2,286 research outputs found

    Agricultural development and the opportunities for aquatic resources research in China

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    China is a large and rapidly developing country. Fisheries and aquaculture have been prominent sectors in the contribution to GDP and the provision of food security, export revenue, and livelihoods for the poor. The rapid development has come at some cost to the environment and the sustainability of natural resources. Levels of marine fisheries catches are stagnant. Some of the rivers and major lakes are polluted and the restoration of the productivity of these lakes is of key concern. These Proceedings, made up of four papers that leading Chinese experts presented to WorldFish Center in 2002, review four aspects of these trends: agricultural development, environmental issues and the contribution of aquaculture and fisheries to development in China.Agricultural development, Aquaculture development, Living resources, Research, WorldFish Center, WorldFish Center Contrib. No. 1668, China,

    Dynamic modelling for ecological and economic sustainability in a rapid urbanizing region

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    AbstractRecently years, most of China's rapidly developed regions are becoming China's large industrial cities and drawing the attention of the world. Consequently, the impacts of rapid urbanization to urban ecosystem will be greatly increased with the increasing economic development. If relationship between economic development and ecological sustainability is not fully realized, urban ecosystem will be degraded at a high rate. Therefore, study on ecological and economic sustainability for this area is of great importance. The objectives of this study are: (1) to find a balance between economic development and ecological protection in these regions; (2) to develop a process-based ecological and economic sustainable development model; (3) to supply the optimal controls for these reigns by conducting a policy analysis. To this end, a system dynamic model for urban sustainable development was constructed. The model was based on the analysis of many index and three subsystems, which are society system, economic system, and environmental system. We also selected typical development policies for a rapidly urbanizing region, Tianjin, in the future

    Influence of auto-organization and fluctuation effects on the kinetics of a monomer-monomer catalytic scheme

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    We study analytically kinetics of an elementary bimolecular reaction scheme of the Langmuir-Hinshelwood type taking place on a d-dimensional catalytic substrate. We propose a general approach which takes into account explicitly the influence of spatial correlations on the time evolution of particles mean densities and allows for the analytical analysis. In terms of this approach we recover some of known results concerning the time evolution of particles mean densities and establish several new ones.Comment: Latex, 25 pages, one figure, submitted to J. Chem. Phy

    Efficient chaining of seeds in ordered trees

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    We consider here the problem of chaining seeds in ordered trees. Seeds are mappings between two trees Q and T and a chain is a subset of non overlapping seeds that is consistent with respect to postfix order and ancestrality. This problem is a natural extension of a similar problem for sequences, and has applications in computational biology, such as mining a database of RNA secondary structures. For the chaining problem with a set of m constant size seeds, we describe an algorithm with complexity O(m2 log(m)) in time and O(m2) in space

    HvbZIP21, a Novel Transcription Factor From Wild Barley Confers Drought Tolerance by Modulating ROS Scavenging

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    Drought stress is a common environmental stress, which adversely affects the yield and quality of crops. Due to its excellent drought tolerance, wild barley from the Middle East region is considered a valuable source for barley improvement. Here, we compared the growth rate, stomatal regulation and capacity to metabolize reactive oxygen species (ROS) of two barley cultivars and one wild barley accession. The results indicated the wild barley EC_S1 showed a more significant decline in stomatal aperture and less ROS production. Transcriptomic analysis revealed that EC_S1 has slower transcriptional regulation (5,050 DEGs) in the early stage of drought stress (14 days) than Baudin (7,022 DEGs) and Tadmor (6,090 DEGs). In addition, 30 hub genes, including nine known drought-related genes were identified by WGCNA analysis. Then, we cloned a novel bZIP transcription factor, HvbZIP21, from EC_S1. HvbZIP21 was subcellularly targeted to the nucleus. Overexpression of HvbZIP21 in Arabidopsis enhanced drought tolerance due to increasing activities of superoxide dismutase, peroxidase, and catalase activities as well as glutathione content. Silencing of HvbZIP21 in EC_S1 suppressed drought tolerance in BSMV:HvbZIP21-inoculated plants. Taken together, our findings suggest that HvbZIP21 play a critical role in drought tolerance by manipulating ROS scavenging

    Genome sequence and analysis of the tuber crop potato

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    Potato (Solanum tuberosum L.) is the world’s most important non-grain food crop and is central to global food security. It is clonally propagated, highly heterozygous, autotetraploid, and suffers acute inbreeding depression. Here we use a homozygous doubled-monoploid potato clone to sequence and assemble 86% of the 844-megabase genome. We predict 39,031 protein-coding genes and present evidence for at least two genome duplication events indicative of a palaeopolyploid origin. As the first genome sequence of an asterid, the potato genome reveals 2,642 genes specific to this large angiosperm clade. We also sequenced a heterozygous diploid clone and show that gene presence/absence variants and other potentially deleterious mutations occur frequently and are a likely cause of inbreeding depression. Gene family expansion, tissue-specific expression and recruitment of genes to new pathways contributed to the evolution of tuber development. The potato genome sequence provides a platform for genetic improvement of this vital cro

    Weak force detection using a double Bose-Einstein condensate

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    A Bose-Einstein condensate may be used to make precise measurements of weak forces, utilizing the macroscopic occupation of a single quantum state. We present a scheme which uses a condensate in a double well potential to do this. The required initial state of the condensate is discussed, and the limitations on the sensitivity due to atom collisions and external coupling are analyzed.Comment: 12 pages, 2 figures, Eq.(41) has been correcte

    Asymptotic function for multi-growth surfaces using power-law noise

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    Numerical simulations are used to investigate the multiaffine exponent αq\alpha_q and multi-growth exponent βq\beta_q of ballistic deposition growth for noise obeying a power-law distribution. The simulated values of βq\beta_q are compared with the asymptotic function βq=1q\beta_q = \frac{1}{q} that is approximated from the power-law behavior of the distribution of height differences over time. They are in good agreement for large qq. The simulated αq\alpha_q is found in the range 1q≤αq≤2q+1\frac{1}{q} \leq \alpha_q \leq \frac{2}{q+1}. This implies that large rare events tend to break the KPZ universality scaling-law at higher order qq.Comment: 5 pages, 4 figures, to be published in Phys. Rev.

    Cosmological equations and Thermodynamics on Apparent Horizon in Thick Braneworld

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    We derive the generalized Friedmann equation governing the cosmological evolution inside the thick brane model in the presence of two curvature correction terms: a four-dimensional scalar curvature from induced gravity on the brane, and a five-dimensional Gauss-Bonnet curvature term. We find two effective four-dimensional reductions of the Friedmann equation in some limits and demonstrate that they can be rewritten as the first law of thermodynamics on the apparent horizon of thick braneworld.Comment: 25 pages, no figure, a definition corrected, several references added, more motivation and discussio

    Dynamics of Bloch vectors and the channel capacity of a non identical charged qubit pair

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    We have considered a system of two superconducting charge qubits capacitively coupled to a microwave resonator. The dynamics of the Bloch vectors are investigated for different regimes. By means of the Bloch vectors and cross dyadic we quantify the degree of entanglement contained in the generated entangled state. We consider different values of the system parameters to discuss the dynamics of the channel capacity between the qubits. We show that there is an important role played by initial state settings, coupling constant and the mean photon number on generating entangled state with high degree of entanglement and high capacity
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