5,992 research outputs found
Lift-and-project ranks of the stable set polytope of joined a-perfect graphs
In this paper we study lift-and-project polyhedral operators defined by
Lov?asz and Schrijver and Balas, Ceria and Cornu?ejols on the clique relaxation
of the stable set polytope of web graphs. We compute the disjunctive rank of
all webs and consequently of antiweb graphs. We also obtain the disjunctive
rank of the antiweb constraints for which the complexity of the separation
problem is still unknown. Finally, we use our results to provide bounds of the
disjunctive rank of larger classes of graphs as joined a-perfect graphs, where
near-bipartite graphs belong
Mutation of the Ser18 phosphorylation site on the sole Saccharomyces cerevisiae UCS protein, She4, can compromise high-temperature survival.
Folding of the myosin head often requires the joint actions of Hsp90 and a dedicated UNC45, Cro1, She4 (UCS) domain-containing cochaperone protein. Relatively weak sequence conservation exists between the single UCS protein of simple eukaryotes (She4 in budding yeast) and the two UCS proteins of higher organisms (the general cell and smooth muscle UNC45s; UNC45-GC and UNC45-SM respectively). In vertebrates, UNC45-GC facilitates cytoskeletal function whereas the 55% identical UNC45-SM assists in the assembly of the contractile apparatus of cardiac and skeletal muscles. UNC45-SM, unlike UNC45-GC, shares with yeast She4 an IDSL sequence motif known to be a site of in vivo serine phosphorylation in yeast. Investigating this further, we found that both a non-phosphorylatable (S18A) and a phosphomimetic (S18E) mutant form of She4 could rescue the type 1 myosin localisation and endocytosis defects of the yeast she4Δ mutant at 39 °C. Nevertheless, at higher temperature (45 °C), only She4 (S18A), not She4(S18E), could substantially rescue the cell lysis defect of she4Δ mutant cells. In the yeast two-hybrid system, the non-phosphorylatable S18A and S251A mutant forms of She4 and UNC45-SM still displayed the stress-enhanced in vivo interaction with Hsp90 seen with the wild-type She4 and UNC45-SM. Such high-temperature enforcement to interaction was though lost with the phosphomimetic mutant forms (She4(S18E) and UNC45-SM (S251E)), an indication that phosphorylation might suppress these increases in She4/Hsp90 and UNC45-SM/Hsp90 interaction with stress
Origins of Human Malaria: Rare Genomic Changes and Full Mitochondrial Genomes Confirm the Relationship of Plasmodium falciparum to Other Mammalian Parasites but Complicate the Origins of Plasmodium vivax
Despite substantial work, the phylogeny of malaria parasites remains debated. The matter is complicated by concerns about patterns of evolution in potentially strongly selected genes as well as the extreme AT bias of some Plasmodium genomes. Particularly contentious has been the position of the most virulent human parasite Plasmodium falciparum, whether grouped with avian parasites or within a larger clade of mammalian parasites. Here, we study 3 classes of rare genomic changes, as well as the sequences of mitochondrial ribosomal RNA (rRNA) genes. We report 3 lines of support for a clade of mammalian parasites: 1) we find no instances of spliceosomal intron loss in a hypothetical ancestor of P. falciparum and the avian parasite Plasmodium gallinaceum, suggesting against a close relationship between those species; 2) we find 4 genomic mitochondrial indels supporting a mammalian clade, but none grouping P. falciparum with avian parasites; and 3) slowly evolving mitochondrial rRNA sequences support a mammalian parasite clade with 100% posterior probability. We further report a large deletion in the mitochondrial large subunit rRNA gene, which suggests a subclade including both African and Asian parasites within the clade of closely related primate malarias. This contrasts with previous studies that provided strong support for separate Asian and African clades, and reduces certainty about the historical and geographic origins of Plasmodium vivax. Finally, we find a lack of synapomorphic gene losses, suggesting a low rate of ancestral gene loss in Plasmodium
Optimizing the Resolution of Hydrodynamic Simulations for MCRaT Radiative Transfer Calculations
Despite their discovery about half a century ago, the Gamma-ray burst (GRB)
prompt emission mechanism is still not well understood. Theoretical modeling of
the prompt emission has advanced considerably due to new computational tools
and techniques. One such tool is the PLUTO hydrodynamics code, which is used to
numerically simulate GRB outflows. PLUTO uses Adaptive Mesh Refinement to focus
computational efforts on the portion of the grid that contains the simulated
jet. Another tool is the Monte Carlo Radiation Transfer (MCRaT) code, which
predicts electromagnetic signatures of GRBs by conducting photon scatterings
within a jet using PLUTO. The effects of the underlying resolution of a PLUTO
simulation with respect to MCRaT post-processing radiative transfer results
have not yet been quantified. We analyze an analytic spherical outflow and a
hydrodynamically simulated GRB jet with MCRaT at varying spatial and temporal
resolutions and quantify how decreasing both resolutions affect the resulting
mock observations. We find that changing the spatial resolution changes the
hydrodynamic properties of the jet, which directly affect the MCRaT mock
observable peak energies. We also find that decreasing the temporal resolution
artificially decreases the high energy slope of the mock observed spectrum,
which increases both the spectral peak energy and the luminosity. We show that
the effects are additive when both spatial and temporal resolutions are
modified. Our results allow us to understand how decreased hydrodynamic
temporal and spatial resolutions affect the results of post-processing
radiative transfer calculations, allowing for the optimization of hydrodynamic
simulations for radiative transfer codes.Comment: 12 pages, 10 figures, submitted to ApJ, for calculations, see:
https://github.com/jaritaes99/MCRaT-resolutio
Reversal of hepatorenal syndrome type 1 with terlipressin plus albumin vs. placebo plus albumin in a pooled analysis of the OT-0401 and REVERSE randomised clinical studies
Background
The goal of hepatorenal syndrome type 1 (HRS-1) treatment is to improve renal function. Terlipressin, a synthetic vasopressin analogue, is a systemic vasoconstrictor used for the treatment of HRS-1, where it is available. Aim
To compare the efficacy of terlipressin plus albumin vs. placebo plus albumin in patients with HRS-1. Methods
Pooled patient-level data from two large phase 3, randomised, placebo-controlled studies were analysed for HRS reversal [serum creatinine (SCr) value ≤133 μmol/L], 90-day survival, need for renal replacement therapy and predictors of HRS reversal. Patients received intravenous terlipressin 1–2 mg every 6 hours plus albumin or placebo plus albumin up to 14 days. Results
The pooled analysis comprised 308 patients (terlipressin: n = 153; placebo: n = 155). HRS reversal was significantly more frequent with terlipressin vs. placebo (27% vs. 14%; P = 0.004). Terlipressin was associated with a more significant improvement in renal function from baseline until end of treatment, with a mean between-group difference in SCr concentration of −53.0 μmol/L (P \u3c 0.0001). Lower SCr, lower mean arterial pressure and lower total bilirubin and absence of known precipitating factors for HRS were independent predictors of HRS reversal and longer survival in terlipressin-treated patients. Conclusions
Terlipressin plus albumin resulted in a significantly higher rate of HRS reversal vs. albumin alone in patients with HRS-1. Terlipressin treatment is associated with improved renal function
Inflation with a constant ratio of scalar and tensor perturbation amplitudes
The single scalar field inflationary models that lead to scalar and tensor
perturbation spectra with amplitudes varying in direct proportion to one
another are reconstructed by solving the Stewart-Lyth inverse problem to
next-to-leading order in the slow-roll approximation.
The potentials asymptote at high energies to an exponential form,
corresponding to power law inflation, but diverge from this model at low
energies, indicating that power law inflation is a repellor in this case. This
feature implies that a fine-tuning of initial conditions is required if such
models are to reproduce the observations. The required initial conditions might
be set through the eternal inflation mechanism.
If this is the case, it will imply that the spectral indices must be nearly
constant, making the underlying model observationally indistinguishable from
power law inflation.Comment: 20 pages, 7 figures. Major changes to the Introduction following
referee's comments. One figure added. Some other minor changes. No conclusion
was modifie
Memory as a human right in Argentina: a reconstruction based on critical theory
Para la teoría crítica de los derechos humanos, la memoria se ha convertido en un instrumento eficaz y necesario para visibilizar a las víctimas y condenar una parte de nuestra historia. La importancia de la memoria como derecho humano recae en su doble dimensión, actúa como reparación de las víctimas y sus familiares evitando el olvido que se traduce en impunidad, y como garantía de no repetición, ya que promueve la creación de una conciencia o memoria colectiva en aquellos países que transitan periodos de justicia transicional.
Sin embargo, el derecho humano a la memoria no ha sido reconocido explícitamente por la normativa y jurisprudencia internacional y nacional, como sí lo fue el derecho a la verdad íntimamente relacionado con el primero como se expone a lo largo del texto. En este trabajo se realizará una aproximación a su reconstrucción desde la teoría crítica asumida y, se indagarán las políticas públicas adoptadas en Argentina que permitan concluir el estado de reconocimiento del derecho a la memoria en el país. La metodología utilizada consiste en el análisis documental del material bibliográfico y normativo pertinente que permita definir conceptos y parámetros mediante el análisis de textos.For the critical theory of human rights, memory has become an effective and necessary instrument to make victims visible and condemn a part of our history. The importance of memory as a human right falls on its double dimension, it acts as reparation for victims and their families, avoiding forgetfulness that results in impunity, and as a guarantee of non-repetition, since it promotes the creation of a collective conscience or memory in those countries that go through periods of transitional justice.
However, the Human Right to Memory has not been explicitly recognized by international and national regulations and jurisprudence, in contrast to the situation of the right to the truth -closely related to the first- and exposed throughout the text. Finally, in in this article we will reconstruct based on critical theory and the public policies adopted in Argentina will be investigated to conclude the status of recognition of the right to memory in the country. The methodology used consists of the documentary analysis of the pertinent bibliographic and normative material.Facultad de Ciencias Jurídicas y Sociale
La memoria como derecho humano en Argentina: una reconstrucción desde la teoría crítica
For the critical theory of human rights, memory has become an effective and necessary instrument to make victims visible and condemn a part of our history. The importance of memory as a human right falls on its double dimension, it acts as reparation for victims and their families, avoiding forgetfulness that results in impunity, and as a guarantee of non-repetition, since it promotes the creation of a collective conscience or memory in those countries that go through periods of transitional justice.
However, the Human Right to Memory has not been explicitly recognized by international and national regulations and jurisprudence, in contrast to the situation of the right to the truth -closely related to the first- and exposed throughout the text. Finally, in in this article we will reconstruct based on critical theory and the public policies adopted in Argentina will be investigated to conclude the status of recognition of the right to memory in the country. The methodology used consists of the documentary analysis of the pertinent bibliographic and normative material.Para la teoría crítica de los derechos humanos, la memoria se ha convertido en un instrumento eficaz y necesario para visibilizar a las víctimas y condenar una parte de nuestra historia. La importancia de la memoria como derecho humano recae en su doble dimensión, actúa como reparación de las víctimas y sus familiares evitando el olvido que se traduce en impunidad, y como garantía de no repetición, ya que promueve la creación de una conciencia o memoria colectiva en aquellos países que transitan periodos de justicia transicional.
Sin embargo, el derecho humano a la memoria no ha sido reconocido explícitamente por la normativa y jurisprudencia internacional y nacional, como sí lo fue el derecho a la verdad íntimamente relacionado con el primero como se expone a lo largo del texto. En este trabajo se realizará una aproximación a su reconstrucción desde la teoría crítica asumida y, se indagarán las políticas públicas adoptadas en Argentina que permitan concluir el estado de reconocimiento del derecho a la memoria en el país. La metodología utilizada consiste en el análisis documental del material bibliográfico y normativo pertinente que permita definir conceptos y parámetros mediante el análisis de textos
Vía navegable de Santa Fe al océano
Incluye los siguientes temas:
Hidrovía Paraná Paraguay
Vías Navegables en Argentina
Buques
Portacontenedores
Buques tanque
Car carrier
Cruceros
Buques tanque con GNL
Buques graneleros
Cargas
La vía navegable, situación actual.
Impacto ambiental
Puerto de Buenos Aires, Río de La Plata, salida al océano
Embarcaciones de la concesión
Peaje en los costos portuariosAcademia de la Ingeniería de la provincia de Buenos Aire
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