Ammunition Type and Shot Placement Determine Lead Fragmentation in Deer

Lead remnants from spent ammunition introduce health risks to humans and wildlife that consume game harvested with firearms. Most current research has focused on effects of high-velocity rifle bullets, whereas low-velocity lead ammunition has received little attention. We examined whether fragmentation characteristics differed between 3 common low-velocity ammunition types when shot into the thoracic cavity or shoulder of white-tailed deer (Odocoileus virginianus) culled in Indiana, USA, from May–September of 2009. We shot and subsequently radiographed 43 deer to determine the number of fragments, fragment size, and distance traveled by individual fragments. We also radiographed deer post-evisceration to determine the proportion of fragments available to humans and wildlife scavengers for consumption in muscle and visceral tissue, respectively. All radiographed deer had evidence of fragmentation, with a geometric mean of 13.1 (95% CI = 10.3, 16.8) fragments/deer. Most fragments (89%) were <5 mm from wound channels, and no fragment traveled beyond 205 mm from a wound channel. Fragments were often retained within the muscle tissue of deer with a geometric mean rate of 0.55 (95% CI = 0.48, 0.65). Muzzleloader bullet fragments were larger than those generated by rifled and sabot slugs, and sabot slug fragments had the shortest dispersal from wound channels. Shoulder-shot placement and bone contact for all ammunition resulted in a greater number of fragments (P < 0.01). Shoulder-shots also generated more small fragments and higher fragment retention in muscle tissue. The overall mean number of lead fragments detected across our ammunition treatments was less than previous studies. Our results indicate ammunition type and shot placement may be considerations for hunters wishing to limit their potential exposure to lead from harvested big game. Additionally, when compared to high-velocity rifle bullets, significantly fewer lead fragments are made available to humans and wildlife that consume game harvested with low-velocity ammunition types, such as those tested here. Complete elimination of lead ingestion by humans and wildlife, however, is only possible by using non-toxic ammunition alternatives. © 2020 The Wildlife Society.     

A stabilized demethoxyviridin derivative inhibits PI3 kinase

The viridins like demethoxyviridin (Dmv) and wortmannin (Wm) are nanomolar inhibitors of the PI3 kinases, a family of enzymes that play key roles in a host of regulatory processes. Central to the use of these compounds to investigate the role of PI3 kinase in biological systems, or as scaffolds for drug development, are the interrelated issues of stability, chemical reactivity, and bioactivity as inhibitors of PI3 kinase. We found that Dmv was an even more potent inhibitor of PI3 kinase than Wm. However, Dmv was notably less stable than Wm in PBS, with a half-life of 26 min versus Wm’s half-life of 3470 min. Dmv, like Wm, disappeared in culture media with a half-life of less than 1 min. To overcome Dmv’s instability, it was esterified at the C1 position, and then reacted with glycine at the C20 position. The resulting Dmv derivative, termed SA–DmvC20-Gly had a half-life of 218 min in PBS and 64 min in culture media. SA–DmvC20-Gly underwent an exchange reaction at the C20 position with N-acetyl lysine in a manner similar to a WmC20 derivative, WmC20-Proline. SA–DmvC20-Gly inhibited PI3 kinase with an IC₅₀ of 44 nM, compared to Wm’s IC₅₀ of 12 nM. These results indicate that the stability of Dmv can be manipulated by reactions at the C1 and C20 positions, while substantially maintaining its ability to inhibit PI3 kinase. Our results indicate it may be possible to obtain stabilized Dmv derivatives for use as PI3 kinase inhibitors in biological systems.     

Differences in the fatty acid composition of soybean seed produced in northern and southern areas of the U.S.A.

The fatty acid composition of soybean (Glycine max) seeds was sensitive to the influence of both genotype and environment. To quantify their relative environmental sensitivities, four soybean cultivars, Wells, Wayne, Cutler and Union, plus two experimental lines, 9656 and 9686, developed for lower concentrations of linolenate, were grown in Indiana (northern area) and Mississippi (southern area) in 1981. Seeds produced in the two environments were analysed for total oil content and for fatty acid composition. Seeds produced in the southern area were slightly higher (20% vs 16%) in oil content, but weighed significantly less than those produced in the north. The oil content per seed of seeds produced in the south was only 51% of the oil content of seeds produced in the north. Seeds produced in the south were significantly lower in both myristate and linolenate, but significantly higher in oleate than seeds produced in the north. Genotype by environment interactions for many oil quality measurements were largely attributable to the responses of the lines 9656 and 9686. These results indicate that higher environmental temperature reduced the linolenate concentration of soybean oil.     

Evaluating the Metal Tolerance Capacity of Microbial Communities Isolated from Alberta Oil Sands Process Water

Anthropogenic activities have resulted in the intensified use of water resources. For example, open pit bitumen extraction by Canada’s oil sands operations uses an estimated volume of three barrels of water for every barrel of oil produced. The waste tailings–oil sands process water (OSPW)–are stored in holding ponds, and present an environmental concern as they are comprised of residual hydrocarbons and metals. Following the hypothesis that endogenous OSPW microbial communities have an enhanced tolerance to heavy metals, we tested the capacity of planktonic and biofilm populations from OSPW to withstand metal ion challenges, using Cupriavidus metallidurans, a known metal-resistant organism, for comparison. The toxicity of the metals toward biofilm and planktonic bacterial populations was determined by measuring the minimum biofilm inhibitory concentrations (MBICs) and planktonic minimum inhibitory concentrations (MICs) using the MBEC ™ assay. We observed that the OSPW community and C. metallidurans had similar tolerances to 22 different metals. While thiophillic elements (Te, Ag, Cd, Ni) were found to be most toxic, the OSPW consortia demonstrated higher tolerance to metals reported in tailings ponds (Al, Fe, Mo, Pb). Metal toxicity correlated with a number of physicochemical characteristics of the metals. Parameters reflecting metal-ligand affinities showed fewer and weaker correlations for the community compared to C. metallidurans, suggesting that the OSPW consortia may have developed tolerance mechanisms toward metals present in their environment.     

Analysis by high-performance liquid chromatography of free amino acids extracted from needles of drought-stressed and shaded Pinus ponderosa seedlings

Free amino acid concentrations in needles of drought-stressed and shaded seedlings of ponderosa pine (Pinus ponderosa Dougl. ex Laws.) were analyzed to determine the influence of low irradiance on a biochemical response to drought stress. A convenient method was developed for separating and quantitating amino acids in needle extracts using derivatization with dansyl chloride and reversed-phase high-performance liquid chromatography (HPLC). Twenty-one amino acids were separated on an Ultrasphere ODS CIS column and detected with a fluorescence spectrophotometer. As little as 10 pmol of each were detected with good peak separation and reproducible retention times. The results of HPLC analysis showed that drought and shading induced an increase in total amino acid concentrations in needles; shading had the greater effect. Arginine and proline concentrations increased most in needles of drought-stressed seedlings and remained high in unshaded seedlings recovering from drought 48 h after rewatering. Arginine and glutamine increased most in the shaded seedlings, which did not survive severe drought. The large increase in arginine in both drought-stressed and severely shaded seedlings suggests that sequestering and storage of ammonia are important when stress reduces carbon fixation.