Determination of Dissolved Iron Speciation in the North East Atlantic Ocean by Flow Injection Chemiluminescence

The knowledge of iron biogeochemistry is constrained by paucity in the understanding of its uptake, transport and the partitioning of the element between different phases, redox states and coordination sites. The work presented in this thesis describes the optimisation and evaluation of a Flow Injection Chemiluminescence (FICL) method for the shipboard determination of dissolved Fe(II) species (< 0.2 µm) in seawater. This includes results from two ship-board trials and a study of the effects of model ligands on iron redox speciation measurements in natural waters. The method was also used to determine the distribution of dissolved iron species (< 0.2 µm) in two contrasting study areas in the North East Atlantic Ocean and for a study of aerosol iron dissolution in seawater. The FI-CL method was evaluated and was found to be robust and sensitive, to have low limits o f detection (5-12 pM) and short analysis times 3 min) suitable for the high resolution spatial and temporal sampling required for shipboard analysis of Fe(II). A study of the effects of model ligands on Fe(II) determination revealed no conclusive evidence for significant interference from organic molecules on the method but Fe(III) in the presence of certain organic molecules had the potential to cause positive and negative interference in aqueous samples. Field survey results obtained for a transect between the Bay of Biscay to the coast of the Netherlands, showed enrichment of dissolved iron (0.7 - 2 nM) on the European continental shelf in March 2002. Near the shelf break, the iron enriched shelf waters were separated from low iron open ocean surface waters (0.15 - 0.4 nM) by a well-defined mixing gradient. Elevated dissolved Fe(II) concentrations (> 100 pM) were observed at the shelf break and during a solar radiation maximum in the coastal waters of the southern North Sea. These features were attributed to the dissolution of Fe(II) from anoxic sediments and photoreduction of iron from dissolved and suspended particles, respectively. hi the surface waters of the Canary Basin in October 2002, low Fe(II) concentrations that varied from below the limit of detection of the FI-CL method (< 5 pM) to 60 pM were determined. A horizontal dissolved iron gradient (0.1 - 1.0 nM) inversely related to distance from the North West African coast was observed. It was hypothesised that the gradient was caused by the advection of enriched coastal and upwelled water, rather than by spatial variation in aerosol deposition. Preliminary aerosol iron dissolution experiments demonstrated the significance of the effect of dust loading and variation in seawater matrix on iron solubility. In conclusion, continental margins were found to be a highly significant source of dFe in both study areas and evidence was found that a major portion comes from the reductive dissolution of iron in sediments. However, the flux of iron from shelf waters to the open ocean is likely to be dependant on several factors, such as the direction and magnitude of lateral and axial advection and the efficiency of scavenging and biological uptake in the surface waters

Effect of suppressing thoughts of desire to smoke on ratings of desire to smoke and tobacco withdrawal symptoms

Studies indicate that while suppressing smoking thoughts increases subsequent smoking, it may have no impact on desire to smoke. However, previous research has examined suppression of general smoking thoughts rather than thoughts specifically related to desire to smoke. The present study investigated whether suppression of thoughts of desire to smoke results in subsequently elevated ratings of desire to smoke. An experimental study examined the effects of suppressing thoughts of desire to smoke, versus expressing thoughts of desire to smoke, versus a control group thinking about anything, on ratings of desire to smoke and tobacco withdrawal symptoms at four time points (before manipulations, just after manipulations, 5 min after, 10 min after). In addition, effects of suppressing thoughts of desire to smoke on subsequent reports of thoughts of desire to smoke were examined. Suppressing the thoughts of desire to smoke caused thought rebound (i.e., greater subsequent reports of thoughts of desire to smoke). However, compared with control groups, this suppression did not elevate subsequent ratings of desire to smoke. Suppressing the thoughts of desire to smoke does not elevate subsequent ratings of this desire. Increased cigarette consumption following suppression of smoking thoughts may be mediated by mechanisms other than increased desire to smoke

Inhibition of Serine Palmitoyl Transferase I Reduces Cardiac Ceramide Levels and Increases Glycolysis Rates following Diet-Induced Insulin Resistance

Objective: Diet-induced obesity (DIO) leads to an accumulation of intra-myocardial lipid metabolites implicated in causing cardiac insulin resistance and contractile dysfunction. One such metabolite is ceramide, and our aim was to determine the effects of inhibiting de novo ceramide synthesis on cardiac function and insulin stimulated glucose utilization in mice subjected to DIO. Materials and Methods: C57BL/6 mice were fed a low fat diet or subjected to DIO for 12 weeks, and then treated for 4 weeks with either vehicle control or the serine palmitoyl transferase I (SPT I) inhibitor, myriocin. In vivo cardiac function was assessed via ultrasound echocardiography, while glucose metabolism was assessed in isolated working hearts. Results: DIO was not associated with an accumulation of intra-myocardial ceramide, but rather, an accumulation of intra-myocardial DAG (2.63±0.41 vs. 4.80±0.97 nmol/g dry weight). Nonetheless, treatment of DIO mice with myriocin decreased intra-myocardial ceramide levels (50.3±7.7 vs. 26.9±2.7 nmol/g dry weight) and prevented the DIO-associated increase in intra-myocardial DAG levels. Interestingly, although DIO impaired myocardial glycolysis rates (7789±1267 vs. 2671±326 nmol/min/g dry weight), hearts from myriocin treated DIO mice exhibited an increase in glycolysis rates. Conclusions: Our data reveal that although intra-myocardial ceramide does not accumulate following DIO, inhibition of de novo ceramide synthesis nonetheless reduces intra-myocardial ceramide levels and prevents the accumulation of intra-myocardial DAG. These effects improved the DIO-associated impairment of cardiac glycolysis rates, suggesting that SPT I inhibition increases cardiac glucose utilization. © 2012 Ussher et al.published_or_final_versio

Toll-Like Receptor 8 Agonist and Bacteria Trigger Potent Activation of Innate Immune Cells in Human Liver

This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.The study was supported by a Grant core funding from the Agency for Science Technology and Research (A*STAR, Singapore) and a Singapore Translational Research Investigator Award (NRMC/StaR/013/2012) to AB as well as NIHR Biomedical Centre, Oxford, WT 091663MA, NIAID1U19AI082630-01, Oxford Martin School funding and an NIHR Senior Investigator award to PK

Argumentum ad misericordiam - the critical intimacies of victimhood

This article discusses the widespread use of victim tropes in contemporary Anglo-American culture by using cultural theory to analyse key social media memes circulating on Facebook in 2015. Since the growth of social media, victim stories have been proliferating, and each demands a response. Victim narratives are rhetorical, they are designed to elicit pity and shame the perpetrator. They are deployed to stimulate political debate and activism, as well as to appeal to an all-purpose humanitarianism. Victimology has its origins in Law and Criminology, but this paper opens up the field more broadly to think about the cultural politics of victimhood, to consider how the victim-figure can be appropriated by/for different purposes, particularly racial and gender politics, including in the case of Rachel Dolezal, and racial passing. In formulating an ethical response to the lived experience of victims, we need to think about the different kinds of critical intimacies elicited by such media

Exercise interventions for smoking cessation

Background Taking regular exercise, whether cardiovascular‐type exercise or resistance exercise, may help people to give up smoking, particularly by reducing cigarette withdrawal symptoms and cravings, and by helping to manage weight gain. Objectives To determine the effectiveness of exercise‐based interventions alone, or combined with a smoking cessation programme, for achieving long‐term smoking cessation, compared with a smoking cessation intervention alone or other non‐exercise intervention. Search methods We searched the Cochrane Tobacco Addiction Group Specialised Register for studies, using the term 'exercise' or 'physical activity' in the title, abstract or keywords. The date of the most recent search was May 2019. Selection criteria We included randomised controlled trials that compared an exercise programme alone, or an exercise programme as an adjunct to a cessation programme, with a cessation programme alone or another non‐exercise control group. Trials were required to recruit smokers wishing to quit or recent quitters, to assess abstinence as an outcome and have follow‐up of at least six months. Data collection and analysis We followed standard Cochrane methods. Smoking cessation was measured after at least six months, using the most rigorous definition available, on an intention‐to‐treat basis. We calculated risk ratios (RRs) and 95% confidence intervals (CIs) for smoking cessation for each study, where possible. We grouped eligible studies according to the type of comparison, as either smoking cessation or relapse prevention. We carried out meta‐analyses where appropriate, using Mantel‐Haenszel random‐effects models. Main results We identified 24 eligible trials with a total of 7279 adult participants randomised. Two studies focused on relapse prevention among smokers who had recently stopped smoking, and the remaining 22 studies were concerned with smoking cessation for smokers who wished to quit. Eleven studies were with women only and one with men only. Most studies recruited fairly inactive people. Most of the trials employed supervised, group‐based cardiovascular‐type exercise supplemented by a home‐based exercise programme and combined with a multi‐session cognitive behavioural smoking cessation programme. The comparator in most cases was a multi‐session cognitive behavioural smoking cessation programme alone. Overall, we judged two studies to be at low risk of bias, 11 at high risk of bias, and 11 at unclear risk of bias. Among the 21 studies analysed, we found low‐certainty evidence, limited by potential publication bias and by imprecision, comparing the effect of exercise plus smoking cessation support with smoking cessation support alone on smoking cessation outcomes (RR 1.08, 95% CI 0.96 to 1.22; I2 = 0%; 6607 participants). We excluded one study from this analysis as smoking abstinence rates for the study groups were not reported. There was no evidence of subgroup differences according to the type of exercise promoted; the subgroups considered were: cardiovascular‐type exercise alone (17 studies), resistance training alone (one study), combined cardiovascular‐type and resistance exercise (one study) and type of exercise not specified (two studies). The results were not significantly altered when we excluded trials with high risk of bias, or those with special populations, or those where smoking cessation intervention support was not matched between the intervention and control arms. Among the two relapse prevention studies, we found very low‐certainty evidence, limited by risk of bias and imprecision, that adding exercise to relapse prevention did not improve long‐term abstinence compared with relapse prevention alone (RR 0.98, 95% CI 0.65 to 1.47; I2 = 0%; 453 participants). Authors' conclusions There is no evidence that adding exercise to smoking cessation support improves abstinence compared with support alone, but the evidence is insufficient to assess whether there is a modest benefit. Estimates of treatment effect were of low or very low certainty, because of concerns about bias in the trials, imprecision and publication bias. Consequently, future trials may change these conclusions.PLAIN LANGUAGE SUMMARY: Can exercise help people quit smoking? Background We reviewed the evidence about whether exercise helps people who want to quit smoking, or have recently stopped smoking, to stop smoking for at least six months. Taking regular exercise may help people give up smoking by helping with cigarette withdrawal and cravings, and by helping them to manage weight gain, which can be a concern among people trying to quit. Study characteristics We found 24 studies with a total of 7279 people. Two studies focused on helping those who had recently stopped smoking and the rest of the studies included current smokers who wished to quit. All the studies were conducted with adults. Eleven studies were with women only and one with men only. Most studies recruited fairly inactive people. Most studies offered supervised and group‐based, aerobic‐type exercise. The evidence is up‐to‐date to May 2019. Key results When we combined the results of 21 studies (6607 participants) which compared exercise and smoking‐cessation programmes to smoking cessation programmes alone, there was no evidence that exercise increased quit rates at six months or longer. There was no evidence that the effect was different for different types of exercise. When we combined results from two studies (453 participants), there was no evidence that exercise helped people who had recently quit to stay quit. Quality of evidence We judged the quality of evidence for whether exercise programmes help people quit smoking as low certainty, suggesting that future research could change these results. The low certainty is because we cannot rule out chance as an explanation for the suggested slight benefit. It could be that exercise may not help at all, or it could be that supporting people to do exercise modestly increases quit rates. We do not know which of these is true. We also consider that a good number of the trials may be biased. We have concerns that small studies which found smaller effects were less likely to be published than small studies which found bigger effects, making the average result misleading. We judged the evidence from two studies examining whether exercise helps people to avoid relapse to smoking to be of very low certainty, again suggesting that more research is needed. This is due to imprecision of the estimated effects and a high risk of bias in the methods used by one of the studies

Language-free graphical signage improves human performance and reduces anxiety when working collaboratively with robots

As robots become more ubiquitous, and their capabilities extend, novice users will require intuitive instructional information related to their use. This is particularly important in the manufacturing sector, which is set to be transformed under Industry 4.0 by the deployment of collaborative robots in support of traditionally low-skilled, manual roles. In the first study of its kind, this paper reports how static graphical signage can improve performance and reduce anxiety in participants physically collaborating with a semi-autonomous robot. Three groups of 30 participants collaborated with a robot to perform a manufacturing-type process using graphical information that was relevant to the task, irrelevant, or absent. The results reveal that the group exposed to relevant signage was significantly more accurate in undertaking the task. Furthermore, their anxiety towards robots significantly decreased as a function of increasing accuracy. Finally, participants exposed to graphical signage showed positive emotional valence in response to successful trials. At a time when workers are concerned about the threat posed by robots to jobs, and with advances in technology requiring upskilling of the workforce, it is important to provide intuitive and supportive information to users. Whilst increasingly sophisticated technical solutions are being sought to improve communication and confidence in human-robot co-working, our findings demonstrate how simple signage can still be used as an effective tool to reduce user anxiety and increase task performance