4,216 research outputs found
Progressive deficit of retrograde axonal transport is associated with the pathogenesis of di-n-butyl dichlorvos axonopathy
No full textIn vivo and in vitro regional differential sensitivity of neuropathy target esterase to Di-n-butyl-2,2 dichlorovinyl phosphate.
No full textOrganophosphate-induced delayed polyneuropathy (OPIDP) is initiated by inhibition/aging of more than 70-75% of neuropathy target esterase (NTE). Di-n-butyl-2,2-dichlorovinyl phosphate (DBDCVP) (1 mg/kg s.c.) inhibited 96%, 86% and 83% of NTE in brain, spinal cord and peripheral nerve, respectively, and induced a typical central peripheral distal axonopathy in hens. A lower dose (0.45 mg/kg s.c.) caused 90%, 83% and 54% NTE inhibition in the same organs; by contrast, hens developed a spastic ataxia with axonal degeneration in spinal cord but not in peripheral nerve. With a dose of 0.2 mg/kg s.c., a suprathreshold inhibition of NTE was produced in brain (78%) but not in spinal cord (56%) and peripheral nerve (33%) and no morphological or clinical signs of neuropathy developed in hens. With doses up to 4.0 mg/kg s.c., acetylcholinesterase (AChE) inhibition was similar throughout the nervous system. In vitro time-course inhibition studies showed a different sensitivity to DBDCVP of NTE from peripheral nerve (ka = 5.4 x 10(6)) relative to that from spinal cord (ka = 13.9 x 10(6)) or brain (ka = 20.6 x 10(6)). In vitro I50s of DBDCVP for AChE were similar in brain, spinal cord and peripheral nerve (11-17 nM). These data support the hypothesis that the critical target for initiation of OPIDP is located in the nerve fiber, possibly in the axon and also suggest that peripheral nerve NTE has a different sensitivity to DBDCVP than the brain enzyme.(ABSTRACT TRUNCATED AT 250 WORDS
Wavelength tunable 10-GHz 3-ps pulse source using a dispersion decreasing fiber-based nonlinear optical loop mirror
No full textWe experimentally demonstrate the use of a dispersion decreasing fiber (DDF)-based nonlinear optical loop mirror (NOLM) for the generation of wavelength tunable soliton-like pulses at a repetition rate of 10 GHz. We compress ~12 ps Gaussian pulses from an electro-absorption modulator (EAM) (followed by 125 m of DCF for preliminary linear dispersion compensation) into 3 ps pedestal-free pulses using both high-order soliton compression and nonlinear switching effects within an 8.5 km DDF-based loop mirror. The output pulses from the DDF-based NOLM show considerable pedestal reduction compared to those obtained by directly compressing the EAM seed pulses via a single passage through the DDF. Wavelength tuning of the compressed pulses over a ~15 nm bandwidth (from 1541 to 1556 nm) is demonstrated without a significant increase in pulse duration or degradation in pulse quality
Introduction
No full textBook synopsis: From William James to Sigmund Freud to Jean Piaget to B. F. Skinner, scholars (and parents) have wondered how children move from the blooming, buzzing confusion of infancy, through the tumult of childhood and adolescence, into adulthood. Does development occur continuously over time or in a series of dramatic stages? Is development driven by learning or by biological maturational processes? What is the nature of experience, and how does it generate change? The study of development has always been organized around these big questions. Answers to these questions have a profound influence on daily life, forming a framework for how parents think about their own children, and influencing both national policy and educational curricula. This book defines and refines two major theoretical approaches within developmental science that address the central issues of development-connectionism and dynamical systems theory. The chapters in this book provide an introduction, overview, and critical evaluation of each approach, including three sets of case studies that illustrate how these approaches have been used to study topics ranging from early motor development to the acquisition of grammar. It also presents a collection of commentaries by leading scholars, which offer a critical view from both an “outsiders” and an “insiders” perspective
Spencer Moore
No full textPhotograph of Spence Moore playing his guitar in his home in Konnarock, Virginia
Player agency in interactive narrative: audience, actor & author
No full textThe question motivating this review paper is, how can
computer-based interactive narrative be used as a constructivist learn-
ing activity? The paper proposes that player agency can be used to
link interactive narrative to learner agency in constructivist theory,
and to classify approaches to interactive narrative. The traditional
question driving research in interactive narrative is, ‘how can an in-
teractive narrative deal with a high degree of player agency, while
maintaining a coherent and well-formed narrative?’ This question
derives from an Aristotelian approach to interactive narrative that,
as the question shows, is inherently antagonistic to player agency.
Within this approach, player agency must be restricted and manip-
ulated to maintain the narrative. Two alternative approaches based
on Brecht’s Epic Theatre and Boal’s Theatre of the Oppressed are
reviewed. If a Boalian approach to interactive narrative is taken the
conflict between narrative and player agency dissolves. The question
that emerges from this approach is quite different from the traditional
question above, and presents a more useful approach to applying in-
teractive narrative as a constructivist learning activity
Connectionist and dynamic systems models of development: two sides of the same coin? the case of analogical completion
No full textBook synopsis: From William James to Sigmund Freud to Jean Piaget to B.F. Skinner, scholars (and parents!) have wondered how children move from the blooming, buzzing confusion of infancy, through the tumult of childhood and adolescence, into adulthood. Does development occur continuously over time or in a series of dramatic stages? Is development driven by learning or by biological maturational processes? What is the nature of experience, and how does it generate change? The study of development has always been organized around these big questions. And answers to these questions have a profound influence on daily life, forming a framework for how parents think about their own children, and influencing both national policy and educational curricula.
This book defines and refines two major theoretical approaches within developmental science that address the central issues of development--connectionism and dynamical systems theory. Spencer, Thomas, and McClelland have brought together chapters that provide an introduction, overview, and critical evaluation of each approach, including three sets of case studies that illustrate how both approaches have been used to study topics ranging from early motor development to the acquisition of grammar. They also present a collection of commentaries by leading scholars, which offer a critical view from both an"outsiders's" and an "insider's" perspective. The book is unique in the range of its treatment--it begins to delineate how developmental science can incorporate advances within neuroscience and computational modeling, and brings the new ideas of connectionism and dynamic systems theory into sharper focus, clarifying their usefulness and explanatory power
Romeo & Juliet ; Blanch Kendall Thomas (right) Annie Spencer (#13)
No full text"Romeo and Juliet" balcony scene. Juliet played by Blanch Kendall Thomas and Romeo played by Annie Spencer. 1 glass negative, size 4 in x 5 in. ; print located at PH2-BNS-PS-03 (BNS-DR-SNS-PR-03 on front cover)
Charisma and Spirituality in the Early Church: A Study of Messalianism and Pseudo-Macarius
No full textThe thesis is an investigation into the concept of Charisma and Spirituality in the Early Church with particular emphasis upon the writings of Ps-Macarius, and of a group of ascetics known as the Messalians, evident in the late fourth / early fifth centuries. The Macarian writings are
examined to see what they reveal about the experiential pneumatic theology of the Early Church, the relationship between Syrian and Hellenic traditions of Christian Rhetoric, and the relationship between Ps-Macarius and the Cappadocian Circle. The Macarian corpus as a whole is examined to assess its rhetorical influences and style. The rhetoric of the Macarian corpus is seen to illustrate a high degree of sophistication. This study also gives definition to two terms that have become imprecise and diverse in their use: 'enkrateia' (self-control), and
`Syrian Christianity'. By isolating the characteristics of enkratefa the definitive stages of an encratic lifestyle are identified. The breaking down of the term into enkrateia, radical enkrateta and exclusive enkrateta enables a much clearer discussion to take place as to the
nature of the encratic theology of a group or individual. The final element of this study is a consideration of the distinct Macarian imagery that is evident within the corpus. Two images are considered in detail, the 'flight of the soul' and 'sober intoxication'. Overall this study
shows the variety of influences upon Ps-Macarius, and the uniqueness of his expression. The influences upon Ps-Macarius include a context of endemic Syrian spirituality, a radical encratic lifestyle, a Hellenic rhetorical training, and a distinct interpretation of Platonic and Neo-
Platonic images, coupled to the wider Judaic / Mesopotamian influences of his Church. It is shown that Ps-Macarius represents an individual voice that is distinct and recognisable amongst the Fathers of the Church
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