938 research outputs found
Sort by
Machine Learning‑assisted Lens‑loaded Cavity Response Optimization for Improved Direction‑of‑arrival estimation
Get PDFThis paper presents a millimeter-wave direction of arrival estimation (DoA) technique powered by dynamic aperture optimization. The frequency-diverse medium in this work is a lens-loaded oversized mmWave cavity that hosts quasi-random wave-chaotic radiation modes. The presence of the lens is shown to confine the radiation within the field of view and improve the gain of each radiation mode; hence, enhancing the accuracy of the DoA estimation. It is also shown, for the first time, that a lens loaded-cavity can be transformed into a lens-loaded dynamic aperture by introducing a mechanically controlled mode-mixing mechanism inside the cavity. This work also proposes a way of optimizing this lens-loaded dynamic aperture by exploiting the mode mixing mechanism governed by a machine learning-assisted evolutionary algorithm. The concept is verified by a series of extensive simulations of the dynamic aperture states obtained via the machine learning-assisted evolutionary optimization technique. The simulation results show a 25% improvement in the conditioning for the DoA estimation using the proposed technique
Selective biomarkers for inflammation and infection are associated with post-operative complications following transperineal template prostate biopsy (TTPB): a single-centre observational clinical pilot-study
Get PDFBackground
Prostate cancer (PCa) and benign prostatic hyperplasia (BPH) are the most common prostate disorders in the UK, which cause considerable ill health in older men. Transperineal template prostate biopsy (TTPB) has emerged as a reliable procedure for the histopathological diagnosis of PCa and BPH due to its higher cancer detection rates. Although antiseptic preparation and antibiotic prophylaxis are used to ensure safety in patients undergoing surgical intervention, post-operative complications, such as infection and bleeding are still unavoidable, resulting in re-admissions, with resource implications. Currently, there is no biomarker profile to predict outcomes or monitor patients during the post-operative course. The main aim of this single-centre observational clinical pilot-study was to investigate the role of inflammatory and infection biomarkers following TTPB and their association with post-operative complications.
Methods
Forty-five patients scheduled for elective TTPB were recruited after informed consent at the Wrexham Maelor and Glan Clwyd Hospitals, North Wales, UK (n = 45). Prior to surgery, venous blood samples were collected at baseline and subsequently at 30, 120, and 240 min post-operatively. Urine samples were collected before and 120 min after the procedure. Serum procalcitonin (PCT), serum ferritin, and urine B2MG analysis were done using enzyme-linked fluorescent assay (ELFA) and the magnetic Luminex® multiplex performance assay was used to analyse IL-6, IL-8, IL-10 and TNF-α plasma concentrations. Data on clinical outcomes were collected from patients’ medical records.
Results
Following TTPB, significant (p ≤ 0.05) increases were observed in uB2MG, IL-6, IL-8, IL-10 and TNF-α. Significant decreases were observed in ferritin (p ≤ 0.05). No significant change was observed in PCT concentration (p ≥ 0.05). One patient developed an infection and severe haematuria post-operatively following TTPB.
Conclusion
Although not confirmative, changes seen in biomarkers such as uB2MG, IL-10 and TNF-α in our observational clinical pilot-study may warrant further investigation, involving larger cohorts, to fully understand the role of these biomarkers and their potential association with post-operative complications such as infection and bleeding which can develop following TTPB for the diagnosis of PCa and BPH
A listening guide to youth work, Methodological approaches to research in youth work: Changing the paradigm
No full textThe Listening Guide (Gilligan, Spencer, Weinberg, & Bertsch, 2003) is an approach that places listening through relationship at the forefront of the research. This is a discovery approach where voice and relationship are central to the encounter. It explores how expressing meaning made from lived experiences is conveyed through the voice of the teller. We propose a rationale for utilising a Voice Centered Relational Methodology (The Listening Guide) in International Youth Work research. Youth Work places the young person at the heart of practice. This is understood to be a relational interaction; however, the quality of that relational interaction is dependent upon the ‘voice’ exhibited by the young person within the boundaries of multiple interactions over a period of time. We suggest that the ‘relational voice’ component of this methodological approach is congruent with Youth Work principles and values and enables the process of listening deeply to the participant’s voice. We demonstrate how the Voice Centered Relational Methodology can be used to explore the multiple layers of meaning within the relational voice that forms the central part of the ongoing relational dialogue Youth Workers hold with young people. We suggest that a Voice Centered Relational Methodological approach enables the uncovering of the voice of the participant and supports an evidence base for Youth Work that is congruent with its principles and values. The Price model of international Youth Work is introduced and explores the multiple layers of meaning within ‘voice’ positioned within an Intercultural context. The model supports the position that relational voice, as espoused by Gilligan (1993), is central to Youth Work
An Efficient Method for Antenna Design Based on a Self-Adaptive Bayesian Neural Network-Assisted Global Optimization Technique
Get PDFGaussian process (GP) is a very popular machine learning method for online surrogate-model-assisted antenna design optimization. Despite many successes, two improvements are important for the GP-based antenna global optimization methods, including: 1) the convergence speed (i.e., the number of necessary electromagnetic (EM) simulations to obtain a high-performance design) and 2) the GP model training cost when there are several tens of design variables and/or specifications. In both aspects, the state-of-the-art GP-based methods show practical but not desirable performance. Therefore, a new method, called the self-adaptive Bayesian neural network surrogate-model-assisted differential evolution (DE) for antenna optimization (SB-SADEA), is presented in this article. The key innovations include: 1) the introduction of the Bayesian neural network (BNN)-based antenna surrogate modeling method into this research area, replacing GP modeling, and 2) a bespoke self-adaptive lower confidence bound (LCB) method for antenna design landscape making use of the BNN-based antenna surrogate model. The performance of SB-SADEA is demonstrated by two challenging design cases, showing considerable improvement in terms of both convergence speed and machine learning cost compared with the state-of-the-art GP-based antenna global optimization methods
Dome-Shaped mmWave Lens Antenna Optimization for Wide-Angle Scanning and Scan Loss Mitigation Using Geometric Optics and Multiple Scattering
Get PDFThis paper presents a new accurate and efficient design methodology for complex integrated lens antenna (ILA), to achieve wide-angle beam coverage with scan loss mitigation at the millimeter-wave (mmWave) spectrum. The proposed ILA comprises inhomogeneous curvatures with internal and external center off-sets, in which multiple parameters instigate high order and non-linear behaviors. A two-dimensional (2-D) ray-tracing model is used to estimate the refractions on the elliptically curved boundaries based on geometrical optics. This approach is integrated into the particle swarm optimization of the 2-D ray-tracing model to determine the near-optimum geometric configuration of the ILA. Denoted as Geometric Optics-based Multiple Scattering (GOMS), the computational memory usage is reduced by a factor of 10,000 using this approach. The devised ILA achieves a wide-angle beam coverage of 156° with a scan loss of 2.10 dB alongside a broad impedance bandwidth of 35.0 GHz to 42.0 GHz. The measurement results for the performance of the fabricated prototype of the ILA validate the wide-angle scanning with scan loss mitigation inferred from the simulation results. This confirms the effectiveness of this method for complex design challenges involving multi-variants and restricted computational resources
Characterization of hydrophilic and hydrophobic core-shell microcapsules prepared using a range of antisolvent approaches
Get PDFThis study describes three straightforward approaches to leveraging gel network-restricted antisolvent precipitation techniques as a means of preparing hydrophilic hydrophobic core-shell microparticles. Briefly, hydrophilic polysaccharides (sodium alginate (ALG), κ-carrageenan (CAR), and agar (AG)) were utilized to prepare microgel beads that were then immersed in zein solutions (70% ethanol aqueous solution, 70% urea aqueous solution, and zein in 70% acetic acid, respectively), thereby facilitating the controlled, slow antisolvent precipitation of the protein layer on the microbead surfaces and inducing hydrophilic hydrophobic core-shell structure formation. This technique can be readily applied to a range of gelling systems and can be tailored to target particle sizes and shell thicknesses. The resultant core-shell particles offer great promise for controlled delivery of fragrances, drugs, or other bioactive compounds in an application-specific fashion, and can be individually tailored based upon the selected input concentrations and preparation methods. Importantly, this technique is generalizable and can be extended to prepare diverse particles with a range of core-shell structures produced from a wide assortment of hydrophobic materials
The application of slotless skewed windings to a rim driven fan for aircraft electrical propulsion (AEP)
Get PDFThis paper investigates the slotless winding characteristics of motors intended for aircraft electrical propulsion (AEP), together with a preliminary design study of a winding model derived from a Faulhaber configuration. Geometrical relationships and magnetic requirements driving the design, such as the width of each phase coil side, the skew angle, and the winding arrangement, are analysed. Finally, electromagnetic (EM) simulations were conducted to study the electromagnetic performance of the Faulhaber model and the influence of the stator conductor skewness. Upon analysis of the results, it is found that the skew angle should remain low to assure efficiency, while it should also be great enough to satisfy the geometric and magnetic requirements. In conclusion, the paper proposes a hybrid slotless winding configuration based on the Faulhaber structure, which is a trade-off between efficiency and end-winding length for a motor powering a rim driven fan
Behavioral Study of Software-Defined Network Parameters Using Exploratory Data Analysis and Regression-Based Sensitivity Analysis
Get PDFTo provide a low-cost methodical way for inference-driven insight into the assessment of SDN operations, a behavioral study of key network parameters that predicate the proper functioning and performance of software-defined networks (SDNs) is presented to characterize their alterations or variations, given various emulated SDN scenarios. It is standard practice to use simulation environments to investigate the performance characteristics of SDNs, quantitatively and qualitatively; hence, the use of emulated scenarios to typify the investigated SDN in this paper. The key parameters studied analytically are the jitter, response time and throughput of the SDN. These network parameters provide the most vital metrics in SDN operations according to literature, and they have been behaviorally studied in the following popular SDN states: normal operating condition without any incidents on the SDN, hypertext transfer protocol (HTTP) flooding, transmission control protocol (TCP) flooding, and user datagram protocol (UDP) flooding, when the SDN is subjected to a distributed denial-of-service (DDoS) attack. The behavioral study is implemented primarily via univariate and multivariate exploratory data analysis (EDA) to characterize and visualize the variations of the SDN parameters for each of the emulated scenarios, and linear regression-based analysis to draw inferences on the sensitivity of the SDN parameters to the emulated scenarios. Experimental results indicate that the SDN performance metrics (i.e., jitter, latency and throughput) vary as the SDN scenario changes given a DDoS attack on the SDN, and they are all sensitive to the respective attack scenarios with some level of interactions between them
Radiation Optimization for Phased Arrays of Antennas Incorporating the Constraints of Active Reflection Coefficients
Get PDFHigh-power radiations from active antenna arrays may result in strong reflected power to cause RF device breakdown by the strong interelement mutual coupling. An excitation weighting synthesis of antenna arrays incorporating the constraint of active reflection/transmission coefficients between antenna elements is presented to optimize the radiation. It may enhance interelement isolation, reducing the effort of using sophisticated hardware-based structures that have difficulty in broad-angle beam steering. In the synthesis, the cost functions incorporate the difference between the optimized and the predefined excitation weightings of radiation patterns with limited reflected power or active reflection coefficients as a constraint. This article first introduces the basic concept to show the operational mechanisms. Practical definitions of cost functions are described to synthesize the radiation pattern considering the mutual coupling effects. The case without setting an initial desired radiation pattern is also examined for comparison. Numerical full-wave simulations are presented to validate the synthesis concepts by examining the characteristics of gain, sidelobe level (SLL), and port reflection coefficients
Understanding Substance Use and the Wider Support Needs of Scotland’s Prison Population
Get PDFIntroduction: The Scottish Government has committed to undertaking a comprehensive, national
assessment of the health and social care needs of Scotland’s prison population.
The last prison health needs assessment was conducted in 2007 and a great deal
has changed in the policy and service delivery landscape since then. This needs
assessment is one of four commissioned studies1 and focuses on an assessment of
the needs of the prison population relating to alcohol, drugs, and tobacco use.
Background
Substance use has long been a concern for the health and wellbeing of people
living in Scotland’s prisons and remains one of the most prominent challenges to
Scotland’s prison system. People who live in prison are disproportionately more
likely to use alcohol, drugs, and tobacco than those individuals who do not enter
prison (Toomey et al., 2022). Crime and substance use are known to be closely
associated2. Problemetic substance use often contributes to the factors involved in
why someone is in prison and often continues (or for some begins) whilst living in
prison (Carnie and Boderick, 2019).
Many people living in prison have substance use needs that pre-date their
imprisonment and can stem from multiple factors, such as experiencing trauma and
social and economic inequality (Devries et al., 2014; Najavits, 2015). Within
custody, people experience limited access to family and community supports,
bullying, and feelings of hopelessness which risks perpetuating and escalating
substance use. The prevalence of substance use within prisons is a serious threat
to the health of people living there and to general public health. It threatens the
safety of prison officers and healthcare staff and creates challenges in terms of
maintaining good order and discipline (O’Hagan, 2017). With the recent rates in
drug-related deaths continuing to soar across Scotland, there is increasing
pressure to take more urgent action to address substances and the harms that they
present (NRS, 2021).
The exact picture of substance use in Scottish prisons is unclear. There is a lack of
available data, which will be highlighted later in this report. Estimating the
prevalence of substance use in Scottish prisons is therefore highly challenging,
particularly in relation to drug use (Toomey et al., 2022). What is apparent though is
that levels of drug deaths across Scotland are very high. In 2019, in reponse to the
high levels of drug deaths in Scotland, the Drug Deaths Taskforce [DDTF] was
established.3 This group is made up of volunteer members who have been
proactive about pushing for the implementation of the MAT [Medical Assisted
Treatment] Standards.4
1 The other three studies are: (1) physical and general health, including major clinical and long-term conditions, infectious
disease, non-communicable disease, sexual health; (2) mental health; and (3) social care and support needs.
2 The Scottish Parliament - Healthcare in Prisons
3 Drug Deaths Task Force
4 MAT Standards, introduced by the Scottish Government in 2021, are an evidence-based set of standards to enable the
consistent delivery of safe, accessible, high-quality drug treatment across Scotland.
2
Current substance use data often relies on self-reporting5 or upon incident reports
which do not present the full picture of substance use. In the most recent Scottish
Prison Service [SPS] Prisoner Survey (Carnie and Boderick, 2019), 41% self
reported that they engaged in problematic drug use prior to imprisonment; 45% had
been under the influence of drugs, and 40% reported being drunk at the time of
their offence. This is indicative of a high level of need.
People living in prison experience substantially poorer health than the general
population, in part because of the high prevalence of smoking amongst those living
in prison (Spaulding, 2018). High rates of smoking in prisons had been consistently
reported in the SPS Prisoner Survey prior to the introduction of a smoke free prison
environment (2018). The 2013 survey reported that 74% of people living in prison
smoked which contrasts with a prevalence rate of around 20% in Scotland as a
whole.
Whilst the prison system continues to be the host for many of those who are found
to have committed substance related crimes, there have been increasing
conversations about whether this is in fact the right place for them (Scottish
Parliament, 2022). It has long been acknowledged that the opportunities and
provisions for rehabilitation within a prison setting are limited (ibid.)6. So too there is
a real sense that the revolving door of prisons can exacerbate and encourage
substance use:
‘We do not rehabilitate prisoners well, we do not prepare them for release well and
we do not support them on release well, because our system is chock-a-block with
people who should not be in it.’ (Professor Fergus McNeill, evidence provided to
Scottish Parliament, 2022, pg. 11)
Alcohol and Drugs
Each prison in Scotland has developed its own policies and procedures to manage
drug and alcohol use. In part this can be traced back to the NHS takeover of
addictions work in Scottish prisons from Phoenix Futures (2011). In the absence of
universal guidance, each NHS Board that had a prison in its catchment area
decided what approach to take (NHS, 2016). One requirement, however, was that
services should be available on an equitable basis to community-based services.
Whilst there are different approaches across prisons, there are a number of policies
and documents that offer guidance to all prisons. One of these is the National
Naloxone Programme which has been active in Scottish Prisons since 2011. This
has provided all those leaving prison with Naloxone in an attempt to address opioid
related overdoses upon release (Bird et al. 2014). As data collection for this study
progressed, some respondents informed us that naloxone provision had continued
to be developed. For example, intranasal naloxone is now offered, making it a
needle-less product. Online service, training and learning opportunities have been
expanded, and there has also been a move to educate and organise peer naloxone
5 Self-reporting results in limited findings as, particularly in relation to substance use, it is uncommon for people to be
completely honest in their self-disclosures and so results in data consisting of what people are willing to self-disclose.
6 It should be acknowledged here that rehabilitation opportunities do vary across prisons and prisoner categories.
3
distributors and trainers, something which has enjoyed much success (DDTF,
2021).
Across Scotland, the SPS’ Management of Offender at Risk Due to Any Substance
[MORS] policy was introduced in December 2014. This guidance instructs prison
staff on how to respond if they identify someone as being at risk from a substance
and how healthcare staff should engage with the incident.
Rights, Respect and Recovery, Scotland’s strategy for reducing drug and alcohol
related harms and deaths, was published in 2018 (Scottish Government, 2018).
The strategy provided a specific focus on prisons as one of the key organisations
that should be involved in delivering on national substance use goals. In January
2021, the strategic approach was further enhanced through the announcement by
the First Minister of a new ‘National Mission’ to reduce drug-related deaths and
harms, supported by an additional £50 million funding per year (for the next five
years). 7
In response to the Covid-19 pandemic, the Scottish Government allocated £1.9
million to support people to switch to Buvidal as an OST treatment option (MacNeill,
2021). Buvidal is a longer-acting form of OST that means people can switch from a
daily medication regime to only needing to take their presciption on a weekly or
monthly basis. Intial small-scale feedback on Buvidal has highlighted its potential to
support people to make positive changes to their lives and demonstrated it may
improve outcomes for prison leavers, such avoiding relapses in the community or
helping them look employment (MacNeill, 2020). Increasing the number of people
being prescribed Buvidal in Scotland’s prisons may also go some way towards
alleviating the current burden placed on prison operations and healthcare by the
daily administration of methadone.
Tobacco
SPS and partners have successfully delivered smoke free environments since
November 2018. This change was introduced as part of a wider Scottish
Government focus on changing smoking habits for future generations. In the lead
up to, and in the aftermath of the introduction of a smoke free policy, smoking in
prison has transformed from an under-researched and poorly understood policy
area, to one which is underpinned by a rich literature base which engenders
ongoing policy and practice conversations.
In January 2022 the final report for the Tobacco in Prisons Study [TiPS] was
published (Hunt et al., 2022). The study documents the impact of smoke free
prisons in Scotland. It indicates that smoke free prisons policy have quickly become
the ‘new normal’. Second hand smoking has been reduced by 90% and e-cigarette
use has became commonplace.
TiPS was the first study internationally to explore this topic and did so extensively.
As such it has not been appropriate nor useful for this needs assessment to
7 National mission - Alcohol and drugs
4
replicate or duplicate evidence gathering with regard to current policy and
programmes around Tobacco. Therefore, the team has focused on alcohol and
drug use as a priority for the data collection for this project whilst considering the
place of tobacco use alongside other substance use.
Study Aim and Objectives
The aim of this needs assessment study was to help the Scottish Government and
its partners better understand what the healthcare needs of people with substance
use problems living in Scotland’s prisons are.
The specific objectives of the needs assessment were to:
1. Conduct a rapid review of the research literature from the UK and (if there
is a strong rationale for it) comparable jurisdictions on the nature and
extent of substance use needs and support within prison populations.
2. Synthesise available national and local-level data and research to report
on the epidemiology of substance use experienced by Scotland’s prison
population, including newer trends such as New Psychoactive Substances
[NPS] usage, compared to others in the criminal justice system (e.g.
people serving community sentences) and the general population.
3. Map current models of substance use care/interventions within Scotland’s
prisons, how they interface with other healthcare interventions within
prisons, and how they interface with community care models and services,
including assessing aspects of treatment continuity, finding examples of
best practice, and throughcare pathways during transition from custody to
the community.
4. Assess the scope for the improved collection of routine data that can be
made available to analysts, managers, and service providers for continued
monitoring and analysis of support needs relating to substance use.
5. Offer insights for future data linkage and data collection priorities.
6. Include the perspectives of people with lived experience of prison and
substance use to incorporate their views and insights.
Methodology
Study methods
The core elements of the study focused on qualitative approaches (comprising of:
(1) semi-structured interviews with a broad range of professional stakeholder
groups; (2) a short-life working group with a diverse range of professional
stakeholders from key partners in SPS, NHS, and the Third Sector; and (3)
interviews with those who have lived and/or living experience). These approaches
were supplemented with a rapid literature review, a review of existing (published)
data, and a mapping exercise (see Table 1 below).
Although the original study design included a desk-based review and synthesis of
all available (published) datasets, and that this would be expected to be seen within
a Health Needs Assessment report, it is not included in the usual way in this report.
5
From our early review of available Scottish health datasets, it became evident that
published healthcare data regarding substance use for Scotland’s prisons was
deficient and would not provide meaningful, real-time insights. We have included
(see Table 2 in Chapter 5) an overview of the available datasets (including
comments upon their individual strengths and limitations), but have focused our
approach on a qualitative high-level strategic review of how healthcare data is
gathered and used in order to identify the areas where substance use data
collection, analysis and linkaging needs to improve (see Chapter 5).
The context of the Covid-19 pandemic necessitated a flexible approach, with all
working group sessions and semi-structured interviews conducted remotely or on
the phone.
Full details of study methods and our approach to analysis is provided in Appendix
A.
Recruitment, sampling, and activity completed
A summary of study methods, recruitment, sampling and activity completed is
presented in the table below. Fieldwork activities took place between October 2021
and February 2022