Identification of modulus of subgrade reaction of soils at pile/soil interface.

This thesis deals with the determination of modulus of subgrade reaction for sandy and clayey soils surrounding laterally loaded short piles. The initial value of modulus of subgrade reaction determined in the laboratory is based on Terzaghi\u27s method. The differences in lateral displacement of laboratory models and their numerical equivalents are associated with inaccurately determined values of modulus of subgrade reaction. The rectification of k which guaranties the same value of horizontal displacement of top pile point in laboratory experiment and its numerical equivalent is performed in the scope of sensitivity theory.Dept. of Civil and Environmental Engineering. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis1998 .S45. Source: Masters Abstracts International, Volume: 39-02, page: 0554. Adviser: Barbara Budkowska. Thesis (M.A.Sc.)--University of Windsor (Canada), 1998

The Distribution of Minimum of Ratios of Two Random Variables and Its Application in Analysis of Multi-hop Systems

The distributions of random variables are of interest in many areas of science. In this paper, ascertaining on the importance of multi-hop transmission in contemporary wireless communications systems operating over fading channels in the presence of cochannel interference, the probability density functions (PDFs) of minimum of arbitrary number of ratios of Rayleigh, Rician, Nakagami-m, Weibull and α-µ random variables are derived. These expressions can be used to study the outage probability as an important multi-hop system performance measure. Various numerical results complement the proposed mathematical analysis

Moment asymptotics for multitype branching random walks in random environment

We study a discrete time multitype branching random walk on a finite space with finite set of types. Particles follow a Markov chain on the spatial space whereas offspring distributions are given by a random field that is fixed throughout the evolution of the particles. Our main interest lies in the averaged (annealed) expectation of the population size, and its long-time asymptotics. We first derive, for fixed time, a formula for the expected population size with fixed offspring distributions, which is reminiscent of a Feynman-Kac formula. We choose Weibull-type distributions with parameter 1/pij for the upper tail of the mean number of j type particles produced by an i type particle. We derive the first two terms of the long-time asymptotics, which are written as two coupled variational formulas, and interpret them in terms of the typical behavior of the system

Étude de l'impact des prophages sur la biologie de Clostridium difficile

La bactérie Clostridium difficile est maintenant considérée comme un pathogène majeur responsable d'infections nosocomiales en Amérique du Nord et en Europe. De plus, l'émergence de souches hypervirulentes, telle la souche NAP1/027 responsable de récentes épidémies, est un phénomène inquiétant. Un enjeu crucial au cours des prochaines années sera de mieux comprendre les mécanismes de virulence et d'évolution de C. difficile. Les bactériophages (c.-à-d. des virus bactériens, ou phages) sont des joueurs clés dans l'évolution de la plupart des bactéries, pathogènes ou non. Les données concernant l'impact des phages sur C. difficile sont très limitées. Par contre, deux études récentes démontrent que les phages semblent influencer la virulence de C. difficile en altérant la production de toxines TcdA et TcdB. L'objectif de mes travaux de recherche est donc d'étudier au niveau microbiologique et moléculaire les phages de C. difficile et de démontrer leur impact sur l'évolution et la virulence de ce pathogène. Dans ce contexte, plusieurs phages ont été induits à partir d'isolats cliniques de C. difficile. Dans cette collection, un phage en particulier, le (pCD38-2, a été choisi pour la caractérisation subséquente dû à sa divergence génomique par rapport aux autres phages et à sa capacité d'infecter la grande majorité des souches ayant le ribotype hypervirulent (027). Ces caractéristiques uniques ont justifié le séquençage complet de son génome. Par contre, aucun facteur de virulence évident n'a été identifié. À l'opposé, une analyse bio-informatique a permis l'identification d'une région spécifique comportant plusieurs gènes de conversion lysogénique potentiels. L'impact de ces gènes sur la virulence bactérienne reste à être déterminé. De plus, lorsqu'on introduit le phage cpCD38-2 dans la souche sensible CD274, on observe une accumulation plus rapide et plus grande des toxines après 48h dans le surnageant de la culture. Ce phénomène a été confirmé avec des tests ELISA sur des réplicas biologiques indépendants ainsi que par un immunodosage avec anticorps spécifiques aux deux toxines. Par ailleurs, une étude transcriptionelle par PCR en temps réel a permis de constater que le phage (pCD38-2 influence également l'expression des gènes tcdA et tcdB dans le temps. Par contre, l'effet du phage cpCD38-2 est variable lorsqu'on l'introduit dans d'autres souches de C. difficile. Donc, les résultats de nos travaux indiquent que certains phages auraient un impact sur la virulence de C. difficile en altérant la production et la transcription des gènes de toxines. Nos données laissent toutefois sous-entendre que cet effet peut varier selon les souches de C. difficile. [Symboles non conformes

PERFORMANCE ANALYSIS OF DUAL-BRANCH SELECTION DIVERSITY SYSTEM USING NOVEL MATHEMATICAL APPROACH

In this paper, novel mathematical approach for evaluation of probability density function (PDF) of instantaneous signal-to-interference ratio (SIR) at the receiver output in interference-limited environment is proposed. Dual-branch selection combining (SC) receiver operating over correlated Weibull fading channels applying SIR algorithm is considered. Analytical expression for joint PDF of desired signal and interference at the receiver output is derived and used for evaluation of PDF of instantaneous SIR. The expression for PDF of SIR is used for system performance analysis via outage probability, average bit error probability (ABEP) and average output SIR as system performance measures. Numerical results are graphically presented showing the effects of fading severity, average SIR at the input and level of correlation on the diversity receiver performance. In addition, results obtained for the PDF of instantaneous SIR in this paper, are compared to the results when the PDF of instantaneous SIR is directly calculated

Which medical disciplines diagnose and treat melanoma in Europe in 2019? A survey of experts from melanoma centres in 27 European countries

Background and objectives The incidence of melanoma is increasing. This places significant burden on societies to provide efficient cancer care. The European Cancer Organisation recently published the essential requirements for quality melanoma care. The present study is aimed for the first time to roughly estimate the extent to which these requirements have been met in Europe. Materials and methods A web-based survey of experts from melanoma centres in 27 European countries was conducted from 1 February to 1 August 2019. Data on diagnostic techniques, surgical and medical treatment, organization of cancer care and education were collected and correlated with national health and economic indicators and mortality-to-incidence ratio (MIR) as a surrogate for survival. Univariate linear regression analysis was performed to evaluate the correlations. SPSS software was used. Statistical significance was set at P < 0.05. Results The MIR was lower in countries with a high health expenditure per capita and with a higher numbers of general practitioners (GPs) and surgeons (SURG) per million inhabitants. In these countries, GPs and dermatologists (DER) were involved in melanoma detection; high percentage of DER used dermatoscopy and were involved in the follow-up of all melanoma stages; both medical oncologists (ONC) and dermato-oncologists administered systemic treatments; and patients had better access to sentinel lymph node biopsy and were treated within multidisciplinary tumour boards. Conclusion Based on these first estimates, the greater involvement of GPs in melanoma detection; the greater involvement of highly trained DER in dermatoscopy, dermatosurgery, follow-up and the systemic treatment of melanoma; and the provision of ongoing dermato-oncology training for pathologists, SURG, DER and ONC are necessary to provide an optimal melanoma care pathway. A comprehensive analysis of the melanoma care pathway based on clinical melanoma registries will be needed to more accurately evaluate these first insights

Impact of freezing and pasteurization on antioxidative enzymes in milk of preterm infants' mothers

Background and Aims: Human milk (HM) feeding has an important role in prevention of oxydative stress in preterm infants. Human milk is a complex biological fluid with an antioxidative function. Antioxidative enzymes present in HM are superoxid dismutase (SOD), glutatione peroxidase (GSH-Px) and glutatione reductase (GR). Evaluation of antioxidative enzymes (SOD, GSH-Px, GR) in HM after heat treatment, ie pasteurisation of donor HM previously freezed for 7 days in HM bank, using spectrophotometric methods. Methods: Cohort study enrolled 30 mothers of preterm neonates (birth before 37 weeks of gestational age) that established lactation. Antioxidative activity of enzymes in milk samples before and after the heat treatment was measured with spectrophotometric methods. Study protocol was approved by Ethical Comittee of Institute for neonatology, all mothers gave their written consent prior to participation. Study was supported by Ministry of education, science and tehchnological development, Serbia. Results: SOD, GSH-Px and GR acitivity was significantly higher in fresh mature milk samples compared to mature, frozen for seven days and then pasteurised, milk of mothers of preterm infants (p<0,001). Conclusions: Process of heat treatment and/or storage of mature milk of mothers of preterm infants reduce enzyme acitivity of HM, thereby decreasing total antioxidative capacity. This implies that it would be optimal to feed the preterm infants with fresh fortified HM whenever possible

Evaluation of total antioxidative capacity in milk of mothers of preterm infants during lactation

Objectives and Study: Human milk (HM) is a complex biological fluid with an antioxidative function. HM feeding has an important role in prevention of antioxidative stress in preterm infants. Evaluation of total antioxidative capacity (TAC) in milk of mothers f preterm infants during lactation (colostrum, transitional and mature milk). Methods: Thirty mothers of preterm infants (infants born before 37 weeks of gestational age) who established lactation were enrolled in this cohort study. TAC of colostrum, transitional and mature milk of these mothers was evaluated using the fluorimetric method of determination of antioxidative capacity of oxygen radical absorption (ORAC). Study protocol was approved by Ethical Comittee of Institute for neonatology, all mothers gave their written consent prior to participation. Study was supported by Ministry of education, science and tehchnological development, Serbia. Results: ORAC method showed that TAC was highest in colostrum, gradual decrease was registered during lactation until reaching its lowest level in mature milk. Conclusions: Significant changes in antioxidative characteristics of human milk occur during the lactation period. Colostrum has a higher TAC compared to mature milk, as shown with ORAC method. This result distinguishes colostrum as a superior sample of HM, indicating its importance in nutrition of preterm infants.ESPGHAN 55th Annual Meeting of the European Society for Paediatric Gastroenterology, Hepatology and Nutrition, 17-20 May 2023, Vienna, Austri

Performance analysis of dual-branch selection diversity receiver that uses desired signal algorithm in correlated Weibull fading environment

Rad je usmjeren na analizu karakteristika višestrukog sustava selektivnog kombiniranja (SC) s dvije grane gdje su i interferencija željenog signala i ko-kanalna interferencija (CCI) izložene Weibull fedingu. Za slučaj kada se algoritam željenog signala rabi kao kriterij za donošenje odluke izvedeni su izrazi zatvorenog oblika za zajedničku funkciju raspodjele vjerojatnosti (PDF) željenog signala i interferencije kao i PDF za trenutačni odnos signal-interferencija (SIR) na izlazu sustava. Ovi se izrazi rabe za analizu karakteristika cijeloga sustava rabeći vjerojatnost otkaza sustava, prosječnu vjerojatnost greške bita (ABEP) i prosječni izlaz SIR kao mjere za karakteristike sustava. Konačno, rezultati dobiveni u ovom radu uspoređeni su s ranije objavljenim rezultatima za isti sustav koji rabi algoritam na bazi SIR-a.This paper focuses on performance analysis of dual-branch selection combining (SC) diversity system where both, desired signal as well as co-channel interference (CCI), are subjected to Weibull fading. For the case when desired signal algorithm is used as decision criterion, closed form expressions for joint probability density function (PDF) of desired signal and interference as well as PDF for instantaneous signal-to-interference ratio (SIR) at the system output are derived. These expressions are used for overall system performance analysis using outage probability, average bit error probability (ABEP) and average output SIR as system performance measures. Finally, the results obtained in this paper are compared to the previously published results for the same system that uses SIR based algorithm