Do Inspection and Traceability Provide Incentives for Food Safety?

One of the goals of inspection and traceability is to motivate suppliers to deliver safer food. The ability of these policies to motivate suppliers depends on the accuracy of the inspection, the cost of failing inspection, the cost of causing a foodborne illness, and the proportion of these costs paid by the supplier. We develop a model of the supplier's expected cost as a function of inspection accuracy, the cost of failure, and the proportion of the failure cost that is allocated to suppliers. The model is used to identify the conditions under which the supplier is motivated to deliver uncontaminated lots. Surprisingly, our results show that when safety failure costs can be allocated to suppliers, minimum levels of inspection error are required to motivate a supplier to deliver uncontaminated lots. This result does not hold when costs cannot be allocated to suppliers. As a case study, we use our results to analyze the technical requirements for suppliers of frozen beef to the USDA's Agricultural Marketing Service.diagnostic error, food safety, inspection, sampling error, traceability, Food Consumption/Nutrition/Food Safety,

Metatranscriptomes from diverse microbial communities: assessment of data reduction techniques for rigorous annotation

Background Metatranscriptome sequence data can contain highly redundant sequences from diverse populations of microbes and so data reduction techniques are often applied before taxonomic and functional annotation. For metagenomic data, it has been observed that the variable coverage and presence of closely related organisms can lead to fragmented assemblies containing chimeric contigs that may reduce the accuracy of downstream analyses and some advocate the use of alternate data reduction techniques. However, it is unclear how such data reduction techniques impact the annotation of metatranscriptome data and thus affect the interpretation of the results. Results To investigate the effect of such techniques on the annotation of metatranscriptome data we assess two commonly employed methods: clustering and de-novo assembly. To do this, we also developed an approach to simulate 454 and Illumina metatranscriptome data sets with varying degrees of taxonomic diversity. For the Illumina simulations, we found that a two-step approach of assembly followed by clustering of contigs and unassembled sequences produced the most accurate reflection of the real protein domain content of the sample. For the 454 simulations, the combined annotation of contigs and unassembled reads produced the most accurate protein domain annotations. Conclusions Based on these data we recommend that assembly be attempted, and that unassembled reads be included in the final annotation for metatranscriptome data, even from highly diverse environments as the resulting annotations should lead to a more accurate reflection of the transcriptional behaviour of the microbial population under investigation

A multiplexed single electron transistor for application in scalable solid-state quantum computing

Single Electron Transistors (SETs) are nanoscale electrometers of unprecedented sensitivity, and as such have been proposed as read-out devices in a number of quantum computer architectures. We show that the functionality of a standard SET can be multiplexed so as to operate as both read-out device and control gate for a solid-state qubit. Multiplexing in this way may be critical in lowering overall gate densities in scalable quantum computer architectures.Comment: 3 pages 3 figure

Traceability, Moral Hazard, and Food Safety

Errors in traceability can significantly impact the moral hazard associated with producing safe food. The effect of moral hazard depends on the proportion of unsafe food costs that can be allocated to the responsible producer, which depends on the efficiency of the traceability system. In this paper, we develop a model that identifies the minimum level of traceability needed to mitigate moral hazard and motivate suppliers to produce safe food. Regulators and consumer can use the results of this research to design regulations and contracts that mitigate moral hazard and motivate producers to deliver safe food.Food safety, traceability, moral hazard, Food Consumption/Nutrition/Food Safety,

Difference in depositional behavior of hypopycnal and hyperpycnal flows in the context of continental margins

The conditions necessary for the development of continuous shelf systems, such as those on the continental margin, are not fully understood. Motivated by the observation that continuous shelf-like benches are found on the continental margins in oceans, but not in most lakes, it is proposed that salt is necessary for the creation of continental shelves. This may be characterized in terms of the difference between hyperpycnal and hypopycnal conditions. The former prevails when the incoming flow is denser than the water of the receiving basin; the flow plunges to the bottom of the lake and forms a bottom density flow. The latter prevails when the incoming flow is lighter than that of the receiving basin; the flow rides on the surface water of the receiving basin to form a surface plume. Sediment-laden rivers which enter a saline receiving body, such as the ocean, usually are not dense enough to plunge. Instead, they create buoyant hypopycnal plumes, which lose momentum so that the sediment falls out of suspension locally. Sediment-laden rivers that enter lakes typically can plunge to create hyperpycnal flows, i.e. turbidity currents, which can run out to the bottom of the lake driven by gravity and sediment re-entrainment. Experiments were run in the Ven Te Chow Hydrosystems Laboratory at the University of Illinois in Urbana-Champaign in order determine the role of dissolved salt in the receiving water in controlling the behavior of the incoming flow. A small flume was constructed, with an upstream experimental region of dimensions 61.0 cm (2 feet) in height, 15.2 cm (6 inches) in width, and 243.8 cm (8 feet) in length, and a deeper and wider downstream tank to dampen reflection of any current that runs into it. Twelve experimental runs were performed with matching input conditions; six hyperpycnal with fresh water in the tank, and six hypopycnal with saline water in the tank. The runs were divided into sets of similar total duration, and after each set was completed sediment deposits on the platform were measured. The results of the experiments show that given the same input conditions it is possible for hypopycnal flows to deposit more sediment proximal to the inflow point, whereas hyperpycnal flows carry more sediment downslope. Results show that in the area of deposition outside of a small region near the diffuser, hypopycnal flows deposit twice as much sediment as hyperpycnal flows. Near the diffuser, hyperpycnal flows deposited slightly more sediment, however over the entire measurement area the hypopycnal flows deposited more. One caveat for these results is that sediment deposition inside the diffuser, which guided the flow into the flume, was not measured. Inclusion of measured values of deposition in the diffuser and could change the results. The particle size distributions of the deposit on the bed were also measured. For hyperpycnal flows, the median particle size of the deposit exhibited steady fining in the downstream direction, while for hypopycnal flows median particle size followed no particular pattern. The results indicate that it is possible that salinity is a driving force for the development of continental shelves. That is, salinity tends to force hypopycnal conditions which creates a tendency for sediment to deposit in the nearshore zone instead of going into deep water. This deposit could eventually build up to wave base to form a shelf-like feature, which could then be elongated along shoreline by alongshelf sediment dispersal processes

Robust sound event detection in bioacoustic sensor networks

Bioacoustic sensors, sometimes known as autonomous recording units (ARUs), can record sounds of wildlife over long periods of time in scalable and minimally invasive ways. Deriving per-species abundance estimates from these sensors requires detection, classification, and quantification of animal vocalizations as individual acoustic events. Yet, variability in ambient noise, both over time and across sensors, hinders the reliability of current automated systems for sound event detection (SED), such as convolutional neural networks (CNN) in the time-frequency domain. In this article, we develop, benchmark, and combine several machine listening techniques to improve the generalizability of SED models across heterogeneous acoustic environments. As a case study, we consider the problem of detecting avian flight calls from a ten-hour recording of nocturnal bird migration, recorded by a network of six ARUs in the presence of heterogeneous background noise. Starting from a CNN yielding state-of-the-art accuracy on this task, we introduce two noise adaptation techniques, respectively integrating short-term (60 milliseconds) and long-term (30 minutes) context. First, we apply per-channel energy normalization (PCEN) in the time-frequency domain, which applies short-term automatic gain control to every subband in the mel-frequency spectrogram. Secondly, we replace the last dense layer in the network by a context-adaptive neural network (CA-NN) layer. Combining them yields state-of-the-art results that are unmatched by artificial data augmentation alone. We release a pre-trained version of our best performing system under the name of BirdVoxDetect, a ready-to-use detector of avian flight calls in field recordings.Comment: 32 pages, in English. Submitted to PLOS ONE journal in February 2019; revised August 2019; published October 201

Using self-categorization theory to uncover the framing of the 2015 Rugby World Cup: a cross-cultural comparison of three nations’ newspapers

Research into the framing of sporting events has been extensively studied to uncover newspaper bias in the coverage of global sporting events. Through discourse, the media attempt to capture, build, and maintain audiences for the duration of sporting events through the use of multiple narratives and/or storylines. Little research has looked at the ways in which the same event is reported across different nations, and media representations of the Rugby World Cup have rarely featured in discussions of the framing of sport events. The present study highlights the different ways in which rugby union is portrayed across the three leading Southern Hemisphere nations in the sport. It also shows the prominence of nationalistic discourse across those nations and importance of self-categorizations in newspaper narratives.</jats:p