Convex relaxation of mixture regression with efficient algorithms

We develop a convex relaxation of maximum a posteriori estimation of a mixture of regression models. Although our relaxation involves a semidefinite matrix variable, we reformulate the problem to eliminate the need for general semidefinite programming. In particular, we provide two reformulations that admit fast algorithms. The first is a max-min spectral reformulation exploiting quasi-Newton descent. The second is a min-min reformulation consisting of fast alternating steps of closed-form updates. We evaluate the methods against Expectation-Maximization in a real problem of motion segmentation from video data

Report on the selection of the reference XT-ADS target design and specifications

The XT-ADS is an experimental accelerator driven system (ADS) that is being developed in the framework of the European FP6 EUROTRANS project. In this deliverable, the specifications of the spallation target and the selection of its reference design are discussed. Justification of the design options, in relation to the performance requirements of the XT-ADS and the interlinking with the design of the sub-critical core and the primary system, are given

Multi-label classification with output kernels

Although multi-label classification has become an increasingly important problem in machine learning, current approaches remain restricted to learning in the original label space (or in a simple linear projection of the original label space). Instead, we propose to use kernels on output label vectors to significantly expand the forms of label dependence that can be captured. The main challenge is to reformulate standard multi-label losses to handle kernels between output vectors. We first demonstrate how a state-of-the-art large margin loss for multi-label classification can be reformulated, exactly, to handle output kernels as well as input kernels. Importantly, the pre-image problem for multi-label classification can be easily solved at test time, while the training procedure can still be simply expressed as a quadratic program in a dual parameter space. We then develop a projected gradient descent training procedure for this new formulation. Our empirical results demonstrate the efficacy of the proposed approach on complex image labeling tasks

Experimental observation of second-harmonic generation and diffusion inside random media

We have experimentally measured the distribution of the second-harmonic intensity that is generated inside a highly-scattering slab of porous gallium phosphide. Two complementary techniques for determining the distribution are used. First, the spatial distribution of second-harmonic light intensity at the side of a cleaved slab has been recorded. Second, the total second-harmonic radiation at each side of the slab has been measured for several samples at various wavelengths. By combining these measurements with a diffusion model for second-harmonic generation that incorporates extrapolated boundary conditions, we present a consistent picture of the distribution of the second-harmonic intensity inside the slab. We find that the ratio $\ell_{2\omega}/L_c$ of the mean free path at the second-harmonic frequency to the coherence length, which was suggested by some earlier calculations, cannot describe the second-harmonic yield in our samples. For describing the total second-harmonic yield, our experiments show that the scattering parameter at the fundamental frequency \k_{1\omega}\ell_{1\omega} is the most relevant parameter in our type of samples.Comment: 10 pages, 7 figure

Theoretical study of dark resonances in micro-metric thin cells

We investigate theoretically dark resonance spectroscopy for a dilute atomic vapor confined in a thin (micro-metric) cell. We identify the physical parameters characterizing the spectra and study their influence. We focus on a Hanle-type situation, with an optical irradiation under normal incidence and resonant with the atomic transition. The dark resonance spectrum is predicted to combine broad wings with a sharp maximum at line-center, that can be singled out when detecting a derivative of the dark resonance spectrum. This narrow signal derivative, shown to broaden only sub-linearly with the cell length, is a signature of the contribution of atoms slow enough to fly between the cell windows in a time as long as the characteristic ground state optical pumping time. We suggest that this dark resonance spectroscopy in micro-metric thin cells could be a suitable tool for probing the effective velocity distribution in the thin cell arising from the atomic desorption processes, and notably to identify the limiting factors affecting desorption under a grazing incidence.Comment: 12 pages, 11 figures theoretical articl

Concordance between nurse-reported quality of care and quality of care as publicly reported by nurse-sensitive indicators

Background: Nurse-sensitive indicators and nurses' satisfaction with the quality of care are two commonly used ways to measure quality of nursing care. However, little is known about the relationship between these kinds of measures. This study aimed to examine concordance between nurse-sensitive screening indicators and nurse-perceived quality of care. Methods: To calculate a composite performance score for each of six Dutch non-university teaching hospitals, the percentage scores of the publicly reported nurse-sensitive indicators: screening of delirium, screening of malnutrition, and pain assessments, were averaged (2011). Nurse-perceived quality ratings were obtained from staff nurses working in the same hospitals by the Dutch Essentials of Magnetism II survey (2010). Concordance between the quality measures was analyzed using Spearman's rank correlation. Results: The mean screening performances ranged from 63 % to 93 % across the six hospitals. Nurse-perceived quality of care differed significantly between the hospitals, also after adjusting for nursing experience, educational level, and regularity of shifts. The hospitals with high-levels of nurse-perceived quality were also high-performing hospitals according to nurse-sensitive indicators. The relationship was true for high-performing as well as lower-performing hospitals, with strong correlations between the two quality measures (r S = 0.943, p = 0.005). Conclusions: Our findings showed that there is a significant positive association between objectively measured nurse-sensitive screening indicators and subjectively measured perception of quality. Moreover, the two indicators of quality of nursing care provide corresponding quality rankings. This implies that improving factors that are associated with nurses' perception of what they believe to be quality of care may also lead to better screening processes. Although convergent validity seems to be established, we emphasize that different kinds of quality measures could be used to complement each other, because various stakeholders may assign different values to the quality of nursing care

Unravelling effectiveness of a nurse-led behaviour change intervention to enhance physical activity in patients at risk for cardiovascular disease in primary care: study protocol for a cluster randomised controlled trial

BACKGROUND: Self-management interventions are considered effective in patients with chronic disease, but trials have shown inconsistent results, and it is unknown which patients benefit most. Adequate self-management requires behaviour change in both patients and health care providers. Therefore, the Activate intervention was developed with a focus on behaviour change in both patients and nurses. The intervention aims for change in a single self-management behaviour, namely physical activity, in primary care patients at risk for cardiovascular disease. The aim of this study is to evaluate the effectiveness of the Activate intervention. METHODS/DESIGN: A two-arm cluster randomised controlled trial will be conducted to compare the Activate intervention with care as usual at 31 general practices in the Netherlands. Approximately 279 patients at risk for cardiovascular disease will participate. The Activate intervention is developed using the Behaviour Change Wheel and consists of 4 nurse-led consultations in a 3-month period, integrating 17 behaviour change techniques. The Behaviour Change Wheel was also applied to analyse what behaviour change is needed in nurses to deliver the intervention adequately. This resulted in 1-day training and coaching sessions (including 21 behaviour change techniques). The primary outcome is physical activity, measured as the number of minutes of moderate to vigorous physical activity using an accelerometer. Potential effect modifiers are age, body mass index, level of education, social support, depression, patient-provider relationship and baseline number of minutes of physical activity. Data will be collected at baseline and at 3 months and 6 months of follow-up. A process evaluation will be conducted to evaluate the training of nurses, treatment fidelity, and to identify barriers to and facilitators of implementation as well as to assess participants' satisfaction. DISCUSSION: To increase physical activity in patients and to support nurses in delivering the intervention, behaviour change techniques are applied to change behaviours of the patients and nurses. Evaluation of the effectiveness of the intervention, exploration of which patients benefit most, and evaluation of our theory-based training for primary care nurses will enhance understanding of what works and for whom, which is essential for further implementation of self-management in clinical practice. TRIAL REGISTRATION: ClinicalTrials.gov identifier: NCT02725203 . Registered on 25 March 2016

Smoking prevention intervention with school classes in university hospital by thoracic surgeon und pulmonologist. The Zurich prevention project

Smoking prevention in schoolchildren to inform and prevent smoking initiation has been widely studied; however, the potential effect of interventions provided in a hospital setting is unknown. An intervention program named "Schoolchildren smoking prevention in the hospital" was developed in which the health aspects of smoking and its individual consequences were presented in an interactive informational event provided by a thoracic surgeon and a pulmonologist. We aimed to assess the feasibility and the short-term effect of smoking-related knowledge improvement in schoolchildren in a hospital setting. Scholars of 45 classes in Canton of Zurich in Switzerland filled in an anonymous 5-item questionnaire with questions on general knowledge about smoking. The answers were evaluated in this prospective observational cohort study. The primary endpoint was to compare the knowledge improvement by interpretation of answers before-and-after the smoking prevention intervention. Additionally, the performance of children was compared after setting up an overall score and specific subgroups according to gender and school-level. Between Jan 2010, and Oct 2019, schoolchildren aged 10 to 16 years participated in this intervention program and completed the questionnaire before (N = 1270) and after (N = 1264) the intervention. The amount of correctly answered questions increased from 40% (±20) before to 81% (±17), p < 0·0001 after the educational session. An intervention program on health effects of smoking provided by lung specialists in the hospital is feasible, well received, leads to a substantial increase of knowledge, and hopefully can be further explored in the development of smoking prevention programs for schoolchildren. Keywords: Adolescent; BASEC, Business Administration System for Ethics Committees; CI, Confidence interval; IQR, Interquartile range; OR, Odds radio; RCT, Randomized control trial; SD, Standard deviation; Schoolchildren; Smoking adverse effects; Smoking cessation interventions; Tobacco smoking prevention; i.e, Id est

Bioassays of Compounds with Potential Juvenoid Activity on \u3ci\u3eDrosophila melanogaster\u3c/i\u3e: Juvenile Hormone III, Bisepoxide Juvenile Hormone III, and Methyl Farnesoates

Metabolites of the 6,7,10,11 bisepoxide juvenile hormone III (JHB3), and other potential juvenoids, were tested for juvenile hormone activity using early instar or early stage pupae of Drosophila mela-nogaster. Importantly, methyl farnesoates were tested as they might have JH-like activity on Dipteran juveniles. Larvae were exposed to compounds in medium, or the compounds were applied to white puparia. In the assays employed in the present study, there was no indication for JH activity associ-ated with the metabolites of JHB3. The activity of methyl farnesoate (MF) was higher than that of JH III and far greater than bisepoxide JH III. As opposed to the two endogenous juvenile hormones, methyl farnesoate has weak activity in the white puparial bioassay. When fluorinated forms of me-thyl farnesoate, which is unlikely to be converted to JH, were applied to Drosophila medium to which fly eggs were introduced, there was a high degree of larval mortality, but no evidence of subsequent mortality at the pupal stage. One possible explanation for the results is that methyl farnesoate is active as a hormone in larval stages, but has little activity at the pupal stage where only juvenile hormone has a major effect