Effects of single mutations on the stability of horseradish peroxidase to hydrogen peroxide

Horseradish peroxidase (HRP) is a commonly used enzyme in many biotechnological fields. Improvement of HRP stability would further increase its potential application range. In the present study, 13 single- and three double-mutants of solvent exposed, proximal lysine and glutamic acid residues were analysed for enhanced H2O2 stability. Additionally, five single- and one pentuple-consensus mutants were investigated. Most mutants displayed little or no alteration in H2O2 stability; however, three (K232N, K241F and T110V) exhibited significantly increased H2O2 tolerances of 25- (T110V), 18- (K232N), and 12-fold (K241F). This improved stability may be due to an altered enzyme-H2O2 catalysis pathway or to removal of potentially oxidisable residues

Stronger Constraints on the Evolution of the MBH−σ∗M_{\rm{BH}}-\sigma_* Relation up to z∼0.6z\sim0.6

We revisit the possibility of redshift evolution in the $M_{\rm{BH}}-\sigma_*$ relation with a sample of 22 Seyfert 1 galaxies with black holes (BHs) in the mass range $10^{6.3}-10^{8.3}~M_\odot$ and redshift range $0.03<z<0.57$ with spectra obtained from spatially resolved Keck/Low-Resolution Imaging Spectrometer observations. Stellar velocity dispersions were measured directly from the Mg Ib region, taking into consideration the effect of Fe II contamination, active galactic nucleus (AGN) dilution, and host-galaxy morphology on our measurements. BH masses are estimated using the H$\beta$ line width, and the luminosity at 5100 \overset{\lower.5em\circ}{\mathrm{A}} is estimated from surface brightness decomposition of the AGN from the host galaxy using high-resolution imaging from the Hubble Space Telescope. Additionally, we investigate the use of the [O III]$\lambda5007$ emission line width as a surrogate for stellar velocity dispersion, finding better correlation once corrected for Fe II contamination and any possible blueshifted wing components. Our selection criteria allowed us to probe lower-luminosity AGNs and lower-mass BHs in the non-local universe than those measured in previous single-epoch studies. We find that any offset in the $M_{\rm{BH}}-\sigma_*$ relation up to $z\sim0.6$ is consistent with the scatter of local BH masses, and address the sources of biases and uncertainties that contribute to this scatter.Comment: Accepted 14 May 2019 for publication in ApJ. 42 pages, 12 figures, 4 tables. Corrected for typographical error

Jonnie Hiner Scrapbook, 1912-1917

This scrapbook which dates from 1912 to 1917 contains photographs compiled by Jonnie J. Hiner. The majority of the scrapbook content relates to Jonnie Hiner’s time at State Normal School for Women but sections also relate to Hiner family vacations in the Blue Ridge Mountains in North Carolina.https://digitalcommons.longwood.edu/scrapbooks/1020/thumbnail.jp

Numerical Investigation of Tonal Noise on a Transitional Airfoil under Varying Conditions

The generation of discrete acoustic tones is a problem of interest in transitional airfoils. Such tones exist for moderate Re below 2,000,000 and for low to moderate angles of attack. The purpose of this study is to use linear stability theory to study the growth of instabilities on the pressure and suction surfaces of airfoils for varying Re between 144,000 and 468,000 and angles of attack between 0˚ and 12˚. High accuracy 2D simulations based on an Implicit Large Eddy Simulation (ILES) code are conducted for a NACA0012 airfoil for varied conditions, and linear stability analysis is performed to predict amplification rates of disturbances within the boundary layers. The acoustic spectra and surface root mean square (RMS) pressure obtained from the high accuracy simulations are analyzed in conjunction with the stability results in order to explain the process of tone generation. Our results indicate that the growth of instability waves in the flow-separation region is a necessary condition for the generation of tones, but the selected tonal frequencies are governed not only by vortex shedding, but also through a feed-back loop that is determined, in addition to the flow instability, by the trailing-edge scattering and the receptivity mechanisms. The predicted tonal frequency coincides with that of the shedding frequency and is lower than that predicted by Linear Stability Theory (LST) for maximum amplifications. The tones disappear at higher incidence angles because the separation region on the suction side decreases. This leads to weaker instability-wave amplification and its dependency on frequency weakens, thus disrupting the feed-back loop mechanism. Additionally, flow unsteadiness at the trailing edge inhibits consistent trailing edge scattering of acoustic waves. At lower Re and moderate angles of attack, the suction surface is the primary surface responsible for the tones because of its larger separation bubble and stronger instability waves. As the Re increase, the separation region on the suction side diminishes, while instability growth on the pressure surface becomes stronger. Thus, the role of the suction side relative to that of the pressure in tone formation decreases with increasing Re

Flexural Bond Strength of Masonry Assemblies with Lightweight Grout

Lightweight grout has many potential benefits in masonry construction, including minimizing mass, improving thermal performance, and potentially reducing shrinkage cracking via internal curing. However, insufficient testing of masonry assemblies with lightweight grout has been conducted to suggest appropriate design modification factors akin to the lambda factor in ACI 318-19. The objective of this paper is to study the tensile bond behavior of masonry assemblies grouted with lightweight grout and to suggest appropriate equations for predicting design capacity. A moment couple test is designed specifically for grouted masonry assemblies and has additional capacity compared to the traditional ASTM 1072 bond wrench device. In this type of test, expanded clay aggregates are used to formulate a grout mix used to form two-unit fully grouted masonry assemblies for the testing. This thesis discusses the design of the moment couple test device, the preparation of the grouted prims used to test flexural bond strength, and the results of the flexural bond strength testing. The results of the testing indicate that the current tabulated values for fully grouted masonry subjected to tension normal to the bed joint may be sufficiently conservative for use with assemblies comprised of lightweight grout. Future research will include the testing of masonry assemblies constructed with expanded slate masonry grout and will examine the relationship between the flexural tensile strength and the equilibrium density of the grout

Critical Reading, Critical Research: Practical Strategies to Develop

Perhaps no other skill affects students’ intellectual achievement more profoundly than the skill of critical reading. The analysis and assessment of written texts requires specific, learned skills in unpacking a text’s meaning, understanding its claims and implications, assessing its logic and coherence, evaluating its evidence, and drawing logical conclusions based on its claims. Both anecdotal evidence and qualitative research suggest that these skills are lacking in many high school and college students, and though teachers are intuitively aware of how crucial such skills are in the research and writing process, they often struggle to help students practice and apply critical reading strategies in consistent and effective ways. This session will articulate a theory of critical reading based on the concepts and methodology of critical thinking experts Dr. Richard Paul and Dr. Linda Elder and will share practical strategies and in-class exercises designed to help students learn how to read, understand, and assess written texts in order to draw logical conclusions and construct persuasive arguments

A Study Of Operational Procedures And Influences Of Vocational Agriculture On Camp County Over A Ten Year Period

For those who are interested in helping farmers in Camp County, this investigation aims to provide some understanding of the basic problems confronting all who make their living, in whole or in part, from the land. For those who are already established on the farms, this investigation seeks to provide factual information for guidance, reference, and review. The investigator\u27s interest in this. problem grew out of his work as a teacher of Vocational Agriculture in Camp County for twelve years. Here he made general observations, surveys, and interviews with farmers, professionals,s and businessmen at the beginning of his teaching career and thereafter. A comparison of these data by the investigator would point out some of the influences of Vocational Agriculture in Camp County. For the convenience of the reader, the subject matter, Study of Operational Procedures and Influences of Vocational Agriculture on Camp County Over A Ten-Year Period, is presented in four main chapters, as follows: Chapter One, Introduction; Chapter Two, Presentation and Analyses of Data; Chapter Three, Summary and Conclusion; and Chapter Four, A Suggested Vocational Agriculture Program For Camp County. Literature cited and Appendix are included at the end

DETERMINANTS OF COW-CALF PAIR PRICES

Cow-calf prices are determined by interaction of many factors. At a particular auction, cow-calf pair prices often had a range of 75% of the mean price. This variability suggests that producers need to be informed regarding cow-calf price determinants. This study uses auction data during 1993 to estimate price differentials associated with cow-calf pair characteristics using a hedonic model. Cow breed, age, health, conditions, horns, frame, and whether the cow had been bred back were significant price determinants. Calf weight, health, and frame had significant price impacts. Highest prices were paid for pens containing 9-12 pairs of young Angus, dehorned, bred back, healthy cows with heavy healthy calves.Demand and Price Analysis,