Origin authentication of distillers' dried grains and solubles (DDGS) - Application and comparison of different analytical strategies

In the context of products from certain regions or countries being banned because of an identified or non-identified hazard, proof of geographical origin is essential with regard to feed and food safety issues. Usually, the product labeling of an affected feed lot shows origin, and the paper documentation shows traceability. Incorrect product labeling is common in embargo situations, however, and alternative analytical strategies for controlling feed authenticity are therefore needed. In this study, distillers' dried grains and solubles (DDGS) were chosen as the product on which to base a comparison of analytical strategies aimed at identifying the most appropriate one. Various analytical techniques were investigated for their ability to authenticate DDGS, including spectroscopic and spectrometric techniques combined with multivariate data analysis, as well as proven techniques for authenticating food, such as DNA analysis and stable isotope ratio analysis. An external validation procedure (called the system challenge) was used to analyze sample sets blind and to compare analytical techniques. All the techniques were adapted so as to be applicable to the DDGS matrix. They produced positive results in determining the botanical origin of DDGS (corn vs. wheat), and several of them were able to determine the geographical origin of the DDGS in the sample set. The maintenance and extension of the databanks generated in this study through the analysis of new authentic samples from a single location are essential in order to monitor developments and processing that could affect authentication.

Powers, liabilities and expertise in community safety: Comparative lessons for ‘urban security’ from the United Kingdom and the Republic of Ireland

This paper begins by outlining and critiquing what we term the dominant anglophone model of neo-liberal community safety and crime prevention. As an alternative to this influential but flawed model, a comparative analysis is provided of the different constitutional-legal settlements in each of the five jurisdictions across the UK and the Republic of Ireland (ROI), and their uneven institutionalization of community safety. In the light of this it is argued that the nature of the anglophone community safety enterprise is actually subject to significant variation. Summarizing the contours of this variation facilitates our articulation of some core dimensions of community safety. Then, making use of Colebatch’s (2002) deconstruction of policy activity into categories of authority and expertise, and Brunsson’s (2002) distinction between policy talk, decisions and action, we put forward a way of understanding policy activity that avoids the twin dangers of ‘false particularism’ and ‘false universalism’ (Edwards and Hughes, 2005); that indicates a path for further empirical enquiry to assess the ‘reality’ of policy convergence; and that enables the engagement of researchers with normative questions about where community safety should be heading.

Towards a better understanding of flood-risk preparedness: A typological review

Preparedness has become a central component to contemporary approaches to flood risk management as there is a growing recognition that our reliance on engineered flood defences is unsustainable within the context of more extreme and unpredictable weather events. Whilst many researchers have focused their attention on exploring the key factors influencing flood-risk preparedness at the individual level, little consideration has been attributed to how we understand preparedness conceptually and practically in the first instance. This paper seeks to address this particular gap by identifying and analysing the diverse range of conceptualisations of preparedness and typologies of preparedness measures that exist within the literature in order to identify areas of convergence and divergence. In doing so, we demonstrate that a considerable degree of confusion remains in terms of how preparedness is defined, conceptualised and categorised. We conclude by reflecting on the implications this has from an academic perspective, but also in terms of the more practical aspects of flood risk management.

Simulation of Distributed Contact in String Instruments: a Modal Expansion Approach

Impactive contact between a vibrating string and a barrier is a strongly nonlinear phenomenon that presents several challenges in the design of numerical models for simulation and sound synthesis of musical string instruments. These are addressed here by applying Hamiltonian methods to incorporate distributed contact forces into a modal framework for discrete-time simulation of the dynamics of a stiff, damped string. The resulting algorithms have spectral accuracy, are unconditionally stable, and require solving a multivariate nonlinear equation that is guaranteed to have a unique solution. Exemplifying results are presented and discussed in terms of accuracy, convergence, and spurious high-frequency oscillations.

An Efficient Precoder Design for Multiuser MIMO Cognitive Radio Networks with Interference Constraints

We consider a linear precoder design for an underlay cognitive radio multiple-input multiple-output broadcast channel, where the secondary system consisting of a secondary base-station (BS) and a group of secondary users (SUs) is allowed to share the same spectrum with the primary system. All the transceivers are equipped with multiple antennas, each of which has its own maximum power constraint. Assuming zero-forcing method to eliminate the multiuser interference, we study the sum rate maximization problem for the secondary system subject to both per-antenna power constraints at the secondary BS and the interference power constraints at the primary users. The problem of interest differs from the ones studied previously that often assumed a sum power constraint and/or single antenna employed at either both the primary and secondary receivers or the primary receivers. To develop an efficient numerical algorithm, we first invoke the rank relaxation method to transform the considered problem into a convex-concave problem based on a downlink-uplink result. We then propose a barrier interior-point method to solve the resulting saddle point problem. In particular, in each iteration of the proposed method we find the Newton step by solving a system of discrete-time Sylvester equations, which help reduce the complexity significantly, compared to the conventional method. Simulation results are provided to demonstrate fast convergence and effectiveness of the proposed algorithm.