454 research outputs found

    Estimation of the head elevation angle that causes clinically important venous air embolism in a semi-sitting position for neurosurgery: a retrospective observational study

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    Introduction: The benefits of a sitting position for neurosurgery involving the posterior fossa remain controversial. The main concern is the risk of venous air embolism (VAE). A recent study showed that the rate of VAE was higher when the head was elevated to 45° than when it was elevated to 30°. However, the degree of head elevation that causes clinically important VAE is unclear. The purpose of this study was to estimate the head elevation angle at which the probability of VAE is 50% by using EtCO2 monitoring to detect of VAE. Methods: The anesthesia records of 23 patients who underwent neurosurgery in a sitting position were reviewed retrospectively. Intraoperative ventilation was set to maintain EtCO2 at approximately 38-42 mmHg. The head elevation angle in each case was determined from a photograph taken by the anesthesiologist or brain surgeon. Nineteen of the 23 cases had photographs available that contained a horizontal reference in the background. Seven cases were treated as VAE during the operation. Six of these cases met the criteria for VAE in this study. Data analysis was performed on a total of 18 patients. The angle between the line connecting the hip joint and the shoulder joint and the horizontal reference was obtained by ImageJ software. Logistic regression was performed using the Python programming language to determine the head elevation angle at which the probability of air embolism was 50%. Results: The decision boundary in the logistic regression was 35.7°. This head elevation angle was the boundary where the probability of VAE was 50%. Conclusion: The angle of head elevation that caused clinically important VAE was estimated to be 35.7°

    "Effects of Information Technology and Aging Work Force on Labor Demand and Technological Progress in Japanese Industries: 1980-1998"

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    The purpose of this paper is two-folds. First, we examine the direction and the magnitude of substitutability or complementarity between information- and communication-related capital stock and various labor inputs to know about differential impacts of information and com-munication technology on labor demand. In this way, we can obtain information about what segments of workers information and communication technology can effectively substu-tute for. Second, we estimate contribution of information- and communication-related capital stock and various labor inputs on the value-added growth of the Japanese economy in the recent turbulent era (1980s and 1990s) and explore factors determining technological progress. In particular, we investigate whether rapid accumulation of information-related capital stock has a positive effect on technological progress, examining IT externality. We also discern the effect of compositional changes in labor inputs on technological progress, examining the inflexibility issue and IT-induced technological obsolescence issue. Three remarkable facts emerge from our result with respect to substitutability/complementarity issues. First, IT capital stocks are shown to be significant substitutes for young workers with a low education level, whereas old workers with a low education level are consistently quasi-fixed in all industries under investigation. Second, IT capital stocks have complemen-tary relationship with workers with a high education level in many industries. Third, workers with a high education level and those with a low education level are substitutes. These all suggest that IT investment and human capital accumulation are of utmost importance to overcome possible shortage (in relative terms) of young workers with a low education level caused by rapidly aging population. As for IT externality, we find at first positive correlation between IT stocks and techno-logical progress in manufacturing, suggesting a strong externality effect of IT capital stocks. In the first glance it is very promising, since this suggests that this IT externality can be used for boosting productivity growth. However, the correlation is not robust. First, if non-manufacturing industries are included, the correlation vanishes. Second, if "Electrical Machinery" is excluded from the sample of manufacturing, the correlation also vanishes. Thus, we fail to discern clear-cut evidence for IT externality. Thus, the proposition that IT "revolution"can pop up productivity growth and can counter the pressure of aging population is not supported by our data, although investment in IT-producing industries is surely an important driving force for economic growth through substitution effects. As for the effect of labor force composition on the rate of technological progress, the results do not support that the "inflexible old worker" hypothesis of productivity slowdown. There is no correlation between the rate of technological progress and the ratio of old workers with low education in the total labor inputs. However, the results suggest that information technology development in the 1990s has a negative impact on the past strength of the Japanese economy: productivity increase through high-education workers' learning by doing. In manufacturing industries where Japan has been strong, the rate of technological progress in the 1980s has positive (though weak) correlation with "maturing" high-education labor force. That is, the ratio of old well-educated workers in the total labor inputs has a positive (though weak) effect on technological progress. This suggests that the increased average skill among well-educated workers due to longer experience has a positive effect to improve productivity. However, the relationship changes significantly in the 1990s, and we have rather negative relationship. The nature of technological progress apparently changed adversely.

    Physiological roles of NOX/NADPH oxidase, the superoxide-generating enzyme

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    NADPH oxidase is a superoxide (O2•−)-generating enzyme first identified in phagocytes, essential for their bactericidal activities. Later, in non-phagocytes, production of O2•− was also demonstrated in an NADPH-dependent manner. In the last decade, several non-phagocyte-type NADPH oxidases have been identified. The catalytic subunit of these oxidases, NOX, constitutes the NOX family. There are five homologs in the family, NOX1 to NOX5, and two related enzymes, DUOX1 and DUOX2. Transgenic or gene-disrupted mice of the NOX family have also been established. NOX/DUOX proteins possess distinct features in the dependency on other components for their enzymatic activities, tissue distributions, and physiological functions. This review summarized the characteristics of the NOX family proteins, especially focused on their functions clarified through studies using gene-modified mice

    Mental Retirement: Evidence from Global Aging Data

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    This study analyzes the effect of retirement on cognitive function; specifically, the hypothesis from human capital theory that because cognitive investment increases a worker's wage, workers may invest in their cognitive ability more than retirees, contributing to a post-retirement decline in cognitive function. While this topic is of great interest to health economics, we show that the method of analysis of some previous studies is not valid for examining this effect, and we propose an alternative method that addresses this concern. Further, our estimates indicate that retirement has only a weak effect on cognitive ability in a wide range of analyzed countries and heterogeneous groups. Therefore, according to our analysis, policies that have been widely adopted in developed countries to delay retirement, such as increasing the pensionable age, appear to have little detrimental affect on post-retirement cognitive ability

    Mental Retirement: Evidence from Global Aging Data

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    This study analyzes the effect of retirement on cognitive function; specifically, the hypothesis from human capital theory that because cognitive investment increases a worker's wage, workers may invest in their cognitive ability more than retirees, contributing to a post-retirement decline in cognitive function. While this topic is of great interest to health economics, we show that the method of analysis of some previous studies is not valid for examining this effect, and we propose an alternative method that addresses this concern. Further, our estimates indicate that retirement has only a weak effect on cognitive ability in a wide range of analyzed countries and heterogeneous groups. Therefore, according to our analysis, policies that have been widely adopted in developed countries to delay retirement, such as increasing the pensionable age, appear to have little detrimental affect on post-retirement cognitive ability

    Applications of the new Remote Sensing Method to the Forest Biomass Estimation

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    For accurate measurement of forest biomass in the Akazawa Forest Reserve, this study analyzed texture measures derived from GeoEye-1 satellite data using the individual tree crown (ITC) method. On this basis, canopy area, tree tops and tree species of individual trees were delineated. Canopy area was used to calculate the DBH of trees in canopy layer based on canopy-DBH curve in this stand. In this study, the estimation models, between DBH and height, and between canopy area and DBH were developed by linear regression using forest survey data. Then according to the results of satellite data interpreted the biomass of every tree was calculated by biomass expansion factor (BEF). This method was verified against the survey data from old–growth Chamaecyparis obtusa stand composed of various cover types. For Chamaecyparis obtusa, the accuracy of biomass estimation was higher than 84%. However, the accuracy of Chamaecyparis pisifera was less than 60%, because some Chamaecyparis pisifera trees were misidentified as Chamaecyparis obtusa, and canopy area of Chamaecyparis pisifera was underestimated in the high-density stand. For Thujopsis dolabrata, the accuracy ranged from 22.4 % to 78.9%, and from 63.4% to 84.6% for broad-leaved trees, because many of them were understory. These results indicated that estimation of old-growth forest biomass based on high resolution satellite data, might be validated for estimating biomass at the individual tree level improved by developing and applying forest stratum–specific models with the ITC-survey data as a bridging reference in addition to spectral information. This approach is useful for biomass estimation whether is used to calculate biomass of individual tree or forest.ArticleThe International Journal of Sciences. 2(8):1-13 (2013)journal articl

    Microwave Effect for Glycosylation Promoted by Solid Super Acid in Supercritical Carbon Dioxide

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    The effects of microwave irradiation (2.45 GHz, 200 W) on glycosylation promoted by a solid super acid in supercritical carbon dioxide was investigated with particular attention paid to the structure of the acceptor substrate. Because of the symmetrical structure and high diffusive property of supercritical carbon dioxide, microwave irradiation did not alter the temperature of the reaction solution, but enhanced reaction yield when aliphatic acceptors are employed. Interestingly, the use of a phenolic acceptor under the same reaction conditions did not show these promoting effects due to microwave irradiation. In the case of aliphatic diol acceptors, the yield seemed to be dependent on the symmetrical properties of the acceptors. The results suggest that microwave irradiation do not affect the reactivity of the donor nor promoter independently. We conclude that the effect of acceptor structure on glycosylation yield is due to electric delocalization of hydroxyl group and dielectrically symmetric structure of whole molecule

    Accurate and molecular-size-tolerant NMR quantitation of diverse components in solution.

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    木質バイオマス中の各成分の物質量を正確に決定する手法の開発に成功 --木質バイオマスからの効率的なバイオエネルギー・製品原料の獲得にはずみ--. 京都大学プレスリリース. 2016-02-18.Determining the amount of each component of interest in a mixture is a fundamental first step in characterizing the nature of the solution and to develop possible means of utilization of its components. Similarly, determining the composition of units in complex polymers, or polymer mixtures, is crucial. Although NMR is recognized as one of the most powerful methods to achieve this and is widely used in many fields, variation in the molecular sizes or the relative mobilities of components skews quantitation due to the size-dependent decay of magnetization. Here, a method to accurately determine the amount of each component by NMR was developed. This method was validated using a solution that contains biomass-related components in which the molecular sizes greatly differ. The method is also tolerant of other factors that skew quantitation such as variation in the one-bond C-H coupling constant. The developed method is the first and only way to reliably overcome the skewed quantitation caused by several different factors to provide basic information on the correct amount of each component in a solution

    Retirement and Health Investment Behaviors: An International Comparison

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    This study aims to better understand the effects of retirement on health outcomes, which is of great interest worldwide, by examining the effects of retirement on health investment behaviors. To this end, we conducted a large-scale international comparison of the changes in health investment behaviors after retirement among the populations of seven developed countries using Global Aging Data, exploiting differences in the financial incentives in the pension systems of each country as our identification strategy. The results show that while elderly change their health investment behaviors in some way after retirement, the patterns of the changes in many health investment behaviors differ across each country. Further, a review of the literature and our results suggest that health investment behaviors are not necessarily determinants of the effects of retirement on health
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