75 research outputs found
The maximum of the local time of a diffusion process in a drifted Brownian potential
We consider a one-dimensional diffusion process in a
-drifted Brownian potential for . We are interested
in the maximum of its local time, and study its almost sure asymptotic
behaviour, which is proved to be different from the behaviour of the maximum
local time of the transient random walk in random environment. We also obtain
the convergence in law of the maximum local time of under the annealed law
after suitable renormalization when . Moreover, we characterize
all the upper and lower classes for the hitting times of , in the sense of
Paul L\'evy, and provide laws of the iterated logarithm for the diffusion
itself. To this aim, we use annealed technics.Comment: 38 pages, new version, merged with hal-00013040 (arXiv:math/0511053),
with some additional result
From offender to victim-oriented monitoring : a comparative analysis of the emergence of electronic monitoring systems in Argentina and England and Wales
The increasingly psychological terrain of crime and disorder management has had a transformative impact upon
the use of electronic monitoring technologies. Surveillance technologies such as electronic monitoring ‑ EM,
biometrics, and video surveillance have flourished in commercial environments that market the benefits of
asocial technologies in managing disorderly behavior and which, despite often chimerical crime prevention
promises, appeal to the ontologically insecure social imagination. The growth of EM in criminal justice has
subsequently taken place despite, at best, equivocal evidence that it protects the public and reduces recidivism.
Innovative developments in Portugal, Argentina and the United States have re-imagined EM technologies
as more personalized devices that can support victims rather than control offenders. These developments
represent a re-conceptualization of the use of the technology beyond the neoliberal prism of rational choice
theories and offender-oriented thinking that influenced first generation thinking about EM. This paper
identifies the socio-political influences that helped conceptualize first generation thinking about EM as, firstly,
a community sentence and latterly, as a technique of urban security. The paper reviews attempts to theorize
the role and function of EM surveillance technologies within and beyond criminal justice and explores the
contribution of victimological perspectives to the use of EM 2.0
Project AUTONOMAD : The design of an unmanned coast guard vessel integrating the use of drones for emission regulation enforcement and territorial water protection in the Mediterranean
Project AUTONOMAD examines the design of an unmanned trimaran vessel for unmanned application, integrating the deployment, recovery and storage of various Unmanned Aerial Vehicles (UAVs) and Unmanned Surface Vehicles (USVs). It is tailor made for the needs of EU Coastguards in order to provide a platform for emission regulation enforcement, maritime monitoring and surveillance in the Mediterranean. This project includes the design of the unmanned vessel, the selection of its payload and the integration of the unmanned technologies in order to create a robust and reliable engineering system. The feasibility of such a vessel is then assessed in terms of reliability and overall benefit
Copolymer with pinning: variational characterization of the phase diagram
This paper studies a polymer chain in the vicinity of a linear interface
separating two immiscible solvents. The polymer consists of random monomer
types, while the interface carries random charges. Both the monomer types and
the charges are given by i.i.d. sequences of random variables. The
configurations of the polymer are directed paths that can make i.i.d.
excursions of finite length above and below the interface. The Hamiltonian has
two parts: a monomer-solvent interaction ("copolymer") and a monomer-interface
interaction ("pinning"). The quenched and the annealed version of the model
each undergo a transition from a localized phase (where the polymer stays close
to the interface) to a delocalized phase (where the polymer wanders away from
the interface). We exploit the approach developed in [5] and [3] to derive
variational formulas for the quenched and the annealed free energy per monomer.
These variational formulas are analyzed to obtain detailed information on the
critical curves separating the two phases and on the typical behavior of the
polymer in each of the two phases. Our main results settle a number of open
questions.Comment: 46 pages, 9 figure
Unseen roots and unfolding flowers? Prison learning, equality and the education of socially excluded groups
The objective of this theoretical article is to critique the notion that adult education, in its current marketised formations, might serve the purpose of rehabilitating learners. To date there has been no detailed interrogation by educationalists of the desirability of rehabilitation as an overarching aim for prison education, or to consider the existing educational philosophies that notions of rehabilitation might cohere with. This article begins to address this gap by engaging with the idea of rehabilitation from a critical adult education perspective. The conceptual framework informing the analysis is critical adult education theory, drawing tangentially on the work of Raymond Williams. The overarching assumption is that education might be understood as the practice of equality, which I employ alongside conceptualisations of empowering adult literacies learning as drawn from writings in the field of New Literacies Studies (NLS). These approaches enable the critique of criminological theory associated with prison learning, alongside the critique of assumptions traceable to NLS. The analysis focuses more specifically on Scotland’s prison system, where the criminological theory of ‘desistance’ currently holds some sway. I observe that whilst perspectives of criminologists and educationists draw upon similar sociological assumptions and underpinnings, different conclusions are inferred about the purpose and practice of adult learning. Here criminologists' conceptualisations tend to neglect power contexts, instead inferring educational practices associated typically with early years education. I also demonstrate the importance of equality in the context of adult education, if educators are to take responsibility for the judgements they make in relation to the education of socially excluded groups
From the outside in: narratives of creative arts practitioners working in the criminal justice system
This is an accepted manuscript of an article published by Wiley-Blackwell in The Howard Journal of Crime and Justice on 31/12/2019, available online: https://doi.org/10.1111/hojo.12318
The accepted version of the publication may differ from the final published version.The penal voluntary sector is highly variegated in its roles, practices and functions, though research to date has largely excluded the experiences of front-line practitioners. We argue that engaging with the narratives of practitioners can provide fuller appreciation of the potential of the sector’s work. Though life story and narrative have been recognised as important in offender desistance (Maruna, 2001), the narrative identities of creative arts practitioners, who are important ‘change agents’ (Albertson, 2015), are typically absent. This is despite evidence to suggest that a practitioner’s life history can be a significant and positive influence in the rehabilitation of offenders (Harris, 2017). Using narratological analysis (Bal, 2009), this study examined the narratives of 19 creative practitioners in prisons in England and Wales. Of particular interest were the formative experiences of arts practitioners in their journey to prison work. The findings suggest that arts practitioners identify with an ‘outsider’ status and may be motivated by an ethic of mutual aid. In the current climate of third sector involvement in the delivery of criminal justice interventions, such a capacity may be both a strength and weakness for arts organisations working in this field
Single-dose administration and the influence of the timing of the booster dose on immunogenicity and efficacy of ChAdOx1 nCoV-19 (AZD1222) vaccine: a pooled analysis of four randomised trials.
BACKGROUND: The ChAdOx1 nCoV-19 (AZD1222) vaccine has been approved for emergency use by the UK regulatory authority, Medicines and Healthcare products Regulatory Agency, with a regimen of two standard doses given with an interval of 4-12 weeks. The planned roll-out in the UK will involve vaccinating people in high-risk categories with their first dose immediately, and delivering the second dose 12 weeks later. Here, we provide both a further prespecified pooled analysis of trials of ChAdOx1 nCoV-19 and exploratory analyses of the impact on immunogenicity and efficacy of extending the interval between priming and booster doses. In addition, we show the immunogenicity and protection afforded by the first dose, before a booster dose has been offered. METHODS: We present data from three single-blind randomised controlled trials-one phase 1/2 study in the UK (COV001), one phase 2/3 study in the UK (COV002), and a phase 3 study in Brazil (COV003)-and one double-blind phase 1/2 study in South Africa (COV005). As previously described, individuals 18 years and older were randomly assigned 1:1 to receive two standard doses of ChAdOx1 nCoV-19 (5 × 1010 viral particles) or a control vaccine or saline placebo. In the UK trial, a subset of participants received a lower dose (2·2 × 1010 viral particles) of the ChAdOx1 nCoV-19 for the first dose. The primary outcome was virologically confirmed symptomatic COVID-19 disease, defined as a nucleic acid amplification test (NAAT)-positive swab combined with at least one qualifying symptom (fever ≥37·8°C, cough, shortness of breath, or anosmia or ageusia) more than 14 days after the second dose. Secondary efficacy analyses included cases occuring at least 22 days after the first dose. Antibody responses measured by immunoassay and by pseudovirus neutralisation were exploratory outcomes. All cases of COVID-19 with a NAAT-positive swab were adjudicated for inclusion in the analysis by a masked independent endpoint review committee. The primary analysis included all participants who were SARS-CoV-2 N protein seronegative at baseline, had had at least 14 days of follow-up after the second dose, and had no evidence of previous SARS-CoV-2 infection from NAAT swabs. Safety was assessed in all participants who received at least one dose. The four trials are registered at ISRCTN89951424 (COV003) and ClinicalTrials.gov, NCT04324606 (COV001), NCT04400838 (COV002), and NCT04444674 (COV005). FINDINGS: Between April 23 and Dec 6, 2020, 24 422 participants were recruited and vaccinated across the four studies, of whom 17 178 were included in the primary analysis (8597 receiving ChAdOx1 nCoV-19 and 8581 receiving control vaccine). The data cutoff for these analyses was Dec 7, 2020. 332 NAAT-positive infections met the primary endpoint of symptomatic infection more than 14 days after the second dose. Overall vaccine efficacy more than 14 days after the second dose was 66·7% (95% CI 57·4-74·0), with 84 (1·0%) cases in the 8597 participants in the ChAdOx1 nCoV-19 group and 248 (2·9%) in the 8581 participants in the control group. There were no hospital admissions for COVID-19 in the ChAdOx1 nCoV-19 group after the initial 21-day exclusion period, and 15 in the control group. 108 (0·9%) of 12 282 participants in the ChAdOx1 nCoV-19 group and 127 (1·1%) of 11 962 participants in the control group had serious adverse events. There were seven deaths considered unrelated to vaccination (two in the ChAdOx1 nCov-19 group and five in the control group), including one COVID-19-related death in one participant in the control group. Exploratory analyses showed that vaccine efficacy after a single standard dose of vaccine from day 22 to day 90 after vaccination was 76·0% (59·3-85·9). Our modelling analysis indicated that protection did not wane during this initial 3-month period. Similarly, antibody levels were maintained during this period with minimal waning by day 90 (geometric mean ratio [GMR] 0·66 [95% CI 0·59-0·74]). In the participants who received two standard doses, after the second dose, efficacy was higher in those with a longer prime-boost interval (vaccine efficacy 81·3% [95% CI 60·3-91·2] at ≥12 weeks) than in those with a short interval (vaccine efficacy 55·1% [33·0-69·9] at <6 weeks). These observations are supported by immunogenicity data that showed binding antibody responses more than two-fold higher after an interval of 12 or more weeks compared with an interval of less than 6 weeks in those who were aged 18-55 years (GMR 2·32 [2·01-2·68]). INTERPRETATION: The results of this primary analysis of two doses of ChAdOx1 nCoV-19 were consistent with those seen in the interim analysis of the trials and confirm that the vaccine is efficacious, with results varying by dose interval in exploratory analyses. A 3-month dose interval might have advantages over a programme with a short dose interval for roll-out of a pandemic vaccine to protect the largest number of individuals in the population as early as possible when supplies are scarce, while also improving protection after receiving a second dose. FUNDING: UK Research and Innovation, National Institutes of Health Research (NIHR), The Coalition for Epidemic Preparedness Innovations, the Bill & Melinda Gates Foundation, the Lemann Foundation, Rede D'Or, the Brava and Telles Foundation, NIHR Oxford Biomedical Research Centre, Thames Valley and South Midland's NIHR Clinical Research Network, and AstraZeneca
- …
