202 research outputs found

    Diet, Health and Work Intensity in England and Wales, 1700-1914

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    In their different ways, both Thomas Malthus and Thomas McKeown raised fundamental questions about the relationship between food supply and the decline of mortality. Malthus argued that food supply was the most important constraint on population growth and McKeown claimed that an improvement in the population’s capacity to feed itself was the most important single cause of mortality change. This paper explores the implications of these arguments for our understanding of the causes of mortality decline in Britain between 1700 and 1914. It presents new estimates showing changes in the calorific value and composition of British diets in 1700, 1750, 1800 and 1850 and compares these with the official estimates published by the Royal Society in 1917. It then considers the implications of these data in the light of new arguments about the relationship between diet, work intensity and economic growth. However the paper is not solely concerned with the analysis of food-related issues. It also considers the ways in which sanitary reform may have contributed to the decline of mortality at the end of the nineteenth century and it pays particular attention to the impact of cohort-specific factors on the pattern of mortality decline from the mid-nineteenth century onwards.

    Multiparameter Moment Matching Model Reduction Approach for Generating Geometrically Parameterized Interconnect Performance Models

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    In this paper we describe an approach for generating geometrically-parameterized integrated-circuit interconnect models that are efficient enough for use in interconnect synthesis. The model generation approach presented is automatic, and is based on a multi-parameter model-reduction algorithm. The effectiveness of the technique is tested using a multi-line bus example, where both wire spacing and wire width are considered as geometric parameters. Experimental results demonstrate that the generated models accurately predict both delay and cross-talk effects over a wide range of spacing and width variation.Singapore-MIT Alliance (SMA

    Insulin and glucagon secretions, and morphological change of pancreatic islets in OLETF rats, a model of type 2 diabetes mellitus.

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    This study was performed to observe the changes of glucose-related hormones and the morphological change including ultrastructure of the pancreatic islets in the male Otsuka Long-Evans Tokushima Fatty rat. Area under the curve (AUC) of glucose at the 30th (709 plus minus 73 mg.h/dL) and at the 40th week (746 plus minus 87 mg.h/ dL) of age were significantly higher than that at the 10th week (360 plus minus 25 mg.h/ dL). AUC of insulin of the 10th week was 2.4 plus minus 0.9 ng.h/mL, increased gradually to 10.8 plus minus 8.3 ng.h/mL at the 30th week, and decreased to 1.8 plus minus 1.2 ng.h/mL at the 40th week. The size of islet was increased at 20th week of age and the distribution of peripheral alpha cells and central beta cells at the 10th and 20th weeks was changed to a mixed pattern at the 40th week. On electron microscopic examination, beta cells at the 20th week showed many immature secretory granules, increased mitochondria, and hypertrophied Golgi complex and endoplasmic reticulum. At the 40th week, beta cell contained scanty intracellular organelles and secretory granules and apoptosis of acinar cell was observed. In conclusion, as diabetes progressed, increased secretion of insulin was accompanied by increases in size of islets and number of beta-cells in male OLETF rats showing obese type 2 diabetes. However, these compensatory changes could not overcome the requirement of insulin according to the continuous hyperglycemia after development of diabetes

    Synthesis of ZnO/rGO nanohybrid for improved photocatalytic activity

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    Nanohybrids of zinc oxide/reduced graphene oxide (ZnO/rGO) with varying graphene oxide content were prepared via precipitation and were subsequently utilised in the photodegradation of methyl orange (MO) under UV light irradiation. The prepared photocatalysts were characterized by X-ray Diffraction (XRD), Field Emission Scanning Electron Microscopy (FESEM), Transmission Electron Microscopy (TEM) and Raman spectroscopy. The surface area and the band gap energy of the photocatalysts were determined by the Brunauer-Emmett-Teller method and UV-visible spectroscopic analysis. The ZnO/rGO nanohybrids produced had smaller particle sizes and lower band gap energy than that of ZnO. All the ZnO/rGO nanohybrids demonstrated better photocatalytic efficiency in the photodegradation of MO compared to ZnO. ZnO/rGO10 exhibited the highest photocatalytic activity with a rate constant that was four times higher than pure ZnO and about 40% enhancement in the photocatalytic activity for the removal of methyl orange within 3 hours. The enhanced photocatalytic performance of the ZnO/rGO photocatalysts was due to the efficient transfer of photogenerated electrons to the graphene sheet that inhibited the recombination of electron-hole pairs

    New insights into the photocatalytic endocrine disruptors dimethyl phathalate esters degradation by UV/MWCNTs-TiO2 nanocomposites

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    Dimethyl phthalate esters (DMPEs) are considered to be endocrine disruptors and environmentally hazardous materials in plastic industries wastewater because of its low solubility and accumulated persistent toxicity. In the present study, MWCNTs/TiO2 nanocomposites were fabricated by modified sol-gel technique using titanium isopropoxide as titanium oxide sources and purified MWCNTs, to degrade DMPEs through photocatalysis using UV irradiation. The effect of MWCNTs loading (3–15 wt %) on TiO2 and the photocatalytic performance of DMPEs in aqueous solution by UV/MWCNTs/TiO2 nanocomposites were investigated. For experiments conducted with the same illumination time, the photodegradration of DMPEs was enhanced with increasing the MWCNTs contents from 3 to 10 wt % and then decreased with a further enhancement to 15 wt %. Basically, the presence of MWCNTs in the nanocomposites can lead to the decrease in the relative amount of TiO2 in the photocatalyst and then to the decrease of the photogenerated carriers. This is because the same amount of photocatalyst was added for the photoreaction, and hence, the photodegradation of DMPEs decreases especially for the nanocomposites containing MWCNTs exceed than 10 wt %. The presence of functional group (COOH) on the MWCNTs surface would help the achievement of direct chemical bonding between MWCNTs and the TiO2 nanoparticles, resulting in the synergistic effect of MWCNTs and TiO2 where the flow of photogenerated electrons in the space charge region to the MWCNTs surface. A method based on high-performance liquid chromatography (HPLC) was developed to study the degraded DMPEs samples produced after exposure to UV light

    Variants of the Distinguished Point Method for Cryptanalytic Time Memory Trade-offs (Full version)

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    The time memory trade-off (TMTO) algorithm, first introduced by Hellman, is a method for quickly inverting a one-way function, using pre-computed tables. The distinguished point method (DP) is a technique that reduces the number of table lookups performed by Hellman\u27s algorithm. In this paper we propose a new variant of the DP technique, named variable DP (VDP), having properties very different from DP. It has an effect on the amount of memory required to store the pre-computed tables. We also show how to combine variable chain length techniques like DP and VDP with a more recent trade-off algorithm called the rainbow table method

    Chemical stability of active ingredients in diluted veterinary disinfectant solutions under simulated storage conditions

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    Introduction: The product labels of veterinary disinfectants specify their expiration dates to prevent the use of outdated products, as these may result in disinfection and biosecurity failures during outbreak situations. However, a clear standard for the storage conditions of diluted disinfectant solutions has not yet been established, and the effects of storage conditions have scarcely been investigated. To fill this research gap, our study examined the stability of the active ingredients of diluted veterinary disinfectants based on their change in concentrations when stored at various temperatures for various time periods.Methods: Twenty veterinary disinfectants effective against either foot-and-mouth disease or avian influenza viruses were selected. The disinfectants were diluted to effective concentrations following the manufacturer’s instructions. Using selective analytical techniques, the concentrations of the active ingredients of the samples that had been stored for varying intervals at different temperatures (4, 20, 30, and 45°C) were determined. These samples included soaps and detergents, acids, oxidizing agents, aldehydes, and copper compounds. The active ingredient concentrations of two of the samples were determined following freezing/thawing cycle, to establish their stability when exposed to simulated winter conditions.Results: Our results showed that most of the active ingredients had concentrations of 90% or greater of their initial concentrations, indicating ≥90% stability over a 21-day period under the experimental storage conditions. However, there were some exceptions. Glutaraldehyde, formaldehyde, and malic acid are over 90% stable at ≤ 30°C for 21 days, but their concentrations decreased to below 90% of their initial concentrations at 45°C, indicating a decline in stability when stored at 45°C for 21 days. The concentrations of potassium peroxymonosulfate and peracetic acid rapidly declined with increasing time and temperature to less than 90% of their initial concentrations.Discussion: Based on our findings, we propose that diluted disinfectant solutions should preferably be prepared daily. However, if the daily preparation of a diluted disinfectant solution is not feasible, then our results can be used as a reference, providing basic scientific data on the chemical stability of diluted disinfectant solutions commonly used in the veterinary field, thus indicating suitable storage conditions

    Hospital-based Diagnosis of Hemorrhagic Fever, Encephalitis, and Hepatitis in Cambodian Children

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    Surveillance was conducted for three clinical syndromes (hemorrhagic fever, encephalitis, and hepatitis) in Cambodian children admitted to the National Pediatric Hospital in Phnom Penh from July 1996 through September 1998. Acute- and convalescent-phase sera, and cerebrospinal fluid, when applicable, underwent diagnostic evaluation for infections with Dengue virus (DENV), Japanese encephalitis virus (JEV), and Hepatitis A, B, C, and E viruses. Of 621 children admitted with hemorrhagic fever, 499 (80%) were confirmed to have either primary or secondary DENV infection. DENV rates were as high as 10.6/100 hospital admissions in September 1998. Of 50 children with clinical encephalitis, 9 (18%) had serologic evidence of JEV infection. Forty-four children had clinical hepatitis, most (55%) due to Hepatitis A virus (HAV). One patient had Hepatitis B virus, and no patients had hepatitis C or E. This study identified a large number of children with vaccine-preventable diseases (JEV and HAV)

    Occupational Reproductive Function Abnormalities and Bladder Cancer in Korea

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    The purpose of this study was to review occupational reproductive abnormalities and occupational bladder cancer in Korea and to discuss their toxicological implications. Reproductive dysfunction as a result of 2-bromopropane poisoning was first reported in Korean workers. In 1995, 23 of the 33 workers (25 female and 8 male workers) who were exposed to 2-bromopropane during the assembly of tactile switch parts developed reproductive and/or hematopoietic disorders. A total of 17 (68%) workers were diagnosed with ovarian failure. Two of the eight male workers experienced azoospermia and four workers experienced some degree of oligospermia or reduced sperm motility. In summary, 2-bromopropane poisoning caused severe reproductive effects in Korean workers. The prognosis was poor for reproductive dysfunction. A few cases of occupational bladder cancer have been reported in Korea, whereas other cancers of the urinary tract have not been reported after occupational exposure. A few cases of benzidine-induced cancer have been reported in Korea and 592 workers in Japan have received compensation for benzidine and β-naphthylamine-induced cancer. In conclusion, a few cases of benzidine-induced occupational bladder cancer have been reported in Korea. However, benzidine-induced bladder cancer will likely be an important occupational health issue in Korea in the coming years
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