1,353 research outputs found

    Lack of Z-DNA Conformation in Mitomycin-Modified Polynucleotides Having Inverted Circular Dichroism

    Get PDF
    Poly(dG-dC)· poly(dG-dC) and Micrococcus lysodeikticus DNA were modified by exposure to reductively activated mitomycin C, an antitumor antibiotic. The resulting covalent drug-polynucleotide complexes displayed varying degrees of CD inversions, which are strikingly similar to the inverted spectrum observed with Z-DNA. The following criteria have been used to establish, however, that the inverted CD pattern seen in mitomycin C-polynucleotide complexes does not reflect a Z-DNA conformation. (i) The ethanol-induced transition of poly(dG-dC)· poly(dG-dC) from B to Z conformation is not facilitated but rather is inhibited by mitomycin C modification. This may be due to the presence of crosslinks. (ii) Radioimmunoassay indicated no competition for Z-DNA-specific antibody by any of the mitomycin C-modified polynucleotides. (iii) 31P NMR of the complexes yielded a single relatively narrow resonance, which is inconsistent with the dinucleotide repeat characteristic of Z-DNA. Alternative explanations for the inverted CD pattern include a drug-induced left-handed but non-Z conformational change or the superposition of an induced CD onto the CD of B-DNA due to drug-base electronic interactions. These results illustrate the need for caution in interpreting CD changes alone as an indication of Z-DNA conformation

    THE CREATION AND VALIDATION OF A LARGE-SCALE COMPUTER MODEL OF THE GOLF SWING

    Get PDF
    The aim of this study was to create and validate a full-body musculoskeletal model of a golfer performing a swing with their driver club. An elite female participant performed ten shots with her driver while wearing retro-reflective markers. An optical 3-D 6-camera system captured the kinematics of the markers at 400 Hz on the participant for each trial. A launch monitor device recorded the ball and club head conditions at impact. The kinematic data from one representative trial was selected to drive inverse and forward dynamics simulations of the created model. The validation results showed a very high level of agreement between experimental and simulated trajectories for selected markers (mean r = 0.966

    THE EFFECT OF THE APPLICATION OF DIFFERENT LEVELS OF MOVEMENT VARIABILITY ON MOVEMENT OUTCOME

    Get PDF
    The aim of this study was to assess the effect of the application of a previously validated golfer computer model on different levels of movement variability relative to a shot outcome measure: club head velocity. Movement variability was applied to the computer model on six measures sequentially throughout the body of the computer model. Four different levels of variability, 25%, 50%, 75% and 100% variability, were applied to x, y and z positional data of the aforementioned measures. Simulations were then performed with ADAMS/LifeMOD software for each level of movement variability applied to the measures in question. Club head velocity was measured during the simulation. The results suggest that movement variability application at these landmarks does not have an effect on outcome. These results potentially have implications for the coaching of the participant

    A METHOD TO QUANITIFY MOVEMENT VARIABILITY OF HIGHLY SKILLED GOLFERS PERFORMING DRIVER SWINGS

    Get PDF
    Variability has been described as inherent in the golf swing (Bradshaw et al., 2009), yet its impact on outcome is not understood. It is necessary to quantify the levels of movement variability before this relationship can be examined effectively. Thus, the aim of this study was to develop a method to quantify movement variability of golfers performing driver swings. 16 highly skilled golfers each performed 10 swings wearing retro reflective markers which were tracked by a 3D motion analysis system operating at 400Hz. Movement variability was calculated for each marker using scalene ellipsoid volume methods; a score representative of the 3D variability over 10 trials was then calculated. The variability levels calculated using this method showed increasing variability from the closed end of the chain (malleoli) to the open end of the chain (wrists)

    Supporting a Culture of Patient Safety: Resident-Led Patient Safety Event Reviews in a Pathology Residency Training Program

    Get PDF
    Patient safety is a critical component of quality patient care at any healthcare institution. In order to support a culture of patient safety, and in the context of a hospital-wide patient safety initiative at our institution, we have created and implemented a new patient safety curriculum within our training program. The curriculum is embedded in an introductory course for first-year residents, in which residents gain an understanding of the multifaceted role of the pathologist in patient care. The patient safety curriculum is a resident-centered event review process and includes 1) identification and reporting of a patient safety event, 2) event investigation and review, and 3) presentation of findings to the residency program including core faculty and safety champions for the consideration of implementation of the identified systems solution. Here we discuss the development of our patient safety curriculum, which was trialed over a series of seven event reviews conducted between January 2021 and June 2022. Resident involvement in patient safety event reporting and patient safety event review outcomes were measured. All event reviews conducted thus far have resulted in the implementation of the solutions discussed during event review presentations based on cause analysis and identification of strong action items. Ultimately this pilot will serve as the basis by which we implement a sustainable curriculum in our pathology residency training program centered on supporting a culture of patient safety, and in line with ACGME requirements

    A New Method of Measuring Online Media Advertising Effectiveness: Prospective Meta-Analysis in Marketing

    Get PDF
    The authors introduce a new method, prospective meta-analysis in marketing (PMM), to estimate consumer response to online advertising on a large and adaptive scale. They illustrate their approach in a field study in the U.S., China and the Netherlands, covering equivalent ad content on social media, online video, display banner, and search engines. The authors tested a conceptual framework based on attention and engagement using a technological solution that allow them to observe participants browsing and clicking activity in depth from their own residences, offices, or places of choice to use the tested media platforms, e.g., Facebook, Weibo, Google, Baidu and others. The authors show how consumers respond differently to the same ad depending on how distant they are from purchase, and uncover which channels are most appropriate to which user at different stages of the funnel. They also show how engagement and attention strengthen consumer response to advertising. The authors show how PMM produces exploratory findings, confirmatory findings, and replications by systematically organizing the incremental exploration of complex phenomena with cycles of discovery and validation

    Parents\u27 perception of stroller use in young children: A qualitative study

    Get PDF
    Background: Despite their wide usage, it has recently been suggested that stroller use may reduce physical activity levels of young children. However, there have been no studies on stroller use as it relates to physical activity outcomes. The objectives of this study were to understand the context of stroller use for young children and parents\u27 perceptions of the relationship between stroller use and their children\u27s physical activity. Methods: Parents of children 1 to 5 years of age were recruited through two sites of TARGet Kids!, a primary-care, practice-based research network in Toronto, Canada. Fourteen semi-structured interviews were conducted. Interviews were audio recorded and transcribed verbatim and two independent reviewers conducted thematic analysis. A number of strategies were employed to ensure the trustworthiness of the data. Results: Parents discussed reasons for stroller use (i.e., transportation; storage; leisure; supervision/confinement; parent physical activity; and sleep), factors that influence the decision to use a stroller (i.e., caregiver choice; convenience, timing, distance; family lifestyle; and child preference), and perceived impact of stroller use on physical activity (i.e., most parents did not recognize a connection between stroller use and physical activity). Conclusion: This study provides a context for researchers and policy makers to consider when developing stroller related physical activity guidelines for young children

    Privacy regulation and online advertising

    Get PDF
    Advertisers use online customer data to target their marketing appeals. This has heightened consumers' privacy concerns, leading governments to pass laws designed to protect consumer privacy by restricting the use of data and by restricting online tracking techniques used by websites. We use the responses of 3.3 million survey takers who had been randomly exposed to 9,596 online display (banner) advertising campaigns to explore how privacy regulation in the European Union (EU) has influenced advertising effectiveness. This privacy regulation restricted advertisers' ability to collect data on Web users in order to target ad campaigns. We find that, on average, display advertising became far less effective at changing stated purchase intent after the EU laws were enacted, relative to display advertising in other countries. The loss in effectiveness was more pronounced for websites that had general content (such as news sites), where non-data-driven targeting is particularly hard to do. The loss of effectiveness was also more pronounced for ads with a smaller presence on the webpage and for ads that did not have additional interactive, video, or audio features

    Hemangioblastoma With Late Leptomeningeal Metastasis: A Case Report

    Get PDF
    BACKGROUND: Hemangioblastoma of the central nervous system is an uncommon benign neoplasm, with about 25% of cases in patients with von Hippel-Lindau disease. The incidence of metastasis is rare, particularly in patients without von Hippel-Lindau disease. We report a case of hemangioblastoma with leptomeningeal dissemination as a late recurrence. CASE PRESENTATION: A 65-year-old Caucasian man with a history of World Health Organization grade I hemangioblastoma of the cerebellar vermis underwent gross total resection in 1997. In early 2018, he developed intracranial recurrences with diffuse leptomeningeal disease of the entire spine. The patient underwent resection of intracranial recurrence, followed by palliative craniospinal irradiation. The disease progressed quickly, and he died 8 months after recurrence. CONCLUSIONS: Despite a benign pathology, hemangioblastoma has a low risk of metastasis. The outcome for hemangioblastoma patients with metastasis is poor. Multidisciplinary care for patients with metastatic hemangioblastoma warrants further investigation, and an effective systemic option is urgently needed. Regular lifelong follow-up of at-risk patients is recommended

    Search Engine Advertising: Channel Substitution when Pricing Ads to Context

    Get PDF
    We explore substitution patterns across advertising platforms. Using data on the advertising prices paid by lawyers for 139 Google search terms in 195 locations, we exploit a natural experiment in “ambulance-chaser” regulations across states. When lawyers cannot contact clients by mail, advertising prices per click for search engine advertisements are 5%–7% higher. Therefore, online advertising substitutes for offline advertising. This substitution toward online advertising is strongest in markets with fewer customers, suggesting that the relationship between the online and offline media is mediated by the marketers' need to target their communications.NET Institut
    • …
    corecore