Transient prenatal vitamin D deficiency is associated with subtle alterations in learning and memory functions in adult rats

Based on clues from epidemiology, low prenatal vitamin D has been proposed as a candidate risk factor for schizophrenia. Recent animal experiments have demonstrated that transient prenatal vitamin D deficiency is associated with persistent alterations in brain morphology and neurotrophin expression. In order to explore the utility of the vitamin D animal model of schizophrenia, we examined different types of learning and memory in adult rats exposed to transient prenatal vitamin D deficiency. Compared to control animals, the prenatally deplete animals had a significant impairment of latent inhibition, a feature often associated with schizophrenia. In addition, the deplete group was (a) significantly impaired on hole board habituation and (b) significantly better at maintaining previously learnt rules of brightness discrimination in a Y-chamber. In contrast, the prenatally deplete animals showed no impairment on the spatial learning task in the radial maze, nor on two-way active avoidance learning in the shuttle-box. The results indicate that transient prenatal vitamin D depletion in the rat is associated with subtle and discrete alterations in learning and memory. The behavioural phenotype associated with this animal model may provide insights into the neurobiological correlates of the cognitive impairments of schizophrenia. (c) 2005 Elsevier B.V. All rights reserved.

Gendered dichotomies and segregation patterns in computing jobs in Australia

Sex segregation in employment is a phenomenon that can be observed and analysed at different levels, ranging from comparisons between broad classifications by industry or occupation through to finely defined jobs within such classifications. From an aggregate perspective, the contribution of information technology (IT) employment to sex segregation is clear--it remains a highly male-dominated field apparently imbued with the ongoing masculinity of science and technology. While this situation is clearly contrary to hopes of a new industry freed from traditional distinctions between 'men's' and 'women's' work, it comes as little surprise to most feminist and labour studies analysts. An extensive literature documents the persistently masculine culture of IT employment and education (see, among many, Margolis and Fisher 2002; Wajcman 1991; Webster 1996; Wright 1996, 1997), and the idea that new occupations might escape sexism by sidestepping 'old traditions' has been effectively critiqued by writers such as Adam, who notes the fallacy of assuming a spontaneous emergence of equality in new settings (2005: 140).

Human resource management in developing countries

Focusing on HRM developments in thirteen developing countries across Asia, Africa and the Middle East, this book explores the contextual functions of HR in these countries. In addition, it analyzes the more general issues of HRM in cross-national settings to give readers an understanding of HR that is both comparative and contextual. Covering the policies and practices of China, South Korea, Taiwan, India, Nepal, Pakistan, Iran, Saudi Arabia, Algeria, Nigeria, Ghana, Kenya and South Africa, each chapter follows a framework that draws out all of the unique and diverse configurations of HRM. This important text is an invaluable resource for all HRM practitioners, students and scholars of HRM, international HRM and international business.

Employment effects of privatisation and foreign acquisition of Chinese state-owned enterprises

This paper investigates the effects of domestic privatisation or foreign acquisition of Chinese State Owned Enterprises (SOEs) on employment growth, using firm level data for China and a combination of propensity score matching and difference-in-differences in order to identify the causal effect. Our results suggest that, controlling for output growth there is some evidence that domestic privatisation leads to contemporaneous reductions in employment growth compared to firms that did not undergo an ownership change. By contrast, there is some evidence that foreign acquisitions show higher employment growth in the post acquisition period than non-acquired SOEs.

Comparative performance of analytical techniques for polyhexamethylene biguanide (PHMB) in ophthalmic solutions

Purpose: The use of PHMB as a disinfectant in contact lens multipurpose solutions has been at the centre of much debate in recent times, particularly in relation to the issue of solution induced corneal staining. Clinical studies have been carried out which suggest different effects with individual contact lens materials used in combination with specific PHMB containing care regimes. There does not appear to be, however, a reliable analytical technique that would detect and quantify with any degree of accuracy the specific levels of PHMB that are taken up and released from individual solutions by the various contact lens materials. Methods: PHMB is a mixture of positively charged polymer units of varying molecular weight that has maximum absorbance wavelength of 236 nm. On the basis of these properties a range of assays including capillary electrophoresis, HPLC, a nickelnioxime colorimetric technique, mass spectrophotometry, UV spectroscopy and ion chromatography were assessed paying particular attention to each of their constraints and detection levels. Particular interest was focused on the relative advantage of contactless conductivity compared to UV and mass spectrometry detection in capillary electrophoresis (CE). This study provides an overview of the comparative performance of these techniques. Results: The UV absorbance of PHMB solutions, ranging from 0.0625 to 50 ppm was measured at 236 nm. Within this range the calibration curve appears to be linear however, absorption values below 1 ppm (0.0001%) were extremely difficult to reproduce. The concentration of PHMB in solutions is in the range of 0.0002–0.00005% and our investigations suggest that levels of PHMB below 0.0001% (levels encountered in uptake and release studies) can not be accurately estimated, in particular when analysing complex lens care solutions which can contain competitively absorbing, and thus interfering, species in the solution. The use of separative methodologies, such as CE using UV detection alone is similarly limited. Alternative techniques including contactless conductivity detection offer greater discrimination in complex solutions together with the opportunity for dual channel detection. Preliminary results achieved by TraceDec1 contactless conductivity detection, (Gain 150%, Offset 150) in conjunction with the Agilent capillary electrophoresis system using a bare fused silica capillary (extended light path, 50 mid, total length 64.5 cm, effective length 56 cm) and a cationic buffer at pH 3.2, exhibit great potential with reproducible PHMB split peaks. Conclusions: PHMB-based solutions are commonly associated with the potential to invoke corneal staining in combination with certain contact lens materials. However this terminology ‘PHMBbased solution’ is used primarily because PHMB itself has yet to be adequately implicated as the causative agent of the staining and compromised corneal cell integrity. The lack of well characterised adequately sensitive assays, coupled with the range of additional components that characterise individual care solutions pose a major barrier to the investigation of PHMB interactions in the lenswearing eye.

Spatial scaling in human peripheral vision

The observation that performance in many visual tasks can be made independent of eccentricity by increasing the size of peripheral stimuli according to the cortical magnification factor has dominated studies of peripheral vision for many years. However, it has become evident that the cortical magnification factor cannot be successfully applied to all tasks. To find out why, several tasks were studied using spatial scaling, a method which requires no pre-determined scaling factors (such as those predicted from cortical magnification) to magnify the stimulus at any eccentricity. Instead, thresholds are measured at the fovea and in the periphery using a series of stimuli, all of which are simply magnified versions of one another. Analysis of the data obtained in this way reveals the value of the parameter E2, the eccentricity at which foveal stimulus size must double in order to maintain performance equivalent to that at the fovea. The tasks investigated include hyperacuities (vernier acuity, bisection acuity, spatial interval discrimination, referenced displacement detection, and orientation discrimination), unreferenced instantaneous and gradual movement, flicker sensitivity, and face discrimination. In all cases tasks obeyed the principle of spatial scaling since performance in the periphery could be equated to that at the fovea by appropriate magnification. However, E2 values found for different spatial tasks varied over a 200-fold range. In spatial tasks (e.g. bisection acuity and spatial interval discrimination) E2 values were low, reaching about 0.075 deg, whereas in movement tasks the values could be as high as 16 deg. Using a method of spatial scaling it has been possible to equate foveal and peripheral perfonnance in many diverse visual tasks. The rate at which peripheral stimulus size had to be increased as a function of eccentricity was dependent upon the stimulus conditions and the task itself. Possible reasons for these findings are discussed.

Contrast matching and discrimation in human vision

The aim of this work was to investigate human contrast perception at various contrast levels ranging from detection threshold to suprathreshold levels by using psychophysical techniques. The work consists of two major parts. The first part deals with contrast matching, and the second part deals with contrast discrimination. Contrast matching technique was used to determine when the perceived contrasts of different stimuli were equal. The effects of spatial frequency, stimulus area, image complexity and chromatic contrast on contrast detection thresholds and matches were studied. These factors influenced detection thresholds and perceived contrast at low contrast levels. However, at suprathreshold contrast levels perceived contrast became directly proportional to the physical contrast of the stimulus and almost independent of factors affecting detection thresholds. Contrast discrimination was studied by measuring contrast increment thresholds which indicate the smallest detectable contrast difference. The effects of stimulus area, external spatial image noise and retinal illuminance were studied. The above factors affected contrast detection thresholds and increment thresholds measured at low contrast levels. At high contrast levels, contrast increment thresholds became very similar so that the effect of these factors decreased. Human contrast perception was modelled by regarding the visual system as a simple image processing system. A visual signal is first low-pass filtered by the ocular optics. This is followed by spatial high-pass filtering by the neural visual pathways, and addition of internal neural noise. Detection is mediated by a local matched filter which is a weighted replica of the stimulus whose sampling efficiency decreases with increasing stimulus area and complexity. According to the model, the signals to be compared in a contrast matching task are first transferred through the early image processing stages mentioned above. Then they are filtered by a restoring transfer function which compensates for the low-level filtering and limited spatial integration at high contrast levels. Perceived contrasts of the stimuli are equal when the restored responses to the stimuli are equal. According to the model, the signals to be discriminated in a contrast discrimination task first go through the early image processing stages, after which signal dependent noise is added to the matched filter responses. The decision made by the human brain is based on the comparison between the responses of the matched filters to the stimuli, and the accuracy of the decision is limited by pre- and post-filter noises. The model for human contrast perception could accurately describe the results of contrast matching and discrimination in various conditions.

Multinational firms, productivity and employment

Over the last three decades foreign direct investment (FDI) has become the most visible driver of globalisation. It has grown faster than world output and international trade and now reports world annual flows exceeding 1,000 billion US dollars. In this period, Germany has undergone significant changes in order to play an important role in the globalisation process. Apart from being a member state of the European Union (EU) whose key feature is the free flow of trade, investment and labour, the re-unification of East and West Germany in 1990 has been a significant development. This in effect has meant that East Germany as well as other Eastern European nations opened up to foreign investment for the first time. In this period, Germany has attracted in excess of 10 per cent of inward FDI into the EU and invested around 15 per cent of all FDI in the EU. This thesis explores empirically the potential impact of FDI on firms operating in and investing from Germany over a ten year period. Using panel data at the firm-level it concentrates on three areas relating to FDI. Firstly, it considers whether foreign-owned firms are more productive than German multinational firms and German non-multinational firms. Secondly, the thesis considers the impact of German investments abroad on domestic productivity. Finally, employment effects emanating from outward high-tech FDI are estimated for the leading OECD (Organisation of Economic Co-operation and Development) countries, namely Germany, Belgium, France, the Netherlands, Sweden, the United Kingdom and Japan. The findings of the first analysis indicate that while foreign-owned firms are generally more productive than German non-multinationals, there is no clear cut difference between foreign-owned firms and German multinationals. These differences would not have been uncovered, had the analysis compared foreign firms with all domestic firms. Equally, location within Germany is also important, as this productivity gap is more pronounced for firms which are located in the Eastern states. The findings of the second analysis suggest that engaging in outward FDI has an overall positive effect on the parent firm's productivity at home. Finally, results of the third analysis show that an expansion of high-tech offshoring activities by OECD multinationals (MNEs) is not associated with any reduction in employment at home.

Privatisation, corporate control and employment growth:evidence from a panel of large Polish firms, 1996-2002

Using data on Polish firms this paper examines the relationship between corporate control structures, sales growth and the determinants of employment change. Privatised and de novo firms are the main drivers of employment growth; in the case of de novo firms, it is foreign ownership which underpins the result. Being privatised has a positive impact on employment but this is concentrated within a range of 3–6 years after privatisation. There are no systematic differences in employment response to negative sales growth across the ownership categories. Employment in state firms is less responsive to positive sales growth. From these results we infer that the behaviour of state firms is affected by both insider rent sharing and binding budget constraints.

Privatisation, corporate control and employment growth:evidence from a panel of large Polish firms, 1996-2002

Using panel data on large Polish firms this paper examines the relationship between corporate control structures, sales growth and the determinants of employment change during the period 1996-2002. We find that privatised and de novo firms are the main drivers of employment growth and that, in the case of de novo firms, it is foreign ownership which underpins the result. Interestingly, we find that being privatised has a positive impact on employment growth but that this impact is concentrated within a range of three to six years after privatisation. In contrast with the findings of earlier literature, we find evidence that there are no systematic differences in employment response to negative sales growth across the ownership categories. On the other hand, employment in state firms is less responsive to positive sales growth. From these combined results we infer that the behaviour of state firms is constrained by both insider rent sharing and binding budget constraints. Consistent with this, we find that privatised companies, three to six years post-privatisation, are the firms for whom employment is most responsive to positive sales growth and as such, offer the best hope for rapid labour market expansion.

Employment law:an introduction for HR and business students

The most accessible and concise law textbook available for undergraduate and postgraduate students studying law for the first time. - Written in a clear, engaging style specifically for non-lawyers - Packed with interactive learning features that will consolidate your learning and get you exploring the subject in more depth - Relates theory and law with real life practice, making the subject relevant - Designed to impart you with the skills you need to study law successfully New to this edition: - Completely updated with the latest developments in employment law and in line with the latest CIPD requirements at UG and PG levels - Questions throughout the text and end of chapter further reading - Excellent tutor and student support sites - Practical guidance on how to prepare for an employment tribunal Online resources: For tutors: - Lecturer Guides (including tasks, examples and cases studies with comments from the author) - HR-inform monthly newsletter - Lecture slides For students: - Annotated web-links - HR-inform monthly newsletter

Union experience of social dialogue and collective participation in India

The labor regulatory framework in India provides a conducive environment for social dialogue and collective participation in the organizational decision-making process (Venkata Ratnam, 2009). Using data from a survey of workplace union representatives in the federal state of Maharashtra, India, this paper examines union experiences of social dialogue and collective participation in public services, private manufacturing, and private services sector. Findings indicate that collective worker participation and voice is at best modest in the public services but weak in the private manufacturing and private services. There is evidence of growing employer hostility to unions and employer refusal to engage in a meaningful social dialogue with unions. These findings are discussed within the political economy framework of employment relations in India examining the role of the state and judiciary in employment relations and, the links between political parties and trade unions in India.

Are marginalized women being left behind? A population-based study of institutional deliveries in Karnataka, India

Background While India has made significant progress in reducing maternal mortality, attaining further declines will require increased skilled birth attendance and institutional delivery among marginalized and difficult to reach populations. Methods A population-based survey was carried out among 16 randomly selected rural villages in rural Mysore District in Karnataka, India between August and September 2008. All households in selected villages were enumerated and women with children 6 years of age or younger underwent an interviewer-administered questionnaire on antenatal care and institutional delivery. Results Institutional deliveries in rural areas of Mysore District increased from 51% to 70% between 2002 and 2008. While increasing numbers of women were accessing antenatal care and delivering in hospitals, large disparities were found in uptake of these services among different castes. Mothers belonging to general castes were almost twice as likely to have an institutional birth as compared to scheduled castes and tribes. Mothers belonging to other backward caste or general castes had 1.8 times higher odds (95% CI: 1.21, 2.89) of having an institutional delivery as compared to scheduled castes and tribes. In multivariable analysis, which adjusted for inter- and intra-village variance, Below Poverty Line status, caste, and receiving antenatal care were all associated with institutional delivery. Conclusion The results of the study suggest that while the Indian Government has made significant progress in increasing antenatal care and institutional deliveries among rural populations, further success in lowering maternal mortality will likely hinge on the success of NRHM programs focused on serving marginalized groups. Health interventions which target SC/ST may also have to address both perceived and actual stigma and discrimination, in addition to providing needed services. Strategies for overcoming these barriers may include sensitization of healthcare workers, targeted health education and outreach, and culturally appropriate community-level interventions. Addressing the needs of these communities will be critical to achieving Millennium Development Goal Five by 2015.