Ionizing irradiation and the salivary gland sequelae

Salivary gland damage due to radiotherapy, leading to xerostomia and causing a great of suffering to patients, is a phenomenon known since the beginning of this century. The mechanism responsible for it has not been elucidated and no adequate treatment for patients is available. According to the mechanism suggested for the parotid irradiation-induced specific damage, the injurious agents resulting in delayed serous cell death, leading to specific parotid radiosensitivity, are transition, highly redox active metal ions, such as Fe and Cu, associated with secretion granules. These ions enhance the lethal effect that irradiation has on DNA, resulting in a reproductive delayed cell death. The immediate effects of metal-mediated enhancement of irradiation damage in cells may occur but does not seem to play a major role in the underlying mechanism. Indeed, in a series of recent experiments, it was succeeded in positively correlating an extended time point (two months) protection of parotid function with preirradiation degranulation and redox active metal ion mobilization out of the gland into the secreted saliva prior to irradiation. In contrast, a negative correlation in the submandibular gland, with no protection, no degranulation, no metal ion mobilization and no redox activity was demonstrated. The ability to protect the parotid function at two months with Zn-DFO, a specific transition metal ion mobilizer, from sensitive intracellular targets lends further credence to these studies.Biomedical Reviews 1998; 9: 121-129

Neutron diffraction in a model itinerant metal near a quantum critical point

Neutron diffraction measurements on single crystals of Cr1-xVx (x=0, 0.02, 0.037) show that the ordering moment and the Neel temperature are continuously suppressed as x approaches 0.037, a proposed Quantum Critical Point (QCP). The wave vector Q of the spin density wave (SDW) becomes more incommensurate as x increases in accordance with the two band model. At xc=0.037 we have found temperature dependent, resolution limited elastic scattering at 4 incommensurate wave vectors Q=(1+/-delta_1,2, 0, 0)*2pi/a, which correspond to 2 SDWs with Neel temperatures of 19 K and 300 K. Our neutron diffraction measurements indicate that the electronic structure of Cr is robust, and that tuning Cr to its QCP results not in the suppression of antiferromagnetism, but instead enables new spin ordering due to novel nesting of the Fermi surface of Cr.Comment: Submitted as a part of proceedings of LT25 (Amsterdam 2008

Risk Management for Ag Families: An Extension Model for Improving Family Business Success

A risky business environment for agricultural producers coupled with human risk elements unique to family businesses, points to the need for extension programs that integrate traditional risk management concepts into curriculums focused on the potentially unique educational needs of family farm management teams. Results in this paper indicate that a multi-state, grant funded program entitled "Risk Management for Ag Families" had impact and provides a model that traditional risk management education programs could benefit from.Risk and Uncertainty, Teaching/Communication/Extension/Profession,

Spin Wave Response in the Dilute Quasi-one Dimensional Ising-like Antiferromagnet CsCo_{0.83}Mg_{0.17}Br_3

Inelastic neutron scattering profiles of spin waves in the dilute quasi-one-dimensional Ising-like antiferromagnet CsCo_{0.83}Mg_{0.17}Br_3 have been investigated. Calculations of S^{xx}(Q,omega), based on an effective spin Hamiltonian, accurately describe the experimental spin wave spectrum of the 2J mode. The Q dependence of the energy of this spin wave mode follows the analytical prediction omega_{xx}(Q)=(2J)(1-5epsilon^{2}cos^{2}Qa+2epsilon^{2})^{1/2}, calculated by Ishimura and Shiba using perturbation theory.Comment: 13 pages, 4 figure

Sublattice Asymmetric Reductions of Spin Values on Stacked Triangular Lattice Antiferromagnet CsCoBr3_3

We study the reductions of spin values of the ground state on a stacked triangular antiferromagnet using the spin-wave approach. We find that the spin reductions have sublattice asymmetry due to the cancellation of the molecular field. The sublattice asymmetry qualitatively analyzes the NMR results of CsCoBr$_3$.Comment: 5pages, 5figure

XUV Opacity of Aluminum between the Cold-Solid to Warm-Plasma Transition

We present calculations of the free-free XUV opacity of warm, solid-density aluminum at photon energies between the plasma frequency at 15 eV and the L-edge at 73 eV, using both density functional theory combined with molecular dynamics and a semi-analytical model in the RPA framework with the inclusion of local field corrections. As the temperature is increased from room temperature to 10 eV, with the ion and electron temperatures equal, we calculate an increase in the opacity in the range over which the degree of ionization is constant. The effect is less pronounced if only the electron temperature is allowed to increase. The physical significance of these increases is discussed in terms of intense XUV-laser matter interactions on both femtosecond and picosecond time-scales.Comment: 4 pages, 3 figure