9,641 research outputs found
Constraining ultra large-scale cosmology with multiple tracers in optical and radio surveys
Multiple tracers of the cosmic density field, with different bias, number and
luminosity evolution, can be used to measure the large-scale properties of the
Universe. We show how an optimal combination of tracers can be used to detect
general-relativistic effects in the observed density of sources. We forecast
for the detectability of these effects, as well as measurements of primordial
non-Gaussianity and large-scale lensing magnification with current and upcoming
large-scale structure experiments. In particular we quantify the significance
of these detections in the short term with experiments such as the Dark Energy
Survey (DES), and in the long term with the Large Synoptic Survey Telescope
(LSST) and the Square Kilometre Array (SKA). We review the main observational
challenges that must be overcome to carry out these measurements.Comment: 19 pages, 10 figure
Reconstructing cosmic growth with kSZ observations in the era of Stage IV experiments
Future ground-based CMB experiments will generate competitive large-scale
structure datasets by precisely characterizing CMB secondary anisotropies over
a large fraction of the sky. We describe a method for constraining the growth
rate of structure to sub-1% precision out to , using a combination
of galaxy cluster peculiar velocities measured using the kinetic
Sunyaev-Zel'dovich (kSZ) effect, and the velocity field reconstructed from
galaxy redshift surveys. We consider only thermal SZ-selected cluster samples,
which will consist of sources for Stage 3 and 4 CMB
experiments respectively. Three different methods for separating the kSZ effect
from the primary CMB are compared, including a novel blind "constrained
realization" method that improves signal-to-noise by a factor of over
a commonly-used aperture photometry technique. Measurements of the integrated
tSZ -parameter are used to break the kSZ velocity-optical depth degeneracy,
and the effects of including CMB polarization and SZ profile uncertainties are
also considered. A combination of future Stage 4 experiments should be able to
measure the product of the growth and expansion rates, , to
better than 1% in bins of out to -- competitive
with contemporary redshift-space distortion constraints from galaxy surveys.Comment: 16 pages, 8 figure
Malaria: deploying a candidate vaccine (RTS,S/AS02A) for an old scourge of humankind
Malaria is an infectious disease caused by the protist Plasmodium spp. and it currently kills more than one million people annually. The burden of malaria is concentrated in sub-Saharan Africa, India, and Southeast Asia. The parasite’s resistance to commonly used anti-malarial drugs has worsened the situation in the poorest countries. The World Health Organization (WHO) estimates that more than 100 countries suffer from endemic malaria episodes. In addition to numerous control measures and treatments, several vaccines are at different research stages and trials. We have assayed RTS,S/AS02A, a pre-erythrocytic candidate vaccine that has shown promising protection levels in phase IIb trials in Mozambique. The vaccine is directed against the sporozoite form of the parasite, which is injected by the mosquito Anopheles spp. The vaccine induces a strong antibody response and stimulates Th1 cells—a subset of helper T cells that participates in cell-mediated immunity. Recent interest by international funding agencies has provided new inputs into initiatives and programs to fight malaria, which, under normal welfare and adequate social development conditions, is a curable disease. [Int Microbiol 2006; 9(2):83-93
La empresa informativa busca nuevos modelos de negocio
Old business model traditionally used in media, based on reader or consumer collection and advertising revenue is insufficient to sustain media companies. It is necessary to reinvent this business model to allow media survive in our new online multi-product and globalized media market.El modelo de negocio tradicionalmente empleado en los medios informativos, basado en el cobro al lector o consumidor y en los ingresos publicitarios, resulta insuficiente para poder sostener la empresa informativa. Es necesario reinventar el modelo de negocio, buscando un sistema que permita a los medios subsistir en el nuevo mercado mediático online, con multiproducto y globalizado
Discretization-dependent model for weakly connected excitable media
Pattern formation has been widely observed in extended chemical and biological processes. Although the biochemical systems are highly heterogeneous, homogenized continuum approaches formed by partial differential equations have been employed frequently. Such approaches are usually justified by the difference of scales between the heterogeneities and the characteristic spatial size of the patterns. Under different conditions, for example, under weak coupling, discrete models are more adequate. However, discrete models may be less manageable, for instance, in terms of numerical implementation and mesh generation, than the associated continuum models. Here we study a model to approach discreteness which permits the computer implementation on general unstructured meshes. The model is cast as a partial differential equation but with a parameter that depends not only on heterogeneities sizes, as in the case of quasicontinuum models, but also on the discretization mesh. Therefore, we refer to it as a discretization-dependent model. We validate the approach in a generic excitable media that simulates three different phenomena: the propagation of action membrane potential in cardiac tissue, in myelinated axons of neurons, and concentration waves in chemical microemulsions.We acknowledge the support from CAPES, grant
88881.065002/2014-01 of the Brazilian program Science
without borders, FAPEMIG, CNPq, UFJF, and from
MINECO of Spain under the Ramon y Cajal program,
grant number RYC-2012-11265Peer ReviewedPostprint (published version
Regional Workshop on Co-management in Small-Scale Fisheries: Lessons Learned and Best Practices 12-13 December 2012, Bangkok, Thailand
An FAO project, the Regional Fisheries Livelihoods Programme, which is funded by Spain, has worked with the Timorese authorities and coastal communities to build local capacity and put in place effective methods to gather a variety of important fisheries data. This is used to help make important decisions relating to the management of the nation's fisheries sector. These actions, which are detailed in this publication, have been carried out at relatively little expense and in a participatory manner that has engaged communities while at the same time providing practical skills to all involved
Analysis of the Machining Process of Inconel 718 Parts Manufactured by Laser Metal Deposition
Laser metal deposition (LMD) is an additive manufacturing process that allows the manufacturing of near-net-shape products. This could mean significant savings in terms of materials and costs in the manufacturing of high-performance components for the aeronautical industry. In this work, an analysis of how the LMD processing of alloy 718 affects the final machining has been carried out. For this purpose, a comparative study has been done by means of the monitoring of the end milling process of a part manufactured by LMD and a rough-milled part from forged material. Differences between process outputs such as chip morphology and cutting forces were studied. Material characteristics such as microstructure, hardness and mechanical properties were also analyzed.This research was funded by European Commission grant number 723440 (PARADDISE project), which is an initiative of the Photonics and Factories of the Future Public Private Partnership, and by the Vice-Counselor of Technology, Innovation and Competitiveness of the Basque Government grant number KK-2018/00115 (ADDISEND project) and grant number KK-2019/00004 (PROCODA project)
Modelling, simulation and experimental verification of a wheeled-locomotion system based on omnidirectional wheels
The following work focuses on the kinematic and dynamic study of a four-wheeled robot,
which is equipped with omnidirectional Mecanum wheels. The main objective of the
thesis is to obtain a mathematical model from which both the kinematics and kinetics of
the robot can be analyzed. Furthermore, the study presents a methodology to optimize
the torques (and subsequent associated voltages) provided by each of the motors on the
robot for a given trajectory.
A system in which a non-powered trailer pulled by the robot is also analyzed at a
kinematic level. In this stage, four different cases are considered. The construction of the
trailer is also described on this work.
In the first chapter, the global state of the art on analysis and control of omnidirectional
robots (with focus on robots with Mecanum wheels) is presented. In the second chapter,
the physical considerations for the general movement of the robot are analyzed, in order
to derive the kinematic constrain equations of the locomotion system. The differential
equation of motion is then derived using Lagrange-equations with multipliers. This
chapter presents as well the kinematic analysis for a robot-trailer system. The third
chapter describes the general process on the design of the trailer, including the rejected
ideas for its construction. The fourth chapter focuses on verifying the final results of the
design process, as well as tests to check the mobility of the system. Conclusions and
future work are analyzed on the final part of the document, as well as the references and
the acknowledgments to all the people involved in the project.Tesi
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