929 research outputs found
Before and After the Commentators: An Essay in Periodization.
No full textL'articolo considera il significato storico e filosofico dei commentatori neoplatonici di Aristotele. Gli autori situano il recente Sourcebook sui commentatori edito da Richard Sorbji in un contesto più ampio, che include il contributo dei commentatori nella formazione della filosofia tardo-antica e la loro posterità nella tradizione filosofica islamica. Dopo una sezione introduttiva (1) sullo stato attuale della ricerca in questo ambito, gli autori affrontano i temi seguenti: (2) Plotino, i commentatori e lo sviluppo del pensiero tardo antico; (3) il Sourcebook e la filosofia islamica. Riccardo Chiaradonna è co-autore della sezione (1) e autore della sezione (2), dove la ricezione dei trattati di scuola aristotelici è presentata come una caratteristica fondamentale nella transizione dalla filosofia post-ellenistica a quella tardo-antica. Plotino ha un ruolo cruciale in questo processo e l'assimilazione neoplatonica dei trattati di Aristotele non avrebbe avuto luoro senza il suo contributo.This article considers the historical and philosophical significance of the Neoplatonic commentators on Aristotle. The authors set Richard Sorabji's recent Sourcebook on the commentators within a wider backgroung, which covers the commentators' contribution in the shaping of late antique philosophy and their posterity in the Islamic philosophical tradition. After an introductory section (1) regarding the current status of research in this area, the authors tackle the following issues: (2) Plotinus, the commentators and the development of late antique thought; (3) the Sourcebook and Islamic Philosophy. Riccardo Chiaradonna is co-author of section (1) and author of section (2), where the reception of Aristotle's school treatises is set out as a key feature in the transition from Post Hellenistic to Late Antique philosophy. Plotinus has a pivotal position in this process and the Neoplatonic incorporation of Aristotle's treatises would have not taken place without Plotinus' contribution
Evaluation of antioxidant, anti-tyrosinase potentials and phytochemical composition of four Egyptian plants
No full textThe aim of this present research is to evaluate antioxidant and antityrosinase potentials and to investigate the phytoconstituents of methanol (70%) extract from four Egyptian plants, Solanum rantonnetii, Tilia cordata, Cichorium intybus (L.), and Lagerstroemia tomentosa. Antioxidant activity was measured by using two different free radical scavenging methods, 2,2'-Azinobis-(3-ethylbenzothiazoline-6-sulfonic acid) (ABTS) and 2,2-diphenyl-1-picrylhydrazyl radical (DPPH•), whereas polyphenols and flavonoids contents were evaluated by using Folin-Ciocalteau, and aluminum nitrate methods respectively. Tyrosinase inhibition was evaluated using commercial enzyme and dihydroxyphenylalanine (DOPA) as substrate and methanol extract of each plant was investigated by phytochemical analysis. The results showed that all the plants had good antioxidant activity where Cichorium intybus exhibited the highest antioxidant activity determined as total content of free-radical scavenging, polyphenol and flavonoid molecules, and showed the best tyrosinase inhibition activity compared with the other plants extracts studied. Chromatogarphic separation and NMR analysis of Cichorium intybus methanol extract revealed the identification of two coumarins, scopoletin and esculetin, and seven flavonoids, dihydroquercetin 7-4'-dimethyl ether, blumeatin, diosmetin, tamarixetin, quercetin, quercetin 3-O-β-galactoside and kaempferol 3-O-rutinoside. These findings suggest that Cichorium intybus is rich with bioactive compounds and could be used as a good source of potentially natural antioxidants and antityrosinase molecules
Polymer multimode waveguide optical and electronic PCB manufacturing
No full textThe paper describes the research in the £1.3 million IeMRC Integrated Optical and Electronic Interconnect PCB Manufacturing (OPCB) Flagship Project in which 8 companies and 3 universities carry out collaborative research and which was formed and is technically led by the author. The consortium’s research is aimed at investigating a range of fabrication techniques, some established and some novel, for fabricating polymer multimode waveguides from several polymers, some formulations of which are being developed within the project. The challenge is to develop low cost waveguide manufacturing techniques compatible with commercial PCB manufacturing and to reduce their alignment cost. The project aims to take the first steps in making this hybrid optical waveguide and electrical copper track printed circuit board disruptive technology widely available by establishing and incorporating waveguide design rules into commercial PCB layout software and transferring the technology for fabricating such boards to a commercial PCB manufacturer. To focus the research the project is designing an optical waveguide backplane to tight realistic constraints, using commercial layout software with the new optical design rules, for a demonstrator into which 4 daughter cards are plugged, each carrying an aggregate of 80 Gb/s data so that each waveguide carries 10 Gb/s
Arabic offensive language on twitter: Analysis and experiments
No full textDetecting offensive language on Twitter has many applications ranging from detecting/predicting bullying to measuring polarization. In this paper, we focus on building a large Arabic offensive tweet dataset. We introduce a method for building a dataset that is not biased by topic, dialect, or target. We produce the largest Arabic dataset to date with special tags for vulgarity and hate speech. We thoroughly analyze the dataset to determine which topics, dialects, and gender are most associated with offensive tweets and how Arabic speakers use offensive language. Lastly, we conduct many experiments to produce strong results (F1 = 83.2) on the dataset using SOTA techniques
Use of molecular techniques for the analysis of foam-causing bacteria in Al Bireh oxidation ditch, Palestine
No full textMuhammad,Ratib:
Al-Sa'Ed,Rashed:
,Roest K.:Activated sludge foaming, a worldwide problem, usually consists of filamentous bacteria occurring
predominantly in the mixed liquor. Because of a lack of pure cultures of most filamentous bacteria
and the limited amount of characterisation data, molecular approaches were used to investigate dominant
filamentous bacterial strains associated with foaming in Al Bireh Wastewater Treatment Plant in
Palestine. Applying denaturing gradient gel electrophoresis (DGGE), 16S rRNA cloning and sequencing
showed the dominance of several filamentous bacteria including Microthrix parvicella, Nocardia
sp., Hyphomicrobium facilis, Chloroflexi, Candidates TM7 and Nocardioides oleivoran
Source misalignment in multimode polymer tapered waveguides for optical backplanes
No full textPolymer tapered multimode waveguides were modeled using the finite difference wide-angle beam propagation method to investigate whether tapered input waveguide couplers decreasing in width away from the waveguide entrance give improved tolerance to lateral misalignments of an optical source compared to straight waveguides and whether there is any effect on angular misalignment tolerance for use in optical backplane interconnections. Input tapered couplers having a larger entrance and tapering down in width do indeed improve the lateral misalignment tolerance compared to straight waveguides but do so at the expense of an increased loss. Tapers have no effect on angular tolerance for strongly driven vertical cavity surface-emitting laser (VCSEL) sources although they cause a loss of angular tolerance for single-mode fiber sources and VCSELs at low drive currents. (c) 2007 Society of Photo-Optical Instrumentation Engineers
Anti-plasmodial activity of Ailanthus excelsa
No full textThe anti-plasmodial activity of Ailanthus excelsa stem bark was investigated. The methanolic extract inhibited in vitro growth of chloroquine-sensitive (D10) and resistant strains (W2) of Plasmodium falciparum (IC50 4.6 and 2.8 μg/ml, respectively). The effect was retained in the chloroform fraction (3.1 and 2.1 μg/ml, respectively). The anti-plasmodial activity could be ascribed to the impairment of haemoglobin degradation through the inhibition of plasmepsin II activity (IC50 of 13.43 ± 1.74 μg/ml) and of the haem detoxification to haemozoin
Modelling of the effects of thermal gradients on optical propagation in polymer multimode tapered waveguides in optical backplanes
No full textFinite difference beam propagation modelling (FD-BPM) calculates the effect of thermal gradients in an optical backplane on the optical field propagation in a polymer multimode linearly tapered waveguide. Compared to straight waveguides, tapered entrances offer improved power coupling for a wide range of optical source lateral offset misalignments. However, surface temperature gradients of 0.5 degrees C/um across the taper were found to degrade this benefit due to the thermo-optic effect of the polymer. Higher surface temperature gradients improve power coupling in two discrete ranges of lateral source offset but the original tolerance to a wide range of source offsets is not recovered
Modeling of a polymer 1x3 MMI power splitter for optical backplane
No full textA 0.4 dB excess loss, 0.01 dB output channel imbalance polymer 1 x 3 MMI power splitter is modeled having linearly tapered input section suitable for use in an optical backplane connector. The device design was additionally optimized using FD-BPM to have a good tolerance to source lateral misalignments
Constraints on Dark Photon and Dark Model Parameters in the and Meson Decays
No full textThe study investigates flavor-changing neutral current (FCNC) decays of and mesons in the context of a dark model with a dark photon/dark mass between 10 MeV and 2 GeV. While the model improves the fit to certain decay distributions, such as and , it is ruled out by stringent experimental constraints, including atomic parity violation, , and mixing. To address these constraints, the model is extended with three modifications; allowing additional invisible decays of , introducing a direct vector coupling of to muons, and including a direct coupling of to both muons and electrons, with fine-tuning to cancel the mixing-induced coupling to electrons. Among these extensions, only the third scenario, involving fine-tuned electron coupling, remains consistent with all experimental constraints.17 pages, 1 table, 14 figure
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