713 research outputs found

    Deformations of the Boson sp(4,R)sp(4,R) Representation and its Subalgebras

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    The boson representation of the sp(4,R) algebra and two distinct deformations of it, are considered, as well as the compact and noncompact subalgebras of each. The initial as well as the deformed representations act in the same Fock space. One of the deformed representation is based on the standard q-deformation of the boson creation and annihilation operators. The subalgebras of sp(4,R) (compact u(2) and three representations of the noncompact u(1,1) are also deformed and are contained in this deformed algebra. They are reducible in the action spaces of sp(4,R) and decompose into irreducible representations. The other deformed representation, is realized by means of a transformation of the q-deformed bosons into q-tensors (spinor-like) with respect to the standard deformed su(2). All of its generators are deformed and have expressions in terms of tensor products of spinor-like operators. In this case, an other deformation of su(2) appears in a natural way as a subalgebra and can be interpreted as a deformation of the angular momentum algebra so(3). Its representation is reducible and decomposes into irreducible ones that yields a complete description of the same

    Evaluation of behavioral changes and subjective distress after exposure to coercive inpatient interventions

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    BACKGROUND: There is a lack of evidence to underpin decisions on what constitutes the most effective and least restrictive form of coercive intervention when responding to violent behavior. Therefore we compared ratings of effectiveness and subjective distress by 125 inpatients across four types of coercive interventions. METHODS: Effectiveness was assessed through ratings of patient behavior immediately after exposure to a coercive measure and 24 h later. Subjective distress was examined using the Coercion Experience Scale at debriefing. Regression analyses were performed to compare these outcome variables across the four types of coercive interventions. RESULTS: Using univariate statistics, no significant differences in effectiveness and subjective distress were found between the groups, except that patients who were involuntarily medicated experienced significant less isolation during the measure than patients who underwent combined measures. However, when controlling for the effect of demographic and clinical characteristics, significant differences on subjective distress between the groups emerged: involuntary medication was experienced as the least distressing overall and least humiliating, caused less physical adverse effects and less sense of isolation. Combined coercive interventions, regardless of the type, caused significantly more physical adverse effects and feelings of isolation than individual interventions. CONCLUSIONS: In the absence of information on individual patient preferences, involuntary medication may be more justified than seclusion and mechanical restraint as a coercive intervention. Use of multiple interventions requires significant justification given their association with significant distress

    Headache in Children with Epilepsy

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    Headache is a common comorbidity in pediatric epileptic patients. The relationship between headache and epilepsy is considered complex and though there is evidence of association, its mechanisms are not yet completely clear. Numerous studies of comorbidity focus on primary headaches, such as migraine and tension-type headache, describing them as the most prevalent in patients with epilepsy. Some authors, though, report similar prevalence of headache and specifically migraine in epilepsy patients as compared to that of the general population. When describing this comorbidity, it should be noted that secondary headaches can also be frequent in patients with structural epilepsy, e.g. in brain tumors or other space-occupying lesions.In this paper we summarize literature data on the problem of epilepsy and headache comorbidity, and also present two clinical cases of patients with tension-type and with secondary headache, respectively

    Isospin symmetry breaking in an algebraic pairing Sp(4) model

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    An exactly solvable sp(4) algebraic approach extends beyond the traditional isospin conserving nuclear interaction to bring forward effects of isospin symmetry breaking and isospin mixing resulting from a two-body nuclear interaction that includes proton-neutron (pn) and like-particle isovector pairing correlations plus significant isoscalar pn interactions. The model yields an estimate for the extent to which isobaric analog 0+ states in light and medium mass nuclei may mix with one another and reveals possible, but still extremely weak, non-analog beta-decay transitions.Comment: 8 pages, 2 figure

    q-Analogue of Am−1⊕An−1⊂Amn−1A_{m-1}\oplus A_{n-1}\subset A_{mn-1}

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    A natural embedding Am−1⊕An−1⊂Amn−1A_{m-1}\oplus A_{n-1}\subset A_{mn-1} for the corresponding quantum algebras is constructed through the appropriate comultiplication on the generators of each of the Am−1A_{m-1} and An−1A_{n-1} algebras. The above embedding is proved in their qq-boson realization by means of the isomorphism between the Aq−\mathcal{A}_q^{-} (mn)∌⊗nAq−\sim {\otimes} ^n \mathcal{A}_q^{-}(m)∌⊗mAq−\sim {\otimes}^m\mathcal{A}_q^{-}(n) algebras.Comment: 11 pages, no figures. In memory of professor R. P. Rousse

    Modelling of interactions of polar and nonpolar pollutants with soil minerals and soil organic matter

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    Environmental pollution of soils by organic contaminants such as pesticides is one of the serious problems of our civilization. Contaminants can undergo various physical, chemical and biological transformation processes in soils governing behaviour, distribution, and fate of organic species in environment and subsequent environmental risks. Mechanistic understanding of molecular interactions of organic pollutants with main soil components represents a key factor for estimating the behaviour of contaminants in soils. Molecular modelling offers an opportunity to investigate and characterize various details of these interactions at molecular level providing specifications, which are difficult to obtain at the experimental level. This work represents a comprehensive overview of our investigations of the molecular interactions of organic contaminants with selected soil components. Particularly, we focused on the characterization of the structure and the surface complexation of the phenoxyacetic acid derivatives (herbicides MCPA and 2,4-D) and typical soil minerals such as clay minerals (kaolinite and montmorillonite) and iron oxyhydroxides (goethite and lepidocrocite). Further, interactions of several representative nonpolar polycyclic aromatic hydrocarbons (e.g. naphthalene, anthracene, pyrene, and phenanthrene) with iron oxyhydroxides were modelled, as well. It was found that in case of polar species, hydrogen bonds and electrostatic interactions play an important role in the formation of the surface complexes. In case of nonpolar PAHs, dispersion forces dominate in the planar stacking of the PAHs molecules on mineral surfaces. Another study focused at a complex 3D model representing humic substances firstly, featuring polar hydrophilic and nonpolar hydrophobic domains and also a nanopore SOM structure. This model was taken to simulate trapping and interactions of MCPA (polar) and naphthalene (nonpolar) species inside of the nanopore. It was found that MCPA is preferentially stabilized close to polar functional groups (carboxyl) whereas naphthalene interacts mostly with nonpolar aliphatic chains through dispersion interactions

    Staggering effects in nuclear and molecular spectra

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    It is shown that the recently observed Delta J = 2 staggering effect (i.e. the relative displacement of the levels with angular momenta J, J+4, J+8, ..., relatively to the levels with angular momenta J+2, J+6, J+10, ...) seen in superdeformed nuclear bands is also occurring in certain electronically excited rotational bands of diatomic molecules (YD, CrD, CrH, CoH), in which it is attributed to interband interactions (bandcrossings). In addition, the Delta J = 1 staggering effect (i.e. the relative displacement of the levels with even angular momentum J with respect to the levels of the same band with odd J) is studied in molecular bands free from Delta J = 2 staggering (i.e. free from interband interactions/bandcrossings). Bands of YD offer evidence for the absence of any Delta J = 1 staggering effect due to the disparity of nuclear masses, while bands of sextet electronic states of CrD demonstrate that Delta J = 1 staggering is a sensitive probe of deviations from rotational behaviour, due in this particular case to the spin-rotation and spin-spin interactions.Comment: LaTeX, 16 pages plus 30 figures given in separate .ps files. To appear in the proceedings of the 4th European Workshop on Quantum Systems in Chemistry and Physics (Marly-le-Roi, France, 1999), ed. J. Maruani et al. (Kluwer, Dordrecht

    In memoriam two distinguished participants of the Bregenz Symmetries in Science Symposia: Marcos Moshinsky and Yurii Fedorovich Smirnov

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    Some particular facets of the numerous works by Marcos Moshinsky and Yurii Fedorovich Smirnov are presented in these notes. The accent is put on some of the common interests of Yurii and Marcos in physics, theoretical chemistry, and mathematical physics. These notes also contain some more personal memories of Yurii Smirnov.Comment: Submitted for publication in Journal of Physics: Conference Serie

    Tailored Training for Building Resilience in Changing Climate: BeWare Project's Approach

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    The objective of the ERASMUS+ funded BeWare project is to provide education and training for professionals in the construction sector, aligning with the requirements of the European Green Deal. This initiative aims to enhance the resilience of buildings to climate change and extreme weather events, while fostering knowledge, innovation, and value addition in the construction industry. The project's core is the Vocational Education and Training (VET) program, tailored for evolving job market demands. Benchmarking was conducted to evaluate emerging trends and professional requirements within the BeWare VET program. The main conclusions from the results are as follows: 1) The majority of the 63 analyzed syllabi focus on "sustainable buildings" and "energy," with less attention given to climate resilience and climate change mitigation; 2) the scarcity of training programs addressing these issues underscores the critical need to prioritize building resilience in the face of climate change and extreme weather events; 3) In the context of Construction Industry 4.0, BIM takes a central role, expanding the use of digitized data beyond traditional 2D modeling and; 4) Sustainable building gains momentum, with an emphasis on materials, life cycle assessment, circularity, sustainable development, environmental sustainability, and certification integrated into VET course curricula
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