971 research outputs found
Linear Tabulated Resolution Based on Prolog Control Strategy
Infinite loops and redundant computations are long recognized open problems
in Prolog. Two ways have been explored to resolve these problems: loop checking
and tabling. Loop checking can cut infinite loops, but it cannot be both sound
and complete even for function-free logic programs. Tabling seems to be an
effective way to resolve infinite loops and redundant computations. However,
existing tabulated resolutions, such as OLDT-resolution, SLG- resolution, and
Tabulated SLS-resolution, are non-linear because they rely on the
solution-lookup mode in formulating tabling. The principal disadvantage of
non-linear resolutions is that they cannot be implemented using a simple
stack-based memory structure like that in Prolog. Moreover, some strictly
sequential operators such as cuts may not be handled as easily as in Prolog.
In this paper, we propose a hybrid method to resolve infinite loops and
redundant computations. We combine the ideas of loop checking and tabling to
establish a linear tabulated resolution called TP-resolution. TP-resolution has
two distinctive features: (1) It makes linear tabulated derivations in the same
way as Prolog except that infinite loops are broken and redundant computations
are reduced. It handles cuts as effectively as Prolog. (2) It is sound and
complete for positive logic programs with the bounded-term-size property. The
underlying algorithm can be implemented by an extension to any existing Prolog
abstract machines such as WAM or ATOAM.Comment: To appear as the first accepted paper in Theory and Practice of Logic
Programming (http://www.cwi.nl/projects/alp/TPLP
Effects of high glucose on expression of OPG and RANKL in rat aortic vascular smooth muscle cells
AbstractObjectiveTo explore effect of high glucose on expression of osteoprotegerin (OPG) and receptor activator of NF– κ B ligand (RANKE) in rat aortic vascular smooth muscle cells.MethodsSD rats were intraperitoneally injected with streptozotocin, OPG and RANKL expression in rat thoracic aortas were detected by immunohistochemical staining. In cultured vascular smooth muscle cells (VSMCs) (A7r5), qRT–PCR and Western blot analysis were used to examine the mRNA and protein levels of OPG and RANKL.ResultsOur results demonstrated that OPG expression was increased in hyperglycemic rat aortic VSMCs, while RANKL expression was decreased. Besides, in vitro experiments high glucose induced OPG expression, but depressed RANKL expression by dose– and time–dependent manner in cultured A7r5.ConclusionsOur findings suggested that high glucose could promote the expression of OPG, and inhibit the expression of RANKL in VSMCs, which may be partly be the molecular mechanism of diabetic vascular calcification
Twin-field quantum key distribution with local frequency reference
Twin-field quantum key distribution (TF-QKD) overcomes the linear rate-loss
limit, which promises a boost of secure key rate over long distance. However,
the complexity of eliminating the frequency differences between the independent
laser sources hinders its practical application. Here, taking the saturated
absorption spectroscopy of acetylene as an absolute reference, we propose and
demonstrate a simple and practical approach to realize TF-QKD without requiring
relative frequency control of the independent laser sources. Adopting the
4-intensity sending-or-not-sending TF-QKD protocol, we experimentally
demonstrate the TF-QKD over 502 km, 301 km and 201 km ultra-low loss optical
fiber respectively. We expect this high-performance scheme will find widespread
usage in future intercity and free-space quantum communication networks.Comment: 13 pages, 5 figures, 7 table
A school-based comprehensive lifestyle intervention among Chinese kids against Obesity (CLICK-Obesity) in Nanjing City, China: The baseline data
Background: urgent development of effective interventions to prevent rapidly rising childhood obesity in China is needed. Methods: Between May 2010 and December 2013, a cluster randomized controlled trial was conducted among 4 graders in eight urban primary schools randomly assigned to intervention or control groups in Nanjing, China. A multi-component intervention program was implemented within the treatment group, while students in the control group followed their usual health education curriculum without additional intervention. Results: At baseline, 638 and 544 students were enrolled in the intervention and control group, respectively. The prevalence of excess body weight was 26.8%, with 27.4% in the intervention group and 26.1% in the control group (p=0.61). The mean (SD) BMI and WC was 18.7 (3.0) and 63.0 (9.2) for participants in intervention schools, and 18.5 (2.9) and 63.6 (8.7) for students in control group, separately (p=0.24 and 0.41, respectively). Compared to those who were not aware of what lifestyle/behavior factors were unhealthy, students who were aware of the unhealthy lifestyle/ behavior factors consumed fewer fried snacks (0.46±0.76 serves/week vs 0.65±0.91 serves/week;
Quantum key distribution over 658 km fiber with distributed vibration sensing
Twin-field quantum key distribution (TF-QKD) promises ultra-long secure key
distribution which surpasses the rate distance limit and can reduce the number
of the trusted nodes in long-haul quantum network. Tremendous efforts have been
made towards implementation of TF-QKD, among which, the secure key with finite
size analysis can distribute more than 500 km in the lab and in the field.
Here, we demonstrate the sending-or-not-sending TF-QKD experimentally,
achieving a secure key distribution with finite size analysis over 658 km
ultra-low-loss optical fiber, improve the secure distance record by around 100
km. Meanwhile, in a TF-QKD system, any phase fluctuation due to temperature
variation and ambient variation during the channel must be recorded and
compensated, and all these phase information can then be utilized to sense the
channel vibration perturbations. With our QKD system, we recovered the external
vibrational perturbations on the fiber generated by an artificial vibroseis and
successfully located the perturbation position with a resolution better than 1
km. Our results not only set a new distance record of QKD, but also demonstrate
that the redundant information of TF-QKD can be used for remote sensing of the
channel vibration, which can find applications in earthquake detection and
landslide monitoring besides secure communication.Comment: 20 pages, 4 figures and 1 tabl
Dynamic diffusion tensor imaging reveals structural changes in the bilateral pyramidal tracts after brain stem hemorrhage in rats
Background and Purpose: Few studies have concentrated on pyramidal tract (PY) changes after brain stem hemorrhage (BSH). In this study, we used a diffusion tensor imaging (DTI) technique and histologic identification to investigate longitudinal PY changes on both the contralateral and ipsilateral sides after experimental BSH. Methods: BSH was induced in 61 Sprague-Dawley rats by infusing 30 μl of autogenous tail blood into each rat’s right pons. DTI and motor function examinations were performed repeatedly on days 1, 3, 7, 14, and 28 after surgery. Fractional anisotropy, mean diffusivity, axial diffusivity, and radial diffusivity were measured in the bilateral PYs. The axon and myelin injury in the PY were evaluated by histologic study. Results: As compared with normal controls, the bilateral PYs in rats with induced BSH showed an early decrease and a late increase in fractional anisotropy and an early increase and a late decrease in mean diffusivity. A progressive decrease in axial diffusivity with dramatic axon loss from day 1 to day 28 after BSH was found bilaterally. The bilateral PYs showed an early increase and a late decrease in radial diffusivity. Early myelin injury and late repair were also detected pathologically in the bilateral PYs of rats with BSH. Thus, the early motor function deficits of rats with BSH began to improve on day 14 and had almost completely disappeared by day 28. Conclusions: DTI revealed dynamic changes in the bilateral PYs after BSH, which was confirmed by histologic findings and which correlated with motor function alteration. These findings support the idea that quantitative DTI can track structural changes in the bilateral PYs and that DTI may serve as a noninvasive tool to predict the prognoses of patients with BSH
Using small molecules to facilitate exchange of bicarbonate and chloride anions across liposomal membranes
Bicarbonate is involved in a wide range of biological processes, which include respiration, regulation of intracellular pH and fertilization. In this study we use a combination of NMR spectroscopy and ion-selective electrode techniques to show that the natural product prodigiosin, a tripyrrolic molecule produced by microorganisms such as Streptomyces and Serratia, facilitates chloride/bicarbonate exchange (antiport) across liposomal membranes. Higher concentrations of simple synthetic molecules based on a 4,6-dihydroxyisophthalamide core are also shown to facilitate this antiport process. Although it is well known that proteins regulate Cl-/HCO3- exchange in cells, these results suggest that small molecules may also be able to regulate the concentration of these anions in biological systems
A simulation study on the measurement of D0-D0bar mixing parameter y at BES-III
We established a method on measuring the \dzdzb mixing parameter for
BESIII experiment at the BEPCII collider. In this method, the doubly
tagged events, with one decays to
CP-eigenstates and the other decays semileptonically, are used to
reconstruct the signals. Since this analysis requires good separation,
a likelihood approach, which combines the , time of flight and the
electromagnetic shower detectors information, is used for particle
identification. We estimate the sensitivity of the measurement of to be
0.007 based on a fully simulated MC sample.Comment: 6 pages, 7 figure
Nuclear receptors in vascular biology
Nuclear receptors sense a wide range of steroids and hormones (estrogens, progesterone, androgens, glucocorticoid, and mineralocorticoid), vitamins (A and D), lipid metabolites, carbohydrates, and xenobiotics. In response to these diverse but critically important mediators, nuclear receptors regulate the homeostatic control of lipids, carbohydrate, cholesterol, and xenobiotic drug metabolism, inflammation, cell differentiation and development, including vascular development. The nuclear receptor family is one of the most important groups of signaling molecules in the body and as such represent some of the most important established and emerging clinical and therapeutic targets. This review will highlight some of the recent trends in nuclear receptor biology related to vascular biology
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