An expert system for scheduling requests for communications Links between TDRSS and ERBS

An ERBS-TDRSS Contact Planning System (ERBS-TDRSS CPS) is described which uses a graphics interface and the NASA Transportable Interference Engine. The procedure involves transfer of the ERBS-TDRSS Ground Track Orbit Prediction data to the ERBS flight operations area, where the ERBS-TDRSS CPS automatically generates requests for TDRSS service. As requested events are rejected, alternative context sensitive strategies are employed to generate new requested events until a schedule is completed. A report generator builds schedule requests for separate ERBS-TDRSS contacts

Operational aspects of a spacecraft planning/scheduling expert system

Various operational aspects of the Earth Radiation Budget Satellite (ERBS) Tracking and Data Relay Satellite System (TDRSS) are described. The ERBS-TDRSS Contract Planning System is an expert system which has been used operationally since June 1987 by the ERBS Flight Operations Team (FOT) at Goddard Space Flight Center to build weekly schedules of requests for service from the TDRSS. The basic operation of the system and significant enhancements and changes are discussed

Business Judgment Dismissal of Shareholder Derivative Suits by Board Litigation Committees: An Expanded Role for the Courts

This Recent Development examines the legal background of the shareholder derivative suit and the business judgment rule and then traces the evolution of the offensive use of the business judgment rule in board of director terminations of stockholder derivative actions. After examining other derivative suit dismissal decisions, the Recent Development analyzes whether Zapata adequately balances the competing interests of the shareholder and the corporate board. Finally, the Recent Development discusses the potential effect of Zapata on future litigation

A multistate model for early decision making in oncology

The development of oncology drugs progresses through multiple phases, where after each phase a decision is made about whether to move a molecule forward. Early phase efficacy decisions are often made on the basis of single arm studies based on RECIST tumor response as endpoint. This decision rules are implicitly assuming some form of surrogacy between tumor response and long-term endpoints like progression-free survival (PFS) or overall survival (OS). The surrogacy is most often assessed as weak, but sufficient to allow a rapid decision making as early phase studies lack the survival follow up and number of patients to properly assess PFS or OS. With the emergence of therapies with new mechanisms of action, for which the link between RECIST tumor response and long-term endpoints is either not accessible yet because not enough data is available to perform a meta-regression, or the link is weaker than with classical chemotherapies, tumor response based rules may not be optimal. In this paper, we explore the use of a multistate model for decision making based on single-arm early phase trials. The multistate model allows to account for more information than the simple RECIST response status, namely, the time to get to response, the duration of response, the PFS time and time to death. We propose to base the decision on efficacy on the OS hazard ratio (HR), predicted from a multistate model based on early phase data with limited survival follow-up, combined with historical control data. Using three case studies and simulations, we illustrate the feasibility of the estimation of the OS HR using a multistate model based on limited data from early phase studies. We argue that, in the presence of limited follow up and small sample size, and on assumptions within the multistate model, the OS prediction is acceptable and may lead to better decisions for continuing the development of a drug

A Generalized Grand-Reaction Method for Modelling the Exchange of Weak (Polyprotic) Acids between a Solution and a Weak Polyelectrolyte Phase

We introduce a Monte-Carlo method that allows for the simulation of a polymeric phase containing a weak polyelectrolyte, which is coupled to a reservoir at a fixed pH, salt concentration and total concentration of a weak polyprotic acid. The method generalizes the established Grand-Reaction Method by Landsgesell et al. [Macromolecules 53, 3007-3020 (2020)] and thus allows for the simulation of polyelectrolyte systems coupled to reservoirs with a more complex chemical composition. In order to set the required input parameters that correspond to a desired reservoir composition, we propose a generalization of the recently published chemical potential tuning algorithm of Miles et al. [Phys. Rev. E 105, 045311 (2022)]. To test the proposed tuning procedure, we perform extensive numerical tests for both ideal and interacting systems. Finally, as a showcase, we apply the method to a simple test system which consists of a weak polybase solution that is coupled to a reservoir containing a small diprotic acid. The complex interplay of the ionization various species, the electrostatic interactions and the partitioning of small ions leads to a non-monotonous, stepwise swelling behaviour of the weak polybase chains.Comment: 18 pages, 9 figure

Explaining Giant Apparent pKA\mathrm{p}K_\mathrm{A} Shifts in Weak Polyelectrolyte Brushes

Recent experiments on weak polyelectrolyte brushes found marked shifts in the effective p$K_\mathrm{A}$ that are linear in the logarithm of the salt concentration. Comparing explicit-particle simulations with mean-field calculations we show that for high grafting densities the salt concentration effect can be explained using the ideal Donnan theory, but for low grafting densities the full shift is due to a combination of the Donnan effect and the polyelectrolyte effect. The latter originates from electrostatic correlations which are neglected in the Donnan picture and which are only approximately included in the mean-field theory. Moreover, we demonstrate that the magnitude of the polyelectrolyte effect is almost invariant with respect to salt concentration but depends on the grafting density of the brush. This invariance is due to a complex cancellation of multiple effects. Based on our results, we show how the experimentally determined p$K_\mathrm{A}$ shifts may be used to infer the grafting density of brushes, a parameter that is difficult to measure directly.Comment: First revised version of the manuscript; 15 pages, 16 figure

Lean Cooperation: A Framework

While both concepts lean management and cooperation not only have received considerable attention in management literature but also have been combined e.g. in the field of supply chain literature, a comprehensive definition of lean cooperation is still missing. Whereas lean supply chain cooperation is only one aspect in a growing field, we aim at considering further forms of cooperation coming up and having consequences for the management of lean initiatives.Based on an extensive literature review, we develop a framework addressing lean cooperation and thus, allowing for systematization. Furthermore we find out that current literature mainly focusses on leancooperation along the supply chain. This paper presents other forms of cooperation focused on lean management. With a case study of lean cooperation within an industry cluster we will show the potential of knowledge-transfer on lean practices for individual firm´s  implementation.This paper provides a definition and a research framework for lean cooperation. Insights will be useful for further analysis of lean management roll-out within outlined forms of cooperation. Practitionerswill learn about benefits and restrictions of lean cooperation. The paper also is of value for researchers giving a structured outline of lean cooperation and stating fields for further research

Virtual Planetary Analysis Environment for Remote Science

All of the data for NASA's current planetary missions and most data for field experiments are collected via orbiting spacecraft, aircraft, and robotic explorers. Mission scientists are unable to employ traditional field methods when operating remotely. We have developed a virtual exploration tool for remote sites with data analysis capabilities that extend human perception quantitatively and qualitatively. Scientists and mission engineers can use it to explore a realistic representation of a remote site. It also provides software tools to "touch" and "measure" remote sites with an immediacy that boosts scientific productivity and is essential for mission operations

Molecular Mechanisms of Stem Cells Pluripotency and Cell Fate Specification

International audienc