6,105 research outputs found
The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) prisons project pilot study: protocol for a randomised controlled trial comparing dihydrocodeine and buprenorphine for opiate detoxification
Background
In the United Kingdom (UK), there is an extensive market for the class 'A' drug heroin. Many heroin users spend time in prison. People addicted to heroin often require prescribed medication when attempting to cease their drug use. The most commonly used detoxification agents in UK prisons are buprenorphine, dihydrocodeine and methadone. However, national guidelines do not state a detoxification drug of choice. Indeed, there is a paucity of research evaluating the most effective treatment for opiate detoxification in prisons. This study seeks to address the paucity by evaluating routinely used interventions amongst drug using prisoners within UK prisons.
Methods/Design
The Leeds Evaluation of Efficacy of Detoxification Study (LEEDS) Prisons Pilot Study will use randomised controlled trial methodology to compare the open use of buprenorphine and dihydrocodeine for opiate detoxification, given in the context of routine care, within HMP Leeds. Prisoners who are eligible and give informed consent will be entered into the trial. The primary outcome measure will be abstinence status at five days post detoxification, as determined by a urine test. Secondary outcomes during the detoxification and then at one, three and six months post detoxification will be recorded
Impact of participatory natural resource management research in cassava-based cropping systems in Vietnam and Thailand
In South-east Asia, many of the poorest farmers live in areas with limited
potential for crop production. Cassava (Manihot esculenta Crantz) is an
important crop on these soils, because it is easy to grow, requires few
external inputs and its roots and leaves can be used as human or animal
feed. Cassava is also planted as an industrial crop for the production of
animal feed and starch where market conditions are developed. The wide
variety of end uses makes it a popular crop and an effective vehicle for
improving the livelihood of poor upland farmers
SPIA review of: Impact of participatory natural resource management research in cassava-based cropping systems in Vietnam and Thailand
Between 1994 and 2003, the International Centre for Tropical Agriculture (CIAT), in collaboration with national agricultural research partners in Thailand and Vietnam implemented a Nippon Foundation funded project titled “Improving the Sustainability of Cassava-based Cropping Systems in Asia.” The purpose of the project was to address the problem of the observed widespread non-adoption of soil conservation and fertility management technologies in cassava production in Asia. Aside from conservation technologies such as contour lines, hedgerows and management technologies including inter cropping, use of manure and mineral fertilizer also genetic improvement technologies, i.e. improved cassava varieties were included in the project. Hence, the nature of the NRM research was that of an applied, adaptive research for already existing NRM technologies and principles but where adoption by farmers was low. Together with NARS researchers and extension agents CIAT was working with farmers in selected project villages. The “farmer participatory research” (FPR) methodology included the joint conduct of on-farm experiments to identify, test and adjust promising natural resource conservation and productivity enhancement cassava technologies. The project therefore encompassed a broader research paradigm that falls under the category of INRM as described in chapter 1.2
Human capital accumulation and productivity improvements in Asian cassava systems: are participatory research approaches beneficial?
Recently, discussion had reemerged over the value of integrated pest and crop management training, through intensive approaches such as farmer field schools or participatory training, as a development approach (Feder et al, 2004). This paper develops a model of human capital accumulation through participatory research and tests several hypotheses on the effectiveness of this approach to increase the adoption of soil conservation and fertility management innovations and improve farm productivity in southeast Asia. Bivariate Probit models with treatment effects are estimated using full information maximum likelihood (Evans and Schwab, 1995: Trost and Lee, 1984) and covariates related to changes in land allocation and productivity, measured before project and after project intervention, are investigates. We follow Greene (1998) to control for simultaneity between adoption and impact by using the predicted adoption decision from the second set of regressions to calculate productivity differentials.
Overall, we find that treatment affects associated with the participatory research activities are significant and positive in explaining the differential adoption rates of intercropping, hedgerows, contour ridging, the usage of farm yard manure and chemical fertilizer. The positive relationship between the adoption of soil conservation and fertility management techniques and participation, given very limited productivity impact, may indicated the "value" of the participatory approach to illustrate the social costs of land degradation, sensitize participants towards internalizing these costs, and demonstrate the importance of long-run strategies to preserve land productivity, or both. Secondly, we find that there are additional benefits to participatory research activities that are not embodied in the adoption of soil conservation or fertility management techniques
Shear stress fluctuations in the granular liquid and solid phases
We report on experimentally observed shear stress fluctuations in both
granular solid and fluid states, showing that they are non-Gaussian at low
shear rates, reflecting the predominance of correlated structures (force
chains) in the solidlike phase, which also exhibit finite rigidity to shear.
Peaks in the rigidity and the stress distribution's skewness indicate that a
change to the force-bearing mechanism occurs at the transition to fluid
behaviour, which, it is shown, can be predicted from the behaviour of the
stress at lower shear rates. In the fluid state stress is Gaussian distributed,
suggesting that the central limit theorem holds. The fibre bundle model with
random load sharing effectively reproduces the stress distribution at the yield
point and also exhibits the exponential stress distribution anticipated from
extant work on stress propagation in granular materials.Comment: 11 pages, 3 figures, latex. Replacement adds journal reference and
addresses referee comment
On Real Fluid Flow Over Yawed Circular Cylinders
The equations for both the boundary layer and the outer potential flow over a yawed cylinder can be resolved into equations for the crosswise and spanwise velocity components. These components of the boundary layer are evaluated using Sears’ method, and the separation point is found to be uninfluenced by the yaw angle. The potential-flow solutions for the spanwise and crosswise flows are added together to determine vortex patterns behind the cylinder. The approximate direct dependence of the Strouhal number upon the cosine of the yaw angle and/or the drag coefficient upon the square of the cosine, are verified. Experimental determinations of the Strouhal number and visualization of the flow pattern are consistent with the analysis
Brownian forces in sheared granular matter
We present results from a series of experiments on a granular medium sheared
in a Couette geometry and show that their statistical properties can be
computed in a quantitative way from the assumption that the resultant from the
set of forces acting in the system performs a Brownian motion. The same
assumption has been utilised, with success, to describe other phenomena, such
as the Barkhausen effect in ferromagnets, and so the scheme suggests itself as
a more general description of a wider class of driven instabilities.Comment: 4 pages, 5 figures and 1 tabl
Woodland caribou persistence and extirpation in relic populations on Lake Superior
Extended: The hypothesis was proposed that woodland caribou (Rangifer tarandus caribou) in North America had declined due to wolf predation and over-hunting rather than from a shortage of winter lichens (Bergerud, 1974). In 1974, two study areas were selected for testing: for the lichen hypothesis, we selected the Slate Islands in Lake Superior (36 km2), a closed canopy forest without terrestrial lichens, wolves, bears, or moose; for the predation hypothesis, we selected the nearby Pukaskwa National Park (PNP) where terrestrial lichens, wolves, bears, and moose were present. Both areas were monitored from 1974 to 2003 (30 years). The living and dead caribou on the Slates were estimated by the ‘King census’ strip transect (mean length 108±9.3 km, extremes 22-190, total 3026 km) and the Lincoln Index (mean tagged 45±3.6, extremes 15-78). The mean annual population on the Slate Islands based on the strip transects was 262±22 animals (extremes 104-606), or 7.3/km2 (29 years) and from the Lincoln Index 303±64 (extremes 181-482), or 8.4/km2 (23 years). These are the highest densities in North America and have persisted at least since 1949 (56 years). Mountain maple (Acer spicatum) interacted with caribou density creating a record in its age structure which corroborates persistence at relatively high density from c. 1930. The mean percentage of calves was 14.8±0.34% (20 years) in the fall and 14.1±1.95% (19 years) in late winter. The Slate Islands herd was regulated by the density dependent abundance of summer green foods and fall physical condition rather than density independent arboreal lichen availability and snow depths. Two wolves (1 wolf/150 caribou) crossed to the islands in 1993-94 and reduced two calf cohorts (3 and 4.9 per cent calves) while female adult survival declined from a mean of 82% to 71% and the population declined ≈100 animals. In PNP, caribou/moose/wolf populations were estimated by aerial surveys (in some years assisted by telemetry). The caribou population estimates ranged from 31 in 1979 to 9 in 2003 (Y=1267 - 0.628X, r=-0.783, n=21, P<0.01) and extirpation is forecast in 2018. Animals lived within 3 km of Lake Superior (Bergerud, 1985) with an original density of 0.06/km2, similar to many other woodland herds coexisting with wolves (Bergerud, 1992), and 100 times less than the density found on the Slate Islands. The mean moose population was 0.25±0.016/km2 and the wolf population averaged 8.5±0.65/1000 km2. Late winter calf percentages in PNP averaged 16.2±1.89 (25 years); the population was gradually reduced by winter wolf predation (Bergerud, 1989; 1996). The refuge habitat available is apparently insufficient for persistence in an area where the continuous distribution of woodland caribou is fragmented due to moose exceeding 0.10/km2 and thereby supporting wolf densities ≥6.5/1000 km2. A second experimental study was to introduce Slate Island caribou to areas with and without wolves. A release to Bowman Island, where wolves and moose were present, failed due to predation. Bowman Island is adjacent to St. Ignace Island where caribou had persisted into the late 1940s. A second release in 1989 to the mainland in Lake Superior Provincial Park of 39 animals has persisted (<10 animals) because the animals utilize off-shore islands but numbers are also declining. A third release to Montréal Island in 1984 doubled in numbers (up to 20 animals) until Lake Superior froze in 1994 and wolves reached the island. A fourth release was to Michipicoten Island (188 km2) in 1982 where wolves were absent and few lichens were available. This herd increased at λ= 1.18 (8 to ±200, 160 seen 2001) in 19 years. This was the island envisioned for the crucial test of the lichen/predation hypotheses (Bergerud, 1974: p.769). These studies strongly support the idea that ecosystems without predators are limited bottom–up by food and those with wolves top-down by predation; however the proposed crucial test which has been initiated on Michipicoten Island remains to be completed and there is a limited window of opportunity for unequivocal results
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