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31.
P.M. Stevenson 《Physics letters. [Part B]》1978,78(4):451-454
A simple derivation of the Sterman-Weinberg jet formula (the QCD perturbation theory formula for the 2-jet cross section) is described. Conditions on the jet parameters ? and δ for this formula to be applicable are discussed and the corrections to the formula up to O(?2), O(δ2) are presented. 相似文献
32.
Ondeykal JG Herath KB Jayasuriya H Polishook JD Bills GF Dombrowski AW Mojena M Koch G DiSalvo J DeMartino J Guan Z Nanakorn W Morenberg CM Balick MJ Stevenson DW Slattery M Borris RP Singh SB 《Molecular diversity》2005,9(1-3):123-129
The chemokines (CXCL9, CXCL10 and CXCL11) and associated CXCR3 receptor are expressed during the inflammatory process from multiple sclerosis, atherosclerosis or organ transplantation resulting in the recruitment of lymphocytes leading to tissue damage. It is hypothesized that blocking of the ligand/CXCR3 receptor interaction has potential to provide opportunity for development of agents that would block tissue rejection. In this paper, four classes of natural product inhibitors (IC50 ranging 0.1–41 M) have been described that block the CXCR3 receptor interaction of IP-10 ligand. These include a cyclic thiopeptide (duramycin), polyketide glycosides (roselipins), steroidal glycosides (hypoglausin A and dioscin) and a novel alkyl pyridinium alkaloid that were isolated by bioassay-guided fractionation of the organic extracts derived from actinomycete, fungal, plant and marine sources and discovered using 125 I IP-10/CXCR3 binding assay. Duramycin was the most potent with an IC50 of 0.1 M. Roselipins 2A, 2B and 1A showed IC50 values of 14.6, 23.5, and 41 M, respectively. Diosgenin glycosides dioscin, hypoglaucin A and kallstroemin D exhibited IC50 values of 2.1, 0.47 and 3 M, respectively. A novel cyclic 3-alkyl pyridinium salt isolated from a sponge displayed a binding IC50 of 0.67 M. 相似文献
33.
Alan L.?CareyEmail author Stuart?Johnson Michael K.?Murray Danny?Stevenson Bai-Ling?Wang 《Communications in Mathematical Physics》2005,259(3):577-613
We develop the theory of Chern-Simons bundle 2-gerbes and multiplicative bundle gerbes associated to any principal G-bundle with connection and a class in H4(BG, ℤ) for a compact semi-simple Lie group G. The Chern-Simons bundle 2-gerbe realises differential geometrically the Cheeger-Simons invariant. We apply these notions to refine the Dijkgraaf-Witten correspondence between three dimensional Chern-Simons functionals and Wess-Zumino-Witten models associated to the group G. We do this by introducing a lifting to the level of bundle gerbes of the natural map from H4(BG, ℤ) to H3(G, ℤ). The notion of a multiplicative bundle gerbe accounts geometrically for the subtleties in this correspondence for non-simply connected Lie groups. The implications for Wess-Zumino-Witten models are also discussed.The authors acknowledge the support of the Australian Research Council. ALC thanks MPI für Mathematik in Bonn and ESI in Vienna and BLW thanks CMA of Australian National University for their hospitality during part of the writing of this paper. 相似文献
34.
Stevenson RM Oades K Thomas BR Schneider M Slark GE Suter LJ Kauffman R Hinkel D Miller MC 《Physical review letters》2005,94(5):055006
A series of experiments conducted on the HELEN laser system [M. J. Norman, Appl. Opt.4120023497], into thermal x-ray generation from hohlraum targets using 527 nm (2omega) wavelength laser light, has shown that it is possible to exceed radiation temperatures previously thought limited by high levels of superthermal or hot electron production or stimulated backscatter. This Letter questions whether the assumptions traditionally applied to hohlraum design with respect to hot plasma filling and the use of 2omega light are too conservative. 相似文献
35.
Singh JB Sirotenko V Slattery P Smith E Smith RP Snihur R Snow GR Snow J Snyder S Solomon J Sorin V Sosebee M Sotnikova N Soustruznik K Souza M Stanton NR Steinbruck G Stephens RW Stevenson ML Stichelbaut F Stoker D Stolin V Stoyanova DA Strauss M Streets K Strovink M 《Physical review letters》2000,85(24):5068-5073
Bottom-quark production in &pmacr;p collisions at sqrt[s] = 1.8 TeV is studied with 5 pb(-1) of data collected in 1995 by the D0 detector at the Fermilab Tevatron Collider. The differential production cross section for b jets in the central rapidity region ( | y(b)|<1) as a function of jet transverse energy is extracted from a muon-tagged jet sample. Within experimental and theoretical uncertainties, D0 results are found to be higher than, but compatible with, next-to-leading-order QCD predictions. 相似文献
36.
Song XF Sorin V Sosebee M Sotnikova N Souza M Stanton NR Steinbruck G Stephens RW Stevenson ML Stichelbaut F Stoker D Stolin V Stoyanova DA Strauss M Streets K Strovink M Stutte L Sznajder A Tarazi J Taylor W Tentindo-Repond S Thomas TL Thompson J Toback D Trippe TG Turcot AS 《Physical review letters》2000,85(2):256-261
The D0 collaboration has performed a study of spin correlation in t&tmacr; production for the process t&tmacr;-->bW(+)&bmacr;W-, where the W bosons decay to enu or &mgr;nu. A sample of six events was collected during an exposure of the D0 detector to an integrated luminosity of approximately 125 pb(-1) of sqrt[s] = 1.8 TeV p&pmacr; collisions. The standard model (SM) predicts that the short lifetime of the top quark ensures the transmission of any spin information at production to the t&tmacr; decay products. The degree of spin correlation is characterized by a correlation coefficient kappa. We find that kappa>-0.25 at the 68% confidence level, in agreement with the SM prediction of kappa = 0.88. 相似文献
37.
Savvidis PG Baumberg JJ Stevenson RM Skolnick MS Whittaker DM Roberts JS 《Physical review letters》2000,84(7):1547-1550
We experimentally demonstrate resonant coupling between photons and excitons in microcavities which can efficiently generate enormous single-pass optical gains approaching 100. This new parametric phenomenon appears as a sharp angular resonance of the incoming pump beam, at which the moving excitonic polaritons undergo very large changes in momentum. Ultrafast stimulated scattering is clearly identified from the exponential dependence on pump intensity. This device utilizes boson amplification induced by stimulated energy relaxation. 相似文献
38.
It was argued in [25, 5] that in the presence of a nontrivial B-field, D-brane charges in type IIB string theories are classified by twisted K-theory. In [4], it was proved that twisted K-theory is canonically isomorphic to bundle gerbe K-theory, whose elements are ordinary Hilbert bundles on a principal projective unitary bundle, with an action of the bundle
gerbe determined by the principal projective unitary bundle. The principal projective unitary bundle is in turn determined
by the twist. This paper studies in detail the Chern-Weil representative of the Chern character of bundle gerbe K-theory that was introduced in [4], extending the construction to the equivariant and the holomorphic cases. Included is a
discussion of interesting examples.
Received: 10 January 2002 / Accepted: 9 December 2002
Published online: 25 February 2003
RID="⋆"
ID="⋆" The authors acknowledge the support of the Australian Research Council
Communicated by R.H. Dijkgraaf 相似文献
39.
Bonner BE Buchanan JA Clement JM Corcoran MD Krishna NM Kruk JW Lincoln DW Miettinen HE Mutchler GS Nessi-Tedaldi F Nessi M Phillips GC Roberts JB Stevenson PM Tonse SR White JL Chung SU Etkin A Fernow RC Protopopescu SD Willutzki H Hallman T Madansky L Pinsky LS 《Physical review letters》1989,62(14):1591-1594
40.
Bonner BE Buchanan JA Clement JM Corcoran MD Krishna NM Kruk JW Miettinen HE Moss RM Mutchler GS Nessi-Tedaldi F Nessi M Phillips GC Roberts JB Stevenson PM Tonse SR Birman A Chung SU Etkin A Fernow RC Kirk H Protopopescu SD Willutzki H Hallman T Madansky L Bar-Yam Z Dowd J Kern W King E Mayes BW Pinsky LS 《Physical review D: Particles and fields》1990,41(1):13-16