Family resemblances? Ligand binding and activation of family A and B G-protein-coupled receptors

In April 2007, the Biochemical Society held a meeting to compare and contrast ligand binding and activation of Family A and B GPCRs (G-protein-coupled receptors). Being the largest class, Family A GPCRs usually receive the most attention, although a previous Biochemical Society meeting has focused on Family B GPCRs. The aim of the present meeting was to bring researchers of both families together in order to identify commonalities between the two. The present article introduces the proceedings of the meeting, briefly commenting on the focus of each of the following articles. ©The Authors.

Testing for market segmentation in the A and B share markets of China

Recent research has suggested that the A and B share markets of China may be informationally segmented. In this paper volatility patterns in the A and B share market are studied to establish whether volatility changes to the A and B share markets are synchronous. A consequence of new information, when investors act upon it is that volatility rises. This means that if the A and B markets are perfectly integrated volatility changes to each market would be expected to occur at the same time. However, if they are segmented there is no reason for volatility changes to occur on the same day. Using the iterative cumulative sum of squares across the different markets. Evidence is found of integration between the two A share markets but not between the A and B markets. © 2005 Taylor & Francis Group Ltd.

Orexin-stimulated MAP kinase cascades are activated through multiple G-protein signalling pathways in human H295R adrenocortical cells: diverse roles for orexins A and B

Orexins A and B (ORA and ORB) are neuropeptide hormones found throughout the central nervous system and periphery. They are required for a host of physiological processes including mitogen-activated protein kinase (MAPK) regulation, steroidogenesis, appetite control and energy regulation. While some signalling mechanisms have been proposed for individual recombinant orexin receptors in generic mammalian cell types, it is clear that the peripheral effects of orexin are spatially and temporally complex. This study dissects the different G-protein signalling and MAPK pathways activated in a pluripotent human adrenal H295R cell line capable of all the physiological steps involved in steroidogenesis. Both extracellular receptor kinase 1/2 (ERK1/2) and p38 were phosphorylated rapidly with a subsequent decline, in a time- and dose-dependent manner, in response to both ORA and ORB. Conversely, there was little or no direct activation of the ERK5 or JNK pathway. Analysis using signalling and MAPK inhibitors as well as receptor-specific antagonists determined the precise mediators of the orexin response in these cells. Both ERK1/2 and p38 activation were predominantly Gq- and to a lesser extent Gs-mediated; p38 activation even had a small Gi-component. Effects were broadly comparable for both orexin sub-types ORA and ORB and although most of the effects were transmitted through the orexin receptor-1 subtype, we did observe a role for orexin receptor-2-mediated activation of both ERK1/2 and p38. Cortisol secretion also differed in response to ORA and ORB. These data suggest multiple roles for orexin-mediated MAPK activation in an adrenal cell-line, this complexity may help to explain the diverse biological actions of orexins with wide-ranging consequences for our understanding of the mechanisms initiated by these steroidogenic molecules.

Automobile friction materials: a test instrument and technique for determining dynamic mechanical properties in relation to brake squeal

This study is primarily concerned with the problem of break-squeal in disc brakes, using moulded organic disc pads. Moulded organic friction materials are complex composites and due to this complexity it was thought that they are unlikely to be of uniform composition. Variation in composition would under certain conditions of the braking system, cause slight changes in its vibrational characteristics thus causing resonance in the high audio-frequency range. Dynamic mechanical propertes appear the most likely parameters to be related to a given composition's tendency to promote squeal. Since it was necessary to test under service conditions a review was made of all the available commercial test instruments but as none were suitable it was necessary to design and develop a new instrument. The final instrument design, based on longitudinal resonance, enabled modulus and damping to be determined over a wide range of temperatures and frequencies. This apparatus has commercial value since it is not restricted to friction material testing. Both used and unused pads were tested and although the cause of brake squeal was not definitely established, the results enabled formulation of a tentative theory of the possible conditions for brake squeal. The presence of a temperature of minimum damping was indicated which may be of use to braking design engineers. Some auxilIary testing was also performed to establish the effect of water, oil and brake fluid and also to determine the effect of the various components of friction materials.

Fiber Bragg gratings of type I in SMF-28 and B/Ge fibre and type IIA B/Ge fibre under gamma radiation up to 0.54 MGy

The sensitivities of type I and IIA fibre Bragg gratings written to different reflectivities in SMF-28 and B/Ge fibres to ionizing radiation up to 0.54MGy are investigated. The Bragg wavelength shows a small and rapid increase at the start of irradiation followed by either a plateau (type I) or a decrease (type IIA).

Real options in multinational decision-making:managerial awareness and risk implications

This paper addresses the theme of real options decision-making in multinational corporations (MNCs) and stresses the role of real options attention and managerial learning in company performance. Using a sample of 278 large MNCs with categorised degrees of managerial real options awareness, we examine the risk implications of switching options in multinational operations, and explore the extent to which the real options logic can be classified as “best practice” in decision-making and risk management. Our results reveal that MNCs which have high managerial awareness about their real options are able to reduce their downside risk through multinationality, organisational slack and other firm characteristics. This finding does not apply fully to MNCs without evidence of such an awareness. Also, although real options awareness does not systematically guarantee lower downside risk from operations, supplementary results indicate that MNCs with evidence of significant investment in the acquisition of real options knowledge tend to outperform competitors that are unaware of their real options. This suggests that if real options are explored and exploited appropriately, real options decision-making can result into superior performance for MNCs in the long-term.

Computer based approaches to managerial decision making:optimism, heuristics and simulation

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Fiber Bragg gratings of type I in SMF-28 and B/Ge fibre and type IIA B/Ge fibre under gamma radiation up to 0.54 MGy

The sensitivities of type I and IIA fibre Bragg gratings written to different reflectivities in SMF-28 and B/Ge fibres to ionizing radiation up to 0.54MGy are investigated. The Bragg wavelength shows a small and rapid increase at the start of irradiation followed by either a plateau (type I) or a decrease (type IIA).

Governance in foreign policy-making in Germany and Poland and Polish-German relations:the role of non-state actors

This thesis examines the influence of non-state actors on Polish-German relations by considering foreign policy-making towards Poland in Germany and vice versa. The approach chosen for this thesis is interdisciplinary and takes into consideration literature from domestic politics (Area Studies), Foreign Policy Analysis and International Relations (IR). The thesis argues that IR, by purely looking into the quality of inter-state relations, too often treats these relations as a result of policies emanating from the relevant governments, without considering the policies’ background. Therefore, the thesis argues that it is necessary to engage with the domestic factors which might explain where foreign policies come from. It points out that non-state actors influence governments’ choices by supplying resources, and by cooperating or competing with the government on an issue at stake. In order to determine the degree of influence that non-state actors can have on foreign policymaking two variables are examined: the institutionalisation of the state relations in question; and the domestic structures of the relevant states. Specifically, the thesis examines the institutionalisation of Polish-German relations, and examines Germany’s and Poland’s domestic structures and their effect on the two states’ foreign policy-making in general. Thereafter, the thesis uses case studies in order to unravel the influence of non-state actors on specific foreign policies. Three case studies are examined in detail: (i) Poland’s EU accession negotiations with regard to the free movement of capital chapter of the acquis communautaire; (ii) Germany’s EU 2004 Eastern Enlargement negotiations with regard to the free movement of workers chapter of the acquis communautaire; and (iii) Germany’s decision to establsh a permanent exhibition in Berlin that will depict the expulsions of millions of Germans from the East following WWII.

Uncovering the root cause of ethnic difference in ability testing:differential test functioning, test familiarity and trait optimism as explanations of ethnic group differences

The present research represents a coherent approach to understanding the root causes of ethnic group differences in ability test performance. Two studies were conducted, each of which was designed to address a key knowledge gap in the ethnic bias literature. In Study 1, both the LR Method of Differential Item Functioning (DIF) detection and Mixture Latent Variable Modelling were used to investigate the degree to which Differential Test Functioning (DTF) could explain ethnic group test performance differences in a large, previously unpublished dataset. Though mean test score differences were observed between a number of ethnic groups, neither technique was able to identify ethnic DTF. This calls into question the practical application of DTF to understanding these group differences. Study 2 investigated whether a number of non-cognitive factors might explain ethnic group test performance differences on a variety of ability tests. Two factors – test familiarity and trait optimism – were able to explain a large proportion of ethnic group test score differences. Furthermore, test familiarity was found to mediate the relationship between socio-economic factors – particularly participant educational level and familial social status – and test performance, suggesting that test familiarity develops over time through the mechanism of exposure to ability testing in other contexts. These findings represent a substantial contribution to the field’s understanding of two key issues surrounding ethnic test performance differences. The author calls for a new line of research into these performance facilitating and debilitating factors, before recommendations are offered for practitioners to ensure fairer deployment of ability testing in high-stakes selection processes.

The appraisal and management of multi-storey dwelling blocks using large concrete panel systems

This exploratory study is concerned with the integrated appraisal of multi-storey dwelling blocks which incorporate large concrete panel systems (LPS). The first step was to look at U.K. multi-storey dwelling stock in general, and under the management of Birmingham City Council in particular. The information has been taken from the databases of three departments in the City of Birmingham, and rearranged in a new database using a suite of PC software called `PROXIMA' for clarity and analysis. One hundred of their stock were built large concrete panel system. Thirteen LPS blocks were chosen for the purpose of this study as case-studies depending mainly on the height and age factors of the block. A new integrated appraisal technique has been created for the LPS dwelling blocks, which takes into account the most physical and social factors affecting the condition and acceptability of these blocks. This appraisal technique is built up in a hierarchical form moving from the general approach to particular elements (a tree model). It comprises two main approaches; physical and social. In the physical approach, the building is viewed as a series of manageable elements and sub-elements to cover every single physical or environmental factor of the block, in which the condition of the block is analysed. A quality score system has been developed which depends mainly on the qualitative and quantitative conditions of each category in the appraisal tree model, and leads to physical ranking order of the study blocks. In the social appraisal approach, the residents' satisfaction and attitude toward their multi-storey dwelling block was analysed in relation to: a. biographical and housing related characteristics; and b. social, physical and environmental factors associated with this sort of dwelling, block and estate in general.The random sample consisted of 268 residents living in the 13 case study blocks. Data collected was analysed using frequency counts, percentages, means, standard deviations, Kendall's tue, r-correlation coefficients, t-test, analysis of variance (ANOVA) and multiple regression analysis. The analysis showed a marginally positive satisfaction and attitude towards living in the block. The five most significant factors associated with the residents' satisfaction and attitude in descending order were: the estate, in general; the service categories in the block, including heating system and lift services; vandalism; the neighbours; and the security system of the block. An important attribute of this method, is that it is relatively inexpensive to implement, especially when compared to alternatives adopted by some local authorities and the BRE. It is designed to save time, money and effort, to aid decision making, and to provide ranked priority to the multi-storey dwelling stock, in addition to many other advantages. A series of solution options to the problems of the block was sought for selection and testing before implementation. The traditional solutions have usually resulted in either demolition or costly physical maintenance and social improvement of the blocks. However, a new solution has now emerged, which is particularly suited to structurally sound units. The solution of `re-cycling' might incorporate the reuse of an entire block or part of it, by removing panels, slabs and so forth from the upper floors in order to reconstruct them as low-rise accommodations.

Test of a mediation model of perceived organisational support

This study examined the mediating influence of trust in organization (TIO) and organization-based self-esteem (OBSE) on the relationship between perceived organization support (POS) and its work outcomes. Data were obtained from employee–supervisor dyads from multiple organizations located in a major city in southern China. Structural equation modeling results revealed that: (a) POS related to TIO and OBSE and (b) TIO and OBSE fully mediated the relationship between POS and the work outcomes of organizational commitment and in-role performance, but partially mediated the POS–organizational citizenship behavior relationship.