731 research outputs found

    The Allure of High-Risk Rewards in Huntington’s disease

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    Objectives: Huntington’s disease (HD) is a neurodegenerative disorder that produces a bias toward risky, reward-driven decisions in situations where the outcomes of decisions are uncertain and must be discovered. However, it is unclear whether HD patients show similar biases in decision-making when learning demands are minimized and prospective risks and outcomes are known explicitly. We investigated how risk decision-making strategies and adjustments are altered in HD patients when reward contingencies are explicit. Methods: HD (N=18) and healthy control (HC; N=17) participants completed a risk-taking task in which they made a series of independent choices between a low-risk/low reward and high-risk/high reward risk options. Results: Computational modeling showed that compared to HC, who showed a clear preference for low-risk compared to high-risk decisions, the HD group valued high-risks more than low-risk decisions, especially when high-risks were rewarded. The strategy analysis indicated that when high-risk options were rewarded, HC adopted a conservative risk strategy on the next trial by preferring the low-risk option (i.e., they counted their blessings and then played the surer bet). In contrast, following a rewarded high-risk choice, HD patients showed a clear preference for repeating the high-risk choice. Conclusions: These results indicate a pattern of high-risk/high-reward decision bias in HD that persists when outcomes and risks are certain. The allure of high-risk/high-reward decisions in situations of risk certainty and uncertainty expands our insight into the dynamic decision-making deficits that create considerable clinical burden in HD

    Macronutrient intake and prevalence of markers of metabolic syndrome in white UK adult males in the National Diet and Nutrition Survey Rolling Programme 2008–2014

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    The amount of carbohydrates recommended for consumption by current dietary guidelines has been challenged in relation to their suitability to prevent or manage cardiometabolic (CM) diseases with suggestions that they should be decreased and replaced by protein or fat( 1 , 2 ). Others have argued that a more personalised approach is required( 3 ). Aim of this investigation was to assess the potential impact of lower versus higher consumption of dietary macronutrients and prevalence of CM risk markers in a representative sample of the UK male white population. Unweighted data from 642 white adult males aged 19 and over in the National Diet and Nutrition Survey Rolling Programme( 4 ) (NDNS RP) 2008–2014 with or without metabolic syndrome (MetS)( 5 ) were analysed for associations of dietary macronutrient intake as percentage food energy (%FE) with CM risk markers. Logistic regression analysis (adjusted for age group and smoking status) was used to compare the odds ratios [OR] of prevalence of individual markers of MetS between the lowest and highest quartiles of dietary macronutrient intake as %FE (⩽44 vs. ≥52 for carbohydrates; ⩽31 vs. ≥39 for fats; ⩽15. vs. ≥19 for protein). There was a significant (p < 0·05) reduction in likelihood of MetS (OR, .55; 95 % confidence interval [CI], .34 to .84), and elevated waist circumference (OR, .50; 95 % CI, .30 to .83) and glucose levels (OR, .51; 95 % CI, .30 to .87) for those in the highest quartile of carbohydrate %FE intake compared to the lowest quartile, whereas those in the highest quartile of protein %FE intake had a significantly (p < 0·05) increased risk of presenting with the same markers of MetS (OR, 1·75; 95 % CI, 1·05 to 2·93; OR, 2·12; 95 % CI, 1·24 to 3·63; and OR, 2·15; 95 % CI, 1·25 to 3·70 respectively). Those with the highest compared to the lowest total dietary fat intake also presented with elevated CM risk markers, albeit these findings were not significant. *Metabolic Syndrome (MetS) definition: 3 out of 5 of the following: triglycerides (TRIG) ≥1·7 mmol/L; High-density lipoprotein cholesterol (HDL-C) ⩽1·03 mmol/L for males; Waist circumference (WC) ≥94 cm for white males; Glucose (GLUC) ≥5·6 mmol/L; Blood pressure (BP) ≥130 mmHg systolic or ≥85 mmHg diastolic respectively; CHO%FE – total carbohydrates percentage food energy; FAT%FE – total fats food energy; PROT%FE– total protein food energy; OR – odds ratio (adjusted for age group and smoking status), 1st vs. 4th quartile of intake; CI – confidence interval; a p < 0·05 Further investigations need to confirm whether the quality of the macronutrients consumed and overall diet quality( 6 ) has had an impact on these results. In the context of a personalised approach to nutrition future cohort studies should also provide data that allow for examining inter-individual variations in responses to dietary macronutrients, especially carbohydrates, to achieve optimum CM health for a larger proportion of the population

    The association between dietary macronutrient intake and fibrogen growth factor 21 in a sample of White UK adults with elevated cardiometabolic risk markers

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    Increased levels of Fibrogen growth factor 21 (FGF21) is an emerging risk marker for cardiometabolic (CM) disease(1). Little detail is known about the impact of the human diet on FGF21 levels. The aim of this investigation was to assess potential associations between mean daily dietary macronutrient intake and FGF21 levels in a sample of 10 healthy normal-weight and overweight Caucasian adults aged 32–60 (80 % male) at increased CM risk(2). This pilot study received ethical approval from Liverpool John Moores University Research Ethics Committee (16/ELS/029) and was registered with ClinicalTrials.gov (Ref. NCT03257085). Participants were randomly allocated to one of two groups and asked to either consume 50 % energy from CHO for a duration of 8 weeks. Blood plasma samples were col- lected at baseline (BL), interim point (IP) and endpoint (EP) after a 12-hour overnight fast, immediately processed and frozen at −80°C. Thawed plasma samples were analysed via Quantikine® enzyme-linked immunosorbent assay (ELISA) (R&D Systems) for FGF21 levels. Two-way mixed ANOVA and Pearson’s partial correlation adjusted for estimated weekly moderate and vigorous activity was undertaken using IBM SPSS 24®. There were no effects for diet between groups or over time (data not shown). Significant correlations between macronutrient intakes and FGF21 levels were found for both groups at IP, but not at BL or EP. Moderate and significant positive correlations were found in the overall group for intake (g/d) for glucose (rpartial = ·699, p = ·04) and fructose (rpartial = ·686, p = ·04) and strong and significant positive correlations for non-milk extrinsic sugars (rpartial = ·742, p = ·02). Strong and significant positive correlations were also found in the LC group for glucose intake (g/d) (rpartial = ·980, p = ·02) and fructose (rpartial = ·967, p = ·03) and for protein (rpartial =·998, p=·002) after adjusting for physical activity. Mean carbohydrate intake (g/d) was 160·0 (s.d. 124·5) overall and 44·2 (s.d. 14·9) in the LC group at IP. Mean protein intake (g/d) was 113·2 (21·4) 130·0 (s.d. 15·9) overall and in the LC group at IP. Mean FGF21 levels were 179·9 pg/mL (s.d. 144·9) in the overall group and 94.4 pg/ML (s.d. 48.6) in the LC group at IP. %TE Intake (g/d) PROT FAT CHO GLU FRU NMES PROT FAT rrrrrrrrrrr −·214 ·623 ·635 −·326 −·491 ·448 ·699* ·686* ·742* −·606 −·496 ·143 ·637 ·937 ·427 −·059 ·722 ·980* ·967* ·919 ·998** −·080 Total kcal CHO NMES T LC CHO-Total carbohydrates, FAT-Total fat, FRU-Fructose, GLUC-Glucose, LC-low-carbohydrate, high-fat group, NMES-non-milk extrinsic sugars, PROT-protein, T – total, %TE – percentage total energy, *p < ·05 **p < ·005. In conclusion, low-carbohydrate diets provide the opportunity to assess responses to even small amounts of CHO, which are likely to be replaced in part by proteins. Despite low overall intakes of fructose and glucose in the LC group, strong and positive correlations with FGF21 levels were observed. The lower levels of FGF21 in the LC compared to the overall group are in line with findings that FGF21 levels are elevated with high-carbohydrate, low-protein diets with dietary fats having only minor impact(3). However, the majority of studies have still been undertaken using rodent models. The impact of dietary macronutrients on FGF21 levels as novel CMR marker in humans and the mechanism behind this relationship warrant further investigation. 1. Lakhani I, Gong M, Wong W et al. (2018) Metabolism 2018 Feb 1. pii: S0026-0495(18)30023-4. [Epub ahead of print]. 2. Jebb S, Lovegrove J, Griffin B et al. (2010) Am J Clin Nutr 92, 748–58. 3. Solon-Biet S, Cogger V, Pulpitel T et al. (2016) Cell Metab 24, 555–565

    Tunneling Spectroscopy of Tl2Ba2CuO6

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    New results from tunneling spectroscopies on near optimally-doped single crystals of Tl_{2}Ba_{2}CuO_{6} (Tl-2201) junctions are presented. The superconductor-insulator-normal metal (SIN) tunnel junctions are obtained using the point-contact technique with a Au tip. The tunneling conductances reproducibly show a sharp cusp-like subgap, prominent quasiparticle peaks with a consistent asymmetry, and weakly decreasing backgrounds. A rigorous analysis of the SIN tunneling data is performed using two different models for the dx2y2d_{x^{2}-y^{2}} (d-wave) density of states (DOS). Based on these and earlier results, the tunneling DOS of Tl-2201 have exhibited the most reproducible data that are consistent with a d-wave gap symmetry. We show that the dip feature at 2Δ2\Delta that is clearly seen in SIN tunneling data of Bi_{2}Sr_{2}CaCu_{2}O_{8+\delta} is also present in Tl-2201, but at a weaker level. The gap values for crystals with a bulk T_c = 86 K are in the range of 19-25 meV.Comment: 7 pages, 5 figure

    Dietary carbohydrate intake, visceral adipose tissue and associated markers of cardiometabolic risk

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    Risk of cardiometabolic (CM) disease is characterised by elevated visceral adipose tissue (VAT) and a number of associated biomar- kers(1). Some dietary carbohydrates (CHO) have been found to contribute to VAT accumulation(2). Little is known about the impact of following a low-carbohydrate diet versus a high-carbohydrate diet on VAT, adiponectin (ADPN), leptin (LEPT) and leptin:adipo- nectin ratio (LAR). The aim of this investigation was to assess the impact of dietary carbohydrates (CHO) on VAT and emerging CM risk markers in a sample of 10 healthy normal-weight and overweight Caucasian adults aged 32–60 (80 % male) at increased CM risk(3). This pilot study received ethical approval from Liverpool John Moores University Research Ethics Committee (16/ELS/ 029) and was registered with ClinicalTrials.gov (Ref. NCT03257085). Participants were randomly allocated to one of two groups and asked to either consume 50 % energy from CHO (high-carb (HC)) for a duration of 8 weeks. VAT was ana- lysed via bioelectrical impedance (SECA mBCA 515). Blood plasma samples were collected at baseline (BL), interim point (IP) and endpoint (EP) after a 12-hour overnight fast, immediately processed and frozen at -80°C. Thawed plasma samples were analysed via immunoassay technology (Randox Evidence InvestigatorTM Metabolic Syndrome Arrays I and II) for ADPN and LEPT levels. Statistical analysis was undertaken using IBM SPSS 24®. Parametric data was analysed via two-way mixed ANOVA; non-parametric data was analysed via Mann-Whitney U test and Friedman test. Average daily carbohydrate intake in the LC group was 44·2 g at IP and 48·9 g at EP. There were no significant differences between groups at any time point for ADPN, LEPT, LAR or VAT and no significant inter- actions for time or group*time for ADPN, LEPT or LAR. However, in the LC group VAT decreased significantly between baseline and endpoint by 15 % (p = ·015) Over the course of the intervention ADPN and LEPT decreased non- significantly (by 4 % and 70 % respectively) in the LC group, whilst increasing non-significantly in the HC group (9 % and 65 % respectively). LAR increased in the HC group throughout the study, whilst LAR in the LC group decreased albeit not significantly. VAT (litre) ADPN (ng/mL) LEPT (ng/mL) LAR BL IP EP Median Median Median M SD M SD M SD BL IP EP BL IP EP BL IP EP LC 4·1a 1·2 3·8 1·3 3·5a 1·2 8·9 8·6 8·5 3·96 1·64 1·20 0·45 0·19 0·14 HC 2·7 0·1 1·6 0·3 2·5 0·1 11·3 13·4 12·3 0·97 1·1 1·60 0·07 0·07 0·46 ADPN = adiponectin, BL = baseline, EP = endpoint, HC = high-carbohydrate, moderate fat diet, IP = interim point, LAR = leptin:adiponectin ratio, LEPT = leptin, LC = low-carbohydrate, high-fat diet, VAT = visceral adipose tissue, ap = ·015. NB: interquartile ranges not provided for median values due to missing data. Higher LAR has been found to be a marker of increased CM risk(4). In conclusion, while the significant reduction in VAT in the LC group corresponds with the reduction of LAR further evidence is required to corroborate these findings. Previous evidence for LC is supportive for improved CM health from various biomarkers(5); LAR should be considered as a useful endocrine addition for future LC studies. 1. Krasimira A, Mozaffarian D & Pischon T (2018) Clin Chem 64, 142–153. 2. Rüttgers D, Fischer K, Koch M et al. (2015) Br J Nutr 114, 1929–1940. 3. Jebb S, Lovegrove J, Griffin B et al. (2010) Am J Clin Nutr 92, 748–58. 4. López-Jaramillo P, Gómez-Arbeláez D, López-López J et al. (2014) Horm Mol Biol Clin Investig 18, 37–45. 5. Bazzano L, Hi T, Reynolds K et al. (2014) Ann Intern Med 161, 309–318

    Perspectives on tracking data reuse across biodata resources.

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    Data reuse is a common and vital practice in molecular biology and enables the knowledge gathered over recent decades to drive discovery and innovation in the life sciences. Much of this knowledge has been collated into molecular biology databases, such as UniProtKB, and these resources derive enormous value from sharing data among themselves. However, quantifying and documenting this kind of data reuse remains a challenge. The article reports on a one-day virtual workshop hosted by the UniProt Consortium in March 2023, attended by representatives from biodata resources, experts in data management, and NIH program managers. Workshop discussions focused on strategies for tracking data reuse, best practices for reusing data, and the challenges associated with data reuse and tracking. Surveys and discussions showed that data reuse is widespread, but critical information for reproducibility is sometimes lacking. Challenges include costs of tracking data reuse, tensions between tracking data and open sharing, restrictive licenses, and difficulties in tracking commercial data use. Recommendations that emerged from the discussion include: development of standardized formats for documenting data reuse, education about the obstacles posed by restrictive licenses, and continued recognition by funding agencies that data management is a critical activity that requires dedicated resources. Summaries of survey results are available at: https://docs.google.com/forms/d/1j-VU2ifEKb9C-sW6l3ATB79dgHdRk5v_lESv2hawnso/viewanalytics (survey of data providers) and https://docs.google.com/forms/d/18WbJFutUd7qiZoEzbOytFYXSfWFT61hVce0vjvIwIjk/viewanalytics (survey of users)

    Using the past to constrain the future: how the palaeorecord can improve estimates of global warming

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    Climate sensitivity is defined as the change in global mean equilibrium temperature after a doubling of atmospheric CO2 concentration and provides a simple measure of global warming. An early estimate of climate sensitivity, 1.5-4.5{\deg}C, has changed little subsequently, including the latest assessment by the Intergovernmental Panel on Climate Change. The persistence of such large uncertainties in this simple measure casts doubt on our understanding of the mechanisms of climate change and our ability to predict the response of the climate system to future perturbations. This has motivated continued attempts to constrain the range with climate data, alone or in conjunction with models. The majority of studies use data from the instrumental period (post-1850) but recent work has made use of information about the large climate changes experienced in the geological past. In this review, we first outline approaches that estimate climate sensitivity using instrumental climate observations and then summarise attempts to use the record of climate change on geological timescales. We examine the limitations of these studies and suggest ways in which the power of the palaeoclimate record could be better used to reduce uncertainties in our predictions of climate sensitivity.Comment: The final, definitive version of this paper has been published in Progress in Physical Geography, 31(5), 2007 by SAGE Publications Ltd, All rights reserved. \c{opyright} 2007 Edwards, Crucifix and Harriso
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