Inventive Tool Use to Comprehend Big Code

Software developers often need to understand a large body of unfamiliar code with little or no documentation, no experts to consult, and little time to do it. A post appeared in January 2008 on Slashdot, a technology news Web site, asking for tools and techniques that could help. This article analyzes 301 often passionate and sometimes articulate responses to this query, including the themes and the associated tool recommendations. The most common suggestions were to use a code navigation tool, use a design recovery tool, use a debugger to step through the code, create a runtime trace, use problem-based learning, ask people for help, study the code from top down, and print out all the code. This analysis presents an intriguing snapshot of how software developers in industry go about comprehending big code.     

Crystallisation of Wild-Type and Variant Forms of a Recombinant Plant Enzyme ��-d-Glucan Glucohydrolase from Barley (Hordeum vulgare L.) and Preliminary X-ray Analysis

Wild-type and variant crystals of a recombinant enzyme β-d-glucan glucohydrolase from barley (Hordeum vulgare L.) were obtained by macroseeding and cross-seeding with microcrystals obtained from native plant protein. Crystals grew to dimensions of up to 500 × 250 × 375 μm at 277 K in the hanging-drops by vapour-diffusion. Further, the conditions are described that yielded the wild-type crystals with dimensions of 80 × 40 × 60 μm by self-nucleation vapour-diffusion in sitting-drops at 281 K. The wild-type and recombinant crystals prepared by seeding techniques achived full size within 5–14 days, while the wild-type crystals grown by self-nucleation appeared after 30 days and reached their maximum size after another two months. Both the wild-type and recombinant variant crystals, the latter altered in the key catalytic and substrate-binding residues Glu220, Trp434 and Arg158/Glu161 belonged to the P4₃2₁2 tetragonal space group, i.e., the space group of the native microcrystals was retained in the newly grown recombinant crystals. The crystals diffracted beyond 1.57–1.95 Å and the cell dimensions were between a = b = 99.2–100.8 Å and c = 183.2–183.6 Å. With one molecule in the asymmetric unit, the calculated Matthews coefficients were between 3.4–3.5 ų·Da⁻¹ and the solvent contents varied between 63.4% and 64.5%. The macroseeding and cross-seeding techniques are advantageous, where a limited amount of variant proteins precludes screening of crystallisation conditions, or where variant proteins could not be crystallized.     

Erythropoietin Action in Stress Response,Tissue Maintenance and Metabolism

Erythropoietin (EPO) regulation of red blood cell production and its induction at reduced oxygen tension provides for the important erythropoietic response to ischemic stress. The cloning and production of recombinant human EPO has led to its clinical use in patients with anemia for two and half decades and has facilitated studies of EPO action. Reports of animal and cell models of ischemic stress in vitro and injury suggest potential EPO benefit beyond red blood cell production including vascular endothelial response to increase nitric oxide production, which facilitates oxygen delivery to brain, heart and other non-hematopoietic tissues. This review discusses these and other reports of EPO action beyond red blood cell production, including EPO response affecting metabolism and obesity in animal models. Observations of EPO activity in cell and animal model systems, including mice with tissue specific deletion of EPO receptor (EpoR), suggest the potential for EPO response in metabolism and disease.     

New galvanic cell designs for minimizing electrode polarization

New galvanic cell designs, incorporating one or two buffer electrodes, are developed to minimize the electrode polarization caused by electrochemical permeability of the electrolyte at high temperature. When a nonpolarizable reference electrode is employed, a cell with three-electrode compartments can be used to measure the chemical potential of oxygen in two-phase fields of ternary systems, associated with one degree of freedom at constant temperature. A buffer electrode is placed between the reference and measuring electrodes. The buffer electrode, maintained at approximately the same oxygen chemical potential as the measuring electrode, absorbs the semipermeability flux of oxygen between reference and measuring electrodes. When the reference electrode is polarizable, two buffer electrodes are required between the reference and measuring electrodes. The reference and reference-buffer electrodes have the same chemical potential of the active species. Similarly the measuring electrode and its buffer are of approximately the same chemical potential. A significant chemical potential difference exists only between the two buffers, which may become polarized due to coupled transport of ions and electronic defects through the electrolyte. Since the reference and measuring electrodes are insulated, the emf of the solid state cell is unaffected. The use of the buffer electrode designs permit more accurate thermodynamic measurements on metal and ceramic systems at high temperature.     

Gradient solid electrolytes for thermodynamic measurements: System Na2CO3-Na2SO4

The thermodynamic properties of Na₂CO₃-Na₂SO₄ solid solution with hexagonal structure have been measured in the temperature range of 873 to 1073 K, using a composite-gradient solid electrolyte. The cell used can be represented as Pt, CO₂′ + O₂∥ Na₂CO₃Na₂ (CO₃)_x(SO₄)_1-x) ∥ CO₂″ + O₂″, Pt The composite-gradient solid electrolyte consisted of pure Na²CO³ at one extremity and the solid solution under study at the other, with variation in composition across the electrolyte. A CO₂ + O₂ + Ar gas mixture was used to fix the chemical potential of sodium at each electrode. The Nernstian response of the cell to changes in partial pressures of CO₂ and O₂ at the electrodes has been demonstrated. The activity of Na₂CO₃ in the solid solution was measured by two techniques. In the first method, the electromotive force (emf) of the cell was measured with the same CO₂ + O₂ + Ar mixture at both electrodes. The resultant emf is directly related to the activity of Na₂CO₃ at the solid solution electrode. By the second approach, the activity was calculated from the difference in compositions of CO₂ + O₂ + Ar mixtures at the two electrodes required to produce a null emf. Both methods gave identical results. The second method is more suitable for gradient solid electrolytes that exhibit significant electronic conduction. The activity of Na₂CO₃ exhibits positive deviation from Raoult’s law. The excess Gibbs’ energy of mixing of the solid solution can be represented using a subregular solution model such as the following: ΔG^E = X(1 - X)[6500(±200)X + 3320(±80)(l - X)] J mol^-1 whereX is the mole fraction of Na₂CO₃. By combining this information with the phase diagram, mixing properties of the liquid phase are obtained.     

Incompleteness of bifurcation diagram in predicting the behaviour of Ćuk converter in discontinuous conduction mode

The bifurcation phenomena have been studied in current mode‐controlled ?uk converter considering continuous conduction as well as discontinuous conduction mode of operation. Some peculiarities have been observed in discontinuous conduction mode, which indicate some incompleteness of the bifurcation diagrams in providing details of the system behaviour. Copyright © 2007 John Wiley & Sons, Ltd.     

The 9‐point hedonic scale and hedonic ranking in food science: some reappraisals and alternatives

The 9‐point hedonic scale has been used routinely in food science, the same way for 60 years. Now, with advances in technology, data from the scale are being used for more and more complex programs for statistical analysis and modeling. Accordingly, it is worth reconsidering the presentation protocols and the analyses associated with the scale, as well as some alternatives. How the brain generates numbers and the types of numbers it generates has relevance for the choice of measurement protocols. There are alternatives to the generally used serial monadic protocol, which can be more suitable. Traditionally, the ‘words’ on the 9‐point hedonic scale are reassigned as ‘numbers’, while other ‘9‐point hedonic scales’ are purely numerical; the two are not interchangeable. Parametric statistical analysis of scaling data is examined critically and alternatives discussed. The potential of a promising alternative to scaling itself, simple ranking with a hedonic R‐Index signal detection analysis, is explored in comparison with the 9‐point hedonic scale. © 2014 Society of Chemical Industry     

Region based coronary artery segmentation using modified Frangi's vesselness measure

Recent research suggests that the cardiovascular diseases (CVDs), seem to be the foremost cause of mortality among the world populace. Three dimensional (3D) imaging modality such as computed tomography angiography(CTA) is a standard noninvasive imaging modality which has great potentials for the visualization of heart and coronary arteries. This article presents a fully automated method for coronary artery extraction using modified Frangi's vesselness measure and region based segmentation. In this article, grayness and gradient based measures are used while computing Frangi's vesselness measure to improve the extraction of coronary arteries. The obtained vesselness measures are utilized for automatically computing the location of ostia. The locations of ostia are then used as starting seed points in region growing segmentation to extract coronary arteries. Three major coronary arteries, namely the left anterior descending artery (LAD), left circumflex artery (LCX) and right coronary artery (RCA) are segmented using the proposed method and the centerlines are extracted for the main coronary branches. The performance of the proposed method is evaluated using 12 3D CCTA data set. The experimental results reveal that during the calculation of modified Frangi's vesselness measure the proposed method gives improved results. The qualitative results obtained during the segmentation stage are also convincing. The average segmentation accuracy and overlap measure of the proposed method are 97.4% and 77.86%, respectively. Hence, the proposed automated approach can detect and extract coronary arteries in CCTA images with high performance.     

Recent developments in the volatile corrosion inhibitor (VCI) coatings for metal: a review

Corrosion is a crucial worldwide problem that strongly affects metals. Out of the several ways to prevent corrosion, volatile corrosion inhibitors (VCIs) are predominantly used as a method of temporary protection. These compounds have the ability to vaporize and condense on the surface of the ferrous or nonferrous material and make the substrate less susceptible to corrosion but work only in a confined space. VCI compounds form a monomolecular layer over the metal surface, thereby preventing the electrochemical reactions on the metal surface which lead to corrosion. This review article outlines the use of volatile corrosion inhibitors (VCIs) as a temporary corrosion protection technique, their working mechanisms and the various compounds used as VCI. It also anchors on the latest research works which have been carried out on VCI coatings along with a glimpse of the works that were carried out in the past. The various factors affecting the volatile corrosion inhibitors along with the merits of VCI coatings are discussed in this paper. Formulations for both strippable and permanent VCI coatings are also reported with the various testing methods. Lastly, an overview of the recent developments of VCI coatings along with the various green VCI is given.