Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consens...Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consensus that sea transport was far cheaper than land transport.This paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally costly.In this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.展开更多
Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii population...Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii populations with different basal insecticide resistance levels,and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance,as well as differences in fitness.Under the same selection pressure,Yarkant A.gossypii(with low basal insecticide resistance)evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A.gossypii(with high basal insecticide resistance),and the evolution of A.gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe,Xingjiang,China.The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid,imidacloprid,thiamethoxam and pymetrozine;while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor,imidacloprid,thiamethoxam,pymetrozine,and chlorpyrifos.The relative fitness of A.gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.The relative fitness levels of the sulfoxaflor-resistant strains(Yarkant-SulR and Jinghe-SulR)were lower than those of the acetamipridresistant strains(Yarkant-AceR and Jinghe-AceR).In addition,the relative fitness levels of sulfoxaflor-and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.In summary,basal insecticide resistance of A.gossypii and insecticide type affected the evolution of resistance to insecticides in A.gossypii,as well as cross-resistance to other insecticides.The sulfoxaflor-and acetamiprid-resistant A.gossypii strains had obvious fitness costs.The results of this work will contribute to the insecticide resistance management and integrated management of A.gossypii.展开更多
Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and ...Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate change.In this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of biomass.Most commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid fuels.Synthetic oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural ores.To determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was conducted.The synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were reached.The techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic material.The synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling material.By comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.展开更多
With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This st...With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This study proposes a low-carbon economic optimization scheduling model for an IES that considers carbon trading costs.With the goal of minimizing the total operating cost of the IES and considering the transferable and curtailable characteristics of the electric and thermal flexible loads,an optimal scheduling model of the IES that considers the cost of carbon trading and flexible loads on the user side was established.The role of flexible loads in improving the economy of an energy system was investigated using examples,and the rationality and effectiveness of the study were verified through a comparative analysis of different scenarios.The results showed that the total cost of the system in different scenarios was reduced by 18.04%,9.1%,3.35%,and 7.03%,respectively,whereas the total carbon emissions of the system were reduced by 65.28%,20.63%,3.85%,and 18.03%,respectively,when the carbon trading cost and demand-side flexible electric and thermal load responses were considered simultaneously.Flexible electrical and thermal loads did not have the same impact on the system performance.In the analyzed case,the total cost and carbon emissions of the system when only the flexible electrical load response was considered were lower than those when only the flexible thermal load response was taken into account.Photovoltaics have an excess of carbon trading credits and can profit from selling them,whereas other devices have an excess of carbon trading and need to buy carbon credits.展开更多
As a novel economic form,the digital economy is reshaping the financial regulatory landscape and significantly impacting regulatory costs.This paper incorporates the digital economy and financial regulatory costs into...As a novel economic form,the digital economy is reshaping the financial regulatory landscape and significantly impacting regulatory costs.This paper incorporates the digital economy and financial regulatory costs into the classic Solow growth model,uncovering an inverted U-shaped relationship between them.A subsequent mechanism analysis explains the rationale behind this relationship.To empirically examine this relationship in China,the paper utilizes inter-provincial panel data from 2013 to 2021 and employs methodologies such as the two-way fixed effects and moderating effects models.These analyses have important implications for the sound and sustainable development of China’s financial industry.The findings indicate:(a)As China’s digital economy develops,its impact on financial regulatory costs follows an inverted U-shaped pattern,initially increasing and then declining.This conclusion remains valid after robustness tests.(b)The influence of the digital economy on regulatory costs depends on favorable external conditions.Specifically,the impact is more pronounced in regions and periods with better digital infrastructure and more abundant human capital.(c)Additionally,redundant resources moderate this impact,which can weaken the inverted U-shaped relationship.Our findings not only provide a theoretical foundation for understanding the impact of the digital economy on financial regulatory costs but also offer valuable policy insights for optimizing financial regulation in China.展开更多
Introduction: Socioeconomic and demographic conditions in a country can influence tuberculosis incidence and mortality, with nearly 95% of tuberculosis-related deaths occurring in poorer countries. Mozambique is among...Introduction: Socioeconomic and demographic conditions in a country can influence tuberculosis incidence and mortality, with nearly 95% of tuberculosis-related deaths occurring in poorer countries. Mozambique is among the 30 countries with the highest TB burden. Objective: The study aimed to estimate the average direct medical cost of treating drug-resistant tuberculosis in 19 health centers in Maputo City, Mozambique. Methods: A retrospective analysis of direct medical costs was conducted on patients aged 18 and older who completed 20-month drug-resistant tuberculosis treatment regimens in Maputo City in 2019. Results: This analysis covered 140 patients who completed a 20-month treatment regimen, with 64.3% (78) being male and 35.7% (62) female. Approximately 50% of the participants were aged between 29 and 47. The average direct medical cost of DRTB treatment was $4789.43, reaching up to $6568.00, with a standard deviation of $753.26, including clinical interventions and treatment. Conclusion: The direct medical costs for a basic treatment package for a patient with drug-resistant TB in Mozambique equal 36 minimum wages. Developing alternative and innovative funding mechanisms and identifying ways to mitigate costs through the use of generic medicines would be beneficial.展开更多
Modern conflicts demand substantial physical and psychological exertion,often resulting in fatigue and diminished combat or operational readiness.Several exoskeletons have been developed recently to address these chal...Modern conflicts demand substantial physical and psychological exertion,often resulting in fatigue and diminished combat or operational readiness.Several exoskeletons have been developed recently to address these challenges,presenting various limitations that affect their operational or everyday usability.This article evaluates the performance of a dual-purpose passive ankle exoskeleton developed for the reduction of metabolic costs during walking,seeking to identify a force element that could be applied to the target population.Based on the 6-min walk test,twenty-nine subjects participated in the study using three different force elements.The results indicate that it is possible to reduce metabolic expenditure while using the developed exoskeleton.Additionally,the comfort and range of motion results verify the exoskeleton's suitability for use in uneven terrain and during extended periods.Nevertheless,the choice of the force element should be tailored to each user,and the control system should be adjustable to optimise the exoskeleton's performance.展开更多
Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vit...Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.展开更多
Creditors,such as banks,often use disclosed environmental information to assess a company’s environmental risk and ensure the safety of debt funds.Consequently,carbon disclosures have become an important consideratio...Creditors,such as banks,often use disclosed environmental information to assess a company’s environmental risk and ensure the safety of debt funds.Consequently,carbon disclosures have become an important consideration for creditors when making investments.This study explores the relationship between carbon disclosure and debt financing costs using data on listed companies from 2008 to 2019.The results show that carbon disclosure can reduce the debt financing costs of enterprises,and that this influence is more significant for private companies than for state-owned enterprises.Instrumental variables and Propensity Score Matching(PSM)were used to evaluate the robustness of negative relationships.Furthermore,carbon disclosure has a more significant impact on debt costs with less environmental supervision pressure,weak residents’environmental awareness,and weak product market competition.These findings provide guidance for companies’carbon information disclosure and support the establishment of official carbon disclosure standards.展开更多
Schizophrenia is classified as a priority mental disorder by the World Health Organization (WHO) and accounts for around 35% of diagnoses at the Bingerville Psychiatric Hospital (HPB). The aims of the study were to id...Schizophrenia is classified as a priority mental disorder by the World Health Organization (WHO) and accounts for around 35% of diagnoses at the Bingerville Psychiatric Hospital (HPB). The aims of the study were to identify the cost drivers for hospitalization and to calculate the costs of managing schizophrenia in hospital, with a view to planning household expenditure on care. This pilot cross-sectional study involved 31 patients with schizophrenia who had been hospitalized in the various third-category wards at the HPB between 1st January 2019 and 31st May 2020. Sampling was accidental. The methods used to estimate costs were based on the actual costs of drugs, hospitalization and additional examinations which prices were known, and on patients’ estimations for certain expenses such as food and transport. Results: The sex ratio was 3.42, the mean age was 29.52 years. The mean length of stay was 46.19 days, and the most frequent clinical forms were paranoid schizophrenia (41.9%) and schizoaffective disorder (29%). The combination of haloperidol and chlorpromazine was the most common medications for initial treatment (67.8%) and maintenance treatment (41.9%). The average cost of hospitalization at HPB for schizophrenia was XOF 164,412 (€249.90). The average direct medical cost was XOF 105,412 (€160.226) and the average direct non-medical cost was XOF 59,000 (€89.68). The average daily cost of antipsychotic treatment was XOF 795/day (€1.2084). The high cost of drugs as a proportion of hospitalization costs suggested the need of a reflection on the simplification of prescribing practices, assistance in psychiatric emergencies and the development of other alternatives to psychiatric hospitalization in Côte d’Ivoire.展开更多
This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from...This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.展开更多
Drilling costs of ultra-deepwell is the significant part of development investment,and accurate prediction of drilling costs plays an important role in reasonable budgeting and overall control of development cost.In o...Drilling costs of ultra-deepwell is the significant part of development investment,and accurate prediction of drilling costs plays an important role in reasonable budgeting and overall control of development cost.In order to improve the prediction accuracy of ultra-deep well drilling costs,the item and the dominant factors of drilling costs in Tarim oilfield are analyzed.Then,those factors of drilling costs are separated into categorical variables and numerous variables.Finally,a BP neural networkmodel with drilling costs as the output is established,and hyper-parameters(initial weights and bias)of the BP neural network is optimized by genetic algorithm(GA).Through training and validation of themodel,a reliable prediction model of ultra-deep well drilling costs is achieved.The average relative error between prediction and actual values is 3.26%.Compared with other models,the root mean square error is reduced by 25.38%.The prediction results of the proposed model are reliable,and the model is efficient,which can provide supporting for the drilling costs control and budget planning of ultra-deep wells.展开更多
Background: The COVID-19 pandemic has presented unprecedented challenges to global healthcare systems. As the pandemic unfolded, it became evident that certain groups of individuals were at an elevated risk of experie...Background: The COVID-19 pandemic has presented unprecedented challenges to global healthcare systems. As the pandemic unfolded, it became evident that certain groups of individuals were at an elevated risk of experiencing severe disease outcomes. Among these high-risk groups, individuals with pre-existing cardiac conditions emerged as particularly vulnerable. Objective: This study aimed to investigate the relationship between the length of stay, mortality, and costs of COVID-19 patients with and without a history of cardiac disease. Design: This retrospective study was conducted in Jam Hospital in Tehran, Iran, from March 21, 2021, to March 21, 2022. All patients with laboratory-confirmed COVID-19 who were hospitalized during this period were included. Results: A total of 500 COVID-19 patients were hospitalized, with 31.6% having a history of cardiac disease and 68.4% without any cardiac disease. Patients with cardiac disease were significantly older (median [range] age, 69.35 [37 - 94] years) compared to non-cardiac patients (54.95 [13 - 97] years) (p Conclusion: Patients with cardiac disease who are hospitalized with COVID-19 have a higher mortality rate, longer hospital stays, greater disease severity, ICU admission, and higher costs. Therefore, improved prevention and management strategies are crucial for these patients.展开更多
As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of ...As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of carbon emissions has drawn wide attention from the international community, necessitating the comparison of the trade benefits and environmental costs of the BRICS participation in GVCS. Based on the Eora database, this paper constructs a decomposition framework for the calculation of export value-added and embodied carbon, based on a multi-region input-output (MRIO) model. The trade benefits and environmental costs paid by the BRICS’ total exports from 1990 to 2015 were measured and the imbalance was analyzed, along with the causes. The results show that the main value-added and carbon embodied in the BRICS’ exports originate from their own countries, and the domestic value-added content of the BRICS’ exports decreased while the foreign value-added content increased.展开更多
An important issue in analyzing accident blackspots is the estimation of severity levels of different types of accidents.This study aims to estimate the severity level of accidents in Bahrain using crash costs.These c...An important issue in analyzing accident blackspots is the estimation of severity levels of different types of accidents.This study aims to estimate the severity level of accidents in Bahrain using crash costs.These crash costs were calculated by the Human Capital Approach(HCA)and total reported costs from the victims.The data was collected from the General Directorate of Traffic,insurance companies,Ministry of Works(MoW)and Ministry of Health.It was found,from the survey responses,that there was no significant effect of victim characteristics on the total cost of the accidents.The severity levels were found to be higher than those found in previous literature or adopted by local authorities which could be attributed to the economic conditions of Bahrain.Moreover,the weights found by both approaches were different from each other.Therefore,it is recommended to use the HCA approach due to its comprehensive calculations involving future costs.展开更多
AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quanti...AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for each surgical intervention in childhood glaucoma. A US perspective was adopted, using Medicare allowable costs to calculate cost/mm Hg IOP reduction($/mm Hg) at 1y postoperatively.RESULTS: At 1y postoperatively, the cost/mm Hg IOP reduction was $226/mm Hg for microcatheter-assisted circumferential trabeculotomy, $284/mm Hg for cyclophotocoagulation, $288/mm Hg for conventional ab-externo trabeculotomy, $338/mm Hg for Ahmed glaucoma valve, $350/mm Hg for Baerveldt glaucoma implant, $351/mm Hg for goniotomy, and $400/mm Hg for trabeculectomy.CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is the most cost-efficient surgical method to lower IOP in childhood glaucoma, while trabeculectomy is the least cost-efficient surgical method.展开更多
Coal has been dominating the electricity supply in Indonesia,especially in long-term power generation from fossil energy.This dominance is due to lower production costs in coal-fired power plant generation.However,thi...Coal has been dominating the electricity supply in Indonesia,especially in long-term power generation from fossil energy.This dominance is due to lower production costs in coal-fired power plant generation.However,this low price is only based on monetary costs and ignores the social costs.Therefore,this study aims to quantify the social costs of coal-fired generation.Using QUERI-AirPacts modeling,the present study quantifies the social costs resulting from the Tenayan Raya coal-fired generation in Riau,Indonesia.It includes the levelized cost of electricity and health costs into the generation costs.After that,this study calculates the net present value,internal rate return,and project payback period.The study found that as much as$50.22/MWh was the levelized cost of electricity.While$15.978/MWh or$0.015978/kWh was the social cost that was not included in the generating cost.At the electricity production level of 1,380,171.69 MWh per year,there is an expected extra cost of$22,052,383.30 uncounted when externalities are included.For instance,the net present value(NPV)is lower and even negative when external costs are included(-$24,062,274.19)compared to$176,108,091.52 when externalities are not considered.The internal rate of return(IRR)is much higher when the social costs are not considered.The payback period is also shorter when the social costs are excluded than when the externalities are included.This global number indicates that the inclusion of external costs would impact NPV,IRR,and the payback period.This result implies that the government should internalize the external cost to stimulate the electricity producers to conduct cost-benefit analyses.The cost-benefit analysis mechanism would lead the producers to be more efficient.展开更多
The collector managed inventory(CMI)management idea is introduced based on the comparison of manufacturer and third-party logistics(3PL)implementing vendor managed inventory(VMI)services.Considering recovery costs,the...The collector managed inventory(CMI)management idea is introduced based on the comparison of manufacturer and third-party logistics(3PL)implementing vendor managed inventory(VMI)services.Considering recovery costs,the service pricing strategies for 3PL corporations implementing VMI are studied to meet two conditions of participation constraints and incentive-compatibility constraints.The numerical simulation results indicate that the supply chain partners' profits change after considering recovery costs,and the 3PL corporation's profits and the total profits increase first,and then decrease.The retailers' and manufacturers' profits also increase.The total profits of the supply chain have a characteristic of increasing first and then decreasing with the increase of the callback ratio of unsold products.The concrete extremum point is codetermined by price flexibility,service pricing of the 3PL corporation,callback price and callback ratio.展开更多
The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis ...The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis of policy options?Administrative costs affect all areas of public education and absorb a large part of the state budget appropriations intended for education.Through the presentation of the general and specific objectives but also the European participation in the rational management of the management costs of the educational units,we lead to a holistic approach to the operational costs of the education that is part of the social costs.展开更多
Objective To determine the impact of smoking on disease-specific health care utilization and medical costs in patients with chronic non-communicable diseases(NCDs).Methods Participants were middle-aged and elderly adu...Objective To determine the impact of smoking on disease-specific health care utilization and medical costs in patients with chronic non-communicable diseases(NCDs).Methods Participants were middle-aged and elderly adults with chronic NCDs from a prospective cohort in China.Logistic regressions and linear models were used to assess the relationship between tobacco smoking,health care utilization and medical costs.Results Totally,1020 patients with chronic obstructive pulmonary disease(COPD),3144 patients with coronary heart disease(CHD),and 1405 patients with diabetes were included in the analysis.Among patients with COPD,current smokers(β:0.030,95%CI:−0.032-0.092)and former smokers(β:0.072,95%CI:0.014-0.131)had 3.0%and 7.2%higher total medical costs than never smokers.Medical costs of patients who had smoked for 21-40 years(β:0.028,95%CI:−0.038-0.094)and≥41 years(β:0.053,95%CI:−0.004β0.110)were higher than those of never smokers.Patients who smoked≥21 cigarettes(β:0.145,95%CI:0.051-0.239)per day had more inpatient visits than never smokers.The association between smoking and health care utilization and medical costs in people with CHD group was similar to that in people with COPD;however,there were no significant associations in people with diabetes.Conclusion This study reveals that the impact of smoking on health care utilization and medical costs varies among patients with COPD,CHD,and diabetes.Tobacco control might be more effective at reducing the burden of disease for patients with COPD and CHD than for patients with diabetes.展开更多
文摘Thucydides asserts that the occupation of Decelea by the Spartans in 413 BC made the grain supply for Athens costly by forcing the transport from land onto the sea.This calls into question the well-established consensus that sea transport was far cheaper than land transport.This paper contends that the cost of protecting supply lines-specifically the expenses associated with the warships which escorted the supply ships-rendered the grain transported on the new route exceptionally costly.In this paper,the benefits and drawbacks of a maritime economy,including transaction costs,trade dependencies,and the capabilities of warships and supply ships are discussed.
基金supported by the National Key R&D Program of China(2022YFD1400300)the Open Fund of Key Laboratory of Integrated Pest Management on Crops in Northwestern Oasis,Ministry of Agriculture and Rural Affairs of China(KFJJ202204)the China Agriculture Research System(CARS-15-20)。
文摘Aphis gossypii has become increasingly difficult to manage due to its strong insecticide resistance.In the laboratory,we established sulfoxaflor-resistant and acetamiprid-resistant strains in two A.gossypii populations with different basal insecticide resistance levels,and evaluated the effects of basal insecticide resistance on the resistance development and cross-resistance,as well as differences in fitness.Under the same selection pressure,Yarkant A.gossypii(with low basal insecticide resistance)evolved resistance to sulfoxaflor and acetamiprid more quickly than Jinghe A.gossypii(with high basal insecticide resistance),and the evolution of A.gossypii resistance to sulfoxaflor developed faster than acetamiprid in both Yarkant and Jinghe,Xingjiang,China.The sulfoxaflor-resistant strains selected from Yarkant and Jinghe developed significant cross-resistance to acetamiprid,imidacloprid,thiamethoxam and pymetrozine;while the acetamiprid-resistant strains developed significant cross-resistance to sulfoxaflor,imidacloprid,thiamethoxam,pymetrozine,and chlorpyrifos.The relative fitness of A.gossypii decreased as the resistance to sulfoxaflor and acetamiprid developed.The relative fitness levels of the sulfoxaflor-resistant strains(Yarkant-SulR and Jinghe-SulR)were lower than those of the acetamipridresistant strains(Yarkant-AceR and Jinghe-AceR).In addition,the relative fitness levels of sulfoxaflor-and acetamiprid-resistant strains were lower in Jinghe than in Yarkant.In summary,basal insecticide resistance of A.gossypii and insecticide type affected the evolution of resistance to insecticides in A.gossypii,as well as cross-resistance to other insecticides.The sulfoxaflor-and acetamiprid-resistant A.gossypii strains had obvious fitness costs.The results of this work will contribute to the insecticide resistance management and integrated management of A.gossypii.
文摘Chemical looping combustion has the potential to be an efficient and low-cost technology capable of contributing to the reduction of the atmospheric concentration of CO_(2) in order to reach the 1.5/2°C goal and mitigate climate change.In this process,a metal oxide is used as oxygen carrier in a dual fluidized bed to generate clean CO_(2) via combustion of biomass.Most commonly,natural ores or synthetic materials are used as oxygen carrier whereas both must meet special requirements for the conversion of solid fuels.Synthetic oxygen carriers are characterized by higher reactivity at the expense of higher costs versus the lower-cost natural ores.To determine the viability of both possibilities,a techno-economic comparison of a synthetic material based on manganese,iron,and copper to the natural ore ilmenite was conducted.The synthetic oxygen carrier was characterized and tested in a pilot plant,where high combustion efficiencies up to 98.4%and carbon capture rates up to 98.5%were reached.The techno-economic assessment resulted in CO_(2) capture costs of 75 and 40€/tCO_(2) for the synthetic and natural ore route respectively,whereas a sensitivity analysis showed the high impact of production costs and attrition rates of the synthetic material.The synthetic oxygen carrier could break even with the natural ore in case of lower production costs and attrition rates,which could be reached by adapting the production process and recycling material.By comparison to state-of-the-art technologies,it is demonstrated that both routes are viable and the capture cost of CO_(2) could be reduced by implementing the chemical looping combustion technology.
基金supported by State Grid Shanxi Electric Power Company Science and Technology Project“Research on key technologies of carbon tracking and carbon evaluation for new power system”(Grant:520530230005)。
文摘With the introduction of the“dual carbon”goal and the continuous promotion of low-carbon development,the integrated energy system(IES)has gradually become an effective way to save energy and reduce emissions.This study proposes a low-carbon economic optimization scheduling model for an IES that considers carbon trading costs.With the goal of minimizing the total operating cost of the IES and considering the transferable and curtailable characteristics of the electric and thermal flexible loads,an optimal scheduling model of the IES that considers the cost of carbon trading and flexible loads on the user side was established.The role of flexible loads in improving the economy of an energy system was investigated using examples,and the rationality and effectiveness of the study were verified through a comparative analysis of different scenarios.The results showed that the total cost of the system in different scenarios was reduced by 18.04%,9.1%,3.35%,and 7.03%,respectively,whereas the total carbon emissions of the system were reduced by 65.28%,20.63%,3.85%,and 18.03%,respectively,when the carbon trading cost and demand-side flexible electric and thermal load responses were considered simultaneously.Flexible electrical and thermal loads did not have the same impact on the system performance.In the analyzed case,the total cost and carbon emissions of the system when only the flexible electrical load response was considered were lower than those when only the flexible thermal load response was taken into account.Photovoltaics have an excess of carbon trading credits and can profit from selling them,whereas other devices have an excess of carbon trading and need to buy carbon credits.
基金This study is funded by National Social Science Fund Major Project:“Research on Stimulating Innovation Vitality of Scientific and Technological Talent in the Context of Building a Talent Powerhouse”(21ZDA014)Research Start-Up Fund for Talent Recruitment of Sichuan Academy of Social Sciences:“Research on the Deep Integration of Sichuan’s Digital Economy and Real Economy to Support the Construction of a Modern Industrial System”(23RYJ03).
文摘As a novel economic form,the digital economy is reshaping the financial regulatory landscape and significantly impacting regulatory costs.This paper incorporates the digital economy and financial regulatory costs into the classic Solow growth model,uncovering an inverted U-shaped relationship between them.A subsequent mechanism analysis explains the rationale behind this relationship.To empirically examine this relationship in China,the paper utilizes inter-provincial panel data from 2013 to 2021 and employs methodologies such as the two-way fixed effects and moderating effects models.These analyses have important implications for the sound and sustainable development of China’s financial industry.The findings indicate:(a)As China’s digital economy develops,its impact on financial regulatory costs follows an inverted U-shaped pattern,initially increasing and then declining.This conclusion remains valid after robustness tests.(b)The influence of the digital economy on regulatory costs depends on favorable external conditions.Specifically,the impact is more pronounced in regions and periods with better digital infrastructure and more abundant human capital.(c)Additionally,redundant resources moderate this impact,which can weaken the inverted U-shaped relationship.Our findings not only provide a theoretical foundation for understanding the impact of the digital economy on financial regulatory costs but also offer valuable policy insights for optimizing financial regulation in China.
文摘Introduction: Socioeconomic and demographic conditions in a country can influence tuberculosis incidence and mortality, with nearly 95% of tuberculosis-related deaths occurring in poorer countries. Mozambique is among the 30 countries with the highest TB burden. Objective: The study aimed to estimate the average direct medical cost of treating drug-resistant tuberculosis in 19 health centers in Maputo City, Mozambique. Methods: A retrospective analysis of direct medical costs was conducted on patients aged 18 and older who completed 20-month drug-resistant tuberculosis treatment regimens in Maputo City in 2019. Results: This analysis covered 140 patients who completed a 20-month treatment regimen, with 64.3% (78) being male and 35.7% (62) female. Approximately 50% of the participants were aged between 29 and 47. The average direct medical cost of DRTB treatment was $4789.43, reaching up to $6568.00, with a standard deviation of $753.26, including clinical interventions and treatment. Conclusion: The direct medical costs for a basic treatment package for a patient with drug-resistant TB in Mozambique equal 36 minimum wages. Developing alternative and innovative funding mechanisms and identifying ways to mitigate costs through the use of generic medicines would be beneficial.
基金the Portuguese Army,through CINAMIL,within project ELITE2-Enhancement LITe ExoskeletonFoundation for Science and Technology (FCT),through IDMEC,under LAETA,project UIDB/50022/2020 for supporting this research。
文摘Modern conflicts demand substantial physical and psychological exertion,often resulting in fatigue and diminished combat or operational readiness.Several exoskeletons have been developed recently to address these challenges,presenting various limitations that affect their operational or everyday usability.This article evaluates the performance of a dual-purpose passive ankle exoskeleton developed for the reduction of metabolic costs during walking,seeking to identify a force element that could be applied to the target population.Based on the 6-min walk test,twenty-nine subjects participated in the study using three different force elements.The results indicate that it is possible to reduce metabolic expenditure while using the developed exoskeleton.Additionally,the comfort and range of motion results verify the exoskeleton's suitability for use in uneven terrain and during extended periods.Nevertheless,the choice of the force element should be tailored to each user,and the control system should be adjustable to optimise the exoskeleton's performance.
基金the National Natural Science Foundation of China(72203214 and 72061147002)China Scholarship Council(CSC)(201913043)。
文摘Excessive consumption of refined grains harms human health and ecosystem viability.Whole grains,as a healthy and sustainable alternative to refined grains,can benefit individual health by providing dietary fiber,B vitamins,and bioactive substances.Additionally,they aid in improving the environment due to their higher extraction rate and lower carbon emission during the processing stage.However,few studies have attempted to evaluate the economic and social benefits of increasing the amount of whole grain in grain intake.This paper estimates the potential savings in healthcare costs and reduced food carbon footprints(CFs)that could result from a shift toward whole grain consumption following the Chinese Dietary Guidelines(CDG).We investigate hypothetical scenarios where a certain proportion(5–100%)of Chinese adults could increase their whole grain intakes as proposed by CDG to meet the average shortfall of 30.2 g.In that case,the healthcare costs for associated diseases(e.g.,type2 diabetes mellitus(T2DM),cardiovascular disease(CVD),and colorectal cancer(CRC))are expected to reduce by a substantial amount,from USD 2.82 to 56.37 billion;the carbon emission levels are also projected to decrease by0.24–5.72 million tons.This study provides compelling evidence that advocating for the transition towards greater consumption of whole grain products could benefit individual health,the environment,and society,by reducing both healthcare costs and carbon emissions.
文摘Creditors,such as banks,often use disclosed environmental information to assess a company’s environmental risk and ensure the safety of debt funds.Consequently,carbon disclosures have become an important consideration for creditors when making investments.This study explores the relationship between carbon disclosure and debt financing costs using data on listed companies from 2008 to 2019.The results show that carbon disclosure can reduce the debt financing costs of enterprises,and that this influence is more significant for private companies than for state-owned enterprises.Instrumental variables and Propensity Score Matching(PSM)were used to evaluate the robustness of negative relationships.Furthermore,carbon disclosure has a more significant impact on debt costs with less environmental supervision pressure,weak residents’environmental awareness,and weak product market competition.These findings provide guidance for companies’carbon information disclosure and support the establishment of official carbon disclosure standards.
文摘Schizophrenia is classified as a priority mental disorder by the World Health Organization (WHO) and accounts for around 35% of diagnoses at the Bingerville Psychiatric Hospital (HPB). The aims of the study were to identify the cost drivers for hospitalization and to calculate the costs of managing schizophrenia in hospital, with a view to planning household expenditure on care. This pilot cross-sectional study involved 31 patients with schizophrenia who had been hospitalized in the various third-category wards at the HPB between 1st January 2019 and 31st May 2020. Sampling was accidental. The methods used to estimate costs were based on the actual costs of drugs, hospitalization and additional examinations which prices were known, and on patients’ estimations for certain expenses such as food and transport. Results: The sex ratio was 3.42, the mean age was 29.52 years. The mean length of stay was 46.19 days, and the most frequent clinical forms were paranoid schizophrenia (41.9%) and schizoaffective disorder (29%). The combination of haloperidol and chlorpromazine was the most common medications for initial treatment (67.8%) and maintenance treatment (41.9%). The average cost of hospitalization at HPB for schizophrenia was XOF 164,412 (€249.90). The average direct medical cost was XOF 105,412 (€160.226) and the average direct non-medical cost was XOF 59,000 (€89.68). The average daily cost of antipsychotic treatment was XOF 795/day (€1.2084). The high cost of drugs as a proportion of hospitalization costs suggested the need of a reflection on the simplification of prescribing practices, assistance in psychiatric emergencies and the development of other alternatives to psychiatric hospitalization in Côte d’Ivoire.
文摘This paper reaches a recommendation for the 10-year e-bus transition roadmap for New York City. The lifecycle model of emission reduction demonstrates the ecological and financial impacts of a complete transition from the current diesel bus fleet to an all-electric bus fleet in New York City by 2033. This study focuses on the NOx pollution, which is the highest among all major cities by Environmental Protection Agency (EPA) and greenhouse gases (GHG) with annual emissions of over five million tons. Our model predicts that switching to an all-electric bus fleet will cut GHG emissions by over 390,000 tons and NOx emissions by over 1300 tons annually, in addition to other pollutants such as VOCs and PM 2.5. yielding an annual economic benefit of over 75.94 million USD. This aligns with the city mayor office’s initiative of achieving total carbon neutrality. We further model an optimized transition roadmap that balances ecological and long-term benefits against the costs of the transition, emphasizing feasibility and alignment with the natural replacement cycle of existing buses, ensuring a steady budgeting pattern to minimize interruptions and resistance. Finally, we advocate for collaboration between government agencies, public transportation authorities, and private sectors, including electric buses and charging facility manufacturers, which is essential for fostering innovation and reducing the costs associated with the transition to e-buses.
基金supported by the Science and Technology Innovation Foundation of CNPC“Multiscale Flow Law and Flow Field Coupling Study of Tight Sandstone Gas Reservoir”(2016D-5007-0208)13th Five-Year National Major Project“Multistage Fracturing Effect and Production of Fuling Shale Gas HorizontalWell Law Analysis Research”(2016ZX05060-009).
文摘Drilling costs of ultra-deepwell is the significant part of development investment,and accurate prediction of drilling costs plays an important role in reasonable budgeting and overall control of development cost.In order to improve the prediction accuracy of ultra-deep well drilling costs,the item and the dominant factors of drilling costs in Tarim oilfield are analyzed.Then,those factors of drilling costs are separated into categorical variables and numerous variables.Finally,a BP neural networkmodel with drilling costs as the output is established,and hyper-parameters(initial weights and bias)of the BP neural network is optimized by genetic algorithm(GA).Through training and validation of themodel,a reliable prediction model of ultra-deep well drilling costs is achieved.The average relative error between prediction and actual values is 3.26%.Compared with other models,the root mean square error is reduced by 25.38%.The prediction results of the proposed model are reliable,and the model is efficient,which can provide supporting for the drilling costs control and budget planning of ultra-deep wells.
文摘Background: The COVID-19 pandemic has presented unprecedented challenges to global healthcare systems. As the pandemic unfolded, it became evident that certain groups of individuals were at an elevated risk of experiencing severe disease outcomes. Among these high-risk groups, individuals with pre-existing cardiac conditions emerged as particularly vulnerable. Objective: This study aimed to investigate the relationship between the length of stay, mortality, and costs of COVID-19 patients with and without a history of cardiac disease. Design: This retrospective study was conducted in Jam Hospital in Tehran, Iran, from March 21, 2021, to March 21, 2022. All patients with laboratory-confirmed COVID-19 who were hospitalized during this period were included. Results: A total of 500 COVID-19 patients were hospitalized, with 31.6% having a history of cardiac disease and 68.4% without any cardiac disease. Patients with cardiac disease were significantly older (median [range] age, 69.35 [37 - 94] years) compared to non-cardiac patients (54.95 [13 - 97] years) (p Conclusion: Patients with cardiac disease who are hospitalized with COVID-19 have a higher mortality rate, longer hospital stays, greater disease severity, ICU admission, and higher costs. Therefore, improved prevention and management strategies are crucial for these patients.
文摘As the international trading system has developed with the division of Global value Chains (GVCS), the export trade of Brazil, Russia, India, China, and South Africa (BRICS) has grown rapidly. The resulting growth of carbon emissions has drawn wide attention from the international community, necessitating the comparison of the trade benefits and environmental costs of the BRICS participation in GVCS. Based on the Eora database, this paper constructs a decomposition framework for the calculation of export value-added and embodied carbon, based on a multi-region input-output (MRIO) model. The trade benefits and environmental costs paid by the BRICS’ total exports from 1990 to 2015 were measured and the imbalance was analyzed, along with the causes. The results show that the main value-added and carbon embodied in the BRICS’ exports originate from their own countries, and the domestic value-added content of the BRICS’ exports decreased while the foreign value-added content increased.
文摘An important issue in analyzing accident blackspots is the estimation of severity levels of different types of accidents.This study aims to estimate the severity level of accidents in Bahrain using crash costs.These crash costs were calculated by the Human Capital Approach(HCA)and total reported costs from the victims.The data was collected from the General Directorate of Traffic,insurance companies,Ministry of Works(MoW)and Ministry of Health.It was found,from the survey responses,that there was no significant effect of victim characteristics on the total cost of the accidents.The severity levels were found to be higher than those found in previous literature or adopted by local authorities which could be attributed to the economic conditions of Bahrain.Moreover,the weights found by both approaches were different from each other.Therefore,it is recommended to use the HCA approach due to its comprehensive calculations involving future costs.
文摘AIM: To analyze and calculate the relative cost of various childhood glaucoma surgical interventions per mm Hg intraocular pressure(IOP) reduction($/mm Hg).METHODS: Representative index studies were reviewed to quantitate the reduction of mean IOP and glaucoma medications for each surgical intervention in childhood glaucoma. A US perspective was adopted, using Medicare allowable costs to calculate cost/mm Hg IOP reduction($/mm Hg) at 1y postoperatively.RESULTS: At 1y postoperatively, the cost/mm Hg IOP reduction was $226/mm Hg for microcatheter-assisted circumferential trabeculotomy, $284/mm Hg for cyclophotocoagulation, $288/mm Hg for conventional ab-externo trabeculotomy, $338/mm Hg for Ahmed glaucoma valve, $350/mm Hg for Baerveldt glaucoma implant, $351/mm Hg for goniotomy, and $400/mm Hg for trabeculectomy.CONCLUSION: Microcatheter-assisted circumferential trabeculotomy is the most cost-efficient surgical method to lower IOP in childhood glaucoma, while trabeculectomy is the least cost-efficient surgical method.
文摘Coal has been dominating the electricity supply in Indonesia,especially in long-term power generation from fossil energy.This dominance is due to lower production costs in coal-fired power plant generation.However,this low price is only based on monetary costs and ignores the social costs.Therefore,this study aims to quantify the social costs of coal-fired generation.Using QUERI-AirPacts modeling,the present study quantifies the social costs resulting from the Tenayan Raya coal-fired generation in Riau,Indonesia.It includes the levelized cost of electricity and health costs into the generation costs.After that,this study calculates the net present value,internal rate return,and project payback period.The study found that as much as$50.22/MWh was the levelized cost of electricity.While$15.978/MWh or$0.015978/kWh was the social cost that was not included in the generating cost.At the electricity production level of 1,380,171.69 MWh per year,there is an expected extra cost of$22,052,383.30 uncounted when externalities are included.For instance,the net present value(NPV)is lower and even negative when external costs are included(-$24,062,274.19)compared to$176,108,091.52 when externalities are not considered.The internal rate of return(IRR)is much higher when the social costs are not considered.The payback period is also shorter when the social costs are excluded than when the externalities are included.This global number indicates that the inclusion of external costs would impact NPV,IRR,and the payback period.This result implies that the government should internalize the external cost to stimulate the electricity producers to conduct cost-benefit analyses.The cost-benefit analysis mechanism would lead the producers to be more efficient.
基金The National Key Technology R&D Program of China during the11th Five-Year Plan Period(No.2006BAH02A06).
文摘The collector managed inventory(CMI)management idea is introduced based on the comparison of manufacturer and third-party logistics(3PL)implementing vendor managed inventory(VMI)services.Considering recovery costs,the service pricing strategies for 3PL corporations implementing VMI are studied to meet two conditions of participation constraints and incentive-compatibility constraints.The numerical simulation results indicate that the supply chain partners' profits change after considering recovery costs,and the 3PL corporation's profits and the total profits increase first,and then decrease.The retailers' and manufacturers' profits also increase.The total profits of the supply chain have a characteristic of increasing first and then decreasing with the increase of the callback ratio of unsold products.The concrete extremum point is codetermined by price flexibility,service pricing of the 3PL corporation,callback price and callback ratio.
文摘The purpose of this paper is to approach the administrative costs in the field of education and to answer questions such as:How are administrative costs measured and evaluated?Is it taken into account in the analysis of policy options?Administrative costs affect all areas of public education and absorb a large part of the state budget appropriations intended for education.Through the presentation of the general and specific objectives but also the European participation in the rational management of the management costs of the educational units,we lead to a holistic approach to the operational costs of the education that is part of the social costs.
基金This work was supported by the National Science and Technology Major Project of the Ministry of Science and Technology of China(No.2017YFC1309401).
文摘Objective To determine the impact of smoking on disease-specific health care utilization and medical costs in patients with chronic non-communicable diseases(NCDs).Methods Participants were middle-aged and elderly adults with chronic NCDs from a prospective cohort in China.Logistic regressions and linear models were used to assess the relationship between tobacco smoking,health care utilization and medical costs.Results Totally,1020 patients with chronic obstructive pulmonary disease(COPD),3144 patients with coronary heart disease(CHD),and 1405 patients with diabetes were included in the analysis.Among patients with COPD,current smokers(β:0.030,95%CI:−0.032-0.092)and former smokers(β:0.072,95%CI:0.014-0.131)had 3.0%and 7.2%higher total medical costs than never smokers.Medical costs of patients who had smoked for 21-40 years(β:0.028,95%CI:−0.038-0.094)and≥41 years(β:0.053,95%CI:−0.004β0.110)were higher than those of never smokers.Patients who smoked≥21 cigarettes(β:0.145,95%CI:0.051-0.239)per day had more inpatient visits than never smokers.The association between smoking and health care utilization and medical costs in people with CHD group was similar to that in people with COPD;however,there were no significant associations in people with diabetes.Conclusion This study reveals that the impact of smoking on health care utilization and medical costs varies among patients with COPD,CHD,and diabetes.Tobacco control might be more effective at reducing the burden of disease for patients with COPD and CHD than for patients with diabetes.
