5,527 research outputs found
Heuristic Classification of Physical Theories based on Quantum Correlations
Taking quantum formalism as a point of reference and connection, we explore
the various possibilities that arise in the construction of physical theories.
Analyzing the distinct physical phenomena that each of them may describe, we
introduce the different types of hidden variables theories that correspond to
these physical phenomena. A hierarchical classification of the offered
theories, based on the degree of correlation between dichotomic observables in
bipartite systems, as quantified by a Bell type inequality, is finally
proposed.Comment: 13 pages, 2 figure
Evidence of ongoing radial migration in NGC 6754: Azimuthal variations of the gas properties
Understanding the nature of spiral structure in disk galaxies is one of the
main, and still unsolved questions in galactic astronomy. However, theoretical
works are proposing new testable predictions whose detection is becoming
feasible with recent development in instrumentation. In particular, streaming
motions along spiral arms are expected to induce azimuthal variations in the
chemical composition of a galaxy at a given galactic radius. In this letter we
analyse the gas content in NGC 6754 with VLT/MUSE data to characterise its 2D
chemical composition and H line-of-sight velocity distribution. We find
that the trailing (leading) edge of the NGC 6754 spiral arms show signatures of
tangentially-slower, radially-outward (tangentially-faster, radially-inward)
streaming motions of metal-rich (poor) gas over a large range of radii. These
results show direct evidence of gas radial migration for the first time. We
compare our results with the gas behaviour in a -body disk simulation
showing spiral morphological features rotating with a similar speed as the gas
at every radius, in good agreement with the observed trend. This indicates that
the spiral arm features in NGC 6754 may be transient and rotate similarly as
the gas does at a large range of radii.Comment: 8 pages, 4 figures, accepted for publication in ApJL 2016 September
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Blockverse: A Cloud Blockchain-based Platform for Tracking in Affiliate Systems
Affiliate systems are a crucial piece of today’s online advertising. In affiliate systems, web traffic is directed from certain sites displaying ads to the websites of those company whose products or services are advertised. The way in which these ads are monetized is diverse and can respond to different models. In many cases, affiliates establish a cost based on impressions (displays of the ad) or on clicks. However, more intricate models are becoming widespread, such as the cost per action, where the affiliate incomes are due to the users
performing certain actions in the target website. In particular, in the world of iGaming, it is frequent that affiliates charges are based on registrations, deposits or money lost on bets. In this scenario, Blockverse is a tool whose objective is to record transactions occurring in affiliate systems at large scale, using a permissioned blockchain implemented atop state-of-the-art cloud technology. Additionally, the system will be able to execute smart deals that generate income for affiliates based on the agreed conditions, and to provide real-time analytics in the context of the affiliate system
Validation of the Spanish version of the five-item General Self-Efficacy (GSE) scale in a sample of nursing students: Evidence of validity, reliability, longitudinal invariance and changes in general self-efficacy and resilience in a two-wave cross-lagged panel model.
The aim of this study is to validate the Spanish version of the five-item General Self-Efficacy scale in a sample of nursing students, by: 1) offering evidence of validity and reliability; 2) studying the longitudinal measurement invariance of the scale; 3) providing evidence on the changes in the levels of self-efficacy that occur after one year of nursing education; and 4) offering longitudinal evidence on the relationship between nursing students' self-efficacy and resilience levels.
Nurses' general self-efficacy has been related to both personal and organizational outcomes. In Spain, some competencies the students must acquire during the Degree in Nursing implicitly refer to self-efficacy. For the measurement of general self-efficacy, the General Self-Efficacy Scale is one of the most widely used in Europe.
A longitudinal design was used. Research took place at the University of Valencia and the University of the Balearic Islands (Spain). Participants were 324 nursing students, in the first year of the Nursing Degree.
The five-item General Self-Efficacy scale and the Brief Resilience Coping Scale were used. Analyses included descriptive statistics, reliability estimates, confirmatory factor analysis, a longitudinal measurement invariance routine and several competing cross-lagged models.
Evidence of reliability shown by the scale was adequate and a one-factor solution for the structure was found. Additionally, the five-item GSE showed evidence of invariance over time. A causal effect of self-efficacy on nursing students' levels of resilience was found.
The Spanish version of the five-item General Self-Efficacy scale is a brief instrument that can contribute to the assessment of some of the basic competencies of the Degree in Nursing, which improve during their education and how these changes are related to other skills important for the nursing profession, such as resilience
The Cynipidae (Hymenoptera) of Comunidad de Madrid: checklist, distributional maps, species richness and conservation status
32 páginas, 2 figuras, 1 tabla, 2 apéndices.[ES] Se presenta por primera vez la lista anotada de especies y los mapas de distribución
de los Cynipidae de la Comunidad de Madrid. Los datos corresponden a 2189 registros
pertenecientes a muestreos y colectas efectuados desde 1982 hasta la actualidad, en 103
localidades de Madrid y en otras 19 cercanas de provincias adyacentes. Se relacionan
107 especies de cinípidos que representan el 73 % del total de especies ibéricas. Cada
especie se acompaña de su correspondiente mapa de distribución en la Comunidad de
Madrid, reflejando los puntos de las localidades de muestreo en los que ha sido encontrada,
junto a su área de distribución potencial en este territorio. Se comentan distintos
aspectos sobre la riqueza y distribución de los cinípidos de Madrid: especies de la fauna
ibérica ausentes y otras que han de buscarse, especies raras y singulares junto a aquellas
áreas de mayor riqueza de especies. El área de mayor riqueza del grupo se sitúa en una
franja siguiendo el eje Guadalix-Venturada-Torrelaguna, de terrenos del Cretácico y del
Terciario, que presenta también altas cifras de diversidad botánica de los géneros de
plantas hospedantes del grupo, especialmente de fagáceas del género Quercus. Algunos
enclaves del sureste de Madrid, ricos en especies singulares y raras de cinípidos de la
tribu Aylacini, las áreas relictas de Q. petraea del nordeste de Madrid con especies exclusivas
asociadas, así como los escasos enclaves remanentes de Quercus suber en la
región, también con especies exclusivas de cinípidos asociadas, merecen la máxima protección
por lo que respecta a la conservación de los cinípidos.[EN] Acheck list of the Cynipidae from Comunidad de Madrid (Spain) is presented for the
first time. The data base contains 2189 records of samplings carried out from 1982 to the
present in 103 sites in Madrid and 19 in nearby adjacent provinces. The list of 127 cynipid
species from Madrid represents 73% of total Cynipidae species from the Iberian
Peninsula. A distribution map in Madrid for each cynipid species is presented, showing
the sampling sites where it has been found together with the potential distribution area
of the species within the territory. Several aspects on the richness and distribution of the
Cynipidae from Madrid are commented: potentially present and absent Iberian species, traindividual
and rare species, and areas of high species richness. The area of highest richness
for the Cynipidae of Madrid follows a strip of Cretacic and Tertiary soils along the
Guadalix-Venturada-Torrelaguna axis, which also shows a high diversity of cynipid host
plants, especially Quercus species. Other areas in SE Madrid deserving protection with
regard to cynipids are also shown. These areas, some rich in rare and singular Aylacini
species, other relictic areas with Quercus petraea in the Northeast and also some small
areas with the presence of Quercus suber in parts of the territory of Madrid, deserve
maximum protection concerning Cynipid conservation.El trabajo ha sido financiado parcialmente con fondos de los
proyectos de la Consejería de Educación de la Comunidad de
Madrid, 07M/0080/2002 y GR/AMB/0750/2004 y del Ministerio
de Ciencia y Tecnología, proyecto de referencia REN2002-
03518/GLO, concedido a J. L. Nieves-Aldrey.Peer reviewe
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