Properties of continuous Fourier extension of the discrete cosine transform and its multidimensional generalization

A versatile method is described for the practical computation of the discrete Fourier transforms (DFT) of a continuous function $g(t)$ given by its values $g_{j}$ at the points of a uniform grid $F_{N}$ generated by conjugacy classes of elements of finite adjoint order $N$ in the fundamental region $F$ of compact semisimple Lie groups. The present implementation of the method is for the groups SU(2), when $F$ is reduced to a one-dimensional segment, and for $SU(2)\times ... \times SU(2)$ in multidimensional cases. This simplest case turns out to result in a transform known as discrete cosine transform (DCT), which is often considered to be simply a specific type of the standard DFT. Here we show that the DCT is very different from the standard DFT when the properties of the continuous extensions of these two discrete transforms from the discrete grid points $t_j; j=0,1, ... N$ to all points $t \in F$ are considered. (A) Unlike the continuous extension of the DFT, the continuous extension of (the inverse) DCT, called CEDCT, closely approximates $g(t)$ between the grid points $t_j$. (B) For increasing $N$, the derivative of CEDCT converges to the derivative of $g(t)$. And (C), for CEDCT the principle of locality is valid. Finally, we use the continuous extension of 2-dimensional DCT to illustrate its potential for interpolation, as well as for the data compression of 2D images.Comment: submitted to JMP on April 3, 2003; still waiting for the referee's Repor

Upstream-binding factor is sequestered into herpes simplex virus type 1 replication compartments

Previous reports have shown that adenovirus recruits nucleolar protein upstream-binding factor (UBF) into adenovirus DNA replication centres. Here, we report that despite having a different mode of viral DNA replication, herpes simplex virus type 1 (HSV-1) also recruits UBF into viral DNA replication centres. Moreover, as with adenovirus, enhanced green fluorescent protein-tagged fusion proteins of UBF inhibit viral DNA replication. We propose that UBF is recruited to the replication compartments to aid replication of HSV-1 DNA. In addition, this is a further example of the role of nucleolar components in viral life cycle

Reducing the Harm of Intimate Partner Violence: Randomized Controlled Trial of the Hampshire Constabulary CARA Experiment

Research Question: Among Southampton-area males arrested for and admitting to low-risk intimate partner violence as a first domestic offence and receiving a conditional caution, did a randomly assigned requirement to attend (with 5 to 7 other male offenders), two weekend day-long Cautioning and Relationship Abuse (CARA) workshops led by experienced professionals reduce the total severity of crime harm relative to a no-workshop control group? Data: Eligible offenders (N =293) were randomly assigned to the CARA workshop attendance requirement (n= 154) or to the no-workshop requirement (n = 139), with 91% of all cases receiving treatment as randomly assigned. Each offender’s records of police contact were tracked for exactly 365 days after the date of random assignment. Methods: All repeat arrests or complaints of crime naming the 293 randomly assigned offenders were coded by the Cambridge Crime Harm Index (CHI) as the primary outcome measure for each offender (Sherman et al 2016), with the sum of total days of recommended imprisonment for each offence (as the guideline starting point for sentencing) summed across all new offences, with both domestic and non-domestic relationships to their victims. Prevalence and frequency of repeat contact were also computed. All analysis was done by intention-to-treat. Findings: Offenders assigned to the workshop group were re-arrested for crimes with a total Crime Harm Index (CHI) value that was 27% lower than for re-arrests of offenders assigned to the control group (P =.011). The CARA workshop group members were arrested for crimes totalling an average of 8.4 days of recommended imprisonment under English sentencing guidelines, compared to an average of 11.6 days per offender assigned to the control group, the equivalent of 38% more harm without the workshop than with it. The effect size was much stronger, however, in the first study period of high caseflow (72% reduction in CHI, P = .001) than in the second period (21% reduction in CHI, P =.178). Frequency of re-arrest for domestic abuse (21% lower for workshop-assigned group) and prevalence (35% lower for workshop-assigned group) also favoured the CARA workshop group. Conclusions: The results of this one-year followup analysis suggest that the CARA workshops are an effective way to reduce the future harm of domestic abuse among first offenders who admit their crime, although effect size may vary over time. Given the highly restrictive eligibility criteria for the programme, these findings provide an evidence-based reason for testing the same treatment among a larger proportion of all first-offender arrests for domestic abuse. Keywords Intimate partner violence – policing – RCT—Crime Harm Index--CAR

On the application of optimal wavelet filter banks for ECG signal classification

This paper discusses ECG signal classification after parametrizing the ECG waveforms in the wavelet domain. Signal decomposition using perfect reconstruction quadrature mirror filter banks can provide a very parsimonious representation of ECG signals. In the current work, the filter parameters are adjusted by a numerical optimization algorithm in order to minimize a cost function associated to the filter cut-off sharpness. The goal consists of achieving a better compromise between frequency selectivity and time resolution at each decomposition level than standard orthogonal filter banks such as those of the Daubechies and Coiflet families. Our aim is to optimally decompose the signals in the wavelet domain so that they can be subsequently used as inputs for training to a neural network classifier

A Finite Element Computation of the Gravitational Radiation emitted by a Point-like object orbiting a Non-rotating Black Hole

The description of extreme-mass-ratio binary systems in the inspiral phase is a challenging problem in gravitational wave physics with significant relevance for the space interferometer LISA. The main difficulty lies in the evaluation of the effects of the small body's gravitational field on itself. To that end, an accurate computation of the perturbations produced by the small body with respect the background geometry of the large object, a massive black hole, is required. In this paper we present a new computational approach based on Finite Element Methods to solve the master equations describing perturbations of non-rotating black holes due to an orbiting point-like object. The numerical computations are carried out in the time domain by using evolution algorithms for wave-type equations. We show the accuracy of the method by comparing our calculations with previous results in the literature. Finally, we discuss the relevance of this method for achieving accurate descriptions of extreme-mass-ratio binaries.Comment: RevTeX 4. 18 pages, 8 figure

Determination of Inter-Phase Line Tension in Langmuir Films

A Langmuir film is a molecularly thin film on the surface of a fluid; we study the evolution of a Langmuir film with two co-existing fluid phases driven by an inter-phase line tension and damped by the viscous drag of the underlying subfluid. Experimentally, we study an 8CB Langmuir film via digitally-imaged Brewster Angle Microscopy (BAM) in a four-roll mill setup which applies a transient strain and images the response. When a compact domain is stretched by the imposed strain, it first assumes a bola shape with two tear-drop shaped reservoirs connected by a thin tether which then slowly relaxes to a circular domain which minimizes the interfacial energy of the system. We process the digital images of the experiment to extract the domain shapes. We then use one of these shapes as an initial condition for the numerical solution of a boundary-integral model of the underlying hydrodynamics and compare the subsequent images of the experiment to the numerical simulation. The numerical evolutions first verify that our hydrodynamical model can reproduce the observed dynamics. They also allow us to deduce the magnitude of the line tension in the system, often to within 1%. We find line tensions in the range of 200-600 pN; we hypothesize that this variation is due to differences in the layer depths of the 8CB fluid phases.Comment: See (http://www.math.hmc.edu/~ajb/bola/) for related movie

On the Matter of Time

Drawing on several disciplinary areas, this article considers diverse cultural concepts of time, space, and materiality. It explores historical shifts in ideas about time, observing that these have gone full circle, from visions in which time and space were conflated, through increasingly divergent linear understandings of the relationship between them, to their reunion in contemporary notions of space-time. Making use of long-term ethnographic research and explorations of the topic of Time at Durham University’s Institute of Advanced Study (2012–13), the article considers Aboriginal Australian ideas about relationality and the movement of matter through space and time. It asks why these earliest explanations of the cosmos, though couched in a wholly different idiom, seem to have more in common with the theories proposed by contemporary physicists than with the ideas that dominated the period between the Holocene and the Anthropocene. The analysis suggests that such unexpected resonance between these oldest and newest ideas about time and space may spring from the fact that they share an intense observational focus on material events. Comparing these vastly different but intriguingly compatible worldviews meets interdisciplinary aims in providing a fresh perspective on both of them

Treatment and Intervention for Opiate Dependence in the United Kingdom:Lessons from Triumph and Failure

The history of opiate treatment in the United Kingdom (UK) since the early 1980s is a rich source of learning about the benefits and pitfalls of drug treatment policy. We present five possible lessons to be learnt about how factors outside the clinic, including government, charities and researchers can influence treatment and outcomes. First, do not let a crisis go to waste. The philosophical shift from abstinence to harm reduction in the 1980s, in response to an HIV outbreak in injecting users, facilitated expansion in addiction services and made a harm reduction approach more acceptable. Second, studies of drug-related deaths can lead to advances in care. By elucidating the pattern of mortality, and designing interventions to address the causes, researchers have improved patient safety in certain contexts, though significant investment in Scotland has not arrested rising mortality. Third, collection of longitudinal data and its use to inform clinical guidelines, as pursued from the mid-1990s, can form an enduring evidence base and shape policy, sometimes in unintended ways. Fourth, beware of the presentation of harm reduction and recovery as in conflict. At the least, this reduces patient choice, and at worst, it has caused some services to be redesigned in a manner that jeopardises patient safety. Fifth, the relationship between the third and state sectors must be carefully nurtured. In the UK, early collaboration has been replaced by competition, driven by changes in funding, to the detriment of service provision

Telephone delivered incentives for encouraging adherence to supervised methadone consumption (TIES): study protocol for a feasibility study for an RCT of clinical and cost effectiveness

The majority of people receiving treatment for their heroin addiction, are prescribed methadone; for which there is an extensive evidence base. When treatment starts, people take their daily dose of methadone under supervision at a community pharmacy. Supervision guarantees methadone is taken as directed by the individual for whom it has been prescribed, helps to ensure individuals take their correct dose every day, and safeguards against diversion and overdose. However, individuals often fail to attend the pharmacy to take their methadone. Each missed dose is of concern. If a patient misses their daily dose of methadone, they will start to experience opiate withdrawal and cravings and are more likely to use heroin. If they miss three days dose, there are concerns that they may lose tolerance to the drug and may be at risk of overdose when the next dose is taken. Hence there is an urgent need to develop effective interventions for medication adherence. Research suggests that incentive-based medication adherence interventions may be very effective, but there are few controlled trials and the provision of incentives requires time and organisational systems which can be challenging in pharmacies. The investigators have developed the technology to deliver incentives by mobile telephone. This cluster randomised trial will test the feasibility of conducting a future trial evaluating the clinical and cost effectiveness of using telephone delivered incentives (praise and modest financial rewards via text messaging) to encourage adherence with supervised consumption of methadone in community pharmacies. Three drug services (each with two or three community pharmacies supervising methadone consumption that will enrol 20 individuals, a total of 60 participants) will be recruited and randomly allocated to deliver either i) telephone delivered incentives, ii) telephone delivered reminders or iii) no telephone system. Acceptability, recruitment, follow-up, and suitable measures of clinical and cost effectiveness will be assessed. Findings from this feasibility study will be assessed against stated progression criteria and used to inform a future confirmatory trial of the clinical and cost effectiveness of telephone delivered incentives to encourage medication adherence. ISRCTN58958179 (retrospectively registered). [Abstract copyright: © 2019 Published by Elsevier Inc.