Mmabatho, 'Mother of the People': identity and development in an 'independent' Bantustan, Bophuthatswana, 1975–1994

The thesis brings together two important themes within Geography and Development Studies. First, post-colonial analyses of social identity and difference; secondly, the relationship between social identity and the 'new' historiography of South Africa. These themes raise important intellectual and practical questions central to rethinking the relationship between the developed and underdeveloped worlds. During the apartheid era political and cultural relations between core and periphery were (are) integral to the fragmentation of South African society and space. Apartheid discourse constantly manipulated social and cultural differences and divisions. These divisions were epitomised by the enforced racial and ethnic partition associated with the Bantustans. By focusing on one Bantustan, namely Bophuthatswana, the thesis shows that complex identities and interests also emerged within these territories. Under the guise of independence various marginal groups sought power and influence through vigorous efforts to create and promote a new national identity. A range of issues are used to identify and emphasise the intersection of two major discourses, ethno-nationalism and modernisation. These serve to illustrate the complex interplay of local and regional characteristics alongside more general processes associated with the changing nature of apartheid. By reference to the creation of the national capital, Mmabatho, the thesis demonstrates the shortcomings and contradictions of this nation-building exercise and of the modernist discourses on which it was based

‘Only the people can defend this struggle’: the politics of the everyday, extrajudicial executions and civil society in Mathare, Kenya

Though a perennial problem in postcolonial Kenya, extrajudicial executions (EJE) show few signs of ending and in recent years are even accelerating amongst young men in informal settlements. Avenues for legal, institutional and civil society redress, nominally expanded in recent years, display an ongoing tendency towards disconnection from the grassroots. A case study from Mathare, Nairobi, seeks explanations for the lack of urgency in addressing EJE and also the limited effectiveness of responses to them that are rooted in the political economy of interests of civil society actors, which tends to perpetuate these ‘excluded spaces’ of the slum. The authors do so, however, by exploring one particular struggle to show how frustration with civil society is being used by social justice activists to articulate ideas of ‘everyday’ violence to mobilise for change that disrupts the apparent normalisation of EJE

Non-renormalization of the full <VVA> correlator at two-loop order

By explicit calculation of the two-loop QCD corrections we show that for singlet axial and vector currents the full off-shell correlation function in the limit of massless fermions is proportional to the one-loop result, when calculated in the MS-bar scheme. By the same finite renormalization which is needed to make the one-loop anomaly exact to all orders, we arrive at the conclusion that two-loop corrections are absent altogether, for the complete correlator not only its anomalous part. In accordance with the one-loop nature of the correlator, one possible amplitude, which seems to be missing by accident at the one-loop level, also does not show up at the two-loop level.Comment: 6 pages, 1 figur

Explicit Results for the Anomalous Three Point Function and Non-Renormalization Theorems

Two-loop corrections for the correlator of the singlet axial and vector currents in QCD are calculated in the chiral limit for arbitrary momenta. Explicit calculations confirm the non-renormalization theorems derived recently by Vainshtein and Knecht et.al. We find that as in the one-loop case also at the two loops the correlator has only 3 independent form-factors instead of 4. From the explicit results we observe that the two-loop correction to the correlator is equal to the one-loop result times the constant factor C_2(R) alpha_s/pi in the MSbar scheme. This holds for the full correlator, for the anomalous longitudinal as well as for the non- anomalous thansversal amplitudes. The finite overall alpha_s dependent constant has to be normalized away by renormalizing the axial current according to Witten's algebraic/geometrical constraint on the anomalous Ward identity. Our observations, together with known facts, suggest that in perturbation theory the correlator is proportional to the one-loop term to all orders and that the non- renormalization theorem of the Adler-Bell-Jackiw anomaly carries over to the full correlator.Comment: 10 pages, 2 Postscript figures, uses axodraw.st

Scalable transactions in the cloud: partitioning revisited

Lecture Notes in Computer Science, 6427Cloud computing is becoming one of the most used paradigms to deploy highly available and scalable systems. These systems usually demand the management of huge amounts of data, which cannot be solved with traditional nor replicated database systems as we know them. Recent solutions store data in special key-value structures, in an approach that commonly lacks the consistency provided by transactional guarantees, as it is traded for high scalability and availability. In order to ensure consistent access to the information, the use of transactions is required. However, it is well-known that traditional replication protocols do not scale well for a cloud environment. Here we take a look at current proposals to deploy transactional systems in the cloud and we propose a new system aiming at being a step forward in achieving this goal. We proceed to focus on data partitioning and describe the key role it plays in achieving high scalability.This work has been partially supported by the Spanish Government under grant TIN2009-14460-C03-02 and by the Spanish MEC under grant BES-2007-17362 and by project ReD Resilient Database Clusters (PDTC/EIA-EIA/109044/2008)

Oncolytic Herpes Simplex Virus Inhibits Pediatric Brain Tumor Migration and Invasion

Paediatric high grade glioma (pHGG) and diffuse intrinsic pontine glioma (DIPG) are invasive tumours with poor survival. Oncolytic virotherapy, initially devised as a direct cytotoxic treatment, is now also known to act via immune-mediated mechanisms. Here we investigate a previously unreported mechanism of action – the inhibition of migration and invasion in paediatric brain tumours. We evaluated the effect of oncolytic herpes simplex virus 1716 (HSV1716) on the migration and invasion of pHGG and DIPG both in vitro using 2D (scratch assay, live cell imaging) and 3D (spheroid invasion in collagen) assays and in vivo using an orthotopic xenograft model of DIPG invasion. HSV1716 inhibited migration and invasion in pHGG and DIPG cell lines. pHGG cells demonstrated reduced velocity and changed morphology in the presence of virus. HSV1716 altered pHGG cytoskeletal dynamics by stabilising microtubules, inhibiting glycogen synthase kinase-3 and preventing localised clustering of adenomatous polyposis coli to the leading edge of cells. HSV1716 treatment also reduced tumour infiltration in a mouse orthotopic xenograft DIPG model. Our results demonstrate that HSV1716 targets the migration and invasion of pHGG and DIPG and indicates the potential of an oncolytic virus to be used as a novel anti-invasive treatment strategy for paediatric brain tumours

What can we learn from geographical comparisons of childhood cancer survival?

With improvements in treatment for childhood cancer, comparisons of survival rates between countries have become important to inform future health policies and treatment strategies. Population-based cancer registry data are viewed as the gold standard for such comparisons, but even these have potential confounding factors. Here, we review the interpretation of recent geographical comparisons of childhood cancer survival from the viewpoint of the British Isles, a region with a 45-year record of national population-based cancer registration and a national childhood cancer clinical trials organisation in place for nearly 30 years. Using national data on referral patterns to tertiary paediatric oncology centres, we explore some of the reasons for lower survival rates in the past for some tumour groups and anticipate continued improvement in the next decade. Participation in international clinical trials coincided with rapid gains in survival for hepatoblastoma. This exemplifies the potential benefits of international collaborative clinical research, particularly for rare subgroups

The Adler Function for Light Quarks in Analytic Perturbation Theory

The method of analytic perturbation theory, which avoids the problem of ghost-pole type singularities and gives a self-consistent description of both spacelike and timelike regions, is applied to describe the "light" Adler function corresponding to the non-strange vector channel of the inclusive decay of the $\tau$ lepton. The role of threshold effects is investigated. The behavior of the quark-antiquark system near threshold is described by using a new relativistic resummation factor. It is shown that the method proposed leads to good agreement with the ``experimental'' Adler function down to the lowest energy scale.Comment: 13 pages, one ps figure, REVTe

Variational Quark Mass Expansion and the Order Parameters of Chiral Symmetry Breaking

We investigate in some detail a "variational mass" expansion approach, generalized from a similar construction developed in the Gross-Neveu model, to evaluate the basic order parameters of the dynamical breaking of the $SU(2)_L \times SU(2)_R$ and $SU(3)_L \times SU(3)_R$ chiral symmetries in QCD. The method starts with a reorganization of the ordinary perturbation theory with the addition of an arbitrary quark mass $m$. The new perturbative series can be summed to all orders thanks to renormalization group properties, with specific boundary conditions, and advocated analytic continuation in $m$ properties. In the approximation where the explicit breakdown of the chiral symmetries due to small current quark masses is neglected, we derive ansatzes for the dynamical contribution to the "constituent" masses $M_q$ of the $u,d,s$ quarks; the pion decay constant $F_\pi$; and the quark condensate $$ in terms of the basic QCD scale $\Lambda_{\bar{MS}}$. Those ansatzes are then optimized, in a sense to be specified, and also explicit symmetry breaking mass terms can be consistently introduced in the framework. The obtained values of $F_\pi$ and $M_q$ are roughly in agreement with what is expected from other non-perturbative methods. In contrast we obtain quite a small value of $|< \bar q q >|$ within our approach. The possible interpretation of the latter results is briefly discussed.Comment: 40 pages, LaTex, 2 PS figures. Additions in section 2.2 to better explain the relation between the current mass and the dynamical mass ansatz. Minor misprints corrected. Version to appear in Phys. Rev.

IgTM: An algorithm to predict transmembrane domains and topology in proteins

<p>Abstract</p> <p>Background</p> <p>Due to their role of receptors or transporters, membrane proteins play a key role in many important biological functions. In our work we used Grammatical Inference (GI) to localize transmembrane segments. Our GI process is based specifically on the inference of Even Linear Languages.</p> <p>Results</p> <p>We obtained values close to 80% in both specificity and sensitivity. Six datasets have been used for the experiments, considering different encodings for the input sequences. An encoding that includes the topology changes in the sequence (from inside and outside the membrane to it and vice versa) allowed us to obtain the best results. This software is publicly available at: <url>http://www.dsic.upv.es/users/tlcc/bio/bio.html</url></p> <p>Conclusion</p> <p>We compared our results with other well-known methods, that obtain a slightly better precision. However, this work shows that it is possible to apply Grammatical Inference techniques in an effective way to bioinformatics problems.</p