589 research outputs found
Effective Sample Size: Quick Estimation of the Effect of Related Samples in Genetic Case-Control Association Analyses
Correlated samples have been frequently avoided in case-control
genetic association
 studies in part because the methods for handling them are either not
easily implemented or not widely known. We
advocate one method for case-control association analysis of correlated
samples -- the effective sample size method -- as a simple and
accessible approach that does not require specialized computer programs.
The effective sample size method captures the variance inflation
of allele frequency estimation exactly, and can be used to modify the
chi-square test statistic, p-value, and 95% confidence interval of
odds-ratio simply by replacing the apparent number of allele counts with the
effective ones. For genotype frequency estimation, although a single
effective sample size is unable to completely characterize the variance inflation,
an averaged one can satisfactorily approximate the simulated result.
The effective sample size method is applied to the rheumatoid arthritis
siblings data collected from the North American Rheumatoid Arthritis Consortium (NARAC)
to establish a significant association with the interferon-induced
helicasel gene (IFIH1) previously being identified as a type 1 diabetes
susceptibility locus. Connections between the effective sample size
method and other methods, such as generalized estimation equation,
variance of eigenvalues for correlation matrices, and genomic controls,
are also discussed.

Autoinflammatory Disease Reloaded: A Clinical Perspective
Our understanding of the etiology of autoinflammatory disease is growing rapidly. Recent advances offer new opportunities for therapeutic intervention and suggest that the definition of what constitutes an autoinflammatory disease should be reassessed
Finite-Temperature Fidelity-Metric Approach to the Lipkin-Meshkov-Glick Model
The fidelity metric has recently been proposed as a useful and elegant
approach to identify and characterize both quantum and classical phase
transitions. We study this metric on the manifold of thermal states for the
Lipkin-Meshkov-Glick (LMG) model. For the isotropic LMG model, we find that the
metric reduces to a Fisher-Rao metric, reflecting an underlying classical
probability distribution. Furthermore, this metric can be expressed in terms of
derivatives of the free energy, indicating a relation to Ruppeiner geometry.
This allows us to obtain exact expressions for the (suitably rescaled) metric
in the thermodynamic limit. The phase transition of the isotropic LMG model is
signalled by a degeneracy of this (improper) metric in the paramagnetic phase.
Due to the integrability of the isotropic LMG model, ground state level
crossings occur, leading to an ill-defined fidelity metric at zero temperature.Comment: 18 pages, 3 figure
Use of OxyraseÂź enzyme to enhance recovery of Escherichia coli O157:H7 from culture media and ground beef
Escherichia coli O157:H7 is a bacterium
that has caused great concern in the meat and
food industry during the last few years
because of several, well-publicized, disease
outbreaks, including the incident at the Jackin-
the-Box fast food chain in Seattle, Washington.
The organism can cause severe
sickness and even death in certain population
groups. To better assure meat safety, federal
meat inspection is focusing on developing
rapid methods to detect this disease agent
and others. Oxyrase is a commercially available
enzyme that can accelerate the growth of
some bacteria. Current techniques for
isolation and culturing of E. coli O157:H7
from foods require an enrichment period of
18 to 24 hours, thus limiting their usefulness
for perishable foods that are marketed quickly.
Our investigation found that Oxyrase
shortened required enrichment periods in
broth culture only. The enzyme was less
effective in sterilized ground beef
Impact des modÚles de comportement sur la modélisation des ouvrages souterrains
La prédiction des tassements en surface étant un élément clé lors de l'exécution des travaux souterrains en milieu urbain, il est donc nécessaire d'utiliser des lois de comportement adaptées au calcul des ouvrages géotechniques en phase de service. Dans cet article, des modÚles de comportement à différents niveaux de complexité sur des argiles surconsolidées sont mis en oeuvre. L'étude ne repose pas sur un chantier réel mais les paramÚtres mécaniques sont déduits d'essais triaxiaux puis utilisés pour la modélisation du creusement d'un tunnel peu profond en déformations planes. L'impact des modÚles de comportement est ainsi mis en évidence sur les déplacements au sein du massif
2-(1,2,3,4-TetraÂhydroÂphenanthren-1-ylÂidene)malononitrile
In the title complex, C17H12N2, the non-aromatic six-membered ring adopts an envelope conformation. The dihedral angle between the eight-membered plane containing the malononitrile group and the aromatic system is 25.88â
(4)°. The distance from the central C atom of the malononitrile group to the centroid of the n-glide-related distal aromatic ring is 3.66â
Ă
, suggesting ÏâÏ interÂactions
IN-SITU COMPRESSION TEST OF ARTIFICIAL BONE FOAMS IN CONTROLLED ENVIRONMENT USING X-RAY MICRO-COMPUTED TOMOGRAPHY
In this study, we investigated specimens of artiïŹcial bone foams, developed by the research group for surgical simulators at the UAS Linz, which are used to mimic the haptic feedback of physiologic and pathologic bone for more realistic surgery training. Specimens with two kinds of mineral ïŹller material as well as diïŹerent amounts of foaming agent were tested in an environmental in-situ loading stage developed by the ITAM CAS and scanned via X-ray micro-computed tomography. In this in-situ stage, specimens can be immersed in liquid and tested under temperature-controlled conditions. Consequently, a total amount of 12 specimens was subjected to compression loading; half of them immersed in water at 36.5âŠC and half in dry condition. Results showed that there is no signiïŹcant inïŹuence of liquid immersion to the compression outcome. However, foams with less amount of foaming agent appeared to have smaller pores resulting in higher compression strength
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