Topological nature of bound states in the radiation continuum

Bound states in the continuum (BICs) are unusual solutions of wave equations describing light or matter: they are discrete and spatially bounded, but exist at the same energy as a continuum of states which propagate to infinity. Until recently, BICs were constructed through fine-tuning parameters in the wave equation or exploiting the separability of the wave equation due to symmetry. More recently, BICs that that are both robust and not symmetry-protected (accidental) have been predicted and experimentally realized in periodic structures; the simplest such system is a periodic dielectric slab, which also has symmetry-protected BICs. Here we show that both types of BICs in such systems are vortex centers in the polarization direction of far-field radiation. The robustness of these BICs is due to the existence of conserved and quantized topological charges, defined by the number of times the polarization vectors wind around the vortex centers. Such charges can only be generated or annihilated by making large changes in the system parameters, and then only according to strict rules, which we derive and test numerically. Our results imply that laser emission based on such states will generate vector beams

Pattern formation in a polymer thin film induced by an in-plane electric field

This letter reports experimental work involving use of an in-plane electric field to induce morphological patterns in a thin polymer film. The film was first spin coated onto a glass wafer. Then, it was heated to above its glass transition temperature to achieve mobility in the fluid. An in-plane electric field was applied using two parallel electrodes, spaced 10 mm10 mm apart, whereupon the initially flat polymer∕air interface lost stability and formed islands. The self-assembled islands exhibited a narrow size distribution and demonstrated spatial ordering. We attribute the pattern formation to a combined mechanism of minimization of combined interface energy and electrostatic energy.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/70549/2/APPLAB-85-7-1161-1.pd

ISOKINETIC EVALUATION OF SHOULDER INTERNAL AND EXTERNAL ROTATORS STRENGTH AND ENDURANCE IN FOUR LEVELS OFSCHOOL-AGED BASEBALL PLAYERS

The purpose of this study was to compare strength and endurance differences in shoulder external and internal rotation torque ratios among four levels of school-aged baseball players, The subjects (N=97) were assessed the strength and endurance strength of shoulder internal and external rotation muscles with Kin Com dynamometer. The functional scapular plane of shoulder movement was used as the testing position, Strength development of IR and ER generally varied with school-aged increased, Comparing with adult pitchers, adolescence and pre-adolescence baseball pitchers had relatively weak shoulder external rotation muscles, especially after high repetition muscle contraction. In order to prevent shoulder injury in adolescence and pre-adolescence baseball throwers, muscle endurance in shoulder external rotators must be emphasized

Rapid identification of Mycobacterium tuberculosis infection by a new array format-based surface plasmon resonance method

Tubercle bacillus [TB] is one of the most important chronic infectious diseases that cause millions of deaths annually. While conventional smear microscopy and culture methods are widely used for diagnosis of TB, the former is insensitive, and the latter takes up to 6 to 8 weeks to provide a result, limiting the value of these methods in aiding diagnosis and intermediate decisions on treatment. Therefore, a rapid detection method is essential for the diagnosis, prognosis assessment, and recurrence monitoring. A new surface plasmon resonance [SPR] biosensor based on an array format, which allowed immobilizing nine TB antigens onto the sensor chip, was constructed. Simultaneous determination of multiple TB antibodies in serum had been accomplished with this array-based SPR system. The results were compared with enzyme-linked immunosorbent assay, a conventional immunological method. Array-based SPR showed more advantages in providing label-free and real-time detection. Additionally, the high sensitivity and specificity for the detection of TB infection showed its potential for future development of biosensor arrays for TB diagnosis

Methyl 4-[(5-chloro­pyrimidin-2-yl)carbamo­yl]benzoate

Mol­ecules of the title compound, C13H10ClN3O3, form centrosymmetric dimers via inter­molecular N—H⋯N hydrogen bonds generating an R 2 2(8) motif. The dimers are further connected through an O⋯Cl—C halogen bond [O⋯Cl = 3.233 (1) Å and O⋯Cl—C = 167.33 (1)°] into a chain along [110]. The secondary amide group adopts a cis conformation. Weak C—H⋯N hydrogen bonds among the methyl benzoate and pyrimidyl rings are also observed in the crystal structure

3D-PL: Domain Adaptive Depth Estimation with 3D-aware Pseudo-Labeling

For monocular depth estimation, acquiring ground truths for real data is not easy, and thus domain adaptation methods are commonly adopted using the supervised synthetic data. However, this may still incur a large domain gap due to the lack of supervision from the real data. In this paper, we develop a domain adaptation framework via generating reliable pseudo ground truths of depth from real data to provide direct supervisions. Specifically, we propose two mechanisms for pseudo-labeling: 1) 2D-based pseudo-labels via measuring the consistency of depth predictions when images are with the same content but different styles; 2) 3D-aware pseudo-labels via a point cloud completion network that learns to complete the depth values in the 3D space, thus providing more structural information in a scene to refine and generate more reliable pseudo-labels. In experiments, we show that our pseudo-labeling methods improve depth estimation in various settings, including the usage of stereo pairs during training. Furthermore, the proposed method performs favorably against several state-of-the-art unsupervised domain adaptation approaches in real-world datasets.Comment: Accepted in ECCV 2022. Project page: https://ccc870206.github.io/3D-PL

RssAB Signaling Coordinates Early Development of Surface Multicellularity in Serratia marcescens

Bacteria can coordinate several multicellular behaviors in response to environmental changes. Among these, swarming and biofilm formation have attracted significant attention for their correlation with bacterial pathogenicity. However, little is known about when and where the signaling occurs to trigger either swarming or biofilm formation. We have previously identified an RssAB two-component system involved in the regulation of swarming motility and biofilm formation in Serratia marcescens. Here we monitored the RssAB signaling status within single cells by tracing the location of the translational fusion protein EGFP-RssB following development of swarming or biofilm formation. RssAB signaling is specifically activated before surface migration in swarming development and during the early stage of biofilm formation. The activation results in the release of RssB from its cognate inner membrane sensor kinase, RssA, to the cytoplasm where the downstream gene promoters are located. Such dynamic localization of RssB requires phosphorylation of this regulator. By revealing the temporal activation of RssAB signaling following development of surface multicellular behavior, our findings contribute to an improved understanding of how bacteria coordinate their lifestyle on a surface