The orientation-preserving diffeomorphism group of S^2 deforms to SO(3) smoothly

Smale proved that the orientation-preserving diffeomorphism group of S^2 has a continuous strong deformation retraction to SO(3). In this paper, we construct such a strong deformation retraction which is diffeologically smooth.Comment: 16 page

From Molecular Cores to Planet-forming Disks with SIRTF

The SIRTF mission and the Legacy programs will provide coherent data bases for extra-galactic and Galactic science that will rapidly become available to researchers through a public archive. The capabilities of SIRTF and the six legacy programs are described briefly. Then the cores to disks (c2d) program is described in more detail. The c2d program will use all three SIRTF instruments (IRAC, MIPS, and IRS) to observe sources from molecular cores to protoplanetary disks, with a wide range of cloud masses, stellar masses, and star-forming environments. The SIRTF data will stimulate many follow-up studies, both with SIRTF and with other instruments.Comment: 6 pages, from Fourth Cologne-Bonn-Zermatt-Symposium, The Dense Interstellar Matter in Galaxie

Computational algebraic methods in efficient estimation

A strong link between information geometry and algebraic statistics is made by investigating statistical manifolds which are algebraic varieties. In particular it it shown how first and second order efficient estimators can be constructed, such as bias corrected Maximum Likelihood and more general estimators, and for which the estimating equations are purely algebraic. In addition it is shown how Gr\"obner basis technology, which is at the heart of algebraic statistics, can be used to reduce the degrees of the terms in the estimating equations. This points the way to the feasible use, to find the estimators, of special methods for solving polynomial equations, such as homotopy continuation methods. Simple examples are given showing both equations and computations. *** The proof of Theorem 2 was corrected by the latest version. Some minor errors were also corrected.Comment: 21 pages, 5 figure

Odderon in baryon-baryon scattering from the AdS/CFT correspondence

Based on the AdS/CFT correspondence, we present a holographic description of various C-odd exchanges in high energy baryon-baryon and baryon-antibaryon scattering, and calculate their respective contributions to the difference in the total cross sections. We predict that, due to the warp factor of AdS_5, the total cross section in pp collisions is larger than in p\bar{p} collisions at asymptotically high energies.Comment: 23 pages, v2: minor changes, to be published in JHE

The Weak Gravity Conjecture and the Viscosity Bound with Six-Derivative Corrections

The weak gravity conjecture and the shear viscosity to entropy density bound place constraints on low energy effective field theories that may help to distinguish which theories can be UV completed. Recently, there have been suggestions of a possible correlation between the two constraints. In some interesting cases, the behavior was precisely such that the conjectures were mutually exclusive. Motivated by these works, we study the mass to charge and shear viscosity to entropy density ratios for charged AdS5 black branes, which are holographically dual to four-dimensional CFTs at finite temperature. We study a family of four-derivative and six-derivative perturbative corrections to these backgrounds. We identify the region in parameter space where the two constraints are satisfied and in particular find that the inclusion of the next-to-leading perturbative correction introduces wider possibilities for the satisfaction of both constraints.Comment: 24 pages, 6 figures, v2: published version, refs added, minor clarificatio

Perturbation of Retinoid Homeostasis Increases Malformation Risk in Embryos Exposed to Pregestational Diabetes

Pregestational diabetes is highly associated with increased risk of birth defects. However, factors that can increase or reduce expressivity and penetrance of malformations in diabetic pregnancies remain poorly identified. All-trans retinoic acid (RA) plays crucial roles in embryogenesis. Here, we find that Cyp26a1, which encodes a key enzyme for catabolic inactivation of RA required for tight control of local RA concentrations, is significantly down-regulated in embryos of diabetic mice. Embryonic tissues expressing Cyp26a1 show reduced efficiency of RA clearance. Diabetes-exposed embryos are thus sensitized to RA and more vulnerable to the deleterious effects of increased RA signalling. Susceptibility to RA teratogenesis is further potentiated in embryos with a pre-existing genetic defect of RA metabolism. Increasing RA clearance efficiency by a pre-conditioning approach can counteract the increased susceptibility to RA teratogenesis in embryos of diabetic mice. Our findings provide new insight into gene-environment interactions that influence individual risk in manifestation of diabetes-related birth defects, and shed light on the environmental risk factors and genetic variants for a stratified medicine approach to screen diabetic women of childbearing age and assess risk of birth defects during pregnancy

High Fidelity Tape Transfer Printing Based On Chemically Induced Adhesive Strength Modulation

Transfer printing, a two-step process (i.e. picking up and printing) for heterogeneous integration, has been widely exploited for the fabrication of functional electronics system. To ensure a reliable process, strong adhesion for picking up and weak or no adhesion for printing are required. However, it is challenging to meet the requirements of switchable stamp adhesion. Here we introduce a simple, high fidelity process, namely tape transfer printing(TTP), enabled by chemically induced dramatic modulation in tape adhesive strength. We describe the working mechanism of the adhesion modulation that governs this process and demonstrate the method by high fidelity tape transfer printing several types of materials and devices, including Si pellets arrays, photodetector arrays, and electromyography (EMG) sensors, from their preparation substrates to various alien substrates. High fidelity tape transfer printing of components onto curvilinear surfaces is also illustrated

Video enhancement using adaptive spatio-temporal connective filter and piecewise mapping

This paper presents a novel video enhancement system based on an adaptive spatio-temporal connective (ASTC) noise filter and an adaptive piecewise mapping function (APMF). For ill-exposed videos or those with much noise, we first introduce a novel local image statistic to identify impulse noise pixels, and then incorporate it into the classical bilateral filter to form ASTC, aiming to reduce the mixture of the most two common types of noises - Gaussian and impulse noises in spatial and temporal directions. After noise removal, we enhance the video contrast with APMF based on the statistical information of frame segmentation results. The experiment results demonstrate that, for diverse low-quality videos corrupted by mixed noise, underexposure, overexposure, or any mixture of the above, the proposed system can automatically produce satisfactory results

Physical Response Functions of Strongly Coupled Massive Quantum Liquids

We study physical properties of strongly coupled massive quantum liquids from their spectral functions using the AdS/CFT correspondence. The generic model that we consider is dense, heavy fundamental matter coupled to SU(N_c) super Yang-Mills theory at finite temperature above the deconfinement phase transition but below the scale set by the baryon number density. In this setup, we study the current-current correlators of the baryon number density using new techniques that employ a scaling behavior in the dual geometry. Our results, the AC conductivity, the quasi-particle spectrum and the Drude-limit parameters like the relaxation time are simple temperature-independent expressions that depend only on the mass-squared to density ratio and display a crossover between a baryon- and meson-dominated regime. We concentrated on the (2+1)-dimensional defect case, but in principle our results can also be generalized straightforwardly to other cases.Comment: 21 pages, 10 figures, extra paragraph and figure are added in response to referee's comment

Effects of SARS on consultations in primary care in Hong Kong

Objective: To study the infection control measures and concerns in primary care practices, and the effects of SARS on primary care consultation using the Leicester Assessment Package (LAP) criteria during the SARS episode in Hong Kong. Design: A postal survey using a questionnaire. The questionnaire consisted of three parts on the demographic data, infection control precautions taken and concerns of the respondents, and the effect of SARS on consultations. Subjects: Full members and fellows of the HKCFP. Main outcome measures: Infection control precautions including performance of initial screening/triage, by whom and how these were carried out, actions for the triaged patients, use of personal protection equipments (PPE), organisation and format of infection control training of staff and decontamination practice; perceptions of adequacy of protection and areas of concern; and proportion and degree to which consultation skills were affected using the LAP criteria. Results: The response rate was 60%. 71.4% respondents triaged their patients. 85.9% took temperatures of their patients. All respondents wore a mask during consultations. 69.8% organised training for their staff and clinic. Most respondents regularly decontaminated their clinic. 56% felt adequately protected by their infection control precautions and use of PPE but 44% did not. The major concerns were the variable clinical presentations of SARS, the practicability of wearing full protection, and the lack of early and reliable diagnostic tests. The type of practice was found to be a factor affecting the choice of infection control precautions. Consultation skills were found to be affected in ≤ 25% of consultations. History taking, physical examination, management and problem solving were found to be more difficult but relationship with patients and anticipatory care became easier. Conclusion: Choice of infection control precautions was related to the type of practice. The major concerns of primary care physicians were the variable clinical presentations of SARS and the lack of early and reliable diagnostic tests. Consultation skills were affected in ≤ 25% of consultations but patients were found to be more receptive to anticipatory care.published_or_final_versio