Detect Spinons via Spin Transport

Existence of spinons is the defining property of quantum spin liquids. These exotic excitations have (fractionalized) spin quantum number and no electric charge, and have been proposed to form Fermi surfaces in the recently discovered organic spin liquid candidates. However direct probes for them are still lacking. In this paper we propose to experimentally identify the spinons by measuring the spin current flowing through the spin liquid candidate materials, which would be a direct test for the existence of spin-carrying mobile excitations. By the nonequilibrium Green function technique we evaluate the spin current through the interface between a Mott insulator and a metal under a spin bias, and find that different kinds of Mott insulators, including quantum spin liquids, can be distinguished by different relations between the spin bias and spin current, In the end we will also discuss relations to experiments and estimate experimentally relevant parameters.Comment: 7 pages with appendix, 3 figure

A distinct sortase SrtB anchors and processes a streptococcal adhesin AbpA with a novel structural property.

Surface display of proteins by sortases in Gram-positive bacteria is crucial for bacterial fitness and virulence. We found a unique gene locus encoding an amylase-binding adhesin AbpA and a sortase B in oral streptococci. AbpA possesses a new distinct C-terminal cell wall sorting signal. We demonstrated that this C-terminal motif is required for anchoring AbpA to cell wall. In vitro and in vivo studies revealed that SrtB has dual functions, anchoring AbpA to the cell wall and processing AbpA into a ladder profile. Solution structure of AbpA determined by NMR reveals a novel structure comprising a small globular α/β domain and an extended coiled-coil heliacal domain. Structural and biochemical studies identified key residues that are crucial for amylase binding. Taken together, our studies document a unique sortase/adhesion substrate system in streptococci adapted to the oral environment rich in salivary amylase

Body Maps of Resistance: Understanding everyday resistance to violent extremism in Kenya

Body Maps of Resistance is collection of personal stories and body map paintings created by twenty participants from around the Kenyan coast during two body mapping workshops held in November 2019 in Mombasa. The body mapping workshops were organised as part of a study on Gender and Resistance to Violent Extremism in Kenya funded by a British Academy ‘Tackling UK International Challenges’ award. This book explores how men and women at the level of local communities perceive, experience, and resist violent extremism in their everyday lives. The book aims to give voice to silenced narratives on communities’ everyday resistance to violent extremism. The body maps and stories in this volume, reveal complex everyday struggles against violence, discrimination and marginalisation. The paintings and stories are personal narratives that offer a window into the lives of the participants in our study and should not be used to generalise about communities living on the coast in Kenya

The statistical properties of galaxy morphological types in compact groups of Main galaxies from the SDSS Data Release 4

In order to explore the statistical properties of galaxy morphological types in compact groups (CGs), we construct a random group sample which has the same distributions of redshift and number of member galaxies as those of the CG sample. It turns out that the proportion of early-type galaxies in different redshift bins for the CG sample is statistically higher than that for random group sample, and with growing redshift z this kind of difference becomes more significant. This may be due to the existence of interactions and mergers within a significant fraction of SDSS CGs. We also compare statistical results of CGs with those of more compact groups and pairs, but do not observe as large statistical difference as Hickson (1982)'results.Comment: 12 pages, 9 figure

Physical accessible transformations on a finite number of quantum states

We consider to treat the usual probabilistic cloning, state separation, unambiguous state discrimination, \emph{etc} in a uniform framework. All these transformations can be regarded as special examples of generalized completely positive trace non-increasing maps on a finite number of input states. From the system-ancilla model we construct the corresponding unitary implementation of pure $\to$ pure, pure $\to$ mixed, mixed $\to$ pure, and mixed $\to$ mixed states transformations in the whole system and obtain the necessary and sufficient conditions on the existence of the desired maps. We expect our work will be helpful to explore what we can do on a finite set of input states.Comment: 7 page

Spin 3 cubic vertices in a frame-like formalism

Till now most of the results on interaction vertices for massless higher spin fields were obtained in a metric-like formalism using completely symmetric (spin-)tensors. In this, the Lagrangians turn out to be very complicated and the main reason is that the higher the spin one want to consider the more derivatives one has to introduce. In this paper we show that such investigations can be greatly simplified if one works in a frame-like formalism. As an illustration we consider massless spin 3 particle and reconstruct a number of vertices describing its interactions with lower spin 2, 1 and 0 ones. In all cases considered we give explicit expressions for the Lagrangians and gauge transformations and check that the algebra of gauge transformations is indeed closed.Comment: 17 pades, no figure

Traditional Chinese Medicine for Acute Myocardial Infarction in Western Medicine Hospitals in China.

BACKGROUND: Amid national efforts to improve the quality of care for people with cardiovascular disease in China, the use of traditional Chinese medicine (TCM) is increasing, yet little is known about its use in the early management of acute myocardial infarction (AMI). METHODS AND RESULTS: We aimed to examine intravenous use of TCM within the first 24 hours of hospitalization (early IV TCM) for AMI. Data come from the China Patient-centered Evaluative Assessment of Cardiac Events Retrospective Study of Acute Myocardial Infarction, restricted to a large, representative sample of Western medicine hospitals throughout China (n=162). We conducted a chart review of randomly sampled patients with AMI in 2001, 2006, and 2011, comparing early intravenous TCM use across years, predictors of any early intravenous TCM use, and association with in-hospital bleeding and mortality. From 2001 to 2011, early intravenous TCM use increased (2001: 38.2% versus 2006: 49.1% versus 2011: 56.1%; P<0.01). Nearly all (99%) hospitals used early intravenous TCM. Salvia miltiorrhiza was most commonly prescribed, used in one third (35.5%) of all patients admitted with AMI. Patients receiving any early intravenous TCM, compared with those who did not, were similar in age and sex and had fewer cardiovascular risk factors. In multivariable hierarchical models, admission to a secondary (versus tertiary) hospital was most strongly associated with early intravenous TCM use (odds ratio: 2.85; 95% confidence interval: 1.98-4.11). Hospital-level factors accounted for 55% of the variance (adjusted median odds ratio: 2.84). In exploratory analyses, there were no significant associations between early intravenous TCM and in-hospital bleeding or mortality. CONCLUSIONS: Early intravenous TCM use for AMI in China is increasing despite the lack of evidence of their benefit or harm. There is an urgent need to define the effects of these medications because they have become a staple of treatment in the world's most populous country. CLINICAL TRIAL REGISTRATION: URL: https://www.clinicaltrials.gov. Unique identifier: NCT01624883

Application of short hairpin RNAs (shRNAs) to study gene function in mammalian systems

Over the past decade, RNA interference (RNAi) plays an important role in biology, especially for silencing gene expression. RNA interference (RNAi) is a natural process through which expression of a targeted gene can be knocked down with high specificity and selectivity. Methods of mediating the RNAi effect involve small interfering RNA (siRNA) and short hairpin RNA (shRNA). In various applications, RNAi has been used to create model systems, to identify novel molecular targets, to study gene function in a genome-wide fashion, and to create new avenues for clinical therapeutics. This article reviews the current knowledge on the mechanism and applications of shRNA in mammalian and human cells.Keyword: shRNA, siRNA, RNAi, dicer, gene silencin

Supervised learning based multimodal MRI brain tumour segmentation using texture features from supervoxels

BACKGROUND: Accurate segmentation of brain tumour in magnetic resonance images (MRI) is a difficult task due to various tumour types. Using information and features from multimodal MRI including structural MRI and isotropic (p) and anisotropic (q) components derived from the diffusion tensor imaging (DTI) may result in a more accurate analysis of brain images. METHODS: We propose a novel 3D supervoxel based learning method for segmentation of tumour in multimodal MRI brain images (conventional MRI and DTI). Supervoxels are generated using the information across the multimodal MRI dataset. For each supervoxel, a variety of features including histograms of texton descriptor, calculated using a set of Gabor filters with different sizes and orientations, and first order intensity statistical features are extracted. Those features are fed into a random forests (RF) classifier to classify each supervoxel into tumour core, oedema or healthy brain tissue. RESULTS: The method is evaluated on two datasets: 1) Our clinical dataset: 11 multimodal images of patients and 2) BRATS 2013 clinical dataset: 30 multimodal images. For our clinical dataset, the average detection sensitivity of tumour (including tumour core and oedema) using multimodal MRI is 86% with balanced error rate (BER) 7%; while the Dice score for automatic tumour segmentation against ground truth is 0.84. The corresponding results of the BRATS 2013 dataset are 96%, 2% and 0.89, respectively. CONCLUSION: The method demonstrates promising results in the segmentation of brain tumour. Adding features from multimodal MRI images can largely increase the segmentation accuracy. The method provides a close match to expert delineation across all tumour grades, leading to a faster and more reproducible method of brain tumour detection and delineation to aid patient management

Radial Velocities as an Exoplanet Discovery Method

The precise radial velocity technique is a cornerstone of exoplanetary astronomy. Astronomers measure Doppler shifts in the star's spectral features, which track the line-of/sight gravitational accelerations of a star caused by the planets orbiting it. The method has its roots in binary star astronomy, and exoplanet detection represents the low-companion-mass limit of that application. This limit requires control of several effects of much greater magnitude than the signal sought: the motion of the telescope must be subtracted, the instrument must be calibrated, and spurious Doppler shifts "jitter" must be mitigated or corrected. Two primary forms of instrumental calibration are the stable spectrograph and absorption cell methods, the former being the path taken for the next generation of spectrographs. Spurious, apparent Doppler shifts due to non-center-of-mass motion (jitter) can be the result of stellar magnetic activity or photospheric motions and granulation. Several avoidance, mitigation, and correction strategies exist, including careful analysis of line shapes and radial velocity wavelength dependence.Comment: Invited review chapter. 13pp. v2 includes corrections to Eqs 3-6, updated references, and minor edit