6,278 research outputs found
Nuclear fusion as a probe for octupole deformation in Ra
: Nuclear fusion has been shown to be a perfect probe to
study the different nuclear shapes. However, the possibility of testing
octupole deformation of a nucleus with this tool has not been fully explored
yet. The presence of a stactic octupole deformation in nuclei will enhanced a
possible permanent electric dipole moment, leading to a possible demonstration
of parity violation.
: To check whether static octupole deformation or octupole
vibration in fusion give qualitatively different results so that both
situations can be experimentally disentangled.
: Fusion cross sections are computed in the Coupled-Channels
formalism making use of the Ingoing-Wave Boundary Conditions (IWBC) for the
systems O+Ba and O+Ra.
: Barrier distributions of the two considered schemes show
different patterns. For the Ra case, the octupole deformation parameter
is large enough to create a sizeable difference.
: The measurement of barrier distributions can be an
excellent probe to clarify the presence of octupole deformation.Comment: Important changes from previous version, 6 pages, 5 figures, 2
tables, submitted to Phys. Rev.
Continuum discretized BCS approach for weakly bound nuclei
The Bardeen-Cooper-Schrieffer (BCS) formalism is extended by including the
single-particle continuum in order to analyse the evolution of pairing in an
isotopic chain from stability up to the drip line. We propose a continuum
discretized generalized BCS based on single-particle pseudostates (PS). These
PS are generated from the diagonalization of the single-particle Hamiltonian
within a Transformed Harmonic Oscillator (THO) basis. The consistency of the
results versus the size of the basis is studied. The method is applied to
neutron rich Oxygen and Carbon isotopes and compared with similar previous
works and available experimental data. We make use of the flexibility of the
proposed model in order to study the evolution of the occupation of the
low-energy continuum when the system becomes weakly bound. We find a larger
influence of the non-resonant continuum as long as the Fermi level approaches
zero.Comment: 20 pages, 16 figures, to be submitte
Interplay between valence and core excitation mechanisms in the breakup of halo nuclei
The phenomenon of core excitation in the breakup of a two-body halo nucleus
is investigated. We show that this effect plays a significant role in the
reaction dynamics and, furthermore, its interference with the valence
excitation mechanism has sizable and measurable effects on the breakup angular
distributions. These effects have been studied in the resonant breakup of 11Be
on a carbon target, populating the resonances at 1.78 MeV (5/2+) and 3.41 MeV
(3/2+). The calculations have been performed using a recently extension of the
DWBA method, which takes into account the effect of core excitation in both the
structure of the halo nucleus and in the reaction mechanism. The calculated
angular distributions have been compared with the available data [Fukuda et
al., Phys. Rev. C70,054606]. Although each of these resonances is dominated by
one of the two considered mechanisms, the angular patterns of these resonances
depend in a very delicate way on the interference between them. This is the
first clear evidence of this effect but the phenomenon is likely to occur in
other similar reactions.Comment: 5 pages, 2 figures, (Version to appear in Physical Review Letters
Determining distributions of weakly bound nuclei from breakup cross sections using Continuum Discretized Coupled Channels calculations. Application to Be
A novel method to extract the strength of a weakly bound nucleus from
experimental Coulomb dissociation data is proposed. The method makes use of
continuum discretized coupled channels (CDCC) calculations, in which both
nuclear and Coulomb forces are taken into account to all orders. This is a
crucial advantage with respect to the standard procedure based on the
Equivalent Photon Method (EPM) which does not properly take into account
nuclear distortion, higher order coupling effects, or Coulomb-nuclear
interference terms. The procedure is applied to the Be nucleus using two
sets of available experimental data at different energies, for which seemingly
incompatible have been reported using the EPM. We show that the present
procedure gives consistent strengths, thus solving the aforementioned
long-standing discrepancy between the two measurements.Comment: Submitted for publicatio
Germanene: a novel two-dimensional Germanium allotrope akin to Graphene and Silicene
Using a gold (111) surface as a substrate we have grown in situ by molecular
beam epitaxy an atom-thin, ordered, two-dimensional multi-phase film. Its
growth bears strong similarity with the formation of silicene layers on silver
(111) templates. One of the phases, forming large domains, as observed in
Scanning Tunneling Microscopy, shows a clear, nearly flat, honeycomb structure.
Thanks to thorough synchrotron radiation core-level spectroscopy measurements
and advanced Density Functional Theory calculations we can identify it to a
xR(30{\deg}) germanene layer in coincidence with a
xR(19.1{\deg}) Au(111) supercell, thence, presenting the
first compelling evidence of the birth of a novel synthetic germanium-based
cousin of graphene.Comment: 16 pages, 4 figures, 1 tabl
Beliefs about the causes and cures of depression
BACKGROUND:
This study used attitude statement and vignette methodology to examine a mixed British sample’s belies about the causes and consequences of depression.
AIMS:
To test whether the group would recognise both vignettes with having depression and that the favoured cure would be Psychotherapy/Talking Cure.
METHOD:
In all, 320 adults completed a two-part questionnaire. In the first part, they were given two vignettes describing a 30-year-old female and a 45-year-old male both with depression. They were asked what they thought (if anything) was wrong with the person and how they could best be helped. In the second part, they completed two questionnaires, one which lists 47 possible causes and the other 48 possible treatments for depression.
RESULTS:
Most participants ‘diagnosed’ depression for the two vignettes although they chose very different terms and offered a variety of ‘cures’, including medication and counselling. The questionnaires about cause and cure factored into seven interpretable factors which were logically correlated. A series of regressions showed that sex, age, media interest, political beliefs, experience with depression and other mental illnesses as well as having known of others diagnosed with depression predicted different beliefs about the causes and cures of depression.
CONCLUSION:
People have a detailed and multidimensional view of the causes and cures for depression which is systematically related to each other
Modulation of Host Immunity by Human Respiratory Syncytial Virus Virulence Factors: A Synergic Inhibition of Both Innate and Adaptive Immunity
Indexación: Web of Science; Scopus.The Human Respiratory Syncytial Virus (hRSV) is a major cause of acute lower respiratory tract infections (ARTIs) and high rates of hospitalizations in children and in the elderly worldwide. Symptoms of hRSV infection include bronchiolitis and pneumonia. The lung pathology observed during hRSV infection is due in part to an exacerbated host immune response, characterized by immune cell infiltration to the lungs. HRSV is an enveloped virus, a member of the Pneumoviridae family, with a non-segmented genome and negative polarity-single RNA that contains 10 genes encoding for 11 proteins. These include the Fusion protein (F), the Glycoprotein (G), and the Small Hydrophobic (SH) protein, which are located on the virus surface. In addition, the Nucleoprotein (N), Phosphoprotein (P) large polymerase protein (L) part of the RNA-dependent RNA polymerase complex, the M2-1 protein as a transcription elongation factor, the M2-2 protein as a regulator of viral transcription and (M) protein all of which locate inside the virion. Apart from the structural proteins, the hRSV genome encodes for the non-structural 1 and 2 proteins (NS1 and NS2). HRSV has developed different strategies to evade the host immunity by means of the function of some of these proteins that work as virulence factors to improve the infection in the lung tissue. Also, hRSV NS-1 and NS-2 proteins have been shown to inhibit the activation of the type I interferon response. Furthermore, the hRSV nucleoprotein has been shown to inhibit the immunological synapsis between the dendritic cells and T cells during infection, resulting in an inefficient T cell activation. Here, we discuss the hRSV virulence factors and the host immunological features raised during infection with this virus.https://www.frontiersin.org/articles/10.3389/fcimb.2017.00367/ful
The 25 October 2010 Mentawai tsunami earthquake (M_w 7.8) and the tsunami hazard presented by shallow megathrust ruptures
The 25 October 2010 Mentawai, Indonesia earthquake (M_w 7.8) ruptured the shallow portion of the subduction zone seaward of the Mentawai islands, off-shore of Sumatra, generating 3 to 9 m tsunami run-up along southwestern coasts of the Pagai Islands that took at least 431 lives. Analyses of teleseismic P, SH and Rayleigh waves for finite-fault source rupture characteristics indicate ∼90 s rupture duration with a low rupture velocity of ∼1.5 km/s on the 10° dipping megathrust, with total slip of 2–4 m over an ∼100 km long source region. The seismic moment-scaled energy release is 1.4 × 10^(−6), lower than 2.4 × 10^(−6) found for the 17 July 2006 Java tsunami earthquake (M_w 7.8). The Mentawai event ruptured up-dip of the slip region of the 12 September 2007 Kepulauan earthquake (M_w 7.9), and together with the 4 January 1907 (M 7.6) tsunami earthquake located seaward of Simeulue Island to the northwest along the arc, demonstrates the significant tsunami generation potential for shallow megathrust ruptures in regions up-dip of great underthrusting events in Indonesia and elsewhere
- …
