Simulation Studies of a Hybrid Network in Order to Enhance the Performance of Hybrid Internet Service

The work reported here addresses the modeling and simulation of a hybrid network that conforms to Hybrid Internet Service, which is an Internet access currently commercialized by Hughes Network Systems. The objective is to research and discover performance enhancement techniques for Hybrid Internet Service. Hybrid Internet Service intends to provide Internet end users with high bandwidth by delivering packets over a satellite channel. It takes advantage of the fact that the vast majority of Internet end-users don't send as much data as they receive. However, long delays experienced over the satellite channel (in the case of a GEO satellite) have catastrophic consequences on the overall throughput with Commercial-Off-The-Shelf TPC/IP stacks. This problem is addressed by the Asymmetric TCP/IP protocol implemented within a gateway, the hybrid gateway. The hybrid gateway acts as a go-between for the server and the end user. The hybrid gateway both acknowledges packets on behalf of the end user and advertises a larger window to the server. We have implemented the Asymmetric TCP/IP within the hybrid gateway with OPNET, which is an industrial-strength, popular network modeling and simulation software. A discussion of the current results of the simulation in the broader perspective of hybrid networks development is provided following the presentation of both Hybrid Internet Service and OPNET along with the various built-in OPNET models used in the course of the simulation. The methodology we have followed is also included in this report

Measurement of vector boson production cross sections and their ratios using pp collisions at √s = 13.6 TeV with the ATLAS detector

Abstract available from publisher's website

Somali women’s political participation and leadership-evidence and opportunities

This report synthesises findings from an eleven month qualitative research project (August 2016 - June 2017), carried out by Social Development Direct and Forcier Consulting, and funded by the Research and Evidence Division (RED) within the UK government’s Department for International Development (DFID). The research aims to provide evidence on the principal enabling and constraining factors for Somali women’s participation and leadership in government and political structures, and offers insight on the strategies and circumstances under which Somali women have, and have not, accessed and influenced within these spaces

Design and analysis of a low profile, high gain rectangular microstrip patch antenna for 28 GHz applications

AbstractThis paper presents a simple, low-profile rectangular microstrip patch antenna for applications in the 28 GHz band. A regular rectangular microstrip patch antenna is initially designed. The antenna is then modified to perfectly resonate at 28 GHz and improve antenna performance in terms of S11, radiation gain, and impedance bandwidth. The antenna is optimized using inset feed to enhance the matching between the radiating patch and the feeding line. Then, a rectangular slit on the front edge of the patch is inserted with altering the antenna’s dimensions to reduce its size. The suggested antenna uses a Rogers RT/Duroid-5880 substrate with a dielectric constant of 2.2, a thickness of 0.508 mm, and a loss tangent of 0.0009. The final design is small, measuring 8 × 8.489 × 0.508 mm3 (≈ 0.75λ × 0.79λ × 0.05λ), having a maximum S11 value of - 45 dB and an impedance bandwidth of 1.43 GHz, extending from 27.28 GHz to 28.71 GHz. The radiation gain is nearly consistent over the operating band, with above 8 dBi is achieved. Besides, the proposed antenna achieves a radiation efficiency of about 99% across the band. HFSS is employed for the design, simulations, and optimizations, while CST is used to validate the HFSS simulation findings. The simulation results from both simulators indicate a high level of agreement

Not Available

Not AvailableThis manuscript describes the cloning and functional characterization of a biphenyl phytoalexin biosynthetic gene, 3,5-dihydroxybiphenyl O-methyltransferase from elicitor-treated cell cultures of scab resistant apple cultivar 'Florina'. Apples belong to the subtribe Malinae of the Rosaceae family. Biphenyls and dibenzofurans are the specialized phytoalexins of Malinae, of which aucuparin is the most widely distributed biphenyl. The precursor of aucuparin, 3,5-dihydroxybiphenyl, is a benzoate-derived polyketide, which is formed by the sequential condensation of three molecules of malonyl-CoA and one molecule of benzoyl-CoA in a reaction catalyzed by biphenyl synthase (BIS). This 3,5-dihydroxybiphenyl then undergoes sequential 5-O-methylation, 4-hydroxylation, and finally 3-O-methylation to form aucuparin. A cDNA encoding O-methyltransferase (OMT) was isolated and functionally characterized from the cell cultures of scab-resistant apple cultivar 'Florina' (Malus domestica cultivar 'Florina'; MdOMT) after treatment with elicitor prepared from the apple scab causing fungus Venturia inaequalis. MdOMT catalyzed the regiospecific O-methylation of 3,5-dihydroxybiphenyl at the 5-position to form 3-hydroxy-5-methoxybiphenyl. The enzyme showed absolute substrate preference for 3,5-dihydroxybiphenyl. The elicitor-treated apple cell cultures showed transient increases in the MdOMT (GenBank ID MF740747) and MdBIS3 (GenBank ID JQ390523) transcript levels followed by the accumulation of biphenyls (aucuparin and noraucuparin) and dibenzofuran (eriobofuran) phytoalexins. MdOMT fused with N- and C-terminal yellow fluorescent protein showed cytoplasmic localization in the epidermis of Nicotiana benthamiana leaves. In scab inoculated greenhouse-grown 'Florina' plants, the expression of MdOMT was transiently induced in the stem followed by the accumulation of biphenyl phytoalexins.Not Availabl