Stars were born in significantly denser regions in the early Universe

The density of the warm ionized gas in high-redshift galaxies is known to be higher than what is typical in local galaxies on similar scales. At the same time, the mean global properties of the high- and low-redshift galaxies are quite different. Here, we present a detailed differential analysis of the ionization parameters of 14 star-forming galaxies at redshift 2.6-3.4, compiled from the literature. For each of those high-redshift galaxies, we construct a comparison sample of low-redshift galaxies closely matched in specific star formation rate (sSFR) and stellar mass, thus ensuring that their global physical conditions are similar to the high-redshift galaxy. We find that the median log [OIII] 5007/ [OII] 3727 line ratio of the high-redshift galaxies is 0.5 dex higher than their local counterparts. We construct a new calibration between the [OIII] 5007/ [OII] 3727 emission line ratio and ionization parameter to estimate the difference between the ionization parameters in the high and low-redshift samples. Using this, we show that the typical density of the warm ionized gas in star-forming regions decreases by a median factor of $7.1^{+10.2}_{-5.4}$ from z ~ 3.3 to z ~ 0 at fixed mass and sSFR. We show that metallicity differences cannot explain the observed density differences. Because the high- and low-redshift samples are comparable in size, we infer that the relationship between star formation rate density and gas density must have been significantly less efficient at z ~2-3 than what is observed in nearby galaxies with similar levels of star formation activity.Comment: 16 pages, 6 figures, accepted for publication in Ap

Coupling between time series: a network view

Recently, the visibility graph has been introduced as a novel view for analyzing time series, which maps it to a complex network. In this paper, we introduce new algorithm of visibility, "cross-visibility", which reveals the conjugation of two coupled time series. The correspondence between the two time series is mapped to a network, "the cross-visibility graph", to demonstrate the correlation between them. We applied the algorithm to several correlated and uncorrelated time series, generated by the linear stationary ARFIMA process. The results demonstrate that the cross-visibility graph associated with correlated time series with power-law auto-correlation is scale-free. If the time series are uncorrelated, the degree distribution of their cross-visibility network deviates from power-law. For more clarifying the process, we applied the algorithm to real-world data from the financial trades of two companies, and observed significant small-scale coupling in their dynamics

The evaluation of shear bond strength of resin-modified glass ionomer cement with the addition of 45S5 bioactive glass using two conventional methods.

Introduction: There is a high prevalence of enamel caries around brackets due to the young age of the majority of orthodontic patients, and to the difficulty of plaque removal in presence of orthodontic appliances. Recently, protective agents such as bioactive glasses (BGs) were introduced to enhance remineralization and prevent demineralization of tooth structures.  This study aimed to assess the shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) with addition of 45S5 BG to enhance its remineralizing potential using two conventional methods. Material and methods: This in-vitro experimental study evaluated three groups (n=20) of orthodontic brackets bonded to enamel using Transbond XT (group 1), light-cure RMGIC (group 2) and RMGIC with BG added (group 3). Samples underwent 7000 thermal cycles and their SBS was measured. The adhesive remnant index (ARI) score was also determined. Quantitative data were analyzed using one-way ANOVA while qualitative data were analyzed using a chi-square test. Discussion: The results showed no significant difference in SBS between study groups, however the ARI scores were significantly different among the groups. The RMGIC group showed the highest ARI while RMGIC doped with BG showed the lowest ARI score. Conclusion: Addition of 30% w/v 45S5 BG to RMGIC does not cause a significant change in SBS of orthodontic brackets bonded to enamel, while resulting in less amount of luting agent remnants on the enamel surface after debonding. Introducción: Existe una alta prevalencia de caries del esmalte alrededor de los brackets debido a la corta edad de la mayoría de los pacientes de ortodoncia y a la dificultad de remoción de la placa en presencia de aparatos de ortodoncia. Recientemente, se introdujeron agentes protectores como los vidrios bioactivos (VB) para mejorar la remineralización y prevenir la desmineralización de las estructuras dentales. Este estudio tuvo como objetivo evaluar la resistencia al cizallamiento (RC) del cemento de ionómero de vidrio modificado con resina (CIVMR) con la adición de 45S5 BG para mejorar su potencial remineralizante utilizando dos métodos convencionales. Material y Métodos: Este estudio expe-rimental in vitro evaluó tres grupos (n = 20) de brackets de ortodoncia adheridos al esmalte usando Transbond XT (grupo 1), CIVMR fotopolimerizable (grupo 2) y CIVMR con VB agregado (grupo 3). Las muestras se sometieron a 7000 ciclos térmicos y se midió su RC. También se determinó la puntuación del índice de restos de adhesivo (IRA). Los datos cuantitativos se analizaron mediante ANOVA de una vía, mientras que los datos cualitativos se analizaron mediante una prueba de chi-cuadrado. Discusión: Los resultados no mostraron diferencias significativas en la RC entre los grupos de estudio, sin embargo, los puntajes IRA fueron significativamente diferentes entre los grupos. El grupo CIVMR mostró el ARI más alto mientras que CIVMR dopado con VB mostró el puntaje IRA más bajo. Conclusión: La adición de un 30% p/v de 45S5 VB a CIVMR no causa un cambio significativo en la RC de los brackets de ortodoncia adheridos al esmalte, mientras que resulta en una menor cantidad de remanentes de agente de fijación en la superficie del esmalte después del desprendimiento. Resistencia al Corte

La evaluación de la resistencia al cizallamiento del cemento de ionómero de vidrio modificado con resina con la adición de vidrio bioactivo 45S5 utilizando dos métodos convencionales.

Introduction: There is a high prevalence of enamel caries around brackets due to the young age of the majority of orthodontic patients, and to the difficulty of plaque removal in presence of orthodontic appliances. Recently, protective agents such as bioactive glasses (BGs) were introduced to enhance remineralization and prevent demineralization of tooth structures.  This study aimed to assess the shear bond strength (SBS) of resin-modified glass ionomer cement (RMGIC) with addition of 45S5 BG to enhance its remineralizing potential using two conventional methods. Material and methods: This in-vitro experimental study evaluated three groups (n=20) of orthodontic brackets bonded to enamel using Transbond XT (group 1), light-cure RMGIC (group 2) and RMGIC with BG added (group 3). Samples underwent 7000 thermal cycles and their SBS was measured. The adhesive remnant index (ARI) score was also determined. Quantitative data were analyzed using one-way ANOVA while qualitative data were analyzed using a chi-square test. Discussion: The results showed no significant difference in SBS between study groups, however the ARI scores were significantly different among the groups. The RMGIC group showed the highest ARI while RMGIC doped with BG showed the lowest ARI score. Conclusion: Addition of 30% w/v 45S5 BG to RMGIC does not cause a significant change in SBS of orthodontic brackets bonded to enamel, while resulting in less amount of luting agent remnants on the enamel surface after debonding. Introducción: Existe una alta prevalencia de caries del esmalte alrededor de los brackets debido a la corta edad de la mayoría de los pacientes de ortodoncia y a la dificultad de remoción de la placa en presencia de aparatos de ortodoncia. Recientemente, se introdujeron agentes protectores como los vidrios bioactivos (VB) para mejorar la remineralización y prevenir la desmineralización de las estructuras dentales. Este estudio tuvo como objetivo evaluar la resistencia al cizallamiento (RC) del cemento de ionómero de vidrio modificado con resina (CIVMR) con la adición de 45S5 BG para mejorar su potencial remineralizante utilizando dos métodos convencionales. Material y Métodos: Este estudio expe-rimental in vitro evaluó tres grupos (n = 20) de brackets de ortodoncia adheridos al esmalte usando Transbond XT (grupo 1), CIVMR fotopolimerizable (grupo 2) y CIVMR con VB agregado (grupo 3). Las muestras se sometieron a 7000 ciclos térmicos y se midió su RC. También se determinó la puntuación del índice de restos de adhesivo (IRA). Los datos cuantitativos se analizaron mediante ANOVA de una vía, mientras que los datos cualitativos se analizaron mediante una prueba de chi-cuadrado. Discusión: Los resultados no mostraron diferencias significativas en la RC entre los grupos de estudio, sin embargo, los puntajes IRA fueron significativamente diferentes entre los grupos. El grupo CIVMR mostró el ARI más alto mientras que CIVMR dopado con VB mostró el puntaje IRA más bajo. Conclusión: La adición de un 30% p/v de 45S5 VB a CIVMR no causa un cambio significativo en la RC de los brackets de ortodoncia adheridos al esmalte, mientras que resulta en una menor cantidad de remanentes de agente de fijación en la superficie del esmalte después del desprendimiento. Resistencia al Corte

On a class between Devaney chaotic and Li-Yorke chaotic generalized shift dynamical systems

In the following text, for finite discrete $X$ with at least two elements, nonempty countable $\Gamma$, and $\varphi:\Gamma\to\Gamma$ we prove the generalized shift dynamical system $(X^\Gamma,\sigma_\varphi)$ is densely chaotic if and only if $\varphi:\Gamma\to\Gamma$ does not have any (quasi-)periodic point. Hence the class of all densely chaotic generalized shifts on $X^\Gamma$ is intermediate between the class of all Devaney chaotic generalized shifts on $X^\Gamma$ and the class of all Li-Yorke chaotic generalized shifts on $X^\Gamma$. In addition, these inclusions are proper for infinite countable $\Gamma$. Moreover we prove $(X^\Gamma,\sigma_\varphi)$ is Li-Yorke sensitive (resp. sensitive, strongly sensitive, asymptotic sensitive, syndetically sensitive, cofinitely sensitive, multi-sensitive, ergodically sensitive, spatiotemporally chaotic, Li-Yorke chaotic) if and only if $\varphi:\Gamma\to\Gamma$ has at least one non-quasi-periodic point.Comment: 14 pages - regarding some errors/mistakes please don't use previous version

Effect of addition of bioactive glass to resin modified glass ionomer cement on enamel demineralization under orthodontic brackets

Background: Enamel demineralization and white spot lesions around orthodontic brackets is a common problem associated with fixed orthodontic treatment. Glass ionomer cements (GICs) are commonly used for bracket bonding and recently, bioactive glass (BAG) was added to GICs to enhance deposition of calcium phosphate in adjacent dental structure. This study sought to assess the effect of addition of BAG particles to resin modified GIC (RMGIC) on enamel demineralization under orthodontic brackets. Material and Methods: In this in vitro, experimental study, 60 sound human premolars were immersed in distilled water at 6°C. The teeth were randomly divided into three groups. Using a sticker, a window measuring 7x7 mm was created on the buccal surface. The remaining surfaces were coated with nail varnish twice with a 3-hour interval. After 24 hours, the stickers were removed. Brackets were bonded to tooth surfaces using Transbond XT (control), Fuji II LC RMGIC and Fuji II LC containing 30% BAG particles. To induce acid attacks, the teeth were immersed in demineralizing solution for 6 hours. For pH cycling, the teeth were then immersed in remineralizing solution for 18 hours. This process was repeated for 21 days. Next, the teeth were longitudinally sectioned into two halves and the depth of demineralization was measured from the deepest point to the surface under a polarized light microscope. Data were analyzed using one-way ANOVA, and pairwise comparisons were carried out using Tukey?s test. Results: The mean depth of demineralization was 73.8±22.29, 118.08±29.42 and 182.98±20.69 µm in the BAG, RMGIC and Transbond XT groups, respectively. One-way ANOVA showed significant differences in terms of depth of demineralization among the three groups (P=0.0001). Tukey?s test revealed significant differences in depth of demineralization. Conclusions: Addition of BAG to RMGIC can significantly decrease the depth of enamel demineralization under orthodontic brackets in vitro

Tinnitus in Avicenna’s Canon of Medicine

Tinnitus is the sensation of hearing continuous or intermittent sounds, when there is no external or mechanical source

Use of Green Fluorescent Protein (GFP) Vector in Classical Restriction Enzyme-based Cloning Methods of Gateway Cloning System

Generating of an expression clone that can produce the pharmaceutical proteins in an efficient and soluble form at high levels is considered as an important step in pharmaceutical industry. Recombination-based cloning could be a quick and efficient way for generating expression vectors. Thus, both efficient and robust subcloning is vital for the construction of gene expression vectors. In this study, we used the traditional restriction enzyme-based cloning methods for generation of expression-ready clones by the most well-known commercial cloning technologies, Gateway