Changing patterns of global-scale vegetation photosynthesis, 1982-1999

The primary objective of this research was to assess changes in global vegetation photosynthesis between 1982 and 1999. Global-scale Advanced Very High Resolution Radiometer (AVHRR) Normalized Difference Vegetation Index (NDVI) data from the Pathfinder AVHRR Land (PAL) and Global Inventory Modeling and Mapping Studies (GIMMS) datasets were analysed for 96% of the non-Antarctic land area of the Earth. The results showed that between 1982 and 1999 over 30% of the Earth's land surface increased and less than 5% decreased in annual average photosynthesis greater than 4%. Although both the PAL and GIMMS datasets produced broadly similar patterns of change, there were distinct differences between the two datasets. Changes in vegetation photosynthesis were occurring in spatial clusters across the globe and were being driven by climate change, El Nino-Southern Oscillation (ENSO) events and human activity

Driving automation: Learning from aviation about design philosophies

Full vehicle automation is predicted to be on British roads by 2030 (Walker et al., 2001). However, experience in aviation gives us some cause for concern for the 'drive-by-wire' car (Stanton and Marsden, 1996). Two different philosophies have emerged in aviation for dealing with the human factor: hard vs. soft automation, depending on whether the computer or the pilot has ultimate authority (Hughes and Dornheim, 1995). This paper speculates whether hard or soft automation provides the best solution for road vehicles, and considers an alternative design philosophy in vehicles of the future based on coordination and cooperation

Differential response of barrier island dune grasses to species interactions and burial

Barrier islands are at the forefront of storms and sea-level rise. High disturbance regimes and sediment mobility make these systems sensitive and dynamic. Island foredunes are protective structures against storm-induced overwash that are integrally tied to dune grasses via biogeomorphic feedbacks. Shifts in dune grass dominance could influence dune morphology and susceptibility to overwash, altering island stability. In a glasshouse study, two dune grasses, Ammophila breviligulata and Uniola paniculata, were planted together and subjected to a 20 cm burial to quantify morphological and physiological responses. Burial had positive effects on both plants as indicated by increased electron transport rate and total biomass. Ammophila breviligulata performance declined when planted with U. paniculata. Uniola paniculata was not affected when planted with A. breviligulata but did have higher water use efficiency and nitrogen use efficiency. Planted in mixture, differential reallocation of biomass occurred between species potentially altering resource acquisition further. As U. paniculata migrates into A. breviligulata dominated habitat and A. breviligulata performance diminishes, biotic interactions between these and other species may affect dune formation and community structure. Our study emphasizes the importance of studying biotic interactions alongside naturally occurring abiotic drivers

Spontaneous Raman scattering as a high resolution XUV radiation source

A type of high resolution XUV radiation source is described which is based upon spontaneous anti-Stokes scattering of tunable incident laser radiation from atoms excited to metastable levels. The theory of the source is summarized and two sets of experiments using He (1s2s)(1)S atoms, produced in a cw hollow cathode and in a pulsed high power microwave discharge, are discussed. The radiation source is used to examine transitions originating from the 3p(6) shell of potassium. The observed features include four previously unreported absorption lines and several sharp interferences of closely spaced autoionizing lines. A source linewidth of about 1.9 cm(-1) at 185,000 cm(-1) is demonstrated

Vacuum ultraviolet holography

The authors report the first demonstration of holographic techniques in the vacuum ultraviolet spectral region. Holograms were produced with coherent 1182 A radiation. The holograms were recorded in polymethyl methacrylate and read out with an electron microscope. A holographic grating with a fringe spacing of 836 A was produced and far-field Fraunhofer holograms of sub-micron particles were recorded

Studies of laser and laser devices

The generation of tunable, infrared, and ultraviolet light, and the control of this light by mode-locking and modulation techniques are discussed. Particular emphasis is given to energy storage and extraction using atomic levels, the development of a tunable narrowband vacuum ultraviolet light source, and to the generation and applications of ultrashort optical pulses

Studies on lasers and laser devices

The goal of this grant was to study lasers, laser devices, and uses of lasers for investigating physical phenomena are studied. The active projects included the development of a tunable, narrowband XUV light source and its application to the spectroscopy of core excited atomic states, and the development of a technique for picosecond time resolution spectroscopy of fast photophysical processes

Building bridges: the third sector responding locally to diversity

This paper focuses on a hitherto unstudied segment of the broad 'third sector': organisations and groupings that aim to build bridges (that is, increase interpersonal contacts) between people of different faiths and/or ethnic groups. We draw on the findings of an empirical study, conducted in three diverse urban areas of England, of community-level projects with bridge building as an explicit aim. We describe the characteristics of bridge-building activities and the challenges they face; both the organisational challenges and those that arise from the nature of bridge building itself. We conclude by exploring the implications of our findings for an understanding of the third sector generally and for the potential role of the sector in responding to our diverse society

Developing community and social cohesion through grassroots bridge-building: an exploration

In the context of the UK public policy goal to increase community and social cohesion, this article explores the nature of local 'bridge-building' – activities intended to increase interpersonal contacts between diverse ethnic, faith and nationality groups. We draw on earlier research in a range of fields to develop the bridge-building concept and present findings from a study that identified community-level projects with bridge-building as a specific aim. We show the range of groupings involved, the activities encompassed and their organisational features. We consider the actual and potential contribution of local bridge-building to cohesion in the light of earlier research and our own study