Mark Ballantyne

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para-Phenylenediamine (PPD), a widely used ingredient of oxidative hair dyes, is converted by human hepatocytes and in the human epidermis, or after topical application to rats, to its N-monoacetylated (MAPPD) and/or N,N'-diacetylated (DAPPD) derivatives. We investigated in vitro genotoxic properties of PPD, MAPPD and DAPPD in the Ames test, the(More)
Facilitation often occurs in environments where extreme climatic factors favour positive rather than negative species interactions. This includes larger ‘nurse’ cushion plants in some alpine environments that shelter other species from abiotic filters such as abrasive winds and low temperatures. This type of facilitation can contribute to higher alpha(More)
Particulate matter (PM) collected from mainstream tobacco smoke is a test article commonly used for in vitro genotoxicity and cytotoxicity testing of combustible tobacco products. However, little published data exists concerning the stability of PM. We completed a 2 year study to quantify the effect of PM storage at -80 °C, on the genotoxicity and(More)
Three commercial brands of Swedish snus (SWS), an experimental SWS, and the 2S3 reference moist snuff were each tested in four in vitro toxicology assays. These assays were: Salmonella reverse mutation, mouse lymphoma, in vitro micronucleus, and cytotoxicity. Water extractions of each of the 5 products were tested using several different concentrations; the(More)
Tourism and recreation are diverse and popular activities. They may also contribute to the risk of extinction for some plants because of the range and severity of their impacts, including in protected areas: but which species, where and how? To evaluate the extent to which tourism and recreation may be threatening process for plants, we conducted a(More)
Salmonella typhimurium strains TA1535, TA1537, TA97, TA102 and TA104 were assessed for their suitability and use in conjunction with a Vitrocell(®) VC 10 Smoking Robot and 3R4F reference mainstream cigarette smoke. Little information exists on TA97, TA104, TA1535, TA1537 and TA102 using an aerosol 35mm spread-plate format. In this study, TA1535 and TA1537(More)
Although there are a multitude of in vitro and in vivo studies on the genotoxic activity of EMS, no lifetime carcinogenicity studies, repeat dose mutation data or exposure analysis are available to serve as a solid basis for risk assessment for human exposure cases. The present studies were undertaken to investigate whether a threshold for mutagenic and(More)
Tourism and recreation are large industries employing millions of people and contribute over US$2.01 trillion to the global economy. Unfortunately they also have diverse and sometimes severe environmental impacts affecting many species, including those that are rare and threatened. To assess the extent to which these industries threaten vascular plants, we(More)
Hiking trails, which are among the most common forms of infrastructure created for nature-based tourism, can alter key ecological processes. Trails can damage plants that facilitate the establishment and growth of other species leading to changes in community and functional composition. This can be a particular concern in harsh alpine ecosystems where plant(More)