Endogenous Information Acquisition on Opponents' Valuations in Multidimensional First Price Auctions

This paper investigates bidder's covert behavior of endogenous information acquisition on her opponents' valuations in first price auction model with independent private values. Such an information acquisition setting leads to bidimensional type space and bidimensional strategy space. We consider two different specifications of the environments: the ex ante information acquisition setting and the interim information acquisition setting. In equilibria the expected payoffs of the bidder under these specifications could exceed the counterpart payoffs of the corresponding standard sealed-bid auctions without information acquisition as long as the cost is small, but the auctioneer has lower payoffs in these models than those of the standard ones. Moreover, the incurred information cost becomes the deadweight loss, resulting in ine±cient outcomes

Vickrey Auctions with Sequential and Costly Participation

This paper investigates the cutoff strategies and the effects of sequential and costly participation in Vickrey auctions with independent private value settings. It demonstrates a Stackelberg version of participation decision in auctions, while simultaneous participation can be regarded as a Cournot version in auctions. Buyers adopt cut-off participation strategies. In two-buyer case, the cutoff strategy equilibrium is unique. The follower's critical values are always monotonic in participation cost in both symmetric and asymmetric settings. This is also true for the leader with mild conditions on c.d.fs. We also characterize equilibria in three-buyer and more general n-buyer environments. We then study buyer's preference to be a leader or a follower. Comparison with simultaneous model shows that the driven-out effect is much stronger in our sequential participation model, which implies the simultaneous specification might not be desirable

One-Step Synthesis of Co@C Composite as High-Performance Anode Material for Lithium-ion Batteries

A carbon-coated cobalt (Co@C) composite was synthesized by a one-step method using ionic liquid as carbon source and reducing agent. The Co@C composite exhibited a core-shell structure, in which the cobalt nanoparticles uniformly embedded in the carbon matrix. When used as the anode material for lithium ion batteries, the cobalt nanoparticles enhanced the kinetics of Li+ and electronic transport during the charge/discharge process. The Co@C composite material delivered a reversible capacity of 657.3 mAh g-1 after 60 cycles at a current density of 0.1C and exhibits improved rate performance when compared with pure carbon

On efficient and scalable time-continuous spatial crowdsourcing

The proliferation of advanced mobile terminals opened up a new crowdsourcing avenue, spatial crowdsourcing, to utilize the crowd potential to perform real-world tasks. In this work, we study a new type of spatial crowdsourcing, called time-continuous spatial crowdsourcing (TCSC in short). It supports broad applications for long-term continuous spatial data acquisition, ranging from environmental monitoring to traffic surveillance in citizen science and crowdsourcing projects. However, due to limited budgets and limited availability of workers in practice, the data collected is often incomplete, incurring data deficiency problem. To tackle that, in this work, we first propose an entropy-based quality metric, which captures the joint effects of incompletion in data acquisition and the imprecision in data interpolation. Based on that, we investigate quality-aware task assignment methods for both single- and multi-task scenarios. We show the NP-hardness of the single-task case, and design polynomial-time algorithms with guaranteed approximation ratios. We study novel indexing and pruning techniques for further enhancing the performance in practice. Then, we extend the solution to multi-task scenarios and devise a parallel framework for speeding up the process of optimization. We conduct extensive experiments on both real and synthetic datasets to show the effectiveness of our proposals

Sea Level Pressure Variability Over the Southern Indian Ocean Inferred from a Glaciochemical Record in Princess Elizabeth Land, East Antarctica

A 250-year, high-resolution, multivariate ice core record from LGB65 (70degrees50\u2707 S, 77degrees04\u2729 E; 1850 m asl), Princess Elizabeth Land (PEL), is used to investigate sea level pressure (SLP) variability over the southern Indian Ocean (SIO). Empirical orthogonal function (EOF) analysis reveals that the first EOF (EOF1) of the glaciochemical record from LGB65 represents most of the variability in sea salt throughout the 250-year record. EOF1 is negatively correlated (95% confidence level and higher) to instrumental mean sea level pressure (MSLP) at Kerguelen and New Amsterdam islands, SIO. On the basis of comparison with NCEP/NCAR reanalysis, strong correlations were found between sea-salt variations and a quasi-stationary low that lies to the north of Prydz Bay, SIO. Comparison with a 250-year-long summer transpolar index (STPI) inferred from sub-Antarctic tree ring records reveals strong coherency. Decadal-scale SLP variability over SIO suggests shifting of the polar vortex. Prominent decadal-scale deepening of the southern Indian Ocean low (SIOL) exists circa 1790, 1810, 1835, 1860, 1880, 1900, and 1940 A. D., continuously after the 1970s, and prominent weakening circa 1750, 1795, 1825, 1850, 1870, 1890, 1910, and 1955 A. D. The LGB65 sea-salt record is characterized by significant decadal-scale variability with a strong similar to21-year periodic structure (99.9% confidence level). The relationship between LGB65 sea salt and solar irradiance changes shows that this periodicity is possibly the solar Hale cycle ( 22 years)

Adipose-derived mesenchymal stem cells improve glucose homeostasis in high-fat diet-induced obese mice

Introduction Effective therapies for obesity and diabetes are still lacking. The aim of this study was to evaluate whether a single intravenous infusion of syngeneic adipose-derived mesenchymal stem cells (ASCs) can reduce obesity, lower insulin resistance, and improve glucose homeostasis in a high-fat diet-induced obese (DIO) mouse model. Methods Seven-week-old C57BL/6 mice were fed a high-fat diet for 20 weeks to generate the DIO mouse model. Mice were given a single intravenous infusion of ex vivo expanded syngeneic ASCs at 2 × 10 6 cells per mouse. DIO or CHOW mice injected with saline were used as controls. Body weights, blood glucose levels, glucose, and insulin tolerance test results were obtained before and 2 and 6 weeks after cell infusion. Triglyceride (TG), high-density lipoprotein (HDL), and insulin levels in serum were measured. Expressions of genes related to insulin resistance, including peroxisome proliferator-activated receptor γ (PPARγ) and insulin receptor (InsR), and inflammation (IL-6, F4/80, and nucleotide-binding oligomerization domain containing 2, or NOD2), were measured in livers at mRNA level by real-time-polymerase chain reaction analysis. Beta-cell mass in pancrheases from CHOW, DIO, and DIO + ASC mice was quantified. GFP + ASCs were injected, and the presence of GFP + cells in livers and pancreases was determined. Results DIO mice that had received ASCs showed reduced body weights, reduced blood glucose levels, and increased glucose tolerance. ASC treatment was found to reduce TG levels and increase serum HDL levels. In livers, less fat cell deposition was observed, as were increased expression of InsR and PPARγ and reduction in expressions of IL-6 and F4/80. Treated mice showed well-preserved pancreatic β-cell mass with reduced expression of F4/80 and TNF-α compared with DIO controls. GFP + cells were found in liver and pancreas tissues at 1 and 2 weeks after cell injection. Conclusions ASC therapy is effective in lowering blood glucose levels and increasing glucose tolerance in DIO mice. The protective effects of ASCs arise at least in part from suppression of inflammation in the liver. In addition, ASCs are associated with better-preserved pancreatic β-cell mass

Effect of milling modes on surface integrity of KDP crystal processed by micro ball-end milling

Micro-milling has been widely considered as the most promising method to repair the micro-defects on the surface of KH2PO4 (KDP) crystal. However, achieving an ultra-smooth repaired surface by ball-end milling remains a longstanding challenge for KDP crystal due to its soft-brittle properties. In micro ball-end milling of KDP crystal, selection of milling mode is the prerequisite to determine the integrated combination of other cutting parameters (e.g. spindle speed, feed rate and the depth of cut). In this paper, with the aim to investigate the influences of the milling mode on the surface integrity of KDP brittle crystal, the micro-groove experiments were carried out comprehensively. All the milling modes were considered (pull-milling, push-milling, up-milling and down-milling) and corresponding cutting parameters selections were also examined. The results demonstrated that the pull-milling and down-milling are both conducive to ductile mode machining, while the push-milling and up-milling cause adverse impacts on the machined surface integrity. In addition, the optimal combination of cutting parameters were also recommended to guide the mitigation of micro-defects on the surface of KDP crystal by micro ball-end milling process

Experimental Implementation of the Quantum Random-Walk Algorithm

The quantum random walk is a possible approach to construct new quantum algorithms. Several groups have investigated the quantum random walk and experimental schemes were proposed. In this paper we present the experimental implementation of the quantum random walk algorithm on a nuclear magnetic resonance quantum computer. We observe that the quantum walk is in sharp contrast to its classical counterpart. In particular, the properties of the quantum walk strongly depends on the quantum entanglement.Comment: 5 pages, 4 figures, published versio

Characterization of manufacturing-induced surface scratches and their effect on laser damage resistance performance of diamond fly-cut KDP crystal

Manufacturing-induced defects have drawn more and more attentions to improve the laser damage resistance performance of KDP crystal applied in high-power laser systems. Here, the morphology of surface scratches on diamond fly-cut KDP crystal is characterized and their effect on the laser damage resistance is theoretically and experimentally investigated. The results indicate that surface scratches could lower laser-induced damage threshold (LIDT) by modulating incident lasers and producing resultant local light intensifications. The induced maximum light intensity enhancement factors (LIEFs) are dependent on scratch shapes and dimensions. The diffraction effects originating from scratch edges are responsible for the strongest light intensification. Even for ultra-precision finished KDP surface with scratches that well satisfy the currently applied scratch/dig specification, the induced LIEFs are quite high, indicating that the actual defect dimension allowance should be amended and specified according to the defect-induced LIEFs. The effect of scratches on laser damage resistance is experimentally verified by the tested LIDT, which is approximately consistent with the simulation one. The morphologies of laser damage sites further confirm the role of scratches in lowering LIDT. This work could offer new perspective and guidance for fully evaluating the performance of ultra-precision manufactured optical materials applied in high-power laser facilities

Glycyrrhizin arginine salt protects against cisplation-induced acute liver injury by repressing BECN1-mediated ferroptosis

The study aimed to investigate the protective effects and biological mechanisms of glycyrrhizin arginine salt (Gly-Arg) against cisplatin (Cis)-induced liver injury. Our data showed that Gly-Arg improved Cis-induced liver injury. Further study showed that BECN1 (beclin1) and LC3-II/LC3-I protein expression was significantly increased in primary hepatocytes and mouse liver tissues after Cis treatment, but Gly-Arg reduced the protein levels of BECN1 and LC3-II/LC3-I in primary hepatocytes and mouse liver tissues. Also, Gly-Arg improved indicators related to Cis-induced ferroptosis. Furthermore, Cis increased colocalization of lysosomal membrane-associated protein 1A (LAMP1) with ferritin heavy chain 1 (FTH1) in primary mouse hepatocytes, while Gly-Arg intervention attenuated this colocalization in primary hepatocytes. More improtantly, Cis enhanced the formation of the BECN1-xCT complex, thus inhibiting solute carrier family 7 member 11 (SLC7A11, xCT) and glutathione peroxidase-4 (GPX4) activity. In contrast, Gly-Arg intervention disrupted the formation of this complex. However, Gly-Arg alleviated Cis-induced liver injury in mice by preventing autophagic death and ferroptosis through the inhibition of BECN1-xCT complex formation