Hasil untuk "Costs"

J. Sacks, K. Gonzales, Ellen E Bouchery et al.

A. Buescher, Zuleyha Cidav, M. Knapp et al.

J. Hinkel, D. Lincke, A. Vafeidis et al.

W. Jack, T. Suri

We explore the impact of reduced transaction costs on risk sharing by estimating the effects of a mobile money innovation on consumption. In our panel sample, adoption of the innovation increased from 43 to 70 percent. We find that, while shocks reduce consumption by 7 percent for nonusers, the consumption of user households is unaffected. The mechanisms underlying these consumption effects are increases in remittances received and the diversity of senders. We report robustness checks supporting these results and use the four-fold expansion of the mobile money agent network as a source of exogenous variation in access to the innovation.

B. McLellan, Ross P. Williams, J. Lay et al.

Abstract Geopolymer concrete is seen as a potential alternative to standard concrete, and an opportunity to convert a variety of waste streams into useful by-products. One key driver in geopolymer development is the desire to reduce greenhouse gas emissions from the production of concrete products. This paper presents an examination of the lifecycle cost and carbon impacts of Ordinary Portland Cement (OPC) and geopolymers in an Australian context, with an identification of some key challenges for geopolymer development. The results of the examination show that there is wide variation in the calculated financial and environmental “cost” of geopolymers, which can be beneficial or detrimental depending on the source location, the energy source and the mode of transport. Some case study geopolymer concrete mixes based on typical Australian feedstocks indicate potential for a 44–64% reduction in greenhouse gas emissions while the financial costs are 7% lower to 39% higher compared with OPC.

G. Guy, S. Machlin, D. Ekwueme et al.

D. Moynihan, P. Herd, H. Harvey

Russ Wermers

A. Alchian, Harold Demsetz

B. Flyvbjerg, M. Holm, Søren L. Buhl

Abstract This article presents results from the first statistically significant study of cost escalation in transportation infrastructure projects. Based on a sample of 258 transportation infrastructure projects worth US$90 billion and representing different project types, geographical regions, and historical periods, it is found with overwhelming statistical significance that the cost estimates used to decide whether such projects should be built are highly and systematically misleading. Underestimation cannot be explained by error and is best explained by strategic misrepresentation, that is, lying. The policy implications are clear: legislators, administrators, investors, media representatives, and members of the public who value honest numbers should not trust cost estimates and cost-benefit analyses produced by project promoters and their analysts.

D. Bates, N. Spell, D. Cullen et al.

Objective. —To assess the additional resource utilization associated with an adverse drug event (ADE). Design. —Nested case-control study within a prospective cohort study. Participants. —The cohort included 4108 admissions to a stratified random sample of 11 medical and surgical units in 2 tertiary-care hospitals over a 6-month period. Cases were patients with an ADE, and the control for each case was the patient on the same unit as the case with the most similar pre-event length of stay. Main Outcome Measures. —Postevent length of stay and total costs. Methods. —Incidents were detected by self-report stimulated by nurses and pharmacists and by daily chart review, and were classified as to whether they represented ADEs. Information on length of stay and charges was obtained from billing data, and costs were estimated by multiplying components of charges times hospital-specific ratios of costs to charges. Results. —During the study period, there were 247 ADEs among 207 admissions. After outliers and multiple episodes were excluded, there were 190 ADEs, of which 60 were preventable. In paired regression analyses adjusting for multiple factors, including severity, comorbidity, and case mix, the additional length of stay associated with an ADE was 2.2 days (P=.04), and the increase in cost associated with an ADE was $3244 (P=.04). For preventable ADEs, the increases were 4.6 days in length of stay (P=.03) and $5857 in total cost (P=.07). After adjusting for our sampling strategy, the estimated postevent costs attributable to an ADE were $2595 for all ADEs and $4685 for preventable ADEs. Based on these costs and data about the incidence of ADEs, we estimate that the annual costs attributable to all ADEs and preventable ADEs for a 700-bed teaching hospital are $5.6 million and $2.8 million, respectively. Conclusions. —The substantial costs of ADEs to hospitals justify investment in efforts to prevent these events. Moreover, these estimates are conservative because they do not include the costs of injuries to patients or malpractice costs.

J. H. Dyer

Jeffrey H. Dyer, W. Chu

M. Correia, D. Waitzberg

Charles T. Carlstrom, T. Fuerst

I. Janssen, D. Shepard, P. Katzmarzyk et al.

H. Frey, M. Klebanoff

Á. S. Millán, R. MacLean, Fernando Baquero et al.

ABSTRACT Plasmids mediate the horizontal transmission of genetic information between bacteria, facilitating their adaptation to multiple environmental conditions. An especially important example of the ability of plasmids to catalyze bacterial adaptation and evolution is their instrumental role in the global spread of antibiotic resistance, which constitutes a major threat to public health. Plasmids provide bacteria with new adaptive tools, but they also entail a metabolic burden that, in the absence of selection for plasmid-encoded traits, reduces the competitiveness of the plasmid-carrying clone. Although this fitness reduction can be alleviated over time through compensatory evolution, the initial cost associated with plasmid carriage is the main constraint on the vertical and horizontal replication of these genetic elements. The fitness effects of plasmids therefore have a crucial influence on their ability to associate with new bacterial hosts and consequently on the evolution of plasmid-mediated antibiotic resistance. However, the molecular mechanisms underlying plasmid fitness cost remain poorly understood. Here, we analyze the literature in the field and examine the potential fitness effects produced by plasmids throughout their life cycle in the host bacterium. We also explore the various mechanisms evolved by plasmids and bacteria to minimize the cost entailed by these mobile genetic elements. Finally, we discuss potential future research directions in the field.

Yu Zhang, Yichao Zhai, Qin Zhang et al.

Abstract Locoweed toxicity is attributed to swainsonine-producing endophytic fungus Alternaria oxytropis, yet the broader ecological significance of fungal metabolites beyond swainsonine remains poorly understood. Here, we integrated untargeted metabolomics with biochemical assays to compare the effects on the plant of the wild-type Alternaria oxytropis endophyte with endophyte-free plants and plants colonised by swnR-silenced strains. Across four symbiotic systems, 3,008 metabolites were identified, with significant alterations enriched in terpenoid backbone, flavonoid, and amino acid metabolism. Fungal-colonized plants exhibited elevated accumulation of sesquiterpene lactones and flavonoid glycosides—metabolites with known allelopathic, antimicrobial, and antioxidant functions. Notably, swnR-silenced symbionts maintained enhanced antioxidant enzyme activity, particularly catalase, despite a marked reduction in swainsonine levels. Growth parameters remained unaffected, indicating that metabolic reprogramming occurred without fitness costs. Our findings reveal that A. oxytropis endophytes modulate host secondary metabolism and oxidative defense independently of swainsonine biosynthesis. This dual role—conferring toxicity while enhancing ecological competitiveness—offers new insight into locoweed persistence and provides a potential strategy for mitigating toxicity while preserving adaptive benefits in host–endophyte symbiosis.

Ali Salmasnia, Maedeh Abbaszadeh, Zohre Kiapasha

Abstract In recent years, the Cloud Manufacturing System (CMS) has received increasing attention as a customer-oriented process for the production of customized products. To increase the market share of the CMS, it’s inevitable to take customer satisfaction into account. Consequently, this study simultaneously addresses both customer satisfaction and CMS satisfaction. In this context, a multi-objective mathematical model is developed for the scheduling of tasks to the CMS, focusing on five core characteristics: (1) setting the customized product price under a mutual benefit policy, (2) designing a maintenance program to reduce machine failure rate and costs, (3) ensuring fairness among customers, (4) providing an order acceptance policy, and (5) factoring in the costs related to earliness and tardiness. The performance of the proposed model was assessed through three comparative experiments: (a) the mutual benefit strategy’s effectiveness, (b) the impact of the provision of the maintenance program, and (c) the effect of tardiness and earliness.