Search results for "contribution"
showing 10 items of 128 documents
Forward light-by-light scattering and electromagnetic correction to hadronic vacuum polarization
2023
Lattice QCD calculations of the hadronic vacuum polarization (HVP) have reached a precision where the electromagnetic (e.m.) correction can no longer be neglected. This correction is both computationally challenging and hard to validate, as it leads to ultraviolet (UV) divergences and to sizeable infrared (IR) effects associated with the massless photon. While we precisely determine the UV divergence using the operator-product expansion, we propose to introduce a separation scale $\Lambda\sim400\;$MeV into the internal photon propagator, whereby the calculation splits into a short-distance part, regulated in the UV by the lattice and in the IR by the scale $\Lambda$, and a UV-finite long-di…
O Brasil na rota das migrações internacionais qualificadas espanholas no século XXI
2018
In order to understand recent migration, it is crucial to analyze the migratory modalities such as skilled international migration to Brazil, especially considering the ongoing transnational economic processes and their effects on the corresponding societies. Therefore, this article seeks to understand how the migratory dynamics of highly skilled Spanish professionals to the country are established taking into account the theoretical contribution of the circulation of brains and the category of knowledge workers. For this purpose, information from Brazilian?s Ministry of Labor is used on labor authorizations, financial contributions and insertion in the formal market in Spain; as well as da…
Akcja imienna jako aport w spółce kapitałowej. Wybrane zagadnienia
2012
Reciprocity, matching and conditional cooperation in two public goods games
2005
Previous experimental and empirical evidence has identified social preferences in the voluntary provision of public goods. A number of competing models of such preferences have been proposed. We provide evidence for one model of behavior in these games, reciprocity (or matching, or conditional cooperation). Consistent with previous research, we find that participants in the voluntary contribution mechanism attempt to match the contributions of others in their group. We also examine participants in a related game with different equilibria, the weakest-link mechanism. Here, in contrast, participants contribute so as to match the minimum contribution of others in their group.
El sector no lucrativo desde el enfoque de la elección pública: Cuando la oferta no lucrativa de bienes públicos es el resultado de decisiones emanad…
2001
The voluntary supply of collective goods by nonprofit institutions has deserved little attention in the Public Choice literature, and the clasical nonprofits approach does not consider nonprofits supply as a collective decision, although individuals, either as consumers or as donors, are in the center of their theoretical constructs. In this paper we hypothesize that voluntary nonprofits' provision is a collective choice. We present a model in which the members of a community, both those who fund the nonprofits and those who do not (free riders) vote, so choosing between a political program of governmental supply and a political program of non governmental supply. Afterward, they must also …
Paul Strand y las paradojas de la modernidad americana
2010
As contribuições de Strand para o cinema estão estreitamente relacionadas com seus trabalhos fotográficos da época e mesmo com um olhar que, apesar de suas múltiplas diferenças, possui muitos pontos em comum. Se em Manhatta (1920), Strand (em colaboração com Sheeler) oferece uma síntese da natureza e da modernidade, em Redes (1934) o que predomina, em contrapartida, é a experiência da arte muralista mexicana e a influência de Eisenstein (em suas andanças por México) são os fatores que determinam seus esforços na construção de uma épica dos operários. Mas sem dúvida, o projeto mais ambicioso de Strand (ao mando da produtora Frontier Films) foi Native Land, o filme que atendeu às demandas do …
Do adolescents with long-term illnesses and disabilities have increased risks of sports related injuries?
2017
peer-reviewed Background: The aim of this study is to examine the rates of sports related injuries in adolescents based on the severity of their long-term illnesses or disabilities (LTID). Few injury prevention strategies in sports and health promotion have explored disaggregation by disability. Methods: Data obtained from the 2014 Finnish Health Behaviour in School-aged Children survey (n = 3716, mean age = 14.8, SD = 1.03) were grouped into adolescents with and without LTID. A further indicator or severity was determined when adolescents reported their LTID affected their participation (affected LTID). Odds ratio (95% CI) were used to determine the associations between sports related inju…
A Contribution to the Schumpeterian Growth Theory and Empirics
2010
Soumis à Journal of Economic Growth; Document de Recherche LEO 2008-25; Cet article propose un cadre théorique et méthodologique unifie caractérisé par la priseen compte explicite des intéractions technologiques dans la modélisation des processus decroissance en adoptant une perspective Schumpétérienne. L'interdépendance globale impliquée par les spillovers internationaux de R&D doit être intégrée non seulement dans lamodélisation théorique mais également dans la spécification économétrique qui en découle.L'économétrie spatiale apparaît alors naturellement comme la méthodologie adéquate pourtraiter le problème de l'estimation de telles spécifications. Le modèle économétrique que nousproposo…
La persistance de la performance des fonds de pension individuels britanniques : une étude empirique sur des fonds investis en actions et des fonds o…
2003
Dans ce présent cahier de recherche, nous nous proposons d’étudier la stabilité des performances de certains fonds de retraite anglais à cotisations définies : les fonds de pension individuels (Personal Pension Scheme). Il s’agit de fonds – pratiquant une gestion active - investissant principalement dans les actions britanniques et de fonds détenant majoritairement des obligations anglaises durant la période novembre 1990 – novembre 2000. Les données sur les fonds de pension individuels proviennent de la base de données UK PENSION de Standard & Poor’s Fund Services et sont de fréquence mensuelle. Nous utilisons des tests paramétriques de l’existence de la persistance, plusieurs mesures de p…
Prowadzenie pozarolniczej działalności gospodarczej jako tytuł ubezpieczeń społecznych - wybrane zagadnienia
2021
Prowadzenie pozarolniczej działalności gospodarczej stanowi szczególny tytuł ubezpieczeń społecznych. Wynika to z faktu, że w zakresie podlegania ubezpieczeniom społecznym wyłącznie przedsiębiorcy (spośród wszystkich osób prowadzących pozarolniczą działalność) posiadają uprawnienia do okresowego wyłączenia obowiązku ubezpieczeń społecznych oraz zawieszenia wykonywania działalności gospodarczej, nie tylko z powodu sprawowania osobistej opieki nad dzieckiem. Z kolei w sferze opłacania składek na ubezpieczenia społeczne istnieją trzy sposoby ustalania podstawy wymiaru składek z tego tytułu (podstawa zwykła, preferencyjna i uzależniona od dochodu). Ogólnie należy stwierdzić, że prowadzenie poza…