6,552 research outputs found

    Science is perception: what can our sense of smell tell us about ourselves and the world around us?

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    Human sensory processes are well understood: hearing, seeing, perhaps even tasting and touch—but we do not understand smell—the elusive sense. That is, for the others we know what stimuli causes what response, and why and how. These fundamental questions are not answered within the sphere of smell science; we do not know what it is about a molecule that … smells. I report, here, the status quo theories for olfaction, highlighting what we do not know, and explaining why dismissing the perception of the input as ‘too subjective’ acts as a roadblock not conducive to scientific inquiry. I outline the current and new theory that conjectures a mechanism for signal transduction based on quantum mechanical phenomena, dubbed the ‘swipe card’, which is perhaps controversial but feasible. I show that such lines of thinking may answer some questions, or at least pose the right questions. Most importantly, I draw links and comparisons as to how better understanding of how small (10’s of atoms) molecules can interact so specially with large (10 000’s of atoms) proteins in a way that is so integral to healthy living. Repercussions of this work are not just important in understanding a basic scientific tool used by us all, but often taken for granted, it is also a step closer to understanding generic mechanisms between drug and receptor, for example

    Folding model analysis of alpha radioactivity

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    Radioactive decay of nuclei via emission of α\alpha particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the α\alpha-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the α\alpha nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic α\alpha-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of α\alpha decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of α\alpha radioactivity of nuclei.Comment: 7 pages including 1 figur

    I\u27d Like To Meet Your Father

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    https://digitalcommons.library.umaine.edu/mmb-vp/1741/thumbnail.jp

    alpha-nucleus potentials for the neutron-deficient p nuclei

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    alpha-nucleus potentials are one important ingredient for the understanding of the nucleosynthesis of heavy neutron-deficient p nuclei in the astrophysical gamma-process where these p nuclei are produced by a series of (gamma,n), (gamma,p), and (gamma,alpha) reactions. I present an improved alpha-nucleus potential at the astrophysically relevant sub-Coulomb energies which is derived from the analysis of alpha decay data and from a previously established systematic behavior of double-folding potentials.Comment: 6 pages, 3 figures, accepted for publication in Phys. Rev.

    Characterization of Knots and Links Arising From Site-specific Recombination on Twist Knots

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    We develop a model characterizing all possible knots and links arising from recombination starting with a twist knot substrate, extending previous work of Buck and Flapan. We show that all knot or link products fall into three well-understood families of knots and links, and prove that given a positive integer nn, the number of product knots and links with minimal crossing number equal to nn grows proportionally to n5n^5. In the (common) case of twist knot substrates whose products have minimal crossing number one more than the substrate, we prove that the types of products are tightly prescribed. Finally, we give two simple examples to illustrate how this model can help determine previously uncharacterized experimental data.Comment: 32 pages, 7 tables, 27 figures, revised: figures re-arranged, and minor corrections. To appear in Journal of Physics

    Possible production of exotic baryonia in relativistic heavy-ion collisions

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    Properties of a hypothetical baryonium with the quark content (uds\ov{u}\ov{d}\ov{s}) are discussed. The MIT bag model predicts its mass to be unexpectedly low, approximately 1210 MeV. Possible hadronic decay modes of this state are analyzed. Ultrarelativistic heavy-ion collisions provide favorable conditions for the formation of such particles from the baryon-free quark-gluon plasma. We estimate multiplicities of such exotic baryonia on the basis of a simple thermal model.Comment: 8 pages, 1 figur

    Revisiting the validity of measures of social cognitive bias in schizophrenia : Additional results from the Social Cognition Psychometric Evaluation (SCOPE) study

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    Objective The ongoing Social Cognition Psychometric Evaluation (SCOPE) study is in the process of forming a gold-standard battery of social cognition tests for use in clinical trials. Previous SCOPE phases have not acknowledged key differences between social cognition skills and biases, and psychometric validity analyses might provide important information if tailored to bias-related outcomes. This study aims to validate these measures with such bias-related outcomes. Methods Two measures of social cognitive bias – the Ambiguous Intention Hostility Questionnaire (AIHQ; hostile attribution bias) and Trustworthiness Task (distrust bias) – were reviewed according to their relationships to (1) current and prospective symptom levels, (2) questionnaires of trait paranoia and hostility and informant-rated hostility, (3) interpersonal conflict, as well as (4) relationships to measures of trait paranoia, hostility, and interpersonal conflict above and beyond the influence of clinically rated symptoms. Results Results supported hypotheses that social cognitive bias provides information about cognition, symptoms, and functioning related to interpersonal conflict. Each bias demonstrated relationships to trait paranoia questionnaires, hostility, or interpersonal conflict outcomes, and these persisted above and beyond the influence of clinically rated symptoms. Hostile attribution bias also predicted change in symptom levels over a brief interval. Conclusions Overall, the current bias-specific psychometric analysis provides support for continued study of social cognitive biases. Practitioner points • Hostile attribution bias may play a role in important outcome variables given relationships to emotional discomfort and suspiciousness symptoms, trait paranoia and hostility, interpersonal conflict, as well as prospective hostility symptoms. • Distrust bias may also impact real-world functioning, as it is related to hostility, suspiciousness, and positive symptoms, trait paranoia, and hostility. • Relationships of social cognitive biases to interpersonal conflict outcomes exist independently of interview-rated symptoms and persist above and beyond the influence of social cognitive skills, which appear to demonstrate weaker relationships to these outcomes. • Understanding and assessing the individual's biases towards distrust or blame might help practioners predict interpersonal conflict and future increases in symptoms

    Quark Description of Hadronic Phases

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    We extend our proposal that major universality classes of hadronic matter can be understood, and in favorable cases calculated, directly in the microscopic quark variables, to allow for splitting between strange and light quark masses. A surprisingly simple but apparently viable picture emerges, featuring essentially three phases, distinguished by whether strangeness is conserved (standard nuclear matter), conserved modulo two (hypernuclear matter), or locked to color (color flavor locking). These are separated by sharp phase transitions. There is also, potentially, a quark phase matching hadronic K-condensation. The smallness of the secondary gap in two-flavor color superconductivity corresponds to the disparity between the primary dynamical energy scales of QCD and the much smaller energy scales of nuclear physics.Comment: 21 pages, 2 figure

    Information and Particle Physics

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    Information measures for relativistic quantum spinors are constructed to satisfy various postulated properties such as normalisation invariance and positivity. Those measures are then used to motivate generalised Lagrangians meant to probe shorter distance physics within the maximum uncertainty framework. The modified evolution equations that follow are necessarily nonlinear and simultaneously violate Lorentz invariance, supporting previous heuristic arguments linking quantum nonlinearity with Lorentz violation. The nonlinear equations also break discrete symmetries. We discuss the implications of our results for physics in the neutrino sector and cosmology

    Prostate Cancer Specific Adenoviral Vectors to Increase the Therapeutic Index of Targeted Radiotherapy

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