1,396 research outputs found
Drugs and diseases: Summary and consensus statements of group 1. The 5th EAO Consensus Conference 2018
No full textSchliephake, H., Sicilia, A., Nawas, B.A., Donos, N., Gruber, R., Jepsen, S., Milinkovic, I., Mombelli, A., Navarro, J.M., Quirynen, M., Rocchietta, I., Schiødt, M., Schou, S., Stähli, A., Stavropoulos, A
Objectivity in law
No full textThe question of objectivity in legal interpretation has emerged in recent years as a highly important topic in contemporary jurisprudence. This original book addresses the issue of how and in what sense legal interpretation can be objective. The author supports the possibility of objectivity in law and spells out the content of objectivity involved. He then provides a comprehensive defence against the classical, as well as less well-known, objections to the possibility of objectivity in legal interpretationThe discussion is firmly grounded in metaphysics, which sets the book apart from other similar discussions in jurisprudence. Stavropoulos identifies an important source of resistance to acceptance of the possibility of objectivity in legal interpretation: a widely-held but faulty semantic. He then develops an alternative semantic framework which draws on influential theories in contemporary philosophy. The book shows that objectivism is a natural, commonsensical position, and rejects the currently popular notion that objectivism requires extravagant or bizarre metaphysics. Furthermore, the discussion presents the opportunity to reinterpret major debates in jurisprudence and to show how influential theories, notably H. L. A. Hart's and Ronald Dworkin's, bear on that central issu
Synthesis, reactivity and catalytic behaviour of Iron/Zinc containing species involved in oxidation of hydrocarbons under Gif-Type conditions
No full textThe present study explores the nature and reactivity of iron- and zinc-containing species generated in hydrocarbon-oxidizing GifIV-type solutions (Fe catalyst/Zn/O2 in pyridine/acetic acid (10:1 v/v). The ultimate goal of this investigation is to unravel the role of metal sites in mediating dioxygen-dependent C−H activation, which in the case of Gif chemistry demonstrates an enhanced selectivity for the ketonization of secondary carbons. Reaction of [Fe3O(O2CCH3)6(py)3]·py (1) with zinc powder in CH3CN/CH3COOH or CH2Cl2/CH3COOH affords the trinuclear compound [Zn2FeII(O2CCH3)6(py)2] (2). Single-crystal X-ray analysis confirms that one monodentate and two bidentate acetate groups bridge adjacent pairs of metals with the iron atom occupying a centrosymmetric position. The analogous reduction of 1 in py/CH3COOH (10:1, 5:1, 2:1 v/v) yields [FeII(O2CCH3)2(py)4] (3), [FeII2(O2CCH3)4(py)3]n (4), and [Zn(O2CCH3)2(py)2] (5) depending on the isolation procedure employed. Compound 3 possesses a distorted octahedral geometry, featuring a C2 axis bisecting the equatorial, pyridine-occupied plane, whereas the two acetate groups reside along the perpendicular axis. Compound 4 is a one-dimensional solid constructed by asymmetric diferrous units. Two bidentate and one monodentate acetate groups bridge the two iron sites, with the monodentate bridge also acting as a chelator to one ferrous center. The two iron centers exhibit weak antiferromagnetic coupling. Compounds 3 and 4 are also accessible from the reduction of 1 with iron powder or treatment with H2/Pd. Solutions of 3 and 4 in pyridine or py/CH3COOH react with pure dioxygen or air to eventually regenerate 1 in a concentration-dependent manner. Oxidation of 2 in py/CH3COOH with pure dioxygen or air yields [Fe2.22(2)Zn0.78(2)O(O2CCH3)6(py)3]·py (1‘) and [Zn2(O2CCH3)4(py)2] (6). Compound 1‘ is isostructural to 1, exhibiting rhombohedral symmetry at 223 K. The filtrate of the reduction of 1 with zinc in neat pyridine, when exposed to dioxygen, affords dichroic red−green crystals of monoclinic [Fe2ZnO(O2CCH3)6(py)3]·py (1‘‘). Species 1‘‘ yields products identical with those provided by 1 under reducing conditions. Compounds 2−6 are related by pyridine-dependent equilibria, as demonstrated by mutual interconversions and electronic absorption data in pyridine and py/CH3COOH solutions. In non-pyridine solutions, Zn-containing species 5 and 6 rearrange to the crystallographically characterized species [Zn(O2CCH3)2(py)]n (7) and [Zn3(O2CCH3)6(py)2] (8). Compound 7 is a one-dimensional solid featuring a chain of Zn sites linked by a bidentate acetate group while additionally coordinated by a chelating acetate. Compound 8 is isostructural to 2. Further perturbations of the described structures are apparent in ionic iron-containing species, such as the pseudo-seven-coordinate iron in [Ph3PNPPh3][FeII(O2CCH3)3(py)] (9), which is obtained from the reaction of 3 with [PPN][O2CCH3], and the water-coordinated iron in [FeII(H2O)4(trans-py)2][O2CCH3]2 (10), which reveals an extensive two-dimensional network of hydrogen-bonding interactions. The pyridine-free species [FeII3(O2CCH3)6(OS(CD3)2)2]n (11) is isolable upon extensive incubation of 3 in (CD3)2SO. Compound 11 exhibits a remarkable one-dimensional structure, featuring four different types of acetate groups. Catalytic oxidations of adamantane, isopentane, benzene, toluene, cis-stilbene, and pyridine mediated by the system 1 (or 2−4)/Zn/O2 in py/AcOH (10:1) afford product profiles which are not fully compatible with the reported outcome of analogous oxidations by hydroxyl radicals or biologically relevant high-valent iron−oxo species alone. The intermolecular deuterium kinetic isotope effect for the oxidation of adamantane to adamantanone is small (kH/kD = 2.01(12)) by comparison to values obtained for oxidation of hydrocarbons by biological oxygenases. Employment of hydrogen peroxide, t-BuOOH, or peracetic acid as potential oxo donors does not provide viable shunt pathways in the catalytic oxygenation of adamantane. The nature of active oxidant in GifIV-type oxidation is discussed in light of these structural and functional findings
Avoidant romantic attachment in adolescence: Gender, excessive internet use and romantic relationship engagement effects
No full textRomantic development is a distinctive characteristic of puberty. However, a significant proportion of adolescents present with avoidant romantic attachment (ARA) tendencies, which have significant impact on their general adaptation. ARA variations have been suggested in relation to age, gender, engagement with a romantic partner and Excessive Internet Use (EIU) behaviours. In this longitudinal, two-wave study of a normative sample of 515 Greek adolescents at 16 and 18 years, ARA was assessed with the relevant subscale of the Experiences in Close Relationships-Revised and EIU with the Internet Addiction Test. A three-level hierarchical linear model found ARA tendencies to decrease between 16 and 18 while engagement in a romantic relationship and EIU were associated with lower and higher ARA tendencies respectively. Gender did not differentiate ARA severity either at the age of 16 or its changes over time. Results highlight the need of adopting a longitudinal-contextualized approach and provide implications for prevention and intervention initiatives in relation to the romantic development of adolescents. © 2018 Stavropoulos et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited
Model-based design of AM components to enable decentralized digital manufacturing systems
No full textAdditive manufacturing (AM) is a versatile technology that could add flexibility in manufacturing processes, whether implemented alone or along other technologies. This technology enables on-demand production and decentralized production networks, as production facilities can be located around the world to manufacture products closer to the final consumer (decentralized manufacturing). However, the wide adoption of additive manufacturing technologies is hindered by the lack of experience on its implementation, the lack of repeatability among different manufacturers and a lack of integrated production systems. The later, hinders the traceability and quality assurance of printed components and limits the understanding and data generation of the AM processes and parameters. In this article, a design strategy is proposed to integrate the different phases of the development process into a model-based design platform for decentralized manufacturing. This platform is aimed at facilitating data traceability and product repeatability among different AM machines. The strategy is illustrated with a case study where a car steering knuckle is manufactured in three different facilities in Sweden and Italy
New ways to specify data edits
No full textData editing is the process by which data that are collected in some way (a statistical
survey for example) are examined for errors and corrected with the help of software. Edits, the logical conditions that should be satisfied by the data, are specified by subject-matter experts with a procedure which could be tedious and could lead to mistakes with practical implications. To render the process of edit specification more efficient we provide a new step—the definition of the so-called abstract data model of a survey—which describes the structure of the phenomenon that is studied in a survey. The existence of this model enables experts to identify all combinations of variables which should be checked by edits and to avoid the definition of conflicting edits.Furthermore, we introduce an automatic data validation strategy—TREEVAL—that
consists of fast tree growing to derive automatically the functional form of edits and of a statistical criterion to clean the incoming data. The TREEVAL strategy is cast within a total quality management framework. The application of the methodologies proposed is demonstrated with the help of a real life application
Greek meat supply response and price volatility in a rational expectations framework: A multivariate GARCH approach
No full textThis paper examines supply response models in a rational expectations framework for each one of the four major Greek meat markets, i.e. beef, broiler, lamb and pork. A multivariate GARCH model with Cholesky decomposition is used to incorporate price volatility into the rational expectations supply response model for each meat category and as a result the conditional covariance matrix remains positive definite without imposing any restrictions on the parameters. The empirical results confirm the existence of rational behaviour by meat producers in the four examined markets and indicate that price volatility is a major risk factor in Greek meat production while feed prices and veterinarian medicine prices are both important cost factors. Furthermore, the last Common Agricultural Policy reform is found to have a negative impact on the beef and lamb production in Greece.meat supply, price volatility, rational expectations, MGARCH., Agricultural and Food Policy,
Η ΙΑΤΡΟΪΣΤΟΡΙΚΗ ΣΚΕΨΗ ΤΟΥ ΑΡΙΣΤΟΤΕΛΗ Κ. ΣΤΑΥΡΟΠΟΥΛΟΥ (1927-1994)
No full textΔεν παρατίθεται περίληψη στα Ελληνικά.In this paper the author presents Ar. Stavropoulos' views and theoretical approach to the history of Medicine and his contribution to the study of the history of that discipline in Greece during the period of Turkish occupation and in the 19th century, as reflected in his work. Aspects such as, the influence of epidemics on the Greek population economy and demography, the function of hospitals, health policy, medical training and the formation of the medical personnel, feature among the topics discussed by Stavropoulos, in this context
Learning Intersections of Halfspaces with Distribution Shift: Improved Algorithms and SQ Lower Bounds
No full textRecent work of Klivans, Stavropoulos, and Vasilyan initiated the study of
testable learning with distribution shift (TDS learning), where a learner is
given labeled samples from training distribution , unlabeled
samples from test distribution , and the goal is to output a
classifier with low error on whenever the training samples pass
a corresponding test. Their model deviates from all prior work in that no
assumptions are made on . Instead, the test must accept (with
high probability) when the marginals of the training and test distributions are
equal.
Here we focus on the fundamental case of intersections of halfspaces with
respect to Gaussian training distributions and prove a variety of new upper
bounds including a -time algorithm
for TDS learning intersections of homogeneous halfspaces to accuracy
(prior work achieved ). We work under the
mild assumption that the Gaussian training distribution contains at least an
fraction of both positive and negative examples
(-balanced). We also prove the first set of SQ lower-bounds for any
TDS learning problem and show (1) the -balanced assumption is
necessary for -time TDS learning for a single
halfspace and (2) a lower bound for the
intersection of two general halfspaces, even with the -balanced
assumption.
Our techniques significantly expand the toolkit for TDS learning. We use
dimension reduction and coverings to give efficient algorithms for computing a
localized version of discrepancy distance, a key metric from the domain
adaptation literature.Comment: To appear in COLT 202
Exploratory structural equation modeling: a streamlined step by step approach using the R Project software
No full textConfirmatory Factor Analysis (CFA) has been a popular yet limited approach to assessing latent factor structures. Despite items rarely loading exclusively on one latent factor in multifactorial scales, CFA assumes all indicators/items should load uniquely on their allocated latent dimensions. To address this weakness, Exploratory Structural Equation Modeling (ESEM) combines exploratory factor analyses (EFA) and CFA procedures, allowing cross-loadings to occur when assessing hypothesized models. Although such advantages have enhanced ESEM popularity, its adoption is often limited by software rigidity and complex coding difficulties. To address these obstacles, the current tutorial presents a streamlined, step-by-step approach using the open-source software R while providing both R and Mplus ESEM syntax. The tutorial demonstrates the sequence of the ESEM stages by examining the frequently debated Strengths and Difficulties Questionnaire (SDQ) factor structure, using openly accessible data from the Longitudinal Study of Australian Children (LSAC). As ESEM may allow a better understanding of the complex associations in multidimensional scales, this tutorial may optimize the epidemiological and clinical assessment of common yet multifaceted psychiatric presentations. © 2023, The Author(s)
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