Event-based Camera Simulation using Monte Carlo Path Tracing with Adaptive Denoising

This paper presents an algorithm to obtain an event-based video from noisy frames given by physics-based Monte Carlo path tracing over a synthetic 3D scene. Given the nature of dynamic vision sensor (DVS), rendering event-based video can be viewed as a process of detecting the changes from noisy brightness values. We extend a denoising method based on a weighted local regression (WLR) to detect the brightness changes rather than applying denoising to every pixel. Specifically, we derive a threshold to determine the likelihood of event occurrence and reduce the number of times to perform the regression. Our method is robust to noisy video frames obtained from a few path-traced samples. Despite its efficiency, our method performs comparably to or even better than an approach that exhaustively denoises every frame.Comment: 8 pages, 6 figures, 3 table

Finite-temperature time-dependent variation with multiple Davydov states

The Dirac-Frenkel time-dependent variational approach with Davydov Ans\"atze is a sophisticated, yet efficient technique to obtain an acuurate solution to many-body Schr\"odinger equations for energy and charge transfer dy- namics in molecular aggregates and light-harvesting complexes. We extend this variational approach to finite temperatures dynamics of the spin-boson model by adopting a Monte Carlo importance sampling method. In or- der to demonstrate the applicability of this approach, we compare real-time quantum dynamics of the spin-boson model calculated with that from numerically exact iterative quasiadiabatic propagator path integral (QUAPI) technique. The comparison shows that our variational approach with the single Davydov Ans\"atze is in excellent agreement with the QUAPI method at high temperatures, while the two differ at low temperatures. Accuracy in dynamics calculations employing a multitude of Davydov trial states is found to improve substantially over the single Davydov Ansatz, especially at low temperatures. At a moderate computational cost, our variational approach with the multiple Davydov Ansatz is shown to provide accurate spin-boson dynamics over a wide range of temperatures and bath spectral densities.Comment: 8 pages, 3 figure

Phase Angle as a Nutritional Assessment Method in Patients with Hip Fractures: A Cross-Sectional Study

Background Phase angle, which is associated with cellular health, has attracted attention as a noninvasive and objective method for nutritional assessment. However, the association between malnutrition and phase angle in older inpatients with hip fractures has not been reported. Therefore, this study investigated this association in older inpatients (aged ≥65 years) with hip fractures and determined the cutoff phase angle for determining malnutrition. Methods This cross-sectional study retrospectively analyzed the data of 96 inpatients with hip fractures who were hospitalized in rehabilitation units after surgery (male, 29.4%; mean age, 82.4±6.2 years). Nutritional status was assessed using the Geriatric Nutritional Risk Index (GNRI), with malnutrition defined as a GNRI ≥98. Bioelectrical impedance analysis was used to measure phase angles. Results The phase angle was associated with malnutrition (B=−1.173; odds ratio=0.310; 95% confidence interval 0.58–0.83; p=0.015). The area under the receiver operating characteristic curve was 0.71. The cutoff phase angle for malnutrition was 3.96° (sensitivity=0.85, specificity=0.63). Conclusion Phase angle could be an indicator of malnutrition in older inpatients with hip fractures. Our findings will help formulate rehabilitation strategies for these patients

Slr0967 and Sll0939 induced by the SphR response regulator in Synechocystis sp. PCC 6803 are essential for growth under acid stress conditions

AbstractTwo-component signal transduction is the primary signaling mechanism for global regulation of the cellular response to environmental changes. We used DNA microarray analysis to identify genes that were upregulated by acid stress in the cyanobacterium Synechocystis sp. PCC 6803. Several of these genes may be response regulators that are directly involved in this type of stress response. We constructed deletion mutants for the response regulator genes and compared the growth rates of cells transfected with mutant and wild-type genes in a low pH medium. Of these mutants, deletion of sphR affected the growth rate under acid stress (pH 6.0) conditions. We examined genome-wide expression in ΔsphR mutant cells using DNA microarray to determine whether SphR was involved in the regulation of other acid stress responsive genes. Microarray and real-time quantitative reverse-transcription polymerase chain reaction (qRT-PCR) analyses of wild-type cells showed that the expression of phoA, pstS1, and pstS2, which are upregulated under phosphate-limiting conditions, increased (2.48-, 1.88-, and 5.07-fold, respectively) after acid stress treatment for 0.5h. In contrast, pstS2 expression did not increase in the ΔsphR mutant cells after acid stress, whereas the phoA and sphX mRNA levels increased. Furthermore, qRT-PCR and northern blot analysis indicated that downregulation of the acid-responsive genes slr0967 and sll0939 occurred with the deletion of sphR. Indeed, mutants of these genes were more sensitive to acid stress than the wild-type cells. Thus, induction of Slr0967 and Sll0939 by SphR may be essential for growth under acid stress conditions. This article is part of a Special Issue entitled: Photosynthesis Research for Sustainability: from Natural to Artificial

First observation of MeV gamma-ray universe with bijective imaging spectroscopy using the Electron-Tracking Compton Telescope aboard SMILE-2+

MeV gamma-rays provide a unique window for the direct measurement of line emissions from radioisotopes, but observations have made little significant progress after COMPTEL/{\it CGRO}. To observe celestial objects in this band, we are developing an electron-tracking Compton camera (ETCC), which realizes both bijective imaging spectroscopy and efficient background reduction gleaned from the recoil electron track information. The energy spectrum of the observation target can then be obtained by a simple ON-OFF method using a correctly defined point spread function on the celestial sphere. The performance of celestial object observations was validated on the second balloon SMILE-2+ installed with an ETCC having a gaseous electron tracker with a volume of 30$\times$30$\times$30 cm$^3$. Gamma-rays from the Crab nebula were detected with a significance of 4.0$\sigma$ in the energy range 0.15--2.1 MeV with a live time of 5.1 h, as expected before launching. Additionally, the light curve clarified an enhancement of gamma-ray events generated in the Galactic center region, indicating that a significant proportion of the final remaining events are cosmic gamma rays. Independently, the observed intensity and time variation were consistent with the pre-launch estimates except in the Galactic center region. The estimates were based on the total background of extragalactic diffuse, atmospheric, and instrumental gamma-rays after accounting for the variations in the atmospheric depth and rigidity during the level flight. The Crab results and light curve strongly support our understanding of both the detection sensitivity and the background in real observations. This work promises significant advances in MeV gamma-ray astronomy

Semiquantitative assessment of FDG uptake in primary tumours

Objective: To semiquantitatively estimate fluorine-18-fluorodeoxyglucose (FDG) uptake in primary lung cancer cells using dynamic and dual-time-point (DTP) positron emission tomography/computed tomography (PET/CT) to obtain a diagnostic index for lymph node (LN) metastasis. Methods: Forty-five patients with lung cancer underwent dynamic and DTP PET/CT examinations. All primary lesions and LN metastases were evaluated pathologically. At each time phase, we assessed the maximum standardised uptake value (SUVmax), metabolic tumour volume (MTV), and total lesion glycolysis (TLG) of the primary tumours. We investigated the relationship between semiquantitative index and the presence of LN metastasis for each case and for all cases satisfying indications for segmentectomy. In cases with LN metastasis, we assessed the SUVmax of pathologically proven metastatic LNs and non-metastatic LNs in each dynamic phase for evaluating temporal change. Results: Among 45 patients, 15 had 17 LN metastasis. SUVmax, MTV, and TLG of primary tumours at each time phase were significantly associated with LN metastasis (p < 0.05). In receiver operating characteristic analysis, dynamic second and third phases showed high diagnostic ability for LN metastasis. The temporal change in SUVmax in the dynamic phase between primary tumours and metastatic LNs were significantly different (p = 0.065). The temporal change in SUVmax was significantly lower in non-metastatic LNs than in primary tumours and metastatic LNs (p < 0.0001). Conclusions: Semiquantitative assessment of FDG uptake in dynamic second and third phases and the assessment of temporal changes in SUVmax on dynamic PET/CT scans were important predictors in diagnosing LN metastasis

A high dust emissivity index beta for a CO-faint galaxy in a filamentary Lyman-alpha nebula at z=3.1

We present CO J=4-3 line and 3 mm dust continuum observations of a 100 kpc-scale filamentary Ly{\alpha} nebula (SSA22 LAB18) at z=3.1 using the Atacama Large Millimeter/submillimeter Array (ALMA). We detected the CO J=4-3 line at a systemic z(CO)=3.093 {\pm} 0.001 at 11 {\sigma} from one of the ALMA continuum sources associated with the Ly{\alpha} filament. We estimated the CO J=4-3 luminosity of L'CO(4-3)=(2.3\pm0.2)x10^9 K km s^{-1} pc^2 for this CO source, which is one order of magnitude smaller than those of typical z>1 dusty star-forming galaxies (DSFGs) of similar far-infrared luminosity L(IR)~10^{12} Lsun. We derived a molecular gas mass of Mgas=(4.4^{+0.9}_{-0.6})x10^9 Msun and a star-formation rate of SFR=270\pm160 Msun yr^{-1}. We also estimated a gas depletion time of {\tau}(dep)=17\pm10 Myr, being shorter than those of typical DSFGs. It is suggested that this source is in a transition phase from DSFG to a gas-poor, early-type galaxy. From ALMA to Herschel multi-band dust continuum observations, we measured a dust emissivity index {\beta}=2.3\pm0.2, which is similar to those of local gas-poor, early-type galaxies. Such a high {\beta} can be reproduced by specific chemical compositions for interstellar dust at the submillimeter wavelengths from recent laboratory experiments. ALMA CO and multi-band dust continuum observations can constrain the evolutionary stage of high-redshift galaxies through {\tau}(dep) and {\beta}, and thus we can investigate dust chemical compositions even in the early Universe.Comment: 6 pagers, 3 figure

Evidence for Direct CP Violation in B0 -> K+- pi-+ Decays

We report evidence for direct CP violation in the decay B0 -> K+-pi-+ with 253/fb of data collected with the Belle detector at the KEKB e+e- collider. Using 275 million B B_bar pairs we observe a B -> K+-pi-+ signal with 2140+-53 events. The measured CP violating asymmetry is Acp(K+-pi-+) = -0.101+-0.025 (stat)+-0.005 (syst), corresponding to a significance of 3.9 sigma including systematics. We also search for CP violation in the decays B+- -> K+-pi0 and B+- -> pi+-pi0. The measured CP violating asymmetries are Acp(K+-pi0) = 0.04+-0.05(stat)+-0.02(syst) and Acp(pi+-pi0) = -0.02+-0.10(stat)+-0.01(syst), corresponding to the intervals -0.05 < Acp(K+-pi0) < 0.13 and -0.18<Acp(pi+-pi0)<0.14 at 90% confidence level.Comment: 9 pages, 3 figures. submitted to Physical Review Letter

Sublingual immunotherapy decreases the avidity of antigen-specific IgE in patients with Japanese cedar pollinosis

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