Ledrappier–Young formulae for a family of nonlinear attractors

LDL was supported by an EPSRC Doctoral Training Grant (EP/N509759/1). NJ was supported by an EPSRC Standard Grant (EP/R015104/1).We study a natural class of invariant measures supported on the attractors of a family of nonlinear, non-conformal iterated function systems introduced by Falconer, Fraser and Lee. These are pushforward quasi-Bernoulli measures, a class which includes the well-known class of Gibbs measures for Hölder continuous potentials. We show that these measures are exact dimensional and that their exact dimensions satisfy a Ledrappier–Young formula.Publisher PDFPeer reviewe

Ethanol-HIV Stimulates Macrophage-derived Extracellular Vesicles to Promote a Profibrotic Phenotype in Hepatic Stellate Cells

Liver fibrosis is the scarring process where excessive extracellular matrix proteins occur and can be caused by exposure to certain toxins or compounds such as alcohol. Alcohol can lead to increased fibrosis and cirrhosis in people living with HIV due to its ability to influence the liver’s microenvironment. Extracellular vesicles (EVs) communicate between cells by transferring their cargo. Under stress, macrophages can communicate with hepatic cells by releasing EVs and potentially progressing liver disease. The current study examines how ethanol affects EVs production from HIV-infected macrophages and how macrophage-derived EVs modulate profibrotic phenotype in hepatic stellate cells. Monocyte-derived macrophages (MDM) were infected with HIV and then exposed to 50 mM EtOH during incubation. The THP-1 monocytes were differentiated to macrophages with PMA (5 ng/mL) before alcohol and HIV treatment. The medium from the macrophages was collected for ultracentrifugation to isolate the EVs. The EVs were quantified using Nanoparticle tracking analysis (NTA). Transcriptional expression of genes was performed with qPCR. LX-2 hepatic stellate cells were exposed to macrophage-derived EVs from different treatment groups to assess profibrotic activation. Ethanol treatment in HIV-infected macrophages increased the production of EVs compared to their respective controls. The majority of the EVs from the MDM cells were in the range of small EVs (50-200 nm). Exposure of EtOH-HIV-induced macrophage EVs to LX2 cells significantly increased the transcriptional expression of profibrotic genes Col1A1, ACTA2, and CTGF. Combined treatment of EtOH and HIV in macrophages downregulated the hsa-miR92a-3p expression in macrophage-derived EVs that binds with its putative target Col1A1 to increase fibrotic changes in recipient LX-2 cells. The findings of this study lead to the conclusion that a combination of ethanol and HIV stimulates macrophage derived EVs with the downregulation of miR92a, which will activate the profibrotic phenotype in hepatic stellate cells. This activation will contribute to the progression of liver disease.https://digitalcommons.unmc.edu/surp2021/1022/thumbnail.jp

Neurofeedback of visual food cue reactivity: a potential avenue to alter incentive sensitization and craving

FMRI-based neurofeedback transforms functional brain activation in real-time into sensory stimuli that participants can use to self-regulate brain responses, which can aid the modification of mental states and behavior. Emerging evidence supports the clinical utility of neurofeedback-guided up-regulation of hypoactive networks. In contrast, down-regulation of hyperactive neural circuits appears more difficult to achieve. There are conditions though, in which down-regulation would be clinically useful, including dysfunctional motivational states elicited by salient reward cues, such as food or drug craving. In this proof-of-concept study, 10 healthy females (mean age = 21.40 years, mean BMI = 23.53) who had fasted for 4 h underwent a novel ‘motivational neurofeedback’ training in which they learned to down-regulate brain activation during exposure to appetitive food pictures. FMRI feedback was given from individually determined target areas and through decreases/increases in food picture size, thus providing salient motivational consequences in terms of cue approach/avoidance. Our preliminary findings suggest that motivational neurofeedback is associated with functionally specific activation decreases in diverse cortical/subcortical regions, including key motivational areas. There was also preliminary evidence for a reduction of hunger after neurofeedback and an association between down-regulation success and the degree of hunger reduction. Decreasing neural cue responses by motivational neurofeedback may provide a useful extension of existing behavioral methods that aim to modulate cue reactivity. Our pilot findings indicate that reduction of neural cue reactivity is not achieved by top-down regulation but arises in a bottom-up manner, possibly through implicit operant shaping of target area activity

Longevinex ® Improves Human Atrophic Aged-related Macular Degeneration (AMD) Photoreceptor / Retinal Pigment Epithelium Mediated Dark Adaptation*

Aim: Gradual photoreceptor/ RPE deterioration/ vision loss in AMD is common, irrespective of US NEI AREDS I/II supplement risk reduction, or intra-vitreal anti-VEGF pharmacology. We evaluated dark adaptation (DA), a broad measure of photoreceptor / RPE health, with / without epigenetic modulation using a resveratrol–based caloric-restriction mimic (Longevinex ®www.longevinex.com). Study Design: Case series, bi-ocular, clinical DA evaluation in deteriorating AMD, before and after supplementation, under medical center compassionate use guidelines. Place and Duration of Study: Captain James A Lovell Federal Health Care Center, Illinois, USA, Optometry/Ophthalmology Departments between 4/2015 and 8/2016. Methods: Baseline clinical DA threshold (log DB), time (min), and fixation (%) were taken for patients with established atrophic AMD (n=14 eyes; 6 M / 1 F; ages 64 - 89 years), using the AdaptDx ® (www.maculogix.com), with pupil dilation and best refraction. Following prescription of Longevinex® 1 capsule qd AM, DA was repeated, with each eye’s response considered independent. Results: All but 2 eyes improved in one or more DA parameters, with 3 cases showing improvement by retinal macula SD OCT. Expected vs. actual (worse vs. same/better), by eye, was significant by Chi Square, P < .01. Additional factors affecting DA: smoking, alcohol, elevated CRP and statins were retrospectively evaluated. Conclusion: These first cases of epigenetic-induced DA stability / improvement are consistent with previous beneficial effects of Longevinex® such as enhanced choriocapillaris circulation. DA is the earliest functional AMD sign and a prime candidate for “AMD prevention”. This work merits expansion to controlled studies

Training response inhibition to reduce food consumption: Mechanisms, stimulus specificity and appropriate training protocols

Training individuals to inhibit their responses towards unhealthy foods has been shown to reduce food intake relative to a control group. Here we aimed to further explore these effects by investigating the role of stimulus devaluation, training protocol, and choice of control group. Restrained eaters received either inhibition or control training using a modified version of either the stop-signal or go/no-go task. Following training we measured implicit attitudes towards food (Study 1) and food consumption (Studies 1 and 2). In Study 1 we used a modified stop-signal training task with increased demands on top-down control (using a tracking procedure and feedback to maintain competition between the stop and go processes). With this task, we found no evidence for an effect of training on implicit attitudes or food consumption, with Bayesian inferential analyses revealing substantial evidence for the null hypothesis. In Study 2 we removed the feedback in the stop-signal training to increase the rate of successful inhibition and revealed a significant effect of both stop-signal and go/no-go training on food intake (compared to double-response and go training, respectively) with a greater difference in consumption in the go/no-go task, compared with the stop-signal task. However, results from an additional passive control group suggest that training effects could be partly caused by increased consumption in the go control group whereas evidence for reduced consumption in the inhibition groups was inconclusive. Our findings therefore support evidence that inhibition training tasks with higher rates of inhibition accuracy are more effective, but prompt caution for interpreting the efficacy of laboratory-based inhibition training as an intervention for behaviour change

The Evidence Information Service: rapid matchmaker for connecting politicians with thousands of UK researchers.

Last month a team of UK academics launched an initiative called the Evidence Information Service (EIS), which seeks to enable rapid dialogue between researchers and policy makers. The initial stage of the EIS includes a citizen-led consultation in which constituents interview their elected politicians, together with a controlled experiment in the UK Parliament. In this post the founders of the EIS describe the response so far and the challenges that lie ahead

Ventral striatum activity in response to reward: differences between bipolar I and II disorders.

addresses: MRC Center for Neuropsychiatric Genetics and Genomics, Institute of Psychological Medicine and Clinical Neurosciences, Cardiff University, UK. [email protected]: PMCID: PMC3640293types: Journal Article; Research Support, Non-U.S. Gov'tThis is an open-access article distributed under the terms of the Creative Commons Attribution Non-commercial License, which permits use, distribution, and reproduction in any medium, provided the original work is properly cited, the use is non commercial and is otherwise in compliance with the license. See: http://creativecommons.org/licenses/by-nc/3.0/ and http://creativecommons.org/licenses/by-nc/3.0/legalcode.Copyright © 2013 by the American Psychiatric AssociationThe official published article is available online at http://ajp.psychiatryonline.org/article.aspx?articleid=1676088Little is known about the neurobiology of bipolar II disorder. While bipolar I disorder is associated with abnormally elevated activity in response to reward in the ventral striatum, a key component of reward circuitry, no studies have compared reward circuitry function in bipolar I and bipolar II disorders. Furthermore, associations among reward circuitry activity, reward sensitivity, and striatal volume remain underexplored in bipolar and healthy individuals. The authors examined reward activity in the ventral striatum in participants with bipolar I and II disorders and healthy individuals, the relationships between ventral striatal activity and reward sensitivity across all participants, and between-group differences in striatal gray matter volume and relationships with ventral striatal activity across all participants

Subgenual cingulum microstructure supports control of emotional conflict

Major depressive disorder (MDD) is associated with specific difficulties in attentional disengagement from negatively valenced material. Diffusion MRI studies have demonstrated altered white matter microstructure in the subgenual cingulum bundle (CB) in individuals with MDD, though the functional significance of these alterations has not been examined formally. This study explored whether individual differences in selective attention to negatively valenced stimuli are related to interindividual differences in subgenual CB microstructure. Forty-six individuals (21 with remitted MDD, 25 never depressed) completed an emotional Stroop task, using happy and angry distractor faces overlaid by pleasant or unpleasant target words and a control gender-based Stroop task. CBs were reconstructed in 38 individuals using diffusion-weighted imaging and tractography, and mean fractional anisotropy (FA) computed for the subgenual, retrosplenial, and parahippocampal subdivisions. No significant correlations were found between FA and performance in the control gender-based Stroop task in any CB region. However, the degree of interference produced by angry face distractors on time to identify pleasant words (emotional conflict) correlated selectively with FA in the subgenual CB (r = −0.53; P = 0.01). Higher FA was associated with reduced interference, irrespective of a diagnosis of MDD, suggesting that subgenual CB microstructure is functionally relevant for regulating attentional bias toward negative interpersonal stimul

Exploring strategies to optimise the impact of food-specific inhibition training on children's food choices

This is the final version. Available on open access from Frontiers Media via the DOI in this recordData Availability Statement: The research data and analysis code supporting this publication are openly available in ORE at: https://doi.org/10.24378/exe.3303Food-specific inhibition training (FSIT) is a computerised task requiring response inhibition to energy dense foods within a reaction-time game. Previous work indicates that FSIT can increase the number of healthy foods (relative to energy-dense foods) children choose, and decrease calories consumed from sweets and chocolate. Across two studies, we explored the impact of FSIT variations (e.g., different response signals, different delivery modes) on children’s food choices within a time-limited hypothetical food-choice task. In Study 1, we varied the FSIT Go/No-Go signals to be emotive (happy vs. sad faces) or neutral (green vs. red signs). One-hundred-and-fifty-seven children were randomly allocated to emotive-FSIT, neutral-FSIT or a non-food control task. Children participated in groups of 4-15. No significant FSIT effects were observed on food choices (all p values > .160). Healthy-food choices decreased over time regardless of condition (p .050). Healthy choices decreased over time in the control group (p = .001) but did not change in the two FSIT groups (both p > .300) supporting previous evidence that FSIT may have a beneficial effect on children’s food choices. Ensuring that children perform FSIT with high accuracy (e.g., by using FSIT in quiet environments and avoiding group-testing) may be important for impacts on food choices though. Future research should continue to explore methods of optimising FSIT as a healthy-eating intervention for children.Economic and Social Research Council (ESRC)European Union Horizon 2020Ghent Universit