A post-structural analysis of perceptions and experiences of continuity and change within the UK automotive supplier base

Firms acting as suppliers to the British automotive industry have a long history of so doing, with some evidencing histories that predate even the invention of the motor car. In exploring the challenges faced by the descendants of these firms in the 1990s, a review is undertaken of the bodies of literature surrounding the changes wrought through the increased globalisation of the industry; the impact of new manufacturing technologies and techniques; the rising levels of co-operation between firms; and the growing impact of the automotive 'service sector'. Moreover, an exploration is undertaken of the perceived 'realities' of the automotive industry as constructed through discourse, including the ways in which discourse effects a continual reinterpretation and re-evaluation of the historical evolution of the industry. Attention is focused on the implications of the above for the automotive supply chain, and the means for its rationalisation proposed by the major car manufacturers and their partner-suppliers. Post-structuralist approaches are introduced as part of an attempt to establish and appropriate research methodology that can explore and deconstruct the discourses surrounding 'modernity', 'supply chain rationalisation', 'flexible specialisation' and 'globalisation' within the automotive industry. Analytical research is conducted into the small- to medium-sized business that constitute the majority of the supplier base in the United Kingdom, and the findings of this research are compared with those of a similar study conducted a quarter-century ago. In this way, the relationships of these firms with their customers, suppliers, and peers are investigated, as are their perceptions of a changing marketplace and their reactions to the impact of policies such as the 'supply chain rationalisation' pursued by the major automotive manufacturers. Authoritative discourses of industry form, function, and structure are challenged, with voice being granted to the marginalised: small suppliers, 'service sector' firms, or those only partly involved in the automotive industry.

Progressive structural analysis for dynamic recognition of on-line handwritten mathematical expressions

Structural analysis in handwritten mathematical expressions focuses on interpreting the recognized symbols using geometrical information such as relative sizes and positions of the symbols. Most existing approaches rely on hand-crafted grammar rules to identify semantic relationships among the recognized mathematical symbols. They could easily fail when writing errors occurred. Moreover, they assume the availability of the whole mathematical expression before being able to analyze the semantic information of the expression. To tackle these problems, we propose a progressive structural analysis (PSA) approach for dynamic recognition of handwritten mathematical expressions. The proposed PSA approach is able to provide analysis result immediately after each written input symbol. This has an advantage that users are able to detect any recognition errors immediately and correct only the mis-recognized symbols rather than the whole expression. Experiments conducted on 57 most commonly used mathematical expressions have shown that the PSA approach is able to achieve very good performance results.

Structural Analysis of Contours as the Sequences of the Digital Straight Segments and of the Digital Curve Arcs

Recognition of the object contours in the image as sequences of digital straight segments and/or digital curve arcs is considered in this article. The definitions of digital straight segments and of digital curve arcs are proposed. The methods and programs to recognize the object contours are represented. The algorithm to recognize the digital straight segments is formulated in terms of the growing pyramidal networks taking into account the conceptual model of memory and identification (Rabinovich [4]).

Frameworks for Systemic and Structural Analysis of Financial Innovations in Infrastructure

Financial innovations have emerged globally to close the gap between the rising global demand for infrastructures and the availability of financing sources offered by traditional financing mechanisms such as fuel taxation, tax-exempt bonds, and federal and state funds. The key to sustainable innovative financing mechanisms is effective policymaking. This paper discusses the theoretical framework of a research study whose objective is to structurally and systemically assess financial innovations in global infrastructures. The research aims to create analysis frameworks, taxonomies and constructs, and simulation models pertaining to the dynamics of the innovation process to be used in policy analysis. Structural assessment of innovative financing focuses on the typologies and loci of innovations and evaluates the performance of different types of innovative financing mechanisms. Systemic analysis of innovative financing explores the determinants of the innovation process using the System of Innovation approach. The final deliverables of the research include propositions pertaining to the constituents of System of Innovation for infrastructure finance which include the players, institutions, activities, and networks. These static constructs are used to develop a hybrid Agent-Based/System Dynamics simulation model to derive propositions regarding the emergent dynamics of the system. The initial outcomes of the research study are presented in this paper and include: (a) an archetype for mapping innovative financing mechanisms, (b) a System of Systems-based analysis framework to identify the dimensions of Systems of Innovation analyses, and (c) initial observations regarding the players, institutions, activities, and networks of the System of Innovation in the context of the U.S. transportation infrastructure financing.

Structural Analysis and Form-Finding of Mycelium-Based Monolithic Domes

As sustainability becomes an integral design driver for current civil structures, new materials and forms are investigated. The aim of this study is to investigate analytically and numerically the mechanical behavior of monolithic domes composed of mycological fungi. The study focuses on hemispherical and elliptical forms, as the most typical solution for domes. The influence of different types of loading, geometrical parameters, material properties and boundary conditions is investigated in this study. For the cases covered by the classical shell theory, a comparison between the analytical and the finite element solution is given. Two case studies regarding the dome of basilica of “San Luca” (Bologna, Italy) and the dome of sanctuary of “Vicoforte” (Vicoforte, Italy) are included. After the linear analysis under loading, buckling is also investigated as a critical type of failure through a parametric study using finite elements model. Since shells rely on their shape, form-found domes are also investigated and a comparison between the behavior of the form-found domes and the hemispherical domes under the linear and buckling analysis is conducted. From the analysis it emerges that form-finding can enhance the structural response of mycelium-based domes, although buckling becomes even more critical for their design. Furthermore, an optimal height to span ratio for the buckling of form-found domes is identified. This study highlights the importance of investigating appropriate forms for the design of novel biomaterial-based structures.

Spectroscopic and structural analysis of somatic and N-domain angiotensin I-converting enzyme isoforms from mesangial cells from Wistar and spontaneously hypertensive rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

STRUCTURAL ANALYSIS OF RIBOSOME BINDING ELEMENTS OF THE 3´ UTR IN TWO POSITIVE-STRAND PLANT RNA VIRUSES

Turnip crinkle virus (TCV) and Pea enation mosaic virus (PEMV) are two positive (+)-strand RNA viruses that are used to investigate the regulation of translation and replication due to their small size and simple genomes. Both viruses contain cap-independent translation elements (CITEs) within their 3´ untranslated regions (UTRs) that fold into tRNA-shaped structures (TSS) according to nuclear magnetic resonance and small angle x-ray scattering analysis (TCV) and computational prediction (PEMV). Specifically, the TCV TSS can directly associate with ribosomes and participates in RNA-dependent RNA polymerase (RdRp) binding. The PEMV kissing-loop TSS (kl-TSS) can simultaneously bind to ribosomes and associate with the 5´ UTR of the viral genome. Mutational analysis and chemical structure probing methods provide great insight into the function and secondary structure of the two 3´ CITEs. However, lack of 3-D structural information has limited our understanding of their functional dynamics. Here, I report the folding dynamics for the TCV TSS using optical tweezers (OT), a single molecule technique. My study of the unfolding/folding pathways for the TCV TSS has provided an unexpected unfolding pathway, confirmed the presence of Ψ3 and hairpin elements, and suggested an interconnection between the hairpins and pseudoknots. In addition, this study has demonstrated the importance of the adjacent upstream adenylate-rich sequence for the formation of H4a/Ψ3 along with the contribution of magnesium to the stability of the TCV TSS. In my second project, I report on the structural analysis of the PEMV kl-TSS using NMR and SAXS. This study has re-confirmed the base-pair pattern for the PEMV kl-TSS and the proposed interaction of the PEMV kl-TSS with its interacting partner, hairpin 5H2. The molecular envelope of the kl-TSS built from SAXS analysis suggests the kl-TSS has two functional conformations, one of which has a different shape from the previously predicted tRNA-shaped form. Along with applying biophysical methods to study the structural folding dynamics of RNAs, I have also developed a technique that improves the production of large quantities of recombinant RNAs in vivo for NMR study. In this project, I report using the wild-type and mutant E.coli strains to produce cost-effective, site-specific labeled, recombinant RNAs. This technique was validated with four representative RNAs of different sizes and complexity to produce milligram amounts of RNAs. The benefit of using site-specific labeled RNAs made from E.coli was demonstrated with several NMR techniques.

Studies on the synthesis of novel PP2A inhibitors and a GPCR detergent

Chapter 1 While targeting kinases in oncology research has been explored extensively, targeting protein phosphatases is currently in its infancy. However, a number of pharmaceutical companies are currently looking to expand their research efforts in this area. PP2A has been shown to down-regulate ERK5, a mitogen-activated protein kinase (MAPK) that has been shown to be important in driving the invasive phenotype of prostate cancer. Fostriecin and its related structural analogues PD 113,270 and 113,271 have been shown to inhibit a mitotic entry checkpoint in cell growth through the potent and selective inhibition of protein phosphatases PP1, PP2A, and PP4 (IC50 of 45 μM, 1.5 nM, and 3 nM respectively). Fostriecin is one of the most selective protein phosphatase inhibitors disclosed to date with a 104 fold selectivity for PP2A/PP4 versus PP1. Unfortunately, fostriecin and its analogues are very unstable, and this instability has effectively prevented them from being used as effective therapeutic leads. The microcystins and nodularins on the other hand, exhibit significant inhibitory activity against PP1 and PP2A (IC50 = 26 pM and 1.8 nM respectively), but their high toxicity has prevented any therapeutic application. Truncation of the ADDA chain from these polypeptides completely attenuates PP inhibitory activity. Simpler analogues incorporating the N-acylated ADDA chain and D-Ala retain moderate activity against PP1 and PP2A (IC50 = 1.0 μM and 0.17 μM respectively). The generation of a new series of fostriecin analogues to further expand its structure-activity relationship is envisaged with a view to creating new more stable PP2A inhibitors. It was hoped that by incorporating some of the more stable structural features of ADDA into fostriecin that stability and activity could be reconciled. With that in mind a series of PP2A inhibitors were synthesised and biologically evaluated. Chapter 2 GPCRs are an important area of research and are the targets of a quarter of the drugs on the market (2005). As a result, GPCRs continue to be at the forefront of research in both small and large drug companies. However one of the difficulties in studying this diverse class of membrane proteins is their tendency to denature in aqueous solution. As a result there is a pressing need to develop new detergents to solubilise, stabilise and crystallise GPCRs in their native form for further study. Cholesterol analogues have been shown to be important for stabilising membrane proteins and preventing their thermal inactivation. In addition the β2-adrenergic receptor, a GPCR membrane protein, has been crystallised in the active state with two cholesterol molecules bound between the I, II, III and IV helices of the protein. This appears to represent a distinct cholesterol binding pocket on the membrane protein that is speculated to be conserved across up to 44% of the rhodopsin class of GPCRs. CHOBIMALT is a cholesterol-based detergent that has been shown to exhibit promising GPCR-stabilising properties. When benchmarked against other cholesterol based detergents it was found to be superior to all others tested except for cholesteryl hemisuccinate.1 CHOBIMALT has an aggregation number of roughly 200 and forms 210 ± 30 kDa micelles, which are significantly larger than those of most detergents used for biological systems which is likely due to the packing constraints associated with CHOBMALT’s large polar headgroup.2 As a result, CHOBIMALT is used mostly as an additive to other commercially available detergents in order to decrease micelle size. A branched dimaltoside motif is common in recently synthesised detergents by Chae and co-workers. These detergents have shown promising detergent properties, for example the maltose neopentyl glycol (MNG) detergent synthesised by Chae. This branched dimaltoside detergent was shown to be able to solubilise and stabilise the very labile light harvesting complex I (LHI) from Rhodopsin capsulatus in its active form for 20 days with little loss of protein conformation.3 A cholesterol-based detergent was envisaged that combines the cholesterol framework of CHOBIMALT but replaces its linear tetrasaccharide with a branched dimaltoside. This detergent would then be investigated to assess its ability to solubilise, stabilise and crystallise GPCR proteins. This cholesterol-based detergent (shown below) was eventually synthesised in 9 linear steps from cholesterol.

Graph-based structural analysis of planar mechanisms.

Kinematic structure of planar mechanisms addresses the study of attributes determined exclusively by the joining pattern among the links forming a mechanism. The system group classification is central to the kinematic structure and consists of determining a sequence of kinematically and statically independent-simple chains which represent a modular basis for the kinematics and force analysis of the mechanism. This article presents a novel graph-based algorithm for structural analysis of planar mechanisms with closed-loop kinematic structure which determines a sequence of modules (Assur groups) representing the topology of the mechanism. The computational complexity analysis and proof of correctness of the implemented algorithm are provided. A case study is presented to illustrate the results of the devised method.

Thylakoid Protein Phosphorylation in Regulation of Photosynthesis

Once the seed has germinated, the plant is forced to face all the environmental changes in its habitat. In order to survive, plants have evolved a number of different acclimation systems. The primary reaction behind plant growth and development is photosynthesis. Photosynthesis captures solar energy and converts it into chemical form. Photosynthesis in turn functions under the control of environmental cues, but is also affected by the growth, development, and metabolic state of a plant. The availability of solar energy fluctuates continuously, requiring non-stop adjustment of photosynthetic efficiency in order to maintain the balance between photosynthesis and the requirements and restrictions of plant metabolism. Tight regulation is required, not only to provide sufficient energy supply but also to prevent the damage caused by excess energy. The very first reaction of photosynthesis is splitting of water into the form of oxygen, hydrogen, and electrons. This most fundamental reaction of life is run by photosystem II (PSII), and the energy required for the reaction is collected by the light harvesting complex II (LHCII). Several proteins of the PSII-LHCII complex are reversibly phosphorylated according to the energy balance between photosynthesis and metabolism. Thylakoid protein phosphorylation has been under extensive investigation for over 30 years, yet the physiological role of phosphorylation remains elusive. Recently, the kinases behind the phosphorylation of PSII-LHCII proteins (STN7 and STN8) were identified and the knockout mutants of these kinases became available, providing powerful tools to elucidate the physiological role of PSII-LHCII phosphorylation. In my work I have used the stn7 and stn8 mutants in order to clarify the role of PSII-LHCII phosphorylation in regulation and protection of the photosynthetic machinery according to environmental cues. I show that STN7- dependent PSII-LHCII protein phosphorylation is required to balance the excitation energy distribution between PSII and PSI especially under low light intensities when the excitation energy transfer from LHC to PSII and PSI is efficient. This mechanism differs from traditional light quality-induced “state 1” – “state 2” transition and ensures fluent electron transfer from PSII to PSI under low light, yet having highest physiological relevance under fluctuating light intensity. STN8-dependent phosphorylation of PSII proteins, in turn, is required for fluent turn-over of photodamaged PSII complexes and has the highest importance upon prolonged exposure of the photosynthetic apparatus to excess light.

Regulation of photosynthetic electron transfer in plant chloroplasts

This thesis focuses on the molecular mechanisms regulating the photosynthetic electron transfer reactions upon changes in light intensity. To investigate these mechanisms, I used mutants of the model plant Arabidopsis thaliana impaired in various aspects of regulation of the photosynthetic light reactions. These included mutants of photosystem II (PSII) and light harvesting complex II (LHCII) phosphorylation (stn7 and stn8), mutants of energy-dependent non-photochemical quenching (NPQ) (npq1 and npq4) and of regulation of photosynthetic electron transfer (pgr5). All of these processes have been extensively investigated during the past decades, mainly on plants growing under steady-state conditions, and therefore many aspects of acclimation processes may have been neglected. In this study, plants were grown under fluctuating light, i.e. the alternation of low and high intensities of light, in order to maximally challenge the photosynthetic regulatory mechanisms. In pgr5 and stn7 mutants, the growth in fluctuating light condition mainly damaged PSI while PSII was rather unaffected. It is shown that the PGR5 protein regulates the linear electron transfer: it is essential for the induction of transthylakoid ΔpH that, in turn, activates energy-dependent NPQ and downregulates the activity of cytochrome b6f. This regulation was shown to be essential for the photoprotection of PSI under fluctuations in light intensity. The stn7 mutants were able to acclimate under constant growth light conditions by modulating the PSII/PSI ratio, while under fluctuating growth light they failed in implementing this acclimation strategy. LHCII phosphorylation ensures the balance of the excitation energy distribution between PSII and PSI by increasing the probability for excitons to be trapped by PSI. LHCII can be phosphorylated over all of the thylakoid membrane (grana cores as well as stroma lamellae) and when phosphorylated it constitutes a common antenna for PSII and PSI. Moreover, LHCII was shown to work as a functional bridge that allows the energy transfer between PSII units in grana cores and between PSII and PSI centers in grana margins. Consequently, PSI can function as a quencher of excitation energy. Eventually, the LHCII phosphorylation, NPQ and the photosynthetic control of linear electron transfer via cytochrome b6f work in concert to maintain the redox poise of the electron transfer chain. This is a prerequisite for successful plant growth upon changing natural light conditions, both in short- and long-term.

The Fast Regulation of Photosynthesis in Diatoms: an inquiry into the physiological and physical origins of non-photochemical chlorophyll fluorescence quenching.

Diatoms are renowned for their robust ability to perform NPQ (Non-Photochemical Quenching of chlorophyll fluorescence) as a dissipative response to heightened light stress on photosystem II, plausibly explaining their dominance over other algal groups in turbulent light environs. Their NPQ mechanism has been principally attributed to a xanthophyll cycle involving the lumenal pH regulated reversible de-epoxidation of diadinoxanthin. The principal goal of this dissertation is to reveal the physiological and physical origins and consequences of the NPQ response in diatoms during short-term transitions to excessive irradiation. The investigation involves diatom species from different originating light environs to highlight the diversity of diatom NPQ and to facilitate the detection of core mechanisms common among the diatoms as a group. A chiefly spectroscopic approach was used to investigate NPQ in diatom cells. Prime methodologies include: the real time monitoring of PSII excitation and de-excitation pathways via PAM fluorometry and pigment interconversion via transient absorbance measurements, the collection of cryogenic absorbance spectra to measure pigment energy levels, and the collection of cryogenic fluorescence spectra and room temperature picosecond time resolved fluorescence decay spectra to study excitation energy transfer and dissipation. Chemical inhibitors that target the trans-thylakoid pH gradient, the enzyme responsible for diadinoxanthin de-epoxidation, and photosynthetic electron flow were additionally used to experimentally manipulate the NPQ response. Multifaceted analyses of the NPQ responses from two previously un-photosynthetically characterised species, Nitzschia curvilineata and Navicula sp., were used to identify an excitation pressure relief ‘strategy’ for each species. Three key areas of NPQ were examined: (i) the NPQ activation/deactivation processes, (ii) how NPQ affects the collection, dissipation, and usage of absorbed light energy, and (iii) the interdependence of NPQ and photosynthetic electron flow. It was found that Nitzschia cells regulate excitation pressure via performing a high amplitude, reversible antenna based quenching which is dependent on the de-epoxidation of diadinoxanthin. In Navicula cells excitation pressure could be effectively regulated solely within the PSII reaction centre, whilst antenna based, diadinoxanthin de-epoxidation dependent quenching was implicated to be used as a supplemental, long-lasting source of excitation energy dissipation. These strategies for excitation balance were discussed in the context of resource partitioning under these species’ originating light climates. A more detailed investigation of the NPQ response in Nitzschia was used to develop a comprehensive model describing the mechanism for antenna centred non-photochemical quenching in this species. The experimental evidence was strongly supportive of a mechanism whereby: an acidic lumen triggers the diadinoxanthin de-epoxidation and protonation mediated aggregation of light harvesting complexes leading to the formation of quencher chlorophyll a-chlorophyll a dimers with short-lived excited states; quenching relaxes when a rise in lumen pH triggers the dispersal of light harvesting complex aggregates via deprotonation events and the input of diadinoxanthin. This model may also be applicable for describing antenna based NPQ in other diatom species.