2,119 research outputs found

    The cross-pathway control system regulates production of the secondary metabolite toxin, sirodesmin PL, in the ascomycete, Leptosphaeria maculans

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    <p>Abstract</p> <p>Background</p> <p>Sirodesmin PL is a secondary metabolite toxin made by the ascomycetous plant pathogen, <it>Leptosphaeria maculans</it>. The sirodesmin biosynthetic genes are clustered in the genome. The key genes are a non-ribosomal peptide synthetase, <it>sirP</it>, and a pathway-specific transcription factor, <it>sirZ</it>. Little is known about regulation of sirodesmin production.</p> <p>Results</p> <p>Genes involved in regulation of sirodesmin PL in <it>L. maculans </it>have been identified. Two hundred random insertional T-DNA mutants were screened with an antibacterial assay for ones producing low levels of sirodesmin PL. Three such mutants were isolated and each transcribed <it>sirZ </it>at very low levels. One of the affected genes had high sequence similarity to <it>Aspergillus fumigatus cpcA</it>, which regulates the cross-pathway control system in response to amino acid availability. This gene was silenced in <it>L. maculans </it>and the resultant mutant characterised. When amino acid starvation was artificially-induced by addition of 3-aminotriazole for 5 h, transcript levels of <it>sirP </it>and <it>sirZ </it>did not change in the wild type. In contrast, levels of <it>sirP </it>and <it>sirZ </it>transcripts increased in the silenced <it>cpcA </it>mutant. After prolonged amino acid starvation the silenced <it>cpcA </it>mutant produced much higher amounts of sirodesmin PL than the wild type.</p> <p>Conclusions</p> <p>Production of sirodesmin PL in <it>L. maculans </it>is regulated by the cross pathway control gene, <it>cpcA</it>, either directly or indirectly via the pathway-specific transcription factor, <it>sirZ</it>.</p

    The immunopathogenesis of tuberculous pericarditis

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    Tuberculous pericarditis is a severe form of extrapulmonary tuberculosis and is the commonest cause of pericardial effusion in high incidence settings. Mortality ranges between 8 and 34%, and it is the leading cause of pericardial constriction in Africa and Asia. Current understanding of the disease is based on models derived from studies performed in the 1940–50s. This review summarises recent advances in the histology, microbiology and immunology of tuberculous pericarditis, with special focus on the effect of Human Immunodeficiency Virus (HIV) and the determinants of constriction

    Exploring corruption in fisheries

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    This paper explores corruption in global fisheries. While reducing corruption is critical for the effective management of the fisheries sector and the fulfilment of the UN’s sustainable development goals (SDGs, and SDGs14 and 16 in particular), to do so, it is necessary to first have a systematic and comprehensive understanding of what corruption is and how it is manifested in the sector. There is literature on illegal, unregulated and unreported (IUU) fishing, but not much on corruption. The paper proposes an analytical framework and applies it with six revelatory cases to improve the conceptual clarity of corruption in fisheries. Specific corruption problems found in licensing, negotiating access agreements, lax enforcement, extortion, political corruption, money laundering and tax manipulation, human trafficking etc. can therefore be better identified through this analysis, which lays a base for systematic responses to tackling corruption in fisheries and accordingly furthering the sustainable development of the sector

    Orchard Day, August 18, 1955; Results of Fruit Research

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    Storing peaches / Donald Comin -- Trends in storages / Donald Comin -- Grape varieties ; Grape soil management and fertilization ; Nitrogen fertilizers for apple trees / J. M. Beattie -- Colorset on Golden Delicious and Grimes ; Planting distance influence on yield of apples ; Harvest dates for apples ; Summer varieties of apples ; Pre-harvest spraying for Baldwin / C. W. Ellenwood -- Peach investigations ; The blueberry planting ; Strawberry studies ; Plum varieties and culture ; Grape weed control studies / R. G. Hill, Jr. -- Semi-dwarf apple trees in Ohio / Freeman S. Howlett and T. E. Fowler -- The Franklin Apple / Freeman S. Howlett and C. W. Ellenwood -- Status of intermediate (trunk-forming) stocks for the apple ; Pruning the newly planted apple tree ; Status of the pear industry in Ohio / Freeman S. Howlett -- Pear variety collection indicates several deserve limited trial / Freeman S. Howlett and C. W. Ellenwoo

    Using legume-based mixtures to enhance the nitrogen use efficiency and economic viability of cropping systems - Final report (LK09106/HGCA3447)

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    As costs for mineral fertilisers rise, legume-based leys are recognised as a potential alternative nitrogen source for crops. Here we demonstrate that including species-rich legume-based leys in rotations helps to maximise synergies between agricultural productivity and other ecosystem services. By using functionally diverse plant species mixtures, these services can be optimised and fine-tuned to regional and farm-specific needs. Replicated field experiments were conducted over three years at multiple locations, testing the performance of 12 legume species and 4 grass species sown in monocultures, as well as in a mixture of 10 of the legumes and all 4 grasses (called the All Species Mix, ASM). In addition, we compared this complex mixture to farmer-chosen ley mixtures on 34 sites across the UK. The trials showed that there is a large degree of functional complementarity among the legume species. No single species scored high on all evaluation criteria. In particular, the currently most frequently used species, white clover, is outscored by other legume species on a number of parameters such as early development and resistance to decomposition. Further complementarity emerged from the different responses of legume species to environmental variables, with soil pH and grazing or cutting regime being among the more important factors. For example, while large birdsfoot trefoil showed better performance on more acidic soils, the opposite was true for sainfoin, lucerne and black medic. In comparison with the monocultures, the ASM showed increased ground cover, increased above-ground biomass and reduced weed biomass. Benefits of mixing species with regard to productivity increased over time. In addition, the stability of biomass production across sites was greater in the ASM than in the legume monocultures. Within the on-farm trials, we further found that on soils low in organic matter the biomass advantage of the ASM over the Control ley was more marked than on the soils with higher organic matter content. Ecological modelling revealed that the three best multifunctional mixtures all contained black medic, lucerne and red clover. Within the long term New Farming Systems (NFS) rotational study, the use of a clover bi-crop showed improvement to soil characteristics compared to current practice (e.g. bulk density and water infiltration rate). Improvements in wheat yield were also noted with respect to the inclusion of a clover bi-crop in 2010, but there was evidence of a decline in response as the N dose was increased. Cumulatively, over both the wheat crop and the spring oilseed rape crop, the clover bi-crop improved margin over N. The highest average yield response (~9%) was associated with the ASM legume species mix cover cropping approach

    Earliest Cretaceous cocoons or plant seed structures from the Wealden Group, Hastings, UK

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    We thank Jason Hilton (University of Birmingham) and Alan Spencer (Imperial College) for discussion. RG is a member of the Interdisciplinary Centre for Ancient Life (UMRI). We are grateful for the reviews of both Jorge Genise, and Duncan McIlroy whose comments and guidance greatly improved the manuscript.Postprin

    Profiles of SUMO and ubiquitin conjugation in an Alzheimer's disease model

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    ► Global levels of ubiquitinated proteins increased in the hippocampus of Tg2576 mice. ► No global changes in either SUMO-1 or SUMO-2/3 conjugation in any brain regions analysed. ► SUMO conjugating and deconjugating enzymes, UBC9 and SENP-1, unaltered in Tg2576 mice. ► Total levels of AMPA and kainate receptors were also unaffected in Tg2576 mice. ► Posttranslational modification by ubiquitin may play a role in Alzheimer's disease

    Nutrition interventions for healthy ageing across the lifespan:a conference report

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    Thanks to advances in modern medicine over the past century, the world's population has experienced a marked increase in longevity. However, disparities exist that lead to groups with both shorter lifespan and significantly diminished health, especially in the aged. Unequal access to proper nutrition, healthcare services, and information to make informed health and nutrition decisions all contribute to these concerns. This in turn has hastened the ageing process in some and adversely affected others' ability to age healthfully. Many in developing as well as developed societies are plagued with the dichotomy of simultaneous calorie excess and nutrient inadequacy. This has resulted in mental and physical deterioration, increased non-communicable disease rates, lost productivity and quality of life, and increased medical costs. While adequate nutrition is fundamental to good health, it remains unclear what impact various dietary interventions may have on improving healthspan and quality of life with age. With a rapidly ageing global population, there is an urgent need for innovative approaches to health promotion as individual's age. Successful research, education, and interventions should include the development of both qualitative and quantitative biomarkers and other tools which can measure improvements in physiological integrity throughout life. Data-driven health policy shifts should be aimed at reducing the socio-economic inequalities that lead to premature ageing. A framework for progress has been proposed and published by the World Health Organization in its Global Strategy and Action Plan on Ageing and Health. This symposium focused on the impact of nutrition on this framework, stressing the need to better understand an individual's balance of intrinsic capacity and functional abilities at various life stages, and the impact this balance has on their mental and physical health in the environments they inhabit
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