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53 Pags.- 16 Figs. The definitive version is available at: http://ascelibrary.org/journal/jhend8 ; Fast flows and avalanches of rock and debris are among the most dangerous of all landslide processes. Understanding and predicting postfailure motion (runout) of this kind of flowlike landslides is thus key for risk assessment, justifying the development of numerical models able to simulate their dynamics. In this paper a numerical method for the resolution of the depth-averaged debris flow model is presented. This set of nonlinear differential equations is formed by a variation of the shallow water equations, including strong bed slope, and a rheology resistance term. This paper focus on the numerical discretization of the resistance term, exploring three different approximations: pointwise, implicit, and unified. Well balance between numerical flux and source terms is only achieved using the unified discretization. In order to avoid nonphysical values of the water depth and discharge, a limitation of the unified resistance term is also needed. This correction is made following three conditions that identify the physical boundaries of the resistance term in the debris flow. This technique does not affect the computational efficiency of the method, keeping the original time step. Furthermore, proposed analytical test cases show that the three resistance limitations do not significantly perturb the numerical solution. The properties of the resulting numerical scheme are studied using a set of numerical experiments that include steady and transient flows. The results show the convenience of the unified discretization and the need of the three-condition limitation in order to avoid unphysical solutions. ; This research was supported by project Changing RISKS(OPE00446/PIM2010ECR-54900726)financed by EU FP7 ERANET CIRCLE Programme,and Grupo de Excelencia E68550 financed by the Aragón Government and the European Social Fund(ESF). ; CIRCLE Project reference:SSA-011793 ; Peer reviewed

We have combined the methods of probabilistic risk analysis and optimization to devise a technique suitable for the efficient treatment of uncertainties (or the effects of random fluctuations) in the design and analysis of mathematically describable processes. The key step is the approximation, by a multivariable Taylor series expansion, of the influence of random variables on the objective function. Statistical averaging of this expansion leads to a description of the objective function in terms of the moments of the random variables. Knowledge or estimation of these moments allows the optimization to be carried out using standard calculus based techniques. An example is treated with three variations to illustrate the use of this technique for nonlinear sets of equations and objective functions. The method presented here is applicable to process models in manufacturing, systems analysis, and risk analysis.

IntroductionProven resistance against HIV drugs, either by phenotyping or genotyping is a rare event in clinical trials. The overall assumption of drug resistance disappearing is additionally driven by the recommendations to screen for transmitted drug resistance, leading to large numbers of examinations with relatively low rates of resistance. Goal of our analysis was to assess if drug resistance in treatment failure is also decreasing outside of clinical trials.Materials and MethodsThe MIB database at timepoint of analysis consists of data from 2876 HIV infected patients. Besides various laboratory parameters, clinical data and treatment history is included. HIV‐1 protease and reverse transcriptase sequences were analyzed using the HIV‐GRADE drug resistance algorithm. As in only a small number of patients genotypic resistance testing for integrase inhibitors was performed, mainly due to reimbursement reasons, it was assumed that failing treatment on a previous integrase inhibitor containing regimen is equate to resistance.ResultsOf the 2876 patients in the database, 220 had a treatment change due to treatment failure between 2009 and 2012, a genotypic resistance testing at an appropriate timepoint of maximum four weeks before treatment change and a treatment duration of at least six months before treatment failure. In 2009, 61% of patients showed no drug resistance while 39% showed resistance against one or more drug classes (two or more drug classes: 19.5%; three or more drug classes: 2.4%, four drug classes 2.4%). In 2012, no resistance was found in 52% of patients while resistance against three or more drug classes was found in nearly 14% of patients (one or more: 48%; two or more 23%; four classes: 4.5%).ConclusionsTreatment failure with viral load sufficiently high for drug resistance testing was not frequently observed in our database. Nevertheless, treatment failure was often associated with drug resistance against at least one drug class. With more use of the newer drug classes, resistance against those new classes will become more common and rates of multiclass resistance will be increasing.

In this work we perform a numerical study on the flow around the hulls of competition kayaks with the aim of predicting accurate drag forces. The numerical simulations were first performed using the Wigley hull geometry, a typical validation case for flows around marine vessels. The total drag force and wave profiles of the hull were determined for different Froude numbers and compared with experimental measurements. After validation and verification of the numerical method, the flow around two competition sprint kayaks was investigated. The drag force was calculated and compared with experimental and numerical data

In der Finanzmathematik hat der Besitzer einer amerikanische Option das Recht aber nicht die Pflicht, eine Aktie innerhalb eines bestimmten Zeitraums, für einen bestimmten Preis zu kaufen oder zu verkaufen. Die Bewertung einer amerikanische Option wird als so genanntes optimale stopping Problem formuliert. Erfolgt die Modellierung des Aktienkurses durch eine geometrische Brownsche Bewegung, wird der Wert einer amerikanischen Option durch ein deterministisches freies Randwertproblem (FRWP), oder einer äquivalenten Variationsungleichung (VU) auf ganz R in gewichteten Sobolev Räumen gegeben. Um Standardmethoden der Numerischen Mathematik anzuwenden, wird das unbeschränkte Gebiet zu einem beschränkten Gebiet abgeschnitten. Mit Hilfe der Fourier-Transformation wird eine Integraldarstellung der Lösung die den freien Rand explizit beinhaltet, hergeleitet. Mittels dieser Integraldarstellung werden Abschneidefehlerschranken bewiesen. Danach werden gewichtete Poincare Ungleichungen mit expliziten Konstanten bewiesen. Der Abschneidefehler und die gewichtete Poincare Ungleichung ermöglichen, einen zuverlässigen a posteriori Fehlerschätzer zwischen der exakten Lösung der VU und der semidiskreten Lösung des penalisierten Problems auf R herzuleiten. Eine hinreichend glatte Lösung der VU garantiert die Konvergenz der Lösung des penaltisierten Problems zur Lösung der VU...

This study investigates treatment resistance in several subpopulations of female offenders in substance abuse treatment programs. Using the Correctional Treatment Resistance Scale, data from 153 adult female inmates were analyzed according to ethnic and treatment group differences. It was found that treatment resistance was consistent across treatment groups, but elevated resistance scores were observed for Black and Hispanic female offenders. Implications of the results are discussed for counselor preparation, treatment planning, and pretreatment orientation when female offenders from diverse backgrounds are in substance abuse treatment programs.

AbstractMany optimization problems occur in both theory and practice when one has to optimize an objective function while an infinite number of constraints must be satisfied. The aim of this paper in to describe methods of handling such problems numerically in an effective manner. We also indicate a number of applications.

Despite recent cost-containment pressures, 28-day inpatient treatment continues to predominate in the field of alcoholism treatment. This paper presents some clinical, pragmatic and fiscal disadvantages of the inpatient model. Day treatment is discussed as an alternative modality and the results of a study supporting day treatment are also presented. Several hypotheses to explain the continued predominance of inpatient treatment are offered.