MEMS flow sensors for nano-fluidic applications

This paper presents micromachined thermal sensors for measuring liquid flow rates in the nanoliter-per-minute range. The sensors use a boron-doped polysilicon thinfilm heater that is embedded in the silicon nitride wall of a microchannel. The boron doping is chosen to increase the heater’s temperature coefficient of resistance within tolerable noise limits, and the microchannel is suspended from the substrate to improve thermal isolation. The sensors have demonstrated a flow rate resolution below 10 nL/min, as well as the capability for detecting micro bubbles in the liquid. Heat transfer simulation has also been performed to explain the sensor operation and yielded good agreement with experimental data

Quantum Bit Commitment with a Composite Evidence

Entanglement-based attacks, which are subtle and powerful, are usually believed to render quantum bit commitment insecure. We point out that the no-go argument leading to this view implicitly assumes the evidence-of-commitment to be a monolithic quantum system. We argue that more general evidence structures, allowing for a composite, hybrid (classical-quantum) evidence, conduce to improved security. In particular, we present and prove the security of the following protocol: Bob sends Alice an anonymous state. She inscribes her commitment $b$ by measuring part of it in the + (for $b = 0$) or $\times$ (for $b=1$) basis. She then communicates to him the (classical) measurement outcome $R_x$ and the part-measured anonymous state interpolated into other, randomly prepared qubits as her evidence-of-commitment.Comment: 6 pages, minor changes, journal reference adde

Quantum Communications with Compressed Decoherence Using Bright Squeezed Light

We propose a scheme for long-distance distribution of quantum entanglement in which the entanglement between qubits at intermediate stations of the channel is established by using bright light pulses in squeezed states coupled to the qubits in cavities with a weak dispersive interaction. The fidelity of the entanglement between qubits at the neighbor stations (10 km apart from each other) obtained by postselection through the balanced homodyne detection of 7 dB squeezed pulses can reach F=0.99 without using entanglement purification, at same time, the probability of successful generation of entanglement is 0.34.Comment: 4 pages, 2 figure

CARING FOR WOMEN ON THE FRONTLINES: ENHANCING WOMEN WORKERS’ CAPABILITIES AND BUILDING SOCIAL FRIENDSHIP

This article examines the vulnerability of frontline cleaning workers and domestic helpers during the COVID-19pandemic and how they empower themselves by joining a community in which they can support each other. Employing surveys by non-governmental organisations, particularly those in Hong Kong, as well as my own interviews and observations, I examine the situation of the frontline workers and discuss the moral principles and conditions for upholding women’s dignity and well-being, based on the capability approach of feminist philosopher Martha Nussbaum. I argue that emphasising women’s moral agency and giving a voice to women themselves through women collectives are important in empowering them and building a life-giving community among women, especially during and after the pandemic. In addition, the notions of political charity and social friendship in Catholic social thought, particularly the social encyclical Fratelli Tutti, and the multi-axial analysis in post-colonial feminist theology are useful in upholding women’s dignity and moral agency in care situations. Examples of social friendship are provided

Asymptotics for a discrete-time risk model with Gamma-like insurance risks

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Topologically protected excitons in porphyrin thin films

The control of exciton transport in organic materials is of fundamental importance for the development of efficient light-harvesting systems. This transport is easily deteriorated by traps in the disordered energy landscape. Here, we propose and analyze a system that supports topological Frenkel exciton edge states. Backscattering of these chiral Frenkel excitons is prohibited by symmetry, ensuring that the transport properties of such a system are robust against disorder. To implement our idea, we propose a two-dimensional periodic array of tilted porphyrins interacting with a homogenous magnetic field. This field serves to break time-reversal symmetry and results in lattice fluxes that that mimic the Aharonov-Bohm phase acquired by electrons. Our proposal is the first blueprint for realizing topological phases of matter in molecular aggregates and suggests a paradigm for engineering novel excitonic materials.Comment: Submitted early March 2014 to a journal; currently in revisio

Learning Temporal Transformations From Time-Lapse Videos

Based on life-long observations of physical, chemical, and biologic phenomena in the natural world, humans can often easily picture in their minds what an object will look like in the future. But, what about computers? In this paper, we learn computational models of object transformations from time-lapse videos. In particular, we explore the use of generative models to create depictions of objects at future times. These models explore several different prediction tasks: generating a future state given a single depiction of an object, generating a future state given two depictions of an object at different times, and generating future states recursively in a recurrent framework. We provide both qualitative and quantitative evaluations of the generated results, and also conduct a human evaluation to compare variations of our models.Comment: ECCV201

The Role of Chitinase Production by Stenotrophomonas maltophilia Strain C3 in Biological Control of Bipolaris sorokiniana

The role of chitinase production by Stenotrophomonas maltophilia strain C3 in biological control of leaf spot on tall fescue (Festuca arundinacea), caused by Bipolaris sorokiniana, was investigated in vitro and in vivo. The filtrate of a broth culture of C3, with chitin as the carbon source, was separated into fractions. A high molecular-weight fraction (\u3e8 kDa) was chitinolytic and more inhibitory than a low-molecularweight, nonchitinolytic fraction to conidial germination and hyphal growth by B. sorokiniana and to leaf spot development. A protein fraction derived by ammonium sulfate precipitation and a chitinase fraction purified by chitin affinity chromatography also were chitinolytic and highly antifungal. The chitinolytic fractions caused swelling and vacuolation of conidia and discoloration, malformation, and degradation of germ tubes. When boiled, the chitinolytic fractions lost chitinase activity along with most of the antifungal properties. Two chitinase-deficient and two chitinase- reduced mutants of C3 were compared with the wild-type strain for inhibition of germination of B. sorokiniana conidia on tall fescue leaves and for suppression of leaf spot development in vivo. The mutants exhibited reduced antifungal activity and biocontrol efficacy, but did not lose all biocontrol activity. An aqueous extract of leaves colonized by wild-type C3 had higher chitinase activity than that of noncolonized leaves and was inhibitory to conidial germination. The addition of chitin to leaves along with the wild-type strain increased both chitinase and antifungal activity. The chitinase activity level of extracts from leaves colonized by a chitinase-deficient mutant of C3, with and without added chitin, was no higher than the background, and the extracts lacked antifungal activity. Chitinolysis appears to be one mechanism of biological control by strain C3, and it functions in concert with other mechanisms