67 research outputs found

    Coming Together Through Object Based Learning in a Pandemic

    Get PDF
    In the summer of 2019, three history teachers from all over the US, met in France for National History Day’s Memorializing the Fallen program and commenced a lasting friendship. While in France, touring the WWI cemeteries, memorial sites, and museums, we all realized the importance of experience-based learning and the seeds were sown for our interest in object based learning. Aside from the philosophical and pedagogical discussions on long bus rides and our passion for history, we shared a belief in the importance of revitalizing history education and helping it to evolve in the face of our twenty-first century world. When we returned back from France we kept in touch and continued to think of ways we could collaborate and work together. Covid-19 provided us that opportunity. With history education and teachers in general having to become more familiar with Google Meets, Zoom, and other video based platforms we decided to get together and have a Zoom session. As we talked and discussed what each of us were doing we found that we all to varying degrees believe in and utilize object based learning in our classrooms. We decided that other teachers could benefit from using objects in their classrooms. So, we decided we would model the technique and lines of questioning that go into using objects in a classroom. For this journal we would like to discuss how we came together, our passion for object based learning, and how, despite the disruption COVID-19 brought to all of our school years and classes, it also provided us the opportunity to come together and create content and resources that could help teachers now and whenever we get back into the classroom

    Dynamic Controllability of Temporally-flexible Reactive Programs

    Get PDF
    In this paper we extend dynamic controllability of temporally-flexible plans to temporally-flexible reactive programs. We consider three reactive programming language constructs whose behavior depends on runtime observations; conditional execution, iteration, and exception handling. Temporally-flexible reactive programs are distinguished from temporally-flexible plans in that program execution is conditioned on the runtime state of the world. In addition, exceptions are thrown and caught at runtime in response to violated timing constraints, and handled exceptions are considered successful program executions. Dynamic controllability corresponds to a guarantee that a program will execute to completion, despite runtime constraint violations and uncertainty in runtime state. An algorithm is developed which frames the dynamic controllability problem as an AND/OR search tree over possible program executions. A key advantage of this approach is the ability to enumerate only a subset of possible program executions that guarantees dynamic controllability, framed as an AND/OR solution subtree

    Macroscopic-Imaging Technique for Subsurface Quantification of Near-Infrared Markers During Surgery

    Get PDF
    Obtaining accurate quantitative information on the concentration and distribution of fluorescent markers lying at a depth below the surface of optically turbid media, such as tissue, is a significant challenge. Here, we introduce a fluorescence reconstruction technique based on a diffusion light transport model that can be used during surgery, including guiding resection of brain tumors, for depth-resolved quantitative imaging of near-infrared fluorescent markers. Hyperspectral fluorescence images are used to compute a topographic map of the fluorophore distribution, which yields structural and optical constraints for a three-dimensional subsequent hyperspectral diffuse fluorescence reconstruction algorithm. Using the model fluorophore Alexa Fluor 647 and brain-like tissue phantoms, the technique yielded estimates of fluorophore concentration within ±25% of the true value to depths of 5 to 9 mm, depending on the concentration. The approach is practical for integration into a neurosurgical fluorescence microscope and has potential to further extend fluorescence-guided resection using objective and quantified metrics of the presence of residual tumor tissue

    Clinical consensus guidelines on the application of cerebrospinal fluid biomarkers for Alzheimer's disease diagnosis: recommendations of the Irish Network for Biomarkers in Neurodegeneration

    Get PDF
    It is accepted that a lumbar puncture (LP) and cerebrospinal fluid (CSF) biomarker analysis support the routine diagnostic work-up for the differential diagnosis of dementia due to Alzheimer’s disease (AD) within certain patient cohorts1. These tests, which measure CSF protein concentrations of amyloid-β42 (Aβ42), total tau (t-tau) and phospho tau (p-tau), were recently validated, accredited and made available clinically for the first time in Ireland. A working group, comprising Irish clinical and scientific researchers, met to review a) the validation results; b) international consensus opinions, and c) research and clinical evidence as to the clinical utility of CSF biomarker analysis for AD dementia diagnosis. The outcome of this meeting was the formulation of a consensus statement paper for the benefit of health care professionals involved in the diagnosis and management of dementia to ensure appropriate use of these biomarker tests in clinical settings in Ireland

    Interplay between HIV-1 infection and host microRNAs

    Get PDF
    Using microRNA array analyses of in vitro HIV-1-infected CD4+ cells, we find that several host microRNAs are significantly up- or downregulated around the time HIV-1 infection peaks in vitro. While microRNA-223 levels were significantly enriched in HIV-1-infected CD4+CD8− PBMCs, microRNA-29a/b, microRNA-155 and microRNA-21 levels were significantly reduced. Based on the potential for microRNA binding sites in a conserved sequence of the Nef-3′-LTR, several host microRNAs potentially could affect HIV-1 gene expression. Among those microRNAs, the microRNA-29 family has seed complementarity in the HIV-1 3′-UTR, but the potential suppressive effect of microRNA-29 on HIV-1 is severely blocked by the secondary structure of the target region. Our data support a possible regulatory circuit at the peak of HIV-1 replication which involves downregulation of microRNA-29, expression of Nef, the apoptosis of host CD4 cells and upregulation of microRNA-223

    Proof-of-Principle Experiment for FEL-Based Coherent Electron Cooling,”

    Get PDF
    Abstract Coherent electron cooling (CEC) has a potential to significantly boost luminosity of high-energy, highintensity hadron-hadron and electron-hadron colliders. In a CEC system, a hadron beam interacts with a cooling electron beam. A perturbation of the electron density caused by ions is amplified and fed back to the ions to reduce the energy spread and the emittance of the ion beam. To demonstrate the feasibility of CEC we propose a proof-of-principle experiment at RHIC using SRF linac. In this paper, we describe the setup for CeC installed into one of RHIC's interaction regions. We present results of analytical estimates and results of initial simulations of cooling a gold-ion beam at 40 GeV/u energy via CeC
    corecore