Knowledge landscape of starter cultures: A bibliometric and patentometric study

Background: Starter cultures are essential in food industry biotechnology, consisting of microorganism preparations inoculated to produce safe fermented foods with desirable sensory characteristics. Objective: This study aims to identify and analyze the growth and flow of knowledge about starter cultures by creating scientific and technological profiles using patentometric and bibliometric indicators. Methods: A search for patents and scientific articles was conducted in December 2020 following a proposed 10-step methodology using the Scopus® and Patentinspiration databases. The search strategy was based on the keywords "starter culture" and “fermentation” considering publications up to 2020. Results: A total of 3035 articles and 719 patents were published until 2020, presenting a more significant number in the last ten (10) years due to the development of biological sciences and molecular biology with enzymes and microorganisms. Italy leads the scientific production while China leads the technological. It was also possible to determine the most productive author and inventors, the most influential articles and inventions, and the main scientific journals and patent offices. Conclusion: Scientific and technological activities have an exponential behavior showing that the knowledge about starter cultures continues to grow, becoming a field of interest for optimizing industrial processes related to food fermentation, thus achieving diversification of products that can satisfy the demand for food in an increasingly competitive global market.

The exponential behavior and stabilizability of quasilinear parabolic stochastic partial differential equation

In this paper, we study the stability of quasilinear parabolic stochastic partial differential equations with multiplicative noise, which are neither monotone nor locally monotone. The exponential mean square stability and pathwise exponential stability of the solutions are established. Moreover, under certain hypothesis on the stochastic perturbations, pathwise exponential stability can be derived, without utilizing the mean square stability.

Electrical Properties and Strain Sensing Mechanisms in Hybrid Graphene Nanoplatelet/Carbon Nanotube Nanocomposites

Electrical and electromechanical properties of hybrid graphene nanoplatelet (GNP)/carbon nanotube (CNT)-reinforced composites were analyzed under two different sonication conditions. The electrical conductivity increases with increasing nanofiller content, while the optimum sonication time decreases in a low viscosity media. Therefore, for samples with a higher concentration of GNPs, an increase of sonication time of the hybrid GNP/CNT mixture generally leads to an enhancement of the electrical conductivity, up to values of 3 S/m. This means that the optimum sonication process to achieve the best performances is reached in the longest times. Strain sensing tests show a higher prevalence of GNPs at samples with a high GNP/CNT ratio, reaching gauge factors of around 10, with an exponential behavior of electrical resistance with applied strain, whereas samples with lower GNP/CNT ratio have a more linear response owing to a higher prevalence of CNT tunneling transport mechanisms, with gauge factors of around 3–4.

Simple Catchments and Where to Find Them: The Storage-Discharge Relationship as a Proxy for Catchment Complexity

Hydrological theory often assumes an exponential relationship between storage and discharge, but how often do we find such a behavior in real catchments? We analyze catchment attributes, discharge and weather conditions from 1992 to 2018 for 88 catchments in Hesse, Germany. All catchments have similar weather conditions, but a wide range of catchment characteristics. We find that only a fraction of catchments follow a roughly exponential behavior in their storage-discharge relationship. Far more catchments are complex and depict irregular patterns with even extreme variation from 1 year to another. This large set of catchments with similar weather conditions reveals that physical attributes that drive catchment complexity are diverse and include soil permeability, hydraulic conductivity, geology, and soil type. We link the examined simple and complex behavior to the fill and spill hypotheses and the interconnectedness of the catchments. Simpler catchments have more preferential flow and more connected hillslopes and thus lower runoff generation thresholds. This creates a more straightforward relationship between storage and discharge.

TWO-POINT PROBLEM FOR LINEAR SYSTEMS OF PARTIAL DIffERENTIAL EQUATIONS

The problem with two nodes on the selected variable $t$ and periodicity conditions in other coordinates $x_1,\ldots,x_p$ for linear partial differential equations is investigated. The conditions of solvability problem in the spaces of smooth functions with exponential behavior of Fourier coefficients are established. The estimates for characteristic determinants of the problem are proved.

Regularity Coefficients for Impulsive Differential Equations

For a linear impulsive differential equation, we introduce a Lyapunov regularity coefficient following as far as possible the non-impulsive case. We recall that a regularity coefficient is a quantity that characterizes the Lyapunov regularity of the dynamics. In particular, we obtain lower and upper bounds for the Lyapunov regularity coefficient and we show that its computation can always be reduced to that of the corresponding coefficient of an impulsive dynamics defined by upper triangular matrices. We also relate the Lyapunov regularity coefficient with the Grobman regularity coefficient. Finally, we combine all the former results to establish a criterion for tempered exponential behavior in terms of the Lyapunov exponents and of the Lyapunov regularity coefficient.