4,428 research outputs found
Continuum effects in reactions involving weakly bound nuclei
The relevance of the continuum effects in transfer reactions is discussed in
conection with the determination of observables of astrophysical interest. In
particular, we examine the validity of the Distorted Wave Born Approximation
(DWBA) as a tool to extract the astrophysical \emph{(S_{17}(0))} factor. For
this purpose, we present calculations for the reaction (^{14})N((^{7}
)Be,(^{8})B)(^{13})C comparing the DWBA method with the more sophysticated
CDCC-Born approximationComment: Contribution to International Symposium on Physics of Unstable Nuclei
(ISPUN02) Halong Bay (Vietnam) November 20 to 25, 2002. To be published in
Nucl. Phy.
The single currency and European citizenship
We could expect that the introduction of the single currency had been accompanied by a significant share of studies and researches about the implications and impacts of such a watershed event on European citizenship. On the contrary, we soon discover to be facing a paradox, which could be phrased as follows: while the purpose of building European citizenship is the very rationale for the project of the single currency, the Scholars – but also the policy community – have mostly underestimated if not neglected this relation, both in terms of public policy making and discourse and of interpretation and forecasting. As a consequence of all of that, relevant features of the single currency happened to remain hidden, poorly considered and almost not thematized. In order to fill this gap, the first part of this article will present the main findings emerged from a documentary research conducted by FONDACA between 2010 and 2011, aimed at mapping the existing academic and policy thematizations about the hidden dimensions of the euro. The second part will be devoted to define “the other side of the coin” as an empirical phenomenon
The Colombian conflict: a description of a mental health program in the Department of Tolima.
Colombia has been seriously affected by an internal armed conflict for more than 40 years affecting mainly the civilian population, who is forced to displace, suffers kidnapping, extortion, threats and assassinations. Between 2005 and 2008, Médecins Sans Frontières-France provided psychological care and treatment in the region of Tolima, a strategic place in the armed conflict. The mental health program was based on a short-term multi-faceted treatment developed according to the psychological and psychosomatic needs of the population. Here we describe the population attending during 2005-2008, in both urban and rural settings, as well as the psychological treatment provided during this period and its outcomes.We observed differences between the urban and rural settings in the traumatic events reported, the clinical expression of the disorders, the disorders diagnosed, and their severity. Although the duration of the treatment was limited due to security reasons and access difficulties, patient condition at last visit improved in most of the patients. These descriptive results suggest that further studies should be conducted to examine the role of short-term psychotherapy, adapted specifically to the context, can be a useful tool to provide psychological care to population affected by an armed conflict
Stochastic vortex dynamics in two-dimensional easy-plane ferromagnets: Multiplicative versus additive noise
We study how thermal fluctuations affect the dynamics of vortices in the
two-dimensional classical, ferromagnetic, anisotropic Heisenberg model
depending on their additive or multiplicative character. Using a collective
coordinate theory, we analytically show that multiplicative noise, arising from
fluctuations in the local field term of the Landau-Lifshitz equations, and
Langevin-like additive noise both have the same effect on vortex dynamics
(within a very plausible assumption consistent with the collective coordinate
approach). This is a non-trivial result, as multiplicative and additive noises
usually modify the dynamics quite differently. We also carry out numerical
simulations of both versions of the model finding that they indeed give rise to
very similar vortex dynamics.Comment: 10 pages, 6 figure
Evidence of strong dynamic core excitation in C resonant break-up
The resonant break-up of C on protons measured at RIKEN [Phys. Lett. B
660, 320 (2008)] is analyzed in terms of a valence-core model for C
including possible core excitations. The analysis of the angular distribution
of a prominent peak appearing in the relative-energy spectrum could be well
described with this model and is consistent with the previous assignment of
for this state. Inclusion of core-excitation effects are found to be
essential to give the correct magnitude of the cross section for this state. By
contrast, the calculation assuming an inert C core is found to largely
underestimate the data.Comment: 5 pages, 2 figures, to be submitte
Time as a limited resource: Communication Strategy in Mobile Phone Networks
We used a large database of 9 billion calls from 20 million mobile users to
examine the relationships between aggregated time spent on the phone, personal
network size, tie strength and the way in which users distributed their limited
time across their network (disparity). Compared to those with smaller networks,
those with large networks did not devote proportionally more time to
communication and had on average weaker ties (as measured by time spent
communicating). Further, there were not substantially different levels of
disparity between individuals, in that mobile users tend to distribute their
time very unevenly across their network, with a large proportion of calls going
to a small number of individuals. Together, these results suggest that there
are time constraints which limit tie strength in large personal networks, and
that even high levels of mobile communication do not fundamentally alter the
disparity of time allocation across networks.Comment: 10 pages, 3 figures. Accepted for publication in Social Network
- …