Probabilistic estimation of microarray data reliability and underlying gene expression

Background: The availability of high throughput methods for measurement of mRNA concentrations makes the reliability of conclusions drawn from the data and global quality control of samples and hybridization important issues. We address these issues by an information theoretic approach, applied to discretized expression values in replicated gene expression data. Results: Our approach yields a quantitative measure of two important parameter classes: First, the probability $P(\sigma | S)$ that a gene is in the biological state $\sigma$ in a certain variety, given its observed expression $S$ in the samples of that variety. Second, sample specific error probabilities which serve as consistency indicators of the measured samples of each variety. The method and its limitations are tested on gene expression data for developing murine B-cells and a $t$-test is used as reference. On a set of known genes it performs better than the $t$-test despite the crude discretization into only two expression levels. The consistency indicators, i.e. the error probabilities, correlate well with variations in the biological material and thus prove efficient. Conclusions: The proposed method is effective in determining differential gene expression and sample reliability in replicated microarray data. Already at two discrete expression levels in each sample, it gives a good explanation of the data and is comparable to standard techniques.Comment: 11 pages, 4 figure

A Workers Perspective On Hierarchical Organization Structure And The Potential For Non-Hierarchical Management Systems

My participation in the Organization Dynamics program has been quite the odyssey, as has my work career at the University of Pennsylvania. Since I was working full time at the School of Dental Medicine, it took me many years to complete the program. My Capstone theme is an explanation of the hierarchical management structures that I have worked within and an exploration of the potential of non-hierarchical systems. Most of the world, and the people working in it, are very familiar with hierarchical management systems. I will explore a few instances of the emergence of non-hierarchical management organizations in this paper, comparing my career experience to the organization models that I investigated As my participation in non-hierarchical management systems is limited and, I want to discern the differences between what I have experienced and what I could have realized if non-hierarchical structures were used as the structure for business organizations. Is it possible for non-hierarchical management systems to become the more dominant form of organizational structure in the modern workforce? My methodologies for the exploration are a literature review of management systems contrasting the differences between hierarchical and non-hierarchical organization structures. Another important component is an analysis and reflection of my own career experience, comparing what I learned in the literature review to what I have experienced in real life. I will additionally report findings in a non-hierarchical organization in which I participated recently. My final method is the analysis of a survey I conducted to determine if non-hierarchical organizing is being utilized. In summary, my findings show that hierarchical management structures are the de-facto standard in business and organizations today, and we are a long way from changing to non-hierarchical modes. However, some methodologies and processes that I have explored will become more prevalent going forward

Heavy Shell Castings Design/Operation And Repairs Criteria.

LecturePg. 3-8Unless the utility industry is prepared as a whole to commit a very large dollar amount to the purchase of new heavy wall castings for turbine casings and valve chests, the use of the art of repair for existing castings will need to be both understood and used in the near future. Existing equipment, some of it well over 40 years old, will need to be operated and in most cases the older the equipment, the more severe this service duty, i. e., cycling

The Development of a Catholic School Leadership Program at Saint Louis University

The development of a new Catholic leadership degree program at Saint Louis University was directly impacted by the Danforth Foundation, which funded a program for the preparation of public school administrators for the city of St. Louis. The lessons learned through this program over the past five years and the presence of a cooperative preparation program for Catholic school principals with the Archdiocese of St. Louis formed the basis for the development of this new program. This article provides a brief review of the program and explains the use of cohorts for the preparation of Catholic school leaders

Building the Research Enterprise in the Academic Environment:

The preponderance of nursing research conducted in the United States occurs in schools of nursing. Accordingly, a major role for academic leaders in nursing education is the development of a resource base to support and expand the research mission of the nursing program. The intersection of research and practice is also an essential element for assuring the relevance of nursing research and advancing the application of the evidence generated by nursing scientists. The following paper presents an introduction to nursing research in the U.S. with an emphasis on the educational and operational resources needed to maintain a robust research enterprise in schools of nursing. Key supports for this important work are profiled, including federal agencies and programs committed to advancing nursing science and the more widespread engagement of nurses in team-based research. The paper concludes with a look at efforts underway to enhance quality in research-focused doctoral programs and an assessment of critical roles nursing deans and faculty play in championing nursing research and preparing the next generation of nurse scientists. _________________ La majeure partie des activités de recherche en sciences infirmières aux États-Unis est effectuée dans les écoles de sciences infirmières. Par conséquent, les leaders académiques en sciences infirmières doivent jouer un rôle majeur dans l’établissement d’un ensemble de ressources pour appuyer et élargir la mission de recherche liée aux programmes de sciences infirmières. De plus, le lien entre la recherche et la pratique est un élément essentiel pour assurer la pertinence de la recherche effectuée en sciences infirmières et pour soutenir la mise en application des résultats probants produits par les scientifiques infirmières. L’article qui suit présente le développement de la recherche en sciences infirmières aux États-Unis, tout en mettant l’accent sur les ressources éducatives et opérationnelles nécessaires au maintien d’une importante activité de recherche dans les écoles de sciences infirmières. Les principaux appuis à cet important travail sont présentés, en particulier celui des organismes et programmes fédéraux mobilisés pour faire avancer les sciences infirmières et l’engagement grandissant des infirmières pour diriger des travaux de recherche en équipe. En guise de conclusion, l’article porte un regard sur les efforts en cours visant à accroître la qualité des programmes de doctorat axés sur la recherche. Il examine les rôles cruciaux que jouent les doyens/doyennes et les professeures de sciences infirmières pour promouvoir la recherche en sciences infirmières et préparer la prochaine génération d’infirmières/d’infirmiers scientifiques

Remediation of chromium(VI) at polypyrrole-coated titanium

The application of conducting polypyrrole (PPy) and polyaniline (PAni) coated substrates in remediation of chromium, Cr(VI), is an area of considerable interest. Here, we discuss the implementation of PPy-coated titanium as a new material for the reduction of Cr(VI) to the less toxic trivalent state, Cr(III). An alkaline-peroxide based etching process was used to ensure the adhesion of the PPy coatings to the underlying titanium. The PPy films showed excellent resistance to acidic Cr(VI) solutions and remained adherent after continuous exposure to the solutions. In order to optimise the remediation process a number of experimental parameters were investigated, including the thickness of the PPy coating, the reduction potential used in pre-treatment of the PPy and the degree of solution agitation. The durability of the materials on exposure to the Cr(VI) test solutions made them suitable for repeated remediation experiments. Following several test-runs, the cleanup efficiency of the material was found to decrease slightly, however, increasing the exposure/experiment time resulted in significantly improved cleanup ability

The politics of Chinese trade and the Asian financial crises : questioning the wisdom of export-led growth

Between 1987 and 1996 Chinese exports increased by an average of 14% each year. During this decade, export growth became a crucial determinant of overall economic growth. However, as a consequence of the East Asian financial crises, Chinese export growth slowed, threatening the successful implementation of plans to restructure the domestic Chinese economy. This paper traces the reasons for the rapid growth and subsequent slowing of Chinese exports, and asks whether the strategy provides a solid basis for the long term development of the Chinese economy. In particular, the paper focuses on the role and significance of the processing trade in boosting Chinese exports. The high proportion of imported components in processed exports questions whether China is really benefiting as much from export growth as aggregate trade figures seem to suggest

SAFEGUI: resampling-based tests of categorical significance in gene expression data made easy

Summary: A large number of websites and applications perform significance testing for gene categories/pathways in microarray data. Many of these packages fail to account for expression correlation between transcripts, with a resultant inflation in Type I error. Array permutation and other resampling-based approaches have been proposed as solutions to this problem. SAFEGUI provides a user-friendly graphical interface for the assessment of categorical significance in microarray studies, while properly accounting for the effects of correlations among genes. SAFEGUI incorporates both permutation and more recently proposed bootstrap algorithms that are demonstrated to be more powerful in detecting differential expression across categories of genes