On the dynamics of bubbles in boiling water

We investigate the dynamics of many interacting bubbles in boiling water by using a laser scattering experiment. Specifically, we analyze the temporal variations of a laser intensity signal which passed through a sample of boiling water. Our empirical results indicate that the return interval distribution of the laser signal does not follow an exponential distribution; contrariwise, a heavy-tailed distribution has been found. Additionally, we compare the experimental results with those obtained from a minimalist phenomenological model, finding a good agreement.Comment: Accepted for publication in Chaos, Solitons & Fractal

Strategy for the development of a new stick formula without microplastics

Plastic is a synthetic, malleable, and durable material that has been used for various applications since its invention in the late 19th century. During its very long-time degradation process, mechanical and/or photochemical processes fragment plastic into increasingly smaller fragments called microplastics (MPs). In the cosmetic field, MPs are directly added to many products for various functions, including to exploit their exfoliating and structuring power. Unfortunately, it has been realized that MPs are not retained in purification plants and therefore end up in the aquatic environment causing a high problem of environmental pollution. Polyethene (PE) is the most widely used MP in cosmetics due to its use as a structuring agent, to provide consistency to formulations and as a key ingredient in lipsticks and mascaras. Given the limitations imposed by regulations and the growing demand from consumers for chemical-free and eco-friendly products, the common synthetic and petroleum-based waxes used in lipstick formulations, such as PE, must necessarily be replaced by natural waxes of plant origin. In this paper we report the development of a chemical-free and eco-friendly cosmetic stick. To achieve the goal, it was necessary to study the compatibility of the ABWAX® Revowax, natural alternative to PE, with oils and colours to predict the behaviour of these structuring waxes in more complex systems. Through a systematic comparative study, the two waxes showed similar thermal characteristics and showed similar penetration curves, presenting overall comparable performance in the MP-free finished product. We can therefore consider ABWAX® Revowax natural wax a valid alternative to PE

The grapevine Pectin Methylesterases gene family and its involvement in Botrytis bunch rot control

Plant Pectin Methylesterases (PMEs) represent a group of tissue-specific and developmentally regulated proteins. The gene family is involved in the plant cell wall (CW) remodelling process, by the control of the degree of cell wall pectin methylesterification. Pectin methylesterification also influence the susceptibility to pathogens as Botrytis cinerea (Bc), a necrotrophic fungus responsible of the Botrytis bunch rot in grapevine. In Botrytis, PME as well as other CW degrading enzymes have been identified as virulence factors. To further characterize the PME gene family and its role in the Botrytis bunch rot, the latest genome assembly and annotation were revised and through sequence homology search, a total of 63 PME domain containing proteins were identified, 16 more than a previous identification in grapevine. The in-silico analyses of the family by means of the Vitis gene expression database VESPUCCI as well as Aggregated Gene Co-expression Network approach (AggGCNs) allowed us to identify and enrich gene co-expression modules and build gene co-expression networks. Interestingly, one of the co-expression modules showed a high modulation in presence of Botrytis cinerea infection and particular attention was paid to it. To investigate the contribution of the genes of that module, their expression level in different organs and developmental stages from two grapevine cultivars with divergent Bc susceptibility was investigated. Furthermore, berries were artificially infected with Bc at mature stage to evaluate PME gene expression level and their possible role in the grapevine bunch rot susceptibility. The results obtained contribute to characterize the grapevine PME gene family and the role of specific members in the grapevine-Bc interaction and to select PME genes candidate to the control of Botrytis bunch rot in grapevine

New strategies for Botrytis bunch rot control for a sustainable viticulture

Grapevine (Vitis vinifera L.) is cultivated throughout the world in a wide range of climates, from temperate to tropical ones. It’s highly susceptible to fungi, being Botrytis cinerea (Bc) among the most important pathogens causing bunch rot (BR), a disease mostly observed on ripe berries, normally controlled through use of chemicals. To date, the defence against Bc is still guaranteed by an intensive use of chemical fungicides. Consequently, the development of alternative strategies for Bc control with benefits both for human health and the environment is of high importance and a priority. In the last years, the concept of “integrated defence” against Bc is increasingly widespread, using defence protocols integrating agronomic control tools with interventions based on synthetic fungicides and natural antagonists to be carried out in the periods of higher susceptibility. In this project, a molecular method for monitoring Bc load in the field was setted-up in order to quantify the colonization by Bc of vineyards of V. vinifera cv Sangiovese and Trebbiano at different locations (hilly site vs plain site) and cultivated applying different integrated defence protocols against Bc. Samples at were collected at three different developmental stages (full flowering, bunch enclosure and veraison) from different biological replicates of different thesis of treatment and molecularly analyzed calculating the colonization coefficient for each sample. The correlation between molecular data with BcBR severity and incidence data at harvest in the different thesis for the two cultivars are here presented. The molecular assay will be useful both to quantify Bc load at the early season in order to predict BcBR severity at harvest, and more in general to evaluate the effect of disease management protocols adopted on the reduction of Bc inoculum

Contamination of a high-cell-density continuous bioreactor

Continuous fermentations were carried out with a recombinant flocculent Saccharomyces cerevisiae strain in an airlift bioreactor. Once operating under steady state at a dilution rate of 0.45 h−1, the bioreactor was contaminated with Escherichia coli cells. The faster growing E. coli strain was washed out of the bioreactor and the recombinant, slower growing flocculating S. cerevisiae strain remained as the only species detected in the bioreactor. Flocculation, besides allowing for the realization of high-cell-density systems with corresponding unusual high productivity, may be used as a selective property for controlling some contamination problems associated with prolonged continuous operation.Fundação para a Ciência e Tecnologia -PRAXIS XXI/BD/11306/97

Photonics-based tunable 1-50 GHz RF transmitter on silicon chip

The paper presents an innovative tunable software-defined RF transmitter based on integrated photonics, able to work in 1-50GHz with very fast tuning. The system has been characterized and verified in a communication scenario