5,460 research outputs found
AN ANALYSIS OF CURRENT PROBLEMS IN CHINA'S AGRICULTURE DEVELOPMENT: AGRICULTURE, RURAL AREAS AND FARMERS
China is the most populous country in the world. Of its 1.3 billion people, 22% of the world population, about 67% are living in rural areas. Although China is the third largest country in terms of area, the arable land is only 7% of the global amount. With relatively meager endowment, it is undoubtedly a daunting task for the agricultural sector to provide adequate supply to fulfil huge needs for food and other agricultural products. In addition, agriculture development in China confronts with challenges to raise the average income and standard of living of the rural population in the long run. Since China's economic reform was launched in 1978, the "People's Commune" system was dismantled and replaced by the "Household Responsibility" system. Agricultural production has achieved rapid growth and income per capita in the rural area has risen 10 times in 20 years. During this transformation process, a number of serious problems have been emerging in the agricultural sector. They include the diminishing size of the arable land, enlarging of income disparity and stagnating of productivity growth, which have been exacerbated by the population growth and increasing demands for agricultural products. The agricultural sector is also plagued by environmental degradation and confronted by township enterprise development. Furthermore, China's recent accession into the World Trade Organization (WTO) brings more tremendous challenges to its agriculture. This paper is intended to provide a concise analysis of the problems and possible policy options associated with current agriculture development. It reveals that the main problems are market partition, inefficiency in government administration in supply and distribution, and price distortions of agricultural products, originating from China's development strategy of preferred industrialization in the industry sector and urban development. This paper also explores and assesses a few government policy options for the alleviation of these problems. Policy options focus on deepening market-oriented reforms, including price deregulation, market integration and property (land) reforms, which also reflect the requirements of the Agriculture Agreement of WTO. Policy options also focus on improvement of government supported programs in investment and subsidies aimed at boosting productivity, narrowing the inequality of income distribution and easing the barriers for mobility of surplus labor into the industry and service sectors in urban areas.International Development,
The Higgs-Boson Decay to Order under the mMOM-Scheme
We study the decay width of the Higgs-boson up to order
under the minimal momentum space subtraction scheme (mMOM-scheme).
To improve the accuracy of perturbative QCD prediction, we adopt the principle
of maximum conformality (PMC) to set its renormalization scales. A detailed
comparison of the total decay width and the separate decay widths at each
perturbative order before and after the PMC scale setting is presented. The PMC
adopts the renormalization group equation to fix the optimal scales of the
process. After the PMC scale setting, the scale-dependence for both the total
and the separate decay widths are greatly suppressed, and the convergence of
perturbative QCD series is improved. By taking the Higgs mass GeV, as recently given by the ATLAS and CMS collaborations, we
predict keV,
where the first error is for Higgs mass and the second error is the residual
scale dependence by varying the initial scale .Comment: 9 pages, 3 figures. Revised version to be published in J.Phys.
HrcU and HrpP are pathogenicity factors in the fire blight pathogen Erwinia amylovora required for the type III secretion of DspA/E
Table S1. Description of data: Sequences of oligonucleotide primers used in this study. (DOCX 109Â kb
Association Signals Unveiled by a Comprehensive Gene Set Enrichment Analysis of Dental Caries Genome-Wide Association Studies
Gene set-based analysis of genome-wide association study (GWAS) data has recently emerged as a useful approach to examine the joint effects of multiple risk loci in complex human diseases or phenotypes. Dental caries is a common, chronic, and complex disease leading to a decrease in quality of life worldwide. In this study, we applied the approaches of gene set enrichment analysis to a major dental caries GWAS dataset, which consists of 537 cases and 605 controls. Using four complementary gene set analysis methods, we analyzed 1331 Gene Ontology (GO) terms collected from the Molecular Signatures Database (MSigDB). Setting false discovery rate (FDR) threshold as 0.05, we identified 13 significantly associated GO terms. Additionally, 17 terms were further included as marginally associated because they were top ranked by each method, although their FDR is higher than 0.05. In total, we identified 30 promising GO terms, including 'Sphingoid metabolic process,' 'Ubiquitin protein ligase activity,' 'Regulation of cytokine secretion,' and 'Ceramide metabolic process.' These GO terms encompass broad functions that potentially interact and contribute to the oral immune response related to caries development, which have not been reported in the standard single marker based analysis. Collectively, our gene set enrichment analysis provided complementary insights into the molecular mechanisms and polygenic interactions in dental caries, revealing promising association signals that could not be detected through single marker analysis of GWAS data. © 2013 Wang et al
Fully integrated InGaAs/InP single-photon detector module with gigahertz sine wave gating
InGaAs/InP single-photon avalanche diodes (SPADs) working in the regime of
GHz clock rates are crucial components for the high-speed quantum key
distribution (QKD). We have developed for the first time a compact, stable and
user-friendly tabletop InGaAs/InP single-photon detector system operating at a
1.25 GHz gate rate that fully integrates functions for controlling and
optimizing SPAD performance. We characterize the key parameters of the detector
system and test the long-term stability of the system for continuous operation
of 75 hours. The detector system can substantially enhance QKD performance and
our present work paves the way for practical high-speed QKD applications.Comment: 11 pages, 6 figures. Accepted for publication in Review of Scientific
Instrument
Life fingerprints of nuclear reactions in the body of animals
Nuclear reactions are a very important natural phenomenon in the universe. On the earth, cosmic rays constantly cause nuclear reactions. High energy beams created by medical devices also induce nuclear reactions in the human body. The biological role of these nuclear reactions is unknown. Here we show that the in vivo biological systems are exquisite and sophisticated by nature in influence on nuclear reactions and in resistance to radical damage in the body of live animals. In this study, photonuclear reactions in the body of live or dead animals were induced with 50-MeV irradiation. Tissue nuclear reactions were detected by positron emission tomography (PET) imaging of the induced beta+ activity. We found the unique tissue "fingerprints" of beta+ (the tremendous difference in beta+ activities and tissue distribution patterns among the individuals) are imprinted in all live animals. Within any individual, the tissue "fingerprints" of 15O and 11C are also very different. When the animal dies, the tissue "fingerprints" are lost. The biochemical, rather than physical, mechanisms could play a critical role in the phenomenon of tissue "fingerprints". Radiolytic radical attack caused millions-fold increases in 15O and 11C activities via different biochemical mechanisms, i.e. radical-mediated hydroxylation and peroxidation respectively, and more importantly the bio-molecular functions (such as the chemical reactivity and the solvent accessibility to radicals). In practice biologically for example, radical attack can therefore be imaged in vivo in live animals and humans using PET for life science research, disease prevention, and personalized radiation therapy based on an individual's bio-molecular response to ionizing radiation
Experimental Test of Tracking the King Problem
In quantum theory, the retrodiction problem is not as clear as its classical
counterpart because of the uncertainty principle of quantum mechanics. In
classical physics, the measurement outcomes of the present state can be used
directly for predicting the future events and inferring the past events which
is known as retrodiction. However, as a probabilistic theory,
quantum-mechanical retrodiction is a nontrivial problem that has been
investigated for a long time, of which the Mean King Problem is one of the most
extensively studied issues. Here, we present the first experimental test of a
variant of the Mean King Problem, which has a more stringent regulation and is
termed "Tracking the King". We demonstrate that Alice, by harnessing the shared
entanglement and controlled-not gate, can successfully retrodict the choice of
King's measurement without knowing any measurement outcome. Our results also
provide a counterintuitive quantum communication to deliver information hidden
in the choice of measurement.Comment: 16 pages, 5 figures, 2 table
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