Drying behavior of organic apples and carrots by using k-means unsupervised learning

Drying prevents food spoilage and decay through moisture removal due to simultaneous heat and mass transfer from food, which may be stored for long period with minimal deterioration occurring. However, drying technology is not always paired with good/excellent organoleptic, nutritional and/or functional properties of food. In fact, during drying the heat-sensitive substances are often destroyed and degradation processes may be exacerbated due to various and concurrent reaction mechanisms. Based on authors’ best knowledge, drying degradation kinetics of biological materials are usually pseudo first-order or first order reactions (i.e. carotenoids degradation in carrots) and may be affected by the initial quality of the product itself. Therefore, the main objective of the proposed study was to investigate the feasibility of k-means unsupervised learning to proactively monitor quality change in organic apples and carrots during hot-air drying. Based on authors’ best knowledge, fruit and vegetables drying has been widely addressed in literature; nevertheless, little insight is available on smart drying, while knowledge of its potential use in the organic sector is totally lacking

The impact of corporate governance on default risk: BERTopic literature review

This study utilizes the BERTopic methodology, a topic modelling tool that facilitates a meticulous exploration of existing literature, to comprehensively review the interplay between corporate governance and default risk. Through analysis of diverse empirical studies, it delves into understanding how corporate governance practices influence default probability. The study underscores the importance of effective governance mechanisms — board attributes, ownership structures, executive compensation, shareholder rights, and disclosure practices — in molding default probabilities. It also highlights the role of external governance mechanisms and regulatory frameworks in managing default risk. Notably, this research advocates for further investigation into emerging governance models and their integration with modern machine-learning techniques to amplify their impact

Non-local skew and non-local sticky Brownian motions

In this paper, we present a comprehensive study on the generalization of skew Brownian motion and two-sided sticky Brownian motion by considering non-local operators at the origin for the heat equations on the real line. To begin, we introduce Marchaud-type operators and Caputo-Dzherbashian-type operators, providing an in-depth exposition of their fundamental properties. Subsequently, we describe the two stochastic processes and the associated equations. The non-local skew Brownian motion exhibits jumps, as a subordinator, at zero where the sign of the jump is determined by a skew coin. Conversely, the non-local sticky Brownian motion displays stickiness at zero, behaving as the inverse of a subordinator, resulting in non-Markovian dynamics

Variación micro y macro fonética en español

Este trabajo constituye un primer intento de elaboración de un modelo del cambio que incorpora tanto teorías de producción y percepción del habla como los resultados de los estudios de la adquisición de las segundas lenguas. Sobre la base de las primeras, se propone una distinción entre micro y macro variación, es decir, entre variación articulatoria no prominente o prominente desde un punto de vista perceptual. Sobre la base de las segundas, se elabora un modelo de categorización de la variación que se apoya en el supuesto de que los aprendices realizan un proceso de clasificación de equivalencia, en el cual comparan sistemáticamente su sistema de sonidos con el de la lengua a la que están expuestos (Flege 1995). Se argumenta aquí que, en una situación de variación y cambio sucede algo semejante y que la incorporación de la noción de clasificación de equivalencia, tomada de los modelos de adquisición de segundas lenguas permite dar cuenta de por qué ciertos cambios siguen una dirección en una comunidad y no en otra. La propuesta se ilustra con distintos procesos de variación y cambio del español de Argentina como así también con trabajos sobre otras variedades del romance (como el francés o el siciliano) y de la adquisición de segundas lenguas.The present paper proposes a sketch of a theory of sound variation and change that integrates both the findings of theories of speech production and perception as well as those of theories of second language acquisition of phonology. First, based on the contributions of the former, a distinction between macro and micro variation (i.e. articulatory variation that may or may not be perceptually salient) is established. Second, a model of categorization of sound variation inspired by Flege’s speech learning model is suggested. Flege’s model relies on the assumption that second language learners build up categories by systematically comparing the sounds of their first language with those of the second language they are exposed to. It is argued here that in a context of sound variation and change speakers face a similar situation; and, thus, the notion of ‘equivalence classification’ taken from the aforementioned model accounts for the fact that a given variation follows different paths in different speech communities. The present proposal is illustrated with processes of variation and change attested in Argentine Spanish, in other Romance languages, such as French and Sicilian, and in the acquisition of French as a L2.Este trabajo constituye un primer intento de elaboración de un modelo del cambio que incorpora tanto teorías de producción y percepción del habla como los resultados de los estudios de la adquisición de las segundas lenguas. Sobre la base de las primeras, se propone una distinción entre micro y macro variación, es decir, entre variación articulatoria no prominente o prominente desde un punto de vista perceptual. Sobre la base de las segundas, se elabora un modelo de categorización de la variación que se apoya en el supuesto de que los aprendices realizan un proceso de clasificación de equivalencia, en el cual comparan sistemáticamente su sistema de sonidos con el de la lengua a la que están expuestos (Flege 1995). Se argumenta aquí que, en una situación de variación y cambio sucede algo semejante y que la incorporación de la noción de clasificación de equivalencia, tomada de los modelos de adquisición de segundas lenguas permite dar cuenta de por qué ciertos cambios siguen una dirección en una comunidad y no en otra. La propuesta se ilustra con distintos procesos de variación y cambio del español de Argentina como así también con trabajos sobre otras variedades del romance (como el francés o el siciliano) y de la adquisición de segundas lenguas

Gene expression profiles of antigenic proteins of third stage larvae of the zoonotic nematode Anisakis pegreffii in response to temperature conditions

Anisakis pegreffii, a recognised etiological agent of human anisakiasis, is a parasite of homeothermic hosts at the adult stage and of ectothermic hosts at the third larval stage. Among distinct factors, temperature appears to be crucial in affecting parasite hatching, moulting and to modulate parasite-host interaction. In the present study, we investigated the gene transcripts of proteins having an antigenic role among excretory secretory products (ESPs) (i.e., a Kunitz-type trypsin inhibitor, A.peg-1; a glycoprotein, A.peg-7; and the myoglobin, A.peg-13) after 24 h, in A. pegreffii larvae maintained in vitro, under controlled temperature conditions. Temperatures were 37 °C and 20 °C, resembling respectively homeothermic and ectothermic hosts conditions, and 7 °C, the cold stress condition post mortem of the fish host. Primers of genes coding for these ESPs to be used in quantitative real-time PCR were newly designed, and qRT-PCR conditions developed. Expression profiles of the genes A.peg-1 and A.peg-13 were significantly up-regulated at 20 °C and 37 °C, with respect to the control (larvae kept at 2 °C for 24 h). Conversely, transcript profiles of A.peg-7 did not significantly change among the chosen temperature conditions. In accordance with the observed transcript profiles, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) revealed the presence of the three target ESPs at 37 °C, while only A.peg-13 was observed at 7 °C. The results suggest that temperature conditions do regulate the gene expression profiles of A.peg-1 and A.peg-13 in A. pegreffii larvae. However, regulation of the glycoprotein A.peg-7 is likely to be related to other factors such as the host's immune response

La aspiración de /s/ en el español rioplatense : Tango vs. rock

En el español rioplatense, la aspiración de /s/ preconsonántica es la norma (Terrell 1978), mientras que el debilitamiento en final de palabra ante vocal o pausa parece estar estigmatizado (Fontanella 1973; Barrios 2002). Los hablantes de este dialecto, sin embargo, tienen en principio la capacidad de controlar la tasa de debilitamiento para acercarse a diferentes normas de pronunciación, en especial en contextos de carácter formal como la interpretación de una canción. La principal hipótesis de este trabajo es que, ante una situación como esa, es esperable hallar una variación en la tasa de aspiración según cuál sea el género musical interpretado, lo cual se enlaza con resultados de estudios sociolingüísticos sobre la música popular (Trudgill 1983; Simpson 1999). En nuestro caso, el análisis se lleva a cabo sobre un corpus de 17 canciones agrupadas en dos géneros (tango y rock), y gira en torno a la figura del cantante y compositor Andrés Calamaro. El número total de realizaciones de /s/ preconsonántica relevados asciende a 701, de los cuales 393 corresponden a grabaciones de tango y 308 a grabaciones de rock. Para cada género, comparamos la tasa de aspiración de /s/ preconsonántica en las interpretaciones de Calamaro con las mismas canciones cantadas por diversos intérpretes (tanto de tango como de rock). Los resultados obtenidos a partir de la transcripción fonética fueron sometidos a un análisis de regresión múltiple (modelo logit), el cual reveló que las variables 'género' e 'intérprete' predicen significativamente controlar por factores de carácter fonético (punto y modo de articulación de la consonante siguiente, acentuación de la sílaba en la cual aparece la /s/ implosiva), posicional (/s/ intermedia o final de palabra) y gramatical (/s/ como marca verbal o de plural), y son también reinterpretados utilizando la lógica del modelo de reglas variables (varbrul). Los resultados de este trabajo indican que la /s/ preconsonántica es aspirada significativamente más en el tango que en el rock. También se verifica que, al interpretar tangos, Andrés Calamaro aspira significativamente menos dicho sonido que los cantantes que grabaron las versiones originales analizadas. Sin embargo, el propio Calamaro utiliza de manera significativamente más frecuente la aspiración cuando interpreta tangos que cuando interpreta canciones de rock. En conclusión, los resultados parecen respaldar la teoría de que los cantantes se acercan a una pronunciación más local cuando interpretan un género vernáculo (tango) y a una norma pan-hispánica cuando interpretan un género de carácter internacional (rock

Non-local Boundary Value Problems for Brownian motions

We consider dynamic boundary conditions involving non-local operators. Our analysis includes a detailed description of such operators together with their relations with random times and random (additive) functionals. We provide some new characterizations for the boundary behaviour of the Brownian motion based on the interplay between non-local operators and boundary value problems. Although our main focus is about Feller diffusions on bounded domains whose boundary is a set of positive Lebesgue measure, due to the novelty of such results we present here a first study concerned with the motions on the positive real line. In our view, also for the real line, the results appears stimulating and they anticipate interesting applications

The use of corporate derivatives: Effects on firm value in the Italian market

It is an empirical question whether the use of derivatives hedging among firms actually contributes to enhancing firm performances. Despite the increasing use of derivatives by non-financial firms, existing literature still debates about their effect, especially in countries with peculiar corporate governance mechanisms. By using a sample of non-financial Italian firms listed from 2007 to 2018, this paper investigates if the use of several types (currency, interest rate, and commodity) of financial derivatives can affect the value of a company. For measuring the impact of the derivatives and in order to address any possible endogeneity problem, besides using the conventional methodologies applied by previous literature (fixed-effect regression models and system GMM estimators), we run a random forest model, a machine learning technique not yet applied before in this field, and calculate the relative importance of each independent and control variable. Differently from other European countries, findings show that the use of derivatives does not affect the firm value in the Italian market. Therefore, our results confirm the role of corporate governance mechanisms on the relationship between firm value and the use of derivatives and that their impact is country-specific

Species-specific Real Time-PCR primers/probe systems to identify fish parasites of the genera Anisakis, Pseudoterranova and Hysterothylacium (Nematoda: Ascaridoidea)

Ascaridoid nematodes belonging to the genera Anisakis and Pseudoterranova are heteroxenous parasites, involving marine mammals as definitive hosts in their life-cycles, whereas crustaceans (krill), fish and squids acting as intermediate/paratenic hosts. These parasites are considered among the most important biological hazards present in “seafood” products. Indeed, larval stages of the Anisakis and Pseudoterranova have been reported as etiological agents of human infections (anisakidosis). We developed a primers/probe system for the identification of five species of anisakid nematodes belonging to the genera Anisakis (i.e. A. pegreffii and A. simplex (s. s.)), and Pseudoterranova (i.e. P. decipiens (s. s.), P. krabbei and P. bulbosa) to be used in a real time polymerase chain reaction (RT-PCR) with specific primers based on the mtDNA cox2 gene. Because those anisakid species could be also found in co-infection in some fish species with the raphidascarid nematode Hysterothylacium aduncum, a species-specific primer probe system to be used in RT-PCR for this nematode species was also developed. The detection limit and specificity of the primer/probe systems were evaluated for each of the six nematode species. Singleplex and multiplex RT-PCR protocols were defined and tested. The detection limit of the nematode species tissue was lower than 0.0006 ng/μl. Efficiency (E) of primers/probe systems developed was carried out by standard curve; E value varied between 2.015 and 2.11, with respect to a perfect reaction efficiency value of E = 2. Considering the sensibility and quantitative nature of the assays, the new primers/probe system may represent a useful tool for future basic and applied research that focuses on the identification of Anisakis spp., Pseudoterranova spp. and H. aduncum larvae in fish, even in co-infections, with a potential for application in fish farming, fish processing industries, fish markets, and food producers