Scapulothoracic motion and muscle activity during the raising and lowering phases of an overhead reaching task

Scapulothoracic muscle activity is essential for normal scapulothoracic motion. While previous research has furthered the understanding of scapulothoracic motion and muscle activity during the raising phase of motion, a gap exists with respect to the lowering phase. The purpose of this study was to compare scapulothoracic motion and scapulothoracic muscle activity between the raising and lowering phases of an overhead reaching task. Twenty healthy subjects volunteered to participate in the study. Three-dimensional scapulothoracic motion was collected using an electromagnetic device. Surface electromyography (EMG) was used to assess muscle activity from the upper trapezius, lower trapezius, and serratus anterior muscles. Overall scapulothoracic motion was similar for the raising and lowering phases of the overhead reaching task. However, significantly lower EMG amplitude values existed during the lowering phase across all muscles. Less muscle activity during the lowering phase may reflect differing neuromuscular control strategies between arm raising and lowering. These findings suggest that scapulothoracic muscle activation levels during eccentric contractions may be closer to an activation threshold below which their ability to control scapulothoracic motion may be compromised subsequently leading to altered scapulothoracic motion (scapular dyskinesis). This provides a possible explanation for why scapular dyskinesis is more notable during the lowering phase of motion.     

Spatial risk modeling of cattle depredation by black vultures in the midwestern United States

Negative economic impacts resulting from wildlife disrupting livestock operations through depredation of stock are a cause of human-wildlife conflict. Management of such conflict requires identifying environmental and non-environmental factors specific to a wildlife species' biology and ecology that influence the potential for livestock depredation to occur. Identification of such factors can improve understanding of the conditions placing livestock at risk. Black vultures (Coragyps atratus) have expanded their historical range northward into the midwestern United States. Concomitantly, an increase in concern among agricultural producers regarding potential black vulture attacks on livestock has occurred. We estimated area with greater or lesser potential for depredation of domestic cattle by black vultures across a 6-state region in the midwestern United States using an ensemble of small models (ESM). Specifically, we identified landscape-scale spatial factors, at a zip code resolution, associated with reported black vulture depredation on cattle in midwestern landscapes to predict future potential livestock depredation. We hypothesized that livestock depredation would be greatest in areas with intensive beef cattle production close to preferred black vulture habitat (e.g., areas with fewer old fields and early successional vegetation paired with more direct edge between older forest and agricultural lands). We predicted that the density of cattle within the county, habitat structure, and proximity to anthropogenic landscape features would be the strongest predictors of black vulture livestock-depredation risk. Our ESM estimated the relative risk of black vulture-cattle depredation to be between 0.154–0.631 across our entire study area. Consistent with our hypothesis, areas of greatest predicted risk of depredation correspond with locations that are favorable to vulture life-history requirements and increased potential to encounter livestock. Our results allow wildlife managers the ability to predict where black vulture depredation of cattle is more likely to occur in the future. It is in these areas where extension and outreach efforts aimed at mitigating this conflict should be focused. Researchers and wildlife managers interested in developing or employing tools aimed at mitigating livestock-vulture conflicts can also leverage our results to select areas where depredation is most likely to occur.     

The development and characterization of a chemical probe targeting PRMT1 over PRMT5

Protein arginine methyltransferases (PRMTs) are a family of mammalian enzymes catalyzing the symmetric dimethylation (Type I), asymmetric dimethylation (Type II), or monomethylation (Type III) of arginine residues within proteins. This family is composed of 11 isozymes, however the vast majority of asymmetric and symmetric dimethylation in mammals is completed by either PRMT1 or PRMT5, respectively. In recent years, a number of chemical probes targeting this family of enzymes have been developed, but the majority of these probes lack isozyme specificity. Herein, we report the development of a chemical probe, based on a non-natural peptide sequence, which specifically labels PRMT1 over PRMT5 with high selectivity and sensitivity.