Stamp duty on shares and its effect on share prices

This paper provides a discussion of stamp duty and its effects. This is followed by an empirical study using changes in the rate of stamp duty in the UK as natural experiments. Because shares will be affected differently depending on how frequently they are traded, we can employ a difference-in-differences methodology. We find that the announcements of cuts in stamp duty had a significant and positive effect on the price of more frequently traded shares compared to other shares. As expected under the efficient markets hypothesis, the implementation of cuts (when at a different date from the announcement) did not affect returns differentially.Stamp duty, transaction tax, Tobin-tax, natural experiment, tax reform

Stamp duty on shares and its effect on share prices

This paper provides a discussion of stamp duty and its effects. This is followed by an empirical study using changes in the rate of stamp duty in the UK as natural experiments. Because shares will be affected differently depending on how frequently they are traded, we can employ a difference-in-differences methodology. We find that the announcements of cuts in stamp duty had a significant and positive effect on the price of more frequently traded shares compared to other shares. As expected under the efficient markets hypothesis, the implementation of cuts (when at a different date from the announcement) did not affect returns differentially

Persistence of scrapie infectivity within a farm environment after cleaning and decontamination

Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs are directly implicated in the transmission of disease. In this study the effectiveness of recommended scrapie farm decontamination regimes was evaluated by a sheep bioassay using buildings naturally contaminated with scrapie. Pens within a farm building were treated with either 20,000ppm free chorine solution for one hour, or were treated to same but were followed with painting and full re-galvanisation or replacement of metalwork within the pen. Scrapie susceptible lambs of the PRNP genotype VRQ/VRQ were reared within these pens and their scrapie status was monitored by RAMALT. All animals became infected over an 18-month period, even in the pen that had been subject to the most stringent decontamination process. This data suggests that recommended current guidelines for the decontamination of farm buildings following outbreaks of scrapie do little to reduce the titre of infectious scrapie material and that environmental re-contamination could also be an issue associated with these premises

Circulation of prions within dust on a scrapie affected farm

Prion diseases are fatal neurological disorders that affect humans and animals. Scrapie of sheep/goats and Chronic Wasting Disease (CWD) of deer/elk are contagious prion diseases where environmental reservoirs have a direct link to the transmission of disease. Using protein misfolding cyclic amplification we demonstrate that scrapie PrPSc can be detected within circulating dusts that are present on a farm that is naturally contaminated with sheep scrapie. The presence of infectious scrapie within airborne dusts may represent a possible route of infection and illustrates the difficulties that may be associated with the effective decontamination of such scrapie affected premises

Objects in contact with classical scrapie sheep act as a reservoir for scrapie transmission

Classical scrapie is an environmentally transmissible prion disease of sheep and goats. Prions can persist and remain potentially infectious in the environment for many years and thus pose a risk of infecting animals after re-stocking. In vitro studies using serial protein misfolding cyclic amplification (sPMCA) have suggested that objects on a scrapie- affected sheep farm could contribute to disease transmission. This in vivo study aimed to determine the role of field furniture (water troughs, feeding troughs, fencing, and other objects that sheep may rub against) used by a scrapie-infected sheep flock as a vector for disease transmission to scrapie-free lambs with the prion protein genotype VRQ/VRQ, which is associated with high susceptibility to classical scrapie. When the field furniture was placed in clean accommodation, sheep became infected when exposed to either a water trough (four out of five) or to objects used for rubbing (four out of seven). This field furniture had been used by the scrapie-infected flock 8 weeks earlier and had previously been shown to harbor scrapie prions by sPMCA. Sheep also became infected (20 out of 23) through exposure to contaminated field furniture placed within pasture not used by scrapie-infected sheep for 40 months, even though swabs from this furniture tested negative by PMCA. This infection rate decreased (1 out of 12) on the same paddock after replacement with clean field furniture. Twelve grazing sheep exposed to field furniture not in contact with scrapie-infected sheep for 18 months remained scrapie free. The findings of this study highlight the role of field furniture used by scrapie-infected sheep to act as a reservoir for disease re-introduction although infectivity declines considerably if the field furniture has not been in contact with scrapie-infected sheep for several months. PMCA may not be as sensitive as VRQ/VRQ sheep to test for environmental contamination

Risk Based Process Safety for Semiconductor Fabrication Operations

PresentationMost semiconductor manufacturing facilities do not contain quantities of highly hazardous chemicals in threshold quantities sufficient to be subject to the Occupational Health and Safety Administration's (OSHA) Process Safety Management (PSM) regulations. However, some organizations are applying Risk Based Process Safety (RBPS) concepts as a systematic means to not only ensure EHS risks are identified and quantified, but also to strengthen overall business performance and provide competitive advantages. Aging Fabrication facilities and infrastructure, their ever-increasing production demands, rapid innovation and need for process modifications are also business drivers for RBPS. The core RBPS concepts not only provide a holistic approach to protect employees from catastrophic accidents and releases; but in most cases also drive production efficiencies, increase equipment/tool reliability and life span, promote quality improvements, and enhance business continuity measures. This is accomplished by application of a wide range of process safety management elements, as applicable to semiconductor operations, which fall under the following four basic pillars of RBPS: Process Safety Leadership/Commitment; Risk Assessment/Identification; Risk Management; and Learning and Continuous Improvement. This session will discuss the basic concepts of RBPS, including a brief review of the 20 elements as provided by the Center for Chemical Process Safety (CCPS) framework, and present the benefits of developing and implementing process safety management systems for semiconductor processes. Case studies will be presented, as applicable, to detail the advantages, as well as the challenges, of RBPS for the semiconductor industry

Dyslipidemia in an HIV-Positive Antiretroviral Treatment-Naive Population in Dar es Salaam, Tanzania.

Limited data are available on dyslipidemia in HIV-infected patients in resource-limited settings. We performed a cross-sectional analysis in antiretroviral therapy (ART)-naive, non-fasting HIV-infected patients in Tanzania between November 2004 to June 2008. Robust linear regression modeling was performed. Lipid parameters were assessed in 12,513 patients [65% women; median (interquartile range) age, 36 (30-42) years; CD4 count, 143 (51-290) cells/mm]. Low high-density lipoprotein was prevalent in 67% and increased triglyceride in 28%. High triglyceride and low high-density lipoprotein levels were associated with low CD4 counts (P < 0.001). In this ART-naive Tanzanian population, dyslipidemia was highly prevalent and associated with advanced disease. The impact of ART on these changes requires further exploration

Durability and inflammogenic impact of carbon nanotubes compared with asbestos fibres

<p>Abstract</p> <p>Background</p> <p>It has been suggested that carbon nanotubes might conform to the fibre pathogenicity paradigm that explains the toxicities of asbestos and other fibres on a continuum based on length, aspect ratio and biopersistence. Some types of carbon nanotubes satisfy the first two aspects of the fibre paradigm but only recently has their biopersistence begun to be investigated. Biopersistence is complex and requires <it>in vivo </it>testing and analysis. However durability, the chemical mimicking of the process of fibre dissolution using <it>in vitro </it>treatment, is closely related to biopersistence and more readily determined. Here, we describe an experimental process to determine the durability of four types of carbon nanotubes in simulated biological fluid (Gambles solution), and their subsequent pathogenicity <it>in vivo </it>using a mouse model sensitive to inflammogenic effects of fibres. The <it>in vitro </it>and <it>in vivo </it>results were compared with well-characterised glass wool and asbestos fibre controls.</p> <p>Results</p> <p>After incubation for up to 24 weeks in Gambles solution, our control fibres were recovered at percentages consistent with their known <it>in vitro </it>durabilities and/or <it>in vivo </it>persistence, and three out of the four types of carbon nanotubes tested (single-walled (CNT_SW) and multi-walled (CNT_TANG2, CNT_SPIN)) showed no, or minimal, loss of mass or change in fibre length or morphology when examined by electron microscopy. However, the fourth type [multi-walled (CNT_LONG1)] lost 30% of its original mass within the first three weeks of incubation, after which there was no further loss. Electron microscopy of CNT_LONG1samples incubated for 10 weeks confirmed that the proportion of long fibres had decreased compared to samples briefly exposed to the Gambles solution. This loss of mass and fibre shortening was accompanied by a loss of pathogenicity when injected into the peritoneal cavities of C57Bl/6 mice compared to fibres incubated briefly. CNT_SWdid not elicit an inflammogenic effect in the peritoneal cavity assay used here.</p> <p>Conclusions</p> <p>These results support the view that carbon nanotubes are generally durable but may be subject to bio-modification in a sample-specific manner. They also suggest that pristine carbon nanotubes, either individually or in rope-like aggregates of sufficient length and aspect ratio, can induce asbestos-like responses in mice, but that the effect may be mitigated for certain types that are less durable in biological systems. Results indicate that durable carbon nanotubes that are either short or form tightly bundled aggregates with no isolated long fibres are less inflammogenic in fibre-specific assays.</p