Immobilized artificial membrane chromatography : quantitative structure-retention relationships of structurally diverse drugs

The chromatographic capacity factors (log k‘) for 32 structurally diverse drugs were determined by high performance liquid chromatography (HPLC) on a stationary phase composed of phospholipids, the so-called immobilized artificial membrane (IAM). In addition, quantitative structure-retention relationships (QSRR) were developed in order to explain the dependence of retention on the chemical structure of the neutral, acidic, and basic drugs considered in this study. The obtained retention data were modeled by means of multiple regression analysis (MLR) and partial least squares (PLS) techniques. The structures of the compounds under study were characterized by means of calculated physicochemical properties and several nonempirical descriptors. For the carboxylic compounds included in the analysis, the obtained results suggest that the IAM-retention is governed by hydrophobicity factors followed by electronic effects due to polarizability in second place. Further, from the analysis of the results obtained of two developed quantitative structure-permeability studies for 20 miscellaneous carboxylic compounds, it may be concluded that the balance between polarizability and hydrophobic effects is not the same toward IAM phases and biological membranes. These results suggest that the IAM phases could not be a suitable model in assessing the acid-membrane interactions. However, it is not possible to generalize this observation, and further work in this area needs to be done to obtain a full understanding of the partitioning of carboxylic compounds in biological membranes. For the non-carboxylic compounds included in the analysis, this work shows that the hydrophobic factors are of prime importance for the IAM-retention of these compounds, while the specific polar interactions, such as electron pair donor−acceptor interactions and electrostatic interactions, are also involved, but they are not dominant.

Peak modeling approach to accurate assignment of first-dimension retention times in comprehensive two-dimensional chromatography

Modeling of first-dimension retention of peaks based on modulation phase and period allows reliable prediction of the modulated peak distributions generated in the comprehensive two-dimensional chromatography experiment. By application of the inverse process, it is also possible to use the profile of the modulated peaks (their heights or areas) to predict the shape and parameters of the original input chromatographic band (retention time, standard deviation, area) for the primary column dimension. This allows an accurate derivation of the firstdimension retention time (RSD 0.02%) which is equal to that for the non-modulated experiment, rather than relying upon the retention time of the major modulated peak generated by the modulation process (RSD 0.16%). The latter metric can produce a retention time that differs by at least the modulation period employed in the experiment, which displays a discontinuity in the retention time vs modulation phase plot at the point of the 180° out-ofphase modulation. In contrast, the new procedure proposed here gives a result that is essentially independent of modulation phase and period. This permits an accurate value to be assigned to the first-dimension retention. The proposed metric accounts for the time on the seconddimension, the phase of the distribution, and the holdup time that the sampled solute is retained in the modulating interface. The approach may also be based on the largest three modulated peaks, rather than all modulated peaks. This simplifies the task of assigning the retention time with little loss of precision in band standard deviation or retention time, provided that these peaks are not all overloaded in the first or second dimension.

Risk management, player welfare and privacy : player development managers and dilemmas for employee relations in Australian football league clubs

This paper reports on one aspect of a research project that was funded by the Australian Football League (AFL) to explore the emergence and evolution of a ‘professional identity’ for AFL footballers. The research was informed by Foucault's later work on the care of the Self to focus on the ways in which player identities are governed by coaches, club officials, and the AFL Commission/Executive; and the manner in which players conduct themselves in ways that can be characterised as professional - or not. The paper explores the roles of Player Development Managers (PDMs) in emerging processes of risk and player management. These roles increasingly involve PDMs in risk management practices and processes that can be seen as intrusive in players’ lives. These risk management processes raise a number of concerns about player privacy and the rights of Clubs to know what their employees are up to away from the workplace.

Does the change of accounting regulation on employee share options give rise to greater scope for earnings management?

Purpose – The purpose of this paper is to address the concern about the impact of accounting regulatory change pertaining to employee share options (ESOs) on earnings management. Following Australia’s adoption of International Financial Reporting Standards (IFRS) in 2005, companies are required to recognise the fair value of ESOs as expenses. Due to inherent imprecision in the estimate of ESO’s fair value, the regulatory change from disclosure to recognition was widely claimed to potentially give rise to an alternative mechanism to manage earnings. This study provides empirical evidence on whether the regulatory change leads to earnings management problems.

Design/methodology/approach – This study uses the regulatory change in accounting for ESOs to provide a direct test of earnings management between disclosed versus recognised regimes for the same sample of firms. The sample consists of Australian firms from S&P/ASX300 for the period from 2003 to 2006.

Findings – The results show that, although the accounting regulatory change from disclosure to recognition may provide an alternative earnings management vehicle, there is no evidence of this occurring. There could be several reasons for this finding. First, the statistical tests lack power. Second, there are stricter audit tests on recognised amounts than on disclosed amounts. Third, given the concern of excessive pay and the close scrutiny of compensation, managers may have already understated ESO values in the disclosure regime. Finally, managers have limited time and resources and the effort involved in the adoption of IFRS in 2005 could have restricted the time available to manage earnings via the ESO reporting channel.

Originality/value – This study adds to the limited research on whether a change in accounting regulation for employee share options from disclosure to recognition gives rise to greater scope for earnings management. One reason for the lack of empirical evidence in the research is due to the problem of designing a test. Bernard and Schipper suggest that within-firm studies have limitations for comparing the effects of recognition versus disclosure when the change is driven by an estimate becoming more reliable. A cross-sectional study is also problematic due to self-selection bias if firms can choose between disclosure versus recognition. This study circumvents potential design problems raised by Bernard and Schipper by setting a test using regulatory change which allows the test to be compared directly using the same company.

Using job strain and organizational justice models to predict multiple forms of employee performance behaviours among Australian policing personnel

The overall purpose of this investigation was to examine the relationship between stress-related working conditions and three forms of employee performance behaviours: in-role behaviours, citizenship behaviours directed at other individuals and citizenship behaviours directed at the organization. The potentially stressful working conditions were based on the job strain model (incorporating job demands, job control and social support) as well as organizational justice theory. A sample of Australian-based police officers (n = 640) took part in this study and the data were collected via a mail-out survey. Multiple regression analyses were undertaken to assess both the strength and the nature of the relationships between the working conditions and employee performance and these analyses included tests for additive, interactional and curvilinear effects. The overall results indicated that a significant proportion of the explained variance in all three outcome measures was attributed to the additive effects of demand, control and support. The level of variance associated with the organizational justice dimensions was relatively small, although there were signs that specific dimensions of justice may provide unique insights into the relationship between job stressors and employee performance. The implications of these and other notable findings are discussed.

Retention a complex issue

The article 'Bradley targets threatened by high drop-out rates among disadvantaged students' could be read as implying that the low retention rate among institutions with good equity performance is caused by these students being under prepared for the rigours of the university.

Creating communities that lead to retention : the social worlds and communities of umpires

Umpires (referees) are essential for sport competition, yet many sports report difficulty in recruiting and retaining umpires. Therefore, this research sought to better understand what experiences will ensure continued participation in umpiring. Previous literature suggests that the communities created are vital to umpire retention. Thus, the aim of this research was to identify the factors that lead to, or detract from sense of community for umpires. Twenty-two Australian Rules football umpires were interviewed using a semi-structured approach. This study revealed that Lack of Administration Consideration, Inequity (specifically related to remuneration and resources), Competition, Common Interest (specifically in the sport, interactions within football community, and/or within social spaces) impacted the development of sense of community for umpires. This study demonstrates that as umpires move through their careers, the outcome of the noted factors to enhance or detract from sense of community change. Implications for umpire education, accreditation, and management aimed at retaining umpires are discussed.

Protocol for a randomized controlled trial of a specialized health coaching intervention to prevent excessive gestational weight gain and postpartum weight retention in women : the HIPP study

Background

Pregnancy is a time of significant physiological and physical change for women. In particular, it is a time at which many women are at risk of gaining excessive weight. We describe the rationale and methods of the Health in Pregnancy and Post-birth (HIPP) Study, a study which aims primarily to determine the effectiveness of a specialized health coaching (HC) intervention during pregnancy, compared to education alone, in preventing excessive gestational weight gain and postpartum weight retention 12 months post birth. A secondary aim of this study is to evaluate the mechanisms by which our HC intervention impacts on weight management both during pregnancy and post birth.
Methods/Design

The randomized controlled trial will be conducted with 220 women who have a BMI > 18.5 (American IOM cut-off for normal weight), are 18 years of age or older, English speaking, no history of disordered eating or diabetes and are less than 18 weeks gestation at recruitment. Women will be randomly allocated to either a specialized HC intervention group or an Education Alone group. Our specialized HC intervention has two components: (1) one-on-one sessions with a Health Coach, and (2) two by two hour educational group sessions led by a Health Coach. Women in the Education Alone group will receive two by two hour educational group sessions with no HC components. Body Mass Index, waist circumference, and psychological factors including motivation, readiness to change, symptoms of depression and anxiety, and body dissatisfaction will be assessed at baseline (14-16 weeks gestation), and again at follow-up: 32 weeks gestation, 6 weeks, 6 months and 12 months postpartum.
Discussion

Our study responds to the urgent need to design effective interventions in pregnancy to prevent excessive gestational weight gain and postpartum weight retention. Our pregnancy HC intervention is novel and innovative and has been designed to be easily adopted by health professionals who work with pregnant women, such as obstetricians, midwives, allied health professionals and health psychologists.

Examination of the effect of mental reinstatement of context acress developmental level, retention interval and type of mnemonic instruction

The effect of mental reinstatement of context was examined using a 4*5*2 factorial design incorporating four age groups (6-year-olds, 8-year-olds, 11-year-olds and adults), two retention intervals (1 day and 2 weeks after the stimulus event) and five interview conditions. The interview conditions included; free recall, mental reinstatement-environment (where the setting was reinstated but no event-related detail was provided in the mnemonic instruction), mental reinstatement-event (where specific event-related content was provided), mental reinstatement-combined (a combination of the two above-mentioned methods) and specific questions. Overall, mental reinstatement (irrespective of the type) was found to enhance correct recall performance compared to free recall and (unlike specific questions) it did not lead to greater number of commission errors. Contrary to our initial predictions, however, there was no evidence of any special benefit of mental reinstatement for children and the effect of the technique did not vary consistently as a function of retention interval.

Retention mechanism divergence of a mixed mode stationary phase for high performance liquid chromatography

Mixed mode stationary phases utilize secondary retention mechanisms to add a dimensionality to the surface of high performance liquid chromatography (HPLC) adsorbents. This approach was used by several authors to improve the separation performance of single dimension separations. We explored the magnitude of these secondary interactions by performing an off-line two-dimensional (2D)-HPLC separation with a Scherzo SM-C18 column of a β-lactoglobulin tryptic digest with a mobile phase pH of 7 in the first dimension and 2 in the second. Mechanism divergence was determined using the peak capacity and a geometric approach to factor analysis, to measure the correlation. This separation was repeated with a C18 stationary phase as a control. It was found that the C18 column had a correlation coefficient of 0.784, smaller than the mixed mode column, 0.884. This indicated that the retention mechanisms of the C18 column were more divergent under these two pH environments than the mixed mode column. However, the SM-C18 still provided alternative selectivity of the peptides to that of the C18 and could be considered as a good alternative for further 2D-HPLC separations.