Study on Noncommutative Representations of Galilean Generators

The representations of Galilean generators are constructed on a space where both position and momentum coordinates are noncommutating operators. A dynamical model invariant under noncommutative phase space transformations is constructed. The Dirac brackets of this model reproduce the original noncommutative algebra. Also, the generators in terms of noncommutative phase space variables are abstracted from this model in a consistent manner. Finally, the role of Jacobi identities is emphasised to produce the noncommuting structure that occurs when an electron is subjected to a constant magnetic field and Berry curvature.Comment: Title changed, new references added, published in Int. J. Mod. Phys.

Nicotine Promotes Tumor Growth and Metastasis in Mouse Models of Lung Cancer

Nicotine is the major addictive component of tobacco smoke. Although nicotine is generally thought to have limited ability to initiate cancer, it can induce cell proliferation and angiogenesis in a variety of systems. These properties might enable nicotine to facilitate the growth of tumors already initiated. Here we show that nicotine significantly promotes the progression and metastasis of tumors in mouse models of lung cancer. This effect was observed when nicotine was administered through intraperitoneal injections, or through over-the-counter transdermal patches.In the present study, Line1 mouse adenocarcinoma cells were implanted subcutaneously into syngenic BALB/c mice. Nicotine administration either by intraperitoneal (i.p.) injection or transdermal patches caused a remarkable increase in the size of implanted Line1 tumors. Once the tumors were surgically removed, nicotine treated mice had a markedly higher tumor recurrence (59.7%) as compared to the vehicle treated mice (19.5%). Nicotine also increased metastasis of dorsally implanted Line1 tumors to the lungs by 9 folds. These studies on transplanted tumors were extended to a mouse model where the tumors were induced by the tobacco carcinogen, NNK. Lung tumors were initiated in A/J mice by i.p. injection of NNK; administration of 1 mg/kg nicotine three times a week led to an increase in the size and the number of tumors formed in the lungs. In addition, nicotine significantly reduced the expression of epithelial markers, E-Cadherin and beta-Catenin as well as the tight junction protein ZO-1; these tumors also showed an increased expression of the alpha(7) nAChR subunit. We believe that exposure to nicotine either by tobacco smoke or nicotine supplements might facilitate increased tumor growth and metastasis.Our earlier results indicated that nicotine could induce invasion and epithelial-mesenchymal transition (EMT) in cultured lung, breast and pancreatic cancer cells. This study demonstrates for the first time that administration of nicotine either by i.p. injection or through over-the-counter dermal patches can promote tumor growth and metastasis in immunocompetent mice. These results suggest that while nicotine has only limited capacity to initiate tumor formation, it can facilitate the progression and metastasis of tumors pre-initiated by tobacco carcinogens

Alienation, power, and gender in sociological theory : a study of Marx, Foucault, and feminism

Includes bibliographical references (pages [69]-71)This thesis investigates certain critical ideas of Karl Marx and Michel Foucault and explores their significance for feminism. Chapter 1 provides a brief introduction to the issues explored in the thesis. Chapter 2 examines Marx's theory of alienation as delineated in the Economic and Philosophic Manuscripts of 1844 and traces its continuity through his later work, with reference to Volume One of Capital. It is argued that the theory of alienation remained critical to his work throughout his life and that it formed the basis for many of his later works, including important economic concepts. The chapter also describes Marx's position on women, based on his early ideas in the Manuscripts, through his last writings, The Ethnological Notebooks. Although it is commonly believed that Marx was indifferent to the issues related to gender, his own writings and activities demonstrate that he was sensitive to them, and that he considered women to play a central role in human history. Chapter 3 presents Foucault's critique of modern society, discourse and the relation between power and knowledge. It focuses on his archaeological work, Madness and Civilization, and two of his genealogical books, Discipline and Punish and Volume I of The History of Sexuality. Foucault analyzes the power relations that develop from the establishment of Enlightenment rationality which presents itself as progressive, emancipatory, and the key to truth and knowledge. The hegemony of Enlightenment rationality creates a social network of normative power which operates at the microlevel. Chapter 4 considers the relevance of these ideas for women through specific feminist responses, and their implications for gender-related issues.M.A. (Master of Arts

Corporate Disclosure, Compliance and Consequences: Evidence from Russia

Does the introduction of corporate transparency and disclosure rules in emerging economies affect compliance, and therefore earnings quality and firm performance? We explore these questions for an important emerging economy, Russia, using a natural experiment, the 2002 introduction of Russian corporate governance code. We exploit the exogenous variation in voluntary disclosure and find a significant increase in corporate disclosure among the domestic Russian firms over the period 2003-07 when firms gradually adopted some but not all disclosure rules. The immediate effect of the introduction was a drop in reported earnings. Market valuation, however, only improved for domestic firms after 2007, when all domestic firms had complied. However, cross-listed firms, which were already satisfying international standards, remained largely unaffected. Though average compliance by domestic firms was only 53%, average firm value of treated domestic firms, relative to cross-listed ones, went up by about 10%. Results are robust, confirm external validity and offer important policy implications for other emerging/ transition economies

Regulation and Firm Value: Curious Case of Transparency and Disclosure Laws in Russia

We provide novel evidence on the effectiveness of mandated changes in Russian transparency and disclosure (henceforth T&D) rules in boosting shareholder welfare. We focus on the staggered implementation of these T&D reforms initiated in 2002 and implemented during 2003-07. Using difference in difference method, we find that the reforms improved earnings quality, which on average reduced the operating performance (i.e., EBIT/Assets) of treated domestically-listed (relative to our control group of cross-listed) Russian firms, but had no significant impact on their market valuation. We argue that low tax alignment, where financial statements are not used for tax purposes, made it possible for managers of domestically-listed firms to inflate pre-reforms earnings, which became difficult post-reforms, leading to a drop in operating earnings. Yet, firm values, on average, remained unchanged because the drop in earnings was roughly offset by a decrease in the required market return due to more reliable accounting information post reform. Also, T&D reforms had negligible effects on cross-listed firms that act as our control group. Further, for domestically listed firms without a domestic controlling shareholder, post-reform reported earnings did not drop, while firm value increased significantly. For the domestically listed firms with a controlling shareholder, just the opposite occurred. Thus, a key finding of our study is that a strong governance structure is a prerequisite for significant gains in shareholder wealth following improved reliability of firm accounting information

Regulation and Firm Value: Curious Case of Transparency and Disclosure Laws in Russia

We provide novel evidence on the effectiveness of mandated changes in Russian transparency and disclosure (henceforth T&D) rules in boosting shareholder welfare. We focus on the staggered implementation of these T&D reforms initiated in 2002 and implemented during 2003-07. Using difference in difference method, we find that the reforms improved earnings quality, which on average reduced the operating performance (i.e., EBIT/Assets) of treated domestically-listed (relative to our control group of cross-listed) Russian firms, but had no significant impact on their market valuation. We argue that low tax alignment, where financial statements are not used for tax purposes, made it possible for managers of domestically-listed firms to inflate pre-reforms earnings, which became difficult post-reforms, leading to a drop in operating earnings. Yet, firm values, on average, remained unchanged because the drop in earnings was roughly offset by a decrease in the required market return due to more reliable accounting information post reform. Also, T&D reforms had negligible effects on cross-listed firms that act as our control group. Further, for domestically listed firms without a domestic controlling shareholder, post-reform reported earnings did not drop, while firm value increased significantly. For the domestically listed firms with a controlling shareholder, just the opposite occurred. Thus, a key finding of our study is that a strong governance structure is a prerequisite for significant gains in shareholder wealth following improved reliability of firm accounting information

Corporate disclosure, compliance and consequences: evidence from Russia

Does the introduction of corporate transparency and disclosure rules in emerging economies affect compliance, and therefore earnings quality and firm performance? We explore these questions for an important emerging economy, Russia, using a natural experiment, the 2002 introduction of Russian corporate governance code. We exploit the exogenous variation in voluntary disclosure and find a significant increase in corporate disclosure among the domestic Russian firms over the period 2003–2007 when firms gradually adopted some but not all disclosure rules. The immediate effect of the introduction was a drop in reported earnings. Market valuation, however, only improved for domestic firms after 2007, when all domestic firms had complied. However, cross-listed firms, which were already satisfying international standards, remained largely unaffected. Though average compliance by domestic firms was only 53%, average firm value of treated domestic firms, relative to cross-listed ones, went up by about 10%. Results are robust, confirm external validity and offer important policy implications for other emerging/ transition economies