774 research outputs found
Unfair dismissal: procedure, fairness and compensation
This article addresses those provisions of Employment Act (EA) 2002 (implemented on 1 October 2004) which introduce statutory disciplinary and grievance procedures. In particular, it will consider the impact of the new provisions on traditional approaches to procedural unfairness by employers, the doctrine established by the House of Lords in Polkey v A E Dayton Services and the calculation of compensation in these cases.
A significant recent decision of the Employment Appeal Tribunal, handed down by Elias P. has answered a number of questions about the meaning of statutory language which is described as ‘elusively vague’ by the President of the EAT. Inevitably, further questions remain
SUMO chain formation is required for response to replication arrest in S. pombe
SUMO is a ubiquitin-like protein that is post-translationally attached to one or more lysine residues on target proteins. Despite having only 18% sequence identity with ubiquitin, SUMO contains the conserved betabetaalphabetabetaalphabeta fold present in ubiquitin. However, SUMO differs from ubiquitin in having an extended N-terminus. In S. pombe the N-terminus of SUMO/Pmt3 is significantly longer than those of SUMO in S. cerevisiae, human and Drosophila. Here we investigate the role of this N-terminal region. We have used two dimensional gel electrophoresis to demonstrate that S. pombe SUMO/Pmt3 is phosphorylated, and that this occurs on serine residues at the extreme N-terminus of the protein. Mutation of these residues (in pmt3-1) results in a dramatic reduction in both the levels of high Mr SUMO-containing species and of total SUMO/Pmt3, indicating that phosphorylation of SUMO/Pmt3 is required for its stability. Despite the significant reduction in high Mr SUMO-containing species, pmt3-1 cells do not display an aberrant cell morphology or sensitivity to genotoxins or stress. Additionally, we demonstrate that two lysine residues in the N-terminus of S. pombe SUMO/Pmt3 (K14 and K30) can act as acceptor sites for SUMO chain formation in vitro. Inability to form SUMO chains results in aberrant cell and nuclear morphologies, including stretched and fragmented chromatin. SUMO chain mutants are sensitive to the DNA synthesis inhibitor, hydroxyurea (HU), but not to other genotoxins, such as UV, MMS or CPT. This implies a role for SUMO chains in the response to replication arrest in S. pomb
Measurement-induced disturbances and nonclassical correlations of Gaussian states
We study quantum correlations beyond entanglement in two-mode Gaussian states
of continuous variable systems, by means of the measurement-induced disturbance
(MID) and its ameliorated version (AMID). In analogy with the recent studies of
the Gaussian quantum discord, we define a Gaussian AMID by constraining the
optimization to all bi-local Gaussian positive operator valued measurements. We
solve the optimization explicitly for relevant families of states, including
squeezed thermal states. Remarkably, we find that there is a finite subset of
two-mode Gaussian states, comprising pure states, where non-Gaussian
measurements such as photon counting are globally optimal for the AMID and
realize a strictly smaller state disturbance compared to the best Gaussian
measurements. However, for the majority of two--mode Gaussian states the
unoptimized MID provides a loose overestimation of the actual content of
quantum correlations, as evidenced by its comparison with Gaussian discord.
This feature displays strong similarity with the case of two qubits. Upper and
lower bounds for the Gaussian AMID at fixed Gaussian discord are identified. We
further present a comparison between Gaussian AMID and Gaussian entanglement of
formation, and classify families of two-mode states in terms of their Gaussian
AMID, Gaussian discord, and Gaussian entanglement of formation. Our findings
provide a further confirmation of the genuinely quantum nature of general
Gaussian states, yet they reveal that non-Gaussian measurements can play a
crucial role for the optimized extraction and potential exploitation of
classical and nonclassical correlations in Gaussian states.Comment: 16 pages, 5 figures; new results added; to appear in Phys. Rev.
Structural basis for the RING catalyzed synthesis of K63 linked ubiquitin chains
This work was supported by grants from Cancer Research UK (C434/A13067), the Wellcome Trust (098391/Z/12/Z) and Biotechnology and Biological Sciences Research Council (BB/J016004/1).The RING E3 ligase catalysed formation of lysine 63 linked ubiquitin chains by the Ube2V2–Ubc13 E2 complex is required for many important biological processes. Here we report the structure of the RING domain dimer of rat RNF4 in complex with a human Ubc13~Ub conjugate and Ube2V2. The structure has captured Ube2V2 bound to the acceptor (priming) ubiquitin with Lys63 in a position that could lead to attack on the linkage between the donor (second) ubiquitin and Ubc13 that is held in the active “folded back” conformation by the RING domain of RNF4. The interfaces identified in the structure were verified by in vitro ubiquitination assays of site directed mutants. This represents the first view of the synthesis of Lys63 linked ubiquitin chains in which both substrate ubiquitin and ubiquitin-loaded E2 are juxtaposed to allow E3 ligase mediated catalysis.PostprintPeer reviewe
Structural insight into SUMO chain recognition and manipulation by the ubiquitin ligase RNF4
The small ubiquitin-like modifier (SUMO) can form polymeric chains that are important signals in cellular processes such as meiosis, genome maintenance and stress response. The SUMO-targeted ubiquitin ligase RNF4 engages with SUMO chains on linked substrates and catalyses their ubiquitination, which targets substrates for proteasomal degradation. Here we use a segmental labelling approach combined with solution nuclear magnetic resonance (NMR) spectroscopy and biochemical characterization to reveal how RNF4 manipulates the conformation of the SUMO chain, thereby facilitating optimal delivery of the distal SUMO domain for ubiquitin transfer
Anticipatory coarticulation in Hungarian VnC sequences
The duration of the vowel and the nasal was analyzed in the casual pronunciation of Hungarian words containing the sequence V
n
.C, where ‘.’ is a syllable boundary and C is a stop, affricate, fricative, or approximant. It was found that due to anticipatory coarticulation the duration of
n
is significantly shorter before fricatives and approximants than before stops and affricates.A teaching algorithm was used to distinguish between stops/affricates and fricatives/approximants in V
n
C sequences. We used an approach to the classification of C by means of the support vector machine (SVM) and the properties of Radial basis function (RBF) kernel (using MATLAB, version 7.0). The results show close to 95% correct responses for the stop/affricate vs. fricative/approximant distinction of C, as opposed to about 60% correct responses for the classification of the voicing feature of C
A Case Study of Crowdsourcing Imagery Coding in Natural Disasters
Crowdsourcing and open licensing allow more people to participate in research and humanitarian activities. Open data, such as geographic information shared through OpenStreetMap and image datasets from disasters, can be useful for disaster response and recovery work. This chapter shares a real-world case study of humanitarian-driven imagery analysis, using open-source crowdsourcing technology. Shared philosophies in open technologies and digital humanities, including remixing and the wisdom of the crowd, are reflected in this case study.This research was funded through the European Commission FP7-ICT project:
Citizen Cyberlab: Technology Enhanced Creative Learning in the field of Citizen Cyberscience
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