1,504 research outputs found
An Integro-Differential Conservation Law arising in a Model of Granular Flow
We study a scalar integro-differential conservation law. The equation was
first derived in [2] as the slow erosion limit of granular flow. Considering a
set of more general erosion functions, we study the initial boundary value
problem for which one can not adapt the standard theory of conservation laws.
We construct approximate solutions with a fractional step method, by
recomputing the integral term at each time step. A-priori L^\infty bounds and
BV estimates yield convergence and global existence of BV solutions.
Furthermore, we present a well-posedness analysis, showing that the solutions
are stable in L^1 with respect to the initial data
Idiopathic thrombocytopenic purpura: current concepts in pathophysiology and management.
Idiopathic thrombocytopenic purpura (ITP) is characterized by
a low platelet count, which is the result of both increased pla-
telet destruction and insufficient platelet production. Although
the development of autoantibodies against platelet glycoproteins remains central in the pathophysiology of ITP, several abnormalities involving the cellular mechanisms of immune modu-
lation have been identified. Conventional treatments for ITP aim
at reducing platelet destruction, either by immunosuppression or splenectomy. Two new thrombopoietic agents,AMG 531 and eltrombopag, have been used in clinical trials to stimulate platelet production in ITP patients not responsive to standard
treatments. These new molecules bear no structural resemblance to thrombopoietin, but still bind and activate the thrombopoietin receptor. This review will focus on the pathophysiology and treatment of ITP in adults, highlighting recent advances
in both fields
The boundary Riemann solver coming from the real vanishing viscosity approximation
We study a family of initial boundary value problems associated to mixed
hyperbolic-parabolic systems:
v^{\epsilon} _t + A (v^{\epsilon}, \epsilon v^{\epsilon}_x ) v^{\epsilon}_x =
\epsilon B (v^{\epsilon} ) v^{\epsilon}_{xx}
The conservative case is, in particular, included in the previous
formulation.
We suppose that the solutions to these problems converge to a
unique limit. Also, it is assumed smallness of the total variation and other
technical hypotheses and it is provided a complete characterization of the
limit.
The most interesting points are the following two.
First, the boundary characteristic case is considered, i.e. one eigenvalue of
can be .
Second, we take into account the possibility that is not invertible. To
deal with this case, we take as hypotheses conditions that were introduced by
Kawashima and Shizuta relying on physically meaningful examples. We also
introduce a new condition of block linear degeneracy. We prove that, if it is
not satisfied, then pathological behaviours may occur.Comment: 84 pages, 6 figures. Text changes in Sections 1 and 3.2.3. Added
Section 3.1.2. Minor changes in other section
Trade Statistics of the Zollverein, 1834-1871
The purpose of this paper is to highlight the fact that the lack of useable German trade statistics for the period preceding the German political unifica- tion is not a fatality. The documents published during the Zollverein period by the Central Bureau of the Zollverein, the Statistische Uebersichten uÌber Waaren- Verkehr und Zoll-Ertrag im Deutschen Zoll-Vereine fuÌr das Jahr..., do not provide prices nor trade flows in value nor any indication of countries of ultimate origin and destination. To overcome these imperfections, a great number of estimates of Zollverein trade statistics have been published since 1842 but they are ques- tionable as well. Nevertheless, the good quality of Statistische UÌbersichtenâs quantity data should make possible the reconstruction of consistent series of German trade, total, by product and in value, over the period 1834-1871
New Insight on Medieval Painting in Sicily: The Virgin Hodegetria Panel in Monreale Cathedral (Palermo, Italy)
: The Virgin Hodegetria, located in the Cathedral of Santa Maria Nuova in Monreale, near
Palermo (Italy), probably dating the first half of the 13th century, is one of the earliest examples
of medieval panel painting in Sicily. A diagnostic campaign was carried out on the panel aiming
to identify the constituting materials and the executive technique, as well as to assess the state of
conservation for supporting the methodological choice of the restoration intervention. Both non invasive (X-ray radiography, digital microscope, multispectral imaging, ED-X-ray fluorescence) and
micro-invasive (polarised light microscopy, ESEM-EDX, ATR-FTIR spectroscopy and micro-Raman
spectroscopy) analyses were performed. According to the results, the executive technique followed
the 13thâ14th-century Italian painting tradition. A complex structure was applied on the wooden
support, consisting of a double layer of canvas and several ground layers of gypsum and glue based binder. The underdrawing was made by a brush using carbonaceous black pigment. The
original palette includes red ochre, red lead, azurite, carbon black and bone black. During the several
restorations, mercury-based red, indigo, smalt blue, orpiment and synthetic mars were used. The
original silver leaf of the frame was covered with red tin-based lake and subsequently regilded with
gold leaf. Proteinaceous and oil binders were also detecte
Cross-species infectivity of H3N8 influenza virus in an experimental infection in swine
Avian influenza A viruses have gained increasing attention due to their ability to cross the species barrier and cause severe disease
in humans and other mammal species as pigs. H3 and particularly H3N8 viruses, are highly adaptive since they are found in
multiple avian and mammal hosts. H3N8 viruses have not been isolated yet from humans; however, a recent report showed that
equine influenza A viruses (IAVs) can be isolated from pigs, although an established infection has not been observed thus far in
this host. To gain insight into the possibility of H3N8 avian IAVs to cross the species barrier into pigs, in vitro experiments and
an experimental infection in pigs with four H3N8 viruses from different origins (equine, canine, avian, and seal) were performed.
As a positive control, an H3N2 swine influenza virus A was used. Although equine and canine viruses hardly replicated
in the respiratory systems of pigs, avian and seal viruses replicated substantially and caused detectable lesions in inoculated pigs
without previous adaptation. Interestingly, antibodies against hemagglutinin could not be detected after infection by hemagglutination
inhibition (HAI) test with avian and seal viruses. This phenomenon was observed not only in pigs but also in mice immunized
with the same virus strains. Our data indicated that H3N8 IAVs from wild aquatic birds have the potential to cross the
species barrier and establish successful infections in pigs that might spread unnoticed using the HAI test as diagnostic tool.We thank Jaime Maldonado and HIPRA (Spain) for the A/Swine/Spain/
54008/2004 (H3N2) strain, Edward J. Dubovi and Cornell University for
the A/Canine/NY/105447/08 (H3N8) IAV strain, T. M. Chambers and the
University of Kentucky for the A/Equine/OH/1/03 (H3N8) IAV strain,
and Hon Ip and the U.S. Geological Survey National Wildlife Health
Center for the A/American black duck/Maine/44411-532/2008 (H3N8)
and the A/Harbor Seal/New Hampshire/179629/2011 (H3N8) IAV
strains. We thank Sergio LĂłpez, David Solanes, Francisco X. Abad, Jordi
Alberola, Jaume Martorell, and Eduard J. Cunilleras for help in providing
different samples and during the experimental infections, as well as the
personnel in Cat3 laboratories and the animal house. We thank Adolfo
GarcĂa-Sastre for providing materials and for support as the principal
investigator of the NIAID-funded Center for Research in Influenza Pathogenesis
(HHSN266200700010C).
The research leading to these results received funding from the European
Communityâs Seventh Framework Programme (FP7, 2007-2013),
the Research Infrastructures Action under grant FP7-228393 (a NADIR
project), and projects AGL2010-22200-C02-01 and AGL2007-60274 of
the Spanish Ministry of Science and Innovation
A Semi-Lagrangian scheme for a modified version of the Hughes model for pedestrian flow
In this paper we present a Semi-Lagrangian scheme for a regularized version
of the Hughes model for pedestrian flow. Hughes originally proposed a coupled
nonlinear PDE system describing the evolution of a large pedestrian group
trying to exit a domain as fast as possible. The original model corresponds to
a system of a conservation law for the pedestrian density and an Eikonal
equation to determine the weighted distance to the exit. We consider this model
in presence of small diffusion and discuss the numerical analysis of the
proposed Semi-Lagrangian scheme. Furthermore we illustrate the effect of small
diffusion on the exit time with various numerical experiments
La traduction dans une perspective de genre. Enjeux politiques, Ă©ditoriaux et professionnels
Cet ouvrage sâinscrit dans le cadre thĂ©orique de la traduction conçue dans une perspective de genre, un contexte qui sous-tend que la langue nâest jamais neutre, et que tout acte de langage a une dimension politique et des retombĂ©es du point de vue culturel et social. Les essais quâil propose abordent quelques sujets majeurs dans ce domaine. Le livre sâouvre avec une rĂ©flexion de nature gĂ©nĂ©rale sur la circulation difficile au niveau transnational de la terminologie et de certains concepts des Ă©tudes de genre ainsi que sur les problĂšmes posĂ©s par leur traduction. Dans le cadre dâune rĂ©flexion attentive Ă la dimension professionnelle, lâexpĂ©rience de Barbara Bray, mĂ©diatrice interculturelle pour la BBC, est ensuite prĂ©sentĂ©e comme un acte politique dâengagement dâune traductrice dâexception. La question du âgender biasâ dans la traduction automatique, un enjeu quâil est dĂ©sormais indispensable dâaffronter, fait lâobjet dâune analyse visant Ă en cerner les causes et Ă suggĂ©rer des solutions possibles. Ces essais sont suivis dâĂ©tudes qui se penchent sur lâĂ©dition de textes littĂ©raires traduits et sâintĂ©ressent en particulier aux enjeux de la traduction du langage non binaire, ainsi quâaux politiques Ă©ditoriales de diverses maisons dâĂ©dition de littĂ©rature jeunesse. Ces deux domaines, qui nâont Ă©tĂ© abordĂ©s par les Ă©tudes de genre que trĂšs rĂ©cemment, ouvrent des perspectives de recherche nouvelles et fĂ©condes
- âŠ