Orbiting Geophysical Observatory Attitude Control Subsystem Design Survey. NASA/ERC Design Criteria Program, Guidance and Control

This design survey summarizes the history of the Orbiting Geophysical Observatories' (OGO) Attitude Control Subsystem (ACS) from the proposal phase through current flight experience. Problems encountered in design, fabrication, test, and on orbit are discussed. It is hoped that the experiences of the OGO program related here will aid future designers

Orbiting Geophysical Observatory Attitude Control Subsystem design survey

Development history and design modifications for attitude control subsystem of OG

An exploration of relative frame potential

A frame for a vector space is a set of vectors which behaves in some ways like a basis for the vector space while having a more flexible structure that allows for frames to be constructed to fit a variety of application situations, such as in signal processing. The frame potential function, developed in 2001, takes a frame as input and returns its “frame potential value”. This value reveals important information about the properties of the input frame. In this paper, we adapt the frame potential function to create a “relative frame potential function”, which takes one frame as input with respect to another frame. We analyze the behavior of this function to determine what information the relative frame potential value can reveal about the relationship between the two frames.Honors CollegeThesis (B.?

Curly Head

https://digitalcommons.library.umaine.edu/mmb-vp/5581/thumbnail.jp

Message and Medium:The Role of Consulting Firms in Globalization and Its Local Interpretation

A century ago, management consulting as we know it all but did not exist. The management consulting industry emerged and structured itself in the twentieth century, growing then very rapidly. In today’s capitalist landscape, it has become a significant actor (Kennedy Information Research Group on-line). Historically, the changing needs of a stable group of large corporate clients were driving growth. In time, however, growth also came from the exploration of uncharted territories – new clients, new industries but also new countries. From traditional engagements with private for profit firms essentially involved in the manufacturing, marketing and distribution of goods, consulting firms have made inroads in the service and non profit sectors as well as in semi-public and public organizations. From the mid-1960s, they have also rapidly internationalized their activities from a mostly American base, often becoming in the process multinational or even global firms. [First paragraph

The Heart of Living and Dying: Upstreaming Advance Care Planning into Community Conversations in the Public Domain in Northern Ireland.

This paper provides an evaluation of the Heart of Living and Dying (HLD) Initiative. This initiative is a group process that attempts to bring Advance Care Planning (ACP) into the public domain. It encourages participants to consider what matters to them in their living along with their hopes, preferences, and wishes for their final years and end-of-life care. An inductive, interpretive, and naturalistic approach allowed the researcher to study these phenomena in their natural setting i.e., the community. This qualitative study used 5 focus groups with 17 people and employed thematic data analysis to identify key themes. All participants in the HLD speak from a personal perspective irrespective of any professional background. It transpired that 16 respondents worked in health and social care, which subsequently became noteworthy in the findings. Three key themes were identified: (a) feeling emotionally safe enough to have such sensitive conversations is vital; (b) participating in the HLD process increases the confidence of those participants who worked in health and social care, to undertake ACP conversations and (c) planning ahead is a complex, staged process rather than a single record-making event. The Covid-19 pandemic crisis reinforced the need to upstream ACP initiatives such as the HLD, as the norm for everyone, since all of us will one day die. It is recommended that the HLD be incorporated within ACP training given that the experiential nature of it and the use of groups was reported to build confidence in facilitating ACP conversations. A virtual HLD process needs to be developed to adapt to restrictions on gatherings due to Covid 19

Hedgehog Signaling Pathway Database: a repository of current annotation efforts and resources for the Hh research community

The Hedgehog Signaling Pathway Database is a curated repository of information pertaining to the Hedgehog developmental pathway. It was designed to provide centralized access to a wide range of relevant information in an organism-agnostic manner. Data are provided for all genes and gene targets known to be involved in the Hh pathway across various organisms. The data provided include DNA and protein sequences as well as domain structure motifs. All known human diseases associated with the Hh pathway are indexed including experimental data on therapeutic agents and their molecular targets. Hh researchers will find useful information on relevant protocols, tissue cell lines and reagents used in current Hh research projects. Curated content is also provided for publications, grants and patents relating to the Hh pathway. The database can be accessed at

Four-wave interaction in gas and vacuum. Definition of a third order nonlinear effective susceptibility in vacuum

Semiclassical methods are used to study the nonlinear interaction of light in vacuum in the context of four wave mixing. This study is motivated by a desire to investigate the possibility of using recently developed powerful ultrashort (femtosecond) laser pulses to demonstrate the existence of nonlinear effects in vacuum, predicted by quantum electrodynamics (QED). An approach, similar to classical nonlinear optics in a medium, is developed in this article. A third order nonlinear effective susceptibility of vacuum is then introduced .Comment: 14 pages, 3 figure

Slow nonequilibrium dynamics: parallels between classical and quantum glasses and gently driven systems

We review an scenario for the non-equilibrium dynamics of glassy systems that has been motivated by the exact solution of simple models. This approach allows one to set on firmer grounds well-known phenomenological theories. The old ideas of entropy crisis, fictive temperatures, free-volume... have clear definitions within these models. Aging effects in the glass phase are also captured. One of the salient features of the analytic solution, the breakdown of the fluctuation-dissipation relations, provides a definition of a bonafide {\it effective temperature} that is measurable by a thermometer, controls heat flows, partial equilibrations, and the reaction to the external injection of heat. The effective temperature is an extremely robust concept that appears in non-equilibrium systems in the limit of small entropy production as, for instance, sheared fluids, glasses at low temperatures when quantum fluctuations are relevant, tapped or vibrated granular matter, etc. The emerging scenario is one of partial equilibrations, in which glassy systems arrange their internal degrees of freedom so that the slow ones select their own effective temperatures. It has been proven to be consistent within any perturbative resummation scheme (mode coupling, etc) and it can be challenged by experimental and numerical tests, some of which it has already passed.Comment: 15 pages, 8 figure

Alloimmunisation to Donor Antigens and Immune Rejection Following Foetal Neural Grafts to the Brain in Patients with Huntington's Disease

BACKGROUND: The brain is deemed “immunologically privileged” due to sparse professional antigen-presenting cells and lymphatic drainage, and to the blood-brain barrier. Although the actual extent of this privilege is controversial, there is general consensus about the limited need in intracerebral neural grafts for immunosuppressive regimens comparable to those used in other cases of allotransplantation. This has led over the past fifteen years to the use of either short-term or even no immunosuppression in most clinical trials with foetal neural transplant in patients with Parkinson's and Huntington's disease. METHODOLOGY/PRINCIPAL FINDINGS: We report biological demonstration of alloimmunisation without signs of rejection in four grafted patients out of 13 studied during the course of a clinical trial involving fetal neural transplantation in patients with Huntington's Disease. Biological, radiological and clinical demonstration of an ongoing rejection process was observed in a fifth transplanted patient. The rejection process was, however, fully reversible under immunosuppressive treatment and graft activity recovered within six months. CONCLUSIONS/SIGNIFICANCE: There had been, up to date, no report of documented cases that could have cast a doubt on those procedures. Our results underline the need for a reconsideration of the extent of the so-called immune privilege of the brain and of the follow-up protocols of patients with intracerebral grafts. It also suggests that some of the results obtained in past studies with foetal neural transplants may have been biased by an unrecognized immune response to donor cells