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Feasibility of the 2-point method to determine the load-velocity relationship variables during the countermovement jump exercise

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Journal of Sport and Health Science 2023年第4期12卷 544-552,F0003页

作者： Alejandro Pérez-Castilla Rodrigo ramirez-Campillo John F.T.Fernandes Amador García-Ramos Department of Physical Education and Sport Faculty of Sport SciencesUniversity of GranadaGranada 18011Spain Human Performance Laboratory Department of Physical Activity SciencesUniversidad de Los LagosSantiago 5170000Chile Centro de Investigacion en Fisiologıa del Ejercicio Facultad de CienciasUniversidad MayorSantiago 8580745Chile Higher Education Sport Hartpury UniversityHartpury GL193BEUK Department of Sports Sciences and Physical Conditioning Faculty of EducationUniversidad Catolica de la Santısima ConcepcionConcepcion 4090541Chile

Purpose:This study aimed to examine the reliability and validity of load-velocity(L-V)relationship variables obtained through the 2-point method using different load combinations and velocity ***:Twenty men performed 2 identical sessions consisting of 2 countermovement jumps against 4 external loads(20 kg,40 kg,60 kg,and80 kg)and a heavy squat against a load linked to a mean velocity(MV)of 0.55 m/s(load_(0.55)).The L-V relationship variables(load-axis intercept(L_(0)),velocity-axis intercept(v_(0)),and area under the L-V relationship line(A_(line)))were obtained using 3 velocity variables(MV,mean propulsive velocity(MPV),and peak velocity)by the multiple-point method including(20-40-60-80-load_(0.55))and excluding(20-40-60-80)the heavy squat,as well as from their respective 2-point methods(20-load_(0.55)and 20-80).Results:The L-V relationship variables were obtained with an acceptable reliability(coefncient of variation(CV)≤7.30%;intra-class correlation coefficient>0.63).The reliability of L_(0)and v_(0)was comparable for both methods(CV_(ratio)(calculated as higher value/lower value):1.11-1.12),but the multiple-point method provided Al_(ine)with a greater reliability(CV_(ratio)=1.26).The use of a heavy squat provided the L-V relationship variables with a comparable or higher reliability than the use of a heavy countermovement jump load(CV_(ratio):1.06-1.19).The peak velocity provided the load-velocity relationship variables with the greatest reliability(CV_(ratio):1.15-1.86)followed by the MV(CV_(ratio):1.07-1.18),and finally the *** 2-point methods only revealed an acceptable validity for the MV and MPV(effect size≤0.19;Pearson s product-moment correlation coefficient≥0.96;Lin's concordance correlation coefficient≥0.94).Conclusion:The 2-point method obtained from a heavy squat load and MV or MPV is a quick,safe,and reliable procedure to evaluate the lower-body maximal neuromuscular capacities through the L-V relationship.

关键词： Force-velocity relationship Mean velocity Multiple-point method Peak velocity Velocity-based training

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Safe reinforcement learning for multi-energy management systems with known constraint functions

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能源与人工智能(英文) 2023年第2期12卷 86-102页

作者： Glenn Ceusters Luis ramirez Camargo Rüdiger Franke Ann Nowé Maarten Messagie ABB Hoge Wei 271930 ZaventemBelgium Vrije Universiteit Brussel(VUB) ETEC-MOBIPleinlaan 21050 BrusselsBelgium Vrije Universiteit Brussel(VUB) AI-labPleinlaan 21050 BrusselsBelgium Copernicus Institute of Sustainable Development-Utrecht University Princetonlaan 8a3584CB UtrechtNetherlands

Reinforcement learning(RL)is a promising optimal control technique for multi-energy management *** does not require a model a priori-reducing the upfront and ongoing project-specific engineering effort and is capable of learning better representations of the underlying system ***,vanilla RL does not provide constraint satisfaction guarantees—resulting in various potentially unsafe interactions within its *** this paper,we present two novel online model-free safe RL methods,namely SafeFallback and GiveSafe,where the safety constraint formulation is decoupled from the RL *** provide hard-constraint satisfaction guarantees both during training and deployment of the(near)optimal *** is without the need of solving a mathematical program,resulting in less computational power requirements and more flexible constraint function *** a simulated multi-energy systems case study we have shown that both methods start with a significantly higher utility compared to a vanilla RL benchmark and Optlayer benchmark(94,6%and 82,8%compared to 35,5%and 77,8%)and that the proposed SafeFallback method even can outperform the vanilla RL benchmark(102,9%to 100%).We conclude that both methods are viably safety constraint handling techniques applicable beyond RL,as demonstrated with random policies while still providing hard-constraint guarantees.

关键词： Reinforcement learning Constraints Multi-energy systems Energy management system

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The bone marrow niche landscape:a journey through aging,extrinsic and intrinsic stressors in the haemopoietic milieu

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Journal of Cancer Metastasis and Treatment 2022年第1期8卷 526-537页

作者： Antonio Giovanni Solimando Assunta Melaccio angelo Vacca Roberto Ria Department of Biomedical Sciences and Human Oncology Section of Internal Medicine and Clinical OncologyUniversity of Bari Medical SchoolBari 70124 Italy

Inflammation and its effects in the bone marrow microenvironment represent a paradigmatic condition in which the hematopoietic niche and the immune systems,thought to properly sustain blood cell production and distinguish between friend and foe,can actively sustain a corrupted neighborhood within a chronic aberrant inflamed *** bone marrow niche hijacks the physiologic *** interactions between the hematopoietic stem cells and the niche in the bone marrow are critical determinants of *** examined several approaches to confront the available evidence;three key points emerged,pointing to the chronic inflammation process,especially the chronic infection and systemic inflammatory states,as leading causes of hematopoietic stem cell *** hematopoiesis,defined as a relative expansion of individual clones,is caused by somatic alterations in essential hematopoietic genes,which increase stem cell ***,terminal differentiation plays a significant role in progenitor loss and inflammatory signaling,promoting clonal selection and clonal hematopoiesis *** myeloid malignancies as paradigmatic examples are discussed as a condition associated with inflammation,including the 5q-syndrome,Philadelphia negative myeloproliferative neoplasms,and chronic myeloid *** with increased fitness and hematopoietic stem cell attrition,extrinsic stress,enhanced stressor-specific fitness,and intrinsic defect across the hematopoietic process represent the route for novel insights in defective *** discussion in this review also points out that the hematopoietic niches’inflammatory stimulation may affect differentiation patterns and the function of downstream cells.

关键词： Hematopoietic niche immune system inflammation tumor microenvironment

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Prevalence and outcomes of pediatric surgical conditions at Connaught Hospital in Freetown:a retrospective study

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World Journal of Pediatric Surgery 2023年第1期6卷 1-7页

作者： Henang Kwasau Juliana Kamanda Aiah Lebbie Cesia Cotache-Condor Pamela espinoza Andie Grimm Naomi Wright Emily Smith Department of Community Health College of Medicine and Allied Health SciencesUniversity of Sierra LeoneFreetownSierra Leone Department of Surgery Duke School of MedicineDuke UniversityDurhamNorth CarolinaUSA Duke Global Health Institute Duke UniversityDurhamNorth CarolinaUSA Duke Center for Global Surgery and Health Equity Duke UniversityDurhamNorth CarolinaUSA Department of Public Health Baylor UniversityWacoTexasUSA King’s Centre for Global Health and Health Partnerships King's College LondonLondonUK Department of Emergency Medicine Duke School of MedicineDuke UniversityDurhamNorth CarolinaUSA

Background Sub-Saharan Africa experiences a disproportionate amount of pediatric surgical disease,with 80%of children lacking access to timely,affordable,and safe surgical *** study aims to characterize the burden of disease and outcomes of pediatric surgical conditions at Connaught Hospital,the main pediatric referral hospital in Sierra *** This retrospective and hospital-based study included children up to 15 years old who were operated on between 2015 and June 2016 at Connaught Hospital in Freetown,Sierra *** and inferential statistics were used to characterize the distribution of disease and compare all variables against age category and *** A total of 215 patients were included in this study of which 72.5%(n=132)were male and 27.5%(n=50)were *** of the patients were diagnosed with congenital anomalies(60.9%;n=131).However,infection was the leading diagnosis(60.5%;n=23)among patients aged 5–10 years(n=38).Inguinal hernia was the leading condition(65.0%;n=85)among patients presenting with a congenital *** condition with the highest mortality was infections(17.0%;n=8),followed by other conditions(9.1%;n=2)and congenital anomalies(3.1%;n=4).Based on the results of this study,over 7000 children with inguinal hernias remain untreated annually in Freetown,Sierra *** This study quantifies the burden of surgical disease among children,a foundational step toward the prioritization of pediatric surgical care in national health agendas,the development of evidence-based interventions,and the strategic allocation of resources in Sierra Leone.

关键词： surgical pediatric mortality

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Deciphering the role of PGC-1α in neurological disorders: from mitochondrial dysfunction to synaptic failure

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Neural Regeneration Research 2022年第2期17卷 237-245页

作者： Jessica D.Panes Aline Wendt Oscar ramirez-Molina Patricio A.Castro Jorge Fuentealba Laboratorio de Screening de Compuestos Neuroactivos(LSCN) Departamento de FisiologiaFacultad de Ciencias BiologicasUniversidad de ConcepcionConcepcionChile Centro de Investigaciones Avanzadas en Biomedicina(CIAB-UdeC) Facultad de Ciencias BiologicasUniversidad de ConcepcionConcepcionChile Departamento de Fisiologia Facultad de Ciencias BiologicasUniversidad de ConcepcionConcepcionChile

The onset and mechanisms underlying neurodegenerative diseases remain uncertain. The main features of neurodegenerative diseases have been related with cellular and molecular events like neuronal loss, mitochondrial dysfunction and aberrant accumulation of misfolded proteins or peptides in specific areas of the brain. The most prevalent neurodegenerative diseases belonging to age-related pathologies are Alzheimer's disease, Huntington's disease, Parkinson's disease and amyotrophic lateral sclerosis. Interestingly, mitochondrial dysfunction has been observed to occur during the early onset of several neuropathological events associated to neurodegenerative diseases. The master regulator of mitochondrial quality control and energetic metabolism is the transcriptional coactivator peroxisome proliferator-activated receptor gamma coactivator 1-alpha(PGC-1α). Additionally, it has been observed that PGC-1α appears to be a key factor in maintaining neuronal survival and synaptic transmission. In fact, PGC-1α downregulation in different brain areas(hippocampus, substantia nigra, cortex, striatum and spinal cord) that occurs in function of neurological damage including oxidative stress, neuronal loss, and motor disorders has been seen in several animal and cellular models of neurodegenerative diseases. Current evidence indicates that PGC-1α upregulation may serve as a potent therapeutic approach against development and progression of neuronal damage. Remarkably, increasing evidence shows that PGC-1α deficient mice have neurodegenerative diseases-like features, as well as neurological abnormalities. Finally, we discuss recent studies showing novel specific PGC-1α isoforms in the central nervous system that appear to exert a key role in the age of onset of neurodegenerative diseases and have a neuroprotective function in the central nervous system, thus opening a new molecular strategy for treatment of neurodegenerative diseases. The purpose of this review is to provide an up-t

关键词： Alzheimer's disease amyotrophic lateral sclerosis Huntington's disease mitochondrial dysfunction Parkinson's disease PGC-1α synaptic function vascular dementia

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Carbon concentrations and carbon storage capacity of three old-growth forests in the Sila National Park,Southern Italy

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Journal of Forestry Research 2023年第1期34卷 233-242页

作者： Giovanni Di Matteo Giuseppe Luzzi Antonio Basile angelo Sposato Giada Bertini Ulderico Neri Bruno Pennelli Rosario Napoli Pierfrancesco Nardi Consiglio per la ricerca e l’analisi dell’economia agraria Research Centre for Agriculture and Environment(CREA-AA)Via della Navicella 2-400184 RomeItaly Sila National Park Via NazionaleLorica Di San Giovanni in Fiore87055 CosenzaItaly Consiglio per la ricerca e l’analisi dell’economia agraria Research Centre for Forestry and Wood(CREA-FL)Viale Santa Margherita 8052100 ArezzoItaly

Old-growth forests play a key-role in reducing atmospheric carbon dioxide(CO_(2)) concentrations by storing large CO_(2)amounts in biomass and soil over *** quantifies the carbon pool into different forest compartments in three Mediterranean old-growth forests of Southern Italy populated by Pinus laricio,Fagus sylvatica and Abies *** carbon pools have been assessed per compartment,i.e.,living trees,dead wood,litterfall(foliar and woody),roots and 0-20 cm topsoil,combining the whole old-growth forest mass,(i.e.,using tree allometric relationships,deadwood factor conversions,root-to-shoot ratios,litterfall and soil samplings) by the respective organic carbon *** results show the considerable capacity of these forest ecosystems in storing CO_(2)in biomass and soil,with carbon pool values ranging from 532.2to 596.5 Mg C *** trees and 0-20 cm topsoil had larger carbon pool,contributing 53.0 and 22.1%,*** most cases,organic carbon concentration was higher(more than 60%) than the average carbon conversion rate of 50%,especially in living trees,deadwood,and woody *** study contributes further scientific evidence of the capacity of old-growth forests in storing CO_(2)in their different compartments,with special evidence on tree biomass,litterfall and mineral soil,thereby highlighting the key role of old-growth forests within the challenge of climate change mitigation.

关键词： Ecosystem carbon pool Organic carbon concentration Ecosystem compartment Climate change mitigation Carbon forestry

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Modelling the long-term geomorphic response to check dam failures in an alpine channel with CAESAR-Lisflood

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International Journal of Sediment Research 2022年第5期37卷 687-700页

作者： Jorge Alberto ramirez Mirjam Mertin Nadav Peleg Pascal Horton Chris Skinner Markus Zimmermann Margreth Keiler Institute of Geography University of Bern Oeschger Centre for Climate Change Research University of Bern Institute of Environmental Engineering ETH Zurich Institute of Earth Surface Dynamics University of Lausanne Energy and Environment Institute University of Hull Department of Geography University of Innsbruck Institute for Interdisciplinary Mountain Research Austrian Academy of Sciences

Globally, between 1950 and 2011 nearly 80,000 debris flow fatalities occurred in densely populated regions in mountainous terrain. Mitigation of these hazards includes the construction of check dams,which limit coarse sediment transport and in the European Alps number in the 100,000s. Check dam functionality depends on periodic, costly maintenance, but maintenance is not always possible and check dams often fail. As such, there is a need to quantify the long-term(10-100 years) geomorphic response of rivers to check dam failures. Here, for the first time, a landscape evolution model(CAESARLisflood) driven by a weather generator is used to replicate check dam failures due to the lack of maintenance, check dam age, and flood occurrence. The model is applied to the Guerbe River,Switzerland, a pre-Alpine catchment containing 73 check dams that undergo simulated failure. Also presented is a novel method to calibrate CAESAR-Lisflood?s hydrological component on this ungauged catchment. Using 100-year scenarios of check dam failure, the model indicates that check dam failures can produce 8 m of channel erosion and a 322% increase in sediment yield. The model suggests that after check dam failure, channel erosion is the remobilization of deposits accumulated behind check dams, and, after a single check dam failure channel equilibrium occurs in five years, but after many check dam failures channel equilibrium may not occur until 15 years. Overall, these findings support the continued maintenance of check dams.

关键词： Landscape evolution model Check dam failure Weather generator Natural hazards

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Effect of malathion on the male reproductive organs of earthworms, Eisenia foetida

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Asian Journal of Andrology 2005年第1期7卷 97-101,页

作者： Omar espinoza-Navarro Eduardo Bustos-Obregon Department of Biology and Health Faculty of Sciences University of Tarapacd Arica Chile Laboratory of Biology of Reproduction ICBM Faculty of Medicine University of Chile Santiago Chile

Aim: To observe the cytotoxic effect of the organophosphate insecticide malathion in the reproductive tissues of the earthworms, Eisenia foetida. Methods: Worms were nourished in soil treated with malathion at single sub-lethal doses of 0, 80, 150, 300 and 600 mg-kg^(-1) soil. (LD_(50) = 880 mg kg^(-1) soil) and evaluated on days 1, 5, 15 and 30 after exposure. The body weights were recorded and male reproductive organs evaluated. Results: Malathion-treated animals showed a significant reduction in body weight in a dose-dependent manner. Malathion treatment modified the disposition of spermatozoa in the basal epithelium of the spermatheca. The Br-deoxyuridine test showed a significant rise in cells in phase S on days 5 and 15. Also, a higher percentage of spermatogonia with fragmented DNA were observed by means of the TdT-mediated dUTP nick-end labeling (TUNEL) technique in the spermatheca of treated animals. Conclusion: Treatment with malathion decreased the body weight and the spermatic viability in spermatheca, altering the cell proliferation and modifying the DNA structure of spermatogonia.

关键词： Eiseniafoetida malathion reproductive organs apoptosis

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Albumin administration in patients with cirrhosis: Current role and novel perspectives

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World Journal of Gastroenterology 2022年第33期28卷 4773-4786页

作者： angelo Zambam de Mattos Douglas Alano Simonetto Carlos Terra Alberto Queiroz Farias Paulo Lisboa Bittencourt Tales Henrique Soares Pase Marlon Rubini Toazza angelo Alves de Mattos Alliance of Brazilian Centers for Cirrhosis Care-the ABC Group Graduate Program in Medicine:Hepatology Federal University of Health Sciences of Porto AlegrePorto Alegre 90050-170Brazil Division of Gastroenterology and Hepatology Mayo ClinicRochesterMN 55902United States Department of Gastroenterology State University of Rio de JaneiroRio de Janeiro 20550-170Brazil Department of Gastroenterology University of São PauloSão Paulo 01246-903Brazil Gastroenterology and Hepatology Unit Hospital PortuguêsSalvador 40130-030Brazil Internal Medicine Unit Irmandade Santa Casa de Misericórdia de Porto AlegrePorto Alegre 90020-090Brazil Gastroenterology and Hepatology Unit Irmandade Santa Casa de Misericórdia de Porto AlegrePorto Alegre 90020-090Brazil 不详

Mortality in cirrhosis is mostly associated with the development of clinical decompensation,characterized by ascites,hepatic encephalopathy,variceal bleeding,or ***,it is important to prevent and manage such ***,the pathophysiology of decompensated cirrhosis was explained by the peripheral arterial vasodilation hypothesis,but it is currently understood that decompensation might also be driven by a systemic inflammatory state(the systemic inflammation hypothesis).Considering its oncotic and nononcotic properties,albumin has been thoroughly evaluated in the prevention and management of several of these decompensating *** are formal evidence-based recommendations from international medical societies proposing that albumin be administered in individuals with cirrhosis undergoing large-volume paracentesis,patients with spontaneous bacterial peritonitis,those with acute kidney injury(even before the etiological diagnosis),and those with hepatorenal ***,there are a few randomized controlled trials and meta-analyses suggesting a possible role for albumin infusion in patients with cirrhosis and ascites(long-term albumin administration),individuals with hepatic encephalopathy,and those with acute-on-chronic liver failure undergoing modest-volume *** studies are necessary to elucidate whether albumin administration also benefits patients with cirrhosis and other complications,such as individuals with extraperitoneal infections,those hospitalized with decompensated cirrhosis and hypoalbuminemia,and patients with hyponatremia.

关键词： Cirrhosis Albumin Paracentesis Spontaneous bacterial peritonitis Acute kidney injury Hepatorenal syndrome

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The effects of plyometric jump training on physical fitness attributes in basketball players:A meta-analysis`

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Journal of Sport and Health Science 2022年第6期11卷 656-670,F0003页

作者： Rodrigo ramirez-Campillo Antonio García-Hermoso Jason Moran Helmi Chaabene Yassine Negra Aaron T.Scanlan Department of Physical Activity Sciences Universidad de Los LagosOsorno 5290000Chile Centro de Investigación en Fisiología del Ejercicio Facultad de CienciasUniversidad MayorSantiago 7500000Chile Navarrabiomed Complejo Hospitalario de Navarra(CHN)Universidad Pública de Navarra(UPNA)IdiSNAPamplona 31008Spain Laboratorio de Ciencias de la Actividad Física el Deporte y la SaludUniversidad de Santiago de ChileUSACHSantiago 9170020Chile School of Sport Rehabilitation and Exercise SciencesUniversity of EssexColchesterEssexCO43SQUnited Kingdom Division of Training and Movement Sciences University of PotsdamPotsdam 14469Germany High Institute of Sports and Physical Education KefUniversity of JendoubaLa Manouba 8189Tunisia Research Unit(UR 17JS01 Sport PerformanceHealth&Society)Higher Institute of Sport and Physical Education of Ksar SaîdUniversity of“La Manouba”Rockhampton 2037Tunisia Human Exercise and Training Laboratory School of HealthMedical and Applied SciencesCentral Queensland UniversityRockhamptonQueenslandQLD 4702Australia

Background:There is a growing body of experimental evidence examining the effects of plyometric jump training(PJT)on physical fitness attributes in basketball players;however,this evidence has not yet been comprehensively and systematically ***,our objective was to meta-analyze the effects of PJT on physical fitness attributes in basketball players,in comparison to a control ***:A systematic literature search was conducted in the databases PubMed,Web of Science,and Scopus,up to July ***-reviewed controlled trials with baseline and follow-up measurements investigating the effects of PJT on physical fitness attributes(muscle power,i.e.,jumping performance,linear sprint speed,change-of-direction speed,balance,and muscle strength)in basketball players,with no restrictions on their playing level,sex,or ***’s g effect sizes(ES)were calculated for physical fitness *** a random-effects model,potential sources of heterogeneity were selected,including subgroup analyses(age,sex,body mass,and height)and single training factor analysis(program duration,training frequency,and total number of training sessions).Computation of metaregression was also ***:Thirty-two studies were included,involving 818 total basketball ***(p10 m(ES=0.92),change-of-direction performance time across distances≤40 m(ES=1.15)and>40 m(ES=1.02),dynamic(ES=1.16)and static balance(ES=1.48),and maximal strength(ES=0.57).The meta-regression revealed that training duration,training frequency,and total number of sessions completed did not predict the effects of PJT on physical fitness *** analysis indicated greater improvement

关键词： Exercise therapy Human physical conditioning Resistance training Stretch reflex Team sports

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