Probabilistic Clustering of Time-Evolving Distance Data

We present a novel probabilistic clustering model for objects that are represented via pairwise distances and observed at different time points. The proposed method utilizes the information given by adjacent time points to find the underlying cluster structure and obtain a smooth cluster evolution. This approach allows the number of objects and clusters to differ at every time point, and no identification on the identities of the objects is needed. Further, the model does not require the number of clusters being specified in advance -- they are instead determined automatically using a Dirichlet process prior. We validate our model on synthetic data showing that the proposed method is more accurate than state-of-the-art clustering methods. Finally, we use our dynamic clustering model to analyze and illustrate the evolution of brain cancer patients over time

The Effectiveness of the Army Medical Command Tobacco Cessation Regulation on Self-Reported Tobacco Quit Rates of Soldiers

On the 4th of March, 2013, LTG Patricia D. Horoho, then the Surgeon General and Commanding General of the United States Army Medical Command (MEDCOM) published the Army Medicine 2020 Campaign Plan. The plan incorporates three different methods to take action within MEDCOM. These are to: “Increase Capacity, Enhance Diplomacy and Improve Stamina” (Army Medicine 2020 Campaign Plan; “Extension”). Within the “Improve Stamina” component of the plan, Campaign Objective 3-3 is to “Increase Healthy Behavior.” Specifically detailed within this section is to promote tobacco-free living under sub-objective 3-3.1. This sub-objective seeks to establish a change in culture throughout the United States Army: decreasing use and subsequently reducing the tobacco-related morbidity and mortality in Soldiers, retirees and their families. One specific method mentioned in the 2020 Campaign Plan is to establish more tobacco-free areas both in Army Medical Treatment Facilities (MTF) as well as locations on Army installations. Going one step further, the MEDCOM issued an Operations Order (Medical Command Tobacco Free Living Operations Order 15-48, 8 May 15), which took effect on 1 April, 2016, which not only mandated tobacco-free MTFs, but also states that all MEDCOM Soldiers are not authorized to use tobacco products (including e-cigarettes) while on duty or in uniform. Although many businesses including hospitals throughout the United States have enacted tobacco-free workplaces and campuses, never before has this requirement extended beyond the range of the campus itself. It can be readily assumed that the scope of a regulation of this nature will have far-reaching effects on improving the health of staff through enforcing a change in culture in much of its workforce. This research will determine what effects the new policy has on MEDCOM Soldiers over a short term in an effort to ascertain the future potential for this policy and others to be based upon it. Need for the Study: The United States Centers for Disease Control and Prevention (CDC) estimates that 21.3% of adults in the United States use tobacco products either every day or some days (Hu et al 2016). Of these, the greatest users were in the 18-24 year old male category. Tobacco use has been found to be the cause of approximately 480,000 American deaths per year, with health costs approaching $170 billion and$156 billion in lost productivity (“Tobacco Use,” 2016). Although tobacco use has gone down in the United States over the last fifty years, it is still attributed to 5%-14% of all U.S. healthcare dollars spent per year (Xu, Bishop, Kennedy, Simpson, & Pechaecek, 2015). Furthermore, Xu et al explains that based on the 2006-2010 Medical Expenditure Panel Survey (MEPS), approximately 32.8% of spending from federal health insurance programs (including the Veterans Affairs, Indian Health, and military treatment facilities) was directed toward cigarette smoking related illness. The United States CDC found that smoking in the military is higher than that of the general population on the whole. In 2008, approximately 31% of all Active Duty military were smokers (Bray et al, 2010). In 2011, 24% of Active military smoked compared with 19% of civilians, and from the period of 2007-2010 male veterans were 5% more likely than nonveterans to be smokers (“Current Cigarette Smoking Among U.S. Adults Aged 18 Years and Older,” 2016). According to GlobalSecurity.org (2016), there were approximately 1,301,300 total members of the Active United States military in 2016. This would mean that as many as 312,312 personnel could be smoking in the active duty. The financial and lost work hours of this are significant. In September, 2015, the Veterans Affairs projected a total Veteran population of 21,681,000 (“Department of Veterans Affairs Statistics at a Glance,” 2016). The five percent difference as mentioned above equates to over a million Veterans who are more likely to smoke than their civilian counterparts, which by extension increases the cost to care for these Veterans. The size of the Veteran population continues to grow as new military retirees enter the system, and modern medicine increases the lifespan of those currently enrolled in the system. Lastly, although an older study, Robert Klesges et al (2000) presented statistics on the effects of smoking on military training. The researchers specifically looked at the relationship between smoking and early discharges from the United States Air Force. It was found that of 29,044 personnel entering the Air Force between August, 1995 and August, 1996, smokers were found to be 1.8 times more likely to be prematurely discharged than non-smokers. This equated to 629 Airmen being discharged for problems related to smoking, costing the Air Force in excess of $18 million in excess cost. Their findings over all services were over$133 million, which approached 1% of the total military training budget. The effects of tobacco use in the United States military plays a significant impact on multiple levels. The impact on health from tobacco use has potential effects from the individual Soldiers and their families’ health, through the unit level and on to the readiness of the entire Army. The direct effects of smoking and tobacco on the individual, and smoking-related illness resulting in lost work time has been well documented by numerous studies. In addition, the effects of second-hand smoke on the general population and on the families of smokers has also been noted. Because of the extremely physical nature of many of the career fields in the Army, any loss of physical capacity equates to a decrease in job performance and a degradation in capability to accomplish assigned missions. This results in a direct impact from tobacco. Lastly, due to the nature of military health insurance, which covers 100% of a Soldier’s and family’s care, there is the direct financial impact on caring for the sequelae of tobacco use, with the additional impact of sick time taken by the Soldier, keeping them from being able to support the unit and their mission. Problem Statement: Although the evidence is apparent for the inherent health risks from tobacco use, quit rates in tobacco users are historically low, with a high degree of recidivism back to tobacco use. The Active Duty Army, in having authority to dictate policies to affect their employees (Soldiers) has the potential to influence tobacco use through policies making it “illegal” to use tobacco during the duty day. The purpose of this study is to assess whether the MEDCOM policy against tobacco use results in greater tobacco quit rates among MEDCOM Soldiers, in comparison to the same sample of Soldiers prior to the implementation of the new MEDCOM tobacco use policy. Specific Aim 1: What are the current statistics of tobacco use in the United States Army at this time, in comparison to the American population-at-large? Specific Aim 2: Is there a difference in tobacco quit rates in MEDCOM Soldiers after implementation of the 2016 Tobacco Cessation Policy? Population The population to be considered by this study includes all Active Duty Soldiers stationed on a large Army installation between October 2015 and October 2016, which includes sample data from before and after policy implementation. Hypotheses: The primary goal of the MEDCOM tobacco policy is to reduce the number of Soldiers using tobacco. Thus, the aim of this study will be to examine the use rates and quit rates before and after the implementation of the new tobacco policy. Through accessing data from routine appointments, the following hypotheses will be studied: Hypothesis 1: There is no difference in tobacco use following implementation of the new MEDCOM tobacco policy, in comparison to prior to the policy implementation. Hypothesis 2: There is no difference in tobacco use between MEDCOM Soldiers and non-MEDCOM Soldiers following the implementation of the new tobacco policy

Familial inference: tests for hypotheses on a family of centres

Statistical hypotheses are translations of scientific hypotheses into statements about one or more distributions, often concerning their centre. Tests that assess statistical hypotheses of centre implicitly assume a specific centre, e.g., the mean or median. Yet, scientific hypotheses do not always specify a particular centre. This ambiguity leaves the possibility for a gap between scientific theory and statistical practice that can lead to rejection of a true null. In the face of replicability crises in many scientific disciplines, significant results of this kind are concerning. Rather than testing a single centre, this paper proposes testing a family of plausible centres, such as that induced by the Huber loss function (the Huber family). Each centre in the family generates a testing problem, and the resulting family of hypotheses constitutes a familial hypothesis. A Bayesian nonparametric procedure is devised to test familial hypotheses, enabled by a novel pathwise optimization routine to fit the Huber family. The favourable properties of the new test are demonstrated theoretically and experimentally. Two examples from psychology serve as real-world case studies.Comment: To appear in Biometrik

Doctors under the microscope: the birth of medical audit

In 1989 a UK government White Paper introduced medical audit as a comprehensive and statutory system of assessment and improvement in quality of care in hospitals. A considerable body of research has described the evolution of medical audit in terms of a struggle between doctors and National Health Service managers over control of quality assurance. In this paper we examine the emergence of medical audit from 1910 to the early 1950s, with a particular focus on the pioneering work of the American surgeons Codman, MacEachern and Ponton. It is contended that medical professionals initially created medical audit in order to articulate a suitable methodology for assessing individual and organisational performance. Rather than a means of protecting the medical profession from public scrutiny, medical auditing was conceived and operationalised as a managerial tool for fostering the active engagement of senior hospital managers and discharging public accountability. These early debates reveal how accounting was implicated in the development of a system for monitoring and improving the work of medical professionals, advancing the quality of hospital care, and was advocated in ways, which included rather than excluded managers

Secondary Traumatic Stress:Prevalence and Symptomology Amongst Detective Officers Investigating Child Protection Cases

It has been increasingly recognised that individuals exposed to the trauma of others within their professional roles can be affected by secondary traumatic stress (STS). Despite this recognition, there is a dearth of literature examining the prevalence of secondary traumatic stress amongst police officers in the UK. This study aims to meet this gap. Sixty-three Detective Officers from Family Protection Units (FPU(s)), primarily engaged in child protection/abuse investigations, self-reported their experiences and symptoms associated with STS through a questionnaire. Findings indicate that over half of the respondents experienced STS symptoms with 11% reporting levels of symptoms that were in the high or severe range. This study is significant in that it provides empirical evidence of issues that have so far been little documented in the UK and considers the implications for policing policy and practice in terms of the health and well-being of serving police officers

Origins of cattle on Chirikof Island, Alaska, elucidated from genome-wide SNP genotypes

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A combined long-range phasing and long haplotype imputation method to impute phase for SNP genotypes

<p>Abstract</p> <p>Background</p> <p>Knowing the phase of marker genotype data can be useful in genome-wide association studies, because it makes it possible to use analysis frameworks that account for identity by descent or parent of origin of alleles and it can lead to a large increase in data quantities via genotype or sequence imputation. Long-range phasing and haplotype library imputation constitute a fast and accurate method to impute phase for SNP data.</p> <p>Methods</p> <p>A long-range phasing and haplotype library imputation algorithm was developed. It combines information from surrogate parents and long haplotypes to resolve phase in a manner that is not dependent on the family structure of a dataset or on the presence of pedigree information.</p> <p>Results</p> <p>The algorithm performed well in both simulated and real livestock and human datasets in terms of both phasing accuracy and computation efficiency. The percentage of alleles that could be phased in both simulated and real datasets of varying size generally exceeded 98% while the percentage of alleles incorrectly phased in simulated data was generally less than 0.5%. The accuracy of phasing was affected by dataset size, with lower accuracy for dataset sizes less than 1000, but was not affected by effective population size, family data structure, presence or absence of pedigree information, and SNP density. The method was computationally fast. In comparison to a commonly used statistical method (fastPHASE), the current method made about 8% less phasing mistakes and ran about 26 times faster for a small dataset. For larger datasets, the differences in computational time are expected to be even greater. A computer program implementing these methods has been made available.</p> <p>Conclusions</p> <p>The algorithm and software developed in this study make feasible the routine phasing of high-density SNP chips in large datasets.</p

Active Learning & Library Instruction : Team Teaching with Faculty Physicians

http://deepblue.lib.umich.edu/bitstream/2027.42/101131/1/ActiveLearningPosterMLA2013.pd

Unraveling bovin phylogeny: accomplishments and challenges

The phylogenetic systematics of bovin species forms a common basis for studies at multiple scales, from the level of domestication in populations to major cladogenesis. The main big-picture accomplishments of this productive field, including two recent works, one in BMC Genomics, are reviewed with an eye for some of the limitations and challenges impeding progress. See Research article http://www.biomedcentral.com/1471-2164/10/17