Direct Shader Sampling in Painterly Rendering for Animation

We present a technique for generating stroke parameters in particlebased painterly rendering algorithms that guarantees temporal coherence in animation through directly sampling shaders. To determine the appropriate color for a brush stroke, techniques like [Meier 1996] render the scene into reference pictures using traditional techniques. This reference picture is then queried by applying the camera transform to the particle’s position. This transform will not always map to the correct pixel which can lead to noticeable temporal discontinuities when there is a significant color difference between two neighboring pixels. When a stroke particle lies on the edge of an object, the brush stroke will sometimes flicker between the two neighboring colors. Previously, as described in [Meier 1996], scenes would be broken up into different layers, and image processing effects were applied to reference pictures to ensure that the right color is sampled. Our method requires no post processing effects to ensure temporal coherence around these edge cases

Evaluation of a COVID-19 convalescent plasma program at a U.S. academic medical center

Amidst the therapeutic void at the onset of the COVID-19 pandemic, a critical mass of scientific and clinical interest coalesced around COVID-19 convalescent plasma (CCP). To date, the CCP literature has focused largely on safety and efficacy outcomes, but little on implementation outcomes or experience. Expert opinion suggests that if CCP has a role in COVID-19 treatment, it is early in the disease course, and it must deliver a sufficiently high titer of neutralizing antibodies (nAb). Missing in the literature are comprehensive evaluations of how local CCP programs were implemented as part of pandemic preparedness and response, including considerations of the core components and personnel required to meet demand with adequately qualified CCP in a timely and sustained manner. To address this gap, we conducted an evaluation of a local CCP program at a large U.S. academic medical center, the University of North Carolina Medical Center (UNCMC), and patterned our evaluation around the dimensions of the Reach, Effectiveness, Adoption, Implementation, and Maintenance (RE-AIM) framework to systematically describe key implementation-relevant metrics. We aligned our evaluation with program goals of reaching the target population with severe or critical COVID-19, integrating into the structure of the hospital-wide pandemic response, adapting to shifting landscapes, and sustaining the program over time during a compassionate use expanded access program (EAP) era and a randomized controlled trial (RCT) era. During the EAP era, the UNCMC CCP program was associated with faster CCP infusion after admission compared with contemporaneous affiliate hospitals without a local program: median 29.6 hours (interquartile range, IQR: 21.2–48.1) for the UNCMC CCP program versus 47.6 hours (IQR 32.6–71.6) for affiliate hospitals; (P<0.0001). Sixty-eight of 87 CCP recipients in the EAP (78.2%) received CCP containing the FDA recommended minimum nAb titer of ≥1:160. CCP delivery to hospitalized patients operated with equal efficiency regardless of receiving treatment via a RCT or a compassionate-use mechanism. It was found that in a highly resourced academic medical center, rapid implementation of a local CCP collection, treatment, and clinical trial program could be achieved through re-deployment of highly trained laboratory and clinical personnel. These data provide important pragmatic considerations critical for health systems considering the use of CCP as part of an integrated pandemic response

CCP program timeline.

Functional neutralizing antibody assays were available by April 1, 2020 and assay results from CCP donors were reported on a rolling basis every 2–4 weeks throughout 12/01/2020. (TIFF)</p

Time from admission to CCP infusion of EAP and RCT recipients at UNCMC and of EUA recipients at affiliates.

UNCMC EAP reported in middle blue circles, UNCMC RCT reported in dark blue squares, Affiliates EUA reported in gray open squares. Medians are reported. P values obtained via a non-parametric Mann-Whitney U test.</p

Comparisons of recipient factors of time from admission to CCP infusion of EAP participants at UNCMC.

(A) those that were consented in English vs those that required use of a Spanish interpreter, (B) sex, (C) race, (D) ethnicity, (E) age, and (F) blood type. Medians are reported. P values obtained via a non-parametric Mann-Whitney U test. (TIF)</p

Proportions and cumulative titered units collected and transfused during the EAP era at UNCMC.

(A) Monthly proportions of low (gray) versus standard (blue) versus high (black) titered units collected. Percentages at tops of bars are cumulative proportions of standard + high titered units. (B) Monthly proportions of low (gray) versus standard (blue) versus high (black) titered units transfused. Percentages at tops of bars are cumulative proportions of standard + high titered units. (C) Cumulative total units collected and transfused over time, cumulative units with titers ≥1:160 collected and transfused over time, cumulative national supplier units transfused over time.</p

CCP recipient and non-recipient characteristics.

CCP recipient and non-recipient characteristics.</p

CCP recipient characteristics.

CCP recipient characteristics.</p

UNC health system hospitals that participated in the CCP EAP and EUA.

(TIFF)</p