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
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
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
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
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
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
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
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
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
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
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
This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid gro...This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.展开更多
AIM:To compare laparoscopic pancreaticoduodenectomy(TLPD) during the initial learning curve with open pancreaticoduodenectomy in terms of outcome and costs.METHODS:This is a retrospective review of the consecutive pat...AIM:To compare laparoscopic pancreaticoduodenectomy(TLPD) during the initial learning curve with open pancreaticoduodenectomy in terms of outcome and costs.METHODS:This is a retrospective review of the consecutive patients who underwent TLPD between December 2009 and April 2014 at our institution.The experiences of the initial 15 consecutive TLPD cases,considered as the initial learning curve of each surgeon,were compared with the same number of consecutive laparotomy cases with the same spectrum of diseases in terms of outcome and costs.Laparoscopic patients with conversion to open surgery were excluded.Preoperative demographic and comorbidity data were obtained.Postoperative data on intestinal movement,pain score,mortality,complications,and costs were obtained for analysis.Complications related to surgery included pneumonia, intra-abdominal abscess,postpancreatectomy hemorrhage,biliary leak,pancreatic fistula,delayed gastric emptying,and multiple organ dysfunction syndrome.The total costs consisted of cost of surgery,anesthesia,and admission examination.RESULTS:A total of 60 patients,including 30 consecutive laparoscopic cases and 30 consecutive open cases,were enrolled for review.Demographic and comorbidity characteristics of the two groups were similar.TLPD required a significantly longer operative time(513.17 ± 56.13 min vs 371.67 ± 85.53 min,P < 0.001).The TLPD group had significantly fewer mean numbers of days until bowel sounds returned(2.03 ± 0.55 d vs 3.83 ± 0.59 d,P < 0.001) and exhaustion(4.17 ± 0.75 d vs 5.37 ± 0.81 d,P < 0.001).The mean visual analogue score on postoperative day 4 was less in the TLPD group(3.5 ± 9.7 vs 4.47 ± 1.11,P < 0.05).No differences in surgery-related morbidities and mortality were observed between the two groups.Patients in the TLPD group recovered more quickly and required a shorter hospital stay after surgery(9.97 ± 3.74 d vs 11.87 ± 4.72 d,P < 0.05).A significant difference in the total cost was found between the two groups(TLPD 81317.43 ± 2027.60 RMB vs laparotomy 78433.23 ± 5788.12 RMB,P < 0.05).TLPD had a statistically higher cost for both surgery(24732.13 ± 929.28 RMB vs 19317.53 ± 795.94 RMB,P < 0.001)and anesthesia(6192.37 ± 272.77 RMB vs 5184.10 ± 146.93 RMB,P < 0.001),but a reduced cost for admission examination(50392.93 ± 1761.22 RMB vs 53931.60 ± 5556.94 RMB,P < 0.05).CONCLUSION:TLPD is safe when performed by experienced pancreatobiliary surgeons during the initial learning curve,but has a higher cost than open pancreaticoduodenectomy.展开更多
AIM:To evaluate long-term endocrine and exocrine pancreatic function,quality of life and health care costs after mild acute pancreatitis and severe acute pancreatitis(SAP).METHODS:Patients prospectively included in 20...AIM:To evaluate long-term endocrine and exocrine pancreatic function,quality of life and health care costs after mild acute pancreatitis and severe acute pancreatitis(SAP).METHODS:Patients prospectively included in 2001-2005 were followed-up after 42(36-53)mo.Pancreatic function was evaluated with laboratory tests,the oral glucose tolerance test(OGTT),fecal elastase-1 and a questionnaire.Short Form(SF)-36,was completed.RESULTS:Fourteen patients with a history of SAP and 26 with mild acute pancreatitis were included.Plasma glucose after OGTT was higher after SAP(9.2 mmol/L vs 7.0 mmol/L,P=0.044).Diabetes mellitus or impaired glucose tolerance in fasting plasma glucose and/or 120 min plasma glucose were more common in SAP patients(11/14 vs 11/25,P=0.037).Sick leave,time until the patients could take up recreational activities and time until they had recovered were all longer after SAP(P <0.001).No significant differences in SF-36 were seen between the groups,or when comparing with age and gender matched reference groups.Total hospital costs,including primary care,follow-up and treatment of complications,were higher after SAP(median€16572 vs €5000,P<0.001).CONCLUSION:Endocrine pancreatic function was affected,especially after severe disease.SAP requires greater resource use with long recovery,but most patients regained a good quality of life.展开更多
The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the ex...The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.展开更多
Background: The cost and economic burden of diabetes are a serious worldwide issue. In this study, we evaluated medical payments for persons diagnosed with diabetes and the factors that led to a person having diabetes...Background: The cost and economic burden of diabetes are a serious worldwide issue. In this study, we evaluated medical payments for persons diagnosed with diabetes and the factors that led to a person having diabetes to reduce its prevalence. Methods: A dataset containing 113,979 medical checkups and 3,671,783 monthly medical, dental, care-giving and pharmacy payment records of one health insurance society was used. The dataset contains information of normal and healthy persons. The sample period ran from April, 2013 to March, 2016. The medical payments for persons diagnosed with diabetes were calculated. The regression analysis was used to remove the effects of age and gender. The probit analysis was used to analyze the factors that led to a person having diabetes. Results: In 2.9% of cases, the person undergoing the checkup was diagnosed with diabetes, and the medical payments for these patients were 2.7 times as much as the average medical payment per person. This result did not change significantly even if age and gender were considered. The results of the probit analysis suggested that body mass index, high systolic blood pressure, low diastolic blood pressure, eating habits, physical activities, smoking, drinking alcohol and sleeping were important factors for diabetes. Conclusion: The diabetes might be a costlier disease than previously thought in Japan. By the estimation, 8% of all medical payments were made for these persons with diabetes, which is much higher than the result shown by national survey data. However, overall prevalence could be recused by efforts such as prevention of overweight and obesity.展开更多
Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail aut...Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.展开更多
There are many inputs into the dairy replacement herd which impact not only on the cost of rearing heifers from birth to first calving, but also on their future longevity and production potential. This study determine...There are many inputs into the dairy replacement herd which impact not only on the cost of rearing heifers from birth to first calving, but also on their future longevity and production potential. This study determined the current cost of rearing dairy heifers in the UK through the calculation and analysis of individual costs on a subset of 102 UK dairy farms. Each farm was visited and an extensive heifer rearing questionnaire was completed. Current heifer rearing practices were recorded to provide insight into critical management decisions. A cost analysis workbook was developed to calculate the costs of inputs in the preweaning period for labour, calving, feed, housing, health treatments and vaccinations, waste storage, machinery and equipment, and utilities. The average age at weaning was 62 d. The mean cost of rearing from birth to weaning was £195.19 per heifer with a mean daily cost of £3.14 (excluding the opportunity cost of the calf). This ranged from £1.68 to £6.11 among farms, reflecting major differences in management strategies and efficiency. The highest contribution to total costs came from feed (colostrum, milk, starter and forage) at 48.5% with milk feeding making up the greatest proportion of this at 37.3%. The next major expenses were bedding and labour, contributing 12.3% and 11.2% respectively. Unsurprisingly, delaying age at weaning increased total cost by £3.53 per day. Total costs were on average 45% higher on organic farms than conventional due to higher feed costs and later weaning. Calving pattern also had a strong association with the total cost being lowest with spring calving, intermediate with autumn calving and highest in multi block and all year round calving herds.展开更多
Payment for ecosystem services(PES) has become an increasingly popular means of ecosystem conservation. Opportunity cost is an important factor to increase the investment efficiency of PES projects.However, the distri...Payment for ecosystem services(PES) has become an increasingly popular means of ecosystem conservation. Opportunity cost is an important factor to increase the investment efficiency of PES projects.However, the distribution of opportunity cost is usually unclear in mountainous regions due to the obvious environment changes. In this study, we developed a framework to assess the distribution of agricultural opportunity costs in mountainous regions and applied this method to Baoxing County, a typical mountainous county in Sichuan Province of southwest China. Planting suitability of 17 crops was assessed based on agricultural statistics and natural conditions data within a GIS environment.Agricultural opportunity cost was quantified with a weighted summation of farmers' willingness to cultivate and each crop's opportunity cost. Finally,specific agricultural opportunity cost was obtained according to the spatial areas of the protection programs and land use status. The results showed that agricultural opportunity costs of PES in Baoxing County were estimated to be more than $30 million,with a mean of 400.85 $/ha. Agricultural opportunity costs in mountainous regions displayed some obvious spatial variation and areas with lower agricultural opportunity costs could be selected as priority areas for PES. Our findings revealed that the planting suitability evaluation can make agricultural opportunity costs mapping more reasonable. It will be helpful for the PES programs implementation in mountainous regions.展开更多
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.
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.
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.
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.
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.
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 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.
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.
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This paper analyzes the corn production cost in China, the U.S. and Brazil from 1997 to 2014. According to the results,(1) corn production cost in China is the highest among these three countries;(2) the rapid growth of labor cost and land cost is the major factor that promotes the increase of total corn production cost in China;(3) the level of agricultural mechanization in China has been gradually improving, and the gap between agricultural mechanization levels in China and other two countries is constantly narrowing;(4) differing from the U.S. and Brazil,China exhibits a "high input, low output" agricultural production mode. Based on the above analyses, corresponding suggestions have been presented to reduce corn production cost in China.
文摘AIM:To compare laparoscopic pancreaticoduodenectomy(TLPD) during the initial learning curve with open pancreaticoduodenectomy in terms of outcome and costs.METHODS:This is a retrospective review of the consecutive patients who underwent TLPD between December 2009 and April 2014 at our institution.The experiences of the initial 15 consecutive TLPD cases,considered as the initial learning curve of each surgeon,were compared with the same number of consecutive laparotomy cases with the same spectrum of diseases in terms of outcome and costs.Laparoscopic patients with conversion to open surgery were excluded.Preoperative demographic and comorbidity data were obtained.Postoperative data on intestinal movement,pain score,mortality,complications,and costs were obtained for analysis.Complications related to surgery included pneumonia, intra-abdominal abscess,postpancreatectomy hemorrhage,biliary leak,pancreatic fistula,delayed gastric emptying,and multiple organ dysfunction syndrome.The total costs consisted of cost of surgery,anesthesia,and admission examination.RESULTS:A total of 60 patients,including 30 consecutive laparoscopic cases and 30 consecutive open cases,were enrolled for review.Demographic and comorbidity characteristics of the two groups were similar.TLPD required a significantly longer operative time(513.17 ± 56.13 min vs 371.67 ± 85.53 min,P < 0.001).The TLPD group had significantly fewer mean numbers of days until bowel sounds returned(2.03 ± 0.55 d vs 3.83 ± 0.59 d,P < 0.001) and exhaustion(4.17 ± 0.75 d vs 5.37 ± 0.81 d,P < 0.001).The mean visual analogue score on postoperative day 4 was less in the TLPD group(3.5 ± 9.7 vs 4.47 ± 1.11,P < 0.05).No differences in surgery-related morbidities and mortality were observed between the two groups.Patients in the TLPD group recovered more quickly and required a shorter hospital stay after surgery(9.97 ± 3.74 d vs 11.87 ± 4.72 d,P < 0.05).A significant difference in the total cost was found between the two groups(TLPD 81317.43 ± 2027.60 RMB vs laparotomy 78433.23 ± 5788.12 RMB,P < 0.05).TLPD had a statistically higher cost for both surgery(24732.13 ± 929.28 RMB vs 19317.53 ± 795.94 RMB,P < 0.001)and anesthesia(6192.37 ± 272.77 RMB vs 5184.10 ± 146.93 RMB,P < 0.001),but a reduced cost for admission examination(50392.93 ± 1761.22 RMB vs 53931.60 ± 5556.94 RMB,P < 0.05).CONCLUSION:TLPD is safe when performed by experienced pancreatobiliary surgeons during the initial learning curve,but has a higher cost than open pancreaticoduodenectomy.
基金Supported by Skane county council research and development foundation
文摘AIM:To evaluate long-term endocrine and exocrine pancreatic function,quality of life and health care costs after mild acute pancreatitis and severe acute pancreatitis(SAP).METHODS:Patients prospectively included in 2001-2005 were followed-up after 42(36-53)mo.Pancreatic function was evaluated with laboratory tests,the oral glucose tolerance test(OGTT),fecal elastase-1 and a questionnaire.Short Form(SF)-36,was completed.RESULTS:Fourteen patients with a history of SAP and 26 with mild acute pancreatitis were included.Plasma glucose after OGTT was higher after SAP(9.2 mmol/L vs 7.0 mmol/L,P=0.044).Diabetes mellitus or impaired glucose tolerance in fasting plasma glucose and/or 120 min plasma glucose were more common in SAP patients(11/14 vs 11/25,P=0.037).Sick leave,time until the patients could take up recreational activities and time until they had recovered were all longer after SAP(P <0.001).No significant differences in SF-36 were seen between the groups,or when comparing with age and gender matched reference groups.Total hospital costs,including primary care,follow-up and treatment of complications,were higher after SAP(median€16572 vs €5000,P<0.001).CONCLUSION:Endocrine pancreatic function was affected,especially after severe disease.SAP requires greater resource use with long recovery,but most patients regained a good quality of life.
基金supported by the Fundamental Research Funds for the Central Universities[CDJSK10 00 68]NSFC Young Scientist Research Fund[0903080]
文摘The hybrid policy is a flexible policy tool that combines features of carbon trading and carbon taxation.Its economic and environmental effects under China's background are still not studied in detail.Given the exogenous carbon reduction targets,carbon prices,and carbon tax-rates,by computable general equilibrium modeling methods and factor decomposition methods,this article investigates direct and cascaded effects of the hybrid policy on economic growth,energy utilization,and carbon emission on the national level and the sector level,with China's national input-output data-set.Stepwisely,policy scenarios with irrational estimated results are selectively excluded based on comprehensive evaluation among economic,carbon reduction and other policy targets.As a result,against national economic conditions in 2007,the hybrid policy,with a carbon reduction target of -10%,a carbon tax-rate of around $10,and a ceiling carbon price of $40,is highly recommended,because of its significant lower economic loss,lower energy utilization cost,and practical robustness against fluctuation of energy market and carbon market.Furthermore,by decomposition analysis,carbon reduction-related costs are decomposed into a direct part that includes carbon allowance price and carbon tax,and an indirect part as the energy price incremental induced by direct carbon costs.Gross carbon reduction may be decomposed into three parts such as energy intensity,economic scale,and technical progress.And,carbon taxation is the main policy tool that stimulates to improve the energy efficiency.
文摘Background: The cost and economic burden of diabetes are a serious worldwide issue. In this study, we evaluated medical payments for persons diagnosed with diabetes and the factors that led to a person having diabetes to reduce its prevalence. Methods: A dataset containing 113,979 medical checkups and 3,671,783 monthly medical, dental, care-giving and pharmacy payment records of one health insurance society was used. The dataset contains information of normal and healthy persons. The sample period ran from April, 2013 to March, 2016. The medical payments for persons diagnosed with diabetes were calculated. The regression analysis was used to remove the effects of age and gender. The probit analysis was used to analyze the factors that led to a person having diabetes. Results: In 2.9% of cases, the person undergoing the checkup was diagnosed with diabetes, and the medical payments for these patients were 2.7 times as much as the average medical payment per person. This result did not change significantly even if age and gender were considered. The results of the probit analysis suggested that body mass index, high systolic blood pressure, low diastolic blood pressure, eating habits, physical activities, smoking, drinking alcohol and sleeping were important factors for diabetes. Conclusion: The diabetes might be a costlier disease than previously thought in Japan. By the estimation, 8% of all medical payments were made for these persons with diabetes, which is much higher than the result shown by national survey data. However, overall prevalence could be recused by efforts such as prevention of overweight and obesity.
基金supported by grants from Innovative Team Project of Nanjing Normal University(Project No.0319PM0902)Priority Academic Program Development of Jiangsu Higher Education Institutions(CXLX11_0885)to Xiang JI
文摘Tail autotomy is a defense mechanism used by many lizards to evade predators, but it entails costs. We used the oriental leaf-toed gecko Hemidactylus bowringii as a model animal to evaluate locomotor costs of tail autotomy. We removed the tail about 5 mm from the tail base from each of the experimental geckos(adult males) initially having intact tails. Tailless experimental geckos and tailed control geckos were measured for overall speed and sprint speed in both vertical and horizontal directions. Overall speed and sprint speed did not differ between tailless and tailed geckos. The influence of locomotor direction on both overall speed and sprint speed was significant, with horizontal speed being greater than vertical speed. The interaction between tail condition and locomotor direction was not significant in overall speed, but was significant in sprint speed. Tailless geckos had faster vertical sprint speed than the tailed individuals. Of the 130 field-caught adults, 59 had previously lost their tails, with most(about 61%) of them shedding their tails near the tail base. Neither the proportion of geckos with tail autotomy nor the frequency distribution of locations of the tail break differed between the sexes. Our data show that tail loss of H. bowringii occurs frequently in nature. However, tail loss does not incur locomotor costs in this gecko.
文摘There are many inputs into the dairy replacement herd which impact not only on the cost of rearing heifers from birth to first calving, but also on their future longevity and production potential. This study determined the current cost of rearing dairy heifers in the UK through the calculation and analysis of individual costs on a subset of 102 UK dairy farms. Each farm was visited and an extensive heifer rearing questionnaire was completed. Current heifer rearing practices were recorded to provide insight into critical management decisions. A cost analysis workbook was developed to calculate the costs of inputs in the preweaning period for labour, calving, feed, housing, health treatments and vaccinations, waste storage, machinery and equipment, and utilities. The average age at weaning was 62 d. The mean cost of rearing from birth to weaning was £195.19 per heifer with a mean daily cost of £3.14 (excluding the opportunity cost of the calf). This ranged from £1.68 to £6.11 among farms, reflecting major differences in management strategies and efficiency. The highest contribution to total costs came from feed (colostrum, milk, starter and forage) at 48.5% with milk feeding making up the greatest proportion of this at 37.3%. The next major expenses were bedding and labour, contributing 12.3% and 11.2% respectively. Unsurprisingly, delaying age at weaning increased total cost by £3.53 per day. Total costs were on average 45% higher on organic farms than conventional due to higher feed costs and later weaning. Calving pattern also had a strong association with the total cost being lowest with spring calving, intermediate with autumn calving and highest in multi block and all year round calving herds.
基金funded by National Natural Science Foundation of China(Grant Nos.41371539)Western Light Talent Culture Project:Standard of Payment for Ecosystem Service based on GISGEF(Global Environment Fund)Project:Payment for Watershed Services in the Chishui River Basin for the Conservation of Globally Significant Biodiversity(Grant Nos.00089388)
文摘Payment for ecosystem services(PES) has become an increasingly popular means of ecosystem conservation. Opportunity cost is an important factor to increase the investment efficiency of PES projects.However, the distribution of opportunity cost is usually unclear in mountainous regions due to the obvious environment changes. In this study, we developed a framework to assess the distribution of agricultural opportunity costs in mountainous regions and applied this method to Baoxing County, a typical mountainous county in Sichuan Province of southwest China. Planting suitability of 17 crops was assessed based on agricultural statistics and natural conditions data within a GIS environment.Agricultural opportunity cost was quantified with a weighted summation of farmers' willingness to cultivate and each crop's opportunity cost. Finally,specific agricultural opportunity cost was obtained according to the spatial areas of the protection programs and land use status. The results showed that agricultural opportunity costs of PES in Baoxing County were estimated to be more than $30 million,with a mean of 400.85 $/ha. Agricultural opportunity costs in mountainous regions displayed some obvious spatial variation and areas with lower agricultural opportunity costs could be selected as priority areas for PES. Our findings revealed that the planting suitability evaluation can make agricultural opportunity costs mapping more reasonable. It will be helpful for the PES programs implementation in mountainous regions.