133 research outputs found

    Self-Closeness Numbers of Rational Mapping Spaces

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    For a closed connected oriented manifold MM of dimension 2n2n, it was proved by M\o ller and Raussen that the components of the mapping space from MM to S2nS^{2n} have exactly two different rational homotopy types. However, since this result was proved by the algebraic models for the components, it is unclear whether other homotopy invariants distinguish their rational homotopy types or not. The self-closeness number of a connected CW complex is the least integer kk such that any of its self-map inducing an isomorphism in π\pi_* for k*\le k is a homotopy equivalence, and there is no result on the components of mapping spaces so far. For a rational Poincar\'e complex XX of dimension 2n2n with finite π1\pi_1, we completely determine the self-closeness numbers of the rationalized components of the mapping space from XX to S2nS^{2n} by using their Brown-Szczarba models. As a corollary, we show that the self-closeness number does distinguish the rational homotopy types of the components. Since a closed connected oriented manifold is a rational Poincar\'e complex, our result partially generalizes that of M\o ller and Raussen

    Homotopy commutativity in symmetric spaces

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    We extend the former results of Ganea and the two of the authors with Takeda on the homotopy commutativity of the loop spaces of Hermitian symmetric spaces such that the loop spaces of all irreducible symmetric spaces but CP3\mathbb{C}P^3 are not homotopy commutative.Comment: 11page

    Homotopy commutativity in quasitoric manifolds

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    We prove that the loop space of a quasitoric manifold is homotopy commutative if and only if the underlying polytope is (Δ3)n(\Delta^3)^n and the characteristic matrix is equivalent to a matrix of certain type. We also construct for each n2n\ge 2 and a positive integer kk, a quasitoric manifold M(k,n)M(k,n) over (Δ3)n(\Delta^3)^n such that its loop space is homotopy commutative if and only if kk is even, where every quasitoric manifold over Δ3\Delta^3 is equivalent to CP3\mathbb{C} P^3 whose loop space is homotopy commutative.Comment: 14 page

    Buddhist monasteries facilitated landscape conservation on the Qinghai-Tibetan Plateau

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    Context: The Sanjiangyuan region of the Qinghai-Tibetan Plateau—also known as the “Three Rivers’ Headwaters”—is the origin of the Yellow, Yangtze, and Mekong Rivers and therefore the key water source for hundreds of millions of downstream residents. Protecting this region’s ecosystems is a key priority for sustainable development in China and Asia. An important social dimension of Sanjiangyuan is the long-established and widespread presence of Tibetan Buddhism, particularly as manifested in the large number of monasteries throughout the region. However, the influence of cultural factors on environmental change remains largely understudied here. / Objective: We focus on two types of spatial associations—point-point and point-area features—to quantitatively investigate the effects of Buddhist monasteries on land use/cover change (LUCC) in surrounding landscapes. / Methods: We conduct a spatially-explicit analysis of Sanjiangyuan for two periods, 1990–2000 and 2010–2015, to identify and quantify the influence of the presence and spatial distributions of Buddhist monasteries on LUCC compared to village communities that lack monasteries. / Results: We found that the presence of monasteries is highly correlated with the preservation of natural ecosystems, specifically of grasslands and forests. Within monastery buffer zones with radii between 1 and 10 km, 7.13–9.30% more grassland area and 7.14–7.47% more forest area remained around monasteries compared to villages. This contrast decreased with increasing distance to the monastery/village. Overall, built-up areas were also much smaller around monasteries than around villages, while unused land was more commonly transformed to forests and grasslands around monasteries. / Conclusions: These findings strongly support the idea that Buddhist culture, as manifested through its physical institutions and communities, are instrumental in achieving desired landscape conservation outcomes

    A cross-sectional study of non-suicidal self-injury in a Chinese adolescent inpatient cohort

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    BackgroundNon-suicidal self-injury (NSSI) is a significant predictor of completed suicide and is increasingly recognized as a serious public health concern. Multiple factors, including social, familial, mental, and genetic factors could influence the occurrence of this behavior. Identifying the early risk factors is important for screening and preventing this behavior.MethodsHere, we recruited a total of 742 adolescent inpatient participants from a mental health center and conducted a series of diagnostic interviews and questionnaires to assess NSSI behavior and other events. Bivariate analysis was used to detect differences between groups in NSSI and non-NSSI. Then, binary logistic regression was fitted to identify predictors of NSSI as a function of these questionnaire scores.ResultsOf the 742 adolescents examined, a total of 382 (51.5%) participants engaged in NSSI. Bivariate analysis showed that age, gender, depression, anxiety, insomnia, and childhood trauma was significantly associated with NSSI. Logistic regression results suggested that females had 2.43 higher odds of engaging in NSSI when compared to their male counterparts (OR = 3.43, 95%CI = 2.09–5.74, p = 1.70 × 10−6). Depression was a primary risk predictor for NSSI with each additional increase in symptoms of depression increasing the odds of engaging in NSSI by 18% (OR = 1.18, 95%CI = 1.12–1.25, p = 2.25 × 10−8).ConclusionMore than half of the adolescent inpatients with psychiatric disorders have NSSI experience. Depression and gender were the risk factors for NSSI. Age at a specific range had a high prevalence of NSSI

    Characteristics of enzymolysis of silkworm pupa protein after tri-frequency ultrasonic pretreatment: kinetics, thermodynamics, structure and antioxidant changes

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    As a by-product of the sericulture industry, the utilization rate of silkworm pupa resources is currently not high. Proteins are converted into bioactive peptides through enzymatic hydrolysis. Not only can it solve the utilization problem, but it also creates more valuable nutritional additives. Silkworm pupa protein (SPP) was pretreated with tri-frequency ultrasonic (22/28/40 kHz). Effects of ultrasonic pretreatment on enzymolysis kinetics, enzymolysis thermodynamics, hydrolysate structure as well as hydrolysate antioxidant of SPP were investigated. Ultrasonic pretreatment significantly increased the hydrolysis efficiency, showing a 6.369% decrease in km and a 16.746% increase in kA after ultrasonic action (p < 0.05). The SPP enzymolysis reaction followed a second-order rate kinetics model. Evaluation of enzymolysis thermodynamics revealed that Ultrasonic pretreatment markedly enhanced the SPP enzymolysis, leading to a 21.943% decrease in Ea. Besides, Ultrasonic pretreatment significantly increased SPP hydrolysate’s surface hydrophobicity, thermal stability, crystallinity, and antioxidant activities (DPPH radical scavenging activity, Fe2+ chelation ability, and reducing power). This study indicated that tri-frequency ultrasonic pretreatment could be an efficient approach to enhancing the enzymolysis and improving the functional properties of SPP. Therefore, tri-frequency ultrasound technology can be applied industrially to enhance enzyme reaction process

    Optimizing postbiotic production through solid-state fermentation with Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 enhances antibacterial, antioxidant, and anti-inflammatory activities

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    BackgroundPostbiotics are an emerging research interest in recent years and are fairly advanced compared to prebiotics and probiotics. The composition and function of postbiotics are closely related to fermentation conditions.MethodsIn this study, we developed a solid-state fermentation preparation method for postbiotics with antimicrobial, antioxidant, and anti-inflammatory activities. The antibacterial activity was improved 3.62 times compared to initial fermentation conditions by using optimization techniques such as single factor experiments, Plackett–Burman design (PBD), steepest ascent method (SAM), and central composite design (CCD) methods. The optimized conditions were carried out with an initial water content of 50% for 8 days at 37°C and fermentation strains of Bacillus amyloliquefaciens J and Lactiplantibacillus plantarum SN4 at a ratio of 1:1 with a total inoculum size of 8%. The optimized SSF medium content ratios of peptide powder, wheat bran, corn flour, and soybean meal were 4, 37.4, 30, and 28.6%, respectively.ResultsUnder these optimized conditions, postbiotics with a concentration of 25 mg/mL showed significant broad-spectrum antibacterial capabilities against Escherichia coli, Salmonella, and Staphylococcus aureus and strong antioxidant activity against ABTS, DPPH, and OH radicals. Moreover, the optimized postbiotics exhibited good anti-inflammatory ability for reducing nitric oxide (NO) secretion in RAW 264.7 macrophage cells in response to LPS-induced inflammation. Furthermore, the postbiotics significantly improved intestinal epithelial wound healing capabilities after mechanical injury, such as cell scratches in IPEC-J2 cells (p < 0.05).ConclusionIn brief, we developed postbiotics through optimized solid-state fermentation with potential benefits for gut health. Therefore, our findings suggested that the novel postbiotics could be used as potential functional food products for improving body health

    Real-time Monitoring for the Next Core-Collapse Supernova in JUNO

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    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 30MM_{\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

    Search for dark matter produced in association with bottom or top quarks in √s = 13 TeV pp collisions with the ATLAS detector

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    A search for weakly interacting massive particle dark matter produced in association with bottom or top quarks is presented. Final states containing third-generation quarks and miss- ing transverse momentum are considered. The analysis uses 36.1 fb−1 of proton–proton collision data recorded by the ATLAS experiment at √s = 13 TeV in 2015 and 2016. No significant excess of events above the estimated backgrounds is observed. The results are in- terpreted in the framework of simplified models of spin-0 dark-matter mediators. For colour- neutral spin-0 mediators produced in association with top quarks and decaying into a pair of dark-matter particles, mediator masses below 50 GeV are excluded assuming a dark-matter candidate mass of 1 GeV and unitary couplings. For scalar and pseudoscalar mediators produced in association with bottom quarks, the search sets limits on the production cross- section of 300 times the predicted rate for mediators with masses between 10 and 50 GeV and assuming a dark-matter mass of 1 GeV and unitary coupling. Constraints on colour- charged scalar simplified models are also presented. Assuming a dark-matter particle mass of 35 GeV, mediator particles with mass below 1.1 TeV are excluded for couplings yielding a dark-matter relic density consistent with measurements
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