3,246 research outputs found
Cross correlation surveys with the Square Kilometre Array
By the time that the first phase of the Square Kilometre Array is deployed it
will be able to perform state of the art Large Scale Structure (LSS) as well as
Weak Gravitational Lensing (WGL) measurements of the distribution of matter in
the Universe. In this chapter we concentrate on the synergies that result from
cross-correlating these different SKA data products as well as external
correlation with the weak lensing measurements available from CMB missions. We
show that the Dark Energy figures of merit obtained individually from WGL/LSS
measurements and their independent combination is significantly increased when
their full cross-correlations are taken into account. This is due to the
increased knowledge of galaxy bias as a function of redshift as well as the
extra information from the different cosmological dependences of the
cross-correlations. We show that the cross-correlation between a spectroscopic
LSS sample and a weak lensing sample with photometric redshifts can calibrate
these same photometric redshifts, and their scatter, to high accuracy by
modelling them as nuisance parameters and fitting them simultaneously
cosmology. Finally we show that Modified Gravity parameters are greatly
constrained by this cross-correlations because weak lensing and redshift space
distortions (from the LSS survey) break strong degeneracies in common
parameterisations of modified gravity.Comment: 12 pages, 3 figures. This article is part of the 'Cosmology Chapter,
Advancing Astrophysics with the SKA (AASKA14) Conference, Giardini Naxos
(Italy), June 9th-13th 2014
A Streamline-Upwind Petrov-Galerkin Finite Element Scheme for Non-Ionized Hypersonic Flows in Thermochemical Nonequilibrium
Presentation topics include background and motivation; physical modeling including governing equations and thermochemistry; finite element formulation; results of inviscid thermal nonequilibrium chemically reacting flow and viscous thermal equilibrium chemical reacting flow; and near-term effort
Review of Orbiter Flight Boundary Layer Transition Data
In support of the Shuttle Return to Flight program, a tool was developed to predict when boundary layer transition would occur on the lower surface of the orbiter during reentry due to the presence of protuberances and cavities in the thermal protection system. This predictive tool was developed based on extensive wind tunnel tests conducted after the loss of the Space Shuttle Columbia. Recognizing that wind tunnels cannot simulate the exact conditions an orbiter encounters as it re-enters the atmosphere, a preliminary attempt was made to use the documented flight related damage and the orbiter transition times, as deduced from flight instrumentation, to calibrate the predictive tool. After flight STS-114, the Boundary Layer Transition Team decided that a more in-depth analysis of the historical flight data was needed to better determine the root causes of the occasional early transition times of some of the past shuttle flights. In this paper we discuss our methodology for the analysis, the various sources of shuttle damage information, the analysis of the flight thermocouple data, and how the results compare to the Boundary Layer Transition prediction tool designed for Return to Flight
Momento Económico (6)
Temas de hoy, 2/ Benjamín Retckiman Kirk:
Ambigüedad de los informes gubernamentales,
3/ ¿Magia de los números?, 6/ Arturo Ortíz
Wadgymar: El sector externo durante 1983, 7/
Saharí Angeles Cornejo: La política monetaria en
1983, 1O/ Carlos Morera: La política financiera
durante 1983, 13/ Bernardo Navarro B. y Jesús
Rodríguez L.: El transporte público, subsidio a las
mayorías o "realismo económico", 1
A systems biology approach to invasive behavior: comparing cancer metastasis and suburban sprawl development
Background
Despite constant progress, cancer remains the second leading cause of death in the United States. The ability of tumors to metastasize is central to this dilemma, as many studies demonstrate successful treatment correlating to diagnosis prior to cancer spread. Hence a better understanding of cancer invasiveness and metastasis could provide critical insight. Presentation of the hypothesis
We hypothesize that a systems biology-based comparison of cancer invasiveness and suburban sprawl will reveal similarities that are instructive. Testing the hypothesis
We compare the structure and behavior of invasive cancer to suburban sprawl development. While these two systems differ vastly in dimension, they appear to adhere to scale-invariant laws consistent with invasive behavior in general. We demonstrate that cancer and sprawl have striking similarities in their natural history, initiating factors, patterns of invasion, vessel distribution and even methods of causing death. Implications of the hypothesis
We propose that metastatic cancer and suburban sprawl provide striking analogs in invasive behavior, to the extent that conclusions from one system could be predictive of behavior in the other. We suggest ways in which this model could be used to advance our understanding of cancer biology and treatment
Projected -SNE for batch correction
Biomedical research often produces high-dimensional data confounded by batch
effects such as systematic experimental variations, different protocols and
subject identifiers. Without proper correction, low-dimensional representation
of high-dimensional data might encode and reproduce the same systematic
variations observed in the original data, and compromise the interpretation of
the results. In this article, we propose a novel procedure to remove batch
effects from low-dimensional embeddings obtained with t-SNE dimensionality
reduction. The proposed methods are based on linear algebra and constrained
optimization, leading to efficient algorithms and fast computation in many
high-dimensional settings. Results on artificial single-cell transcription
profiling data show that the proposed procedure successfully removes multiple
batch effects from t-SNE embeddings, while retaining fundamental information on
cell types. When applied to single-cell gene expression data to investigate
mouse medulloblastoma, the proposed method successfully removes batches related
with mice identifiers and the date of the experiment, while preserving clusters
of oligodendrocytes, astrocytes, and endothelial cells and microglia, which are
expected to lie in the stroma within or adjacent to the tumors.Comment: 16 pages, 3 figure
Cosmology from HI galaxy surveys with the SKA
The Square Kilometer Array (SKA) has the potential to produce galaxy redshift surveys which
will be competitive with other state of the art cosmological experiments in the next decade. In this
chapter we summarise what capabilities the first and the second phases of the SKA will be able
to achieve in its current state of design. We summarise the different cosmological experiments
which are outlined in further detail in other chapters of this Science Book. The SKA will be
able to produce competitive Baryonic Oscillation (BAOs) measurements in both its phases. The
first phase of the SKA will provide similar measurements in optical and IR experiments with
completely different systematic effects whereas the second phase being transformational in terms
of its statistical power. The SKA will produce very accurate Redshift Space Distortions (RSD)
measurements, being superior to other experiments at lower redshifts, due to the large number
of galaxies. Cross correlations of the galaxy redshift data from the SKA with radio continuum
surveys and optical surveys will provide extremely good calibration of photometric redshifts as
well as extremely good bounds on modifications of gravity. Basing on a Principle Component
Analysis (PCA) approach, we find that the SKA will be able to provide competitive constraint
on dark energy and modified gravity models. Due to the large area covered the SKA it will be a
transformational experiment in measuring physics from the largest scales such as non-Gaussian
signals. Finally, the SKA might produce the first real time measurement of the redshift
drift. The SKA will be a transformational machine for cosmology as it grows from an early Phase
1 to its full power
A prospective cohort study assessing clinical referral management & workforce allocation within a UK regional medical genetics service
Abstract
Ensuring patient access to genomic information in the face of increasing demand requires clinicians to develop innovative ways of working. This paper presents the first empirical prospective observational cohort study of UK multi-disciplinary genetic service delivery. It describes and explores collaborative working practices including the utilisation and role of clinical geneticists and non-medical genetic counsellors. Six hundred and fifty new patients referred to a regional genetics service were tracked through 850 clinical contacts until discharge. Referral decisions regarding allocation of lead health professional assigned to the case were monitored, including the use of initial clinical contact guidelines. Significant differences were found in the cases led by genetic counsellors and those led by clinical geneticists. Around a sixth, 16.8% (109/650) of referrals were dealt with by a letter back to the referrer or re-directed to another service provider and 14.8% (80/541) of the remaining patients chose not to schedule an appointment. Of the remaining 461 patients, genetic counsellors were allocated as lead health professional for 46.2% (213/461). A further 61 patients did not attend. Of those who did, 86% (345/400) were discharged after one or two appointments. Genetic counsellors contributed to 95% (784/825) of total patient contacts. They provided 93.7% (395/432) of initial contacts and 26.8% (106/395) of patients were discharged at that point. The information from this study informed a planned service re-design. More research is needed to assess the effectiveness and efficiency of different models of collaborative multi-disciplinary working within genetics services. Keywords (MeSH terms)
Genetic Services, Genetic Counseling, Interdisciplinary Communication, Cohort Studies, Delivery of Healthcare, Referral and Consultation
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