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1.
We revise Strang and Macy's model of adaptive emulation throughinspection of empirical efforts at innovation. Self-reportsof managers participating in benchmarking teams are consistentwith the argument that innovation is problem-driven, focusedon performance and draws heavily on success stories. But managerialaccounts also indicate close attention to prestigious firms,an orientation that broadens prior arguments about imitationof top performers. We develop a version of adaptive emulationwhere firms imitate members of a corporate élite whoseprestige is related to but not reducible to performance. Computationalmodeling indicates that socially oriented emulation is collectivelyadaptive but that it also widens the range of innovations thatexperience faddish careers.  相似文献   
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It has been suggested that in the presence of astigmatism some individuals make cyclic changes in focus over the astigmatic interval to obtain better visual performance. The aim in the present study was to identify such cyclic accommodative behavior and to characterize the variability of the response in the presence of astigmatism. The dynamic accommodation response in the presence of induced astigmatism was recorded objectively with an infrared optometer in seven young adults. Astigmatism led directly to increased accommodative variability in certain individuals. In two of seven participants there was evidence for aperiodic cyclic accommodative responses between different portions of the astigmatic interval. However, the amplitude of these tracking responses was much smaller than the astigmatic interval.  相似文献   
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BACKGROUND: The primary care setting has been regarded in government policy and the scientific literature as an ideal setting for the work needed to meet the Health of the Nation drug and alcohol targets. Although studies have pointed to the negative attitudes held by general practitioners (GPs) towards alcohol- and drug-misusing patients, there has been no direct comparison of the work and attitudes of the GP towards these patients. AIM: To compare the work and attitudes of GPs towards alcohol- and drug-misusing patients. METHOD: All GPs in an outer London area (157 doctors) were surveyed, using an eight-page postal questionnaire, collecting clinical and attitudinal data alongside demographics and practice information. A response rate of 52% was achieved. RESULTS: General practitioners reported working with only 3.5 patients drinking above recommended guidelines in the previous four working weeks, and even fewer drug-using patients (0.75). While they viewed the alcohol-misusing patients negatively, the drug misuser elicited substantially more negative attitudes. The primary care setting was seen as appropriate to work with the alcohol-misusing patient but not with drug users. Training and support from local services would encourage substantially more GPs to work with alcohol misusers but not with drug misusers. CONCLUSIONS: Our findings indicate that there are some cautious grounds for optimism that GPs are willing to work with alcohol misusers; however, with regard to drug misusers, we find a GP workforce that is only minimally involved with this group and would not be greatly encouraged by the provision of additional training, support, or incentives. The Health of the Nation targets are not being met, and GPs are not detecting adequate numbers of the patients at whom these targets are aimed. Emphasis has been placed on the role of primary care, but the real achievements that can be made require detection of the less severe drinkers and injecting drug misusers.  相似文献   
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AIM: To develop a brief, multi-dimensional instrument for assessing treatment outcome for people with drug and/or alcohol problems. The Maudsley Addiction Profile (MAP) is the first instrument to be developed in the United Kingdom for this purpose. DESIGN: Field testing with quota-recruitment of problem drug users and problem alcohol users in treatment with researcher and clinician-administered test-retest interviews. SETTING: Two community and two inpatient services at the Bethlem Royal and Maudsley Hospital, London. PARTICIPANTS: Subjects (160 drug users and 80 alcohol users) interviewed by eight interviews (four researchers and four clinicians), each of whom interviewed 30 subjects on two occasions. MEASURES: Sixty items across substance use, health risk, physical/psychological health and personal/social functioning domains. FINDINGS: Average completion time of the MAP was 12 minutes. The questionnaire was acceptable to a majority of subjects and performed well with both researcher and clinician interviewers. Internal reliability and feasible concurrent validity assessments of the scales and items were highly satisfactory. Test-retest reliability was good, average intraclass correlation coefficients across eight substances were 0.94 and 0.81 across health risk, health problems, relationship conflict, employment and crime measures. CONCLUSIONS: The MAP can serve as a core research instrument with additional outcome measures added as required. The collection of a set of reliable quantitative measures of problems among drug and alcohol users by research or treatment personnel for outcome evaluation purposes need not be time-consuming.  相似文献   
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An algorithm is described which appears to give an efficient solution of nonlinear finite element equations. It is a quisi-Nowton method, and we compare it with some of the alternatives. Initial tests of its application to both material and geometric nonlinearities are discussed.  相似文献   
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The use of quasi-Newton methods is studied for the solution of the nonlinear finite element equations that arise in the analysis of incompressible fluid flow. An effective procedure for the use of Broyden's method in finite element analysis is presented. The quasi-Newton method is compared with the commonly employed successive substitution and Newton-Raphson procedures, and it is concluded that the use of Broyden's method can constitute an effective solution strategy.  相似文献   
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Managing the interference effects from thin (multi‐)layers allows for the control of the optical transmittance/reflectance of widely used and technologically significant structures such as antireflection coatings (ARCs) and distributed Bragg reflectors (DBRs). These rely on the destructive/constructive interference between incident, reflected, and transmitted radiation. While known for over a century and having been extremely well investigated, the emergence of printable and large‐area electronics brings a new emphasis: the development of materials capable of transferring well‐established ideas to a solution‐based production. Here, demonstrated is the solution‐fabrication of ARCs and DBRs utilizing alternating layers of commodity plastics and recently developed organic/inorganic hybrid materials comprised of poly(vinyl alcohol) (PVAl), cross‐linked with titanium oxide hydrates. Dip‐coated ARCs exhibit an 88% reduction in reflectance across the visible compared to uncoated glass, and fully solution‐coated DBRs provide a reflection of >99% across a 100 nm spectral band in the visible region. Detailed comparisons with transfermatrix methods (TMM) highlight their excellent optical quality including extremely low optical losses. Beneficially, when exposed to elevated temperatures, the hybrid material can display a notable, reproducible, and irreversible change in refractive index and film thickness while maintaining excellent optical performance allowing postdeposition tuning, e.g., for thermo‐responsive applications, including security features and product‐storage environment monitoring.  相似文献   
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This paper introduces super absorbent polymer valves and colorimetric sensing reagents as enabling components of soft, skin‐mounted microfluidic devices designed to capture, store, and chemically analyze sweat released from eccrine glands. The valving technology enables robust means for guiding the flow of sweat from an inlet location into a collection of isolated reservoirs, in a well‐defined sequence. Analysis in these reservoirs involves a color responsive indicator of chloride concentration with a formulation tailored to offer stable operation with sensitivity optimized for the relevant physiological range. Evaluations on human subjects with comparisons against ex situ analysis illustrate the practical utility of these advances.  相似文献   
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