Anatomy-specific classification of medical images using deep convolutional nets

Automated classification of human anatomy is an important prerequisite for many computer-aided diagnosis systems. The spatial complexity and variability of anatomy throughout the human body makes classification difficult. "Deep learning" methods such as convolutional networks (ConvNets) outperform other state-of-the-art methods in image classification tasks. In this work, we present a method for organ- or body-part-specific anatomical classification of medical images acquired using computed tomography (CT) with ConvNets. We train a ConvNet, using 4,298 separate axial 2D key-images to learn 5 anatomical classes. Key-images were mined from a hospital PACS archive, using a set of 1,675 patients. We show that a data augmentation approach can help to enrich the data set and improve classification performance. Using ConvNets and data augmentation, we achieve anatomy-specific classification error of 5.9 % and area-under-the-curve (AUC) values of an average of 0.998 in testing. We demonstrate that deep learning can be used to train very reliable and accurate classifiers that could initialize further computer-aided diagnosis.Comment: Presented at: 2015 IEEE International Symposium on Biomedical Imaging, April 16-19, 2015, New York Marriott at Brooklyn Bridge, NY, US

Discrete R-symmetries and Anomaly Universality in Heterotic Orbifolds

We study discrete R-symmetries, which appear in 4D low energy effective field theory derived from hetetoric orbifold models. We derive the R-symmetries directly from geometrical symmetries of orbifolds. In particular, we obtain the corresponding R-charges by requiring that the couplings be invariant under these symmetries. This allows for a more general treatment than the explicit computations of correlation functions made previously by the authors, including models with discrete Wilson lines, and orbifold symmetries beyond plane-by-plane rotational invariance. Surprisingly, for the cases covered by earlier explicit computations, the R-charges differ from the previous result. We study the anomalies associated with these R-symmetries, and comment on the results.Comment: 21 pages, 2 figures. Minor changes, typos corrected. Matches JHEP published versio

Multiculturalism in Singapore and Malaysia: approaches and outcomes

Purpose: This paper examines cases of multiculturalism in Singapore and Malaysia. Through causal socio-cultural mechanisms, we observe how two countries in proximity, with shared histories and demographic profiles, achieve differing outcomes in regard to social cohesion and competitiveness. Design/methodology/approach: The paper employs case-centric process tracing (CPT) to build a ‘plausible’ explanation of causal mechanisms that can contribute to social cohesion and competitiveness. We adopt a common analytical framework to distil the nuances of generalizability and a cross-case analysis in order to ascertain factors that enable multiculturalism. Findings: Different causal mechanisms result in diverging outcomes in the two countries. In managing multiculturalism, Singapore has pursued policy actions emphasizing ‘integration and pragmatism’, while Malaysia has followed a model of ‘separation and preferentialism’. Judging by a selected number of established indicators, Singapore’s multiculturalism outcomes seem more successful than that of Malaysia in respect to areas of national competitiveness and interethnic tolerance. Practical implications: This paper shed insights on the policy actions that promoted multicultural integration. The process tracing approach is found to be a useful tool in helping policy makers understand how intrinsic mechanisms can contribute to more/less desirable socioeconomic outcomes. Originality/value: Together with the evidence using the CPT approach, the paper draws attention to multiculturalism evolving through distinctive sets of public policy. We ultimately suggest that such policies can be paralleled to the function played by institutions in leading to ‘varieties of capitalism’ and have an impact on achieving cohesive and competitive societies

Technical efficiency and environmental impact of seabream and seabass farms

Sea cage farming of seabream and seabass is the most important form of aquaculture production in the Mediterranean Sea. Despite the continuous global growth in aquaculture production and demand, the economic performance of seabream and seabass companies has not followed the same trend. In recent years, companies have faced successive periods of market instability, with high volatility in supply and market prices that have strongly affected their operational margins. Despite the regional importance of this industry, only a handful of studies have examined the economic performance of these farms. In this paper, we investigate the technical efficiency and scale effects of Mediterranean aquaculture farms. Furthermore, environmental impact in terms of nutrient emissions from the farms is examined and discussed. Technical efficiency effects are analyzed using Data Envelopment Analysis (DEA), and the bootstrap procedure is used for bias correction. The results show that the mean technical efficiency could be improved by between 16% and 34%, and scale efficiency suggests that farms could improve their efficiency by operating at an optimal scale. Compared to measurements in previous studies, the environmental variables show that the emission of nutrients from the farms per kilo of fish produced has not changed over the past twenty years. Finally, policy implications suggest that more attention toward improving technical efficiency may help improve the robustness of the sector and that environmental regulation might be needed in order to improve the environmental performance of farms

Unifying CP violations of quark and lepton sectors

A preliminary determination of the Dirac phase in the PMNS matrix is \dell\approx -\frac{\pi}{2}. A rather accurately determined Jarlskog invariant $J$ in the CKM matrix is close to the maximum. Since the phases in the CKM and PMNS matrices will be accurately determined in the future, it is an interesting problem to relate these two phases. This can be achieved in a families-unified grand unification if the weak CP violation is introduced spontaneously {\it \`a la} Froggatt and Nielsen at a high energy scale, where only one meaningful Dirac CP phase appears.Comment: 10 pages with 3 figure

Moxifloxacin: Clinically compatible contrast agent for multiphoton imaging

Multiphoton microscopy (MPM) is a nonlinear fluorescence microscopic technique widely used for cellular imaging of thick tissues and live animals in biological studies. However, MPM application to human tissues is limited by weak endogenous fluorescence in tissue and cytotoxicity of exogenous probes. Herein, we describe the applications of moxifloxacin, an FDA-approved antibiotic, as a cell-labeling agent for MPM. Moxifloxacin has bright intrinsic multiphoton fluorescence, good tissue penetration and high intracellular concentration. MPM with moxifloxacin was demonstrated in various cell lines, and animal tissues of cornea, skin, small intestine and bladder. Clinical application is promising since imaging based on moxifloxacin labeling could be 10 times faster than imaging based on endogenous fluorescence.1152sciescopu

Generation of broad XUV continuous high harmonic spectra and isolated attosecond pulses with intense mid-infrared lasers

We present experimental results showing the appearance of a near-continuum in the high-order harmonic generation (HHG) spectra of atomic and molecular species as the driving laser intensity of an infrared pulse increases. Detailed macroscopic simulations reveal that these near-continuum spectra are capable of producing IAPs in the far field if a proper spatial filter is applied. Further, our simulations show that the near-continuum spectra and the IAPs are a product of strong temporal and spatial reshaping (blue shift and defocusing) of the driving field. This offers a possibility of producing IAPs with a broad range of photon energy, including plateau harmonics, by mid-IR laser pulses even without carrier-envelope phase stabilization.Comment: 7 pages, 5 figures, submitted to J.Phys. B (Oct 2011

Internal phase inversion narrow bandwidth MEMS filter

This paper reports a novel capacitively coupled twin beam resonator internal phase inversion filter fabricated in a SOI MEMS process. A narrow bandwidth of 0.0157% is demonstrated with a low control-voltage of -0.87 V. The bandwidth can be substantially reduced by utilizing an electrical coupling spring as opposed to a mechanical coupling-spring. The bandwidth is tunable with control achieved using a differential DC bias. A summary and comparison with other members of the phase inversion filter family is also included