Effects of ethylenediamine – a putative GABA-releasing agent – on rat hippocampal slices and neocortical activity in vivo

The simple diamine diaminoethane (ethylenediamine, EDA) has been shown to activate GABA receptors in the central and peripheral nervous systems, partly by a direct action and partly by releasing endogenous GABA. These effects have been shown to be produced by the complexation of EDA with bicarbonate to form a carbamate. The present work has compared EDA, GABA and [beta]-alanine responses in rat CA1 neurons using extracellular and intracellular recordings, as well as neocortical evoked potentials in vivo. Superfusion of GABA onto hippocampal slices produced depolarisation and a decrease of field epsps, both effects fading rapidly, but showing sensitivity to blockade by bicuculline. EDA produced an initial hyperpolarisation and increase of extracellular field epsp size with no fade and only partial sensitivity to bicuculline, with subsequent depolarisation, while [beta]-alanine produces a much larger underlying hyperpolarisation and increase in fepsps, followed by depolarisation and inhibition of fepsps. The responses to [beta]-alanine, but not GABA or EDA, were blocked by strychnine. In vivo experiments, recording somatosensory evoked potentials, confirmed that EDA produced an initial increase followed by depression, and that this effect was not fully blocked by bicuculline. Overall the results indicate that EDA has actions in addition to the activation of GABA receptors. These actions are not attributable to activation of [beta]-alanine-sensitive glycine receptors, but may involve the activation of sites sensitive to adipic acid, which is structurally equivalent to the dicarbamate of EDA. The results emphasise the complex pharmacology of simple amines in bicarbonate-containing solution

What makes useful evidence for educational leadership practice? An interview

An interview with Eric Addae-Kyeremeh about his views on the pressing question ‘What makes useful evidence for educational leadership practice?’ as advice for leaders in educational settings

International Portfolio of Real Estate Investment and Hedging: A Revisit

We use office data from ten cities in the Asia-Pacific region from 4Q2001 to 2Q2012 to propose a forward-looking investment appraisal framework to compare the effectiveness of two currency risk hedging strategies for a portfolio of real estate investments in ten cities of seven Asia-Pacific countries. This is aimed at determining the optimal choice among “unhedged”, “artificially” hedged and “natural” hedged options. Analyses based on NPV, IRR, Sharpe Ratio, Jensen’s alpha and stochastic dominance were done for 3, 5 and 7-year holding periods. All the results show that the “natural” hedge strategy is the optimal choice as it provides superior returns

Industrial real estate investment:does the contrarian strategy work?

The superiority of the contrarian investment strategy, though well attested to in the finance literature, has received scant attention, if any, in the real estate literature. This study uses empirical industrial real estate investment return data from 1985Q1 to 2005Q3 for the US, and some Asia Pacific cities in order to ascertain the relative superiority of “value” and “growth” industrial real estate investments. The results show that “value” industrial property investment outperformed “growth” industrial property investment in all the holding periods under consideration. Furthermore the industrial property investments exhibit return reversal. This implies that the superiority of the contrarian strategy is sustainable. The results of stochastic dominance tests validate the relative superiority of “value” over “growth” industrial property investment. This implies that fund managers who traditionally have been favoring prime (i.e. growth) industrial property investment may have to reconsider their investment strategy if they want to maximize their return

Theories of Poverty: A Critical Review

The study reviewed literature on the theories of poverty. The theories reviewed included theory of individual deficiencies, theory of cultural beliefs, theory of economic, political and social distortions, theory of geographical disparities, and theory of cumulative and cyclical dependencies. The theories were analysed, criticised and measures that will bring the poor out of poverty were recommended.  Some of the recommended solutions included: encouraging the poor to embrace self-help strategies, replacing the culture with one that encourages hard work and investment, changing the system for the better, improving infrastructure and local industries competitiveness, and developing comprehensive programmes that will help the poor to be self-sufficient. Key words: Poverty, Cultural beliefs, Individual deficiencies, Geographical disparities, Economic, political, and structural f actors, psychological theories, sociological theories. DOI: 10.7176/JPID/48-0

The effectiveness of the direct sales comparison approach to office appraisal in Singapore

The skyline of Singapore’s Central Business District (CBD) reflects the prestige and multitude of office buildings in the city state. Investment in CBD office buildings can amount to billions of Singapore dollars. Any investor in office buildings has indubitably relied or relies primarily on the valuations of these buildings to determine investment returns. The most popular and universally used method for valuing these investment buildings is the Direct Sales Comparison approach. The position adopted in this paper is that even though the wealth of practical experience favours the use of the Direct Sales Comparison approach, it encounters methodological constraints. The lack of some critical information in the available data tends to make the method less effective than it is claimed to be for office valuation; failure to account for the conditions of sale and the terms of financing can introduce distortion of market values. This can lead to the distortion of the asset pricing of local office space. There will be growing concern to regularise the direct sales comparison approach in this regard, and to re-consider the use of the income approach as well as the discounted cash flow approaches, in part or in full

The impact of positive margins and crypt involvement in excisional procedures of the cervix on recurrence rates of premalignant diseases of the cervix

BACKGROUND Recurrent disease after cervical excisional procedures has been linked to many factors. We aim to determine if positive margins and crypt involvement increased the rate of recurrence of premalignant disease in patients who had excisional procedures. METHODS In this retrospective review of the colposcopy database, patient records and pathology database, women who had cervical excisional procedures at the Groote Schuur Hospital colposcopy clinic in 2010 were followed up until 2015. Recurrence was based on high grade cytology or histology at follow up. Chi-square tests were used to compare recurrence rates. RESULTS Two hundred and seventy women were included in the final analysis. 130 women had CIN 3 and 94 had CIN 2 at the excisional procedure. Eighty five (31.5%) had endo-margin involvement, 46 (17%) had ecto-margin involvement, and 24 (8.9%) had dual margin involvement. Two hundred and thirteen (79.2%) had crypt involvement. Recurrence occurred in 30 (19.4%) of the 155 patients we had follow up data on. Of those that recurred, 19 (P<0.001) had positive endo-margin involvement, 10 (P=0.007) had ecto-margin involvement, 9 (P< <0.001) had dual margin involvement, and 28 (P=0.058) had crypt involvement. 155 women (43%) were lost to follow-up CONCLUSION Positive margins at excisional procedure of the cervix have a statistically significant increased risk of recurrence of pre-malignant disease. There was a trend towards recurrence of disease in those who have crypt involvement. In limited resource setting follow up protocols can be adjusted so that women without margin involvement can be seen at longer intervals