1,170 research outputs found
Evidence of package trading in a mature multi-species ITQ market
In multi-species fisheries managed under ITQs, the existence of joint production may lead to complex catch-quota balancing issues. Previous modelling and experimental research suggest that, in such fisheries, some fishers may benefit from the ability to trade packages of fishing quotas, rather than fulfil their quota needs by simultaneously bidding on separate single-species quota markets. This note presents evidence of naturally occurring package trades in a real fishery. Based on this evidence, we suggest that further empirical and modelling research is required on the potential and limitations of package quota trading in mixed fisheries managed with ITQs. © 2014
Induced ferromagnetism in Mn3N2 phase embedded in Mn/Si3N4 multilayers
Room temperature ferromagnetism has been obtained for different sets of Mn/Si3N4 multilayers
prepared by sputtering. In order to find the most suitable conditions to stabilize the ferromagnetic
ordering in this system, the evolution of the magnetic properties has been studied for films in which
the Si3N4 layer thickness was maintained constant while that of the Mn layer was varied,
Mn tm/Si3N4 3.4 nm n, and conversely, in Mn 0.7 nm/Si3N4 tsn 43 samples, in which the Mn
layer thickness was kept constant while varying the Si3N4 layer thickness. Structural, compositional,
electronic and magnetic characterizations have been performed by means of x-ray reflectometry,
Rutherford backscattering spectrometry, x-ray photoemission spectroscopy, x-ray absorption, and
superconducting quantum interference device for further knowledge of the magnetic-structural
relationship in this system. Our results show that the peculiar magnetic behavior of these films is
mainly related to the stabilization of a slightly distorted Mn3N2 phase that is induced by the Si3N4
at the interfaces. For samples with larger Mn layer thickness, metallic Mn and Mn3N2 phases
coexist, which leads to a reduction of the total magnetization per Mn atom due to the presence of
metallic Mn. For small Mn layer thickness tm 0.86 nm, where noncontinuous Mn3N2 layers are
formed, the magnetization decreases noticeably due to the superparamagnetic size limit. It has been
found that the best conditions for the stabilization of the ferromagnetism in this system occur when
both, the manganese-rich and the silicon nitride layers, are continuous and with similar thickness,
close to 3.5 nm.Ministerio de Educación y Ciencia de España-MAT2006-01004, MAT2008-06542-C04-01, MAT2008-06765-C02-02, S-0505/MAT/0194, Consolider 2010_26400 y Nanoselect CSD2007-0004
The Recent Star Formation History of NGC 5102
We present Hubble Space Telescope photometry of young stars in NGC 5102, a
nearby gas-rich post-starburst S0 galaxy with a bright young stellar nucleus.
We use the IAC-pop/MinnIAC algorithm to derive the recent star formation
history in three fields in the bulge and disk of NGC 5102. In the disk fields,
the recent star formation rate has declined monotonically and is now barely
detectable, but a starburst is still in progress in the bulge and has added
about 2 percent to the mass of the bulge over the last 200 Myr. Other studies
of star formation in NGC 5102 indicate that about 20 percent of its stellar
mass was added over the past Gyr. If this is correct, then much of the stellar
mass of the bulge may have formed over this period. It seems likely that this
star formation was fueled by the accretion of a gas-rich system with HI mass of
about 2 x 10^9 Msol which has now been almost completely converted into stars.
The large mass of recently formed stars and the blue colours of the bulge
suggest that the current starburst, which is now fading, may have made a
significant contribution to build the bulge of NGC 5102.Comment: 36 pages, 16 figures, accepted in A
Differential symptom weighting in estimating empirical thresholds for underlying PTSD severity: Toward a “platinum” standard for diagnosis?
Objective: Symptom counts as the basis for Post-Traumatic Stress Disorder (PTSD) diagnoses in the DSM presume each symptom is equally reflective of underlying disorder severity. However, the “equal weight” assumption fails to fit PTSD symptom data when tested. The present study developed an enhanced PTSD diagnosis based on (a) a conventional PTSD diagnosis from a clinical interview and (b) an empirical classification of full PTSD that reflected the relative clinical weights of each symptom.
Method: Baseline structured interview data from Project Harmony (N = 2658) was used. An enhanced diagnosis for full PTSD was estimated using an empirical threshold from moderated nonlinear factor analysis (MNLFA) latent PTSD scale scores, in combination with a full conventional PTSD diagnosis based on interview data.
Results: One in 4 patients in the sample had a PTSD diagnosis that was inconsistent with their empirical PTSD grouping, such that the enhanced diagnostic standard reduced the diagnostic discrepancy rate by 20%. Veterans, and in particular female Veterans, were at greatest odds for discrepancy between their underlying PTSD severity and DSM diagnosis.
Conclusion: Psychometric methodologies that differentially weight symptoms can complement DSM criteria and may serve as a platform for symptom prioritization for diagnoses in future editions of DSM
Chagas disease in Latin American migrants: a Spanish challenge
AbstractChagas’ disease affects millions in Latin America and is the leading cause of cardiomyopathy and death due to cardiovascular disease in patients aged 30–50 years. As a consequence of immigration it has settled in several European countries, where besides imported cases, autochthonous infections arise through vertical transmission and blood/organ donation. All Latin American immigrants who attended our Unit were screened for T. cruzi infection (ELISA and IFAT ± PCR). An ECG and echocardiogram were requested for all positive patients, and oesophageal manometry, barium swallow and barium enema were requested according to patient symptoms. All patients under 50 years without severe cardiac involvement and who had not received correct treatment previously were treated with benznidazole 5 mg/kg/day for 60 days. Patients were followed-up with serology and PCR 1 month after treatment ended and every 6 months thereafter. A total of 1146 Latin Americans were screened for T. cruzi (357 positive serology results). The typical patient profile was a Bolivian female, of rural origin, in her fourth decade of life, without evidence of visceral involvement. Treatment tolerance was poor, with 29.7% discontinuing treatment due to adverse reactions. Among those with adverse reactions (52%), the most frequent were cutaneous hypersensitivity (68.7%), gastrointestinal upset (20%) and nervous system disturbances (16.2%). T. cruzi infection is no longer limited to Latin America. Poor treatment tolerance can limit current treatment options. More epidemiological data are necessary to estimate the magnitude of a problem of great relevance for public health and health resource planning
Interplay among critical temperature, hole content, and pressure in the cuprate superconductors
Within a BCS-type mean-field approach to the extended Hubbard model, a
nontrivial dependence of T_c on the hole content per unit CuO_2 is recovered,
in good agreement with the celebrated non-monotonic universal behaviour at
normal pressure. Evaluation of T_c at higher pressures is then made possible by
the introduction of an explicit dependence of the tight-binding band and of the
carrier concentration on pressure P. Comparison with the known experimental
data for underdoped Bi2212 allows to single out an `intrinsic' contribution to
d T_c / d P from that due to the carrier concentration, and provides a
remarkable estimate of the dependence of the inter-site coupling strength on
the lattice scale.Comment: REVTeX 8 pages, including 5 embedded PostScript figures; other
required macros included; to be published in Phys. Rev. B (vol. 54
Moisture content modeling and effective moisture diffusivity determination during convective solar drying of blackberry (rubus spp) and basil (Ocimum basilicum L.)
[EN] The goal of reducing energy consumption (EC), losses and waste (FL) in the food processing is a challenges in the worldwide. The use of active solar greenhouse dryers (GHD) for EC and FL reductions has increased due to its capacity, and low operating costs. In this work the effective diffusivity (Deff) and the moisture content modeling were analized for basil (Ocimum basilicum) and blackberry pulp (Rubus rosoideae) dried in a conventional stove (CD) and an GHD coupled to an additional air solar heating system (SCHa). The loss of water and the drying rate in food materials dehydrated in the GHD is consistent with the increment or decrement of temperature during the solar day. The Deff values for basil and blackberry pulp was ranged between -1.1044x10-7 and -3.9167x10-9. The solar energy obtained in the GHD supplied the heating requirements. In general, the Page’s model was the best fit for the drying kinetics for basil and blackberry pulp.López-Ortiz, A.; Gallardo-Brígido, JC.; Silva-Norman, A.; Pilatowsky-Figueroa, I.; García-Valladares, O.; Rodríguez-Ramírez, J. (2018). Moisture content modeling and effective moisture diffusivity determination during convective solar drying of blackberry (rubus spp) and basil (Ocimum basilicum L.). En IDS 2018. 21st International Drying Symposium Proceedings. Editorial Universitat Politècnica de València. 505-512. https://doi.org/10.4995/IDS2018.2018.7841OCS50551
The Milky Way Bulge: Observed properties and a comparison to external galaxies
The Milky Way bulge offers a unique opportunity to investigate in detail the
role that different processes such as dynamical instabilities, hierarchical
merging, and dissipational collapse may have played in the history of the
Galaxy formation and evolution based on its resolved stellar population
properties. Large observation programmes and surveys of the bulge are providing
for the first time a look into the global view of the Milky Way bulge that can
be compared with the bulges of other galaxies, and be used as a template for
detailed comparison with models. The Milky Way has been shown to have a
box/peanut (B/P) bulge and recent evidence seems to suggest the presence of an
additional spheroidal component. In this review we summarise the global
chemical abundances, kinematics and structural properties that allow us to
disentangle these multiple components and provide constraints to understand
their origin. The investigation of both detailed and global properties of the
bulge now provide us with the opportunity to characterise the bulge as observed
in models, and to place the mixed component bulge scenario in the general
context of external galaxies. When writing this review, we considered the
perspectives of researchers working with the Milky Way and researchers working
with external galaxies. It is an attempt to approach both communities for a
fruitful exchange of ideas.Comment: Review article to appear in "Galactic Bulges", Editors: Laurikainen
E., Peletier R., Gadotti D., Springer Publishing. 36 pages, 10 figure
Multi-particle azimuthal correlations in p-Pb and Pb-Pb collisions at the CERN Large Hadron Collider
Measurements of multi-particle azimuthal correlations (cumulants) for charged
particles in p-Pb and Pb-Pb collisions are presented. They help address the
question of whether there is evidence for global, flow-like, azimuthal
correlations in the p-Pb system. Comparisons are made to measurements from the
larger Pb-Pb system, where such evidence is established. In particular, the
second harmonic two-particle cumulants are found to decrease with multiplicity,
characteristic of a dominance of few-particle correlations in p-Pb collisions.
However, when a gap is placed to suppress such correlations,
the two-particle cumulants begin to rise at high-multiplicity, indicating the
presence of global azimuthal correlations. The Pb-Pb values are higher than the
p-Pb values at similar multiplicities. In both systems, the second harmonic
four-particle cumulants exhibit a transition from positive to negative values
when the multiplicity increases. The negative values allow for a measurement of
to be made, which is found to be higher in Pb-Pb collisions at
similar multiplicities. The second harmonic six-particle cumulants are also
found to be higher in Pb-Pb collisions. In Pb-Pb collisions, we generally find
which is indicative of a Bessel-Gaussian
function for the distribution. For very high-multiplicity Pb-Pb
collisions, we observe that the four- and six-particle cumulants become
consistent with 0. Finally, third harmonic two-particle cumulants in p-Pb and
Pb-Pb are measured. These are found to be similar for overlapping
multiplicities, when a gap is placed.Comment: 25 pages, 11 captioned figures, 3 tables, authors from page 20,
published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/87
Multiplicity dependence of jet-like two-particle correlations in p-Pb collisions at = 5.02 TeV
Two-particle angular correlations between unidentified charged trigger and
associated particles are measured by the ALICE detector in p-Pb collisions at a
nucleon-nucleon centre-of-mass energy of 5.02 TeV. The transverse-momentum
range 0.7 5.0 GeV/ is examined,
to include correlations induced by jets originating from low
momen\-tum-transfer scatterings (minijets). The correlations expressed as
associated yield per trigger particle are obtained in the pseudorapidity range
. The near-side long-range pseudorapidity correlations observed in
high-multiplicity p-Pb collisions are subtracted from both near-side
short-range and away-side correlations in order to remove the non-jet-like
components. The yields in the jet-like peaks are found to be invariant with
event multiplicity with the exception of events with low multiplicity. This
invariance is consistent with the particles being produced via the incoherent
fragmentation of multiple parton--parton scatterings, while the yield related
to the previously observed ridge structures is not jet-related. The number of
uncorrelated sources of particle production is found to increase linearly with
multiplicity, suggesting no saturation of the number of multi-parton
interactions even in the highest multiplicity p-Pb collisions. Further, the
number scales in the intermediate multiplicity region with the number of binary
nucleon-nucleon collisions estimated with a Glauber Monte-Carlo simulation.Comment: 23 pages, 6 captioned figures, 1 table, authors from page 17,
published version, figures at
http://aliceinfo.cern.ch/ArtSubmission/node/161
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