ENFT: Efficient Non-Consecutive Feature Tracking for Robust Structure-from-Motion

Structure-from-motion (SfM) largely relies on feature tracking. In image sequences, if disjointed tracks caused by objects moving in and out of the field of view, occasional occlusion, or image noise, are not handled well, corresponding SfM could be affected. This problem becomes severer for large-scale scenes, which typically requires to capture multiple sequences to cover the whole scene. In this paper, we propose an efficient non-consecutive feature tracking (ENFT) framework to match interrupted tracks distributed in different subsequences or even in different videos. Our framework consists of steps of solving the feature `dropout' problem when indistinctive structures, noise or large image distortion exists, and of rapidly recognizing and joining common features located in different subsequences. In addition, we contribute an effective segment-based coarse-to-fine SfM algorithm for robustly handling large datasets. Experimental results on challenging video data demonstrate the effectiveness of the proposed system.Comment: 15 pages, 12 figure

Differentiation induction in acute promyelocytic leukemia

Hematopoiesis or blood cell formation is a continuous process in which maturing hematopoietic cells with a limited life span are formed. The formation of all different blood cell lineages originates from a small population of pluripotent stem cells that reside in the bone marrow. Progenitor cells that are committed to a certain lineage of differentiation orginate from these pluripotent stem cells. Hematopoiesis is regulated by a network of cytokines and hematopoietic growth factors (HGF). The HGFs are produced locally by stromal cells. mature blood cells, endothelial cells or specialized cells in organs such as lungs, liver and kidney. The levels of HGFs are elevated in response to extracellular stimuli, such as infection or bleeding, when a rapid rise of specific blood cell types is necessary. HGFs exert their effect by binding to their corresponding receptors expressed on the membrane of their target cells. Ligand binding results in the activation of downstream signaling pathways. A cascade of phosphorylation events is involved in signal transduction. In one pathway, the JAK Uanus kinase) family of protein tyrosine kinases are tyrosine phosphorylated and in turn activate a family of latent cytoplasmic transcription factors, called STAT (Signal Transduction and Activation of Transcription) proteins. Following their activation, these STAT proteins are assembled into complexes which then translocate to the nucleus and activate target genes by interaction with specific DNA sequences. Another major HGF receptor signal transduction pathway includes proteins that belong to the Ras family. Signaling molecules like Shc and Grb2 function as adaptor proteins in this pathway by linking phosphorylated receptors to downstream effectors. Grb2 binds to the activated receptor, and to Sos (Son of sevenless) which after translocation to the plasma membrane activates Ras triggering phosphorylation of Rat. The products of Raf, a serine tyrosine kinase and mitogen activated protein kinases (MAPK) transmit signals for futher transmission to the nucleus. In the nucleus, activation of transcription factors by phosphorylation or other mechanisms results in activation of genes involved in cellular proliferation and differentiation. Apart from affecting transcription, activated Ras results in cyclin D1 activation and stimulates p27kip1 degradation via Rho. Both events positively infiuence cell cycle entry (Figure 1.2)

Above 400 K Robust Perpendicular Ferromagnetic Phase in a Topological Insulator

The quantum anomalous Hall effect (QAHE) that emerges under broken time-reversal symmetry in topological insulators (TI) exhibits many fascinating physical properties for potential applications in nano-electronics and spintronics. However, in transition-metal doped TI, the only experimentally demonstrated QAHE system to date, the effect is lost at practically relevant temperatures. This constraint is imposed by the relatively low Curie temperature (Tc) and inherent spin disorder associated with the random magnetic dopants. Here we demonstrate drastically enhanced Tc by exchange coupling TI to Tm3Fe5O12, a high-Tc magnetic insulator with perpendicular magnetic anisotropy. Signatures that the TI surface states acquire robust ferromagnetism are revealed by distinct squared anomalous Hall hysteresis loops at 400 K. Point-contact Andreev reflection spectroscopy confirms that the TI surface is indeed spin-polarized. The greatly enhanced Tc, absence of spin disorder, and perpendicular anisotropy are all essential to the occurrence of the QAHE at high temperatures

Etiologic subtype predicts outcome in mild stroke: prospective data from a hospital stroke registry

BACKGROUND: Few studies on whether etiologic subtype can predict outcome in mild stroke are available. The study aim to explore the effect of different etiologic subtype on prognosis of these patients. METHODS: We prospectively registered consecutive cases of acute ischemic stroke from September. 01, 2009 to August. 31, 2011. Patients with National Institute of Health Stroke Scale (NIHSS) ≦3 and within 30 days of symptom onset were included. All cause death or disability (defined as modified Rankin Scale >2) were followed up at 3 months. The multivariate logistical regression model was used to analyse relationship between etiologic subtype and clinical outcomes. RESULTS: We included 680 cases, which accounted for 41.1% (680/1655) of the total registered cases. Mean age were 62.54 ± 13.51 years, and males were 65.4%. The median time of symptoms onset to admission was 72 hours. 3.8% (26/680) of cases admitted within 3 hours and 4.7% (32/680) admitted within 4.5 hours. However, no patient received intravenous thrombolysis. Of included patients, 21.5% large-artery atherosclerosis, 40.6% small-vessel disease, 7.5% cardioembolisms, 2.2% other causes and 28.2% undetermined causes. The rate of case fatality and death/disability was 2.2% and 10.1% respectively at 3 months. After adjustment of potential confounders, such as age, sex, NIHSS on admission and vascular risk factors et al., cardioembolism (RR = 3.395;95%CI 1.257 ~ 9.170) was the predictor of death or disability at 3 months and small vessel occlusion (RR = 0.412;95%CI 0.202 ~ 0.842) was the protective factor of death or disability at 3 months. CONCLUSION: Different etiologic subtype can predict the outcome in patients with mild stroke and it can help to stratify these patients for individual decision-making

High-resolution dynamic inversion imaging with motion-aberrations-free using optical flow learning networks.

Dynamic optical imaging (e.g. time delay integration imaging) is troubled by the motion blur fundamentally arising from mismatching between photo-induced charge transfer and optical image movements. Motion aberrations from the forward dynamic imaging link impede the acquiring of high-quality images. Here, we propose a high-resolution dynamic inversion imaging method based on optical flow neural learning networks. Optical flow is reconstructed via a multilayer neural learning network. The optical flow is able to construct the motion spread function that enables computational reconstruction of captured images with a single digital filter. This works construct the complete dynamic imaging link, involving the backward and forward imaging link, and demonstrates the capability of the back-ward imaging by reducing motion aberrations

Lithium titanate hydrates with superfast and stable cycling in lithium ion batteries

Lithium titanate and titanium dioxide are two best-known high-performance electrodes that can cycle around 10,000 times in aprotic lithium ion electrolytes. Here we show there exists more lithium titanate hydrates with superfast and stable cycling. That is, water promotes structural diversity and nanostructuring of compounds, but does not necessarily degrade electrochemical cycling stability or performance in aprotic electrolytes. As a lithium ion battery anode, our multi-phase lithium titanate hydrates show a specific capacity of about 130 mA h g⁻¹ at ∼35 C (fully charged within ∼100 s) and sustain more than 10,000 cycles with capacity fade of only 0.001% per cycle. In situ synchrotron diffraction reveals no 2-phase transformations, but a single solid-solution behavior during battery cycling. So instead of just a nanostructured intermediate to be calcined, lithium titanate hydrates can be the desirable final destination.United States. Department of Energy (Contract DE-AC0206CH11357