5,893 research outputs found
Incompatibility of Observables as State-Independent Bound of Uncertainty Relations
For a pair of observables, they are called "incompatible", if and only if the
commutator between them does not vanish, which represents one of the key
features in quantum mechanics. The question is, how can we characterize the
incompatibility among three or more observables? Here we explore one possible
route towards this goal through Heisenberg's uncertainty relations, which
impose fundamental constraints on the measurement precisions for incompatible
observables. Specifically, we quantify the incompatibility by the optimal
state-independent bounds of additive variance-based uncertainty relations. In
this way, the degree of incompatibility becomes an intrinsic property among the
operators, but not on the quantum state. To justify our case, we focus on the
incompatibility of spin systems. For an arbitrary setting of two or three
linearly-independent Pauli-spin operators, the incompatibility is analytically
solved, the spins are maximally incompatible if and only if they are orthogonal
to each other. On the other hand, the measure of incompatibility represents a
versatile tool for applications such as testing entanglement of bipartite
states, and EPR-steering criteria.Comment: Comments are welcom
Re-flaring of a Post-Flare Loop System Driven by Flux Rope Emergence and Twisting
In this letter, we study in detail the evolution of the post-flare loops on
2005 January 15 that occurred between two consecutive solar eruption events,
both of which generated a fast halo CME and a major flare. The post-flare loop
system, formed after the first CME/flare eruption, evolved rapidly, as
manifested by the unusual accelerating rise motion of the loops. Through
nonlinear force-free field (NLFFF) models, we obtain the magnetic structure
over the active region. It clearly shows that the flux rope below the loops
also kept rising accompanied with increasing twist and length. Finally, the
post-flare magnetic configuration evolved to a state that resulted in the
second CME/flare eruption. This is an event in which the post-flare loops can
re-flare in a short period of 16 hr following the first CME/flare
eruption. The observed re-flaring at the same location is likely driven by the
rapid evolution of the flux rope caused by the magnetic flux emergence and the
rotation of the sunspot. This observation provides valuable information on
CME/flare models and their prediction.Comment: 11 pages, 4 figures, 1 table, accepted for publication in ApJ Lette
3,4-Bis(2-pyridyl)-5-(3-pyridyl)-4H-1,2,4-triazole
In the title molecule, C17H12N6, the 2-pyridyl rings in the 3- and 4-positions and the 3-pyridyl ring in the 5-position make dihedral angles of 29.78 (16), 67.06 (16) and 32.97 (16)°, respectively, with the triazole group. The dihedral angle between the two 2-pyridyl rings is 65.72 (15)°. The dihedral angles between the 3-pyridyl ring and the two 2-pyridyl rings in the 3- and 4-positions are 61.28 (15) and 63.11 (15)°, respectively. In the crystal, C—H⋯π and π–π interactions [centroid-centroid distance = 3.6248 (19) Å] link the molecules, forming a two-dimensional network
Association between work stress and health behaviours in Korean and Japanese ageing studies: a cross-sectional study
OBJECTIVES: Limited research has focused on the association between work stress and health behaviours in Asian countries. We aimed to explore the effect of work stress on two health behaviours among employees aged 45 years or above in two countries with ageing populations, Korea and Japan. DESIGN: A cross-sectional study. SETTING: This secondary data analysis was conducted on baseline data from the Korean Longitudinal Study of Aging (KLoSA, 2006) and the Japanese Study of Aging and Retirement (JSTAR, 2007 and 2009). PARTICIPANTS: Included in the analytical sample were 4982 responders without missing data aged 45 years or older who reported work positions and hours (KLoSA n=3478, JSTAR n=1504). MAIN OUTCOME MEASURES: Work stress was represented by the short version of the effort-reward imbalance (ERI) model. We used logistic regression and multinomial logistic regression to investigate the association between work stress and smoking (binary current smoking) and between work stress and drinking (categorical volume of alcohol). Socioeconomic and work-related characteristics were taken into consideration, and we examined the potential interaction between ERI and gender. RESULTS: Work stress as measured by ERI ratio was significantly associated with both smoking and drinking in the KLoSA analysis; after the model was fully adjusted, ORs were 1.45 (95% CI 1.17 to 1.80) and 1.44 (95% CI 1.09 to 1.90), respectively. In analysis of the data from JSTAR, the ERI ratio was associated with smoking (OR 1.37, 95% CI 1.01 to 1.89) but not with drinking. No statistically significant interaction was found between ERI and gender in any model (p=0.82 in KLoSA data and p=0.19 in JSTAR data). CONCLUSIONS: Statistically significant associations were found between work stress and both smoking and drinking behaviours in Korea and between work stress and smoking in Japan. Government integration of effort-reward balance programmes and health promotion programmes could effectively promote population health in these two Asian countries
MIN-COST WITH DELAY SCHEDULING FOR LARGE SCALE CLOUD-BASED WORKFLOW APPLICATIONS PLATFORM
Cloud computing is a promising solution to provide the resource scalability dynamically. In order to support large scale workflow applications, we present Nuts-LSWAP which is implementation for Cloud workflow. Then, a novel Min-cost with delay scheduling algorithm is presented in this paper. We also focuses on the global scheduling including genetic evolution method and other scheduling methods (sequence and greedy) to evaluate and decrease the execution cost. Finally, three primary experiments divided into two parts. One parts of experiment demonstrate the global mapping algorithm effectively, and the second parts compare execution of a large scale workflow instances with or without delay scheduling. It is primarily proved the Nuts-LSWAP is efficient platform for building Cloud workflow environment
HIF-1α Contributes to Hypoxia-induced Invasion and Metastasis of Esophageal Carcinoma via Inhibiting E-cadherin and Promoting MMP-2 Expression
Hypoxia-inducible factor-1α (HIF-1α) has been found to enhance tumor invasion and metastasis, but no study has reported its action in esophageal carcinoma. The goal of this study was to explore the probable mechanism of HIF-1α in the invasion and metastasis of esophageal carcinoma Eca109 cells in vitro and in vivo. mRNA and protein expression of HIF-1α, E-cadherin and matrix metalloproteinase-2 (MMP-2) under hypoxia were detected by RT-PCR and Western blotting. The effects of silencing HIF-1α on E-cadherin, MMP-2 mRNA and protein expression under hypoxia or normoxia were detected by RT-PCR and Western blotting, respectively. The invasive ability of Eca109 cells was tested using a transwell chambers. We established an Eca109-implanted tumor model and observed tumor growth and lymph node metastasis. The expression of HIF-1α, E-cadherin and MMP-2 in xenograft tumors was detected by Western blotting. After exposure to hypoxia, HIF-1α protein was up-regulated, both mRNA and protein levels of E-cadherin were down-regulated and MMP-2 was up-regulated, while HIF-1α mRNA showed no significant change. SiRNA could block HIF-1α effectively, increase E-cadherin expression and inhibit MMP-2 expression. The number of invading cells decreased after HIF-1α was silenced. Meanwhile, the tumor volume was much smaller, and the metastatic rate of lymph nodes and the positive rate were lower in vivo. Our observations suggest that HIF-1α inhibition might be an effective strategy to weaken invasion and metastasis in the esophageal carcinoma Eca109 cell line
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