Nonlinear models for estimating GSFC travel requirements

A methodology is presented for estimating travel requirements for a particular period of time. Travel models were generated using nonlinear regression analysis techniques on a data base of FY-72 and FY-73 information from 79 GSFC projects. Although the subject matter relates to GSFX activities, the type of analysis used and the manner of selecting the relevant variables would be of interest to other NASA centers, government agencies, private corporations and, in general, any organization with a significant travel budget. Models were developed for each of six types of activity: flight projects (in-house and out-of-house), experiments on non-GSFC projects, international projects, ART/SRT, data analysis, advanced studies, tracking and data, and indirects

Where Literature and Philosophy Meet and Diverge

Many writers and philosophers have asked “What is art?” or “What is philosophy?” but it is difficult to encounter a text where these questions are set beside each other. Many works of philosophy appear very literary in form and content, just as there are many literary works that are very philosophical in nature. This essay examines the intersection of literature and philosophy, using Kant’s Critique of Judgement as a way into analyzing Plato’s Phaedo, as an example of literary philosophy; and Shakespeare’s Hamlet, as an example of philosophical literature. The first section deals with literature and philosophy as texts, looking at the relationship these texts have with facts, details, and the different kinds of abstractions that each type of text concerns itself with. The second section deals with literature and philosophy as disciplines and areas of study, examining the different ways in which these texts are studied and evaluated as works of literature or works of philosophy. This discussion can help to illuminate the distinctions between literary philosophy and philosophical literature, as well as the strengths of each discipline, and what might be necessary for a text to succeed both as a work of literature and as a work of philosophy

Freedom to and Freedom from

This paper seeks to answer the question, If I cannot express my hatred, am I less free? The discussion is framed through an examination of positive and negative freedom, looking at whether or not the loss of certain freedoms-from, such as freedom from injustice, freedom from discrimination, and freedom from fear might potentially outweigh the right of an individual to express his or her hatred

A theory for viral capsid assembly around electrostatic cores

We develop equilibrium and kinetic theories that describe the assembly of viral capsid proteins on a charged central core, as seen in recent experiments in which brome mosaic virus (BMV) capsids assemble around nanoparticles functionalized with polyelectrolyte. We model interactions between capsid proteins and nanoparticle surfaces as the interaction of polyelectrolyte brushes with opposite charge, using the nonlinear Poisson Boltzmann equation. The models predict that there is a threshold density of functionalized charge, above which capsids efficiently assemble around nanoparticles, and that light scatter intensity increases rapidly at early times, without the lag phase characteristic of empty capsid assembly. These predictions are consistent with, and enable interpretation of, preliminary experimental data. However, the models predict a stronger dependence of nanoparticle incorporation efficiency on functionalized charge density than measured in experiments, and do not completely capture a logarithmic growth phase seen in experimental light scatter. These discrepancies may suggest the presence of metastable disordered states in the experimental system. In addition to discussing future experiments for nanoparticle-capsid systems, we discuss broader implications for understanding assembly around charged cores such as nucleic acids.Comment: This version has been updated from v1 as follows. The calculation accounts for curvature, explicitly represents the polymeric nature of surface functionalization molecules, and determines the dissociation equilibrium of the functionalized carboxylate groups. 13 pages main text, 4 pages appendix, 14 figure

Catholic School Faculty Meetings: A Case Study Linking Catholic Identity, School Improvement, and Teacher Engagement

While research on faculty meetings is limited, existing literature suggests that meetings could be an arena where schools can address their most pressing challenges (Brandenburg, 2008; Michel, 2011; Riehl, 1998). Building on Macey and Schneider’s (2008) Model of Employee Engagement and McGrath’s Model of Group Effectiveness (1964), this case study examined the perceptions of teachers in a high-performing Catholic school regarding their own faculty meetings and how those meetings engaged them in the work of promoting Catholic identity and school improvement. Findings revealed signs of Catholic culture were visible within the physical environment of the faculty meeting, which provided opportunities for prayer, catechesis, and strategies for sharing faith with students. Teachers reported the faculty meetings served as a catalyst in developing, discussing, and reviewing school improvement plans, and provided opportunities for professional development. Faculty meetings assisted in creating a participant-centered learning environment and creating a sense of community among the faculty. Reuniones de profesorado de escuelas católicas: un estudio de caso vinculando identidad católica, mejoras escolares y participación del profesorado A pesar de la poca investigación sobre las reuniones de profesorado, la que existe sugiere que las reuniones podrían ser el escenario en el que las escuelas abordan sus retos más urgentes (Brandenburg, 2008; Michel, 2011; Riehl, 1998). Ampliando el Modelo de participación del empleado de Macey y Schneider (2008) y el Modelo de eficacia de grupo de McGrath (1964), el presente estudio de caso examinó las percepciones de los profesores en una escuela católica de alto rendimiento en relación a sus propias reuniones de profesores y cómo esas reuniones les animaba a promover la identidad católica y la mejora escolar. Los hallazgos revelaron que eran visibles muestras de cultura católica en el ambiente físico de las reuniones de profesorado, lo que proporcionó oportunidades para rezo, catequesis y estrategias para compartir la fe con los estudiantes. Los profesores afirmaron que las reuniones de profesorado servían como catalizador en el desarrollo, discusión y revisión de los planes de mejora escolares, y ofrecían oportunidades para el desarrollo profesional. Las reuniones de profesorado ayudaron a crear un medio de aprendizaje centrado en el participante y a crear un sentimiento de comunidad entre el profesorado. Palabras clave: Reuniones de profesorado, identidad católica, involucración del profesorado Réunion de professeurs dans les écoles catholiques : une étude cas établissant un lien entre l\u27identité catholique, l\u27amélioration de l\u27école et l\u27engagement de l\u27enseignant Tandis que les recherches sur les réunions de professeurs sont limitées, les textes existants indiquent que ces réunions pourraient être pour les écoles un lieu de résolution de leurs difficultés les plus urgentes (Brandenburg, 2008 ; Michel, 2011 ; Riehl, 1998). En s\u27appuyant sur le Modèle d\u27engagement de l\u27employé (Model of Employee Engagement) par Macey et Schneider (2008), et le Modèle d\u27efficacité de groupe (Model of Group Effectiveness) de McGrath (1964), cette étude de cas examine la manière dont les enseignants d\u27une école catholique très performante perçoivent leurs réunions et la manière dont elles les incitent à travailler pour promouvoir l\u27identité catholique et l\u27amélioration scolaire. Les conclusions ont révélé que des signes de culture catholique étaient visibles dans l\u27environnement physique de la réunion des professeurs, qui donnait des occasions de prière, de catéchèse et des stratégies pour parler de la foi avec les élèves. Les enseignants ont indiqué que les réunions de professeurs servaient de catalyseurs pour l\u27élaboration, la discussion et l\u27examen des plans d\u27amélioration de l\u27école et offraient des occasions de développement personnel. Ces réunions de professeurs ont permis de créer un environnement axé sur le participant et le sentiment d\u27être membres d’une communauté chez les enseignants. Mots-clés : Réunion de professeurs, identité catholique, engagement de l\u27enseignan

Reduction and reconstruction of stochastic differential equations via symmetries

An algorithmic method to exploit a general class of infinitesimal symmetries for reducing stochastic differential equations is presented and a natural definition of reconstruction, inspired by the classical reconstruction by quadratures, is proposed. As a side result the well-known solution formula for linear one-dimensional stochastic differential equations is obtained within this symmetry approach. The complete procedure is applied to several examples with both theoretical and applied relevance