The rise of chamber music for clarinet and strings through the nineteenth century

Thesis (D.M.A)--Boston University

Minimal Competencies in Reading for Secondary Content Teachers

In discussions among secondary reading teachers you are almost sure to hear the statement that every teacher should be a teacher of reading. This is a recurrent theme of reading conferences and the vigor with which an author espouses this end is one of the criteria by which secondary reading texts are judged. On paper or as a conference theme this is a wonderful concept. In reality though it seems at best difficult to achieve and at worst represents tremendous naivete on the part of reading educators

Development of heat flux sensors for turbine airfoils

The objectives of this program are to develop heat flux sensors suitable for installation in hot section airfoils of advanced aircraft turbine engines and to experimentally verify the operation of these heat flux sensors in a cylinder in a cross flow experiment. Embedded thermocouple and Gardon gauge sensors were developed and fabricated into both blades and vanes. These were then calibrated using a quartz lamp bank heat source and finally subjected to thermal cycle and thermal soak testing. These sensors were also fabricated into cylindrical test pieces and tested in a burner exhaust to verify heat flux measurements produced by these sensors. The results of the cylinder in cross flow tests are given

Remembering is Not Necessarily Understanding in Content Areas

Improving comprehension in middle-grade content areas would be an easier topic to address if we had available validated theoretical models, and hence an understanding, of 1) how one learns from text, and 2) how intellectual operations develop in adolescence. Our current state of ignorance in these areas has been aptly summarized by Miller (1976) and Neimark (1975) respectively. We are then, like everyone else who would discuss improving comprehension of text, reduced to drawing upon the available body of literature and from this attempting to produce a framework from which useful strategies can be developed

Structural Evidence for a Copper-Bound Carbonate Intermediate in the Peroxidase and Dismutase Activities of Superoxide Dismutase

Copper-zinc superoxide dismutase (SOD) is of fundamental importance to our understanding of oxidative damage. Its primary function is catalysing the dismutation of superoxide to O2 and H2O2. SOD also reacts with H2O2, leading to the formation of a strong copper-bound oxidant species that can either inactivate the enzyme or oxidise other substrates. In the presence of bicarbonate (or CO2) and H2O2, this peroxidase activity is enhanced and produces the carbonate radical. This freely diffusible reactive oxygen species is proposed as the agent for oxidation of large substrates that are too bulky to enter the active site. Here, we provide direct structural evidence, from a 2.15 Å resolution crystal structure, of (bi)carbonate captured at the active site of reduced SOD, consistent with the view that a bound carbonate intermediate could be formed, producing a diffusible carbonate radical upon reoxidation of copper. The bound carbonate blocks direct access of substrates to Cu(I), suggesting that an adjunct to the accepted mechanism of SOD catalysed dismutation of superoxide operates, with Cu(I) oxidation by superoxide being driven via a proton-coupled electron transfer mechanism involving the bound carbonate rather than the solvent. Carbonate is captured in a different site when SOD is oxidised, being located in the active site channel adjacent to the catalytically important Arg143. This is the probable route of diffusion from the active site following reoxidation of the copper. In this position, the carbonate is poised for re-entry into the active site and binding to the reduced copper. © 2012 Strange et al

A spin-label ESR study of drug binding to DNA

A spin-labelled derivative of the drug Proflavine was prepared and its interactions with natural DNA in fibres were investigated using the technique of electron spin resonance (ESR). Computer simulations of the ESR spectra showed that spin-labelled proflavine adopts a preferred orientation in each of the different DNA conformations. In A- and C-form DNA the binding geometry is explained by an external interaction between the drug molecules and the phosphate groups of the double helix. In B-form DNA the drug molecules exhibited some form of rotational motion. Simulations indicated that this motion was directed about the helix axis, a conclusion which is consistent with an intercalative mode of binding. An examination of the B-form X-ray diffraction patterns confirmed that intercalation had occurred. A difference was observed in the binding of the drug to different species of DNA, suggesting that some form of site specific interaction is involved. The importance of drug concentration on the conformational properties of DNA was recognised. The binding of several Phenothiazine tranquilisers to DNA was also investigated. The solution ESR spectra of these (oxidised) drug molecules showed that the distribution of unpaired spin density over the heterocyclic ring depends upon the substituted groups present. However, in DNA fibres the different drug species adopted the same binding geometry. Although the ESR results were consistent with both intercalation and external binding, the large spread of drug orientations estimated from computer simulations suggests that external binding is more likely. DNA from the bacteriophage dW-14 was spin-labelled in order to determine the conformation of the putrescine groups attached to the thymine bases. The information obtained from these experiments suggests that the putrescine groups project into the major groove in B- and C-form DNA, whereas in the A-conformation they lie close to each other in the hollow interior of the helix

Elbows of internal resistance rise curves in Li-ion cells

The degradation of lithium-ion cells with respect to increases of internal resistance (IR) has negative implications for rapid charging protocols, thermal management and power output of cells. Despite this, IR receives much less attention than capacity degradation in Li-ion cell research. Building on recent developments on ‘knee’ identification for capacity degradation curves, we propose the new concepts of ‘elbow-point’ and ‘elbow-onset’ for IR rise curves, and a robust identification algorithm for those variables. We report on the relations between capacity’s knees, IR’s elbows and end of life for the large dataset of the study. We enhance our discussion with two applications. We use neural network techniques to build independent state of health capacity and IR predictor models achieving a mean absolute percentage error (MAPE) of 0.4% and 1.6%, respectively, and an overall root mean squared error below 0.0061. A relevance vector machine, using the first 50 cycles of life data, is employed for the early prediction of elbow-points and elbow-onsets achieving a MAPE of 11.5% and 14.0%, respectively

A QM/MM Study of Nitrite Binding Modes in a Three-Domain Heme-Cu Nitrite Reductase

Copper-containing nitrite reductases (CuNiRs) play a key role in the global nitrogen cycle by reducing nitrite (NO₂‾) to nitric oxide, a reaction that involves one electron and two protons. In typical two-domain CuNiRs, the electron is acquired from an external electron-donating partner. The recently characterised Rastonia picketti (RρNiR) system is a three-domain CuNiR, where the cupredoxin domain is tethered to a heme c domain that can function as the electron donor. The nitrite reduction starts with the binding of NO₂‾ to the T2Cu centre, but very little is known about how NO₂‾ binds to native RpNiR. A recent crystallographic study of an RpNiR mutant suggests that NO₂‾ may bind via nitrogen rather than through the bidentate oxygen mode typically observed in two-domain CuNiRs. In this work we have used combined quantum mechanical/molecular mechanical (QM/MM) methods to model the binding mode of NO₂‾ with native RρNiR in order to determine whether the N-bound or O-bound orientation is preferred. Our results indicate that binding via nitrogen or oxygen is possible for the oxidised Cu(II) state of the T2Cu centre, but in the reduced Cu(I) state the N-binding mode is energetically preferred.</jats:p

Online Story Comprehension among Children with ADHD: Which Core Deficits are Involved?

Children with ADHD have difficulty understanding causal connections and goal plans within stories. This study examined mediators of group differences in story narrations between children ages 7-9 with and without ADHD, including as potential mediators both the core deficits of ADHD (i.e., inattention, disinhibition, planning/working memory) as well measures of phonological processing and verbal skills. Forty-nine children with ADHD and 67 non-referred children narrated a wordless book and completed tasks assessing the core deficits of ADHD, phonological processing, and verbal skills. Results revealed that, although no shorter than those of non-referred children, the narratives of children with ADHD contained fewer elements relating to the story’s causal structure and goal plan. Deficits in sustained attention accounted for the most variance in these differences. Results have implications for understanding and ameliorating the academic problems experienced by children with ADHD