Effect of weightlessness and radiation on the growth of the wheat coleoptile for the purpose of defining and verifying an experiment suitable for use in a biosatellite

Effects of temperature, X-ray irradiation, and elevated gravity on wheat seedling growt

Fragments of the earliest land plants

The earliest fossil evidence for land plants comes from microscopic dispersed spores. These microfossils are abundant and widely distributed in sediments, and the earliest generally accepted reports are from rocks of mid-Ordovician age (Llanvirn, 475 million years ago). Although distribution, morphology and ultrastructure of the spores indicate that they are derived from terrestrial plants, possibly early relatives of the bryophytes, this interpretation remains controversial as there is little in the way of direct evidence for the parent plants. An additional complicating factor is that there is a significant hiatus between the appearance of the first dispersed spores and fossils of relatively complete land plants (megafossils): spores predate the earliest megafossils (Late Silurian, 425 million year ago) by some 50 million years. Here we report the description of spore-containing plant fragments from Ordovician rocks of Oman. These fossils provide direct evidence for the nature of the spore-producing plants. They confirm that the earliest spores developed in large numbers within sporangia, providing strong evidence that they are the fossilized remains of bona fide land plants. Furthermore, analysis of spore wall ultrastructure supports liverwort affinities

Stratosphere-troposphere transport in a numerical simulation of midlatitude convection

The transport of stratospheric air deep into the troposphere via convection is investigated numerically using the UK Met Office Unified Model. A convective system that formed on 27 June 2004 near southeast England, in the vicinity an upper level potential vorticity anomaly and a lowered tropopause, provides the basis for analysis. Transport is diagnosed using a stratospheric tracer that can either be passed through or withheld from the model’s convective parameterization scheme. Three simulations are performed at increasingly finer resolutions, with horizontal grid lengths of 12, 4, and 1 km. In the 12 and 4 km simulations, tracer is transported deeply into the troposphere by the parameterized convection. In the 1 km simulation, for which the convective parameterization is disengaged, deep transport is still accomplished but with a much smaller magnitude. However, the 1 km simulation resolves stirring along the tropopause that does not exist in the coarser simulations. In all three simulations, the concentration of the deeply transported tracer is small, three orders of magnitude less than that of the shallow transport near the tropopause, most likely because of the efficient dilution of parcels in the lower troposphere

The impact of drought on carers

Carers have, on average, a more tenuous and weaker attachment to the labour market than non-carers because they face a complex set of demands on their time and must balance the needs of other people. Accordingly, it is plausible that regional shocks from droughts may adversely affect carers compared to other residents. This paper combines meteorological data with recent census data to illustrate that drought in agricultural labour markets has a greater impact on employment outcomes for carers than other residents. Furthermore, the employment differential is not manifest for part-time employment outcomes. Implications for policy makers are considered in some detail

Baryon operators and spectroscopy in lattice QCD

The construction of the operators and correlators required to determine the excited baryon spectrum is presented, with the aim of exploring the spatial and spin structure of the states while minimizing the number of propagator inversions. The method used to construct operators that transform irreducibly under the symmetries of the lattice is detailed, and the properties of example operators are studied using domain-wall fermion valence propagators computed on MILC asqtad dynamical lattices.Comment: 7 pages, 2 figures, to appear in Proceedings of Workshop on Lattice Hadron Physics 2003, Cairns, Australia, July 22 - July 30, 200

Do riparian forest fragments provide ecosystem services or disservices in surrounding oil palm plantations?

Agricultural expansion across tropical regions is causing declines in biodiversity and altering ecological processes. However, in some tropical agricultural systems, conserving natural habitat can simultaneously protect threatened species and support important ecosystem services. Oil palm cultivation is expanding rapidly throughout the tropics but the extent to which non-crop habitat supports biodiversity and ecosystem services in these landscapes is poorly documented. We investigated whether riparian forest fragments (riparian reserves) provide a pest control service or increase pest activity (disservice) within oil palm dominated landscapes in Sabah, Malaysian Borneo. We assessed the activity of potential predators of pest herbivores using plasticine caterpillar mimics and quantified herbivory rates on oil palm fronds in areas with and without riparian reserves. We also manipulated the shape and colour of the mimics to assess the extent to which artificial pest mimics reflect a predatory response. The presence of riparian reserves increased the attack rate on mimics by arthropods, but not by birds. Our methodological study suggested attacks on artificial pest mimics provide a better indication of predatory activity for birds than for arthropod predators. Herbivory rates were also not significantly affected by the presence of a riparian reserve, but we found some evidence that herbivory rates may decrease as the size of riparian reserves increases. Overall, we conclude that riparian forest fragments of 30 – 50 m width on each side of the river are unlikely to provide a pest control service. Nevertheless, our results provide evidence that these riparian buffer strips do not increase the density of defoliating pests, which should reassure managers concerned about possible negative consequences of preserving riparian buffers

Theatre in Towns

Theatre in Towns offers a contemporary perspective on the role of theatre in the cultural life of towns in England. Exploring volunteer-led, professional and community theatres, this book investigates the rich and diverse ways that theatres in towns serve their locality, negotiate their civic role, participate in networks of mutual aid and exchange, and connect audiences beyond their geographical borders. With a geographical focus on post-industrial, seaside, commuter and market towns in England, the book opens questions about how theatre shapes the narratives of town life, and how localism, networks and partnerships across and between towns contribute to living sustainably. Each chapter is critically and historically informed, drawing on original research in towns, including visits to performances and many conversations with townspeople, from theatre-makers, performers, set-builders, front-of-house volunteers, to audience members and civic leaders. Theatre in Towns asks urgent questions about how the relationships between towns and theatres can be redefined in new and equitable ways in the future. Theatre in Towns brings new research to scholars and students of theatre studies, cultural geography, cultural and social policy and political sociology. It will also interest artists, policy-makers and researchers wanting to develop their own and others’ understanding of the value of active theatre cultures in towns

Theatres in Towns:Why they matter

This briefing paper reports on research on theatre in towns undertaken between 2021 and 2022. When the research began in March 2021, the long-term effects of the Covid-19 global pandemic on theatres, town centres, and the cultural life of towns was only just coming into focus. By 31st March 2023, one of the most iconic of town theatres, Oldham Coliseum, had closed its doors for the last time. This closure throws a spotlight on the value of theatres in towns for local employment, audiences, artists, and communities.Our research identifies the positive contribution theatres make to towns across England. Where theatres are supported and thrive, they bring a range of social benefits and creative opportunities to communities and townspeople. The research also shows the risks and challenges theatres face, and what would be lost if theatres in towns close

Magnetic Control of Convection in Nonconducting Paramagnetic Fluids

An inhomogeneous magnetic field exerts a magnetic body force on magnetically permeable fluids. A recent experiment [D. Braithwaite, E. Beaugnon, and R. Tournier, Nature (London) 354, 134 (1991)] demonstrates that this force can be used to compensate for gravity and to control convection in a paramagnetic solution of gadolinium nitrate. We provide the theory of magnetically controlled convection in a horizontal paramagnetic fluid layer heated from either above or below. Our theoretical predictions agree with the experiments