536 research outputs found
A worldwide correlation of lactase persistence phenotype and genotypes
Get PDFBackground: The ability of adult humans to digest the milk sugar lactose - lactase persistence - is a dominant Mendelian trait that has been a subject of extensive genetic, medical and evolutionary research. Lactase persistence is common in people of European ancestry as well as some African, Middle Eastern and Southern Asian groups, but is rare or absent elsewhere in the world. The recent identification of independent nucleotide changes that are strongly associated with lactase persistence in different populations worldwide has led to the possibility of genetic tests for the trait. However, it is highly unlikely that all lactase persistence-associated variants are known. Using an extensive database of lactase persistence phenotype frequencies, together with information on how those data were collected and data on the frequencies of lactase persistence variants, we present a global summary of the extent to which current genetic knowledge can explain lactase persistence phenotype frequency.
Results: We used surface interpolation of Old World lactase persistence genotype and phenotype frequency estimates obtained from all available literature and perform a comparison between predicted and observed trait frequencies in continuous space. By accommodating additional data on sample numbers and known false negative and false positive rates for the various lactase persistence phenotype tests (blood glucose and breath hydrogen), we also apply a Monte Carlo method to estimate the probability that known lactase persistence-associated allele frequencies can explain observed trait frequencies in different regions.
Conclusion: Lactase persistence genotype data is currently insufficient to explain lactase persistence phenotype frequency in much of western and southern Africa, southeastern Europe, the Middle East and parts of central and southern Asia. We suggest that further studies of genetic variation in these regions should reveal additional nucleotide variants that are associated with lactase persistence
Intern experience at Dallas Power and Light Company: an internship report
Get PDF"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical referencesA survey of the author's internship experience with the Dallas Power
& Light Company during the period January, 1979 through January, 1980 is presented. During
this one year internship, the author worked as an engineer in the Executive Department. The
intent of this report is to demonstrate that this experience fulfills the requirements for the
Doctor of Engineering internship. The author's activities during this period can be
categorized into two major areas. First, technically oriented, in which he developed a model
to project future electrical demands based on land usage, and a computer program that
implements this model. Secondly, a selection of non-technical business oriented areas were
investigated. The tasks in these areas offered him the opportunity to be exposed to the
organization and operation of an investor owned public utility company and to gain experience
in a non-academic business environment
Intern experience at URS Company: an internship report
No full textIncludes author's vita"Submitted to the College of Engineering of Texas A&M University in partial
fulfillment of the requirement for the degree of Doctor of Engineering."Includes bibliographical references (leaf 94)This report describes the author's internship experience with URS
Company - Dallas, Texas, from May 1980 to May 1981. The internship company is a consulting
engineering firm engaged in providing professional services in the transportation, energy,
pollution abatement, water resources, and water and wastewater treatment fields. The author
worked as an electrical design engineer during the internship period. The author was also
assigned the responsibilities and duties of a project engineer for one of the ongoing
projects. The internship objectives were set to provide the author with an internship
experience that fulfills the requirements of the Doctor of Engineering Program. These
objectives were to become familiar with the organizational characteristics of the company; to
make an identifiable contribution in the electrical engineering field; and to gain experience
in the non-academic activities of the company, industry standards, ethical practices, and the
interactions between the company and the industrial environments. During the internship period
the author was involved in designing electrical power distribution, lighting, and control
systems for the Dallas East Side Water Treatment Plant and some other projects. The author
also developed a computer program to calculate feeder, conduit, and circuit breaker sizes for
electrical power circuits. Furthermore, the author gained experience in project management,
industry practices, and the internal and external activities of the internship
company
Mucin methods: Genes encoding mucins and their genetic variation with a focus on gel-forming mucins
No full textMucin genes encode the polypeptide backbone of the mucin glycoproteins which are expressed on all epithelial surfaces and are major constituents of the mucus layer. Mucins are, thus, expressed at the interface between the external and the internal environment of the organism, and represent the first line of defence of our body. These genes often have an extensive region of repetitive exonic sequence which codes for the heavily glycosylated domain, whose roles include bacterial interactions and gel hydration. This region shows, in several of the genes, considerable inter-individual variation in repeat number and sequence. Because of their site of expression and their high variability in this important domain, mucin genes are good candidates for conferring differences in genetic susceptibility to multifactorial epithelial and inflammatory disease. However, progress in characterizing the genes has been considerably slower than the rest of the genome because of their size and the GC-rich content of the large, repetitive variable region. Some of the issues relating to the study of these genes are discussed in this chapter. In addition, methods and approaches that have been used successfully are described. © 2012 Springer Science+Business Media, LLC
The streamwise turbulence intensity in the intermediate layer of high Reynolds turbulent pipe flow
No full textA modification of the Townsend-Perry attached eddy model is derived in order to reproduce a more realistic variation of the integral length scale. A new wavenumber range is introduced to the model at wavenumbers smaller than the Townsend-Perry k^(-1) spectrum. This necessary addition can also account for the high Reynolds number outer peak of the turbulent kinetic energy in the intermediate layer. An analytic expression is obtained for this outer peak in agreement with extremely high Reynolds number data by Hultmark et al (2012, 2013). The finding of Dallas et al (2009) that it is the eddy turnover time and not the mean flow gradient which scales with distance to the wall and skin friction velocity in the intermediate layer implies, when combined with Townsend's (1976) production-dissipation balance, that the mean flow gradient has an outer peak at the same location as the turbulent kinetic energy
[Report concerning information by Earlene Roberts, by an unknown author]
No full textReport concerning information from Mrs. Earlene Roberts concerning Lee Harvey Oswald and Dallas Police Squad Car 207, by an unknown author. Mrs. Roberts stated that she saw Oswald return to his room at 1026 N. Beckley after the assassination of the President, around 1:00 p. m. After seeing him return home she looked out her window and saw Dallas Police Squad Car 207
MUC5AC & inflammatory mediators associated with respiratory outcomes in the British 1946 birth cohort
No full textBACKGROUND AND OBJECTIVE: Dysregulation of respiratory mucins, MUC5AC in particular, has been implicated in respiratory disease and MUC5AC expression is up-regulated in response to environmental challenges and inflammatory mediators. Our aim is to examine the effect of genetic variation on susceptibility to common respiratory conditions.METHODS: We test for association of MUC5AC and the closely linked genes MUC2 and MUC5B with respiratory outcomes in the MRC National Survey of Health and Development (NSHD), a longitudinal birth cohort of men and women born in 1946. We also examine functional variants of the genes encoding inflammatory mediators, IL13, IL1B, IL1RN, TNFA and ERBB1 for which there is a likely influence on MUC5AC expression, and explore potential gene-gene interactions with these inflammatory mediators with respect to respiratory disease.RESULTS: We report here statistically significant associations between the 3'ter MUC5AC SNP rs1132440 and various non-independent respiratory outcomes (bronchitis, wheeze, asthma, hay fever) while the adjacent loci show slight (but largely non-statistically significant) differences, presumably reflective of linkage disequilibrium (allelic association) across the region. A novel association between bronchitis and a non-synonymous functional ERBB1 SNP, rs2227983 (aka EGFR: R497K, R521K) is also reported and evidence presented of interaction between MUC5AC and ERBB1 and between MUC5AC and IL1RN with respect to bronchitis. The ERBB1 interaction suggests a clear mechanism for a biological interaction in which the allelic variants of EGFR differentially affect mucin expression.CONCLUSIONS: The MUC5AC association and the interactions with inflammatory mediators suggest that genetically determined differences in MUC5AC expression alter susceptibility to respiratory disease
An Economic Study Of The Negro Chamber Of Commerce Of Dallas, Texas
Get PDFAs stated in the Foreword, this treatise is an attempt to ascertain and evaluate facts about the Negro Chamber of Commerce of Dallas, Texas. The need for such a study has come out of the alleged importance of the Dallas Negro. Chamber of Commerce Itself. This organization has interwoven itself socially, politically, and economically into the lives of more than 40,000 Negroes in Dallas. In addition, the Dallas Negro Chamber of Commerce has also become a model for the organization of similar units in other cities. Thus, the author deems it necessary to find out for Dallas and Texas citizens the structure, function, accomplishments, and influences of this organization. A study of the Negro Chamber of Commerce of Dallas from either a political, social, or economic viewpoint would overlap. This treatise is an attempt to explore and emphasize the economic accomplishments of the Chamber. The reader must bear this in mind throughout the study. However much of the activities of the Chamber involve these three fields, the author has attempted to describe and interpret the money-making and money-spending activities of the Dallas Negro Chamber. The study also gives an analysis of the needs of Negroes in Dallas and attempts to discover and describe some of the influences of the Chamber in Dallas and throughout the State. In a way, it shows the reaction of the white man as a result of organized Negro participation in civic, commercial and industrial development of his Negro community
Peace and defense of the country
No full textPresidential campaign speech by Barry M. Goldwater, Dallas, Texas
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