Testing Semi-strong Form Efficiency of Stock Market

The efficient market hypothesis suggests that stock markets are “informationally efficient”. That is, any new information relevant to the market is spontaneously reflected in the stock prices. A consequence of this hypothesis is that past prices cannot have any predictive power for future prices once the current prices have been used as an explanatory variable. In other words the change in future prices depends only on arrival of new information that was unpredictable today hence it is based on surprise information. Another consequence of this hypothesis is that arbitrage opportunities are wiped out instantaneously. Empirical tests of the efficient market hypothesis actually test for these consequences in various ways. Some of them have been summarised in earlier chapters. These tests generally could not conclusively accept the random-walk hypothesis of stock returns even when GARCH effects were accounted for. Many studies have found empirical regularities that are contrary to the efficient market hypothesis. For example, the monthly, weekly and daily returns on stocks tend to exhibit discernable patterns, such as seasonal affects, month of the year affect, day of the week affect, hourly affect etc. In case of Pakistan’s stock markets too such affects are identified. Such as the Ramadan affect [see Hussain and Uppal (1999)], seasonal effects and day of the week affect. Further, the wide spread use of “technical analysis” among stock traders and their ability to predict to some extent the direction of movements in the prices of individual stocks over medium term testifies to the existence of patterns and seasonal trends.

Dynamics of Growth, Poverty, and Inequality in Pakistan

The relationship between growth, inequality, and poverty has been a moot point. On the one hand growth is considered central or the best course to reduce poverty (e.g. World Development Report 1990) with the preconditions that access to education, health, and social services are available to all by means of other policies. On the other hand, there is a realisation that growth, inequality, and poverty relations are non-linear, complex, and path dependent in their dynamics. An important point made in this context by Kuznets (1955) was the empirical finding of an inverted U (arch) shape relationship between growth and inequality which suggested that the inequality would increase with growth in the beginning, but will decline at higher levels of growth as the benefits of growth trickle down to lower income strata. This argument has been debated since then in the literature with empirical support gathered for and against this hypothesis. Recent theoretical literature on the issue tries to find the micro-foundations of the dynamical relations between these three variables (see for example, proceedings of the 5th ABCDE Annual (World) Bank Conference on Development Economics). Institutional factors do not change in a few years while they matter in the reduction of poverty as well as in sustaining it at low levels. Hence these relationships are likely to be non-linearity and path dependent, i.e., history matters in the determination of the impact of growth on poverty, of growth on inequality, of inequality on poverty etc. Therefore an understanding of these relationships require knowledge of both the short-run as well as the long-run elasticities of poverty. The method developed by Kakwani (1993) and Kanbur (1987), make use of single survey and provides information on the short-term elasticities but remain silent about longer term relationships between poverty, growth, and inequality.

Enhanced dynamic source routing for verifying trust in mobile ad hoc network for secure routing

Secure data transfer in mobile ad hoc network (MANET) against malicious attacks is of immense importance. In this paper, we propose a new enhanced trust model for securing the MANET using trust-based scheme that uses both blind trust and referential trust. In order to do this, the trust relationship function has to be integrated with the dynamic source routing (DSR) protocol for making the protocol more secure. We thoroughly analyze the DSR protocol and generate the performance matrices for the data pertaining to packets sent, packets received, packets loss, and throughput. We also analyze the outcome attained from the improvised trust establishment scheme by using the three algorithm implementations in NS2 simulator for detecting and preventing various types of attacks

Testing Semi-strong Form Efficiency of Stock Market

The efficient market hypothesis suggests that stock markets are “informationally efficient”. That is, any new information relevant to the market is spontaneously reflected in the stock prices. A consequence of this hypothesis is that past prices cannot have any predictive power for future prices once the current prices have been used as an explanatory variable. In other words the change in future prices depends only on arrival of new information that was unpredictable today hence it is based on surprise information. Another consequence of this hypothesis is that arbitrage opportunities are wiped out instantaneously. Empirical tests of the efficient market hypothesis actually test for these consequences in various ways. Some of them have been summarised in earlier chapters. These tests generally could not conclusively accept the random-walk hypothesis of stock returns even when GARCH effects were accounted for. Many studies have found empirical regularities that are contrary to the efficient market hypothesis. For example, the monthly, weekly and daily returns on stocks tend to exhibit discernable patterns, such as seasonal affects, month of the year affect, day of the week affect, hourly affect etc. In case of Pakistan’s stock markets too such affects are identified. Such as the Ramadan affect [see Hussain and Uppal (1999)], seasonal effects and day of the week affect. Further, the wide spread use of “technical analysis” among stock traders and their ability to predict to some extent the direction of movements in the prices of individual stocks over medium term testifies to the existence of patterns and seasonal trends

Dynamics of Growth, Poverty, and Inequality in Pakistan

The relationship between growth, inequality, and poverty has been a moot point. On the one hand growth is considered central or the best course to reduce poverty (e.g. World Development Report 1990) with the preconditions that access to education, health, and social services are available to all by means of other policies. On the other hand, there is a realisation that growth, inequality, and poverty relations are non-linear, complex, and path dependent in their dynamics. An important point made in this context by Kuznets (1955) was the empirical finding of an inverted U (arch) shape relationship between growth and inequality which suggested that the inequality would increase with growth in the beginning, but will decline at higher levels of growth as the benefits of growth trickle down to lower income strata. This argument has been debated since then in the literature with empirical support gathered for and against this hypothesis. Recent theoretical literature on the issue tries to find the micro-foundations of the dynamical relations between these three variables (see for example, proceedings of the 5th ABCDE Annual (World) Bank Conference on Development Economics)

COMPARATIVE PHARMACOGNOSTICAL EVALUATION OF COSTUS SPECIOSUS (WILD GINGER) AND ZINGIBER OFFICINALE (GINGER) RHIZOME

Objective: Costus speciosus Koen. (Ginger) is an Indian ornamental plant, belonging to family Costaceae. The present research work deals with the establishment of standardization parameter regarding comparative pharmacognostic study between Costus speciosus and Zingiber officinale rhizome.Methods: Macroscopic and microscopic evaluation, physicochemical parameters like ash values, moisture content, extractive value, fluorescence analysis and the preliminary phytochemical investigation was done.Results: The Macroscopic difference was found as an absence of odor and taste in Costus speciosus and presence of pungent and aromatic odor in Zingiber officinale. Oil globule, tracheids, starch granules in Zingiber officinale was found whereas the absence of the same in Costus speciosus rhizome was found in the microscopic evaluation. Fluorescence study also exhibits differences. The presence of saponin, carbohydrate, glycosides in Costus speciosus whereas Zingiber officinale revealed the presence of alkaloids, glycosides, flavonoids and protein.Conclusion: These finding can serve as the basis for Identification and investigation of Costus speciosus and Zingiber officinale rhizome and can also establish the characteristic differentiating features of both

Sero-negative celiac disease with dermatitis herpetiformes: a case report

Introduction:We report a case of sero-negative celiac disease in Pakistan. Case Presentation: A 20-year-old female presented with papulovesicular rash for 15 years, diarrhea for 8 years, spasms of hands and twitching of face for 4-5 months. She had mild anemia, low vitamin-D3 and serum calcium. On exclusion of other causes of malabsorption, anti-tissue transglutaminase antibodies (immunoglobulin-A & immunoglobulin-G), anti-endomysial antibodies, total immunoglobulin-A levels and skin biopsy were performed, which were normal. Intestinal biopsy revealed subtotal villous atrophy. Patient was prescribed gluten-free diet, to which she responded with alleviation of symptoms. Conclusions: Negative serology should not rule out celiac disease, intestinal biopsy should be performed if there is strong clinical suspicion

Formulation and invitro evaluation of oral extended release microspheres of aceclofenac using various natural polymers

In the present work, bioadhesive microspheres of Aceclofenac using Sodium alginate along with Carbopol 934, Carbopol 971, HPMC K4M as copolymers were formulated to deliver Aceclofenac via oral route. The results of this investigation indicate that ionic cross-linking technique Ionotropic gelation method can be successfully employed to fabricate Aceclofenac microspheres. The technique provides characteristic advantage over conventional microsphere method, which involves an “all-aqueous” system, avoids residual solvents in microspheres. FT-IR spectra of the physical mixture revealed that the drug is compatible with the polymers and copolymers used. Micromeritic studies revealed that the mean particle size of the prepared microspheres was in the size range of 512-903µm and are suitable for bioadhesive microspheres for oral administration. The in-vitro mucoadhesive study demonstrated that microspheres of Aceclofenac using sodium alginate along with Carbopol934 as copolymer adhered to the mucus to a greater extent than the microspheres of Aceclofenac using sodium alginate along with Carbopol 971 and HPMC K4M as copolymers. The invitro drug release decreased with increase in the polymer and copolymer concentration. Analysis of drug release mechanism showed that the drug release from the formulations followed non-Fickian diffusion and the best fit model was found to be Korsmeyer-Peppas. Based on the results of evaluation tests formulation coded T4 was concluded as best formulation

Compound heterozygosity for a whole gene deletion and p.R124C mutation in CYP21A2 causing nonclassic congenital adrenal hyperplasia

We present a family with 2 members who received long-term steroid treatment for presumed classic congenital adrenal hyperplasia (CAH) due to 21-hydroxylase deficiency, until molecular testing revealed nonclassic CAH, not necessarily requiring treatment. A 17-year-old male presented to our clinic on glucocorticoid and mineralocorticoid treatment for classic CAH. He was diagnosed at 4 years of age based on mild-moderate elevations of 17-hydroxyprogesterone (17-OHP) and adrenocorticotropic hormone (ACTH), but without evidence of precocious adrenarche/puberty. Due to his diagnosis, his clinically asymptomatic 3-year-old sister was tested and also found to have elevated ACTH and 17-OHP levels and was started on glucocorticoids for classic CAH. Family history revealed a healthy sibling who had no biochemical evidence of CAH and consanguineous healthy parents. We questioned the diagnosis of classic CAH and performed an ACTH1-24 stimulation test, which showed a level of 17-OHP in the borderline range between classic and nonclassic CAH. Molecular testing, using sequencing and multiplex ligation-dependent probe amplification analysis of CYP21A2, revealed that both affected siblings were compound heterozygotes for a whole-gene deletion and a, likely pathogenic (nonclassical), sequence variant, p.R124C. The asymptomatic father had the same genotype, while the mother showed one deleted copy and 2 active copies, making her an asymptomatic carrier. Our report demonstrates the importance of molecular testing in atypical cases of CAH, as well as the importance of both sequencing and deletion analysis. The results of molecular testing should be interpreted in clinical context, and treatment should be prescribed according to guidelines when available