The reliability of energy systems is strongly influenced by the prevailing climate conditions.With the increasing prevalence of renewable energy sources,the interdependence between energy and climate systems has becom...The reliability of energy systems is strongly influenced by the prevailing climate conditions.With the increasing prevalence of renewable energy sources,the interdependence between energy and climate systems has become even stronger.This study examines the impact of different spatial resolutions in climate modeling on energy grid reliability assessment,with the Texas interconnection between 2033 and 2043 serving as a pilot case study.Our preliminary findings indicate that while low-resolution climate simulations can provide a rough estimate of system reliability,high-resolution simulations can provide more informative assessment of low-adequacy extreme events.Furthermore,both high-and low-resolution assessments suggest the need to prepare for severe blackout events in winter due to extremely low temperatures.展开更多
The aim of this study is to investigate the mechanism of magnesium isoglycyrrhizinate(MgIG)in the treatment of myocardial remodeling induced by isoproterenol(ISO)in mice.We assessed the impact of MgIG on ISO-induced m...The aim of this study is to investigate the mechanism of magnesium isoglycyrrhizinate(MgIG)in the treatment of myocardial remodeling induced by isoproterenol(ISO)in mice.We assessed the impact of MgIG on ISO-induced myocardial remodeling by activating the PI3K/AKT1 pathway.The cardiac function of mice was evaluated by echocardiography,revealing that MgIG could improve left ventricular function.Pathological staining analysis showed that MgIG could reduce the degree of myocardial injury caused by ISO.Serum data detected by ELISA demonstrated that MgIG could decrease the levels of CK-MB,MDA,and LDH while increasing the activity of GSH-Px.Western blotting analysis revealed that protein expression levels of Collagen I,BNP,Bax,cleaved caspase-3,p-PI3K,and p-AKT1 were decreased,whereas the protein expressions of Bcl-2,COX2,and SOD1 were increased upon MgIG treatment.However,the activation of the PI3K pathway reversed the cardioprotective effects of MgIG,as evidenced by the addition of PI3K activators.Taken together,our comprehensive results suggested that MgIG could improve ISO-induced myocardial remodeling,potentially through its mechanism of inhibiting the PI3K/AKT1 pathway to regulate apoptosis and oxidative stress.展开更多
Today, the oil and gas industry, and in particular hydraulic fracturing operations, have come under increasing pressure from regulators and the public to reduce emissions. As the industry evolves, oil and gas producer...Today, the oil and gas industry, and in particular hydraulic fracturing operations, have come under increasing pressure from regulators and the public to reduce emissions. As the industry evolves, oil and gas producers are in the position of evaluating alternative technologies which will support their objectives of reducing their overall emissions profile and carbon footprint. As a response, the deployment of technology and solutions to reduce emissions related to hydraulic fracturing applications has recently accelerated, creating various options to address these industry challenges. BJ Energy Solutions and West Virginia University have been working on the application and emissions characterization of various hydraulic fracturing technologies. A study was conducted to evaluate the efficiency and resultant emissions from various technologies, including natural gas reciprocating engines, diesel-natural gas dual-fuel engines, large (>24 MW) gas turbines, and direct drive turbines. The study involved the development of an emissions model with the purpose of estimating total emissions of carbon dioxide (CO<sub>2</sub>), nitrous oxide (N2O) and exhaust methane (CH<sub>4</sub>) slip, all Greenhouse Gases (GHGs), and converted to tons of CO<sub>2</sub> equivalent emissions per day of operation. The model inputs are the required Hydraulic Horsepower (HHP) based on pumping rate and pressure for various shale play scenarios. The model calculates emissions from the TITAN, which is a direct-drive turbine model fielded by BJ, using data collected following U.S. Environmental Protection Agency (EPA) testing protocols. The model also calculates and compares other hydraulic fracturing technologies utilizing published Original Equipment Manufacturer (OEM) data. Relevant EPA-regulated criteria emissions of oxides of nitrogen (NO<sub>x</sub>), Carbon Monoxide (CO) and Particulate Matter (PM) are also reported. Modeling results demonstrated that in most cases, the TITAN gas turbine system has lower total GHG emissions than conventional diesel and other next-generation technologies, and also has lower criteria emissions. The benefits of the TITAN gas turbine system compared to the other technologies stems from significantly lower methane slip, and the high-power transfer efficiency resulting from directly connecting a turbine to a reciprocating pump, despite the comparatively lower thermal efficiency.展开更多
AIM:To assess objective visual quality after presbyopia correction using the Presby MAX monocular mode.METHODS:This prospective,nonrandomized study included 28 eyes from 18 patients(mean age 50.4±5.6 y)who underw...AIM:To assess objective visual quality after presbyopia correction using the Presby MAX monocular mode.METHODS:This prospective,nonrandomized study included 28 eyes from 18 patients(mean age 50.4±5.6 y)who underwent presbyopia correction with the Presby MAX monocular mode.Monocular and binocular visual acuities were evaluated preoperatively,1 d,1 wk,1,3 mo,and 1 y after surgery.Optical quality was analyzed by HartmannShack wavefront aberration supported cornea ablation.Modulation transfer function(MTF)cutoff frequency,Strehl ratio,and objective scattering index(OSI)were analyzed using an optical quality analysis system.RESULTS:One year after surgery,100%and 94.4%of patients achieved binocular uncorrected distance and near visual acuity of 20/25,respectively.At the last visit Spherical aberration and total higher aberration were higher than the corresponding preoperative levels(P<0.001);however,no significant difference was found in MTF,OSI,or Strehl ratio.Transient decreases in OSI and MTF mainly occurred in the nondominant eyes.There was no significant difference in optical quality between the dominant and nondominant eyes,except for spherical aberration and horizontal coma(P<0.05).CONCLUSION:The Presby MAX monocular mode is safe and effective for presbyopia correction.It has little effect on optical quality,though short-term degraded optical quality occurred mainly in the bi-aspheric ablated eyes.展开更多
AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision(LBV).METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between J...AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision(LBV).METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between Jan 2019 and Aug 2020. The patients were asked to attend a followup outpatient visit one year after surgery. Distance and near visual acuity as well as subjective refraction were examined. Optical quality was assessed using wavefront-supported custom ablation. A questionnaire evaluating optical quality and satisfaction was completed at the last visit.RESULTS: The average patient age was 48.1±7.4 y(range, 41 to 58 y). The mean preoperative spherical equivalent was-7.59±2.39D. At the one-year follow-up, two eyes(both dominant eyes) lost one line of corrected distance visual acuity(CDVA), while the remaining eyes(38/40) maintained or gained lines of CDVA. The average binocular uncorrected distance visual acuity improved from 0.15±0.03 to 0.90±0.26(decimal vision;P<0.001). The average binocular uncorrected near visual acuity increased from 0.34±0.28 to 0.97±0.07(P<0.001). The spherical aberration was 0.04±0.06 μm in the nondominant eye and 0.09±0.09 μm in the dominant eye(P=0.02). All patients were satisfied with or accepted the outcomes of the surgery. The primary complaints were related to disturbances in night vision and relatively inferior near vision.CONCLUSION: Over the one-year observation period, PRESBYOND is a safe and effective option for presbyopia correction. The optical quality and near vision deserve further investigation.展开更多
AIM： To investigate cap morphology after small-incision lenticule extraction （SMILE） and its effects on intraocular scattering. METHODS： Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition ...AIM： To investigate cap morphology after small-incision lenticule extraction （SMILE） and its effects on intraocular scattering. METHODS： Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at ld, lwk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System （OQAS） values, and objective scattering index （OSI）, were evaluated using OQASTM. RESULTS： Cap thickness decreased from ld to lwk （P〈0.001）, but remained higher than intended thickness of 120 μm after 3mo （P〈0.001）. Cap thickness in central area was thinner than that of in the paracentral and peripheral areas （P〈0.0001）. Total number of microdistortions decreased from ld to 3mo （P〈0.0001）. Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at ld and lmo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at ld and lmoafter surgery. CONCLUSION： The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.展开更多
Ferritins can generally be divided into four subfamilies based on their structural characteristics,namely,the classic ferritins(Ftns),bacterioferritins(Bfrs),DNA-binding proteins from starved cells(Dps’),and encapsul...Ferritins can generally be divided into four subfamilies based on their structural characteristics,namely,the classic ferritins(Ftns),bacterioferritins(Bfrs),DNA-binding proteins from starved cells(Dps’),and encapsulated ferritins(Enc Ftns).However,the ferritin from Mycoplasma penetrans(Mpef)possesses a particular ferroxidase center with an extreme low activity and exhibits unusual characteristics,indicating that it could be a member of a quite different subfamily of ferritins.Hereby,the crystal structure of the ferritin from Ureaplasma urealyticum(Uurf)is presented,Mpef and Uurf have very similar properties,though they display very low sequence similarity.Thus,ferritins from Mycoplasma with these unique properties do not belong to any known subfamily,but they should rather be placed in a novel ferritin subfamily,which we term Mycoplasma Ferritin(Mfr).展开更多
With the enrollment expansion of college and continuous reform of college education system and college charging system,the number of college students with financial difficulties is increasing. The college students wit...With the enrollment expansion of college and continuous reform of college education system and college charging system,the number of college students with financial difficulties is increasing. The college students with family financial difficulties not only bear the huge economic burden,but also bear the huge pressure of learning and mental stress,and they have many kinds of psychological problems including psychological distress of tension and anxiety,psychological conflict of self-respect and self-abasement,conflict of desire for interpersonal interaction and self-containment and strong vanity and dependence mentality. This paper puts forward the corresponding recommendations to solve these problems.展开更多
The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing pr...The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing precautionary management strategies.We compare catch advice obtained from applications of various datalimited methods(DLMs)with forecasted catch advice from existing data-rich stock assessment models for the Indian Ocean bigeye tuna(Thunnus obesus).Our goal was to evaluate the consistency of catch advice derived from data-rich methods and data-limited approaches when only a subset of data is available.The Stock Synthesis(SS)results were treated as benchmarks for comparison because they reflect the most comprehensive and best possible scientific information of the stock.This study indicated that although the DLMs examined appeared robust for the Indian Ocean bigeye tuna,the implied catch advice differed between data-limited approaches and the current assessment,due to different data inputs and model assumptions.Most DLMs tended to provide more optimistic catch advice compared with the SS,which was mostly influenced by historical catches,current abundance and depletion estimates,and natural mortality,but was less sensitive to life-history parameters(particularly those related to growth).This study highlights the utility of DLMs and their implications on catch advice for the management of tuna stocks.展开更多
Based on the empirical survey of 2013-2016 college students in Northwest A&F University,we analyze the 9260 valid samples,and the survey involves emotional state,self-worth,psychological adjustment capacity and st...Based on the empirical survey of 2013-2016 college students in Northwest A&F University,we analyze the 9260 valid samples,and the survey involves emotional state,self-worth,psychological adjustment capacity and students’ attitude towards mental health education.On the basis of statistical data,we summarize the general situation of agricultural college students’ mental health,analyze the problems in agricultural college students’ psychological development and bring forward the feasible recommendations.展开更多
Dear Editor, African swine fever (ASF) is a highly contagious disease of domestic pigs caused by African swine fever virus (ASFV),with mortality rates approaching 90%-100%.The first ASF case was described in 1921 in K...Dear Editor, African swine fever (ASF) is a highly contagious disease of domestic pigs caused by African swine fever virus (ASFV),with mortality rates approaching 90%-100%.The first ASF case was described in 1921 in Kenya.Over the past decades, ASF has spread from Sub-Saharan Africa to Europe and Asia, and pose a huge threat to global food safety.Since the first ASF case reported in August 2018, more than 10 million pigs had been culled in China at an enormous economic loss.The risk of ASFV mutating to infect humans is extremely low.However, ASF not only threatens food security but also severely strikes the world economy in many fields, such as the global supply of the blood thinner heparin,most of which is produced from pigs.Hence, ASF is a strictly monitored infectious animal disease by OIE (World Organization for Animal Health), unfortunately, there is no approved drug or vaccine against this lethal viral disease.展开更多
Dear Editor,The African swine fever(ASF)is a highly contagious hemorrhagic and lethal disease in domestic pigs.The ASF outbreaks of in many Asia countries,including China,Vietnam,Mongolia,and South Korea,have posed a ...Dear Editor,The African swine fever(ASF)is a highly contagious hemorrhagic and lethal disease in domestic pigs.The ASF outbreaks of in many Asia countries,including China,Vietnam,Mongolia,and South Korea,have posed a huge threat to the pig indusry.In the attempt to stop ASF from spreading further in China's Mainland,more than 10 million pigs have been culled since August 2018.The causative agent for ASF is a DNA virus,African swine fever virus(ASFV).Although this deadly disease has been reported in Kenya nearly one hundred years ago,there has been no vaccine for protection from ASFV infection or effective treatments to cure ASF until now.展开更多
文摘The reliability of energy systems is strongly influenced by the prevailing climate conditions.With the increasing prevalence of renewable energy sources,the interdependence between energy and climate systems has become even stronger.This study examines the impact of different spatial resolutions in climate modeling on energy grid reliability assessment,with the Texas interconnection between 2033 and 2043 serving as a pilot case study.Our preliminary findings indicate that while low-resolution climate simulations can provide a rough estimate of system reliability,high-resolution simulations can provide more informative assessment of low-adequacy extreme events.Furthermore,both high-and low-resolution assessments suggest the need to prepare for severe blackout events in winter due to extremely low temperatures.
基金Jiangxi Provincial Department of Education Science and Technology Project(Grant No.GJJ2401615)Jiangxi Provincial Department of Education Teaching Reform Project(Grant No.JXJG-24-15-15).
文摘The aim of this study is to investigate the mechanism of magnesium isoglycyrrhizinate(MgIG)in the treatment of myocardial remodeling induced by isoproterenol(ISO)in mice.We assessed the impact of MgIG on ISO-induced myocardial remodeling by activating the PI3K/AKT1 pathway.The cardiac function of mice was evaluated by echocardiography,revealing that MgIG could improve left ventricular function.Pathological staining analysis showed that MgIG could reduce the degree of myocardial injury caused by ISO.Serum data detected by ELISA demonstrated that MgIG could decrease the levels of CK-MB,MDA,and LDH while increasing the activity of GSH-Px.Western blotting analysis revealed that protein expression levels of Collagen I,BNP,Bax,cleaved caspase-3,p-PI3K,and p-AKT1 were decreased,whereas the protein expressions of Bcl-2,COX2,and SOD1 were increased upon MgIG treatment.However,the activation of the PI3K pathway reversed the cardioprotective effects of MgIG,as evidenced by the addition of PI3K activators.Taken together,our comprehensive results suggested that MgIG could improve ISO-induced myocardial remodeling,potentially through its mechanism of inhibiting the PI3K/AKT1 pathway to regulate apoptosis and oxidative stress.
文摘Today, the oil and gas industry, and in particular hydraulic fracturing operations, have come under increasing pressure from regulators and the public to reduce emissions. As the industry evolves, oil and gas producers are in the position of evaluating alternative technologies which will support their objectives of reducing their overall emissions profile and carbon footprint. As a response, the deployment of technology and solutions to reduce emissions related to hydraulic fracturing applications has recently accelerated, creating various options to address these industry challenges. BJ Energy Solutions and West Virginia University have been working on the application and emissions characterization of various hydraulic fracturing technologies. A study was conducted to evaluate the efficiency and resultant emissions from various technologies, including natural gas reciprocating engines, diesel-natural gas dual-fuel engines, large (>24 MW) gas turbines, and direct drive turbines. The study involved the development of an emissions model with the purpose of estimating total emissions of carbon dioxide (CO<sub>2</sub>), nitrous oxide (N2O) and exhaust methane (CH<sub>4</sub>) slip, all Greenhouse Gases (GHGs), and converted to tons of CO<sub>2</sub> equivalent emissions per day of operation. The model inputs are the required Hydraulic Horsepower (HHP) based on pumping rate and pressure for various shale play scenarios. The model calculates emissions from the TITAN, which is a direct-drive turbine model fielded by BJ, using data collected following U.S. Environmental Protection Agency (EPA) testing protocols. The model also calculates and compares other hydraulic fracturing technologies utilizing published Original Equipment Manufacturer (OEM) data. Relevant EPA-regulated criteria emissions of oxides of nitrogen (NO<sub>x</sub>), Carbon Monoxide (CO) and Particulate Matter (PM) are also reported. Modeling results demonstrated that in most cases, the TITAN gas turbine system has lower total GHG emissions than conventional diesel and other next-generation technologies, and also has lower criteria emissions. The benefits of the TITAN gas turbine system compared to the other technologies stems from significantly lower methane slip, and the high-power transfer efficiency resulting from directly connecting a turbine to a reciprocating pump, despite the comparatively lower thermal efficiency.
基金Supported by National Natural Science Foundation of China(No.81770955)National Natural Science Foundation of China for Young Scholar(No.81600762)+1 种基金Project of Shanghai Science and Technology(No.17411950200)Joint Research Project of New Frontier Technology in Municipal Hospitals(No.SHDC12018103)。
文摘AIM:To assess objective visual quality after presbyopia correction using the Presby MAX monocular mode.METHODS:This prospective,nonrandomized study included 28 eyes from 18 patients(mean age 50.4±5.6 y)who underwent presbyopia correction with the Presby MAX monocular mode.Monocular and binocular visual acuities were evaluated preoperatively,1 d,1 wk,1,3 mo,and 1 y after surgery.Optical quality was analyzed by HartmannShack wavefront aberration supported cornea ablation.Modulation transfer function(MTF)cutoff frequency,Strehl ratio,and objective scattering index(OSI)were analyzed using an optical quality analysis system.RESULTS:One year after surgery,100%and 94.4%of patients achieved binocular uncorrected distance and near visual acuity of 20/25,respectively.At the last visit Spherical aberration and total higher aberration were higher than the corresponding preoperative levels(P<0.001);however,no significant difference was found in MTF,OSI,or Strehl ratio.Transient decreases in OSI and MTF mainly occurred in the nondominant eyes.There was no significant difference in optical quality between the dominant and nondominant eyes,except for spherical aberration and horizontal coma(P<0.05).CONCLUSION:The Presby MAX monocular mode is safe and effective for presbyopia correction.It has little effect on optical quality,though short-term degraded optical quality occurred mainly in the bi-aspheric ablated eyes.
基金Supported by National Natural Science Foundation of China(No.81770955)National Natural Science Foundation of China for Young Scholars(No.82000929)+6 种基金Project of Shanghai Science and Technology(No.20410710100)Clinical Research Plan of SHDC(No.SHDC2020CR1043B)Project of Shanghai Xuhui District Science and Technology(No.2020-015)Project of Shanghai Xuhui District Science and Technology(No.XHLHGG202104)Shanghai Engineering Research Center of Laser and Autostereoscopic 3D for Vision Care(No.20DZ2255000)Shanghai Sailing Program(No.20YF1405000)。
文摘AIM: To investigate the one-year refractive outcomes and optical quality following PRESBYOND laser-blended vision(LBV).METHODS: This retrospective study included 20 patients who underwent PRESBYOND treatment between Jan 2019 and Aug 2020. The patients were asked to attend a followup outpatient visit one year after surgery. Distance and near visual acuity as well as subjective refraction were examined. Optical quality was assessed using wavefront-supported custom ablation. A questionnaire evaluating optical quality and satisfaction was completed at the last visit.RESULTS: The average patient age was 48.1±7.4 y(range, 41 to 58 y). The mean preoperative spherical equivalent was-7.59±2.39D. At the one-year follow-up, two eyes(both dominant eyes) lost one line of corrected distance visual acuity(CDVA), while the remaining eyes(38/40) maintained or gained lines of CDVA. The average binocular uncorrected distance visual acuity improved from 0.15±0.03 to 0.90±0.26(decimal vision;P<0.001). The average binocular uncorrected near visual acuity increased from 0.34±0.28 to 0.97±0.07(P<0.001). The spherical aberration was 0.04±0.06 μm in the nondominant eye and 0.09±0.09 μm in the dominant eye(P=0.02). All patients were satisfied with or accepted the outcomes of the surgery. The primary complaints were related to disturbances in night vision and relatively inferior near vision.CONCLUSION: Over the one-year observation period, PRESBYOND is a safe and effective option for presbyopia correction. The optical quality and near vision deserve further investigation.
文摘AIM： To investigate cap morphology after small-incision lenticule extraction （SMILE） and its effects on intraocular scattering. METHODS： Sixty-five eyes of 33 patients undergoing SMILE were enrolled. In addition to regular evaluation, Fourier-domain optical coherence tomography was used to investigate cap thickness at ld, lwk, 1 and 3mo postoperatively. The optical quality including modulation transfer function cutoff frequency, Strehl ratio, Optical Quality Analysis System （OQAS） values, and objective scattering index （OSI）, were evaluated using OQASTM. RESULTS： Cap thickness decreased from ld to lwk （P〈0.001）, but remained higher than intended thickness of 120 μm after 3mo （P〈0.001）. Cap thickness in central area was thinner than that of in the paracentral and peripheral areas （P〈0.0001）. Total number of microdistortions decreased from ld to 3mo （P〈0.0001）. Pearson analysis revealed a weak correlation between OSI and standard deviation of cap thickness at ld and lmo, as well as between range of cap thickness and OSI at 1mo. No correlation was found between microdistortion and OSI, but a negative correlation existed between microdistortion and range at ld and lmoafter surgery. CONCLUSION： The corneal cap tends to be more accurate and regular with time lapse. Better cap morphology tends to contribute less intraocular scattering in the eyes undergoing SMILE.
基金supported partially by the National Natural Science Foundation of China(Nos.62075118,21601112)the Natural Science Foundation of Shanxi Province(No.20210302123433)+2 种基金Key R&D program of Shanxi Province(International Cooperation,No.201903D421070,2021XM21)Shanxi Key Laboratory of Pharmaceutical Biotechnology(No.KF202003)Scientific and Technological Innovation Programs of Higher Education Institutions in Shanxi(No.2019L0020)。
文摘Ferritins can generally be divided into four subfamilies based on their structural characteristics,namely,the classic ferritins(Ftns),bacterioferritins(Bfrs),DNA-binding proteins from starved cells(Dps’),and encapsulated ferritins(Enc Ftns).However,the ferritin from Mycoplasma penetrans(Mpef)possesses a particular ferroxidase center with an extreme low activity and exhibits unusual characteristics,indicating that it could be a member of a quite different subfamily of ferritins.Hereby,the crystal structure of the ferritin from Ureaplasma urealyticum(Uurf)is presented,Mpef and Uurf have very similar properties,though they display very low sequence similarity.Thus,ferritins from Mycoplasma with these unique properties do not belong to any known subfamily,but they should rather be placed in a novel ferritin subfamily,which we term Mycoplasma Ferritin(Mfr).
基金Supported by Basic Scientific Research Project on Ideological and Political Theory in Northwest Forestry and Forestry University in 2017(2017RWSZ01)Fine Student Project in Northwest Forestry and Forestry University in 2016(2016JP002)
文摘With the enrollment expansion of college and continuous reform of college education system and college charging system,the number of college students with financial difficulties is increasing. The college students with family financial difficulties not only bear the huge economic burden,but also bear the huge pressure of learning and mental stress,and they have many kinds of psychological problems including psychological distress of tension and anxiety,psychological conflict of self-respect and self-abasement,conflict of desire for interpersonal interaction and self-containment and strong vanity and dependence mentality. This paper puts forward the corresponding recommendations to solve these problems.
基金The National Natural Science Foundation of China under contract No.41676120。
文摘The majority of fishery stocks in the world are data limited,which limits formal stock assessments.Identifying the impacts of input data on stock assessment is critical for improving stock assessment and developing precautionary management strategies.We compare catch advice obtained from applications of various datalimited methods(DLMs)with forecasted catch advice from existing data-rich stock assessment models for the Indian Ocean bigeye tuna(Thunnus obesus).Our goal was to evaluate the consistency of catch advice derived from data-rich methods and data-limited approaches when only a subset of data is available.The Stock Synthesis(SS)results were treated as benchmarks for comparison because they reflect the most comprehensive and best possible scientific information of the stock.This study indicated that although the DLMs examined appeared robust for the Indian Ocean bigeye tuna,the implied catch advice differed between data-limited approaches and the current assessment,due to different data inputs and model assumptions.Most DLMs tended to provide more optimistic catch advice compared with the SS,which was mostly influenced by historical catches,current abundance and depletion estimates,and natural mortality,but was less sensitive to life-history parameters(particularly those related to growth).This study highlights the utility of DLMs and their implications on catch advice for the management of tuna stocks.
基金Supported by Supported by Basic Scientific Research Project on Ideological and Political Theory in Northwest Forestry and Forestry University in 2017(2017RWSZ01)Fine Student Project in Northwest Forestry and Forestry University in 2016(2016JP002)
文摘Based on the empirical survey of 2013-2016 college students in Northwest A&F University,we analyze the 9260 valid samples,and the survey involves emotional state,self-worth,psychological adjustment capacity and students’ attitude towards mental health education.On the basis of statistical data,we summarize the general situation of agricultural college students’ mental health,analyze the problems in agricultural college students’ psychological development and bring forward the feasible recommendations.
文摘Dear Editor, African swine fever (ASF) is a highly contagious disease of domestic pigs caused by African swine fever virus (ASFV),with mortality rates approaching 90%-100%.The first ASF case was described in 1921 in Kenya.Over the past decades, ASF has spread from Sub-Saharan Africa to Europe and Asia, and pose a huge threat to global food safety.Since the first ASF case reported in August 2018, more than 10 million pigs had been culled in China at an enormous economic loss.The risk of ASFV mutating to infect humans is extremely low.However, ASF not only threatens food security but also severely strikes the world economy in many fields, such as the global supply of the blood thinner heparin,most of which is produced from pigs.Hence, ASF is a strictly monitored infectious animal disease by OIE (World Organization for Animal Health), unfortunately, there is no approved drug or vaccine against this lethal viral disease.
文摘Dear Editor,The African swine fever(ASF)is a highly contagious hemorrhagic and lethal disease in domestic pigs.The ASF outbreaks of in many Asia countries,including China,Vietnam,Mongolia,and South Korea,have posed a huge threat to the pig indusry.In the attempt to stop ASF from spreading further in China's Mainland,more than 10 million pigs have been culled since August 2018.The causative agent for ASF is a DNA virus,African swine fever virus(ASFV).Although this deadly disease has been reported in Kenya nearly one hundred years ago,there has been no vaccine for protection from ASFV infection or effective treatments to cure ASF until now.
