638 research outputs found
The PSEIKI Report—Version 2. Evidence Accumulation and Flow of Control in a Hierarchical Spatial Reasoning System
A fundamental goal of computer vision is the development of systems capable of carrying out scene interpretation while taking into account all the available knowledge. In this report, we have focused on how the interpretation task may be aided by expected-scene information which, in most cases, would not be in registration with the perceived scene. In this report, we describe PSEIKI, a framework for expectation-driven interpretation of image data. PSEIKI builds abstraction hierarchies in image data using, for cues, supplied abstraction hierarchies in a scene expectation map. Hypothesized abstractions in the image data are geometrically compared with the known abstractions in the expected scene; the metrics used for these comparisons translate into belief values. The Dempster-Shafer formalism is used to accumulate beliefs for the synthesized abstractions in the image data. For accumulating belief values, a computationally efficient variation of Dempster’s rule of combination is developed to enable the system to deal with the overwhelming amount of information present in most images. This variation of Dempster’s rule allows the reasoning process to be embedded into the abstraction hierarchy by allowing for the propagation of belief values between elements at different levels of abstraction. The system has been implemented as a 2- panel, 5-level blackboard in OPS 83. This report also discusses the control aspects of the blackboard, achieved via a distributed monitor using the OPS83 demons and a scheduler. Various knowledge sources for forming groupings in the image data and for labeling such groupings with abstractions from the scene expectation map are also discussed
PSEIKI: A Production System Environment for Integrating Knowledge with Images
A description of work-in-progress on PSEIKI is presented. PSEIKI is a computer vision system designed to use multiple sources of knowledge to aid in the image understanding task. In this report we describe the concepts used in PSEIKI and how the incorporation of world knowledge is used to make PSEIKI expectation driven. The world knowledge in the system is represented as a line drawing of the expected scene. The system is implemented as a 2 panel / 6 level blackboard and uses the Dempster-Shafer formalism to accomplish inexact reasoning in a hierarchical spac
Cumulative mutagenesis of the basic residues in the 201-218 region of insulin-like growth factor (IGF)-binding protein-5 results in progressive loss of both IGF-I binding and inhibition of IGF-I biological action
We have reported previously that mutation of two conserved nonbasic amino acids (G203 and Q209) within the highly basic 201–218 region in the C-terminal domain of IGF-binding protein-5 (IGFBP-5) decreases binding to IGFs. This study reveals that cumulative mutagenesis of the 10 basic residues in this region, to create the C-Term series of mutants, ultimately results in a 15-fold decrease in the affinity for IGF-I and a major loss in heparin binding. We examined the ability of mutants to inhibit IGF-mediated survival of MCF-7 cells and were able to demonstrate that this depended not only upon the affinity for IGF-I, but also the kinetics of this interaction, because IGFBP-5 mutants with similar affinity constants (KD) values, but with different association (Ka) and dissociation (Kd) rate values, had markedly different inhibitory properties. In contrast, the affinity for IGF-I provided no predictive value in terms of the ability of these mutants to enhance IGF action when bound to the substratum. Instead, these C-Term mutants appeared to enhance the actions of IGF-I by a combination of increased dissociation of IGF-IGFBP complexes from the substratum, together with dissociation of IGF-I from IGFBP-5 bound to the substratum. These effects of the IGFBPs were dependent upon binding to IGF-I, because a non-IGF binding mutant (N-Term) was unable to inhibit or enhance the actions of IGF-I. These results emphasize the importance of the kinetics of association/dissociation in determining the enhancing or inhibiting effects of IGFBP-5 and demonstrate the ability to generate an IGFBP-5 mutant with exclusively IGF-enhancing activity
Molecular Mechanistic Explanation for the Spectrum of Cholestatic Disease Caused by the S320F Variant of ABCB4
This article has been accepted for publication and undergone full peer review but has not been
through the copyediting, typesetting, pagination and proofreading process which may lead to
differences between this version and the Version of Record. Please cite this article as
doi: 10.1002/hep.26970E.J.A. was funded by Barts and the London Charity award 458/1495. M.N. was funded by a Medical Research Council centenary award. M.R.R. was supported by funding from the Spanish Ministry of Science (Grant SAF2010-15517). The groups of K.J.L. and C.W. are supported by the Medical Research Council, UK (MC_U120088463) and Imperial College Healthcare NHS trust biomedical research centre, respectively
New broad 8Be nuclear resonances
Energies, total and partial widths, and reduced width amplitudes of 8Be
resonances up to an excitation energy of 26 MeV are extracted from a coupled
channel analysis of experimental data. The presence of an extremely broad J^pi
= 2^+ ``intruder'' resonance is confirmed, while a new 1^+ and very broad 4^+
resonance are discovered. A previously known 22 MeV 2^+ resonance is likely
resolved into two resonances. The experimental J^pi T = 3^(+)? resonance at 22
MeV is determined to be 3^-0, and the experimental 1^-? (at 19 MeV) and 4^-?
resonances to be isospin 0.Comment: 16 pages, LaTe
From the National to the Local: Issues of Trust and a Model For Community-Academic-Engagement
Inequities in health and health care in the United States have persisted for decades, and the impacts on equity from the COVID-19 pandemic were no exception. In addition to the disproportionate burden of the disease across various populations, the pandemic posed several challenges, which exacerbated these existing inequities. This has undoubtedly contributed to deeply rooted public mistrust in medical research and healthcare delivery, particularly among historically and structurally oppressed populations. In the summer of 2020, given the series of social injustices posed by the pandemic and highly publicized incidents of police brutality, notably the murder of George Floyd, the Association of American Medical Colleges (AAMC) enlisted the help of a national collaborative, the AAMC Collaborative for Health Equity: Act, Research, Generate Evidence (CHARGE) to establish a three-way partnership that would gather and prioritize community perspectives and lived experiences from multiple regions across the US on the role of academic medicals centers (AMCs) in advancing health and social justice. Given physical gathering constraints posed by the pandemic, virtual interviews were conducted with 30 racially and ethnically diverse community members across the country who expressed their views on how medical education, clinical care, and research could or did impact their health experiences. These interviews were framed within the context of the relationship between historically oppressed groups and the COVID-19 vaccine clinical trials underway. From the three-way partnership formed with the AAMC, AAMC CHARGE participants, and 30 community members from racially and ethnically diverse groups, qualitative methods provided lived experiences supporting other literature on the lack of trust between oppressed communities and AMCs. This led to the development of the Principles of Trustworthiness (PoT) toolkit, which features ten principles inspired by community members\u27 insights into how AMCs can demonstrate they are worthy of their community\u27s trust. In the end, the three-way partnership serves as a successful model for other national medical and health organizations to establish community engaged processes that elicit and prioritize lived experiences describing relationships between AMCs and oppressed communities
Survival following parathyroidectomy among United States dialysis patients
Survival following parathyroidectomy among United States dialysis patients.BackgroundSecondary hyperparathyroidism (SHPTH) is highly prevalent among persons with end-stage renal disease (ESRD). SHPTH has been linked to uremic bone disease, vascular calcification, and a higher risk of death. Parathyroidectomy (PTX) can dramatically reduce parathyroid hormone (PTH) and phosphate levels; however, the relationship between PTX and survival is not known.MethodsWe conducted an observational matched cohort study utilizing data from the United States Renal Database System (USRDS) in which 4558 patients undergoing a first PTX while on hemodialysis or peritoneal dialysis were individually matched by age, race, gender, cause of ESRD, dialysis duration, prior transplantation status, and dialysis modality to 4558 control patients who did not undergo PTX. Patients were followed from the date of PTX until they died or were lost to follow-up.ResultsThe 30-day postoperative mortality rate following PTX was 3.1%. Long-term relative risks of death among patients undergoing PTX were estimated to be 10% to 15% lower than those of matched control patients not undergoing surgery. Survival curves between the 2 groups crossed 587 days following PTX. Median survival was 53.4 months (95% CI: 51.2–56.4) in the PTX group, and 46.8 months (95% CI: 44.7–48.9) in the control group.ConclusionPTX was associated with higher short-term, and lower long-term, mortality rates among U.S. patients receiving chronic dialysis. Measures to attenuate SHPTH may play an important role in reducing mortality among patients with end-stage renal disease
Migraine, arousal and sleep deprivation: comment on: "sleep quality, arousal and pain thresholds in migraineurs: a blinded controlled polysomnographic study"
We discuss the hypothesis proposed by Engstrom and coworkers that Migraineurs have a relative sleep deprivation, which lowers the pain threshold and predispose to attacks. Previous data indicate that Migraineurs have a reduction of Cyclic Alternating Pattern (CAP), an essential mechanism of NREM sleep regulation which allows to dump the effect of incoming disruptive stimuli, and to protect sleep. The modifications of CAP observed in Migraineurs are similar to those observed in patients with impaired arousal (narcolepsy) and after sleep deprivation. The impairment of this mechanism makes Migraineurs more vulnerable to stimuli triggering attacks during sleep, and represents part of a more general vulnerability to incoming stimuli
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A preliminary evaluation of the ability of from-reactor casks to geometrically accommodate commercial LWR spent nuclear fuel
The Department of Energy has sponsored a number of cask design efforts to define several transportation casks to accommodate the various assemblies expected to be accepted by the Federal Waste Management System. At this time, three preliminary cask designs have been selected for the final design--the GA-4 and GA-9 truck casks and the BR-100 rail cask. In total, this assessment indicates that the current Initiative I cask designs can be expected to dimensionally accommodate 100% of the PWR fuel assemblies (other than the extra-long South Texas Fuel) with control elements removed, and >90% of the assemblies having the control elements as an integral part of the fuel assembly. For BWR assemblies, >99% of the assemblies can be accommodated with fuel channels removed. This paper summarizes preliminary results of one part of that evaluation related to the ability of the From-Reactor Initiative I casks to accommodate the physical and radiological characteristics of the Spent Nuclear Fuel projected to be accepted into the Federal Waste Management System. 3 refs., 5 tabs
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