Low energy, low rate experiments, such as searches for neutrinoless double $\ensuremath{\beta}$ decay and dark matter, require unprecedentedly levels of background in order to deliver their full science potential. $^{210}\mathrm{Po}$ driven, neutron induced background, caused by nuclear $(\ensuremath{\alpha},n)$ reactions on low-$Z$ materials, direct contributions the $^{210}\mathrm{Po}\phantom...

Evidence is presented to show that cells of the ependymal layer surrounding the ventricles of the mammalian (rat) forebrain act as neural stem cells (NSCs), and that these cells can be activated to divide by a combination of injury and growth factor stimulation. Several markers of asymmetric cell division (ACD), a characteristic of true stem cells, are expressed asymmetrically in the ependymal ...

Calculation of lung dose from established lung dosimetry models requires use of the unattached fraction of potential alpha energy concentration (PAEC) of radon progeny and the activity median diameter (AMD) of attached radon progeny, in addition to the total PAEC. In the present work, for indoor environments without the nucleation mode of aerosols, a method based on the wire screen penetration ...

Radon is a noble gas formed from the natural radioactive decay of uranium (U) and thorium (Th), natural components of the earth’s crust, which decay to radium (Ra) and then to radon (Rn). Decay chains include Ra and Rn for U; Ra and Rn for U; and Ra and Rn for Th. As radium decays, radon is formed and released into pores in the soil. Fissures and pores in the substrate allow the radon to migrat...

A thoron experimental house was constructed in a laboratory room of Helmholtz Zentrum München to perform exposure studies of thoron and its decay products under controlled conditions. The single room house (7.1 m(3)) was built from unfired clay stones and clay plaster. For the plaster of the inner side, the clay was mixed with granite powder enriched with (232)Th. The thoron inventory increased...

Aldosterone receptor blockade and thiazide therapy effectively lower blood pressure in geriatric hypertension. Their impact on sympathetic nervous system function has not been evaluated. In a double-blind, randomized study, 36 patients with stage 1 hypertension underwent 6 months of therapy with either aldosterone receptor blockade (spironolactone, n=19; 68+/-1 years) or hydrochlorothiazide (n=...