108 research outputs found

    Coronagraphic Low Order Wave Front Sensor : post-processing sensitivity enhancer for high performance coronagraphs

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    Detection and characterization of exoplanets by direct imaging requires a coronagraph designed to deliver high contrast at small angular separation. To achieve this, an accurate control of low order aberrations, such as pointing and focus errors, is essential to optimize coronagraphic rejection and avoid the possible confusion between exoplanet light and coronagraphic leaks in the science image. Simulations and laboratory prototyping have shown that a Coronagraphic Low Order Wave-Front Sensor (CLOWFS), using a single defocused image of a reflective focal plane ring, can be used to control tip-tilt to an accuracy of 10^{-3} lambda/D. This paper demonstrates that the data acquired by CLOWFS can also be used in post-processing to calibrate residual coronagraphic leaks from the science image. Using both the CLOWFS camera and the science camera in the system, we quantify the accuracy of the method and its ability to successfully remove light due to low order errors from the science image. We also report the implementation and performance of the CLOWFS on the Subaru Coronagraphic Extreme AO (SCExAO) system and its expected on-sky performance. In the laboratory, with a level of disturbance similar to what is encountered in a post Adaptive Optics beam, CLOWFS post-processing has achieved speckle calibration to 1/300 of the raw speckle level. This is about 40 times better than could be done with an idealized PSF subtraction that does not rely on CLOWFS.Comment: 10 pages, 7 figures, accepted for publication in PAS

    Thorough elucidation of synthesis and structure of poly(glycerol) functionalized nanodiamonds

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    Poly(glycerol) (PG) is one of the most promising platforms for the surface modification of nanomaterials especially for in vivo applications. Since the “grafting-from” process is facile to functionalize the nanomaterial surface covalently through the ring-opening polymerization of glycidol (GD), it has been applied to a variety of nanomaterials. The resulting numerous hydroxy groups in the hyperbranched structure serve as scaffolds for further functionalization and provide good dispersibility under physiological conditions. On the other hand, nanodiamond (ND) is a nanomaterial most intensely worked with PG because of its prominent properties including fluorescence from color centers. Despite the wide-spread use, the process has not been extended to be scalable and controllable. In addition, the structural details of PG chain on ND surface are yet elusive. In this work, we develop more scalable and safer PG functionalization of NDs by dropwise-addition of GD to ethylene glycol (EG) suspension of ND. The resulting PG amount can be controlled or even estimated by the reaction conditions (weights of GD, ND and EG) and the ND properties (diameter and oxygen content). The structure of PG chain was qualitatively and quantitatively analyzed by ¹³C nuclear magnetic resonance (NMR) and dynamic light scattering (DLS) measurements. Based on these results, the structure of PG is elucidated

    Role-Play-Based Guidance for Job Interviews Using an Android Robot for Individuals With Autism Spectrum Disorders

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    Interventions for job interviews targeting the impaired theory of mind observed in individuals with autism spectrum disorders (ASD) are limited. We developed a role-play-based guidance system for job interviews using an android robot resembling a real person. Individuals with ASD worked in pairs and played dual roles in mock job interviews. Specifically, one participant acted as the interviewee, while the other participant operated the android robot and acted as the interviewer. Eight individuals with high-functioning ASD participated in this study. After the training sessions, participants learned to understand the point of view of the interviewer, which may contribute to increased recognition of the importance of gestures and the motivation to learn how to behave in a job interview. In addition, participants reported improved self-confidence. These results provide preliminary support for the efficacy of playing dual roles using android robots

    Intervention with a humanoid robot avatar for individuals with social anxiety disorders comorbid with autism spectrum disorders

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    For some individuals with social anxiety disorders (SAD) comorbid with autism spectrum disorders (ASD), it is difficult to speak in front of others. Herein, we report the case of a patient with SAD comorbid with ASD who could not speak in front of others until she used a humanoid robot as her avatar. During the intervention, her personality changed from shy to outgoing, which is explained by the Proteus effect. These case findings suggest that interventions with a robot avatar might improve the motivation for individuals with SAD comorbid with ASD who cannot speak in front of others to communicate

    Straightforward synthesis of silicon vacancy (SiV) center-containing single-digit nanometer nanodiamonds via detonation process

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    Silicon vacancy (SiV) color centers in diamond have attracted widespread attention owing to their stable photoluminescence (PL) with a sharp emission band in the near-infrared region (ZPL 738 nm). Especially, SiV center containing single-digit nanometer-sized nanodiamonds (single-digit SiV-NDs) are desirable for various applications such as bioimaging and biosensing because of their extremely small size, comparable to many biomaterials. Therefore, several attempts have been made to fabricate the single-digit SiV-NDs. However, there are no reports on the successful fabrication of such materials in reasonable scale of production. Here, we report the successful synthesis of single-digit SiV-NDs via straightforward detonation process, which is known to have the high productivity in fabrication of single-digit NDs. Triphenylsilanol (TPS), as a silicon source, was mixed with explosives (TPS/TNT/RDX = 1/59/40 wt%) and the detonation process was carried out. The obtained single-digit NDs exhibit PL at approximately 738 nm, indicating that single-digit SiV-NDs were successfully synthesized. Moreover, we conjectured that the physics behind this achievement may be attributed to the aromatic ring of TPS under the consideration of ND formation mechanism newly built up based on the results of time-resolved optical emission measurements for the detonation reaction

    The Subaru Coronographic Extreme AO (SCExAO) system: Implementation and performances of the Coronographic Low Order WaveFront Sensor

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    The Subaru Coronagraphic Extreme AO project (SCExAO) is a high performance coronagraph designed to deliver high contrast at small angular separation. For the detection of structures near the diffraction limit, an accurate control of low order wavefront aberrations - tip-tilt and focus - is essential as these aberrations create light leaks that are the source of confusion in the final science image. To address this major difficulty, we have equipped SCExAO with a specially designed Coronagraphic Low Order WaveFront Sensor (CLOWFS) using defocused images of a reflective ring located in the focal plane, that can track tip-tilt errors as small as 10-3?/D. CLOWFS was originally designed to drive actuators in a closed-loop. Here, we show that it can also be used in post-processing to efficiently subtract the tip-tilt induced coronagraphic leaks in the final science image

    Differences in the Optimal Motion of Android Robots for the Ease of Communications Among Individuals With Autism Spectrum Disorders

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    Android robots are employed in various fields. Many individuals with autism spectrum disorders (ASD) have the motivation and aptitude for using such robots. Interactions with these robots are structured to resemble social situations in which certain social behaviors can occur and to simulate daily life. Considering that individuals with ASD have strong likes and dislikes, ensuring not only the optimal appearance but also the optimal motion of robots is important to achieve smooth interaction and to draw out the potential of robotic interventions. We investigated whether individuals with ASD found it easier to talk to an android robot with little motion (i.e., only opening and closing its mouth during speech) or an android robot with much motion (i.e., in addition to opening and closing its mouth during speech, moving its eyes from side to side and up and down, blinking, deeply breathing, and turning or moving its head or body at random). This was a crossover study in which a total of 25 participants with ASD experienced mock interviews conducted by an android robot with much spontaneous facial and bodily motion and an android robot with little motion. We compared demographic data between participants who answered that the android robot with much motion was easier to talk to than android robot with little motion and those who answered the opposite. In addition, we investigated how each type of demographic data was related to participants\u27 feeling of comfort in an interview setting with an android robot. Fourteen participants indicated that the android robot with little motion was easier to talk to than the robot with much motion, whereas 11 participants answered the opposite. There were significant differences between these two groups in the sensory sensitivity score, which reflects the tendency to show a low neurological threshold. In addition, we found correlations between the sensation seeking score, which reflects the tendency to show a high neurological threshold, and self-report ratings of comfort in each condition. These results provide preliminary support for the importance of setting the motion of an android robot considering the sensory traits of ASD

    Effect of Luseogliflozin on Heart Failure With Preserved Ejection Fraction in Patients With Diabetes Mellitus

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    Background Effects of sodium‐glucose cotransporter 2 inhibitors on reducing hospitalization for heart failure have been reported in randomized controlled trials, but their effects on patients with heart failure with preserved ejection fraction (HFpEF) are unknown. This study aimed to evaluate the drug efficacy of luseogliflozin, a sodium‐glucose cotransporter 2 inhibitor, in patients with type 2 diabetes mellitus and HFpEF. Methods and Results We performed a multicenter, open‐label, randomized, controlled trial for comparing luseogliflozin 2.5 mg once daily with voglibose 0.2 mg 3 times daily in patients with type 2 diabetes mellitus suffering from HFpEF (left ventricular ejection fraction >45% and BNP [B‐type natriuretic peptide] concentrations ≥35 pg/mL) in a 1:1 randomization fashion. The primary outcome was the difference from baseline in BNP levels after 12 weeks of treatment between the 2 drugs. A total of 173 patients with diabetes mellitus and HFpEF were included. Of these, 83 patients were assigned to receive luseogliflozin and 82 to receive voglibose. There was no significant difference in the reduction in BNP concentrations after 12 weeks from baseline between the 2 groups. The ratio of the mean BNP value at week 12 to the baseline value was 0.79 in the luseogliflozin group and 0.87 in the voglibose group (percent change, −9.0% versus −1.9%; ratio of change with luseogliflozin versus voglibose, 0.93; 95% CI, 0.78–1.10; P=0.26). Conclusion In patients with type 2 diabetes mellitus and HFpEF, there is no significant difference in the degree of reduction in BNP concentrations after 12 weeks between luseogliflozin and voglibose

    Effects of luseogliflozin and voglibose on high-risk lipid profiles and inflammatory markers in diabetes patients with heart failure

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    Sodium-glucose cotransporter 2 inhibitors could reduce cardiovascular events in patients with heart failure irrespective of diabetes status. In this prespecified sub-analysis of randomised-controlled trial, we investigated the efficacy of luseogliflozin (2.5 mg daily), a sodium-glucose cotransporter 2 inhibitor, with that of voglibose (0.6 mg daily), an alpha-glucosidase inhibitor, on high-risk lipid profile and inflammatory markers in patients with type-2 diabetes and heart failure. Among the 157 patients studied, there were no significant differences in the mean malondialdehyde LDL or small-dense LDL cholesterol levels between the luseogliflozin and voglibose groups (percent change: 0.2% vs. - 0.6%, p = 0.93; - 1.7% vs. - 8.6%, p= 0.21) after 12 weeks in comparison to levels at the baseline. No significant difference was observed between the two groups in the adiponectin and high-sensitivity C-reactive protein levels after 12 weeks compared to the baseline levels (percent change, - 1.6% vs. - 4.0% and 22.5% vs. 10.0%; p = 0.52 and p = 0.55, respectively). In conclusion, in patients with type-2 diabetes and heart failure, compared to voglibose, luseogliflozin did not significantly improve the high-risk lipoprotein profile including malondialdehyde LDL and small-dense LDL cholesterol or the levels of inflammatory markers, including adiponectin and high-sensitivity C-reactive protein

    Effects of luseogliflozin on estimated plasma volume in patients with heart failure with preserved ejection fraction

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    Aims Sodium glucose co-transporter 2 inhibitors have diuretic effects in both patients with glycosuria and with natriuresis. We sought to assess the effect of luseogliflozin on estimated plasma volume (ePV) in patients with type 2 diabetes and heart failure with preserved ejection fraction (HFpEF). Methods and results This study was a post-hoc analysis of the MUSCAT-HF trial (UMIN000018395), a multicentre, prospective, open-label, randomized controlled trial that assessed the effect of 12 weeks of luseogliflozin (2.5 mg, once daily, n = 83) as compared with voglibose (0.2 mg, three times daily, n = 82) on the reduction in brain natriuretic peptide (BNP) in patients with type 2 diabetes and HFpEF. The analysis compared the change in ePV calculated by the Straus formula from baseline to Weeks 4, 12, and 24, using a mixed-effects model for repeated measures. We also estimated the association between changes in ePV and changes in other clinical parameters, including BNP levels. Luseogliflozin significantly reduced ePV as compared to voglibose at Week 4 {adjusted mean group-difference -6.43% [95% confidence interval (CI): -9.11 to -3.74]}, at Week 12 [-8.73% (95%CI: -11.40 to -6.05)], and at Week 24 [-11.02% (95%CI: -13.71 to -8.33)]. The effect of luseogliflozin on these parameters was mostly consistent across various patient clinical characteristics. The change in ePV at Week 12 was significantly associated with log-transformed BNP (r = 0.197, P = 0.015) and left atrial volume index (r = 0.283, P = 0.019). Conclusions Luseogliflozin significantly reduced ePV in patients with type 2 diabetes and HFpEF, as compared with voglibose. The reduction of intravascular volume by luseogliflozin may provide clinical benefits to patients with type 2 diabetes and HFpEF
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