Maximizing the utility of peer support in carceral settings: A few stumbling blocks to consider

Emerging research advocates prison-based peer support programmes not only for the recipients of support but also for those providing it. Such programmes are founded on principles such as reciprocity, shared problem-solving and empathy. Accordingly, there have been recent claims that such structures may engender a magnified impact in carceral settings characterized by deprivation and adversity. Specifically, it has been argued that peer supporters garner opportunities to enact prosocial behaviours and consequently energize desistance narratives while serving time. However, as intrigue and optimism around this untapped resource grow, so too does the need to explore any hindrances that might halt progressive developments. This article presents data from qualitative interviews held with incarcerated peer supporters in the UK. Transcripts of the institutional challenges that participants faced when undertaking their roles were thematically analysed, and suggestions for practitioners are offered. The article calls for professionals and policy makers to further explore the redemptive potential of prison-based peer support

Patient-specific simulation of stent-graft deployment within an abdominal aortic aneurysm

In this study, finite element analysis is used to simulate the surgical deployment procedure of a bifurcated stent-graft on a real patient's arterial geometry. The stent-graft is modeled using realistic constitutive properties for both the stent and most importantly for the graft. The arterial geometry is obtained from pre-operative imaging exam. The obtained results are in good agreement with the post-operative imaging data. As the whole computational time was reduced to less than 2 hours, this study constitutes an essential step towards predictive planning simulations of aneurysmal endovascular surger

Statistical inverse problems for non-Gaussian vector valued random fields with a set of experimental realizations

International audienceThe railway track irregularities, which is a four dimensions vector-valued random field, are the main source of excitation of the train. At first, using a revisited Karhunen-Loève expansion, the considered random field is approximated by its truncated projection on a particularly well adapted orthogonal basis. Then, the distribution of the random vector that gathers the projection coefficients of the random field on this spatial basis is characterized using a polynomial chaos expansion. The dimension of this random vector being very high (around five hundred), advanced identification techniques are introduced to allow performing relevant convergence analysis and identification. Based on the stochastic modeling of the non- Gaussian non-stationary vector-valued track geometry random field, realistic track geometries, which are representative of the experimental measurements and representative of the whole railway network, can be generated. These tracks can then be introduced as an input of any railway software to characterize the stochastic behavior of any normalized train

Karhunen-Loève based sensitivity analysis

International audienceThe identification of the most dangerous combinations of excitations that a non-linear mechanical system can be confronted to is not an easy task. Indeed, in such cases, the link between the maximal values of the inputs and of the outputs is not direct, as the system can be more sensitive to a problematic succession of excitations of low amplitudes than to high amplitudes for each kind of excitations. This work presents therefore an innovative method to identify the combined shapes of excitations that are the most correlated to problematic responses of the studied mechanical system

Influence of the track geometry variability on the train behavior

International audienceThis paper is devoted to the development of a stochastic modeling of the track geometry and its identiication with experimental measurements. This modeleing, which has to integrate the statistical and spatial variabilities and dependencies , is a keyu issue when using simulation for conception, maintenance or certification purposes

Modeling the track geometry variability

International audienceAt its building, the theoretical new railway line is supposed to be made of perfect straight lines and curves. This track geometry is however gradually damaged and regularly subjected to maintenance operations. The analysis of these track irregularities is a key issue as the dynamic behaviour of the trains is mainly induced by the track geometry. In this context, this work is devoted to the development of a stochastic modeling of the track geometry and its identification with experimental measurements. Based on a spatial and statistical decomposition, this model allows the spatial and statistical variability and dependency of the track geometry to be taken into account. Moreover, it allows the generation of realistic track geometries that are representative of a whole railway network. These tracks can be used in any deterministic railway dynamic software to characterize the dynamic behavior of the train

Karhunen-Loeve expansion revisited for vector-valued random fields: scaling, errors and optimal basis

International audienceDue to scaling effects, when dealing with vector-valued random fields, the classical Karhunen-Loève expansion, which is optimal with respect to the total mean square error, tends to favorize the components of the random field that have the highest signal energy. When these random fields are to be used in mechanical systems, this phenomenon can introduce undesired biases for the results. This paper presents therefore an adaptation of the Karhunen- Loève expansion that allows us to control these biases and to minimize them. This original decomposition is first analyzed from a theoretical point of view, and is then illustrated on a numerical example

Codon 215 Mutations in Human Immunodeficiency Virus—Infected Pregnant Women

In 1994, the Pediatric AIDS Clinical Trials Group (PACTG) Protocol 076 demonstrated a two-thirds reduction of perinatal human immunodeficiency virus (HIV) type 1 transmission with zidovudine chemoprophylaxis. However, zidovudine alone does not fully suppress HIV replication, and chemoprophylaxis with zidovudine alone might select for zidovudine-resistant viral variants, decreasing the efficacy of zidovudine prophylaxis and affecting future responses to combined antiretroviral regimens. Sixty-two HIV-infected pregnant women consecutively enrolled in the ongoing Swiss HIV and Pregnancy Study were prospectively evaluated for the presence or development of zidovudine resistance by analysis of codon 215 of the reverse transcriptase gene. Six women (9.6%) harbored a codon T215Y/F mutation, which is associated with high-level resistance to zidovudine. Postnatal evaluation was completed in all children of mothers harboring the mutation. None was HIV-infected. The observed prevalence of codon 215 mutations of 9.6% raises important concerns regarding the future use of the PACTG 076 regime