2,147 research outputs found
Analysis of β-globin chromatin micro-environment using a novel 3C variant, 4Cv
Copyright: © 2010 Pink et al.Higher order chromatin folding is critical to a number of developmental processes, including the regulation of gene expression. Recently developed biochemical techniques such as RNA TRAP and chromosome conformation capture (3C) have provided us with the tools to probe chromosomal structures. These techniques have been applied to the β-globin locus, revealing a complex pattern of interactions with regions along the chromosome that the gene resides on. However, biochemical and microscopy data on the nature of β-globin interactions with other chromosomes is contradictory. Therefore we developed a novel 4C variant, Complete-genome 3C by vectorette amplification (4Cv), which allows an unbiased and quantitative method to examine chromosomal structure. We have used 4Cv to study the microenvironment of the β-globin locus in mice and show that a significant proportion of the interactions of β-globin are inter-chromosomal. Furthermore, our data show that in the liver, where the gene is active, β-globin is more likely to interact with other chromosomes, compared to the brain where the gene is silent and is more likely to interact with other regions along the same chromosome. Our data suggest that transcriptional activation of the β-globin locus leads to a change in nuclear position relative to the chromosome territory.Ryan Pink is supported by a grant from Action Medical Research; Daniel Caley is supported by a grant from The Dunhill Medical Trust; David Carter is supported by a grant from the British Society for Haematology
The dark triad in male and female athletes and non-athletes: Group differences and psychometric properties of the short dark triad (SD3)
© 2019 Elsevier Ltd Objectives: The Short Dark Triad (SD3) is a popular, brief measure of narcissism, Machiavellianism, and psychopathy, which are known as the Dark Triad. The present study adopted this measure and had two aims. First, to assess the psychometric properties of the SD3 with a focus on measurement invariance across gender, athletic expertise, and sport type. Second, to examine mean differences in Dark Triad scores across these groups. Design: Cross-sectional. Method: In total, 1258 participants (625 women; mean age 23.47 years) with a range of athletic experience (non-athletes, N = 408; amateur, N = 557; elite, N = 293) from team (N = 577) and individual (N = 273) sports completed the SD3. Factorial validity was assessed using exploratory structural equation modelling. Results: Analyses indicated that the three-factor model provided adequate fit, however, a bifactor model incorporating the three specific factors and a general factor, provided superior fit to the data. Moreover, invariance testing suggested some inconsistency in the observed factor structures across groups. In addition, findings indicated group differences with men scoring higher than women, athletes with greater expertise scoring higher than those with less expertise, and individual athletes scoring higher than team athletes across all factors. Conclusions: We suggest that researchers continue to use the SD3 using both composite and subscale scores, but recommend caution when interpreting subscale scores among women and team athletes until further psychometric work has been conducted within these populations. Our findings also suggest that the Dark Triad may be worth examining in future studies in sport
Cohomology of the minimal nilpotent orbit
We compute the integral cohomology of the minimal non-trivial nilpotent orbit
in a complex simple (or quasi-simple) Lie algebra. We find by a uniform
approach that the middle cohomology group is isomorphic to the fundamental
group of the sub-root system generated by the long simple roots. The modulo
reduction of the Springer correspondent representation involves the sign
representation exactly when divides the order of this cohomology group.
The primes dividing the torsion of the rest of the cohomology are bad primes.Comment: 29 pages, v2 : Leray-Serre spectral sequence replaced by Gysin
sequence only, corrected typo
Cool Jupiters greatly outnumber their toasty siblings : Occurrence rates from the Anglo-Australian Planet Search
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society ©2019 The Authors. Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.Our understanding of planetary systems different to our own has grown dramatically in the past 30 yr. However, our efforts to ascertain the degree to which the Solar system is abnormal or unique have been hindered by the observational biases inherent to the methods that have yielded the greatest exoplanet hauls. On the basis of such surveys, one might consider our planetary system highly unusual - but the reality is that we are only now beginning to uncover the true picture. In this work, we use the full 18-yr archive of data from the Anglo-Australian Planet Search to examine the abundance of 'cool Jupiters' - analogues to the Solar system's giant planets, Jupiter and Saturn. We find that such planets are intrinsically far more common through the cosmos than their siblings, the hot Jupiters.We find that the occurrence rate of such 'cool Jupiters' is 6.73 +2.09 -1.13 per cent, almost an order of magnitude higher than the occurrence of hot Jupiters (at 0.84 +0.70 -0.20 per cent). We also find that the occurrence rate of giant planets is essentially constant beyond orbital distances of ~1 au. Our results reinforce the importance of legacy radial velocity surveys for the understanding of the Solar system's place in the cosmos.Peer reviewe
Kepler-413b: a slightly misaligned, Neptune-size transiting circumbinary planet
We report the discovery of a transiting, Rp = 4.347+/-0.099REarth,
circumbinary planet (CBP) orbiting the Kepler K+M Eclipsing Binary (EB) system
KIC 12351927 (Kepler-413) every ~66 days on an eccentric orbit with ap =
0.355+/-0.002AU, ep = 0.118+/-0.002. The two stars, with MA =
0.820+/-0.015MSun, RA = 0.776+/-0.009RSun and MB = 0.542+/-0.008MSun, RB =
0.484+/-0.024RSun respectively revolve around each other every
10.11615+/-0.00001 days on a nearly circular (eEB = 0.037+/-0.002) orbit. The
orbital plane of the EB is slightly inclined to the line of sight (iEB =
87.33+/-0.06 degrees) while that of the planet is inclined by ~2.5 degrees to
the binary plane at the reference epoch. Orbital precession with a period of
~11 years causes the inclination of the latter to the sky plane to continuously
change. As a result, the planet often fails to transit the primary star at
inferior conjunction, causing stretches of hundreds of days with no transits
(corresponding to multiple planetary orbital periods). We predict that the next
transit will not occur until 2020. The orbital configuration of the system
places the planet slightly closer to its host stars than the inner edge of the
extended habitable zone. Additionally, the orbital configuration of the system
is such that the CBP may experience Cassini-States dynamics under the influence
of the EB, in which the planet's obliquity precesses with a rate comparable to
its orbital precession. Depending on the angular precession frequency of the
CBP, it could potentially undergo obliquity fluctuations of dozens of degrees
(and complex seasonal cycles) on precession timescales.Comment: 48 pages, 13 figure
Dual Computations of Non-abelian Yang-Mills on the Lattice
In the past several decades there have been a number of proposals for
computing with dual forms of non-abelian Yang-Mills theories on the lattice.
Motivated by the gauge-invariant, geometric picture offered by dual models and
successful applications of duality in the U(1) case, we revisit the question of
whether it is practical to perform numerical computation using non-abelian dual
models. Specifically, we consider three-dimensional SU(2) pure Yang-Mills as an
accessible yet non-trivial case in which the gauge group is non-abelian. Using
methods developed recently in the context of spin foam quantum gravity, we
derive an algorithm for efficiently computing the dual amplitude and describe
Metropolis moves for sampling the dual ensemble. We relate our algorithms to
prior work in non-abelian dual computations of Hari Dass and his collaborators,
addressing several problems that have been left open. We report results of spin
expectation value computations over a range of lattice sizes and couplings that
are in agreement with our conventional lattice computations. We conclude with
an outlook on further development of dual methods and their application to
problems of current interest.Comment: v1: 18 pages, 7 figures, v2: Many changes to appendix, minor changes
throughout, references and figures added, v3: minor corrections, 22 page
Tension Perturbations of Black Brane Spacetimes
We consider black-brane spacetimes that have at least one spatial translation
Killing field that is tangent to the brane. A new parameter, the tension of a
spacetime, is defined. The tension parameter is associated with spatial
translations in much the same way that the ADM mass is associated with the time
translation Killing field. In this work, we explore the implications of the
spatial translation symmetry for small perturbations around a background black
brane. For static charged black branes we derive a law which relates the
tension perturbation to the surface gravity times the change in the the horizon
area, plus terms that involve variations in the charges and currents. We find
that as a black brane evaporates the tension decreases. We also give a simple
derivation of a first law for black brane spacetimes. These constructions hold
when the background stress-energy is governed by a Hamiltonian, and the results
include arbitrary perturbative stress-energy sources.Comment: 21 pages, o figures, harvma
Wake Measurement Probe
A probe includes a stem having a tip that measures a wake produced by an object moving through a fluid. The probe includes temperature and pressure sensors co-located in the tip
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