154 research outputs found

    MOSES: MHT Optical Star and Exoplanet Survey

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    This thesis presents the design and instigation of a new optical imaging survey to search for stellar variability, exoplanets and solar system bodies. The data collection was carried out using the Moses Holden Telescope based at Alston Observatory, Preston UK. Over the course of 183 nights from our first observing season and 3 nights from our second season (with actual observing achieved on 25 nights from season 1) the survey obtained 3728 images, and obtained at least 200 repeat observations for 29,399 objects. Preliminary analysis indicates a total of 430 stars display variability above 3σ, thereby increasing the number of known variables in the survey region by a factor of at least 200. Ongoing observations and analysis will classify the various forms of variability, and further push down the thresholds for detection of variability to allow the detection of transiting exoplanets

    Intravascular heavy chain-modification of hyaluronan during endotoxic shock

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    During inflammation, the covalent linking of the ubiquitous extracellular polysaccharide hyaluronan (HA) with the heavy chains (HC) of the serum protein inter alpha inhibitor (IαI) is exclusively mediated by the enzyme tumor necrosis factor α (TNFα)-stimulated-gene-6 (TSG-6). While significant advances have been made regarding how HC-modified HA (HC-HA) is an important regulator of inflammation, it remains unclear why HC-HA plays a critical role in promoting survival in intraperitoneal lipopolysaccharide (LPS)-induced endotoxemia while exerting only a modest role in the outcomes following intratracheal exposure to LPS. To address this gap, the two models of intraperitoneal LPS-induced endotoxic shock and intratracheal LPS-induced acute lung injury were directly compared in TSG-6 knockout mice and littermate controls. HC-HA formation, endogenous TSG-6 activity, and inflammatory markers were assessed in plasma and lung tissue. TSG-6 knockout mice exhibited accelerated mortality during endotoxic shock. While both intraperitoneal and intratracheal LPS induced HC-HA formation in lung parenchyma, only systemically-induced endotoxemia increased plasma TSG-6 levels and intravascular HC-HA formation. Cultured human lung microvascular endothelial cells secreted TSG-6 in response to both TNFα and IL1β stimulation, indicating that, in addition to inflammatory cells, the endothelium may secrete TSG-6 into circulation during systemic inflammation. These data show for the first time that LPS-induced systemic inflammation is uniquely characterized by significant vascular induction of TSG-6 and HC-HA, which may contribute to improved outcomes of endotoxemia

    SkydancerPlex: A novel STR multiplex validated for forensic use in the hen harrier (Circus cyaneus)

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    The hen harrier (Circus cyaneus) is a bird of prey which is heavily persecuted in the UK because it preys on the game bird red grouse (Lagopus lagopus scoticus). To help investigations into illegal killings of hen harrier, a STR multiplex kit containing eight short tandem repeat (STR) markers and a chromohelicase DNA binding protein 1 (CHD 1) sexing marker was developed. The multiplex kit was tested for species specificity, sensitivity, robustness, precision, accuracy and stability. Full profiles were obtained with as little as 0.25 ng of template DNA. Concurrent development of an allelic ladder to ensure reliable and accurate allele designation across laboratories makes the SkydancerPlex the first forensic DNA profiling system in a species of wildlife to be fully validated according to SWGDAM and ISFG recommendations. An average profile frequency of 3.67 × 10(-8), a PID estimate of 5.3 × 10(-9) and a PID-SIB estimate of 9.7 × 10(-4) make the SkydancerPlex an extremely powerful kit for individualisation

    Protocol for the ProFHER (PROximal Fracture of the Humerus: Evaluation by Randomisation) trial: a pragmatic multi-centre randomised controlled trial of surgical versus non-surgical treatment for proximal fracture of the humerus in adults

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    <p>Abstract</p> <p>Background</p> <p>Proximal humeral fractures, which occur mainly in older adults, account for approximately 4 to 5% of all fractures. Approximately 40% of these fractures are displaced fractures involving the surgical neck. Management of this group of fractures is often challenging and the outcome is frequently unsatisfactory. In particular it is not clear whether surgery gives better outcomes than non-surgical management. Currently there is much variation in the use of surgery and a lack of good quality evidence to inform this decision.</p> <p>Methods/Design</p> <p>We aim to undertake a pragmatic UK-based multi-centre randomised controlled trial evaluating the effectiveness and cost-effectiveness of surgical versus standard non-surgical treatment for adults with an acute closed displaced fracture of the proximal humerus with involvement of the surgical neck. The choice of surgical intervention is left to the surgeon, who must use techniques that they are fully experienced with. This will avoid 'learning curve' problems. We will promote good standards of non-surgical care, similarly insisting on care-provider competence, and emphasize the need for comparable provision of rehabilitation for both groups of patients.</p> <p>We aim to recruit 250 patients from a minimum of 18 NHS trauma centres throughout the UK. These patients will be followed-up for 2 years. The primary outcome is the Oxford Shoulder Score, which will be collected via questionnaires completed by the trial participants at 6, 12 and 24 months. This is a 12-item condition-specific questionnaire providing a total score based on the person's subjective assessment of pain and activities of daily living impairment. We will also collect data for other outcomes, including general health measures and complications, and for an economic evaluation. Additionally, we plan a systematic collection of reasons for non-inclusion of eligible patients who were not recruited into the trial, and their baseline characteristics, treatment preferences and intended treatment.</p> <p>Discussion</p> <p>This article presents the protocol for a multi-centre randomised controlled trial. It gives extensive details of, and the basis for, the chosen methods, and describes the key measures taken to avoid bias and to ensure validity.</p> <p>Trial Registration</p> <p>Current Controlled Trials ISRCTN50850043</p

    Woodland Recovery after Suppression of Deer: Cascade effects for Small Mammals, Wood Mice (Apodemus sylvaticus) and Bank Voles (Myodes glareolus)

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    Over the past century, increases in both density and distribution of deer species in the Northern Hemisphere have resulted in major changes in ground flora and undergrowth vegetation of woodland habitats, and consequentially the animal communities that inhabit them. In this study, we tested whether recovery in the vegetative habitat of a woodland due to effective deer management (from a peak of 0.4–1.5 to <0.17 deer per ha) had translated to the small mammal community as an example of a higher order cascade effect. We compared deer-free exclosures with neighboring open woodland using capture-mark-recapture (CMR) methods to see if the significant difference in bank vole (Myodes glareolus) and wood mouse (Apodemus sylvaticus) numbers between these environments from 2001–2003 persisted in 2010. Using the multi-state Robust Design method in program MARK we found survival and abundance of both voles and mice to be equivalent between the open woodland and the experimental exclosures with no differences in various metrics of population structure (age structure, sex composition, reproductive activity) and individual fitness (weight), although the vole population showed variation both locally and temporally. This suggests that the vegetative habitat - having passed some threshold of complexity due to lowered deer density - has allowed recovery of the small mammal community, although patch dynamics associated with vegetation complexity still remain. We conclude that the response of small mammal communities to environmental disturbance such as intense browsing pressure can be rapidly reversed once the disturbing agent has been removed and the vegetative habitat is allowed to increase in density and complexity, although we encourage caution, as a source/sink dynamic may emerge between old growth patches and the recently disturbed habitat under harsh conditions

    Can subunit-specific phenotypes guide surveillance imaging decisions in asymptomatic SDH mutation carriers?

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    Objective With the discovery that familial phaeochromocytoma and paraganglioma syndrome can be caused by mutations in each subunit of the succinate dehydrogenase enzyme (SDH), has come the recognition that mutations in the individual subunits have their own distinct natural histories. Increased genetic screening is leading to the identification of increasing numbers of, mostly asymptomatic, gene mutation carriers and the implementation of screening strategies for these individuals. Yet there is, to date, no international consensus regarding screening strategies for asymptomatic carriers. Design A comprehensive PubMed search from 1/1/2000 to 28/2/2018 was undertaken using multiple search terms and subsequently a manual review of references in identified papers to identify all clinically relevant cases and cohorts. In this review, the accumulated, published experience of phenotype and malignancy risks of individual SDH subunits is analysed. Where possible screening results for asymptomatic SDH mutation carriers have been analysed separately to define the penetrance in asymptomatic carriers (asymptomatic penetrance). Results The combined data confirms that “asymptomatic penetrance” is highest for SDHD and when there is penetrance, the most likely site to develop a PGL is head and neck (SDHD) and extra‐adrenal abdominal (SDHB). However, the risk in SDHB carriers of developing HNPGL is also high (35.5%) and a PCC is low (15.1%), and in SDHD carriers there is a high risk of developing a PCC (35.8%) or abdominal PGL (9.4%) and a small, but significant risk at other sympathetic sites. The data suggest that the risk of malignant transformation is the same for both PCC and extra‐adrenal abdominal PGLs (30%‐35%) in SDHB carriers. In SDHD carriers, the risk of malignant transformation was highest in HNPGLs (7.5%) and similar for sympathetic sites (3.8%‐5.2%). Conclusions Using this data, we suggest surveillance screening of asymptomatic carriers can be tailored to the underlying SDH subunit and review possible surveillance programmes

    Gut Microbiota, Probiotics and Diabetes

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    Diabetes is a condition of multifactorial origin, involving several molecular mechanisms related to the intestinal microbiota for its development. In type 2 diabetes, receptor activation and recognition by microorganisms from the intestinal lumen may trigger inflammatory responses, inducing the phosphorylation of serine residues in insulin receptor substrate-1, reducing insulin sensitivity. In type 1 diabetes, the lowered expression of adhesion proteins within the intestinal epithelium favours a greater immune response that may result in destruction of pancreatic β cells by CD8+ T-lymphocytes, and increased expression of interleukin-17, related to autoimmunity. Research in animal models and humans has hypothesized whether the administration of probiotics may improve the prognosis of diabetes through modulation of gut microbiota. We have shown in this review that a large body of evidence suggests probiotics reduce the inflammatory response and oxidative stress, as well as increase the expression of adhesion proteins within the intestinal epithelium, reducing intestinal permeability. Such effects increase insulin sensitivity and reduce autoimmune response. However, further investigations are required to clarify whether the administration of probiotics can be efficiently used for the prevention and management of diabetes

    Rattusin, an intestinal a-defensin-related peptide in rats with a unique cysteine spacing pattern and salt-insensitive antibacterial activities

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    Cationic antimicrobial peptides are essential components of the innate immune system. As a major family of mammalian antimicrobial peptides, defensins are expressed mainly by mucosal epithelial cells and promyelocytes. Despite the capacity to kill a broad spectrum of bacteria through physical disruption of membranes, most defensins show substantially reduced antibacterial activities in the presence of monovalent and divalent cations, thereby limiting their therapeutic potential, particularly for the treatment of systemic infections. Genome-wide computational screening of the rat genome led to the identification of the gene for a novel a-defensin-related peptide that we termed rattusin. Rattusin shares a highly conserved signal and prosequence with mammalian a-defensins, but instead of the canonical a-defensin six-cysteine motif, rattusin consists of five cysteines with a distinctive spacing pattern. Furthermore, rattusin is preferentially expressed in Paneth cells of the distal small intestine with potent antibacterial activity against a broad range of Gram-negative and Gram-positive bacteria, including antibiotic-resistant strains. The MICs were mostly in the range of 2 to 4 uM, with no appreciable toxicity to mammalian cells at up to 100 uM. In contrast to classical a- and B-defensins, rattusin retained its activity in the presence of physiological concentrations of NaCl and Mg2+, making it an attractive antimicrobial candidate for both topical and systemic applications.Peer reviewedAnimal Scienc

    Maintaining Integrity Under Stress:Envelope Stress Response Regulation of Pathogenesis in Gram-Negative Bacteria

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    The Gram-negative bacterial envelope is an essential interface between the intracellular and harsh extracellular environment. Envelope stress responses (ESRs) are crucial to the maintenance of this barrier and function to detect and respond to perturbations in the envelope, caused by environmental stresses. Pathogenic bacteria are exposed to an array of challenging and stressful conditions during their lifecycle and, in particular, during infection of a host. As such, maintenance of envelope homeostasis is essential to their ability to successfully cause infection. This review will discuss our current understanding of the σE- and Cpx-regulated ESRs, with a specific focus on their role in the virulence of a number of model pathogens
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