The effect of socioeconomic deprivation on corneal graft survival in the United Kingdom

Objective: To investigate the effect of socioeconomic deprivation on cornea graft survival in the United Kingdom.

Design: Retrospective cohort study.

Participants: All the recipients (n = 13?644) undergoing their first penetrating keratoplasty (PK) registered on the United Kingdom Transplant Registry between April 1999 and March 2011 were included.

Methods: Data of patients' demographic details, indications, graft size, corneal vascularization, surgical complication, rejection episodes, and postoperative medication were collected at the time of surgery and 1, 2, and 5 years postoperatively. Patients with endophthalmitis were excluded from the study. Patients' home postcodes were used to determine the socioeconomic status using a well-validated deprivation index in the United Kingdom: A Classification of Residential Neighborhoods (ACORN). Kaplan–Meier survival and Cox proportional hazards regression were used to evaluate the influence of ACORN categories on 5-year graft survival, and the Bonferroni method was used to adjust for multiple comparisons.

Main Outcome Measures: Patients' socioeconomic deprivation status and corneal graft failure.

Results: A total of 13?644 patients received their first PK during the study periods. A total of 1685 patients (13.36%) were lost to follow-up, leaving 11?821 patients (86.64%) for analysis. A total of 138 of the 11?821 patients (1.17%) developed endophthalmitis. The risk of graft failure within 5 years for the patients classified as hard-pressed was 1.3 times that of the least deprived (hazard ratio, 1.3; 95% confidence interval, 1.1–1.5; P = 0.003) after adjusting for confounding factors and indications. There were no statistically significant differences between the causes of graft failure and the level of deprivation (P = 0.14).

Conclusions: Patients classified as hard-pressed had an increased risk of graft failure within 5 years compared with the least deprived patients.

Financial Disclosure(s): The author(s) have no proprietary or commercial interest in any materials discussed in this article

Multiple Regulatory Pathways Associated with High-Level Ciprofloxacin and Multidrug Resistance in Salmonella enterica Serovar Enteritidis: Involvement of ramA and Other Global Regulators

Mechanisms of antibiotic resistance were examined in nalidixic acid-resistant Salmonella enterica serovar Enteritidis field isolates displaying decreased susceptibility to ciprofloxacin and in in vitro-derived ciprofloxacin-resistant mutants (104-cip and 5408-cip). All field isolates harbored a single gyrA mutation (D87Y). Deletion of acrB and complementation with wild-type gyrA increased quinolone susceptibility. Selection for ciprofloxacin resistance was associated with the development of an additional gyrA (S83F) mutation in 104-cip, novel gyrB (E466D) and parE (V461G) mutations in 5408-cip, overexpression of acrB and decreased susceptibility to nonquinolone antibiotics in both mutants, and decreased OmpF production and altered lipopoly- saccharide in 104-cip. Complementation of mutated gyrA and gyrB with wild-type alleles restored susceptibility to quinolones in 104-cip and significantly decreased the ciprofloxacin MIC in 5408-cip. Complementation of parE had no effect on quinolone MICs. Deletion of acrB restored susceptibility to ciprofloxacin and other antibiotics tested. Both soxS and marA were overexpressed in 104-cip, and ramA was overexpressed in 5408-cip. Inactivation of each of these global regulators lowered ciprofloxacin MICs, decreased expression of acrB, and restored susceptibility to other antibiotics. Mutations were found in soxR (R20H) and in soxS (E52K) in 104-cip and in ramR (G25A) in 5408-cip. In conclusion, both efflux activity and a single gyrA mutation contribute to nalidixic acid resistance and reduced ciprofloxacin sensitivity. Ciprofloxacin resistance and decreased susceptibility to multiple antibiotics can result from different genetic events leading to development of target gene mutations, increased efflux activity resulting from differential expression of global regulators associated with mutations in their regulatory genes, and possible altered membrane permeability.

Flow due to multiple jets downstream of a barrage: Experiments, 3-D CFD and depth-averaged modelling

The flow through and downstream of a row of seven open draft tubes in a barrage has been investigated through laboratory experiments in a wide flume, a three-dimensional (3D) computational fluid dynamics simulation, and a two-dimensional depth-averaged computation. Agreement between the experiments and the 3D modeling is shown to be good, including the prediction of an asymmetric Coandă effect. One aim is to determine the distance downstream at which depth-averaged modeling provides a reasonable prediction; this is shown to be approximately 20 tube diameters downstream of the barrage. Upstream of this, the depth-averaged modeling inaccurately predicts water level, bed shear, and the 3D flow field. The 3D model shows that bed shear stress can be markedly magnified near the barrage, particularly where the jets become attached.

New Views on Effect of Recycled Aggregates on Concrete Compressive Strength

This paper presents an in-depth study on the effect that composition and properties of recycled coarse aggregates from previous concrete structures, together with water/cement ratio (w/c) and a replacement ratio of coarse aggregate, have on compressive strength, its evolution through time, and its variability. A rigorous approach through statistical inference based on multiple linear regression has identified the key factors. A predictive equation is given for compressive strength when recycled coarse aggregates are used. The w/c and replacement ratio are the capital factors affecting concrete compressive strength. Their effect is significantly modified by the properties and composition of the recycled aggregates used. An equation that accurately predicts concrete compressive strength in terms of these parameters is presented. Particular attention has been paid to the complex effect that old concrete and adhered mortar have on concrete compressive strength and its mid-term evolution. It has been confirmed that the presence of contaminants tends to increase variability of compressive strength values.

Experiences of youth justice: Youth justice discourses and their multiple effects

Interventions within youth justice systems draw on a range of rationales and philosophies. Traditionally demarcated by a welfare/justice binary, the complex array of contemporary rationales meld different philosophies and practices, suggesting a mutability that gives this sphere a continued (re)productive and felt effect. While it may be increasingly difficult to ascertain which of these discourses is dominant in different jurisdictions in the UK, particular models of justice are perceived to be more prominent (Muncie, 2006). Traditionally it is assumed that Northern Ireland prioritises restoration, Wales prioritises rights, England priorities risk and Scotland welfare (McVie, 2011; Muncie, 2008, 2011). However, how these discourses are enacted in practice, how multiple and competing rationales circulate within them and most fundamentally how they are experienced by young people is less clear. This paper, based on research with young people who have experienced the full range of interventions in the youth justice system in Northern Ireland examines their narratives of ‘justice’. It considers how different discourses might influence the same intervention and how the deployment of multiple rationalities gives the experience of ‘justice’ its effect.

Genetic pleiotropy between multiple sclerosis and schizophrenia but not bipolar disorder: differential involvement of immune-related gene loci

Converging evidence implicates immune abnormalities in schizophrenia (SCZ), and recent genome-wide association studies (GWAS) have identified immune-related single-nucleotide polymorphisms (SNPs) associated with SCZ. Using the conditional false discovery rate (FDR) approach, we evaluated pleiotropy in SNPs associated with SCZ (n=21 856) and multiple sclerosis (MS) (n=43 879), an inflammatory, demyelinating disease of the central nervous system. Because SCZ and bipolar disorder (BD) show substantial clinical and genetic overlap, we also investigated pleiotropy between BD (n=16 731) and MS. We found significant genetic overlap between SCZ and MS and identified 21 independent loci associated with SCZ, conditioned on association with MS. This enrichment was driven by the major histocompatibility complex (MHC). Importantly, we detected the involvement of the same human leukocyte antigen (HLA) alleles in both SCZ and MS, but with an opposite directionality of effect of associated HLA alleles (that is, MS risk alleles were associated with decreased SCZ risk). In contrast, we found no genetic overlap between BD and MS. Considered together, our findings demonstrate genetic pleiotropy between SCZ and MS and suggest that the MHC signals may differentiate SCZ from BD susceptibility.Molecular Psychiatry advance online publication, 28 January 2014; doi:10.1038/mp.2013.195.

Meta-analysis of the influence of experimental design on effect size in peer tutoring outcomes in elementary, middle and high school settings.

A meta-analysis was undertaken on a form of cooperative learning, peer tutoring. The effects of experimental design on outcomes were explored, as measured by Effect Size (ES). 185 studies were included in the meta-analysis. Highest ES were reported for quasi-experimental studies. ES reduced as experimental design moved from single pre-test factor matched, to multiple-factor matched randomized controlled trials. ES reduced when designs used standardised, rather than self-designed measures, The implications for future meta-analyses and research in cooperative learning are explored.

A self-learning teaching-learning based optimization for dynamic economic/environmental dispatch considering multiple plug-in electric vehicle loads

Economic and environmental load dispatch aims to determine the amount of electricity generated from power plants to meet load demand while minimizing fossil fuel costs and air pollution emissions subject to operational and licensing requirements. These two scheduling problems are commonly formulated with non-smooth cost functions respectively considering various effects and constraints, such as the valve point effect, power balance and ramp rate limits. The expected increase in plug-in electric vehicles is likely to see a significant impact on the power system due to high charging power consumption and significant uncertainty in charging times. In this paper, multiple electric vehicle charging profiles are comparatively integrated into a 24-hour load demand in an economic and environment dispatch model. Self-learning teaching-learning based optimization (TLBO) is employed to solve the non-convex non-linear dispatch problems. Numerical results on well-known benchmark functions, as well as test systems with different scales of generation units show the significance of the new scheduling method.

Enhancing performance: The moderating effect of environmental integration and environmental capabilities on the performance outcomes of pollution prevention

Over the last two decades there has been ongoing debate about the impact of environmental practices on operational performance. In recent years, studies have started to move beyond assessing the direct impact of environmental management on different dimensions of performance to consider factors that might moderate or mediate this relationship. This study considers the extent to which environmental integration and environmental capabilities moderate the relationship between pollution prevention and environmental performance outcomes. The mediating influence of environmental performance on the relationship between pollution prevention and cost and flexibility performance is also considered. Data were collected from a sample of UK food manufacturers and analysed using multiple regression analysis. The findings indicate the existence of some moderated and mediated relationships suggesting that there is more to improving performance than implementing environmental practices.

Field test of multiple 1/10 scale tidal turbines in steady flows

Queen's University Belfast and Wave Barrier Ltd have developed a tidal testing platform to test hydrokinetic turbines at medium scale. Multiple turbines can be pushed through still water conditions, in steady-state pushing tests. Experiments were conducted to evaluate the interactions between two identical, mono-strut, horizontal axis tidal turbines (HATTs) of 1.5 m diameter (D) rotor. Their relative performance when located individually, in-plane and in-line are investigated. The data shows a high consistency in the power curves at different flow speeds, which indicates high repeatability in this Reynolds range. For an individual turbine, there is no performance difference when the rotor is mounted either upstream or downstream of the supporting structure. When placed in-plane, the turbines have no adverse effect on one another. When spaced in-line with 2D separation, there is a 63% reduction in the performance of the downstream turbine. At 6D downstream this performance reduction is still 59%, indicating some wake recovery between 2D and 6D, though the influence from the upstream rotor persists to at least 6D downstream of the first device. In contrast the performance of the downstream turbine when placed at 1.5D offset of the upstream device at 6D downstream is approximately recovered to the individual turbine performance.

Response of soil microbial communities to single and multiple doses of an organic pollutant

The effect of 100 μg 1,2-dichlorobenzene (1,2-DCB) g^-1 dry weight (dw) of soil introduced either as a single dose or multiple (10 fortnightly) doses of 10 μg g^-1 dw, on the microbial biomass, diversity of culturable bacterial community and the rate of 1,2-DCB mineralisation, were compared. After 22 weeks exposure both application regimes significantly reduced total bacterial counts and viable fungal hyphal length. The single dose had the greatest overall inhibitory effect, although the extent of inhibition varied throughout the study. Total culturable bacterial counts, determined after 22 weeks exposure showed little response to 1,2-DCB, but pseudomonad counts in single and multiple treatments were reduced to 9.7 and 0.147%, respectively, of the numbers detected in the control soil. The effect of 1,2-DCB application on the taxonomic composition of the culturable bacteria community was determined by fatty acid methyl ester (FAME) analysis. Compared to control soils, the single dose treatment had a lower percentage of Arthrobacter and Micrococcus. Multiple applications had a significant effect upon pseudomonad abundance, which represented only 2% of the identified community, compared to 45.6% in the control. The multi-dosed soils contained a high percentage of bacilli (> 25%). The effects of 1,2-DCB applications on the metabolic potential of the soil microbial community was determined by BIOLOG profiling. The number of carbon compounds utilised by the community in the multi-dosed soils (49 positives) was significantly less (P < 0.05) than detected in the single dose treatment (76) and control (66). The rate of 1,2-DCB mineralisation, determined by ¹⁴CO₂ production from radiolabelled [UL-¹⁴C] 1,2-DCB, declined throughout the study, and after 22 weeks was slightly but significantly (P < 0.05) lower in the multiply- than the singly-dosed soils. The differential response to 1,2-DCB treatments was attributed to its reduced bioavailability in soils after a single exposure, compared to multiple applications.

Spatial and temporal variability of the freshwater reservoir effect (FRE) in lacustrine sediments in a cold climate zone, Northwest Territories (Canada)

Climate variability along the 600 km Tibbitt to Contwyoto Winter Road (TCWR) in central Northwest Territories is poorly understood. With the transportation of goods from Yellowknife to the mines projected to increase significantly as new mines open, it is critical that planners and mine developers have reasonable data on the future viability of the road, as alternative transportation costs (e.g. air transport) are prohibitively high.

The research presented here is part of a paleoclimate study based on the analysis of multiple proxy data derived from freeze cores in lakes along the TCWR.

Effect of Cyclic Carbonation on Chloride Ingression in GGBS Concrete

Carbonation and chloride ingress are the two main causes of corrosion in reinforced concrete structures. An investigation to monitor the ingress of chlorides and the effect of carbonation on chloride ingression during an accelerated 12 month cyclic wetting and drying exposure regime that simulates conditions in which multiple mode transport mechanisms are active was conducted on ground granulated blast furnace slag (GGBS) concrete. The penetration of chloride and carbon dioxide was evaluated using water and acid soluble chloride profiles and phenolphthalein indicator, respectively. The results indicated that when chloride and carbon dioxide ingress concomitantly the effects can be adverse. Carbonation has a detrimental effect on the binding capacity of the concrete, increasing the concentration of free (water soluble) chlorides. This contributed to greater concentration and greater penetration of chlorides and thus an increased corrosion risk.

The influence of experimental design on the magnitude of the effect size -peer tutoring for elementary, middle and high school settings: A meta-analysis

A meta-analysis was undertaken on a form of cooperative learning, peer tutoring. The effects of experimental design on outcomes were explored, as measured by Effect Size (ES). Forty three articles with 82 effect size studies were included in the meta-analysis. Highest ES were reported for quasi-experimental studies. ES reduced as experimental design moved from single pre-test factor matched, to multiple-factor matched randomized controlled trials. ES reduced when designs used standardised, rather than self-designed measures. The implications for future meta-analyses and research in cooperative learning are explored.

The effect of clock jitter on the performance of continuous-time delta-sigma ADC for GNSS signals

Next generation Global Navigation Satellite System (GNSS) receivers will operate in multiple navigation bands. An efficient way to achieve this with lower power and cost is to employ BandPass Sampling (BPS); nevertheless, the sampling operation injects large amounts of jitter noise, which degrades the performance of the receiver. Continuous–Time (CT) Delta–Sigma (ΔΣ) modulators are capable of suppressing this noise but the impact of clock jitter at the output of the Digital– to–Analog Converter (DAC) in the feedback path of the modulator should be taken into account. This paper presents an analytical approach for describing clock jitter in GNSS receivers when a CT–ΔΣ modulator is utilized for Analog–to–Digital Conversion (ADC). The validity of the presented approach is verified through time–domain simulations using a behavioural model of the fourth–order CT–ΔΣ modulator with 1–bit NRZ DAC feedback pulse.