344 research outputs found

    Prevalence and Correlates of Insomnia in a Polish Sample of Alcohol‐Dependent Patients

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/93735/1/acer1771.pd

    Optical manipulation of a single Mn spin in a CdTe-based quantum dot

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    A system of two coupled CdTe quantum dots, one of them containing a single Mn ion, was studied in continuous wave and modulated photoluminescence, photoluminescence excitation, and photon correlation experiments. Optical writing of information in the spin state of the Mn ion has been demonstrated, using orientation of the Mn spin by spin-polarized carriers transferred from the neighbor quantum dot. Mn spin orientation time values from 20 ns to 100 ns were measured, depending on the excitation power. Storage time of the information in the Mn spin was found to be enhanced by application of a static magnetic field of 1 T, reaching hundreds of microseconds in the dark. Simple rate equation models were found to describe correctly static and dynamical properties of the system.Comment: 4 pages, 3 figure

    Who receives treatment for alcohol use disorders in the European Union? A cross-sectional representative study in primary and specialized health care

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    Background Alcohol use disorders (AUDs) are highly prevalent in Europe, but only a minority of those affected receive treatment. It is therefore important to identify factors that predict treatment in order to reframe strategies aimed at improving treatment rates. Methods Representative cross-sectional study with patients aged 18\u201364 from primary health care (PC, six European countries, n = 8476, data collection 01/13\u201301/14) and from specialized health care (SC, eight European countries, n = 1762, data collection 01/13\u201303/14). For descriptive purposes, six groups were distinguished, based on type of DSM-IV AUD and treatment setting. Treatment status (yes/no) for any treatment (model 1), and for SC treatment (model 2) were main outcome measures in logistic regression models. Results AUDs were prevalent in PC (12-month prevalence: 11.8%, 95% confidence interval (CI): 11.2\u201312.5%), with 17.6% receiving current treatment (95%CI: 15.3\u201319.9%). There were clear differences between the six groups regarding key variables from all five predictor domains. Prediction of any treatment (model 1) or SC treatment (model 2) was successful with high overall accuracy (both models: 95%), sufficient sensitivity (model 1: 79%/model 2: 76%) and high specificity (both models: 98%). The most predictive single variables were daily drinking level, anxiety, severity of mental distress, and number of inpatient nights during the last 6 months. Conclusions Variables from four domains were highly predictive in identifying treatment for AUD, with SC treatment groups showing very high levels of social disintegration, drinking, comorbidity and functional losses. Earlier intervention and formal treatment for AUD in PC should be implemented to reduce these high levels of adverse outcomes

    Processing and Transmission of Information

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    Contains research objectives and reports on one research projects.Lincoln Laboratory, Purchase Order DDL B-00368U. S. ArmyU. S. NavyU. S. Air Force under Air Force Contract AF19(604)-7400National Institutes of Health (Grant MH-04737-02

    Analiza nastanka grešaka u zasićenim kompozitnim metalima u lijevanom stanju

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    In research into the porosity of casts from metal saturated composites there is a need to identify the pores. Problems encountered here are connected with the following: - the difficulty in differentiating the pores from other structure components of materials, - the necessity of differentiating the porosity types resulting from non-saturation, gas occlusion and gas emission during coagulation and contraction of the matrix. The report presents research results conducted to identify the pores by means of computer image analysis with the application of an analyzing scanning computer.U istraživanju poroznosti na ljevovima metala od zasićenih kompozita postoji nužnost određivanja poroznosti. Prolemi koji se ovdje susreću su povezani sa slijedećim: - teškoćama u razlikovanju pora od drugih strukturnih sastavnica materijala; - potreba za razlikovanjem vrsta poroznosti zbog nezasićenosti plinske poroznosti i emisijom plinova tijekom zgrušavanja i stezanja matrice. Izvješće predstavlja rezultate istraživanja provedenog radi određivanja pora kompjutorske analize slike uz primjenu kompjutorskog skenera za provođenje analize

    Stellar structure models in modified theories of gravity: lessons and challenges.

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    The understanding of stellar structure represents the crossroads of our theories of the nuclear force and the gravitational interaction under the most extreme conditions observably accessible. It provides a powerful probe of the strong field regime of General Relativity, and opens fruitful avenues for the exploration of new gravitational physics. The latter can be captured via modified theories of gravity, which modify the Einstein-Hilbert action of General Relativity and/or some of its principles. These theories typically change the Tolman-Oppenheimer-Volkoff equations of stellar's hydrostatic equilibrium, thus having a large impact on the astrophysical properties of the corresponding stars and opening a new window to constrain these theories with present and future observations of different types of stars. For relativistic stars, such as neutron stars, the uncertainty on the equation of state of matter at supranuclear densities intertwines with the new parameters coming from the modified gravity side, providing a whole new phenomenology for the typical predictions of stellar structure models, such as mass-radius relations, maximum masses, or moment of inertia. For non-relativistic stars, such as white, brown and red dwarfs, the weakening/strengthening of the gravitational force inside astrophysical bodies via the modified Newtonian (Poisson) equation may induce changes on the star's mass, radius, central density or luminosity, having an impact, for instance, in the Chandrasekhar's limit for white dwarfs, or in the minimum mass for stable hydrogen burning in high-mass brown dwarfs. This work aims to provide a broad overview of the main such results achieved in the recent literature for many such modified theories of gravity, by combining the results and constraints obtained from the analysis of relativistic and non-relativistic stars in different scenarios. Moreover, we will build a bridge between the efforts of the community working on different theories, formulations, types of stars, theoretical modelings, and observational aspects, highlighting some of the most promising opportunities in the field. (C) 2020 Elsevier B.V. All rights reserved

    Minimum main sequence mass in quadratic Palatini f(R) gravity

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    General relativity yields an analytical prediction of a minimum required mass of roughly similar to 0.08-0.09 M-circle dot for a star to stably burn sufficient hydrogen to fully compensate photospheric losses and, therefore, to belong to the main sequence. Those objects below this threshold ( brown dwarfs) eventually cool down without any chance to stabilize their internal temperature. In this work we consider quadratic Palatini f(R) gravity and show that the corresponding Newtonian hydrostatic equilibrium equation contains a new term whose effect is to introduce a weakening/strengthening of the gravitational interaction inside astrophysical bodies. This fact modifies the general relativity prediction for this minimum main sequence mass. Through a crude analytical modeling we use this result in order to constraint a combination of the quadratic f(R) gravity parameter and the central density according to astrophysical observations

    Parameterized nonrelativistic limit of stellar structure equations in Ricci-based gravity theories

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    We present the nonrelativistic limit of the stellar structure equations of Ricci-based gravities, a family of metric-affine theories whose Lagrangian is built via contractions of the metric with the Ricci tensor of an a priori independent connection. We find that this limit is characterized by four parameters that arise in the expansion of several geometric quantities in powers of the stress-energy tensor of the matter fields. We discuss the relevance of this result for the phenomenology of nonrelativistic stars, such as main-sequence stars as well as several substellar objects
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