81 research outputs found

    Global Weinstein Type Theorem on Multiple Rotating Periodic Solutions for Hamiltonian Systems

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    This paper concerns the existence of multiple rotating periodic solutions for 2n2n dimensional convex Hamiltonian systems. For the symplectic orthogonal matrix QQ, the rotating periodic solution has the form of z(t+T)=Qz(t)z(t+T)=Qz(t), which might be periodic, anti-periodic, subharmonic or quasi-periodic according to the structure of QQ. It is proved that there exist at least nn geometrically distinct rotating periodic solutions on a given convex energy surface under a pinched condition, so our result corresponds to the well known Ekeland and Lasry's theorem on periodic solutions. It seems that this is the first attempt to solve the symmetric quasi-periodic problem on the global energy surface. In order to prove the result, we introduce a new index on rotating periodic orbits.Comment: arXiv admin note: text overlap with arXiv:1812.0583

    Characteristics and drivers of plant C, N, and P stoichiometry in Northern Tibetan Plateau grassland

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    Understanding vegetation C, N, and P stoichiometry helps us not only to evaluate biogeochemical cycles and ecosystem functions but also to predict the potential impact of environmental change on ecosystem processes. The foliar C, N, and P stoichiometry in Northern Tibetan grasslands, especially the controlling factors, has been highlighted in recent years. In this study, we have collected 340 plant samples and 162 soil samples from 54 plots in three grassland types, with the purpose of evaluating the foliar C, N, and P stoichiometry and underlying control factors in three grassland types along a 1,500-km east-to-west transect in the Northern Tibetan Plateau. Our results indicated that the averaged foliar C, N, and P concentrations were 425.9 Β± 15.8, 403.4 Β± 22.2, and 420.7 Β± 30.7Β g kgβˆ’1; 21.7 Β± 2.9, 19.0 Β± 2.3, and 21.7 Β± 5.2Β g kgβˆ’1; and 1.71 Β± 0.29, 1.19 Β± 0.16, and 1.59 Β± 0.6Β g kgβˆ’1 in the alpine meadow (AM), alpine steppe (AS), and desert steppe (DS) ecosystems, respectively. The foliar C and N ratios were comparable, with values of 19.8 Β± 2.8, 20.6 Β± 1.9, and 19.9 Β± 5.8 in the AM, AS, and DS ecosystems, respectively. Both the C/P and N/P ratios are the lowest in the AM ecosystem, with values of 252.2 Β± 32.6 and 12.8 Β± 1.3, respectively, whereas the highest values of 347.3 Β± 57.0 and 16.2 Β± 3.2 were obtained in the AS ecosystem. In contrast, the soil C, N, C/P, and N/P values decreased from the AM to DS ecosystem. Across the whole transects, leaf C, N, and P stoichiometry showed no obvious trend, but soil C and N concentrations showed an increasing trend, and soil P concentrations showed a decreasing trend with the increasing longitude. Based on the general linear model analysis, the vegetation type was the dominant factor controlling the leaf C, N, and P stoichiometry, accounting for 42.8% for leaf C, 45.1% for leaf N, 35.2% for leaf P, 52.9% for leaf C/N, 39.6% for leaf C/P, and 48.0% for leaf N/P; the soil nutrients and climate have relatively low importance. In conclusion, our results supported that vegetation type, rather than climatic variation and soil nutrients, are the major determinants of north Tibet grassland leaf stoichiometry

    Energy coverage in wireless powered sub-6 GHz and millimeter wave dense cellular networks

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    This paper focuses on the energy coverage in wireless powered sub-6 GHz and millimeter wave (mmWave) dense cellular networks, where mobile devices harvest RF energy from sub-6 GHz or mmWave base stations (BSS). The expressions for energy coverage probability in sub-6 GHz and mmWave tiers are respectively derived. The comparisons between sub-6 GHz and mmWave RF energy harvesting are analyzed. In particular, we provide the sufficient conditions for the case that wireless energy harvesting in mmWave tier is better than that in sub-6 GHz tier. Furthermore, in hybrid cellular networks with mode selection mechanism, the probability that a mobile device selects a sub-6 GHz BS or mmWave BS for wireless power transfer is also theoretically obtained

    Bufei Huoxue capsule attenuates COPD-related inflammation and regulates intestinal microflora, metabolites

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    Background: Bufei Huoxue capsule (BFHX) is widely used for the clinical treatment of chronic obstructive pulmonary disease (COPD) in China.Objectives: The aim of this study is to explore the effects on COPD and the underlying mechanism of BFHX.The process and methods: In this study, we established a COPD mouse model through cigarette smoke (CS) exposure in combination with lipopolysaccharide (LPS) intratracheal instillation. Subsequently, BFHX was orally administrated to COPD mice, and their pulmonary function, lung pathology, and lung inflammation, including bronchoalveolar lavage fluid (BALF) cell count and classification and cytokines, were analyzed. In addition, the anti-oxidative stress ability of BFHX was detected by Western blotting, and the bacterial diversity, abundance, and fecal microbiome were examined using 16S rRNA sequencing technology.Outcome: BFHX was shown to improve pulmonary function, suppress lung inflammation, decrease emphysema, and increase anti-oxidative stress, whereas 16S rRNA sequencing indicated that BFHX can dynamically regulate the diversity, composition, and distribution of the intestinal flora microbiome and regulate the lysine degradation and phenylalanine metabolism of COPD mice. These results highlight another treatment option for COPD and provide insights into the mechanism of BFHX

    The genome of broomcorn millet

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    Broomcorn millet (Panicum miliaceum L.) is the most water-efficient cereal and one of the earliest domesticated plants. Here we report its high-quality, chromosome-scale genome assembly using a combination of short-read sequencing, single-molecule real-time sequencing, Hi-C, and a high-density genetic map. Phylogenetic analyses reveal two sets of homologous chromosomes that may have merged ~5.6 million years ago, both of which exhibit strong synteny with other grass species. Broomcorn millet contains 55,930 proteincoding genes and 339 microRNA genes. We find Paniceae-specific expansion in several subfamilies of the BTB (broad complex/tramtrack/bric-a-brac) subunit of ubiquitin E3 ligases, suggesting enhanced regulation of protein dynamics may have contributed to the evolution of broomcorn millet. In addition, we identify the coexistence of all three C4 subtypes of carbon fixation candidate genes. The genome sequence is a valuable resource for breeders and will provide the foundation for studying the exceptional stress tolerance as well as C4 biology

    Genetic Polymorphisms in CYP2E1: Association with Schizophrenia Susceptibility and Risperidone Response in the Chinese Han Population

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    CYP2E1 is a member of the cytochrome P450 superfamily, which is involved in the metabolism and activation of both endobiotics and xenobiotics. The genetic polymorphisms of CYP2E1 gene (Chromosome 10q26.3, Accession Number NC_000010.10) are reported to be related to the development of several mental diseases and to be involved in the clinical efficacy of some psychiatric medications. We investigated the possible association of CYP2E1 polymorphisms with susceptibility to schizophrenia in the Chinese Han Population as well as the relationship with response to risperidone in schizophrenia patients.In a case-control study, we identified 11 polymorphisms in the 5' flanking region of CYP2E1 in 228 schizophrenia patients and 384 healthy controls of Chinese Han origin. From among the cases, we chose 130 patients who had undergone 8 weeks of risperidone monotherapy to examine the relationship between their response to risperidone and CYP2E1 polymorphisms. Clinical efficacy was assessed using the Brief Psychiatric Rating Scale (BPRS).Statistically significant differences in allele or genotype frequencies were found between cases and controls at rs8192766 (genotype pβ€Š=β€Š0.0048, permutation pβ€Š=β€Š0.0483) and rs2070673 (allele: pβ€Š=β€Š0.0018, permutation pβ€Š=β€Š0.0199, ORβ€Š=β€Š1.4528 95%CIβ€Š=β€Š1.1487-1.8374; genotype: pβ€Š=β€Š0.0020, permutation pβ€Š=β€Š0.0225). In addition, a GTCAC haplotype containing 5 SNPs (rs3813867, rs2031920, rs2031921, rs3813870 and rs2031922) was observed to be significantly associated with schizophrenia (pβ€Š=β€Š7.47E-12, permutation p<0.0001). However, no association was found between CYP2E1 polymorphisms/haplotypes and risperidone response.Our results suggest that CYP2E1 may be a potential risk gene for schizophrenia in the Chinese Han population. However, polymorphisms of the CYP2E1 gene may not contribute significantly to individual differences in the therapeutic efficacy of risperidone. Further studies in larger groups are warranted to confirm our results

    A Framework for Detecting False Data Injection Attacks in Large-Scale Wireless Sensor Networks

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    False data injection attacks (FDIAs) on sensor networks involve injecting deceptive or malicious data into the sensor readings that cause decision-makers to make incorrect decisions, leading to serious consequences. With the ever-increasing volume of data in large-scale sensor networks, detecting FDIAs in large-scale sensor networks becomes more challenging. In this paper, we propose a framework for the distributed detection of FDIAs in large-scale sensor networks. By extracting the spatiotemporal correlation information from sensor data, the large-scale sensors are categorized into multiple correlation groups. Within each correlation group, an autoregressive integrated moving average (ARIMA) is built to learn the temporal correlation of cross-correlation, and a consistency criterion is established to identify abnormal sensor nodes. The effectiveness of the proposed detection framework is validated based on a real dataset from the U.S. smart grid and simulated under both the simple FDIA and the stealthy FDIA strategies
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