The contribution of electrostatic interactions to the collapse of oligoglycine in water

Protein solubility and conformational stability are a result of a balance of interactions both within a protein and between protein and solvent. The electrostatic solvation free energy of oligoglycines, models for the peptide backbone, becomes more favorable with an increasing length, yet longer peptides collapse due to the formation of favorable intrapeptide interactions between CO dipoles, in some cases without hydrogen bonds. The strongly repulsive solvent cavity formation is balanced by van der Waals attractions and electrostatic contributions. In order to investigate the competition between solvent exclusion and charge interactions we simulate the collapse of a long oligoglycine comprised of 15 residues while scaling the charges on the peptide from zero to fully charged. We examine the effect this has on the conformational properties of the peptide. We also describe the approximate thermodynamic changes that occur during the scaling both in terms of intrapeptide potentials and peptide-water potentials, and estimate the electrostatic solvation free energy of the system.Comment: 10 pages, 7 figure

Robert L. Bailey\u27s Disciplined Creativity Process for Engineers Compared to the Creative Problem-solving Process

emerging from this process with a piece of literature that I have always dreamed o

An Inversion Disrupting FAM134B Is Associated with Sensory Neuropathy in the Border Collie Dog Breed

Sensory neuropathy in the Border Collie is a severe neurological disorder caused by the degeneration of sensory and, to a lesser extent, motor nerve cells with clinical signs starting between 2 and 7 months of age. Using a genome-wide association study approach with three cases and 170 breed matched controls, a suggestive locus for sensory neuropathy was identified that was followed up using a genome sequencing approach. An inversion disrupting the candidate gene FAM134B was identified. Genotyping of additional cases and controls and RNAseq analysis provided strong evidence that the inversion is causal. Evidence of cryptic splicing resulting in novel exon transcription for FAM134B was identified by RNAseq experiments. This investigation demonstrates the identification of a novel sensory neuropathy associated mutation, by mapping using a minimal set of cases and subsequent genome sequencing. Through mutation screening, it should be possible to reduce the frequency of or completely eliminate this debilitating condition from the Border Collie breed population

Validity of Critical Velocity Concept for Weighted Sprinting Performance

International Journal of Exercise Science 11(4): 900-909, 2018. We investigated the validity of a recently developed equation for predicting sprinting times of various tactical loads based upon the performance of a running 3-min all-out exercise test (3MT). Thirteen recreationally trained participants completed the running 3MT to determine critical velocity (CV) and finite running capacity for running velocities exceeding CV (D’). Two subsequent counterbalanced loaded sprints of 800 and 1000 m distances with 20 and 15% of their body mass, respectively, were evaluated. Estimated times (t, sec) for running 800 and 1000 m with a tactical load was derived using t = (D – D’)/CV. Critical velocity adjusted for an added load using the following regression equation: original CV + (-0.0638 x %load) + 0.6982, D was 800 or 1000 m, and whole percentage load was ~15 or 20% of the participant\u27s body mass. From the 3MT, CV (3.80 ±0.5 m.s-1) and D’(200 ±49.88 m) values were determined.The typical error of predicting actual times for the 800 and 1000 m loaded sprints were 5.6 and 10.1 s, with corresponding ICCs of 0.95 and 0.87, and coefficient of variations of 2.9 and 4.3%. The effect size differences between estimated and actual sprint times were small (0.27) and moderate (0.60) for 800 and 1000 m, respectively. The adjustment to CV through the regression equation yields small to moderate overestimates of maximally loaded sprint times for distances of 800 and 1000 m. Whether such errors remain pervasive for prescribing high-intensity interval training is unclear and requires further investigation

Differential invasion success in aquatic invasive species: the role of within- and among-population genetic diversity

© 2017, Springer International Publishing AG Switzerland. Despite a well-developed theoretical basis for the role of genetic diversity in the colonization process, contemporary investigations of genetic diversity in biological invasions have downplayed its importance. Observed reductions in genetic diversity have been argued to have a limited effect on the success of establishment and impact based on empirical studies; however, those studies rarely include assessment of failed or comparatively less-successful biological invasions. We address this gap by comparing genetic diversity at microsatellite loci for taxonomically and geographically paired aquatic invasive species. Our four species pairs contain one highly successful and one less-successful invasive species (Gobies: Neogobius melanostomus, Proterorhinus semilunaris; waterfleas: Bythotrephes longimanus, Cercopagis pengoi; oysters: Crassostrea gigas, Crassostrea virginica; tunicates: Bortylloides violaceous, Botryllus schlosseri). We genotyped 2717 individuals across all species from multiple locations in multiple years and explicitly test whether genetic diversity is lower for less-successful biological invaders within each species pair. We demonstrate that, for gobies and tunicates, reduced allelic diversity is associated with lower success of invasion. We also found that less-successful invasive species tend to have greater divergence among populations. This suggests that intraspecific hybridization may be acting to convert among-population variation to within-population variation for highly successful invasive species and buffering any loss of diversity. While our findings highlight the species-specific nature of the effects of genetic diversity on invasion success, they do support the use of genetic diversity information in the management of current species invasions and in the risk assessment of potential future invaders

Association Between Maternal Diabetes in Utero and Age at Offspring's Diagnosis of Type 2 Diabetes

OBJECTIVE—The purpose of this study was to examine age of diabetes diagnosis in youth who have a parent with diabetes by diabetes type and whether the parent's diabetes was diagnosed before or after the youth's birth