Nuclear effects in positive pion electroproduction on the deuteron near threshold

Positive pion electroproduction from the deuteron near threshold has been considered within an approach based on the unitary transformation method. The gauge independence of the treatment is provided by using an explicitly gauge independent expression for the reaction amplitude. The results of calculations for kinematics of the experiments on forward-angle $\pi^+$ meson electroproduction accomplished at Saclay and Jefferson Laboratory are discussed and compared with those given by the impulse approximation. It is shown that the observed behaviour of the cross sections is in accordance with the calculations based on the pion-nucleon dynamics. In particular, the pion production rate suppression in the $^2H(e,e'\pi^+)nn$ reaction compared to that for the $^1H(e,e'\pi^+)n$ one can be due to such ``nuclear medium'' effects as nucleon motion and binding along with Pauli blocking in the final $nn$ state.Comment: 15 pages, 8 figure

Theodoretou episcopou Kyrou, peri pronoias logoi deka = Theodoreti episcopi Cyri De providentia sermones X

Copia digital. Madrid : Ministerio de Educación, Cultura y Deporte. Subdirección General de Coordinación Bibliotecaria, 2013Sign.: [alpha]-[pi]8Port. con grab. xil. y con el escudo del cardenal Rodolfi, a quien está dedicada la obr

Livingston, Kincaid & Co

35-1Indian AffairsOn the Relief of Livingston, Kincaid, and Company. [968] Sioux depredations near fort Laramie.1858-12

Eastern band of Cherokee Indians

Part 1 of 245-2Indian AffairsEastern Band of Cherokees. [1823] Claim of North Carolina Cherokees against the Cherokee Nation based on the treaty of 29 Dec. 1835.1878-7

The biological effects of diagnostic cardiac imaging on chronically exposed physicians: the importance of being non-ionizing

Ultrasounds and ionizing radiation are extensively used for diagnostic applications in the cardiology clinical practice. This paper reviewed the available information on occupational risk of the cardiologists who perform, every day, cardiac imaging procedures. At the moment, there are no consistent evidence that exposure to medical ultrasound is capable of inducing genetic effects, and representing a serious health hazard for clinical staff. In contrast, exposure to ionizing radiation may result in adverse health effect on clinical cardiologists. Although the current risk estimates are clouded by approximations and extrapolations, most data from cytogenetic studies have reported a detrimental effect on somatic DNA of professionally exposed personnel to chronic low doses of ionizing radiation. Since interventional cardiologists and electro-physiologists have the highest radiation exposure among health professionals, a major awareness is crucial for improving occupational protection. Furthermore, the use of a biological dosimeter could be a reliable tool for the risk quantification on an individual basis

The Radiation Issue in Cardiology: the time for action is now

The "radiation issue" is the need to consider possible deterministic effects (e.g., skin injuries) and long-term cancer risks due to ionizing radiation in the risk-benefit assessment of diagnostic or therapeutic testing. Although there are currently no data showing that high-dose medical studies have actually increased the incidence of cancer, the "linear-no threshold" model in radioprotection assumes that no safe dose exists; all doses add up in determining cancer risks; and the risk increases linearly with increasing radiation dose. The possibility of deterministic effects should also be considered when skin or lens doses may be over the threshold. Cardiologists have a special mission to avoid unjustified or non-optimized use of radiation, since they are responsible for 45% of the entire cumulative effective dose of 3.0 mSv (similar to the radiological risk of 150 chest x-rays) per head per year to the US population from all medical sources except radiotherapy. In addition, interventional cardiologists have an exposure per head per year two to three times higher than that of radiologists. The most active and experienced interventional cardiologists in high volume cath labs have an annual exposure equivalent to around 5 mSv per head and a professional lifetime attributable to excess cancer risk on the order of magnitude of 1 in 100. Cardiologists are the contemporary radiologists but sometimes imperfectly aware of the radiological dose of the examination they prescribe or practice, which can range from the equivalent of 1-60 mSv around a reference dose average of 10-15 mSv for a percutaneous coronary intervention, a cardiac radiofrequency ablation, a multi-detector coronary angiography, or a myocardial perfusion imaging scintigraphy. A good cardiologist cannot be afraid of life-saving radiation, but must be afraid of radiation unawareness and negligence

breweri

Packera breweri (Burtt Davy) W.A. Weber & Á. LöveBrewer's ragwortCalifornia #25, along west side of road near ravineopen oak-pine savanna

parviflora

Anemone parviflora Michx.Gwen WalkerSpecimens collected along the Bow River, near the Mount Eisenhower Research Station (Dept. of Forestry), about 20 miles west of Banff, Alberta

forma Shirley

Papaver rhoeas L.Shirley PoppyShirley CoquelicotE. BorkentPoppy collected from the Borkent garden, Horticultural Station, Brooks, Alberta (Hort. Station). Shirley poppies have been obtained by selection and elimination. Flowers are medium pink in color

parviflora

Luzula parviflora (Ehrhart) Desvauxsmall-flowered woodrushluzule parvifloreparvifloraMt. RichardsNorth East 60� slope5000 feetAbies lasiocarpa, Piceaher