2,199 research outputs found
An economic evaluation of the early impact of Aimhigher: excellence challenge on pre-16 outcomes: update to previous analysis
The Aimhigher: Excellence Challenge intervention seeks to encourage more young people to articipate in tertiary education. This paper updates previous estimates of the impact of the programme on the GCSE marks and reported expected school leaving ages, among year 11 pupils. Information from 3 different cohorts is used (whereas the previous analysis had data on the first 2 cohorts). In some schools the second and third cohorts have been exposed to the policy, whereas in others only the third cohort was exposed to the policy. This distinction is used to model the impact of the policy using linear regression analysis. However the lack of a comparison group in Spring 2004 means that the impact of the policy can only be estimated under relatively strong assumptions about the evolution of the impact of the policy across time.
Under the assumption that the policy had the same impact in the original treatment (EiC Phase 1 & 2 areas) in Spring 2004 as in Spring 2003, we find evidence that being part of the Aimhigher: Excellence Challenge programme in the new areas (EiC Phase 3) has led to a 5.2 percentage point increase in the year 11 pupils expecting to leave education at age 20 or over. Although slightly larger, this estimate is not statistically significantly different from the increase of 3.7 percentage points found in the original (EiC Phase 1 & 2) areas. Across both types of area (EiC Phase 1& 2 and EiC Phase 3) we estimate that the average impact of the policy is to increase the percentage of year 11 pupils reporting that they will leave education at age 20 or above by 4.6 percentage points. We also find some evidence of a similar positive impact on GCSE English results, although the impact across other GCSEs is less clear.
While the assumptions made in producing these new estimates are relatively strong it is clear that the analysis of the new data does not contradict the previous estimates (which were reliant on less strong assumptions)
Spatially resolved investigation of the optical and structural properties of CuCl thin films on Si
CuCl thin films grown on (100) Si by thermal evaporation are studied by means of low temperature photoluminescence (PL) and reflectance spectroscopies. Spatially and wavelength resolved room temperature cathodoluminescence (CL) imaging of the surface of the CuCl samples in a scanning electron microscope (SEM) has also been performed. The reflectance spectra are modeled using a dielectric response function with various models involving dead layers and reflected waves in the thin film and the exciton-polariton structure obtained is compared to other studies of CuCl. The modeling is shown to match the experimental data quite well when a dead layer is included at the air/CuCl and CuCl/Si interfaces. Some inconsistencies between the CL spectra and those measured by PL and reflectance have been observed. The effects of changing the accelerating voltage of the probe from 10 keV to the range 1-5 keV to allow depth analysis of the CL are reported, in order to pinpoint the spatial origin of the CL emission within the thin film
Low-mass planet migration in three-dimensional wind-driven inviscid discs: a negative corotation torque
We present simulations of low-mass planet–disc interactions in inviscid three-dimensional discs. We show that a wind-driven laminar accretion flow through the surface layers of the disc does not significantly modify the migration torque experienced by embedded planets. More importantly, we find that 3D effects lead to a dramatic change in the behaviour of the dynamical corotation torque compared to earlier 2D theory and simulations. Although it was previously shown that the dynamical corotation torque could act to slow and essentially stall the inward migration of a low-mass planet, our results in 3D show that the dynamical corotation torque has the complete opposite effect and speeds up inward migration. Our numerical experiments implicate buoyancy resonances as the cause. These have two effects: (i) they exert a direct torque on the planet, whose magnitude relative to the Lindblad torque is measured in our simulations to be small; (ii) they torque the gas librating on horseshoe orbits in the corotation region and drive evolution of its vortensity, leading to the negative dynamical corotation torque. This indicates that at low turbulent viscosity, the detailed vertical thermal structure of the protoplanetary disc plays an important role in determining the migration behaviour of embedded planets. If this result holds up under a more refined treatment of disc thermal evolution, then it has important implications for understanding the formation and early evolution of planetary systems
A bridge too far? The influence of socio-cultural values on the adaptation responses of smallholders to a devastating pest outbreak in cocoa
The influence of socio-cultural factors on the adaptive capacity, resilience and trade-offs in decision-making of households and communities is receiving growing scholarly attention. In many partly transformed societies, where the market economy is not well developed, livelihood practices are heavily structured by kinship and indigenous social and economic values. Farm investment decisions and incentives to produce agricultural commodities are shaped by a host of considerations in addition to market imperatives like profit. In one such partly transformed society in East New Britain Province, Papua New Guinea, we examine the adaptation decisions of smallholders in response to the drastic drop of yield in their cocoa plots caused by the sudden outbreak of Cocoa Pod Borer. To explain why the impact of the pest has been so great we examine the interconnections between household responses, the local socio-cultural and economic context of smallholder commodity crop production and the wider institutional environment in which household choices and decisions are made. We argue that the significant lifestyle changes and labour intensive farming methods required for the effective control of Cocoa Pod Borer are incompatible with existing smallholder farming systems, values and livelihoods. To adopt a high input cropping system requires more than a technical fix and some training; it also requires abandoning a 'way of life' that provides status, identity and a moral order, and which is therefore highly resistant to change. The paper highlights the enduring influence and significance of local, culturally-specific beliefs and socio-economic values and their influence on how individuals and communities make adaptation decisions
No Rise in Incidence but Geographical Heterogeneity in the Occurrence of Primary Biliary Cirrhosis in North East England
In this study, we examined temporal changes in the incidence of primary biliary cirrhosis (PBC) and investigated associations between PBC incidence and sociodemographic factors and spatial clustering. We included 982 patients aged ≥40 years from North East England with incident PBC diagnosed during 1987–2003. Age-standardized incidence rates with 95% confidence intervals were calculated. Negative binomial regression was used to analyze incidence and socioeconomic deprivation. Clustering analysis was performed using point process methods, testing the null hypothesis that disease risk does not vary spatially and that PBC cases occur independently. The age-standardized incidence rate was 53.50 per million persons per year (95% confidence interval: 48.65, 58.35) in 1987–1994 and 45.09 per million persons per year (95% confidence interval: 41.10, 49.07) in 1995–2003. Risk of PBC increased in areas with higher levels of socioeconomic deprivation (P = 0.035). More specifically, risk increased in areas with higher levels of overcrowded homes (P = 0.040), higher levels of households without cars (P < 0.001), and higher levels of non-owner-occupied homes (P < 0.001). Overall, there was evidence of spatial clustering (P = 0.001). The findings confirm that overall incidence of PBC did not rise over time, but sociodemographic variations suggest that certain aspects of deprivation are involved in its etiology
Phenotypic microarrays suggest Escherichia coli ST131 is not a metabolically distinct lineage of extra-intestinal pathogenic E. coli
Extraintestinal pathogenic E. coli (ExPEC) are the major aetiological agent of urinary tract infections (UTIs) in humans. The emergence of the CTX-M producing clone E. coli ST131 represents a major challenge to public health worldwide. A recent study on the metabolic potential of E. coli isolates demonstrated an association between the E. coli ST131 clone and enhanced utilisation of a panel of metabolic substrates. The studies presented here investigated the metabolic potential of ST131 and other major ExPEC ST isolates using 120 API test reagents and found that ST131 isolates demonstrated a lower metabolic activity for 5 of 120 biochemical tests in comparison to non-ST131 ExPEC isolates. Furthermore, comparative phenotypic microarray analysis showed a lack of specific metabolic profile for ST131 isolates countering the suggestion that these bacteria are metabolically fitter and therefore more successful human pathogens
Space–time clustering patterns in childhood leukaemia support a role for infection
Previous studies of space–time clustering in childhood leukaemia have produced equivocal and inconsistent results. To address this issue we have used Manchester Children's Tumour Registry leukaemia data in space–time clustering analyses. Knox tests for space–time interactions between cases were applied with fixed thresholds of close in space, < 5 km and close in time < 1 year apart. Addresses at birth as well as diagnosis were utilized. Tests were repeated replacing geographical distance with distance to the Nth nearest neighbour. N was chosen such that the mean distance was 5 km. Data were also examined by a second order procedure based on K-functions. All methods showed highly significant evidence of space–time clustering based on place of birth and time of diagnosis, particularly for all leukaemias aged 0–14 and 0–4 years, and acute lymphoblastic leukaemia (ALL) 0–4 years. Some results based on location at diagnosis were significant but mainly gave larger P -values. The results are consistent with an infectious hypothesis. Furthermore, we found an excess of male cases over females involved in space–time pairs. We suggest this may be related to genetic differences in susceptibility to infection between males and females. These findings provide the basis for future studies to identify possible infectious agents. © 2000 Cancer Research Campaig
Factors in perioperative care that determine blood loss in liver surgery
AbstractObjectivesExcessive blood loss during liver surgery contributes to postoperative morbidity and mortality and the minimizing of blood loss improves outcomes. This study examines pre- and intraoperative factors contributing to blood loss and identifies areas for improvement.MethodsAll patients who underwent elective hepatic resection between June 2007 and June 2009 were identified. Detailed information on the pre- and perioperative clinical course was analysed. Univariate and multivariate analyses were used to identify factors associated with intraoperative blood loss.ResultsA total of 175 patients were studied, of whom 95 (54%) underwent resection of three or more segments. Median blood loss was 782ml. Greater blood loss occurred during major resections and prolonged surgery and was associated with an increase in postoperative complications (P= 0.026). Peak central venous pressure (CVP) of >10cm H2O was associated with increased blood loss (P= 0.01). Although no differences in case mix were identified, blood loss varied significantly among anaesthetists, as did intraoperative volumes of i.v. fluids and transfusion practices.ConclusionsThis study confirms a relationship between CVP and blood loss in hepatic resection. Intraoperative CVP values were higher than those described in other studies. There was variation in the intraoperative management of patients. Collaboration between surgical and anaesthesia teams is required to minimize blood loss and the standardization of intraoperative anaesthesia practice may improve outcomes following liver surgery
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