Measuring the robustness of resource allocations for distributed domputer systems in a stochastic dynamic environment

Heterogeneous distributed computing systems often must function in an environment where system parameters are subject to variations during operation. Robustness can be defined as the degree to which a system can function correctly in the presence of parameter values different from those assumed. We present a methodology for quantifying the robustness of resource allocations in a dynamic environment where task execution times vary within predictable ranges and tasks arrive randomly. The methodology is evaluated through measuring the robustness of three different resource allocation heuristics within the context of the stochastically modeled dynamic environment. A Bayesian regression model is fit to the combined results of the three heuristics to demonstrate the correlation between the stochastic robustness metric and the presented performance metric. The correlation results demonstrated the significant potential of the stochastic robustness metric to predict the relative performance of the three heuristics given a common objective function

Evaluation of individual and ensemble probabilistic forecasts of COVID-19 mortality in the United States

Short-term probabilistic forecasts of the trajectory of the COVID-19 pandemic in the United States have served as a visible and important communication channel between the scientific modeling community and both the general public and decision-makers. Forecasting models provide specific, quantitative, and evaluable predictions that inform short-term decisions such as healthcare staffing needs, school closures, and allocation of medical supplies. Starting in April 2020, the US COVID-19 Forecast Hub (https://covid19forecasthub.org/) collected, disseminated, and synthesized tens of millions of specific predictions from more than 90 different academic, industry, and independent research groups. A multimodel ensemble forecast that combined predictions from dozens of groups every week provided the most consistently accurate probabilistic forecasts of incident deaths due to COVID-19 at the state and national level from April 2020 through October 2021. The performance of 27 individual models that submitted complete forecasts of COVID-19 deaths consistently throughout this year showed high variability in forecast skill across time, geospatial units, and forecast horizons. Two-thirds of the models evaluated showed better accuracy than a naïve baseline model. Forecast accuracy degraded as models made predictions further into the future, with probabilistic error at a 20-wk horizon three to five times larger than when predicting at a 1-wk horizon. This project underscores the role that collaboration and active coordination between governmental public-health agencies, academic modeling teams, and industry partners can play in developing modern modeling capabilities to support local, state, and federal response to outbreaks

The United States COVID-19 Forecast Hub dataset

Academic researchers, government agencies, industry groups, and individuals have produced forecasts at an unprecedented scale during the COVID-19 pandemic. To leverage these forecasts, the United States Centers for Disease Control and Prevention (CDC) partnered with an academic research lab at the University of Massachusetts Amherst to create the US COVID-19 Forecast Hub. Launched in April 2020, the Forecast Hub is a dataset with point and probabilistic forecasts of incident cases, incident hospitalizations, incident deaths, and cumulative deaths due to COVID-19 at county, state, and national, levels in the United States. Included forecasts represent a variety of modeling approaches, data sources, and assumptions regarding the spread of COVID-19. The goal of this dataset is to establish a standardized and comparable set of short-term forecasts from modeling teams. These data can be used to develop ensemble models, communicate forecasts to the public, create visualizations, compare models, and inform policies regarding COVID-19 mitigation. These open-source data are available via download from GitHub, through an online API, and through R packages

A Study of Alternative Education Programs in the State of Missouri

The focus of this study was to examine the characteristics of alternative programs in the state of Missouri and to determine whether a statistical difference in the persistence to graduation rate existed between the two variations of programs. When identifying the characteristics, several commonalities emerged. These commonalities could be the focus of future studies to determine a list of best-practices among alternative programs. When focusing on the statistical element of this study, the two programs in question were revolving door and one-way programs. For the purpose of this study, a revolving door style program was defined as one that assesses and addresses student needs within an alternative setting. Once they record significant progress, these students return to the regular classroom setting. A one-way program style assigns students to an educational setting once they prove that the regular classroom setting is not an appropriate situation. The at-risk students in this program will either graduate from the alternative school or choose not to complete high school. According to the findings of this study, there was no statistically significant difference between and among the persistence to graduation rate midst the revolving door and one-way styles of alternative programs

Marine Geology of Kure and Midway Atolls, Hawaii: A Preliminary Report

Midway and Kure islands are the world's northernmost atolls but have flourishing algal-coral reefs with typical coral reef structures. An almost circular outer reef and a broad, shallow (< 5 meters deep), sediment-built lagoon terrace surround the deeper parts of each lagoon (maximum depths: Midway, 21 meters; Kure, 14 meters). Unconsolidated carbonate sand and gravel form islands along the southern margins of the atolls. Patch reefs form a series of intersecting ridges partly covered by sediment. Emergent parts of older presumed reef rock, built primarily of coralline algae, extend about 1 meter above sea level; they are especially well developed on Midway and are present but less conspicuous on Kure. Sediment grain size decreases lagoonward. Carbonate -gravel and coarse sands predominate on the reef flats, on the seaward sides of the islands, and on the lagoon terrace. Fine carbonate sands and silts cover the deeper parts of the lagoon bottom. Major sediment-contributing organisms are (in order of abundance): coralline algae, corals, foraminifers, and mollusks. Halimeda is nowhere a major constituent. Most sediment grains deposited in the lagoons are reef-derived, primarily from the windward reefs on the northeastern margin. There is no distinctive lagoonal sediment facies

Portage la Prairie Social Planning Initiative: Phase One Report

Report: 115 pp.; ill., digital file.The Institute of Urban Studies (IUS), in partnership with the Portage Community Network (PCN), undertook a public engagement process to produce a social planning framework for the city of Portage la Prairie. This report highlights the findings of the process and provides 26 recommendations. It also includes a demographic profile and mapping study of the city, a summary of findings from the stakeholder and public engagement process, and a review of social planning theory and practices. The overall intent is to gain an initial understanding of the issues at hand, and to set out the theoretical and practical issues involved in social planning. Staff at the IUS engaged in reviews of best practices in social planning, emphasizing small cities; analyzed demographic data related to social conditions in Portage la Prairie; engaged in broad consultation with key informants and residents about social needs and assets; identified social policy and program areas of strength and weakness, and proposed improvements and additions to the programming environment; and proposed elements, dimensions and values into an evaluative framework to guide the production of a social plan, and suggest indicators to gauge its effectiveness.Neighbourhoods Alive!, The City of Portage la Prairie, Regional Health Authority Central Manitoba, Inc. - Healthy Living Program, Community Foundation of Portage and District, Inc., Healthy Child Coalition - Central Manitoba, Child and Family Services of Central Manitoba Foundation, Inc., Portage Plains United Way

IP3R activity increases propensity of RyR-mediated sparks by elevating dyadic [Ca2＋].

Calcium (Ca2＋) plays a critical role in the excitation contraction coupling (ECC) process that mediates the contraction of cardiomyocytes during each heartbeat. While ryanodine receptors (RyRs) are the primary Ca2＋ channels responsible for generating the cell-wide Ca2＋ transients during ECC, Ca2＋ release, a=via inositol 1,4,5-trisphosphate (IP3) receptors (IP3Rs) are also reported in cardiomyocytes and to elicit ECC-modulating effects. Recent studies suggest that the localization of IP3Rs at dyads grant their ability to modify the occurrence of Ca2＋ sparks (elementary Ca2＋ release events that constitute cell wide Ca2＋ releases associated with ECC) which may underlie their modulatory influence on ECC. Here, we aim to uncover the mechanism by which dyad-localized IP3Rs influence Ca2＋ spark dynamics. To this end, we developed a mathematical model of the dyad that incorporates the behaviour of IP3Rs, in addition to RyRs, to reveal the impact of their activity on local Ca2＋ handling and consequent Ca2＋ spark occurrence and its properties. Consistent with published experimental data, our model predicts that the propensity for Ca2＋ spark formation increases in the presence of IP3R activity. Our simulations support the hypothesis that IP3Rs elevate Ca2＋ in the dyad, sensitizing proximal RyRs toward activation and hence Ca2＋ spark formation. The stochasticity of IP3R gating is an important aspect of this mechanism. However, dyadic IP3R activity lowers the Ca2＋ available in the junctional sarcoplasmic reticulum (JSR) for release, thus resulting in Ca2＋ sparks with similar durations but lower amplitudes