Context. Radial-velocity (RV) signals arising from stellar photospheric phenomena are the main limitation for precise RV measurements. Those signals induce RV variations an order of magnitude larger ...than the signal created by the orbit of Earth-twins, thus preventing their detection. Aims. Different methods have been developed to mitigate the impact of stellar RV signals. The goal of this paper is to compare the efficiency of these different methods to recover extremely low-mass planets despite stellar RV signals. However, because observed RV variations at the meter-per-second precision level or below is a combination of signals induced by unresolved orbiting planets, by the star, and by the instrument, performing such a comparison using real data is extremely challenging. Methods. To circumvent this problem, we generated simulated RV measurements including realistic stellar and planetary signals. Different teams analyzed blindly those simulated RV measurements, using their own method to recover planetary signals despite stellar RV signals. By comparing the results obtained by the different teams with the planetary and stellar parameters used to generate the simulated RVs, it is therefore possible to compare the efficiency of these different methods. Results. The most efficient methods to recover planetary signals take into account the different activity indicators, use red-noise models to account for stellar RV signals and a Bayesian framework to provide model comparison in a robust statistical approach. Using the most efficient methodology, planets can be found down to \hbox{$K/N= K_{\mathrm{pl}}/\mathrm{RV}_{\mathrm{rms}}\times\sqrt{N_{\mathrm{obs}}}=5$}K/N=Kpl/RVrms×Nobs=5 with a threshold of K/N = 7.5 at the level of 80–90% recovery rate found for a number of methods. These recovery rates drop dramatically for K/N smaller than this threshold. In addition, for the best teams, no false positives with K/N > 7.5 were detected, while a non-negligible fraction of them appear for smaller K/N. A limit of K/N = 7.5 seems therefore a safe threshold to attest the veracity of planetary signals for RV measurements with similar properties to those of the different RV fitting challenge systems.
Lung epithelial cells are a primary target for reactive oxygen species (ROS). ROS can cause oxidative deoxyribonucleic acid modification, such as 8-hydroxy-deoxyguanosine (8-OHdG). A human homologue ...of the MutT protein (hMTH1) prevents this modification. Mitochondria are the most important cellular source of ROS and may be susceptible to oxidative damage. The purpose of this study is to investigate oxidative stress and mitochondrial damage in lung epithelial cells from idiopathic interstitial pneumonias (IIPs). The authors analysed 8-OHdG, hMTH1, and mitochondrial proteins on lung specimens from 13 patients with IlPs consisted of eight patients with usual interstitial pneumonia and five patients with nonspecific interstitial pneumonia using Western blot analysis and immunohistochemistry. Immunoreactivity for 8-OHdG and hMTH1 was significantly increased in the lung epithelial cells from patients with IIPs compared with controls. The expression of hMTH1 was localised in the nuclear and cytoplasmic, but not the mitochondrial, fraction of lung homogenates. Immunoreactivity for mitochondrial protein and cytochrome c oxidase complex subunit IV was increased in the lung epithelial cells from patients with IIPs compared with controls. The current study concludes that oxidative stress may participate in epithelial cell damage in idiopathic interstitial pneumonia, and that increased mitochondrial mass may associate with increased reactive oxygen species production in idiopathic interstitial pneumonia.
Personality differences between Asian American (N = 320) and European American men (N = 242) and also among Asian American ethnic groups (Korean, Chinese, Japanese, Filipino, and mixed Asian) are ...examined on the Big Five personality dimension. Personality structures for Asian Americans and European Americans closely replicate established norms. However, congruence is greater for European American and highly acculturated Asian American men than for low acculturated Asian American men. Similar patterns are found for the construct loss of face (LOF). Asian American men with a high concern for LOF are less similar in their personality structure to European American men than Asian American men with low LOF concern. Mean differences are also found among Asian American and European American men, who differ significantly on Extraversion, Conscientiousness, Openness, and Neuroticism. Results indicate that acculturation and LOF are significantly associated with these four personality dimensions for both Asian American and European American men.
Abstract
Introduction/Objective
Several studies have explored the feasibility of measuring PD-L1 in cell block cytology and indicated cytological materials could be a reliable source for PD-L1 ...evaluation in non-small cell lung carcinoma patients. A few studies have investigated the compatibility and performance of PD-L1 clone SP263 testing between cytology and histology specimens. The study was pursued to evaluate PD-L1 expression in cell blocks from EBUS- TBNA compared to that in biopsied tissues from patients with lung carcinoma in our institution to evaluate a feasibility of PD-L1 clone SP263 in cell blocks and histology samples.
Methods/Case Report
A total of 57 specimens cytologically diagnosed lung carcinoma using endobronchial ultrasound guided transbronchial needle aspiraton (EBUS-TBNA) from Jan 1st, 2020, to Dec 31st, 2021 were screened for enrollment. Among them, 24 patients diagnosed with lung carcinoma using EBUS-TBNA and matched transbronchial biopsy (TBB) specimens were reviewed for study. After careful selection, 13 paired formalin-fixed tissues from lung carcinoma patients, including cell blocks and matched histology samples, were included. PD-L1 expression was assessed using the SP263 assay, and the tumor proportion score (TPS) was evaluated. PD-L1 expression was finally divided into three categories according to the TPS: < 1% (negative), 1–49% (low expression) and ≥ 50% (high expression).
Results (if a Case Study enter NA)
Of the 13 matched pairs, 12 (92.3%) showed concordant PD-L1 expression. On cytology, 3 cases were positive (2 high expressors and 1 low- expressors) of which 2 were concordant and 1 discordant with matched histology specimens. Ten cytology samples were negative for PD-L1 expression, and they were concordant to histology samples. The correlation coefficient for TPS was 0.75 considered as having good value. Conclusion: With an overall concordance rate of 92.3% between cytology and histology specimen, this study demonstrates the feasibility of PD-L1 IHC with SP263 clone on limited quality and quantity of cytology samples from lung carcinoma in our institute. It is required for further evaluation with additional specimens to conclude that the usefulness of cytology cell blocks for PD-L1 expression analysis.
A W -band millimeter-wave transmitter and receiver that are based on impulse radio (IR) architecture were developed. The IR-based apparatuses have an optical-fiber input/output interface board that ...supports multi protocol signals (OC-192 and 10 GbE) and that implements a forward error correction (FEC), enabling 10-Gb/s data transmission both in space and fiber seamlessly. Analyzing an IR-based receiver model with simple on/off demodulation architecture, required signal-to-noise ratios were calculated for IR-based systems affected by various inter-symbol interference (ISI) levels. A millimeter-wave module used in the transmitter, consisting of a 6.5-ps pulse modulator with InP-based HEMTs and a band-pass filter formed on an alumina substrate, emitted wavelets, or RF pulses, with an average power of -26 dBm, occupying frequencies between 78-93 GHz. A front-end module used in the receiver, consisting of two cascaded low-noise amplifiers, an envelope detector, and a limiting amplifier, had a sensitivity of -36 dBm. In a back-to-back test where the transmitter and receiver were connected by a waveguide, disabling the FEC, error-free operation was achieved with a test pattern of PRBS 2 31 -1 at the OC-192 compliant data rate of 9.95328 Gb/s. Furthermore, using a horn antenna and enabling the FEC, radio transmission and reception in a distance of 20 cm were confirmed with a bit error rate of less than 10 -12 . These results confirmed the basic technologies for simple and compact IR-based systems, which could be used as an alternative to fiber optic cables.
Aims. Since 2011, the SOPHIE spectrograph has been used to search for Neptunes and super-Earths in the northern hemisphere. As part of this observational program, 290 radial velocity measurements of ...the 6.4 V magnitude star HD 158259 were obtained. Additionally, TESS photometric measurements of this target are available. We present an analysis of the SOPHIE data and compare our results with the output of the TESS pipeline.Methods. The radial velocity data, ancillary spectroscopic indices, and ground-based photometric measurements were analyzed with classical and ℓ1 periodograms. The stellar activity was modeled as a correlated Gaussian noise and its impact on the planet detection was measured with a new technique.Results. The SOPHIE data support the detection of five planets, each with m sin i ≈ 6 M⊕, orbiting HD 158259 in 3.4, 5.2, 7.9, 12, and 17.4 days. Though a planetary origin is strongly favored, the 17.4 d signal is classified as a planet candidate due to a slightly lower statistical significance and to its proximity to the expected stellar rotation period. The data also present low frequency variations, most likely originating from a magnetic cycle and instrument systematics. Furthermore, the TESS pipeline reports a significant signal at 2.17 days corresponding to a planet of radius ≈1.2 R⊕. A compatible signal is seen in the radial velocities, which confirms the detection of an additional planet and yields a ≈2 M⊕ mass estimate.Conclusions. We find a system of five planets and a strong candidate near a 3:2 mean motion resonance chain orbiting HD 158259. The planets are found to be outside of the two and three body resonances.
The death receptor Fas (Apo1/CD95) and Fas ligand (FasL) system is recognised as a major pathway for the induction of apoptosis in vivo, and antiapoptosis via its blockade plays a critical role in ...carcinogenesis and progression in several malignancies. However, the function of Fas-FasL system in urothelial cancer (UC) has not been elucidated. We therefore investigated the expression of Fas, FasL and Decoy receptor 3 for FasL (DcR3) in UC specimens and cell lines, and examined the cytotoxic effect of an anti-Fas-activating monoclonal antibody (mAb) in vitro. Immunohistochemical examinations of Fas-related molecules were performed on 123 UC and 30 normal urothelium surgical specimens. Normal urothelium showed Fas staining in the cell membrane and cytoplasm. In UC, less frequent Fas expression was significantly associated with a higher pathological grade (P < 0.0001), a more advanced stage (P = 0.023) and poorer prognosis (P = 0.010). Fas and the absence thereof were suggested to be crucial factors with which to select patients requiring more aggressive treatment. Moreover, low-dose anti-Fas-activating mAb sensitised resistant cells to adriamycin, and this synergistic effect could be applied in the development of new treatment strategy for UC patients with multidrug-resistant tumours.
The present paper considers singular value decomposition (SVD) for a class of linear time-varying systems. The class considered herein describes time-driven switched linear systems. Based on an ...appropriate input–output description, the calculation method of singular values and singular vectors is derived. The SVD enables us to characterize the dominant input–output signals using singular vectors, which form orthogonal systems in input and output spaces. The SVD is then applied to switched linear systems to improve the transient response. A numerical example is provided to demonstrate the proposed method.
Correlated noise affects most astronomical datasets and to neglect accounting for it can lead to spurious signal detections, especially in low signal-to-noise conditions, which is often the context ...in which new discoveries are pursued. For instance, in the realm of exoplanet detection with radial velocity time series, stellar variability can induce false detections. However, a white noise approximation is often used because accounting for correlated noise when analyzing data implies a more complex analysis. Moreover, the computational cost can be prohibitive as it typically scales as the cube of the dataset size. For some restricted classes of correlated noise models, there are specific algorithms that can be used to help bring down the computational cost. This improvement in speed is particularly useful in the context of Gaussian process regression, however, it comes at the expense of the generality of the noise model. In this article, we present the S + LEAF noise model, which allows us to account for a large class of correlated noises with a linear scaling of the computational cost with respect to the size of the dataset. The S + LEAF model includes, in particular, mixtures of quasiperiodic kernels and calibration noise. This efficient modeling is made possible by a sparse representation of the covariance matrix of the noise and the use of dedicated algorithms for matrix inversion, solving, determinant computation, etc. We applied the S + LEAF model to reanalyze the HARPS radial velocity time series of the recently published planetary system HD 136352. We illustrate the flexibility of the S + LEAF model in handling various sources of noise. We demonstrate the importance of taking correlated noise into account, and especially calibration noise, to correctly assess the significance of detected signals.
Efficient modeling of correlated noise Delisle, J.-B.; Hara, N.; Ségransan, D.
Astronomy and astrophysics (Berlin),
06/2020, Letnik:
638
Journal Article
Recenzirano
Correlated noise affects most astronomical datasets and to neglect accounting for it can lead to spurious signal detections, especially in low signal-to-noise conditions, which is often the context ...in which new discoveries are pursued. For instance, in the realm of exoplanet detection with radial velocity time series, stellar variability can induce false detections. However, a white noise approximation is often used because accounting for correlated noise when analyzing data implies a more complex analysis. Moreover, the computational cost can be prohibitive as it typically scales as the cube of the dataset size. For some restricted classes of correlated noise models, there are specific algorithms that can be used to help bring down the computational cost. This improvement in speed is particularly useful in the context of Gaussian process regression, however, it comes at the expense of the generality of the noise model. In this article, we present the
S + LEAF
noise model, which allows us to account for a large class of correlated noises with a linear scaling of the computational cost with respect to the size of the dataset. The
S + LEAF
model includes, in particular, mixtures of quasiperiodic kernels and calibration noise. This efficient modeling is made possible by a sparse representation of the covariance matrix of the noise and the use of dedicated algorithms for matrix inversion, solving, determinant computation, etc. We applied the
S + LEAF
model to reanalyze the HARPS radial velocity time series of the recently published planetary system HD 136352. We illustrate the flexibility of the
S + LEAF
model in handling various sources of noise. We demonstrate the importance of taking correlated noise into account, and especially calibration noise, to correctly assess the significance of detected signals.
PDF
