2,244 research outputs found

    An artificial intelligence algorithm analyzing 30 years of research in mass appraisals

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    The research papers issued in scientific journals, for a variety of thematic areas, are not only increasing, nonetheless exhibit an exponential growth over the last years. Accordingly, the researchers, struggle to retrieve information apropos of novel knowledge and get informed in their field, while the rigor and at the same time, the extensive composition of surveys, reviews, and overviews of research works, has become difficult or even impossible, as the number of the available research studies is enormous. However, such reviews, contain vital information regarding the evolution of a scientific subject, the trends of the literature, the most significant concepts, and the concealed associations among research papers, their references, as well as authors’ clusters. In this work, a scientometric study of the relevant to Mass Appraisals literature is for a first time accomplished, regarding the numerical models, computational procedures, and automated methods, utilized in the Mass Appraisals and Property Valuations literature. The study is based on an adequate pool of papers, constituted in Scopus database, utilizing a machine learning algorithm developed from one of the authors, for multidimensional scaling and clustering of the keywords found in the papers’ database, the authors and their cooperation and the co-occurrences of the references in the papers studied. The time-series of the most frequent keywords are also computed, demonstrating the evolution of the mass appraisals research and identifying future trends

    Dual Heterotic Black-Holes in Four and Two Dimensions

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    We consider a class of extremal and non-extremal four-dimensional black-hole solutions occuring in toroidally compactified heterotic string theory, whose ten-dimensional interpretation involves a Kaluza-Klein monopole and a five-brane. We show that these four-dimensional solutions can be connected to extremal and non-extremal two-dimensional heterotic black-hole solutions through a change in the asymptotic behaviour of the harmonic functions associated with the Kaluza-Klein monopole and with the five-brane. This change in the asymptotic behaviour can be achieved by a sequence of S and T-S-T duality transformations in four dimensions. These transformations are implemented by performing a reduction on a two-torus with Lorentzian signature. We argue that the same mechanism can be applied to extremal and non-extremal black-hole solutions in the FHSV model.Comment: 10 pages, latex, 1 reference adde

    Organotin(IV) Derivatives of L-Cysteine and their in vitro Anti-Tumor Properties

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    The synthesis and characterization of the organotin compounds [(n-C4H9)2Sn(cys)] (1), [(C6H5)2Sn(cys)] (2), [(C6H5)3Sn(Hcys).(H2o)] (3), {[(CH3)2Sn(Kcys)2].2(H20)} (4), {[(n-C4H9)2Sn(Kcys)2].2(H20)} (5) and {[(C6H5)2Sn(Kcys)2].2(H20)} (6) (where H2cys = L-cysteine) are reported. The compounds have been characterized by elemental analysis and 1H-NMR, Uv-Vis, FT-IR and MOssbauer spectroscopic techniques. Attempted recrystallization of (2) in DMSO/methanol 2:1 solution yielded after several days unexpectedly the dimeric compound bis(tri-phenyltin)sulphide {[(C6H5)3Sn]2S} (7) which has been characterized by x-ray analysis. The structure of the parent complex (2) as well as the mechanism of the decomposition of cysteine are being further investigated. The in vitro anticancer activity of complexes (I)- (6), against human leukemia (HL60), human liver (Bel7402), human stomach (BGC823) and human cervix epithelial human carcinoma (Hela), nasopharyngeal carcinoma (KB) and lung cancer (PG) tumor cells, were evaluated

    Development and Validation of the Tele-Pulmonary Rehabilitation Acceptance Scale

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    BACKGROUND: Using telehealth in pulmonary rehabilitation (telerehabilitation) is a new field of health-care practice. To successfully implement a telerehabilitation program, measures of acceptance of this new type of program need to be assessed among potential users. The purpose of this study was to develop a scale to measure acceptance of using telerehabilitation by health-care practitioners and patients. METHODS: Three objectives were met (a) constructing a modified scale of the technology acceptance model, (b) judging the items for content validity, and (c) judging the scale for face validity. Nine experts agreed to participate and evaluate item relevance to theoretical definitions of domains. To establish face validity, 7 health-care practitioners and 5 patients were interviewed to provide feedback about the scale's clarity and ease of reading. RESULTS: The final items were divided into 2 scales that reflected the health-care practitioner and patient responses. Each scale included 3 subscales: perceived usefulness, perceived ease of use, and behavioral intention. CONCLUSIONS: The 2 scales, each with 3 subscales, exhibited evidence of content validity and face validity. The 17-item telerehabilitation acceptance scale for health-care practitioners and the 13-item telerehabilitation acceptance scale among patients warrant further psychometric testing as valuable measures for pulmonary rehabilitation programs

    Health Care Practitioners’ Determinants of Telerehabilitation Acceptance

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    Background: Pulmonary rehabilitation is a multidisciplinary patient-tailored intervention that aims to improve the physical and psychological condition of people with chronic respiratory diseases. Providing pulmonary rehabilitation (PR) services to the growing population of patients is challenging due to shortages in health care practitioners and pulmonary rehabilitation programs. Telerehabilitation has the potential to address this shortage in practitioners and PR programs as well as improve patients’ participation and adherence. This study’s purpose was to identify and evaluate the influences of intention of health care practitioners to use telerehabilitation. Methods: Data were collected through a self-administered Internet-based survey. Results: Surveys were completed by 222 health care practitioners working in pulmonary rehabilitation with 79% having a positive intention to use telerehabilitation. Specifically, perceived usefulness was a significant individual predictor of positive intentions to use telerehabilitation. Conclusion: Perceived usefulness may be an important factor associated with health care providers’ intent to use telerehabilitation for pulmonary rehabilitation

    Synthesis, Characterization, and Biological Studies of Organotin(IV) Derivatives with o- or p-hydroxybenzoic Acids

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    Organotin(IV) complexes with o- or p-hydroxybenzoic acids (o-H2BZA or p-H2BZA) of formulae [R2Sn(HL)2] (where H2L = o-H2BZA and R = Me- (1), n-Bu- (2)); [R3Sn(HL)] (where H2L = o-H2BZA and R = n-Bu- (3), Ph- (4) or H2L = p-H2BZA and R = n-Bu- (5), Ph- (6)) were synthesized by reacting a methanolic solution of di- and triorganotin(IV) compounds with an aqueous solution of the ligand (o-H2BZA or p-H2BZA) containing equimolar amounts of potassium hydroxide. The complexes were characterized by elemental analysis, FT-IR, Far-IR, TGA-DTA, FT-Raman, Mössbauer spectroscopy, 1H, 119Sn-NMR, UV/Vis spectroscopy, and Mass spectroscopy. The X-ray crystal structures of complexes 1 and 2 have also been determined. Finally, the influence of these complexes 1–6 upon the catalytic peroxidation of linoleic acid to hydroperoxylinoleic acid by the enzyme lipoxygenase (LOX) was kinetically studied and the results showed that triorganotin(IV) complex 6 has the lowest IC50 value. Also complexes 1–6 were studied for their in vitro cytotoxicity against sarcoma cancer cells (mesenchymal tissue) from the Wistar rat, and the results showed that the complexes have high activity against these cell lines with triphenyltin((IV) complex 4 to be the most active one

    Fermionic Coset, Critical Level W^(2)_4-Algebra and Higher Spins

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    The fermionic coset is a limit of the pure spinor formulation of the AdS5xS5 sigma model as well as a limit of a nonlinear topological A-model, introduced by Berkovits. We study the latter, especially its symmetries, and map them to higher spin algebras. We show the following. The linear A-model possesses affine \AKMSA{pgl}{4}{4}_0 symmetry at critical level and its \AKMSA{psl}{4}{4}_0 current-current perturbation is the nonlinear model. We find that the perturbation preserves W4(2)\mathcal{W}^{(2)}_4-algebra symmetry at critical level. There is a topological algebra associated to \AKMSA{pgl}{4}{4}_0 with the properties that the perturbation is BRST-exact. Further, the BRST-cohomology contains world-sheet supersymmetric symplectic fermions and the non-trivial generators of the W4(2)\mathcal{W}^{(2)}_4-algebra. The Zhu functor maps the linear model to a higher spin theory. We analyze its \SLSA{psl}{4}{4} action and find finite dimensional short multiplets.Comment: 25 page

    Noncommutative geometry, Quantum effects and DBI-scaling in the collapse of D0-D2 bound states

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    We study fluctuations of time-dependent fuzzy two-sphere solutions of the non-abelian DBI action of D0-branes, describing a bound state of a spherical D2-brane with N D0-branes. The quadratic action for small fluctuations is shown to be identical to that obtained from the dual abelian D2-brane DBI action, using the non-commutative geometry of the fuzzy two-sphere. For some of the fields, the linearized equations take the form of solvable Lam\'e equations. We define a large-N DBI-scaling limit, with vanishing string coupling and string length, and where the gauge theory coupling remains finite. In this limit, the non-linearities of the DBI action survive in both the classical and the quantum context, while massive open string modes and closed strings decouple. We describe a critical radius where strong gauge coupling effects become important. The size of the bound quantum ground state of multiple D0-branes makes an intriguing appearance as the radius of the fuzzy sphere, where the maximal angular momentum quanta become strongly coupled.Comment: 34 pages, Latex; v2: Minor correction in conformal transformation of couplings, references adde
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