Time-dependent attractors for non-autonomous nonlocal reaction-diffusion equations

In this paper, the existence and uniqueness of weak and strong solutions for a non-autonomous nonlocal reaction-diffusion equation is proved. Next, the existence of minimal pullback attractors in the L2 -norm in the frameworks of universes of fixed bounded sets and those given by a tempered growth condition, and some relationships between them are established. Finally, we prove the existence of minimal pullback attractors in the H1-norm and study relationships among these new families and those given previously in the L2 - context. The results are also new in the autonomous framework in order to ensure the existence of global compact attractors, as a particular case.Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

Robustness of time-dependent attractors in H1-norm for nonlocal problems

In this paper, the existence of regular pullback attractors as well as their upper semicontinuous behaviour in H1-norm are analysed for a parameterized family of non-autonomous nonlocal reaction-diffusion equations without uniqueness, improving previous results [Nonlinear Dyn. 84 (2016), 35–50].Ministerio de Economía y CompetitividadFondo Europeo de Desarrollo RegionalJunta de Andalucí

Coupling Human Mobility and Social Ties

Studies using massive, passively data collected from communication technologies have revealed many ubiquitous aspects of social networks, helping us understand and model social media, information diffusion, and organizational dynamics. More recently, these data have come tagged with geographic information, enabling studies of human mobility patterns and the science of cities. We combine these two pursuits and uncover reproducible mobility patterns amongst social contacts. First, we introduce measures of mobility similarity and predictability and measure them for populations of users in three large urban areas. We find individuals' visitations patterns are far more similar to and predictable by social contacts than strangers and that these measures are positively correlated with tie strength. Unsupervised clustering of hourly variations in mobility similarity identifies three categories of social ties and suggests geography is an important feature to contextualize social relationships. We find that the composition of a user's ego network in terms of the type of contacts they keep is correlated with mobility behavior. Finally, we extend a popular mobility model to include movement choices based on social contacts and compare it's ability to reproduce empirical measurements with two additional models of mobility

F2 region maximum electron density height predictions for South American latitudes

Values of the F2 region maximum electron density height (hmF2) calculated using ground ionosonde data at South American latitudes are used to check the validity of the International Reference Ionosphere (IRI) to predict this variable. With this in mind we compare hmF2 predictions given by the model when measurements of critical frequency of F2 region and propagation parameter M(3000)F2 were used as input parameter in IRI (hmF2IRI-Exp), against those obtained using the standard International Radio Consultative Committee (CCIR) option (hmF2IRI-CCIR)- In this paper we used hmF2 IRI-Exp values because hmF2 measurements were not available for the considered cases. Moreover, a comparison of the measured M(3000)F2 values with the CCIR predictions have been done. The results show that, in general, the standard predictions follow the diurnal tendency observed in the hmF2 IRI-Exp values. At low latitudes the hmF2IRI-Exp values show oscillations not reproduced by the standard option. Cases with disagreements for 24 hours have been observed at high latitudes. Other cases with good agreement have been also obtained. The results suggest that, in general, the standard option of the model gives good hmF2 predictions at South American latitudes. Few cases showed deviation between 15 and 25%. As we expected, the obtained results suggest that the deviation between predicted and measured M(3000)F2 values is the main contribution for the deviation between hmF2IRI-CCIR and hmF2IRI-Exp. The comparison with the results obtained in previous work shows that the IRI performance in predicting M(3000)F2 and hmF2 is better than in predicting foF2.Fil: Ezquer, Rodolfo Gerardo. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionósfera; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Scidá, Luis. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionósfera; ArgentinaFil: Mansilla, Gustavo Adolfo. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionósfera; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Tucumán; ArgentinaFil: Mosert, Marta Estela. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio. Universidad Nacional de San Juan. Instituto de Ciencias Astronómicas, de la Tierra y del Espacio; ArgentinaFil: Herrera, Marcelo F.. Universidad Nacional de Tucumán. Facultad de Ciencias Exactas y Tecnología. Departamento de Física. Laboratorio de Ionósfera; Argentin

El Sexting no siempre es deseado: consecuencias sobre la satisfacción y el papel de la coerción sexual y la victimización sexual en línea

The understanding of sexting as a new form of interpersonal communication is increasing; however, little is known about whether the incidence, correlates, and outcomes of sexting vary depending on whether such behavior is done willingly or not. In this non-experimental study, we aimed to investigate the prevalence, predictors, and consequences of sexting among 310 Spanish young adults, who completed an online survey re-garding their previous experiences of wanted and unwanted sexting behav-iors, their sexual coercion and online sexual victimization experiences, and their levels of sexual and life satisfaction. The results showed that more than half and one third of the sample had been involved in wanted and unwanted sexting behaviors, respectively. Additionally, sexual coercion and online sexual victimization predicted a higher probability of engaging in unwanted sexual behaviors and, with that, a decrease of life satisfaction. Finally, having experienced more instances of sexual coercion was associated with lower life satisfaction by increasing the likelihood of suffering online sexual victimization experiences and engaging in additional unwanted sexting behaviors. Our findings show the importance of discerning between wanted and unwanted sexting and how doing so differently conditions the predictors and consequences of this phenomena.La comprensión del sexting como una nueva forma de comunicación interpersonal es cada vez mayor; sin embargo, poco se sabe sobre si la incidencia, correlatos y resultados del sexting varían en función de si se realiza de forma voluntaria o no. En este estudio no experimental, nos proponemos investigar la prevalencia, los predictores y las consecuencias del sexting entre 310 jóvenes españoles, que completaron una encuesta online sobre sus experiencias previas de sexting deseado y no deseado, coerción sexual y victimización sexual online, así como sus niveles de satisfacción sexual y vital. Los resultados mostraron que la mitad y un tercio de la muestra habían estado involucrados en comportamientos de sexting deseados y no deseados, respectivamente. Además, la coerción sexual y la victimización sexual online predijeron una mayor probabilidad de participar en conductas sexuales no deseadas y, con ello, una disminución de la satisfacción vital. Por último, haber experimentado mayor coerción sexual se asoció con menor satisfacción vital al aumentar la probabilidad de sufrir victimización sexual online y de participar en conductas adicionales de sexting no deseado. Nuestros hallazgos muestran la importancia de discernir entre el sexting deseado y el no deseado y cómo el hacerlo de forma diferente condiciona los predictores y las consecuencias de este fenómeno

Occurrence and exposure assessment of major mycotoxins in foodstuffs from Algeria

Cereal-based products, nuts and dried fruits are staple foods for the Algerian population. However, these foodstuffs may be sources of harmful mycotoxins, with negative impacts on human health. The purpose of this study was to investigate the occurrences and levels of aflatoxins (B1, B2, G1 and G2), ochratoxin A (OTA), deoxynivalenol (DON) and zearalenone (ZEA) in 198 samples of nuts, dried fruits and cereal products commercialized in Algeria, as well as to calculate the estimated daily intakes (EDIs). Aflatoxins were found in 26.2% of the nut samples (in peanuts and almonds, but not in walnuts), 38.7% of the dried fruit samples (in dried figs, dates and bradj pastries) and 47.9% of the cereal-based products (in rechta noodles and metlou bread, but not in couscous), with mean concentrations ranging from 0.03 to 0.49 μg/kg. OTA occurred in 16.9% of the cereal-based samples, averaging 0.15 μg/kg, but it was not detected in nuts or dried fruits. The incidence of DON in the cereal-based products was 85.9% on average, with a mean concentration from 90 to 123 μg/kg. ZEA mycotoxin was not detected in any samples. Four peanut samples exceeded the EU maximum level for aflatoxin B1 set at 2 μg/kg, while three of them surpassed the maximum level for the sum of aflatoxins (4 μg/kg). Traditional foods such as bradj, rechta and metlou were significant sources of aflatoxins, with MOE (margin of exposure) values ranging from 648 to 9333, indicating a potential risk for the Algerian population

Effects of Bread Making and Wheat Germ Addition on the Natural Deoxynivalenol Content in Bread

Deoxynivalenol (DON, vomitoxin) is a type-B trichothecene mycotoxin produced by several field fungi such as Fusarium graminearum and Fusarium culmorum and known to have various toxic effects. This study investigated the effect of the bread making process on the stability of DON in common bread and wheat germ-enriched bread using naturally contaminated ingredients at the level of 560 µg/kg. The concentration of DON and its evolution during bread making were determined by immunoaffinity column cleanup followed by liquid chromatography with diode array detection (HPLC-DAD). During the bread making process, DON was reduced by 2.1% after fermentation and dropped by 7.1% after baking, reaching a maximum reduction of 19.8% in the crust as compared with a decrease of 5.6% in the crumb. The addition of 15% wheat germ to the dough did not affect DON stability during bread making, showing an apparent increase of 3.5% after fermentation and a reduction by 10.2% after baking

Limits of Predictability in Commuting Flows in the Absence of Data for Calibration

The estimation of commuting flows at different spatial scales is a fundamental problem for different areas of study. Many current methods rely on parameters requiring calibration from empirical trip volumes. Their values are often not generalizable to cases without calibration data. To solve this problem we develop a statistical expression to calculate commuting trips with a quantitative functional form to estimate the model parameter when empirical trip data is not available. We calculate commuting trip volumes at scales from within a city to an entire country, introducing a scaling parameter α to the recently proposed parameter free radiation model. The model requires only widely available population and facility density distributions. The parameter can be interpreted as the influence of the region scale and the degree of heterogeneity in the facility distribution. We explore in detail the scaling limitations of this problem, namely under which conditions the proposed model can be applied without trip data for calibration. On the other hand, when empirical trip data is available, we show that the proposed model's estimation accuracy is as good as other existing models. We validated the model in different regions in the U.S., then successfully applied it in three different countries

Long-time behavior of a non-autonomous parabolic equation with nonlocal diffusion and sublinear terms

This paper is devoted to study the asymptotic behavior of a time-dependent parabolic equation with nonlocal diffusion and nonlinear terms with sublinear growth. Namely, we extend some previous results from the literature, obtaining existence, uniqueness, and continuity results, analyzing the stationary problem and decay of the solutions of the evolutionary problem, and finally, under more general assumptions, ensuring the existence of pullback attractors for the associated dynamical system in both L2L2 and H1H1 norms. Relationships among these objects are established using regularizing properties of the equation