Cavity quantum electro-optics. II. Input-output relations between traveling optical and microwave fields

In the previous paper [M. Tsang, Phys. Rev. A 81, 063837 (2010), e-print arXiv:1003.0116], I proposed a quantum model of a cavity electro-optic modulator, which can coherently couple an optical cavity mode to a microwave resonator mode and enable novel quantum operations on the two modes, including laser cooling of the microwave mode, electro-optic entanglement, and backaction-evading optical measurement of a microwave quadrature. In this sequel, I focus on the quantum input-output relations between traveling optical and microwave fields coupled to a cavity electro-optic modulator. With red-sideband optical pumping, the relations are shown to resemble those of a beam splitter for the traveling fields, so that in the ideal case of zero parasitic loss and critical coupling, microwave photons can be coherently up-converted to "flying" optical photons with unit efficiency, and vice versa. With blue-sideband pumping, the modulator acts as a nondegenerate parametric amplifier, which can generate two-mode squeezing and hybrid entangled photon pairs at optical and microwave frequencies. These fundamental operations provide a potential bridge between circuit quantum electrodynamics and quantum optics.Comment: 12 pages, 10 figures, v2: updated and submitte

Age-related changes to lumbosacral spinal cord motoneurons that modulate bladder and bowel functions in male C57BL/6 mice

Incontinence and sexual dysfunction are often increased in the aged human population. In rats and mice the pattern of micturition and faecal clearance also changes with ageing and is suggestive of bladder and bowel dysfunction

Regulation of RUNX3 in gastric and breast cancer

RUNX3 is a transcription factor that is ubiquitously expressed in different tissues and has been shown to have diverse functions in many developmental procedures. Recently it has also been acknowledged that RUNX3 is involved as a tumor suppressor in many distinct cancers in different tissues. In this thesis, we will examine the regulation of this tumor suppressor in gastric cancer and breast cancer. Chronic infection with cagA-positive Helicobacter pylori is the strongest risk factor for the development of gastric adenocarcinoma. The cagA gene product CagA is injected into gastric epithelial cells and disturbs cellular functions by physically interacting with and deregulating a variety of cellular signaling molecules. RUNX3 is expressed gastric epithelial tissues, and is frequently inactivated in gastric cancer. In the first part of the thesis, we showed that H. pylori infection inactivates the gastric tumor suppressor RUNX3 in a CagA-dependent manner. CagA directly associates with RUNX3 through a specific recognition of the PY motif of RUNX3 by a WW domain of CagA. Deletion of the WW domains of CagA or mutation of the PY motif in RUNX3 abolishes the ability of CagA to induce the ubiquitination and degradation of RUNX3, thereby extinguishing its ability to inhibit the transcriptional activation of RUNX3. This study identify RUNX3 as a novel cellular target of H. pylori CagA and also reveal a mechanism by which CagA functions as an oncoprotein by blocking the activity of gastric tumor suppressor RUNX3. RUNX3 has also been known to be inactivated in breast cancer through dual mechanism of cytoplasmic mislocalization as well as promoter hypermethylation. Recent studies in our lab have shown that RUNX3 knockout mice have an approximate 20% increased chance of ii developing breast cancer compared to WT mice. At the same time, MCF7 cells expressing RUNX3 resulted in smaller tumor growth in a tumorigenicity assay compared to MCF7 cells expressing a control vector, further affirming RUNX3’s importance as a tumor suppressor in breast cancer. Pin1 is an isomerase that is over-expressed in human breast cancer. Pin1 specifically isomerizes only the Ser/Thr-Pro bonds in certain proteins, which allows it to act as a molecular switch controlling protein functions. In the second part of this thesis, we discuss the findings that Pin1 interacts specifically with tumor suppressor protein RUNX3 through 4 separate phosphorylated Ser/Thr-Pro motifs on the RUNX3 protein. Through this interaction with Pin1, the ubiquitination of RUNX3 is markedly enhanced, resulting in decreased protein stability. RUNX3 is therefore targeted to the 26S proteasome for degradation in the presence of Pin1. Our data shows a novel pathway through which tumor suppressor protein RUNX3 can be inactivated and hence regulated in breast tissues by Pin1

CSM-401 - Population based Incremental Learning vesus Genetic Algorithms: Iterated Prisoners Dilemma

Axelrod?s originally experiments for evolving IPD player strategies involved the use of a basic GA. In this paper we examine how well a simple GA performs against the more recent Population Based Incremental Learning system under similar conditions. We find that while PBIL performs well, GA in general does slightly better although more experiments should be conducted

Classifying Generalization: Paradigm War or abuse of Terminology?

Lee and Baskerville (2003) attempted to clarify the concept of generalization and classify it into four types. In Tsang and Williams (2012) we objected to their account of generalization as well as their classification and offered repairs. Then we proposed a classification of induction, within which we distinguished five types of generalization. In their (2012) rejoinder, they argue that their classification is compatible with ours, claiming that theirs offers a ‘new language.’ Insofar as we resist this ‘new language’ and insofar as they think that our position commits us to positivism and the rejection of interpretivism, they conclude both that our classification is more restrictive than theirs and also that we embrace ‘paradigmatic domination.’ Lee and Baskerville\u27s classification of generalization is based on a distinction between theoretical and empirical statements. Accordingly we will first clarify the terms ‘theoretical statement’ and ‘empirical statement.’ We note that they find no fault with our classification of induction, we restate our main objections to their classification that remain unanswered and we show that their classification of generalizing is in fact incompatible with ours. We argue that their account of generalization retains fatal flaws, which means it should not be relied upon. We demonstrate that our classification is not committed to any paradigm and so we do not embrace ‘paradigmatic domination.

Quantum temporal correlations and entanglement via adiabatic control of vector solitons

It is shown that optical pulses with a mean position accuracy beyond the standard quantum limit can be produced by adiabatically expanding an optical vector soliton followed by classical dispersion management. The proposed scheme is also capable of entangling positions of optical pulses and can potentially be used for general continuous-variable quantum information processing.Comment: 5 pages, 1 figure, v2: accepted by Physical Review Letters, v3: minor editing and shortening, v4: included the submitted erratu

Effect of isospin dependent cross-section on fragment production in the collision of charge asymmetric nuclei

To understand the role of isospin effects on fragmentation due to the collisions of charge asymmetric nuclei, we have performed a complete systematical study using isospin dependent quantum molecular dynamics model. Here simulations have been carried out for $^{124}X_{n}+ ^{124}X_{n}$, where n varies from 47 to 59 and for $^{40}Y_{m}+ ^{40}Y_{m}$, where m varies from 14 to 23. Our study shows that isospin dependent cross-section shows its influence on fragmentation in the collision of neutron rich nuclei

Intermittency in Two-Dimensional Turbulence with Drag

We consider the enstrophy cascade in forced two-dimensional turbulence with a linear drag force. In the presence of linear drag, the energy wavenumber spectrum drops with a power law faster than in the case without drag, and the vorticity field becomes intermittent, as shown by the anomalous scaling of the vorticity structure functions. Using a previous theory, we compare numerical simulation results with predictions for the power law exponent of the energy wavenumber spectrum and the scaling exponents of the vorticity structure functions $\zeta_{2q}$ obtained in terms of the distribution of finite time Lyapunov exponents. We also study, both by numerical experiment and theoretical analysis, the multifractal structure of the viscous enstrophy dissipation in terms of its R\'{e}nyi dimension spectrum $D_q$ and singularity spectrum $f(\alpha)$. We derive a relation between $D_q$ and $\zeta_{2q}$, and discuss its relevance to a version of the refined similarity hypothesis. In addition, we obtain and compare theoretically and numerically derived results for the dependence on separation $r$ of the probability distribution of \delta_{\V{r}}\omega, the difference between the vorticity at two points separated by a distance $r$. Our numerical simulations are done on a $4096 \times 4096$ grid.Comment: 18 pages, 17 figure

Kongish Daily: researching translanguaging creativity and subversiveness

This paper analyses Kongish Daily, a Facebook page that trans-scripts local news in Hong Kong into a creative and dynamic mix of Cantonese in traditional Chinese characters, Romanisation and made-up characters, simplified Chinese, pinyin, English, Hong Kong English, other phonetic symbols, emoji and other signs and images. We trace the origin of the site and rationale for the Facebook page, and analyse it as a translanguaging phenomenon. The main objective is to understand the political motivations for the Facebook account and the social critique it offers through its dynamic translanguaging practice. In particular, we want to highlight the subversive nature of the translanguaging practice. Methodologically, it develops the participatory linguistics framework, which transformed our own understandings of the phenomenon as well as the cultural politics of translingualism and social media in Hong Kong