A code tagging approach to software product line development

Software product line engineering seeks to systematise reuse when developing families of similar software systems so as to minimise development time, cost and defects. To realise variability at the code level, product line methods classically advocate usage of inheritance, components, frameworks, aspects or generative techniques. However, these might require unaffordable paradigm shifts for developers if the software was not thought at the outset as a product line. Furthermore, these techniques can be conflicting with a company’s coding practices or external regulations. These concerns were the motivation for the industry–university collaboration described in this paper in which we developed a minimally intrusive coding technique based on tags. The approach was complemented with traceability from code to feature diagrams which were exploited for automated configuration. It is supported by a toolchain and is now in use in the partner company for the development of flight-grade satellite communication software libraries.     

A predicted three-dimensional structure for the human immunodeficiency virus binding domains of CD4 antigen

A predicted three-dimensional structure of the two N-terminalextracellular domains of human CD4 antigen, a cell surface glycoprotein,is reported. This region of CD4, particularly the first domain,has been identified as containing the binding region for theenvelope gp120 protein of the human immuno-deficiency virus.The model was predicted based on the sequence homology of eachdomain with the variable light chain of immunoglobulins. Theframework ß-sheet regions were taken from the crystalcoordinates of REI. For one region in the first domain of CD4there was an ambiguity in the alignment with REI and two alternatemodels are presented. Loops connecting the framework were modeledfrom fragments selected from a database of main chain coordinatesfrom all known protein structures. Residues identified as involvedin binding gp120 have been located in several other studieswithin the first domain of CD4. Epitopes from eight monoclonalantibodies have been mapped onto residues in both domains. Competitionof these antibodies with each other and with gp120 can be interpretedfrom the structural model.     

A Multiscale Approach to Optimal Transport

In this paper, we propose an improvement of an algorithm of Aurenhammer, Hoffmann and Aronov to find a least square matching between a probability density and finite set of sites with mass constraints, in the Euclidean plane. Our algorithm exploits the multiscale nature of this optimal transport problem. We iteratively simplify the target using Lloyd's algorithm, and use the solution of the simplified problem as a rough initial solution to the more complex one. This approach allows for fast estimation of distances between measures related to optimal transport (known as Earth‐mover or Wasserstein distances). We also discuss the implementation of these algorithms, and compare the original one to its multiscale counterpart.     

The effect of noble gas bombarding on nitrogen diffusion in steel

The low energy (∼50–350 eV) noble gases ion bombardment of the steel surface shows that the pre-treatments increase nitrogen diffusion by modifying the outermost structure of the material. The surface microstructure and morphology of the studied samples were characterized by Scanning Electron Microscopy (SEM) and Atomic Force Microscopy (AFM). The crystalline and chemical structures in the outermost layers of the surface were analyzed by grazing angle X-ray diffraction (GAXRD) and photoemission electron spectroscopy (XPS). Temperature effusion studies of the implanted ions are used to elucidate the noble gases site localization in the network. The local compressive stress induced by the nearby iron atoms on the core level electron wave functions of the trapped noble gases are studied by photoemission electron spectroscopy (XPS) and interpreted considering a simple mechanical model. Nano-hardness measurements show the dependence of the material elastic constant on the energy of the implanted noble gases. Although the ion implantation range is about few nanometers, the atomic attrition effect is larger enough to modify the material structure in the range of micrometers. Two material stress zones were detected where the outermost layers shows compressive stress and the underneath layers shows tensile stress. The implanted noble gases can be easily removed by heating. A diffusion model for polycrystalline-phase systems is used in order to discuss the influence of the atomic attrition on the N diffusion coefficient. The concomitant effect of grain refining, stress, and surface texture on the enhancing nitrogen diffusion effect is discussed.     

Development of open-cathode polymer electrolyte fuel cells using printed circuit board flow-field plates: Flow geometry characterisation

Open-cathode air-breathing fuel cells have the advantage of reduced system complexity and simplified operation, as oxygen is taken directly from ambient air without the need for blowers/compressors. In this study, printed circuit boards (PCBs) are used as flow-field plates. The use of PCBs offers the potential for significant cost reduction due to their well-established manufacturing processing and low materials cost. This study investigates the effect of varying the cathode geometry (parallel and circular) and opening ratios (43%, 53% and 63%) on fuel cell performance using polarisation curves, electrochemical impedance spectroscopy (EIS) and thermal imaging. The results obtained indicate that circular openings afford lower Ohmic resistance than parallel flow-field designs, which helps improve contact between the gas diffusion layer and flow-field plate. However, flow-field plates with circular openings suffer from greater mass transport limitation effects. Likewise, greater opening ratios offer better mass transport but increased Ohmic resistance as a result of the reduced area of lands/ribs. The thermal imaging results reveal lower temperature in the middle of the fuel cell due to “bowing” of the printed circuit board flow field plates which reduces the local current density. A trade-off between these factors results in a design with a maximum area specific power density of 250 mW cm⁻².     

On cause hypotheses of earthquakes with external tectonic plate and/or internal dense gas loadings

This paper examines and compares the two loading systems and their associated energy and basic stress fields in elastic crustal rock mass for the cause of tectonic earthquakes. The first loading system is an external loading system and associated with the conventional earthquake cause hypothesis of active fault elastic rebounding. The second is a combined loading system where the first external loading system is added with a dense gas loading in the interior of deep crustal rock faults/defects. It is associated with the methane gas hypothesis for the cause of tectonic earthquakes. Five elastic stresses in rock solids with some idealized faults and caverns are presented to illustrate the similarities and differences of the stress fields and the possible rupture failure modes in association of the two loading systems. The theoretical results can show that any changes in the local stress concentrations due the external loading alone can be reflected and noticed in the corresponding stresses at the far field. On the other hand, any changes in the local stress concentrations due to the internal gas loading cannot be observed and distinguished in the tectonic stress field at the far distance. These theoretical results can be used to well explain the consensus of earthquake unpredictability with present technology. The theoretical results can further show that the external tectonic loading alone can only cause shear ruptures in crustal fault rocks with high compressive stresses, and such shear rupture or frictional failure is also difficult to occur because its shear plane has extremely high compressive normal stress. The combined loading can cause not only shear ruptures, but also tensile ruptures in crustal fault rocks, and such shear and tensile ruptures occur much easier since the rupture plane can have very low compressive or even high-tensile normal stress. It is argued that the earthquake energy is the volumetric expansion energy of dense gas mass escaped from the deep traps along crustal rock faults. The migration and expansion of the escaped dense gas mass in the crustal rock faults and defects cause the seismic body waves, the ground sounding, the seismic surface waves, the ground co-seismic ruptures and damages. Its rapid migration and expansion in thick water cause tsunamis in lakes and oceans. Its rapid migration and expansion in the atmosphere cause the sky to become cloudy. The dense methane gas is produced every day in the mantle and core of the Earth, migrates outward and accumulates and stores beneath the lower crustal rock in high compression. It forms a thin spherical layer of dense methane gas separating the cold crustal rocks and the hot mantle materials. Its leaking along deep faults or plate boundaries causes earthquakes and supplies to shallow gas and oil reservoirs beneath secondary traps in adjacent basins of the upper crustal rock mass.     

Recovery of Oil,Erucic Acid,and Phenolic Compounds from Rapeseed and Rocket Seeds

Erucic acid‐enriched oil, sought for industrial purposes, from rapeseed (agronomic plant) and rocket seeds (non‐agronomic plant) was extracted by three different processes: supercritical CO₂, mechanical expression, and hexane extraction. Oil extraction yields were determined and the extracted oils were characterized for their fatty acid and phenolic compound compositions. Higher oil yields were achieved using hexane compared to mechanical expression and supercritical CO₂ extractions. Fatty acid analysis indicated a higher content of erucic acid in rapeseed oil than in rocket oil. In addition, supercritical CO₂ extraction allowed better recovery of phenolic compounds with high antioxidant activities. The most prominent identified polyphenols were vanillin, sinapic acid, syringic acid, and apigenin.     

Revisiting the size selective performance of EPA's high-volume total suspended particulate matter (Hi-Vol TSP) sampler

Under the National Ambient Air Quality Standard (NAAQS) for airborne lead, measurements are conducted by means of a high-volume total suspended particulate matter (Hi-Vol TSP) sampler. In the decade between 1973 and 1983, there were 12 publications that explored the sampling characteristics and effectiveness of the Hi-Vol TSP, yet there persists uncertainty regarding its performance. This article presents an overview of the existing literature on the performance of the Hi-Vol TSP, and identifies the reported sampler effectiveness with respect to four factors: particle size (reported effectiveness of 7%–100%), wind speed (?36% to 100%), sampler orientation (7%–100%), and operational state (107%–140%). Effectiveness of the Hi-Vol TSP was evaluated with a solid, polydisperse aerosol in a controlled wind tunnel setting. Isokinetic samplers were deployed alongside the Hi-Vol TSP to investigate three wind speeds (2, 8, and 24 km h^?1), three sampler orientations (0°, 45°, 90°), and two operational states (on, off) for aerosols with aerodynamic diameters from 5 to 35 µm. Results indicate that particle diameter was the largest determining factor of effectiveness followed by wind speed. Orientation of the sampler did not have a significant effect at 2 and 8 km h^?1 but did at 24 km h^?1. In a passive state, the Hi-Vol TSP was collected between 1% and 7% of available aerosol depending on particle size and wind speed. Results of this research do not invalidate results of previous studies but rather contribute to our overall understanding of the Hi-Vol TSP's size-selective performance. While results generally agreed with previous studies, the Hi-Vol TSP was found to exhibit less dependence on these four factors than previously reported.

© 2017 American Association for Aerosol Research     

Environmental Phenol and Paraben Exposure Risks and Their Potential Influence on the Gene Expression Involved in the Prognosis of Prostate Cancer

Prostate cancer (PCa) is one of the leading malignant tumors in US men. The lack of understanding of the molecular pathology on the risk of food supply chain exposures of environmental phenol (EP) and paraben (PB) chemicals limits the prevention, diagnosis, and treatment options. This research aims to utilize a risk assessment approach to demonstrate the association of EP and PB exposures detected in the urine samples along with PCa in US men (NHANES data 2005–2015). Further, we employ integrated bioinformatics to examine how EP and PB exposure influences the molecular pathways associated with the progression of PCa. The odds ratio, multiple regression model, and Pearson coefficients were used to evaluate goodness-of-fit analyses. The results demonstrated associations of EPs, PBs, and their metabolites, qualitative and quantitative variables, with PCa. The genes responsive to EP and PB exposures were identified using the Comparative Toxicogenomic Database (CTD). DAVID.6.8, GO, and KEGG enrichment analyses were used to delineate their roles in prostate carcinogenesis. The plug-in CytoHubba and MCODE completed identification of the hub genes in Cytoscape software for their roles in the PCa prognosis. It was then validated by using the UALCAN database by evaluating the expression levels and predictive values of the identified hub genes in prostate cancer prognosis using TCGA data. We demonstrate a significant association of higher levels of EPs and PBs in the urine samples, categorical and numerical confounders, with self-reported PCa cases. The higher expression levels of the hub genes (BUB1B, TOP2A, UBE2C, RRM2, and CENPF) in the aggressive stages (Gleason score > 8) of PCa tissues indicate their potential role(s) in the carcinogenic pathways. Our results present an innovative approach to extrapolate and validate hub genes responsive to the EPs and PBs, which may contribute to the severity of the disease prognosis, especially in the older population of US men.     

A New Strategy to Preserve and Assess Oxygen Consumption in Murine Tissues

Mitochondrial dysfunctions are implicated in several pathologies, such as metabolic, cardiovascular, respiratory, and neurological diseases, as well as in cancer and aging. These metabolic alterations are usually assessed in human or murine samples by mitochondrial respiratory chain enzymatic assays, by measuring the oxygen consumption of intact mitochondria isolated from tissues, or from cells obtained after physical or enzymatic disruption of the tissues. However, these methodologies do not maintain tissue multicellular organization and cell-cell interactions, known to influence mitochondrial metabolism. Here, we develop an optimal model to measure mitochondrial oxygen consumption in heart and lung tissue samples using the XF24 Extracellular Flux Analyzer (Seahorse) and discuss the advantages and limitations of this technological approach. Our results demonstrate that tissue organization, as well as mitochondrial ultrastructure and respiratory function, are preserved in heart and lung tissues freshly processed or after overnight conservation at 4 °C. Using this method, we confirmed the repeatedly reported obesity-associated mitochondrial dysfunction in the heart and extended it to the lungs. We set up and validated a new strategy to optimally assess mitochondrial function in murine tissues. As such, this method is of great potential interest for monitoring mitochondrial function in cohort samples.