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Please cite this paper as: Quinn, Hamilton, McCann, Agnew, Millar, Lockhart, Harbinson and McVeigh (2011). Ocular Blood Flow Analysis Detects Microvascular Abnormalities in Impaired Glucose Tolerance. Microcirculation 18(7), 532–540. Abstract Objective: Waveform analysis has been used to assess vascular resistance and predict cardiovascular events. We aimed to identify microvascular abnormalities in patients with IGT using ocular waveform analysis. The effects of pioglitazone were also assessed. Methods: Forty patients with IGT and 24 controls were studied. Doppler velocity recordings were obtained from the central retinal, ophthalmic, and common carotid arteries, and sampled at 200 Hz. A discrete wavelet-based analysis method was employed to quantify waveforms. The RI was also determined. Patients with IGT were randomized to pioglitazone or placebo, and measurements were repeated after 12-week treatment. Results: In the ocular waveforms, significant differences in power spectra were observed in frequency band 4 (corresponding to frequencies between 6.25 and 12.50 Hz) between groups (p

Purpose. This research provided a detailed analysis of the types of questions and verbal strategies used by police officers and caregivers when interviewing children with intellectual disabilities about events. Method. Twenty eight children aged 9 to 13 years with a mild or moderate intellectual disability participated in a staged event at their school. Each child was then interviewed on separate occasions by the child's primary caregiver and by a police officer who was authorized to conduct investigative interviews with children. Results. While the approach used by the police officers was broadly consistent with best-practice recommendations (i.e. their interviews contained few leading, coercive or negative strategies), they frequently interrupted the child's account and used relatively few minimal encouragers and other strategies designed to keep the child talking. The caregivers used a high proportion of direct, leading and coercive strategies to elicit information from their children. Even when caregivers used open-ended questions, their children provided less event-related information than they did to the police interviewers. Conclusion. The quality of evidence obtained from children with intellectual disabilities is likely to be dependent (albeit in part) on the degree to which police interviewers adhere to best-practice guidelines, as well as the children's general experience with an open-ended style of communication.

The rate constants for hydrolysis of diazomethane, diazoethane and 1-diazopropane in aqueous 5% acetonitrile at 25°C and ionic strength 1 M (NaClO4) were measured by stopped-flow spectrophotometry. The pH-rate profile for diazomethane hydrolysis exhibits a pH-independent section in the lower pH range, 8–10, with a downward break at higher pH, as has been reported for slightly different reaction conditions. In the case of diazoethane and 1-diazopropane, the reaction remains pH independent up to pH > 13. General acid catalysis of the hydrolysis reactions of diazomethane and diazoethane were examined in the pH-independent regions. For a limited number of catalysts, the value of Bronsted α was 0.58 for both diazoalkanes. The downward break in the pH rate profile for diazomethane hydrolysis is consistent with what was previously concluded, rate-limiting protonation by H2O in the pH-independent region changing to rate-limiting attack of water on the diazonium ion in the pH-dependent region, the decrease in rate constant with increasing pH being attributed to deprotonation of the diazonium ion by hydroxide ion. The lack of a downward break in the pH–rate profiles for hydrolysis of the diazoethane and 1-diazopropane is attributed specifically to the increase, relative to the methyldiazonium ion, in the rate constant for water attack on the ethyl- and 1-propyldiazonium ions, perhaps by as much as >103-fold. Copyright © 2004 John Wiley & Sons, Ltd.

An experiment was carried out to examine silage fermentation, effluent production and aerobic stability in unwilted grass silage, which was either ensiled without additive or with a commercially available blend of ammonium hexamethanoate, ammonium hexapropionate and octanoic acid (6 l t−1, Maxgrass, BP Chemicals Ltd., Northwich, UK) and to determine alternative approaches to obtaining the same performance in finishing beef cattle. Seventy-two Limousin × Friesian and Charolais × Friesian steers (mean initial live weight 424 kg s.d. 28·3) were blocked into groups of nine according to live weight and previous performance and offered silage, either with or without the additive, and supplemented with 0, 1·5, 3·0 or 4·5 kg d−1 of a concentrate with a crude protein content of 150 g kg−1 DM or allocated to a pre-experimental slaughter group to enable calculation of daily carcass gain. Daily silage intakes were recorded for 112 days. At the end of the experiment, all cattle were slaughtered and daily carcass gain, omental, mesenteric, perinephric and retroperitoneal fat depots [kidney-knob and channel fat (KKCF)], fatness, conformation, subcutaneous fat depth over M. longissimus dorsi muscle and carcass fat, protein and bone contents were assessed. Across all levels of supplementation, cattle offered the silage with the additive showed significantly (P

Purpose: In this study the Octavius detector 729 ionization chamber (IC) array with the Octavius 4D phantom was characterized for flattening filter (FF) and flattening filter free (FFF) static and rotational beams. The device was assessed for verification with FF and FFF RapidArc treatment plans. Methods: The response of the detectors to field size, dose linearity, and dose rate were assessed for 6 MV FF beams and also 6 and 10 MV FFF beams. Dosimetric and mechanical accuracy of the detector array within the Octavius 4D rotational phantom was evaluated against measurements made using semiflex and pinpoint ionization chambers, and radiochromic film. Verification FF and FFF RapidArc plans were assessed using a gamma function with 3%/3 mm tolerances and 2%/2 mm tolerances and further analysis of these plans was undertaken using film and a second detector array with higher spatial resolution. Results: A warm-up dose of >6 Gy was required for detector stability. Dose-rate measurements were stable across a range from 0.26 to 15 Gy/min and dose response was linear, although the device overestimated small doses compared with pinpoint ionization chamber measurements. Output factors agreed with ionization chamber measurements to within 0.6% for square fields of side between 3 and 25 cm and within 1.2% for 2 × 2c m 2 fields. The Octavius 4D phantom was found to be consistent with measurements made with radiochromic film, where the gantry angle was found to be within 0.4 ◦ of that expected during rotational deliveries. RapidArc FF and FFF beams were found to have an accuracy of >97.9% and >90% of pixels passing 3%/3 mm and 2%/2 mm, respectively. Detector spatial resolution was observed to be a factor in determining the accurate delivery of each plan, particularly at steep dose gradients. This was confirmed using data from a second detector array with higher spatial resolution and with radiochromic film. Conclusions: The Octavius 4D phantom with associated Octavius detector 729 ionization chamber array is a dosimetrically and mechanically stable device for pretreatment verification of FF and FFF RapidArc treatments. Further improvements may be possible through use of a detector array with higher spatial resolution (detector size and/or detector spacing). © 2013 American Association of Physicists in Medicine .[ http://dx.doi.org/10.1118/1.4817482]

Prophylactic phenytoin (DPH) has been evaluated in 20 patients undergoing diagnostic myelography. DPH (0.75 g) was ingested at 20.00 h the night before and 0.5 g at 08.00 h on the morning of the procedure. Total DPH concentrations at myelography (mean +/- s.d.: 12.7 +/- 4.3 mg l-1; range 6.3-21.5 mg l-1) correlated with CSF values (1.3 +/- 0.46 mg l-1; range 0.7-2.2 mg l-1; r = 0.83, P less than 0.001). DPH protein binding at that time varied two-fold (9.2-18.5%) and free drug levels (1.7 +/- 0.6 mg l-1) correlated with CSF (r = 0.83, P less than 0.001) and total (r = 0.89, P less than 0.001) plasma DPH concentrations. There were significant negative correlations between patient weight (n = 17) and total (r = 0.57, P less than 0.05) and CSF (r = -0.55, P less than 0.05) DPH concentrations at myelography. Total plasma DPH levels 8 h (14.5 +/- 3.9 mg l-1; range 7.3-20.6 mg l-1) and 24 h (12.3 +/- 3.8 mg l-1; range 5.0-19.8 mg l-1) after myelography were largely within the 'therapeutic range' of 10-20 mg l-1 for the drug. No patient suffered a seizure although, in two, spike discharges were seen on a post-myelography electroencephalogram. A simple regime involving two doses of DPH would provide acceptable plasma CSF concentrations as a basis for controlled studies in seizure prophylaxis following neuroradiological investigations involving intrathecal contrast.

Simultaneous cerebrospinal fluid (CSF), total and free plasma valproic acid (VPA) concentrations were measured in 17 patients receiving two weight-adjusted VPA doses as seizure prophylaxis prior to diagnostic myelography or cisternography. Free drug concentrations were similar when measured by equilibrium dialysis (ED) at 37 degrees C for 24 h (Dianorm) or by a novel ultrafiltration (UF) method (EMIT freelevel system 1, SYVA) (ED:2.3-35.5 mg-1; UF:1.3-33.6 mg-1; r = 0.78, P less than 0.002). There was wide variation in total VPA concentration (39-154 mg-1) and in free fraction (ED: 3.3-25.6%; UF: 5.9-24%). Concentration dependent protein binding was not demonstrated. CSF VPA varied between 4.2 and 25.6 mg-1 and was accurately reflected by free plasma VPA concentrations (ED: r = 0.75, P less than 0.005: UF: r = 0.93, P less than 0.001). CSF concentration also correlated with the total plasma VPA (r = 0.76, P less than 0.005). The Emit freelevel system 1 provides a rapid measure of unbound VPA in the plasma which may be suitable for routine clinical use.

Economists, like other forecasters, share knowledge, data and theories in common. Consequently, their forecast errors are likely to be highly dependent. This paper reports on an empirical study of 16 macroeconomic forecasters. Composite forecasts are computed using a sequential weighting scheme that takes dependence into account; these are compared to a simple average and median forecasts. A within-sample composite is also calculated. Both these methods perform significantly better than the average or median of the forecasts. This improvement in accuracy is apparently because the dependence between the forecasters' errors is so high that the optimal composite forecasts sometimes lie outside the range of the individual forecasts.