3,481 research outputs found

    Diversification rates and phenotypic evolution in venomous snakes (Elapidae)

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    Published by the Royal Society under the terms of the Creative Commons Attribution License http://creativecommons.org/licenses/by/4.0/, which permits unrestricted use, provided the original author and source are credited.The relationship between rates of diversification and of body size change (a common proxy for phenotypic evolution) was investigated across Elapidae, the largest radiation of highly venomous snakes. Time-calibrated phylogenetic trees for 175 species of elapids (more than 50% of known taxa) were constructed using seven mitochondrial and nuclear genes. Analyses using these trees revealed no evidence for a link between speciation rates and changes in body size. Two clades (Hydrophis, Micrurus) show anomalously high rates of diversification within Elapidae, yet exhibit rates of body size evolution almost identical to the general elapid ‘background’ rate. Although correlations between speciation rates and rates of body size change exist in certain groups (e.g. ray-finned fishes, passerine birds), the two processes appear to be uncoupled in elapid snakes. There is also no detectable shift in diversification dynamics associated with the colonization of Australasia, which is surprising given that elapids appear to be the first clade of venomous snakes to reach the continent

    Intimate Partner Violence and Pregnancy Termination in Armenia: Evidence from Nationally-Representative Survey Data

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    Intimate partner violence has been associated with numerous consequences for women, including pregnancy termination. This study examined the association between predictive capacity of intimate partner violence and pregnancy termination among women in Armenia. The study analyzed the 2015–16 Armenia Demographic and Health Survey (ADHS) data on women aged 15–49 (Mean: 31.49; Standard Deviation, SD: 9.51). Marital control exercised by husbands, ever experienced physical violence, sexual violence, and emotional violence by husbands were the four indicators of intimate partner violence used in this study. To assess the association between intimate partner violence and pregnancy termination, a binary logistic regression model was fitted. After controlling for confounders, we found that women whose husbands exercised marital control were 26% more likely to experience pregnancy termination, compared to women whose husbands did not exercise marital control (adjusted odds ratio (aOR): 1.26, 95% Confidence interval (CI): 1.03–1.53). Women who ever experienced sexual violence were about 10 times likely to experience pregnancy termination than women who did not experience sexual violence (aOR: 9.76, 95% CI: 1.91–49.96). Both ever experienced physical violence and emotional violence did not have any significant associations with pregnancy termination. Forms of intimate partner violence are associated with pregnancy termination. The findings of this study provide evidence for government and policymakers to formulate, modify, and implement policies and program that target both men and women regarding the prevailing intimate partner violence and its consequences. Strengthening the policy implementation will ensure that women are empowered to make decisions about their reproductive health. Making husbands and their family members aware of the basics and consequences of intimate partner violence and focusing on child cognitive development which can be hampered due to the prevalence violence in families are recommended

    The effects of cannabidiol on impulsivity and memory during abstinence in cigarette dependent smokers

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    This is the final version of the article. Available from Springer Nature via the DOI in this record.The dataset generated during the current study are available from the corresponding author on reasonable request.Acute nicotine abstinence in cigarette smokers results in deficits in performance on specific cognitive processes, including working memory and impulsivity which are important in relapse. Cannabidiol (CBD), the non-intoxicating cannabinoid found in cannabis, has shown pro-cognitive effects and preliminary evidence has indicated it can reduce the number of cigarettes smoked in dependent smokers. However, the effects of CBD on cognition have never been tested during acute nicotine withdrawal. The present study therefore aimed to investigate if CBD can improve memory and reduce impulsivity during acute tobacco abstinence. Thirty, non-treatment seeking, dependent, cigarette smokers attended two laboratory-based sessions after overnight abstinence, in which they received either 800 mg oral CBD or placebo (PBO), in a randomised order. Abstinence was biologically verified. Participants were assessed on go/no-go, delay discounting, prose recall and N-back (0-back, 1-back, 2-back) tasks. The effects of CBD on delay discounting, prose recall and the N-back (correct responses, maintenance or manipulation) were null, confirmed by a Bayesian analysis, which found evidence for the null hypothesis. Contrary to our predictions, CBD increased commission errors on the go/no-go task. In conclusion, a single 800 mg dose of CBD does not improve verbal or spatial working memory, or impulsivity during tobacco abstinence.This research was funded by a PhD Studentship from the Medical Research Council (MRC) to the C.H. and an MRC DPFS award (MR/K015524/1) to HVC and CJAM.TPF is funded by a Senior Academic Fellowship from the Society for the Study of Addiction

    How do we speak about algorithms and algorithmic media futures? Using vignettes and scenarios in a citizen council on data-driven media personalisation

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    ‘New’ media and algorithmic rules underlying many emerging technologies present particular challenges in fieldwork, because the opacity of their design, and, sometimes, their real or perceived status as ‘not quite here yet’ – makes speaking about these challenging in the field. In this article, we use insights from a three-stage citizens council investigating citizens’ views on developments in data-driven media personalisation to reflect on the potentials of using future-orientated vignettes and scenarios in data collection on user experiences, expectations and the ethics of algorithms. We present the possibilities and potentials of using vignettes as part of a data collection approach in user-centric algorithm studies which invites users’ contextual experiences of algorithms but also enables more normative reflections on what good looks like in contemporary datafied societies

    A frequentist framework of inductive reasoning

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    Reacting against the limitation of statistics to decision procedures, R. A. Fisher proposed for inductive reasoning the use of the fiducial distribution, a parameter-space distribution of epistemological probability transferred directly from limiting relative frequencies rather than computed according to the Bayes update rule. The proposal is developed as follows using the confidence measure of a scalar parameter of interest. (With the restriction to one-dimensional parameter space, a confidence measure is essentially a fiducial probability distribution free of complications involving ancillary statistics.) A betting game establishes a sense in which confidence measures are the only reliable inferential probability distributions. The equality between the probabilities encoded in a confidence measure and the coverage rates of the corresponding confidence intervals ensures that the measure's rule for assigning confidence levels to hypotheses is uniquely minimax in the game. Although a confidence measure can be computed without any prior distribution, previous knowledge can be incorporated into confidence-based reasoning. To adjust a p-value or confidence interval for prior information, the confidence measure from the observed data can be combined with one or more independent confidence measures representing previous agent opinion. (The former confidence measure may correspond to a posterior distribution with frequentist matching of coverage probabilities.) The representation of subjective knowledge in terms of confidence measures rather than prior probability distributions preserves approximate frequentist validity.Comment: major revisio

    Single to Double Hump Transition in the Equilibrium Distribution Function of Relativistic Particles

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    We unveil a transition from single peaked to bimodal velocity distribution in a relativistic fluid under increasing temperature, in contrast with a non-relativistic gas, where only a monotonic broadening of the bell-shaped distribution is observed. Such transition results from the interplay between the raise in thermal energy and the constraint of maximum velocity imposed by the speed of light. We study the Bose-Einstein, the Fermi-Dirac, and the Maxwell-J\"uttner distributions, all exhibiting the same qualitative behavior. We characterize the nature of the transition in the framework of critical phenomena and show that it is either continuous or discontinuous, depending on the group velocity. We analyze the transition in one, two, and three dimensions, with special emphasis on two-dimensions, for which a possible experiment in graphene, based on the measurement of the Johnson-Nyquist noise, is proposed.Comment: 5 pages, 5 figure

    How do we speak about algorithms and algorithmic media futures? Using vignettes and scenarios in a citizen council on data-driven media personalisation

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    ‘New’ media and algorithmic rules underlying many emerging technologies present particular challenges in fieldwork, because the opacity of their design, and, sometimes, their real or perceived status as ‘not quite here yet’ – makes speaking about these challenging in the field. In this article, we use insights from a three-stage citizens council investigating citizens’ views on developments in data-driven media personalisation to reflect on the potentials of using future-orientated vignettes and scenarios in data collection on user experiences, expectations and the ethics of algorithms. We present the possibilities and potentials of using vignettes as part of a data collection approach in user-centric algorithm studies which invites users’ contextual experiences of algorithms but also enables more normative reflections on what good looks like in contemporary datafied societies

    A protocol for manual segmentation of medial temporal lobe subregions in 7 Tesla MRI

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    Recent advances in MRI and increasing knowledge on the characterization and anatomical variability of medial temporal lobe (MTL) anatomy have paved the way for more specific subdivisions of the MTL in humans. In addition, recent studies suggest that early changes in many neurodegenerative and neuropsychiatric diseases are better detected in smaller subregions of the MTL rather than with whole structure analyses. Here, we developed a new protocol using 7 Tesla (T) MRI incorporating novel anatomical findings for the manual segmentation of entorhinal cortex (ErC), perirhinal cortex (PrC; divided into area 35 and 36), parahippocampal cortex (PhC), and hippocampus; which includes the subfields subiculum (Sub), CA1, CA2, as well as CA3 and dentate gyrus (DG) which are separated by the endfolial pathway covering most of the long axis of the hippocampus. We provide detailed instructions alongside slice-by-slice segmentations to ease learning for the untrained but also more experienced raters. Twenty-two subjects were scanned (19–32 yrs, mean age = 26 years, 12 females) with a turbo spin echo (TSE) T2-weighted MRI sequence with high-resolution oblique coronal slices oriented orthogonal to the long axis of the hippocampus (in-plane resolution 0.44 × 0.44 mm2) and 1.0 mm slice thickness. The scans were manually delineated by two experienced raters, to assess intra- and inter-rater reliability. The Dice Similarity Index (DSI) was above 0.78 for all regions and the Intraclass Correlation Coefficients (ICC) were between 0.76 to 0.99 both for intra- and inter-rater reliability. In conclusion, this study presents a fine-grained and comprehensive segmentation protocol for MTL structures at 7 T MRI that closely follows recent knowledge from anatomical studies. More specific subdivisions (e.g. area 35 and 36 in PrC, and the separation of DG and CA3) may pave the way for more precise delineations thereby enabling the detection of early volumetric changes in dementia and neuropsychiatric diseases

    Microcalorimetry and spectroscopic studies on the binding of dye janus green blue to deoxyribonucleic acid

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    The interaction of the phenazinium dye janus green blue (JGB) with deoxyribonucleic acid was investigated using isothermal titration calorimetry and thermal melting experiments. The calorimetric data were supplemented by spectroscopic studies. Calorimetry results suggested the binding affinity of the dye to DNA to be of the order of 105 M-1. The binding was predominantly entropy driven with a small negative favorable enthalpy contribution to the standard molar Gibbs energy change.The binding became weaker as the temperature and salt concentration was raised. The temperature dependence of the standard molar enthalpy changes yielded negative values of standard molar heat capacity change for the complexation revealing substantial hydrophobic contribution in the DNA binding. An enthalpy–entropy compensation behavior was also observed in the system. The salt dependence of the binding yielded the release of 0.69 number of cations on binding of each dye molecule. The non-polyelectrolytic contribution was found to be the predominant force in the binding interaction. Thermal melting studies revealed that the DNA helix was stabilized against denaturation by the dye. The binding was also characterized by absorbance, resonance light scattering and circular dichroism spectral measurements. The binding constants from the spectral results were close to those obtained from the calorimetric data. The energetic aspects of the interaction of the dye JGB to double stranded DNA are supported by strong binding revealed from the spectral data
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