Quantization of Magnetic Poisson Structures:LMS/EPSRC Durham Symposium on Higher Structures in M-Theory

We describe three perspectives on higher quantization, using the example of magnetic Poisson structures which embody recent discussions of nonassociativity in quantum mechanics with magnetic monopoles and string theory with non-geometric fluxes. We survey approaches based on deformation quantization of twisted Poisson structures, symplectic realization of almost symplectic structures, and geometric quantization using 2-Hilbert spaces of sections of suitable bundle gerbes. We compare and contrast these perspectives, describing their advantages and shortcomings in each case, and mention many open avenues for investigation.Comment: 13 pages, Contribution to Proceedings of LMS/EPSRC Durham Symposium Higher Structures in M-Theory, August 201

Dislocation Nucleation and Propagation in Semiconductor Heterostructures

This paper considers misfit dislocation nucleation and propagation in dilute magnetic semiconductor heterostructures in the CdTe-ZnTe-MnTe system. It is shown that, where the deposit is in tension, 1/2 \u3c 110 \u3e dislocations with inclined Burgers vectors propagate by glide along interfacial \u3c 110 \u3e directions and may dissociate giving intrinsic stacking faults. In cases where the deposit is in compression, 1/2 \u3c 110 \u3e dislocations show no evidence of dissociation and propagate by extensive cross-slip to give networks of dislocations close to interfacial \u3c 100 \u3e directions. Evidence for dislocation sources in ZnTe/GaSb films is presented. ZnTe films contained stacking fault pyramids, single Frank faults and a new type of diamond defect are present at densities up to about 107 cm-2. Analysis showed that the diamond defects, which were four-sided defects on {111} planes with \u3c 110 \u3e edges, were of vacancy type with 1/3 \u3c 111 \u3e Frank Burgers vectors and intrinsic stacking faults. Although faulted defects showed no tendency to grow by climb, evidence is given for an unfaulted reaction in which a glissile 1/2 \u3c 110 \u3e dislocation is generated. This new model for dislocation nucleation is discussed

Penetration of high intensity focused ultrasound in vitro and in vivo rabbit brain using MR imaging

In this paper magnetic resonance imaging (MRI) is investigated for monitoring the penetration of high intensity focused ultrasound (HIFU) ex vivo and in vivo rabbit brain. A single element spherically focused transducer of 5 cm diameter, focusing at 10 cm and operating at 2 MHz was used. A prototype MRI- compatible positioning device is described. MRI images were taken using fast spin echo (FSE). The length of the lesions in vivo rabbit brain was much higher than the length ex vivo, proving that the penetration in the ex vivo brain is limited by reflection due to trapped bubbles in the blood vessels

Claimed Co-ethnics and Kin-State Citizenship in Southeastern Europe

The paper introduces the often neglected concept of 'claimed co-ethnics' in the analysis of citizenship policies. It argues that this is an interstitial category that further complicates the triadic nexus between national minorities, nationalising states and kin-states. The 'claimed co-ethnics' are defined as people who are recognised by the citizenship (or ethnizenship) conferring state as belonging to its main ethnic group, although they themselves do not embrace that definition. In addition to bringing the issue of claimed co-ethnics into focus, the paper elucidates how citizenship policies can affect groups that challenge the exact fit between ethnicity and nation, showing how national governments through particular citizenship policies and categorisation practices engage in the construction of these groups. The paper shows that the triadic nexus framework, which has had a strong influence on citizenship and minorities scholarship, needs to be revised to include unidirectional relations between the elements of the triadic nexus. The paper is based on the comparison between the cases of ethnic Vlachs (in the context of Albania and Greece) and Bunjevci (in the context of Serbia and Croatia).European Commission - Seventh Framework Programme (FP7

A Game Theoretical Method for Cost-Benefit Analysis of Malware Dissemination Prevention

Copyright © Taylor & Francis Group, LLC. Literature in malware proliferation focuses on modeling and analyzing its spread dynamics. Epidemiology models, which are inspired by the characteristics of biological disease spread in human populations, have been used against this threat to analyze the way malware spreads in a network. This work presents a modified version of the commonly used epidemiology models Susceptible Infected Recovered (SIR) and Susceptible Infected Susceptible (SIS), which incorporates the ability to capture the relationships between nodes within a network, along with their effect on malware dissemination process. Drawing upon a model that illustrates the network’s behavior based on the attacker’s and the defender’s choices, we use game theory to compute optimal strategies for the defender to minimize the effect of malware spread, at the same time minimizing the security cost. We consider three defense mechanisms: patch, removal, and patch and removal, which correspond to the defender’s strategy and use probabilistically with a certain rate. The attacker chooses the type of attack according to its effectiveness and cost. Through the interaction between the two opponents we infer the optimal strategy for both players, known as Nash Equilibrium, evaluating the related payoffs. Hence, our model provides a cost-benefit risk management framework for managing malware spread in computer networks

Developmental expression of DAXI in the European sea bass, Dicentrarchus labrax: lack of evidence for sexual dimorphism during sex differentiation

Background: DAX1 (NR0B1), a member of the nuclear receptors super family, has been shown to be involved in the genetic sex determination and in gonadal differentiation in several vertebrate species. In the aquaculture fish European sea bass, Dicentrarchus labrax, and in the generality of fish species, the mechanisms of sex determination and differentiation have not been elucidated. The present study aimed at characterizing the European DAX1 gene and its developmental expression at the mRNA level. Methods: A full length European sea bass DAX1 cDNA (sbDAX1) was isolated by screening a testis cDNA library. The structure of the DAX1 gene was determined by PCR and Southern blot. Multisequence alignments and phylogenetic analysis were used to compare the translated sbDAX1 product to that of other vertebrates. sbDAX1 expression was analysed by Northern blot and relative RT-PCR in adult tissues. Developmental expression of mRNA levels was analysed in groups of larvae grown either at 15°C or 20°C (masculinising temperature) during the first 60 days, or two groups of fish selected for fast (mostly females) and slow growth. Results: The sbDAX1 is expressed as a single transcript in testis and ovary encoding a predicted protein of 301 amino acids. A polyglutamine stretch of variable length in different DAX1 proteins is present in the DNA binding domain. The sbDAX1 gene is composed of two exons, separated by a single 283 bp intron with conserved splice sites in same region of the ligand binding domain as other DAX1 genes. sbDAX1 mRNA is not restricted to the brain-pituitary-gonadal axis and is also detected in the gut, heart, gills, muscle and kidney. sbDAX1 mRNA was detected as early as 4 days post hatching (dph) and expression was not affected by incubation temperature. Throughout gonadal sex differentiation (60–300 dph) no dimorphic pattern of expression was observed. Conclusion: The sbDAX1 gene and putative protein coding region is highly conserved and has a wide pattern of tissue expression. Although gene expression data suggests sbDAX1 to be important for the development and differentiation of the gonads, it is apparently not sex specific

Matrix theory origins of non-geometric fluxes

We explore the origins of non-geometric fluxes within the context of M theory described as a matrix model. Building upon compactifications of Matrix theory on non-commutative tori and twisted tori, we formulate the conditions which describe compactifications with non-geometric fluxes. These turn out to be related to certain deformations of tori with non-commutative and non-associative structures on their phase space. Quantization of flux appears as a natural consequence of the framework and leads to the resolution of non-associativity at the level of the unitary operators. The quantum-mechanical nature of the model bestows an important role on the phase space. In particular, the geometric and non-geometric fluxes exchange their properties when going from position space to momentum space thus providing a duality among the two. Moreover, the operations which connect solutions with different fluxes are described and their relation to T-duality is discussed. Finally, we provide some insights on the effective gauge theories obtained from these matrix compactifications.Comment: 1+31 pages, reference list update

A Usability Evaluation of Privacy Add-ons for Web Browsers

The web has improved our life and has provided us with more opportunities to access information and do business. Nonetheless, due to the prevalence of trackers on websites, web users might be subject to profiling while accessing the web, which impairs their online privacy. Privacy browser add-ons, such as DuckDuckGo Privacy Essentials, Ghostery and Privacy Badger, extend the privacy protection that the browsers offer by default, by identifying and blocking trackers. However, the work that focuses on the usability of the privacy add-ons, as well as the users’ awareness, feelings, and thoughts towards them, is rather limited. In this work, we conducted usability evaluations by utilising System Usability Scale and Think-Aloud Protocol on three popular privacy add-ons, i.e., DuckDuckGo Privacy Essentials, Ghostery and Privacy Badger. Our work also provides insights into the users’ awareness of online privacy and attitudes towards the abovementioned privacy add-ons; in particular trust, concern, and control. Our results suggest that the participants feel safer and trusting of their respective add-on. It also uncovers areas for add-on improvement, such as a more visible toolbar logo that offers visual feedback, easy access to thorough help resources, and detailed information on the trackers that have been found