9,832 research outputs found
Nilsson-SU3 selfconsistency in heavy N=Z nuclei
It is argued that there exist natural shell model spaces optimally adapted to
the operation of two variants of Elliott' SU3 symmetry that provide accurate
predictions of quadrupole moments of deformed states. A selfconsistent
Nilsson-like calculation describes the competition between the realistic
quadrupole force and the central field, indicating a {\em remarkable stability
of the quadruplole moments}---which remain close to their quasi and pseudo SU3
values---as the single particle splittings increase. A detailed study of the
even nuclei from Ni to Cd reveals that the region of
prolate deformation is bounded by a pair of transitional nuclei Kr and
Mo in which prolate ground state bands are predicted to dominate, though
coexisting with oblate ones,Comment: Replacement I) Title simplified. II) Major revision: structure of
paper kept but two thirds totally rewritten (same number of pages); 20
references adde
Extensive Characterization of Seismic Laws in Acoustic Emissions of Crumpled Plastic Sheets
Statistical similarities between earthquakes and other systems that emit
cracking noises have been explored in diverse contexts, ranging from materials
science to financial and social systems. Such analogies give promise of a
unified and universal theory for describing the complex responses of those
systems. There are, however, very few attempts to simultaneously characterize
the most fundamental seismic laws in such systems. Here we present a complete
description of the Gutenberg-Richter law, the recurrence times, Omori's law,
the productivity law, and Bath's law for the acoustic emissions that happen in
the relaxation process of uncrumpling thin plastic sheets. Our results show
that these laws also appear in this phenomenon, but (for most cases) with
different parameters from those reported for earthquakes and fracture
experiments. This study thus contributes to elucidate the parallel between
seismic laws and cracking noises in uncrumpling processes, revealing striking
qualitative similarities but also showing that these processes display unique
features.Comment: Accepted for publication in EP
Are the therapeutic strategies in anorexia of ageing effective on nutritional status? A systematic review with meta-analysis
BACKGROUND:
Anorexia of ageing (AA) may be considered as a risk factor for frailty and has an important impact on quality of life, morbidity and mortality.
METHODS:
A systematic review and a meta-analysis were performed to summarise the results from several trials on the effectiveness of treatments in AA, as associated with depression, sensory impairment of taste and smell, decreased appetite or early satiety, and disability. Eligible studies were required to report baseline and follow-up values, the mean change (∆-change) from baseline, and/or the mean difference among intervention groups versus control group, concerning food intake (kcal/daily) and/or nutritional outcomes, such as body weight, body mass index, albumin and Mini Nutritional Assessment.
RESULTS:
The systematic review included 20 papers based on different therapeutic approaches concerning food intake and/or nutritional outcomes. The results of the meta-analysis indicate that the interventions for AA have an important impact on body weight [+1.59 kg; 95% confidence interval (CI) = 1.48-+1.71 kg; P < 0.001) and on energy intake (+56.09 kcal; 95% CI = -54.05 to +166.25 kcal; P = 0.32). Regarding secondary outcomes, it was not possible to meta-analyse the limited amount of data availab le.
CONCLUSIONS:
The different variants of AA need to be defined because diverse therapeutic approaches are available. A more precise definition of the functional impairments associated with AA may allow a more correct decision about the most appropriate therapy to be prescribed. Moreover, this may allow for a more effective performance of the different therapeutic approaches once they are better targeted to the different scenarios of AA
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