508 research outputs found

    Achieving Good Angular Resolution in 3D Arc Diagrams

    Full text link
    We study a three-dimensional analogue to the well-known graph visualization approach known as arc diagrams. We provide several algorithms that achieve good angular resolution for 3D arc diagrams, even for cases when the arcs must project to a given 2D straight-line drawing of the input graph. Our methods make use of various graph coloring algorithms, including an algorithm for a new coloring problem, which we call localized edge coloring.Comment: 12 pages, 5 figures; to appear at the 21st International Symposium on Graph Drawing (GD 2013

    Drawing Planar Graphs with a Prescribed Inner Face

    Full text link
    Given a plane graph GG (i.e., a planar graph with a fixed planar embedding) and a simple cycle CC in GG whose vertices are mapped to a convex polygon, we consider the question whether this drawing can be extended to a planar straight-line drawing of GG. We characterize when this is possible in terms of simple necessary conditions, which we prove to be sufficient. This also leads to a linear-time testing algorithm. If a drawing extension exists, it can be computed in the same running time

    Post-operative bilateral adrenal haemorrhage: A case report

    Get PDF
    AbstractINTRODUCTIONBilateral adrenal haemorrhage is a rare, but serious, illness carrying an estimated 15% mortality.1,2 The majority of cases occur in patients with acute, stressful illness, however the exact mechanism underlying adrenal haemorrhage remains unclear. This medical emergency carries significant diagnostic difficulty4 with non-specific clinical symptoms and variations in electrolyte abnormalities. Timely treatment is important as it prevents both the acute and long-term sequelae of adrenal failure.PRESENTATION OF CASEThis report describes a medical emergency in a surgical patient following emergency surgery for intra-abdominal sepsis. The patient reported non-specific symptoms of confusion, mild pyrexia and vague abdominal pain during the post-operative phase, with subtle electrolyte abnormalities and a low serum cortisol suggestive of adrenal crisis. Timely medical treatment, with intravenous hydrocortisone and intensive monitoring, and appropriate medical follow-up with addition of long-term fludrocortisone resulted in a satisfactory outcome.DISCUSSIONThis report describes a potentially life-threatening complication of intra-abdominal sepsis with adrenal crisis secondary to bilateral adrenal haemorrhage. In particular, this case highlights the diagnostic difficulty in such surgical patients due to vague symptoms and, in this case, the presence of a presentation variant with acute hyponatraemia and normal potassium.CONCLUSIONThis case highlights the importance of awareness of both the symptoms and signs and variation in electrolyte profile when assessing surgical patients post-operatively. In addition, this case highlights the benefit of early recognition and initiation of treatment and the importance of follow-up as long-term medical management is often required to prevent further relapse

    High throughput methodology for synthesis, screening, and optimization of solid state Lithium ion electrolytes

    No full text
    A study of the lithium ion conductor Li3xLa2/3ā€“xTiO3 solid solution and the surrounding composition space was carried out using a high throughput physical vapor deposition system. An optimum total ionic conductivity value of 5.45 Ɨ 10ā€“4 S cmā€“1 was obtained for the composition Li0.17La0.29Ti0.54 (Li3xLa2/3ā€“xTiO3x = 0.11). This optimum value was calculated using an artificial neural network model based on the empirical data. Due to the large scale of the data set produced and the complexity of synthesis, informatics tools were required to analyze the data. Partition analysis was carried out to determine the synthetic parameters of importance and their threshold values. Multivariate curve resolution and principal component analysis were applied to the diffraction data set. This analysis enabled the construction of phase distribution diagrams, illustrating both the phases obtained and the compositional zones in which they occur. The synthetic technique presented has significant advantages over other thin film and bulk methodologies, in terms of both the compositional range covered and the nature of the materials produce

    Drawing Graphs within Restricted Area

    Full text link
    We study the problem of selecting a maximum-weight subgraph of a given graph such that the subgraph can be drawn within a prescribed drawing area subject to given non-uniform vertex sizes. We develop and analyze heuristics both for the general (undirected) case and for the use case of (directed) calculation graphs which are used to analyze the typical mistakes that high school students make when transforming mathematical expressions in the process of calculating, for example, sums of fractions

    Effect of an alkaloidal fraction of Tabernaemontana elegans (Stapf.) on selected micro-organisms

    Get PDF
    Ethnopharmacological relevance: Bacterial infections remain a significant threat to human health. Due to the emergence of widespread antibiotic resistance, development of novel antibiotics is required in order to ensure that effective treatment remains available. There are several reports on the ethnomedical use of Tabernaemontana elegans pertaining to antibacterial activity. Aim of the study: The aim of this study was to isolate and identify the fraction responsible for the antimicrobial activity in T. elegans (Stapf.) root extracts. Materials and methods: The active fraction was characterised by thin layer chromatography (TLC) and gas chromatography ā€“ mass spectrometry (GC-MS). Antibacterial activity was determined using the broth micro-dilution assay and antimycobacterial activity using the BACTEC radiometric assay. Cytotoxicity of the crude extract and fractions was assessed against primary cell cultures; lymphocytes and fibroblasts; as well as a hepatocarcinoma (HepG2) and macrophage (THP-1) cell line using the Neutral Red uptake and MTT assays. Results: The crude root extracts were found to contain a high concentration of alkaloids (1.2% w/w). GC-MS analysis identified the indole alkaloids, voacangine and dregamine, as major components. Antibacterial activity was limited to the Grampositive bacteria and Mycobacterium species, with MIC values in the range of 64 ā€“ 256 Ī¼g/ml. When combined with antibiotics, additive antibacterial effects were observed. Marked cytotoxicity to all cell lines tested was evident in the MTT and Neutral Red uptake assays, with IC50 values < 9.81 Ī¼g/ml.Conclusions: This study confirms the antibacterial activity of T. elegans and supports its potential for being investigated further for the development of a novel antibacterial compound.National Research Foundationhttp://www.elsevier.com/locate/jethphar

    Incidence and risk factors of exposure keratopathy in critically ill patients in an academic hospital complex - a cohort study

    Get PDF
    https://drive.google.com/file/d/11XauRd8_w4e_c8jgLxEPF4urCvPHclHW/view?usp=sharinghttps://drive.google.com/drive/folders/15cWFPxccGylThfsRch-tJaKg7fI7IFb1?usp=sharinghttps://drive.google.com/drive/folders/1NTHIc69Pd2HCKI1p1Lr2-1qLZ4GewJq7?usp=sharin

    Planar and Poly-Arc Lombardi Drawings

    Full text link
    In Lombardi drawings of graphs, edges are represented as circular arcs, and the edges incident on vertices have perfect angular resolution. However, not every graph has a Lombardi drawing, and not every planar graph has a planar Lombardi drawing. We introduce k-Lombardi drawings, in which each edge may be drawn with k circular arcs, noting that every graph has a smooth 2-Lombardi drawing. We show that every planar graph has a smooth planar 3-Lombardi drawing and further investigate topics connecting planarity and Lombardi drawings.Comment: Expanded version of paper appearing in the 19th International Symposium on Graph Drawing (GD 2011). 16 pages, 8 figure

    Lombardi Drawings of Graphs

    Full text link
    We introduce the notion of Lombardi graph drawings, named after the American abstract artist Mark Lombardi. In these drawings, edges are represented as circular arcs rather than as line segments or polylines, and the vertices have perfect angular resolution: the edges are equally spaced around each vertex. We describe algorithms for finding Lombardi drawings of regular graphs, graphs of bounded degeneracy, and certain families of planar graphs.Comment: Expanded version of paper appearing in the 18th International Symposium on Graph Drawing (GD 2010). 13 pages, 7 figure

    Factors associated with the presence and prevalence of contagious ovine digital dermatitis: a 2013 study of 1136 random English sheep flocks

    Get PDF
    In 2013, a questionnaire was used to gather data on risks for introduction, and factors associated with prevalence, of contagious ovine digital dermatitis (CODD). There were 1136 (28.4%) usable responses from 4000 randomly selected sheep farmers in England. CODD was present in 58% (662) of flocks, with a reported prevalence of CODD lesions of 2.3%. The geometric mean period prevalence of all lameness was 4.2% and 2.8% in CODD positive and negative flocks respectively. Factors associated with a greater risk of presence of CODD were purchasing replacement ewes, not always checking the feet of sheep before purchase, not isolating purchased sheep, foot bathing returning ewes, foot trimming the flock more than twice in the year all compared with not doing these activities and increasing log10 flock size. Farmers who vaccinated sheep with Footvaxā„¢ were less likely to report presence of CODD. Factors associated with increasing prevalence of CODD lesions were not always checking the feet of purchased sheep, flocks that mixed with other flocks and sheep that left the farm for summer grazing and later returned. In addition, flocks where farmers followed the current recommended managements for control of footrot, had a lower prevalence of CODD whilst those who used foot bathing and where feet bled during routine foot trimming had a higher prevalence of CODD. The prevalence of CODD decreased with each log10 increase in flock size. We conclude that CODD is an infectious cause of lameness in sheep of increasing importance in GB. Introduction is linked to poor biosecurity with one likely source of the pathogen being introduction of or mixing with infected sheep. As with footrot, prevalence of CODD was lower in flocks where farmers focused on individual treatment to manage lameness and avoided foot bathing and trimming feet. We conclude that most of the currently recommended biosecurity and treatment approaches to control footrot in GB are also effective for control of CODD
    • ā€¦
    corecore