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Straw return increases crop production by improving soil organic carbon sequestration and soil aggregation in a long-term wheat-cotton cropping system 被引量:2
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作者 Changqin Yang Xiaojing Wang +6 位作者 Jianan Li Guowei Zhang Hongmei Shu Wei Hu Huanyong Han Ruixian Liu Zichun Guo 《Journal of Integrative Agriculture》 SCIE CAS CSCD 2024年第2期669-679,共11页
Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cott... Straw return is a promising strategy for managing soil organic carbon(SOC)and improving yield stability.However,the optimal straw return strategy for sustainable crop production in the wheat(Triticum aestivum L.)-cotton(Gossypium hirsutum L.)cropping system remains uncertain.The objective of this study was to quantify the long-term(10 years)impact of carbon(C)input on SOC sequestration,soil aggregation and crop yields in a wheat-cotton cropping system in the Yangtze River Valley,China.Five treatments were arranged with a single-factor randomized design as follows:no straw return(Control),return of wheat straw only(Wt),return of cotton straw only(Ct),return of 50%wheat and 50%cotton straw(Wh-Ch)and return of 100%wheat and 100%cotton straw(Wt-Ct).In comparison to the Control,the SOC content increased by 8.4 to 20.2%under straw return.A significant linear positive correlation between SOC sequestration and C input(1.42-7.19 Mg ha^(−1)yr^(−1))(P<0.05)was detected.The percentages of aggregates of sizes>2 and 1-2 mm at the 0-20 cm soil depth were also significantly elevated under straw return,with the greatest increase of the aggregate stability in the Wt-Ct treatment(28.1%).The average wheat yields increased by 12.4-36.0%and cotton yields increased by 29.4-73.7%,and significantly linear positive correlations were also detected between C input and the yields of wheat and cotton.The average sustainable yield index(SYI)reached a maximum value of 0.69 when the C input was 7.08 Mg ha^(−1)yr^(−1),which was close to the maximum value(SYI of 0.69,C input of 7.19 Mg ha^(−1)yr^(-1))in the Wt-Ct treatment.Overall,the return of both wheat and cotton straw was the best strategy for improving SOC sequestration,soil aggregation,yields and their sustainability in the wheat-cotton rotation system. 展开更多
关键词 straw return crop yields SOC soil aggregates wheat-cotton cropping system
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Increased number of symptoms during the acute phase of SARS-CoV-2 infection in athletes is associated with prolonged time to return to full sports performance—AWAREⅧ
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作者 Carolette Snyders Marlise Dyer +2 位作者 Nicola Sewry Esme Jordaan Martin Schwellnus 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第3期280-287,I0001,共9页
Purpose The aim of the study was to identify factors associated with prolonged time to return to full performance(RTFP)in athletes with recent severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.Metho... Purpose The aim of the study was to identify factors associated with prolonged time to return to full performance(RTFP)in athletes with recent severe acute respiratory syndrome coronavirus 2(SARS-CoV-2)infection.Methods Prospective cohort study with cross sectional analysis.A total of 84 athletes with confirmed SARS-CoV-2 infection assessed at a coronavirus disease 2019 recovery clinic gave a history of age,sex,type/level of sport,co-morbidities,pre-infection training hours,and 26 acute SARS-CoV-2 symptoms from 3 categories(“nose and throat”,“chest and neck”,and“whole body”/systemic).Data on days to RTFP were obtained by structured interviews.Factors associated with RTFP were demographics,sport participation,history of co-morbidities,pre-infection training history,and acute symptoms(type,number).Outcomes were:(a)days to RTFP(median,interquartile range(IQR))in asymptomatic(n=7)and symptomatic athletes(n=77),and(b)hazard ratios(HRs;95%confidence interval)for symptomatic athletes with vs.without a factor(univariate,multiple models).HR<1 was predictive of higher percentage chance of prolonged RTFP.Significance was p<0.05.Results Days to RTFP were 30 days(IQR:23–40)for asymptomatic and 64 days(IQR:42–91)for symptomatic participants(p>0.05).Factors associated with prolonged RTFP(univariate models)were:females(HR=0.57;p=0.014),endurance athletes(HR=0.41;p<0.0001),co-morbidity number(HR=0.75;p=0.001),and respiratory disease history(HR=0.54;p=0.026).In symptomatic athletes,prolonged RTFP(multiple models)was significantly associated with increased“chest and neck”(HR=0.85;p=0.017)and“nose and throat”(HR=0.84;p=0.013)symptoms,but the association was more profound between prolonged RFTP and increased total number of“all symptoms”(HR=0.91;p=0.001)and“whole body”/systemic(HR=0.82;p=0.007)symptoms.Conclusion A larger number of total symptoms and specifically“whole body”/systemic symptoms during the acute phase of SARS-CoV-2 infection in athletes is associated with prolonged RTFP. 展开更多
关键词 ATHLETES COVID-19 Performance Recovery return to play
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Symptom presentation and evolution in the first 48 hours after injury are associated with return to play after concussion in elite Rugby Union
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作者 Ross Tucker Matt Cross +7 位作者 Keith Stokes Lindsay Starling Rosy Hyman Simon Kemp Stephen West Martin Raftery Eanna Falvey James Brown 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第3期387-397,共11页
Background:Return to play(RTP)in elite rugby is managed using a 6-stage graduated RTP protocol,which can result in clearance to play within 1 week of injury.We aimed to explore how symptom,cognitive,and balance presen... Background:Return to play(RTP)in elite rugby is managed using a 6-stage graduated RTP protocol,which can result in clearance to play within 1 week of injury.We aimed to explore how symptom,cognitive,and balance presentation and evolution during concussion screens 2 h(head injury assessment(HIA2)and 48 h(HIA3)after injury were associated with time to RTP)to identify whether a more conservative graduated RTP may be appropriate.Methods:A retrospective cohort study was conducted in 380 concussed rugby players from elite men’s rugby over 3 consecutive seasons.Players were classified as shorter or longer returns,depending on whether RTP occurred within 7 days(allowing them to be considered to play the match 1 week after injury)or longer than 8 days,respectively.Symptom,cognitive,and balance performance during screens was assessed relative to baseline(normal or abnormal)and to the preceding screen(improving or worsening).Associations between sub-test abnormalities and RTP time were explored using odds ratios(OR,longer vs.shorter).Median day absence was compared between players with abnormal or worsening results and those whose results were normal or improving.Results:Abnormal symptom results during screens 2 h and 48 h after concussion were associated with longer return time(HIA2:OR=2.21,95%confidence interval(95%CI):1.39-3.50;HIA3:OR=3.30,95%CI:1.89-5.75).Worsening symptom number or severity from the time of injury to 2 h and 48 h post-injury was associated with longer return(HIA2:OR=2.49,95%CI:1.36-4.58;HIA3:OR=3.34,95%CI:1.10-10.15).Median days absence was greater in players with abnormal symptom results at both HIA2 and HIA3.Cognitive and balance performance were not associated with longer return and did not affect median days absence.Conclusion:Symptom presentation and evolution within 48 h of concussion were associated with longer RTP times.This may guide a more conservative approach to RTP,while still adhering to individualized concussion management principles. 展开更多
关键词 Brain injury Concussion management General return to play Medical management
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Early endotracheal intubation is not associated with the rate of return of spontaneous circulation following cardiac arrest at the emergency department:an exploratory analysis
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作者 Siwat Neamjun Phichayut Phinyo +1 位作者 Borwon Wittayachamnankul Wachira Wongtanasarasin 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第4期297-300,共4页
Cardiac arrest poses a significant global public health challenge,manifesting in approximately 550,000 cases annually within the United States.[1]In-hospital cardiac arrest(IHCA)is commonly attributed to airways and r... Cardiac arrest poses a significant global public health challenge,manifesting in approximately 550,000 cases annually within the United States.[1]In-hospital cardiac arrest(IHCA)is commonly attributed to airways and respiratory issues.[2]Recommendations emphasize the expertise of responders in airway management.[3]Various options exist,such as chest compression-only cardiopulmonary resuscitation(CPR),bag-mask ventilation(BMV),and advanced airways.The BMV and advanced airways are not deemed equivalent or superior based on previous evidence.[4]Achieving consistency in choosing and timing the optimal airway approach during IHCA is crucial.The current American Heart Association guidelines suggest an advanced airway strategy when endotracheal intubation(ETI)success rates are high,but the optimal time for advanced airway management remains unclear.[5]Wong et al[6]revealed that survival improved by less than 5 min with advanced airway management.According to a subgroup analysis of IHCA patients in emergency departments(EDs),early intubation was associated with a 1.5-fold greater rate of return of spontaneous circulation(ROSC)than in other locations.[7]ED patients’constant monitoring and immediate management,with readily available intubation equipment,enhance early intubation and survival rates.[6]Nonetheless,IHCA patients intubated within the first 15 min had a lower ROSC rate. 展开更多
关键词 INTUBATION return annually
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Eight of ten patients return to daily activities, work, and sports after total knee arthroplasty
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作者 Maud Cornelia Wilhelmina Maria Peters Yvette Pronk Justus-Martijn Brinkman 《World Journal of Orthopedics》 2024年第7期608-617,共10页
BACKGROUND Besides return to work(RTW)and return to sports(RTS),patients also prefer to return to daily activities(RTA)such as walking,sleeping,grocery shopping,and domestic work following total knee arthroplasty(TKA)... BACKGROUND Besides return to work(RTW)and return to sports(RTS),patients also prefer to return to daily activities(RTA)such as walking,sleeping,grocery shopping,and domestic work following total knee arthroplasty(TKA).However,evidence on the timelines and probability of patients’RTA is sparse.AIM To assess the percentage of patients able to RTA,RTW,and RTS after TKA,as well as the timeframe and influencing factors of this return.METHODS A retrospective cohort study with prospectively collected data was conducted at a medium-sized Dutch orthopedic hospital.Assessments of RTA,RTW,and RTS were performed at 3 mo and/or 6 mo following TKA.Investigated factors en-compassed patient characteristics,surgical characteristics,and preoperative patient-reported outcomes.RESULTS TKA patients[n=2063;66 years old(interquartile range[IQR]:7 years);47%male;28 kg/m2(IQR:4 kg/m2)]showed RTA ranging from 28%for kneeling to 94%for grocery shopping,with 20 d(IQR:27 d)spent for putting on shoes to 74 d(IQR:57 d)for kneeling.RTW rates varied from 62%for medium-impact work to 87%for low-impact work,taking 33 d(IQR:29 d)to 78 d(IQR:55 d).RTS ranged from 48%for medium-impact sports to 90%for low-impact sports,occurring within 43 d(IQR:24 d)to 90 d(IQR:60 d).One or more of the investigated factors influenced the return to each of the 14 activities examined,with R²values ranging from 0.013 to 0.127.CONCLUSION Approximately 80%of patients can RTA,RTW,and RTS within 6 mo after TKA.Return is not consistently in-fluenced by predictive factors.Results help set realistic pre-and postoperative expectations. 展开更多
关键词 KNEE ARTHROPLASTY Replacement return to work return to daily activities return to sports
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A novel predictor of unsustained return of spontaneous circulation in cardiac arrest patients through a combination of capnography and pulse oximetry: a multicenter observational study
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作者 Jing Yang Hanqi Tang +11 位作者 Shihuan Shao Feng Xu Yangyang Fu Shengyong Xu Chen Li Yan Li Yang Liu Joseph Harold Walline Huadong Zhu Yuguo Chen Xuezhong Yu Jun Xu 《World Journal of Emergency Medicine》 SCIE CAS CSCD 2024年第1期16-22,共7页
BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysm... BACKGROUND:Unsustained return of spontaneous circulation(ROSC)is a critical barrier to survival in cardiac arrest patients.This study examined whether end-tidal carbon dioxide(ETCO_(2))and pulse oximetry photoplethysmogram(POP)parameters can be used to identify unsustained ROSC.METHODS:We conducted a multicenter observational prospective cohort study of consecutive patients with cardiac arrest from 2013 to 2014.Patients’general information,ETCO_(2),and POP parameters were collected and statistically analyzed.RESULTS:The included 105 ROSC episodes(from 80 cardiac arrest patients)comprised 51 sustained ROSC episodes and 54 unsustained ROSC episodes.The 24-hour survival rate was significantly higher in the sustained ROSC group than in the unsustained ROSC group(29.2%vs.9.4%,P<0.05).The logistic regression analysis showed that the difference between after and before ROSC in ETCO_(2)(ΔETCO_(2))and the difference between after and before ROCS in area under the curve of POP(ΔAUCp)were independently associated with sustained ROSC(odds ratio[OR]=0.931,95%confi dence interval[95%CI]0.881-0.984,P=0.011 and OR=0.998,95%CI 0.997-0.999,P<0.001).The area under the receiver operating characteristic curve ofΔETCO_(2),ΔAUCp,and the combination of both to predict unsustained ROSC were 0.752(95%CI 0.660-0.844),0.883(95%CI 0.818-0.948),and 0.902(95%CI 0.842-0.962),respectively.CONCLUSION:Patients with unsustained ROSC have a poor prognosis.The combination ofΔETCO_(2) andΔAUCp showed signifi cant predictive value for unsustained ROSC. 展开更多
关键词 return of spontaneous circulation Pulse oximetry photoplethysmogram End-tidal carbon dioxide Cardiac arrest Cardiopulmonary resuscitation
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Fast solution to the free return orbit's reachable domain of the manned lunar mission by deep neural network
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作者 YANG Luyi LI Haiyang +1 位作者 ZHANG Jin ZHU Yuehe 《Journal of Systems Engineering and Electronics》 SCIE CSCD 2024年第2期495-508,共14页
It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly eval... It is important to calculate the reachable domain(RD)of the manned lunar mission to evaluate whether a lunar landing site could be reached by the spacecraft. In this paper, the RD of free return orbits is quickly evaluated and calculated via the classification and regression neural networks. An efficient databasegeneration method is developed for obtaining eight types of free return orbits and then the RD is defined by the orbit’s inclination and right ascension of ascending node(RAAN) at the perilune. A classify neural network and a regression network are trained respectively. The former is built for classifying the type of the RD, and the latter is built for calculating the inclination and RAAN of the RD. The simulation results show that two neural networks are well trained. The classification model has an accuracy of more than 99% and the mean square error of the regression model is less than 0.01°on the test set. Moreover, a serial strategy is proposed to combine the two surrogate models and a recognition tool is built to evaluate whether a lunar site could be reached. The proposed deep learning method shows the superiority in computation efficiency compared with the traditional double two-body model. 展开更多
关键词 manned lunar mission free return orbit reachable domain(RD) deep neural network computation efficiency
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Influencing Factors and Prediction of Risk of Returning to Ecological Poverty in Liupan Mountain Region,China
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作者 CUI Yunxia LIU Xiaopeng +2 位作者 JIANG Chunmei TIAN Rujun NIU Qingrui 《Chinese Geographical Science》 SCIE CSCD 2024年第3期420-435,共16页
China has resolved its overall regional poverty in 2020 by attaining moderate societal prosperity.The country has entered a new development stage designed to achieve its second centenary goal.However,ecological fragil... China has resolved its overall regional poverty in 2020 by attaining moderate societal prosperity.The country has entered a new development stage designed to achieve its second centenary goal.However,ecological fragility and risk susceptibility have increased the risk of returning to ecological poverty.In this paper,the Liupan Mountain Region of China was used as a case study,and the counties were used as the scale to reveal the spatiotempora differentiation and influcing factors of the risk of returning to poverty in study area.The indicator data for returning to ecological poverty from 2011-2020 were collected and summarized in three dimensions:ecological,economic and social.The autoregressive integrated moving average model(ARIMA)time series and exponential smoothing method(ES)were used to predict the multidimensional indicators of returning to ecological poverty for 61 counties(districts)in the Liupan Mountain Region for 2021-2030.The back propagation neural network(BPNN)and geographic information system(GIS)were used to generate the spatial distribution and time variation for the index of the risk of returning to ecological poverty(RREP index).The results show that 1)ecological factors were the main factors in the risk of returning to ecological poverty in Liupan Mountain Region.2)The RREP index for the 61 counties(districts)exhibited a downward trend from 2021-2030.The RREP index declined more in medium-and high-risk areas than in low-risk areas.From 2021 to 2025,the RREP index exhibited a slight downward trend.From 2026 to2030,the RREP index was expected to decline faster,especially from 2029-2030.3)Based on the RREP index,it can be roughly divided into three types,namely,the high-risk areas,the medium-risk areas,and the low-risk areas.The natural resource conditions in lowrisk areas of returning to ecological poverty,were better than those in medium-and high-risk areas. 展开更多
关键词 risk of returning to ecological poverty autoregressive integrated moving average model(ARIMA) exponential smoothing model back propagation neural network(BPNN) Liupan Mountain Region China
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Exploring influences and risk of bias of studies on return to sport and work after lateral ankle sprain:A systematic review and metaanalysis
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作者 Priscilla A Maria Gwendolyn Vuurberg Gino MMJ Kerkhoffs 《World Journal of Meta-Analysis》 2024年第1期11-25,共15页
BACKGROUND Lateral ankle sprains are the most common traumatic musculoskeletal injuries of the lower extremity,with an incidence rate of 15%-20%.The high incidence and prevalence highlights the economic impact of this... BACKGROUND Lateral ankle sprains are the most common traumatic musculoskeletal injuries of the lower extremity,with an incidence rate of 15%-20%.The high incidence and prevalence highlights the economic impact of this injury.Ankle sprains lead to a high socioeconomic burden due to the combination of the high injury incidence and high medical expenses.Up to 40%of patients who suffer from an ankle sprain develop chronic ankle instability.Chronic instability can lead to prolonged periods of pain,immobility and injury recurrence.Identification of factors that influence return to work(RTW)and return to sports(RTS)after a lateral ankle sprain(LAS)may help seriously reduce healthcare costs.AIM To explore which factors may potentially affect RTW and RTS after sustaining an LAS.METHODS EMBASE and PubMed were systematically searched for relevant studies published until June 2023.Inclusion criteria were as follows:(1)Injury including LAS or chronic ankle instability;(2)Described any form of treatment;(3)Assessment of RTW or RTS;(4)Studies published in English;and(5)Study designs including randomized controlled clinical trials,clinical trials or cohort studies.Exclusion criteria were:(1)Studies involving children(age<16 year);or(2)Patients with concomitant ankle injury besides lateral ankle ligament damage.A quality assessment was performed for each of the included studies using established risk of bias tools.Additionally quality of evidence was assessed using the GRADEpro tool in cases where outcomes were included in the quantitative analysis.A best evidence synthesis was performed in cases of qualitative outcome analysis.For all studied outcomes suitable for quantitative analysis a forest plot was created to calculate the effect on RTW and RTS.RESULTS A total of 8904 patients were included in 21 studies,10 randomized controlled trials,7 retrospective cohort studies and 4 prospective cohort studies.Fifteen studies were eligible for meta-analysis.The overall RTS rate ranged were 80%and 83%in the all treatments pool and surgical treatments pool,respectively.The pooled mean days to RTS ranged from 23-93 d.The overall RTW rate was 89%.The pooled mean time to RTW ranged from 5.8-8.1 d.For patients with chronic ankle instability,higher preoperative motivation was the sole factor significantly and independently(P=0.001)associated with the rate of and time to RTS following ligament repair or reconstruction.Higher body mass index was identified as a significant factor(P=0.04)linked to not resuming sports or returning at a lower level(median 24,range 20-37),compared to those who resumed at the same or higher level(median 23,range 17-38).Patients with a history of psychological illness or brain injury,experienced a delay in their rehabilitation process for sprains with fractures and unspecified sprains.The extent of the delayed rehabilitation was directly proportional to the increased likelihood of experiencing a recurrence of the ankle sprain and the number of ankle-related medical visits.We also observed that 10%of athletes who did return to sport after lateral ankle sprain without fractures described non-ankle-related reasons for not returning.CONCLUSION All treatments yielded comparable results,with each treatment potentially offering unique advantages or benefits.Preoperative motivation may influence rehabilitation after LAS.Grading which factor had a greater impact was not possible due to the lack of comparability among the included patients. 展开更多
关键词 Ankle sprain Prognostic factors BIAS return to work return to sport Preoperative motivation
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Exploring the Factors Associated with 12-Month Non-Return to Work among Motorcyclists Involved in Road Accidents
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作者 Yolaine Glèlè-Ahanhanzo Donatien Daddah +2 位作者 Alphonse Kpozehouen Bella Hounkpè Dos Santos Moussiliou N. Paraiso 《Open Journal of Preventive Medicine》 2024年第1期1-16,共16页
Introduction: Motorcyclists bear a disproportionate burden of morbidity and mortality from road accidents. In addition, the consequences of these accidents affect the ability of victims to return to work. This study a... Introduction: Motorcyclists bear a disproportionate burden of morbidity and mortality from road accidents. In addition, the consequences of these accidents affect the ability of victims to return to work. This study aimed to determine the prevalence and factors associated with non-return to work among surviving motorcyclists involved in road accidents 12 months after the event. Materials and Methods: It was a cross-sectional study conducted using data from a cohort of motorcyclists involved in accidents and recruited in five hospitals in Benin from July 2019 to January 2020. The dependent variable was non-return to work 12 months after the accident (yes vs no). The independent variables were categorized into two groups: baseline and 12-month follow-up variables. Logistic regression was used to determine the factors associated with non-return to work at 12 months among the participants. Results: Among the 362 participants, 55 (15.19%, 95% CI = 11.84 - 19.29) had not returned to work 12 months after the accident. Risk factors for non-return to work identified were: smoking (aOR = 4.41, 95% CI = 1.44 - 13.56, p = 0.010), hospitalization (aOR = 2.87, 95% CI = 1.14 - 7.24, p Conclusion: The prevalence of non-return to work at 12 months was high among surviving motorcyclists involved in road accidents in Benin. Integrated support for patients based on identified risk factors should effectively improve their return to work. 展开更多
关键词 Road Accident return to Work MOtoRCYCLISTS HOSPITAL Mental Health COHORT BENIN
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Exploring the Relationship Between Patent Forward Citation and Stock Return Rate Using Empirical Data of China Stock Market
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作者 Hong-Wen Tsai Hui-Chung Che 《Management Studies》 2024年第2期67-83,共17页
A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than tw... A novel indicator called price-citation was proposed.Based on the company integrated patent database of China listed companies of common stocks(A-shares)with the stock price and the stock return rate data,more than two thousand of A-shares from 2017 to 2020 were selected.The effect of the traditional patent forward citation and the price-citation for discriminating the stock return rate was thoroughly analyzed via ANOVA.The A-shares of forward citation counts above the average showed higher stock return rate means than the A-shares having patents but receiving no forward citations.The price-citation,combining both the financial and patent attributes,defined as the multiplication of the current stock price and the currently receiving forward citation count,showed its excellence in discriminating the stock return rate.The A-shares of higher price-citation showed significantly higher stock return rate means while the A-shares of lower price-citation showed significantly lowest stock return rate means.The price-citation effect had not been changed by COVID-19 though COVID-19 affected the social and economic environment to a considerable extent in 2020. 展开更多
关键词 China A-share PATENT ANOVA stock return rate forward citation price-citation
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China's New Proposal of Returning Lost Cultural Objects Earns International Support Milestone in New Era
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作者 Chen Xi 《China & The World Cultural Exchange》 2024年第7期22-26,共5页
China launched a recommendation for the protection and return of cultural objects removed from colonial contexts or acquired by other unjustifiable or unethical means,winning a big applause from many countries which a... China launched a recommendation for the protection and return of cultural objects removed from colonial contexts or acquired by other unjustifiable or unethical means,winning a big applause from many countries which are seeking for more cooperation in solving this serious problem. 展开更多
关键词 MILES return removed
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Using Return and Risk Model for Choosing Perfect Portfolio Applied Study in Cairo Stock Exchange
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作者 Essam Al Arbed 《American Journal of Operations Research》 2024年第1期32-58,共27页
Modern financial theory, commonly known as portfolio theory, provides an analytical framework for the investment decision to be made under uncertainty. It is a well-established proposition in portfolio theory that whe... Modern financial theory, commonly known as portfolio theory, provides an analytical framework for the investment decision to be made under uncertainty. It is a well-established proposition in portfolio theory that whenever there is an imperfect correlation between returns risk is reduced by maintaining only a portion of wealth in any asset, or by selecting a portfolio according to expected returns and correlations between returns. The major improvement of the portfolio approaches over prior received theory is the incorporation of 1) the riskiness of an asset and 2) the addition from investing in any asset. The theme of this paper is to discuss how to propose a new mathematical model like that provided by Markowitz, which helps in choosing a nearly perfect portfolio and an efficient input/output. Besides applying this model to reality, the researcher uses game theory, stochastic and linear programming to provide the model proposed and then uses this model to select a perfect portfolio in the Cairo Stock Exchange. The results are fruitful and the researcher considers this model a new contribution to previous models. 展开更多
关键词 Game Theory Stochastic and Linear Programming Perfect Portfolio Portfolio Theory returns and Risks
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Return direction forecasting:a conditional autoregressive shape model with beta density
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作者 Haibin Xie Yuying Sun Pengying Fan 《Financial Innovation》 2023年第1期2251-2266,共16页
This paper derives a new decomposition of stock returns using price extremes and proposes a conditional autoregressive shape(CARS)model with beta density to predict the direction of stock returns.The CARS model is con... This paper derives a new decomposition of stock returns using price extremes and proposes a conditional autoregressive shape(CARS)model with beta density to predict the direction of stock returns.The CARS model is continuously valued,which makes it different from binary classification models.An empirical study is performed on the US stock market,and the results show that the predicting power of the CARS model is not only statistically significant but also economically valuable.We also compare the CARS model with the probit model,and the results demonstrate that the proposed CARS model outperforms the probit model for return direction forecasting.The CARS model provides a new framework for return direction forecasting. 展开更多
关键词 return direction forecasting Price extremes CARS Beta distribution
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Robust monitoring machine:a machine learning solution for out‑of‑sample R_(2)‑hacking in return predictability monitoring
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作者 James Yae Yang Luo 《Financial Innovation》 2023年第1期2701-2728,共28页
The out-of-sample R^(2) is designed to measure forecasting performance without look-ahead bias.However,researchers can hack this performance metric even without multiple tests by constructing a prediction model using ... The out-of-sample R^(2) is designed to measure forecasting performance without look-ahead bias.However,researchers can hack this performance metric even without multiple tests by constructing a prediction model using the intuition derived from empirical properties that appear only in the test sample.Using ensemble machine learning techniques,we create a virtual environment that prevents researchers from peeking into the intuition in advance when performing out-of-sample prediction simulations.We apply this approach to robust monitoring,exploiting a dynamic shrink-age effect by switching between a proposed forecast and a benchmark.Considering stock return forecasting as an example,we show that the resulting robust monitoring forecast improves the average performance of the proposed forecast by 15%(in terms of mean-squared-error)and reduces the variance of its relative performance by 46%while avoiding the out-of-sample R^(2)-hacking problem.Our approach,as a final touch,can further enhance the performance and stability of forecasts from any models and methods. 展开更多
关键词 Machine learning Out-of-sample R^(2)-hacking return predictability MONItoRING
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Return to sport following toe phalanx fractures:A systematic review
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作者 Greg A J Robertson Amit Sinha +1 位作者 Thomas Hodkinson Togay Koç 《World Journal of Orthopedics》 2023年第6期471-484,共14页
BACKGROUND Evidence-based guidance on return to sport following toe phalanx fractures is limited.AIM To systemically review all studies recording return to sport following toe phalanx fractures(both acute fractures an... BACKGROUND Evidence-based guidance on return to sport following toe phalanx fractures is limited.AIM To systemically review all studies recording return to sport following toe phalanx fractures(both acute fractures and stress fractures),and to collate information on return rates to sport(RRS)and mean return times(RTS)to the sport.METHODS A systematic search of PubMed,MEDLINE,EMBASE,CINAHL,Cochrane Library,Physiotherapy Evidence Database,and Google Scholar was performed in December 2022 using the keywords‘Toe’,‘Phalanx’,‘Fracture’,‘injury’,‘athletes’,‘sports’,‘non-operative’,‘conservative’,‘operative’,‘return to sport’.All studies which recorded RRS and RTS following toe phalanx fractures were included.RESULTS Thirteen studies were included:one retrospective cohort study and twelve case series.Seven studies reported on acute fractures.Six studies reported on stress fractures.For the acute fractures(n=156),63 were treated with primary conservative management(PCM),6 with primary surgical management(PSM)(all displaced intra-articular(physeal)fractures of the great toe base of the proximal phalanx),1 with secondary surgical management(SSM)and 87 did not specify treatment modality.For the stress fractures(n=26),23 were treated with PCM,3 with PSM,and 6 with SSM.For acute fractures,RRS with PCM ranged from 0 to 100%,and RTS with PCM ranged from 1.2 to 24 wk.For acute fractures,RRS with PSM were all 100%,and RTS with PSM ranged from 12 to 24 wk.One case of an undisplaced intra-articular(physeal)fracture treated conservatively required conversion to SSM on refracture with a return to sport.For stress fractures,RRS with PCM ranged from 0%to 100%,and RTS with PCM ranged from 5 to 10 wk.For stress fractures,RRS with PSM were all 100%,and RTS with surgical management ranged from 10 to 16 wk.Six cases of conservatively-managed stress fractures required conversion to SSM.Two of these cases were associated with a prolonged delay to diagnosis(1 year,2 years)and four cases with an underlying deformity[hallux valgus(n=3),claw toe(n=1)].All six cases returned to the sport after SSM.CONCLUSION The majority of sport-related toe phalanx fractures(acute and stress)are managed conservatively with overall satisfactory RRS and RTS.For acute fractures,surgical management is indicated for displaced,intra-articular(physeal)fractures,which offers satisfactory RRS and RTS.For stress fractures,surgical management is indicated for cases with delayed diagnosis and established nonunion at presentation,or with significant underlying deformity:both can expect satisfactory RRS and RTS. 展开更多
关键词 ACUTE Stress Fracture toE PHALANX return SPORT Rate Time
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Returning to Yiwu
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作者 MA LI 《China Today》 2023年第3期34-37,共4页
The risk of a global recession in 2023 continues to increase,and products from Yiwu will resume supplying the world,injecting new vitality into the world economy.HAVING worked and lived in Yiwu,Zhejiang Province,for m... The risk of a global recession in 2023 continues to increase,and products from Yiwu will resume supplying the world,injecting new vitality into the world economy.HAVING worked and lived in Yiwu,Zhejiang Province,for more than two decades,trading company owner Tirera Sourakhata from Senegal will return to his second home in late February.“I dream of meeting[up with]my Chinese friends[again]and am really looking forward to it,”said Sourakhata,who has been outside of China for the past three years,due to the COVID-19 restrictions. 展开更多
关键词 return OUTSIDE RESUME
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A Critical Review of the Effects of Stock Returns and Market Timing on Capital Structure
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作者 YE Hongru JI Jie ZOU Yuanyuan 《Management Studies》 2023年第6期312-321,共10页
Capital structure is regarded as the combination of debt and equity firms used to finance operations and investments.The choice of capital structure significantly impacts a company’s cost of capital,profitability,and... Capital structure is regarded as the combination of debt and equity firms used to finance operations and investments.The choice of capital structure significantly impacts a company’s cost of capital,profitability,and risk profile.Among a series of factors that affect capital structure,this paper focuses on stock returns and market timing.In this review,an array of papers is analyzed to summarize what current research claims regarding the influence of stock returns and market timing on capital structure.This paper centers on the stock return and market timing theories and also discusses other theories like the trade-off theory,the pecking order theory,and the signaling theory. 展开更多
关键词 capital structure stock returns market timing
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Gut microbiota affects the estrus return of sows by regulating the metabolism of sex steroid hormones
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作者 Min Liu Jia Zhang +11 位作者 Yunyan Zhou Shuqi Xiong Mengqing Zhou Lin Wu Qin Liu Zhe Chen Hui Jiang Jiawen Yang Yuxin Liu Yaxiang Wang Congying Chen Lusheng Huang 《Journal of Animal Science and Biotechnology》 SCIE CAS CSCD 2024年第2期578-599,共22页
Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the ext... Background Sex hormones play important roles in the estrus return of post-weaning sows.Previous studies have demonstrated a complex and bi-directional regulation between sex hormones and gut microbiota.However,the extent to which the gut microbiota affects estrus return of post-weaning sows is largely unknown.Results In this study,we first screened 207 fecal samples from well-phenotyped sows by 16S rRNA gene sequencing and identified significant associations between microbes and estrus return of post-weaning sows.Using metagenomic sequencing data from 85 fecal samples,we identified 37 bacterial species that were significantly associated with estrus return.Normally returning sows were characterized by increased abundances of L.reuteri and P.copri and decreased abundances of B.fragilis,S.suis,and B.pseudolongum.The changes in gut microbial composition significantly altered the functional capacity of steroid hormone biosynthesis in the gut microbiome.The results were confirmed in a validation cohort.Significant changes in sex steroid hormones and related compounds were found between normal and non-return sows via metabolome analysis.An integrated analysis of differential bacterial species,metagenome,and fecal metabolome provided evidence that normal return-associated bacterial species L.reuteri and Prevotella spp.participated in the degradation of pregnenolone,progesterone,and testosterone,thereby promoting estrogen biosynthesis.Furthermore,the microbial metabolites related to sow energy and nutrient supply or metabolic disorders also showed relationships with sow estrus return.Conclusions An integrated analysis of differentially abundant bacterial species,metagenome,and fecal metabolome revealed the involvement of L.reuteri and Prevotella spp.in sow estrus return.These findings provide deep insight into the role of gut microbiota in the estrus return of post-weaning sows and the complex cross-talk between gut microbiota and sex hormones,suggesting that the manipulation of the gut microbiota could be an effective strategy to improve sow estrus return after weaning. 展开更多
关键词 Estrus return Fecal metabolome Gut microbiota METAGENOMICS Sex steroid hormones SOW
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Go to the back before going forward:Addressing psychological responses in anterior cruciate ligament reconstruction rehabilitation
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作者 Terese L.Chmielewski Adam Meierbachtol +3 位作者 Rick Aberman Travis Gunderson Jonathon Sikorski Kathleen Cummer 《Journal of Sport and Health Science》 SCIE CAS CSCD 2024年第5期666-669,共4页
Helping athletes return to sports participation is a primary goal of anterior cruciate ligament(ACL)reconstruction rehabilitation.To facilitate the achievement of this goal,decades of research studies have sought to i... Helping athletes return to sports participation is a primary goal of anterior cruciate ligament(ACL)reconstruction rehabilitation.To facilitate the achievement of this goal,decades of research studies have sought to identify knee impairments that reduce knee function as well as interventions to resolve them.1Yet,over the past 10 years,research pertaining to psychological responses(i.e.,cognitions and emotions)after ACL reconstruction has grown exponentially—a phenomenon that can be visualized by entering the search terms"psychological"and"anterior cruciate ligament reconstruction"into the PubMed search engine. 展开更多
关键词 LIGAMENT return PSYCHOLOGICAL
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