GLOBAL RIGIDITY THEOREMS FOR SUBMANIFOLDS WITH PARALLEL MEAN CURVATURE

In this paper,we mainly study the global rigidity theorem of Riemannian submanifolds in space forms.Let Mn(n≥3)be a complete minimal submanifold in the unit sphere Sn+p(1).Forλ∈[0,n2−1/p),there is an explicit positive constant C(n,p,λ),depending only on n,p,λ,such that,if∫MSn/2dM<∞,∫M(S−λ)n/2+dM<C(n,p,λ),then Mn is a totally geodetic sphere,where S denotes the square of the second fundamental form of the submanifold and∫+=max{0,f}.Similar conclusions can be obtained for a complete submanifold with parallel mean curvature in the Euclidean space Rn+p.

Function of note strings in Japanese Tit alarm calls to the Common Cuckoo:a playback experiment

Background: Birds produce alarm calls to convey information about threats. Some Passerine alarm calls consist of several note strings, but few studies have examined their function. Previous studies have shown that Japanese Tits(Parus minor) can alter the calling rate and number and combination of notes in response to predators. We previously found the combinations of note types in Japanese Tit alarm calls to be significantly different in response to the Sparrowhawk(Accipiter nisus) and Common Cuckoo(Cuculus canorus).Methods: Through playback experiments, we tested whether the note strings in Japanese Tit alarm calls to the Common Cuckoo have different functions in conveying information. The note strings of selected alarm calls were divided into the categories of C and D, and different calls were then constructed separately based on the two note string categories. Original alarm calls(C–D), C calls and D calls were played back to male Japanese Tits during the incubation period.Results: Male Japanese Tits had a significantly stronger response to C calls than to C–D calls, and they showed a significantly stronger response to both C and C–D calls than to D calls, suggesting that Japanese Tits discriminated between the C and D calls.Conclusions: Our study demonstrated that the C-and D-category note strings of Japanese Tit alarm calls to the Common Cuckoo have different functions, which supports the previous finding that different note strings in an alarm call can provide different information to receivers. However, the exact meanings of these note strings are not yet known, and further investigation is therefore required.

Susceptibility gene for stroke or cerebral infarction in the Han population in Hunan Province of China

The scavenger receptor class B type I gene can protect against atherosclerosis; a mononucleotide polymorphism is associated with differences in blood lipid metabolism, postprandial serum lipid levels, insulin resistance, coronary artery disease and familial hyperlipidemia. In this study, the scavenger receptor class B type I gene exon 1 G4A gene polymorphism in atherosclerotic cerebral infarction patients, cerebral hemorrhage patients and normal controls was detected using the polymerase chain reaction-restriction fragment length polymorphism method. The results showed that the GA ＋ AA genotype frequency of scavenger receptor class B type I gene G4A in atherosclerotic cerebral infarction patients was similar to that in cerebral hemorrhage patients and normal controls; however, the A allele frequency was significantly lower than that in normal controls. The serum level of high-density lipoprotein cholesterol in patients with the scavenger receptor class B type I gene G4A GA ＋ AA genotype was significantly higher, while the serum level of low-density lipoprotein cholesterol was significantly lower than that in patients with the GG genotype, in both the atherosclerotic cerebral infarction and cerebral hemorrhage groups. The serum level of high-density lipoprotein cholesterol in patients with the scavenger receptor class B type I gene G4A GA ＋ AA genotype was significantly higher, while the serum levels of low-density lipoprotein cholesterol and total cholesterol were significantly lower than those in normal controls with the GG genotype. Our experimental results suggest that the G4A polymorphism of the scavenger receptor class B type I gene is a possible predisposing risk factor for atherosclerotic cerebral infarction, and that it has no association with cerebral hemorrhage in the Hart population in Hunan province of China. The A allele is possibly associated with the metabolism of high-density and low-density lipoprotein cholesterol.

The Influence of Survival Analysis on Runx3 Gene Expression in the Primary Tumor of Patients Suffering from Stomach Carcinoma

Background: Runt domain transcription factor 3 (Runx3) is a putative tumor suppressor in human neoplasia. Previous researches suggested that a lack of Runx3 function contributed to human gastric carcinogenesis, however, it is not clear whether Runx3 is closely associated with clinicopathological features of primary stomach tumor and survival rate of patients. Aims: The article is to investigate the influence of survival analysis on Runx3 gene expression in the primary stomach tumor. Methods: Runx3 mRNA expression was detected in 108 primary gastric tumors and non-tumor tissue by semiquantitative reverse transcription-PCR (RT-PCR). All patients were followed up more than five years after radical gastrectomy. Results: There was a loss or substantial decrease of Runx3 mRNA expression in 108 cases of gastric tumors as compared with that in normal gastric mucosa (p 0.001). According to the gray scale median of Runx3 mRNA in primary tumors, the 108 cases were separated into two groups: The lower expressing group (≤0.403) and the over one (>0.403). By comparing analysis of clinical information between two groups, it was found that the lower expression of Runx3 mRNA in the primary tumor was not only associated with the poor clinicopathological factors, but also the inferior survival duration and cumulative survival rate of patients (p 0.05). Conclusions: These results strongly suggest that Runx3 was an independent prognostic factor and a potential therapeutic target for gastric cancer.

Phytohormones Accumulation and Distribution in Shoots and Roots of Haploid,Diploid and Tetraploid Barley Seedlings Derived from Microspore Culture

Phytohormones play important roles in plant growth and development,and polyploids are thought to be an important method for plant breeding.However,the relationship between ploidy and phytohormone is still unclear.In this study,barley at three ploidy levels were produced by microspore culture.Therefore,we further analyzed the phytohormone content in the shoots and roots of the three kinds of barley materials to study the effect of ploidy on phytohormones accumulation and distribution.The results showed that Abscisic acid(ABA),gibberellin(GA),jasmonic acid(JA),auxin(IAA),salicylic acid(SA)and cytokinin(CTK)were successfully determined in shoots and roots using LC-MS(liquid chromatography mass spectrometry).By comparing the shoots of the haploid and diploid plants,it was found that the distribution trend of the six phytohormones was consistent,and another consistent trend was found in the roots of the diploid and tetraploid plants.In addition,we further analyzed the shoot/root ratio of the different phytohormones to identify the potential differences for haploid,diploid and tetraploid.Here,the relationship between ploidy and phytohormone we provided would provide new insights into understanding the new phenotypes that occur in polyploid species.

Transcriptome Profiling of Barley Cultivar Hua 30 MDEC in Response to Agrobacterium Infection

Agrobacterium-mediated transformation has been widely used in plants.However,the mechanism in plant cells’response to Agrobacterium infection was very complex.The mechanism of the determinants in host cell remains obscure,especially in barley,which is recalcitrant for Agrobacterium-mediated transformation.In the present study,microspore-derived embryogenic calli(MDEC)from barley elite cultivar were employed as unique subjects to characterize the mechanisms during the Agrobacterium infection process.Hua 30 MDEC can be successfully infected by Agrobacterium.RNA-sequencing at different infection points(0,2,6,12,24 hpi)was performed.The average expressional intensity of the whole genomics increased from 0 to 2 hpi,and then decreased subsequently.More upregulated than downregulated differentially expressed genes(DEGs)were counted at the same time.GO enrichment analysis showed that protein modification was significantly overrepresented in upregulated DEGs.Chromosome-related biological processes,gene expression and cellular metabolic processes were significantly overrepresented in downregulated DEGs.KEGG analysis showed that plant defense responses,phenylpropanoid biosynthesis and biosynthesis of amino acids were significantly enriched across the infection time course.Nine DEGs related to defense responses were identified.All DEGs were upregulated from 2 to 24 hpi.We speculate that these genes are possibly related to Agrobacterium infection.These findings will provide deep insights into the molecular events occurring during the process of Agrobacterium-mediated transformation.

On the Protective Effects of Aplysin on Ethanol-induced Oxidative Damage in Rat Primary Hepatocytes

[Objective] To investigate the protective effects of Aplysin on ethanol-induced oxidative damage in rat primary hepatocytes.[Methods]Rat primary hepatocytes were obtained via the portal vein collagenase IV in situ perfusion technique followed by a Percoll density gradient centrifuge; MTT test was used to determine the optimum dose of Aplysin and ethanol,and detect the cell vitality in primary hepatocytes; supernatants of primary hepatocytes were harvested to measure AST and LDH level,and the SOD,GSH-PX activities and MDA content in primary hepatocytes were observed; flow cytometry was used to detect the cell apoptosis rate; DNA damage in primary hepatocytes were detected by single-cell gel electrophoresis assay; The level of mitochondrial membrane potential in primary hepatocytes was tested by fluorogenic probe JC-1; the CYP2E1 activity in primary hepatocytes were detected by colorimetry; the proteins of CYP2E1 were detected by Western blotting. [Results]300 mmol/L dose of ethanol and 30 mg/L dose of Aplysin were the optimal dosages and were used in the subsequent experiments. Hepatocyte vitality was significantly increased in the Aplysin group relative to that in the ethanol group,and Aplysin inhibited the release of AST and LDH( P < 0. 05). For the Aplysin treatment group,the activities of hepatocyte SOD and GSH were significantly increased and MDA was markedly lowered as compared with those in the ethanol group( P < 0. 05). And Aplysin can alleviate hepatocyte apoptosis significantly,and hepatocyte DNA damage rate of II-III level and IV level were significantly lowered in the Aplysin treatment group as compared with those in the ethanol group,and Aplysin has evidently improved on alcohol induced mitochondria damage of hepatocyte. Primary hepatocytes activities and protein expression of CYP2E1 were markedly lowered in the Aplysin treatment group as compared with those in the ethanol group( P < 0. 05). [Conclusion] Aplysin has protective effects on liver oxidative damage induced by alcohol of primary cultured rat hepatocytes by blocking CYP2E1 activation,relieving oxidative stress,and sharpening the oxidation resistance ability.

A graph-based pan-genome of Brassica oleracea provides new insights into its domestication and morphotype diversification

The domestication of Brassica oleracea has resulted in diverse morphological types with distinct patterns of organ development.Here we report a graph-based pan-genome of B.oleracea constructed from high-quality genome assemblies of different morphotypes.The pan-genome harbors over 200 structural variant hotspot regions enriched in auxin-andflowering-related genes.Population genomic analyses revealed that early domestication of B.oleracea focused on leaf or stem development.Geneflows resulting from agricultural practices and variety improvement were detected among different morphotypes.Selective-sweep and pan-genome analyses identified an auxin-responsive small auxin up-regulated RNA gene and a CLAV-ATA3/ESR-RELATED family gene as crucial players in leaf–stem differentiation during the early stage of B.oleracea domestication and the BoKAN1 gene as instrumental in shaping the leafy heads of cabbage and Brussels sprouts.Our pan-genome and functional analyses further revealed that variations in the BoFLC2 gene play key roles in the divergence of vernalization andflowering characteristics among different morphotypes,and variations in thefirst intron of BoFLC3 are involved infine-tuning theflowering process in cauliflower.This study provides a comprehensive understanding of the pan-genome of B.oleracea and sheds light on the domestication and differential organ development of this globally important crop species.

Simulation study on the security of consensus algorithms in DAG-based distributed ledger

Due to the advantages of high volume of transactions and low resource consumption,Directed Acyclic Graph(DAG)-based Distributed Ledger Technology(DLT)has been considered a possible next-generation alternative to blockchain.However,the security of the DAG-based system has yet to be comprehensively understood.Aiming at verifying and evaluating the security of DAG-based DLT,we develop a Multi-Agent based IOTA Simulation platform called MAIOTASim.In MAIOTASim,we model honest and malicious nodes and simulate the configurable network environment,including network topology and delay.The double-spending attack is a particular security issue related to DLT.We perform the security verification of the consensus algorithms under multiple double-spending attack strategies.Our simulations show that the consensus algorithms can resist the parasite chain attack and partially resist the splitting attack,but they are ineffective under the large weight attack.We take the cumulative weight difference of transactions as the evaluation criterion and analyze the effect of different consensus algorithms with parameters under each attack strategy.Besides,MAIOTASim enables users to perform largescale simulations with multiple nodes and tens of thousands of transactions more efficiently than state-of-the-art ones.

球面中极小超曲面的陈省身猜想及其相关问题

本文介绍关于球面中极小超曲面的陈省身猜想及其相关问题.首先,本文扼要地回顾陈省身猜想的问题背景.其次,本文着重介绍关于球面中常数量曲率极小超曲面的陈省身猜想以及关于球面中极小超曲面的陈省身猜想的研究成果.最后,本文进一步讨论关于球面中常平均曲率超曲面和球面中高余维极小子流形的两类广义陈省身猜想的进展.

Individualized red-cell transfusion strategy for non-cardiac surgery in adults:a randomized controlled trial

Background:Red-cell transfusion is critical for surgery during the peri-operative period;however,the transfusion threshold remains controversial mainly owing to the diversity among patients.The patient’s medical status should be evaluated before making a transfusion decision.Herein,we developed an individualized transfusion strategy using the West-China-Liu’s Score based on the physiology of oxygen delivery/consumption balance and designed an open-label,multicenter,randomized clinical trial to verify whether it reduced red cell requirement as compared with that associated with restrictive and liberal strategies safely and effectively,providing valid evidence for peri-operative transfusion.Methods:Patients aged>14 years undergoing elective non-cardiac surgery with estimated blood loss>1000 mL or 20%blood volume and hemoglobin concentration<10 g/dL were randomly assigned to an individualized strategy,a restrictive strategy following China’s guideline or a liberal strategy with a transfusion threshold of hemoglobin concentration<9.5 g/dL.We evaluated two primary outcomes:the proportion of patients who received red blood cells(superiority test)and a composite of in-hospital complications and all-cause mortality by day 30(non-inferiority test).Results:We enrolled 1182 patients:379,419,and 384 received individualized,restrictive,and liberal strategies,respectively.Approximately 30.6%(116/379)of patients in the individualized strategy received a red-cell transfusion,less than 62.5%(262/419)in the restrictive strategy(absolute risk difference,31.92%;97.5%confidence interval[CI]:24.42-39.42%;odds ratio,3.78%;97.5%CI:2.70-5.30%;P<0.001),and 89.8%(345/384)in the liberal strategy(absolute risk difference,59.24%;97.5%CI:52.91-65.57%;odds ratio,20.06;97.5%CI:12.74-31.57;P<0.001).No statistically significant differences were found in the composite of in-hospital complications and mortality by day 30 among the three strategies.Conclusion:The individualized red-cell transfusion strategy using the West-China-Liu’s Score reduced red-cell transfusion without increasing in-hospital complications and mortality by day 30 when compared with restrictive and liberal strategies in elective non-cardiac surgeries.Trial registration:ClinicalTrials.gov,NCT01597232.

A multifunctional optoelectronic device based on 2D material with wide bandgap

Low-dimensional materials exhibit unique quantum confinement effects and morphologies as a result of their nanoscale size in one or more dimensions,making them exhibit distinctive physical properties compared to bulk counterparts.Among all low-dimensional materials,due to their atomic level thickness,two-dimensional materials possess extremely large shape anisotropy and consequently are speculated to have large optically anisotropic absorption.In this work,we demonstrate an optoelectronic device based on the combination of two-dimensional material and carbon dot with wide bandgap.High-efficient luminescence of carbon dot and extremely large shape anisotropy(>1500)of two-dimensional material with the wide bandgap of>4 eV cooperatively endow the optoelectronic device with multi-functions of optically anisotropic blue-light emission,visible light modulation,wavelength-dependent ultraviolet-light detection as well as blue fluorescent film assemble.This research opens new avenues for constructing multi-function-integrated optoelectronic devices via the combination of nanomaterials with different dimensions.

Soil fauna accelerated litter C and N release by improving litter quality across an elevational gradient

Background Soil fauna is an important driver of carbon(C)and nitrogen(N)release from decomposing litter in forest ecosystems.However,its role in C and N cycling concerning climate and litter traits remains less known.In a 4-year field experiment,we evaluated the effects of soil fauna on litter C and N release across an elevation gradient(453,945,3023,and 3582 m)and litter traits(coniferous vs.broadleaf)in southwestern China.Results Our results showed that N was retained by–0.4%to 31.5%,but C was immediately released during the early stage(156–516 days)of decomposition for most litter species.Soil fauna significantly increased the peak N content and N retention across litter species,but reduced the C/N ratio for certain species(i.e.,Juniperus saltuaria,Betula albosinensis,Quercus acutissima,and Pinus massoniana litter),leading to more C and N being released from decomposing litter across the elevation gradient.Contributions of soil fauna to C and N release were 3.87–9.90%and 1.10–8.71%,respectively,across litter species after 4 years of decomposition.Soil environment and initial litter quality factors caused by elevation directly affected litter C and N release.Changes in soil fauna resulting from elevation and fauna exclusion factors had a direct or indirect impact on C and N release during litter decomposition.Conclusions Our findings suggest that soil fauna promote C and N release from decomposing litter in different magnitudes,mainly controlled by environmental conditions(i.e.,temperature and moisture),litter quality(i.e.,lignin and cellulose content,and lignin/cellulose),and its diversity across the elevation gradient.

Mean Curvature Flow of Arbitrary Codimension in Complex Projective Spaces

Recently,Pipoli and Sinestrari[Pipoli,G.and Sinestrari,C.,Mean curvature flow of pinched submanifolds of CPn,Comm.Anal.Geom.,25,2017,799-846]initiated the study of convergence problem for the mean curvature flow of small codimension in the complex projective space CPm.The purpose of this paper is to develop the work due to Pipoli and Sinestrari,and verify a new convergence theorem for the mean curvature flow of arbitrary codimension in the complex projective space.Namely,the authors prove that if the initial submanifold in CPm satisfies a suitable pinching condition,then the mean curvature flow converges to a round point in finite time,or converges to a totally geodesic submanifold as t→∞.Consequently,they obtain a differentiable sphere theorem for submanifolds in the complex projective space.

Soil legacy effects and plant-soil feedback contribution to secondary succession processes

Secondary succession is the process by which a community develops into a climax community over time.However,knowledge on the mechanisms,relating to soil legacy effects(soil chemistry and enzyme activity)and plant-soil feedback(PSF),driving community succession remains limited.In this work,we examined the PSF associated with three succession stage species through a 2-year greenhouse experiment.Setaria viridis,Stipa bungeana,and Bothriochloa ischemum were selected to represent dominant and representative early-,mid-,and late-successional stage species,respectively,of semiarid grasslands on the Loess Plateau.In response to the different soil origin,the shoot biomass of early-,mid-,and late-species were all higher when grown in their own soil than in other species’soils,which indicated that the PSF of three species were positive.Over two growth periods,the early-species experienced a negative PSF,but the mid-and late-species experienced negative,neutral and positive PSF in the soil of early-,mid-and late-species,respectively.Our study demonstrates that soil legacy effects and PSF have a significant impact on community succession processes.

教育资源再配置与创新研发——基于高校合并的视角

本文基于20世纪90年代开始的高校合并政策,研究高等教育资源再配置对高校创新研发活动的影响。研究发现,高校合并显著提高了高校创新研发产出,且部属院校所受的影响更大。机制分析表明,高校合并通过影响科研经费投入、学科发展水平和基础研发能力进而增加创新研发产出。进一步讨论发现,规模依赖和互补类型的高校合并对创新研发的影响效应更大。本文对于当前深化高等教育综合改革,激发高校创新研发潜能和建设“双一流”高校具有启示意义。

On the generalized Chern conjecture for hypersurfaces with constant mean curvature in a sphere

Let M be a compact hypersurface with constant mean curvature in Denote by H and S the mean curvature and the squared norm of the second fundamental form of M,respectively.We verify that there exists a positive constantγ(n)depending only on n such that if|H|≤γ(n)andβ(n,H)≤S≤β(n,H)+n/18,then S≡β(n,H)and M is a Clifford torus.Here,β(n,H)=n+n^(3)/2(n-1)H^(2)+n(n-2)/2(n-1)(1/2)n^(2)H^(4)+4(n-1)H^(2).

A new pinching theorem for complete self-shrinkers and its generalization

In this paper,we firstly verify that if Mn is an n-dimensional complete self-shrinker with polynomial volume growth in Rn+1,and if the squared norm of the second fundamental form of M satisfies 0≤S-1≤1/18,then S≡1 and M is a round sphere or a cylinder.More generally,let M be a complete λ-hypersurface of codimension one with polynomial volume growth in Rn+1 with λ≠0.Then we prove that there exists a positive constant γ,such that if |λ|≤γ and the squared norm of the second fundamental form of M satisfies0≤S-βλ≤1/18,then S≡βλ,λ> 0 and M is a cylinder.Here βλ=1/2(2+λ2+|λ|(λ2+4)1/2).

The Environmental Consequences of Place-Based Policies in China:An Empirical Study Based on SO_(2)Emission Data

Previous studies of place-based policies in China have ignored their effect on pollution.Using event study and difference-in-differences methodologies,we investigated the consequences of place-based policies on sulfur dioxide(SO_(2))emissions.We first documented the increase in SO_(2)emissions and SO_(2)emission intensity in the inland region after 2003 at the provincial level.The firm-level data for the period between 1998 and 2010 also showed that the performance of enterprises in noneastern regions in reducing SO_(2)emissions had worsened relatively since 2003,and this effect was particularly strong in enterprises located in central and northeast China,where urban land supply experienced significant growth after 2003.We found that,compared with environmental regulation changes,inland region-biased economic policies after 2003 were more important in explaining the relative changes in SO_(2)emissions between coastal and inland regions.The policy implication is that the central government should address environmental consequences when designing place-based economic policies.

Migration characteristics and profile control capabilities of preformed particle gel in porous media

Inspired by the viscoelastic displacement theory,a product called preformed particle gel(PPG)is developed as conformance control agent to enhance oil recovery and control excess water production.The migration law of PPG suspension in porous media is related to its deep profile control and displacement capability.Laboratory experiments indicate that PPG suspension has good viscosity increasing,and the apparent viscosity decreases with the increase of shear rate.PPG suspension is mainly elastic,and its network structure makes it have certain shear stability.PPG particles realize migration in porous media in the way of“accumulation and blockage/pressure increase/deformation and migration”.When the ratio of the PPG particle size to the pore throat diameter d ranges from 35.52 to 53.38,the particles can match through the porous medium.When the permeability difference of the parallel model is 5,PPG suspension has the highest profile improvement rate,69.10%.PPG suspension can adjust the planar heterogeneity,and increase the oil recovery rate by 20.75%.The PPG suspension can effectively start“cluster"、“film”and“blind end residual oil”,and has a high oil washing efficiency.The core NMR T2 spectrum shows that PPG suspension mainly reduces oil saturation in mesopores and macropores.After PPG flooding,the EOR capacity of small pores is the highest,39.11%.