899 research outputs found

    A Chronicle of Global Evolution of Product Warranty

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    This article provides a chronological account of the evolution of the concept of product warranty and its development over the four millennia to its present state at the dawn of twenty-first century A.D. This study examines how the concept of product warranty originated and illustrates how this concept was an integral element of accepted business practices in commerce and trade over the ages in almost all civilizations spanning the entire globe. The civilizations include the Babylonian and Assyrian civilizations of twenty-first century B.C., the Roman era of the fifth century B.C., Bavarian rule at the start of the Christian era, earlier Jewish period of the second century A.D., Hindu period of the fifth, Islamic era of the eighth, Russian period of the early tenth, church rule of the medieval times, customs of the English borough, and ultimately the post-industrial era of consumerism and today\u27s times of warranty legislation

    Advantageous Cost Structure: A Strategic Costing Case Study

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    Today\u27 s increasingly competitive environment has prompted many fim1S to view organizational cost control as a strategic initiative through programs such as advantageous cost structure. Although strategic costing has been a concern of managers at the strategic level, finns are now trying to find ways to implement strategic initiatives at the operational level as well. These initiatives force organizations to address their major cost drivers and often result in improved processes, reduced number of non-value-added activities, improved supplier relations, and increased productivity. This article offers a case study of a large multinational manufacturing company that has successfully implemented advantageous cost structure in its effort to reduce costs and sustain competitive advantage

    Near Infrared Spectroscopic Monitoring During Cardiopulmonary Exercise Testing Detects Anaerobic Threshold

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    Cardiopulmonary exercise testing (CPET) provides assessment of the integrative responses involving the pulmonary, cardiovascular, and skeletal muscle systems. Application of exercise testing remains limited to children who are able to understand and cooperate with the exercise protocol. Near-infrared spectroscopy (NIRS) provides a noninvasive, continuous method to monitor regional tissue oxygenation (rSO2). Our specific aim was to predict anaerobic threshold (AT) during CPET noninvasively using two-site NIRS monitoring. Achievement of a practical noninvasive technology for estimating AT will increase the compatibility of CPET. Patients without structural or acquired heart disease were eligible for inclusion if they were ordered to undergo CPET by a cardiologist. Data from 51 subjects was analyzed. The ventilatory anaerobic threshold (VAT) was computed on VCO2 and respiratory quotient post hoc using the standard V-slope method. The inflection points of the regional rSO2 time-series were identified as the noninvasive regional NIRS AT for each of the two monitored regions (cerebral and kidney). AT calculation made using an average of kidney and brain NIRS matched the calculation made by VAT for the same patient. Two-site NIRS monitoring of visceral organs is a predictor of AT

    Effect of Fontan Fenestration on Regional Venous Oxygen Saturation During Exercise: Further Insights Into Fontan Fenestration Closure

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    Fontan fenestration closure is a topic of great debate. The body of data regarding the risks and benefits of fenestration closure is limited yet growing. Previous studies have demonstrated that Fontan patients have less exercise capacity than those with normal cardiovascular anatomy. Differences also have been noted within various subgroups of Fontan patients such as whether Fontan is fenestrated or not. This study aimed to compare trends in regional oxygen saturations using near-infrared spectroscopy (NIRS) in patients with Fontan circulations during ramping exercise to further delineate differences between patients with and without a fenestration. It was hypothesized that Fontan patients with fenestrations have better exercise times, higher absolute regional oxygen venous saturations, and smaller arteriovenous differences than Fontan patients without fenestrations. For this study, 50 consecutive Fontan patients and 51 consecutive patients with normal cardiovascular anatomy were recruited. Placement of NIRS probes was performed to obtain regional oxygen saturations from the brain and the kidney. Readings were obtained at 1-min intervals during rest, exercise, and recovery. A standard Bruce protocol was used with a 5-min recovery period. Absolute regional tissue oxygenation values (rSO2) and arterial-venous oxygen saturation differences (AVDO2) calculated as arterial oxygen saturation (SPO2)—rSO2 for normal versus Fontan patients and for fenestrated versus unfenestrated Fontan patients were compared using independent t tests. When normal and Fontan patients were compared, the Fontan patients had a significantly shorter duration of exercise (9.3 vs 13.2 min; p \u3c 0.001). No statistically significant difference in rSO2 change or AVDO2 was evident at the time of peak exercise, at 2 min into the recovery, or at 5 min into the recovery. A small oxygen debt also was paid back to the brain in the Fontan patients after exercise, as evidenced by a narrower AVDO2 than at baseline. The comparison of Fontan patients with and without fenestration showed no statistically significant difference in exercise time, rSO2 change, or AVDO2. The Fontan patients were noted to have shorter exercise times than the normal patients and also appeared to have an alteration in postexertional regional blood flow. However, when the various Fontan subtypes were compared by presence or absence of a fenestration, no significant differences were noted with regard to change in regional oxygen saturation or arteriovenous oxygen saturation. Thus, for patients with Fontan physiology, closure of the fenestration does not seem to have an impact on the dynamics of regional oxygen extraction during exercise or recovery

    Comparison of 12-Month Outcomes with Zotarolimus- and Paclitaxel-Eluting Stents: A Meta-Analysis

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    Revascularization after myocardial infarction is often achieved via percutaneous coronary intervention, which often entails stenting. Drug-eluting stents have shown benefits over bare metal stents in this setting, and a variety of drug-eluting stents are now available, including sirolimus-, paclitaxel-, and zotarolimus-eluting stents. There are studies that have compared the various drug-eluting stents and this meta-analysis pools data comparing 12-month clinical outcomes of zotarolimus- and paclitaxel-eluting stents. End points studied were myocardial infarction, major adverse cardiac events, cardiac death, all-cause death, stent thrombosis, target vessel revascularization, and target lesion revascularization.There was a statistically significant reduction in risk of myocardial infarction (odds ratio, 0.250, confidence interval, 0.160 to 0.392) and statistically insignificant reductions in major adverse cardiac events (odds ratio, 0.813, confidence interval, 0.656 to 1.007), cardiac death (odds ratio, 0.817, confidence interval, 0.359 to 1.857), all cause death (odds ratio, 0.820, confidence interval, 0.443 to 1.516), and target lesion revascularization (odds ratio, 0.936, confidence interval 0.702 to 1.247). There was a statistically significant increase in target vessel revascularization (odds ratio, 1.336, confidence interval, 1.003 to 1.778) and a statistically insignificant increase in stent thrombosis (odds ratio, 1.174, confidence interval, 0.604 to 2.280). These findings are similar to the individual studies although other studies have noted increased late loss with zotarolimus-eluting stents and this current data associated with late loss should be kept in mind when makimg clinical decisions regarding sent selection

    Assessment of selenium levels and risk factors for stroke and other cardiovascular disease: a cross sectional study in a seleniferous area of Punjab, India

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    Background and aims: Rural areas of Punjab in India have been found to have soil rich in selenium (Se); about 2160 hectare area is seleniferous and is populated by about 10,000 inhabitants. Selenium concentrations in these villages were reported to be as high as 65 times over non-seleniferous areas. The aim of this cross-sectional study was to evaluate selenium levels in blood, hair and nails in a group of subjects living in this area, and to evaluate the correlation between selenium exposure levels and a relevant cardiovascular risk factor and blood pressure. Methods: In a random sample of rural residents in three districts of a seleniferous area of Punjab, we determined selenium concentration in hair, nail clippings and serum samples. Analyses were carried out using atomic absorption spectrophotometry at National Dairy Research Institute (NDRI), Karnal, India. Data analysis was performed using the STATA 15.0 software (STATA Corp. TX). Results: A total of 680 human subjects were recruited in this study, with a male/female ratio of 0.65 and a median age of 43 (IQR 32-52). Medium selenium levels in blood, hair and nail were 86.7 µg/l (IQR 55.9-200.3), 20.7 µg/g (IQR 12.6-40.3) and 56.9 µg/g (IQR 42.8-83.9), respectively, with lower levels in women in all three kind of samples. Concerning systolic blood pressure, Pearson’s correlation coefficients were 0.102 (95 % CI -0.025 to 0.226, p=0.116); 0.076 (95% CI -0.010 to 0.160, p=0.085); 0.072 (95% CI -0.015 to 0.157, p=0.104) with blood, hair and nail, respectively. For diastolic blood pressure, Pearson’s correlation coefficients are 0.106 (95% CI -0.022 to 0.230, p=0.104), 0.036 (95% CI -0.050 to 0.122, p=0.409), 0.049 (95% CI -0.038 to 0.135, p=0.272), respectively. Conclusions: Our findings indicate a positive correlation between selenium content in blood, hair and nails and increasing systolic and diastolic pressure levels, in line with previous epidemiologic findings, indicating a possible health concern for this highly exposed population. The possible relation between selenium over-exposure and onset of hypertension and other cardiovascular diseases deserves further investigation

    First measurement of the Head-Tail directional nuclear recoil signature at energies relevant to WIMP dark matter searches

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    We present first evidence for the so-called Head-Tail asymmetry signature of neutron-induced nuclear recoil tracks at energies down to 1.5 keV/amu using the 1m^3 DRIFT-IIc dark matter detector. This regime is appropriate for recoils induced by Weakly Interacting Massive Particle (WIMPs) but one where the differential ionization is poorly understood. We show that the distribution of recoil energies and directions induced here by Cf-252 neutrons matches well that expected from massive WIMPs. The results open a powerful new means of searching for a galactic signature from WIMPs.Comment: 4 pages, 6 figures, 1 tabl
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