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51.
This article presents data from a population-based, random-digit dialing telephone survey of 1228 employed adults in Washington State, conducted 1989 through 1990. Eighty-one percent of men and 91% of women reported work-site smoking restrictions. Employees in work sites with no-smoking policies were less likely to be current smokers; men in work sites with policies restricting smoking smoked fewer cigarettes on both workdays and nonworkdays. Forty-eight percent of male and 53% of female smokers reported reduced smoking as a result of work-site policy. Work-site smoking policies, intended to protect against smoke exposure, may also reduce employee smoking. 相似文献
52.
The Morris water-escape task is an extensively used experimental paradigm to assess the spatial discrimination performance and effects of brain lesions and drugs on this performance. In the first experiment, we compared the acquisition of this task by different strains (CFW1, BALB, NMRI, and C57BL) of mice and their performance in a probe trial. In a second experiment, C57BL mice were tested in Morris mazes where black and white tanks were combined with white or black platforms to investigate if and how the contrast between the tank and the platform affects the performance of the mice. In addition, four brightness conditions were compared to investigate whether or not the degree of brightness of the tank itself affects the learning performance. The results of these experiments indicated that 1. mice could readily learn the Morris task, 2. one of the contrast conditions affected the swimming speed, 3. the maze brightness per se did not affect water escape performance at all, and that 4. the swimming speed can strongly bias the outcome of Morris water-escape experiments in mice. 相似文献
53.
Williams K.A. White I.H. Burns D. Sibbett W. 《Quantum Electronics, IEEE Journal of》1996,32(11):1988-1994
Following a comparison of picosecond-pulse generation techniques, feedback schemes are reported for the generation of picosecond pulse trains with improved jitter for both multicontact and conventional single-contact InGaAsP-InP lasers. Subpicosecond jitter is achieved for Q-switched laser sources using a novel optoelectronic feedback scheme. The use of resonant electrical feedback is shown to improve the timing jitter of gain-switched pulses by up to six times. Pulse-to-pulse timing jitter as low as 250 fs is demonstrated for a hybrid of optical and electrical feedback schemes. Limits for timing jitter in diode lasers are established for optoelectronic, electrical, and optical feedback schemes, and the key picosecond pulse generation schemes are compared in terms of timing jitter for the first time 相似文献
54.
Jet injection can be used to introduce genes into the cells of differentiated tissues of living animals and organ cultures. When a solution of plasmid DNA is jet injected into a selected tissue or organ, cells lying in or near the path of the jet injection are transfected with the DNA and the introduced gene(s) are expressed. Since there is minimal morbidity from each jet injection, multiple injections can be performed at the same or nearby sites. Both mRNA and protein expression from transfected genes can be quantitated using standard methods. In addition, the technique is an efficient means of DNA immunization. Methodology for using jet injection to transfer plasmid DNA into the cells of skin, fat, mammary gland, and muscle are described. 相似文献
55.
Chun Hu Ji Zhao Li G.P. Liu P. Worley E. White J. Kjar R. 《Electron Device Letters, IEEE》1995,16(2):61-63
The effects of the plasma etching process induced gate oxide damages on device's low frequency noise behavior are investigated on MOSFET's fabricated with different field plate perimeter to gate area ratio antennas. Abnormal 1/f noise spectrum with a shoulder centered in the frequency range of 100 and to 1 kHz was frequently observed in small geometry devices, and it is attributable to a nonuniform distribution of oxide traps induced by plasma etching process 相似文献
56.
DW Nigg FJ Wheeler DE Wessol J Capala M Chadha 《Canadian Metallurgical Quarterly》1997,33(1-2):93-104
The longitudinal, expert, all data (LEAD) procedure has been employed as a criterion for the assessment of the procedural validity of diagnostic instruments. This study evaluated the procedure's concurrent, discriminant and predictive validity. Interview and questionnaire data obtained from 100 individuals in a substance abuse treatment program were used to assess current and lifetime substance use disorders and common comorbid disorders. An experienced, doctoral-level clinician formulated LEAD diagnoses for each patient, based on an initial interview, ongoing clinical contact and the results of the research assessment and all available clinical records. LEAD-derived substance use diagnoses showed good concurrent, discriminant and predictive validity. The validity of comorbid diagnoses obtained using the LEAD procedure was generally fair to good. Comparison with diagnoses based only on the clinician's unstructured initial interview showed that the availability of additional data enhanced diagnostic validity. Diagnoses derived by a research technician using the Structured Clinical Interview for DSM-III-R showed validity comparable to that of LEAD diagnoses. To enhance its diagnostic validity, applications of the LEAD standard should include a structured interview. Other variations in the application of the LEAD standard, including a longer evaluation period, may also enhance its performance as a diagnostic criterion measure. 相似文献
57.
DA Carter A Burt JW Taylor GL Koenig BM Dechairo TJ White 《Canadian Metallurgical Quarterly》1997,18(7):1047-1053
A set of eleven biallelic and three multiallelic molecular markers have been developed to analyze populations of Histoplasma capsulatum. All markers are amplified by polymerase chain reaction (PCR) and can be readily scored using minimal amounts of template DNA. The 11 biallelic loci have polymorphic restriction endonuclease sites or small insertions or deletions which may be assessed by agarose gel electrophoresis. These markers are inherited in an unambiguous manner and are ideal for assessing structure and gene flow within US populations of H. capsulatum, but are monomorphic in non-US populations. Both length and sequence variation are present in the multiallelic loci, which can be scored by direct sequencing, polyacrylamide gel electrophoresis, or single-strand conformation polymorphism (SSCP): As they are hypervariable, the multiallelic loci can be used to type isolates and to assess the level of genetic variation within populations. Preliminary results indicate that the three multiallelic markers presented are sufficient to distinguish isolates at the individual level and are polymorphic in both US and non-US populations. This collection of molecular markers will be a useful tool in population and epidemiology studies of H. capsulatum. 相似文献
58.
Tempest Philip R.; White Patricia; Williamson E.Diane; Titball Richard W.; Kelly David C.; Kemp Graham J.L.; Gray Peter M.D.; Forster Simon J.; Carr Frank J.; Harris William J. 《Protein engineering, design & selection : PEDS》1994,7(12):1501-1507
We have used the technique of antibody reshaping to producea humanized antibody specific for the a toxin of Clostridiumperfringens. The starting antibody was from a mouse hybridomafrom which variable (V) region nucleo-tide sequences were determined.The complementarity-determining regions (CDRs) from these Vregions were then inserted into human heavy and light chainV region genes with human constant region gene fragments subsequentlyadded. The insertion of CDRs alone into human frameworks didnot produce a functional reshaped antibody and modificationsto the V region framework were required. With minor frameworkmodifications, the affinity of the original murine mAb was restoredand even exceeded. Where affinity was increased, an alteredbinding profile to overlapping peptides was observed. Computermodelling of the reshaped heavy chain V regions suggested thatamino acids adjacent to CDRs can either contribute to, or distort,CDR loop conformation and must be adjusted to achieve high bindingaffinity. 相似文献
59.
J Caballero Güeto R Arana G Calle FJ Caballero Güeto E García del Río M Sancho C Pi?ero 《Canadian Metallurgical Quarterly》1997,50(12):906-908
Propionibacterium acnes is often considered to be a contaminant but it has also been found to be the principal pathogen in serious infections. P. acnes is a rare cause of infective endocarditis. It has been suggested that aortic root abscesses are caused by bacteria that are particularly virulent. The strongest risk factor for serious infections by this bacteria is the presence of foreign bodies. A case is presented in which endocarditis of a native aortic valve caused by P. acnes was associated with an aortic root abscess. Transesophageal echocardiography is particularly helpful in the diagnosis of this severe complication of infective endocarditis. The literature for P. acnes endocarditis is reviewed. 相似文献
60.
The behavioral response (e.g. changes in indoor temperatures, attention to window and door openings) to residential technical efficiency improvements (e.g. attic insulation, storm windows) is an important and largely unresolved issue. Although there is considerable discussion concerning the extent to which households take back some of the energy savings due to technical efficiency improvements in increased comfort, there is almost no empirical evidence on the subject.Detailed electricity billing data (from mid-1981 to mid-1983) were analyzed for 79 households that received financial assistance from the Bonneville Power Administration to retrofit their homes in mid-1982. The mean retrofit expenditure in these homes was $1900; the mean reduction in annual electricity use was 4700 kWh, of which 83% was due to reductions in space heating electricity use. Analysis of the electricity billing data suggests that these households increased their indoor temperature settings after retrofit by almost 1 °F on average. This temperature increase led to an estimated average loss of almost 600 kWh of electricity saving. In other words, roughly 10% of the energy saving due to retrofit was taken back in terms of increased comfort. These results concerning changes in indoor temperatures should be viewed cautiously because of limitations in the analytical method and the large variation across households. 相似文献