505 research outputs found

    Geometric View of Measurement Errors

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    The slope of the best fit line from minimizing the sum of the squared oblique errors is the root of a polynomial of degree four. This geometric view of measurement errors is used to give insight into the performance of various slope estimators for the measurement error model including an adjusted fourth moment estimator introduced by Gillard and Iles (2005) to remove the jump discontinuity in the estimator of Copas (1972). The polynomial of degree four is associated with a minimun deviation estimator. A simulation study compares these estimators showing improvement in bias and mean squared error

    Pinning an Ion with an Intracavity Optical Lattice

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    We report one-dimensional pinning of a single ion by an optical lattice. The lattice potential is produced by a standing-wave cavity along the rf-field-free axis of a linear Paul trap. The ion's localization is detected by measuring its fluorescence when excited by standing-wave fields with the same period, but different spatial phases. The experiments agree with an analytical model of the localization process, which we test against numerical simulations. For the best localization achieved, the ion's average coupling to the cavity field is enhanced from 50% to 81(3)% of its maximum possible value, and we infer that the ion is bound in a lattice well with over 97% probability.Comment: 5 pages, 4 figures; Text edited for clarity, results unchange

    Neuronal and psychological underpinnings of pathological gambling

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    Like in the case of drugs, gambling hijacks reward circuits in a brain which is not prepared to receive such intense stimulation. Dopamine is normally released in response to reward and uncertainty in order to allow animals to stay alive in their environment – where rewards are relatively unpredictable. In this case, behavior is regulated by environmental feedbacks, leading animals to persevere or to give up. In contrast, drugs provide a direct, intense pharmacological stimulation of the dopamine system that operates independently of environmental feedbacks, and hence causes “motivational runaways”. With respect to gambling, the confined environment experienced by gamblers favors the emergence of excitatory conditioned cues, so that positive feedbacks take over negative feedbacks. Although drugs and gambling may act differently, their abnormal activation of reward circuitry generates an underestimation of negative consequences and promotes the development of addictive/compulsive behavior. In Parkinson’s and Huntington’s disease, dopamine-related therapies may disrupt these feedbacks on dopamine signalling, potentially leading to various addictions, including pathological gambling. The goal of this Research Topic is to further our understanding of the neurobiological mechanisms underlying the development of pathological gambling. This eBook contains a cross-disciplinary collection of research and review articles, ranging in scope from animal behavioral models to human imaging studies

    relax: the analysis of biomolecular kinetics and thermodynamics using NMR relaxation dispersion data

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    International audienceNuclear Magnetic Resonance (NMR) is a powerful tool for observing the motion of biomolecules at the atomic level. One technique, the analysis of relaxation dispersion phenomenon, is highly suited for studying the kinetics and thermodynamics of biological processes. Built on top of the relax computational environment for NMR dynamics is a new dispersion analysis designed to be comprehensive, accurate and easy to use. The software supports more models, both numeric and analytic, than current solutions. An automated protocol, available for scripting and driving the GUI, is designed to simplify the analysis of dispersion data for NMR spectroscopists. Decreases in optimisation time are granted by parallelisation for running on computer clusters and by skipping an initial grid search by using parameters from one solution as the starting point for another – using analytic model results for the numeric models, taking advantage of model nesting, and using averaged non-clustered results for the clustered analysis. Availability: The software relax is written in Python with C modules and is released under the GPLv3+ licence. Source code and precompiled binaries for all major operating systems are available from http://www.nmr-relax.com

    relax: the analysis of biomolecular kinetics and thermodynamics using NMR relaxation dispersion data

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    Nuclear magnetic resonance (NMR) is a powerful tool for observing the motion of biomolecules at the atomic level. One technique, the analysis of relaxation dispersion phenomenon, is highly suited for studying the kinetics and thermodynamics of biological processes. Built on top of the relax computational environment for NMR dynamics is a new dispersion analysis designed to be comprehensive, accurate and easy-to-use. The software supports more models, both numeric and analytic, than current solutions. An automated protocol, available for scripting and driving the graphical user interface (GUI), is designed to simplify the analysis of dispersion data for NMR spectroscopists. Decreases in optimization time are granted by parallelization for running on computer clusters and by skipping an initial grid search by using parameters from one solution as the starting point for another —using analytic model results for the numeric models, taking advantage of model nesting, and using averaged non-clustered results for the clustered analysis. Availability and implementation: The software relax is written in Python with C modules and is released under the GPLv3+ license. Source code and precompiled binaries for all major operating systems are available from http://www.nmr-relax.com. Contact: [email protected]

    Fatal poisoning among drug users in Denmark in 2017

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    INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant.INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant

    Fatal poisoning among drug users in Denmark in 2017

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    INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant.INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant

    Fatal poisoning among drug users in Denmark in 2017

    Get PDF
    INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant.INTRODUCTION: Knowledge of trends of illegal drug use is vital for planning initiatives to reduce accidents and deaths among drug users. The aim of this study was to describe the cause of death, abuse pattern and geographic differences in fatal poisonings among drug users in Denmark in 2017.METHODS: All fatal poisonings among drug users examined at the three institutes of forensic medicine in Denmark in 2017 were included in the study.RESULTS: Overall, fatal poisonings declined from a maximum of 226 in 2007 to 162 in 2017. Methadone (52%) was the most common cause of death, followed by heroin/morphine (25%). A marked increase in deaths was due to stimulants (13%), especially cocaine. The abuse pattern has changed since 2012. Methadone remained the most frequently detected drug, but clonazepam and cocaine surpassed heroin/morphine, diazepam and tetrahydrocannabinol as the second-most frequently detected drugs. Ketobemidone had disappeared, whereas buprenorphine, oxycodone, fentanyl, pregabalin and gabapentin had increased. Antidepressants/antipsychotics were detected in half (47%) of the cases. Cocaine was more frequent in the areas covered by Copenhagen and Aarhus, whereas heroin/morphine was most frequently detected in the area covered by Odense. Amphetamine was more frequent in the Aarhus area.CONCLUSIONS: Methadone and heroin/morphine still account for most fatal poisonings. However, deaths due to stimulants, especially cocaine, have increased. The abuse pattern has changed and geographical differences have emerged.FUNDING: none.TRIAL REGISTRATION: not relevant

    ICD-11 adjustment disorder: Translation and validation of the Danish International Adjustment Disorder Questionnaire among a working population of social educators

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    Adjustment disorder is frequently used as a diagnostic category for work-related stress disorders in Denmark. However, the diagnostic category is poorly delineated in ICD-10 which has hampered clinical practice as well as research studying the development of work-related adjustment disorders. In ICD-11, the diagnostic category of adjustment disorder has been refined and a new self-report measure is available to operationalize symptoms. The aim of the current study is to translate the International Adjustment Disorder Questionnaire (IADQ) to Danish and test the psychometric properties of the scale in a sample of social educators. A total of 609 social educators in current employment participated in an online survey including the IADQ and data was analyzed using confirmatory factor analysis. Findings suggested that a two-factor model reflecting the distinction between preoccupation and failure to adapt as part of the diagnostic criterion fitted the data best, although strong factor correlations and one cross-factor loading suggests that differentiating between the dimensions of preoccupation and failure to adapt is difficult. Relationships to burnout, posttraumatic stress and general distress support the validity of the Danish translation of the IADQ. Further research should explore the structure of adjustment disorder among other working populations
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