Benthic Habitat Quality Assessment in Estuarine Intertidal Flats Based on Long-Term Data with Focus on Responses to Eco-Restoration Activity

A long-term assessment of the benthic habitat quality of intertidal flats in Liaohe Estuary was conducted by three integrating ecological indices, AZTI’s Marine Biotic Index (AMBI), Multivariate-AMBI (M-AMBI), and Shannon–Wiener diversity index (H′) based on macrobenthos data from 2013 to 2020. The results showed that the macrobenthic communities were characterized by indifferent and sensitive species of AMBI ecological groups. The annual ranges of H′, AMBI, and M-AMBI were 0.77–1.56, 1.44–3.73 and 0.36–0.54, respectively. Noticeable differences were found among assessment obtained by these biotic indices. Approximately 100%, 24%, and 78% sampling sites had “moderate”, “poor”, and “bad” statuses as assessed by H′, AMBI, and M-AMBI, respectively. Compared with H′ and AMBI, M-AMBI may be more applicable to evaluate the benthic habitat quality of intertidal flats in Liaohe Estuary. Results suggest that the benthic habitat quality in the middle parts of intertidal flats still had an unacceptable status and has not improved radically to date after large-scale “mariculture ponds restored to intertidal flats”.publishedVersio

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$M_{\odot}$ 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

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

JUNO Sensitivity to Invisible Decay Modes of Neutrons

We explore the bound neutrons decay into invisible particles (e.g., $n\rightarrow 3 \nu$ or $nn \rightarrow 2 \nu$) in the JUNO liquid scintillator detector. The invisible decay includes two decay modes: $n \rightarrow { inv}$ and $nn \rightarrow { inv}$. The invisible decays of $s$-shell neutrons in $^{12}{\rm C}$ will leave a highly excited residual nucleus. Subsequently, some de-excitation modes of the excited residual nuclei can produce a time- and space-correlated triple coincidence signal in the JUNO detector. Based on a full Monte Carlo simulation informed with the latest available data, we estimate all backgrounds, including inverse beta decay events of the reactor antineutrino $\bar{\nu}_e$, natural radioactivity, cosmogenic isotopes and neutral current interactions of atmospheric neutrinos. Pulse shape discrimination and multivariate analysis techniques are employed to further suppress backgrounds. With two years of exposure, JUNO is expected to give an order of magnitude improvement compared to the current best limits. After 10 years of data taking, the JUNO expected sensitivities at a 90% confidence level are $\tau/B( n \rightarrow { inv} ) > 5.0 \times 10^{31} \, {\rm yr}$ and $\tau/B( nn \rightarrow { inv} ) > 1.4 \times 10^{32} \, {\rm yr}$.Comment: 28 pages, 7 figures, 4 table

727-2 Changes in Left Ventricular Mechanics and Energetics in Canine Microembolization Model of Heart Failure

Myocardial mechanics and energetics have been shown previously to be markedly abnormal in a canine model of pacing induced heart failure. However, whether those abnormalities pertain to other, more clinically relevant forms of heart failure is unknown. To investigate this question, heart failure was created by ischemic damage in 6 dogs (CHF group) that underwent repeated coronary microsphere injections over 2 months resulting in afinal area ejection fraction (aEF) of 34±4%. A control group of 6 normal dogs had an aEF of 46±8%, Hearts of these animals were isolated, cross-perfused and balloons placed in the LV to control volume. We measured the LV endsystolic (ESPVR) and end-diastolic (EDPVR) pressure-volume relations and the relationship between oxygen consumption (mVO2) and pressure-volume area (PVA). β-responsiveness of the CHF group was significantly depressed compared to control as assessed by the increased amount of isoproterenol required to increase peak isovolumic LV pressure by 40% (72±36 vs. 29±14pg/min, p<0.05) providing pharmacologic evidence of the heart failure state, CHF hearts had a depressed and dilated LV as assessed by the ESPVR slope, Ees, and volume axis intercept, Vo, (both normalized to LV mass) compared to control (TABLE). EDPVR of CHF hearts was shifted to the right compared to control. Systolic and diastolic stress-strain relationships. estimated from the pressure-volume relations. were similar in the two groups. These data suggest that with the degree of chronic ischemic damage achieved, there was systolic LV chamber dysfunction and chamber remodeling but not myocardial property changes in surviving muscle. The mVO2-PVA relation in CHF hearts had smaller mVO2-intercept (B)than control with no change in the slope (A)(TABLE). This contrasts with a previous report using a rapid pacing CHF model in which myocardial strength was decreased, Awas decreased and Bwas unchanged. These data suggest that 1) in spite of the notable structural and functional changes in chamber mechanics, energetic aspects of the failing heart remained unaltered in this model and 2) conclusions about myocardial energetics in CHF are model dependent.ESPVR: Ees mmHg/ml.l00gVo ml/l00gmVO2-PVA:AmlO2/mmHg/mlBmlO2/beat/l00gCHF3.9±1.2*6.9±5.3**(1.3±04)×10-50.030±0.005**Control47±1.90.5±2.9(1.3±0.6)×10-50.036±0.004*p<0.05.**p<0.01 vs. Control by ANCOV

Angiogenesis Is Enhanced in Ischemic Canine Myocardium by Transmyocardial Laser Revascularization 11This study was supported in part by a research grant from CardioGenesis Corporation, Sunnyvale, California.

AbstractObjectives. This study sought to test whether transmyocardial laser revascularization (TMLR) stimulates angiogenesis in an animal model of chronic ischemia.Background. TMLR relieves angina and may also improve blood flow in patients who are not candidates for traditional therapies. The mechanisms of these benefits are not fully defined.Methods. Ischemia was created in 14 dogs by proximal left anterior descending coronary ameroid constrictors. TMLR was performed in the anterior wall (∼1 channel/cm2) of seven dogs; the remaining dogs served as the ischemic control group. Myocardial blood flow was measured (colored microspheres) at rest and during chemical stress (adenosine) in the acute setting and after 2 months.Results. TMLR did not influence blood flow in the acute setting. After 2 months, resting blood flow increased comparably in the anterior wall in both groups to ∼80% of normal. However, the TMLR-treated dogs demonstrated an ∼40% increase in blood flow capacity during stress in the ischemic territory compared with untreated dogs (left anterior descending coronary artery/left circumflex coronary artery flow 0.53 ± 0.16 in the control group vs. 0.73 ± 0.08 in TMLR animals, p < 0.05). Vascular proliferation, assessed by bromodeoxyuridine incorporation and proliferating cell nuclear antigen positivity in endothelial and smooth muscle cells was about four times greater in the TMLR group than in the control group (p < 0.001). The density of vessels with at least one smooth muscle cell layer was ∼1.4 times greater in the myocardium surrounding the TMLR channel remnants than in control ischemic tissue (p < 0.001).Conclusions. In this canine model of chronic ischemia, TMLR significantly enhances angiogenesis as evidenced by the increased number of vessels lined with smooth muscle cells, markedly increased vascular proliferation and increased blood flow capacity during stress