17837 research outputs found
Sort by
Commercial processing of Oriental lilies affects bud opening and metabolic dynamics
Get PDFLilies are a high value cut flower typically producing 4–5 flowers per stem, but the opening of young buds of Oriental hybrid lilies is often affected in cut flowers. Commercial treatment includes harvesting of the stem when the oldest bud is closed and at turning colour, approximately 2 ds before it would open on the plant. Stems are then rehydrated, stored chilled for up to 72 h and transported dry. To understand the effect of commercial treatment on the nutrient status metabolomes were compared throughout bud opening from different positions on the stem. At each developmental stage the metabolomic profile was affected by bud position and commercial treatment. Starch accumulated as long as buds remain closed; upon bud opening starch content declined. Reciprocally, sugar levels rose during flower opening and were affected by edge/ midrib location and commercial treatment. Glucose, fructose and sucrose levels remained higher in opened flowers still on the plant. AMY2 (amylase) transcript levels rose as did those of two sugar transporters (MST6 and SWEET7). Commercial processing therefore impacts on the metabolome and the ability to accumulate sugars in the opening flower bud. Commercial treatment delayed bud opening and the effect was dependent on the position of the bud on the stem. However, it had little impact on the rate of cell expansion during flower opening. Cell expansion in the different areas of the adaxial epidermis was unaffected by the commercial treatment. Furthermore, edge and adaxial tepal cells expanded faster during opening. Expression of cell expansion related genes (EXPA1 and LoPIP1) fell as flowers opened. This differential cell expansion in the tepal sectors could underpin the transition of a convex to a concave tepal shape during opening. In conclusion, commercial processing mainly affects the early stages of bud opening. Sugar and metabolite accumulation is compromised by commercial treatment, but this did not affect the capacity for cell expansion in the tepal. Furthermore, our data indicate that differential cell expansion in the different sectors of the tepals is important in lily flower opening, and that this is associated with starch breakdown and sugar accumulation
Theory and Practice of Deploying Anonymous Credential Schemes
Get PDFAnonymous credentials are a complex and versatile primitive designed to provide users with tight and fine-grained control over the information they disclose while securely authenticating themselves to digital services and organisations. This thesis explores the theory and practice of anonymous credential schemes, describing their features and variants, explaining the challenges they face, and proposing solutions and improvements.In the theoretical portion of the thesis, we formally define anonymous credentials and identify different methods and approaches to constructing them, yielding a framework that can be used to categorise and compare credential schemes. Using this framework, we summarise the existing anonymous credential literature, sorting credential schemes into a loose taxonomy and identifying notable trends and innovations. We then explore one such innovation, looking in detail at the recent development of mercurial signatures, a new primitive capable of functioning as an anonymous credential without the need for extensive zero-knowledge protocols. We recount the development of this family of credentials and then provide and prove our own novel extension to them, showing how they can be made to include selectively-disclosed attributes, a feature that is central to most anonymous credential schemes.The latter chapters of the thesis address the more practical concerns facing anonymous credential development, investigating issues that have made it difficult for them to gain a foothold in real-world use cases. We analyse the efficiency of existing anonymous credentials, noting the differences between older, more established credential schemes and newer, more innovative ones, and the ways in which efficiency is impacted by different design approaches. We also highlight other challenges that arise in implementation, such as the problem of how to revoke credentials that are lost or abused, and how to prevent the illicit sharing of credentials. We then explore the broader field of identity management, compare the ways in which some identity management systems apply anonymous credentials, and see how they address the implementation challenges they face. Finally, we point to the open areas for future research that this work helps to identify
New insights into morphological adaptation in common mole-rats (Cryptomys hottentotus hottentotus) along an aridity gradient
Get PDFMargaret Macdonald, Philosopher of Language
Get PDFI chart the philosophical development of neglected figure Margaret Macdonald and situate that development in the context of mid-century analytic philosophy more broadly. I examine Macdonald’s changing attitude towards verificationism, and show that these changing views led her, in 1950 and beyond, to a very thorough appreciation of language use as capable of being employed in the execution of distinctive kinds of performative act. I compare Macdonald’s views with the far better known work of J. L. Austin, and I emphasise the extent to which she has, despite her insightful contributions, been omitted from the history of philosophy
‘So the child feels loved’:Mothers with learning disabilities’ experiences of attachment and emotional relationships with their children
Get PDFAn extension of the Liouville theorem for Fourier multipliers to sub-exponentially growing solutions
Get PDFWe study the equation in a large class of sub-exponentially growing functions. Under appropriate restrictions on we show that every such solution can be analytically continued to a sub-exponentially growing entire function on \comp^n if, and only if, for
Prediction of Long-Term Poor Clinical Outcomes in Cerebral Venous Thrombosis Using Neural Networks Model:The BEAST Study
Get PDFIntroductionRisk prediction models are commonly performed with logistic regression analysis but are limited by skewed datasets. We utilised neural networks (NNs) model to identify independent predictors of poor outcomes in cerebral venous thrombosis (CVT) due to the limitations of logistic regression (LR) analysis with complex datasets.MethodsWe evaluated 1309 adult CVT patients from the prospective BEAST (Biorepository to Establish the Aetiology of Sinovenous Thrombosis) study. The area under the receiver operating characteristic (AUROC) curve confirmed the goodness-of-fit of prediction models. The normalised importance (NI) of the NNs determines the significance of independent predictors.ResultsThe stepwise logistic regression model found thrombolysis (OR 32.1; 95% CI 3.6–287.0; P=0.002), craniotomy (OR 6.9; 95% CI 1.3–36.8; P=0.02), and cerebral haemorrhage (OR 4.5; 95% CI 1.3–15.4; P=0.01) as predictors of poor clinical outcome with the AUROC of 0.71. Conversely, the NNs model identified major independent predictors of long-term poor clinical outcomes as cerebral haemorrhage (NI 100%) and thrombolysis (NI 98%), as well as trivial predictors of age (NI 2.8%) and altered mental status (NI 3.5%). The accuracy of the NNs model was 95.1% and 94.1% for self-learned randomly selected training and testing samples with an AUROC of 0.82. Positive and negative predictive values for poor outcomes were 13.2% and 97.1% for the LR model, compared with the NNs model of 18.8% and 98.7%, respectively.ConclusionCerebral haemorrhage and thrombolysis was a strong independent predictor, whereas age merely impacts the long-term poor clinical outcome in adult CVT. Integrating unorthodox neural networks risk prediction model can improve decision-making as it outperforms conventional logistic regression with complex datasets
Data sources:
Access Repository Dashboard
Do you manage Royal Holloway - Pure? Access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard!