Confined one-way mode at magnetic domain wall for broadband high-efficiency one-way waveguide, splitter and bender

We find the one-way mode can be well-confined at the magnetic domain wall by the photonic bandgap of gyromagnetic bulk material. Utilizing the well-confined one-way mode at the domain wall, we demonstrate the photonic one-way waveguide, splitter and bender can be realized with simple structures, which are predicted to be high-efficiency, broadband, frequency-independent, reflection-free, crosstalk-proof and robustness against disorder. Additionally, we find that the splitter and bender in our proposal can be transformed into each other with magnetic control, which may have great potential applications in all photonic integrated circuit.Comment: Appl. Phys. Lett. 100, 041108 (2012); (4 pages

Exemplar-AMMs: Recognizing Crowd Movements From Pedestrian Trajectories

In this paper, we present a novel method to recognize the types of crowd movement from crowd trajectories using agent-based motion models (AMMs). Our idea is to apply a number of AMMs, referred to as exemplar-AMMs, to describe the crowd movement. Specifically, we propose an optimization framework that filters out the unknown noise in the crowd trajectories and measures their similarity to the exemplar-AMMs to produce a crowd motion feature. We then address our real-world crowd movement recognition problem as a multi-label classification problem. Our experiments show that the proposed feature outperforms the state-of-the-art methods in recognizing both simulated and real-world crowd movements from their trajectories. Finally, we have created a synthetic dataset, SynCrowd, which contains 2D crowd trajectories in various scenarios, generated by various crowd simulators. This dataset can serve as a training set or benchmark for crowd analysis work

Holey Carbon Nanotubes from Controlled Air Oxidation

Defects in various nanomaterials are often desirable to enable enhanced functional group attachments and attain properties that are not available with their intact counterparts. A new paradigm in the defective low-dimensional carbon nanomaterials is to create holes on the graphitic surfaces via partial etching. For example, holey graphene, graphene sheets with through-thickness holes, was synthesized using several different partial etching approaches and found useful for various applications such as field-effect transistors, sensors, energy storage devices, and separation membranes. In these applications, the presence of holes led to unique advantages, such as bandgap widening, chemical functionalization of hole edges, improved through-the-thickness ion transport with lowered tortuosity, and improved accessible surface area. Here, we present a facile method to prepare holey carbon nanotubes via controlled air oxidation. Although no additional catalyst was added, the residual iron nanoparticles from nanotube growth encapsulated in the nanotube cavity significantly contributed to the hole generation through the nanotube walls. The holey carbon nanotube products exhibited enhanced surface area, pore volume, and oxygen-containing functional groups, which led to their much enhanced electrochemical capacitive properties. Synthesis and characterization details of this novel class of holey carbon nanomaterials are presented, and their potential applications are discussed

Ownership Type, Home?Country Government?Directed Investment Policies and Firm Value in Strategic Sectors: Evidence from Chinese Acquiring Firms

Using data of Chinese acquirers in strategic sectors, we assess the role of home government and the effects of the interaction between ownership type and government-directed investment policies on acquiring firm value in cross-border acquisitions (CBAs). We find that CBA activities in strategic sectors encouraged by the home-country government through its investment policies experience significant increase in acquiring firm value. We also find that firms investing in government-designated strategic sectors generate wealth for acquirers, but contrary to efficiency logic rooted in agency theory, state-owned enterprises appear to outperform private-owned enterprises. Further analysis indicates that three financial incentives associated with government-directed policies – namely, interest-rate reduction, tax incentives and direct subsidies – constitute sources of firm value. Our results raise several policy implications, including the need for transparent and rule-based policies and governance systems to be developed and implemented by governments in the home and host countries to regulate state-supported firms investing in sensitive strategic sectors

Optical pumping NMR in the compensated semiconductor InP:Fe

The optical pumping NMR effect in the compensated semiconductor InP:Fe has been investigated in terms of the dependences of photon energy (E_p), helicity (sigma+-), and exposure time (tau_L) of infrared lights. The {31}P and {115}In signal enhancements show large sigma+- asymmetries and anomalous oscillations as a function of E_p. We find that (i) the oscillation period as a function of E_p is similar for {31}P and {115}In and almost field independent in spite of significant reduction of the enhancement in higher fields. (ii) A characteristic time for buildup of the {31}P polarization under the light exposure shows strong E_p-dependence, but is almost independent of sigma+-. (iii) The buildup times for {31}P and {115}In are of the same order (10^3 s), although the spin-lattice relaxation times (T_1) are different by more than three orders of magnitude between them. The results are discussed in terms of (1) discrete energy spectra due to donor-acceptor pairs (DAPs) in compensated semiconductors, and (2) interplay between {31}P and dipolar ordered indium nuclei, which are optically induced.Comment: 8 pages, 6 figures, submitted to Physical Review

Modeling and analysis of energy distribution networks using switched differential systems

It is a pleasure to dedicate this contribution to Prof. Arjan van der Schaft on the occasion of his 60th birthday. We study the dynamics of energy distribution networks consisting of switching power converters and multiple (dis-)connectable modules. We use parsimonious models that deal effectively with the variant complexity of the network and the inherent switching phenomena induced by power converters. We also present the solution to instability problems caused by devices with negative impedance characteristics such as constant power loads. Elements of the behavioral system theory such as linear differential behaviors and quadratic differential forms are crucial in our analysis

Helicobacter pylori chronic infection and mucosal inflammation switches the human gastric glycosylation pathways

Helicobacter pylori exploits host glycoconjugates to colonize the gastric niche. Infection can persist for decades promoting chronic inflammation, and in a subset of individuals lesions can silently progress to cancer. This study shows that H. pylori chronic infection and gastric tissue inflammation result in a remodeling of the gastric glycophenotype with increased expression of sialyl-Lewis a/x antigens due to transcriptional up-regulation of the B3GNT5, B3GALT5, and FUT3 genes. We observed that H. pylori infected individuals present a marked gastric local pro-inflammatory signature with significantly higher TNF-a levels and demonstrated that TNF-induced activation of the NF-kappaB pathway results in B3GNT5 transcriptional up-regulation. Furthermore, we show that this gastric glycosylation shift, characterized by increased sialylation patterns, favors SabA-mediated H. pylori attachment to human inflamed gastric mucosa. This study provides novel clinically relevant insights into the regulatory mechanisms underlying H. pylori modulation of host glycosylation machinery, and phenotypic alterations crucial for life-long infection. Moreover, the biosynthetic pathways here identified as responsible for gastric mucosa increased sialylation, in response to H. pylori infection, can be exploited as drug targets for hindering bacteria adhesion and counteract the infection chronicity.IPATIMUP integrates the i3S Research Unit, which is partially supported by FCT, the Portuguese Foundation for Science and Technology (PEst C/SAU/LA0003/2013). This work is funded by FEDER funds through the Operational Programme for Competitiveness Factors-COMPETE (NORTE 07 0124 FEDER 000024; FCOMP-01-0124-FEDER028188; FCOMP-01-0124-FEDER 041276) and National Funds through the FCT-Foundation for Science and Technology (EXPL/CTM-BIO/0762/2013, PTDC/BBB-EBI/0786/2012) and acknowledges support by the EuropeanUnion (Seventh Framework Programme GastricGlycoExplorer project, grant number 316929). Grants were received from FCT, POPH (Programa Operacional Potencial Humano) and FSE (Fundo Social Europeu) (SFRH/BPD/75871/2011 to AM;SFRH/SINTD/60034/2009 to RMP; SFRH/BPD/84084/2012 to RMF; SFRH/BPD/89764/2012 to PO). AM acknowledges EMBO for a Short-Term Fellowship (EMBO ASTF 330-212). Transcript analysis was funded by NIH (grant P41GM103490) to KWM

Spatiotemporal patterns of population in mainland China, 1990 to 2010

According to UN forecasts, global population will increase to over 8 billion by 2025, with much of this anticipated population growth expected in urban areas. In China, the scale of urbanization has, and continues to be, unprecedented in terms of magnitude and rate of change. Since the late 1970s, the percentage of Chinese living in urban areas increased from ~18% to over 50%. To quantify these patterns spatially we use time-invariant or temporally-explicit data, including census data for 1990, 2000, and 2010 in an ensemble prediction model. Resulting multi-temporal, gridded population datasets are unique in terms of granularity and extent, providing fine-scale (~100 m) patterns of population distribution for mainland China. For consistency purposes, the Tibet Autonomous Region, Taiwan, and the islands in the South China Sea were excluded. The statistical model and considerations for temporally comparable maps are described, along with the resulting datasets. Final, mainland China population maps for 1990, 2000, and 2010 are freely available as products from the WorldPop Project website and the WorldPop Dataverse Repository