11,294 research outputs found

    Habituation of the C-start response in larval zebrafish exhibits several distinct phases and sensitivity to NMDA receptor blockade.

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    The zebrafish larva has been a valuable model system for genetic and molecular studies of development. More recently, biologists have begun to exploit the surprisingly rich behavioral repertoire of zebrafish larvae to investigate behavior. One prominent behavior exhibited by zebrafish early in development is a rapid escape reflex (the C-start). This reflex is mediated by a relatively simple neural circuit, and is therefore an attractive model behavior for neurobiological investigations of simple forms of learning and memory. Here, we describe two forms of short-lived habituation of the C-start in response to brief pulses of auditory stimuli. A rapid form, persisting for ≥1 min but <15 min, was induced by 120 pulses delivered at 0.5-2.0 Hz. A more extended form (termed "short-term habituation" here), which persisted for ≥25 min but <1 h, was induced by spaced training. The spaced training consisted of 10 blocks of auditory pulses delivered at 1 Hz (5 min interblock interval, 900 pulses per block). We found that these two temporally distinguishable forms of habituation are mediated by different cellular mechanisms. The short-term form depends on activation of N-methyl-d-aspartate receptors (NMDARs), whereas the rapid form does not

    High Resolution Technology in Digital Imaging and its Remote Sensing Applications

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    Remote Sensing is a markable achievement in- last century. High resolution is a vital technol- ogy to digital image characteristics. Especially, in recent 20 years, digital technology promotes the development of spatial information field. As the increasing requirement of people, achieving high resolution images is urgent. For this target, we work from four parts: spatial resolution, ra- diant resolution, spectral resolution, temporal resolution and proposed schemes for each of them with different imaging manners, designed several prototype systems and carried out many experiments to verify their feasibilities

    Hotspots of dendritic spine turnover facilitate clustered spine addition and learning and memory.

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    Modeling studies suggest that clustered structural plasticity of dendritic spines is an efficient mechanism of information storage in cortical circuits. However, why new clustered spines occur in specific locations and how their formation relates to learning and memory (L&M) remain unclear. Using in vivo two-photon microscopy, we track spine dynamics in retrosplenial cortex before, during, and after two forms of episodic-like learning and find that spine turnover before learning predicts future L&M performance, as well as the localization and rates of spine clustering. Consistent with the idea that these measures are causally related, a genetic manipulation that enhances spine turnover also enhances both L&M and spine clustering. Biophysically inspired modeling suggests turnover increases clustering, network sparsity, and memory capacity. These results support a hotspot model where spine turnover is the driver for localization of clustered spine formation, which serves to modulate network function, thus influencing storage capacity and L&M

    Naming Game on Adaptive Weighted Networks

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    We examine a naming game on an adaptive weighted network. A weight of connection for a given pair of agents depends on their communication success rate and determines the probability with which the agents communicate. In some cases, depending on the parameters of the model, the preference toward successfully communicating agents is basically negligible and the model behaves similarly to the naming game on a complete graph. In particular, it quickly reaches a single-language state, albeit some details of the dynamics are different from the complete-graph version. In some other cases, the preference toward successfully communicating agents becomes much more relevant and the model gets trapped in a multi-language regime. In this case gradual coarsening and extinction of languages lead to the emergence of a dominant language, albeit with some other languages still being present. A comparison of distribution of languages in our model and in the human population is discussed.Comment: 22 pages, accepted in Artificial Lif

    The Properties of Radio Galaxies and the Effect of Environment in Large Scale Structures at z∼1z\sim1

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    In this study we investigate 89 radio galaxies that are spectroscopically-confirmed to be members of five large scale structures in the redshift range of 0.65≤z≤0.960.65 \le z \le 0.96. Based on a two-stage classification scheme, the radio galaxies are classified into three sub-classes: active galactic nucleus (AGN), hybrid, and star-forming galaxy (SFG). We study the properties of the three radio sub-classes and their global and local environmental preferences. We find AGN hosts are the most massive population and exhibit quiescence in their star-formation activity. The SFG population has a comparable stellar mass to those hosting a radio AGN but are unequivocally powered by star formation. Hybrids, though selected as an intermediate population in our classification scheme, were found in almost all analyses to be a unique type of radio galaxies rather than a mixture of AGN and SFGs. They are dominated by a high-excitation radio galaxy (HERG) population. We discuss environmental effects and scenarios for each sub-class. AGN tend to be preferentially located in locally dense environments and in the cores of clusters/groups, with these preferences persisting when comparing to galaxies of similar colour and stellar mass, suggesting that their activity may be ignited in the cluster/group virialized core regions. Conversely, SFGs exhibit a strong preference for intermediate-density global environments, suggesting that dusty starbursting activity in LSSs is largely driven by galaxy-galaxy interactions and merging.Comment: 28 pages, 10 figures, accepted to MNRA

    Ventricular function, myocardial delayed enhancement and patient-reported quality of life in adolescents and adults with repaired tetralogy of Fallot

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    INTRODUCTION: In patients with repaired tetralogy of Fallot (TOF), right ventricular myocardial delayed enhancement (MDE) and diastolic dysfunction are common, and have been associated with decreased exercise capacity and increased arrhythmia. Predictors of quality of life (QOL) have not been reported in this population. PURPOSE: We assessed the hypothesis that a greater degree of MDE in adolescents and adults with repaired TOF would correlate with diastolic dysfunction and decreased QOL

    Ventricular function, myocardial delayed enhancement and patient-reported quality of life in adolescents and adults with repaired tetralogy of Fallot

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    INTRODUCTION: In patients with repaired tetralogy of Fallot (TOF), right ventricular myocardial delayed enhancement (MDE) and diastolic dysfunction are common, and have been associated with decreased exercise capacity and increased arrhythmia. Predictors of quality of life (QOL) have not been reported in this population. PURPOSE: We assessed the hypothesis that a greater degree of MDE in adolescents and adults with repaired TOF would correlate with diastolic dysfunction and decreased QOL
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