535 research outputs found
The Effect of Transposable Element Insertions on Gene Expression Evolution in Rodents
Background:Many genomes contain a substantial number of transposable elements (TEs), a few of which are known to be involved in regulating gene expression. However, recent observations suggest that TEs may have played a very important role in the evolution of gene expression because many conserved non-genic sequences, some of which are know to be involved in gene regulation, resemble TEs. Results:Here we investigate whether new TE insertions affect gene expression profiles by testing whether gene expression divergence between mouse and rat is correlated to the numbers of new transposable elements inserted near genes. We show that expression divergence is significantly correlated to the number of new LTR and SINE elements, but not to the numbers of LINEs. We also show that expression divergence is not significantly correlated to the numbers of ancestral TEs in most cases, which suggests that the correlations between expression divergence and the numbers of new TEs are causal in nature. We quantify the effect and estimate that TE insertion has accounted for ~20% (95% confidence interval: 12% to 26%) of all expression profile divergence in rodents. Conclusions:We conclude that TE insertions may have had a major impact on the evolution of gene expression levels in rodents
Improved Spatial Resolution Achieved by Chromatic Intensity Interferometry
Interferometers are widely used in imaging technologies to achieve enhanced
spatial resolution, but require that the incoming photons be indistinguishable.
In previous work, we built and analyzed color erasure detectors which expand
the scope of intensity interferometry to accommodate sources of different
colors. Here we experimentally demonstrate how color erasure detectors can
achieve improved spatial resolution in an imaging task, well beyond the
diffraction limit. Utilizing two 10.9 mm-aperture telescopes and a 0.8 m
baseline, we measure the distance between a 1063.6 nm source and a 1064.4 nm
source separated by 4.2 mm at a distance of 1.43 km, which surpasses the
diffraction limit of a single telescope by about 40 times. Moreover, chromatic
intensity interferometry allows us to recover the phase of the Fourier
transform of the imaged objects - a quantity that is, in the presence of modest
noise, inaccessible to conventional intensity interferometry.Comment: 5 pages, 3 figure
Detection of multipartite entanglement with two-body correlations
We show how to detect entanglement with criteria built from simple two-body
correlation terms. Since many natural Hamiltonians are sums of such correlation
terms, our ideas can be used to detect entanglement by energy measurement. Our
criteria can straightforwardly be applied for detecting different forms of
multipartite entanglement in familiar spin models in thermal equilibrium.Comment: 5 pages including 2 figures, LaTeX; for the proceedings of the DPG
spring meeting, Berlin, March 200
Stochastic Gravity: Theory and Applications
Whereas semiclassical gravity is based on the semiclassical Einstein equation
with sources given by the expectation value of the stress-energy tensor of
quantum fields, stochastic semiclassical gravity is based on the
Einstein-Langevin equation, which has in addition sources due to the noise
kernel.In the first part, we describe the fundamentals of this new theory via
two approaches: the axiomatic and the functional. In the second part, we
describe three applications of stochastic gravity theory. First, we consider
metric perturbations in a Minkowski spacetime: we compute the two-point
correlation functions for the linearized Einstein tensor and for the metric
perturbations. Second, we discuss structure formation from the stochastic
gravity viewpoint. Third, we discuss the backreaction of Hawking radiation in
the gravitational background of a quasi-static black hole.Comment: 75 pages, no figures, submitted to Living Reviews in Relativit
Stochastic Gravity: Theory and Applications
Whereas semiclassical gravity is based on the semiclassical Einstein equation
with sources given by the expectation value of the stress-energy tensor of
quantum fields, stochastic semiclassical gravity is based on the
Einstein-Langevin equation, which has in addition sources due to the noise
kernel. In the first part, we describe the fundamentals of this new theory via
two approaches: the axiomatic and the functional. In the second part, we
describe three applications of stochastic gravity theory. First, we consider
metric perturbations in a Minkowski spacetime, compute the two-point
correlation functions of these perturbations and prove that Minkowski spacetime
is a stable solution of semiclassical gravity. Second, we discuss structure
formation from the stochastic gravity viewpoint. Third, we discuss the
backreaction of Hawking radiation in the gravitational background of a black
hole and describe the metric fluctuations near the event horizon of an
evaporating black holeComment: 100 pages, no figures; an update of the 2003 review in Living Reviews
in Relativity gr-qc/0307032 ; it includes new sections on the Validity of
Semiclassical Gravity, the Stability of Minkowski Spacetime, and the Metric
Fluctuations of an Evaporating Black Hol
Chromatic interferometry with small frequency differences
By developing a `two-crystal' method for color erasure, we can broaden the
scope of chromatic interferometry to include optical photons whose frequency
difference falls outside of the 400 nm to 4500 nm wavelength range, which is
the passband of a PPLN crystal. We demonstrate this possibility experimentally,
by observing interference patterns between sources at 1064.4 nm and 1063.6 nm,
corresponding to a frequency difference of about 200 GHz.Comment: 5 pages, 3 figure
Electromagnetic Wave Theory and Applications
Contains table of content for Section 3, reports on ten research projects and a list of publications.U.S. Navy - Office of Naval Research Contract N00014-92-J-4098U.S. Federal Aviation Administration Contract 94-G-007U.S. Federal Aviation Administration Contract 97-G-031California Institute of Technology Contract JPL 960408National Aeronautics and Space Administration Contract JPL 958461U.S. Navy - Office of Naval Research Contract N00014-92-J-1616National Science Foundation Grant ECS 96-15799U.S. Navy - Office of Naval Research Contract N00014-97-1-0172Joint Services Electronics Program Contract DAAH04-95-1-0038Mitsubishi Corporatio
Candidates in Astroviruses, Seadornaviruses, Cytorhabdoviruses and Coronaviruses for +1 frame overlapping genes accessed by leaky scanning
<p>Abstract</p> <p>Background</p> <p>Overlapping genes are common in RNA viruses where they serve as a mechanism to optimize the coding potential of compact genomes. However, annotation of overlapping genes can be difficult using conventional gene-finding software. Recently we have been using a number of complementary approaches to systematically identify previously undetected overlapping genes in RNA virus genomes. In this article we gather together a number of promising candidate new overlapping genes that may be of interest to the community.</p> <p>Results</p> <p>Overlapping gene predictions are presented for the astroviruses, seadornaviruses, cytorhabdoviruses and coronaviruses (families <it>Astroviridae</it>, <it>Reoviridae</it>, <it>Rhabdoviridae </it>and <it>Coronaviridae</it>, respectively).</p
Might Depression, Psychosocial Adversity, and Limited Social Assets Explain Vulnerability to and Resistance against Violent Radicalisation?
BACKGROUND: This study tests whether depression, psychosocial adversity, and limited social assets offer protection or suggest vulnerability to the process of radicalisation. METHODS: A population sample of 608 men and women of Pakistani or Bangladeshi origin, of Muslim heritage, and aged 18-45 were recruited by quota sampling. Radicalisation was measured by 16 questions asking about sympathies for violent protest and terrorism. Cluster analysis of the 16 items generated three groups: most sympathetic (or most vulnerable), most condemning (most resistant), and a large intermediary group that acted as a reference group. Associations were calculated with depression (PHQ9), anxiety (GAD7), poor health, and psychosocial adversity (adverse life events, perceived discrimination, unemployment). We also investigated protective factors such as the number social contacts, social capital (trust, satisfaction, feeling safe), political engagement and religiosity. RESULTS: Those showing the most sympathy for violent protest and terrorism were more likely to report depression (PHQ9 score of 5 or more; RR = 5.43, 1.35 to 21.84) and to report religion to be important (less often said religion was fairly rather than very important; RR = 0.08, 0.01 to 0.48). Resistance to radicalisation measured by condemnation of violent protest and terrorism was associated with larger number of social contacts (per contact: RR = 1.52, 1.26 to 1.83), less social capital (RR = 0.63, 0.50 to 0.80), unavailability for work due to housekeeping or disability (RR = 8.81, 1.06 to 37.46), and not being born in the UK (RR = 0.22, 0.08 to 0.65). CONCLUSIONS: Vulnerability to radicalisation is characterised by depression but resistance to radicalisation shows a different profile of health and psychosocial variables. The paradoxical role of social capital warrants further investigation
Recent Advances in Childhood Arterial Ischemic Stroke
Although many underlying diseases have been reported in the setting of childhood arterial ischemic stroke, emerging research demonstrates that non-atherosclerotic intracerebral arteriopathies in otherwise healthy children are prevalent. Minor infections may play a role in arteriopathies that have no other apparent underlying cause. Although stroke in childhood differs in many aspects from adult stroke, few systematic studies specific to pediatrics are available to inform stroke management. Treatment trials of pediatric stroke are required to determine the best strategies for acute treatment and secondary stroke prevention. The high cost of pediatric stroke to children, families, and society demands further study of its risk factors, management, and outcomes. This review focuses on the recent findings in childhood arterial ischemic stroke
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