737 research outputs found
Control of chronic excessive alcohol drinking by genetic manipulation of the Edinger-Westphal nucleus urocortin-1 neuropeptide system
Midbrain neurons of the centrally projecting Edinger-Westphal nucleus (EWcp) are activated by alcohol, and enriched with stress-responsive neuropeptide modulators (including the paralog of corticotropin-releasing factor, urocortin-1). Evidence suggests that EWcp neurons promote behavioral processes for alcohol-seeking and consumption, but a definitive role for these cells remains elusive. Here we combined targeted viral manipulations and gene array profiling of EWcp neurons with mass behavioral phenotyping in C57BL/6 J mice to directly define the links between EWcp-specific urocortin-1 expression and voluntary binge alcohol intake, demonstrating a specific importance for EWcp urocortin-1 activity in escalation of alcohol intake
Reduction of species identification errors in surveys of marine wildlife abundance utilising unoccupied aerial vehicles (UAVs)
The advent of unoccupied aerial vehicles (UAVs) has enhanced our capacity to survey wildlife abundance, yet new protocols are still required for collecting, processing, and analysing image-type observations. This paper presents a methodological approach to produce informative priors on species misidentification probabilities based on independent experiments. We performed focal follows of known dolphin species and distributed our imagery amongst 13 trained observers. Then, we investigated the effects of reviewer-related variables and image attributes on the accuracy of species identification and level of certainty in observations. In addition, we assessed the number of reviewers required to produce reliable identification using an agreement-based framework compared with the majority rule approach. Among-reviewer variation was an important predictor of identification accuracy, regardless of previous experience. Image resolution and sea state exhibited the most pronounced effects on the proportion of correct identifications and the reviewersâ mean level of confidence. Agreement-based identification resulted in substantial data losses but retained a broader range of image resolutions and sea states than the majority rule approach and produced considerably higher accuracy. Our findings suggest a strong dependency on reviewer-related variables and image attributes, which, unless considered, may compromise identification accuracy and produce unreliable estimators of abundance
Tacrolimus pretreatment attenuates preexisting xenospecific immunity and abrogates hyperacute rejection in a presensitized hamster to rat liver transplant model
In the hamster to rat liver transplant model, we determined the efficacy of tacrolimus in attenuating natural xenospecific humoral immunity and in abrogating the hyperacute liver rejection that is produced by presensitizing the Lewis rat recipient. Hamster livers, transplanted orthotopically into naive rats (controls), were rejected with animal death after 6.4±0.5 (SD) days. The infusion on (day -6) of 1.5 x 107 hamster hepatocytes, or of 1.5 x 108 nonparenchymal cells (NPC), resulted in hyperacute rejection and death in â€1.9 days. However, when the rats were pretreated with 1 mg/kg/day tacrolimus from days -6 to -1, survival of non-presensitized animals was prolonged to 25±20 days and that of recipients presensitized with hamster hepatocytes to 36±16 days or with NPC to 32±1.7 days. The tacrolimus pretreatment significantly reduced the hamster-specific complement-dependent cytotoxic antibodies response directed to liver NPC but not to lymph node cell targets. These observations suggest that the prolongation of survival by appropriately timed treatment with this T cell directed drug model is caused by the inhibition of humoral as well as cellular xenograft rejection
4-PAM Dispersion-Uncompensated Transmission with Micro-Ring Resonator Enhanced 1.55-”m DML
International audienceReal-time transmission of 14-GBd 4-PAM signal is demonstrated by combining a commercial 1.55-”m DML with a silicon MRR. BER below the HD-FEC threshold is measured after 26-km SSMF transmission without offline digital signal processing
CMOS compatible integrated all-optical radio frequency spectrum analyzer
We report an integrated all-optical radio frequency spectrum analyzer based on a ~4cm long doped silica glass waveguide, with a bandwidth greater than 2.5 THz. We use this device to characterize the intensity power spectrum of ultrahighrepetition rate mode-locked lasers at repetition rates up to 400 GHz, and observe dynamic noise related behavior not observable with other technique
Wavelength conversion of QAM signals in a low loss CMOS compatible spiral waveguide
We demonstrate wavelength conversion of quadrature amplitude modulation (QAM)
signals,
including 32-GBd quadrature phase-shift keying and 10-GBd 16-QAM, in a 50-cm long high
index doped
glass spiral
waveguide. The quality of the generated idlers for up to 20 nm of
wavelength shift is sufficient to achieve a BER performance below the hard decision
forward error correction threshold BER performance (<3.8 Ă 103), with an
optical signal-to-noise ratio penalty of less than 0.3 dB compared to the original
signal.
Our results confirm that this is a promising platform for nonlinear
optical signal
processing, as a result of both very low linear propagation loss
(<0.07 dB/cm) and a large material bandgap, which in turn ensures negligible
nonlinear loss
at telecom
wavelengths
Wavelength Conversion of QPSK and 16-QAM Coherent Signals in a CMOS Compatible Spiral Waveguide
<p>
We characterize a wavelength converter based on a 50-cm long low-loss spiral Hydex waveguide. A 10-nm FWM bandwidth is shown over which low OSNR penalty (< 0.5dB) wavelength conversion of QPSK and 16-QAM is reported. © OSA 2016.</p
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