Relation between mutation yield and cell lethality over a wide range of X-ray and fission neutron doses in maize

Dry maize seeds, of a genetic stock heterozygous for the yellow-green locus (Yg^ Λ ^ ) ι were irradiated with fission neutron doses up to 2700 rads and with 250 kVp X-rays to 40 000 rads. The frequency of yellow-green (yg) sectors in seedling leaves 4 and 5 is largely a measure of the frequency of breakage (or incomplete exchange) and loss of the part of the short arm of chromosome I X carrying Yj>. Plots of dose versus yj* sector frequency per leaf show a linear increase with neutrons which reaches a maximum (leaf 4 = S. 5, leaf 5 = 2. 5) followed by a rapid decline; and a curvilinear increase with X-rays reaching a higher maximum (leaf 4 = 8. 5, leaf 5 = 3.6) followed by a decrease. The observed rise and subsequent fall of numbers of yg_ mutations can be accounted for by a model in which the decline of the curves is due to cell killing which may also be due to chromosome breakage and deletion. The interpretation is based on the principles of the dual action theory, which explains radiobiological action in terms of microdosimetry. One of the observations accounted for is the higher maximum mutation rate for X-rays as compared to neutrons

A History of the Early Fairfield Town Lots

In 1732 Charles Carroll of Maryland received a grant of 5000 acres of land in present Adams County, Pennsylvania, from the authorities of Maryland. Soon after, a survey of that land, known as “Carroll’s Tract” or “Carroll’s Delight,” was conducted. At that point in time there was still some dispute over the location of the boundary between the two states. A temporary line was agreed upon in 1739, and a more permanent line (very near that temporary boundary) was surveyed by Charles Mason and Jeremiah Dixon during the 1760s. And even though it was established that Carroll’s Tract was in Pennsylvania, an agreement was made that Marylanders would retain their rights to the lands previously granted to them. But it is important to note that at an early date the people settling in this area knew they were in Pennsylvania. According to Charles H. Glatfelter, the most respected of local historians, “the widely held and long persisting notion that until many years later people did not know where the boundary line was and that it shifted from time to time has no basis whatsoever in fact.” [excerpt

Physics and Detectors at the LHC and the SLHC

The capabilities of the ATLAS and CMS detectors being prepared for the LHC are reviewed. Examples of physics signals accessible during early running and during mature high luminosity LHC operation are examined. The planning and options for the LHC and these detectors to increase the luminosity to 10^{35}cm^{-2}s^{-1} is presented. This upgrade, entitled the Super LHC (SLHC), would occur in the next decade. The resulting physics scope is discussed.Comment: Invited talk at 2005 International Linear Collider Physics and Detector Workshop and Second ILC Accelerator Workshop, Snowmass, CO (Snowmass05), 3 pages, PD

Southeasterly Town Lot Histories of Fairfield, Pennsylvania

Each lot history give the original lot number, original owner, the current address, the owner of the lot in 1860, a description of the lot or dwelling in 1860, a recital of ownership with as much detail as is known, a comprehensive lot history, any known residents in 1860 (may be different than lot owner), and any family notes on any residents mentioned in the lot history. The research is comprehensive, but not necessarily exhaustive. Thorough information for all lots was not always available to the researcher

Rural Fairfield Property Histories

Each lot history give the original lot number, original owner, the current address, the owner of the lot in 1860, a description of the lot or dwelling in 1860, a recital of ownership with as much detail as is known, a comprehensive lot history, any known residents in 1860 (may be different than lot owner), and any family notes on any residents mentioned in the lot history. The research is comprehensive, but not necessarily exhaustive. Thorough information for all lots was not always available to the researcher

Variable resistance constant tension and lubrication device

A variable resistance device is described which includes a cylindrical housing having elongated resistance wires. A movable arm having a supporting block carried on the outer end is rotatably carried by the cylindrical housing. An arcuate steel spring member is pivotally supported by the movable arm. A leather wiper member is carried adjacent to one end of the spring steel member, and an electrically conductive surface is carried adjacent to the other end. The supporting block maintains the spring steel member in compression so that a constant pressure is applied to the conductive end of the spring steel member and the leather wiper. The leather wiper is saturated with a lubricating oil for maintaining the resistance wire clean as the movable arm is manipulated

Northern Town Lot Histories of Fairfield, Pennsylvania

Each lot history give the original lot number, original owner, the current address, the owner of the lot in 1860, a description of the lot or dwelling in 1860, a recital of ownership with as much detail as is known, a comprehensive lot history, any known residents in 1860 (may be different than lot owner), and any family notes on any residents mentioned in the lot history. The research is comprehensive, but not necessarily exhaustive. Thorough information for all lots was not always available to the researcher

Communications system for zero-g simulation tests in water

System connects seven observers, diver, and spare station, and utilizes public address system with underwater speakers to provide two-way communications between test subject and personnel in control of life support, so that test personnel are warned immediately of malfunction in pressure suit or equipment