Ergativity and Accusativity in Nisgha Syntax

Proceedings of the Sixteenth Annual Meeting of the Berkeley Linguistics Society: Special Session on General Topics in American Indian Linguistics (1990), pp. 3-1

Role of Fiber Orientation in Atrial Arrythmogenesis

Electrical wave-front propagation in the atria is determined largely by local fiber orientation. Recent study suggests that atrial fibrillation (AF) progresses with enhanced anisotropy. In this work, a 3D rabbit atrial anatomical model at 20 × 20 × 20 μm3 resolution with realistic fiber orientation was constructed based on the novel contrast-enhanced micro-CT imaging. The Fenton-Karma cellular activation model was adapted to reproduce rabbit atrial action potential period of 80 ms. Diffusivities were estimated for longitudinal and transverse directions of the fiber orientation respectively. Pacing was conducted in the 3D anisotropic atrial model with a reducing S2 interval to facilitate initiation of atrial arrhythmia. Multiple simulations were conducted with varying values of diffusion anisotropy and stimulus locations to evaluate the role of anisotropy in initiating AF. Under physiological anisotropy conditions, a rapid right atrial activation was followed by the left atrial activation. Excitation waves reached the atrio-ventricular border where they terminated. Upon reduction of conduction heterogeneity, re-entry was initiated by the rapid pacing and the activation of both atrial chambers was almost simultaneous. Myofiber orientation is an effective mechanism for regulating atrial activation. Modification of myoarchitecture is proarrhythmic

NASA Research Center Contributions to Space Shuttle Return to Flight (SSRTF)

Contributions provided by the NASA Research Centers to key Space Shuttle return-to-flight milestones, with an emphasis on debris and Thermal Protection System (TPS) damage characterization, are described herein. Several CAIB recommendations and Space Shuttle Program directives deal with the mitigation of external tank foam insulation as a debris source, including material characterization as well as potential design changes, and an understanding of Orbiter TPS material characteristics, damage scenarios, and repair options. Ames, Glenn, and Langley Research Centers have performed analytic studies, conducted experimental testing, and developed new technologies, analysis tools, and hardware to contribute to each of these recommendations. For the External Tank (ET), these include studies of spray-on foam insulation (SOFI), investigations of potential design changes, and applications of advanced non-destructive evaluation (NDE) technologies to understand ET TPS shedding during liftoff and ascent. The end-to-end debris assessment included transport analysis to determine the probabilities of impact for various debris sources. For the Orbiter, methods were developed, and validated through experimental testing, to determine thresholds for potential damage of Orbiter TPS components. Analysis tools were developed and validated for on-orbit TPS damage assessments, especially in the area of aerothermal environments. Advanced NDE technologies were also applied to the Orbiter TPS components, including sensor technologies to detect wing leading edge impacts during liftoff and ascent. Work is continuing to develop certified TPS repair options and to develop improved methodologies for reinforced carbon-carbon (RCC) damage progression to assist in on-orbit repair decision philosophy

The Nuclear Cryogenic Propulsion Stage

The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation Nuclear Cryogenic Propulsion Stage (NCPS) based on NTP could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of the NCPS in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation. Progres made under the NCPS project could help enable both advanced NTP and advanced Nuclear Electric Propulsion (NEP)

NASA's Nuclear Thermal Propulsion Project

The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation NTP system could provide high thrust at a specific impulse above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of a first generation NTP in the development of advanced nuclear propulsion systems could be analogous to the role of the DC- 3 in the development of advanced aviation. Progress made under the NTP project could also help enable high performance fission power systems and Nuclear Electric Propulsion (NEP)

The NASA Advanced Exploration Systems Nuclear Thermal Propulsion Project

The fundamental capability of Nuclear Thermal Propulsion (NTP) is game changing for space exploration. A first generation NTP system could provide high thrust at a specific impulse (Isp) above 900 s, roughly double that of state of the art chemical engines. Characteristics of fission and NTP indicate that useful first generation systems will provide a foundation for future systems with extremely high performance. The role of a first generation NTP in the development of advanced nuclear propulsion systems could be analogous to the role of the DC-3 in the development of advanced aviation systems

The NASA Advanced Exploration Systems Nuclear Thermal Propulsion Project

No abstract availabl

Nisgha syntax and the ergativity hypothesis

Nisgha has been classified by at least three different linguists as syntactically ergative (Rigsby, Rood, and Tarpent). This is motivated by the fact that in certain constructions the agent of a transitive verb patterns differently than the patient of the transitive or the single argument of an intransitive. A new definition of syntactic ergativity has been proposed recently by Alec Marantz (1981) and is called the Ergativity Hypothesis. The definition essentially says, given the grammatical functions [NP,VP] and [NP,S], we will have the following associations of grammatical functions and thematic roles: Syntactically Ergative Syntactically Accusative Language Language Agent-[NP,VP] Agent-[NP,S] Patient-[NP,S] Patient-[NP,VP] Morphological ergativity is considered a different phenomenon. It is essentially defined as follows (following the traditional definition): Morphologically ergative languages mark the subject of a transitive verb, and leave the object of a transitive and the single argument of an intransitive unmarked. Given the above definition of syntactic ergativity and syntactic accusativity, I believe Nisgha can be shown to be syntactically accusative and morphologically ergative. Levin (1983) proposes a number of diagnostics for syntactic ergativity, none of which come out "positive" for Nishga. Some don't apply, and some show syntactic accusativity. As well as outlining the Ergativity Hypothesis in Chapter 1, I also present some of the foundational principles of the Government-Binding framework (Chomsky 1981) which will be relevant to the subsequent analysis of Nisgha. In particular, I discuss the theta-criter ion, the Projection Principle, the Case Filter, Government, Proper Government and the Empty Category Principle. Chapter II In Chapter 2 it is argued that Nisgha shows syntactic accusativity because of the position of subcategorized prepositional phrases and also because of the distribution of reflexive anaphors. The position of prepositional phrases suggests movement. I can find no factor to force extraposition of the prepositional phrase, but there does appear to be a factor forcing verb movement, namely the need to provide a means for assigning Case to [NP,S]. If we assume a D-structure SVO and verb movement to clause-initial position we get correct predictions concerning both the position of prepositional phrases and that of reflexive anaphors. We also explain the weak crossover facts in Nisgha in this way. One of the conclusions of this discussion of verb movement is that Nisgha categories only govern rightward. A further argument for rightward government (based on the structure of genitives) is also presented here. Also in Chapter 2 I discuss Marie-Lucie Tarpent's analysis of Nisgha, which is the most recent and comprehensive analysis of the language. Tarpent (1982) argues that Nisgha is syntactically ergative. Her arguments for ergativity are reviewed in the light of the Ergativity Hypothesis and are shown to be non-arguments. Chapter III This chapter contains a short discussion of the learnability issue and how it might be used as a criterion for evaluating competing analyses, such as those discussed above.Arts, Faculty ofLinguistics, Department ofGraduat

Development of the HRL Route Navigation Dialogue System

In this paper we report on our work on a prototype route navigation dialogue system for use in a vehicle. The system delivers spoken turn-by-turn directions, and has been developed to accept naturally phrased navigation queries, as part of our overall effort to create an in-vehicle information system which delivers information as requested while placing minimal cognitive load on the driver