Developing a scientific basis for radiation risk estimates: goal of the DOE Low Dose Research Program.

The U.S. Department of Energy's Low Dose Radiation Research Program is a 10 y activity currently funded at $21 million per year.

Photodetachment of zwitterions: probing intramolecular Coulomb repulsion and attraction in the gas phase using mono-decarboxylated pyridinium dicarboxylates. Implications on the mechanism of orotidine 5'-monophosphate decarboxylase.

Negative ion photoelectron spectra resulting from the decarboxylation of nine zwitterionic pyridinium dicarboxylates (D(x,y)) are reported. Structural assignments are made on the basis of analogy to the spectra of related species, labeling experiments with (13)C- or (2)H-containing substrates, independent syntheses, and comparison to density functional theory and ab initio (B3LYP and CCSD(T), respectively) results. In some cases, an acid-catalyzed isomerization of the D(x,y)-CO(2) ions was found to take place.

Disposal and degradation of pesticide waste.

Generation of pesticide waste is inevitable during every agricultural operation from storage to use and equipment cleanup. Large-scale pesticide manufacturers can afford sophisticated recovery, treatment, and cleanup techniques. Small-scale pesticide users, for example, single farms or small application businesses, struggle with both past waste problems, including contaminated soils, and disposal of unused product and equipment rinsewater.

Methodology for quantifying residues of chlorhexidine in raw dairy milk.

A residue method was developed as part of a pharmacokinetics study to determine the elimination of chlorhexidine in raw milk after intramammary infusion into dairy cows affected with bovine mastitis. The developed liquid/liquid and solid-phase extraction procedures effectively reduced sources of milk product interferences in the final extract. By optimizing mobile-phase pH buffer/acetonitrile gradient conditions and employing an end-capped reverse-phase polar embedded-phase chromatographic column, excellent peak resolution was achieved without the additional need of mobile-phase amine modifiers or ion-pairing reagents.

Photodetachment of zwitterions: probing intramolecular coulomb repulsion and attraction in the gas phase using pyridinium dicarboxylate anions.

Zwitterions are critically important in many biological transformations and are used in numerous chemical processes. The consequences of electrostatic effects on reactivity and physical properties, however, are largely unknown. In this work, we report the results of negative ion photoelectron spectra of nine isomeric pyridinium dicarboxylate zwitterions and three nonzwitterionic methoxycarbonylpyridine carboxylate isomers (-O(2)CPyrCO(2)CH(3)).

Estimation of actinide skeletal content in humans based on bone samples collected at autopsy.

The USTUR has developed simple linear and multiple regression models for estimating skeletal actinide concentrations on the basis of bone samples collected at autopsies of non-whole body tissue donors. Bone samples usually collected include a clavicle, the patella(e), one or more ribs, the sternum, and a vertebral wedge cut from within the abdominal cavity. The described models were derived by regression analyses with the analytical results from those bones and the entire skeletons of eight whole body donations to the USTUR.

Coulomb- and antiferromagnetic-induced fission in doubly charged cubelike fe-s clusters.

We report the observation of symmetric fission in doubly charged Fe-S cluster anions, [Fe(4)S(4)X(4)](2-)-->2[Fe(2)S(2)X(2)](-) (X=Cl,Br), owing to both Coulomb repulsion and antiferromagnetic coupling. Photoelectron spectroscopy shows that both the parent and the fission fragments have similar electronic structures and confirms the inverted energy schemes due to the strong spin polarization of the Fe 3d levels. The current observation provides direct confirmation for the unusual spin couplings in the [Fe(4)S(4)X(4)](2-) clusters, which contain two valent-delocalized and ferromagnetically coupled Fe2S2 subunits.

Probing the electronic structure of [MoOS(4)](-) centers using anionic photoelectron spectroscopy.

Using photodetachment photoelectron spectroscopy (PES) in the gas phase, we investigated the electronic structure and chemical bonding of six anionic [Mo(V)O](3+) complexes, [MoOX(4)](-) (where X = Cl (1), SPh (2), and SPh-p-Cl (3)), [MoO(edt)(2)](-) (4), [MoO(bdt)(2)](-) (5), and [MoO(bdtCl(2))(2)](-) (6) (where edt = ethane-1,2-dithiolate, bdt = benzene-1,2-dithiolate, and bdtCl(2) = 3,6-dichlorobenzene-1,2-dithiolate). The gas-phase PES data revealed a wealth of new electronic structure information about the [Mo(V)O](3+) complexes. The energy separations between the highest occupied molecular orbital (HOMO) and HOMO-1 were observed to be dependent on the O-Mo-S-C(alpha) dihedral angles and ligand types, being relatively large for the monodentate ligands, 1.

Treating antisocial behavior: a context for substance abuse prevention.

A large body of literature illustrates an association between antisocial behavior and substance abuse. In the present paper, this association is reviewed from a behavioral-economic standpoint. It is suggested that childhood antisocial behavior is a behavioral complement of substance abuse, and that prosocial behavior is a substitute for substance abuse.

Imidacloprid residues in Willapa Bay (Washington State) water and sediment following application for control of burrowing shrimp.

Pesticides have been used in the Willapa Bay estuary in western Washington State to control the exotic invasive plant species Spartina alterniflora (cordgrass) and the native species of burrowing shrimp (Callianassa sp.; Upogebia sp.) that affect oyster production.

In search of covalently bound tetra- and penta-oxygen species: a photoelectron spectroscopic and Ab initio investigation of MO4- and MO5- (M = Li, Na, K, Cs).

Although neutral and ionic O4(0/-/+) species have been observed experimentally and considered for energetic materials, O4(2-) and O5(2-) dianions have not yet been explored. O4(2-) is valent isoelectronic to the well-known ClO3- and SO3(2-) anions, and O5(2-) is valent isoelectronic to ClO4- and SO4(2-). All are stable, common anions in solutions and inorganic salts.

WEB resources for pesticide toxicology, environmental chemistry, and policy: a utilitarian perspective.

Information about pesticides has grown exponentially over the last four decades and is marked by a diversity of sources including government, universities, environmental advocates, and industry. The internet has made access to this unprecedented amount of information faster than ever, but judging the validity and usefulness of the information is problematic. To avoid turning this discussion of web resources for pesticide information into a narrative about a personal 'top ten' list, a utilitarian perspective of resources useful to a research, educator, and risk communicator is elucidated.

Coordination of maternal directives with preschoolers' behavior: influence of maternal coordination training on dyadic activity and child compliance.

Investigated the impact of a specific intervention on child cooperation. The intervention was designed to increase maternal coordination with child behavior. Mothers assigned to the experimental condition were instructed on how to modulate the specificity of directives to their preschooler as a function of the child's moment-to-moment behavior.

Biomarkers of exposure and dose: state of the art.

Biomarkers provide methods to measure changes in biological systems and to relate them to environmental insults and disease processes. Biomarkers can be classified as markers of exposure and dose, markers of sensitivity, and markers of disease. It is important that the differences and applications of the various types of biomarkers be clearly understood.

Bulk-like features in the photoemission spectra of hydrated doubly charged anion clusters.

We produced gaseous hydrated clusters of sulfate and oxalate anions [SO4(2-)-(H2O)n and C2O4(2-)(H2O)n, where n = 4 to 40]. Photoelectron spectra of these clusters revealed that the solute dianions were in the center of the water cluster, (H2O)n. For small clusters, these spectra were characteristic of the respective solutes, but beyond the first solvation shell (n approximately 12), features in the spectra from the solutes were diminished and a new feature from ionization of water emerged, analogous to bulk aqueous solutions.

Organizational adoption of preemployment drug testing.

This study explored the adoption of preemployment drug testing by 360 organizations. Survival models were developed that included internal organizational and labor market factors hypothesized to affect the likelihood of adoption of drug testing. Also considered was another set of variables that included social and political variables based on institutional theory.

Observation of all-metal aromatic molecules.

Aromaticity is a concept invented to account for the unusual stability of an important class of organic molecules: the aromatic compounds. Here we report experimental and theoretical evidence of aromaticity in all-metal systems. A series of bimetallic clusters with chemical composition MAl4- (M = Li, Na, or Cu), was created and studied with photoelectron spectroscopy and ab initio calculations.