84 research outputs found

    Empirical forecasting practices of a British university

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    This article is based on a single case study aimed at examining behavioral issues of forecasting, in particular the role and practice of forecasting in a British university settings. Key variables were identified in establishing associations between the variables that provide suitable criteria for the purpose of this study. Data collection was based on questionnaires distributed to people involved and interviews which were held with prominent staff of the University. Fisher-exact tests were performed to identify significant associations between variables. Results indicated the various levels of perceptions and practices of forecasting produced by the people involved at the University. The study implies that useful insights can be gathered through forecasting from a different perspective of the non-profit making service industry

    A comparison of Olympic and Paralympic performances

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    In 2012, Oscar Pistorius created history as the first amputee sprinter to compete in the Olympics. Other athletes achieved amazing feats long before the Paralympics were introduced, including gymnast\ud George Eyser who won six medals at the 1904 Olympics with a wooden leg, and others who competed in both Games. An exciting challenge of considerable interest is to compare performances of Olympic and Paralympic athletes, so contributing to improving integration of the two competitions. We generalize the recent dynamic shrinkage method for class handicapping and apply it to competition results from equestrian individual dressage at the London 2012 Summer Games and cross country skiing at the Sochi 2014 Winter Games. Our analysis generates promising results and surprising revelations. It also offers a fair method for comparing performances by athletes from other diverse groups, with potential benefits of extra incentive and reward systems for motivating unified sporting participation in general settings

    Strategy selection and outcome prediction in sport using dynamic learning for stochastic processes

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    We study reliability equivalence factors of a system of independent and identical components with exponentiated Weibull lifetimes. The system has n subsystems connected in parallel and subsystem i has mi components connected in series, i=1,
,n. We consider improving the reliability of the system by (a) a reduction method and (b) several duplication methods: (i) hot duplication; (ii) cold duplication with perfect switching; (iii) cold duplication with imperfect switching. We compute two types of reliability equivalence factors: survival equivalence factors and mean equivalence factors. Although our methods adapt to allow for general lifetime models, we use the exponentiated Weibull distribution because it is flexible and enables comparisons with other reliability equivalence studies. The example we present demonstrates the potential for applying these methods to address specific questions that arise when attempting to improve the reliability of simple systems or simple configurations of possibly complex subsystems in many diverse applications

    Soil respiration in northern forests exposed to elevated atmospheric carbon dioxide and ozone

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    The aspen free-air CO 2 and O 3 enrichment (FACTS II–FACE) study in Rhinelander, Wisconsin, USA, is designed to understand the mechanisms by which young northern deciduous forest ecosystems respond to elevated atmospheric carbon dioxide (CO 2 ) and elevated tropospheric ozone (O 3 ) in a replicated, factorial, field experiment. Soil respiration is the second largest flux of carbon (C) in these ecosystems, and the objective of this study was to understand how soil respiration responded to the experimental treatments as these fast-growing stands of pure aspen and birch + aspen approached maximum leaf area. Rates of soil respiration were typically lowest in the elevated O 3 treatment. Elevated CO 2 significantly stimulated soil respiration (8–26%) compared to the control treatment in both community types over all three growing seasons. In years 6–7 of the experiment, the greatest rates of soil respiration occurred in the interaction treatment (CO 2  + O 3 ), and rates of soil respiration were 15–25% greater in this treatment than in the elevated CO 2 treatment, depending on year and community type. Two of the treatments, elevated CO 2 and elevated CO 2  + O 3 , were fumigated with 13 C-depleted CO 2 , and in these two treatments we used standard isotope mixing models to understand the proportions of new and old C in soil respiration. During the peak of the growing season, C fixed since the initiation of the experiment in 1998 (new C) accounted for 60–80% of total soil respiration. The isotope measurements independently confirmed that more new C was respired from the interaction treatment compared to the elevated CO 2 treatment. A period of low soil moisture late in the 2003 growing season resulted in soil respiration with an isotopic signature 4–6‰ enriched in 13 C compared to sample dates when the percentage soil moisture was higher. In 2004, an extended period of low soil moisture during August and early September, punctuated by a significant rainfall event, resulted in soil respiration that was temporarily 4–6‰ more depleted in 13 C. Up to 50% of the Earth’s forests will see elevated concentrations of both CO 2 and O 3 in the coming decades and these interacting atmospheric trace gases stimulated soil respiration in this study.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45867/1/442_2006_Article_381.pd

    Systematic Review of Potential Health Risks Posed by Pharmaceutical, Occupational and Consumer Exposures to Metallic and Nanoscale Aluminum, Aluminum Oxides, Aluminum Hydroxide and Its Soluble Salts

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    Aluminum (Al) is a ubiquitous substance encountered both naturally (as the third most abundant element) and intentionally (used in water, foods, pharmaceuticals, and vaccines); it is also present in ambient and occupational airborne particulates. Existing data underscore the importance of Al physical and chemical forms in relation to its uptake, accumulation, and systemic bioavailability. The present review represents a systematic examination of the peer-reviewed literature on the adverse health effects of Al materials published since a previous critical evaluation compiled by Krewski et al. (2007). Challenges encountered in carrying out the present review reflected the experimental use of different physical and chemical Al forms, different routes of administration, and different target organs in relation to the magnitude, frequency, and duration of exposure. Wide variations in diet can result in Al intakes that are often higher than the World Health Organization provisional tolerable weekly intake (PTWI), which is based on studies with Al citrate. Comparing daily dietary Al exposures on the basis of “total Al”assumes that gastrointestinal bioavailability for all dietary Al forms is equivalent to that for Al citrate, an approach that requires validation. Current occupational exposure limits (OELs) for identical Al substances vary as much as 15-fold. The toxicity of different Al forms depends in large measure on their physical behavior and relative solubility in water. The toxicity of soluble Al forms depends upon the delivered dose of Al+ 3 to target tissues. Trivalent Al reacts with water to produce bidentate superoxide coordination spheres [Al(O2)(H2O4)+ 2 and Al(H2O)6 + 3] that after complexation with O2‱−, generate Al superoxides [Al(O2‱)](H2O5)]+ 2. Semireduced AlO2‱ radicals deplete mitochondrial Fe and promote generation of H2O2, O2 ‱ − and OH‱. Thus, it is the Al+ 3-induced formation of oxygen radicals that accounts for the oxidative damage that leads to intrinsic apoptosis. In contrast, the toxicity of the insoluble Al oxides depends primarily on their behavior as particulates. Aluminum has been held responsible for human morbidity and mortality, but there is no consistent and convincing evidence to associate the Al found in food and drinking water at the doses and chemical forms presently consumed by people living in North America and Western Europe with increased risk for Alzheimer\u27s disease (AD). Neither is there clear evidence to show use of Al-containing underarm antiperspirants or cosmetics increases the risk of AD or breast cancer. Metallic Al, its oxides, and common Al salts have not been shown to be either genotoxic or carcinogenic. Aluminum exposures during neonatal and pediatric parenteral nutrition (PN) can impair bone mineralization and delay neurological development. Adverse effects to vaccines with Al adjuvants have occurred; however, recent controlled trials found that the immunologic response to certain vaccines with Al adjuvants was no greater, and in some cases less than, that after identical vaccination without Al adjuvants. The scientific literature on the adverse health effects of Al is extensive. Health risk assessments for Al must take into account individual co-factors (e.g., age, renal function, diet, gastric pH). Conclusions from the current review point to the need for refinement of the PTWI, reduction of Al contamination in PN solutions, justification for routine addition of Al to vaccines, and harmonization of OELs for Al substances

    Resting state EEG abnormalities in autism spectrum disorders

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    Assessing student teams developing mathematical models applied to business and industrial mathematics

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    Using case studies and group work, this project attempted to provide students with experience of business and industrial working practices and also to address the issue of how to solve practical mathematical problems. Students were organised into teams and tasked with solving a problem presented in the form of a real world industrial case study. Each group was assessed on their problem solving abilities, mathematical modelling skills and also on their team work and contribution to the group. Industrial partners were also invited to judge the final solutions presented by the group and feedback was offered, based on the ‘real world’ situation presented by the case studies
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