Behaviour of 4-(4-acetoaminophenyl)-4-oxobut-2-enoic acid towards carbon and nitrogen nucleophiles and use of these products in the synthesis of some interesting heterocycles

The present work is devoted to study the interaction of-aroylacrylic acid derivative (1) with some containing active methylene compounds under Michael reaction conditions and afforded the Michael adducts (2a-e). When compound 1 was allowed to react with cyclohexanone in the presence of ammonium acetate as catalyst, it afforded hydroquinoline derivative (3). Interaction of the acid 1 with highly and moderately reactive hydrocarbons e.g. p-xylene and acetanilide in the presence of anhydrous aluminumchloride under Friedel-Crafts reaction conditions afforded (4a-b). On the other hand, when the acid 1 was allowed to react with benzyl amine in dry benzene yielded 2-benzylamino-4-(4-acetaminophenyl)-4-oxobutanoic acid (5). This later compound was used to synthesize some heterocyclic compounds (7-11). Also, aza Michael adduct (6) used asthe key starting material for the synthesis of some interesting heterocyclic compounds e.g. pyridazinone, oxazinoneand furanone derivatives (13-16)

Utility of 4-(4-acetoaminophenyl)-4-oxo-but-2-enoic acid to prepare Pyranand Pyridine derivatives as building blocks in Heterocyclic Synthesis

The present work is devoted to study the interaction of β -aroylacrylic acid derivative (1) with malononitrile in the presence of piperidine and/or ammonium acetate, then using the formed compounds as a starting material for synthesizing fused and isolated heterocyclic system. Ithas been established that the β-aroylacrylic acid (1) reactwith malononitrile in (DMF) in the presence of piperidineas catalyst with formation of 4H-pyran derivative (2). Bychanging the catalyst into ammonium acetate, pyridine derivative (3) has been obtained. When compound (2) wasallowed to react with triethylorthoformate afforded ethoxymethyleneamino-4H-pyran (4). Compound (4) was used askey starting material for synthesizing some interesting annulated and heterocyclic systems (5-8). Also, the maleamic acid derivatives (9) and (15) have been synthesized via the interaction of (2) and (3) with maleic anhydride to study the behavior of the formed maleamic acid derivatives asanalogies of β-aroylacrylic towards different active methylene compounds under Michael addition reaction (10-14); (16-18)

Molecular bases underlying chromosome fragility at Replication Slow Zones in Saccharomyces cerevisiae

Chromosome rearrangements such as translocations and deletions are frequently associated with human cancers. Such rearrangement of the chromosome can be initiated by a DNA break (DSB) that, when inappropriately repaired, may alter chromosome structure. Mammalian common fragile sites are the best-characterised, naturally occurring breakage-prone regions and are deleted or rearranged in many tumour cells. Analogous chromosomal regions also exist in the budding yeast, S. cerevisiae. One example of a yeast fragile site is the replication slow zone (RSZ), so called because the rate of replication fork progression through these regions is slow compared to other regions within the same chromosome. Inactivation of the essential checkpoint kinase, Mec1, in mec1-ts mutants results in replication fork stalling followed by chromosome breakage at RSZs. Interestingly, inhibition of ATR, the mammalian homologue of Mec1, also leads to chromosome instability at common fragile sites, suggesting that the mechanism by which endogenous DSBs are generated is conserved between yeast and mammals. This study aims to enhance our current understanding of common fragile sites using yeast RSZs as a model. First, RSZs were characterised in terms of chromosomal features and determinants in order to identify similarities between RSZs and mammalian common fragile sites and to assess whether yeast RSZs as a suitable system for studying common fragile sites in more complex organisms. Next, the mechanism underlying chromosome fragility at RSZs was investigated by examining the contribution of various chromosomal processes to break formation at these sites. These include: (i) replication fork restart processes (ii) spindle force, (iii) chromosome condensation and decatenation, (iv) chromosome segregation, and (v) cytokinesis. The analyses suggest that chromosome breakage within RSZs requires the actions of the evolutionarily conserved type II topoisomerase and condensin complex. Finally, factors involved in maintaining the stability of RSZs were also explored. The Rrm3 helicase and Psy2 phosphatase complex were found to suppress chromosome breakage at RSZs in a manner dependent on Tel1, another checkpoint kinase. These findings suggest that Tel1 is somehow implicated in chromosome stability at RSZs. The findings presented in this study further our understanding of RSZs and the molecular bases governing their fragility, providing some insight into the mechanism of fragile site instability in mammals

L1L^1-Contraction Property of Entropy Solutions for Scalar Conservation Laws with Minimal Regularity Assumptions on the Flux

This paper is concerned with entropy solutions of scalar conservation laws of the form \partial_{t}u+\diver f=0 in $\mathbb{R}^d\times(0,\infty)$. The flux $f=f(x,u)$ depends explicitly on the spatial variable $x$. Using an extension of Kruzkov's method, we establish the $L^1$-contraction property of entropy solutions under minimal regularity assumptions on the flux

Social media browsing while driving : effects on driver performance and attention -

Thesis. M.E.M. American University of Beirut. Department of Industrial Engineering and Management, 2017. ET:6672Advisor : Dr. Nadine Marie Moacdieh, Assistant Professor, Industrial Engineering and Management ; Committee members : Dr. Saif Al-Qaisi, Assistant Professor, Industrial Engineering and Management ; Dr. Maya Abou Zeid, Associate Professor, Civil and Environmental Engineering.Includes bibliographical references (leaves 50-58)Driver distraction is one of the leading causes of road accident fatalities worldwide. Whereas texting while driving is known to lead to performance decrements, it is still unclear whether and to what extent browsing social media while driving also negatively affects driver performance and attention. The prevalence of social media applications on mobile phones means there is a need to determine what guidelines or legislation should be in place. The problem is especially relevant for young and less experienced drivers, who are more at risk for driver distraction-related accidents and also tend to use social media applications more frequently. The aim of this research study is to analyze and model the effects of browsing social media on driver performance and attention. Eye tracking is be used as a means of tracing driver attention. To this end, a driving simulator experiment is carried out with AUB students between the ages of 18 and 26. Participants are asked to drive a given path and either browse social media or send text messages on given a cell phone. Performance measures such as lane keeping, average speed, and time to brake are collected, and an eye tracker traces where participants are looking at all times. The collected data is compared across experiment conditions in order to assess the impact of different phone applications on both performance and attention. This research provides the basis for improved guidelines and legislation for drivers, and ultimately a reduction in the number of accidents that are caused by distracted driving. In addition, the results of this research can help lead to the development of in-vehicle safety systems that detect and prevent driver distraction

Jumps in Besov spaces and fine properties of Besov and fractional Sobolev functions

In this paper we analyse functions in Besov spaces $B^{1/q}_{q,\infty}(\mathbb{R}^N,\mathbb{R}^d),q\in (1,\infty)$, and functions in fractional Sobolev spaces $W^{r,q}(\mathbb{R}^N,\mathbb{R}^d),r\in (0,1),q\in [1,\infty)$. We prove for Besov functions $u\in B^{1/q}_{q,\infty}(\mathbb{R}^N,\mathbb{R}^d)$ the summability of the difference between one-sided approximate limits in power $q$, $|u^+-u^-|^q$, along the jump set $\mathcal{J}_u$ of $u$ with respect to Hausdorff measure $\mathcal{H}^{N-1}$, and establish the best bound from above on the integral $\int_{\mathcal{J}_u}|u^+-u^-|^qd\mathcal{H}^{N-1}$ in terms of Besov constants. We show for functions $u\in B^{1/q}_{q,\infty}(\mathbb{R}^N,\mathbb{R}^d),q\in (1,\infty)$ that \begin{equation} \liminf\limits_{\varepsilon \to 0^+}\fint_{B_{\varepsilon}(x)} |u(z)-u_{B_{\varepsilon}(x)}|^qdz=0 \end{equation} for every $x$ outside of a $\mathcal{H}^{N-1}$-sigma finite set. For fractional Sobolev functions $u\in W^{r,q}(\mathbb{R}^N,\mathbb{R}^d)$ we prove that \begin{equation} \lim_{\rho\to 0^+}\fint_{B_{\rho}(x)}\fint_{B_{\rho}(x)} |u\big(z\big)-u(y)|^qdzdy=0 \end{equation} for $\mathcal{H}^{N-rq}$ a.e. $x$, where $q\in[1,\infty)$, $r\in(0,1)$ and $rq\leq N$. We prove for $u\in W^{1,q}(\mathbb{R}^N),1<q\leq N$, that \begin{equation} \lim\limits_{\varepsilon\to 0^+}\fint_{B_{\varepsilon}(x)} |u(z)-u_{B_{\varepsilon}(x)}|^qdz=0 \end{equation} for $\mathcal{H}^{N-q}$ a.e. $x\in \mathbb{R}^N$

Antioksidativno djelovanje metanolnih ekstrakata listova sedam egipatskih vrsta roda Cassia

In the present study, antioxidant activity of methanolic extracts of the leaves of seven Egyptian Cassia species was investigated using two methods, the phosphomolybdate method and 1,1 diphenyl-2-picrylhydrazyl radical (DPPH•) scavenging activity method. The results revealed that C. glauca is the most potent species and that the activity of other plant species decreases in the following order C. grandis > C. nodosa > C. fistula > C. didymobtrya > C. occidentalis > C. sophera. Defatted methanolic extract of the most active plant C. glauca was subjected to fractionation process using different organic solvents such as CHCl3, EtOAc and BuOH. Antioxidant activities of these fractions were investigated and the results showed that ethyl acetate fraction possessed high activity. Total phenolic and flavonoid concentration of each plant extract were determined using the Folin-Ciocaltu reagent and aluminum chloride. Correlation between radical scavenging capacities of extracts and total phenolic concentration was observed.U radu je ispitano antioksidativno djelovanje metanolnih ekstrakata listova sedam egipatskih vrsta roda Cassia koristeći fosfomolibdatnu metodu i metodu vezanja slobodnih 1,1-difenil-2-pikrilhidrazil radikala (DPPH.). Rezultati pokazuju da C. glauca ima najveću aktivnost te da se djelovanje smanjuje sljedećim redom: C. grandis C. nodosa C. fistula C. didymobtrya C. occidentalis C. sophera. Odmašćeni metanolni ekstrakt najaktivnije biljke C. glauca frakcioniran je pomoću različitih organskih otapala kao što su CHCl3, EtOAc i BuOH. Ispitivanje antioksidativnog djelovanja pojedinih frakcija pokazuje da je etil-acetatna frakcija najaktivnija. Pomoću Folin-Ciocaltuovog reagensa i aluminijevog klorida određena je ukupna koncentracija fenola i flavonoida svakog pojedinog ekstrakta. Uočena je korelacija između sposobnosti hvatanja slobodnih radikala i ukupnog sadržaja fenola