222 research outputs found
Structure and magnetic order in Fe2+xV1-xAl
We present a detailed structural investigation via neutron diffraction of
differently heat treated samples Fe2VAl and Fe2+xV1-xAl. Moreover, the magnetic
behaviour of these materials is studied by means of mSR and
Mossbauer-experiments. Our structural investigation indicates that quenched
Fe2VAl, exhibiting the previously reported "Kondo insulating like" behaviour,
is off-stoichiometric (6%) in its Al content. Slowly cooled Fe2VAl is
structurally better ordered and stoichiometric, and the microscopic magnetic
probes establish long range ferromagnetic order below TC = 13K, consistent with
results from bulk experiments. The magnetic state can be modelled as being
generated by diluted magnetic ions in a non-magnetic matrix. Quantitatively,
the required number of magnetic ions is too large as to be explained by a model
of Fe/V site exchange. We discuss the implications of our findings for the
ground state properties of Fe2VAl, in particular with respect to the role of
crystallographic disorder.Comment: accepted for publication in J. Phys.: Condens. Matte
The emergence of integrated information, complexity, and \u27consciousness\u27 at criticality
© 2020 by the authors. Integrated Information Theory (IIT) posits that integrated information (F) represents the quantity of a conscious experience. Here, the generalized Ising model was used to calculate F as a function of temperature in toy models of fully connected neural networks. A Monte-Carlo simulation was run on 159 normalized, random, positively weighted networks analogous to small five-node excitatory neural network motifs. Integrated information generated by this sample of small Ising models was measured across model parameter spaces. It was observed that integrated information, as an order parameter, underwent a phase transition at the critical point in the model. This critical point was demarcated by the peak of the generalized susceptibility (or variance in configuration due to temperature) of integrated information. At this critical point, integrated information was maximally receptive and responsive to perturbations of its own states. The results of this study provide evidence that F can capture integrated information in an empirical dataset, and display critical behavior acting as an order parameter from the generalized Ising model
Public health training in internal medicine residency programs: a national survey
BACKGROUND:
The IOM recommends public health training for all physicians. Data characterizing such training of internal medicine (IM) residents are lacking. PURPOSE:
To describe the current state of public health education at IM residency programs, characterize programs offering public health education, and quantify interest in expanding training opportunities. METHODS:
IM residency program directors from the 380 Accreditation Council for Graduate Medical Education-accredited residency programs in the U.S were invited to participate in a cross-sectional survey. Responses were received from 127 programs (33%). Data were collected July-December 2012 and analyzed in January 2013. Participants were queried on domestic public health training offered, perceived resident interest in and satisfaction with this training, and interest in expanding training. RESULTS:
Eighty-four respondents (66%) provide some form of public health training, but structure and content vary widely. In many programs offering public health training, few residents (\u3c10%) receive it. Although 93 programs (73%) integrate public health into core curricula, only three topics were common to a majority of these programs. Sixty-six respondents (52%) offer clinical training at community-based health centers. Most residency program directors (90%) are very or somewhat interested in expanding their public health training. CONCLUSIONS:
This study characterizes the structures and content of public health training across IM residency programs. The wide range highlights the diverse definition of public health training used by IM residency program directors and lack of universal public health competencies required for IM physicians. Opportunities exist for collaboration among residency programs and between IM and public health educators to share best practices
Third Bose Fugacity Coefficient in One Dimension, as a Function of Asymptotic Quantities
In one of the very few exact quantum mechanical calculations of fugacity
coefficients, Dodd and Gibbs (\textit{J. Math.Phys}.,\textbf{15}, 41 (1974))
obtained and for a one dimensional Bose gas, subject to
repulsive delta-function interactions, by direct integration of the wave
functions. For , we have shown (\textit{Mol. Phys}.,\textbf{103}, 1301
(2005)) that Dodd and Gibbs' result can be obtained from a phase shift
formalism, if one also includes the contribution of oscillating terms, usually
contributing only in 1 dimension. Now, we develop an exact expression for
(where is the free particle fugacity coefficient)
in terms of sums and differences of 3-body eigenphase shifts. Further, we show
that if we obtain these eigenphase shifts in a distorted-Born approximation,
then, to first order, we reproduce the leading low temperature behaviour,
obtained from an expansion of the two-fold integral of Dodd and Gibbs. The
contributions of the oscillating terms cancel. The formalism that we propose is
not limited to one dimension, but seeks to provide a general method to obtain
virial coefficients, fugacity coefficients, in terms of asymptotic quantities.
The exact one dimensional results allow us to confirm the validity of our
approach in this domain.Comment: 29 page
Spontaneous splenic rupture due to Plasmodium Falciparum-nonoperative management
Universitatea de Medicină și Farmacie “Carol Davila”, București, Clinica Chirurgie, Spitalul de Urgență, București, Al XI-lea Congres al Asociației Chirurgilor „Nicolae Anestiadi” din Republica Moldova și cea de-a XXXIII-a Reuniune a Chirurgilor din Moldova „Iacomi-Răzeșu” 27-30 septembrie 2011Introducere. Ruptura spontană a splinei malarice (Plasmodium Falciparum) este o complicație rară fiind frecvent asociată cu malaria
cauzată de Plasmodium Vivax. Material și metode. Lucrarea prezintă cazul unui pacient de 30 de ani internat de urgență prin transfer
de la Spitalul Clinic de Boli Infecțioase cu diagnosticul ruptura spontană de splină patologică (malarică), hemoperitoneu mare tratat
nonoperator (angioembolizare splenică proximală).Rezultate. Evoluție favorabilaă cu recuperare compleăa.Concluzii. Ruptura splinei malarice poate fi tratată nonoperator cu succes iar prezervarea acesteia trebuie sa fie obiectivul tratamentului. Pentru stabilirea precoce a
diagnosticului este necesar un indice ridicat de suspiciune pentru evitarea unor consecințe catastrofale.Introduction Spontaneous rupture of malarial spleen due to Plasmodium Falciparum is uncommon. It is most frequently associated with Plasmodium
Vivax malaria. Material and methodsWe report the case of a 30-years old male transferred to our hospital from Clinical Hospital of Infectious and
Tropical Diseases. He was admitted with the diagnosis of spontaneous splenic rupture and large haemoperitoneum. Because the hemodynamic stability
we decided a nonoperative management and performed a proximal splenic angioembolization.ResultsThe evolution was uneventful and the patient
was discharged on day 14th.ConcluziiRupture of the pathologic spleen do heal and attempt at splenic salvage should be the aim in management. A high
index of suspicion of splenic rupture is imperative because delay in diagnosis may lead to catastrophic consequences
Exploring electroencephalography with a model inspired by quantum mechanics.
An outstanding issue in cognitive neuroscience concerns how the brain is organized across different conditions. For instance, during the resting-state condition, the brain can be clustered into reliable and reproducible networks (e.g., sensory, default, executive networks). Interestingly, the same networks emerge during active conditions in response to various tasks. If similar patterns of neural activity have been found across diverse conditions, and therefore, different underlying processes and experiences of the environment, is the brain organized by a fundamental organizational principle? To test this, we applied mathematical formalisms borrowed from quantum mechanisms to model electroencephalogram (EEG) data. We uncovered a tendency for EEG signals to be localized in anterior regions of the brain during "rest", and more uniformly distributed while engaged in a task (i.e., watching a movie). Moreover, we found analogous values to the Heisenberg uncertainty principle, suggesting a common underlying architecture of human brain activity in resting and task conditions. This underlying architecture manifests itself in the novel constant KBrain, which is extracted from the brain state with the least uncertainty. We would like to state that we are using the mathematics of quantum mechanics, but not claiming that the brain behaves as a quantum object
Invariant higher-order variational problems II
Motivated by applications in computational anatomy, we consider a
second-order problem in the calculus of variations on object manifolds that are
acted upon by Lie groups of smooth invertible transformations. This problem
leads to solution curves known as Riemannian cubics on object manifolds that
are endowed with normal metrics. The prime examples of such object manifolds
are the symmetric spaces. We characterize the class of cubics on object
manifolds that can be lifted horizontally to cubics on the group of
transformations. Conversely, we show that certain types of non-horizontal
geodesics on the group of transformations project to cubics. Finally, we apply
second-order Lagrange--Poincar\'e reduction to the problem of Riemannian cubics
on the group of transformations. This leads to a reduced form of the equations
that reveals the obstruction for the projection of a cubic on a transformation
group to again be a cubic on its object manifold.Comment: 40 pages, 1 figure. First version -- comments welcome
Integrated modeling and validation for phase change with natural convection
Water-ice systems undergoing melting develop complex spatio-temporal
interface dynamics and a non-trivial temperature field. In this contribution,
we present computational aspects of a recently conducted validation study that
aims at investigating the role of natural convection for cryo-interface
dynamics of water-ice. We will present a fixed grid model known as the enthalpy
porosity method. It is based on introducing a phase field and employs mixture
theory. The resulting PDEs are solved using a finite volume discretization. The
second part is devoted to experiments that have been conducted for model
validation. The evolving water-ice interface is tracked based on optical images
that shows both the water and the ice phase. To segment the phases, we use a
binary Mumford Shah method, which yields a piece-wise constant approximation of
the imaging data. Its jump set is the reconstruction of the measured phase
interface. Our combined simulation and segmentation effort finally enables us
to compare the modeled and measured phase interfaces continuously. We conclude
with a discussion of our findings
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