1,347 research outputs found
Simultaneous analysis of elastic scattering and transfer/breakup channels for the 6He+208Pb reaction at energies near the Coulomb barrier
The elastic and alpha-production channels for the 6He+208Pb reaction are
investigated at energies around the Coulomb barrier (E_{lab}=14, 16, 18, 22,
and 27 MeV). The effect of the two-neutron transfer channels on the elastic
scattering has been studied within the Coupled-Reaction-Channels (CRC) method.
We find that the explicit inclusion of these channels allows a simultaneous
description of the elastic data and the inclusive alpha cross sections at
backward angles. Three-body Continuum-Discretized Coupled-Channels (CDCC)
calculations are found to reproduce the elastic data, but not the
transfer/breakup data. The trivially-equivalent local polarization potential
(TELP) derived from the CRC and CDCC calculations are found to explain the
features found in previous phenomenological optical model calculations for this
system.Comment: 7 pages, 6 figures (replaced with updated version
Integrated soil degradation analysis of tierra de Barros region (Badajoz, Spain).
This study assesses the soil degradalion in Tierra de Barros region (Badajoz province, Spain (280.900 ha). The sludy emphasizes on lhe soil susceptibilily to sealing and crusting, compactation and soilloss by water erosion
Four-body continuum-discretized coupled-channels calculations
The development of a continuum-bins scheme of discretization for three-body
projectiles is necessary for studies of reactions of Borromean nuclei such as
6He within the continuum-discretized coupled-channels approach. Such a
procedure, for constructing bin states on selected continuum energy intervals,
is formulated and applied for the first time to reactions of a three-body
projectile. The continuum representation uses the eigenchannel expansion of the
three-body S-matrix. The method is applied to the challenging case of the 6He +
208Pb reaction at 22 MeV, where an accurate treatment of both the Coulomb and
the nuclear interactions with the target is necessary.Comment: To be published in Phys. Rev. C (R) (5 pages, 5 figures, 1 table
The Right to Code and Share Arms
Glycerol is, to date, the most widely used cryoprotectant to freeze stallion spermatozoa at concentrations between 2% and 5%. Cryoprotectant toxicity has been claimed to be the single most limiting factor for the success of cryopreservation. In order to evaluate the toxic effects of the concentrations of glycerol used in practice, stallion spermatozoa were incubated in Biggers Whitten and Whittingham (BWW) media supplemented with 0%, 0.5%, 1.5%, 2.5%, 3.5%, and 5% glycerol. In two additional experiments, a hyposmotic (75 mOsm/kg) and a hyperosmotic (900 mOsm/kg) control media were included. Sperm parameters evaluated included cell volume, membrane integrity, lipid peroxidation, caspase 3, 7, and 8 activation, mitochondrial membrane potential, and integrity of the cytoskeleton. Glycerol exerted toxicity at concentrations 3.5% and the maximal toxicity was observed at 5%. The actin cytoskeleton was especially sensitive to glycerol presence, inducing rapid F actin depolymerization at concentrations over 1.5%. The sperm membrane and the mitochondria were other structures affected. The toxicity of glycerol is apparently related to osmotic and nonosmotic effects. In view of our results the concentration of glycerol in the freezing media for stallion spermatozoa should not surpass 2.5%.Funding Agencies|Ministerio de Ciencia e Innovacion-FEDER Madrid, Spain|AGL 2010 20758 (GAN)|Inia|RZ2008-00018-00-00|Junta de Extremadura FEDER GR|10010
Effectiveness of Exercise on Fatigue and Sleep Quality in Fibromyalgia: A Systematic Review and Meta-analysis of Randomized Trials
Objectives: To determine the effects of exercise on fatigue and sleep quality in fibromyalgia (primary aim) and to identify which type of exercise
is the most effective in achieving these outcomes (secondary aim).
Data Sources: PubMed and Web of Science were searched from inception until October 18, 2018.
Study Selection: Eligible studies contained information on population (fibromyalgia), intervention (exercise), and outcomes (fatigue or sleep).
Randomized controlled trials (RCT) testing the effectiveness of exercise compared with usual care and randomized trials (RT) comparing the
effectiveness of 2 different exercise interventions were included for the primary and secondary aims of the present review, respectively. Two
independent researchers performed the search, screening, and final eligibility of the articles. Of 696 studies identified, 17 RCTs (nZ1003) were
included for fatigue and 12 RCTs (nZ731) for sleep. Furthermore, 21 RTs compared the effectiveness of different exercise interventions (nZ1254).
Data Extraction: Two independent researchers extracted the key information from each eligible study.
Data Synthesis: Separate random-effect meta-analyses were performed to examine the effects from RCTs and from RTs (primary and secondary
aims). Standardized mean differences (SMD) effect sizes were calculated using Hedges’ adjusted g. Effect sizes of 0.2, 0.4, and 0.8 were considered
small, moderate, and large. Compared with usual care, exercise had moderate effects on fatigue and a small effect on sleep quality (SMD, e0.47; 95%
confidence interval [CI], e0.67 to e0.27; P<.001 and SMD, e0.17; 95% CI, e0.32 to e0.01; PZ.04). RTs in which fatigue was the primary outcome
were the most beneficial for lowering fatigue. Additionally, meditative exercise programs were the most effective for improving sleep quality.
Conclusions: Exercise is moderately effective for lowering fatigue and has small effects on enhancing sleep quality in fibromyalgia. Meditative
exercise programs may be considered for improving sleep quality in fibromyalgi
La gran erupción de hace 4.2 ka cal en Cerro Blanco, Zona Volcánica Central, Andes: nuevos datos sobre los depósitos eruptivos holocenos en la Puna sur y regiones adyacentes
The eruption of the Cerro Blanco Volcanic Complex, in the southern Puna, NW Argentina dated at 4410–4150 a cal BP, was investigated to produce new information on stratigraphy, geomorphology, physical volcanology, radiocarbon dating, petrography, and geochemistry. Identification of pre–, syn–, and post–caldera products allowed us to estimate the distribution of the Plinian fallout during the paroxysmal syn–caldera phase of the eruption. The new results provide evidence for a major rhyolitic explosive eruption that spread volcanic deposits over an area of ~500,000 km2, accumulating > 100 km3 of tephra (bulk volume). This last value exceeds the lower threshold of Volcanic Explosive Index (VEI) of 7. Ash-fall deposits mantled the region at distances > 400 km from source and thick pyroclastic-flow deposits filled neighbouring valleys up to 35 km away. This eruption is the largest documented during the past five millennia in the Central Volcanic Zone of the Andes, and is probably one of the largest Holocene explosive eruptions in the world. We have also identified two additional rhyolitic eruptions in the region from two other eruptive sources: one during the Early–Holocene and another in the Late–Holocene. The identification and characterisation of these significant volcanic events provide new constraints into regional Holocene geological and archaeological records, and offer extensive regional chronostratigraphic markers over a wide geographical area of South America.La erupción del Complejo Volcánico Cerro Blanco en el sur de la Puna, noroeste de Argentina (4410–4150 a BP) se investigó para obtener nueva información sobre estratigrafía, geomorfología, volcanología física, dataciones por radiocarbono, petrografía y geoquímica. La caracterización de los productos en relación a la evolución de la caldera de Cerro Blanco permitió estimar la distribución de los depósitos de ceniza de la fase paroxísmica Plineana de la erupción. Estos novedosos resultados evidencian una gran erupción explosiva riolítica que generó depósitos cineríticos en un área de aproximadamente 500.000 km2, acumulando > 100 km3 de tefra (volumen total). Este último valor supera el umbral inferior del Índice de Explosividad Volcánica (IEV) de 7. Los depósitos de caída de ceniza cubrieron la región, llegando a más de 400 km desde el Complejo Volcánico de Cerro Blanco, y los potentes depósitos de flujos piroclásticos rellenaron los valles vecinos alcanzando una distancia de 35 km. Esta erupción es la más grande documentada durante los últimos cinco milenios en la Zona Volcánica Central de los Andes y es probablemente una de las mayores erupciones explosivas holocenas del mundo. Además, se han identificado otras dos erupciones riolíticas en la región procedentes de otros dos centros eruptivos: una durante el Holoceno temprano y otra en el Holoceno tardío. La identificación y caracterización de estos grandes eventos volcánicos proporcionan nuevas guías para los registros geológicos y arqueológicos regionales del Holoceno, siendo marcadores cronostratigráficos de aplicación a una extensa área geográfica de América del Sur
Different Methods for the Two-Nucleon T-Matrix in the Operator Form
We compare three methods to calculate the nucleon-nucleon t-matrix based on
the three-dimensional formulation of J. Golak et al., Phys. Rev. C 81, 034006,
(2010). In the first place we solve a system of complex linear inhomogeneous
equations directly for the t-matrix. Our second method is based on iterations
and a variant of the Lanczos algorithm. In the third case we obtain the
t-matrix in two steps, solving a system of real linear equations for the
k-matrix expansion coefficients and then solving an on-shell equation, which
connects the scalar coefficients of the k- and t-matrices. A very good
agreement among the three methods is demonstrated for selected nucleon-nucleon
scattering observables using a chiral next-to-next-to-leading-order
neutron-proton potential. We also apply our three-dimensional framework to the
demanding problem of proton-proton scattering, using a corresponding version of
the nucleon-nucleon potential and supplementing it with the (screened) Coulomb
force, taken also in the three-dimensional form. We show converged results for
two different screening functions and find a very good agreement with other
methods dealing with proton-proton scattering.Comment: 18 pages, 10 figures (54 eps files
DNA Vaccination Partially Protects against African Swine Fever Virus Lethal Challenge in the Absence of Antibodies
The lack of available vaccines against African swine fever virus (ASFV) means that the evaluation of new immunization strategies is required. Here we show that fusion of the extracellular domain of the ASFV Hemagglutinin (sHA) to p54 and p30, two immunodominant structural viral antigens, exponentially improved both the humoral and the cellular responses induced in pigs after DNA immunization. However, immunization with the resulting plasmid (pCMV-sHAPQ) did not confer protection against lethal challenge with the virulent E75 ASFV-strain. Due to the fact that CD8+ T-cell responses are emerging as key components for ASFV protection, we designed a new plasmid construct, pCMV-UbsHAPQ, encoding the three viral determinants above mentioned (sHA, p54 and p30) fused to ubiquitin, aiming to improve Class I antigen presentation and to enhance the CTL responses induced. As expected, immunization with pCMV-UbsHAPQ induced specific T-cell responses in the absence of antibodies and, more important, protected a proportion of immunized-pigs from lethal challenge with ASFV. In contrast with control pigs, survivor animals showed a peak of CD8+ T-cells at day 3 post-infection, coinciding with the absence of viremia at this time point. Finally, an in silico prediction of CTL peptides has allowed the identification of two SLA I-restricted 9-mer peptides within the hemagglutinin of the virus, capable of in vitro stimulating the specific secretion of IFNγ when using PBMCs from survivor pigs. Our results confirm the relevance of T-cell responses in protection against ASF and open new expectations for the future development of more efficient recombinant vaccines against this disease
- …