The effects of periodic and continuous market environments on the performance of trading agents

Simulation experiments are conducted on simple continuous double auction (CDA) markets based on the experimental economics work of Vernon Smith. CDA models within experimental economics usually consist of a sequence of discrete trading periods or “days”, with allocations of stock and currency replenished at the start of each day, a situation we call “periodic” replenishment. In our experiments we look at both periodic and continuous-replenishment versions of the CDA. In this we build on the work of Cliff and Preist (2001) with human subjects, but we replace human traders with Zero Intelligence Plus (ZIP) trading agents, a minimal algorithm that can produce equilibrating market behaviour in CDA models. Our results indicate that continuous-replenishment (CR) CDA markets are similar to conventional periodic CDA markets in their ability to show equilibration dynamics. Secondly we show that although both models produce the same behaviour of price formation, they are different playing fields, as periodic markets are more efficient over time than their continuous counterparts. We also find, however, that the volume of trade in periodic CDA markets is concentrated in the early period of each trading day, and the market is in this sense inefficient. We look at whether ZIP agents require different parameters for optimal behaviour in each market type, and find that this is indeed the case. Overall, our conclusions mirror earlier findings on the robustness of the CDA, but we stress that a CR-CDA marketplace equilibrates in a different way to a periodic one

N terminus is key to the dominant negative suppression of CaV2 calcium channels: implications for episodic ataxia type 2

Expression of the calcium channels CaV2.1 and CaV2.2 is markedly suppressed by co-expression with truncated constructs containing Domain I. This is the basis for the phenomenon of dominant negative suppression observed for many of the episodic ataxia type 2 mutations in CaV2.1 that predict truncated channels. The process of dominant negative suppression has been shown previously to stem from interaction between the full-length and truncated channels and to result in downstream consequences of the unfolded protein response and endoplasmic reticulum-associated protein degradation. We have now identified the specific domain that triggers this effect. For both CaV2.1 and CaV2.2, the minimum construct producing suppression was the cytoplasmic N terminus. Suppression was enhanced by tethering the N terminus to the membrane with a CAAX motif. The 11-amino acid motif (including Arg52 and Arg54) within the N terminus, which we have previously shown to be required for G protein modulation, is also essential for dominant negative suppression. Suppression is prevented by addition of an N-terminal tag (XFP) to the full-length and truncated constructs. We further show that suppression of CaV2.2 currents by the N terminus-CAAX construct is accompanied by a reduction in CaV2.2 protein level, and this is also prevented by mutation of Arg52 and Arg54 to Ala in the truncated construct. Taken together, our evidence indicates that both the extreme N terminus and the Arg52, Arg54 motif are involved in the processes underlying dominant negative suppression

Challenges in the Management of Non-Alcoholic Fatty Liver Disease (NAFLD): Towards a Compassionate Approach

From Crossref journal articles via Jisc Publications RouterHistory: epub 2023-08-25, issued 2023-08-25Article version: VoRPublication status: PublishedRepresenting a growing ‘silent epidemic’, non-alcoholic fatty liver disease (NAFLD) affects around 25–30% of the general population. Alarmingly, NAFLD increases the risk of cardiovascular disease, both independently and through its strong associations with obesity, type 2 diabetes, and metabolic syndrome, whilst posing a substantial burden from an economic and health-related quality of life perspective. Moreover, growing evidence links NAFLD to common mental health disorders including depression, anxiety, and stress. In this context, recent clinical and research attention further focuses on potential additional problems faced by patients with NAFLD, such as perceived stigma, lack of awareness regarding the condition, and possible feelings of loneliness and isolation that might emerge from unmet support needs. To date, despite a wealth of literature on NAFLD, management of the condition remains challenging and not straightforward, with most cases in primary care being treated with lifestyle modification on top of any other comorbidity treatment. However, for many patients with NAFLD, weight loss is hard to accomplish and/or sustain (e.g., patients may lack the skills, confidence, and motivation required to adhere to dietary changes, and/or may have problems limiting opportunities for increased physical activity). Therefore, tailored interventions which are manageable from the perspective of the individual patient with NAFLD could glean greater results. Accordingly, although there is a lack of research exploring the potential benefits of person-centered and compassion-based approaches to the management of NAFLD, in the present review, we draw on evidence from methods utilized in the treatment of other chronic conditions in postulating the view that such approaches might prove beneficial in the future management of NAFLD

Non-Alcoholic Fatty Liver Disease (NAFLD) and Potential Links to Depression, Anxiety, and Chronic Stress

From MDPI via Jisc Publications RouterHistory: accepted 2021-11-13, pub-electronic 2021-11-16Publication status: PublishedNon-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease worldwide, and is frequently linked to the metabolic syndrome. The latter represents a clustering of related cardio-metabolic components, which are often observed in patients with NAFLD and increase the risk of cardiovascular disease. Furthermore, growing evidence suggests a positive association between metabolic syndrome and certain mental health problems (e.g., depression, anxiety, and chronic stress). Given the strong overlap between metabolic syndrome and NAFLD, and the common underlying mechanisms that link the two conditions, it is probable that potentially bidirectional associations are also present between NAFLD and mental health comorbidity. The identification of such links is worthy of further investigation, as this can inform more targeted interventions for patients with NAFLD. Therefore, the present review discusses published evidence in relation to associations of depression, anxiety, stress, and impaired health-related quality of life with NAFLD and metabolic syndrome. Attention is also drawn to the complex nature of affective disorders and potential overlapping symptoms between such conditions and NAFLD, while a focus is also placed on the postulated mechanisms mediating associations between mental health and both NAFLD and metabolic syndrome. Relevant gaps/weaknesses of the available literature are also highlighted, together with future research directions that need to be further explored

Non-Alcoholic Fatty Liver Disease (NAFLD) and Potential Links to Depression, Anxiety, and Chronic Stress

Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease worldwide, and is frequently linked to the metabolic syndrome. The latter represents a clustering of related cardio-metabolic components, which are often observed in patients with NAFLD and increase the risk of cardiovascular disease. Furthermore, growing evidence suggests a positive association between metabolic syndrome and certain mental health problems (e.g., depression, anxiety, and chronic stress). Given the strong overlap between metabolic syndrome and NAFLD, and the common underlying mechanisms that link the two conditions, it is probable that potentially bidirectional associations are also present between NAFLD and mental health comorbidity. The identification of such links is worthy of further investigation, as this can inform more targeted interventions for patients with NAFLD. Therefore, the present review discusses published evidence in relation to associations of depression, anxiety, stress, and impaired health-related quality of life with NAFLD and metabolic syndrome. Attention is also drawn to the complex nature of affective disorders and potential overlapping symptoms between such conditions and NAFLD, while a focus is also placed on the postulated mechanisms mediating associations between mental health and both NAFLD and metabolic syndrome. Relevant gaps/weaknesses of the available literature are also highlighted, together with future research directions that need to be further explored

Non-alcoholic fatty liver disease (NAFLD) and potential links to depression, anxiety, and chronic stress

© 2021 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/biomedicines9111697Non-alcoholic fatty liver disease (NAFLD) constitutes the most common liver disease worldwide, and is frequently linked to the metabolic syndrome. The latter represents a clustering of related cardio-metabolic components, which are often observed in patients with NAFLD and increase the risk of cardiovascular disease. Furthermore, growing evidence suggests a positive association between metabolic syndrome and certain mental health problems (e.g., depression, anxiety, and chronic stress). Given the strong overlap between metabolic syndrome and NAFLD, and the common underlying mechanisms that link the two conditions, it is probable that potentially bidirectional associations are also present between NAFLD and mental health comorbidity. The identification of such links is worthy of further investigation, as this can inform more targeted interventions for patients with NAFLD. Therefore, the present review discusses published evidence in relation to associations of depression, anxiety, stress, and impaired health-related quality of life with NAFLD and metabolic syndrome. Attention is also drawn to the complex nature of affective disorders and potential overlapping symptoms between such conditions and NAFLD, while a focus is also placed on the postulated mechanisms mediating associations between mental health and both NAFLD and metabolic syndrome. Relevant gaps/weaknesses of the available literature are also highlighted, together with future research directions that need to be further explored.Published versio

Challenges in the management of non-alcoholic fatty liver disease (NAFLD) : Towards a compassionate approach

© 2023 The authors. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/livers3030031Representing a growing ‘silent epidemic’, non-alcoholic fatty liver disease (NAFLD) affects around 25–30% of the general population. Alarmingly, NAFLD increases the risk of cardiovascular disease, both independently and through its strong associations with obesity, type 2 diabetes, and metabolic syndrome, whilst posing a substantial burden from an economic and health-related quality of life perspective. Moreover, growing evidence links NAFLD to common mental health disorders including depression, anxiety, and stress. In this context, recent clinical and research attention further focuses on potential additional problems faced by patients with NAFLD, such as perceived stigma, lack of awareness regarding the condition, and possible feelings of loneliness and isolation that might emerge from unmet support needs. To date, despite a wealth of literature on NAFLD, management of the condition remains challenging and not straightforward, with most cases in primary care being treated with lifestyle modification on top of any other comorbidity treatment. However, for many patients with NAFLD, weight loss is hard to accomplish and/or sustain (e.g., patients may lack the skills, confidence, and motivation required to adhere to dietary changes, and/or may have problems limiting opportunities for increased physical activity). Therefore, tailored interventions which are manageable from the perspective of the individual patient with NAFLD could glean greater results. Accordingly, although there is a lack of research exploring the potential benefits of person-centered and compassion-based approaches to the management of NAFLD, in the present review, we draw on evidence from methods utilized in the treatment of other chronic conditions in postulating the view that such approaches might prove beneficial in the future management of NAFLD.Published onlin

Support needs and coping strategies in non-alcoholic fatty liver disease (NAFLD): a multidisciplinary approach to potential unmet challenges beyond pharmacological treatment

© 2022 The Authors. Published by MDPI. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.3390/livers3010001Non-alcoholic fatty liver disease (NAFLD) is the most frequently occurring chronic liver disease, affecting approximately 25–30% of the adult general population worldwide. NAFLD reflects excess hepatic accumulation of fat in the absence of increased alcohol intake, and, due to its close association with obesity, is frequently referred to as the ‘hepatic manifestation’ of metabolic syndrome. Indeed, a high percentage of individuals with NAFLD present with a combination of the cardio-metabolic comorbidities that are associated with the metabolic syndrome. In addition to its well-established link with the metabolic syndrome and increased risk for cardiovascular disease, NAFLD has also been associated with certain mental health issues (e.g., depression and stress). Although this link is now being increasingly recognized, there are still unmet needs regarding the holistic management of patients with NAFLD, which could further contribute to feelings of social isolation and loneliness. The latter conditions are also increasingly reported to pose a substantial risk to overall health and quality of life. To date, there is limited research that has explored these issues among patients with NAFLD, despite existing data which indicate that perceived loneliness and isolation may pose an additional health risk. Notably, many features associated with NAFLD have been related to these concepts, such as perceived stigma, fatigue, stress, and confusion regarding this diagnosis. As such, this review aimed to assess such potential problems faced by patients with NAFLD, and to explore the possibility of unmet support needs which could lead to perceived social isolation. Moreover, the importance of a compassionate approach towards such patients is discussed, together with potential coping strategies. Future research directions and the need for a multidisciplinary approach are also highlighted.Published onlin

Non-alcoholic fatty liver disease and coexisting depression, anxiety and/or stress in adults:a systematic review and meta-analysis

Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, affecting 25-30% of the general population globally. The condition is even more prevalent in individuals with obesity and is frequently linked to the metabolic syndrome. Given the known associations between the metabolic syndrome and common mental health issues, it is likely that such a relationship also exists between NAFLD and mental health problems. However, studies in this field remain limited. Accordingly, the aim of this systematic review and meta-analysis was to explore the prevalence of one or more common mental health conditions (i.e., depression, anxiety, and/or stress) in adults with NAFLD. Methods: PubMed, EBSCOhost, ProQuest, Ovid, Web of Science, and Scopus were searched in order to identify studies reporting the prevalence of depression, anxiety, and/or stress among adults with NAFLD. A random-effects model was utilized to calculate the pooled prevalence and confidence intervals for depression, anxiety and stress. Results: In total, 31 studies were eligible for inclusion, involving 2,126,593 adults with NAFLD. Meta-analyses yielded a pooled prevalence of 26.3% (95% CI: 19.2 to 34) for depression, 37.2% (95% CI: 21.6 to 54.3%) for anxiety, and 51.4% (95% CI: 5.5 to 95.8%) for stress among adults with NAFLD. Conclusion: The present findings suggest a high prevalence of mental health morbidity among adults with NAFLD. Given the related public health impact, this finding should prompt further research to investigate such associations and elucidate potential associations between NAFLD and mental health morbidity, exploring potential shared underlying pathophysiologic mechanisms. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42021288934

Non-alcoholic fatty liver disease and coexisting depression, anxiety and/or stress in adults: a systematic review and meta-analysis

Copyright © 2024 Shea, Lionis, Kite, Lagojda, Uthman, Dallaway, Atkinson, Chaggar, Randeva and Kyrou. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.Background: Non-alcoholic fatty liver disease (NAFLD) is a common chronic liver disease, affecting 25-30% of the general population globally. The condition is even more prevalent in individuals with obesity and is frequently linked to the metabolic syndrome. Given the known associations between the metabolic syndrome and common mental health issues, it is likely that such a relationship also exists between NAFLD and mental health problems. However, studies in this field remain limited. Accordingly, the aim of this systematic review and meta-analysis was to explore the prevalence of one or more common mental health conditions (i.e., depression, anxiety, and/or stress) in adults with NAFLD. Methods: PubMed, EBSCOhost, ProQuest, Ovid, Web of Science, and Scopus were searched in order to identify studies reporting the prevalence of depression, anxiety, and/or stress among adults with NAFLD. A random-effects model was utilized to calculate the pooled prevalence and confidence intervals for depression, anxiety and stress. Results: In total, 31 studies were eligible for inclusion, involving 2,126,593 adults with NAFLD. Meta-analyses yielded a pooled prevalence of 26.3% (95% CI: 19.2 to 34) for depression, 37.2% (95% CI: 21.6 to 54.3%) for anxiety, and 51.4% (95% CI: 5.5 to 95.8%) for stress among adults with NAFLD. Conclusion: The present findings suggest a high prevalence of mental health morbidity among adults with NAFLD. Given the related public health impact, this finding should prompt further research to investigate such associations and elucidate potential associations between NAFLD and mental health morbidity, exploring potential shared underlying pathophysiologic mechanisms. Systematic review registration: https://www.crd.york.ac.uk/prospero/, identifier CRD42021288934.Acknowledgements: SS, IK, and HR would like to thank the University Hospitals Coventry and Warwickshire (UHCW) NHS Trust and the General Charities of Coventry for their ongoing support