2,091 research outputs found
Network Synthesis of Linear Dynamical Quantum Stochastic Systems
The purpose of this paper is to develop a synthesis theory for linear
dynamical quantum stochastic systems that are encountered in linear quantum
optics and in phenomenological models of linear quantum circuits. In
particular, such a theory will enable the systematic realization of
coherent/fully quantum linear stochastic controllers for quantum control,
amongst other potential applications. We show how general linear dynamical
quantum stochastic systems can be constructed by assembling an appropriate
interconnection of one degree of freedom open quantum harmonic oscillators and,
in the quantum optics setting, discuss how such a network of oscillators can be
approximately synthesized or implemented in a systematic way from some linear
and non-linear quantum optical elements. An example is also provided to
illustrate the theory.Comment: Revised and corrected version, published in SIAM Journal on Control
and Optimization, 200
Attenuated Effects of Opiates in Adolescent vs. Adult Male Rats: Reinforcement, Relapse, and Withdrawal
Adolescence in humans is a vulnerable period for illicit drug use, and teenage onset of drug use is associated with long-term addiction. Adolescent sensitivity to drug reinforcement, relapse, and withdrawal has not been explored thoroughly in animal models, especially considering opiate drugs such as morphine and heroin. The present series of studies profiles adolescent sensitivity to opiates using adolescent and adult male rats to test for age differences in opiate self-administration, reinstatement, withdrawal signs, locomotor sensitization, and even brain activation during drug-seeking. To test for acute sensitivity to the reinforcing effects of morphine or heroin, we compared patterns of self-administration by adolescent vs. adult male rats on various schedules of reinforcement, drug doses, and daily access conditions. Using fixed ratio schedules and short daily access, adolescents self-administered less morphine than adults, an effect commonly interpreted as higher drug sensitivity. In contrast, escalation of morphine intake under long access conditions was similar across ages, as was heroin intake using fixed or progressive ratio schedules of reinforcement. To test for enduring effects of opiates, we compared opiate-seeking in the absence of the drug in tests of extinction responding and cue-induced reinstatement. Regardless of the acute effects of morphine or heroin, all adolescent treatment groups showed attenuated opiate-seeking compared to adults. Next we considered behavioral correlates of reinforcement, drug withdrawal and locomotor sensitization, during and after escalating doses of experimenter-administered heroin. Consistent with attenuated opiate-seeking, adolescents exhibited attenuated somatic and locomotor signs of withdrawal compared with adults, although locomotor sensitization was similar across ages. Finally, the medial prefrontal cortex (mPFC) is a brain region heavily implicated in drug reinforcement, so we used tissue levels of Fos-like immunoreactivity to compare activation of this region by heroin-seeking. Indeed mPFC activation was absent in rats that self-administered heroin as adolescents, but robust in adults. Together these behavioral and neuroanatomical results surprisingly suggest that adolescent male rats are less sensitive than adults to some acute and enduring effects of opiates, and may predict better response profiles among younger human addicts. Through future studies, adolescent rats may provide a new model to help identify treatments for drug abuse
Inverse Technology Transfer: Development Opportunities Defined from Practice
In the world of technology today, scientists and engineers are concerned about having the results of their work proceed through development to application. This concern exists because of a funding-source pressure to be relevant. One response to this pressure is to become a method evangelist and another is to transfer emphasis from research to technology development. However, a way is available to avoid this unfortunate circumstance and that is to focus on appropriate technology
A study of the Catholic Youth Organization in the twelve Catholic parishes of Dorchester
Thesis (M.S.)--Boston University, 1948. This item was digitized by the Internet Archive
Alien Registration- Doherty, James H. (Van Buren, Aroostook County)
https://digitalmaine.com/alien_docs/33438/thumbnail.jp
Americans’ support for freedom of speech depends on who’s doing the speaking and their message.
Freedom of speech is one of the founding concepts of the American Republic. But at what point do people become unwilling to tolerate the statements of others? In new research, David Doherty and James Stancliffe investigated what affects people’s willingness to tolerate speech related to terrorism and violence. By varying the features of a story about a speech-related arrest participants read, they find that people are less tolerant of speech when the speaker was apparently Arabic or when media reports characterized the speech as advocating violence
NASA's progress in nuclear electric propulsion technology
The National Aeronautics and Space Administration (NASA) has established a requirement for Nuclear Electric Propulsion (NEP) technology for robotic planetary science mission applications with potential future evolution to systems for piloted Mars vehicles. To advance the readiness of NEP for these challenging missions, a near-term flight demonstration on a meaningful robotic science mission is very desirable. The requirements for both near-term and outer planet science missions are briefly reviewed, and the near-term baseline system established under a recent study jointly conducted by the Lewis Research Center (LeRC) and the Jet Propulsion Laboratory (JPL) is described. Technology issues are identified where work is needed to establish the technology for the baseline system, and technology opportunities which could provide improvement beyond baseline capabilities are discussed. Finally, the plan to develop this promising technology is presented and discussed
8. The 1980s
From the Introduction, “The Changes at ILR that began in the seventies slipped imperceptibly into the eighties, and those that may have originated at that time have, for better or worse, left their mark on the present decade. In other words, dividing history into decades is not a particularly precise way of delineating times. Clearly, there was much gaiety preceding and following the Gay Nineties, as there were certainly many roars heard before and after the Roaring Twenties. Moreover, since the speed of change in academia runs at such a leisurely pace, it is virtually impossible to say exactly when an idea found its way into formal practice. Includes: Introduction; A Dean’s View, 1980-85; Deaning, 1985-88; Robert Risley; and An Advisory Council Perspective
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