196,064 research outputs found
The influence of cholesterol, progesterone, 4-androstenedione and testosterone on the growth of Treponema denticola ATCC 33520 in batch cultures
No full textPreviously, we have shown that reference and freshly isolated Treponema denticola cultures are capable of metabolising cholesterol, progesterone, 4-androstenedione and testosterone by means of 5 alpha-reductase, 3 beta-and 17 beta-hydroxysteroid dehydrogenase activity [Clark DT, Soory M. The metabolism of cholesterol and certain hormonal steroids by Treponema denticola. Steroids. 2006;71:352-63. [10]]. The aim of the work presented in this paper was to investigate the modulation of T denticola growth in batch cultures by these steroids, using T denticola ATCC 33520 as a model system. Growth curves were summarised using statistics based on optical density and protein yield. Cholesterol was found to stimulate growth at concentrations of 10 and 25 mu g/mL. Certain hormonal steroids inhibited the maximum achievable optical density at concentrations of 1 and 10 mu g/mL while the minimum concentration shown to inhibit protein yield was 0.001 mu g/mL of progesterone. The potential of the hormonal steroids to inhibit growth was in the order of progesterone, 4-androstenedione and testosterone. (c) 2006 Elsevier Ltd. All rights reserve
Periodontal disease severity and systemic diseases prevalent in a Caribbean catchment area of patients
No full textObjective: To describe associations between the prevalence of periodontal disease severity and coexistence of systemic disease(s) and a smoking habit amongst periodontal referrals in a Caribbean catchment area of patients. Methods: A total of 100 patients completed a medical history questionnaire and were categorized for periodontal disease severity, using clinical and radiographic parameters for association with the prevalence of systemic diseases. Results: Twenty-two per cent presented with moderate periodontal disease (M/F ratio: 1:2.7). 68% of patients examined presented with severe periodontal disease (M/F ratio: 1: 1.35). Amongst patients of the same mean age of 48 years presenting with moderate or severe periodontal disease, there was a two-fold increase in the number of missing teeth, amongst patients with severe periodontal disease. In this category there was twice the proportion of smokers and twice the number of mobile teeth, compared with those with moderate periodontal disease. In addition, there was twice the prevalence of diabetics and three times the proportion of patients with combined systemic diseases amongst those with severe periodontal disease, compared with those presenting with moderate periodontal disease, who were predominantly hypertensive or had rheumatoid arthritis. A history of smoking, diabetes mellitus and a combined manifestation of systemic diseases appeared to be more prevalent amongst those with severe periodontal disease. All these findings were significant (p <0.001). Conclusion: An association between severity of periodontal disease and co-existence of systemic diseases may have implications for a unified therapeutic strategy for healt
Dr. Duane M. Jackson, Morehouse College, July 2011
No full textThis video is a conversation with Dr. Duane M. Jackson. Dr. Jackson talks about his paper, "Recall and the Serial Position Effect: The Role of Primacy and Recency on Accounting Students' Performance." Jackie Daniel, AUC Woodruff Library, is the interviewer
"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States" By M. Carey.
No full text"Reflections on the subject of Emigration from Europe with a view to Settlement in the United States: containing bried sketches of the moral and political character of those states.
By M. Carey, member of the American philosophical, and of the American Antiquarian Society, and author of The Olive Branch, Cindiciae Hibernicae, essays on banking, on political economy, and on internal improvement.
To which are now added the English editor's comments on the subject; together with Important Advice to Emigrants, and Cautions Against Impositions Practiced in the Outports
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Dr. Glendon Swarthout
No full textHosted by Roger M. Busfield, MSU Assistant Professor of Speech and Theater, Meet the Author is designed to introduce a general audience to a contemporary author and their work through in-depth interviews. This episode features a conversation between Dr. Glendon Swarthout, prolific author and English professor at MSU, and assistant professors Sam S. Baskett and Theodore B. Strandness
Simulation of thermal plant optimization and hydraulic aspects of thermal distribution loops for large campuses
No full textFollowing an introduction, the author describes Texas A&M University and its utilities system. After that, the author presents how to construct simulation models for chilled water and heating hot water distribution systems. The simulation model was used in a $2.3 million Ross Street chilled water pipe replacement project at Texas A&M University. A second project conducted at the University of Texas at San Antonio was used as an example to demonstrate how to identify and design an optimal distribution system by using a simulation model. The author found that the minor losses of these closed loop thermal distribution systems are significantly higher than potable water distribution systems. In the second part of the report, the author presents the latest development of software called the Plant Optimization Program, which can simulate cogeneration plant operation, estimate its operation cost and provide optimized operation suggestions. The author also developed detailed simulation models for a gas turbine and heat recovery steam generator and identified significant potential savings. Finally, the author also used a steam turbine as an example to present a multi-regression method on constructing simulation models by using basic statistics and optimization algorithms. This report presents a survey of the author??s working experience at the Energy Systems Laboratory (ESL) at Texas A&M University during the period of January 2002 through March 2004. The purpose of the above work was to allow the author to become familiar with the practice of engineering. The result is that the author knows how to complete a project from start to finish and understands how both technical and nontechnical aspects of a project need to be considered in order to ensure a quality deliverable and bring a project to successful completion. This report concludes that the objectives of the internship were successfully accomplished and that the requirements for the degree of Degree of Engineering have been satisfied
The Modulation of Androgen Metabolism by Estradiol, Minocycline, and Indomethacin in a Cell Culture Model
No full textBackground: This investigation attempts to clarify the proanabolic effects of minocycline and indomethacin by studying their effects on androgen metabolism and mediation by estradiol. A cell culture model was used with androgen substrates because of the proanabolic effects of androgen metabolites. Methods: Monolayer cultures of human gingival fibroblasts (HGF) derived from 6 patients were incubated in duplicate with 14C- testosterone or 14C-4-androstenedione as substrates and optimal concentrations of estradiol (E-1,E-3 mug/ml) and minocycline (M-25 mug/ml) or indomethacin (I, 1 mug/ml) alone and in combination (E-1,E-3+I-1 or E-1,E-3+M-25 mug/ml); similar experiments were carried out with human oral periosteal fibroblasts (HPF), M, 1, E, and the combinations. At the end of a 24-hour incubation period in Eagle's MEM, the medium was solvent extracted with ethyl acetate and the metabolites were separated by TLC in a benzene:acetone solvent system (4:1 v/v). The separated metabolites were quantified using a radioisotope scanner. Results: Both androgens were metabolized to 5alpha-dihydrotestosterone (DHT) and 4-androstenedione (4-A) or testosterone (T) at baseline and in response to the agents tested, by HGF and HPF. With HGF, there were significant increases in the yields of DHT and 4-A or T in response to M, E, and M+E, resulting in 50% to 2.4-fold increases in these metabolites over control incubations (n = 6;
Hormonal Factors in Periodontal Disease
No full text This article discusses the effects of sex steroid hormones, glucocorticoids and insulin deficiency on periodontal tissues, and the possible consequences on periodontal disease progression. The androgens and oestrogens have predominantly anabolic functions in stimulating matrix synthesis, which is applicable to periodontal repair and medication-induced gingival overgrowth. Oestrogen and progesterone can contribute to pregnancy gingivitis; long-term use of hormonal contraceptives can accelerate progression of periodontal disease. Higher levels of circulating cortisol, associated with stress, can influence the onset of acute necrotic ulcerative gingivitis. Gingivitis and periodontal disease are reported to be more prevalent in type 1 and type 2 diabetes mellitus (periodontal disease, particularly in older, less well controlled subjects) than in non-diabetic individuals. </jats:p
Intern experience at CH���M Hill, Inc.: 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 referencesA review of the author's internship experience with CH���M HILL, Inc.
during the period September 1975 through May 1976 is presented. During this nine month
internship the author worked as an Engineer II in the Industrial Processes discipline of this
large consulting engineering firm... The author's prime responsibility was as one of three
lead design engineers on the design of a large wastewater treatment facility for a pulp mill
in Hoquiam, Washington owned by ITT Rayonier Inc. The work generally consisted of the design
of individual treatment units and associated piping and pumping. The purpose of the project
was to provide wastewater treatment capabilities that would satisfy the effluent limitations
(standards) imposed upon the mill by the State of Washington Department of Ecology and the
U.S. Environmental Protection Agency. The author's assignment also entailed necessary
interaction with the project manager and other CH���M HILL design engineers and support staff
members, the client's representatives, and representatives of two other consulting engineering
firms working on the project. Thus, the internship position at CH���M HILL provided considerable
experience coordinating the author's work with the work of other engineers, guiding the design
and administrative efforts of a support staff, and interacting regularly with the client and
other consulting firms. This broad exposure to a variety of engineering and organizational
problems provided a valuable educational experience
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