Structure and activity in assessing antioxidant activity in vitro and in vivo:a critical appraisal illustrated with the flavonoids

Structure–activity relationships are indispensable to identify the most optimal antioxidants. The advantages of in vitro over in vivo experiments for obtaining these relationships are, that the structure is better defined in vitro, since less metabolism takes place. It is also the case that the concentration, a parameter that is directly linked to activity, is more accurately controlled. Moreover, the reactions that occur in vivo, including feed-back mechanisms, are often too multi-faceted and diverse to be compensated for during the assessment of a single structure–activity relationship. Pitfalls of in vitro antioxidant research include: (i) by definition, antioxidants are not stable and substantial amounts of oxidation products are formed and (ii) during the scavenging of reactive species, reaction products of the antioxidants accumulate. Another problem is that the maintenance of a defined concentration of antioxidants is subject to processes such as oxidation and the formation of reaction products during the actual antioxidant reaction, as well as the compartmentalization of the antioxidant and the reactive species in the in vitro test system. So determinations of in vitro structure-activity relationships are subject to many competing variables and they should always be evaluated critically. (c) 2005 Published by Elsevier B.V.

Organizational commitment profiles and job satisfaction among Greek private and public sector employees

Recent research into organizational commitment has advocated a profiles-based approach. However, with the exception of Wasti, published findings are confined to North American samples. This article examines the relationships between organizational commitment profiles and job satisfaction in Greece. Greek organizations have rarely been the subject of detailed examination, so the study provides baseline information regarding levels of organizational commitment and job satisfaction in Greece. Both private sector (N = 1119) and public sector (N = 476) employees in Greece were surveyed, as this sectoral distinction is regularly associated with different patterns of job-related attitudes. The contrasts between Greek and Anglo-American values present a new challenge to the profiles approach. The results confirm the utility of the profiles approach to the study of organizational commitment. Affective organizational commitment was found to be most influential with respect to levels of intrinsic and extrinsic job satisfaction. This concurs with other studies of the behavioural outcomes of commitment. Copyright © 2007 Sage Publications.

Estimating additionality and leverage:between public and private sector equity finance in Ireland (2000 – 2002)

This paper aims to contribute to the debate about the role of the public sector in stimulating greater use of private sector equity for business start-up and growth in two ways. First, to examine the extent to which the provision of public sector equity finance enables individual firms to raise additional funds in the private sector market place. Second, to consider the methodological implications for an economic impact assessment of industrial policy interventions (especially those which include an equity component) at the level of the individual firm. We assess the extent to which there may be indirect positive effects (externalities) associated with public sector financial assistance to individual firms and if so how they distort standard evaluation methodologies designed to estimate the level of additionality of that support. The paper draws upon the results of a recent study of the impact of Enterprise Ireland (EI) financial assistance to indigenous Irish industry in the period 2000 to 2002. The paper demonstrates that a process of re-calibration is necessary in estimates of economic impact in order to account for these positive externalities and the result in this study was a ‘boost’ to additionality. In operational and conceptual terms, the study underlines the importance of the relationship between private and public sector sources of equity finance as an important dynamic in the attempt by industrial and regional policy to stimulate the number of firms with viable investment proposals accessing external equity finance.

Professionals, discretion and public sector reform in the UK:re-visiting Lipsky

Purpose – Seeks to examine how far Michael Lipsky's theory of discretion as it relates to public sector professionals as “street-level bureaucrats” is still applicable in the light of public sector reform and in particular the introduction of increased managerial control over professionals. Design/methodology/approach – The main thesis in Lipsky's work, Street-Level Bureaucracy, that street-level bureaucrats devise their own rules and procedures to deal with the dilemmas of policy implementation is linked to public sector reform over the past 25 years or so. The article differentiates between three forms of discretion, rule, task and value and assesses the extent to which these different forms of discretion have been compromised by reform. Examples are drawn principally from the literature on school teachers and social workers Findings – The findings suggest that the rule-making (hence bureaucratic) capacity of professionals at street-level is much less influential than before although it is questionable whether or not the greater accountability of professionals to management and clarity of the targets and objectives of organisations delivering public policy has liberated them from the dilemmas of street-level bureaucracy. Research limitations/implications – The work has focussed on the UK and in particular on two professions. However, it may be applied to any country which has undergone public sector reform and in particular where “new public management” processes and procedures have been implemented. There is scope for in-depth studies of a range of occupations, professional and otherwise in the UK and elsewhere. Practical implications – Policy makers and managers should consider how far the positive aspects of facilitating discretion in the workplace by reducing the need for “rule-making” to cope with dilemmas have been outweighed by increased levels of bureaucracy and the “de-skilling” of professionals. Originality/value – Lipsky's much cited and influential work is evaluated in the light of public sector reform some 25 years since it was published. The three forms of discretion identified offer the scope for their systematic application to the workplace.

It's what you do and the way that you do it:team task, team size, and innovation-related group processes

This article describes a study of the relationships between team inputs (task type and team size) and team processes in 87 cross industry Portuguese teams, some of which had high and some low requirements to innovate. Team processes were measured using the Team Climate Inventory (TCI), which focuses on clarity of and commitment to team objectives, levels of participation, support for innovation, and quality emphases. Three hypotheses were tested. The first proposed that teams carrying out tasks with a high innovation requirement would have high scores on a measure of team processes. This was supported insofar as such teams reported higher levels of participation and support for innovation. The second hypothesis proposed that large teams would have poorer team processes. This hypothesis was confirmed. The third hypothesis concerned the interaction between size and innovation. The results suggested that large teams operating under a relatively high pressure to innovate have poorer team processes than large teams that do not have a high requirement to innovate.

Typical kernel size and number of sparse random matrices over Galois fields: a statistical physics approach

Using methods of statistical physics, we study the average number and kernel size of general sparse random matrices over GF(q), with a given connectivity profile, in the thermodynamical limit of large matrices. We introduce a mapping of GF(q) matrices onto spin systems using the representation of the cyclic group of order q as the q-th complex roots of unity. This representation facilitates the derivation of the average kernel size of random matrices using the replica approach, under the replica symmetric ansatz, resulting in saddle point equations for general connectivity distributions. Numerical solutions are then obtained for particular cases by population dynamics. Similar techniques also allow us to obtain an expression for the exact and average number of random matrices for any general connectivity profile. We present numerical results for particular distributions.