Purification of TrkA intracellular domain and the characterization of novel intracellular proteins : a thesis presented in partial fulfilment of the requirements for the degree of Masters of Science in Molecular Biology at Massey University

Nerve growth factor (NGF) binds to its receptor, TrkA, at the tips of nerve cell axons to inhibit apoptosis, causing survival and differentiation. Some factors within this process are largely unknown, such as the role of the p75 receptor and the molecular mechanisms that occur within the cell. NGF binding causes dimerization of TrkA, which activates the intracellular kinase domain. Autophosphorylation on tyrosine residues stimulates binding to the receptor of several intracellular proteins that mediate the NGF response. This receptor complex has been demonstrated to be retrogradely transported to the cell body. Retrograde transport is hypothesized to occur in small vesicles that have been isolated in our lab using a cell fractionation protocol using in vitro reactions with an ATP regenerating system. Discovering the initial molecular interactions that occur upon NGF binding could further our knowledge of NGF's inhibition of apoptosis, providing us with a possible tool for treatment of diseases that occur when the regulation of apoptosis no longer exists. Novel proteins that were not previously identified were associated with TrkA in small vesicles after NGF activation. To isolate these proteins for further characterization, TrkA's intracellular domain (TrkAID) was expressed in E. Coli. This protein was found to be constitutively tyrosine-phosphorylated and therefore presumably active. In E.Coli, TrkAID protein was localized to the soluble fraction but smaller amounts were detected in the insoluble fraction. TrkAID was partially purified from the soluble fraction using a combination of salt disruption and denaturing techniques. The unpurified TrkAID was immunoprecipitated from the bacterial soluble fraction with an antibody to the C-terminus of TrkA, and some results suggest that immunoprecipitated TrkAID was able to stimulate ERK activation in untreated PC12 cells, but unfortunately this was not reproducible. If the protein could be purified with a combination of techniques, then it would provide a useful tool for studying the initial events in NGF stimulation, that is, the recruitment of several intracellular proteins to the tyrosine-phosphorylated intracellular domain of TrkA

Higher categories, colimits, and the blob complex

We summarize our axioms for higher categories, and describe the blob complex. Fixing an n-category C, the blob complex associates a chain complex B_*(W;C)$ to any n-manifold W. The 0-th homology of this chain complex recovers the usual topological quantum field theory invariants of W. The higher homology groups should be viewed as generalizations of Hochschild homology (indeed, when W=S^1 they coincide). The blob complex has a very natural definition in terms of homotopy colimits along decompositions of the manifold W. We outline the important properties of the blob complex, and sketch the proof of a generalization of Deligne's conjecture on Hochschild cohomology and the little discs operad to higher dimensions.Comment: 7 page

The centre of the extended Haagerup subfactor has 22 simple objects

We explain a technique for discovering the number of simple objects in $Z(C)$, the center of a fusion category $C$, as well as the combinatorial data of the induction and restriction functors at the level of Grothendieck rings. The only input is the fusion ring $K(C)$ and the dimension function $K(C) \to \mathbb{C}$. The method is not guaranteed to succeed (it may give spurious answers besides the correct one, or it may simply take too much computer time), but it seems it often does. We illustrate by showing that there are 22 simple objects in the center of the extended Haagerup subfactor [arXiv:0909.4099].Comment: 10 page

Retailing under resale price maintenance: economies of scale and scope, and firm strategic response, in the inter-war British retail pharmacy sector

The article examines the impact of resale price maintenance (RPM) on market structure, productivity, and competitive advantage in British retail pharmacy. In contrast to influential studies, but consistent with contemporary and recent work, it is shown that the major multiples were able to ameliorate the negative growth impacts of RPM. Higher profit margins ‒ principally from larger manufacturer discounts and backward integration – were used to fund initiatives aimed at boosting aggregate sales and economies of scale and scope. These relationships are explored using a recently discovered national establishment-level survey of retail pharmacists’ costs and margins, together with internal data for Boots Ltd

Sales and Advertising Rivalry in Interwar US Department Stores

Department stores represented one of the most advertising-intensive sectors of American inter-war retailing. Yet it has been argued that a competitive spiral of high advertising spending, to match the challenge of other local department stores, contributed to a damaging inflation of costs that eroded long-term competitiveness. We test these claims, using both qualitative archival data and establishment-level national data sets. Returns to stores’ advertising are shown to have fallen over the period, while own advertising led to retaliatory advertising by rival department stores, which substantially lowered returns on advertising dollars in the 1930s (but not the 1920s).Department stores, Interwar U.S. economic history, Advertising, Marketing

Advertising, promotion, and the competitive advantage of interwar UK department stores

Promotional activity proved key to the success of department stores in fending off competition from the expanding chain stores by drawing in customers to their large, central, premises. This paper uses a combination of quantitative and qualitative archival data to examine the promotional methods of interwar British department stores, variations in the promotional mix between types of store, and returns to promotional activities. A number of distinct regional promotional strategies are identified, shaped by variations in the types of consumer markets served. Meanwhile there was considerable policy convergence among stores towards using promotional activity primarily as a means of imprinting a strong institutionalrand image in the minds of the consuming public.advertising, promotion, mail order, retailing, department stores

Reggae to Rachmaninoff: How and Why People Participate in Arts and Culture

Provides the results of a telephone survey conducted to help inform those whose aim is to broaden and diversify cultural participation, and promote the role of arts and culture in strengthening American communities

Man and machine thinking about the smooth 4-dimensional Poincar\'e conjecture

While topologists have had possession of possible counterexamples to the smooth 4-dimensional Poincar\'{e} conjecture (SPC4) for over 30 years, until recently no invariant has existed which could potentially distinguish these examples from the standard 4-sphere. Rasmussen's s-invariant, a slice obstruction within the general framework of Khovanov homology, changes this state of affairs. We studied a class of knots K for which nonzero s(K) would yield a counterexample to SPC4. Computations are extremely costly and we had only completed two tests for those K, with the computations showing that s was 0, when a landmark posting of Akbulut (arXiv:0907.0136) altered the terrain. His posting, appearing only six days after our initial posting, proved that the family of ``Cappell--Shaneson'' homotopy spheres that we had geared up to study were in fact all standard. The method we describe remains viable but will have to be applied to other examples. Akbulut's work makes SPC4 seem more plausible, and in another section of this paper we explain that SPC4 is equivalent to an appropriate generalization of Property R (``in S^3, only an unknot can yield S^1 x S^2 under surgery''). We hope that this observation, and the rich relations between Property R and ideas such as taut foliations, contact geometry, and Heegaard Floer homology, will encourage 3-manifold topologists to look at SPC4.Comment: 37 pages; changes reflecting that the integer family of Cappell-Shaneson spheres are now known to be standard (arXiv:0907.0136

Promoting Component Reuse by Separating Transmission Policy from Implementation

In this paper we present a methodology and set of tools which assist the construction of applications from components, by separating the issues of transmission policy from component definition and implementation. This promotes a greater degree of software reuse than is possible using traditional middleware environments. Whilst component technologies are usually presented as a mechanism for promoting reuse, reuse is often limited due to design choices that permeate component implementation. The programmer has no direct control over inter-address-space parameter passing semantics: it is fixed by the distributed application's structure, based on the remote accessibility of the components. Using traditional middleware tools and environments, the application designer may be forced to use an unnatural encoding of application level semantics since application parameter passing semantics are tightly coupled with the component deployment topology. This paper describes how inter-address-space parameter passing semantics may be decided independently of component implementation. Transmission policy may be dynamically defined on a per-class, per-method or per-parameter basis.Comment: Submitted to ICDCS 200

Long, paired A'A/Pahoehoe flows of Mauna Loa: Volcanological significance and insights they provide into volcano plumbing systems

The long lava flows of Mauna Loa, Hawaii have been cited as Earth's closed analogs to the large Martian flows. It is therefore important to understand the flow mechanics and characteristics of the Mauna Loa flows and to make use of these in an attempt to gain insights into Martian eruptive processes. Two fundamentally different kinds of long lava flows can be distinguished on Hawaiian volcanoes as in Martian flows. The two kinds may have identical initial viscosities, chemical compositions, flow lengths, and flow volumes, but their flow mechanisms and thermal energy budgets are radically different. One travels a distance set by the discharge rate as envisaged by Walker and Wadge, and the other travels a distance set mainly by the eruption duration and ground slope. In the Mauna Loa lavas, yield strength becomes an important flow morphology control only in the distal part of a'a lavas. The occurrence of paired flows on Mauna Loa yields insights into the internal plumbing systems of the volcano, and it is significant that all of the volume of the a'a flow must be stored in a magma chamber before eruption, while none of the volume of the pahoehoe needs to be so stored. Differentiation between the two kinds of flows on images of Martian volcanoes is possible and hence an improved understanding of these huge structures is acquired