Examination of ethnicity in controlled treatment outcome studies involving adolescent substance abusers: A comprehensive literature review.

The extent to which adolescent drug treatment outcome studies address ethnicity was systematically examined. Reliability coefficients were calculated for both the search methodology used to obtain these outcome studies and the extent to which ethnicity was addressed along several dimensions. The resulting coefficients were highly reliable. Findings indicated that although investigators of 94% of the outcome studies considered ethnicity to some extent, only 28% of these studies incorporated ethnicity into their design, and only 6% of studies involved statistical analyses to examine differential response to treatment or moderating effects of ethnicity with a sufficient number of ethnic minority participants. Overall, results indicated that there is much work to do regarding the examination of ethnicity in controlled treatment outcome studies involving adolescent substance abusers. Indeed, modifications were rarely made to the treatment components to accommodate ethnicity-related variables. Future recommendations are presented in light of these findings. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

En bloc nephrectomy in patients undergoing post-chemotherapy retroperitoneal lymph node dissection for nonseminomatous testis cancer: indications, implications and outcomes

PURPOSE: We review the indications for nephrectomy at post-chemotherapy retroperitoneal lymph node dissection, identify patients at risk for nephrectomy and assess the impact of nephrectomy on outcome. MATERIALS AND METHODS: Using a computerized data base and chart review we retrospectively reviewed the records of 848 patients who underwent retroperitoneal lymph node dissection after chemotherapy. RESULTS: En bloc nephrectomy was performed at retroperitoneal lymph node dissection after chemotherapy in 162 of the 848 patients (19%). The indications for nephrectomy included contiguous involvement of perirenal structures in 73% of the cases, renal vein thrombosis in 6%, a poorly functioning or nonfunctioning renal unit in 5% and a combination of these conditions in 16%. Pathological studies of the hilum revealed cancer in 20% of the cases, teratoma in 49% and fibrosis in 31%. Patients requiring nephrectomy had significantly more advanced disease and larger disease volume at presentation and after chemotherapy. There were no significant differences in perioperative morbidity or mortality compared with patients who did not undergo nephrectomy. Only 3 patients required perioperative dialysis and none required long-term renal support. CONCLUSIONS: These findings support en bloc nephrectomy at post-chemotherapy retroperitoneal lymph node dissection in select patients with large volume perihilar retroperitoneal disease.     

Reversible colostomy--what is the outcome?

PURPOSE: The trend toward avoidance of a colostomy at both elective and emergency large-bowel surgery is partly driven by the perceived morbidity and low closure rates of temporary stomas. The aim of this study was to examine whether significant colostomy-related morbidity remains persistently high. METHODS: To examine this, we reviewed 120 patients with a potentially reversible colostomy performed during either elective or emergency large-bowel surgery during a seven-year period. RESULTS: Forty-seven patients underwent elective and 73 patients underwent emergency colonic or colorectal resection. Fifty-eight patients had colorectal carcinoma (48.3 percent), diverticular disease accounted for 39 patients (32.5 percent), and a miscellaneous group of 23 patients (19.2 percent) made-up the remainder. Seven patients died, all in the emergency group (9.6 percent). Colostomy-related morbidity, which included stenosis, retraction, prolapse, and hernia formation, occurred in 19.2 percent of patients, with no difference between the elective (14.9 percent) and emergency (21.9 percent) groups or underlying pathologic condition. Colostomy closure was performed initially in 71 patients (59.2 percent). Highest closure rates occurred in the diverticular group (84.6 percent), followed by the colorectal carcinoma group (48.3 percent), and then the miscellaneous group (43.5 percent). One patient died undergoing colostomy closure, and complications occurred in 25 patients (35.2 percent), requiring fashioning of a second colostomy in eight patients, two of whom were closed. Final colostomy closure rate was 54.2 percent. CONCLUSIONS: This study confirms the contention that both formation and closure of defunctioning colostomies are associated with significant complications; furthermore, approximately one-half of patients will not have their colostomy closed.     

A crystal plasticity finite element analysis of cross-grain deformation heterogeneity in equal channel angular extrusion and its implications for texture evolution

A crystal plasticity finite element (CPFE) method was applied to evaluate cross-grain deformation heterogeneity and its implication on texture evolution during equal channel angular extrusion (ECAE) of pure copper. The simulations were conducted for one to four passes of ECAE via route C, assuming simple shear in each pass at the macroscopic level. Analyses of the stress and strain distributions reveal considerable deformation heterogeneities across individual grains in the polycrystal. The grain interactions are found to be remarkable after even-numbered passes and they partly contribute to the retained shear textures. The CPFE model captures very well the experimental textures after odd-numbered passes; however, it is not able to model the measured textures subsequent to even-numbered passes, and the results are only slightly improved as compared to a visco-plasticity self-consistent polycrystal model. These results suggest that dedicated considerations of deformation heterogeneities at both the macro- and meso-levels are necessary in modeling texture evolution during severe plastic deformation.     

Quantifying variability within water samples: the need for adequate subsampling

Accurate and precise determination of the concentration of nutrients and other substances in waterbodies is an essential requirement for supporting effective management and legislation. Owing primarily to logistic and financial constraints, however, national and regional agencies responsible for monitoring surface waters tend to quantify chemical indicators of water quality using a single sample from each waterbody, thus largely ignoring spatial variability. We show here that total sample variability, which comprises both analytical variability and within-sample heterogeneity, of a number of important chemical indicators of water quality (chlorophyll a, total phosphorus, total nitrogen, soluble molybdate-reactive phosphorus and dissolved inorganic nitrogen) varies significantly both over time and among determinands, and can be extremely high. Within-sample heterogeneity, whose mean contribution to total sample variability ranged between 62% and 100%, was significantly higher in samples taken from rivers compared with those from lakes, and was shown to be reduced by filtration. Our results show clearly that neither a single sample, nor even two sub-samples from that sample is adequate for the reliable, and statistically robust, detection of changes in the quality of surface waters. We recommend strongly that, in situations where it is practicable to take only a single sample from a waterbody, a minimum of three sub-samples are analysed from that sample for robust quantification of both the concentrations of determinands and total sample variability.     

A Model of Phase Transition Kinetics in Lead Scandium Tantalate Thin Films

The phase transformations from amorphous to pyrochlore to perovskite in lead scandium tantalate (PST) thin films during rapid thermal annealing process (RTA) have been studied by X-ray diffraction (XRD) techniques. The growth and decay of the pyrochlore phase, the growth of the perosvkite PST were analysed using the Avrami model. Integral equations have been derived and numerical calculation been used to simulate the volume fractions for pyrochlore and perovskite as functions of annealing time. Transformation parameters k and n were obtained by comparing the simulated to the experimental intensities using a least-squares curve fitting technique. Activation energies for perovskite formation were calculated. The results indicate that the phase transitions are diffusion-limited. TEM, SEM, and EDS were employed to study the lead loss and other factors affecting phase transitions.     

Pulse-Extended Excimer Laser Crystallisation of Pb(Zr,Ti)O 3 Thin Films for Integration on Low Thermal Budget Substrates

Excimer laser annealing has been used to convert low temperature (non-ferroelectric) deposited lead zirconate titanate (PZT) to the perovskite phase without significantly heating underlying layers. A pulse-extension technique has been used to lengthen the laser pulse duration from 25 ns to 374 ns, lowering the surface temperature and improving the heat distribution in the PZT, as compared to the non-extended case, but still not significantly heating the substrate. Initial experiments are reported which have shown the technique to be capable of crystallising over half a 500 nm thick PZT film to perovskite although a melting effect limited the converted thickness. The thickness crystallised is however of the order of that used in FeRAM devices and modelled temperature profiles suggest that the technique provides a tractable solution for high temperature processing of ferroelectric thin films of thickness 200-300 nm on low thermal budget substrates.     

A meta-analysis of the effectiveness of placebo manipulations in alcohol-challenge studies.

Our meta-analysis examined the impact of specific alcohol placebo procedures on two manipulation checks (participant reports of number of alcohol drinks consumed and subjective intoxication) to determine which procedures produced the smallest effect sizes in comparisons between alcohol and placebo conditions. Databases for the years 1990–2007 yielded 44 studies that met inclusion criteria. These were subjected to detailed coding of procedures pertinent to placebo effectiveness. Alcohol versus placebo condition comparisons generally produced large effect sizes for both manipulation checks, but they were moderated by double-blind procedures and by peak breath-alcohol concentration (BrAC) attained in the alcohol condition. Other procedures moderated only the estimated number of alcohol drinks consumed. Implications for selection and assessment of alcohol placebo manipulations and for interpretability of experiments using them are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Study of gate loads related to stress states in mass-flow bins during bulk solids filling and settlement

This paper concerns the determination of the loads on discharge isolating gates of mass-flow bins such as those used in the coal and iron ore industries for train loading. The gate loads are closely associated with the stress states of the bulk solids that are difficult to determine since they are highly dependent on the degree of the compressibility of the bulk solids and the rigidity of the gate. The so-called j factor as outlined in the Australian Standard 3774-1996 is incorporated in the gate load analysis to account for these properties. In this study, an analytical review of gate loads is combined with an experimental study employing a pilot mass-flow bin handling iron ore and plastic pellets. Of particular interest are the transient load changes due to the time-dependent settling of the bulk solid. The research findings are presented along with guidelines to assist the bin gate design.