On The Strong-Coupling Spectrum of Pure SU(3) Seiberg-Witten Theory

We consider the two complex dimensional moduli space of supersymmetric vacua for low energy effective N=2 SYM with gauge group SU(3). We describe, at the topological level, a consistent model of how the relevant curves of marginal stability (CMS) intertwine with the branch cuts to partition the moduli space into pieces carrying different BPS spectra. At strong coupling we find connected cores which carry a smaller BPS spectrum than that at weak coupling. At the strongest coupling we find double cores which carry a finite BPS spectrum. These include not only states one can deduce from the monodromy group, but three states, bounded away from weak coupling, each of which we interpret as a bound state of two BPS gauge bosons. We find new BPS states at weak coupling corresponding to a excitations of a state with magnetic charge a simple co-root, with respect to the other simple root direction.Comment: 27 pages, uses JHEP.cls; typos corrected, references adde

Zero temperature black holes in semiclassical gravity

The semiclassical Einstein equations are solved to first order in $\epsilon = \hbar/M^2$ for the case of an extreme or nearly extreme Reissner-Nordstr\"{o}m black hole perturbed by the vacuum stress-energy of quantized free fields. It is shown that, for realistic fields of spin 0, 1/2, or 1, any zero temperature black hole solution to the equations must have an event horizon at $r_h < |Q|$, with $Q$ the charge of the black hole. It is further shown that no black hole solutions with $r_h < |Q|$ can be obtained by solving the semiclassical Einstein equations perturbatively.Comment: 7 pages, to appear in the Proceedings of the Ninth Marcel Grossmann Meeting, change in titl

Can Clustering Improve Requirements Traceability? A Tracelab-enabled Study

Software permeates every aspect of our modern lives. In many applications, such in the software for airplane flight controls, or nuclear power control systems software failures can have catastrophic consequences. As we place so much trust in software, how can we know if it is trustworthy? Through software assurance, we can attempt to quantify just that. Building complex, high assurance software is no simple task. The difficult information landscape of a software engineering project can make verification and validation, the process by which the assurance of a software is assessed, very difficult. In order to manage the inevitable information overload of complex software projects, we need software traceability, the ability to describe and follow the life of a requirement, in both forwards and backwards direction. The Center of Excellence for Software Traceability (CoEST) has created a compelling research agenda with the goal of ubiquitous traceability by 2035. As part of this goal, they have developed TraceLab, a visual experimental workbench built to support design, implementation, and execution of traceability experiments. Through our collaboration with CoEST, we have made several contributions to TraceLab and its community. This work contributes to the goals of the traceability research community. The three key contributions are (a) a machine learning component package for TraceLab featuring six (6) classifier algorithms, five (5) clustering algorithms, and a total of over 40 components for creating TraceLab experiments, built upon the WEKA machine learning package, as well as implementing methods outside of WEKA; (b) the design for an automated tracing system that uses clustering to decompose the task of tracing into many smaller tracing subproblems; and (c) an implementation of several key components of this tracing system using TraceLab and its experimental evaluation

Role of Cytoskeletal Dynamics in Platelet Arf6 Activation

Platelets undergo morphological changes upon activation, such as shape change and aggregation. These changes are known to be the result of actin remodeling, whereas the role of microtubule remodeling has been controversial. The objective of this study was to re-examine the role of actin and microtubule dynamics in platelet function. We used aggregometry to measure the effect of cytoskeletal inhibitors on platelet shape change, aggregation, and dense core release. Microtubule assembly was found to have no role in platelet function, because treatment with vinblastine or nocodazole had no effect on shape change, aggregation, or secretion. Microtubule disassembly was necessary for some aspects of platelet function, because treatment with paclitaxel inhibited aggregation and secretion, but not shape change. Actin assembly was confirmed to be an essential event in platelet activation. We then assessed the role of microtubule disassembly and actin assembly in ADP-ribosylation factor 6 (Arf6) activation, because Arf6 is a key signaling component in platelet activation. Using GST-GGA3, we monitored Arf6-GTP levels over time in paclitaxel and latrunculin A-treated platelets. Paclitaxel and latrunculin A treatment blocked Arf6 activation in thrombin and convulxin-stimulated platelets, respectively. These results suggest that microtubule disassembly and actin assembly are important for Arf6 activation in platelets

The Human Rights Act 1998: A Bill of Rights for Britain?

On the eve of the tenth anniversary of the coming into force of the Human Rights Act 1998 (HRA), this thesis endeavours to explore the extent to which New Labour’s flagship piece of legislation can be considered a Bill of Rights for Britain. It explores the debate surrounding the characteristics of Bills of Rights in comparison to the traditional UK approach towards human rights protection, arguing that a compromise between the two positions exists in the form of third wave Bills of Rights; a model which increases the power of the judiciary whilst still preserving parliamentary sovereignty. Although the HRA has the potential on paper to be a third wave Bill of Rights, it is argued that it can only be so if the judiciary takes a relatively expansive approach towards its key provisions: sections 2, 3, 4 and 6. Much of the thesis therefore focuses on finding traces of such expansive judicial reasoning, discovering that the judiciary’s application of the Act has been distinctively uneven. In some instances, the judiciary have taken a severely restrictive approach towards the HRA, whilst in others they have taken a more expansive approach akin to a third wave Bill of Rights. However, despite any inconsistency, this thesis nevertheless argues that a general trend by the judiciary, to move beyond the traditional British model of human rights protection towards a Bill of Rights, is beginning to emerge. The thesis also argues that the HRA must, in order to be considered a Bill of Rights, have the support and backing of the public. This, however, has not happened; despite the fact that the HRA displays many of the general characteristics of Bills of Rights, as well as also reflecting British legal tradition. With calls for the repeal and replacement of the HRA, it appears unlikely that it will have the time needed to fulfil its potential as a Bill of Rights for Britain

The Contested Constitution : An Analysis of the Competing Models of British Constitutionalism

Available on Westlaw UK. I am grateful to the anonymous reviewer and to Adelyn Wilson and Mike Radford for their comments on an earlier draft.Peer reviewedPostprin

Public Law Declarators, the Jurisdiction of the Court, and Scottish Independence : Keatings v Advocate General

Peer reviewedPostprin

The Political Constitution No More?

The British constitution has recently undergone some dramatic changes which, according to leading constitutional scholar Vernon Bogdanor, signals the demise of the 'old' political constitution and its replacement with a 'new' more legal constitution. The aim of thesis is to challenge the assertion that the British constitution is undergoing a fundamental transformation from a political to a legal constitution by conducting a thorough analysis of the extent to which the contemporary British constitution can still be said to resemble a political constitution. This will be achieved through an exhaustive examination of three key areas of the constitution: the Royal Prerogative; Constitutional Conventions; and the Human Rights Act 1998. In so doing, however, it is not the aim of this thesis to produce a simple either/or account of the British constitution, but instead to advance and provide evidence of a middle-ground between the two opposing schools of constitutionalism: complementary constitutionalism. It will be argued that both the legal and the political constitutions share many common characteristics and disagree with one another primarily, although not exclusively, on emphasis. No real world constitution, therefore, was or ever will be solely legal or solely political in character. A real world constitution is instead a complementary mixture of elements from both the legal and political schools which can be either primarily legal or primarily political in character. As a result, it will be shown that the British constitution, although undisputedly more legal, nevertheless remains primarily political