1,694 research outputs found
Applications of graphics to support a testbed for autonomous space vehicle operations
Researchers describe their experience using graphics tools and utilities while building an application, AUTOPS, that uses a graphical Machintosh (TM)-like interface for the input and display of data, and animation graphics to enhance the presentation of results of autonomous space vehicle operations simulations. AUTOPS is a test bed for evaluating decisions for intelligent control systems for autonomous vehicles. Decisions made by an intelligent control system, e.g., a revised mission plan, might be displayed to the user in textual format or he can witness the effects of those decisions via out of window graphics animations. Although a textual description conveys essentials, a graphics animation conveys the replanning results in a more convincing way. Similarily, iconic and menu-driven screen interfaces provide the user with more meaningful options and displays. Presented here are experiences with the SunView and TAE Plus graphics tools used for interface design, and the Johnson Space Center Interactive Graphics Laboratory animation graphics tools used for generating out out of the window graphics
Landmarking the brain for geometric morphometric analysis: An error study
Neuroanatomic phenotypes are often assessed using volumetric analysis. Although powerful and versatile, this approach is limited in that it is unable to quantify changes in shape, to describe how regions are interrelated, or to determine whether changes in size are global or local. Statistical shape analysis using coordinate data from biologically relevant landmarks is the preferred method for testing these aspects of phenotype. To date, approximately fifty landmarks have been used to study brain shape. Of the studies that have used landmark-based statistical shape analysis of the brain, most have not published protocols for landmark identification or the results of reliability studies on these landmarks. The primary aims of this study were two-fold: (1) to collaboratively develop detailed data collection protocols for a set of brain landmarks, and (2) to complete an intra- and inter-observer validation study of the set of landmarks. Detailed protocols were developed for 29 cortical and subcortical landmarks using a sample of 10 boys aged 12 years old. Average intra-observer error for the final set of landmarks was 1.9 mm with a range of 0.72 mm-5.6 mm. Average inter-observer error was 1.1 mm with a range of 0.40 mm-3.4 mm. This study successfully establishes landmark protocols with a minimal level of error that can be used by other researchers in the assessment of neuroanatomic phenotypes. © 2014 Chollet et al
The Impact of Traumatic Brain Injury on the Receipt of Services Following Release from Prison
Traumatic brain injury (TBI) is found at substantially higher rates among incarcerated individuals compared to the general adult population. Individuals with TBI report a higher likelihood to experience a range of deleterious outcomes including substance abuse, depression, post-traumatic stress disorder, aggressive behavior, and violence. Thus, a history of TBI is likely to lead to the types of behaviors that will significantly increase the odds of an individual returning to incarceration post-release, as supported by recent research with a cohort of state prisoners. TBI has largely gone unaddressed by prison reentry programs that are integral to rehabilitating individuals returning to the community. Relatively little is known, however, about the effects of TBI on the receipt of services post-release. Additionally, few studies have examined sex differences in the prevalence of TBI in reentry populations. This chapter uses data from a multi-state prisoner reentry program randomized control trial to examine whether individuals with TBI are significantly different than their peers without TBI with respect to a variety of demographic and psychological metrics and in expressions of needs for and participation in services and programming during the transition from incarceration to the community
Reduced Cardiovascular Reserve in Chronic Kidney Failure: A Matched Cohort Study
Background:
Patients with chronic kidney failure (CKF) experience impaired functional cardiovascular reserve with reduced oxygen consumption at peak exercise (Vo2peak). No studies have examined whether this is related to impaired cardiovascular compliance as a consequence of loss of adaptive structural alterations, resulting from chronic uremia or hypertension.
Study Design:
Prospective matched-cohort study.
Setting & Participants:
We assessed CKF in parallel with patients with essential hypertension but without cardiovascular disease. Patients with CKF were either scheduled for kidney transplantation or transplant waitlisted. 80 patients with CKF and 80 with essential hypertension matched in age, sex, and body mass index were evaluated. 61 patients with CKF (76.3%) were dialysis dependent.
Predictor:
CKF versus essential hypertension without cardiovascular disease.
Measurements & Outcomes:
Vo2peak was measured during maximal exercise testing. 2-dimensional echocardiography and arterial applanation tonometry were performed prior to exercise testing. To evaluate for the difference in Vo2peak between study groups, statistically significant predictors of Vo2peak in multiple regression models were additionally assessed by fitting models comprising the interaction term of patient group with the predictor variable of interest.
Results:
Vo2peak was significantly lower in patients with CKF than those with essential hypertension (18.8 vs 24.5 mL/min·kg; P < 0.001). Independent predictors of Vo2peak for CKF included left ventricular (LV) filling pressure (E/mean e′; unstandardized regression coefficient: change in Vo2peak [in mL/min·kg] per 1-unit change of variable = −5.1) and pulse wave velocity (−4.0); in essential hypertension, these were LV mass index (0.2), LV end-diastolic volume index (0.4), peak heart rate (0.2), and pulse wave velocity (−8.8). The interaction effect of Vo2peak between patient groups with LV mass index (P < 0.001), LV end-diastolic volume index (P < 0.001), and peak heart rate (P < 0.01) were significantly stronger in the hypertension group, whereby higher values led to greater Vo2peak.
Limitations:
Skeletal muscle strength was not assessed.
Conclusion:
This study suggests that maladaptive LV changes, as well as blunted chronotropic response, are important mechanistic factors resulting in reduced cardiovascular reserve in patients with CKF, beyond predominantly vascular changes associated with hypertension
Cost-effectiveness of psychological intervention within services for depression delivered by primary care workers in Nepal: economic evaluation of a randomized control trial
Abstract
Background
Integrating services for depression into primary care is key to reducing the treatment gap in low- and middle-income countries. We examined the value of providing the Healthy Activity Programme (HAP), a behavioral activation psychological intervention, within services for depression delivered by primary care workers in Chitwan, Nepal using data from the Programme for Improving Mental Health Care.
Methods
People diagnosed with depression were randomized to receive either standard treatment (ST), comprised of psychoeducation, antidepressant medication, and home-based follow up, or standard treatment plus psychological intervention (T + P). We estimated incremental costs and health effects of T + P compared to ST, with quality adjusted life years (QALYs) and depression symptom scores over 12 months as health effects. Nonparametric uncertainty analysis provided confidence intervals around each incremental effectiveness ratio (ICER); results are presented in 2020 international dollars.
Results
Sixty participants received ST and 60 received T + P. Implementation costs (ST = 617) were substantially higher than service delivery costs (ST = 22.4) per participant. ST and T + P participants accrued 46.5 and 49.4 QALYs, respectively. The ICERs for T + P relative to ST were 2484 to 53.21 (95% confidence interval: −30.2) per unit change on the Patient Health Questionnaire.
Conclusion
Providing HAP within integrated depression services in Chitwan was cost-effective, if not highly cost-effective. Efforts to scale up integrated services in Nepal and similar contexts should consider including evidence-based psychological interventions as a part of cost-effective mental healthcare for depression
An exploratory randomised controlled trial of a premises-level intervention to reduce alcohol-related harm including violence in the United Kingdom
<b>Background</b><p></p>
To assess the feasibility of a randomised controlled trial of a licensed premises intervention to reduce severe intoxication and disorder; to establish effect sizes and identify appropriate approaches to the development and maintenance of a rigorous research design and intervention implementation.<p></p>
<b>Methods</b><p></p>
An exploratory two-armed parallel randomised controlled trial with a nested process evaluation. An audit of risk factors and a tailored action plan for high risk premises, with three month follow up audit and feedback. Thirty-two premises that had experienced at least one assault in the year prior to the intervention were recruited, match paired and randomly allocated to control or intervention group. Police violence data and data from a street survey of study premises’ customers, including measures of breath alcohol concentration and surveyor rated customer intoxication, were used to assess effect sizes for a future definitive trial. A nested process evaluation explored implementation barriers and the fidelity of the intervention with key stakeholders and senior staff in intervention premises using semi-structured interviews.<p></p>
<b>Results</b><p></p>
The process evaluation indicated implementation barriers and low fidelity, with a reluctance to implement the intervention and to submit to a formal risk audit. Power calculations suggest the intervention effect on violence and subjective intoxication would be raised to significance with a study size of 517 premises.<p></p>
<b>Conclusions</b><p></p>
It is methodologically feasible to conduct randomised controlled trials where licensed premises are the unit of allocation. However, lack of enthusiasm in senior premises staff indicates the need for intervention enforcement, rather than voluntary agreements, and on-going strategies to promote sustainability
‘You just have to work with what you’ve got’ Practitioner research with precarious migrant families
This is an accepted manuscript of an article published by Taylor and Francis in Practice on 09/10/2017, available online: https://doi.org/10.1080/09503153.2017.1385756
The accepted version of the publication may differ from the final published version.Undocumented migrant families experience high levels of food poverty, exclusion from mainstream benefits, and sometimes from social work services. This is an under-researched area for social work in the UK, and there is no statutory guidance for social workers on supporting undocumented migrants. Practitioner research is one way of ‘visibilising’ their experiences. Six migrant families accessing a voluntary sector stay and play project were interviewed using a practitioner research model of semi-structured interviews on the themes of food, access to services and children. The research found that families responded to their situation with a seemingly contradictory strategy of resignation and resilience. The implications for practitioners working with this user group are considered, and suggestions for support services for this group of families are offered
The politics of protest in newspaper campaigns: dissent, populism and the rhetoric of authenticity
Newspaper campaigns embody newspaper’ most emphatic claims to speak for ‘the people’, and as such are generally regarded as populist. However, they can be oppositional, engaging in dissent of one sort or another, and often assume a certain amount of political engagement with that dissent on the part of the audience. This article examines the potential of newspaper camapigns to facilitate the political engagement of citizens through the politics of protest. It draws on qualitative analysis of seven campaigns that ran in the Scottish press between 2000 and 2005, and semi-structured interviews with relevant journalists. The distinction between legitimate protest and manipulative populism is made in terms of: (a) the rhetoric and strategies of political representation, participation and influence and (b) the construction of political legitimacy in terms of the public interest and the moral authority of the ‘victim’. It is argued that populist impulses dominate, driving a tendency to use discourses of emotional authenticity and offence to legitimise demands for a plebiscitary response to popular of ‘victim’ preference and to close down controversy and debate, with the principal objective marketing the newspaper as an influential community champion
Utilisation of an operative difficulty grading scale for laparoscopic cholecystectomy
Background
A reliable system for grading operative difficulty of laparoscopic cholecystectomy would standardise description of findings and reporting of outcomes. The aim of this study was to validate a difficulty grading system (Nassar scale), testing its applicability and consistency in two large prospective datasets.
Methods
Patient and disease-related variables and 30-day outcomes were identified in two prospective cholecystectomy databases: the multi-centre prospective cohort of 8820 patients from the recent CholeS Study and the single-surgeon series containing 4089 patients. Operative data and patient outcomes were correlated with Nassar operative difficultly scale, using Kendall’s tau for dichotomous variables, or Jonckheere–Terpstra tests for continuous variables. A ROC curve analysis was performed, to quantify the predictive accuracy of the scale for each outcome, with continuous outcomes dichotomised, prior to analysis.
Results
A higher operative difficulty grade was consistently associated with worse outcomes for the patients in both the reference and CholeS cohorts. The median length of stay increased from 0 to 4 days, and the 30-day complication rate from 7.6 to 24.4% as the difficulty grade increased from 1 to 4/5 (both p < 0.001). In the CholeS cohort, a higher difficulty grade was found to be most strongly associated with conversion to open and 30-day mortality (AUROC = 0.903, 0.822, respectively). On multivariable analysis, the Nassar operative difficultly scale was found to be a significant independent predictor of operative duration, conversion to open surgery, 30-day complications and 30-day reintervention (all p < 0.001).
Conclusion
We have shown that an operative difficulty scale can standardise the description of operative findings by multiple grades of surgeons to facilitate audit, training assessment and research. It provides a tool for reporting operative findings, disease severity and technical difficulty and can be utilised in future research to reliably compare outcomes according to case mix and intra-operative difficulty
Purification and characterisation of a carboxylesterase from the latex ofSynadenium grantii Hook, ‘f’
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