Application of the novel Droplet digital PCR technology for identification of meat species

The authenticity and traceability of meat products are issues of primary importance to ensure food safety. Unfortunately, food adulteration (e.g. the addition of inexpensive cuts to minced meat products) and mislabelling (e.g. the inclusion of meat from species other than those declared) happens frequently worldwide. The aim of this study was to apply a droplet digital PCR assay for the detection and quantification (copies μL⁻¹) of the beef, pork, horse, sheep, chicken and turkey in meat products. The analysis conducted on commercial meat showed the presence of traces of DNA from other animal species than those declared. We show that the method is highly sensitive, specific and accurate (accuracy = 100%). This method could be adopted by competent food safety authorities to verify compliance with the labelling of meat products and to ensure quality and safety throughout the meat supply chain, from primary production to consumption.     

Effect of Bonder at Skin/Core Interface on the Mechanical Performances of Sandwich Structures Used in Marine Industry

The present work is aimed to extend the knowledge of mechanical properties of sandwich structures used for marine applications focusing on the possibility to increase the performances of such structures by adding a bonder at the skin/core interface. Therefore, three sandwich structures that are utilised in different structural components of a yacht were realised by manual lay-up. The mechanical characterisation was performed by flatwise compressive, edgewise compressive and three point flexural tests. The tests execution has allowed both to determine the mechanical performances and to understand the fracture mechanisms that take place when the bonder is added in the stacking sequence of the samples.     

Role of anionic and nonionic surfactants on the control of particle size and latex colloidal stability in the seeded emulsion polymerization of butyl methacrylate

The evolution of the main colloidal parameters in the seeded starved‐feed semi‐continuous emulsion polymerization of butyl methacrylate (BMA) was investigated, with the main purpose of assessing the effectiveness of the semi‐empirical relationship S = K · S_S · ΔA/A_S as a tool to define the surfactant/monomer feed ratio (∝ K) best suited to achieve a target particle size. In particular, the effect of the type and amount of surfactant [i.e., anionic, sodium dodecyl sulfate (SDS), or nonionic, Brij 58P] added during the semi‐continuous stage was considered. Coagulum formation was never observed under the adopted experimental conditions. To detect the occurrence of secondary nucleation or particle aggregation, or both, the particle size and number of particles, the surface tension and the particle surface coverage ratio were correlated. The best results were obtained with SDS and 0.8 ≤ K ≤ 3. In fact, under the selected experimental conditions, only with SDS did the number of particles remain nearly constant throughout the polymerization at the value defined by the seed latex; the particle size distribution was highly monodisperse, and the final particle diameter closely matched the calculated one (～ 120 nm). The above semi‐empirical relationship based on the adjustable parameter K was validated by running test polymerizations aimed at lattices with well‐defined particle size. © 2006 Wiley Periodicals, Inc. J Appl Polym Sci 102: 3083–3094, 2006     

Deformation Bands in Ceria-Stabilized Tetragonal Zirconia/Alumina : II, Stress-Induced Aging at Room Temperature

A stress-induced aging phenomenon is observed to occur at room temperature in deformation bands introduced into a 8.5 mol% ceria-stabilized tetragonal zirconia/alumina (CeTZP/A1₂O₃) composite by flexural loading. The aging occurs with time after unloading and in laboratory air. Over a period of 100 days, the concentration of monoclinic zirconia within a deformation band increases and, in addition, the wedge-shaped deformation band grows with time. Accompanying these two changes are an increase in the tensile stress in the remaining tetragonal zirconia within the deformation band and a consequential increase in the overall compressive stress within the band. The average value of the monoclinic concentration within the deformation band is found to increase parabolically with time, suggesting the mechanism responsible for the observed aging is diffusion limited. Away from the deformation bands, no aging is observed to occur, suggesting aging is stress dependent. Although a water-vapor-mediated mechanism cannot be ruled out, it is proposed that the observed aging is in fact due to a tensile stress assisted chemical reduction of Ce⁴⁺ to Ce³⁺ whose rate is controlled by the indiffusion of oxygen vacancies driven by the tensile stress gradient. It is further proposed that the deformation band grows with time, since the region ahead of the band is under tension and hence subject to an enhanced rate of reduction     

Computations with quasiseparable polynomials and matrices

In this paper, we survey several recent results that highlight an interplay between a relatively new class of quasiseparable matrices and univariate polynomials. Quasiseparable matrices generalize two classical matrix classes, Jacobi (tridiagonal) matrices and unitary Hessenberg matrices that are known to correspond to real orthogonal polynomials and Szegö polynomials, respectively. The latter two polynomial families arise in a wide variety of applications, and their short recurrence relations are the basis for a number of efficient algorithms. For historical reasons, algorithm development is more advanced for real orthogonal polynomials. Recent variations of these algorithms tend to be valid only for the Szegö polynomials; they are analogues and not generalizations of the original algorithms.     

The principle of guarantee availability for security protocol analysis

Conformity to prudent design principles is an established approach to protocol correctness although it is not free of limitations. We term goal availability a design principle that is often implicitly followed, prescribing protocols to aim at principal-centric goals. Adherence to a design principle is normally established through protocol analysis that is an evaluation of whether a protocol achieves its goals. However, the literature shows that there exists no clear guidance on how to conduct and interpret such an analysis, a process that is only left to the analyzer’s skill and experience. Goal availability has the desirable feature that its supporting protocol analysis can be precisely guided by what becomes a principle of realistic analysis, which we call guarantee availability. It prescribes that the outcome of the analysis, which is the set of guarantees confirming the protocol goals, be practically applicable by the protocol participants. In consequence, the guarantees must be based on assumptions that the principals have the capacity to verify. Our focus then turns entirely to protocol analysis, because an analysis conforming to guarantee availability signifies that the analyzed protocol conforms to goal availability. Existing analysis of (both classical and deployed) protocols has been reconsidered with the aim of studying their conformity to guarantee availability. Some experiments clarify the relationships between goal availability and the existing design principles, with particular reference to explicitness. Other experiments demonstrate that boosting an analysis with guarantee availability generally makes it deeper, unveiling additional protocol niceties that depending on the analyzer’s skills may remain overseen otherwise. In particular, an established claim about a protocol (made using a well-known formal method) can be subverted.     

An integrated computer-controlled system for assisting researchers in cortical excitability studies by using transcranial magnetic stimulation

Transcranial magnetic stimulation (TMS) is the most important technique currently available to study cortical excitability. Additionally, TMS can be used for therapeutic and rehabilitation purposes, replacing the more painful transcranial electric stimulation (TES). In this paper we present an innovative and easy-to-use tool that enables neuroscientists to design, carry out and analyze scientific studies based on TMS experiments for both diagnostic and research purposes, assisting them not only in the practicalities of administering the TMS but also in each step of the entire study's workflow. One important aspect of this tool is that it allows neuroscientists to specify research designs at will, enabling them to define any parameter of a TMS study starting from data acquisition and sample group definition to automated statistical data analysis and RDF data storage. It also supports the diagnosing process by using on-line support vector machines able to learn incrementally from the diseases instances that are continuously added into the system. The proposed system is a neuroscientist-centred tool where the protocols being followed in TMS studies are made explicit, leaving to the users flexibility in exploring and sharing the results, and providing assistance in managing the complexity of the final diagnosis. This type of tool can make the results of medical experiments more easily exploitable, thus accelerating scientific progress.     

Geometry and Stacking Sequence Effect on Composite Spinnaker Pole's Stiffness: Experimental and Numerical Analysis

Composite materials are widely employed in sailing sports, a possible application is for the mast pole or other sail poles. In the paper the attention is focused on the spinnaker poles mechanical performances; in particular the focus is on axial and ring compressive properties of three different carbon fibre/epoxy resin spinnaker poles, to investigate both the diameter and stacking sequence effect on the mechanical performance of the structure. Starting from the stacking sequence used in the production of a particular spinnaker pole, the effect of a lamina at 0° in the middle of wall thickness is investigated with the purpose to obtain a more stiff structure. Moreover to test the proposed stacking sequence on different size products, a prototype with lower diameter is realized. To properly evaluate axial and ring stiffness, axial compression test and ring stiffness one are performed. Then a numerical model is developed to support the design of the finished product: A simple and versatile numerical analysis (FEA with software ANSYS), by simulating ring stiffness and pull-direction compression tests, is carried out in elastic regime. Such model should be suitable for designing and/or verifying the mechanical performance of pole structures, even though differing from those above described, for materials, geometry and stacking sequence.