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Statistical Analysis of the Exchange Rate of Bitcoin
No full textBitcoin, the first electronic payment system, is becoming a popular currency. We provide a statistical analysis of the log-returns of the exchange rate of Bitcoin versus the United States Dollar. Fifteen of the most popular parametric distributions in finance are fitted to the log-returns. The generalized hyperbolic distribution is shown to give the best fit. Predictions are given for future values of the exchange rate
Characterising glaucoma using texture
No full textIn this paper, we present our ongoing work on glaucoma classification usingfundus images. The approach makes use of texture analysis based on Binary RobustIndependent Elementary Features (BRIEF). This texture measurement is chosenbecause it can address the illumination issues of the retinal images and has a lowerdegree of computational complexity than most of the existing texture measurementmethods. Unlike other approaches, the texture measures are extracted from the whole retina without targeting any specific region. The method was tested on a set of 196 images composed of 110 healthy retina images and 86 glaucomatous images and achieved an area under curve (AUC) of 84%. A comparison performance with other texture measurements is also included, which shows our method to be superior
Interventions for bronchiectasis: an overview of Cochrane systematic reviews.
No full textBACKGROUND: Bronchiectasis is a chronic respiratory disease characterised by abnormal dilatation of the bronchi, and presents typically with a chronic productive cough (or chronic wet cough in children) and recurrent infective exacerbations. It significantly impacts daily activities and quality of life, and can lead to recurrent hospitalisations, severe lung function impairment, respiratory failure and even death. OBJECTIVES: To provide an overview of the efficacy and safety of interventions for adults and children with bronchiectasis from Cochrane reviews.To identify gaps in the evidence base that will inform recommendations for new research and reviews, and to summarise information on reported outcomes and make recommendations for the reporting of standard outcomes in future trials and reviews. METHODS: We included Cochrane reviews of non-cystic fibrosis (CF) bronchiectasis. We searched the Cochrane Database of Systematic Reviews. The search is current to 11 February 2015. We also identified trials that were potentially eligible for, but not currently included in, published reviews to make recommendations for new Cochrane reviews. We assessed the quality of included reviews using the AMSTAR criteria. We presented an evidence synthesis of data from reviews alongside an evidence map of clinical trials and guideline data. The primary outcomes were exacerbations, lung function and quality of life. MAIN RESULTS: We included 21 reviews but extracted data from, and rated the quality of, only nine reviews that reported results for people with bronchiectasis alone. Of the reviews with no usable data, two reviews included studies with mixed clinical populations where data were not reported separately for people with bronchiectasis and 10 reviews did not contain any trials. Of the 40 studies included across the nine reviews, three (number of participants nine to 34) included children. The studies ranged from single session to year-long studies. Each review included from one to 11 trials and 28 (70%) trials in the overview included 40 or fewer participants. The total number of participants included in reviews ranged from 40 to 1040. The age range of adult participants was from 36 to 73 years and children ranged from six to 16 years. The proportion of male participants ranged from 21% to 72%. Where reported, mean baseline forced expiratory volume in one second (FEV1) ranged from 1.17 L to 1.66 L and from 47% to 88% predicted. Most of the reviews had search dates older than two years.We have summarised the published evidence as outlined in Cochrane reviews, but it was not possible to draw definitive conclusions. There was inconclusive evidence on the use of long-term antibiotics and nebulised hypertonic saline for reducing exacerbation frequency and evidence that human deoxyribonuclease (RhDNase) increases exacerbation frequency. Improvements in lung function were reported for inhaled corticosteroids (ICS) though this was small and not clinically relevant. Evidence of benefit for hyperosmolar agents and mucolytics was inconclusive. There was limited evidence of improvements in quality of life with airway clearance techniques and physical therapy but evidence of benefit for hyperosmolar agents was inconclusive. Secondary outcomes were not clearly reported in all trials in the included reviews. Improvements in dyspnoea, wheeze and cough-free days were reported for small trials of ICS and LABA (long-acting beta2-agonsts)/ICS and cough reduction was also reported for a small bromhexine trial. Reduction in sputum production was reported for long-term antibiotics and airway clearance techniques but evidence of benefit for hyperosmolar agents was inconclusive.Adverse events were included as outcomes in seven reviews. The review of long-term (four weeks to one year) prophylactic courses of antibiotics reported significantly more cases of wheeze (Peto odd ratio (OR) 8.56, 95% confidence intervals (CI) 1.63 to 44.93), dyspnoea (12 versus three, P value = 0.01) and chest pain (seven versus zero, P value = 0.01) from the same trial (74 participants) but no differences in occurrence of diarrhoea, rash or number of withdrawals. In the review of mucolytics versus placebo, relevant outcomes were not reported for erdosteine comparisons and no significant adverse effects were reported for bromhexine, though adverse events were associated with RhDNase (OR 28.19, 95% CI 3.77 to 210.85, 1 study). Of the remaining five reviews, adverse events were not reported in the single trials included in the ICS review or the physical therapy review and the impact of adverse events in the single trial included in the inhaled LABA/ICS combination versus ICS review were unclear. The reviews of short-term courses of antibiotics and inhaled hyperosmolar agents reported no significant differences in occurrence of adverse events. Fewer admissions to hospital were reported for long-term antibiotics, but this outcome was not reported in all reviews. No reviews reported differences in mortality, but again this outcome was not included in all reviews.We did not explicitly include antibiotic resistance as an outcome in the review, but this was unclear in the Cochrane reviews and evidence from other trials should be considered.We rated all reviews as high quality (AMSTAR), though opportunities for improved reporting (e.g. summary of findings and GRADE evaluation of the evidence) were identified for inclusion in future updates of the reviews. However, the majority of trials were not high quality and confidence in the effects of treatments, therefore, requires additional evidence from larger and more methodologically robust trials. We evaluated the overall coverage of important topics in bronchiectasis by mapping the quality of the current evidence base against published guidelines and identifying high priority areas for new research on; use of short-course and long-term antibiotics, ICS and oral corticosteroids, inhaled hyperosmolars, mucolytics, and use of airway clearance techniques. AUTHORS' CONCLUSIONS: This overview clearly points to significant opportunities for further research aimed at improving outcomes for people with bronchiectasis. We have highlighted important endpoints for studies (particularly exacerbations, quality of life and lung function), and areas of clinical practice that are in most urgent need of evidence-based support (including long-term antibiotics, ICSs and mucolytics).As the evidence is confined to small trials of short duration, it is not currently possible to assess the balance between the benefits and potential harms of treatments for bronchiectasis
Using realist review to inform intervention development: methodological illustration and conceptual platform for collaborative care in offender mental health
No full textPrognostic significance of L1 cell adhesion molecule (L1CAM) expression and its association with mutant p53 expression in high-risk endometrial cancer.
No full textStudies in early-stage, predominantly low- and intermediate-risk endometrial cancer have demonstrated that L1 cell adhesion molecule (L1CAM) overexpression identifies patients at increased risk of recurrence, yet its prognostic significance in high-risk endometrial cancer is unclear. To evaluate this, its frequency, and the relationship of L1CAM with the established endometrial cancer biomarker p53, we analyzed the expression of both markers by immunohistochemistry in a pilot series of 116 endometrial cancers (86 endometrioid, 30 non-endometrioid subtype) with high-risk features (such as high tumor grade and deep myometrial invasion) and correlated results with clinical outcome. We used The Cancer Genome Atlas (TCGA) endometrial cancer series to validate our findings. Using the previously reported cutoff of 10% positive staining, 51/116 (44%) tumors were classified as L1CAM-positive, with no significant association between L1CAM positivity and the rate of distant metastasis (P=0.195). However, increasing the threshold for L1CAM positivity to 50% resulted in a reduction of the frequency of L1CAM-positive tumors to 24% (28/116), and a significant association with the rate of distant metastasis (P=0.018). L1CAM expression was strongly associated with mutant p53 in the high-risk and TCGA series (P10% does not predict prognosis in high-risk endometrial cancer, whereas an alternative threshold (>50%) does. L1CAM expression is strongly, but not universally, associated with mutant p53, and may be strong enough for clinical implementation as prognostic marker in combination with p53. The high frequency of L1CAM expression in high-risk endometrial cancers suggests that it may also be a promising therapeutic target in this tumor subset
Monte Carlo Simulations of Mesoscale Fracture of Concrete with Random Aggregates and Pores:a Size Effect Study
No full textSize effect in concrete under tension is studied by Monte Carlo simulations of mesoscale finite element models containing random inclusions (aggregates and pores) with prescribed volume fractions, shapes and size distributions (called meso-structure controls). For a given size and a set of controls, a number of realisations with different spatial distribution of inclusions are simulated to produce statistical data for macroscopic load/stress-strain curves. The complex meso-crack initiation and propagation is captured by pre-inserted cohesive interface elements. The effects of specimen size and meso-structure controls on macroscopic strength and toughness are analysed, and empirical size-effect laws for their dependences are proposed by data regression. It is also shown that the mesoscale porosity affects both strength and toughness and should not be ignored in size effect studies of concrete
Ames positive boronic acids are not all eukaryotic genotoxins
No full textBoronic acids and their derivatives have been exploited for their pharmacological activity and their utility as intermediates in the synthesis of novel non-boron containing compounds. A recent study reported that boronic acids are bacterial mutagens. Here, results are reported from the testing of nine boronic acids using the pan-mechanistic eukaryotic GADD45a genotoxicity assays, BlueScreen HC and GreenScreen HC. Positive results were produced for one compound in GreenScreen and four compounds in BlueScreen. Only negative results were produced when tested with S9 metabolic activation. These data suggest that there is not a general genotoxic liability in eukaryotes, within this chemical domain. Furthermore, they are not potent eukaryotic genotoxins: positive results were produced only at concentrations between 1 mM and 10 mM. Their presence as low concentration contaminants or impurities would be unlikely to produce misleading positive results for a test material
A 'rule of 0.5' for the metabolite-likeness of approved pharmaceutical drugs
No full textWe exploit the recent availability of a community reconstruction of the human metabolic network (‘Recon2’) to study how close in structural terms are marketed drugs to the nearest known metabolite(s) that Recon2 contains. While other encodings using different kinds of chemical fingerprints give greater differences, we find using the 166 Public MDL Molecular Access (MACCS) keys that 90 % of marketed drugs have a Tanimoto similarity of more than 0.5 to the (structurally) ‘nearest’ human metabolite. This suggests a ‘rule of 0.5’ mnemonic for assessing the metabolite-like properties that characterise successful, marketed drugs. Multiobjective clustering leads to a similar conclusion, while artificial (synthetic) structures are seen to be less human-metabolite-like. This ‘rule of 0.5’ may have considerable predictive value in chemical biology and drug discovery, and may represent a powerful filter for decision making processes
antiSMASH 3.0:a comprehensive resource for the genome mining of biosynthetic gene clusters.
No full textMicrobial secondary metabolism constitutes a rich source of antibiotics, chemotherapeutics, insecticides and other high-value chemicals. Genome mining of gene clusters that encode the biosynthetic pathways for these metabolites has become a key methodology for novel compound discovery. In 2011, we introduced antiSMASH, a web server and stand-alone tool for the automatic genomic identification and analysis of biosynthetic gene clusters, available at http://antismash.secondarymetabolites.org. Here, we present version 3.0 of antiSMASH, which has undergone major improvements. A full integration of the recently published ClusterFinder algorithm now allows using this probabilistic algorithm to detect putative gene clusters of unknown types. Also, a new dereplication variant of the ClusterBlast module now identifies similarities of identified clusters to any of 1172 clusters with known end products. At the enzyme level, active sites of key biosynthetic enzymes are now pinpointed through a curated pattern-matching procedure and Enzyme Commission numbers are assigned to functionally classify all enzyme-coding genes. Additionally, chemical structure prediction has been improved by incorporating polyketide reduction states. Finally, in order for users to be able to organize and analyze multiple antiSMASH outputs in a private setting, a new XML output module allows offline editing of antiSMASH annotations within the Geneious software