Technique for measuring very small angle changes.

A method for making accurate and precise measurements of small angles is described using an interferometer and a test fixture with reference control surfaces. The test is relatively insensitive to test fixture alignment. Typical measurement uncertainties are better than 0.2 arcsec (1σ). This technique is applicable for verifying the angular stability of opto-mechanical systems that must undergo rigorous environmental testing.

Student nurses' ethical views on responses to the severe acute respiratory syndrome outbreak.

BACKGROUND: Fifteen years have passed since the outbreak of severe acute respiratory syndrome in Hong Kong. At that time, there were reports of heroic acts among professionals who cared for these patients, whose bravery and professionalism were highly praised. However, there are concerns about changes in new generation of nursing professionals. OBJECTIVE: We aimed to examine the attitude of nursing students, should they be faced with severe acute respiratory syndrome patients during their future work. RESEARCH DESIGN: A questionnaire survey was carried out to examine the attitude among final-year nursing students to three ethical areas, namely, duty of care, resource allocation, and collateral damage. ETHICAL CONSIDERATIONS: This study was carried out in accordance with the requirements and recommendations of the Central Research and Ethics Committee, School of Health Sciences at Caritas Institute of Higher Education. FINDINGS: Complete responses from 102 subjects were analyzed. The overwhelming majority (96.1%) did not agree to participate in the intubation of severe acute respiratory syndrome patients if protective measures, that is, N95 mask and gown, were not available. If there were insufficient N95 masks for all the medical, nursing, and allied health workers in the hospital (resource allocation), 37.3% felt that the distribution of N95 masks should be by casting lot, while the rest disagreed. When asked about collateral damage, more than three-quarters (77.5%) said that severe acute respiratory syndrome patients should be admitted to intensive care unit. There was sex difference in nursing students' attitude toward severe acute respiratory syndrome care during pregnancy and influence of age in understanding intensive care unit care for these patients. Interestingly, 94.1% felt that there should be a separate intensive care unit for severe acute respiratory syndrome patients. CONCLUSION: As infection control practice and isolation facilities improved over the years, relevant knowledge and nursing ethical issues related to infectious diseases should become part of nursing education and training programs, especially in preparation for outbreaks of infectious diseases or distress.

Decreased dopamine receptor 1 activity and impaired motor-skill transfer in Dyt1 ΔGAG heterozygous knock-in mice.

DYT1 dystonia is a movement disorder caused by a trinucleotide deletion (ΔGAG) in DYT1 (TOR1A), corresponding to a glutamic acid loss in the C-terminal region of torsinA. Functional alterations in the basal ganglia circuits have been reported in both DYT1 dystonia patients and rodent models. Dyt1 ΔGAG heterozygous knock-in (KI) mice exhibit motor deficits and decreased striatal dopamine receptor 2 (D2R) binding activity, suggesting a malfunction of the indirect pathway. However, the role of the direct pathway in pathogenesis of dystonia is not yet clear. Here, we report that Dyt1 KI mice exhibit significantly decreased striatal dopamine receptor 1 (D1R) binding activity and D1R protein levels, suggesting the alteration of the direct pathway. The decreased D1R may be caused by translational or post-translational processes since Dyt1 KI mice had normal levels of striatal D1R mRNA and a normal number of striatal neurons expressing D1R. Levels of striatal ionotropic glutamate receptor subunits, dopamine transporter, acetylcholine muscarinic M4 receptor and adenosine A2A receptor were not altered suggesting a specificity of affected polytopic membrane-associated proteins. Contribution of the direct pathway to motor-skill learning has been suggested in another pharmacological rat model injected with a D1R antagonist. In the present study, we developed a novel motor skill transfer test for mice and found deficits in Dyt1 KI mice. Further characterization of both the direct and the indirect pathways in Dyt1 KI mice will aid the development of novel therapeutic drugs.

Time-varying effect moderation using the structural nested mean model: estimation using inverse-weighted regression with residuals.

This article considers the problem of examining time-varying causal effect moderation using observational, longitudinal data in which treatment, candidate moderators, and possible confounders are time varying. The structural nested mean model (SNMM) is used to specify the moderated time-varying causal effects of interest in a conditional mean model for a continuous response given time-varying treatments and moderators. We present an easy-to-use estimator of the SNMM that combines an existing regression-with-residuals (RR) approach with an inverse-probability-of-treatment weighting (IPTW) strategy. The RR approach has been shown to identify the moderated time-varying causal effects if the time-varying moderators are also the sole time-varying confounders. The proposed IPTW+RR approach provides estimators of the moderated time-varying causal effects in the SNMM in the presence of an additional, auxiliary set of known and measured time-varying confounders. We use a small simulation experiment to compare IPTW+RR versus the traditional regression approach and to compare small and large sample properties of asymptotic versus bootstrap estimators of the standard errors for the IPTW+RR approach. This article clarifies the distinction between time-varying moderators and time-varying confounders. We illustrate the methodology in a case study to assess if time-varying substance use moderates treatment effects on future substance use.