Robust Reflection Removal with Flash-only Cues in the Wild

We propose a simple yet effective reflection-free cue for robust reflection removal from a pair of flash and ambient (no-flash) images. The reflection-free cue exploits a flash-only image obtained by subtracting the ambient image from the corresponding flash image in raw data space. The flash-only image is equivalent to an image taken in a dark environment with only a flash on. This flash-only image is visually reflection-free and thus can provide robust cues to infer the reflection in the ambient image. Since the flash-only image usually has artifacts, we further propose a dedicated model that not only utilizes the reflection-free cue but also avoids introducing artifacts, which helps accurately estimate reflection and transmission. Our experiments on real-world images with various types of reflection demonstrate the effectiveness of our model with reflection-free flash-only cues: our model outperforms state-of-the-art reflection removal approaches by more than 5.23dB in PSNR. We extend our approach to handheld photography to address the misalignment between the flash and no-flash pair. With misaligned training data and the alignment module, our aligned model outperforms our previous version by more than 3.19dB in PSNR on a misaligned dataset. We also study using linear RGB images as training data. Our source code and dataset are publicly available at https://github.com/ChenyangLEI/flash-reflection-removal.Comment: Extension of CVPR 2021 paper [arXiv:2103.04273], submitted to TPAMI. Our source code and dataset are publicly available at http://github.com/ChenyangLEI/flash-reflection-remova

DESIGN, SYNTHESIS AND CHARACTERIZATION OF MOLECULAR AND POLYMERIC CYCLOSILANES

The structural complexity of crystalline silicon has inspired synthetic chemists to design cyclosilane building blocks for well-defined novel silicon materials with tunable optical properties. This dissertation describes synthetic strategies of constructing novel molecular and polymeric cyclosilane materials and their structure-property-relationships. Polycyclosilanes exhibit microstructure-dependent thermal properties and connectivity-dependent UV-vis absorption features. Novel hybrid sigma,pi-conjugated cyclosilane building blocks with pre-defined stereochemistry allow access to stereoregular polysilanes. Constitutional isomers of sulfur-incorporated π,n,σ-conjugated cyclosilanes can exhibit distinct conformations and delocalization patterns. Theoretical investigations through density functional theory calculations contribute to understanding the optical and electronic properties of these molecular and polymeric cyclosilane materials

Microstructure et anisotropie macroscopique de suspensions hors régime de Stokes

Une évaluation expérimentale sur un lit fluidisé 2D de la fonction de corrélation à deux particules sera présentée. Les résultats pour des nombres de Reynolds particulaires compris entre 1 et 1000 montrent le rôle des sillages sur le comportement microscopique de la suspension. Leur conséquence sur l’anisotropie de la répartition macroscopique de la phase solide sera ensuite expliquée à partir d’un schéma montrant comment ils conduisent à la formation de chaînes de particules

Caldesmon regulates the motility of vascular smooth muscle cells by modulating the actin cytoskeleton stability

<p>Abstract</p> <p>Background</p> <p>Migration of vascular smooth muscle cells (SMCs) from the media to intima constitutes a critical step in the development of proliferative vascular diseases. To elucidate the regulatory mechanism of vacular SMC motility, the roles of caldesmon (CaD) and its phosphorylation were investigated.</p> <p>Methods</p> <p>We have performed Transwell migration assays, immunofluorescence microscopy, traction microscopy and cell rounding assays using A7r5 cells transfected with EGFP (control), EGFP-wtCaD or phosphomimetic CaD mutants, including EGFP-A1A2 (the two PAK sites Ser452 and Ser482 converted to Ala), EGFP-A3A4 (the two Erk sites Ser497 and Ser527 converted to Ala), EGFP-A1234 (both PAK- and Erk-sites converted to Ala) and EGFP-D1234 (both PAK- and Erk-sites converted to Asp).</p> <p>Results</p> <p>We found that cells transfected with wtCaD, A1A2 or A3A4 mutants of CaD migrated at a rate approximately 50% more slowly than those EGFP-transfected cells. The migration activity for A1234 cells was only about 13% of control cells. Thus it seems both MAPK and PAK contribute to the motility of A7r5 cells and the effects are comparable and additive. The A1234 mutant also gave rise to highest strain energy and lowest rate of cell rounding. The migratory and contractile properties of these cells are consistent with stabilized actin cytoskeletal structures. Indeed, the A1234 mutant cells exhibited most robust stress fibers, whereas cells transfected with wtCaD or A3A4 (and A1A2) had moderately reinforced actin cytoskeleton. The control cells (transfected with EGFP alone) exhibited actin cytoskeleton that was similar to that in untransfected cells, and also migrated at about the same speed as the untransfected cells.</p> <p>Conclusions</p> <p>These results suggest that both the expression level and the level of MAPK- and/or PAK-mediated phosphorylation of CaD play key roles in regulating the cell motility by modulating the actin cytoskeleton stability in dedifferentiated vascular SMCs such as A7r5.</p

Flipbot: Learning Continuous Paper Flipping via Coarse-to-Fine Exteroceptive-Proprioceptive Exploration

This paper tackles the task of singulating and grasping paper-like deformable objects. We refer to such tasks as paper-flipping. In contrast to manipulating deformable objects that lack compression strength (such as shirts and ropes), minor variations in the physical properties of the paper-like deformable objects significantly impact the results, making manipulation highly challenging. Here, we present Flipbot, a novel solution for flipping paper-like deformable objects. Flipbot allows the robot to capture object physical properties by integrating exteroceptive and proprioceptive perceptions that are indispensable for manipulating deformable objects. Furthermore, by incorporating a proposed coarse-to-fine exploration process, the system is capable of learning the optimal control parameters for effective paper-flipping through proprioceptive and exteroceptive inputs. We deploy our method on a real-world robot with a soft gripper and learn in a self-supervised manner. The resulting policy demonstrates the effectiveness of Flipbot on paper-flipping tasks with various settings beyond the reach of prior studies, including but not limited to flipping pages throughout a book and emptying paper sheets in a box.Comment: Accepted to International Conference on Robotics and Automation (ICRA) 202

Learn to Grasp via Intention Discovery and its Application to Challenging Clutter

Humans excel in grasping objects through diverse and robust policies, many of which are so probabilistically rare that exploration-based learning methods hardly observe and learn. Inspired by the human learning process, we propose a method to extract and exploit latent intents from demonstrations, and then learn diverse and robust grasping policies through self-exploration. The resulting policy can grasp challenging objects in various environments with an off-the-shelf parallel gripper. The key component is a learned intention estimator, which maps gripper pose and visual sensory to a set of sub-intents covering important phases of the grasping movement. Sub-intents can be used to build an intrinsic reward to guide policy learning. The learned policy demonstrates remarkable zero-shot generalization from simulation to the real world while retaining its robustness against states that have never been encountered during training, novel objects such as protractors and user manuals, and environments such as the cluttered conveyor.Comment: Accepted to IEEE Robotics and Automation Letters (RA-L

ERRA: An Embodied Representation and Reasoning Architecture for Long-horizon Language-conditioned Manipulation Tasks

This letter introduces ERRA, an embodied learning architecture that enables robots to jointly obtain three fundamental capabilities (reasoning, planning, and interaction) for solving long-horizon language-conditioned manipulation tasks. ERRA is based on tightly-coupled probabilistic inferences at two granularity levels. Coarse-resolution inference is formulated as sequence generation through a large language model, which infers action language from natural language instruction and environment state. The robot then zooms to the fine-resolution inference part to perform the concrete action corresponding to the action language. Fine-resolution inference is constructed as a Markov decision process, which takes action language and environmental sensing as observations and outputs the action. The results of action execution in environments provide feedback for subsequent coarse-resolution reasoning. Such coarse-to-fine inference allows the robot to decompose and achieve long-horizon tasks interactively. In extensive experiments, we show that ERRA can complete various long-horizon manipulation tasks specified by abstract language instructions. We also demonstrate successful generalization to the novel but similar natural language instructions.Comment: Accepted to IEEE Robotics and Automation Letters (RA-L

Adjuvant chemotherapy for lymph node positive esophageal squamous cell cancer: The prediction role of low mean platelet volume

BackgroundThis study aimed to examine whether MPV is a useful prognostic marker and investigated whether MPV is a risk factor that helps identify patients with locally advanced-stage ESCC who will most likely benefit from adjuvant chemotherapy.MethodsPatients (n =1690) with histologically confirmed ESCC were diagnosed with locally advanced stage (pT3-4N0M0 and pT1-4N+M0) at Sichuan Cancer Hospital from 2009 to 2017. Clinicopathological factors and platelet-related values were tested for their associations with survival using univariate and multivariate Cox regression analyses. The optimal cut-off value for continuous variables was determined using the ‘maxstat’ R package. The KM curve continuous variable analysis was performed to identify the optimal cut-off value for MPV. Cumulative survival rates were determined using the Kaplan–Meier estimator and compared using the log-rank test. The survival analysis was performed using the ‘survival’ R package. All statistical analyses were performed using R software 4.1.3 (https://www.r-project.org/), and a two-sided p-value &lt;0.05 was considered to indicate statistical significance.ResultsMultivariate analysis indicated that low MPV was an important risk factor for overall survival in locally advanced ESCC, independent of classic clinicopathological factors. The optimal cut-off value of MPV (11.8 fL) was used to stratify high-risk patients. Patients with low mean platelet volumes had a worse prognosis than those with larger platelet volumes, according to Kaplan–Meier analysis and the log-rank test. Patients diagnosed with a pathological lymph node-positive stage with a low MPV (≤11.8 fL) benefited from postoperative chemotherapy, but not those with a high-level MPV (&gt;11.8 fL).ConclusionMPV served as an independent predictor of prognosis of locally advanced-stage ESCC and predicted a survival benefit conferred by postoperative adjuvant chemotherapy in lymph node-positive ESCC

A Review of Design Considerations of Centrifugal Pump Capability for Handling Inlet Gas-Liquid Two-Phase Flows

Most of the pumps working under two phase flows conditions are used in petroleum industry applications, like electrical submersible pumps (ESP) for hydrocarbon fluids, in chemistry, nuclear industries and in agriculture for irrigation purposes as well. Two-phase flows always deteriorate overall pump performances compared with single flow conditions. Several papers have been published aiming to understand flow physics and to model all the main mechanisms that govern gas pocket formation and surging phenomena. These mechanisms depend on the pump type, the impeller geometry, the rotational speed, design and off-design liquid flow rate conditions, the volumetric gas fraction, the fluid properties and the inlet pressure. In the present paper, a review on two phase performances from various centrifugal pumps designs is presented, mainly based on experimental results. The main focus is devoted to detect the significant geometrical parameters that: (1) Modify the pump head degradation level under bubbly flow regime assumption; (2) Allow single stage centrifugal pumps keep working under two-phase flow conditions with high inlet void fraction values before pump shut down, whatever the pump performance degradations and liquid production rates should be. Because most of the published experimental studies are performed on dedicated laboratory centrifugal pump models, most of the present review is based on air-water mixtures as the working fluid with inlet pressures close to atmospheric conditions. The following review supposes that gas phase is considered as a non-condensable perfect gas, while the liquid phase is incompressible. Both phases are isolated from external conditions: neither mass nor heat transfer take place between the phases

Acetyl-CoA synthetase 2 promotes acetate utilization and maintains cancer cell growth under metabolic stress

A functional genomics study revealed that the activity of acetyl-CoA synthetase 2 (ACSS2) contributes to cancer cell growth under low-oxygen and lipid-depleted conditions. Comparative metabolomics and lipidomics demonstrated that acetate is used as a nutritional source by cancer cells in an ACSS2-dependent manner, and supplied a significant fraction of the carbon within the fatty acid and phospholipid pools. ACSS2 expression is upregulated under metabolically stressed conditions and ACSS2 silencing reduced the growth of tumor xenografts. ACSS2 exhibits copy-number gain in human breast tumors, and ACSS2 expression correlates with disease progression. These results signify a critical role for acetate consumption in the production of lipid biomass within the harsh tumor microenvironment