NEUROTOXICOLOGICAL EFFECTS OF CHLORPYRIFOS AND DELTAMETHRIN ON DOPAMINE AND ACETYLCHOLINE SYSTEMS IN DROSOPHILA MELANOGASTER

Emerging evidence suggests a positive association between pesticide exposure and sporadic Parkinson\u27s disease (PD) development. The molecular mechanisms of PD and other neurodegenerative diseases are not fully understood, which hinders the development of therapeutic agents to cure or prevent the development of such diseases. Drosophila has been widely used as a model organism to study various neurodegenerative diseases and to screen for promising therapeutic agents. The aims of this study were: (i) investigating the toxic effect of 24 hours exposure to chlorpyrifos (CPF) and deltamethrin (DLM) on the dopaminergic system and AChE activity in Drosophila melanogaster; (ii) comparing different methodologies to test negative geotaxis behavior in D. melanogaster; and (iii) investigating the combined neuroprotective effects of ferulic acid (FA), and Thymoquinone (TQ) natural compounds on DLM induced neurotoxicity. Adult male wild-type flies were exposed to either CPF, DLM, for 24 hours, or concomitantly exposed to DLM and individual neuroprotective agents, or their mix for 72 hours in 10% sucrose on a cotton swab. CPF/DLM-treated flies climbed shorter distances in the negative geotaxis assay as well as had a higher incidence of mortality when compared to the control group. Evidently, CPF/DLM exposure caused a disturbance in the expression of DA-related genes. The DLM exposure for 72 hours caused a higher incidence of mortality and severe locomotor defects. Co-treatment with neuroprotective agents offered protection against these toxic effects of DLM after 72 hours. DLM caused significant inhibition of AChE which was ameliorated with the concomitant exposure with FA. Our results suggest that FA and TQ were effective in reducing the toxicity induced by DLM in D. melanogaster as well as confirm the utility of this model to investigate potential therapeutic strategies on movement disorders, including PD. The present study indicates that a single molecule can interact and affect multiple systems that are not related to their main mechanism of action. Data gathered in the present study may be important for the assessment of the safety of insecticides that humans are at risk of daily exposure to them. Moreover, this study presents a potential natural compound that can ameliorate and protect against the neurotoxicity that is caused by these insecticides

The value-relevanceof Accounting Information in Nigeria: Analysts’ perception in the IFRS regime

This study investigates the effect of IFRS adoption on the value-relevance of accounting information in Nigeria. The study builds on the explanation of extant finance theories on the value and timing of information. IFRS was measured with more disclosure of economic events as well as the fair valuation of economic events under IFRS. The opinions of a number of financial analysts with the aid of e-mail questionnaire were sourced. A log-linear test was run to test the interaction of the variables and the significance of such interaction. A significant relationship was found between the each of the independent variables and the dependent variable at 5% level of significance. The study therefore offers explanations regarding the IFRS adoption as a bridge of the gap between accounting and finance measurement of information. Hence, concludes that IFRS adoption has enhanced the value relevance of accounting information in Nigeria. However, recommendation was made that more measures should be put in place to ensure full compliance of IFRS by all affected Nigerian entities

Effects of Deicing Salts on the Durability of Concrete Incorporating Supplementary Cementitious Materials

Structural Engineering and Materials Laboratory of the University of Kansa

Accounting regulation in Nigeria : institutionalisation, accounting quality effects and capital market effects

This study examines three different aspects of accounting regulation in Nigeria. The first empirical chapter (chapter 2) examines the process of the institutionalisation of IFRS in Nigeria and its outcome. Using data from documents, interviews and survey, the chapter finds that IFRS is substantively adopted by Nigerian listed firms, as they use it for internal reporting. Furthermore, the institutionalisation process involves three levels of social order (i.e., Social, political and economic level; organisational field; and organisational level) at which different agents reinforce one another to ensure that institutionalisation of IFRS in Nigeria is substantive. The second empirical chapter examines whether accounting regulation in the form of IFRS adoption and/or enforcement of accounting standards lead(s) to higher accounting quality. The effects of these two regulatory mechanisms were assessed on three dimensions of accounting quality using fixed-effect regressions for earnings management, binary logistic regression for timely loss recognition, and a system dynamic panel model for earnings persistence on a sample of non-financial companies listed on the Nigerian Stock Exchange. The chapter finds that IFRS adoption significantly increases earnings management and reduces earnings persistence, while institutional reform, through the setting up of the Financial Reporting Council of Nigeria (FRCN) to enforce and monitor compliance with accounting standards, reduces earnings management. The third empirical chapter examines the effect of accounting regulation in the form of IFRS adoption and enforcement on market liquidity in Nigeria. The chapter adopts a longitudinal research design and analyses hand-collected panel data sets from semi-structured archives. Three proxies of market liquidity (i.e., bid-ask spread, zero returns, and volume) were adopted for the study. Firm-quarter observations of 1,416, 1,417 and 1,418 were analysed using a random-effect model for bid-ask-spread and a fixed-effect regression for both zero returns and volume, respectively. The chapter finds that both IFRS adoption and enforcement significantly improve the Nigerian stock market liquidity.School of Social Sciences PhD scholarshi

Do information asymmetry proxies measure information asymmetry?

Market microstructure based proxies for information asymmetry have been widely used for over two decades. However, their empirical validation is surprisingly scarce. We attempt to address this gap by empirically testing two of the more popular proxies, namely, Glosten and Harris (1988) adverse selection cost component of the bid-ask spread (lambda), and Easley, Hvidkjaer, and O’Hara (2002) probability of informed trading (PIN). We estimate these proxies across three portfolios: broad-based ETFs, sector ETFs, and common stocks. Arguably, information asymmetry about broad-based ETFs should be primarily related to market wide information asymmetry, while information asymmetry about stocks should be mostly related to firm characteristics. We find that while PIN is highest for the broad-based portfolio and lowest for the stock portfolio, lambda is highest for the stock portfolio and lowest for the broad-based portfolio. To the extent that information asymmetry about stocks should be greater than information asymmetry about systematic factors, we provide evidence in support of lambda as a measure of information asymmetry. PIN is more closely related to liquidity

Perspectives of learning science effectively: comparison between Western Australian teachers and Malaysian teachers

Malaysia hopes to be a developed country which is driven by the industrial and agricultural sectors by the year 2020. This aspiration is guided by Vision 2020 and in order to achieve this, the manpower of the country must be developed and furnished with strong technological, mathematical, and science backgrounds as early as the primary level. It is important to note that effective learning influences the attitude of the students towards science, and if Malaysia is to develop in accordance with Vision 2020, this issue must be addressed. In developed countries like Australia, the learning of science is developed humanistically to attract students to science. The learning of science in Australia involves materials, environments, and activities which encourage students to actively participate in the class. Therefore, it is important to investigate teachers’ perspectives towards students’ learning as teachers are facilitators of learning. This paper discusses the findings of a qualitative study that was carried out to compare the perspectives of primary science teachers from Malaysia and from Western Australia, with the focus on five research questions. The first question is “what are the teachers’ perspectives of learning science?”, whereas the second, third and fourth are, “what are the teachers’ perspectives of effective teaching methods, the importance of teaching aids and implementing science process skills in the learning of science?” and the fifth question is, “how to assess the progress of the students in learning science?” The participants of the study were twelve primary science teachers from Western Australia and from Malaysia, respectively. The data collection approaches employed included open-ended questions, non-participant observation techniques, and document collection. The findings indicated that there are four types of teachers’ perspectives of learning science, three perspectives of the implementation of science process skills in learning science, and five methods in assessing students’ progress in learning science

Clinical and Pathological Characteristics of Brain Tumor

Background: CNS tumors comprise 2% to 5% of all tumors. There was no epidemiological and statistical data regarding various features of brain tumors in this country. 80% involve the brain and 20% involve the spinal cord. Brain tumors cause approximately 2% of all cancer deaths. Objectives: to evaluate the clinical and pathological characteristics of brain tumors. Methods: This prospective study was done at Oncology department and Neurosurgery department of Bangabandhu Shiekh Mujib Medical University from July 2006 to June 2007. Total 50 patient age 2-60 years attending the oncology department with the diagnosis of primary brain tumor were included in this study. Clinical symptoms and sign in relation to brain tumor were recorded. X ray skull and CT scan reports of all cases were evaluated. To find out the histopathological pattern of the brain tumors all histopathological reports were also evaluated. Results: Most common symptoms of brain tumor were headache (76%), mental change (64%), vomiting (52%), visual defect (46%), difficulty in movement (42%) and convulsion (36%). Astrocytoma was found in 40% patients and 30% brain tumor was associated with hydrocephalus Conclusion: This study represent the brain tumor and gives some idea about the clinicopathological aspects of the disease in our country. It will help to do further studies to evaluate the clinical, epidemiological and pathological characteristics of brain tumor  DOI: 10.3329/bsmmuj.v3i2.7054BSMMU J 2010; 3(2): 68-7

Resisting institutionalized corruption: The case of public audit in Nigeria

In a highly corrupt environment such as Nigeria, accounting practices have been permeated by corruption in the wider society. As such, several studies on the relationship between accounting and corruption have unveiled a symbiotic association between accountants and corruption. Contrary to this popular viewpoint, this study shows that there are instances of resistance to corruption by accountants in such environments. This study adopts a multiple case study approach. We used two case studies to demonstrate the consistency of the Auditors-General for the Federation (AuGFs) in resisting institutionalized corruption and one case study to show that AuGFs’ resistance is not commonplace in Nigeria. Data were gathered from interviews, videos, and documents. We found that AuGFs resist corruption through the disclosure of accounting irregularities in their audit reports despite the severe consequences associated with exposing corrupt practices in Nigeria. However, they hide this resistance through a number of strategies to sustain the resistance and avert possible repercussions of corruption disclosure. Prior studies of accounting and corruption in developing countries often find accountants enabling corrupt practices through their silence or through active participation in such practices. However, this study shows how accountants also resist corruption in a highly corrupt developing country, which is rare in the literature

Design and distortion analysis of fully integrated image reject RF CMOS frontends

This thesis presents the design and experimental results of a 7.3GHz notch image reject filter, combined with a 5.8GHz low-noise amplifier (LNA), for integrated heterodyne receiver front-ends. A new image reject filter implementation is proposed. Q-enhancement circuitry for on-chip inductors are used to optimize the depth of image rejection. Experimental results show that more than 62dB of image rejection at 7.3GHz can be obtained in a standard CMOS 0.18mum technology, while operating from a 1.8V supply. The LNA exhibits a gain of 15.8dB and an IIP3 of -5.3dBm while consuming 9mW of power. With maximum image rejection, the LNA-notch combination circuit achieves a 4.1dB noise figure at 5.8GHz. The proposed notch filter alone can operate from a 1V supply voltage. It is shown analytically how circuit stability can be ensured.The implementation of new robust and stable high-Q CMOS image reject filters, which enables the realization of fully integrated heterodyne 5GHz RF receivers is also presented. A cascade of two notch filters with their image reject frequencies slightly offsetted is proposed, in order to obtain a wide image rejection bandwidth, without having to resort to the overhead of automatic tuning circuitry. Thus, power consumption, area, and complexity are significantly reduced. Experimental results show that more than 30d$ of image rejection can be obtained in a standard 0.18mum CMOS technology, over a 400MHz bandwidth centered at 7.4GHz