84 research outputs found
Taiji Data Challenge for Exploring Gravitational Wave Universe
The direct observation of gravitational waves (GWs) opens a new window for
exploring new physics from quanta to cosmos and provides a new tool for probing
the evolution of universe. GWs detection in space covers a broad spectrum
ranging over more than four orders of magnitude and enables us to study rich
physical and astronomical phenomena. Taiji is a proposed space-based GW
detection mission that will be launched in the 2030s. Taiji will be exposed to
numerous overlapping and persistent GW signals buried in the foreground and
background, posing various data analysis challenges. In order to empower
potential scientific discoveries, the Mock LISA Data Challenge and the LISA
Data Challenge (LDC) were developed. While LDC provides a baseline framework,
the first LDC needs to be updated with more realistic simulations and adjusted
detector responses for Taiji's constellation. In this paper, we review the
scientific objectives and the roadmap for Taiji, as well as the technical
difficulties in data analysis and the data generation strategy, and present the
associated data challenges. In contrast to LDC, we utilize second-order
Keplerian orbit and second-generation time delay interferometry techniques.
Additionally, we employ a new model for the extreme-mass-ratio inspiral
waveform and stochastic GW background spectrum, which enables us to test
general relativity and measure the non-Gaussianity of curvature perturbations.
Furthermore, we present a comprehensive showcase of parameter estimation using
a toy dataset. This showcase not only demonstrates the scientific potential of
the Taiji Data Challenge but also serves to validate the effectiveness of the
pipeline. As the first data challenge for Taiji, we aim to build an open ground
for data analysis related to Taiji sources and sciences. More details can be
found on the official website at http://taiji-tdc.ictp-ap.org.Comment: 15 pages, 3 figure
31st Annual Meeting and Associated Programs of the Society for Immunotherapy of Cancer (SITC 2016) : part two
Background
The immunological escape of tumors represents one of the main ob- stacles to the treatment of malignancies. The blockade of PD-1 or CTLA-4 receptors represented a milestone in the history of immunotherapy. However, immune checkpoint inhibitors seem to be effective in specific cohorts of patients. It has been proposed that their efficacy relies on the presence of an immunological response. Thus, we hypothesized that disruption of the PD-L1/PD-1 axis would synergize with our oncolytic vaccine platform PeptiCRAd.
Methods
We used murine B16OVA in vivo tumor models and flow cytometry analysis to investigate the immunological background.
Results
First, we found that high-burden B16OVA tumors were refractory to combination immunotherapy. However, with a more aggressive schedule, tumors with a lower burden were more susceptible to the combination of PeptiCRAd and PD-L1 blockade. The therapy signifi- cantly increased the median survival of mice (Fig. 7). Interestingly, the reduced growth of contralaterally injected B16F10 cells sug- gested the presence of a long lasting immunological memory also against non-targeted antigens. Concerning the functional state of tumor infiltrating lymphocytes (TILs), we found that all the immune therapies would enhance the percentage of activated (PD-1pos TIM- 3neg) T lymphocytes and reduce the amount of exhausted (PD-1pos TIM-3pos) cells compared to placebo. As expected, we found that PeptiCRAd monotherapy could increase the number of antigen spe- cific CD8+ T cells compared to other treatments. However, only the combination with PD-L1 blockade could significantly increase the ra- tio between activated and exhausted pentamer positive cells (p= 0.0058), suggesting that by disrupting the PD-1/PD-L1 axis we could decrease the amount of dysfunctional antigen specific T cells. We ob- served that the anatomical location deeply influenced the state of CD4+ and CD8+ T lymphocytes. In fact, TIM-3 expression was in- creased by 2 fold on TILs compared to splenic and lymphoid T cells. In the CD8+ compartment, the expression of PD-1 on the surface seemed to be restricted to the tumor micro-environment, while CD4 + T cells had a high expression of PD-1 also in lymphoid organs. Interestingly, we found that the levels of PD-1 were significantly higher on CD8+ T cells than on CD4+ T cells into the tumor micro- environment (p < 0.0001).
Conclusions
In conclusion, we demonstrated that the efficacy of immune check- point inhibitors might be strongly enhanced by their combination with cancer vaccines. PeptiCRAd was able to increase the number of antigen-specific T cells and PD-L1 blockade prevented their exhaus- tion, resulting in long-lasting immunological memory and increased median survival
Multi-TDOA Location Algorithm for Three Satellites TDOA Passive Location System
Location precision of radiant source is the primary performance of passive location system, and how to improve location precision is an important problem which always attracts attention. In three satellites TDOA (Time Difference Of Arrival) passive location system, location precision of single pulse location is limited by the error of TDOA measure. For improving location precision of radiant source, multi-TDOA location algorithm which estimates the position of target combining all the TDOAs is proposed in this paper. The new algorithm calculates three satellitesâ positions at the arrival time of each pulse firstly, and then combines all pulsesâTDOA equations and earth equation, lastly estimates the position of radiant source using least square algorithm. The result of simulations shows that the new algorithm can improve location precision of radiant source, and it is a steady and effective location method with higher location precision
Novel Cavity Disinfectants Containing Quaternary Ammonium Monomer Dimethylaminododecyl Methacrylate
This study was set to assess the possible benefits of novel cavity disinfectants with 5% dimethylaminododecyl methacrylate (DMADDM); and compare the effectiveness of saliva microbial-aging method with water-aging in measuring the changing of resinâdentin bond strength. Three cavity disinfectants were tested: 0.2% Chlorhexidine (CHX); 5% DMADDM; and 5% DMADDM + 0.2% CHX. Microtensile bond strength (ÎŒTBS) test was performed after microbial-aging with saliva microbial or water aging for one month. Hydroxyproline (HYP), the production of collagen degradation, was measured spectrophotometrically. Additionally, the antibacterial effects of each reagent were evaluated. The 5% DMADDM exerted the least percentage of resinâdentin bond strength loss after one month microbial-aging (p < 0.05). There were no statistically significant differences of bond strength decrease after one month water aging among the tested groups (p > 0.05). Microbial-aging method yield more drop of bond strength than water aging in all groups except 5% DMADDM (p < 0.05). Meanwhile, 5% DMADDM had the same matrix metalloproteinases (MMPs) inhibitory effects as the other two agents (p > 0.05), but much stronger antibacterial capability than 0.2% CHX (p < 0.05). This indicated that a cavity disinfectant with 5% DMADDM is promising for improving the stability of resinâdentin bonds in appearance of saliva biofilm; and the saliva microbial-aging method is more promising for studying the durability of resinâdentin bonds than water aging
Surface Photocatalysis-TPD Spectrometer for Photochemical Kinetics
A surface photocatalysis-TPD apparatus devoted to studying kinetics and mechanism of photocatalytic processes with various signal crystal surfaces has been constructed. Extremely high vacuum (similar to 0.2 nPa) in the ionization region is obtained by using multiple ultrahigh vacuum pumps. Compared with similar instruments built previously by others, the H-2, CH4 background in the ionization region can be reduced by about two orders of magnitude, and other residual gases in the ionization region can be reduced by about an order of magnitude. Therefore, the signal-to-noise ratio for the temperature programmed desorption (TPD) and time of flight (TOF) spectra is substantially enhanced, making experimental studies of photocatalytic processes on surfaces much easier. In this work, we describe the new apparatus in detail and present some preliminary studies on the photo-induced oxygen vacancy defects on TiO2(110) at 266 nm by using the TPD and TOF methods. Preliminary results suggest that the apparatus is a powerful tool for studying kinetics and mechanism of photochemical processes
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