Real-time pcr method combined with a matrix lysis procedure for the quantification of listeria monocytogenes in meat products

In this study a real-time PCR method has been developed for the specific quantification of the foodborne pathogen Listeria monocytogenes on meat products through the gene hlyA. The PCR was combined with a matrix lysis that allowed the obtaining of the microorganisms without sample dilution and the elimination the PCR inhibitors from dry-cured ham. The qPCR method calibration curve had an efficiency of 100.4%, limits of detection and quantification were 30.1 ± 6.2 CFU/g which is under the legal limit of L. monocytogenes in ready-to-eat products, and an analytical variability <0.25 log hlyA gene copies/reaction. The analysis was performed simultaneously with the reference method ISO 11290-2. The comparison of the qPCR-matrix lysis results with the reference method showed an excellent correspondence, with a relative accuracy between 95.83–105.20%. Finally, the method was applied to commercial derived meat samples and the pathogen was quantified in one of the commercial samples assayed in 69.1 ± 13.9 CFU/g while the reference method did not quantify it. The optimized qPCR showed higher precision and sensitivity than the reference method at low concentrations of the microorganism in a shorter time. Therefore, qPCR-matrix lysis shows a potential application in the meat industry for L. monocytogenes routine control. © 2021 by the authors. Licensee MDPI, Basel, Switzerland

Improving reality. An analysis of Spanish makeover reality television

The main aim of this paper is to identify the values conveyed by Spanish makeover reality television. There are two aspects that make these programmes relevant study objects: first, their widespread presence in Spanish television schedules, and second, the role they play in constructing the social imaginary due to their didactic and prescriptive nature. We analysed six Spanish makeover reality shows, Cambio Radical, Desnudas, Esta casa era una ruina, Supernanny, Hermano Mayor and Ajuste de Cuentas, using a methodology that combines narrative semiotics and the analysis of narrative form (plot/syhuzet) and audiovisual style. This paper summarises the main research results and conclusions of a doctoral thesis presented in September 2010

Can the Mystery of the Speed of Light be Unveiled by Kinetic Waves?

An in-depth analysis of the dynamics connected to the Doppler-effect brings clear light to elements of contradiction with the original ground on which the axiom of the constancy of lightspeed was based. Thereby, with regard to electromagnetic phenomenology, the duality waves/particles and the wavy dynamic of light-propagation suggest the existence of a natural kind of waves, which differently from the classic ones, are originating by kinetic thrust and propagating, also though vacuum, by inertial force. The model taken into consideration, to which has been given the name of “kinetic waves” is, like the classic one, a concretely existing natural phenomenon which can also be visually perceived if produced on molecular scale. Moreover, kinetic waves seem to offer many more points of similarity, in dynamic and behavior, with the electromagnetic waves, than the classic model. Applying the obtained results to astrophysical field, taking as example the quasar 3C-273, the recently found, most far galaxy GN-z11 and the galaxy NGC 224 (better known as Andromeda), can mathematically and concretely be sustained that none of the energy sources we optically perceive, showing a Doppler-shift, is regressing nor approaching. In the appendix, a suggested and accurately described experiment on base of Radar Astronomy to possibly confirm the validity of the model presented by this article

Scalar Field Oscillations Contributing to Dark Energy

We use action-angle variables to describe the basic physics of coherent scalar field oscillations in the expanding universe. These analytical mechanics methods have some advantages, like the identification of adiabatic invariants. As an application, we show some instances of potentials leading to equations of state with $p<-\rho/3$, thus contributing to the dark energy that causes the observed acceleration of the universe.Comment: 17 pages, 6 figures, Latex file. Sec.II reduced, discussion on sound speed added in Sec.IV, new references added. Accepted for publication in Physical Review

Condensate fraction in liquid 4He at zero temperature

We present results of the one-body density matrix (OBDM) and the condensate fraction n_0 of liquid 4He calculated at zero temperature by means of the Path Integral Ground State Monte Carlo method. This technique allows to generate a highly accurate approximation for the ground state wave function Psi_0 in a totally model-independent way, that depends only on the Hamiltonian of the system and on the symmetry properties of Psi_0. With this unbiased estimation of the OBDM, we obtain precise results for the condensate fraction n_0 and the kinetic energy K of the system. The dependence of n_0 with the pressure shows an excellent agreement of our results with recent experimental measurements. Above the melting pressure, overpressurized liquid 4He shows a small condensate fraction that has dropped to 0.8% at the highest pressure of p = 87 bar.Comment: 12 pages. 4 figures. Accepted for publication on "Journal of Low Temperature Physics

Modulational instability in dispersion-kicked optical fibers

We study, both theoretically and experimentally, modulational instability in optical fibers that have a longitudinal evolution of their dispersion in the form of a Dirac delta comb. By means of Floquet theory, we obtain an exact expression for the position of the gain bands, and we provide simple analytical estimates of the gain and of the bandwidths of those sidebands. An experimental validation of those results has been realized in several microstructured fibers specifically manufactured for that purpose. The dispersion landscape of those fibers is a comb of Gaussian pulses having widths much shorter than the period, which therefore approximate the ideal Dirac comb. Experimental spontaneous MI spectra recorded under quasi continuous wave excitation are in good agreement with the theory and with numerical simulations based on the generalized nonlinear Schr\"odinger equation

Urban Heat Island (UHI) risk maps as innovative tool for urban regeneration strategies. The case of Parma

For the purposes of regeneration of the consolidated city it is increasingly important to have the knowledge of the micro-scale distribution of the vulnerability of the population to the consequences of climate change and increasing urbanization. The work to be presented starts with the creation of maps of the risk classification induced by the heat islands in the city of Parma, and aims to investigate which are the most effective strategies that a Public Administration can adopt. The maps that have been created allow to assess the risk for the fragile population at the level of the single building. They relate the climatic datum of thermal variation with the population residing within each building, and verify the causal relationship with the soil sealing and with the morphology of the urban fabric. The results of the study can help to identify the thermal hot spot, receivers of specific mitigation actions. The risk map is itself a tool to develop multilevel actions, designed according to the peculiarities of the sites, where the possible adaptive solutions are compared with the physical and morphological characteristics of the places. The positive function of green infrastructures (contrast of overheating, flood mitigation, creation of places and services with a recreational function) is acquired by research and urban planning practice. It is equally well known the difficulty faced by Local Authorities in the maintenance and increase of unbuilt public areas, fundamental for the connection of ecological networks

Mixable Shuffles, Quasi-shuffles and Hopf Algebras

The quasi-shuffle product and mixable shuffle product are both generalizations of the shuffle product and have both been studied quite extensively recently. We relate these two generalizations and realize quasi-shuffle product algebras as subalgebras of mixable shuffle product algebras. As an application, we obtain Hopf algebra structures in free Rota-Baxter algebras.Comment: 14 pages, no figure, references update