GO-SHIP Repeat Hydrography Nutrient Manual: The Precise and Accurate Determination of Dissolved Inorganic Nutrients in Seawater, Using Continuous Flow Analysis Methods

The GO-SHIP nutrient manual covers all aspects of nutrient analysis from basic sample collection and storage, specifically for Continuous Flow analysis using an Auto-Analyzer, and describes some specific nutrient methods for Nitrate, Nitrite, Silicate, Phosphate and Ammonium that are in use by many laboratories carrying out at-sea analysis and repeat hydrography sections across the world. The focus is on segmented flow analyzers not flow injection analyzers. It also covers laboratory best practices including quality control and quality assurance (QC/QA) procedures to obtain the best results, and suggests protocols for the use of reference materials (RM) and certified reference materials (CRMs)

Seasonal variation of serotonin turnover in human cerebrospinal fluid, depressive symptoms and the role of the 5-HTTLPR.

Studying monoaminergic seasonality is likely to improve our understanding of neurobiological mechanisms underlying season-associated physiological and pathophysiological behavior. Studies of monoaminergic seasonality and the influence of the serotonin-transporter-linked polymorphic region (5-HTTLPR) on serotonin seasonality have yielded conflicting results, possibly due to lack of power and absence of multi-year analyses. We aimed to assess the extent of seasonal monoamine turnover and examined the possible involvement of the 5-HTTLPR. To determine the influence of seasonality on monoamine turnover, 5-hydroxyindoleacetic acid (5-HIAA) and homovanillic acid (HVA) were measured in the cerebrospinal fluid of 479 human subjects collected during a 3-year period. Cosine and non-parametric seasonal modeling were applied to both metabolites. We computed serotonin (5-HT) seasonality values and performed an association analysis with the s/l alleles of the 5-HTTLPR. Depressive symptomatology was assessed using the Beck Depression Inventory-II. Circannual variation in 5-HIAA fitted a spring-peak cosine model that was significantly associated with sampling month (P=0.0074). Season of sampling explained 5.4% (P=1.57 × 10(-7)) of the variance in 5-HIAA concentrations. The 5-HTTLPR s-allele was associated with increased 5-HIAA seasonality (standardized regression coefficient=0.12, P=0.020, N=393). 5-HIAA seasonality correlated with depressive symptoms (Spearman's rho=0.13, P=0.018, N=345). In conclusion, we highlight a dose-dependent association of the 5-HTTLPR with 5-HIAA seasonality and a positive correlation between 5-HIAA seasonality and depressive symptomatology. The presented data set the stage for follow-up in clinical populations with a role for seasonality, such as affective disorders

Absence of Evidence for MHC–Dependent Mate Selection within HapMap Populations

The major histocompatibility complex (MHC) of immunity genes has been reported to influence mate choice in vertebrates, and a recent study presented genetic evidence for this effect in humans. Specifically, greater dissimilarity at the MHC locus was reported for European-American mates (parents in HapMap Phase 2 trios) than for non-mates. Here we show that the results depend on a few extreme data points, are not robust to conservative changes in the analysis procedure, and cannot be reproduced in an equivalent but independent set of European-American mates. Although some evidence suggests an avoidance of extreme MHC similarity between mates, rather than a preference for dissimilarity, limited sample sizes preclude a rigorous investigation. In summary, fine-scale molecular-genetic data do not conclusively support the hypothesis that mate selection in humans is influenced by the MHC locus

Unmappable ventricular tachycardia after an old myocardial infarction. Long-term results of substrate modification in patients with an implantable cardioverter defibrillator

Purpose The frequent occurrence of ventricular tachycardia can create a serious problem in patients with an implantable cardioverter defibrillator. We assessed the long-term efficacy of catheter-based substrate modification using the voltage mapping technique of infarct-related ventricular tachycardia and recurrent device therapy. Methods The study population consisted of 27 consecutive patients (age 68 +/- 8 years, 25 men, mean left ventricular ejection fraction 31 +/- 9%) with an old myocardial infarction and multiple and/or hemodynamically not tolerated ventricular tachycardia necessitating repeated device therapy. A total of 31 substrate modification procedures were performed using the three-dimensional electroanatomical mapping system. Patients were followed up for a median of 23.5 (interquartile range 6.5-53.2) months before and 37.8 (interquartile range 11.7-71.8) months after ablation. Antiarrhythmic drugs were not changed after the procedure, and were stopped 6 to 9 months after the procedure in patients who did not show ventricular tachycardia recurrence. Results Median ventricular tachycardias were 1.6 (interquartile range 0.7-6.7) per month before and 0.2 (interquartile range 0.00-1.3) per month after ablation (P = 0.006). Nine ventricular fibrillation episodes were registered in seven patients before and two after ablation (P = 0.025). Median antitachycardia pacing decreased from 1.6 (interquartile range 0.01-5.5) per month before to 0.18 (interquartile range 0.00-1.6) per month after ablation (P = 0.069). Median number of shocks decreased from 0.19 (interquartile range 0.04-0.81) per month before to 0.00 (interquartile range 0.00-0.09) per month after ablation (P = 0.001). One patient had a transient ischemic attack during the procedure, and another developed pericarditis. Nine patients died during follow-up, eight patients due to heart failure and one patient during valve surgery. Conclusion Catheter-based substrate modification using voltage mapping results in a long-lasting reduction of cardioverter defibrillator therapy in patients with multiple and/or hemodynamically not tolerated infarct-related ventricular tachyarrhythmia

Public Versus Private: Does It Matter for Water Conservation? Insights from California

This article asks three connected questions: First, does the public view private and public utilities differently, and if so, does this affect attitudes to conservation? Second, do public and private utilities differ in their approaches to conservation? Finally, do differences in the approaches of the utilities, if any, relate to differences in public attitudes? We survey public attitudes in California toward (hypothetical but plausible) voluntary and mandated water conservation, as well as to price increases, during a recent period of shortage. We do this by interviewing households in three pairs of adjacent public and private utilities. We also survey managers of public and private urban water utilities to see if they differ in their approaches to conservation and to their customers. On the user side we do not find pronounced differences, though a minority of customers in all private companies would be more willing to conserve or pay higher prices under a public operator. No respondent in public utility said the reverse. Negative attitudes toward private operators were most pronounced in the pair marked by a controversial recent privatization and a price hike. Nonetheless, we find that California’s history of recurrent droughts and the visible role of the state in water supply and drought management undermine the distinction between public and private. Private utilities themselves work to underplay the distinction by stressing the collective ownership of the water source and the collective value of conservation. Overall, California’s public utilities appear more proactive and target-oriented in asking their customers to conserve than their private counterparts and the state continues to be important in legitimating and guiding conservation behavior, whether the utility is in public hands or private

LC–MS-based absolute metabolite quantification:Application to metabolic flux measurement in trypanosomes

Human African trypanosomiasis is a neglected tropical disease caused by the protozoan parasite, Trypanosoma brucei. In the mammalian bloodstream, the trypanosome’s metabolism differs significantly from that of its host. For example, the parasite relies exclusively on glycolysis for energy source. Recently, computational and mathematical models of trypanosome metabolism have been generated to assist in understanding the parasite metabolism with the aim of facilitating drug development. Optimisation of these models requires quantitative information, including metabolite concentrations and/or metabolic fluxes that have been hitherto unavailable on a large scale. Here, we have implemented an LC–MS-based method that allows large scale quantification of metabolite levels by using U-13C-labelled E. coli extracts as internal standards. Known amounts of labelled E. coli extract were added into the parasite samples, as well as calibration standards, and used to obtain calibration curves enabling us to convert intensities into concentrations. This method allowed us to reliably quantify the changes of 43 intracellular metabolites and 32 extracellular metabolites in the medium over time. Based on the absolute quantification, we were able to compute consumption and production fluxes. These quantitative data can now be used to optimise computational models of parasite metabolism

Working conditions as predictors of retirement intentions and exit from paid employment: a 10-year follow-up of the English Longitudinal Study of Ageing

This work was funded by the Economic and Social Research Council and the Medical Research Council as part of the Lifelong Health and Well-Being (LLHW) initiative (grant number ES/L002892/1)

Ten years of lesbian health survey research in the UK West Midlands

Abstract Background Very little is known about the physical health needs of lesbian and bisexual women in the UK; most research has looked at mental or sexual health only. This article reports the results of four surveys carried out in the West Midlands between 1995 and 2005. Methods The first two surveys were conducted in 1995–6 by a volunteer group, with participants from a lesbian health conference (n = 69) and in a convenience sample from a wide range of relevant groups and venues (n = 354). The second two surveys were commissioned by the West Midlands South Strategic Health Authority in partnership with the Gay Men's Health Network and were conducted in 2002 (n = 449) and 2005 (n = 166) and again used convenience sampling methods including the internet. Results The mean age of respondents varied between 29–33 years and 5–7% were from a non-white ethnic background. The smoking rates varied from 42% o 55%, being twice the West Midlands regional average of 21% for women aged 16 or more. Similarly, problems with alcohol were reported in 25–37% of respondents, higher than the West Midlands regional average of 7% for women aged 16+. The prevalence of any mental health problem varied between 31–35% and any suicide attempt between 20–31%. Only 29–45% had revealed their sexual orientation to their GP and of these, approximately 50% had experienced a positive reaction. Conclusion The results suggest health needs that current UK health services may not be meeting. There is a need to identify and target specific health measures for lesbians and bisexual women in order to ensure improved physical and mental health in the longer term.</p