226 research outputs found

    Follow-up of X-ray transients detected by SWIFT with COLORES using the BOOTES network

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    The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes that allows the continuous monitoring of transient astrophysical sources. It was originally devoted to the study of the optical emission from gamma-ray bursts (GRBs) that occur in the Universe. In this paper we show the initial results obtained using the spectrograph COLORES (mounted on BOOTES-2), when observing compact objects of diverse nature.Comment: 6 pages, 2 figues, to appear in "Swift: 10 years of discovery", Proceedings of Scienc

    From Protecting the Heart to Improving Athletic Performance - the Benefits of Local and Remote Ischaemic Preconditioning

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    Remote Ischemic Preconditioning (RIPC) is a non-invasive cardioprotective intervention that involves brief cycles of limb ischemia and reperfusion. This is typically delivered by inflating and deflating a blood pressure cuff on one or more limb(s) for several cycles, each inflation-deflation being 3-5 min in duration. RIPC has shown potential for protecting the heart and other organs from injury due to lethal ischemia and reperfusion injury, in a variety of clinical settings. The mechanisms underlying RIPC are under intense investigation but are just beginning to be deciphered. Emerging evidence suggests that RIPC has the potential to improve exercise performance, via both local and remote mechanisms. This review discusses the clinical studies that have investigated the role of RIPC in cardioprotection as well as those studying its applicability in improving athletic performance, while examining the potential mechanisms involved

    Development and characterisation of a collagen nano-hydroxyapatite composite scaffold for bone tissue engineering.

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    Bone regeneration requires scaffolds that possess suitable mechanical and biological properties. This study sought to develop a novel collagen-nHA biocomposite scaffold via two new methods. Firstly a stable nHA suspension was produced and added to a collagen slurry (suspension method), and secondly, porous collagen scaffolds were immersed in nHA suspension after freeze-drying (immersion method). Significantly stronger constructs were produced using both methods compared to collagen only scaffolds, with a high porosity maintained (\u3e98.9%). It was found that Coll-nHA composite scaffolds produced by the suspension method were up to 18 times stiffer than the collagen control (5.50 +/- 1.70 kPa vs. 0.30 +/- 0.09 kPa). The suspension method was also more reproducible, and the quantity of nHA incorporated could be varied with greater ease than with the immersion technique. In addition, Coll-nHA composites display excellent biological activity, demonstrating their potential as bone graft substitutes in orthopaedic regenerative medicine

    INITIAL FOLLOW-UP OF OPTICAL TRANSIENTS WITH COLORES USING THE BOOTES NETWORK

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    The Burst Observer and Optical Transient Exploring System (BOOTES) is a network of telescopes that allows the continuous monitoring of transient astrophysical sources. It was originally devoted to the study of the optical emissions from gamma-raybursts (GRBs) that occur in the Universe. In this paper we show the initial results obtained using the spectrograph COLORES (mounted on BOOTES-2), when observing optical transients (OTs) of a diverse nature

    Use of Bacteriocins to Improve Cheese Quality and Safety

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    End of Project ReportThe objectives of this project were to generate, characterise and exploit a range of novel bacteriocin producing starter cultures to improve both the safety and the quality of fermented dairy foods. The main conclusions were as follows: Lacticin 3147 is a broad spectrum bacteriocin which inhibits a wide range of Gram-positive bacteria including lactobacilli, clostridia and Listeria. The bacteriocin has been purified by chromatographic procedures and has been shown to be composed of two peptides, both of which are required for biological activity. The mechanism of action of lacticin 3147 has been elucidated. The entire plasmid encoding lacticin 3147 has been sequenced and the bacteriocin in distinct from any previously characterised lactococcal bacteriocin. The Food Grade introduction of the bacteriocin genes into cheese starters was carried out. Lacticin 3147 producing starters have been used to control the pathogen Listeria monocytogenes on the surface of mould ripened cheese. Lacticin 3147 producing starters have been used to control the non-starter lactic acid bacteria complement in Cheddar cheese during the ripening process. A novel starter system using a bacteriocin (lactococcin)- producing adjunct has been designed which gives increased cell lysis during Cheddar cheese manufacture while ensuring that efficient acid production is not compromised. In summary these studies have found that naturally occurring antimicrobials such as bacteriocins have a wide range of applications in the food industry for improving both the quality and safety of fermented dairy products.Department of Agriculture, Food and the Marin

    Spatiotemporal dynamics and modelling support the case for area-wide management of citrus greasy spot in a Brazilian smallholder farming region

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    Citrus greasy spot (CGS), caused by Zasmidium citri, induces premature defoliation and yield loss in Citrus spp. The epidemiology of CGS is well understood in high humidity areas, but remains unaddressed in Brazil, despite differing climatic conditions and disease management practices. The spatiotemporal dynamics of CGS was characterized in the Recôncavo of Bahia (Brazil) at four hierarchical levels (quadrant, plant, grove and region). A survey conducted in 19 municipalities found the disease to be present throughout the region with an incidence of 100% in groves and plants, and higher than 70% on leaves. Index of dispersion (D) values suggest the spatial pattern of symptomatic units lies between random and regular. This was confirmed by the parameters of the binary power law for plants and their quadrants (log(A)<0 and b<1). No consistent differences were observed in the disease incidence at different plant heights. We introduce a compartmental model synthesizing CGS epidemiology. The collected data allow such a model to be parameterised, albeit with some ambiguity over the proportion of new infections that result from inoculum produced within the grove vs. external sources of infection. By extending the model to include two populations of growers – those who control and those who do not – coupled by the airborne inoculum, we investigate likely performance of cultural controls accessible to citrus growers in Northeastern Brazil. The results show that control via removal of fallen leaves can be very effective. However, successful control is likely to require area-wide strategies, in which a large proportion of growers actively manage disease

    Risk-based management of invading plant disease

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    - Effective control of plant disease remains a key challenge. Eradication attempts often involve removal of host plants within a certain radius of detection, targeting asymptomatic infection. Here we develop and test potentially more effective, epidemiologically motivated, control strategies, using a mathematical model previously fitted to the spread of citrus canker in Florida. - We test risk-based control, which preferentially removes hosts expected to cause a high number of infections in the remaining host population. Removals then depend on past patterns of pathogen spread and host removal, which might be nontransparent to affected stakeholders. This motivates a variable radius strategy, which approximates risk-based control via removal radii that vary by location, but which are fixed in advance of any epidemic. - Risk-based control outperforms variable radius control, which in turn outperforms constant radius removal. This result is robust to changes in disease spread parameters and initial patterns of susceptible host plants. However, efficiency degrades if epidemiological parameters are incorrectly characterised. - Risk-based control including additional epidemiology can be used to improve disease management, but it requires good prior knowledge for optimal performance. This focuses attention on gaining maximal information from past epidemics, on understanding model transferability between locations and on adaptive management strategies that change over time.Part of this work was funded by the USDA-APHIS Farm Bill; C.A.G. acknowledges support from USDA-APHIS
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