2,002 research outputs found

    New Terms for the Compact Form of Electroweak Chiral Lagrangian

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    The compact form of the electroweak chiral Lagrangian is a reformulation of its original form and is expressed in terms of chiral rotated electroweak gauge fields, which is crucial for relating the information of underlying theories to the coefficients of the low-energy effective Lagrangian. However the compact form obtained in previous works is not complete. In this letter we add several new chiral invariant terms to it and discuss the contributions of these terms to the original electroweak chiral Lagrangian.Comment: 3 pages, references adde

    Assessing impacts of climate change and human activities on streamflow and sediment discharge in the Ganjiang River basin (1964-2013)

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    © 2019 by the authors. National large-scale soil and water conservation controls on the Gangjiang River basin have been documented, but the effect of governance on regional watershed hydrology and how the main driving factors act have not been systematically studied yet. To do this, this study evaluated changing trends and detected transition years for both streamflow and sediment discharge using long-term historical records at seven hydrological stations in the Ganjiang River basin over the past 50 years. The double mass curve (DMC) method was used to quantify the effects of both climate change and human activities on hydrological regime shifts. The results showed that the distributions of precipitation, streamflow, and sediment discharge within a year are extremely uneven and mainly concentrated in the flood season of Jiangxi Province. None of the stations showed significant trends over time for either annual precipitation or streamflow, while the annual sediment discharge at most stations decreased significantly over time. The estimation of sediment discharge via DMC indicated that after the transition years, there were rapid reductions in sediment discharge at all hydrological stations, and the average decline degree of midstream and downstream were much larger than that of upstream. Human activities, especially the increase of vegetation cover and construction of large and medium-sized reservoirs, provided a significantly greater contribution to the reduction of sediment discharge than did precipitation changes. As a case study of river evolution under global change environment, this study could provide scientific basis for the control of soil erosion and the management of water resources in Ganjiang River, as well as for the related research of Poyang Lake and the Yangtze River basin of China

    The reliability and validity of the Chinese version of Abbreviated PAD Emotion Scales

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    The study aimed at testing the reliabilityand validity of the Chinese version of Abbreviated PAD Emotion Scales using a Chinese sample. 297 Chinese undergraduate students were tested with the Chinese version of Abbreviated PAD Emotion Scales; 98 of them were retested with the same scales after seven days in order to assess thetest-retest reliability; and 102 of them were tested with SCL-90 at the same time which was intended as criteria for validity to assess the criterion validity. The results showedthat the Chinese version of Abbreviated PAD Emotion Scales displayed satisfying reliability and validity on P (pleasure-displeasure), only moderate reliability and validityon D (dominance-submissiveness), but quite low reliability and validity on A(arousal-nonarousal)The study aimed at testing the reliability and validity of the Chinese version of Abbreviated PAD Emotion Scales using a Chinese sample. 297 Chinese undergraduate students were tested with the Chinese version of Abbreviated PAD Emotion Scales; 98 of them were retested with the same scales after seven days in order to assess the test-retest reliability; and 102 of them were tested with SCL-90 at the same time which was intended as criteria for validity to assess the criterion validity. The results showed that the Chinese version of Abbreviated PAD Emotion Scales displayed satisfying reliability and validity on P (pleasure-displeasure), only moderate reliability and validity on D (dominance-submissiveness), but quite low reliability and validity on A (arousal-nonarousal)

    Experimental GHZ Entanglement beyond Qubits

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    The Greenberger-Horne-Zeilinger (GHZ) argument provides an all-or-nothing contradiction between quantum mechanics and local-realistic theories. In its original formulation, GHZ investigated three and four particles entangled in two dimensions only. Very recently, higher dimensional contradictions especially in three dimensions and three particles have been discovered but it has remained unclear how to produce such states. In this article we experimentally show how to generate a three-dimensional GHZ state from two-photon orbital-angular-momentum entanglement. The first suggestion for a setup which generates three-dimensional GHZ entanglement from these entangled pairs came from using the computer algorithm Melvin. The procedure employs novel concepts significantly beyond the qubit case. Our experiment opens up the possibility of a truly high-dimensional test of the GHZ-contradiction which, interestingly, employs non-Hermitian operators.Comment: 6+6 pages, 8 figure

    Hormonal regulation of ovarian bursa fluid in mice and involvement of aquaporins.

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    In rodent species, the ovary and the end of oviduct are encapsulated by a thin membrane called ovarian bursa. The biological functions of ovarian bursa remain unexplored despite its structural arrangement in facilitating oocytes transport into oviduct. In the present study, we observed a rapid fluid accumulation and reabsorption within the ovarian bursa after ovarian stimulation (PMSG-primed hCG injection), suggesting that the ovarian bursa might play an active role in regulating local fluid homeostasis around the timing of ovulation. We hypothesized that the aquaporin proteins, which are specialized channels for water transport, might be involved in this process. By screening the expression of aquaporin family members (Aqp1-9) in the ovarian tissue and isolated ovarian bursa (0, 1, 2 and 5 h after hCG injection), we found that AQP2 and AQP5 mRNA showed dynamic changes after hCG treatment, showing upregulation at 1-2 h followed by gradually decrease at 5 h, which is closely related with the intra-bursa fluid dynamics. Further immunofluorescence examinations of AQP2 and AQP5 in the ovarian bursa revealed that AQP2 is specifically localized in the outer layer (peritoneal side) while AQP5 localized in the inner layer (ovarian side) of the bursa, such cell type specific and spatial-temporal expressions of AQP2 and 5 support our hypothesis that they might be involved in efficient water transport through ovarian bursa under ovulation related hormonal regulation. The physiological significance of aquaporin-mediated water transport in the context of ovarian bursa still awaits further clarification

    Optimal In Silico Target Gene Deletion through Nonlinear Programming for Genetic Engineering

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    Optimal selection of multiple regulatory genes, known as targets, for deletion to enhance or suppress the activities of downstream genes or metabolites is an important problem in genetic engineering. Such problems become more feasible to address in silico due to the availability of more realistic dynamical system models of gene regulatory and metabolic networks. The goal of the computational problem is to search for a subset of genes to knock out so that the activity of a downstream gene or a metabolite is optimized.Based on discrete dynamical system modeling of gene regulatory networks, an integer programming problem is formulated for the optimal in silico target gene deletion problem. In the first result, the integer programming problem is proved to be NP-hard and equivalent to a nonlinear programming problem. In the second result, a heuristic algorithm, called GKONP, is designed to approximate the optimal solution, involving an approach to prune insignificant terms in the objective function, and the parallel differential evolution algorithm. In the third result, the effectiveness of the GKONP algorithm is demonstrated by applying it to a discrete dynamical system model of the yeast pheromone pathways. The empirical accuracy and time efficiency are assessed in comparison to an optimal, but exhaustive search strategy.Although the in silico target gene deletion problem has enormous potential applications in genetic engineering, one must overcome the computational challenge due to its NP-hardness. The presented solution, which has been demonstrated to approximate the optimal solution in a practical amount of time, is among the few that address the computational challenge. In the experiment on the yeast pheromone pathways, the identified best subset of genes for deletion showed advantage over genes that were selected empirically. Once validated in vivo, the optimal target genes are expected to achieve higher genetic engineering effectiveness than a trial-and-error procedure

    Exploratory spatial data analysis for the identification of risk factors to birth defects

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    BACKGROUND: Birth defects, which are the major cause of infant mortality and a leading cause of disability, refer to "Any anomaly, functional or structural, that presents in infancy or later in life and is caused by events preceding birth, whether inherited, or acquired (ICBDMS)". However, the risk factors associated with heredity and/or environment are very difficult to filter out accurately. This study selected an area with the highest ratio of neural-tube birth defect (NTBD) occurrences worldwide to identify the scale of environmental risk factors for birth defects using exploratory spatial data analysis methods. METHODS: By birth defect registers based on hospital records and investigation in villages, the number of birth defects cases within a four-year period was acquired and classified by organ system. The neural-tube birth defect ratio was calculated according to the number of births planned for each village in the study area, as the family planning policy is strictly adhered to in China. The Bayesian modeling method was used to estimate the ratio in order to remove the dependence of variance caused by different populations in each village. A recently developed statistical spatial method for detecting hotspots, Getis's [Image: see text] [7], was used to detect the high-risk regions for neural-tube birth defects in the study area. RESULTS: After the Bayesian modeling method was used to calculate the ratio of neural-tube birth defects occurrences, Getis's [Image: see text] statistics method was used in different distance scales. Two typical clustering phenomena were present in the study area. One was related to socioeconomic activities, and the other was related to soil type distributions. CONCLUSION: The fact that there were two typical hotspot clustering phenomena provides evidence that the risk for neural-tube birth defect exists on two different scales (a socioeconomic scale at 6.84 km and a soil type scale at 22.8 km) for the area studied. Although our study has limited spatial exploratory data for the analysis of the neural-tube birth defect occurrence ratio and for finding clues to risk factors, this result provides effective clues for further physical, chemical and even more molecular laboratory testing according to these two spatial scales

    The generalized Hamiltonian model for the shafting transient analysis of the hydro turbine generating sets.

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    yesTraditional rotor dynamics mainly focuses on the steady- state behavior of the rotor and shafting. However, for systems such as hydro turbine generating sets (HTGS) where the control and regulation is frequently applied, the shafting safety and stabilization in transient state is then a key factor. The shafting transient state inevitably involves multiparameter domain, multifield coupling, and coupling dynamics. In this paper, the relative value form of the Lagrange function and its equations have been established by defining the base value system of the shafting. Takingthe rotation angle and the angular speed of the shafting as a link, the shafting lateral vibration and generator equations are integrated into the framework of generalized Hamiltonian system. The generalized Hamiltonian control model is thus established. To make the model more general, additional forces of the shafting are taken as the input excitation in proposed model. The control system of the HTGS can be easily connected with the shafting model to form the whole simulation system of the HTGS. It is expected that this study will build a foundation for the coupling dynamics theory using the generalized Hamiltonian theory to investigate coupling dynamic mechanism among the shafting vibration, transient of hydro turbine generating sets, and additional forces of the shafting.National Natural Science Foundation of China under Grant Nos. 51179079 and 5083900
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