Multi-Channel Stochastic Variational Inference for the Joint Analysis of Heterogeneous Biomedical Data in Alzheimer's Disease

The joint analysis of biomedical data in Alzheimer's Disease (AD) is important for better clinical diagnosis and to understand the relationship between biomarkers. However, jointly accounting for heterogeneous measures poses important challenges related to the modeling of the variability and the interpretability of the results. These issues are here addressed by proposing a novel multi-channel stochastic generative model. We assume that a latent variable generates the data observed through different channels (e.g., clinical scores, imaging, ...) and describe an efficient way to estimate jointly the distribution of both latent variable and data generative process. Experiments on synthetic data show that the multi-channel formulation allows superior data reconstruction as opposed to the single channel one. Moreover, the derived lower bound of the model evidence represents a promising model selection criterion. Experiments on AD data show that the model parameters can be used for unsupervised patient stratification and for the joint interpretation of the heterogeneous observations. Because of its general and flexible formulation, we believe that the proposed method can find important applications as a general data fusion technique.Comment: accepted for presentation at MLCN 2018 workshop, in Conjunction with MICCAI 2018, September 20, Granada, Spai

Alcohol consumption and sleep problems in Hong Kong adolescents

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Isoflurane and propofol synergy in reducing myocardial ischemia-reperfusion injury in patients

Abstract no. A285postprin

Fiber-coupled light-emitting diode with a capillary-bonded hemispherical lens

A hemispherical lens capillary-bonded to an InGaN flip-chip light-emitting diode (LED) is demonstrated to efficiently couple light to a plastic optical fiber. The BK-7 hemispherical lens is bonded onto a circularly shaped LED chip with inclined sidewalls cut by laser-micromachining, so that lateral emissions are effectively suppressed. Capillary bonding minimizes air-gap between chip and lens enabling transmission of evanescent waves, thus maximizing overall optical transmission. With the lens attached, emission divergence from the assembly is significantly reduced, diverting rays into the acceptance cone of the fiber. Fiber coupling efficiency as high as 53.8% has been demonstrated. © 2011 IEEE.published_or_final_versio

Independent association between parental smoking and non-authoritative parenting style as reported by Chinese adolescents in Hong Kong

Poster Discussion 35. Engaging New Partners: no. PD-1005-20Conference Theme: Tobacco and Non-Communicable DiseasesBACKGROUND: Both parental smoking and non-authoritative parenting style predict adolescent smoking, but the association between the two risk factors was seldom studied. We investigated this association in Chinese parents of adolescents in Hong Kong, where smoking is socially undesirable, especially in females. DESIGN/METHODS: In the Hong Kong Student Obesity Surveillance project 2006/07, 33692 adolescents aged 11-18 (44.9% boys, mean age 14.8, SD 1.9 years) from 42 randomly selected schools reported smoking status (yes vs no) and the level (frequent/sometimes as high; seldom/none as low) of care and control of each parent. Parenting style (dependent variable) was defined as authoritative …published_or_final_versio

Exercise-Induced Changes in Exhaled NO Differentiates Asthma With or Without Fixed Airway Obstruction From COPD With Dynamic Hyperinflation.

Asthmatic patients with fixed airway obstruction (FAO) and patients with chronic obstructive pulmonary disease (COPD) share similarities in terms of irreversible pulmonary function impairment. Exhaled nitric oxide (eNO) has been documented as a marker of airway inflammation in asthma, but not in COPD. To examine whether the basal eNO level and the change after exercise may differentiate asthmatics with FAO from COPD, 27 normal subjects, 60 stable asthmatics, and 62 stable COPD patients were studied. Asthmatics with FAO (n = 29) were defined as showing a postbronchodilator FEV(1)/forced vital capacity (FVC) ≤70% and FEV(1) less than 80% predicted after inhaled salbutamol (400 μg). COPD with dynamic hyperinflation (n = 31) was defined as a decrease in inspiratory capacity (ΔIC%) after a 6 minute walk test (6MWT). Basal levels of eNO were significantly higher in asthmatics and COPD patients compared to normal subjects. The changes in eNO after 6MWT were negatively correlated with the percent change in IC (r = −0.380, n = 29, P = 0.042) in asthmatics with FAO. Their levels of basal eNO correlated with the maximum mid-expiratory flow (MMEF % predicted) before and after 6MWT. In COPD patients with air-trapping, the percent change of eNO was positively correlated to ΔIC% (rs = 0.404, n = 31, P = 0.024). We conclude that asthma with FAO may represent residual inflammation in the airways, while dynamic hyperinflation in COPD may retain NO in the distal airspace. eNO changes after 6MWT may differentiate the subgroups of asthma or COPD patients and will help toward delivery of individualized therapy for airflow obstruction

Cross-sectional difference in BMI between senior and junior students predicts prospective change in BMI at the school level

Poster Presentation: abstract no. 1196The Conference abstracts's website is located at http://www2.kenes.com/apccn/scientific/Pages/ListofAbstracts.aspxOBJECTIVES: To examine whether cross-sectional BMI difference between senior and junior secondary school students was correlated with prospective changes in BMI at the school level. BACKGROUND: Schools are known to exert prospective influences on adolescent BMI. The school effects may also be reflected in cross-sectional BMI differences between senior and junior students in each school. Schools could quickly be identified for weight-control interventions if such cross-sectional differences could predict prospective changes in BMI. METHODS: In the Hong Kong Student …postprin

A School-based Survey on Adolescent Alcohol Drinking in Hong Kong

Symposium Theme: Translating Health Research into Policy and Practice for Health of the PopulationParallel Session 1 - Population Health & Policy: no. S2INTRODUCTION: The effective control of underage drinking requires a thorough understanding of its risk factors and effects, but little is known about the drinking pattern in Hong Kong adolescents. OBJECTIVES: We investigated the drinking pattern and associated risk factors and problems in Hong Kong secondary school students. METHODS: In a territory-wide survey of 44 randomly selected schools, 21627 Secondary 1 to 6 students (mean age 14.7, SD 1.8; 51.6% boys) provided valid data using an anonymous questionnaire in 2012-13. Data on socio-demographic characteristics, alcohol drinking, peer and co-residents’ drinking, exposure to pro-drinking and anti-drinking messages, parental pro-drinking practices and health outcomes were collected. Descriptive data were weighted by sex, age and grade distribution of students in Hong Kong. Risk factors and problems associated with adolescent drinking were …published_or_final_versio

A pancake-shaped nano-aggregate for focusing surface plasmons

We proposed a pancake-shaped nano-aggregate that highly focuses surface plasmons. The structure is a superposition of bowtie-shaped dimers, where surface plasmons are excited, resonated with the structure, and coupled. Surface integral equation method (Poggio-Miller-Chang-Harrington-Wu-Tsai method) is used to predict the performance of the proposed structure. It is a method which can accurately calculate the near-fields of nanoparticles. Based on the numerical prediction, the proposed structure shows an electric field (E-field) enhancement of more than 400 times, which is equivalent to a Raman enhancement factor of more than 2.5 e 10 times. It is promising for single molecule detections using surface-enhanced Raman scattering. The physics of the proposed structure are revealed. It is useful to design nanostructures for high E-field enhancement. © 2012 American Institute of Physics.published_or_final_versio