Spatial confinement of exciton transfer and the role of conformational order in organic nanoparticles

Organic nanoparticles consisting of single conjugated polymer chains were investigated as a function of degree of conjugation by means of single-molecule spectroscopy. The degree of conjugation was synthetically controlled. For highly conjugated chains, singlet excitons are efficiently funneled over nanometer distances to a small number of sites. In contrast, chains with less conjugation and a high number of saturated bonds do not exhibit energy funneling due to a highly disordered conformation.

On the Decidability of Model-Checking Information Flow Properties

Current standard security practices do not provide substantial assurance about information flow security: the end-to-end behavior of a computing system. Noninterference is the basic semantical condition used to account for information flow security. In the literature, there are many definitions of noninterference: Non-inference, Separability and so on. Mantel presented a framework of Basic Security Predicates (BSPs) for characterizing the definitions of noninterference in the literature. Model-checking these BSPs for finite state systems was shown to be decidable in [8]. In this paper, we show that verifying these BSPs for the more expressive system model of pushdown systems is undecidable. We also give an example of a simple security property which is undecidable even for finite-state systems: the property is a weak form of non-inference called WNI, which is not expressible in Mantel’s BSP framework.

Exploring use of climate information for optimal design of water resources infrastructure

We conducted surveys of fire and fuels managers at local, regional, and national levels to gain insights into decision processes and information flows in wildfire management. Survey results in the form of fire managers’ decision calendars show how climate information needs vary seasonally, over space, and through the organizational network, and help determine optimal points for introducing climate information and forecasts into decision processes. We identified opportunities to use climate information in fire management, including seasonal to interannual climate forecasts at all organizational levels, to improve the targeting of fuels treatments and prescribed burns, the positioning and movement of initial attack resources, and staffing and budgeting decisions. Longer-term (5–10 years) outlooks also could be useful at the national level in setting budget and research priorities. We discuss these opportunities and examine the kinds of organizational changes that could facilitate effective use of existing climate information and climate forecast capabilities.

Materials, Processing, and Testing of Flexible Image Sensor Arrays

Editors' note:Flexible, large-area display and sensor arrays are finding growing applications in multimedia and future smart homes. This article first analyzes and compares current flexible devices, then discusses the implementation, requirements, and testing of flexible sensor arrays.—Jiun-Lang Huang (National Taiwan University) and Kwang-Ting (Tim) Cheng (University of California, Santa Barbara)

A stochastic dynamical system for image segmentation

Image segmentation is formulated as a stochastic process whose invariant distribution is concentrated at points of the desired region. By choosing multiple seed points, different regions can be segmented. The algorithm is based on the theory of time-homogeneous Markov chains and has been largely motivated by the technique of simulated annealing. The method proposed here has been found to perform well on real-world clean as well as noisy images while being computationally far less expensive than stochastic optimisation techniques

Averting biodiversity collapse in tropical forest protected areas

The rapid disruption of tropical forests probably imperils global biodiversity more than any other contemporary phenomenon(1-3). With deforestation advancing quickly, protected areas are increasingly becoming final refuges for threatened species and natural ecosystem processes. However, many protected areas in the tropics are themselves vulnerable to human encroachment and other environmental stresses(4-9). As pressures mount, it is vital to know whether existing reserves can sustain their biodiversity. A critical constraint in addressing this question has been that data describing a broad array of biodiversity groups have been unavailable for a sufficiently large and representative sample of reserves. Here we present a uniquely comprehensive data set on changes over the past 20 to 30 years in 31 functional groups of species and 21 potential drivers of environmental change, for 60 protected areas stratified across the world's major tropical regions. Our analysis reveals great variation in reserve `health': about half of all reserves have been effective or performed passably, but the rest are experiencing an erosion of biodiversity that is often alarmingly widespread taxonomically and functionally. Habitat disruption, hunting and forest-product exploitation were the strongest predictors of declining reserve health. Crucially, environmental changes immediately outside reserves seemed nearly as important as those inside in determining their ecological fate, with changes inside reserves strongly mirroring those occurring around them. These findings suggest that tropical protected areas are often intimately linked ecologically to their surrounding habitats, and that a failure to stem broad-scale loss and degradation of such habitats could sharply increase the likelihood of serious biodiversity declines.

Sapientia, 1984, Vol. XXXIX, nº 153 (número completo)

Contenido: Aspectos fundamentales del conocimiento humano. III. Valor trascendente del conocimiento / Octavio N. Derisi -- Del ente participado al Ser imparticipado / Octavio N. Derisi -- Las tesis de C. Fabro / Julio Raúl Méndez -- Exigencias filosóficas para determinar "lo psicológico" en el proceso de aprendizaje / William R. Darós -- Lo inteligible / Alejandro De Paoli -- Notas y comentarios -- Bibliografía

La administración en la Iglesia después del código de 1917

Sumario: Introducción. I.- La potestad de gobierno en la Iglesia. II.- La potestad administrativa (aspecto estático). III.- La administración eclesiástica (aspecto dinámico). 1. Fundamentos teológicos y jurídicos de la administración. 1.1. teológicos. 1.2. jurídicos. 2. Función administrativa en sentido amplio. 3. Función administrativa en sentido estricto: el acto administrativo. IV.- Principio de legalidad. V.- Derecho administrativo. VI.- La tutela de los derechos de los fieles. VII.- La justicia administrativa. Conclusión

Sapientia, 1984, Vol. XXXIX, nº 152 (número completo)

Contenido: Aspectos fundamentales del conocimiento humano. II. El conocimiento intelectivo / Octavio N. Derisi -- El ser y los entes / Octavio N. Derisi -- Poder y persona en la sociedad humana / Pedro E. Baquero Lazcano -- Refutaciones actuales de la "falacia naturalista" / Carlos I. Massini -- La sabiduría en Santo Tomás : ascensión a la intimidad con Dios por la participación de la verdad y el amor / Ciro Schmidt Andrade -- Consideraciones en torno al tema de los valores / Mieczyslaw Gogacz -- Notas y comentarios -- Bibliografía

Letras, 1984, nº 10 (número completo)

Contenido: Los modos de producción y “reproducción” del texto literario y la noción de apertura / Diego Catalán – La poesía de Santiago Sylvester: entre la protección y el desamparo / Alicia Chibán – Cultura y espiritualidad: San Juan de Dios / María Rosa Saurín de la Iglesia – Sobre algunos problemas en el estudio del romancero español / Daniel Devoto – La música en Hermann Hesse y Thomas Mann / Dolores de Durañona y Vedia – En busca de Orélie Antoine Primero / Luis Martínez Cuitiño – Aproximaciones a Benito Lynch y su obra / María Luisa Montero – El suicidio de Melibea: ¿Voluntad personal o influencia mágica? / Iván Marco Pelicaric – Notas sobre la titulación de capítulos en Galdós / Beatriz Entenza de Solare – Reseñas bibliográficas

Teología, 1984, Tomo XXI nº 044 (número completo)

La verdad del alma. Una lectura de la cuestión 10 “De Veritate” / Héctor Aguer -- Naturaleza teológica de los Nuevos Ministerios / Osvaldo D. Santagada -- Teoría de la evolución: actualización bibliográfica / Miguel de Asúa – Cecilia Demargasso Nuevos aportes bibliográficos I. Teología cristiana del judaísmo (Jorge Mejía) II. Ontología y libertad. A propósito de un libro de E. Briancesco sobre San Anselmo (José Pablo Martín) -- Crónica de la Facutad -- Notas bibliográficas -- Libros recibidos – Índice del volumen XXI

Prudentia Iuris, 1984, n° 14 (número completo)

Contenido: Editorial – Acerca del conocimiento especulativo y del conocimiento práctico / Domingo Basso – Actitudes gnoseológicas y concepciones de la norma jurídica / Juan A. Casaubón – Principios y niveles de la solidaridad comunitaria / Avelino Manuel Quintás – En torno a la figura del contrato administrativo / Juan Carlos Cassagne – La figura del contrato en el derecho norteamericano / José María Monzón – La adopción en derecho internacional privado / María Susana Najurieta – Inexistencia del acto jurídico / Juan Carlos Garibotto – Reflexiones sobre el concepto de comunidad internacional / Ángel Ernesto Molinari – Escolios – Documentos – Notas bibliográficas

Sapientia, 1984, Vol. XXXIX, nº 151 (número completo)

Contenido: Aspectos fundamentales del conocimiento humano. 1. El conocimiento sensitivo / Octavio N. Derisi -- Filosofía griega y cristianismo según W. Jaeger / Cesáreo López Salgado -- La analogía en el concepto de ciencia aristotélico-tomista / William R. Darós -- Pasión e instinto en B. Pascal / Francisco Leocata -- Notas y comentarios -- Bibliografía