748 research outputs found
Exact Relativistic 'Antigravity' Propulsion
The Schwarzschild solution is used to find the exact relativistic motion of a
payload in the gravitational field of a mass moving with constant velocity. At
radial approach or recession speeds faster than 3^-1/2 times the speed of
light, even a small mass gravitationally repels a payload. At relativistic
speeds, a suitable mass can quickly propel a heavy payload from rest nearly to
the speed of light with negligible stresses on the payload.Comment: 4 pages, 3 figures, changed format only, attached 5 AVI files
(animated exact solutions of black holes incident on initially stationary
payloads
Concurrent TNFRSF1A R92Q and pyrin E230K mutations in a child with multiple sclerosis
We report a 16-year-old female patient with a severe course of multiple sclerosis and concomitant symptoms suggestive of a hereditary autoinflammatory disease. Genetic analyses revealed that she inherited a TNFRSF1A R92Q mutation from her mother and a pyrin E230K mutation from her father. To our knowledge, this is the first report of a patient with severe childhood multiple sclerosis and mutations in two genes which predispose to hereditary autoinflammatory disorders. We speculate that these mutations contribute to early multiple sclerosis manifestation and enhance the inflammatory damage inflicted by the autoimmune response
Introgression of wheat DNA markers from A, B and D genomes in early generation progeny of Aegilops cylindrica Host × Triticum aestivum L. hybrids
Introgression from allohexaploid wheat (Triticum aestivum L., AABBDD) to allotetraploid jointed goatgrass (Aegilops cylindrica Host, CCDD) can take place in areas where the two species grow in sympatry and hybridize. Wheat and Ae. cylindrica share the D genome, issued from the common diploid ancestor Aegilops tauschii Coss. It has been proposed that the A and B genome of bread wheat are secure places to insert transgenes to avoid their introgression into Ae. cylindrica because during meiosis in pentaploid hybrids, A and B genome chromosomes form univalents and tend to be eliminated whereas recombination takes place only in D genome chromosomes. Wheat random amplified polymorphic DNA (RAPD) fragments, detected in intergeneric hybrids and introgressed to the first backcross generation with Ae. cylindrica as the recurrent parent and having a euploid Ae. cylindrica chromosome number or one supernumerary chromosome, were assigned to wheat chromosomes using Chinese Spring nulli-tetrasomic wheat lines. Introgressed fragments were not limited to the D genome of wheat, but specific fragments of A and B genomes were also present in the BC1. Their presence indicates that DNA from any of the wheat genomes can introgress into Ae. cylindrica. Successfully located RAPD fragments were then converted into highly specific and easy-to-use sequence characterised amplified regions (SCARs) through sequencing and primer design. Subsequently these markers were used to characterise introgression of wheat DNA into a BC1S1 family. Implications for risk assessment of genetically modified wheat are discusse
Patterns of Coastal Land Cover and Estuarine Habitat Quality: Application of Long-term Monitoring Data
2008 S.C. Water Resources Conference - Addressing Water Challenges Facing the State and Regio
Dipole radio-frequency power from laser plasmas with no dipole moment
The radio-frequency power radiated from laser-target plasmas in a vacuum can
be orders of magnitude greater than expected from such sources that have a
negligible electric dipole moment. A model combining the Tidman-Stamper circuit
model of a laser-target plasma with the theory of radiation from currents
immersed in plasmas, however, predicts scaling of electric-dipole power
radiated from laser plasmas in agreement with experiments.Comment: 3 pages, 2 figures, as published in Applied Physics Letter
Research on the properties of binary liquid metal systems with lithium as one component - The electrical resistivity of liquid lithium saturated with cesium Final report
Electrical resistivity of liquid lithium saturated with cesiu
First generation of optical fiber phase reference distribution system for TESLA
This report describes the design of a phase stable Fiber Optic (FO) link for the TESLA technology based projects. The concept of this long optical link, with a feedback system suppressing long term drifts of the RF signal phase is described. Stability requirements are given and most important design issues affecting the system performance are discussed. The technical design issues of system components like laser transmitter and optical phase shifter are described in detail. Last sections depict the software developed for system control and experimental results obtained after system was assembled
Bouncing Neutrons and the Neutron Centrifuge
The recent observation of the quantum state of the neutron bouncing freely
under gravity allows some novel experiments. A method of purifying the ground
state is given, and possible applications to the measurement of the electric
dipole moment of the neutron and the short distance behaviour of gravity are
discussed.Comment: 7 pages, 7 figure
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