MODELED DIFFUSION-CONTROLLED RESPONSE AND RECOVERY BEHAVIOR OF A NAKED OPTICAL FILM SENSOR WITH A HYPERBOLIC-TYPE RESPONSE TO ANALYTE CONCENTRATION

The diffusion-controlled response and recovery behaviour of a naked optical film sensor (i.e., with no protective membrane) with a hyperbolic-type response [i.e., S0/S = (1 + Kc), where S is the measured value of the absorbance or luminescence intensity of one form of the sensor dye in the presence of the analyte, S0 is the observed value of S in the absence of analyte and K is a constant] to changes in analyte concentration, c, in a system under test is approximated using a simple model, and described more accurately using a numerical model; in both models it is assumed that the system under test represents an infinite reservoir. Each model predicts the variations in the response and recovery times of such an optical sensor, as a function of the final external analyte concentration, the film thickness (I) and the analyte diffusion coefficient (D). From an observed signal versus time profile for a naked optical film sensor it is shown how values for K and D/I2 can be extracted using the numerical model. Both models provide a qualitative description of the often cited asymmetric nature of the response and recovery for hyperbolic-type response naked optical film sensors. It is envisaged that the models will help in the interpretation of the response and recovery behaviour exhibited by many naked optical film sensors and might be especially apposite when the analyte is a gas.

A Monte Carlo model of DNA double-strand break clustering and rejoining kinetics for the analysis of pulsed-field gel electrophoresis data

In studies of radiation-induced DNA fragmentation and repair, analytical models may provide rapid and easy-to-use methods to test simple hypotheses regarding the breakage and rejoining mechanisms involved. The random breakage model, according to which lesions are distributed uniformly and independently of each other along the DNA, has been the model most used to describe spatial distribution of radiation-induced DNA damage. Recently several mechanistic approaches have been proposed that model clustered damage to DNA. In general, such approaches focus on the study of initial radiation-induced DNA damage and repair, without considering the effects of additional (unwanted and unavoidable) fragmentation that may take place during the experimental procedures. While most approaches, including measurement of total DNA mass below a specified value, allow for the occurrence of background experimental damage by means of simple subtractive procedures, a more detailed analysis of DNA fragmentation necessitates a more accurate treatment. We have developed a new, relatively simple model of DNA breakage and the resulting rejoining kinetics of broken fragments. Initial radiation-induced DNA damage is simulated using a clustered breakage approach, with three free parameters: the number of independently located clusters, each containing several DNA double-strand breaks (DSBs), the average number of DSBs within a cluster (multiplicity of the cluster), and the maximum allowed radius within which DSBs belonging to the same cluster are distributed. Random breakage is simulated as a special case of the DSB clustering procedure. When the model is applied to the analysis of DNA fragmentation as measured with pulsed-field gel electrophoresis (PFGE), the hypothesis that DSBs in proximity rejoin at a different rate from that of sparse isolated breaks can be tested, since the kinetics of rejoining of fragments of varying size may be followed by means of computer simulations. The problem of how to account for background damage from experimental handling is also carefully considered. We have shown that the conventional procedure of subtracting the background damage from the experimental data may lead to erroneous conclusions during the analysis of both initial fragmentation and DSB rejoining. Despite its relative simplicity, the method presented allows both the quantitative and qualitative description of radiation-induced DNA fragmentation and subsequent rejoining of double-stranded DNA fragments. (C) 2004 by Radiation Research Society.

Exercise rehabilitation following intensive care unit discharge for recovery from critical illness

Background: Skeletal muscle wasting and weakness are significant complications of critical illness, associated with the degree of illness severity and periods of reduced mobility during mechanical ventilation. They contribute to the profound physical and functional deficits observed in survivors. These impairments may persist for many years following discharge from the intensive care unit (ICU) and may markedly influence health-related quality of life. Rehabilitation is a key strategy in the recovery of patients following critical illness. Exercise based interventions are aimed at targeting this muscle wasting and weakness. Physical rehabilitation delivered during ICU admission has been systematically evaluated and shown to be beneficial. However its effectiveness when initiated after ICU discharge has yet to be established. Objectives: To assess the effectiveness of exercise rehabilitation programmes, initiated after ICU discharge, on functional exercise capacity and health-related quality of life in adult ICU survivors who have been mechanically ventilated for more than 24 hours. Search methods:We searched the following databases: the Cochrane Central Register of Controlled Trials (CENTRAL) (The Cochrane Library), OvidSP MEDLINE, Ovid SP EMBASE, and CINAHL via EBSCO host to 15th May 2014. We used a specific search strategy for each database. This included synonyms for ICU and critical illness, exercise training and rehabilitation. We searched the reference lists of included studies and contacted primary authors to obtain further information regarding potentially eligible studies. We also searched major clinical trials registries (Clinical Trials and Current Controlled Trials) and the personal libraries of the review authors. We applied no language or publication restriction. We reran the search in February 2015. We will deal with any studies of interest when we update the review.  Selection criteria:We included randomized controlled trials (RCTs), quasi-RCTs, and controlled clinical trials (CCTs) that compared an exercise interventioninitiated after ICU discharge to any other intervention or a control or ‘usual care’ programme in adult (≥18years) survivors ofcritical illness. Data collection and analysis:We used standard methodological procedures expected by The Cochrane Collaboration. Main results:We included six trials (483 adult ICU participants). Exercise-based interventions were delivered on the ward in two studies; both onthe ward and in the community in one study; and in the community in three studies. The duration of the intervention varied according to the length of stay in hospital following ICU discharge (up to a fixed duration of 12 weeks).Risk of bias was variable for all domains across all trials. High risk of bias was evident in all studies for performance bias, although blinding of participants and personnel in therapeutic rehabilitation trials can be pragmatically challenging. Low risk of bias was at least 50% for all other domains across all trials, although high risk of bias was present in one study for random sequence generation (selection bias), incomplete outcome data (attrition bias) and other sources. Risk of bias was unclear for remaining studies across the domains.All six studies measured effect on the primary outcome of functional exercise capacity, although there was wide variability in natureof intervention, outcome measures and associated metrics, and data reporting. Overall quality of the evidence was very low. Only two studies using the same outcome measure for functional exercise capacity, had the potential for pooling of data and assessment of heterogeneity. On statistical advice, this was considered inappropriate to perform this analysis and study findings were therefore qualitatively described. Individually, three studies reported positive results in favour of the intervention. A small benefit (versus. control)was evident in anaerobic threshold in one study (mean difference, MD (95% confidence interval, CI), 1.8 mlO2/kg/min (0.4 to 3.2),P value = 0.02), although this effect was short-term, and in a second study, both incremental (MD 4.7 (95% CI 1.69 to 7.75) Watts, P value = 0.003) and endurance (MD 4.12 (95% CI 0.68 to 7.56) minutes, P value = 0.021) exercise testing demonstrated improvement.Finally self-reported physical function increased significantly following a rehabilitation manual (P value = 0.006). Remaining studies found no effect of the intervention.Similar variability in with regard findings for the primary outcome of health-related quality of life were also evident. Only two studies evaluated this outcome. Following statistical advice, these data again were considered inappropriate for pooling to determine overall effect and assessment of heterogeneity. Qualitative description of findings was therefore undertaken. Individually, neither study reported differences between intervention and control groups for health-related quality of life as a result of the intervention. Overall quality of the evidence was very low.Mortality was reported by all studies, ranging from 0% to 18.8%. Only one non-mortality adverse event was reported across all patients in all studies (a minor musculoskeletal injury). Withdrawals, reported in four studies, ranged from 0% to 26.5% in control groups,and 8.2% to 27.6% in intervention groups. Loss to follow-up, reported in all studies, ranged from 0% to 14% in control groups, and 0% to 12.5% in intervention groups. Authors’ conclusions:We are unable, at this time, to determine an overall effect on functional exercise capacity, or health-related quality of life, of an exercise based intervention initiated after ICU discharge in survivors of critical illness. Meta-analysis of findings was not appropriate. This was due to insufficient study number and data. Individual study findings were inconsistent. Some studies reported a beneficial effect of the intervention on functional exercise capacity, and others not. No effect was reported on health-related quality of life. Methodological rigour was lacking across a number of domains influencing quality of the evidence. There was also wide variability in the characteristics of interventions, outcome measures and associated metrics, and data reporting.If further trials are identified, we may be able to determine the effect of exercise-based interventions following ICU discharge, on functional exercise capacity and health-related quality of life in survivors of critical illness.

Uncertainty in the Cloud: An Angel-Daemon Approach to Modelling Performance

Uncertainty profiles are used to study the effects of contention within cloud and service-based environments. An uncertainty profile provides a qualitative description of an environment whose quality of service (QoS) may fluctuate unpredictably. Uncertain environments are modelled by strategic games with two agents; a daemon is used to represent overload and high resource contention; an angel is used to represent an idealised resource allocation situation with no underlying contention. Assessments of uncertainty profiles are useful in two ways: firstly, they provide a broad understanding of how environmental stress can effect an application’s performance (and reliability); secondly, they allow the effects of introducing redundancy into a computation to be assessed

Electron-impact excitation of Xe 26+ and its resultant spectral signature

We have carried out a 129 close-coupling level Dirac-Coulomb R-matrix calculation for the electron-impact excitation of Ni-like Xe. We have utilized this data to generate the spectral signature of Xe26+ in terms of feature photon-emissivity coefficients (F-PεCs). We have compared these F-PεCs with those generated using semi-relativistic plane-wave Born excitation data, which forms the heavy species baseline for the Atomic Data and Analysis Structure (ADAS), We find that the Born-based F-PεCs give a reasonable qualitative description of the spectral signature but that, quantitatively, the R-matrix-based F-PεCs differ by up to a factor of 2. The spectral signature of heavy species is key to diagnosing hot plasmas such as will be found in the International Thermonuclear Experimental Reactor.

Primary Health Care Providers' Perspectives: Facilitating Older Patients' Access to Community Support Services

The purpose of the study examined in this article was to understand how non-physician health care professionals working in Canadian primary health care settings facilitate older persons’ access to community support services (CSSs). The use of CSSs has positive impacts for clients, yet they are underused from lack of awareness. Using a qualitative description approach, we interviewed 20 health care professionals from various disciplines and primary health care models about the processes they use to link older patients to CSSs. Participants collaborated extensively with interprofessional colleagues within and outside their organizations to fi nd relevant CSSs. They actively engaged patients and families in making these linkages and ensured follow-up. It was troubling to fi nd that they relied on out-of-date resources and ineffi cient search strategies to fi nd CSSs. Our fi ndings can be used to develop resources and approaches to better support primary health care providers in linking older adults to relevant CSSs. 

Supervisor Continuity or Co-Location: Which Matters in Residency Education? Findings From a Qualitative Study of Remote Supervisor Family Physicians in Australia and Canada

Purpose: Changes to health care systems andworking hours have fragmentedresidents’ clinical experiences withpotentially negative effects ontheir development as professionals.Investigation of off-site supervision,which has been implemented in isolatedrural practice, could reveal importantbut less overt components of residencyeducation. 

Method: Insights from sociocultural learningtheory and work-based learning provideda theoretical framework. In 2011–2012,16 family physicians in Australia andCanada were asked in-depth how theyremotely supervised residents’ workand learning, and for their reflectionson this experience. The verbatiminterview transcripts and researchers’memos formed the data set. Templateanalysis produced a description andinterpretation of remote supervision. 

Results: Thirteen Australian family physiciansfrom five states and one territory, andthree Canadians from one province,participated. The main themes werehow remoteness changed the dynamicsof care and supervision; the importanceof ongoing, holistic, nonhierarchical,supportive supervisory relationships; andthat residents learned “clinical courage”through responsibility for patients’ careover time. Distance required supervisorsto articulate and pass on their expertiseto residents but made monitoringdifficult. Supervisory continuityencouraged residents to build on pastexperiences and confront deficiencies. 

Conclusions: Remote supervision enabled residents todevelop as clinicians and professionals.This questions the supremacy of co-locationas an organizing principle forresidency education. Future specialists maybenefit from programs that give themongoing and increasing responsibilityfor a group of patients and supportive.

Beyond the Orange and the Green. The Diversification of the Qualitative Social Research Landscape in Northern Ireland.

The Northern Ireland conflict has been described as one of the most over-researched conflicts in the world. However, this is a relatively recent development. For many years, when the conflict was most intense, social scientists in Northern Ireland were silent and not vocal. The sectarian violence that dominated the life in Northern Ireland as well as the fact that the country was a fundamentally unjust society contributed to this silence. However, since the peace process began in the mid 1990s, a growing number of qualitative studies have been published, utilising one-to-one interviews and focus group discussions, in order to "make people's voices heard" and deal with the consequences of the so-called "Troubles". This paper looks into the emergence of a qualitative social research landscape in Northern Ireland beyond the conflict and explores issues so far neglected. It is argued that a number of factors have contributed to this, among them the availability of research funding to voluntary and community sector organisations that use their data to influence policy-making and equality legislation in a country which is still deeply divided along socio-religious lines.

Qualitative methods in the study of children's racial attitudes and identities

This article examines the role that qualitative methods can play in the study of children's racial attitudes and behaviour. It does this by discussing a number of examples taken from a qualitative, ethnographic study of five- and six-year-old children in an English multi-ethnic, inner-city primary school. The examples are used to highlight the limitations of research that relies solely on quantitative methods and the potential that qualitative methods have for addressing these limitations. Within this context the article contrasts the strengths and weaknesses of qualitative and quantitative methods in the study of children's racial attitudes and identities. The article concludes by arguing that a much more integrated multi-method approach is needed in this area and sets out some of the most effective ways this could be achieved.

Evaluation of extended training for general practice in Northern Ireland: qualitative study.

Objective To evaluate participants' perceptions of the impact on them of an additional six months' training beyond the standard 12 month general practice vocational training scheme. Design Qualitative study using focus groups. Setting General practice vocational training in Northern Ireland. Participants 13 general practitioner registrars, six of whom participated in the additional six months' training, and four trainers involved in the additional six months' training. Main outcome measures: Participants' views about their experiences in 18 month and 12 month courses. Results Participants reported that the 12 month course was generally positive but was too pressurised and focused on examinations, and also that it had a negative impact on self care. The nature of the learning and assessment was reported to have left participants feeling averse to further continuing education and lacking in confidence. In contrast, the extended six month component was reported to have restimulated learning by focusing more on patient care and promoting self directed learning. It developed confidence, promoted teamwork, and gave experience of two practice contexts, and was reported as valuable by both ex-registrars and trainers. However, both the 12 and 18 month courses left participants feeling underprepared for practice management and self care. Conclusions 12 months' training in general practice does not provide doctors with the necessary competencies and confidence to enter independent practice. The extended period was reported to promote greater professional development, critical evaluation skills, and orientation to lifelong learning but does not fill all the gaps.