4,772 research outputs found

    Effects of Acute Nicotine on Larval Zebrafish Exploratory Behavior in a Complex Environment

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    The larval zebrafish is emerging as a useful model to assess neurobehavioral toxicity. A variety of behavioral assays have been developed to characterize normal behavior and the acute and chronic effects of a variety of compounds. To date, such behavioral assays have been limited to relatively simple behavioral measures (e.g., swimming activity in a single well). The present experiment describes methodology to assess exploratory behavior in 5 days-post-fertilization (5 dpf) larval zebrafish using a six-chamber, complex well-plate. In addition, the effect of acute nicotine exposure on exploratory activity in this complex environment was examined. Five dpf TU strain larvae were studied. Larvae were treated with either 0, 16.25μM or 48.25μM nicotine and were observed for 15 minutes. General Locomotor Activity, Zone Preference, Thigmotaxis (outer zone preference), Thigmotaxis Path Type, Chamber Transitions, and Latency to enter the Center Zone were measured using a Noldus tracking system. These results demonstrate (1) the utility of this novel testing methodology, (2) that a low and high dose of nicotine increased exploratory behavior in a complex environment and (3) dose-dependent behavioral changes due to nicotine treatment, suggesting altered control of a specific type of exploratory behavior as compared to a general increase in behavioral activation. These results while inconsistent with the current literature on anxiety-driven behavior in other animal models may be explained by the intrinsic properties of larval zebrafish behavioral phenotypes and molecular and cellular differences in nicotinic receptor function

    Multiplexing Free-Space Channels using Twisted Light

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    We experimentally demonstrate an interferometric protocol for multiplexing optical states of light, with potential to become a standard element in free-space communication schemes that utilize light endowed with orbital angular momentum (OAM). We demonstrate multiplexing for odd and even OAM superpositions generated using different sources. In addition, our technique permits one to prepare either coherent superpositions or statistical mixtures of OAM states. We employ state tomography to study the performance of this protocol, and we demonstrate fidelities greater than 0.98.Comment: 4 pages, 3 figure

    Rapid Generation of Light Beams Carrying Orbital Angular Momentum

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    We report a technique for encoding both amplitude and phase variations onto a laser beam using a single digital micro-mirror device (DMD). Using this technique, we generate Laguerre-Gaussian and vortex orbital-angular-momentum (OAM) modes, along with modes in a set that is mutually unbiased with respect to the OAM basis. Additionally, we have demonstrated rapid switching among the generated modes at a speed of 4 kHz, which is much faster than the speed regularly achieved by spatial light modulators (SLMs). The dynamic control of both phase and amplitude of a laser beam is an enabling technology for classical communication and quantum key distribution (QKD) systems that employ spatial mode encoding

    ARcode: HPC Application Recognition Through Image-encoded Monitoring Data

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    Knowing HPC applications of jobs and analyzing their performance behavior play important roles in system management and optimizations. The existing approaches detect and identify HPC applications through machine learning models. However, these approaches rely heavily on the manually extracted features from resource utilization data to achieve high prediction accuracy. In this study, we propose an innovative application recognition method, ARcode, which encodes job monitoring data into images and leverages the automatic feature learning capability of convolutional neural networks to detect and identify applications. Our extensive evaluations based on the dataset collected from a large-scale production HPC system show that ARcode outperforms the state-of-the-art methodology by up to 18.87% in terms of accuracy at high confidence thresholds. For some specific applications (BerkeleyGW and e3sm), ARcode outperforms by over 20% at a confidence threshold of 0.8

    Charter Rights & Health Care Funding: A Typology of Canadian Health Rights Litigation

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    Canadian health consumers have increasingly relied on the Charter of Rights and Freedoms to demand certain therapies and reasonably timely access to care. Organizing these cases into a 5-part typology, we examine how a rights-based discourse affects allocation of health care resources. First, successful Charter challenges can, in theory, lead to courts granting and enforcing positive rights to therapies or to timely care. Second, courts may grant a right to certain health services; however, subsequently government fails to deliver on this right. Third, successful litigation may create negative rights, i.e. rights to access care or private health insurance without government interference. Fourth, consumers can fail in their legal pursuit of a right but galvanize public support in the process, ultimately effecting the desired policy changes. Lastly, a failed lawsuit can stifle an entire advocacy campaign for the sought-after therapies. The typology illustrates the need to examine both legal and policy outcomes of health right litigation. This broader analysis reveals that the pursuit of health rights seems to have caused largely a regressive rather than progressive impact on Canadian Medicare

    Edge analytics in the internet of things

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    High-data-rate sensors are becoming ubiquitous in the Internet of Things. GigaSight is an Internet-scale repository of crowd-sourced video content that enforces privacy preferences and access controls. The architecture is a federated system of VM-based cloudlets that perform video analytics at the edge of the Internet
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