20,477 research outputs found
Recommended from our members
Evolution: functional evolution of nuclear structure.
The evolution of the nucleus, the defining feature of eukaryotic cells, was long shrouded in speculation and mystery. There is now strong evidence that nuclear pore complexes (NPCs) and nuclear membranes coevolved with the endomembrane system, and that the last eukaryotic common ancestor (LECA) had fully functional NPCs. Recent studies have identified many components of the nuclear envelope in living Opisthokonts, the eukaryotic supergroup that includes fungi and metazoan animals. These components include diverse chromatin-binding membrane proteins, and membrane proteins with adhesive lumenal domains that may have contributed to the evolution of nuclear membrane architecture. Further discoveries about the nucleoskeleton suggest that the evolution of nuclear structure was tightly coupled to genome partitioning during mitosis
Higgs Boson Production with Bottom Quarks at Hadron Colliders
We present results for the production cross section of a Higgs Boson with a
pair of bottom/anti-bottom quarks, including next-to-leading order (NLO) QCD
corrections.Comment: 3 pages, 2 figures, uses ws-ijmpa.cls. Talk given by C.B. Jackson at
the Meeting of the Division of Particles and Fields (DPF2004) in Riverside,
CA, August 26-31, 200
Theoretical progress for the associated production of a Higgs boson with heavy quarks at hadron colliders
The production of a Higgs boson in association with a pair of top-antitop or
bottom-antibottom quarks plays a very important role at both the Tevatron and
the Large Hadron Collider. The theoretical prediction of the corresponding
cross sections has been improved by including the complete next-to-leading
order QCD corrections. After a brief introduction, we review the results
obtained for both the Tevatron and the Large Hadron Collider.Comment: 3 pages, 6 figures, uses svjour.cls. Talk given by L. Reina at the
HEP2003 Europhysics Conference in Aachen, Germany (EPS 2003), July 17-23,
200
A simple encoding of a quantum circuit amplitude as a matrix permanent
A simple construction is presented which allows computing the transition
amplitude of a quantum circuit to be encoded as computing the permanent of a
matrix which is of size proportional to the number of quantum gates in the
circuit. This opens up some interesting classical monte-carlo algorithms for
approximating quantum circuits.Comment: 6 figure
Study and applications of retrodirective and self-adaptive electromagnetic wave controls to a Mars probe Quarterly report, 1 Oct. - 31 Dec. 1965
Design feasibility and applications of adaptive antenna circuits for deep space communication - antenna concepts, environmental effects, and phase lock loops and adaptive circuitr
The influence of altitude on the anaerobic and aerobic capacities of men in work Final scientific report
Altitude influence on anaerobic and aerobic capacities of working me
Pulmonary arterial remodeling revealed by microfocal x-ray tomography
Animal models and micro-CT imaging are useful for understanding the functional consequences of, and identifying the genes involved in, the remodeling of vascular structures that accompanies pulmonary vascular disease. Using a micro-CT scanner to image contrast-enhanced arteries in excised lungs from fawn hooded rats (a strain genetically susceptible to hypoxia induced pulmonary hypertension), we found that portions of the pulmonary arterial tree downstream from a given diameter were morphometrically indistinguishable. This \u27self-consistency\u27 property provided a means for summarizing the pulmonary arterial tree architecture and mechanical properties using a parameter vector obtained from measurements of the contiguous set of vessel segments comprising the longest (principal) pathway and its branches over a range of vascular pressures. This parameter vector was used to characterize the pulmonary vascular remodeling that occurred in rats exposed to a hypoxic (11.5% oxygen) environment and provided the input to a hemodynamic model relating structure to function. The major effect of the remodeling was a longitudinally (pulmonary artery to arterioles) uniform decrease in vessel distensibility that resulted in a 90% increase in arterial resistance. Despite the almost uniform change in vessel distensibility, over 50% of the resistance increase was attributable to vessels with unstressed diameters less than 125 microns
- …