2,092 research outputs found
Artificial Incoherent Speckles Enable Precision Astrometry and Photometry in High-Contrast Imaging
State-of-the-art coronagraphs employed on extreme adaptive optics enabled instruments are constantly improving the contrast detection limit for companions at ever-closer separations from the host star. In order to constrain their properties and, ultimately, compositions, it is important to precisely determine orbital parameters and contrasts with respect to the stars they orbit. This can be difficult in the post-coronagraphic image plane, as by definition the central star has been occulted by the coronagraph. We demonstrate the flexibility of utilizing the deformable mirror in the adaptive optics system of the Subaru Coronagraphic Extreme Adaptive Optics system to generate a field of speckles for the purposes of calibration. Speckles can be placed up to 22.5 λ/D from the star, with any position angle, brightness, and abundance required. Most importantly, we show that a fast modulation of the added speckle phase, between 0 and π, during a long science integration renders these speckles effectively incoherent with the underlying halo. We quantitatively show for the first time that this incoherence, in turn, increases the robustness and stability of the adaptive speckles, which will improve the precision of astrometric and photometric calibration procedures. This technique will be valuable for high-contrast imaging observations with imagers and integral field spectrographs alike
Soybean as supplement of growing cattle on tropical pasture: effects on intake, digestibility and animal performance
An indoor trial was conducted with weaning heifers (experiment 1). Raw whole soybean (RSB), whole soybean heated with steam (SHSB) and extruded whole soybean (EXSB) were given as supplements at 0.7% of live weight (LW). One group was the control, with no supplement. All supplements increased total dry matter (DM) intake and did not affect hay intake. RSB was the most degradable crude protein (CP) source. Total digestive tract digestibility was not affected by treatments, except for apparent CP digestibility. Because total DM intake increased in supplemented animals, all supplements increased intake of digestible DM, organic matter (OM) and CP over the control. In another assay (experiment 2) a performance trial was conducted with forty weaned heifers. The same supplements used in experiment 1 were used. Heifers supplemented with EXSB gained the highest and had better apparent feed efficiency. Apparent feed efficiency was similar to those observed in protein supplementation, suggesting that some increase in DM intake from pasture may have occurred. RSB had the poorest apparent feed efficiency which agreed with the numerical lower OM intake observed in experiment 1. All supplemented heifers had higher gain, hip height change, thoracic perimeter and body condition score change than the control group
ヒト角化上皮細胞における5-FU誘発性酸化ストレスおよび炎症応答に対するresveratrolの保護効果
Although 5-fluorouracil (5-FU) is currently used as an anti-cancer chemotherapy, adverse effects such as oral mucositis potentially limit its clinical application. Additionally, the prevention of 5-FU-induced side effects are scarce. Resveratrol is known to decrease oxidative damage and inflammation. In this study, we examined the protective effects of resveratrol on 5-FU-induced oxidative stress and inflammatory responses in normal human keratinocytes (HaCaT cell) as in vitro oral mucositis model. HaCaT cells were exposed to 5-FU and simultaneously treated with resveratrol. The effects of resveratrol on 5-FU-induced cytotoxicity were evaluated using cell viability assay. The production of reactive oxygen species (ROS) was measured using a fluorescence spectrophotometer. The effects of resveratrol on nuclear factor erythroid 2-related factor 2 (Nrf2), silent information regulator transcript-1 (SIRT-1), and nuclear factor kappa B (NF-κB) signaling and inflammatory cytokine expression were examined. Resveratrol suppressed 5-FU-induced overproduction of ROS by upregulating anti-oxidant defense genes through Nrf2 activation and SIRT-1 expression. Concerning inflammatory responses, resveratrol suppressed the 5-FU-induced expression of pro-inflammatory cytokines via NF-κB nuclear translocation. Conversely, N-acetylcysteine reduced ROS levels without affecting the expression of pro-inflammatory cytokines. Resveratrol might be useful for preventing 5-FU-induced adverse effects by activating anti-oxidant and anti-inflammatory responses
Charge-Stripe Order and Superconductivity in
A combined resistivity and hard x-ray diffraction study of superconductivity
and charge ordering in , as a function of Pt
substitution and externally applied hydrostatic pressure, is presented.
Experiments are focused on samples near the critical composition where competition and switching between charge order and
superconductivity is established. We show that charge order as a function of
pressure in is preempted - and hence
triggered - by a structural transition. Charge ordering appears uniaxially
along the short crystallographic (1,0,1) domain axis with a
modulation. Based on these results we
draw a charge-order phase diagram and discuss the relation between stripe
ordering and superconductivity.Comment: 8 pages, 4 figures: Accepted in Scientific Report
Conception d'un réseau de stations de pompage des eaux pluviales pour améliorer et stabiliser les systèmes d'assainissement urbains
Detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-D-glucose positron emission tomography and computed tomography (FDG-PET/CT)
The purpose of this study was to analyze the detectability of colorectal neoplasia with fluorine-18-2-fluoro-2-deoxy-d-glucose positron emission tomography/computed tomography (FDG-PET/CT).
Data for a total of 492 patients who had undergone both PET/CT and colonoscopy were analyzed. After the findings of PET/CT and colonoscopy were determined independently, the results were compared in each of the six colonic sites examined in all patients. The efficacy of PET/CT was determined using colonoscopic examination as the gold standard.
In all, 270 colorectal lesions 5 mm or more in size, including 70 pathologically confirmed malignant lesions, were found in 172 patients by colonoscopy. The sensitivity and specificity of PET/CT for detecting any of the colorectal lesions were 36 and 98%, respectively. For detecting lesions 11 mm or larger, the sensitivity was increased to 85%, with the specificity remaining consistent (97%). Moreover, the sensitivity for tumors 21 mm or larger was 96% (48/50). Tumors with malignant or high-grade pathology were likely to be positive with PET/CT. A size of 10 mm or smaller [odds ratio (OR) 44.14, 95% confidence interval (95% CI) 11.44-221.67] and flat morphology (OR 7.78, 95% CI 1.79-36.25) were significant factors that were associated with false-negative cases on PET/CT.
The sensitivity of PET/CT for detecting colorectal lesions is acceptable, showing size- and pathology-dependence, suggesting, for the most part, that clinically relevant lesions are detectable with PET/CT. However, when considering PET/CT for screening purposes caution must be exercised because there are cases of false-negative results
The Subaru Coronagraphic Extreme Adaptive Optics system: enabling high-contrast imaging on solar-system scales
The Subaru Coronagraphic Extreme Adaptive Optics (SCExAO) instrument is a
multipurpose high-contrast imaging platform designed for the discovery and
detailed characterization of exoplanetary systems and serves as a testbed for
high-contrast imaging technologies for ELTs. It is a multi-band instrument
which makes use of light from 600 to 2500nm allowing for coronagraphic direct
exoplanet imaging of the inner 3 lambda/D from the stellar host. Wavefront
sensing and control are key to the operation of SCExAO. A partial correction of
low-order modes is provided by Subaru's facility adaptive optics system with
the final correction, including high-order modes, implemented downstream by a
combination of a visible pyramid wavefront sensor and a 2000-element deformable
mirror. The well corrected NIR (y-K bands) wavefronts can then be injected into
any of the available coronagraphs, including but not limited to the phase
induced amplitude apodization and the vector vortex coronagraphs, both of which
offer an inner working angle as low as 1 lambda/D. Non-common path, low-order
aberrations are sensed with a coronagraphic low-order wavefront sensor in the
infrared (IR). Low noise, high frame rate, NIR detectors allow for active
speckle nulling and coherent differential imaging, while the HAWAII 2RG
detector in the HiCIAO imager and/or the CHARIS integral field spectrograph
(from mid 2016) can take deeper exposures and/or perform angular, spectral and
polarimetric differential imaging. Science in the visible is provided by two
interferometric modules: VAMPIRES and FIRST, which enable sub-diffraction
limited imaging in the visible region with polarimetric and spectroscopic
capabilities respectively. We describe the instrument in detail and present
preliminary results both on-sky and in the laboratory.Comment: Accepted for publication, 20 pages, 10 figure
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