Biophysical characterisation of domain 1 of rat CD2

CD2, a glycoprotein found on the T-lymphocyte, plays an important role in mediating the adhesion of T-lymphocytes to its accessory and target cells. The ligand-binding surface of CD2, which is located on the N-terminal domain of CD2 (CD2d1), has an unusually high proportion of charged residues. The ionic interactions of these charged residues are though to play a significant role in defining the ligand-specificity and binding affinity of CD2 with its ligands CD48 and CD58. The determination of the electrostatic properties of these proteins can therefore contribute to our understanding of the structure-activity relationships for these adhesion complexes. In this thesis, the biophysical characterisation of the electrostatic properties of CD2d1 is described. The principal method used for the investigation is nuclear magnetic resonance (NMR) which permit the accurate determination of the ionisation constants of all the individual acidic residues. The characterisation of the binding interaction involved site-directed mutagenesis of these residues on the binding surface. In addition, the dynamic properties of CD2d1 are also investigated by NMR relaxation experiments. The significance of the finding are discussed The pH titration of CD2d1 revealed a glutamate (Glu41) on the binding surface that has an anomalously high pka. This anomalous pka has an extensive effect on the chemical shift that suggests protein self-association mediated by this residue. This self-association was confirmed by relaxation analysis, and the CD2 was shown to dimerise with a very low affinity, but this dimerisation is nevertheless highly specific and has a pronounced effect on the relaxation parameters. The results indicated that CD2 dimerisation is maximal when Glu41 is protonated and Glu29 is deprotonated. The implication of the findings to the analysis of dynamics by NMR in discussed, and the significance of the observations to recent structural and functional analyses of rat CD2 interaction with CD48 is also examined

The influence of communication, empowerment and trust on organizational ethical climates

In this study, communication, empowerment and trust were examined to determine their influence on an organization’s ethical climate. A total of 150 questionnaires completed by managers and executives based in the Klang Valley, Malaysia were analysed. The results demonstrated that empowerment was positively related to a benevolent-local climate while trust was positively related to both benevolent-local and principled-local climates. However, communication did not have a significant influence on all three ethical climate types. We discuss our results and the implications for both future academic research and practice

Formation of Warped Disks by Galactic Fly-by Encounters. I. Stellar Disks

Warped disks are almost ubiquitous among spiral galaxies. Here we revisit and test the `fly-by scenario' of warp formation, in which impulsive encounters between galaxies are responsible for warped disks. Based on N-body simulations, we investigate the morphological and kinematical evolution of the stellar component of disks when galaxies undergo fly-by interactions with adjacent dark matter halos. We find that the so-called `S'-shaped warps can be excited by fly-bys and sustained for even up to a few billion years, and that this scenario provides a cohesive explanation for several key observations. We show that disk warp properties are governed primarily by the following three parameters; (1) the impact parameter, i.e., the minimum distance between two halos, (2) the mass ratio between two halos, and (3) the incident angle of the fly-by perturber. The warp angle is tied up with all three parameters, yet the warp lifetime is particularly sensitive to the incident angle of the perturber. Interestingly, the modeled S-shaped warps are often non-symmetric depending on the incident angle. We speculate that the puzzling U- and L-shaped warps are geometrically superimposed S-types produced by successive fly-bys with different incident angles, including multiple interactions with a satellite on a highly elongated orbit.Comment: 16 pages, 13 figures, 3 tables. Accepted for publication in Ap

The relationship between job insecurity, shock, and turnover intention, amongst survivors of organizational downsizing

It is often thought that survivors of a downsized organization should be thankful for remaining in their jobs, and that they should respond positively by helping the organization to achieve its goals. However, these individuals often have the intention of leaving the organization. The purpose of this study is to examine the factors that influence the turnover intention of survivors of downsized organizations. We hypothesized that survivors were more likely to think about leaving their organization when they perceived insecurity in their jobs and considered the downsizing decision taken by top management as a "shock." We tested this hypothesis on 187 surviving employees of downsized organizations in Malaysia. The important findings of this study are that the survivors' turnover intention is significantly related to shock, job insecurity, and organizational level. Hence, organization leaders need to plan carefully before implementing their organization's downsizing, as shocks do influence survivors' turnover intention

Institutional corporate social responsibility (CSR) practices: the influence of leadership styles and their perceived ethics and social responsibility role

This paper investigates leader's perceptions of ethics and social responsibility (PRESOR) on organisation's institutional CSR practices. The results indicate that while the managers in this study perceive that ethics and social responsibility play an important role in determining the organisation's long-term and short-term gains, they do not think that ethics and social responsibility are the only important factors in determining firm's profitability and survival, as indicated by the non-significant results of the PRESOR (social responsibility and profitability) dimension. Another objective was to determine the types of leadership style in influencing the adoption and practices of CSR. As oppose to many previous studies, the results indicate that among the leadership styles, transactional leadership influences institutional CSR practices, while transformational leadership does not. This finding implies that for CSR practices to be implemented, leaders need to use rewards, rules and regulations in a Malaysian context. In other words, in order to institutionalise CSR practices in Malaysia, corporations should start by introducing extrinsic incentives

Pressures, green supply chain management practices and performance of ISO 14001 certified manufacturers in Malaysia

As the language of environmentalism become more vocal globally— including in Malaysia—a growing number of organizations are intending to adopt green approaches throughout their entire supply chains. Issues of environmental protection are central and dynamic; as such, there is an ongoing need for studies to fully understand and update knowledge in this area. This paper investigates green supply chain management (GSCM) among 112 ISO14001 certified manufacturers in Malaysia. Specifically, the objectives of this study are to examine the influence of various pressures (regulation, marketing, competition, management, and cost) on the level of green practices, and the interrelationships between drivers, practices, and performance. The study also looks at the moderating effect of partner relationships. Results indicate that manufacturers in Malaysia experience high external pressures such as regulatory and marketing/customers pressures. The GSCM implementation, especially on external activities, are still at a moderate level except for internal environmental initiatives. GSCM practices affect firms’ financial/market performance and customer satisfaction, but are not significant to environmental performances. The partner relationship (trust and commitment) moderate the relationship between GSCM practices and environmental performances but is not applicable to relationships between GSCM practices and other firms’ performances such as market/financial outcomes and customer satisfaction. Subsequent implications for both theory and practice are discussed in the paper

Chloride Transport of High Alumina Cement Mortar Exposed to a Saline Solution

Chloride transport in different types of high alumina cement (HAC) mortar was investigated in this study. Three HAC cement types were used, ranging from 52.0 to 81.1% of aluminum oxides in clinker. For the development of the strength, the setting time of fresh mortar was measured immediately after mixing and the mortar compressive strength was cured in a wet chamber at 25 ± 2°C and then measured at 1–91 days. Simultaneously, to assess the rate of chloride transport in terms of diffusivity, the chloride profile was performed by an exposure test in this study, which was supported by further experimentation including an examination of the pore structure, chloride binding, and chemical composition (X-ray diffraction) analysis. As a result, it was found that an increase in the Al2O3 content in the HAC clinker resulted in an increase in the diffusion coefficient and concentration of surface chloride due to increased binding of chloride. However, types of HAC did not affect the pore distribution in the cement matrix, except for macro pores

Corporate Debt Policy of Malaysian SMEs: Empirical Evidence from Firm Dynamic Panel Data

Financing has been identified as a dominant constraint to Malaysian small and medium-sized enterprises (SMEs). Yet, limited attention has been given to the challenges faced by the SMEs in financing their operations. This paper investigates the determinants of capital structure and use of financing for Malaysian SMEs in manufacturing sector and examines hypotheses by utilising a static trade-off choice or pecking order framework by employing a series of firm characteristics including: size, age, asset structure, profitability, growth, taxation and risk. The system Generalised Method of Moment (GMM) approach has been used for the estimation. The findings suggest that most of the determinants of capital structure presented by the theory of finance appear to be relevant for the Malaysian SMEs. Firm size and asset structure have a significantly positive effect on the leverage ratio in SMEs, while age and taxation have a negative effect. Though, growth has an impact on the total debt of the firms, profitability and risk does not have any significant effect on the decision of debt decision making in Malaysian SMEs. Furthermore, the findings of the study show that Malaysian SMEs in the manufacturing sector generally operate based on a combination of the pecking order and the trade-off theory while borrowing in the long-term and short-term

Ethical perception: are differences between ethnic groups situation dependent?

This study was conducted to determine how culture influences the ethical perception of managers. Most studies conducted so far have only stated similarities and differences in ethical perception between cultural or ethnic groups and little attention has been paid towards understanding how cultural values influence the ethnic groups' ethical perception. Moreover, most empirical research in this area has focused on moral judgement, moral decision making and action, with limited empirical work in the area of ethical perception. A total of 22 interviews were conducted and the questionnaire survey yielded 272 managerial responses. Three implications were obtained based on the findings of the study. The first implication is that differences in ethical perception can exist when one culture attributes moral significance to something that another culture does not. The results of the study also suggest that similarities in ethical perception can occur when a situation is viewed as an accepted and institutionalised part of doing business. Finally, the findings of the study also show that the influence of culture on ethical perception varied according to the different types of scenarios