21,440 research outputs found
Electroweak and Bottom Quark Contributions to Higgs Boson plus Jet Production
This paper presents predictions for jet pseudorapidity (eta) and transverse
momentum (p_T) distributions for the production of the Standard Model Higgs
boson in association with a high-p_T hadronic jet. We discuss the contributions
of electroweak loops and of bottom-quark parton processes to the cross section.
The latter arise in the five-flavour scheme. Predictions for the Tevatron and
the Large Hadron Collider with 10 TeV collision energy are presented. For Higgs
boson masses of 120 GeV, 160 GeV and 200 GeV, we find the maximal effects of
the electroweak contributions to the Higgs plus jet p_T and eta distribution to
be -14 % and -5.3 %, respectively, for the Tevatron, and -3 % and -2 %,
respectively, for the LHC. For the maximal contribution of bottom-quark parton
processes to the p_T and eta distribution, we find +3 % and + 2.5 %,
respectively, for the Tevatron, and +3.5 % and +3 %, respectively, for the LHC.
A separate study of the Higgs + b-jet cross section demonstrates that a
calculational approach which respects the hierarchies of Yukawa couplings
yields a leading order cross section prediction which is more accurate in the
high-p_T regime than conventional approaches.Comment: 25 pages, 14 figure
Boundary conditions for free surface inlet and outlet\ud problems
We investigate and compare the boundary conditions that are to be applied to free surface problems involving inlet and outlets of Newtonian fluid, typically found in coating processes. The flux of fluid is a priori known at an inlet, but unknown at an outlet, where it is governed by the local behaviour near the film-forming meniscus. In the limit of vanishing capillary number Ca it is well-known that the flux scales with Ca2/3, but this classical result is nonuniform as the contact angle approaches . By examining this limit we find a solution that is uniformly valid for all contact angles. Furthermore, by considering the far-field behaviour of the free surface we show that there exists a critical capillary number above which the problem at an inlet becomes over-determined. The implications of this result for the modelling of coating flows are discussed
'It's a Form of Freedom': The experiences of people with disabilities within equestrian sport
This paper explores the embodied, gendered experiences of disabled horseâriders. Drawing on data from five inâdepth interviews with paradressage riders, the ways in which their involvement in elite disability sport impacts upon their sense of identity and confidence are explored, as well as the considerable health and social benefits that this involvement brings. Social models of disability are employed and the shortcomings of such models, when applied to disability sport, are highlighted. The data presented here demonstrates the necessity of seeing disability sport as an embodied experience and acknowledging the importance of impairment to the experiences of disabled athletes. Living within an impaired body is also a gendered experience and the implications of this when applied to elite disability sport are considered
Microwave Spectroscopy
Contains reports on two research projects.United States Army Signal Corps (Contract DA36-039-sc-74895
Expansion Of Meteorological Satellite Potential
Meteorological satellites in polar and geostationary orbit are presented in this paper along with examples and limitations. NOAA and NASA satellite programs, present and future in the meteorological field, are discussed along with spectral interval, ground resolution and operational applications. The USAF/AWS Defense Meteorological Satellite Program (DMSP) is scheduled for operation at the Air Force Eastern Test Range (AFETR) in the Spring of 1974. The DMSP acquisition system is described with respect to sensor type and satellite orbital parameters. Two satellites are in orbit at any given time providing real time, visual and infrared, imagery every six hours. Imagery examples depicting meteorological, geophysical, oceanographic, and earth resources applications are presented. Some added benefits with regard to the energy crisis are a possibility with the DMSP system or similar sensor use
Metal-insulator transition in EuO
It is shown that the spectacular metal-insulator transition in Eu-rich EuO
can be simulated within an extended Kondo lattice model. The different orders
of magnitude of the jump in resistivity in dependence on the concentration of
oxygen vacancies as well as the low-temperature resistance minimum in
high-resistivity samples are reproduced quantitatively. The huge colossal
magnetoresistance (CMR) is calculated and discussed
Tricarbonylchlorido(6'7'-dihydro-5âH-spiro[cyclopentane-1,6'-dipyrido-[3,2-d:2',3'-f][1,3]diazepine]-Îș2N1,N11)-rhenium(I)
In the title compound, [ReCl(C15H16N4)(CO)3], the ReI ion is coordinated in a distorted octahedral geometry by one Cl atom, two N atoms of the bidentate ligand and three carbonyl groups. The cyclopentane group is orientated in a transoid fashion with respect to the chloride ligand. The dihedral angle between the pryridine rings is 10.91 (12)°. In the crystal, N-H...Cl hydrogen bonds link complex molecules, forming a two-dimensional network parallel to (001)
Tricarbonylchlorido(6â,7â-dihydro-5âH-spiro[cyclohexane-1,6â-dipyrido[3,2-d :2â,3â-f][1,3]diazepine]-Îș2N1,N11)rhenium(I)
In the title compound, [ReCl(C16H18N4)(CO)3], the ReI ion is coordinated in a distorted octahedral geometry by one Cl atom, two N atoms of the bidentate ligand and three carbonyl groups. The cyclohexane group is orientated in a transoid fashion with respect to the chloride ligand. In the crystal, N-H...Cl hydrogen bonds link complex molecules, forming a two-dimensional network parallel to (100)
A reservoir of 'historical' antibiotic resistance genes in remote pristine Antarctic soils
Background: Soil bacteria naturally produce antibiotics as a competitive mechanism, with a concomitant evolution, and exchange by horizontal gene transfer, of a range of antibiotic resistance mechanisms. Surveys of bacterial resistance elements in edaphic systems have originated primarily from human-impacted environments, with relatively little information from remote and pristine environments, where the resistome may comprise the ancestral gene diversity.
Methods: We used shotgun metagenomics to assess antibiotic resistance gene (ARG) distribution in 17 pristine and remote Antarctic surface soils within the undisturbed Mackay Glacier region. We also interrogated the phylogenetic placement of ARGs compared to environmental ARG sequences and tested for the presence of horizontal gene transfer elements flanking ARGs.
Results: In total, 177 naturally occurring ARGs were identified, most of which encoded single or multi-drug efflux pumps. Resistance mechanisms for the inactivation of aminoglycosides, chloramphenicol and beta-lactam antibiotics were also common. Gram-negative bacteria harboured most ARGs (71%), with fewer genes from Gram-positive Actinobacteria and Bacilli (Firmicutes) (9%), reflecting the taxonomic composition of the soils. Strikingly, the abundance of ARGs per sample had a strong, negative correlation with species richness (r=-0.49, P < 0.05). This result, coupled with a lack of mobile genetic elements flanking ARGs, suggests that these genes are ancient acquisitions of horizontal transfer events.
Conclusions: ARGs in these remote and uncontaminated soils most likely represent functional efficient historical genes that have since been vertically inherited over generations. The historical ARGs in these pristine environments carry a strong phylogenetic signal and form a monophyletic group relative to ARGs from other similar environments
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