Search results for "interaction [dark matter]"
showing 10 items of 363 documents
Interactions, spillovers de connaissance et croissance des villes européennes. Faut-il préférer la géographie, le climat institutionnel ou les réseau…
2013
Knowledge spillovers within urban economies are also sources of spillovers between cities. We examine how knowledge spillovers influenced the economic growth of 82 European metropolises over the 1990-2005 period. We model knowledge spillovers between cities on the basis of five specific interaction patterns based on geography, networks of multinational firms in advanced services, institutional climate and two combinations of these factors. Spatial models are estimated to detail the effects of growth factors in terms of spillovers and externalities. We show that spillovers are local rather than global and that interactions among cities accelerate the convergence process based on gross value …
Productivity analysis of Latvian companies using ORBIS database
2021
International audience; This research study uses ORBIS microdata at the company level to analyse productivity of 167 thousand economically active Latvian companies over 2011-2018. The aim of the study is twofold-to find factors consistently associated with productivity at the company level; and to recommend possible criteria for companies to receive a state support (from the view of enhancing aggregate productivity in the long term). Our research results show that productivity of Latvian companies is positively related to their size, age, as well as location closer to Riga and other big cities. However, there is a substantial within-group variation in productivity between companies. Multiva…
DIGITALE MODERATION IN DER DAF-LEHRENDENBILDUNG
2022
The aim of this paper is to show patterns in the moderation of video conferences. The corpus used comes from the Erasmus+ project LEELU (development of teaching skills for extensive reading lessons). The subject of the investigation was how changes in the agenda are negotiated at the beginning of the meetings. A multimodal method based on conversation analysis was chosen for the analysis.
Reply to the “Comment by Delmelle et al. (2013) on ‘Scavenging of sulfur, halogens and trace metals by volcanic ash: The 2010 Eyjafjallajökull erupti…
2014
Abstract With this short communication we address the principal issues raised by Delmelle et al. (2014) in relation to the work of Bagnato et al. (2013) concerning the 2010 eruption of Eyjafjallajokull, Iceland. The principal conclusions of the work of Bagnato et al. (2013) include the observation that protracted gas-aerosol interaction in the plume promotes selective leaching of cation species from ash, with alkalis and Ca (and, among trace elements, Zn and Cu) being more rapidly re-mobilized (and transferred to soluble surface salts) relative to more inert elements (Mg, Ti). They also observed that adsorption onto ash surfaces is a major atmospheric sink of volcanic acidic gases, with 282…
Interactions of the hormones leptin, ghrelin, adiponectin, resistin, and PYY3-36 with the reproductive system.
2006
Objective To summarize the effects of novel hormones (leptin, ghrelin, adiponectin, resistin, and PYY3-36) secreted from adipose tissue and the gastrointestinal tract that have been discovered to exert different effects on several reproductive functions, such as the hypothalamic–pituitary–gonadal axis, embryo development, implantation physiology, and clinically relevant conditions. Design A MEDLINE computer search was performed to identify relevant articles. Result(s) Leptin and ghrelin exert important roles on body weight regulation, eating behavior, and reproduction, acting on the central nervous system and target reproductive organs. As a marker of adequate nutritional stores, these horm…
N-Heterocyclic Carbenes with Inorganic Backbones: Electronic Structures and Ligand Properties
2008
The electronic structures of known N-heterocyclic carbenes (NHCs) with boron, nitrogen, and phosphorus backbones are examined using quantum chemical methods and compared to the experimental results and to the computational data obtained for a classical carbon analogue, imidazol-2-ylidene. The sigma-donor and pi-acceptor abilities of the studied NHCs in selected transition-metal complexes are evaluated using a variety of approaches such as energy and charge decomposition analysis, as well as calculated acidity constants and carbonyl stretching frequencies. The study shows that the introduction of selected heteroatoms into the NHC backbone generally leads to stronger metal-carbene bonds and t…
Focal social actions through which space is configured and reconfigured when orienting to a Finnish Sign Language class
2018
Abstract This paper focuses on how signing students organise themselves spatially in social interactions in a university lecture hall. One may view space as a concrete location, a social construct, and a normative actor with historical trajectories. The study addresses the question, ‘What are the mediated actions through which the students and teacher (re)configure space for participating in a class?' Following a methodological framework of Mediated Discourse Analysis and multimodal interaction analysis, I approach this question by examining the social actions occurring when entering a lecture hall. The primary data includes video recordings, photos, and participatory observations, document…
Molecular Motions within Self-Assembled Dimeric Capsules with Tetraethylammonium Cations as Guest
2001
Hydrogen-bonded, dimeric capsules of calix[4]arenes substituted at the wide rim by four urea functions show unprecedented dynamic features when a tetraethylammonium cation is included as a guest. The seam of hydrogen bonds C=O...(HN)2C=O in the equatorial region which holds the two calixarene counterparts together changes its directionality fast (at 25 degrees C), while the dimer itself is kinetically stable on the NMR time scale. An energy barrier of deltaG++ = 49.9 kJmol(-1) (Tc 276 K) was estimated for this reorientation from variable-temperature (VT) NMR measurements. Lowering the temperature to about -50 degrees C restricts also the rotation of the encapsulated tetraethylammonium catio…
Maximin Model Robust Discrete Choice Experiments
2013
Discrete choice experiments have their genesis in conjoint analysis, which was based on first-order models. For this and other reasons, discrete choice experiments in practice are usually designed for estimation of main effects. In this paper, we explore the construction of maximin model robust designs when the experimenter is concerned about the presence of interactions. We consider three classes of models—main effects models, main effects models plus first-order interactions, and secondorder models, and we construct designs that maximize the minimum efficiency of the design for the three competing models. We do so first with standard linear models and then extend our analysis to nonlinear…
Mating systems and protein–protein interactions determine evolutionary rates of primate sperm proteins
2013
To assess the relative impact of functional constraint and post-mating sexual selection on sequence evolution of reproductive proteins, we examined 169 primate sperm proteins. In order to recognize potential genome-wide trends, we additionally analysed a sample of altogether 318 non-reproductive (brain and postsynaptic) proteins. Based on cDNAs of eight primate species (Anthropoidea), we observed that pre-mating sperm proteins engaged in sperm composition and assembly show significantly lower incidence of site-specific positive selection and overall lower non-synonymous to synonymous substitution rates ( d N / d S ) across sites as compared with post-mating sperm proteins involved in capac…