The effect of sexual hormone abnormalities on proximal femur bone mineral density in hemodialysis patients and the possible role of RANKL

Sexual hormone concentrations are commonly affected in chronic renal failure. The contribution of sex steroids to bone turnover regulation implies that sex steroid's dysfunction may be implicated in the emergence of renal osteodystrophy. This study was conducted to evaluate sex steroids and gonadotrophins in hemodialysis (HD) patients and to investigate their role in bone homeostasis in concert with other hormones and cytokines. Bone mineral density (BMD) at the proximal femur and intact parathyroid hormone (iPTH), osteoprotegerin, soluble receptor activator of NF-kappaB ligand (sRANKL), prolactin, total testosterone, estradiol, follicle-stimulating hormone (FSH), and luteinizing hormone (LH) were measured in serum samples in 42 patients, 21 men and 21 women, on maintenance HD therapy. Possible associations between clinical characteristics, biochemical parameters, and BMD values were investigated. In male HD patients, the testosterone concentration declined significantly with aging, whereas the estradiol level increased with longer duration of HD. Concurrently, testosterone correlated negatively with sRANKL concentrations (r=-0.520, p=0.016). Luteinizing hormone levels in male patients demonstrated statistically significant negative correlations with BMD values of the proximal femur. In the entire cohort of patients, FSH and LH were negatively associated with absolute values of proximal femur BMD. Gonadotrophin and sexual hormone concentrations in HD patients are associated with bone mineral status and consequently their derangements appear to contribute to the development of bone composition abnormalities in different types of renal osteodystrophy. Furthermore, testosterone's association with sRANKL levels in male HD patients suggests that RANKL may mediate the effect of testosterone on bone metabolism in these patients.     

Numerical evaluation of multi-metric data fusion based structural health monitoring of long span bridge structures

This work focuses on structural health monitoring of long span bridges for damage detection. A feature extraction level data fusion based damage isolation strategy is presented using multi-metric sensing. The multi-metric sensing uses two types of sensors, namely strain sensors and accelerometers. The methodology combines the advantages offered by each type of sensors, while at the same time overcomes their limitations. The flexibility index method is applied and the flexibility matrices based on the strain and displacement data are combined after performing co-ordinate transformation. A study has been carried out on a simulated finite element model of the Great Belt East Bridge where realistic damage scenarios like damage in the girder, breaking of hanger cables, pier settlement, and loss of cable pretension were introduced on the structure. The study indicates that multi-metric sensing is indeed necessary as it reduces the possibility of false detections and increases the sensitivity and robustness of the methodology.     

Modeling and predicting spoilage of cooked, cured meat products by multivariate analysis

A cooked, cured meat product is a perishable product spoiled mainly by lactic acid bacteria (LAB). LAB cause discoloration, slime formation, off-odors and off-flavors as the result of their metabolic activity producing various products. These microbial products in conjunction with the microbial population could be used to assess the degree of spoilage of this type of product. The spoilage evaluation was achieved by following a multivariate approach. Cluster analysis, principal component analysis and partial least square regression were employed to associate spoilage with microbiological and physicochemical parameters. The developed model was capable of giving accurate predictions of spoilage describing the spoilage associations. The study might contribute to the improvement of quality assurance systems of meat enterprises.     

Application of Inductive Topological Transfer Function Generation for a Cascaded Low-Pass Filter

This work presents applications of an inductive topological approach in the calculation of the transfer function of a cascading network control system. The method provides a very versatile and effective way of counting all the graphs that contribute and of translating them into their algebraic contribution. The contributing graphs are very simple and reflect the morphology of the original control system signal flow graph. Application of the method and results are presented for an n-cell RC network. We derive an analytical formula relating ω(3 dB) to the filter size (n) and R _j C _j (j=1,2,…,n). This formula can be used for designing preset frequency range self-loaded LP filters by varying their size. We also derive general expressions for the sensitivities which we use to observe a sensitivity-insensitivity filter transition for various frequency ranges, relaxation times, and, most importantly, filter sizes.     

A numerical study of prestressed high strength steel tubular members

The structural behavior of prestressed high strength steel (HSS) tubular members is investigated through the execution of advanced finite element modeling. Numerical models are developed and validated against published experimental data on HSS tubular members subjected to different levels of initial prestress and loaded either in tension or compression. The effect of the presence or absence of grouting on the strength and ductility of the members is also considered. To numerically replicate the structural response recorded in the tests, some key modeling features including the employed numerical solver, the adopted material models and the element types warrant careful consideration. Upon developing of the finite element models, the numerically generated ultimate loads, the corresponding failure modes and the full load-deformation curves are compared to the experimental ones, indicating a successful validation. As anticipated, prestressing enhances the load-bearing capacity for the tensile members, whereas it is detrimental for the compressive ones. A series of parametric studies is performed to assess the influence of key factors on the structural response of prestressed HSS members and the obtained results are discussed. Design guidance for tensile and compressive prestressed tubular members is also provided.     

The microbiological condition of minced pork prepared at retail stores in Athens, Greece

Minced pork samples (n = 150) obtained from butchers' shops and supermarkets in Greece, during summer (n = 75) and winter (n = 75), were subjected to microbiological analysis. Microbial counts (log CFU/g) for the parameters tested were: total viable count (TVC), 6.8 ± 1.0; Pseudomonas spp., 6.4 ± 1.2; Brochothrix thermosphacta, 5.9 ± 1.1; lactic acid bacteria, 5.3 ± 1.0; yeasts and moulds, 4.6 ± 0.7; hydrogen sulfide (H(2)S)-producing bacteria, 4.3 ± 1.3; Enterobacteriaceae, 3.6 ± 1.2; total coliforms, 2.9 ± 1.1; Escherichia coli, 1.4 ± 0.7; Staphylococcus spp., 4.3 ± 1.0; S. aureus, 2.4 ± 0.9, and Listeria spp., 1.4 ± 0.6. The highest correlations were between TVC and pseudomonads, B. thermosphacta and H(2)S-producing bacteria, while the lowest were between total coliforms and all other groups of microorganisms except Enterobacteriaceae. The type of retail outlet and the seasonality of sampling did not have any significant effects (p>0.05) on minced pork meat quality. Interrelationships between (i) meat quality and shelf life, (ii) hygienic conditions during mince preparation and (iii) personnel hygiene were revealed.     

Bayesian inference for quantifying Listeria monocytogenes prevalence and concentration in minced pork meat from presence/absence microbiological testing

The purpose of this work was to estimate the prevalence and concentration of Listeria monocytogenes in minced pork meat by the application of a Bayesian modeling approach. Samples (n?=?100) collected from local markets were tested for L.?monocytogenes using in parallel the PALCAM, ALOA and RAPID'L.mono selective media. Presence of the pathogen was confirmed through biochemical and molecular tests. Independent experiments (n?=?10) for validation purposes were performed. No L.?monocytogenes was enumerated by direct-plating (<10?CFU/g), though the pathogen was detected in 22% of the samples. Sensitivity and specificity varied depending on the culture method. L.?monocytogenes concentration was estimated at 14-17?CFU/kg. Validation showed good agreement between observed and predicted prevalence (error?=?-2.17%). The use of at least two culture media in parallel enhanced the efficiency of L.?monocytogenes detection. Bayesian modeling may reduce the time needed to draw conclusions regarding L.?monocytogenes presence and the uncertainty of the results obtained.     

Developing Knowledge-Based Intelligent Multimedia Tutoring Systems Using Semantic Content-Based Modelling

The complex nature of semantic video and audio content has made multimedia difficult to use within the traditional architecture of a knowledge-based intelligent tutoring system (ITS). This paper investigates how multimedia syntax and semantics may be integrated into the confines of the knowledge-based ITS architecture so as to develop a knowledge-based intelligent multimedia tutoring system (IMTS). The paper contributes a semantic content-based model that can be used for this purpose. Multimedia frames (m-frames) are used as the framework by which the syntactic and semantic information is represented within the model. The paper discusses how IMTSs may be developed using the model, and then demonstrates the use of our approach in the development of ARISTOTLE, an IMTS for teaching young children basic zoology.     

Study on the kinetics of hazardous pollutants adsorption and desorption by biomass: Mechanistic considerations

The kinetics of biosorption and desorption of lindane, diazinon and 2-chlorobiphenyl by inactive activated sludge and Rhizopus arrhizus biomass was studied. The effects of solution initial concentration, temperature and type of biomass on the observed biosorption and desorption rates were also examined. The results of the present work show that the biosorption rates are reasonably rapid, with equilibrium attained within 4 h by activated sludge and 1 h by R. arrhizus. The observed biosorption kinetics consist of a rapid initial stage followed by a slower second stage. The observed rate of organic pollutants biosorption by activated sludge during the first stage can be described by second order kinetics. The biosorption of lindane by both biomass types is reversible and the desorption process is rapid and could be described by zero order kinetics when activated sludge is used as adsorbent. The type of biomass can have a significant effect on the observed biosorption and desorption rates.