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91.
Mark T. Muldoon Dale V. Onisk Michael C. Brown & James W. Stave 《International Journal of Food Science & Technology》2004,39(8):851-861
Bovine spongiform encephalopathy (BSE), or ‘mad cow disease’, is one of several transmissable spongiform encephalopathies (TSEs) known to affect certain mammals and is spread through the ingestion of infected animal tissue. It is believed that the inadvertent contamination of meat and bone meal (MBM) with infected animal tissue and the subsequent use of this material as a feed supplement contributed to the spread of the disease in cattle. As a result, the use of processed animal proteins (PAPs) in animal feeds is regulated in many parts of the world. Although feed testing is the only definitive means to certify compliance, regulatory compliance often relies solely on paper certification. Recently, rapid methods have become available that can be used by regulators to determine compliance during routine inspections. We describe a rapid, immunochromatographic strip test that can detect 0.1% MBM in animal feed. The test takes 15 min to perform and large numbers of samples can be screened for PAPs simultaneously. 相似文献
92.
Scott Crino Donald E Brown 《IEEE transactions on systems, man, and cybernetics. Part B, Cybernetics》2007,37(2):333-340
This paper presents a novel procedure for approximating the global optimum in structural design by combining multivariate adaptive regression splines (MARS) with a response surface methodology (RSM). MARS is a flexible regression technique that uses a modified recursive partitioning strategy to simplify high-dimensional problems into smaller yet highly accurate models. Combining MARS and RSM improves the conventional RSM by addressing highly nonlinear high-dimensional problems that can be simplified into lower dimensions, yet maintains a low computational cost and better interpretability when compared to neural networks and generalized additive models. MARS/RSM is also compared to simulated annealing and genetic algorithms in terms of computational efficiency and accuracy. The MARS/RSM procedure is applied to a set of low-dimensional test functions to demonstrate its convergence and limiting properties. 相似文献
93.
The modality effect in immediate recall refers to superior recall of the last few items within lists presented in spoken as opposed to printed form. The locus of this well-known effect has been unclear. N. Cowan, J. S. Saults, E. M. Elliott, and M. Moreno (2002) introduced a new method to distinguish between the effects of input serial position, output serial position, and the number of items yet to be recalled and found that large modality effects occurred only in conditions in which delay and interference at output (from items already recalled) was high. The authors replicated that finding, even when the response period included output interference acoustically similar to the spoken stimuli to be recalled. However, the authors found that output delay and interference act only by lowering the level of performance to a more sensitive range. The modality effect thus originates during encoding of the list to be recalled, not during output. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
94.
95.
Children between 7 and 8 years old took pan in a staged event at school and 1 week later were assessed using a short form of the Wechsler Intelligence scale for children (third edition) and measures of metamemory, narrative ability, and socioeconomic status. Two weeks following the event, children either received narrative elaboration training (NET; K.J. Saywitz & L. Snyder, 1996) and were prompted with the four NET cue cards at interview; received verbal prompts corresponding to the cue card categories, but without prior training; or were presented with the cards at interview without prior training. Children given verbal labels as prompts recalled as much information as children who received NET training and cue cards. Measures of intelligence were predictive of amount recalled for cards-only children but not for the other 2 groups, indicating that differences in recall between low- and high-IQ groups were attenuated when recall was supported by NET training or verbal prompting. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
96.
CONTEXT: Adolescent smoking prevalence is tracked annually and has increased since 1991. In contrast, little is known about trends in smoking among college students, a group that has previously been more resistant to tobacco use than other young adults. OBJECTIVE: To examine changes in cigarette smoking among college students between 1993 and 1997 and among different types of students and colleges. DESIGN: Self-administered survey (Harvard School of Public Health College Alcohol Study). SETTING: One hundred sixteen nationally representative 4-year colleges. SUBJECTS: A total of 15103 randomly selected students in 1993 (70% response rate) and 14251 students in 1997 (60% response rate). MAIN OUTCOME MEASURES: Self-reports of cigarette smoking in the past 30 days and in the past year, age at smoking first cigarette, and number of attempts to quit. RESULTS: Over 4 years, the prevalence of current (30-day) cigarette smoking rose by 27.8%, from 22.3% to 28.5% (P<.001). The increase was observed in 99 of 116 colleges and was statistically significant (P<.05) in 27 (23%) of them. Current smoking increased across all student subgroups (defined by sex, race/ethnicity, and year in school) and in all types of colleges. Smoking is rising faster in public schools (from 22.0% to 29.3%) than in private schools (from 22.9% to 26.8%). Eleven percent of college smokers had their first cigarette and 28% began to smoke regularly at or after age 19 years, by which time most were already in college. Half of current smokers tried to quit in the previous year; 18% had made 5 or more attempts to quit. CONCLUSIONS: Cigarette use is increasing on campuses nationwide in all subgroups and types of colleges. Substantial numbers of college students are both starting to smoke regularly and trying to stop. National efforts to reduce smoking should be extended to college students. 相似文献
97.
M Brown M Webb E Phillips E Skidmore P McIntyre 《Canadian Metallurgical Quarterly》1995,73(7):780-786
We describe the results of functional studies on DNA clones encoding functional bradykinin receptors derived from human, rat, and mouse sources and including both genomic and complementary DNA clones. In both the Xenopus oocyte and the COS cell expression systems, the receptors from human and rat showed the pharmacological properties of B2 receptors, but receptors from mouse displayed both B1- and B2-like pharmacological properties. We further investigated the molecular relationship between the B1 and B2 receptor subtypes expressed by a human fibroblast cell line, and we demonstrate that these two receptor subtypes are encoded by distinct mRNA species. 相似文献
98.
99.
Perchloric acid (70%) was used to create simulated periapical lesions in tooth sockets of 15 dentate cadaver jaw specimens. Using the Trophy USA direct digital radiographic system, linear images were captured at selected time intervals after initial acid application and altered by contrast reversal, pseudocolor enhancement, and two forms of histogram equalization. The 525 total images were randomized for display on a computer monitor for evaluation by five endodontists. Images were evaluated twice by each rater, with viewings 1 to 2 wk apart. Statistical analysis determined interrater variability, intrarater reproducibility, and the relative merits of each enhancement technique. At 8, 12, 16, and 24 h after acid application, both techniques of histogram equalization yielded a statistically significant improvement over reverse contrast in perception of periapical patholais. Linear and pseudocolor-enhanced images were also significantly more diagnostic than reverse contrast at 12, 16, and 24 h. Intrarater reproducibility showed moderate agreement, but analysis showed only a fair level of interrater agreement. 相似文献
100.
CD Holyoak M Stratford Z McMullin MB Cole K Crimmins AJ Brown PJ Coote 《Canadian Metallurgical Quarterly》1996,62(9):3158-3164
The weak acid sorbic acid transiently inhibited the growth of Saccharomyces cerevisiae in media at low pH. During a lag period, the length of which depended on the severity of this weak-acid stress, yeast cells appeared to adapt to this stress, eventually recovering and growing normally. This adaptation to weak-acid stress was not due to metabolism and removal of the sorbic acid. A pma1-205 mutant, with about half the normal membrane H+-ATPase activity, was shown to be more sensitive to sorbic acid than its parent. Sorbic acid appeared to stimulate plasma membrane H+-ATPase activity in both PMA1 and pma1-205. Consistent with this, cellular ATP levels showed drastic reductions, the extent of which depended on the severity of weak-acid stress. The weak acid did not appear to affect the synthesis of ATP because CO2 production and O2 consumption were not affected significantly in PMA1 and pma1-205 cells. However, a glycolytic mutant, with about one-third the normal pyruvate kinase and phosphofructokinase activity and hence a reduced capacity to generate ATP, was more sensitive to sorbic acid than its isogenic parent. These data are consistent with the idea that adaptation by yeast cells to sorbic acid is dependent on (i) the restoration of internal pH via the export of protons by the membrane H+-ATPase in an energy-demanding process and (ii) the generation of sufficient ATP to drive this process and still allow growth. 相似文献