Sampling for Explosives-Residues at Fort Greely,Alaska

Fort Greely, Alaska has an extensive complex of weapon training and testing areas located on lands withdrawn from the public domain under the Military Lands Withdrawal Act (PL106-65). The Army has pledged to implement a program to identify possible munitions contamination. Because of the large size (344,165,000 m²) of the high hazard impact areas, characterization of these constituents will be difficult. We used an authoritative sampling design to find locations most likely to contain explosives-residues on three impact areas. We focused our sampling on surface soils and collected multi-increment and discrete samples at locations of known firing events and from areas on the range that had craters, pieces of munitions, targets, or a designation as a firing point. In the two impact areas used primarily by the Army, RDX was the most frequently detected explosive. In the impact area that was also used by the Air Force, TNT was the most frequently detected explosive. Where detected, the explosives concentrations generally were low (<0.05 mg/kg) except in soils near low-order detonations, where the explosive-filler was in contact with the soil surface. These low-order detonations potentially can serve as localized sources for groundwater contamination if positioned in recharge areas.     

Systematics within Gyps vultures: a clade at risk

Background  

Populations of the Oriental White-backed Vulture (Gyps bengalensis) have declined by over 95% within the past decade. This decline is largely due to incidental consumption of the non-steroidal anti-inflammatory veterinary pharmaceutical diclofenac, commonly used to treat domestic livestock. The conservation status of other Gyps vultures in southern Asia is also of immediate concern, given the lack of knowledge regarding status of their populations and the continuing existence of taxonomic uncertainties. In this study, we assess phylogenetic relationships for all recognized species and the majority of subspecies within the genus Gyps. The continuing veterinary use of diclofenac is an unknown but potential risk to related species with similar feeding habits to Gyps bengalensis. Therefore, an accurate assessment of the phylogenetic relationships among Gyps vultures should aid in their conservation by clarifying taxonomic uncertainties, and enabling inference of their respective relatedness to susceptible G. bengalensis.     

Embryonal carcinoma-derived growth factor activates protein kinase C in vivo and in vitro.

We have recently reported that a polypeptide mitogen, the embryonal carcinoma-derived growth factor (ECDGF), induces phosphorylation of the epidermal growth factor (EGF) receptor in intact C3H 10T 1/2 mouse fibroblasts with concomittant loss of high affinity EGF binding sites. This phenomenon appears to be mediated through an activation of protein kinase C. Several groups have described an acidic 80,000 dalton protein substrate of protein kinase C. In this paper, we demonstrate that the addition of ECDGF or the phorbol ester TPA to intact C3H 10T 1/2 cells results in the enhanced phosphorylation of this 80 kd protein in vivo. Furthermore, this response is demonstrable in vitro. Thus the addition of ECDGF, the phorbol ester TPA, protein kinase C or phosphoinositidase C to crude membranes prepared from C3H 10T 1/2 cells resulted in the enhanced phosphorylation of this protein. Data obtained by phosphopeptide mapping of the 80 kd protein show that the ECDGF-induced activation of protein kinase C in our membrane preparations is comparable with that obtained in vivo. The availability of an in vitro system in which this response is preserved should now allow a detailed biochemical analysis of the steps between binding of a mitogen to its receptor and the activation of protein kinase C.     

On the mechanism of cellular cadmium uptake

Review of the available evidence on the mechanism of cellular Cd uptake in the rat jejunum supports the concept that this process consists of nonspecific binding to anionic sites on the membrane, followed by a temperature-dependent and rate-limiting internalization step. Because temperature-sensitive transmembrane movement of Cd can be demonstrated also in isolated brush-border vesicles and in erythrocyte ghosts, it is not likely to result from pinocytosis but may be related directly to membrane fluidity. There is no need to assume the existence of saturable Cd carriers, or competition of Cd with essential polyvalent cations for their specific transport systems. Uptake of Cd by tubular epithelium in the kidney of the intact rabbit appears to resemble that described for the jejunum, with the internalization step limiting the rate of uptake.     

Point mutations in the 23 S rRNA genes of four lincomycin resistant Nicotiana plumbaginifolia mutants could provide new selectable markers for chloroplast transformation

Summary Experiments designed to establish stable chloroplast transformation require selectable marker genes encoded by the chloroplast genome. The antibiotic lincomycin is a specific inhibitor of chloroplast ribosomal activity and is known to bind to the large ribosomal subunit. We have investigated a defined region of the chloroplast 23 S rRNA genes from four lincomycin resistant Nicotiana plumbaginifolia mutants and from wild-type N. plumbaginifolia. The mutants LR415, LR421 and LR446 have A to G transitions at positions equivalent to the nucleotides 2058 and 2059 in the Escherichia coli 23 S rRNA. The mutant, LR400, possesses a G to A transition at a position corresponding to nucleotide 2032 of the E. coli 23 S rRNA.