Summary. The lazy caching protocol proposed by Afek, Brown and Merritt [ABM93], is explained and formally proven correct by means
of compositional methods. The protocol is decomposed into four simple protocols, which are of interest on their own. A top
level proof is given that is to a large extent independent of the particular model used for the more detailed proofs and allows
for a number of generalizations of the original lazy caching protocol. Detailed proofs of safety and liveness properties are
given using CSP and trace logic. 相似文献
The reliability of the current (1978) Thai Food Composition Table was estimated by determining the contents of crude fat, total carbohydrate, protein, calcium, iron, vitamin A activity, vitamin B1, vitamin B2 and niacin of eight food groups, each composed of related foods. These food groups were: rice and cereals, fruit, meat, eggs, vegetables, fish, dessert and poultry. The composition of each group was proportional to the contribution of the individual foodstuffs to the average daily intake of children aged 3–8 living in north-eastern Thailand. The groups covered circa 95% of their daily intake. Foods were prepared according to traditional local habits prior to weighing, mixing and analysis.
Within the rice/cereals group—contributing 63% to the daily food intake of the children—all nutrient levels calculated using the 1978 Thai Food Composition Table (TFT) were higher than those measured, whereas most of the TFT-based values were below measured values in the groups meat and fish.
The intakes by Thai children—when using TFT values—of fat, total carbohydrate, protein, energy and vitamin B2 are considerably overestimated (10–35%), while the intakes of iron, vitamin A-active compounds, vitamin B1 and niacin are highly overestimated (56–243%); the intake of calcium is underestimated by 16%. The rice/cereals group contributes most to the overestimations except for vitamin A activity. The overestimation of the intake of the latter nutrient originates primarily from the fruit group. The underestimation of the calcium intake originates mainly from the fish group.
It is recommended to revise the Thai Food Composition Table by analysing the processed foods with the classical methods for macronutrients and with more selective analytical methods for micronutrients. 相似文献
The inactivation of eight different bacteria comprising Escherichia coli LMM1010 and MG1655, respectively a pressure-resistant strain and the corresponding wild-type, Salmonella Typhimurium, Pseudomonas fluorescens, Staphylococcus aureus, Enterococcus faecalis, Listeria innocua and Lactobacillus plantarum, by high hydrostatic pressure in skim milk supplemented with the lactoperoxidase-hydrogen peroxide-thiocyanate (LP) system at naturally occurring concentration was studied. In the absence of pressure treatment, the LP system had either no effect, i.e. on S. Typhimurium and E. coli LMM1010, a growth inhibiting effect, i.e. on E. coli MG1655, L. innocua, S. aureus, L. plantarum and E. faecalis, or a bactericidal effect, i.e. on P. fluorescens. The presence of the LP system affected inactivation by high pressure in a cell density-dependent manner. At low cell concentration (10(6) cfu/ml), the LP system strongly increased high-pressure inactivation as measured immediately after pressure treatment of all bacteria except the pressure-resistant E. coli. At high cell density (10(9) cfu/ml), only inactivation of L. innocua, E. faecalis and L. plantarum were enhanced. For both E. coli strains, the fate of the bacteria during 24 h following pressure treatment was also studied. It was found that in the presence of the LP system, considerable further inactivation occurred in the first hours after pressure treatment. The potential of the LP system to improve the bactericidal efficiency of high-pressure treatment for food preservation is discussed. 相似文献
A method for the determination of iodine value (IV) by Fourier transform-near infrared (FT-NIR) spectroscopy was developed
and evaluated in an international collaborative study. The FT-NIR analyzer employed in this work uses disposable vials for
sample handling and incorporates validation protocols designed to ensure that the calibration will give accurate results from
analyzer to analyzer and stability over time without any further calibration development work. The global IV calibration was
developed from over 1,200 animal, marine, and vegetable oils and fats, which were obtained on a number of different instruments
worldwide. The Standard Error of Cross Validation measured from a range of 0–190 IV varied from ±0.2–1.4 IV (1 sigma). The
repeatability for all models was on the order of 0.1 IV, which states that most of the error was inherited from the primary
methods. Finally, an international interlaboratory study was carried out with 16 samples obtained from the AOCS Smalley Laboratory
Proficiency Program and an oil processor. The average reproducibility error in any one lab was better than 0.15, and the average
reproducibility between labs was better than 0.33. An uncertainty of 0.45 was calculated from the average FT-NIR values obtained
from the collaborative study vs. the AOCS Certified Wijs method (Cd 1d-92). 相似文献
Maedi-Visna-like genotype A strains and Caprine arthritis encephaltis-like genotype B strains are small ruminant lentiviruses (SRLV) which, for incompletely understood reasons, appear to be more virulent in sheep and goats, respectively. A 9-month in vivo infection experiment using Belgian genotype A and B SRLV strains showed that almost all homologous (genotype A in sheep; genotype B in goats) and heterologous (genotype A in goats; genotype B in sheep) intratracheal inoculations resulted in productive infection. No differences in viremia and time to seroconversion were observed between homologous and heterologous infections. Higher viral loads and more severe lesions in the mammary gland and lung were however detected at 9 months post homologous compared to heterologous infection which coincided with strongly increased IFN-γ mRNA expression levels upon homologous infection. Pepscan analysis revealed a strong antibody response against immune-dominant regions of the capsid and surface proteins upon homologous infection, which was absent after heterologous infection. These results inversely correlated with protection against virus replication in target organs and observed histopathological lesions, and thus require an in-depth evaluation of a potential role of antibody dependent enhancement in SRLV infection. Finally, no horizontal intra- and cross-species SRLV transmission to contact animals was detected. 相似文献
Hydraulic components in mobile machines are subjected to varying conditions and loads, which limit their lifetime. In particular, high pressure drop rates are suspected to increase fatigue crack growth rates. Existing studies on the fluid-structure interaction inside fatigue cracks during fast pressure drops do not explain increased crack growth in hydraulic systems. A laminar flow model was developed to simulate the fluid flow inside a crack under periodic pressure loads. The viscosity restrained the oil inside the crack, and the mechanical resistance of the closing crack led to a high pressure increase. Knowledge of the pressure profiles inside fatigue cracks helps to estimate the effective fatigue damage during transient loads. 相似文献
Herein, hot-spot generation in bulk barium titanate samples is investigated during controlled current ramping at various rates using in situ dilatometry. The incubation of the flash event is separated from dielectric breakdown at high current densities, which has previously been attributed to cause flash incubation in barium titanate. The lower boundary of the onset temperature of the flash event in barium titanate is investigated through conventional flash experiments at high electric fields. Despite incubating through thermal runaway, the lower boundary does not coincide with the Debye temperature of barium titanate. 相似文献