A handheld sensor assay for the identification of grouper as a safeguard against seafood mislabeling fraud

Increases in international trade and global seafood consumption, along with fluctuations in the supply of different seafood species, have resulted in fraudulent product mislabeling. Grouper species, due to their high demand and varied commercial availability, are common targets for mislabeling by exploiting inefficient inspection practices. Compounding this problem is the fact that there are currently 64 species of fish from eleven different genera allowed to be labeled “grouper” per U.S. Food and Drug Administration guidelines. This wide diversity makes it difficult for regulators to discern legally salable groupers from restricted species. To obviate taxonomic misidentification when relying on external phenotypic characteristics, regulatory agencies are now employing genetic authentication methods which typically offer species-level resolution. However, standard genetic methods such as DNA barcoding require technical expertise and long turnover times, and the required instrumentation is not amenable for on-site analysis of seafood. To obviate some of these limitations, we have developed a handheld genetic sensor that employs a real-time nucleic acid sequence-based amplification assay (RT-NASBA) previously devised in our lab, for the analysis of fish tissue in the field. The base RT-NASBA assay was validated using a lab-based, benchtop RNA purification method as well as non-portable, commercial RT-NASBA analyzer. Described herein, is an uncomplicated method for purifying RNA from fish tissue in the field, which had similar efficiency to the benchtop method demonstrated through direct comparisons. We have also demonstrated that the field sensor is only slightly less sensitive than the benchtop instrument, and could discern 80.3% of groupers (no target sequence available for three species) on the 2014 FDA Seafood List from potential impostors. The complete field assay requires fewer than 80 min for completion and can be performed outside of the lab in its entirety.     

Distributed wireless power transfer in sensor networks with multiple Mobile Chargers

We investigate the problem of efficient wireless power transfer in wireless sensor networks. In our approach, special mobile entities (called the Mobile Chargers) traverse the network and wirelessly replenish the energy of sensor nodes. In contrast to most current approaches, we envision methods that are distributed and use limited network information. We propose four new protocols for efficient charging, addressing key issues which we identify, most notably (i) what are good coordination procedures for the Mobile Chargers and (ii) what are good trajectories for the Mobile Chargers. Two of our protocols (DC, DCLK) perform distributed, limited network knowledge coordination and charging, while two others (CC, CCGK) perform centralized, global network knowledge coordination and charging. As detailed simulations demonstrate, one of our distributed protocols outperforms a known state of the art method, while its performance gets quite close to the performance of the powerful centralized global knowledge method.     

An investigation into the cause of loss of containment from the supply of mini-bulk lubricants

An Intermediate Bulk Container (IBC) was punctured during its handling, releasing oil onto soil at an environmentally-sensitive region of Australia. The telehandler did not pierce the plastic of the IBC directly (as was expected) but rather one of the tynes had caught on the underside of the metal base plate, despite numerous controls being in place at time of spill, revealing a previously unreported mechanism for a fluid spill from handling of petroleum hydrocarbons. The diverse investigation team used a root cause analysis (RCA) technique to identify the underlying cause: the inspection process was inadequate with contributing factors of not using a spotter and design of IBC did not anticipate conditions. Engineering controls were put in place as part of the change management process to help prevent spills from occurring from piercing from telehandler tynes on the current project site.     

Kinetics of light-induced degradation in compensated boron-doped silicon investigated using photoluminescence and numerical simulation

We use photoluminescence to observe light-induced degradation in silicon in real time. Numerical simulations are used to match our results and lifetime decay data from the literature with theoretical models for the generation of the light-induced boron–oxygen defects. It is found that the existing model of the slowly generated defect SRC, where its saturated concentration is a function of the majority carrier concentration, does not explain certain results in both p- and n-type samples. A new model is proposed in which the saturated SRC concentration is controlled by the total hole concentration under illumination.     

Preparation of Bi2Ti2O7/TiO2 nanocomposites and their photocatalytic performance under visible light irradiation

To improve visible-light-driven photocatalytic activity of TiO₂, the octahedral Bi₂Ti₂O₇ nanoparticles have been successfully supported on TiO₂ nanotubes (Bi₂Ti₂O₇/TiO₂) for the first time by a simple hydrothermal method. The structure and electro-optical property of the Bi₂Ti₂O₇/TiO₂ were characterized in detail. The obtained Bi₂Ti₂O₇/TiO₂ exhibited a markedly enhanced photocatalytic activity and good stability for degradation of organic pollutants under visible light. The study presents a new way to synthesize Bi₂Ti₂O₇/TiO₂ using TiO₂ nanotubes as both supporter and reactant.     

Why do small business butcher shops fail to fully implement HACCP?

This study aims to assess the degree of HACCP implementation in small business butcher shops and understand which factors most influence butchers' intention to fully implement it, through the application of the Theory of Planned Behaviour. One hundred and one butchers managing or owning small butcher's responded to the interview regarding their Attitudes, Subjective Norm, Perceived Behavioural Control, Personal Norm, and Knowledge with regard to their Intention to fully implement a HACCP system in their shops. Before the interviews, a certified veterinarian visited all the shops. Visits included an inspection of the establishments using the Official Portuguese Control Plan checklist for meat retailers. Conformance level measured past performance regarding food safety practices. Based on past performance, butchers were divided into “high performers” and “low performers”. “High performers” yielded high values of Attitude and Intention towards the Behaviour. For these, Attitude and Personal Norm emerge as predictors of the Intention to fully implement a HACCP system. For “low performers”, Personal Norm was the strongest predictor of Intention, with results pointing to the need for an intervention from the authorities to promote increased conformance to food safety practices. For both groups, neither Social Norm nor Perceived Behavioural Control acted as significant predictors of Intention.     

Improving the multi-objective evolutionary optimization algorithm for hydropower reservoir operations in the California Oroville–Thermalito complex

This study demonstrates the application of an improved Evolutionary optimization Algorithm (EA), titled Multi-Objective Complex Evolution Global Optimization Method with Principal Component Analysis and Crowding Distance Operator (MOSPD), for the hydropower reservoir operation of the Oroville–Thermalito Complex (OTC) – a crucial head-water resource for the California State Water Project (SWP). In the OTC's water-hydropower joint management study, the nonlinearity of hydropower generation and the reservoir's water elevation–storage relationship are explicitly formulated by polynomial function in order to closely match realistic situations and reduce linearization approximation errors. Comparison among different curve-fitting methods is conducted to understand the impact of the simplification of reservoir topography. In the optimization algorithm development, techniques of crowding distance and principal component analysis are implemented to improve the diversity and convergence of the optimal solutions towards and along the Pareto optimal set in the objective space. A comparative evaluation among the new algorithm MOSPD, the original Multi-Objective Complex Evolution Global Optimization Method (MOCOM), the Multi-Objective Differential Evolution method (MODE), the Multi-Objective Genetic Algorithm (MOGA), the Multi-Objective Simulated Annealing approach (MOSA), and the Multi-Objective Particle Swarm Optimization scheme (MOPSO) is conducted using the benchmark functions. The results show that best the MOSPD algorithm demonstrated the best and most consistent performance when compared with other algorithms on the test problems. The newly developed algorithm (MOSPD) is further applied to the OTC reservoir releasing problem during the snow melting season in 1998 (wet year), 2000 (normal year) and 2001 (dry year), in which the more spreading and converged non-dominated solutions of MOSPD provide decision makers with better operational alternatives for effectively and efficiently managing the OTC reservoirs in response to the different climates, especially drought, which has become more and more severe and frequent in California.     

ECISER: Efficient Clip-art Image SEgmentation by Re-rasterization

Clip-art image segmentation is widely used as an essential step to solve many vision problems such as colorization and vectorization. Many of these applications not only demand accurate segmentation results, but also have little tolerance for time cost, which leads to the main challenge of this kind of segmentation. However, most existing segmentation techniques are found not sufficient for this purpose due to either their high computation cost or low accuracy. To address such issues, we propose a novel segmentation approach, ECISER, which is well-suited in this context. The basic idea of ECISER is to take advantage of the particular nature of cartoon images and connect image segmentation with aliased rasterization. Based on such relationship, a clip-art image can be quickly segmented into regions by re-rasterization of the original image and several other computationally efficient techniques developed in this paper. Experimental results show that our method achieves dramatic computational speedups over the current state-of-the-art approaches, while preserving almost the same quality of results.     

Neutral axis depth and moment redistribution in FRP and steel reinforced concrete continuous beams

The neutral axis depth is considered the best parameter for quantifying the moment redistribution in continuous concrete beams, as exemplified in various design codes worldwide. It is therefore important to well understand the variation of neutral axis depth against moment redistribution. This paper describes a theoretical investigation into the neutral axis depth and moment redistribution in concrete beams reinforced with fibre reinforced polymer (FRP) and steel bars. A finite element model has been developed. The model predictions are in favourable agreement with experimental results. Three types of reinforcement are considered, namely, glass fibre, carbon fibre and steel. Various levels of reinforcement ratio are used for a parametric evaluation. The results indicate that FRP reinforced concrete continuous beams exhibit significantly different response characteristics regarding the moment redistribution and variation of neutral axis depth from those of steel reinforced ones. In addition, it is found that the code recommendations are generally unsafe for calculating the permissible moment redistribution in FRP reinforced concrete beams, but the neglect of redistribution in such beams may be overconservative.