1,216 research outputs found
Challenges in evaluating Welfare to Work policy interventions: Would an RCT design have been the answer to all our problems?
<p>Background: UK policy direction for recipients of unemployment and sickness benefits is to support these people into employment by increasing 'into work' interventions. Although the main aim of associated interventions is to increase levels of employment, improved health is stated as a benefit, and a driver of these interventions. This is therefore a potentially important policy intervention with respect to health and health inequalities, and needs to be validated through rigorous impact evaluation.</p>
<p>We attempted to evaluate the Pathways Advisory Service intervention which aims to provide employment support for Incapacity Benefit recipients, but encountered a number of challenges and barriers to evaluation. This paper explores the issues that arose in designing a suitable evaluation of the Pathways Advisory Service.</p>
<p>Discussion: The main issues that arose were that characteristics of the intervention lead to difficulties in defining a suitable comparison group; and governance restrictions such as uncertainty regarding ethical consent processes and data sharing between agencies for research. Some of these challenges threatened fundamentally to limit the validity of any experimental or quasi-experimental evaluation we could design - restricting recruitment, data collection and identification of an appropriate comparison group. Although a cluster randomised controlled trial design was ethically justified to evaluate the Pathways Advisory Service, this was not possible because the intervention was already being widely implemented. However, this would not have solved other barriers to evaluation. There is no obvious method to perform a controlled evaluation for interventions where only a small proportion of those eligible are exposed. Improved communication between policymakers and researchers, clarification of data sharing protocols and improved guidelines for ethics committees are tangible ways which may reduce the current obstacles to this and other similar evaluations of policy interventions which tackle key determinants of health.</p>
<p>Summary: The evaluation of social interventions is hampered by more than their suitability to randomisation. Data sharing, participant identification and recruitment problems are common to randomised and non-randomised evaluation designs. These issues require further attention if we are to learn from current social policy.</p>
Foragebeef.ca Web Site: A Model for Technology Transfer
We live in an age of information overload. As budgets for technology transfer of scientific information and extension education continue to fall, new ways to disseminate agricultural knowledge are needed. Research findings, published in many scientific journals and reports, are seldom readily available to extension agents and farmers. Over time some of this material is lost. This program aimed to locate the best information on various forage and beef topics relative to Canada and the Northern USA and to summarise them in condensed form and in scientific review papers for a web-based site
Use of a hydrological model for environmental management of the Usangu Wetlands, Tanzania
Wetlands / Rivers / Ecology / Environmental effects / Remote sensing / Hydrology / Simulation models / Water budget / Irrigated sites / Land cover / Time series analysis / Tanzania / Usangu Wetlands / Great Ruaha River
Land-Use Experiments in the Loch Laidon Catchment
This report presents the results from the Stream Water Quality component
of the Loch Laidon catchment land-use experiment which commenced in
1992. The experiment was established with the aim of examining the effects
of cattle grazing on the aquatic and terrestrial habitats and biota of a
moorland area of upland Scotland
Eutectic Colony Formation: A Stability Analysis
Experiments have widely shown that a steady-state lamellar eutectic
solidification front is destabilized on a scale much larger than the lamellar
spacing by the rejection of a dilute ternary impurity and forms two-phase cells
commonly referred to as `eutectic colonies'. We extend the stability analysis
of Datye and Langer for a binary eutectic to include the effect of a ternary
impurity. We find that the expressions for the critical onset velocity and
morphological instability wavelength are analogous to those for the classic
Mullins-Sekerka instability of a monophase planar interface, albeit with an
effective surface tension that depends on the geometry of the lamellar
interface and, non-trivially, on interlamellar diffusion. A qualitatively new
aspect of this instability is the occurence of oscillatory modes due to the
interplay between the destabilizing effect of the ternary impurity and the
dynamical feedback of the local change in lamellar spacing on the front motion.
In a transient regime, these modes lead to the formation of large scale
oscillatory microstructures for which there is recent experimental evidence in
a transparent organic system. Moreover, it is shown that the eutectic front
dynamics on a scale larger than the lamellar spacing can be formulated as an
effective monophase interface free boundary problem with a modified
Gibbs-Thomson condition that is coupled to a slow evolution equation for the
lamellar spacing. This formulation provides additional physical insights into
the nature of the instability and a simple means to calculate an approximate
stability spectrum. Finally, we investigate the influence of the ternary
impurity on a short wavelength oscillatory instability that is already present
at off-eutectic compositions in binary eutectics.Comment: 26 pages RevTex, 14 figures (28 EPS files); some minor changes;
references adde
Synthesis, characterization and modeling of high quality ferromagnetic Cr-doped AlN thin films
We report a theoretical and experimental investigation of Cr-doped AlN.
Density functional calculations predict that the isolated Cr t2 defect level in
AlN is 1/3 full, falls approximately at midgap, and broadens into an impurity
band for concentrations over 5%. Substitutional Al1-xCrxN random alloys with
0.05 <= x <= 0.15 are predicted to have Curie temperatures over 600 K.
Experimentally, we have characterized and optimized the molecular beam epitaxy
thin film growth process, and observed room temperature ferromagnetism with a
coercive field, Hc, of 120 Oersted. The measured magnetic susceptibility
indicates that over 33% of the Cr is magnetically active at room temperature
and 40% at low temperature.Comment: 13 pages, 4 figures, submitted to AP
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