3,069 research outputs found
Dynamics of axial separation in long rotating drums
We propose a continuum description for the axial separation of granular
materials in a long rotating drum. The model, operating with two local
variables, concentration difference and the dynamic angle of repose, describes
both initial transient traveling wave dynamics and long-term segregation of the
binary mixture. Segregation proceeds through ultra-slow logarithmic coarsening.Comment: 4 pages, 3 Postscript figures; submitted to PR
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Patient-Related Barriers to Timely Dialysis Access Preparation: A Qualitative Study of the Perspectives of Patients, Family Members, and Health Care Providers
Rational & Objective
A key aspect of smooth transition to dialysis is the timely creation of a permanent access. Despite early referral to kidney care, initiation onto dialysis is still suboptimal for many patients, which has clinical and cost implications. This study aimed to explore perspectives of various stakeholders on barriers to timely access creation.
Study Design
Qualitative study.
Setting & Participants
Semi-structured interviews with 96 participants (response rate, 67%), including patients with stage 4 chronic kidney disease (n = 30), new hemodialysis patients with (n = 18) and without (n = 20) permanent access (arteriovenous fistula), family members (n = 19), and kidney health care providers (n = 9).
Analytical Approach
Thematic analysis.
Results
Patients reported differential levels of behavioral activation toward access creation: avoidance/denial, wait and see, or active intention. 6 core themes were identified: (1) lack of symptoms, (2) dialysis fear and practical concerns (exaggerated fear, pain, cost, lifestyle disruptions, work-related concerns, burdening their families), (3) evaluating value against costs/risks of access creation (benefits, threat of operation, viability, prompt for early initiation), (4) preference for alternatives, (5) social influences (hearsay, family involvement, experiences of others), and (6) health care provider interactions (mistrust, interpersonal tension, lack of clarity on information). Themes were common to all groups, whereas nuanced perspectives of family members and health care providers were noted in some subthemes.
Limitations
Response bias.
Conclusions
Individual, interpersonal, and psychosocial factors compromise dialysis preparation and contribute to suboptimal dialysis initiation. Our findings support the need for interventions to improve patient and family engagement and address emotional concerns and misperceptions about preparing for dialysis
Chemical Raman Enhancement of Organic Adsorbates on Metal Surfaces
Using a combination of first-principles theory and experiments, we provide a
quantitative explanation for chemical contributions to surface-enhanced Raman
spectroscopy for a well-studied organic molecule, benzene thiol, chemisorbed on
planar Au(111) surfaces. With density functional theory calculations of the
static Raman tensor, we demonstrate and quantify a strong mode-dependent
modification of benzene thiol Raman spectra by Au substrates. Raman active
modes with the largest enhancements result from stronger contributions from Au
to their electron-vibron coupling, as quantified through a deformation
potential, a well-defined property of each vibrational mode. A straightforward
and general analysis is introduced that allows extraction of chemical
enhancement from experiments for specific vibrational modes; measured values
are in excellent agreement with our calculations.Comment: 5 pages, 4 figures and Supplementary material included as ancillary
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Forensic investigation of cooperative storage cloud service: Symform as a case study
Researchers envisioned Storage as a Service (StaaS) as an effective solution to the distributed management of digital data. Cooperative storage cloud forensic is relatively new and is an under-explored area of research. Using Symform as a case study, we seek to determine the data remnants from the use of cooperative cloud storage services. In particular, we consider both mobile devices and personal computers running various popular operating systems, namely Windows 8.1, Mac OS X Mavericks 10.9.5, Ubuntu 14.04.1 LTS, iOS 7.1.2, and Android KitKat 4.4.4. Potential artefacts recovered during the research include data relating to the installation and uninstallation of the cloud applications, log-in to and log-out from Symform account using the client application, file synchronization as well as their time stamp information. This research contributes to an in-depth understanding of the types of terrestrial artifacts that are likely to remain after the use of cooperative storage cloud on client devices
Effect of Inflow and Infiltration in Sewerage System of Residential Area, Kuantan, Pahang
Inflow and infiltration is a phenomenon in sewerage systems that can have negative effects on the environment and human health if not treated properly. Collaboration has been made between Universiti Malaysia Pahang (UMP) and Indah Water Konsortium Sdn. Bhd. (IWK) where the purpose is to evaluate the amount of inflow and infiltration happening in sewerage systems of residential areas in Kuantan. For this part of the study, one sewer pipeline (MH92a–MH92b) was selected at the residential area of Bandar Putra, having a population equivalent of 1694. The method used in this research was the Flowrate method to tabulate data. ISCO 2150 and 4250 Area Velocity Flowmeters were used to measure flow rate data in the sewer pipeline, whereas ISCO 674 Rain Gauge was used to collect rainfall intensity data. Calibration of all the equipment was done at the Hydrology and Hydraulic Laboratory in UMP. The data was collected for 41 days with each measurement separated by an interval of five minutes. The result shows that the average percentage Infiltration Rate of Qpeak and Qave in this residential catchment were 10.3% and 26.5% which is higher than the value mentioned in Hammer and Hammer (2012). Inflow and infiltration is a real concern, so more study is required to determine whether revision of the infiltration rate recommended in the Malaysian Standard is needed
Shared Risk Factors for Mood-, Eating-, and Weight-Related Health Outcomes
Objective: Given the overlap among depressive symptoms, disordered eating, and overweight, identifying shared risk factors for these conditions may inform public health interventions. This study aimed to examine cross-sectional and prospective relationships among these 3 conditions, and identify potential shared eating-related and psychosocial variable risk factors (i.e., body dissatisfaction, dieting, teasing experiences).
Method: A population-based sample (n = 1,902) self-reported depressive symptoms, disordered eating (binge eating, extreme weight control behaviors), weight status, and several putative risk factors (body satisfaction, dieting frequency, weight-related teasing) at 5-year intervals spanning early/middle adolescence, middle adolescence/early young adulthood, and early/middle young adulthood.
Results: There was moderate overlap among depressive symptoms, disordered eating, and overweight at each time point, and moderate stability in each condition over time. Body dissatisfaction and dieting were the most potent shared risk factors for later depressive symptoms, disordered eating, and overweight among males and females (ps \u3c .05).
Conclusions: Depressive symptoms, disordered eating, and overweight share several risk factors, including dieting and body dissatisfaction, which may be effective targets for interventions aiming to simultaneously prevent these 3 conditions
An Explicit Bound for Dynamical Localisation in an Interacting Many-Body System
We characterise and study dynamical localisation of a finite interacting
quantum many-body system. We present explicit bounds on the disorder strength
required for the onset of localisation of the dynamics of arbitrary ensemble of
sites of the XYZ spin-1/2 model. We obtain these results using a novel form of
the fractional moment criterion, which we establish, together with a
generalisation of the self-avoiding walk representation of the system Green's
functions, called path-sums. These techniques are not specific to the XYZ model
and hold in a much more general setting. We further present bounds for two
observable quantities in the localised regime: the magnetisation of any
sublattice of the system as well as the linear magnetic response function of
the system. We confirm our results through numerical simulations.Comment: 35 pages; 5 figure
Traveling Granular Segregation Patterns in a Long Drum Mixer
Mixtures of granular media often exhibit size segregation along the axis of a
partially-filled, horizontal, rotating cylinder. Previous experiments have
observed axial bands of segregation that grow from concentration fluctuations
and merge in a manner analogous to spinodal decomposition. We have observed
that a new dynamical state precedes this effect in certain mixtures:
bi-directional traveling waves. By preparing initial conditions, we found that
the wave speed decreased with wavelength. Such waves appear to be inconsistent
with simple PDE models which are first order in time.Comment: 11 page
Methods for delivering the UK's multi-centre prison-based naloxone-on-release pilot randomised trial (N-ALIVE): Europe's largest prison-based randomised controlled trial
INTRODUCTION AND AIMS: Naloxone is an opioid antagonist used for emergency resuscitation following opioid overdose. Prisoners with a history of heroin use by injection have a high risk of drug-related death in the first weeks after prison-release. The N-ALIVE trial was planned as a large prison-based randomised controlled trial (RCT) to test the effectiveness of naloxone-on-release in the prevention of fatal opiate overdoses soon after release. The N-ALIVE pilot trial was conducted to test the main trial's assumptions on recruitment of prisons and prisoners, and the logistics for ensuring that participants received their N-ALIVE pack on release. DESIGN AND METHODS: Adult prisoners who had ever injected heroin, were incarcerated for ≥7 days and were expected to be released within 3 months were eligible. Participants were randomised to receive, on liberation, a pack containing a single 'rescue' injection of naloxone or a control pack with no naloxone syringe. The trial was double-blind prior to prison-release. RESULTS: We randomised 1685 prisoners (842 naloxone; 843 control) across 16 prisons in England. We stopped randomisation on 8 December 2014 because only one-third of administrations of naloxone-on-release were to the randomised ex-prisoner; two-thirds were to others whom we were not tracing. DISCUSSION AND CONCLUSIONS: Prevention RCTs are seldom conducted within prisons; we demonstrated the feasibility of conducting a multi-prison RCT to prevent fatality from opioid overdose in the outside community. We terminated the N-ALIVE trial due to the infeasibility of individualised randomisation to naloxone-on-release. Large RCTs are feasible within prisons
The first CCD photometric study of the open cluster NGC 2126
We present the first CCD photometric observations of the northern open
cluster NGC 2126. Data were taken on eight nights in February and December 2002
with a total time span of ~57 hours. Almost 1000 individual V-band frames were
examined to find short-period variable stars. We discovered six new variable
stars, of which one is a promising candidate for an eclipsing binary with a
pulsating component. Two stars were classified as delta Scuti stars and one as
Algol-type eclipsing binary. Two stars are slow variables with ambiguous
classification. From absolute VRI photometry we have estimated the main
characteristics of the cluster: m-M=11.0+/-0.5, E(V-I)=0.4+/-0.1,
E(V-R)=0.08+/-0.06 (E(B-V)=0.2+/-0.15) and d=1.3+/-0.6 kpc. Cluster membership
is suggested for three variable stars from their positions on the
colour-magnitude diagram.Comment: 7 pages, 10 figures, accepted for publication in A&
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