10,537 research outputs found

    Process for synthesizing enediynes

    Get PDF
    A process for synthesizing enediynes is provided. Specifically, the formed enediynes contain a hex-3-ene-1,5-diynyl group. Production of the enediynes involves adding a base to a propargylic halide in the presence of a chelating agent, which causes a carbenoid coupling-elimination sequence of the propargylic halides. A carbenoid destabilizing agent can also be added to the reaction mixture in order to enhance yield. Acyclic and cyclic enediynes can be synthesized according to this process. The enediynes are useful compounds that can be used in a variety of applications including use in the production of anti-tumor agents

    New approaches to object classification in synoptic sky surveys

    Get PDF
    Digital synoptic sky surveys pose several new object classification challenges. In surveys where real-time detection and classification of transient events is a science driver, there is a need for an effective elimination of instrument-related artifacts which can masquerade as transient sources in the detection pipeline, e.g., unremoved large cosmic rays, saturation trails, reflections, crosstalk artifacts, etc. We have implemented such an Artifact Filter, using a supervised neural network, for the real-time processing pipeline in the Palomar-Quest (PQ) survey. After the training phase, for each object it takes as input a set of measured morphological parameters and returns the probability of it being a real object. Despite the relatively low number of training cases for many kinds of artifacts, the overall artifact classification rate is around 90%, with no genuine transients misclassified during our real-time scans. Another question is how to assign an optimal star-galaxy classification in a multi-pass survey, where seeing and other conditions change between different epochs, potentially producing inconsistent classifications for the same object. We have implemented a star/galaxy multipass classifier that makes use of external and a priori knowledge to find the optimal classification from the individually derived ones. Both these techniques can be applied to other, similar surveys and data sets

    Subfactors of index less than 5, part 1: the principal graph odometer

    Full text link
    In this series of papers we show that there are exactly ten subfactors, other than AA_\infty subfactors, of index between 4 and 5. Previously this classification was known up to index 3+33+\sqrt{3}. In the first paper we give an analogue of Haagerup's initial classification of subfactors of index less than 3+33+\sqrt{3}, showing that any subfactor of index less than 5 must appear in one of a large list of families. These families will be considered separately in the three subsequent papers in this series.Comment: 36 pages (updated to reflect that the classification is now complete

    Size-at-maturity of Brown Crab (Cancer pagurus) in Scottish waters based on gonadal and morphometric traits

    Get PDF
    CRediT authorship contribution statement Carlos Mesquita: Conceptualization, Methodology, Formal analysis, Writing - original draft. Helen Dobby: Conceptualization, Writing - review & editing, Supervision. Stephanie Sweeting: Methodology, Data curation, Formal analysis. Catherine S. Jones: Supervision, Writing - review & editing. Graham J. Pierce: Conceptualization, Writing - review & editing, Supervision.Peer reviewedPostprin

    Viral load, clinical disease severity and cellular immune responses in primary varicella zoster virus infection in Sri Lanka

    Get PDF
    Background In Sri Lanka, varicella zoster virus (VZV) is typically acquired during adulthood with significant associated disease morbidity and mortality. T cells are believed to be important in the control of VZV replication and in the prevention of reactivation. The relationship between viral load, disease severity and cellular immune responses in primary VZV infection has not been well studied. Methodology We used IFNγ ELISpot assays and MHC class II tetramers based on VZV gE and IE63 epitopes, together with quantitative real time PCR assays to compare the frequency and phenotype of specific T cells with virological and clinical outcomes in 34 adult Sri Lankan individuals with primary VZV infection. Principal Findings Viral loads were found to be significantly higher in patients with moderate to severe infection compared to those with mild infection (p<0.001) and were significantly higher in those over 25 years of age (P<0.01). A significant inverse correlation was seen between the viral loads and the ex vivo IFNγ ELISpot responses of patients (P<0.001, r = −0.85). VZV-specific CD4+ T cells expressed markers of intermediate differentiation and activation. Conclusions Overall, these data show that increased clinical severity in Sri Lankan adults with primary VZV infection associates with higher viral load and reduced viral specific T cell responses

    Towards real-time classification of astronomical transients

    Get PDF
    Exploration of time domain is now a vibrant area of research in astronomy, driven by the advent of digital synoptic sky surveys. While panoramic surveys can detect variable or transient events, typically some follow-up observations are needed; for short-lived phenomena, a rapid response is essential. Ability to automatically classify and prioritize transient events for follow-up studies becomes critical as the data rates increase. We have been developing such methods using the data streams from the Palomar-Quest survey, the Catalina Sky Survey and others, using the VOEventNet framework. The goal is to automatically classify transient events, using the new measurements, combined with archival data (previous and multi-wavelength measurements), and contextual information (e.g., Galactic or ecliptic latitude, presence of a possible host galaxy nearby, etc.); and to iterate them dynamically as the follow-up data come in (e.g., light curves or colors). We have been investigating Bayesian methodologies for classification, as well as discriminated follow-up to optimize the use of available resources, including Naive Bayesian approach, and the non-parametric Gaussian process regression. We will also be deploying variants of the traditional machine learning techniques such as Neural Nets and Support Vector Machines on datasets of reliably classified transients as they build up

    Quantum Vacuum Contribution to the Momentum of the Dielectric Media

    Full text link
    Momentum transfer between matter and electromagnetic field is analyzed. The related equations of motion and conservation laws are derived using relativistic formalism. Their correspondence to various, at first sight self-contradicting, experimental data (the so called Abraham-Minkowski controversy) is demonstrated. A new, Casimir like, quantum phenomenon is predicted: contribution of vacuum fluctuations to the motion of dielectric liquids in crossed electric and magnetic fields. Velocities about 50nm/s50nm/s can be expected due to the contribution of high frequency vacuum modes

    Simple and objective prediction of survival in patients with lung cancer: staging the host systemic inflammatory response

    Get PDF
    Background. Prediction of survival in patients diagnosed with lung cancer remains problematical. The aim of the present study was to examine the clinical utility of an established objective marker of the systemic inflammatory response, the Glasgow Prognostic Score, as the basis of risk stratification in patients with lung cancer. Methods. Between 2005 and 2008 all newly diagnosed lung cancer patients coming through the multidisciplinary meetings (MDTs) of four Scottish centres were included in the study. The details of 882 patients with a confirmed new diagnosis of any subtype or stage of lung cancer were collected prospectively. Results. The median survival was 5.6 months (IQR 4.8–6.5). Survival analysis was undertaken in three separate groups based on mGPS score. In the mGPS 0 group the most highly predictive factors were performance status, weight loss, stage of NSCLC, and palliative treatment offered. In the mGPS 1 group performance status, stage of NSCLC, and radical treatment offered were significant. In the mGPS 2 group only performance status and weight loss were statistically significant. Discussion. This present study confirms previous work supporting the use of mGPS in predicting cancer survival; however, it goes further by showing how it might be used to provide more objective risk stratification in patients diagnosed with lung cancer
    corecore