2,140 research outputs found
Observation of a uniform temperature dependence in the electrical resistance across the structural phase transition in thin film vanadium oxide ()
An electrical study of thin films in the vicinity of the structural
phase transition at shows (a) that the electrical resistance
follows over the -range,
covering both sides of the structural transition, and (b) a history dependent
hysteresis loop in upon thermal cycling. These features are attributed here
to transport through a granular network.Comment: 3 pages, 3 color figure
¿Un 'discours aux architectes'?
El artículo retorna sobre el profundo impacto que produjeron los temas reaccionarios en la modernidad francesa tras la Primera Guerra Mundial. Para ello, considera el regionalismo en las permutaciones de la Segunda Guerra Mundial y explica sus diferentes significados en Italia y Alemania como base interpretativa para el caso de España. Aplica la distinción entre el regionalismo, el parroquialismo y el provincialismo, considera su susceptibilidad a las condiciones de neo-, pseudo-, y faux-, y diferencia los conceptos de hibricidad y eclecticismo Beaux-Arts. Estas condiciones llevan a su fin la distancia de la obra de Le corbusier con el regionalismo en los años 30. Después de la Segunda Guerra Mundial lo vernacular reemplazó al regionalismo y Gran Bretaña emergió por su posición insular respecto a la vanguardia histórica europea, que por su antagonismo entre el romanticismo, nuevo humanismo, nuevo empirismo, nueva pintoresca y el abandono atropellado vernacular del nuevo brutalismo, consigue crear una ruptura con los años de entreguerras
Designing a physical activity parenting course : parental views on recruitment, content and delivery
Background
Many children do not engage in sufficient levels of physical activity (PA) and spend too much time screen-viewing (SV). High levels of SV (e.g. watching TV, playing video games and surfing the internet) and low levels of PA have been associated with adverse health outcomes. Parenting courses may hold promise as an intervention medium to change children’s PA and SV. The current study was formative work conducted to design a new parenting programme to increase children’s PA and reduce their SV. Specifically, we focussed on interest in a course, desired content and delivery style, barriers and facilitators to participation and opinions on control group provision.
Methods
In-depth telephone interviews were conducted with thirty two parents (29 female) of 6–8 year olds. Data were analysed thematically. An anonymous online survey was also completed by 750 parents of 6–8 year old children and descriptive statistics calculated.
Results
Interview participants were interested in a parenting course because they wanted general parenting advice and ideas to help their children be physically active. Parents indicated that they would benefit from knowing how to quantify their child’s PA and SV levels. Parents wanted practical ideas of alternatives to SV. Most parents would be unable to attend unless childcare was provided. Schools were perceived to be a trusted source of information about parenting courses and the optimal recruitment location. In terms of delivery style, the majority of parents stated they would prefer a group-based approach that provided opportunities for peer learning and support with professional input. Survey participants reported the timing of classes and the provision of childcare were essential factors that would affect participation. In terms of designing an intervention, the most preferred control group option was the opportunity to attend the same course at a later date.
Conclusions
Parents are interested in PA/SV parenting courses but the provision of child care is essential for attendance. Recruitment is likely to be facilitated via trusted sources. Parents want practical advice on how to overcome barriers and suggest advice is provided in a mutually supportive group experience with expert input
Characterizing rings in terms of the extent of injectivity and projectivity of their modules
Given a ring R, we define its right i-profile (resp. right p-profile) to be
the collection of injectivity domains (resp. projectivity domains) of its right
R-modules. We study the lattice theoretic properties of these profiles and
consider ways in which properties of the profiles may determine the structure
of rings and viceversa. We show that the i-profile is isomorphic to an interval
of the lattice of linear filters of right ideals of R, and is therefore modular
and coatomic. In particular, we give a practical characterization of the
i-profile of a right artinian ring. We show through an example that the
p-profile is not necessarily a set, and also characterize the right p-profile
of a right perfect ring. The study of rings in terms of their (i- or p-)profile
was inspired by the study of rings with no (i- or p-) middle class, initiated
in recent papers by Er, L\'opez-Permouth and S\"okmez, and by Holston,
L\'opez-Permouth and Orhan-Ertas. In this paper, we obtain further results
about these rings and we also use our results to provide a characterization of
a special class of QF-rings in which the injectivity and projectivity domains
of any module coincide.Comment: 19 pages, examples and propositions added. Title change
Long Memory and Volatility Clustering: is the empirical evidence consistent across stock markets?
Long memory and volatility clustering are two stylized facts frequently
related to financial markets. Traditionally, these phenomena have been studied
based on conditionally heteroscedastic models like ARCH, GARCH, IGARCH and
FIGARCH, inter alia. One advantage of these models is their ability to capture
nonlinear dynamics. Another interesting manner to study the volatility
phenomena is by using measures based on the concept of entropy. In this paper
we investigate the long memory and volatility clustering for the SP 500, NASDAQ
100 and Stoxx 50 indexes in order to compare the US and European Markets.
Additionally, we compare the results from conditionally heteroscedastic models
with those from the entropy measures. In the latter, we examine Shannon
entropy, Renyi entropy and Tsallis entropy. The results corroborate the
previous evidence of nonlinear dynamics in the time series considered.Comment: 8 pages; 2 figures; paper presented in APFA 6 conferenc
- …