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We present several algorithms for rapidly four-coloring large planar graphs and discuss the results of extensive experimentation with over 140 graphs from two distinct classes of randomly generated instances having up to 128,000 vertices. Although the algorithms can potentially require exponential time, the observed running times of our more sophisticated algorithms are linear in the number of vertices over the range of sizes tested. The use of Kempe chaining and backtracking together with a fast heuristic which usually, but not always, resolves impasses gives us hybrid algorithms that: (1) successfully four-color all our test graphs, and (2) in practice run, on average, only twice as slow as the well-known, nonexact, simple to code, Θ(n) saturation algorithm of Brélaz.  相似文献   
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Negative consequences are an important component of the substance use change process, yet no standardized measure exists to assess consequences of use. This study evaluated the psychometric properties of the Inventory of Drug Use Consequences, a self-report measure assessing drinking and drug use consequences. Participants (N=252) were assessed at entry into outpatient substance abuse treatment. Items loaded strongly on 1 factor, and internal consistency of the total scale was high. Fifteen items with the highest correlations with the total scale were chosen to represent the construct. The shortened measure exhibited good internal consistency, convergent and discriminant validity, and detected change over time and may be the measure of substance use consequences that is lacking in the field. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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Computational Visual Media - Accurate and temporally consistent modeling of human bodies is essential for a wide range of applications, including character animation, understanding human social...  相似文献   
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The magnetism of Ni(1 1 0) and Fe(1 1 0) surfaces was investigated by electron capture spectroscopy. He+ and He2+ ions impinged on the Fe(1 1 0) and Ni(1 1 0) surfaces under grazing incidence, and the degree of polarization of the light emitted by the neutralized projectiles was analyzed. Our measurements show that in Ni(1 1 0) minority electrons have a higher density of states at the Fermi energy than majority electrons, opposed to the Fe(1 1 0) case. From a comparison of our measurements we estimate the ratio between captured minority and majority electrons in Ni(1 1 0) to be similar as the ratio between captured majority and minority electrons in Fe(1 1 0).  相似文献   
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Heterogeneous foods are widely consumed but little is known about the dynamics of their breakdown during mastication. To investigate these dynamics the particle size and bolus mass at regular stages of the chewing sequence were investigated using a single subject, who was carefully selected according to strict mastication and dental criteria. A standardized volume of both a gelatine gel and chocolate matrix containing roasted peanuts was chewed and expectorated after a specified number of chews or at the point of swallowing. The mass of various components of the bolus was determined along with peanut particle parameters (d50, broadness (b), and specific surface area) at each interval.Results showed that for this subject the type of matrix influenced the pathway that the peanut particles (embedded inside each matrix) were broken down. The d50 of peanut particles within the bolus of the gelatine gel were greater than within the bolus of the chocolate throughout the chewing sequence until the point of swallowing. At the point of swallowing, the d50 of peanut particles inside the bolus of the gelatine gel and chocolate were the same. The broadness value (b) and specific surface area of the peanut particles in the bolus of the chocolate were greater than those in the bolus of the gelatine gel throughout the chewing sequence. The matrices also induced different dynamic trends in the mass of bolus components during the chewing sequence.  相似文献   
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This study was undertaken to screen fatty acids, conjugated isomers of linoleic acid (CLA), and monolaurin for antilisterial effects in broth, and to further test the active compounds in cooked comminuted beef and hot dogs. Capric, lauric, myristic, palmitic, stearic, oleic, linoleic, and linolenic acid, CLA and monolaurin were screened in sterile nutrient broth at concentrations of 5 to 700 μg/ml. The media were inoculated with 103 cfu/ml of L. monocytogenes strain Scott A and incubated at 32°C for up to 8 days. Cell enumeration data showed that lauric acid was most inhibitory, followed by monolaurin, and capric acid. Tests in comminuted sterile beef stored at 5°C for 21 days showed log cfu/g of: 8.5 (control), 7.3 (500 μg/g lauric acid), and 4.7 (500 lauric acid+300 capric acid). Similar results were observed in beef hot dog emulsion to which lauricidin, lauric acid, capric acid, and the acid combination were added prior to heat treatment. At 500 μg/g, monolaurin and lauric acid caused similar delayed growth effects at 5°C, whereas the combination of the two acids showed enhanced inhibition on prolonged storage. Nonetheless, the observed 5-log increase in numbers of L. monocytogenes during 45 days of storage indicates limited control of the pathogen in refrigerated cooked meat products.  相似文献   
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This study tested whether coordinated care management (CCM), a continuity of care intervention for substance use disorders (SUD), improved rates of abstinence when compared with usual welfare management for substance-using single adults and adults with dependent children applying for public assistance. The study was designed as a practical clinical trial and was implemented in partnership with a large city welfare agency. Participants were 421 welfare applicants identified via SUD screening and assigned via an unbiased computerized allocation program to a site that provided either CCM (n = 232) or usual care (UC; n = 189). Outcomes were assessed for 1 year postbaseline with self-reports and biological measures of substance use. As hypothesized, for participants not enrolled in methadone maintenance programs (n = 313), CCM clients received significantly more services than did UC clients. Nonmethadone CCM also showed significantly higher abstinence rates (odds ratio = 1.75; 95% confidence interval = 1.12, 2.76; d = 0.31) that emerged early in treatment and were sustained throughout follow-up. In contrast, no treatment services or outcome effects were found for methadone maintenance clients (n = 108). Findings suggest that CCM is promising as a wraparound to SUD treatment for welfare recipients. (PsycINFO Database Record (c) 2010 APA, all rights reserved)  相似文献   
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