The independent and interactive effects of snail grazing and nutrient enrichment on structuring periphyton communities

We investigated the independent and interactive effects of nutrient enrichment and snail grazing on structuring periphyton communities in a northern temperate lake. Nutrient releasing substrates and grazer enclosures were used to simultaneously manipulate nutrient availability and herbivory. Periphyton was allowed 18 days to accrue before grazers ( Elimia livescens = Goniobasis livescens ) were introduced.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42878/1/10750_2004_Article_BF00006063.pd

Distribution of Hyperpolarized Xenon in the Brain Following Sensory Stimulation: Preliminary MRI Findings

In hyperpolarized xenon magnetic resonance imaging (HP 129Xe MRI), the inhaled spin-1/2 isotope of xenon gas is used to generate the MR signal. Because hyperpolarized xenon is an MR signal source with properties very different from those generated from water-protons, HP 129Xe MRI may yield structural and functional information not detectable by conventional proton-based MRI methods. Here we demonstrate the differential distribution of HP 129Xe in the cerebral cortex of the rat following a pain stimulus evoked in the animal's forepaw. Areas of higher HP 129Xe signal corresponded to those areas previously demonstrated by conventional functional MRI (fMRI) methods as being activated by a forepaw pain stimulus. The percent increase in HP 129Xe signal over baseline was 13–28%, and was detectable with a single set of pre and post stimulus images. Recent innovations in the production of highly polarized 129Xe should make feasible the emergence of HP 129Xe MRI as a viable adjunct method to conventional MRI for the study of brain function and disease

The 'local turn' in historical perspective: two city case studies in Britain & Germany

This article addresses the ‘local turn’ of migration and integration policies in historical perspective in Newcastle upon Tyne and Bremen. It draws upon a wide range of government documentation and offers a comparative assessment of both cities’ policies from the 1960s onwards. It discusses the vertical dimension of policymaking though an exploration of the local governance of migrant integration in relation to the national level. Although Britain and Germany's post-war immigration histories and political structures have often been perceived as contrasting, this article reveals a convergence in these cities’ governments’ approaches to their own local diverse societies. These case studies question the long-term impact of overarching national constitutional structures on city-level migration policies. Findings are framed within the local governance and multi-level governance MLG debates. Points for practitioners - European cities are increasingly being recognized for the role they play in devising and implementing their own migration and integration policies. Yet very little is known about the relationship between this ‘local turn’ and multi-level governance (MLG). Practitioners can learn more about cities’ policymaking processes and the extent to which these have been influenced by national agendas, as well as about how research of a historical and cross-country and cross-city nature can inform the on-going policy debate

A dedicated storage ring for Far-IR coherent synchrotron radiation at the ALS

We present the concepts for a storage ring dedicated to and optimized for the production of stable coherent synchrotron radiation (CSR) over the far-infrared wavelength range from about 200 microns to 1 mm