M G Shepherd

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Activities and properties of the ammonium assimilation enzymes NADP+-dependent glutamate dehydrogenase (GDH), glutamate synthase (GOGAT) and glutamine synthetase (GS) were determined in batch and continuous cultures of Candida albicans. NADP+-dependent GDH activity showed allosteric kinetics, with an S0.5 for 2-oxoglutarate of 7.5 mM and an apparent Km for(More)
Dopamine, glutamic acid decarboxylase (G.A.D.) and choline acetyltransferase (C.A.T.) were measured in four regions of post-mortem brains. 41 patients with the hospital diagnosis of schizophrenia (psychotic group) were compared with a control grout normal in the putamen. G.A.D. activity was significantly reduced in the psychotic group, by about 50% in the(More)
[1] In recent times it has become increasingly clear that releases of trace gases from human activity have a potential for causing change in the upper atmosphere. However , our knowledge of systematic changes and trends in the temperature of the mesosphere and lower thermo-sphere is relatively limited compared to the Earths lower atmosphere, and not much(More)
Temperature data from the COSMIC GPS-RO satellite constellation are used to study the distribution and variability of planetary wave activity in the low to mid-stratosphere (15–40 km) of the Arctic and Antarctic from September 2006 until March 2009. Stationary waves are separated from travelling waves and their amplitudes, periods and small-scale vertical(More)
Airglow observations with a Spectral Airglow Temperature Imager (SATI), installed at the Sierra Nevada Observatory (37.06 • N, 3.38 • W) at 2900-m height, have been used to investigate the presence of tidal variations at mid-latitudes in the mesosphere/lower thermosphere region. Diurnal variations of the column emission rate and vertically averaged(More)
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