The fission yeast FANCM ortholog directs non-crossover recombination during meiosis

Peer reviewedPostprin

CloudScope: diagnosing and managing performance interference in multi-tenant clouds

© 2015 IEEE.Virtual machine consolidation is attractive in cloud computing platforms for several reasons including reduced infrastructure costs, lower energy consumption and ease of management. However, the interference between co-resident workloads caused by virtualization can violate the service level objectives (SLOs) that the cloud platform guarantees. Existing solutions to minimize interference between virtual machines (VMs) are mostly based on comprehensive micro-benchmarks or online training which makes them computationally intensive. In this paper, we present CloudScope, a system for diagnosing interference for multi-tenant cloud systems in a lightweight way. CloudScope employs a discrete-time Markov Chain model for the online prediction of performance interference of co-resident VMs. It uses the results to optimally (re)assign VMs to physical machines and to optimize the hypervisor configuration, e.g. the CPU share it can use, for different workloads. We have implemented CloudScope on top of the Xen hypervisor and conducted experiments using a set of CPU, disk, and network intensive workloads and a real system (MapReduce). Our results show that CloudScope interference prediction achieves an average error of 9%. The interference-aware scheduler improves VM performance by up to 10% compared to the default scheduler. In addition, the hypervisor reconfiguration can improve network throughput by up to 30%

Hygrothermal performance of building envelopes in the tropics under operative conditions : condensation and mould growth risk appraisal

Poor indoor hygrothermal performance increases the risk of indoor moisture problems and deterioration due to mould growth, corrosion and damage to archival materials. Hence, proper control of indoor thermohygric intensity abates indoor moisture and its associated problems. This paper presents the results of envelopes hygrothermal performance assessments in a hot and humid climate building with varying operational profile between adjacent spaces. The case-studied building runs on 24hrs cooling mode in one part against natural and/or mechanical supply-exhaust fan means on the other. In-situ experiments were combined with hygrothermal analytical methods to assess the envelope thermal quality together with the operative conditions against condensation and mould growth risks. The results show that the building is overcooled leading to poor envelope hygrothermal performance with associated condensation and mould growth problems on non-airconditioned sides of the envelopes

Biochemical characterization and DNA repair pathway interactions of Mag1-mediated base excision repair in Schizosaccharomyces pombe

The Schizosaccharomyces pombe mag1 gene encodes a DNA repair enzyme with sequence similarity to the AlkA family of DNA glycosylases, which are essential for the removal of cytotoxic alkylation products, the premutagenic deamination product hypoxanthine and certain cyclic ethenoadducts such as ethenoadenine. In this paper, we have purified the Mag1 protein and characterized its substrate specificity. It appears that the substrate range of Mag1 is limited to the major alkylation products, such as 3-mA, 3-mG and 7-mG, whereas no significant activity was found towards deamination products, ethenoadducts or oxidation products. The efficiency of 3-mA and 3-mG removal was 5–10 times slower for Mag1 than for Escherichia coli AlkA whereas the rate of 7-mG removal was similar to the two enzymes. The relatively low efficiency for the removal of cytotoxic 3-methylpurines is consistent with the moderate sensitivity of the mag1 mutant to methylating agents. Furthermore, we studied the initial steps of Mag1-dependent base excision repair (BER) and genetic interactions with other repair pathways by mutant analysis. The double mutants mag1 nth1, mag1 apn2 and mag1 rad2 displayed increased resistance to methyl methanesulfonate (MMS) compared with the single mutants nth1, apn2 and rad2, respectively, indicating that Mag1 initiates both short-patch (Nth1-dependent) and long-patch (Rad2-dependent) BER of MMS-induced damage. Spontaneous intrachromosomal recombination frequencies increased 3-fold in the mag1 mutant suggesting that Mag1 and recombinational repair (RR) are both involved in repair of alkylated bases. Finally, we show that the deletion of mag1 in the background of rad16, nth1 and rad2 single mutants reduced the total recombination frequencies of all three double mutants, indicating that abasic sites formed as a result of Mag1 removal of spontaneous base lesions are substrates for nucleotide excision repair, long- and short-patch BER and RR

Transforming the post-school sector in South Africa: Limits of a skills-driven agenda

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The elicitation of key performance indicators of e-government providers: A bottom-up approach

Copyright @ 2013 EMCIS.Delivering an adequate e-Government service (e-service) is becoming more of a necessity in today's digital world. In order to improve e-services and increase the engagement of both users' and providers' side, studies on the performance evaluation of such provided e-services are taking places. However a clear identification of the key performance indicators from the e-Government providers’ side is not well explored. This shortcoming hampers the conduct of a holistic evaluation of an e-service provision from the perspective of its stakeholders in order to improve e-services as well as to increase e-services take-ups. In this paper, a systematic process to identify indicators is implemented based on a bottom-up approach. The process used three focus-group meetings with providers, users, and academics in Qatar, Lebanon and UK to collect, identify and validate key indicators from the perspective of e-services’ providers. The approach resulted in the identification of five factors levels (service, technology, employees, policy and management and social responsibilities) with fifteen sub-categories of SMART variables. Hence, leading to the development of a new model, STEPS, that can fully explain and predict e-government success from the providers’ point of view. It will work as a strategic management tool to align various stakeholders on common goal and values based on evidence based evaluation of e-services using smart measurable indicators for the improvement of an e-service at the engagement level in the field of e-government. In addition, other fields can benefit from the outcome of this work, such as logistics service providers, who make their services available across new and existing relationships between the Internet commerce firms, their customers, and their vendors

Decision making in uncertain times: what can cognitive and decision sciences say about or learn from economic crises?

B.M. was supported by a Visiting Scholar Award from the British Academy and Grant ME 3717/2 from the Deutsche Forschungsgemeinschaft (DFG) as part of the priority program ‘New Frameworks of Rationality’ (SPP 1516)

An Electronically Reconfigurable Patch Antenna Design for Polarization Diversity with Fixed Resonant Frequency

In this paper, an electronically polarization reconfigurable circular patch antenna with fixed resonant frequency operating at Wireless Local Area Network (WLAN) frequency band (2.4-2.48 GHz) is presented. The structure of the proposed design consists of a circular patch as a radiating element fed by coaxial probe, cooperated with four equal-length slits etched on the edge along x-axis and y-axis. A total of four switches was used and embedded across the slits at specific locations, thus controlled the length of the slits. By activating and deactivating the switches (ON and OFF) across the slits, the current on the patch is changed, thus modifying the electric field and polarization of the antenna. Consequently, the polarization excited by the proposed antenna can be switched into three types, either linear polarization, left-hand circular polarization or right-hand circular polarization. This paper proposes a simple approach that able to switch the polarizations and excited at the same operating frequency. Simulated and measured results of ideal case (using copper strip switches) and real case (using PIN diode switches) are compared and presented to demonstrate the performance of the antenna