The glycaemic effects of single doses of Panax ginseng in young healthy volunteers

The results of two acute placebo-controlled, double-blind cross-over studies assessing the effect of Panax ginseng (G115) on blood glucose levels are reported. In study 1, thirty participants received three treatments: placebo; 200 mg G115; 400 mg G115. In study 2, twenty-seven participants received four treatments: placebo (0 mg ginseng and 30 mg saccharin); ginseng (200 mg ginseng and 30 mg saccharin); placebo–glucose (0 mg ginseng and 25 g oral glucose); ginseng–glucose (200 mg ginseng and 25 g oral glucose). Blood glucose levels were measured at baseline (at 09.00 hours after an overnight fast) and then 60, 90 (study 1 only) and 120 min post-dose. Both studies demonstrated that G115 alone significantly lowers fasting blood glucose levels. Conversely, in study 2 there was a significant drink × ginseng interaction suggesting opposing glycaemic effects of ginseng under fasting and raised blood glucose conditions. These data have implications for the use of ginseng in individuals with poor gluco-regulation

DHA-rich oil modulates the cerebral haemodynamic response to cognitive tasks in healthy young adults: a near IR spectroscopy pilot study

The impact of dietary n-3 PUFA on behavioural outcomes has been widely researched; however, very little attention has been given to their impact on brain functioning in physiological terms. A total of twenty-two healthy adults took part in this double-blind, placebo-controlled study, wherein the cerebral haemodynamic effects of 12 weeks of daily dietary supplementation with either 1 g DHA-rich or 1 g EPA-rich fish oil (FO) or placebo (1 g olive oil) were assessed. Relative changes in the concentration of oxygenated Hb (oxy-Hb) and deoxygenated Hb were assessed in the prefrontal cortex using near IR spectroscopy (NIRS) during the performance of four computerised cognitive tasks. Supplementation with DHA-rich FO, in comparison with placebo, resulted in a significant increase in the concentrations of oxy-Hb and total levels of Hb, indicative of increased cerebral blood flow (CBF), during the cognitive tasks. In comparison, no effect on CBF was observed following supplementation with EPA-rich FO, where concentration changes in the chromophores followed the same pattern as placebo. These encouraging pilot data warrant further application of NIRS in this area

Panax ginseng has no effect on indices of glucose regulation following acute or chronic ingestion in healthy volunteers

In the absence of effective pharmacotherapy for diabetes there has been an increase in the use of, and research into, alternative treatment strategies. These include exercise, dietary interventions and the use of supplements including extracts of ginseng. Two separate, placebo-controlled, double-blind, cross-over studies investigating the effects of chronic ingestion of Panax ginseng (study 1 used G115, study 2 used Cheong Kwan Jang) on glycated Hb (HbA1c; study 1, n 18; study 2, n 11), fasting plasma insulin (study 1, n 17; study 2, n 12), fasting plasma glucose and postprandial response (following breakfast) (study 1, n 23; study 2, n 14) in healthy volunteers are reported. In both studies it was found that Panax ginseng had no effect on any gluco-regulatory parameter investigated. These results are not consistent with those reported for a diabetic sample (albeit using slightly different outcomes). These results would suggest that chronic use of Panax ginseng by non-diabetic individuals will have little long-term effect on glucose regulation. The benefits to glucose regulation associated with long-term ginseng use may only be present in populations with compromised glucose control; however, further research is needed to confirm such a speculation

Neurocognitive and gluco-regulatory effects of Panax ginseng

Complementary and Alternative Medicine (CAM) has long been used in the Far East to aid in the recovery and prevention of illness. Ginseng, an over-the-counter herbal product in the UK, is amongst these herbal CAMs currently available to the general public. Ginseng is renowned for its rejuvenating properties and its purported ability to aid cognitive function and well-being. Despite the huge global market for ginseng there is little in the way of human research, utilising standardised ginseng extracts and well controlled methodology to support many of these claims. Additionally, ginseng's underlying mechanisms of action are poorly understood. The present thesis documents 5 double-blind, placebo-controlled, cross-over trials investigating the effects of Panax ginseng, following acute and chronic ingestion, on behaviour, mood and indices of glucose regulation in young healthy volunteers. The results of the five studies making this thesis suggest that both acute and chronic dosing with Panax ginseng is capable of modulating mood and cognitive performance in healthy young volunteers. Chapters 2 and 3 also demonstrate, for the first time, Panax ginseng's ability to modulate blood glucose levels following a single acute dose in overnight fasted healthy volunteers. In chapters 2 and 3, significant reductions in blood glucose levels and concomitant improvements in mental arithmetic (working memory) performance were reported. Chapter 4 revealed for the first time Panax ginseng's positive effects on traditional measures of working memory, thus posing the suggestion that previous failures to report working memory effects (using traditional working memory tasks) may have been due to poor task selection. Chapter 5 revealed an unexpected superimposed relationship between chronic and acute ingestion of Panax ginseng. The pattern of results suggests that following chronic dosing, an acute dose can further modulate cognition and mood (suggestive of a psychological dependence). The final chapter documents a different profile of cognitive and mood effects following a non-standardised Panax ginseng extract, thus highlighting the need for caution when generalising results across ginseng types and beyond the specific parameters of the methodologies utilised in any given study. Methodological differences between studies may go some way in explaining the inconsistent data patterns reported between studies, research groups and ginseng extracts. These data further highlight the need for well-controlled studies utilising standardised ginseng extracts and the need for the integration of 'theory driven' research in order to fractionate any behavioural effect. Such methodologies will inevitably lead to greater consistency between behavioural studies, at least in the first instance within the restricted population of volunteers utilised in the present thesis.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Molecular Dynamics Simulations Reveal the Protective Role of Cholesterol in β-Amyloid Protein-Induced Membrane Disruptions in Neuronal Membrane Mimics

Interactions of β-amyloid (Aβ) peptides with neuronal membranes have been associated with the pathogenesis of Alzheimer\u27s disease (AD); however, the molecular details remain unclear. We used atomistic molecular dynamics (MD) simulations to study the interactions of Aβ40 and Aβ42 with model neuronal membranes. The differences between cholesterol-enriched and depleted lipid domains were investigated by the use of model phosphatidylcholine (PC) lipid bilayers with and without 40 mol % cholesterol. A total of 16 independent 200 ns simulation replicates were investigated. The surface area per lipid, bilayer thickness, water permeability barrier, and lipid order parameter, which are sensitive indicators of membrane disruption, were significantly altered by the inserted state of the protein. We conclude that cholesterol protects Aβ-induced membrane disruption and inhibits β-sheet formation of Aβ on the lipid bilayer. The latter could represent a two-dimensional (2D) seeding template for the formation of toxic oligomeric Aβ in the pathogenesis of AD

Activation workers’ perceptions of their long-term unemployed clients’ attitudes towards employment

The Work Programme’s use of severe social security benefit sanctions reflects British coalition ministers’ belief that many people on out-of-work benefits do not want a job. While a substantial empirical literature has repeatedly demonstrated that in fact unemployed benefit claimants possess the same work values as the employed and that the vast majority want paid work, it has ignored some conservative authors’ pleas to consider the views and experiences of people who work with the unemployed. Forty employees of agencies contracted to help unemployed people into employment were interviewed in summer 2011. Respondents had spent an estimated combined total of 147,000 hours in the presence of people who have claimed Jobseeker’s Allowance (JSA) for over six months. Most said that between a quarter and half of their present clients did not want employment. This finding does not contradict existing research, given that most JSA claimants re-enter employment within six months. However, all forty agreed that many others remained unemployed because they were choosy in the jobs they were willing to undertake, and,most strikingly, respondents overwhelmingly endorsed the view that a ‘dependency culture’ exists in households and neighbourhoods that have experienced joblessness for several generations

Through-life NEC scenario development

Scenarios are an important planning tool used by individuals, businesses and governments (especially in the military domain), but many of the currently used approaches focus solely on acute probabilistic timeframes and specific metricated instances of possible future states. Using a mixed method research methodology, we develop a scenario approach in which multiple timeframes are accommodated by fitting vignettes within each other to represent different time levels. This has the advantage of presenting the end-to-end process of capability development and instantiation. We describe the methodology employed to generate such a scenario as a demonstration aid for a large, multidisciplinary research program in systems of systems engineering. The process of scenario generation was an effective integration tool within this program (that included twelve distributed research groups). The resultant scenario enabled engagement of multiple stakeholders in an integrated demonstration of systems related research outputs. We recommend a new class of scenario (a “research scenario”) for incorporation within the standard classifications of scenario types

Welfare conditionality, inequality and unemployed people with alternative values

Labour and Conservatives’ claims that welfare conditionality is ‘fair’ rely upon an empirically unsupported assumption that almost-equal opportunities can exist alongside starkly unequal outcomes. Fifty interviews examined in-depth a diverse sample’s values, views about work and welfare, and labour market choices. Respondents’ views on equality strongly influenced their views on conditionality and what they considered acceptable labour market behaviour. ‘Alternative’ unemployed respondents, who rejected politicians’ suggestions they ‘should work’, nevertheless favoured an equal society with work obligations and often undertook voluntary work. The article concludes that policymakers should be more sensitive to Jobseeker’s Allowance claimants’ diverse moralities and motivations

Understanding the Barriers Fathers Face to Seeking Help for Paternal Perinatal Depression: Comparing Fathers to Men Outside the Perinatal Period

Research has shown that men are less likely than women to seek help for depression at any time of life due to barriers, including stereotypical masculine norms and stigma. The evidence suggests that approximately 10% of fathers experience postnatal depression, yet new and expectant fathers are not routinely offered screening or support in the same way as mothers. Therefore, this research explored the barriers fathers face to seeking help for paternal perinatal depression (PPD). Data were collected using an online survey. Initially, fathers with postnatal depression were compared to men experiencing depression at another time of their life in terms of their attitudes to seeking psychological help, conformity to masculine norms, self-stigma, and awareness of services. Secondly, a proposed model of help-seeking amongst fathers with postnatal depression was evaluated. Finally, additional barriers to help-seeking for paternal postnatal depression were explored qualitatively. A total of 125 participants took part in the quantitative comparison, and 50 of the fathers also provided qualitative data. No between-group differences were found, suggesting that the existing literature on barriers to seeking help for male depression is applicable to fathers with postnatal depression. The qualitative results also highlighted the need for better awareness of paternal postnatal depression and better access to services for fathers. Limitations, implications for policy, and directions for future research are discussed