7,447 research outputs found

    Electrophysiological Evidence of Atypical Processing Underlying Mental Set Shifting in Ecstasy Polydrug and Polydrug Users

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    Executive functioning deficits are reported in ecstasy users. However research into mental set switching has been equivocal, with behavioural studies suggesting the function is preserved. The current study sought to address the issue of switching deficits in ecstasy users by combining behavioural performance with electrophysiological correlates (EEG). Twenty ecstasy polydrug users, 20 non-ecstasy polydrug users and 20 drug naive controls were recruited. Participants completed questionnaires about their drug use, sleep quality, fluid intelligence and current mood state. Each participant completed a mental set switching task (the number-letter task) whilst EEG measures were recorded. ANOVA revealed no between group differences on performance of the task, however a regression suggested that ecstasy use was a significant predictor for performance, after controlling for cannabis use. Mixed ANOVA revealed a significant effect of group on the P3, with significant differences between both drug groups and naives. There was also an interaction between electrode and group on the P2 component, with ecstasy users differing from both other groups. On the P3 component the results suggest a reduction in positivity at parieto-occipital electrodes for drug users compared to controls. Furthermore a significant increase in negativity in ecstasy users compared to control groups could be observed in several occipito-parietal electrodes at an N2 component as well as observable atypicalities in early processing (P2) displayed by ecstasy users and polydrug controls. The present study provides evidence of atypical processing of attentional shifting in ecstasy and polydrug users. Deficits in this executive function could reflect cognitive inflexibility and paucity of rapid behavioural adjustment, which may be problematic in real world situations. Keywords: Ecstasy; cannabis; executive function; stimulants; cannabis

    Analysing the rising price of new private housing in the UK: A national accounting approach

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    Copyright © 2022 The Authors. Discussion of the price of private new-build housing is dominated by land price, but is this the most important element? Other factors are examined for increasing prices, using the rich and robust datasets produced by government departments and agencies. In organising these complex datasets a Sankey diagram is introduced to explain the relationship between type of trade and type of work to show the relative importance of prices. The land value component has been trending downwards, so is not a factor in the rising prices of new private dwellings. Prices of components, other than land value, are obtained from gross fixed capital formation data and construction output. When corrected for inflation, these have risen by factors of 1.7 and 2.0, respectively, over 1998–2018. By including the self-employed, the total labour per new-build private dwelling is derived which has risen 2.4 to 3.0 man-years over 2011–2020. Since 2000, construction companies’ gross operating surplus per job has risen much faster than compensation of employees per job. This extra gross operating surplus, which can be associated with profit, totalled £11.6b in 2019 reaching £70k (at 2016 prices) per new private dwelling in 2019. Rising prices have created the opportunity for housebuilders to extract larger profits

    A Upf3b-mutant mouse model with behavioral and neurogenesis defects.

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    Nonsense-mediated RNA decay (NMD) is a highly conserved and selective RNA degradation pathway that acts on RNAs terminating their reading frames in specific contexts. NMD is regulated in a tissue-specific and developmentally controlled manner, raising the possibility that it influences developmental events. Indeed, loss or depletion of NMD factors have been shown to disrupt developmental events in organisms spanning the phylogenetic scale. In humans, mutations in the NMD factor gene, UPF3B, cause intellectual disability (ID) and are strongly associated with autism spectrum disorder (ASD), attention deficit hyperactivity disorder (ADHD) and schizophrenia (SCZ). Here, we report the generation and characterization of mice harboring a null Upf3b allele. These Upf3b-null mice exhibit deficits in fear-conditioned learning, but not spatial learning. Upf3b-null mice also have a profound defect in prepulse inhibition (PPI), a measure of sensorimotor gating commonly deficient in individuals with SCZ and other brain disorders. Consistent with both their PPI and learning defects, cortical pyramidal neurons from Upf3b-null mice display deficient dendritic spine maturation in vivo. In addition, neural stem cells from Upf3b-null mice have impaired ability to undergo differentiation and require prolonged culture to give rise to functional neurons with electrical activity. RNA sequencing (RNAseq) analysis of the frontal cortex identified UPF3B-regulated RNAs, including direct NMD target transcripts encoding proteins with known functions in neural differentiation, maturation and disease. We suggest Upf3b-null mice serve as a novel model system to decipher cellular and molecular defects underlying ID and neurodevelopmental disorders

    The energy budget in Rayleigh-Benard convection

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    It is shown using three series of Rayleigh number simulations of varying aspect ratio AR and Prandtl number Pr that the normalized dissipation at the wall, while significantly greater than 1, approaches a constant dependent upon AR and Pr. It is also found that the peak velocity, not the mean square velocity, obeys the experimental scaling of Ra^{0.5}. The scaling of the mean square velocity is closer to Ra^{0.46}, which is shown to be consistent with experimental measurements and the numerical results for the scaling of Nu and the temperature if there are strong correlations between the velocity and temperature.Comment: 5 pages, 3 figures, new version 13 Mar, 200

    Luminescence of F2 and F3 + centres in LiF crystals irradiated with 12 MeV 12C ions

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    Dependences of the nanohardness and photoluminescence of F 2 and F 3 + centers on the depth in LiF crystals irradiated with 12 MeV 12 C ions to fluences 10 10 -10 15 ions/cm 2 were studied using laser scanning confocal microscopy, luminescent spectroscopy, and the nanoindentation method. The nanohardness measurements showed a significant hardening effect at the end of the ion run with the dominant contribution of defects formed by the mechanism of elastic collisions. The observed attenuation of the luminescence intensity at high fluences is associated with the intense nucleation of dislocations as traps for aggregate color centers.The work was carried out within the framework of the grant GF AP05134257 of the Ministry of Education and Science of the Republic of Kazakhstan; Institute of Solid State Physics, University of Latvia as the Center of Excellence has received funding from the European Union’s Horizon 2020 Framework Programme H2020-WIDESPREAD-01-2016-2017-TeamingPhase2 under grant agreement No. 739508, project CAMART

    Review and assessment of the potential of post-IR IRSL dating methods to circumvent the problem of anomalous fading in feldspar luminescence

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    Quartz has been the main mineral used for optically stimulated luminescence (OSL) dating of sediments over the last decade. The quartz OSL signal, however, has been shown to saturate at relatively low doses of ∼200–400 Gy, making it difficult to be used for dating beyond about 200 thou-sand years (ka), unless the environmental dose rate is low. The infrared stimulated luminescence (IRSL) from feldspars has been shown to continue to grow to higher dose levels than quartz OSL. The application of IRSL dating of feldspars, however, has long been hampered by the anomalous fading effect. Recent progress in understanding anomalous fading of the infrared stimulated luminescence (IRSL) signals in potassium-feldspar has led to the development of post-IR IRSL (pIRIR) protocols and also a multiple elevated temperature (MET) stimulation (MET-pIRIR) protocol. These procedures have raised the prospect of isolating a non-fading IRSL component for dating Quaternary deposits containing feldspars. In this study, we review the recent progress made on (1) overcoming anomalous fading of feldspar, and (2) the development of pIRIR dating techniques for feldspar. The potential and problems associated with these methods are discussed.link_to_OA_fulltex

    Review and assessment of the potential of post-IR IRSL dating methods to circumvent the problem of anomalous fading in feldspar luminescence

    Get PDF
    Quartz has been the main mineral used for optically stimulated luminescence (OSL) dating of sediments over the last decade. The quartz OSL signal, however, has been shown to saturate at relatively low doses of ∼200–400 Gy, making it difficult to be used for dating beyond about 200 thou-sand years (ka), unless the environmental dose rate is low. The infrared stimulated luminescence (IRSL) from feldspars has been shown to continue to grow to higher dose levels than quartz OSL. The application of IRSL dating of feldspars, however, has long been hampered by the anomalous fading effect. Recent progress in understanding anomalous fading of the infrared stimulated luminescence (IRSL) signals in potassium-feldspar has led to the development of post-IR IRSL (pIRIR) protocols and also a multiple elevated temperature (MET) stimulation (MET-pIRIR) protocol. These procedures have raised the prospect of isolating a non-fading IRSL component for dating Quaternary deposits containing feldspars. In this study, we review the recent progress made on (1) overcoming anomalous fading of feldspar, and (2) the development of pIRIR dating techniques for feldspar. The potential and problems associated with these methods are discussed.link_to_OA_fulltex

    Consequences of selecting technology pathways on cumulative carbon dioxide emissions for the United Kingdom

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    The UK has an ambitious target of an 80% reduction in carbon dioxide emissions by 2050, to be reached using a series of ‘carbon budgets’ to aid policy development. Current energy systems modelling methods do not explore, or are unable to account for, physical (thermodynamic) limits to the rate of change of infrastructure. The power generation sector has a variety of technological options for this low-carbon transition. We compare physically constrained scenarios that accentuate either carbon capture and storage, fastest plausible nuclear new build, or fastest plausible build rate of offshore wind. We set these in the context of the UK’s legislated fifth carbon budget, which has a comprehensive range of carbon reduction measures with respect to business-as-usual. The framework for our scenario comparison uses our novel system dynamics model to substantiate the policy’s ability to meet 2035 emissions targets while maintaining financial productivity and socially expected employment levels. For an ambitious nuclear new build programme we find that even if it stays on track it is more expensive than offshore wind generation and delays emissions reductions. This affects the cumulative emissions and impacts on the UK’s ability to contribute to international climate change targets. If delays or cancellation occur to the deployment programmes of carbon capture and storage technologies or nuclear new build, we suggest the electricity and decarbonisation targets can by met by a fast growth of offshore wind generation with no change to financial and employment levels.Arup’s internal Design and Technical Fun

    Modelling socio-economic and energy data to generate business-as-usual scenarios for carbon emissions

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    The UK Government is legally committed to achieving an 80% reduction in carbon dioxide emissions compared with 1990 by 2050. The use of scenarios is wide ranging to inform policy development and forming a businessas-usual scenario helps to understand possible effects of different policy interventions. However, the term business-as-usual is frequently misused. We show how econo-physical business-as-usual scenarios can be developed by examining the historical behaviour of coefficients which manifest the relationship between components of an economy. We endogenise economic growth by mimicking national level policies that focus on a target level of unemployment. Our case-study demonstrates the ‘trendability’ of coefficients which for one example coefficient is replicated for Australia, Colombia, Taiwan and the USA. We manifest a gross domestic product growth of 2% falling to 1% which contrasts with an exogenous growth of 2.3% of a comparator business-as-usual scenario. We suggest that it may be possible to achieve a greater reduction in the business-asusual carbon dioxide emissions in the UK fifth carbon budget than currently projected.Arup’s internal Design and Technical Fun
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