Preliminary Results from a Study of the Effect of Deer Browsing on Bearded and Unbearded Wheat Yield

Wheat is an important agronomic crop that is a common winter food source for white-tailed deer (Odocoileus virginianus) in agricultural landscapes. In 2007 and 2008, I investigated spatial and temporal browsing on 2 types of wheat (bearded and unbearded) in fields bordered on one side by a forest. I placed 960 4.6 m2 plots in the middle of 10 m distance classes (5m, 15m, 25m, 35m, 45m, 55m). In 2007, I systematically assigned 1 of 2 treatments (no protection, protected at planting), and in 2008, I added a third treatment, protected prior to heading. After head emergence, I conducted weekly browse surveys and collected biomass samples. I harvested a 1 m2 area in the middle of each plot to determine yield . We used a two-way ANOVA with the main effects of wheat type and protection to determine the impact on yield. The main effects did not interact to affect yield either year (P\u3e0.05). In 2007, bearded wheat yielded 523.7 kg/ha greater than unbearded wheat (P\u3c0.001), whereas the opposite was true in 2008 with unbearded yielding 155.3 kg/ha greater (P\u3c0.001). In 2007, deer browsing increased yield by 284.8 kg/ha (P\u3c0.015), conversely in 2008, fully protected wheat yielded 226.3 kg/ha greater than all other treatments (P\u3c0.008). Browsing increased in intensity as head development progressed with most browsing occurring on the unbearded wheat. Our results varied annually, which suggests that factors other than deer browsing may be more important to determining wheat yield. More research is needed to better elucidate the effect of deer browse on wheat yield

Abstract 224: Sub-cytotoxic Levels of Heavy Metals Induce Pro-inflammatory Signaling in the Aortic Endothelium without Impairing Flow-Mediated Dilation in Rats

Introduction: Acute exposure to tobacco or marijuana secondhand smoke (SHS) causes endothelial dysfunction. The identity of specific SHS constituents that cause vascular toxicity is unclear. Heavy metals are present in SHS and at elevated levels in the blood of smokers, and may mediate acute endothelial dysfunction through reactive oxygen species formation and decreasing NO bioavailability. We assessed the effects of exposure to cadmium, lead, mercury, and arsenic at levels present in the blood of human smokers on flow-mediated dilation (FMD) as a measure of endothelial function in rats. We also evaluated the effects of heavy metal exposure on intimal structure, protein localization pattern, and inflammatory gene expression in the aortic endothelium. Hypothesis: Sub-cytotoxic levels of heavy metals impair FMD, alter intimal structure, and induce pro-inflammatory signaling in endothelium. Methods: We injected rats (n=8/group) with heavy metal cocktail or vehicle intravenously and quantitated pre- and post-exposure FMDs measures defined as percent vasodilation of femoral artery after transient ischemia. We performed en face aorta immunostaining and assessed endothelial cell axis alignment, cell length ratio, and localization pattern of PECAM-1, VE-cadherin, and vimentin. We also quantified gene expression of key endothelial proteins in aorta homogenates. Results: FMD was not impaired in the heavy metal group (8.8±3.6(SD)% vs. 12.9±8.0%, p=.31 or controls (7.5±2.7% vs. 8.8±5.8%, p=.63). No significant difference in cell length ratio and endothelial x and y axes of alignment were detected between groups (p>.8) and localization of PECAM-1, VE-cadherin, and vimentin in the aorta endothelium remained unaltered following heavy metal injection. However, expression of PECAM-1 and VE-cadherin was significantly lower in the heavy metal-treated rats, while VCAM-1 gene expression was significantly higher (p<.05). Conclusion: Acute exposure to sub-cytotoxic levels of heavy metals can induce pro-inflammatory signaling in endothelium, which could potentially lead to vascular injury. However, FMD and endothelial structure remain unchanged by heavy metal exposure

Evaluating the long-term storage of Cryphonectria parasitica

Isolates of the Chestnut blight pathogen, Cryphonectria parasitica, from six populations in Michigan, were stored in the late 1990s as agar plugs of mycelium in vials of sterile water held at room temperature. Approximately 29% of the fungal isolates were infected with mycoviruses at the time of storage. Each isolate was tested for revivification effectiveness by taking aliquots from vials filled with agar plugs of C. parasitica and sterile water and plating onto potato dextrose agar. Average revivification success was 70.5% across populations with a range of 33—84% within populations. In situations where vials had dried out during storage, success was low (4%), while success for vials that retained sterile water averaged 90%. Most importantly however, is the loss of mycoviruses from stored isolates; only 2 of 119 stored mycovirus infected isolates still contained mycoviruses after storage, suggesting that the double-stranded RNA mycoviruses are degraded during storage

Assessing Surgical Task Load and Performance: A Comparison of Simulation and Maritime Operation

The article of record as published may be found at http://dx.doi.org/10.1093/milmed/usz297This study examined the effects of simulated and actual vessel motion at high seas on task load and surgical performance. Methods: This project was performed in phases. Phase I was a feasibility study. Phase II utilized a motion base simulator to replicate vessel motion. Phase III was conducted aboard the U.S. Naval Ship Brunswick. After performing surgical tasks on a surgical simulation mannequin, participants completed the Surgical Task Load Index (TLX) designed to collect workload data. Simulated surgeries were evaluated by subject matter experts. Results: TLX scores were higher in Phase III than Phase II, particularly at higher sea states. Surgical performance was not significantly different between Phase II (84%) and Phase III (89%). Simulated motions were comparable in both phases. Conclusions: Simulated motion was not associated with a significant difference in surgical performance or deck motion, suggesting that this simulator replicates the conditions experienced during surgery at sea on the U.S. Naval Ship Brunswick. However, Surgical TLX scores were dramatically different between the two phases, suggesting increased workload at sea, which may be the result of time at sea, the stress of travel, or other factors. Surgical performance was not affected by sea state in either phase.Bureau of Medicine USN; OPNAV N-81 Assessments Division, Medical Analysis Branch; Navy Advanced Medical Development; Naval Surface Warfare Center, PC.Phase I of this study was sponsored by the Office of Naval Research. Phase II was sponsored by the Office of the Chief of Naval Operations (OPNAV) N-81 Assessments Division, Medical Analysis Branch (N813). Phase III was sponsored by the OPNAV N-81 (N813) and Navy Advanced Medical Development (AMD).Bureau of Medicine USN; OPNAV N-81 Assessments Division, Medical Analysis Branch; Navy Advanced Medical Development; Naval Surface Warfare Center, PC.Phase I of this study was sponsored by the Office of Naval Research. Phase II was sponsored by the Office of the Chief of Naval Operations (OPNAV) N-81 Assessments Division, Medical Analysis Branch (N813). Phase III was sponsored by the OPNAV N-81 (N813) and Navy Advanced Medical Development (AMD)

Epigenetic and Genetic Influences on DNA Methylation Variation in Maize Populations

DNA methylation is a chromatin modification that is frequently associated with epigenetic regulation in plants and mammals. However, genetic changes such as transposon insertions can also lead to changes in DNA methylation. Genome-wide profiles of DNA methylation for 20 maize (Zea mays) inbred lines were used to discover differentially methylated regions (DMRs). The methylation level for each of these DMRs was also assayed in 31 additional maize or teosinte genotypes, resulting in the discovery of 1966 common DMRs and 1754 rare DMRs. Analysis of recombinant inbred lines provides evidence that the majority of DMRs are heritable. A local association scan found that nearly half of the DMRs with common variation are significantly associated with single nucleotide polymorphisms found within or near the DMR. Many of the DMRs that are significantly associated with local genetic variation are found near transposable elements that may contribute to the variation in DNA methylation. Analysis of gene expression in the same samples used for DNA methylation profiling identified over 300 genes with expression patterns that are significantly associated with DNA methylation variation. Collectively, our results suggest that DNA methylation variation is influenced by genetic and epigenetic changes that are often stably inherited and can influence the expression of nearby genes

Dietary flavanol intervention lowers the levels of endothelial microparticles in coronary artery disease patients

Current evidence suggests that regenerative v. degenerative endothelial responses can be integrated in a clinical endothelial phenotype, reflecting the net result between damage from risk factors and endogenous repair capacity. We have previously shown that a cocoa flavanol (CF) intervention can improve endothelial function and increase the regenerative capacity of the endothelium by mobilising circulating angiogenic cells in patients with coronary artery disease (CAD). The aim of the present study was to investigate whether CF can lower the levels of circulating endothelial microparticles (EMP), markers of endothelial integrity, along with improvements in endothelial function. The levels of EMP in the frozen plasma samples of CAD patients were measured along with endothelial function (flow-mediated vasodilation, FMD); n 16, FMD data published previously), and these data were compared with those of young (n 12) and age-matched (n 12) healthy control subjects. The CAD patients exhibited significantly increased levels of EMP along with impaired FMD when compared with the healthy control subjects. The levels of CD144+ and CD31+/41− EMP were inversely correlated with FMD (r − 0·67, P= 0·01 and r − 0·59, P= 0·01, respectively). In these CAD patients, the levels of EMP were measured after they had consumed a drink containing 375 mg of CF (high-CF intervention, HiFI) or 9 mg of CF (macro- and micronutrient-matched low-CF control, LoFl) twice daily over a 30-d period in a randomised, double-blind, cross-over study. After 1 month of HiFI, the levels of CD31+/41− and CD144+ EMP decreased ( − 25 and − 23 %, respectively), but not after LoFl. Our data show that flavanols lower the levels of EMP along with higher endothelial function, lending evidence to the novel concept that flavanols may improve endothelial integrity

Independent age estimates resolve the controversy of ancient human footprints at White Sands

Human footprints at White Sands National Park, New Mexico, USA, reportedly date to between ~23,000 and 21,000 years ago according to radiocarbon dating of seeds from the aquatic plant Ruppia cirrhosa. These ages remain controversial because of potential old carbon reservoir effects that could compromise their accuracy. We present new calibrated 14C ages of terrestrial pollen collected from the same stratigraphic horizons as those of the Ruppia seeds, along with optically stimulated luminescence ages of sediments from within the human footprint–bearing sequence, to evaluate the veracity of the seed ages. The results show that the chronologic framework originally established for the White Sands footprints is robust and reaffirm that humans were present in North America during the Last Glacial Maximum

Evaluation of bacteriophage as an adjunct therapy for treatment of peri-prosthetic joint infection caused by Staphylococcus aureus

Phage therapy offers a potential alternate strategy for the treatment of peri-prosthetic joint infection (PJI), particularly where limited effective antibiotics are available. We undertook preclinical trials to investigate the therapeutic efficacy of a phage cocktail, alone and in combination with vancomycin, to reduce bacterial numbers within the infected joint using a clinically-relevant model of Staphylococcus aureus-induced PJI. Infected animals were randomised to 4 treatment groups, with treatment commencing 21-days post-surgery: bacteriophage alone, vancomycin alone, bacteriophage and vancomycin, and sham. At day 28 post-surgery, animals were euthanised for microbiological and immunological assessment of implanted joints. Treatment with phage alone or vancomycin alone, led to 5-fold and 6.2-fold reductions, respectively in bacterial load within peri-implant tissue compared to shamtreated animals. Compared to sham-treated animals, a 22.5-fold reduction in S. aureus burden was observed within joint tissue of animals that were administered phage in combination with vancomycin, corresponding with decreased swelling in the implanted knee. Microbiological data were supported by evidence of decreased inflammation within the joints of animals administered phage in combination with vancomycin, compared to sham-treated animals. Our findings provide further support for phage therapy as a tolerable and effective adjunct treatment for PJI

Extensive Gains and Losses of Olfactory Receptor Genes in Mammalian Evolution

Odor perception in mammals is mediated by a large multigene family of olfactory receptor (OR) genes. The number of OR genes varies extensively among different species of mammals, and most species have a substantial number of pseudogenes. To gain some insight into the evolutionary dynamics of mammalian OR genes, we identified the entire set of OR genes in platypuses, opossums, cows, dogs, rats, and macaques and studied the evolutionary change of the genes together with those of humans and mice. We found that platypuses and primates have <400 functional OR genes while the other species have 800–1,200 functional OR genes. We then estimated the numbers of gains and losses of OR genes for each branch of the phylogenetic tree of mammals. This analysis showed that (i) gene expansion occurred in the placental lineage each time after it diverged from monotremes and from marsupials and (ii) hundreds of gains and losses of OR genes have occurred in an order-specific manner, making the gene repertoires highly variable among different orders. It appears that the number of OR genes is determined primarily by the functional requirement for each species, but once the number reaches the required level, it fluctuates by random duplication and deletion of genes. This fluctuation seems to have been aided by the stochastic nature of OR gene expression

The Evolution of Mammalian Gene Families

Gene families are groups of homologous genes that are likely to have highly similar functions. Differences in family size due to lineage-specific gene duplication and gene loss may provide clues to the evolutionary forces that have shaped mammalian genomes. Here we analyze the gene families contained within the whole genomes of human, chimpanzee, mouse, rat, and dog. In total we find that more than half of the 9,990 families present in the mammalian common ancestor have either expanded or contracted along at least one lineage. Additionally, we find that a large number of families are completely lost from one or more mammalian genomes, and a similar number of gene families have arisen subsequent to the mammalian common ancestor. Along the lineage leading to modern humans we infer the gain of 689 genes and the loss of 86 genes since the split from chimpanzees, including changes likely driven by adaptive natural selection. Our results imply that humans and chimpanzees differ by at least 6% (1,418 of 22,000 genes) in their complement of genes, which stands in stark contrast to the oft-cited 1.5% difference between orthologous nucleotide sequences. This genomic “revolving door” of gene gain and loss represents a large number of genetic differences separating humans from our closest relatives