90 research outputs found

    Graphical functions in parametric space

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    Graphical functions are positive functions on the punctured complex plane C{0,1}\mathbb{C}\setminus\{0,1\} which arise in quantum field theory. We generalize a parametric integral representation for graphical functions due to Lam, Lebrun and Nakanishi, which implies the real analyticity of graphical functions. Moreover we prove a formula that relates graphical functions of planar dual graphs.Comment: v2: extended introduction, minor changes in notation and correction of misprint

    A new measure for in vivo thrombin activity in comparison with in vitro thrombin generation potential in patients with hyper- and hypocoagulability

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    The thrombin generation potential is an in vitro measure for the capacity of an individual to generate thrombin and recognized as a reflection of a hypo- or hypercoagulable status. Measurement of the in vivo thrombin activity, however, may be of clinical significance. We evaluated a new assay for in vivo thrombin activity and compared it to the in vitro thrombin generation potential in patients with hemophilia A (N = 15), oral anticoagulation for atrial fibrillation (AF) (N = 20), subjects with active cancer (N = 21), and healthy volunteers (N = 10). Thrombin activity was measured with a commercially available oligonucleotide enzyme capture assay in argatroban-stabilized plasma samples. Thrombin generation potential was determined with a commercially available assay in citrated plasma. Thrombin activity was detected in 17 (30.4 %) patients (mean 0.30 mU/ml [SD 0.80]), and in 39 patients (69.6 %) no thrombin activity was present. In cancer patients, thrombin activity was detected in 11 patients (52 %) (range 0.14-5.00 mU/ml) and was particularly increased in 3 patients with vessel-invasive tumors (1.2, 1.5, and 5.0 mU/ml). In AF patients, thrombin activity was only measureable in two patients (10 %) (recent hematoma [0.4 mU/ml] and recent ischemic stroke [1.5 mU/ml]). Thrombin activity was detected in four patients (27 %) with hemophilia (range 0.29-1.75 mU/ml), all of whom had received a factor VIII infusion on the same day. Thrombin activity did not correlate with any of the parameters of the thrombin generation potential. Only patients in acute procoagulatory states or after clotting factor replacement had elevated in vivo thrombin activity, which was, however, unrelated to the in vitro thrombin generation potential

    Reconstructing the Life of an Unknown (ca. 500 Years-Old South American Inca) Mummy - Multidisciplinary Study of a Peruvian Inca Mummy Suggests Severe Chagas Disease and Ritual Homicide

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    The paleopathological, paleoradiological, histological, molecular and forensic investigation of a female mummy (radiocarbon dated 1451-1642 AD) provides circumstantial evidence for massive skull trauma affecting a young adult female individual shortly before death along with chronic infection by Trypanosoma cruzi (Chagas disease). The mummy (initially assumed to be a German bog body) was localized by stable isotope analysis to South America at/near the Peruvian/Northern Chilean coast line. This is further supported by New World camelid fibers attached to her plaits, typical Inca-type skull deformation and the type of Wormian bone at her occiput. Despite an only small transverse wound of the supraorbital region computed tomography scans show an almost complete destruction of face and frontal skull bones with terrace-like margins, but without evidence for tissue reaction. The type of destruction indicates massive blunt force applied to the center of the face. Stable isotope analysis indicates South American origin: Nitrogen and hydrogen isotope patterns indicate an extraordinarily high marine diet along with C4-plant alimentation which fits best to the coastal area of Pacific South America. A hair strand over the last ten months of her life indicates a shift to a more "terrestric" nutrition pattern suggesting either a move from the coast or a change in her nutrition. Paleoradiology further shows extensive hypertrophy of the heart muscle and a distended large bowel/rectum. Histologically, in the rectum wall massive fibrosis alternates with residual smooth muscle. The latter contains multiple inclusions of small intracellular parasites as confirmed by immunohistochemical and molecular ancient DNA analysis to represent a chronic Trypanosoma cruzi infection. This case shows a unique paleopathological setting with massive blunt force trauma to the skull nurturing the hypothesis of a ritual homicide as previously described in South American mummies in an individual that suffered from severe chronic Chagas disease

    Identification of Habitat-Specific Biomes of Aquatic Fungal Communities Using a Comprehensive Nearly Full-Length 18S rRNA Dataset Enriched with Contextual Data

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    Molecular diversity surveys have demonstrated that aquatic fungi are highly diverse, and that they play fundamental ecological roles in aquatic systems. Unfortunately, comparative studies of aquatic fungal communities are few and far between, due to the scarcity of adequate datasets. We combined all publicly available fungal 18S ribosomal RNA (rRNA) gene sequences with new sequence data from a marine fungi culture collection. We further enriched this dataset by adding validated contextual data. Specifically, we included data on the habitat type of the samples assigning fungal taxa to ten different habitat categories. This dataset has been created with the intention to serve as a valuable reference dataset for aquatic fungi including a phylogenetic reference tree. The combined data enabled us to infer fungal community patterns in aquatic systems. Pairwise habitat comparisons showed significant phylogenetic differences, indicating that habitat strongly affects fungal community structure. Fungal taxonomic composition differed considerably even on phylum and class level. Freshwater fungal assemblage was most different from all other habitat types and was dominated by basal fungal lineages. For most communities, phylogenetic signals indicated clustering of sequences suggesting that environmental factors were the main drivers of fungal community structure, rather than species competition. Thus, the diversification process of aquatic fungi must be highly clade specific in some cases.The combined data enabled us to infer fungal community patterns in aquatic systems. Pairwise habitat comparisons showed significant phylogenetic differences, indicating that habitat strongly affects fungal community structure. Fungal taxonomic composition differed considerably even on phylum and class level. Freshwater fungal assemblage was most different from all other habitat types and was dominated by basal fungal lineages. For most communities, phylogenetic signals indicated clustering of sequences suggesting that environmental factors were the main drivers of fungal community structure, rather than species competition. Thus, the diversification process of aquatic fungi must be highly clade specific in some cases

    ITS-NANO - Prioritising nanosafety research to develop a stakeholder driven intelligent testing strategy

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    Background To assess the risk of all nanomaterials (NMs) on a case-by-case basis is challenging in terms of financial, ethical and time resources. Instead a more intelligent approach to knowledge gain and risk assessment is required. Methods A framework of future research priorities was developed from the accorded opinion of experts covering all major stake holder groups (government, industry, academia, funders and NGOs). It recognises and stresses the major topics of physicochemical characterisation, exposure identification, hazard identification and modelling approaches as key components of the current and future risk assessment of NMs. Results The framework for future research has been developed from the opinions of over 80 stakeholders, that describes the research priorities for effective development of an intelligent testing strategy (ITS) to allow risk evaluation of NMs. In this context, an ITS is a process that allows the risks of NMs to be assessed accurately, effectively and efficiently, thereby reducing the need to test NMs on a case-by-case basis. For each of the major topics of physicochemical characterisation, exposure identification, hazard identification and modelling, key-priority research areas are described via a series of stepping stones, or hexagon diagrams structured into a time perspective. Importantly, this framework is flexible, allowing individual stakeholders to identify where their own activities and expertise are positioned within the prioritisation pathway and furthermore to identify how they can effectively contribute and structure their work accordingly. In other words, the prioritisation hexagon diagrams provide a tool that individual stakeholders can adapt to meet their own particular needs and to deliver an ITS for NMs risk assessment. Such an approach would, over time, reduce the need for testing by increasing the reliability and sophistication of in silico approaches. The manuscript includes an appraisal of how this framework relates to the current risk assessment approaches and how future risk assessment could adapt to accommodate these new approaches. A full report is available in electronic format (pdf) at http://www.nano.hw.ac.uk/research-projects/itsnano.html webcite. Conclusion ITS-NANO has delivered a detailed, stakeholder driven and flexible research prioritisation (or strategy) tool, which identifies specific research needs, suggests connections between areas, and frames this in a time-perspective

    Agreement of Self-Reported and Genital Measures of Sexual Arousal in Men and Women: A Meta-Analysis

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    The assessment of sexual arousal in men and women informs theoretical studies of human sexuality and provides a method to assess and evaluate the treatment of sexual dysfunctions and paraphilias. Understanding measures of arousal is, therefore, paramount to further theoretical and practical advances in the study of human sexuality. In this meta-analysis, we review research to quantify the extent of agreement between self-reported and genital measures of sexual arousal, to determine if there is a gender difference in this agreement, and to identify theoretical and methodological moderators of subjective-genital agreement. We identified 132 peer- or academically-reviewed laboratory studies published between 1969 and 2007 reporting a correlation between self-reported and genital measures of sexual arousal, with total sample sizes of 2,505 women and 1,918 men. There was a statistically significant gender difference in the agreement between self-reported and genital measures, with men (r = .66) showing a greater degree of agreement than women (r = .26). Two methodological moderators of the gender difference in subjective-genital agreement were identified: stimulus variability and timing of the assessment of self-reported sexual arousal. The results have implications for assessment of sexual arousal, the nature of gender differences in sexual arousal, and models of sexual response

    Ultra-stiff large-area carpets of carbon nanotubes

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    Herewith, we report the influence of post-synthesis heat treatment (≤2350 °C and plasma temperatures) on the crystal structure, defect density, purity, alignment and dispersibility of free-standing large-area (several cm2) carpets of ultra-long (several mm) vertically aligned multi-wall carbon nanotubes (VA-MWCNTs). VA-MWCNTs were produced in large quantities (20–30 g per batch) using a semi-scaledup aerosol-assisted chemical vapour deposition (AACVD) setup. Electron and X-ray diffraction showed that the heat treatment at 2350 °C under inert atmosphere purifies, removes residual catalyst particles, and partially aligns adjacent single crystals (crystallites) in polycrystalline MWCNTs. The purification and improvement in the crystallites alignment within the MWCNTs resulted in reduced dispersibility of the VA-MWCNTs in liquid media. High-resolution microscopy revealed that the crystallinity is improved in scales of few tens of nanometres while the point defects remain largely unaffected. The heat treatment also had a marked benefit on the mechanical properties of the carpets. For the first time, we report compression moduli as high as 120 MPa for VA-MWCNT carpets, i.e. an order of magnitude higher than previously reported figures. The application of higher temperatures (arc-discharge plasma, ≥4000 °C) resulted in the formation of a novel graphite–matrix composite reinforced with CVD and arc-dischargelike carbon nanotubes

    Updated census of Feynman periods up to 11 loops

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    The file Periods contains phi^4 periods, the file PeriodsNonPhi4 contains periods of non-phi^4 graphs. These are text files in Maple format. A detailed description of these files and the format is given in the appendix of the paper

    Updated census of Feynman periods up to 11 loops

    No full text
    The file Periods contains phi^4 periods, the file PeriodsNonPhi4 contains periods of non-phi^4 graphs. These are text files in Maple format. A detailed description of these files and the format is given in the appendix of the paper
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