Ice tectonic deformation during the rapid in situ drainage of a supraglacial lake on the Greenland Ice Sheet.

We present detailed records of lake discharge, ice motion and passive seismicity capturing the behaviour and processes preceding, during and following the rapid drainage of a 4 km<sup>2</sup> supraglacial lake through 1.1-km-thick ice on the western margin of the Greenland Ice Sheet. Peak discharge of 3300 m<sup>3</sup> s<sup>−1</sup> coincident with maximal rates of vertical uplift indicates that surface water accessed the ice–bed interface causing widespread hydraulic separation and enhanced basal motion. The differential motion of four global positioning system (GPS) receivers located around the lake record the opening and closure of the fractures through which the lake drained. We hypothesise that the majority of discharge occurred through a 3-km-long fracture with a peak width averaged across its wetted length of 0.4 m. We argue that the fracture's kilometre-scale length allowed rapid discharge to be achieved by combining reasonable water velocities with sub-metre fracture widths. These observations add to the currently limited knowledge of in situ supraglacial lake drainage events, which rapidly deliver large volumes of water to the ice–bed interface

Functional genomics of ozone stress in Arabidopsis.

The gas ozone (O3) functions as a protector against ultra-violet radiation in the stratosphere. However, in the troposphere it is toxic to plants and causes significant reductions in crop yields. Ozone is a reactive oxygen species (ROS) and can cause oxidative damage directly by entering stomata and interacting with cell wall and membrane components. Ozone can also form other ROS such as hydrogen peroxide and hydroxyl radicals that can cross the plasma membrane and cause further damage, leading to reduced transpiration, accelerated senescence and decreased photosynthesis. A plant-derived oxidative burst also occurs after plants have been exposed to ozone. This closely resembles the hypersensitive response (HR) displayed when plants are challenged by a pathogen. Plants react to oxidative stress by increasing their antioxidant defences in an attempt to neutralise harmful ROS. The individual roles of several antioxidants have been extensively studied, however their regulation and interaction in planta have yet to be fully elucidated. The specificity of antioxidants and other stress-related molecules to each unique stress is also poorly understood. In this work a functional genomics approach has been used to identify novel genes in Arabidopsis thaliana, that are regulated by ozone. A DNA microarray has been utilised to determine gene regulation at the transcriptional level and NMR spectroscopy has been employed to investigate ozone-induced changes to the metabolite profile of Arabidopsis. Twenty genes, which are significantly up-regulated and one gene that is down-regulated by ozone treatment have been identified. The expression of these genes in response to a range of ozone concentrations and time points has been further investigated

The wetlands of Greater Manchester North west wetlands survey 2

Includes map of Chat Moss inside back coverAvailable from British Library Document Supply Centre-DSC:5145.7605(3) / BLDSC - British Library Document Supply CentreSIGLEGBUnited Kingdo

A method for the determination of the relative reactivities of monomers towards the 1-phenylethyl radical

Several monomers have been polymerized using 1,1′-azobis(1-phenyl [1-^(13)C] ethane as initiator; the initiator fragments incorporated in the polymers have been examined by ^(13)C-NMR. The chemical shift for the enriched site in the end-group depends upon the nature of the attached monomeric unit. It is concluded that acenaphthylene is suitable as a reference monomer in comparisons of the reactivities of monomers towards the 1-phenylethyl radical (regarded as a model for the polystyrene radical) by consideration of end-groups in copolymers

Reactivities of monomers towards the 1-phenylethyl radical: Monomers with low ceiling temperatures

The reactivities towards the 1-phenylethyl radical of 2-vinylnaphthalene and some monomers with low ceiling temperatures (α-methylstyrene, 2-isopropenylnaphthalene and α-methoxystyrene) have been assessed by ^(13)C-NMR examination of end-groups in terpolymers prepared at 100° using ^(13)C-enriched azobis-1,1′-phenylethane as initiator. In each case, acenaphthylene has been used with styrene (STY) or methyl methacrylate and a third monomer selected from the quoted list. The present and previous results suggest that, for many monomers, the reactivity towards the 1-phenylethyl radical is very similar to that predicted from data on copolymerizations with STY, regarding the initiating small radical as a model for the polystyrene radical. There are appreciable differences between the observed and predicted relative reactivities in cases where either the copolymerization of the monomer with STY may show quite pronounced penultimate group effects or the monomer has a low ceiling temperature