Synthetic studies on chaksine

This thesis is concerned with the studies in the synthesis of a monoterpenoid alkaloid, chaksine. Ethyl 2-n~butyl-4-bromoacetoacetate (11) was treated with sodium azide to give ethyl 2-n-butyl-4-azidoacetoacetate (12), Catalytic hydrogenation of (12) in presence of hydrochloric acid followed by the reaction of the hydrogenation product (13) with potassium cyanate afforded 4-(1'- carbethoxypenty1)-2-imidazolone (14) or 4-(1'-carboxypentyl)- 2-imidazolone (15) depending on reaction condition. 4-(1'-carbethoxymethyl)-2-imidazolone (25) was also prepared starting from ethyl 4-bromoacetoacetate (23a) following the same series of reaction as described for the compound (14). Ethyl 2-[4'-methy1-5'-(2"-tetrahydropyranyloxy1)pentyl] acetoacetate (20) was prepared from the reaction of ethyl acetoacetate and 5-bromo-2-methyl-1-(2'-tetrahydropyranyloxyl)pentane (19). Removal of the 3,4- dihydropyran protecting group from (20) yielded ethyl 2-(4'-methyl—5'-hydroxypentyl)acetoacetate (21). The compound (21) was also prepared directly by the reaction of ethylacetoacetate with 5-bromo-2-methyl- pentanol (18), The compound (21) was then subjected to bromination to give (22a) followed by the treatment of (22a) with sodium azide to yield ethyl 2-(4'-methyl-5'-hydroxypentyl)-4-azidoacetoacetate (22b)

Locating NAPLs in Ground Water Using Partitioning Fluorescent Dyes

A major challenge in ground water remediation is locating nonaqueous phase liquids (NAPLs). Partitioning tracers can be used to identify NAPL sources between injection and extraction wells. NAPLs are only slightly soluble in water, pose a long-term source of groundwater contamination, and can be difficult to remove. The complexity of recovery processes requires the development of new technologies that guarantee cost effective methods for locating and quantifying NAPLs. Traditional methods like soil coring have been inefficient since they underestimate the quantity of NAPLs and are expensive. Partitioning tracer tests are some of the most recent methods developed for locating these contaminants and determining the volume of the NAPL present in the inter-well zone. The results of the tests can be used to develop remediation techniques to recover NAPLs entrapped in the contaminated zone. Fluorescent dyes may be useful as partitioning tracers. They can be analyzed quickly at the field site, resulting in a shorter analysis time and lower costs than other partitioning tracers. This project pursued the selection of suitable tracers and the development of partitioning tracer techniques to locate and quantify NAPLs in the subsurface

Contact transmission of influenza virus between ferrets imposes a looser bottleneck than respiratory droplet transmission allowing propagation of antiviral resistance

Influenza viruses cause annual seasonal epidemics and occasional pandemics. It is important to elucidate the stringency of bottlenecks during transmission to shed light on mechanisms that underlie the evolution and propagation of antigenic drift, host range switching or drug resistance. The virus spreads between people by different routes, including through the air in droplets and aerosols, and by direct contact. By housing ferrets under different conditions, it is possible to mimic various routes of transmission. Here, we inoculated donor animals with a mixture of two viruses whose genomes differed by one or two reverse engineered synonymous mutations, and measured the transmission of the mixture to exposed sentinel animals. Transmission through the air imposed a tight bottleneck since most recipient animals became infected by only one virus. In contrast, a direct contact transmission chain propagated a mixture of viruses suggesting the dose transferred by this route was higher. From animals with a mixed infection of viruses that were resistant and sensitive to the antiviral drug oseltamivir, resistance was propagated through contact transmission but not by air. These data imply that transmission events with a looser bottleneck can propagate minority variants and may be an important route for influenza evolution

The ‘caged torch procession’: Celebrities, protesters and the 2008 Olympic torch relay in London, Paris and San Francisco

Along with the opening and closing ceremonies, one of the major non-sports events associated with the modern Olympic Games is the torch relay. Although initiated in 1936, the relay has been subject to relatively little academic scrutiny. The events of April 2008 however will have cast a long shadow on the practice. This essay focuses primarily on one week (6–13 April) in the press coverage of the 2008 torch relay as the flame made its way from London to Paris in Europe and then to San Francisco in the USA. It discusses the interpretations offered in the mediated coverage about the relay, the Olympic movement, the host city and the locations where the relay was taking place, and critically analyses the role of agencies, both for and against the Olympics, that framed the ensuing debate

Nanoethics, science communication, and a fourth model for public engagement

This paper develops a fourth model of public engagement with science, grounded in the principle of nurturing scientific agency through online participatory bioethics. It argues that social media is an effective device through which to enable such engagement, as it has the capacity to empower users and transforms audiences into co-producers of knowledge, rather than consumers of content, the value of which is recognised within the citizen science movement. Social media also fosters greater engagement with the political and legal implications of science, thus promoting the value of scientific citizenship through the acquisition of science capital. This argument is explored by considering the case of nanoscience and nanotechnology, as an exemplar for how emerging technologies may be handled by the scientific community and science policy makers, and as a technology that has defined a second era of science communication

Photo-Induced Spin Dynamics in Semiconductor Quantum Wells

We experimentally investigate the dynamics of spins in GaAs quantum wells under applied electric bias by photoluminescence (PL) measurements excited with circularly polarized light. The bias-dependent circular polarization of PL (PPL) with and without magnetic field is studied. ThePPLwithout magnetic field is found to be decayed with an enhancement of increasing the strength of the negative bias. However,PPLin a transverse magnetic field shows oscillations under an electric bias, indicating that the precession of electron spin occurs in quantum wells. The results are discussed based on the electron–hole exchange interaction in the electric field

Mobile, wearable and ingestible health technologies : towards a critical research agenda

In this article, we review critical research on mobile and wearable health technologies focused on the promotion of ‘healthy lifestyles’. We begin by discussing key governmental and policy interests which indicate a shift towards greater digital integration in health care. Subsequently, we review relevant research literature, which highlights concerns about inclusion, social justice, and ownership of mobile health data, which we argue, provoke a series of key sociological questions that are in need of additional investigation. We examine the expansion of what counts as health data, as a basis for advocating the need for greater research into this area. Finally, we consider how digital devices raise questions about the reconfiguration of relationships, behaviours, and concepts of individuality

From Utopia to Science: Challenges of Personalised Genomics Information for Health Management and Health Enhancement

From 1900 onwards, scientists and novelists have explored the contours of a future society based on the use of “anthropotechnologies” (techniques applicable to human beings for the purpose of performance enhancement ranging from training and education to genome-based biotechnologies). Gradually but steadily, the technologies involved migrated from (science) fiction into scholarly publications, and from “utopia” (or “dystopia”) into science. Building on seminal ideas borrowed from Nietzsche, Peter Sloterdijk has outlined the challenges inherent in this development. Since time immemorial, and at least since the days of Plato’s Academy, human beings have been interested in possibilities for (physical or mental) performance enhancement. We are constantly trying to improve ourselves, both collectively and individually, for better or for worse. At present, however, new genomics-based technologies are opening up new avenues for self-amelioration. Developments in research facilities using animal models may to a certain extent be seen as expeditions into our own future. Are we able to address the bioethical and biopolitical issues awaiting us? After analyzing and assessing Sloterdijk’s views, attention will shift to a concrete domain of application, namely sport genomics. For various reasons, top athletes are likely to play the role of genomics pioneers by using personalized genomics information to adjust diet, life-style, training schedules and doping intake to the strengths and weaknesses of their personalized genome information. Thus, sport genomics may be regarded as a test bed where the contours of genomics-based self-management are tried out

Strategic & Applied Research & Coordination in Action: Climate Services for Resilient Development (CSRD) in South Asia

A global partnership that is aligned with the Global Framework for Climate Services, Climate Services for Resilient Development (CSRD) works to link climate science, data streams, decision support tools, and training with decision-makers in developing countries. CSRD is led by the United States Government and is supported by the UK Government Department for International Development (DFID), UK Meteorological Office, ESRI, Google, the Inter-American Development Bank, the Asian Development Bank, and the American Red Cross. Led by the International Maize and Wheat Improvement Center (CIMMYT), the CSRD initiative in South Asia works with partners to conduct applied research and facilitate the use of climate information to reduce risk for smallholder farmers. This report details activities of the CSRD project in South Asia during 2018, with emphasis on the second half of 201