466 research outputs found
GABRB1 Single Nucleotide Polymorphism Associated with Altered Brain Responses (but not Performance) during Measures of Impulsivity and Reward Sensitivity in Human Adolescents.
Variations in genes encoding several GABAA receptors have been associated with human drug and alcohol abuse. Among these, a number of human studies have suggested an association between GABRB1, the gene encoding GABAA receptor β1 subunits, with Alcohol dependence (AD), both on its own and comorbid with other substance dependence and psychiatric illnesses. In the present study, we hypothesized that the GABRB1 genetically-associated increased risk for developing alcoholism may be associated with impaired behavioral control and altered sensitivity to reward, as a consequence of altered brain function. Exploiting the IMAGEN database (Schumann et al., 2010), we explored in a human adolescent population whether possession of the minor (T) variant of the single nucleotide polymorphism (SNP) rs2044081 is associated with performance of tasks measuring aspects of impulsivity, and reward sensitivity that are implicated in drug and alcohol abuse. Allelic variation did not associate with altered performance in either a stop-signal task (SST), measuring one aspect of impulsivity, or a monetary incentive delay (MID) task assessing reward anticipation. However, increased functional magnetic resonance imaging (fMRI) blood-oxygen-level dependent (BOLD) response in the right hemisphere inferior frontal gyrus (IFG), left hemisphere caudate/insula and left hemisphere inferior temporal gyrus (ITG) during MID performance was higher in the minor (T) allelic group. In contrast, during SST performance, the BOLD response found in the right hemisphere supramarginal gyrus, right hemisphere lingual and left hemisphere inferior parietal gyrus indicated reduced responses in the minor genotype. We suggest that β1-containing GABAA receptors may play a role in excitability of brain regions important in controlling reward-related behavior, which may contribute to susceptibility to addictive behavior
The discovery of potent, selective, and reversible inhibitors of the house dust mite peptidase allergen Der p 1: an innovative approach to the treatment of allergic asthma.
Blocking the bioactivity of allergens is conceptually attractive as a small-molecule therapy for allergic diseases but has not been attempted previously. Group 1 allergens of house dust mites (HDM) are meaningful targets in this quest because they are globally prevalent and clinically important triggers of allergic asthma. Group 1 HDM allergens are cysteine peptidases whose proteolytic activity triggers essential steps in the allergy cascade. Using the HDM allergen Der p 1 as an archetype for structure-based drug discovery, we have identified a series of novel, reversible inhibitors. Potency and selectivity were manipulated by optimizing drug interactions with enzyme binding pockets, while variation of terminal groups conferred the physicochemical and pharmacokinetic attributes required for inhaled delivery. Studies in animals challenged with the gamut of HDM allergens showed an attenuation of allergic responses by targeting just a single component, namely, Der p 1. Our findings suggest that these inhibitors may be used as novel therapies for allergic asthma
Quantum critical dynamics in a 5000-qubit programmable spin glass
Experiments on disordered alloys suggest that spin glasses can be brought
into low-energy states faster by annealing quantum fluctuations than by
conventional thermal annealing. Due to the importance of spin glasses as a
paradigmatic computational testbed, reproducing this phenomenon in a
programmable system has remained a central challenge in quantum optimization.
Here we achieve this goal by realizing quantum critical spin-glass dynamics on
thousands of qubits with a superconducting quantum annealer. We first
demonstrate quantitative agreement between quantum annealing and time-evolution
of the Schr\"odinger equation in small spin glasses. We then measure dynamics
in 3D spin glasses on thousands of qubits, where simulation of many-body
quantum dynamics is intractable. We extract critical exponents that clearly
distinguish quantum annealing from the slower stochastic dynamics of analogous
Monte Carlo algorithms, providing both theoretical and experimental support for
a scaling advantage in reducing energy as a function of annealing time
Distinct microbial and immune niches of the human colon.
Gastrointestinal microbiota and immune cells interact closely and display regional specificity; however, little is known about how these communities differ with location. Here, we simultaneously assess microbiota and single immune cells across the healthy, adult human colon, with paired characterization of immune cells in the mesenteric lymph nodes, to delineate colonic immune niches at steady state. We describe distinct helper T cell activation and migration profiles along the colon and characterize the transcriptional adaptation trajectory of regulatory T cells between lymphoid tissue and colon. Finally, we show increasing B cell accumulation, clonal expansion and mutational frequency from the cecum to the sigmoid colon and link this to the increasing number of reactive bacterial species
Quantum error mitigation in quantum annealing
Quantum Error Mitigation (QEM) presents a promising near-term approach to
reduce error when estimating expectation values in quantum computing. Here, we
introduce QEM techniques tailored for quantum annealing, using Zero-Noise
Extrapolation (ZNE). We implement ZNE through zero-temperature extrapolation as
well as energy-time rescaling. We conduct experimental investigations into the
quantum critical dynamics of a transverse-field Ising spin chain, demonstrating
the successful mitigation of thermal noise through both of these techniques.
Moreover, we show that energy-time rescaling effectively mitigates control
errors in the coherent regime where the effect of thermal noise is minimal. Our
ZNE results agree with exact calculations of the coherent evolution over a
range of annealing times that exceeds the coherent annealing range by almost an
order of magnitude.Comment: 10 pages, 5 figure
PIK3CA mutations are common in lobular carcinoma in situ, but are not a biomarker of progression
Sample and data collection were funded by Cancer Research UK. Analysis was funded by Breast Cancer Now, the Rosetrees Trust, Guys & St Thomas’ Charity (CanHelp) and the National Institute for Health Research (NIHR) Biomedical Research Centre based at Guy’s and St. Thomas’ NHS Foundation Trust and King’s College London
Discovery of four recessive developmental disorders using probabilistic genotype and phenotype matching among 4,125 families.
Discovery of most autosomal recessive disease-associated genes has involved analysis of large, often consanguineous multiplex families or small cohorts of unrelated individuals with a well-defined clinical condition. Discovery of new dominant causes of rare, genetically heterogeneous developmental disorders has been revolutionized by exome analysis of large cohorts of phenotypically diverse parent-offspring trios. Here we analyzed 4,125 families with diverse, rare and genetically heterogeneous developmental disorders and identified four new autosomal recessive disorders. These four disorders were identified by integrating Mendelian filtering (selecting probands with rare, biallelic and putatively damaging variants in the same gene) with statistical assessments of (i) the likelihood of sampling the observed genotypes from the general population and (ii) the phenotypic similarity of patients with recessive variants in the same candidate gene. This new paradigm promises to catalyze the discovery of novel recessive disorders, especially those with less consistent or nonspecific clinical presentations and those caused predominantly by compound heterozygous genotypes
Physical activity and nutrition program for seniors (PANS): protocol of a randomized controlled trial
Background Along with reduced levels of physical activity, older Australian's mean energy consumption has increased. Now over 60% of older Australians are considered overweight or obese. This study aims to confirm if a low-cost, accessible physical activity and nutrition program can improve levels of physical activity and diet of insufficiently active 60-70 year-olds. Methods/Design This 12-month home-based randomised controlled trial (RCT) will consist of a nutrition and physical activity intervention for insufficiently active people aged 60 to 70 years from low to medium socio-economic areas. Six-hundred participants will be recruited from the Australian Federal Electoral Role and randomly assigned to the intervention (n = 300) and control (n = 300) groups. The study is based on the Social Cognitive Theory and Precede-Proceed Model, incorporating voluntary cooperation and self-efficacy. The intervention includes a specially designed booklet that provides participants with information and encourages dietary and physical activity goal setting. The booklet will be supported by an exercise chart, calendar, bi-monthly newsletters, resistance bands and pedometers, along with phone and email contact. Data will be collected over three time points: pre-intervention, immediately post-intervention and 6-months post-study. Discussion This trial will provide valuable information for community-based strategies to improve older adults' physical activity and dietary intake. The project will provide guidelines for appropriate sample recruitment, and the development, implementation and evaluation of a minimal intervention program, as well as information on minimising barriers to participation in similar programs
A new era in the treatment of multiple sclerosis
Multiple sclerosis (MS) is an autoimmune disease of the central nervous system with a multifactorial aetiology and highly variable natural history. A growing understanding of the immunopathogenesis of the condition has led to an expanding array of therapies for this previously untreatable disease. While a cure for MS remains elusive, the potential to reduce inflammatory disease activity by preventing relapses and minimising disease progression is achievable. The importance of early treatment in minimising long-term disability is increasingly recognised. Most of the newer, more effective therapies are associated with risks and practical problems that necessitate an active management strategy and continuous vigilance. While the initiation of these therapies is likely to remain the responsibility of neurologists, other specialist physicians and general practitioners will be involved in the identification and management of adverse effects
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