Duquesne University

About: Duquesne University is a education organization based out in Pittsburgh, Pennsylvania, United States. It is known for research contribution in the topics: Population & Health care. The organization has 3615 authors who have published 7169 publications receiving 180066 citations. The organization is also known as: Duquesne University of the Holy Spirit.

The Interrater Reliability of 4 Clinical Tests Used to Assess Individuals With Musculoskeletal Hip Pain

Abstract: Study Design Descriptive and reliability study. Objectives To evaluate the interrater reliability of the FABER test, flexion-internal rotation-adduction impingement test, log roll test, and the palpation of the greater trochanter for tenderness. Background Clinical examination for individuals with muscuioskeletal hip pain is believed to provide critical diagnostic information. However, there is very limited information in the literature on the reproducibility of examination techniques for the hip region. Methods and Measures Seventy subjects were evaluated prospectively by an orthopaedic surgeon and physical therapist. Subjects had a mean age of 42 years (range, 18–76 years; SD, 15.4) and included 32 (46%) females and 38 (54%) males. Subject diagnoses were as follows: degenerative joint disease (n = 27 [39% of subjects]), labral tear (n = 35 [50% of subjects]), femoroacetabular impingement (n = 48 [69% of subjects]), capsular laxity (n = 28 [40% of subjects]), trochanteric bursitis (n = 29 [41% of subject...

Methods for Applying the Quantitative Structure-Activity Relationship Paradigm

Abstract: There are several Quantitative Structure-Activity Relationship (QSAR) methods to assist in the design of compounds for medicinal use. Owing to the different QSAR methodologies, deciding which QSAR method to use depends on the composition of system of interest and the desired results. The relationship between a compound's binding affinity/activity to its structural properties was first noted in the 1930s by Hammett and later refined by Hansch and Fujita in the mid-1960s. In 1988 Cramer and coworkers created Comparative Molecular Field Analysis (CoMFA) incorporating the three-dimensional (3D) aspects of the compounds, specifically the electrostatic fields of the compound, into the QSAR model. Hopfinger and coworkers included an additional dimension to 3D-QSAR methodology in 1997 that eliminated the question of "Which conformation to use in a QSAR study?", creating 4D-QSAR. In 1999 Chemical Computing Group Inc. (CCG) developed the Binary-QSAR methodology and added novel 3D-QSAR descriptors to the traditional QSAR model allowing the 3D properties of compounds to be incorporated into the traditional QSAR model. Recently CCG released Probabilistic Receptor Potentials to calculate the substrate's atomic preferences in the active site. These potentials are constructed by fitting analytical functions to experimental properties of the substrates using knowledge-based methods. An overview of these and other QSAR methods will be discussed along with an in-depth examination of the methodologies used to construct QSAR models. Also, included in this chapter is a case study of molecules used to create QSAR models utilizing different methodologies and QSAR programs.

Self-Interest, Reciprocity, and Participation in Online Reputation Systems

Abstract: Reputation systems are emerging as an increasingly important component of online communities, helping elicit good behavior and cooperation among loosely connected and geographically dispersed economic agents A deeper understanding of the factors that drive voluntary online feedback contribution is crucial to the long-term viability of such systems and of the online communities that rely on them This paper contributes in this direction by offering what we believe to be the first in-depth study of the motivations of trader participation in eBay's reputation system To examine these questions, we analyze data from 51,452 eBay rare coin auctions We find evidence suggesting that the high levels (50-70%) of voluntary online feedback contribution on eBay are not strongly driven by pure altruism Rather, we analytically and empirically demonstrate that the expectation of reciprocal behavior from partners increases reputation system participation from self-interested eBay buyers and sellers We develop a random effects probit model that sheds light on the drivers of feedback submission in individual transactions, and find that participation levels rise, then decline as users accumulate experience within the eBay community

Influence of Pilin Glycosylation on Pseudomonas aeruginosa 1244 Pilus Function

Abstract: The opportunistic pathogen Pseudomonas aeruginosa is a leading cause of nosocomial pneumonia. Among its virulence factors, the type IV pili of P. aeruginosa strain 1244 contain a covalently linked, three-sugar glycan of previously unknown significance. The work described in this paper was carried out to determine the influence of the P. aeruginosa 1244 pilin glycan on pilus function, as well as a possible role in pathogenesis. To accomplish this, a deletion was introduced into the pilO gene of this organism. The isogenic knockout strain produced, 1244G7, was unable to glycosylate pilin but could produce pili normal in appearance and quantity. In addition, this strain had somewhat reduced twitching motility, was sensitive to pilus-specific bacteriophages, and could form a normal biofilm. Analysis of whole cells and isolated pili from wild-type P. aeruginosa strain 1244 by transmission electron microscopy with a glycan-specific immunogold label showed that this saccharide was distributed evenly over the fiber surface. The presence of the pilin glycan reduced the hydrophobicity of purified pili as well as whole cells. With regard to pathogenicity, P. aeruginosa strains producing glycosylated pili were commonly found among clinical isolates and particularly among those strains isolated from sputum. Competition index analysis using a mouse respiratory model comparing strains 1244 and 1244G7 indicated that the presence of the pilin glycan allowed for significantly greater survival in the lung environment. These results collectively suggest that the pilin glycan is a significant virulence factor and may aid in the establishment of infection.

Selenihalanaerobacter shriftii gen. nov., sp. nov., a halophilic anaerobe from Dead Sea sediments that respires selenate

Abstract: We isolated an obligately anaerobic halophilic bacterium from the Dead Sea that grew by respiration of selenate. The isolate, designated strain DSSe-1, was a gram-negative, non-motile rod. It oxidized glycerol or glucose to acetate+CO2 with concomitant reduction of selenate to selenite plus elemental selenium. Other electron acceptors that supported anaerobic growth on glycerol were nitrate and trimethylamine-N-oxide; nitrite, arsenate, fumarate, dimethylsulfoxide, thiosulfate, elemental sulfur, sulfite or sulfate could not serve as electron acceptors. Growth on glycerol in the presence of nitrate occurred over a salinity range from 100 to 240 g/l, with an optimum at 210 g/l. Analysis of the 16S rRNA gene sequence suggests that strain DSSe-1 belongs to the order Halanaerobiales, an order of halophilic anaerobes with a fermentative or homoacetogenic metabolism, in which anaerobic respiratory metabolism has never been documented. The highest 16S rRNA sequence similarity (90%) was found with Acetohalobium arabaticum (X89077). On the basis of physiological properties as well as the relatively low homology of 16S rRNA from strain DSSe-1 with known genera, classification in a new genus within the order Halanaerobiales, family Halobacteroidaceae is warranted. We propose the name Selenihalanaerobacter shriftii. Type strain is strain DSSe-1 (ATCC accession number BAA-73).