123 research outputs found
Impact of Simulated Warming on Growthand Floral Characteristics of Two Varieties of Medicinal Epimedium
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Impact of Simulated Warming on Growthand Floral Characteristics of Two Varieties of Medicinal Epimedium
ABSTRACT An open top chamber (OTC) warming system was established in natural field conditions to study the impact of simulated warming on growth and floral characteristics of E. wushanense and E. acuminatum. Results: plant height and leaf growth were affected significantly.In +2°C warming condition, increment of plant height, leaf length and width and daily mean incrementof the two varieties were significantly greater than those of the control group; however, in warming +5°C condition, the increments were significantly lower than those of the control group. Floral differentiation was presented when different treatment was adopted. Floral quantitative character of E. acuminatum increased markedly after +2°C warming, but declined markedly after +5°C warming; however, floral quantitative characters of E. wushanense declined after +2°C and +5°C warming. The results can be used as a reference for cultivation and introduction of the two varieties
Response of photosynthesis to different concentrations of heavy metals in Davidia involucrata.
Lead (Pb) and cadmium (Cd) are highly toxic and are widespread in agricultural soils, representing risks to plant and human health. In this study, Davidia involucrata was cultivated in soil with different concentrations of Pb and Cd and sampled after 90 days. We used ANOVA to analyse the photosynthesis of D. involucrata and the ability of Pb and Cd to enrich and migrate in roots, stems and leaves. Various results are described here. 1) Under individual and combined Pb and Cd stress, the accumulation factors in the roots were greater than 1, which was significantly greater than those in the stems and leaves (P < 0.05), and the translocation factors both were less than 1. The Pb and Cd enrichment ability of D. involucrata roots was significantly higher than that of stems and leaves, and the migration ability of the two heavy metals in D. involucrata was weak. 2) The Mg-dechelatase activities of chlorophyll degradation products increased under stress due to high concentrations of Pb and Cd. However, chlorophyllase activity was higher at relatively low concentrations of the two heavy metals (P < 0.05). δ-Aminolevulinic acid and porphobilinogen of chlorophyll synthesis products are easily converted to uroporphyrinogen III under low concentrations of Cd, which promotes the synthesis of chlorophyll. 3) The effect of Cd stress alone on the chlorophyll concentration was not significant. Under combined stress, concentrations of Pb and Cd in the range of 400~800 mg·kg-1 and 5~20 mg·kg-1 significantly promoted an increase in photosynthetic pigments (P < 0.05). 4) Inhibition of the net photosynthetic rate increased with increasing Pb and Cd concentrations under both individual and combined stress. In addition, the root of D. involucrata had a strong absorption and fixation effect on heavy metals, thereby reducing metal toxicity and improving the tolerance of D. involucrata to heavy metals
DNA Barcoding Revealing the Parrotfish (Perciformes: Scaridae) Diversity of the Coral Reef Ecosystem of the South China Sea
Parrotfish are an important group in the coral reef ecosystem that maintain ecological stability and have a close relationship with coral reefs. Around the world, parrotfish and coral reefs are being destroyed due to human activities and global climate change. Here, we investigated the diversity of parrotfish in the South China Sea (SCS) using DNA barcoding, and initially established a DNA barcode database of the SCS parrotfish. A total of 1620 parrotfish specimens, belonging to 23 species of 6 genera in the family Scaridae, were collected in the SCS, accounting for 64% of the parrotfish species in the SCS. Genetic distance analysis at each taxonomic level showed that the average genetic distance was 0.23% within species, 8.52% within genus and 13.89% within family. The average inter-specific distance was 37.04-fold the intra-specific distance. Barcode gap analysis showed that 6 of the 21 parrotfish species with multiple samples had no barcode gap, resulting in an overall identification success rate of 74%. The ABGD analysis revealed that there could be 37 potential operational taxonomic units (OTUs) and the BIN analysis showed 32 identifiable taxonomic units, which by far exceed the number of morphologically previously known species. Overall, this study complements the lack of parrotfish DNA barcode sequences, and our findings provide an important stepping-stone to further study the diversity of parrotfish in South China
Single VHH-directed BCMA CAR-NK cells for multiple myeloma
Abstract Natural killer (NK) cells are promising alternatives for the production of “off-the-shelf” CAR products, posing a lower risk of cytokine release syndrome (CRS) than CAR-T cells. We synthesized four single VHH-directed anti-BCMA CARs, incorporating various intracellular regions (2B4 versus CD28) and hinge domains (CD28 versus IgG1) and ectopically producing IL-15. NK cells derived from peripheral blood (PB) were expanded ex vivo by K562-mbIL21 feeder cells. Stable CAR transduction was obtained through lentiviral transduction with the BaEV-Rless pseudotyped lentiviral vector. BCMA-CD28-IL15 CAR-NK cells with ectopic expression of IL-15 exhibited superior cytotoxicity were compared to BCMA-CD28 CAR-NK cells lacking IL-15 and BCMA-hIgG1-IL15 CAR-NK cells with an IgG1 hinge domain. We further assessed the cytotoxic capabilities of BCMA-2B4-IL15 CAR-NK cells with 2B4 intracellular domain. The BCMA-CD28-IL15 CAR-NK cells revealed stronger cytotoxicity and higher cytokine secretion against BCMA+ tumor cells than BCMA-2B4-IL15 CAR-NK cells in vitro. In the MM.1S-Luc mouse model, BCMA-CD28-IL15 CAR-NK inhibited the growth of tumor cells and prolonged mouse survival. These results show that the single VHH-directed BCMA CAR-NK cells exhibited remarkable specific killing ability, making them a potential candidate for immunotherapy in multiple myeloma treatment
Additional file 1 of Single VHH-directed BCMA CAR-NK cells for multiple myeloma
Supplementary Material
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