Quantitative detection of Listeria monocytogenes in raw milk and soft cheeses: Culture-independent versus liquid- and solid-based culture-dependent real time PCR approaches

A culture-independent and two culture-dependent real time (rt-) PCR approaches were developed to quantitatively identify Listeria monocytogenes in raw milk and soft cheeses. The optimised rt-PCR revealed 100% inclusivity and exclusivity. DNA- and cell-based standard curves showed a good linearity of response (R² ≥ 0.987 and R² ≥ 0.998, respectively) for five orders of magnitude (39 × 10⁵ – 3 × 10⁰ genome equivalents and 10⁶–10¹ CFU equivalents, respectively) with about 100% relative accuracy and inter-assay variability ≤0.90%. Up to 1 genome equivalent/and 10 CFU/reaction were quantified in the DNA and cell standard curves, respectively. The rt-PCR was then combined with a liquid- (MPN technique) or a solid- (ALOA and PALCAM) based enumeration. The diagnostic sensitivity of the different approaches was investigated in artificially contaminated raw milk and soft cheeses. The rt-PCR culture-independent approach performed well in raw milk and (with a lower sensitivity) in stracchino cheese-based standard curves. MPN/rt-PCR was the best approach to enumerate low levels of L. monocytogenes in raw milk and stracchino cheese, while the ALOA-based rt-PCR quantification was more effective than the PALCAM-based. These performances were confirmed when 23 real samples of raw milk and soft cheeses by both the rt-PCR approaches were assayed.     

Phase transformation and microstructural evolution after heat treatment of a terbium-doped lithium–aluminum phosphate glass

The crystallization kinetics and phase transformation of a transparent Tb³⁺-doped lithium–aluminum phosphate glass, prepared by melt quenching, were investigated. The energy associated to the glass transition and the crystallization parameters (activation energy for crystallization and Avrami exponent) were evaluated by different methods using the experimental data obtained by differential thermal analysis performed at different heating rates. Using an isoconversional method to determine the change of the activation energy for crystallization with the fraction of crystallization, it was verified that with the increase in the fraction of crystallization from 0.1 to 0.9, the value of the activation energy decreased slightly from ~370 to ~310 kJ mol^?1 and that the Avrami exponent varied from 0.8 to 1, suggesting a surface crystal growth mechanism. Observation of the microstructural evolution of heat-treated glass samples confirmed a surface crystallization process revealing spherulitic crystals constituted mainly by aluminum metaphosphate.     

Intentional and unintentional contributions of nonspecific preparation during reaction time foreperiods.

The nonspecific preparation that follows a warning stimulus (WS) to speed responding to an impending imperative stimulus (IS) is generally viewed as a strategic, intentional process. An alternative view holds that WS acts as a conditioned stimulus that unintentionally elicits a tendency to respond at the moment of IS presentation as a result of a process of trace conditioning. These views were contrasted as explanatory frameworks for classical effects on reaction time of the duration and intertrial variability of the foreperiod, the interval between WS and IS. It is shown that the conditioning view accounts for the available data at least as well as the strategic view. In addition, the results of 3 experiments provide support for the conditioning view by showing that unintentional contributions to nonspecific preparation can be dissociated from intentional contributions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Modulation of magnetic and structural properties of cobalt thin films by means of electrodeposition

Cobalt electrodeposits were prepared from an electrolytic bath containing cobalt perchlorate. The effect of different species, organic (thiourea and sodium gluconate) and inorganic (boric acid), on the crystallographic structure, morphology, magnetic properties and electrochemical behaviour of cobalt electrodeposits was investigated. Amorphous cobalt, hcp cobalt and a non-usual primitive cubic cobalt phase were observed depending on the bath composition. Depending on the structure, different morphologies and magnetic properties were found. Coercivity values of the cobalt coatings ranged from around 15 Oe for amorphous, nodular deposits to 380 Oe for cobalt coatings showing acicular morphology and hcp structure with a (002) preferred orientation. Knowledge of the influence of the species on the properties of cobalt makes it possible to obtain tailored cobalt films.     

Evaluation of the Feasibility of Irrigation Storage in a Flood Detention Pond in an Agricultural Catchment in Northern Italy

During recent years, the international attention paid to rational use and saving of water has increased, partly because of frequent water shortages occurring also in countries not usually involved in these problems, and partly as a consequence of rising conflicts on water allocation. Hence it is important to find new surface-water volumes satisfying agricultural water demand, as well as new ways and areas to store them. The simulation model presented by the paper enables evaluation, in a phase of design feasibility analysis, of whether a flood detention pond can be adapted to act as water storage during irrigation periods in order to reduce agricultural water shortages; it simulates detention pond response to floods and droughts under different hydraulic conditions and reservoir management rules. The first policy goal of the model is to maintain the stored volume within the maximum admissible for flood safety. The second goal is to maintain at the same time a minimum flow in the river and to satisfy irrigation water demand. The model, implemented in a purpose-made simulation software, was applied to an Italian river in the Emilia Romagna region: the results demonstrate that the use of a flood detention pond as an irrigation reservoir is not only possible, if it complies with the operating rules that emerge from this study, but also it brings tangible benefits in reducing agricultural water deficit.     

Solutionizing effects on deformation-induced phase transformations in 2014 aluminum composite

A solutionizing heat treatment of 2014 aluminum alloy reinforced with 0.15 volume fraction of alumina particles (VFAP) results in deformation-induced precipitation during rolling and tensile deformation, with 0.10 VFAP, at room temperature. The extent of precipitation increases with increase in time and/or temperature of solutionizing. An attempt has been made to identify the various types of precipitates in the samples deformed to a given strain and in fractured conditions. The work-hardening curves and tensile properties of the composites have been shown to be dependent on the time and temperature combination of the solutionizing process.     

Critical Review of the Evolution of Extracellular Vesicles’ Knowledge: From 1946 to Today

Extracellular vesicles (EVs) are a family of particles/vesicles present in blood and body fluids, composed of phospholipid bilayers that carry a variety of molecules that can mediate cell communication, modulating crucial cell processes such as homeostasis, induction/dampening of inflammation, and promotion of repair. Their existence, initially suspected in 1946 and confirmed in 1967, spurred a sharp increase in the number of scientific publications. Paradoxically, the increasing interest for EV content and function progressively reduced the relevance for a precise nomenclature in classifying EVs, therefore leading to a confusing scientific production. The aim of this review was to analyze the evolution of the progress in the knowledge and definition of EVs over the years, with an overview of the methodologies used for the identification of the vesicles, their cell of origin, and the detection of their cargo. The MISEV 2018 guidelines for the proper recognition nomenclature and ways to study EVs are summarized. The review finishes with a “more questions than answers” chapter, in which some of the problems we still face to fully understand the EV function and potential as a diagnostic and therapeutic tool are analyzed.