Functional analysis of high-content high-throughput imaging data

High-content automated imaging platforms allow the multiplexing of several targets simultaneously to generate multi-parametric single-cell data sets over extended periods of time. Typically, standard simple measures such as mean value of all cells at every time point are calculated to summarize the temporal process, resulting in loss of time dynamics of the single cells. Multiple experiments are performed but observation time points are not necessarily identical, leading to difficulties when integrating summary measures from different experiments. We used functional data analysis to analyze continuous curve data, where the temporal process of a response variable for each single cell can be described using a smooth curve. This allows analyses to be performed on continuous functions, rather than on original discrete data points. Functional regression models were applied to determine common temporal characteristics of a set of single cell curves and random effects were employed in the models to explain variation between experiments. The aim of the multiplexing approach is to simultaneously analyze the effect of a large number of compounds in comparison to control to discriminate between their mode of action. Functional principal component analysis based on T-statistic curves for pairwise comparison to control was used to study time-dependent compound effects.     

A NEW CLASS OF MODELS FOR THE DISCRIMINANT PROBLEM

Discriminant analysis is relevant to business decision making in a variety of contexts, such as when one decides to make or buy a specified component, fund a venture project, or hire a particular person. Potential applications in artificial intelligence, particularly in the area of pattern recognition, have further underscored the importance of the field. A recent innovation in discriminant analysis is provided by special linear programming (LP) models, which offer attractive alternatives to classical statistical approaches. The scope of application in which discriminant analysis can be advantageously employed is broadened by the flexibility to tailor parameters in the LP approaches to reflect diverse goals and by the power to explore the sensitivity of these parameters. In spite of the promise of the LP formulations, however, limitations to their effectiveness have been uncovered in certain settings. A recent advance involving a normalization construct removes some of the limitations but entails solving the LP model twice (to allow for different signs of a normalization constant) and does not yield equivalent solutions for different rotations of the problem data. This paper introduces a new model and a new class of normalizations that remedy both remaining limitations, making it possible to take advantage of the modeling capabilities of the LP formulations without the attendant shortcomings encountered by earlier investigations. Our development shows by empirical testing and illustrative analysis that the quality of solutions from LP discriminant approaches is more favorable (relative to the classical model) than previously supposed.     

人造卫星捕捉污染物的全球迁移(上)

在20世纪中期,高耸的烟囱是解决工业废气排放的常见方法.把废气泵到足够高的空中,便想当然地认为污染问题也随之解决了.然而,随后的许多研究却强有力地显示高大烟囱不足以减轻污染的影响,那些高耸的大烟囱排放的污染物最终还是会回到地面,当然可能是到达几十里或数千里以外的其它地方.     

Immigrants and Employer-provided Training

Much has been written about the labour market outcomes for immigrants in their host countries, particularly with regard to earnings, employment and occupational attainment. However, much less attention has been paid to the question of whether immigrants are as likely to receive employer-provided training relative to comparable natives. As such training should be crucial in determining the labour market success of immigrants in the long run it is a critically important question. Using data from a large-scale survey of employees in Ireland, we find that immigrants are less likely to receive training from employers, with immigrants from the New Member States of the EU experiencing a particular disadvantage. The immigrant training disadvantage arises in part from a failure on the part of immigrants to get employed by training-oriented firms. However, they also experience a training disadvantage relative to natives within firms where less training is provided.     

Construction of a Markov Chain with Given Stationary Distribution

Given a rational, finite probability vector, a Markov chain is constructed having the given vector as its stationary distribution.     

The industrial athlete?

Many similarities can be drawn between the athletic and industrial population. It is time for a shift in the approach toward injured workers utilizing a sports medicine perspective. We must think of workers as industrial athletes and recognize that the sports medicine model can be appropriately adapted to the injured worker. This model includes prevention, early intervention/identification, training and conditioning, and progressive treatment. Sports medicine rehabilitation concepts include treating the entire kinetic chain that is associated with a specific injury and the SAID principle (Specific Adaptations to Imposed Demands).     

Exploring self-care among dementia caregivers:the role of perceived support in accomplishing exercise goals

Support provided by family and friends may influence the extent to which older women who are primary caregivers for a spouse with dementia adhere to an exercise routine. The current study reports on qualitative interviews with 30 older female caregivers taking part in an exercise intervention regarding the support they received for their exercise goals. Results indicate that nearly all women received some level of verbal encouragement from family and friends, though far fewer had exercise partners or someone to stay with their husbands while they exercised. To reflect the wide variation observed in the amount of exercise support received and needed by caregivers, a typology of support situations was constructed as follows: Self-reliant, Well-supported, Under-supported, and Superfluous support. Implications for future exercise interventions targeting this population are discussed.     

Health Risk Characterization of Chlorpyrifos Using Epidemiological Dose‐Response Data and Probabilistic Techniques: A Case Study with Rice Farmers in Vietnam

Various methods for risk characterization have been developed using probabilistic approaches. Data on Vietnamese farmers are available for the comparison of outcomes for risk characterization using different probabilistic methods. This article addresses the health risk characterization of chlorpyrifos using epidemiological dose‐response data and probabilistic techniques obtained from a case study with rice farmers in Vietnam. Urine samples were collected from farmers and analyzed for trichloropyridinol (TCP), which was converted into absorbed daily dose of chlorpyrifos. Adverse health response doses due to chlorpyrifos exposure were collected from epidemiological studies to develop dose‐adverse health response relationships. The health risk of chlorpyrifos was quantified using hazard quotient (HQ), Monte Carlo simulation (MCS), and overall risk probability (ORP) methods. With baseline (prior to pesticide spraying) and lifetime exposure levels (over a lifetime of pesticide spraying events), the HQ ranged from 0.06 to 7.1. The MCS method indicated less than 0.05% of the population would be affected while the ORP method indicated that less than 1.5% of the population would be adversely affected. With postapplication exposure levels, the HQ ranged from 1 to 32.5. The risk calculated by the MCS method was that 29% of the population would be affected, and the risk calculated by ORP method was 33%. The MCS and ORP methods have advantages in risk characterization due to use of the full distribution of data exposure as well as dose response, whereas HQ methods only used the exposure data distribution. These evaluations indicated that single‐event spraying is likely to have adverse effects on Vietnamese rice farmers.