399 research outputs found
Diagnostic medical microbiology
• Bacterial Exotoxins• Comparison of Bacterial Exotoxins with Endotoxin• Summary of Host-Parasite Interactions• Pathogen Virulenc
Buckling of Radially Loaded Concrete Cylinders in Fire Condition
Concrete cylinders are commonly used in water treatment and sewerage plants, in the form of wells or basins. They are mainly subjected to axial compression resulting from soil lateral pressure and aqueous hydrostatic pressure, in case of the presence of a groundwater table; that is why they are mostly designed in the form of a circular hollow section. Concrete cylinders face a complicated case of loading in fire condition, as a result of material degradation in addition to thermally induced stresses. This paper studies buckling stability of that case where, a concrete cylinder is subjected to an internal fire load in addition to superimposed structural loads from the surrounding environment. The main objective of the research is to study buckling stability of concrete cylinders through identifying various structural and thermal parameters, controlling that behaviour. Finite element modelling using "Ansys 18.1" has been chosen as an approach to deal with the research problem. Twenty-five solid elements models have been prepared to study both thermal and structural behaviour of concrete cylinders in fire condition. Cylinder thickness, slenderness ratio, load ratio, and groundwater presence have been adopted as main research parameters to identify their effect on well's fire buckling endurance, in accordance with ISO 834 standard fire curve. A parametric study has been designed to study fire endurance vulnerability to cylinder thickness ranging from 50 mm up to 800 mm; diameter to thickness ratio [D/t] ranging from "10" up to "160"; full spectrum of structural load ratios; in addition to the presence of a surrounding groundwater. Outputs of the parametric study have been introduced in the form of figures, which could be used as preliminary design aids to identify buckling fire endurance as function of load ratio for various spectrums of thickness and slenderness ratios. Moreover, critical thicknesses and load ratios have been revealed
Vancomycin Resistant Enterococci (VRE) among Non–Hospitalized Individuals in Gaza City, Palestine
Objectives: This study was conducted to investigate the occurrence of VRE among non–hospitalized individuals and to evaluate the public awareness of the globally escalating issue of antibiotics resistance.
Methods: One hundred non-hospitalized individuals were interviewed and stool sample was collected from each during the period between January and June, 2006. Isolation of Enterococci was performed according to standard method. Each Enterococcus isolate was subjected to vancomycin susceptibility test. Results were statistically analyzed using SPSS software
Results: We obtained 84 enterococcal isolates out of one hundred stool sample, 32.1% of them were resistant to vancomycin. No significant difference between male and female, level of education, hospitalization, age and Enterococcus carriage or VRE. Higher percentage of VRE was observed among those who were previously admitted to hospitals.
Conclusions: A high percentage of Vancomycin resistance was demonstrated among Enterococcus spp. isolated from non-hospitalized individuals. No single risk factor could be attributed to acquiring VRE. Therefore, we may conclude that the general population is equally exposed
MEASURING THE COGNITIVE STRUCTURE OF GFL (GERMAN FOREIGN LANGUAGE) HIGH AND LOW ACHIEVED STUDENTS AT THE FACULTY OF EDUCATION THROUGH WAT (WORD ASSOCIATION TEST)
The current research aims to determine the cognitive structure of GFL high and low achieved students. The researcher employed WAT (Word Association Test) on 26 students at the second level. An Achievement Test was used to define the GFL high and low achieved students. WAT (Word Association Test) was implemented to investigate the cognitive structure of the students. Qualitative and quantitative analyses of data were used. Implications for GFL teacher education were presented. Article visualizations
Intraoperative ERCP for Management of Gallbladder and Common Bile Duct Stones
It is not an uncommon scenario to have CBD stones in association with gallbladder stones. There is a general agreement in the surgical society that CBD stones should be removed. The classic option is to do open cholecystectomy and CBD exploration. With the emergence of minimally invasive surgery, namely laparoscopic cholecystectomy and ERCP, the therapist has better option to treat such patients such as preoperative ERCP, postoperative ERCP, and laparoscopic CBD exploration. The latest advance in that field is the use of ERCP at the time of laparoscopic cholecystectomy, i.e. intraoperative ERCP. This chapter with discuss the issue of minimally invasive management of cholecystocholedocholithiasis stressing on intraoperative ERCP
Deformations of R.C.Circular Slabs in Fire Condition
Reinforced concrete slabs are elements in direct contact with superimposed loads, having high surface area and small thickness. Such a condition makes slabs highly vulnerable to fire conditions. Fire results in exaggerated deformations in reinforced concrete slabs, as a result of material deterioration and thermal induced stresses. The main objective of this paper is to deeply investigate how circular R.C. slabs, of different configurations, behave in fire condition. That objective has been achieved through finite element modelling. Thermal-structural finite element models have been prepared, using "Ansys". Finite element models used solid elements to model both thermal and structural slab behaviour. Structural loads had been applied, representing slab operational loads, then thermal loads were applied in accordance with ISO 843 fire curve. Outputs in the form of deflection profile and edge rotation have been extracted out of the models to present slab deformations. A parametric study has been conducted to figure out the significance of various parameters such as; slab depth, slenderness ratio, load ratio, and opening size; regarding slab deformations. It was found that deformational behaviour differs significantly for slabs of thickness equal or below 100 mm, than slabs of thickness equal or above 200 mm. On the other hand considerable changes in slabs behaviour take place after 30 minutes of fire exposure for slabs of thickness equals or below 100 mm, while such changes delay till 60 minutes for slabs of thickness equals or above 200 mm
Quantitative Static Analysis of Communication Protocols using Abstract Markov Chains
International audienceIn this paper we present a static analysis of probabilistic programs to quantify their performance properties by taking into account both the stochastic aspects of the language and those related to the execution environment. More particularly, we are interested in the analysis of communication protocols in lossy networks and we aim at inferring statically parametric bounds of some important metrics such as the expectation of the throughput or the energy consumption. Our analysis is formalized within the theory of abstract interpretation and soundly takes all possible executions into account. We model the concrete executions as a set of Markov chains and we introduce a novel notion of abstract Markov chains that provides a finite and symbolic representation to over-approximate the (possi-bly unbounded) set of concrete behaviors. We show that our proposed formalism is expressive enough to handle both probabilistic and pure non-deterministic choices within the same semantics. Our analysis operates in two steps. The first step is a classic abstract interpretation of the source code, using stock numerical abstract domains and a specific automata domain, in order to extract the abstract Markov chain of the program. The second step extracts from this chain particular invari-ants about the stationary distribution and computes its symbolic bounds using a parametric Fourier-Motzkin elimination algorithm. We present a prototype implementation of the analysis and we discuss some preliminary experiments on a number of communication protocols. We compare our prototype to the state-of-the-art probabilistic model checker Prism and we highlight the advantages and shortcomings of both approaches
Study of risk factors for erectile dysfunction in patients with type 2 diabetes mellitus: Correlation to serum testosterone level
Background: Diabetes mellitus (DM) is one of the most frequent etiologies of erectile dysfunction (ED). Risk factors of ED in type 2 diabetes mellitus (T2 DM) include patient age, disease duration, sedentary life and glycemic control. Subnormal testosterone concentrations contribute to ED as testosterone regulatesnearly every component of erectile function.The aim of the work was to study the age of the patient, duration of diabetes mellitus, body mass index (BMI), glycosylated hemoglobin (HbAIc) and urinary albumin creatinine ratio (uACR) in type 2 male diabetic patients as risk factors for erectile dysfunction and their relation to serum testosterone level.Patients and methods: This study was conducted on 100 male type 2 diabetics selected from inpatient department and out patient clinics of the Internal Medicine Department in Menoufia University Hospital. The patients were divided into two groups: Group 1: 50 patients with type 2 DM with erectile dysfunction and Group 2: 50 patientswith type 2 DMwithout erectile dysfunction. The study groups were subjected to thorough history with special emphasis on age of the patients, disease duration and investigations including testosterone level, glycosylated hemoglobin, and uACR. The patients answered the abridged 5-item version of the International Index of Eectile Function (IIEF-5) questionnaire.Results: Total serum testosterone was significantly lower in diabetics with ED compared to those without ED. HbAIc, diabetes duration and uACR were independently negatively correlated with testosterone level.Conclusion: The diabetes duration, glycemic control and uACR contribute to erectile dysfunction in type 2 diabetics, and they were independently and negatively correlated with total serum testosterone level.Keywords: Type 2 diabetes mellitus, Erectile dysfunction, Serum testosteron
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