Numerical Analysis of the Changes in Dense Medium Feed Solids on Dense Medium Cyclone Performance

Numerical simulations of changes in feed medium solids on dense medium cyclone performance were performed using a multi-phase mixture CFD (Computational Fluid Dynamics) model for medium and air-core coupled with Lagrangian model for coal particles for a 350mm DSM cyclone. The turbulence was resolved using Large Eddy Simulation (LES). The mixture model considered the interactions between water and solid phases in terms of hindered settling, lift and Bagnold forces at high feed medium solid loadings. The medium properties were modified by changing the particle size distribution and concentration. Three different medium sizes (ultrafine, superfine and fine) were used in the simulations. The effect of medium stability and rheology on DMC performance is related to feed medium size in terms of density differential and medium segregation. The simulations predicted low Ep (Ecort probability) values with finer medium which gives high separation efficiency on density. A reduction in cyclone efficiency observed for a given feed medium solids distribution at higher feed medium concentrations due to an increase in slurry viscosit

Water velocity measurements inside a hydrocyclone using an Aeroprobe & Comparison with CFD predictions

Water Velocities inside a 150mm KrebsTM DF6 classifying hydrocyclone have been measured using an AeroprobeTM. Although the Aeroprobe disturbs the flow, the axial and tangential velocity measurements are qualitatively sensible and the integral wall pressure obtained from the measured tangential velocity profile is close to the measured wall pressure at the same elevation, which suggests that the measured tangential velocities are still reasonably accurate. The time averaged velocities from Large Eddy Simulations of the same cyclone geometry in FluentTM are within 15% of the measured velocities

Metabolic Alterations in Obstructive Jaundice: Effect of Duration of Jaundice and Bile-Duct Decompression

We examined the effect of prolonged bile duct obstruction, and subsequent biliary decompression, on biochemical and metabolic parameters, using a reversible jaundice model in male Fischer 344 rats. The animals were studied after biliary obstruction for varying periods (4 days, one week, and two weeks) and following decompression. They were sacrificed one or two weeks following decompression. All the rats were compared to sham operated, pair-fed, controls. Obstructive jaundice rapidly increased bilirubin, liver enzymes, serum free fatty acid, and triglyceride levels. Glucose levels were significantly decreased in the jaundice rats compared to their pair-fed controls. Only after two weeks of jaundice was significant hypoalbuminemia observed. Following decompression, all biochemical and metabolic values gradually returned to normal levels, except for albumin. Hypoalbuminemia was not reversed within the two-week post-decompression period. The rats jaundiced for two weeks had significantly higher mortality, compared to the other groups. We conclude that prolonged jaundice adversely affects the metabolic capacity of the rats, with albumin concentration being markedly decreased, and that biliary decompression could not reverse completely all the alterations seen with cholestasis, especially following two weeks of bile duct obstruction

Effects of Carbohydrate-Based and Protein-Carbohydrate Rations on Wild Bobwhite Nesting and Harvest Demographics

Northern bobwhite (Colinus virginianus) reproduction is a nutrient-intensive process. Arthropods are essential for breeding bobwhite hens and their offspring. Traditional supplemental feeding programs use corn and milo and typically neglect the protein needs of bobwhites. Commercial bobwhite rations are widely available but are seldom used in feeding programs due to high cost and lack of an appropriate supplement for field use. We compared the effect of a protein-carbohydrate ration (PC) to the effects of a carbohydrate only ration (CO) on: (1) bobwhite hen nesting demographics (clutch size, ordinal clutch initiation date, Mayfield nest survival), and (2) fall relative abundance (coveys moved/hr hunting). Nesting parameters for bobwhites based on a sample of 60 hens during the 2008 breeding season in South Texas were statistically similar based on overlap of 95% confidence intervals for both the PC and CO supplements. Mayfield nest success was high for both the PC ration (75.2%) and the CO ration (73.1%). Coveys moved during hunting (4.17 6 14 coveys/hr in pastures with CO feed and 4.2 6 12.5 coveys/hr in pastures with PC feed) did not differ during the 2008–2009 hunting season. The 2009 nesting season was a failure because all study animals died due to drought. Weekly Kaplan-Meier survival estimates of bobwhite hens were 6 times higher in 2008 than in 2009. The PC ration in our study provided no benefit to bobwhite populations or enhancement of wild bobwhite reproductive parameters over the CO ration. The additional cost of using PC over CO is not justified based on our results

Early childhood adversity and adolescent depression: the mediating role of continued stress

Background. While various conceptualizations of the link between childhood adversity and later depression have been offered, most have not accounted for the possibility that early adversity predicts continuing stress proximal to depression onset. Thus, the present study tested the possible mediating role of recent stress in the association between early adversity and depression in late adolescence

GPAQ-R: development and psychometric properties of a version of the general practice assessment questionnaire for use for revalidation by general practitioners in the UK.

BACKGROUND: The General Practice Assessment Questionnaire (GPAQ) has been widely used to assess patient experience in general practice in the UK since 2004. In 2013, new regulations were introduced by the General Medical Council (GMC) requiring UK doctors to undertake periodic revalidation, which includes assessment of patient experience for individual doctors. We describe the development of a new version of GPAQ - GPAQ-R which addresses the GMC's requirements for revalidation as well as additional NHS requirements for surveys that GPs may need to carry out in their own practices. METHODS: Questionnaires were given out by doctors or practice staff after routine consultations in line with the guidance given by the General Medical Council for surveys to be used for revalidation. Data analysis and practice reports were provided independently. RESULTS: Data were analysed for questionnaires from 7258 patients relating to 164 GPs in 29 general practices. Levels of missing data were generally low (typically 4.5-6%). The number of returned questionnaires required to achieve reliability of 0.7 were around 35 for individual doctor communication items and 29 for a composite score based on doctor communication items. This suggests that the responses to GPAQ-R had similar reliability to the GMC's own questionnaire and we recommend 30 completed GPAQ-R questionnaires are sufficient for revalidation purposes. However, where an initial screen raises concern, the survey might be repeated with 50 completed questionnaires in order to increase reliability. CONCLUSIONS: GPAQ-R is a development of a well-established patient experience questionnaire used in general practice in the UK since 2004. This new version can be recommended for use in order to meet the UK General Medical Council's requirements for surveys to be used in revalidation of doctors. It also meets the needs of GPs to ask about patient experience relating to aspects of practice care that are not specific to individual general practitioners (e.g. receptionists, telephone access) which meet other survey requirements of the National Health Service in England. Use of GPAQ-R has the potential to reduce the number of surveys that GPs need to carry out in their practices to meet the various regulatory requirements which they face

Association of Genome-Wide Association Study (GWAS) identified SNPs and risk of breast cancer in an Indian population

To date, no studies have investigated the association of the GWAS-identified SNPs with BC risk in Indian population. We investigated the association of 30 previously reported and replicated BC susceptibility SNPs in 1,204 cases and 1,212 controls from a hospital based case-control study conducted at the Tata Memorial Hospital, Mumbai. As a measure of total susceptibility burden, the polygenic risk score (PRS) for each individual was defined by the weighted sum of genotypes from 21 independent SNPs with weights derived from previously published estimates of association odds-ratios. Logistic regression models were used to assess risk associated with individual SNPs and overall PRS, and stratified by menopausal and receptor status. A total of 11 SNPs from eight genomic regions (FGFR2, 9q31.2, MAP3K, CCND1, ZM1Z1, RAD51L11, ESR1 and UST) showed statistically significant (p-value = 0.05) evidence of association, either overall or when stratified by menopausal status or hormone receptor status. BC SNPs previously identified in Caucasian population showed evidence of replication in the Indian population mainly with respect to risk of postmenopausal and hormone receptor positive BC. © 2017 The Author(s)

Handling misclassified stratification variables in the analysis of randomised trials with continuous outcomes

Many trials use stratified randomisation, where participants are randomised within strata defined by one or more baseline covariates. While it is important to adjust for stratification variables in the analysis, the appropriate method of adjustment is unclear when stratification variables are affected by misclassification and hence some participants are randomised in the incorrect stratum. We conducted a simulation study to compare methods of adjusting for stratification variables affected by misclassification in the analysis of continuous outcomes when all or only some stratification errors are discovered, and when the treatment effect or treatment-by-covariate interaction effect is of interest. The data were analysed using linear regression with no adjustment, adjustment for the strata used to perform the randomisation (randomisation strata), adjustment for the strata if all errors are corrected (true strata), and adjustment for the strata after some errors are discovered and corrected (updated strata). The unadjusted model performed poorly in all settings. Adjusting for the true strata was optimal, while the relative performance of adjusting for the randomisation strata or the updated strata varied depending on the setting. As the true strata are unlikely to be known with certainty in practice, we recommend using the updated strata for adjustment and performing subgroup analyses, provided the discovery of errors is unlikely to depend on treatment group, as expected in blinded trials. Greater transparency is needed in the reporting of stratification errors and how they were addressed in the analysis