Uniform expansivity outside the critical neighborhood in the quadratic family

We use rigorous numerical techniques to compute a lower bound for the exponent of expansivity outside a neighborhood of the critical point for thousands of intervals of parameter values in the quadratic family. We compute a possibly small radius of the critical neighborhood, and a lower bound for the corresponding expansivity exponent outside this neighborhood, valid for all the parameters in each of the intervals. We illustrate and study the distribution of the radii and these exponents. The results of our computations are mathematically rigorous. The source code of the software and the results of the computations are made publicly available at http://www.pawelpilarczyk.com/quadratic/..Comment: 12 pages, 7 figure

On The Relative N-Tensor Nilpotent Degree of Finite Groups

In this paper, we introduce the relative $n$-tensor nilpotent degree of a finite group $G$ with respect to a subgroup $H$ of $G$. The aim of this paper is to investigate this concept and give some results on this topic

The effects of Zataria multiflora on inhibition of polyphenoloxidase and melanosis formation in shrimp (Litopenaeus vannamei)

Shrimp melanosis (black spot) is an important surface discoloration caused by polyphenol oxidase (tyrosinase) enzyme, which oxidizes phenols and leads to insoluble black pigments, the melanins. Sulphiting agents are widely used as melanosis inhibitors; but, the hazards related to sulphated foods, such as allergic reactions and severe disorders in asthmatic patients have created a necessity to find the effective natural alternatives. The current study was accomplished to assay the in vitro antityrosinase effect of Z. multiflora EO as well as its capability to retard the melanosis formation in shrimp during iced storage. According to GC/MS results, carvacrol, thymol and p-cymene were the major components of Z.multiflora EO, representing 50.8, 14.4 and 10.6, respectively. DPPH radical scavenging activity of EO was 0.8±0.02 mg/ml and 63.2% of tyrosinase activity decreased when EO with a concentration of 0.25% was applied. Furthermore, it has been observed that immersing the shrimps in 1% EO aqueous suspension retarded the melanosis formation in shrimp during 10 days of iced storage. It can be concluded that Z. multiflora EO could be used as an effective natural processing aid to increase the shrimp shelf-life during iced storage

A study on the essential oil Ferulago campestris. How much does exstraction method influence the oil composition?

The essential oil of different parts of Ferulago campestris (Bess.) collected in Sicily has been extracted by microwave-assisted hydrodistillation (MAHD) and by classic hydrodistillation (HD). A comparative qualitative–quantitative study on the composition of the oils was carried out. A total of 100 compounds were identified in the oils obtained by MAHD, whereas 88 compounds characterized the HD oils. The most prominent components were, in all different parts of F. campestris and in both extraction methods, 2,4,5-trimethylbenzaldehyde and 2,4,6-trimethylbenzaldehyde isomers; the latter was not previously found. The attempt to evaluate where the oil components are located in all parts of the plant was carried out by means of a kinetic study. Then, electron microscopy observation on the different parts before and after MAHD and HD was performed

Investigación sobre el impacto del aceite de palma refinado en la estabilidad oxidativa de su mezcla con aceite de linaza: un enfoque cinético

This study investigates whether blending palm oil with linseed oil can enhance the oxidative stability of linseed oil, which is prone to oxidation due to its high polyunsaturated fatty acid content. Four blends were prepared: 66 % linseed oil with 33 % crude palm oil (33C), 33 % linseed oil with 66 % crude palm oil (66C), 66 % linseed oil with 33 % refined palm oil (33R), and 33% linseed oil with 66 % refined palm oil (66R). Oxidation kinetics were analyzed using peroxide value, p-anisidine value, TOTOX value, induction period, activation energy, and Gibbs free energy. The results showed that palm oil blends, particularly refined palm oil, significantly improved oxidative stability. The 66R sample exhibited the highest stability, with lower oxidation values, longer induction periods, and higher activation energy. Refining palm oil further enhanced its stabilizing effect. These findings offer practical solutions for the food industry to extend the shelf-life of linseed oil-based products, such as margarines and dressings, while maintaining their nutritional quality.Este estudio investiga si la mezcla de aceite de palma con aceite de linaza puede mejorar la estabilidad oxidativa del aceite de linaza, que es propenso a la oxidación debido a su alto contenido de ácidos grasos poliinsaturados. Se prepararon cuatro mezclas: 66 % de aceite de linaza con 33 % de aceite de palma crudo (33C), 33 % de aceite de linaza con 66 % de aceite de palma crudo (66C), 66 % de aceite de linaza con 33% de aceite de palma refinado (33R) y 33 % de aceite de linaza con 66 % de aceite de palma refinado (66R). Se analizó la cinética de oxidación utilizando el índice de peróxido, el índice de p-anisidina, el índice de TOTOX, el período de inducción, la energía de activación y la energía libre de Gibbs. Los resultados mostraron que las mezclas de aceite de palma, en particular el aceite de palma refinado, mejoraron significativamente la estabilidad oxidativa. La muestra 66R exhibió la mayor estabilidad, con valores de oxidación más bajos, períodos de inducción más largos y mayor energía de activación. El refinado del aceite de palma mejoró aún más su efecto estabilizador. Estos hallazgos ofrecen soluciones prácticas para que la industria alimentaria pueda extender la vida útil de los productos a base de aceite de linaza, como margarinas y aderezos, manteniendo al mismo tiempo la calidad nutricional

Composition and antioxidant activity of thymus vulgaris volatiles: comparison between supercritical fluid extraction and hydrodistillation

Supercritical fluid extraction (SEE) of the volatile oil from Thymus vulgaris L. aerial flowering parts was performed under different conditions of pressure, temperature, mean particle size and CO2 flow rate and the correspondent yield and composition were compared with those of the essential oil isolated by hydrodistillation (HD). Both the oils were analyzed by GC and GC-MS and 52 components were identified. The main volatile components obtained were p-cymene (10.0-42.6% for SFE and 28.9-34.8% for HD), gamma-terpinene (0.8-6.9% for SFE and 5.1-7.0% for HD), linalool (2.3-5.3% for SFE and 2.8-3.1% for HD), thymol (19.5-40.8% for SFE and 35.4-41.6% for HD), and carvacrol (1.4-3.1% for SFE and 2.6-3.1% for HD). The main difference was found to be the relative percentage of thymoquinone (not found in the essential oil) and carvacryl methyl ether (1.0-1.2% for HD versus t-0.4 for SFE) which can explain the higher antioxidant activity, assessed by Rancimat test, of the SFE volatiles when compared with HD. Thymoquinone is considered a strong antioxidant compound

Audio-visual speech enhancement with a deep Kalman filter generative model

Deep latent variable generative models based on variational autoencoder (VAE) have shown promising performance for audiovisual speech enhancement (AVSE). The underlying idea is to learn a VAEbased audiovisual prior distribution for clean speech data, and then combine it with a statistical noise model to recover a speech signal from a noisy audio recording and video (lip images) of the target speaker. Existing generative models developed for AVSE do not take into account the sequential nature of speech data, which prevents them from fully incorporating the power of visual data. In this paper, we present an audiovisual deep Kalman filter (AV-DKF) generative model which assumes a first-order Markov chain model for the latent variables and effectively fuses audiovisual data. Moreover, we develop an efficient inference methodology to estimate speech signals at test time. We conduct a set of experiments to compare different variants of generative models for speech enhancement. The results demonstrate the superiority of the AV-DKF model compared with both its audio-only version and the non-sequential audio-only and audiovisual VAE-based models