Publications by authors named "Ian Townsend"

England's 10 national parks are renowned for their landscapes, wildlife, and recreational value. However, surface waters in the national parks may be vulnerable to pollution from human-use chemicals, such as active pharmaceutical ingredients (APIs), because of factors like ineffective wastewater treatment, seasonal tourism, a high proportion of elderly residents, and the presence of low-flow water bodies that limit dilution. The present study determined the extent of API contamination in the English national parks by monitoring 54 APIs in 37 rivers across all national parks over two seasons.

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Acidic herbicides are used to control broad-leaved weeds. They are stable, water-soluble, and with low binding to soil are found frequently in surface waters, often at concentrations above the EU Drinking Water Directive limit of 0.10 μg L.

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Metaldehyde is a potent molluscicide. It is the active ingredient in most slug pellets used for crop protection. This polar compound is considered an emerging pollutant.

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Tributyltin (TBT) is a legacy pollutant in the aquatic environment, predominantly from its use in anti-foulant paints and is listed as a priority hazardous substance in the European Union's Water Framework Directive (WFD). Measuring low concentrations of TBT and other organotins (e.g.

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New Zealand biodiversity has often been viewed as Gondwanan in origin and age, but it is increasingly apparent from molecular studies that diversification, and in many cases origination of lineages, postdate the break-up of Gondwanaland. Relatively few studies of New Zealand animal species radiations have as yet been reported, and here we consider the species-rich genus of carabid beetles, Mecodema. Constrained stratigraphic information (emergence of the Chatham Islands) and a substitution rate for Coleoptera were separately used to calibrate Bayesian relaxed molecular clock date estimates for diversification of Mecodema.

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Methallyl chloride serves as an efficient allyl donor in highly enantioselective Grignard Nozaki-Hiyama methallylations from the alcohol or aldehyde oxidation level via iridium catalyzed transfer hydrogenation. Under identical conditions, methallyl acetate does not react efficiently. Double methallylation of 1,3-propanediol provides the C(2)-symmetric adduct as a single enantiomer, as determined by HPLC analysis.

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The cyclometalated iridium complex (S)-I derived from [Ir(cod)Cl](2), 4-cyano-3-nitrobenzoic acid, allyl acetate, and (S)-SEGPHOS is conveniently isolated by precipitation or through conventional silica gel flash chromatography. This single-component precatalyst allows alcohol mediated carbonyl crotylations to be performed at significantly lower temperature, resulting in enhanced levels of anti-diastereo- and enantioselectivity. Most significantly, the chromatographically isolated precatalyst (S)-I enables carbonyl crotylations that are not possible under previously reported conditions involving in situ generation of (S)-I.

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Background: Perioperative ischemic optic neuropathy occurs after major surgical procedures, which are often associated with hypotension, anemia, or venous congestion. However, the effects of these conditions on optic nerve (ON) blood flow are unknown and cannot be studied adequately in humans.

Methods: Farm-raised pigs were anesthetized with isoflurane, kept normocapnic and normothermic, and subjected to conditions of euvolemic or hypovolemic hypotension (mean arterial pressure 50-55 mm Hg), anemia (hematocrit 17%), venous congestion, and combinations thereof.

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