9,206 research outputs found

    Towards greener horizontal-axis wind turbines: Analysis of carbon emissions, energy and costs at the early design stage

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    This paper describes the development of a quantitative analysis system as a platform for rapidly estimate energy, costs and carbon emission to facilitate the comparison of different wind turbine concept designs. This system aimed specifically at wind turbine manufacturing processes due to the fact that a large proportion of the environmental, costs and energy impacts would occur at this stage. The proposed method supports an initial assessment of multiple design concepts which allows the selection and development of a “greener” wind turbine. The developed system enables concept design of commercial wind turbine towers of hub heights between 44 and 135 m. The method supports an accurate estimation in regards to the dimension, energy consumed, maximum power output, costs and carbon emission in the early design phases of a wind turbine. As a result of the development, the proposed approach could potentially be used to minimise the carbon footprints of major engineering projects such as wind farms

    Neurochemical Changes Following Stroke: Role In Neuroprotection And Cardiac Susceptibility

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    The mechanisms mediating neuronal recovery and cardiovascular complications after ischemic stroke are not completely known. In these investigations, I examined changes in neuropeptides and a catecholamine synthesizing enzyme, tyrosine hydroxylase (TH), following middle cerebral artery occlusion (MCAO) in adult male Wistar rats.;Five days following MCAO, the immunoreactivity for TH and neuropeptide Y (NPY) increased in the insular cortex (IC) within the peri-infarct zone. NPY also increased ipsilaterally in the basolateral nucleus of the amygdala, whereas leucine-enkephalin, dynorphin and neurotensin increased ipsilaterally in the central nucleus of the amygdala. Sham MCAO was ineffective.;Neurochemical changes were assessed 5 days after localized excitotoxic lesion of the IC or primary somatosensory cortex (SSC-I). Damage to the IC but not SSC-I reproduced the ipsilateral neurochemical changes of MCAO. Nevertheless, damage to the SSC-I produced local increases in NPY. Saline injection was ineffective.;The time-course of these changes was studied to understand the possible mechanisms for these neurochemical changes. The cortical NPY increase became significant at 1 day, maximal at 3-5 days, and subsiding by 10 days after MCAO. The amygdalar changes followed a similar time-course with peaks at 3-5 days and complete recovery by 10 days.;MCAO with intracerebroventricular injection of colchicine demonstrated that cortical neurons were responsible for the local NPY increase and that ipsilateral transmission of signals from the ischemic IC to the amygdala was involved in producing the amygdalar neurochemical changes.;The role of cortical NPY increase as an endogenous neuroprotective response to stroke was investigated using antisense oligodeoxynucleotide specific for NPY-Y1 receptors. A reduction in Y1 binding sites within the IC produced a doubling of the infarctolume following MCAO.;The possibility that these neurochemical changes mediate cardiovascular complications of stroke was investigated by comparing the cardiovascular responses to stress at different time after MCAO or sham MCAO. MCAO exaggerated the cardiovascular responses to stress in a time-course comparable to that of the amygdalar neurochemical changes.;Thus, my results clearly showed specific neurochemical changes in the peri-infarct zone and the ipsilateral amygdala. I also provided evidence to implicate these changes in neuroprotection and cardiac consequences of stroke

    Banking Information Success Acceptance: An Empirical Evaluation

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    Extending the technology acceptance model, we present a two-level analysis to empirically evaluate the acceptance of business information systems in customer-based retail banking.  Utilizing survey data from a representative banking group in a representative international financial center, regression analysis first indicated that end-user satisfaction, usage and acceptance depend significantly on the system’s perceived usefulness, perceived ease of use and expected ability to meet customer information requirements. In turn, these perceptual-anticipatory considerations were found to be positively and significantly affected by technical-functional factors in the form of user-friendliness and system reliability.  For the corporate strategist, our empirical results suggest enhancing perceived ease of use, perceived usefulness and ability to meet customer information needs in order of importance when introducing or up-grading information systems in retail banking and other service-based business activities

    Contexts Paired with Junk Food Impair Goal-Directed Behavior in Rats: Implications for Decision Making in Obesogenic Environments.

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    The high prevalence of obesity and related metabolic diseases calls for greater understanding of the factors that drive excess energy intake. Calorie-dense palatable foods are readily available and often are paired with highly salient environmental cues. These cues can trigger food-seeking and consumption in the absence of hunger. Here we examined the effects of palatable food-paired environmental cues on control of instrumental food-seeking behavior. In Experiment 1, adult male rats received exposures to one context containing three "junk" foods (JFs context) and another containing chow (Chow context). Next, rats were food-deprived and trained to perform instrumental responses (lever-press) for two novel food rewards in a third, distinct context. Contextual influences on flexible control of food-seeking behavior were then assessed by outcome devaluation tests held in the JF, chow and training contexts. Devaluation was achieved using specific satiety and test order was counterbalanced. Rats exhibited goal-directed control over behavior when tested in the training and chow-paired contexts. Notably, performance was habitual (insensitive to devaluation) when tested in the JF context. In Experiment 2 we tested whether the impairment found in the JF context could be ameliorated by the presentation of a discrete auditory cue paired with the chow context, relative to a second cue paired with the JF context. Consistent with the results of Experiment 1, the devaluation effect was not significant when rats were tested in the JF context with the JF cue. However, presenting the chow cue increased the impact of the devaluation treatment leading to a robust devaluation effect. Further tests confirmed that performance in the chow context was goal-directed and that sensory-specific satiety in the JF context was intact. These results show that environments paired with palatable foods can impair goal-directed control over food-seeking behavior, but that this deficit was improved by a cue paired with chow. This has promising implications for assisting individuals in controlling their eating behavior in environments designed to dysregulate it

    Mapping and direct valuation: Do they give equivalent EQ-5D-5L index scores?

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    © 2015 Luo et al. Objective: Utility values of health states defined by health-related quality of life instruments can be derived from either direct valuation ('valuation-derived') or mapping ('mapping-derived'). This study aimed to compare the utility-based EQ-5D-5L index scores derived from the two approaches as a means to validating the mapping function developed by van Hout et al for the EQ-5D-5L instrument. Methods: This was an observational study of 269 breast cancer patients whose EQ-5D-5L index scores were derived from both methods. For comparing discriminatory ability and responsiveness to change, multivariable regression models were used to estimate the effect sizes of various health indicators on the index scores. Agreement and test-retest reliability were examined using intraclass correlation coefficient (ICC). Whenever appropriate, the 90 % confidence intervals (90 % CI) were compared to predefined equivalence margins. Results: The mean difference in and ICC between the valuation- and mapping-derived EQ-5D-5L index scores were 0.015 (90 % CI = 0.006 to 0.024) and 0.915, respectively. Discriminatory ability and responsiveness of the two indices were equivalent in 13 of 15 regression analyses. However, the mapping-derived index score was lower than the valuation-derived index score in patients experiencing extreme health problems, and the test-retest reliability of the former was lower than the latter, for example, their ICCs differed by 0.121 (90 % CI = 0.051 to 0.198) in patients who reported no change in performance status in the follow-up survey. Conclusion: This study provided the first evidence supporting the validity of the mapping function for converting EQ-5D-5L profile data into a utility-based index score.published_or_final_versio

    Superfaults and Pseudotachylytes: Evidence of Catastrophic Earth Movements

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    Superfaults often exhibit an unusual rock called pseudotachylyte, and together these two features are critical to our understanding of catastrophic tectonics. Superfaults are rapid-moving, single-slip displacement surfaces involving very large offsets with the moving-block side of the fault being unconfined or unpinned during rapid gravity offset. Pseudotachylyte is the dark-colored, metamorphic silicate glass formed by frictional melting upon the superfault surface at temperature exceeding 1000 oC, and often displaying distinctive isotropic or cryptocrystalline optical properties. Pseudotachylyte is understood to be evidence of high-speed rock movement during superquakes, where displacements occurred much faster than during modern magnitude 9 earthquakes. Superfaults, pseudotachylyte and superquakes are interpreted as support for global catastrophic tectonic activity. Hand specimens and field data were collected from Homestake Shear Zone in central Colorado, and from the Pasagshak Thrust, Kodiak Island, Alaska. Thin-section analysis shows the presence of glass melt and/or aphanitic black rocks containing pseudotachylyte, and the development of numerous pressure solution surfaces within cataclasite rocks. Cross-cutting relationships support repeated episodes of fault movement and subsequent melt development at both sites. Data gathered from the Homestake Shear Zone supports rapid catastrophic Earth movements during the formation of the North American continent on Day 3 of the Creation Week. Evidence from the Pasagshak Thrust supports the subduction model of catastrophic plate tectonics, with the fault being active during and after Noah’s Flood

    Direct health care costs of treating seasonal affective disorder: a comparison of light therapy and fluoxetine.

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    Objective. To compare the direct mental health care costs between individuals with Seasonal Affective Disorder randomized to either fluoxetine or light therapy. Methods. Data from the CANSAD study was used. CANSAD was an 8-week multicentre double-blind study that randomized participants to receive either light therapy plus placebo capsules or placebo light therapy plus fluoxetine. Participants were aged 18-65 who met criteria for major depressive episodes with a seasonal (winter) pattern. Mental health care service use was collected for each subject for 4 weeks prior to the start of treatment and for 4 weeks prior to the end of treatment. All direct mental health care services costs were analysed, including inpatient and outpatient services, investigations, and medications. Results. The difference in mental health costs was significantly higher after treatment for the light therapy group compared to the medication group-a difference of 111.25(z=3.77,P=0.000).However,whentheamortizedcostofthelightboxwastakenintotheaccount,thegroupswereswitchedwiththefluoxetinegroupincurringgreaterdirectcarecostsadifferenceof111.25 (z = -3.77, P = 0.000). However, when the amortized cost of the light box was taken into the account, the groups were switched with the fluoxetine group incurring greater direct care costs-a difference of 75.41 (z = -2.635, P = 0.008). Conclusion. The results suggest that individuals treated with medication had significantly less mental health care cost after-treatment compared to those treated with light therapy

    The Complete Sequence of a Human Parainfluenzavirus 4 Genome

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    Although the human parainfluenza virus 4 (HPIV4) has been known for a long time, its genome, alone among the human paramyxoviruses, has not been completely sequenced to date. In this study we obtained the first complete genomic sequence of HPIV4 from a clinical isolate named SKPIV4 obtained at the Hospital for Sick Children in Toronto (Ontario, Canada). The coding regions for the N, P/V, M, F and HN proteins show very high identities (95% to 97%) with previously available partial sequences for HPIV4B. The sequence for the L protein and the non-coding regions represent new information. A surprising feature of the genome is its length, more than 17 kb, making it the longest genome within the genus Rubulavirus, although the length is well within the known range of 15 kb to 19 kb for the subfamily Paramyxovirinae. The availability of a complete genomic sequence will facilitate investigations on a respiratory virus that is still not completely characterized
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