Gamma-based clustering via ordered means with application to gene-expression analysis

Discrete mixture models provide a well-known basis for effective clustering algorithms, although technical challenges have limited their scope. In the context of gene-expression data analysis, a model is presented that mixes over a finite catalog of structures, each one representing equality and inequality constraints among latent expected values. Computations depend on the probability that independent gamma-distributed variables attain each of their possible orderings. Each ordering event is equivalent to an event in independent negative-binomial random variables, and this finding guides a dynamic-programming calculation. The structuring of mixture-model components according to constraints among latent means leads to strict concavity of the mixture log likelihood. In addition to its beneficial numerical properties, the clustering method shows promising results in an empirical study.Comment: Published in at http://dx.doi.org/10.1214/10-AOS805 the Annals of Statistics (http://www.imstat.org/aos/) by the Institute of Mathematical Statistics (http://www.imstat.org

Western Clinicians’ Diagnostic Accuracy of Culture-Bound Syndromes

Culture-bound syndromes are of increasing importance in today’s more diverse world. The current study measured the ability of clinicians trained in a western setting to accurately diagnose culture-bound syndromes from cultures outside of their background. Eight-four clinicians were recruited through the American Psychological Association (APA) membership directory. All recruited clinicians were asked to read three vignettes. In two vignettes a patient was suffering from either Hwabyung or Ataque de Nervios and the third vignette represented a control GAD vignette. The clinicians were asked to diagnose the patient in the vignette, to explain what information informed their diagnosis, to complete two indications of what portions of the vignette informed their decision, and also to describe what strategies they used to help reach their diagnosis. The clinicians then completed both the Multicultural Counseling Self-Efficacy Scale-Racial Diversity Form and the Self-Construal Scale to measure their perceived competence in interacting with clients of minority backgrounds as well as their cultural orientation toward individualism or collectivism. Demographic questions were also completed to assess information such as participants’ cultural and clinical background. The present study found that clinicians had difficulty correctly diagnosing cultural disorders while there was greater accuracy in diagnosing the western GAD vignette. Clinicians paid more attention to familiar symptoms of cultural disorders (those that resembled western symptoms) while dismissing uniquely cultural symptoms. Individualism and high perceived cultural competence levels were also correlated with reduced accuracy in the diagnosis of Hwabyung. The study revealed that western clinicians lack experience with encountering and diagnosing unique cultural disorders and are quick to give inaccurate western diagnoses to these foreign presentations. It can be concluded from the results that more cultural training whether it is through graduate programs or CE credits are needed and of great importance

Bias detection and correction in RNA-Sequencing data

<p>Abstract</p> <p>Background</p> <p>High throughput sequencing technology provides us unprecedented opportunities to study transcriptome dynamics. Compared to microarray-based gene expression profiling, RNA-Seq has many advantages, such as high resolution, low background, and ability to identify novel transcripts. Moreover, for genes with multiple isoforms, expression of each isoform may be estimated from RNA-Seq data. Despite these advantages, recent work revealed that base level read counts from RNA-Seq data may not be randomly distributed and can be affected by local nucleotide composition. It was not clear though how the base level read count bias may affect gene level expression estimates.</p> <p>Results</p> <p>In this paper, by using five published RNA-Seq data sets from different biological sources and with different data preprocessing schemes, we showed that commonly used estimates of gene expression levels from RNA-Seq data, such as reads per kilobase of gene length per million reads (RPKM), are biased in terms of gene length, GC content and dinucleotide frequencies. We directly examined the biases at the gene-level, and proposed a simple generalized-additive-model based approach to correct different sources of biases simultaneously. Compared to previously proposed base level correction methods, our method reduces bias in gene-level expression estimates more effectively.</p> <p>Conclusions</p> <p>Our method identifies and corrects different sources of biases in gene-level expression measures from RNA-Seq data, and provides more accurate estimates of gene expression levels from RNA-Seq. This method should prove useful in meta-analysis of gene expression levels using different platforms or experimental protocols.</p

A narrative exploration of the sense of self of women recovering from childhood sexual abuse

Objectives: To explore how the sense of self evolves through the recovery process after intensive therapy that focuses on issues pertaining to childhood sexual abuse (CSA). Design: A retrospective qualitative study. Method: Four women with CSA experiences, who completed a local sexual abuse intervention group programme, participated in the study. They were interviewed using a narrative life story approach and a narrative analysis was conducted on the data. Results: Participants had a \u27traumatised self\u27 characterised by shame and guilt, leading to self-perceptions of being insignificant and undeserving. After intervention, an overall positive sense of self resulted characterised by an increased sense of self-awareness, self-acceptance and self-confidence. This was enhanced by being able to externalise their abuse and to shift the responsibility of the abuse from the abused to the abuser. Self-control was gained through the use of effective coping strategies. Being part of a group with similar experiences was found to enhance feelings of solidarity and commonality and instilled a sense of optimism about the future. Conclusions: After therapy, the concept of sense of self evolved from a traumatised self to a more enduring positive sense of self. The participants made self-improvements, connections with people and were able to live autonomous lives. © 2011 Taylor & Francis

Perceived similarity of other customers on service experience

This study aims to examine how a mere appearance of other similar customers will influence the perceived service quality of a potential customer. This research involves two experimental studies. Findings shows that if potential customers perceive other customers to be similar (vs. dissimilar) in a hospitality setting with regard to age, they will have more favorable perceptions toward the service quality and have a higher purchase intention. However, the positive impact of the similarity in age cohort can override the negative impact of dissimilarity in ethnicity on one\u27s perceived service quality and purchase intentions. The results provide implications for hospitality managers

Melanoma Cancer Survivors: An Online Community Perspective and Prevention Effort

AbstractMelanoma cancer is a major public health issue and has been associated with tanning and exposure to ultraviolet radiation. Minimal information is known about prevention efforts specific to survivors of melanoma cancer who participate in an online community. Surveys of this community differ from previous research of individuals through nononline research; the online community is more likely to be younger in age, comfortable seeking health information using Internet resources, and more advanced in technological capabilities. The main aim of this cross-sectional study was to investigate the impact of age, gender, and race on melanoma prevention efforts (health maintenance and skin protection), controlled for education, marital status, and income, in an online community. The health belief model was the theoretical framework of this study. The study sample consisted of 101 volunteer melanoma cancer survivor participants from an online community of the American Cancer Society cancer survivor network who completed an online survey. Chi-square tests and multiple regression analyses were applied to address the research questions. Study findings revealed that women and participants with higher education levels and income levels had significantly better prevention and health maintenance efforts. These results provide an opportunity for organizations to develop programs, services, and policies for online communities to keep them abreast of prevention measures to manage their health and to promote positive social chang