Sample Tracking
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2021 ◽  
Author(s):  
Guihua Wang ◽  
Ronghuo Zheng ◽  
Tinglong Dai

Every year, nearly 5,000 patients die while waiting for kidney transplants, and yet an estimated 3,500 procured kidneys are discarded. Such a polarized coexistence of dire scarcity and massive wastefulness has been mainly driven by insufficient pooling of cadaveric kidneys across geographic regions. Although numerous policy initiatives are aimed at broadening organ pooling, they rarely account for a key friction—efficient airline transportation, ideally direct flights, is necessary for long-distance sharing, because of the time-sensitive nature of kidney transplantation. Conceivably, transplant centers may be reluctant to accept kidney offers from far-off locations without direct flights. In this paper, we estimate the effect of the introduction of new airline routes on broader kidney sharing. By merging the U.S. airline transportation and kidney transplantation data sets, we create a unique sample tracking (1) the evolution of airline routes connecting all the U.S. airports and (2) kidney transplants between donors and recipients connected by these airports. We estimate the introduction of a new airline route increases the number of shared kidneys by 7.3%. We also find a net increase in the total number of kidney transplants and a decrease in the organ discard rate with the introduction of new routes. Notably, the posttransplant survival rate remains largely unchanged, although average travel distance increases after the introduction of new airline routes. Our results are robust to alternative empirical specifications and have important implications for improving access to the U.S. organ transplantation system. This paper was accepted by Vishal Gaur, operations management.


2021 ◽  
Author(s):  
Chandra Sekhar Pedamallu ◽  
Joon Sang Lee ◽  
Shu Yan ◽  
Adalis Maisonet ◽  
Aleksandr Sidoruk ◽  
...  

Mathematics ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 1445
Author(s):  
Rodi Lykou ◽  
George Tsaklidis

Observational errors of Particle Filtering are studied over the case of a state-space model with a linear observation equation. In this study, the observational errors are estimated prior to the upcoming observations. This action is added to the basic algorithm of the filter as a new step for the acquisition of the state estimations. This intervention is useful in the presence of missing data problems mainly, as well as sample tracking for impoverishment issues. It applies theory of Homogeneous and Non-Homogeneous closed Markov Systems to the study of particle distribution over the state domain and, thus, lays the foundations for the employment of stochastic control against impoverishment. A simulating example is quoted to demonstrate the effectiveness of the proposed method in comparison with existing ones, showing that the proposed method is able to combine satisfactory precision of results with a low computational cost and provide an example to achieve impoverishment prediction and tracking.


2021 ◽  
Author(s):  
Shaina Robbins ◽  
Sirisha Achanta ◽  
Rajanikanth Vadigepalli

Abstract This protocol demonstrates the use of Laser Capture Microdissection (LCM), a precise cell isolation technique, for acquiring single neurons from right atrial ganglionated plexus (RAGP) porcine heart tissue in sync with image acquisition to enable 3D location tracking of collected samples. Fresh frozen RAGP tissue sectioned and stained for neurons (Nissl stain) is processed through LCM for sample collection. The LCM workflow is comprised of four steps: instrument setup, slide loading and tissue inspection, microdissection and image acquisition and sample processing and storage. LCM collected samples were processed for gene expression experiments : High-throughput-qRT-PCR or Single cell RNA sequencing. Gene expression data along with 3D sample tracking was used to generate a functional map of porcine RAGP. The techniques described in this protocol can be adapted to a wide variety of sample and tissue types with minor modifications. This protocol is a part of a protocol pipeline that includes cryosectioning and staining protocols upstream and Tissue Mapper protocol, High-Throughput q-RT-PCR and RNA Seq protocols downstream.


2021 ◽  
Author(s):  
Justin D Vrana ◽  
Nuttada Panpradist ◽  
Nikki Higa ◽  
Daisy Ko ◽  
Parker Ruth ◽  
...  

Introduction: Usability is an overlooked aspect of implementing lab-based assays, particularly novel assays in low-resource-settings. Esoteric instructions can lead to irreproducible test results and patient harm. To address these issues, we developed a software application based on ″Aquarium″, a laboratory-operating system run on a computer tablet that provides step-by-step digital interactive instructions, protocol management, and sample tracking. Aquarium was paired with a near point-of-care HIV drug resistance test, ″OLA-Simple″, that detects mutations associated with virologic failure. In this observational study we evaluated the performance of Aquarium in guiding untrained users through the multi-step laboratory protocol with little supervision. Methods: A feasibility study was conducted in a laboratory at Coptic Hope Center in Nairobi, Kenya. To evaluate the training by Aquarium software, twelve volunteers who were unfamiliar with the kit performed the test on blinded samples (2 blood specimens; 5 codons/sample). Steps guided by Aquarium included: CD4+ T-Cell separation, PCR, ligation, detection, and interpretation of test results. Participants filled out a short survey regarding their demographics and experience with the software and kit. Results and discussion: 12/12 laboratory technicians had no prior experience performing CD4+ separation and 7/12 had no experience performing laboratory-based molecular assays. 12/12 isolated CD4+ T cells from whole blood with yields comparable to isolations performed by trained personnel. The OLA-Simple workflow was completed by all, with correct visual and software interpretation of results for 90% (108/120) and 97% (116/120) of codons, respectively. In the surveys, participants favorably assessed the use of software guidance. Conclusions: Aquarium digital instructions enabled first-time users in Kenya to complete the OLA-simple kit workflow with minimal training. Aquarium could increase the accessibility of laboratory assays in low-resource-settings and potentially standardize implementation of clinical laboratory tests.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Melissa M. Matthews ◽  
Tae Gyun Kim ◽  
Satoshi Shibata ◽  
Noriko Shibata ◽  
Christian Butcher ◽  
...  

AbstractDuring August 2020, we carried out a serological survey among students and employees at the Okinawa Institute of Science and Technology Graduate University (OIST), Japan, testing for the presence of antibodies against SARS-CoV-2, the causative agent of COVID-19. We used a FDA-authorized 2-step ELISA protocol in combination with at-home self-collection of blood samples using a custom low-cost finger prick-based capillary blood collection kit. Although our survey did not find any COVID-19 seropositive individuals among the OIST cohort, it reliably detected all positive control samples obtained from a local hospital and excluded all negatives controls. We found that high serum antibody titers can persist for more than 9 months post infection. Among our controls, we found strong cross-reactivity of antibodies in samples from a serum pool from two MERS patients in the anti-SARS-CoV-2-S ELISA. Here we show that a centralized ELISA in combination with patient-based capillary blood collection using as little as one drop of blood can reliably assess the seroprevalence among communities. Anonymous sample tracking and an integrated website created a stream-lined procedure. Major parts of the workflow were automated on a liquid handler, demonstrating scalability. We anticipate this concept to serve as a prototype for reliable serological testing among larger populations.


2021 ◽  
Author(s):  
Yueyang Xia ◽  
Dirk Klaeschen ◽  
Heidrun Kopp ◽  
Michael Schnabel

Abstract. Accurate subsurface velocity models are crucial for geological interpretations based on seismic depth images. Seismic reflection tomography is an effective iterative method to update and refine a preliminary velocity model for depth imaging. Based on residual move-out analysis of reflectors in common image point gathers an update of the velocity is estimated by a ray-based tomography. To stabilize the tomography, several preconditioning strategies exist. Most critical is the estimation of the depth error to account for the residual move-out of the reflector in the common image point gathers. Because the depth errors for many closely spaced image gathers must be picked, manual picking is extremely time-consuming, human biased, and not reproducible. Data-driven picking algorithms based on coherence or semblance analysis are widely used for hyperbolic or linear events. However, for complex-shaped depth events, pure data-driven picking is difficult. To overcome this, the warping method named Non-Rigid Matching is used to estimate a depth error displacement field. Warping is used, e.g., to merge photographic images or to match two seismic images from time-lapse data. By calculating the displacements between an offset to its neighbouring offset in the common image point domain, a locally smooth-shaped displacement field is defined for each data sample. Depending on the complexity of the subsurface, sample tracking through the displacement field along predefined horizons or on a simple regular grid yields discrete depth error values for the tomography. The application to a multi-channel seismic line across the Sunda subduction zone offshore Lombok island, Indonesia, illustrates the approach and documents the advantages of the method to estimate a detailed velocity structure in a complex tectonic regime. By incorporating the warping scheme into the reflection tomography, we demonstrate an increase in the velocity resolution and precision by improving the data-driven accuracy of depth error picks with arbitrary shapes. This approach offers the possibility to use the full capacities of tomography and further leads to more accurate interpretations of complex geological structures.


protocols.io ◽  
2020 ◽  
Author(s):  
Shashank Sathe ◽  
Clarence Mah ◽  
Noorsher Ahmed ◽  
Michelle Franc ◽  
John Williams

Author(s):  
G.C. Donaldson ◽  
D.J. Wiseman ◽  
A.I. Ritchie ◽  
M. Macleod ◽  
J. Allinson ◽  
...  

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