1,149 research outputs found
Can crop science really help us to produce more better quality food while reducing the world-wide environmental footprint of agriculture?
This paper reviews recent developments in crop science that can be the basis of a revolution in the global food system but it is also emphasized that such a revolution requires more than changes in food production and supply. We must more effectively feed a growing global population with a healthy diet while also defining and delivering the kinds of sustainable food systems that will minimise damage to our planet. There are exciting new developments in crop production biology but much existing crop science can be exploited to increase yields with the aid of a knowledge exchange (KE) framework requiring the use of new technology now available to most people across the globe. We discuss novel approaches at both the plant and the crop level that will enhance nutrient and water productivity and we also outline ways in which energy use and greenhouse gas (GHG) emissions can be reduced and labor shortages combatted. Exploitation of new biology and new engineering opportunities will require development of public-private partnerships and collaborations across the disciplines to allow us to move effectively from discovery science to practical application. It is also important that consumers contribute to the debate over proposed changes to food and farming and so effective KE mechanisms are required between all relevant communities
Mechanism for the formation of the high-altitude stagnant cusp: Cluster and SuperDARN observations
On 16 March 2002, Cluster moved from nightside to dayside, across the high-altitude northern cusp during an extended period of relatively steady positive IMF BY and BZ. Combined Cluster and SuperDARN data imply the existence of two reconnection sites: in the high- latitude northern hemisphere dusk and southern hemisphere dawn sectors. Within the cusp, Cluster encounters 3 distinct plasma regions. First, injections of magnetosheath-like plasma associated with dawnward and sunward convection suggest Cluster crosses newly- reconnected field lines related to the dusk reconnection site. Second, Cluster observes a Stagnant Exterior Cusp (SEC), characterized by nearly isotropic and stagnant plasma. Finally, Cluster crosses a region with significant antifield-aligned flows. We suggest the observed SEC may be located on newly re-closed field lines, reconnected first poleward of the northern hemisphere cusp and later reconnected again poleward of the southern hemisphere cusp. We discuss how the Cluster observations correspond to expectations of âdouble reconnectionâ model
A qualitative evaluation of a preceptorship programme to support newly qualified midwives
Background. Contemporary UK midwifery practice has its own particular pressures upon â and requirements of â newly qualified practitioners. The NMC recommends that the focus of pre-registration programmes of midwifery must be on the skills and attitudes needed to support and promote normal birth (NMC, 2007). In relation to the skills of caring for women at high risk of complications, the NMC states that âskills required for taking on the role of lead carer for women with complex medical and/or obstetric needs is developmental, and competence is to be achieved after initial registrationâ (NMC, 2009: 19). It is therefore likely that the midwife, at the point of qualification, will not be fully conversant with the range of skills associated with the care of women with complex needs, and some structured programme is required (DH, 2008).Aim. A midwifery programme of preceptorship was implemented in 2004 in one NHS foundation trust in north-west England and a structured evaluation was undertaken, starting in June 2009, to identify strengths and weaknesses to further develop the programme.Method. Focus groups and interviews were used to collect data from one cohort of six newly qualified midwives (NQMs), six preceptors and four midwifery managers over an 18-month period from June 2009 to December 2010. Data were collected on participantsâ perceptions of strengths and weaknesses in the programme with regard to curriculum content, support and professional development. Data were analysed using thematic analysis. Three overarching themes were identified from the data: developing competence and confidence, support, and organisational constraints. The head of midwifery gave permission for the study to be conducted and the proposal received ethical approval from the university ethics committee.Results. The structured preceptorship programme was viewed as helpful in developing the NQMâs confidence and competence. The relationships built up during this time were considered to be valuable and mutually beneficial. Organisational constraints at times made achieving the aims of the programme more difficult and necessitated a flexible, individualised approach. Implications. The evaluation supports the evidence for implementation of a personalised, structured, and equitable approach to UK midwifery preceptorship, accompanied by further research on its effects on the care of women and retention of staff
Total joint replacement in sub-Saharan Africa:a systematic review
Outcomes of arthroplasty in sub-Saharan Africa are not widely reported. To our knowledge, this systematic review is the first to explore this topic. Scopus, EMBASE, Medline and PubMed databases were searched, utilising MeSH headings and Boolean search strategies. All papers from South Africa were excluded. Twelve papers reporting 606 total hip replacements (THRs) and 763 total knee replacements (TKRs) were included. Avascular necrosis was the most common indication for THR, whereas osteoarthritis was the main indication for TKR. HIV prevalence of up to 33% was seen. Improvements were seen in patient-reported outcome measures in both THR and TKR. The dislocation rate in THR was 1.6%. The deep infection rate was 1.6% for TKRs and 0.5% for THRs. Positive results were reported, with comparable complications to high-income countries. However, there is likely to be significant reporting bias and the introduction of mandatory registries would enable more accurate monitoring across the region
Catch crop strategy and nitrate leaching following grazed grass-clover
Cultivation of grassland presents a high risk of nitrate leaching. This study aimed to determine if leaching could be reduced by growing spring barley (Hordeum vulgare L.) as a green crop for silage with undersown Italian ryegrass (Lolium multiïŹorum Lam.) compared with barley grown to maturity with or without an undersown conventional catch crop of perennial ryegrass (Lolium perenne L.). All treatments received 0,60 or 120 kg of ammonium-N ha-1 in cattle slurry. In spring 2003, two grass-clover ïŹelds (3 and 5 years old, respectively, with different management histories) were ploughed. The effects of the treatments on yield and nitrate leaching were determined in the ïŹrst year, while the residual effects of the treatments were determined in the second year in a crop of spring barleyâperennial ryegrass. Nitrate leaching was estimated in selected treatments using soil water samples from ceramic cups. The experiment showed that compared with treatments without catch crop, green barleyâItalian ryegrass reduced leaching by 163â320 kg Nha-1, corresponding to 95â99%, and the perennial ryegrass reduced leaching to between 34 and 86 kg Nha-1, corresponding to a reduction of 80 and 66%. Also, in the second growing season, leaching following catchcrops was reduced compared with the bare soil treatment. It was concluded that the green barleyâItalian ryegrass offers advantages not only for the environment but also for farmers, for whom it provides a fodder high in roughage and avoids the difïŹculties with clover fatigue increasingly experienced by Danish farmers
Fission widths of hot nuclei from Langevin dynamics
Fission dynamics of excited nuclei is studied in the framework of Langevin
equation. The one body wall-and-window friction is used as the dissipative
force in the Langevin equation. In addition to the usual wall formula friction,
the chaos weighted wall formula developed earlier to account for
nonintegrability of single-particle motion within the nuclear volume is also
considered here. The fission rate calculated with the chaos weighted wall
formula is found to be faster by about a factor of two than that obtained with
the usual wall friction. The systematic dependence of fission width on
temperature and spin of the fissioning nucleus is investigated and a simple
parametric form of fission width is obtained.Comment: RevTex, 12 pages including 9 Postscript figure
Urban geology of Swansea: Neath : Port Talbot
The conurbation of SwanseaâNeathâPort Talbot is one of the main centres of
industrial development in South Wales. A long history of mineral extraction and
processing, which stoked the initial growth of the towns, declined during the 20th
Century. Many of these former industries have left a legacy of groundwater, watercourse
and land contamination.
A project funded by the Environment & Hazards Directorate (British Geological
Survey) between 2000-2005 used available geological data to determine potential
areas of contaminated land and understand the influence of the geology to pollutant
pathways (Waters et al., In press a). The study covered 100 km2 of the Swansea-
Neath-Port Talbot area (Fig. 2.1) and was aimed at providing data relevant to
contaminated land issues, to augment the study by Arup (1997) on earth science
information relevant to planning and development for the Swansea-Llanelli district,
and look at new methodologies of presenting the data
Time-Dependent Hartree-Fock simulation of the expansion of abraded nuclei
A recent interpretation of the caloric curve based on the expansion of the
abraded spectator nucleus is re-analysed in the framework of the Time-Dependent
Hartree-Fock (TDHF) evolution. It is shown that the TDHF dynamics is more
complex than a single monopolar collective motion at moderate energy. The
inclusion of other important collective degrees of freedom may lead to the
dynamical creation of hollow structure. Then, low density regions could be
locally reached after a long time by the creation of these exotic density
profiles. In particular the systematic of the minimum density reached during
the expansion (the so-called turning points) appears to be different.Comment: 30 Latex pages including 9 figure
Prescission neutron multiplicity and fission probability from Langevin dynamics of nuclear fission
A theoretical model of one-body nuclear friction which was developed earlier,
namely the chaos-weighted wall formula, is applied to a dynamical description
of compound nuclear decay in the framework of the Langevin equation coupled
with statistical evaporation of light particles and photons. We have used both
the usual wall formula friction and its chaos-weighted version in the Langevin
equation to calculate the fission probability and prescission neutron
multiplicity for the compound nuclei W, Pt, Pb,
Fr, Th, and Es. We have also obtained the contributions
of the presaddle and postsaddle neutrons to the total prescission multiplicity.
A detailed analysis of our results leads us to conclude that the chaos-weighted
wall formula friction can adequately describe the fission dynamics in the
presaddle region. This friction, however, turns out to be too weak to describe
the postsaddle dynamics properly. This points to the need for a suitable
explanation for the enhanced neutron emission in the postsaddle stage of
nuclear fission.Comment: RevTex, 14 pages including 5 Postscript figures, results improved by
using a different potential, conclusions remain unchanged, to appear in Phys.
Rev.
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