105 research outputs found

    Polarization transfer observables for quasielastic proton-nucleus scattering in terms of a complete Lorentz invariant representation of the NN scattering matrix

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    For the calculation of polarization transfer observables for quasielastic scattering of protons on nuclei, a formalism in the context of the Relativistic Plane Wave Impulse Approximation is developed, in which the interaction matrix is expanded in terms of a complete set of 44 independent invariant amplitudes. A boson-exchange model is used to predict the 39 amplitudes which were omitted in the formerly used five-term parameterization(the SPVAT form) of the nucleon-nucleon scattering matrix. Use of the complete set of amplitudes eliminates the arbitrariness of the five-term representation.Comment: 29 pages, 2 figure

    Multiphoton Quantum Optics and Quantum State Engineering

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    We present a review of theoretical and experimental aspects of multiphoton quantum optics. Multiphoton processes occur and are important for many aspects of matter-radiation interactions that include the efficient ionization of atoms and molecules, and, more generally, atomic transition mechanisms; system-environment couplings and dissipative quantum dynamics; laser physics, optical parametric processes, and interferometry. A single review cannot account for all aspects of such an enormously vast subject. Here we choose to concentrate our attention on parametric processes in nonlinear media, with special emphasis on the engineering of nonclassical states of photons and atoms. We present a detailed analysis of the methods and techniques for the production of genuinely quantum multiphoton processes in nonlinear media, and the corresponding models of multiphoton effective interactions. We review existing proposals for the classification, engineering, and manipulation of nonclassical states, including Fock states, macroscopic superposition states, and multiphoton generalized coherent states. We introduce and discuss the structure of canonical multiphoton quantum optics and the associated one- and two-mode canonical multiphoton squeezed states. This framework provides a consistent multiphoton generalization of two-photon quantum optics and a consistent Hamiltonian description of multiphoton processes associated to higher-order nonlinearities. Finally, we discuss very recent advances that by combining linear and nonlinear optical devices allow to realize multiphoton entangled states of the electromnagnetic field, that are relevant for applications to efficient quantum computation, quantum teleportation, and related problems in quantum communication and information.Comment: 198 pages, 36 eps figure

    Electrochemical Characterization of Coinage Techniques the 17(th) Century: The maravedis Case

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    This is the peer reviewed version of the following article: Doménech Carbó, A.; Domenech Carbo, MT.; Álvarez-Romero, C.; Montoya, N.; Pasies-Oviedo, T.; Buendía Ortuño, MDM. (2017). Electrochemical Characterization of Coinage Techniques the 17(th) Century: The maravedis Case. Electroanalysis. 29(9):2008-2018. doi:10.1002/elan.201700326, which has been published in final form at http://doi.org/10.1002/elan.201700326. This article may be used for non-commercial purposes in accordance with Wiley Terms and Conditions for Self-Archiving."[EN] The voltammetry of immobilized particles (VIMP) methodology was applied to the discrimination of Spanish maravedis produced in 10 different mints between 1661 and 1664 using characteristic signatures for the reduction of cuprite and tenorite in the patina of the coins and catalytic effects on the hydrogen evolution reaction (HER). The variation of the apparent tenorite/cuprite ratio with depth was fitted to potential laws differing from one mint to another for A Coruna, Burgos, Cordoba, Cuenca, Granada, Madrid, Trujillo, Segovia, Sevilla and Valladolid coins. Electrochemical data permitted to detect the changes in the composition (with lowering of the silver content) and manufacturing technique (from hammer to mill) occurring in this historical period.Financial support from the MICIN Projects CTQ2014-53736-C3-1-P and CTQ2014-53736-C3-2-P, which are also supported with ERDF funds, is gratefully acknowledged. Thanks to the Museum of Prehistory of Valencia for facilitating the access to its collections.Domenech Carbo, A.; Domenech Carbo, MT.; Álvarez-Romero, C.; Montoya, N.; Pasies-Oviedo, T.; Buendía Ortuño, MDM. (2017). Electrochemical Characterization of Coinage Techniques the 17(th) Century: The maravedis Case. Electroanalysis. 29(9):2008-2018. https://doi.org/10.1002/elan.201700326S2008201829

    Short-term prediction of threatening and violent behaviour in an Acute Psychiatric Intensive Care Unit based on patient and environment characteristics

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    <p>Abstract</p> <p>Background</p> <p>The aims of the present study were to investigate clinically relevant patient and environment-related predictive factors for threats and violent incidents the first three days in a PICU population based on evaluations done at admittance.</p> <p>Methods</p> <p>In 2000 and 2001 all 118 consecutive patients were assessed at admittance to a Psychiatric Intensive Care Unit (PICU). Patient-related conditions as actuarial data from present admission, global clinical evaluations by physician at admittance and clinical nurses first day, a single rating with an observer rated scale scoring behaviours that predict short-term violence in psychiatric inpatients (The Brøset Violence Checklist (BVC)) at admittance, and environment-related conditions as use of segregation or not were related to the outcome measure Staff Observation Aggression Scale-Revised (SOAS-R). A multiple logistic regression analysis with SOAS-R as outcome variable was performed.</p> <p>Results</p> <p>The global clinical evaluations and the BVC were effective and more suitable than actuarial data in predicting short-term aggression. The use of segregation reduced the number of SOAS-R incidents.</p> <p>Conclusions</p> <p>In a naturalistic group of patients in a PICU segregation of patients lowers the number of aggressive and threatening incidents. Prediction should be based on clinical global judgment, and instruments designed to predict short-term aggression in psychiatric inpatients.</p> <p>Trial registrations</p> <p><a href="http://www.clinicaltrials.gov/ct2/show/NCT00184119">NCT00184119</a>/<a href="http://www.clinicaltrials.gov/ct2/show/NCT00184132">NCT00184132</a></p

    Recent Contributions of Air- and Biomarkers to the Control of Secondhand Smoke (SHS): A Review

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    Since the publication of the US Surgeon General Reports in 1996 and 2006 and the report of the California Environmental Protection Agency in 1999, many reports have appeared on the contribution of air and biomarkers to different facets of the secondhand smoke (SHS) issue, which are the targets of this review. These recent studies have allowed earlier epidemiological surveys to be biologically validated, and their plausibility demonstrated, quantified the levels of exposure to SHS before the bans in various environments, showed the deficiencies of mechanical control methods and of partial bans and the frequently correct implementation of the efficient total bans. More stringent regulation remains necessary in the public domain (workplaces, hospitality venues, transport sector, etc.) in many countries. Personal voluntary protection efforts against SHS are also needed in the private domain (homes, private cars). The effects of SHS on the cardiovascular, respiratory and neuropsychic systems, on pregnancy and fertility, on cancers and on SHS genotoxicity are confirmed through experimental human studies and through the relationship between markers and prevalence of disease or of markers of disease risk

    Improving risk management for violence in mental health services: a multimethods approach

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    contractual_start_date: 07-2008 editorial_review_begun: 07-2014 accepted_for_publication: 06-2015contractual_start_date: 07-2008 editorial_review_begun: 07-2014 accepted_for_publication: 06-2015contractual_start_date: 07-2008 editorial_review_begun: 07-2014 accepted_for_publication: 06-2015contractual_start_date: 07-2008 editorial_review_begun: 07-2014 accepted_for_publication: 06-201

    Suicide risk in schizophrenia: learning from the past to change the future

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    Suicide is a major cause of death among patients with schizophrenia. Research indicates that at least 5–13% of schizophrenic patients die by suicide, and it is likely that the higher end of range is the most accurate estimate. There is almost total agreement that the schizophrenic patient who is more likely to commit suicide is young, male, white and never married, with good premorbid function, post-psychotic depression and a history of substance abuse and suicide attempts. Hopelessness, social isolation, hospitalization, deteriorating health after a high level of premorbid functioning, recent loss or rejection, limited external support, and family stress or instability are risk factors for suicide in patients with schizophrenia. Suicidal schizophrenics usually fear further mental deterioration, and they experience either excessive treatment dependence or loss of faith in treatment. Awareness of illness has been reported as a major issue among suicidal schizophrenic patients, yet some researchers argue that insight into the illness does not increase suicide risk. Protective factors play also an important role in assessing suicide risk and should also be carefully evaluated. The neurobiological perspective offers a new approach for understanding self-destructive behavior among patients with schizophrenia and may improve the accuracy of screening schizophrenics for suicide. Although, there is general consensus on the risk factors, accurate knowledge as well as early recognition of patients at risk is still lacking in everyday clinical practice. Better knowledge may help clinicians and caretakers to implement preventive measures. This review paper is the results of a joint effort between researchers in the field of suicide in schizophrenia. Each expert provided a brief essay on one specific aspect of the problem. This is the first attempt to present a consensus report as well as the development of a set of guidelines for reducing suicide risk among schizophenia patients

    Integrating DSM-IV Factors to Predict Violence in High-Risk Psychiatric Patients

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    This study incorporated Axis-II and Axis-IV factors in DSM-IV to test the relationship between predicted risk for violence assessed in the psychiatric emergency room and actual violence during hospitalization. Psychiatric nurses lack an objective instrument to use during the acute psychiatric assessment. The retrospective study comprised consecutive psychiatric admissions ( n = 161) in one tertiary veterans’ hospital. Statistical testing for the predictive power of risk factors, relationships between variables, and violent events included nonparametric tests, factor analysis, and logistic regression. Of the 32 patients who committed violence during hospitalization, 12 had committed violence in the psychiatric emergency room. Statistical significance was shown for violent incidents and dementia, court-ordered admission, mood disorder, and for three or more risk factors. The 13-item Risk of Violence Assessment (ROVA) scale suggests validity and sensitivity for rating DSM-IV factors and psychosocial stressors to predict risk for violence during hospitalization. Replication studies are recommended to strengthen validity of the ROVA scale
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