Parametric and non-parametric estimates of willingness to pay for forest recreation in Northern Ireland: A discrete choice contingent valuation study with follow-ups

In this study we show that forest areas contribute significantly to the estimated benefits from om outdoor recreation in Northern Ireland. Secondly we provide empirical evidence of the gains in the statistical efficiency of both benefit and parameter estimates obtained by analysing follow-up responses with Double Bounded interval data analysis. As these gains are considerable, it is clearly worth considering this method in CVM survey design even when moderately large sample sizes are used. Finally we demonstrate that estimates of means and medians of WTP distributions for access to forest recreation show plausible magnitude, are consistent with previous UK studies, and converge across parametric and non-parametic methods of estimation.

Genetic parentage in the squat lobsters Munida rugosa and M. sarsi (Crustacea, Anomura, Galatheidae)

Munida is the most diverse and cosmopolitan genus of the galatheid squat lobsters. The group has attracted much attention in recent years from both systematic and evolutionary perspectives, yet information on the biology, ecology, and evolution of this genus is very limited. We investigated the genetic parentage of two North Atlantic species; Munida rugosa and M. sarsi sampled from the Clyde Sea on the west coast of Scotland. Microsatellite markers were used to establish the parental contribution from embryos of berried females (M. rugosa, n=25 and M. sarsi, n=5). The frequency of multiple paternity observed in both species (86% for M. rugosa and 100% for M. sarsi) is the highest ever reported for any marine crustaceans. Invariably more than two sires were involved in each case (minimum of two to three for M. rugosa and four for M. sarsi). Findings indicate that multiple paternity is likely to be the norm in both species. Within most multiply sired broods, sire contribution was highly skewed towards a single male (66% of broods for M. rugosa and 100% for M. sarsi). Furthermore, embryos from different sires were randomly distributed across the female's brood patch. This is the first report of multiple paternity in galatheids. While a number of theories can account for the high incidence of multiple paternity in these species (e.g. convenience polyandry as a result of cryptic female choice, forced copulations, the influence of fishing pressures), at present it is not possible to disentangle their individual and/or combined effects.

Differences in mouse models of diabetes mellitus in studies of male reproduction

Diabetes Mellitus (DM) has been found to have subtle yet profound effects on the metabolic status of the testis, the expression of numerous spermatogenic genes and is associated with increased numbers of sperm with nuclear DNA damage. The precise mechanism causing these detrimental effects remains unknown. The presence of increased levels of the most prominent member (carboxymethyllysine - CML) of the advanced glycation end product adducts and their receptor (RAGE) in the reproductive tract of DM men has provided a new avenue for research. As there are suspicions that the antibiotic (streptozotocin - STZ) employed to induce DM is also capable of causing oxidative stress and DNA damage, we compared CML and RAGE levels in the reproductive tract and sperm nDNA status of STZ mice with the levels in the Ins(2Akita) mouse to determine which more closely mimics the situation described in the human diabetic. CML was observed in the testes, epididymes and sperm of all animals. Sperm from DM mice showed particularly strong CML immunolocalization in the acrosomal cap, the equatorial region and whenever present, cytoplasmic droplets. Although increased, the level of CML on the sperm of the STZ and Ins(2Akita) DM mice did not reach statistical significance. RAGE was present on the developing acrosome and epididymal sperm of all animals and in discrete regions of the epididymes of the DM models. Only the epididymal sperm of the Ins(2Akita) mice were found to have significantly increased (p < 0.0001) nDNA damage. The Ins(2Akita) mouse therefore appears to more accurately reflect the conditions found in the human and, as such, is a more representative model for the study of diabetes and glycation's influence on male fertility.

Sperm DNA damage measured by the alkaline Comet assay as an independent predictor of male infertility and in vitro fertilization success

Objective: To evaluate sperm DNA fragmentation and semen parameters to diagnose male factor infertility and predict pregnancy after IVF.
Design: Prospective study.
Setting: Academic research laboratory.
Patient(s): Seventy-five couples undergoing IVF and 28 fertile donors.
Intervention(s): Sperm DNA fragmentation was measured by the alkaline Comet assay in semen and sperm after density gradient centrifugation (DGC). Binary logistic regression was used to analyze odds ratios (OR) and relative risks (RR) for IVF outcomes.
Main Outcome Measure(s): Semen parameters and sperm DNA fragmentation in semen and DGC sperm compared with fertilization rates, embryo quality, and pregnancy.
Result(s): Men with sperm DNA fragmentation at more than a diagnostic threshold of 25% had a high risk of infertility (OR: 117.33, 95% confidence interval [CI]: 12.72–2,731.84, RR: 8.75). Fertilization rates and embryo quality decreased as sperm DNA fragmentation increased in semen and DGC sperm. The risk of failure to achieve a pregnancy increased when sperm DNA fragmentation exceeded a prognostic threshold value of 52% for semen (OR: 76.00, CI: 8.69–1,714.44, RR: 4.75) and 42% for DGC sperm (OR: 24.18, CI: 2.89–522.34, RR: 2.16).
Conclusion(s): Sperm DNA testing by the alkaline Comet assay is useful for both diagnosis of male factor infertility and prediction of IVF outcome.

A Preference for Mephedrone: Drug Markets, Drugs of Choice, and the Emerging “Legal High” Scene

This study focuses on individuals' preferences for mephedrone, a new psychoactive substance that has emerged in several countries. We examine the reasons for mephedrone preferences, and describe the positive and negative effects of the drug experience, route of administration and consumers' views about the legality of mephedrone. Data were collected through semi-structured interviews with 45 adults who had used mephedrone since January 2010. Respondents resided in one of two jurisdictions that were characterized by different legislative controls over mephedrone. The findings suggest the importance of macro-level drug market factors that shaped people's preferences for mephedrone. Additionally, respondents' preferences were guided by pharmacological properties that helped them conceal the effects of mephedrone in public and semi-public spaces. Respondents were not deterred by the (impending) change from legal to illicit drug. The findings have implications for the study of localized drug markets, and in particular, legislative controls over emerging legal highs.