen to regenerate the copper-zeolite active sites to enable selective anaerobic oxidation of methane to methanol. In this work, we report that the methanol yield increased from 36 μmol/g (Cu-MOR₁) to 92 μmol/g (Cu-MOR₁-water) as a result of water enhancing the activity of copper ion-exchange mordenite catalyst. We show for the first time that water could convert inactive copper species into active copper species during catalyst activation. A combination of the XPS, FTIR, and NMR results indicates that water dissociates and then converts ZCu^IIZ into ZCu^II(OH) (where Z indicates framework O (O_fw) bonded to one isolated Al in a framework T-site, i.e., 1Al) and simultaneously produces a Brönsted acid site during catalyst activation. This finding can be used to tune the state of copper species and design highly active copper-zeolite catalysts for methane oxidation to methanol. Full article

The Army Combat Fitness Test (ACFT), consisting of deadlift, standing power throw, hand release push-up, sprint-drag-carry, leg tuck or plank, and 2-mile run, is the United States Army’s new fitness test. The ACFT is designed to measure multiple fitness components required to perform combat tasks. One critical task is the tactical foot march (TFM), where soldiers cover long distances while carrying loads comprised of mission-essential equipment. As the ACFT is meant to predict soldier task performance, determining the relationships between the ACFT and the TFM is important. Data from 29 cadets (♂ = 20, ♀ = 9) from one university Reserve Officers’ Training Corps program were analyzed. The ACFT was recorded in raw and scaled scores. The TFM was performed over 6.44 km, with time recorded. Cadets carried a 15.88-kg rucksack, fighting load carrier, 3-L hydration pack, and replica M4 carbine. Independent samples t-tests evaluated ACFT and TFM between-sex differences. Partial correlations, controlling for sex, determined ACFT event and TFM relationships. Male cadets outperformed females in all ACFT tasks (p ≤ 0.039), except the push-up. ACFT total score, leg tuck, 2-mile run, and sprint-drag-carry showed large correlations with the TFM (r = ±0.463–0.531, p ≤ 0.026). Aerobic and anaerobic capacity and upper body/trunk strength were important fitness components for cadet TFM performance. Full article

Owing to progressive aging in the population, there is an increase in patients with cognitive impairment. For the prevention of dementia, the use of plant remedies is relevant. Of particular interest is Klasea centauroides (L.) Cass. (Serratula centauroides L., Asteraceae), which has significant natural reserves, contains a wide range of biologically active substances, and is used in folk medicine to treat nervous system diseases. This study aimed to estimate the neuroprotective, energy-protective, and antioxidant effects of K. centauroides extract in cholinergic deficiency caused by long-term scopolamine administration. It has been established that K. centauroides extract accelerates passive avoidance-conditioned reflex development and ensures its preservation over a longer time period under cholinergic deficiency conditions. The K. centauroides extract increases the resistance of brain tissues to the toxic effects of scopolamine, reducing the number of neuron regressive forms in the cerebral cortex and hippocampus. The K. centauroides extract enhances the predominance of aerobic glycolysis over anaerobic glycolysis and enhances the NADH-dehydrogenase and succinate-dehydrogenase complexes activity, thus promoting more intensive ATP synthesis against this background, the introduction of scopolamine. The use of K. centauroides extracts reduces the malonic dialdehyde (MDA) content in the brain structures and increases the catalase (CAT) and antioxidant system glutathione unit activities. Full article

Historically, fetal heart rate (FHR) decelerations were classified into “early”, “late”, and “variable” based on their relationship with uterine contractions. So far, three different putative etiologies were taken for granted. Recently, this belief, passed down through generations of birth attendants, has been questioned by physiologists. This narrative review aimed to assess the evidence on pathophysiology behind intrapartum FHR decelerations. This narrative review is based on information sourced from online peer-reviewed articles databases and recommendations from the major scientific societies in the field of obstetrics. Searches were performed in MEDLINE/PubMed, EMBASE, and Scopus and selection criteria included studies in animals and humans, where the physiology behind FHR decelerations was explored. The greater affinity for oxygen of fetal hemoglobin than the maternal, the unicity of fetal circulation, and the high anaerobic reserve of the myocardium, ensure adequate oxygenation to the fetus, under basal conditions. During acute hypoxic stress the efficiency of these mechanisms are increased because of the peripheral chemoreflex. This reflex, activated at each uterine contraction, is characterized by the simultaneous activation of two neural arms: the parasympathetic arm, which reduces the myocardial consumption of oxygen by decreasing the FHR and the sympathetic component, which promotes an intense peripheric vasoconstriction, thus centralizing the fetal blood volume. This review summarizes the evidence supporting the hypoxic origin of FHR decelerations, therefore archiving the historical belief that FHR decelerations have different etiologies, according to their shape and relationship with uterine contractions. The present review suggests that it is time to welcome the new scientific evidence and to update the CTG classification systems. Full article