A comparison of OSPFv3 and EIGRPv6 in a small IPv6 enterprise network

As the Internet slowly transitions towards IPv6, the routing protocols that are used to forward traffic across this global network must adapt to support this gradual transition. Two of the most frequently discussed interior dynamic routing protocols today are the IETF’s OSPF and Cisco’s EIGRP routing protocol. A wealth of papers have compared OSPF and EIGRP in terms of converge times and resource usage, however few papers have assessed the performance of each when implementing their respective security mechanisms. Therefore a comparison of OSPFv3 and EIGRPv6 will be conducted using dedicated Cisco hardware. This paper will firstly introduce each protocol and its security mechanisms, before conducting a comparison of OSPFv3 and EIGRPv6 using Cisco equipment. After discussing the simulation results, a conclusion will be drawn to reveal the findings of this paper and which protocol performs the best upon implementing their respective security mechanisms within a small IPv6 enterprise network

Parsimonious and efficient assessment of health-related quality of life in osteoarthritis research: validation of the Assessment of Quality of Life (AQoL) instrument

BACKGROUND: The Assessment of Quality of Life (AQoL) utility instrument was psychometrically developed for the general population. This study aimed to explore its potential as an osteoarthritis (OA) outcome measure. METHODS: WOMAC, Lequesne index, SF-36, Visual analogue scales and the AQoL were administered to 222 people with OA. The ability of each questionnaire to detect differences between groups was based on (i) self-rated health (SRH) and, (ii) differences between people on an orthopedic waiting list (WL) vs people with OA in the community (C). Comparisons included effect size, relative efficiency and receiver operator characteristic curves. RESULTS: All instruments detected differences between groups; however no one instrument exhibited superior efficiency. The AQoL demonstrated strong psychometric properties. CONCLUSION: The AQoL has equivalent performance to comparator questionnaires commonly used in OA research and would be a useful adjunct to well-established disease specific scales. The AQoL has important advantages; brevity (12 items), facilitates comparisons between disease groups, and delivers a utility score that can be used in health economic evaluations

Aqueous copper(II) photoinduced polymerization of acrylates : low copper concentration and the importance of sodium halide salts

Photoinduced metal mediated radical polymerization is a rapidly developing technique which allows for the synthesis of macromolecules with defined molecular weight and narrow molecular weight distributions, although typically exhibiting significant limitations in aqueous media. Herein we demonstrate that the presence of alkali metal halide salts in conjunction with low copper concentration and UV irradiation, allows for the controlled polymerization of water soluble acrylates in aqueous media, yielding narrow molecular weight distributions and high conversions. Despite the aqueous environment which typically compromises polymer end group fidelity, chain extensions have also been successfully performed and different degrees of polymerization were targeted. Importantly, no conversion was observed in the absence of UV light and the polymerization could be switched “on” and “off” upon demand as demonstrated by intermittent light and dark periods and thus allowing access to spatiotemporal control

Copper mediated reversible deactivation radical polymerization in aqueous media

Key advances within the past 10 years have transformed copper mediated radical polymerization from a technique which was not very tolerant to protic media into a range of closely related processes capable of control over the polymerization of a wide range of monomers in pure water at ppm catalyst loadings; yielding water soluble macromolecules of desired molecular weight, architecture and chemical functionality, with applications ranging from drug delivery to oil field recovery. In this review we highlight and critically evaluate the synthetic methods that have been developed to control radical polymerization in water using copper complexes, identify future areas of interest and challenges still to be overcome

Copper mediated polymerization without external deoxygenation or oxygen scavengers

Overcoming the challenge of rigorous deoxygenation in copper mediated controlled radical polymerization processes (e.g. ATRP), we report a simple Cu(0)‐RDRP system in the absence of external additives (e.g. reducing agents, enzymes etc.). By simply adjusting the headspace of the reaction vessel, a wide range of monomers, namely acrylates, methacrylates, acrylamides and styrene, can be polymerized in a controlled manner yielding polymers with low dispersities, near‐quantitative conversions and high end group fidelity. Significantly, this approach is scalable (~ 125 g), tolerant to elevated temperatures, compatible with both organic and aqueous media and does not rely on external stimuli which may limit the monomer pool. The robustness and versatility of this methodology is further demonstrated by the applicability to a number of other copper mediated techniques including conventional ATRP and light‐mediated approaches

Well-defined PDMAEA stars via Cu(0)-mediated reversible deactivation radical polymerisation

The Cu(0)-mediated reversible deactivation radical polymerisation of N,N’-dimethylaminoethyl acrylate in DMSO and IPA at ambient temperature using Cu(0) wire is investigated. Tetra-functional and octa-functional initiators were utilised to facilitate the synthesis of well-defined PDMAEA star homo and block copolymers with a range of molecular weights (Mn ~ 5000-41000 g mol-1). Both solvents demonstrated to be excellent media for the controlled polymerisation of DMAEA yielding narrow molecular weight distributions (Ð ~ 1.1) when the reactions were ceased at ~ 40% conversion. Interestingly, at high conversions (typically > 55%) high and low molecular weight shoulders were evident by SEC when DMSO and IPA were used respectively, suggesting large extent of termination and/or side reactions at prolonged reaction times. Nevertheless, high end group fidelity could be maintained when immediate precipitation of the polymers (at lower conversion) was performed yielding low dispersed P(DMAEA-b-MA) star block copolymers (Ð < 1.19, Mn ~ 20000 g mol-1). Importantly, guidelines on how to prevent hydrolysis, termination and side reactions of PDMAEA as well as how to purify and store such materials are also provided and discussed

A User\u27s Guide to the Encyclopedia of DNA Elements (ENCODE)

The mission of the Encyclopedia of DNA Elements (ENCODE) Project is to enable the scientific and medical communities to interpret the human genome sequence and apply it to understand human biology and improve health. The ENCODE Consortium is integrating multiple technologies and approaches in a collective effort to discover and define the functional elements encoded in the human genome, including genes, transcripts, and transcriptional regulatory regions, together with their attendant chromatin states and DNA methylation patterns. In the process, standards to ensure high-quality data have been implemented, and novel algorithms have been developed to facilitate analysis. Data and derived results are made available through a freely accessible database. Here we provide an overview of the project and the resources it is generating and illustrate the application of ENCODE data to interpret the human genome

Ultra-low volume oxygen tolerant photoinduced Cu-RDRP

We introduce the first oxygen tolerant ultra-low volume (as low as 5 μL total reaction volume) photoinduced copper-RDRP of a wide range of hydrophobic, hydrophilic and semi-fluorinated monomers including lauryl and hexyl acrylate, poly(ethylene glycol methyl ether acrylate) and trifluoroethyl (meth)acrylate. In the absence of any external deoxygenation, well-defined homopolymers can be obtained with low dispersity values, high end-group fidelity and near-quantitative conversions. Block copolymers can be efficiently synthesized in a facile manner and the compatibility of the system to larger scale polymerizations (up to 0.5 L) is also demonstrated by judiciously optimizing the reaction conditions. Importantly, the online monitoring of oxygen consumption was also conducted through an oxygen probe and the role of each component is identified and discussed

Functional analysis of transcription factor binding sites in human promoters

BACKGROUND: The binding of transcription factors to specific locations in the genome is integral to the orchestration of transcriptional regulation in cells. To characterize transcription factor binding site function on a large scale, we predicted and mutagenized 455 binding sites in human promoters. We carried out functional tests on these sites in four different immortalized human cell lines using transient transfections with a luciferase reporter assay, primarily for the transcription factors CTCF, GABP, GATA2, E2F, STAT, and YY1. RESULTS: In each cell line, between 36% and 49% of binding sites made a functional contribution to the promoter activity; the overall rate for observing function in any of the cell lines was 70%. Transcription factor binding resulted in transcriptional repression in more than a third of functional sites. When compared with predicted binding sites whose function was not experimentally verified, the functional binding sites had higher conservation and were located closer to transcriptional start sites (TSSs). Among functional sites, repressive sites tended to be located further from TSSs than were activating sites. Our data provide significant insight into the functional characteristics of YY1 binding sites, most notably the detection of distinct activating and repressing classes of YY1 binding sites. Repressing sites were located closer to, and often overlapped with, translational start sites and presented a distinctive variation on the canonical YY1 binding motif. CONCLUSIONS: The genomic properties that we found to associate with functional TF binding sites on promoters -- conservation, TSS proximity, motifs and their variations -- point the way to improved accuracy in future TFBS predictions

Inverse relationship between galactokinase activity and 2-deoxygalactose resistance in Chinese hamster ovary cells

Galactokinase activity is reduced in 12 independent clones of Chinese hamster ovary cells resistant to 2-deoxygalactose. The frequency of resistant colonies is increased with chemical mutagens. The resistant phenotype is stable in the absence of selection. There is an inverse correlation between the levels of galactokinase activity and the cloning efficiency in deoxygalactose. Cells with high resistance have 1%or less of the enzyme activity observed in the parental cells; while cells with low resistance have 10–30% galactokinase activity. Studies with tetraploid hybrid cells reveal that resistance to deoxygalactose is a recessive trait and that cells with high resistance do not complement those with low resistance. In cell lines with low resistance, the K m for galactose , K i for deoxygalactose , K m for ATP, and thermolability were not significantly altered compared to sensitive parental cells. Although the possibility of mutation at the structural gene locus has not been ruled out, the reduced enzyme activity may also be due to mutation at a regulatory site which affects the number of galactokinase molecules per cell .Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/45552/1/11188_2005_Article_BF01543159.pd