1,217 research outputs found
A Quantum Bousso Bound
The Bousso bound requires that one quarter the area of a closed codimension
two spacelike surface exceeds the entropy flux across a certain lightsheet
terminating on the surface. The bound can be violated by quantum effects such
as Hawking radiation. It is proposed that at the quantum level the bound be
modified by adding to the area the quantum entanglement entropy across the
surface. The validity of this quantum Bousso bound is proven in a
two-dimensional large N dilaton gravity theory.Comment: 17 page
Development of an informative set of Simple Sequence Repeat (SSR) markers for sweetpotato fingerprinting and diversity assessment in the West African sub-region.
The assessment of levels of genetic diversity in sweetpotato is important for conservation and utilization of genetic resources. Molecular markers can play an important role in determining genetic diversity. A number of informative markers have been developed for sweetpotato. Different research groups have identified different markers, and there is little overlap among the sets of markers. This study was conducted to validate polymorphic SSR markers for sweetpotato diversity studies in the West Africa sub-region. A collection of twenty one sweetpotato genotypes was assembled from Ghana and Nigeria. They were assessed with twenty five expressed sequence tag (EST) and twenty one simple sequence repeat (SSR) markers. Popgene software was used to assess results. A set of informative markers was identified for the rationalization of sweetpotato germplasm conservation and uilization in Ghana and West Afric
On the Truncated Pareto Distribution with applications
The Pareto probability distribution is widely applied in different fields
such us finance, physics, hydrology, geology and astronomy. This note deals
with an application of the Pareto distribution to astrophysics and more
precisely to the statistical analysis of mass of stars and of diameters of
asteroids. In particular a comparison between the usual Pareto distribution and
its truncated version is presented. Finally a possible physical mechanism that
produces Pareto tails for the distribution of the masses of stars is suggested.Comment: 10 pages 6 figure
Mechanical characterisation of a fibre reinforced oxide/oxide ceramic matrix composite
Monotonic tension, fatigue and creep experiments were conducted on an oxide/oxide ceramic matrix composite over the range of temperature 20–1200 °C. The role of continuous fibre reinforcement, differential thermal expansion, stress redistribution interactions between fibres and matrix and the influence of inherent processing defects are all considered when describing the deformation and ultimate mechanical failure of these systems
The interpretive approach to religious education : challenging Thompson's interpretation
In a recent book chapter, Matthew Thompson makes some criticisms of my work, including the interpretive approach to religious education and the research and activity of Warwick Religions and Education Research Unit. Against the background of a discussion of religious education in the public sphere, my response challenges Thompson’s account, commenting on his own position in relation to dialogical approaches to religious education. The article rehearses my long held view that the ideal form of religious education in fully state funded schools of a liberal democracy should be ‘secular’ but not ‘secularist’; there should be no implication of an axiomatic secular humanist interpretation of religions
Genetic relationships within and among Iberian fescues (Festuca L.) based on PCR-amplified markers
The genus Festuca comprises approximately 450 species and is widely distributed around the world. The Iberian Penninsula, with more than 100 taxa colonizing very diverse habitats, is one of its main centers of diversification. This study was conducted to assess molecular genetic variation and genetic relatedness among 91 populations of 31 taxa of Iberian fescues, based on several molecular markers (random amplified polymorphic DNA, amplified fragment length polymorphisms, and trnL sequences). The analyses showed the paraphyletic origin of the broad-leaved (subgenus Festuca, sections Scariosae and Subbulbosae, and subgenus Schedonorus) and the fine-leaved fescues (subgenus Festuca, sections Aulaxyper, Eskia, and Festuca). Schedonorus showed a weak relationship with Lolium rigidum and appeared to be the most recent of the broad-leaved clade. Section Eskia was the most ancient and Festuca the most recent of the fine-leaved clade. Festuca and Aulaxyper were the most related sections, in concordance with their taxonomic affinities. All taxa grouped into their sections, except F. ampla and F. capillifolia (section Festuca), which appeared to be more closely related to Aulaxyper and to a new independent section, respectively. Most populations clustered at the species level, but some subspecies and varieties mixed their populations. This study demonstrated the value in combining different molecular markers to uncover hidden genetic relationships between populations of Festuca
(Sub)mm Interferometry Applications in Star Formation Research
This contribution gives an overview about various applications of (sub)mm
interferometry in star formation research. The topics covered are molecular
outflows, accretion disks, fragmentation and chemical properties of low- and
high-mass star-forming regions. A short outlook on the capabilities of ALMA is
given as well.Comment: 20 pages, 7 figures, in proceedings to "2nd European School on Jets
from Young Star: High Angular Resolution Observations". A high-resolution
version of the paper can be found at
http://www.mpia.de/homes/beuther/papers.htm
Herschel*-ATLAS: correlations between dust and gas in local submm-selected galaxies
We present an analysis of CO molecular gas tracers in a sample of 500
μ
m-selected
Herschel
-ATLAS galaxies at
z <
0
.
05 (
cz <
14990 km s
−
1
). Using 22
−
500
μ
m photom-
etry from
WISE
,
IRAS
and
Herschel
, with H
i
data from the literature, we investigate
correlations between warm and cold dust, and tracers of the gas in
different phases.
The correlation between global CO(3–2) line fluxes and FIR–submm fl
uxes weakens
with increasing IR wavelength (
λ
&
60
μ
m), as a result of colder dust being less
strongly associated with dense gas. Conversely, CO(2–1) and H
i
line fluxes both ap-
pear to be better correlated with longer wavelengths, suggesting
that cold dust is more
strongly associated with diffuse atomic and molecular gas phases, co
nsistent with it
being at least partially heated by radiation from old stellar populations
. The increased
scatter at long wavelengths implies that sub-millimetre fluxes are a po
orer tracer of
SFR. Fluxes at 22 and 60
μ
m are also better correlated with diffuse gas tracers than
dense CO(3–2), probably due to very-small-grain emission in the diffu
se interstellar
medium, which is not correlated with SFR. The FIR/CO luminosity ratio a
nd the
dust mass/CO luminosity ratio both decrease with increasing luminosit
y, as a result
of either correlations between mass and metallicity (changing CO/H
2
) or between CO
luminosity and excitation [changing CO(3–2)/CO(1–0)].Web of Scienc
SUMO-2 and PIAS1 modulate insoluble mutant Huntingtin protein accumulation
A key feature in Huntington disease (HD) is the accumulation of mutant Huntingtin (HTT) protein, which may be regulated by posttranslational modifications. Here, we define the primary sites of SUMO modification in the amino-terminal domain of HTT, show modification downstream of this domain, and demonstrate that HTT is modified by the stress-inducible SUMO-2. A systematic study of E3 SUMO ligases demonstrates that PIAS1 is an E3 SUMO ligase for both HTT SUMO-1 and SUMO-2 modification and that reduction of dPIAS in a mutant HTT Drosophila model is protective. SUMO-2 modification regulates accumulation of insoluble HTT in HeLa cells in a manner that mimics proteasome inhibition and can be modulated by overexpression and acute knockdown of PIAS1. Finally, the accumulation of SUMO-2-modified proteins in the insoluble fraction of HD postmortem striata implicates SUMO-2 modification in the age-related pathogenic accumulation of mutant HTT and other cellular proteins that occurs during HD progression
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Family-Friendly Management, Organizational Performance and Social Legitimacy
Research on family-friendly practices has concentrated on the predictors of their use, particularly from the perspective of either institutional theory or the high involvement or commitment management vogue. This paper first shows how such perspectives can be used to generate hypotheses about the link between family-friendly management and organizational performance. Second, the paper reports research designed to test these, using data from a national representative sample of workplaces across the British economy, the Workplace Employment Relations Survey of 2004 (WERS2004). The results support the high commitment thesis that family-friendly management will strengthen the relationship between commitment and key economic outcomes, as the relationships between workforce commitment and productivity or quality are stronger in organizations when friendly management is high, which is consistent with social exchange theory. Family-friendly management is not, however, related to the human resource outcomes of labour turnover and absenteeism. Nor does the study find support for the argument that its use in conjunction with high involvement management enhances the performance effects of both. Equally, there is no support for the hypothesis from the institutional thesis that family-friendly management has positive effects on the legitimacy of the organization
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