399 research outputs found
Finite Size Effects in Quark-Gluon Plasma Formation
Using lattice simulations of quenched QCD we estimate the finite size effects
present when a gluon plasma equilibrates in a slab geometry, i.e., finite width
but large transverse dimensions. Significant differences are observed in the
free energy density for the slab when compared with bulk behavior. A small
shift in the critical temperature is also seen. The free energy required to
liberate heavy quarks relative to bulk is measured using Polyakov loops; the
additional free energy required is on the order of at .Comment: LATTICE98(hightemp), talk at Lattice 98, 3 pages, 3 encapsulated
postscript figures, uses espcrc2.st
A First Principles Estimate of Finite Size Effects in Quark-Gluon Plasma Formation
Using lattice simulations of quenched QCD we estimate the finite size effects
present when a gluon plasma equilibrates in a slab geometry, i.e., finite width
but large transverse dimensions. Significant differences are observed in the
free energy density for the slab when compared with bulk behavior. A small
shift in the critical temperature is also seen. The free energy required to
liberate heavy quarks relative to bulk is measured using Polyakov loops; the
additional free energy required is on the order of 30-40 MeV at 2-3 T_c.Comment: 10 pages, 5 figures, RevTeX; revised version includes comparison with
the Bjorken model and various small improvement
No-Boundary Thinking in Bioinformatics
The following sections are included:Bioinformatics is a Mature DisciplineThe Golden Era of Bioinformatics Has BegunNo-Boundary Thinking in BioinformaticsReference
A genetic variation map for chicken with 2.8 million single-nucleotide polymorphisms
We describe a genetic variation map for the chicken genome containing 2.8 million single-nucleotide polymorphisms ( SNPs). This map is based on a comparison of the sequences of three domestic chicken breeds ( a broiler, a layer and a Chinese silkie) with that of their wild ancestor, red jungle fowl. Subsequent experiments indicate that at least 90% of the variant sites are true SNPs, and at least 70% are common SNPs that segregate in many domestic breeds. Mean nucleotide diversity is about five SNPs per kilobase for almost every possible comparison between red jungle fowl and domestic lines, between two different domestic lines, and within domestic lines - in contrast to the notion that domestic animals are highly inbred relative to their wild ancestors. In fact, most of the SNPs originated before domestication, and there is little evidence of selective sweeps for adaptive alleles on length scales greater than 100 kilobases
Local Lyman Break Galaxy Analogs: The Impact of Massive Star-forming Clumps on the Interstellar Medium and the Global Structure of Young, Forming Galaxies
We present HST UV/optical imaging, Spitzer mid-IR photometry, and optical
spectroscopy of a sample of 30 low-redshift (z=0.1-0.3) galaxies chosen from
SDSS/GALEX to be accurate local analogs of the high-z Lyman Break Galaxies. The
Lyman Break Analogs (LBAs) are similar in mass, metallicity, dust, SFR, size
and gas velocity dispersion, thus enabling a detailed investigation of
processes that are important at high-z. The optical emission line properties of
LBAs are also similar to those of LBGs, indicating comparable conditions in
their ISM. In the UV, LBAs are characterized by complexes of massive
star-forming "clumps", while in the optical they most often show evidence for
(post-)mergers/interactions. In 6 cases, we find an extremely massive (>10^9
Msun) compact (R~100 pc) dominant central object (DCO). The DCOs are
preferentially found in LBAs with the highest mid-IR luminosities and
correspondingly high SFRs (15-100 Msun/yr). We show that the massive SF clumps
(including the DCOs) have masses much larger than the nuclear super star
clusters seen in normal late type galaxies. However, the DCOs have masses,
sizes, and densities similar to the excess-light/central-cusps seen in typical
elliptical galaxies with masses similar to the LBA galaxies. We suggest that
the DCOs form in present-day examples of the dissipative mergers at high
redshift that are believed to have produced the central-cusps in local
ellipticals. More generally, the properties of the LBAs are consistent with the
idea that instabilities in a gas-rich disk lead to very massive star-forming
clumps that eventually coalesce to form a spheroid. We speculate that the DCOs
are too young at present to be growing a supermassive black hole because they
are still in a supernova-dominated outflow phase.Comment: The Astrophysical Journal, In Press (22 pages, 16 figures). For the
full version with high-resolution colour figures, see:
http://www.mpa-garching.mpg.de/~overzier/Overzier_LBApaper09.pd
No-Boundary Thinking in Bioinformatics Research
Currently there are definitions from many agencies and research societies defining bioinformatics as deriving knowledge from computational analysis of large volumes of biological and biomedical data. Should this be the bioinformatics research focus? We will discuss this issue in this review article. We would like to promote the idea of supporting human-infrastructure (HI) with no-boundary thinking (NT) in bioinformatics (HINT)
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