Approximating the selected-internal Steiner tree

AbstractIn this paper, we consider a variant of the well-known Steiner tree problem. Given a complete graph G=(V,E) with a cost function c:E→R+ and two subsets R and R′ satisfying R′⊂R⊆V, a selected-internal Steiner tree is a Steiner tree which contains (or spans) all the vertices in R such that each vertex in R′ cannot be a leaf. The selected-internal Steiner tree problem is to find a selected-internal Steiner tree with the minimum cost. In this paper, we present a 2ρ-approximation algorithm for the problem, where ρ is the best-known approximation ratio for the Steiner tree problem

Extraconnectivity of k-ary n-cube networks

AbstractGiven a graph G and a non-negative integer g, the g-extraconnectivity of G is the minimum cardinality of a set of vertices in G, if such a set exists, whose deletion disconnects G and leaves every remaining component with more than g vertices. This study shows that the 2-extraconnectivity of a k-ary n-cube Qnk for k≥4 and n≥5 is equal to 6n−5

Data Compression Strategies for Use in Advanced Metering Infrastructure Networks

Internet of Things technology has advanced rapidly. For example, numerous sensors can be deployed in a city to collect a variety of data, and such data can be used to monitor the city’s situation. A possible application of such data is smart metering implemented by power suppliers for their consumers; smart metering involves installing a multiplicity of smart meters that, in conjunction with data centers, form a smart grid. Because a smart gird must collect and send data automatically, the establishment of advanced metering infrastructure (AMI) constitutes the primary step to establishing a smart grid. However, problems remain in smart metering: data traffic from smart meters flows rapidly at a huge volume, resulting in bandwidth bottlenecks. Thus, this chapter proposes some data compression technologies as well as a novel scheme for reducing the communication data load in AMI architectures

In-situ Monitoring of Internal Local Temperature and Voltage of Proton Exchange Membrane Fuel Cells

The distribution of temperature and voltage of a fuel cell are key factors that influence performance. Conventional sensors are normally large, and are also useful only for making external measurements of fuel cells. Centimeter-scale sensors for making invasive measurements are frequently unable to accurately measure the interior changes of a fuel cell. This work focuses mainly on fabricating flexible multi-functional microsensors (for temperature and voltage) to measure variations in the local temperature and voltage of proton exchange membrane fuel cells (PEMFC) that are based on micro-electro-mechanical systems (MEMS). The power density at 0.5 V without a sensor is 450 mW/cm2, and that with a sensor is 426 mW/cm2. Since the reaction area of a fuel cell with a sensor is approximately 12% smaller than that without a sensor, but the performance of the former is only 5% worse

Cbl negatively regulates nlrp3 inflammasome activation through glut1-dependent glycolysis inhibition

Activation of the nod-like receptor 3 (NLRP3) inflammasomes is crucial for immune defense, but improper and excessive activation causes inflammatory diseases. We previously reported that Cbl plays a pivotal role in suppressing NLRP3 inflammasome activation by inhibiting Pyk2-mediated apoptosis-associated speck-like protein containing a CARD (ASC) oligomerization. Here, we showed that Cbl dampened NLRP3 inflammasome activation by inhibiting glycolysis, as demonstrated with Cbl knockout cells and treatment with the Cbl inhibitor hydrocotarnine. We revealed that the inhibition of Cbl promoted caspase-1 cleavage and interleukin (IL)-1β secretion through a glycolysis-dependent mechanism. Inhibiting Cbl increased cellular glucose uptake, glycolytic capacity, and mitochondrial oxidative phosphorylation capacity. Upon NLRP3 inflammasome activation, inhibiting Cbl increased glycolysis-dependent activation of mitochondrial respiration and increased the production of reactive oxygen species, which contributes to NLRP3 inflammasome activation and IL-1β secretion. Mechanistically, inhibiting Cbl increased surface expression of glucose transporter 1 (GLUT1) protein through post-transcriptional regulation, which increased cellular glucose uptake and consequently raised glycolytic capacity, and in turn enhanced NLRP3 inflammasome activation. Together, our findings provide new insights into the role of Cbl in NLRP3 inflammasome regulation through GLUT1 downregulation. We also show that a novel Cbl inhibitor, hydrocortanine, increased NLRP3 inflammasome activity via its effect on glycolysis

Significance of Coronary Calcification for Prediction of Coronary Artery Disease and Cardiac Events Based on 64-Slice Coronary Computed Tomography Angiography

This work aims to validate the clinical significance of coronary artery calcium score (CACS) in predicting coronary artery disease(CAD) and cardiac events in 100 symptomatic patients (aged 37–87 years, mean 62.5, 81 males) that were followed up for a mean of 5 years. Our results showed that patients with CAD and cardiac events had significantly higher CACS than those without CAD and cardiac events, respectively. The corresponding data were 1450.42 ± 3471.24 versus 130 ± 188.29 (P 1000. Increased CACS (>100)was also associated with an increased frequency of multi-vessel disease. Nonetheless, 3 (20%) out of 15 patients with zero CACS had single-vessel disease. Significant correlation (P < 0.001) was observed between CACS and CAD on a vessel-based analysis for coronary arteries. It is concluded that CACS is significantly correlated with CAD and cardiac events

A microsecond-response polymer-stabilized blue phase liquid crystal

A polymer-stabilized blue-phase liquid crystal (BPLC) with microsecond response time is demonstrated using a vertical field switching cell. The measured decay time is 39 mu s at room temperature (21 degrees C) and then decreases to 9.6 mu s at 44.3 degrees C. Such a response time is 1-2 orders of magnitude faster than that of a typical BPLC device. The responsible physical mechanisms are the collective effects of short pitch length, strong polymer network, and low viscosity through temperature effect. The on-state voltage of our BPLC device is 44.2 V, hysteresis is below 0.7%, and contrast ratio is over 1300:1