7,415 research outputs found
rPICARD: A CASA-based Calibration Pipeline for VLBI Data
Currently, HOPS and AIPS are the primary choices for the time-consuming
process of (millimeter) Very Long Baseline Interferometry (VLBI) data
calibration. However, for a full end-to-end pipeline, they either lack the
ability to perform easily scriptable incremental calibration or do not provide
full control over the workflow with the ability to manipulate and edit
calibration solutions directly. The Common Astronomy Software Application
(CASA) offers all these abilities, together with a secure development future
and an intuitive Python interface, which is very attractive for young radio
astronomers. Inspired by the recent addition of a global fringe-fitter, the
capability to convert FITS-IDI files to measurement sets, and amplitude
calibration routines based on ANTAB metadata, we have developed the the
CASA-based Radboud PIpeline for the Calibration of high Angular Resolution Data
(rPICARD). The pipeline will be able to handle data from multiple arrays: EHT,
GMVA, VLBA and the EVN in the first release. Polarization and phase-referencing
calibration are supported and a spectral line mode will be added in the future.
The large bandwidths of future radio observatories ask for a scalable reduction
software. Within CASA, a message passing interface (MPI) implementation is used
for parallelization, reducing the total time needed for processing. The most
significant gain is obtained for the time-consuming fringe-fitting task where
each scan be processed in parallel.Comment: 6 pages, 1 figure, EVN 2018 symposium proceeding
The challenge of valuing ecosystem services that have no material benefits
Since the Millennium Ecosystem Assessment, ecosystem service science has made much progress in framing core concepts and approaches, but there is still debate around the notion of cultural services, and a growing consensus that ecosystem use and ecosystem service use should be clearly differentiated. Part of the debate resides in the fact that the most significant sources of conflict around natural resource management arise from the multiple managements (uses) of ecosystems, rather than from the multiple uses of ecosystem services. If the ecosystem approach or the ecosystem service paradigm are to be implemented at national levels, there is an urgent need to disentangle what are often semantic issues, revise the notion of cultural services, and more broadly, practically define the less tangible ecosystem services on which we depend. This is a critical step to identifying suitable ways to manage trade-offs and promote adaptive management. Here we briefly review the problems associated with defining and quantifying cultural ecosystem services and suggest there could be merit in discarding this term for the simpler non-material ecosystem services. We also discuss the challenges in valuing the invaluable, and suggest that if we are to keep ecosystem service definition focused on the beneficiary, we need to further classify these challenging services, for example by differentiating services to individuals from services to communities. Also, we suggest that focussing on ecosystem service change rather than simply service delivery, and identifying common boundaries relevant for both people and ecosystems, would help meet some of these challenges
Suxibuzona en la clínica canina
Los procesos patológicos y secuelas originadas por traumatismos, esfuerzos, choques, intervenciones quirúrgicas, etc., que dan lugar a dolor, inflamación e incluso fiebre, son frecuentes en la clínica canina. En la resolución de este tipo de procesos resulta útil y necesaria una terapéutica antiinflamtoria que, aún siendo sintomática, los resuelve por si sola en muchos casos o hacen su pronóstico mucho más favorable, o bien complementan eficazmente los tratamientos quirúrgicos correspondientes. Un nuevo antiinflamatorio, análgesico y antipirético en clínica canina, denominado Suxibuzona, ha sido experimentado por vía oral con resultados satisfactorios en el tratamiento de procesos traumáticos, miositis-reumatismo, nueralgías y afecciones osteoarticulares
Preoperative neutrophil-lymphocyte ratio and outcome from coronary artery bypass grafting
Background: An elevated preoperative white blood cell count has been associated with a worse outcome after coronary artery bypass grafting (CABG). Leukocyte subtypes, and particularly the neutrophil-lymphocyte (N/L) ratio, may however, convey superior prognostic information. We hypothesized that the N/L ratio would predict the outcome of patients undergoing surgical revascularization. Methods: Baseline clinical details were obtained prospectively in 1938 patients undergoing CABG. The differential leukocyte was measured before surgery, and patients were followed-up 3.6 years later. The primary end point was all-cause mortality. Results: The preoperative N/L ratio was a powerful univariable predictor of mortality (hazard ratio [HR] 1.13 per unit, P 3.36). Conclusion: An elevated N/L ratio is associated with a poorer survival after CABG. This prognostic utility is independent of other recognized risk factors.Peer reviewedAuthor versio
Condensation of Silica Nanoparticles on a Phospholipid Membrane
The structure of the transient layer at the interface between air and the
aqueous solution of silica nanoparticles with the size distribution of
particles that has been determined from small-angle scattering has been studied
by the X-ray reflectometry method. The reconstructed depth profile of the
polarizability of the substance indicates the presence of a structure
consisting of several layers of nanoparticles with the thickness that is more
than twice as large as the thickness of the previously described structure. The
adsorption of 1,2-distearoyl-sn-glycero-3-phosphocholine molecules at the
hydrosol/air interface is accompanied by the condensation of anion silica
nanoparticles at the interface. This phenomenon can be qualitatively explained
by the formation of the positive surface potential due to the penetration and
accumulation of Na+ cations in the phospholipid membrane.Comment: 7 pages, 5 figure
Elastic energy of polyhedral bilayer vesicles
In recent experiments [M. Dubois, B. Dem\'e, T. Gulik-Krzywicki, J.-C.
Dedieu, C. Vautrin, S. D\'esert, E. Perez, and T. Zemb, Nature (London) Vol.
411, 672 (2001)] the spontaneous formation of hollow bilayer vesicles with
polyhedral symmetry has been observed. On the basis of the experimental
phenomenology it was suggested [M. Dubois, V. Lizunov, A. Meister, T.
Gulik-Krzywicki, J. M. Verbavatz, E. Perez, J. Zimmerberg, and T. Zemb, Proc.
Natl. Acad. Sci. U.S.A. Vol. 101, 15082 (2004)] that the mechanism for the
formation of bilayer polyhedra is minimization of elastic bending energy.
Motivated by these experiments, we study the elastic bending energy of
polyhedral bilayer vesicles. In agreement with experiments, and provided that
excess amphiphiles exhibiting spontaneous curvature are present in sufficient
quantity, we find that polyhedral bilayer vesicles can indeed be energetically
favorable compared to spherical bilayer vesicles. Consistent with experimental
observations we also find that the bending energy associated with the vertices
of bilayer polyhedra can be locally reduced through the formation of pores.
However, the stabilization of polyhedral bilayer vesicles over spherical
bilayer vesicles relies crucially on molecular segregation of excess
amphiphiles along the ridges rather than the vertices of bilayer polyhedra.
Furthermore, our analysis implies that, contrary to what has been suggested on
the basis of experiments, the icosahedron does not minimize elastic bending
energy among arbitrary polyhedral shapes and sizes. Instead, we find that, for
large polyhedron sizes, the snub dodecahedron and the snub cube both have lower
total bending energies than the icosahedron
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