Risk factors for horse falls in New Zealand Thoroughbred jumps racing.

This study aimed to determine the incidence of, and risk factors for race-day horse falls in Thoroughbred jumps (hurdle and steeplechase) racing in New Zealand. Incidence rates for race-day horse falls in jumps races from 2005/6 - 2018/19 racing seasons (n = 13,648 race day starts) were calculated per 1000 starts. Univariable and multivariable analyses of race-, horse- and jockey-level risk factors for horse falls were conducted using Poisson regression in a generalised linear mixed model. The incidence rate of horse falls in jumps races was 42 (95 % confidence intervals [CI], 39 - 45) per 1000 starts. Horse falls in steeplechase races were 1.6 (95 % CI, 1.4 - 1.9) times more likely than hurdle races. The incidence rate ratio (IRR) for horses falling at the last three jumps in comparison with the first three jumps was 3.1 (95 % CI, 2.8 - 3.5) for hurdle and 4.4 (95 % CI, 3.9 - 5.0) for steeplechase races. Greater jockey (age, P = 0.02) and horse experience (P = 0.001) were associated with a lower IRR of falls (P = 0.05). Longer races (P = 0.02) and those held in autumn compared to winter (IRR 1.4; 95 % CI, 1.0 - 1.8; P = 0.05) were associated with a higher rate of falling in steeplechase races. A regulatory change enhancing discretionary ability of jockeys to pull up 'in-race' was associated with reduced horse falls (IRR 0.65; 95 % CI, 0.51 - 0.82; P = 0.001). Pragmatic rule changes within the industry can have a positive effect on reducing risk and improving equine welfare.

Pharmacokinetic and safety profile of raltegravir and ribavirin, when dosed separately and together, in healthy volunteers.

BACKGROUND: Treatment of chronic hepatitis C virus (HCV) infection in HIV-1-co-infected individuals remains challenging due to numerous factors, including drug-drug interactions. The aim of this study was to assess the safety and pharmacokinetic (PK) profile of raltegravir and ribavirin when dosed separately and together. METHODS: Fourteen healthy volunteers [mean (standard deviation) age 35 (10) years, 71% male] entered this phase 1 PK study and received single-dose ribavirin (800 mg) on day 1 (phase 1). Following a washout period, subjects received raltegravir (400 mg twice daily) on days 15-19 (phase 2) and single-dose ribavirin (800 mg) with raltegravir (400 mg) on day 20 (phase 3). Intensive PK sampling was undertaken on days 1, 19 and 20 and differences in geometric mean ratios (GMRs) for PK parameters between study periods were assessed. RESULTS: No statistically significant differences in PK parameters were observed for raltegravir between phases 2 and 3. A statistically significant decrease in maximum plasma concentration (C(max)) and an increase in time to maximum plasma concentration (T(max)) were observed for ribavirin in phase 3 compared with phase 1 [GMR (95% confidence interval) 0.79 (0.62-1.00) and 1.39 (1.08-1.78), respectively], whereas no significant differences in other ribavirin PK parameters were observed between study phases. No clinically significant safety concerns were reported. CONCLUSIONS: The PK profile of ribavirin is altered when administered with raltegravir (reduced C(max) and increased T(max)), with no safety concerns identified. This is unlikely to be of clinical significance or have an impact on the antiviral effects of ribavirin in HIV-1- and HCV-co-infected subjects.

Lessons from IAVI-006, a phase I clinical trial to evaluate the safety and immunogenicity of the pTHr.HIVA DNA and MVA.HIVA vaccines in a prime-boost strategy to induce HIV-1 specific T-cell responses in healthy volunteers.

IAVI-006 was the first large randomised, double-blinded, placebo-controlled Phase I clinical trial to systematically investigate the prime-boost strategy for induction of HIV-1 specific CD8+ cytotoxic T-lymphocytes (CTL) in a factorial trial design using (i) priming with 0.5 mg or 2 mg of pTHr.HIVA DNA vaccine, followed by (ii) two booster vaccinations with 5 x 10(7) MVA.HIVA at weeks 8 and 12 (early boost) or weeks 20 and 24 (late boost). This study set the basis for later clinical trials and demonstrated the safety of these candidate HIV vaccines. The safety and immunogenicity results are presented and the lessons derived from this clinical trial are discussed.

Participation in two phase II prophylactic HIV vaccine trials in the UK.

There will be a continued imperative to recruit large numbers of healthy volunteers to early phase prophylactic HIV vaccine (PHV) trials. We studied mechanisms associated with participation in two related phase II PHV trials. The most cited reasons for volunteering were altruism and a personal connection to HIV. The most successful recruiting strategies targeted organisations dealing with HIV, health or social issues, or were directed to large audiences through the mass media. However, circulated emails and word of mouth were the most resource-effective approaches. Group discussions and the collection of a pool of potential volunteers were much less effective than one-to-one discussions and immediate screening after recruitment. We utilised our findings to devise key recommendations to assist PHV trial teams who are planning future studies.

Single fiber-optic pH sensor based on changes in reflection accompanying polymer swelling.

We have prepared fiber-optic pH sensors consisting of a small drop of aminated polystyrene on the tip of a single optical fiber with a core diameter of 100 microns. The sensor is prepared by dipcoating a partially polymerized solution and then completing the polymerization on the fiber. This is followed by amination with diethanolamine. The polymer formulation includes xylene/dodecane to introduce porosity and Kraton G1652, a styrene-ethylene, butylene-styrene, triblock copolymer as a toughening agent. The polymer swells as the amine groups are protonated. This is accompanied by an increase in clarity of the polymer and a decrease in the intensity of light reflected back into the optical fiber. Intensity decreases by over a factor of 2 as the pH is decreased from 8.0 to 6.5. The resulting sensor is small and mechanically stable with a response time of several minutes.

Establishing the direct-potentiometric "normal" range for Na/K: residual liquid junction potential and activity coefficient effects.

The observed reference ranges for sodium and potassium as determined by direct potentiometry vary from instrument to instrument, depending on the composition of the calibration standards. To resolve the existing confusion as to which reference intervals are most appropriately considered "normal," we propose a straightforward convention (based on plasma-water concentration units) in which the difference between direct (undiluted sample) and indirect (diluted sample) methodologies is accounted for by the volume displacement effect of proteins, lipids, and other dissolved substances in a typical plasma sample. Thus, the proposed reference intervals for sodium and potassium are approximately 7% greater by direct potentiometry than by procedures involving dilution. Data consistent with this convention can be obtained with a variety of aqueous-based calibrants, provided care is taken to minimize the errors resulting from activity coefficient and liquid junction potential effects. Additional experimental results are presented to show that these effects also account for the apparent suppression of the sodium ion concentration observed in the presence of bicarbonate ion.

n-Type Si-based photoelectrochemical cell: New liquid junction photocell using a nonaqueous ferricenium/ferrocene electrolyte.

n-Type Si has been shown to serve as a stable photoanode in a cell for the conversion of light to electricity. The other components of the cell are a Pt cathode and an electrolyte consisting of an ethanol solution of [n-Bu(4)N]ClO(4) with a redox couple of ferricenium/ferrocene. Data from a two-compartment cell show that ferrocene is oxidized to ferricenium with 100 +/- 2% current efficiency at the Si photoanode. Furthermore, prolonged irradiation of the Si in a one-compartment cell yields constant photocurrent and output characteristics. The maximum open-circuit photopotential is approximately 700 mV, and the short-circuit quantum yield for electron flow at low light intensity exceeds 0.5. Conversion of monochromatic 632.8-nm light to electricity with approximately 2% power efficiency at an output voltage of approximately 200 mV has been sustained. These results represent a stable n-type Si-based photoelectrochemical cell.