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Nutrition early in life may influence adult mortality. The fetal-origins hypothesis suggests that nourishment before birth and during the individual's infancy programs the development of risk factors for several important diseases of middle and old age. The present study was designed to evaluate the impact of extreme nutritional deprivation in utero and during infancy and early childhood on mortality in later life. The authors analyzed the survival of the cohorts born in Finland during the severe 1866-1868 famine and during the 5 years immediately preceding and 5 years immediately following the famine. The study included 331,932 individuals born prior to the famine, 161,744 born during the famine, and 323,321 born after the famine. The authors assessed survival by cohorts from birth to age 17 years and from age 17 to 40, 60, and 80 years, as well as average length of life after age 80 years. Survival from birth to age 17 years was significantly lower in cohorts born before and during the famine than in the cohorts born after the famine (males, 0.566 vs. 0.671, a difference of 0.105 (95% confidence interval (CI) 0.102-0.108); females, 0.593 vs. 0.692, a difference of 0.099 (95% CI 0.096-0.102)). At subsequent ages, including old age, mortality was practically identical in the famine-born cohorts and in the five cohorts born before and after the crisis. For both males and females, survival from 17 to 80 years and mean remaining lifetime at age 80 years were very similar across the 13 cohorts studied. These findings suggest that, although cohorts subjected to prolonged and extreme nutritional deprivation in utero and during infancy and early childhood suffer an immediate rise in mortality, after the crisis has passed, they carry no aftereffects that influence their survival in later life.  相似文献   
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Security service level agreements (SSLAs) provide a systematic way for end users at home or in the office to guarantee sufficient security level when doing business or exchanging sensitive personal or organizational data with an online service. In this paper, we propose an SSLA negotiation protocol that implements non‐repudiation with cryptographic identities and digital signatures and includes features that make it resistant to denial of service attacks. The basic version of the protocol does not rely on the use of a trusted third party, and it can be used for all kinds of simple negotiations. For the negotiation about SSLAs, the protocol provides an option to use an external knowledge base that may help the user in the selection of suitable security measures. We have implemented a prototype of the system, which uses JSON Web Signature for the message exchange and made some performance tests with it. The results show that the computational effort required by the cryptographic operations of the negotiation protocol remains at a reasonable level. Copyright © 2014 John Wiley & Sons, Ltd.  相似文献   
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The influence of ageing temperature, silver loading and type of reducing agent on the lean NO x reduction over silver–alumina catalysts was investigated with n-octane and bio-diesel (NExBTL) as reducing agent. The catalysts (2 and 6 wt% Ag–Al2O3) were prepared with a sol–gel method including freeze drying and the evaluation of NO x reduction and aging were performed using a synthetic gas-flow reactor. The results indicate a relatively high NO x reduction for both reducing agents. The hydrothermally treated 6 wt% Ag–Al2O3 sample displays a maximum NO x reduction of 78 % at 350 °C for n-octane as reductant and the corresponding value for NExBTL is 60 %. Furthermore, the catalysts show high durability and an increase in activity for NO x reduction after ageing at temperatures up to 650 °C, with n-octane as reducing agent.  相似文献   
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Biodemographic trajectories of longevity   总被引:2,自引:0,他引:2  
Old-age survival has increased substantially since 1950. Death rates decelerate with age for insects, worms, and yeast, as well as humans. This evidence of extended postreproductive survival is puzzling. Three biodemographic insights--concerning the correlation of death rates across age, individual differences in survival chances, and induced alterations in age patterns of fertility and mortality--offer clues and suggest research on the failure of complicated systems, on new demographic equations for evolutionary theory, and on fertility-longevity interactions. Nongenetic changes account for increases in human life-spans to date. Explication of these causes and the genetic license for extended survival, as well as discovery of genes and other survival attributes affecting longevity, will lead to even longer lives.  相似文献   
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The role of hydrogen in H2-assisted HC–SCR of NO x over Ag–Al2O3 is investigated by XPS and in situ DRIFT spectroscopy. Hydrogen does not reduce the surface silver species to metallic silver, however direct reduction of surface nitrates by hydrogen is observed. It is proposed that one important role of hydrogen is the removal of nitrates from the Ag–Al2O3 surface.  相似文献   
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Abstract  

Silver particle size and dispersion on a Ag/Al2O3 for HC-SCR were examined by means of chemisorption and TEM. Experimental results showed that determination of the accurate mean particle size (mps) is challenging and that the both applied methods have specific characteristics increasing the inaccuracy in the results which has to be taken into account in evaluation of catalytic activity. The results from TEM imaging were found to depend highly on the mode in which the surface was scanned (bright field versus dark field). Generally the point resolution was higher in dark field but the obtained mps did not increased along with the increasing silver loading. The main limitation with the O2-chemisorption was related to the choice of the stoichiometric factor between the adsorbent and silver atoms. However, together these techniques support each other and help to give a more realistic picture of the mean silver particle size, distribution and indications of the oxidation states on the alumina support.  相似文献   
7.
Cognition, Technology & Work - Forklift drivers in in-house logistics are at a high risk of occupational injuries. This study piloted a video-based learning game for forklift drivers, designed...  相似文献   
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