368 research outputs found

    Compressive sensing based imaging via belief propagation

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    Multiple description coding (MDC) using Compressive Sensing (CS) mainly aims at restoring an image from a small subset of samples with reasonable accuracy using an iterative message passing decoding algorithm commonly known as Belief Propagation (BP). The CS technique can accurately recover any compressible or sparse signal from a lesser number of non-adaptive, randomized linear projection samples than that specified by the Nyquist rate. In this work, we demonstrate how CS-based encoding generates measurements from the sparse image signal and the measurement matrix. Then we demonstrate how a BP decoding algorithm reconstructs the image from the measurements generated. In our work, the CS-BP algorithm assumes that all the unknown variables have the same prior distribution as we do not have any knowledge of the side information available during the initiation of the decoding process. Thus, we prove that this algorithm is effective even in the absence of side information

    An Integrated Camera and Radar on-Robot System for Human Robot Collaboration

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    The increased demand for collaborative tasks between humans and robots has caused an upsurge in newer sensor technologies to detect, locate, track, and monitor workers in a robot workspace. The challenge is to balance the accuracy, cost, and responsiveness of the system to maximize the safety of the worker. This work presents a sensor system that combines six 60GHz radar modules and six cameras to accurately track the location and speed of the workers in all 360 degrees around the robot. While the radar is tuned to identify moving targets, the cameras perform pose detection to evaluate the humans in the workspace and when fused, provide 4D pose estimates: 3D location and velocity. A custom PCB and enclosure is designed for it and it is mounted to the end-effector of a UR-10 robot. This system performs all of its computation on an Nvidia AGX Xavier for offline processing which allows it to be mounted to a mobile robot for outdoor use. Lastly, this system was evaluated for accuracy in human detection as well as accuracy in velocity measurements through numerous static and dynamic scenarios for the robot, the human, and both combined

    Context-dependent spatially periodic activity in the human entorhinal cortex

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    The spatially periodic activity of grid cells in the entorhinal cortex (EC) of the rodent, primate, and human provides a coordinate system that, together with the hippocampus, informs an individual of its location relative to the environment and encodes the memory of that location. Among the most defining features of grid-cell activity are the 60 degrees rotational symmetry of grids and preservation of grid scale across environments. Grid cells, however, do display a limited degree of adaptation to environments. It remains unclear if this level of environment invariance generalizes to human grid-cell analogs, where the relative contribution of visual input to the multimodal sensory input of the EC is significantly larger than in rodents. Patients diagnosed with nontractable epilepsy who were implanted with entorhinal cortical electrodes performing virtual navigation tasks to memorized locations enabled us to investigate associations between grid-like patterns and environment. Here, we report that the activity of human entorhinal cortical neurons exhibits adaptive scaling in grid period, grid orientation, and rotational symmetry in close association with changes in environment size, shape, and visual cues, suggesting scale invariance of the frequency, rather than the wavelength, of spatially periodic activity. Our results demonstrate that neurons in the human EC represent space with an enhanced flexibility relative to neurons in rodents because they are endowed with adaptive scalability and context dependency

    Forkhead box O-class 1 and Forkhead box G1 as Prognostic Markers for Bladder Cancer

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    Forkhead box O-class 1 (FOXO1) is a key regulator of glucose homeostasis, cell-cycle progression, and apoptosis. Its functions are modulated by forkhead box G1 (FOXG1), which acts as a transcriptional repressor with oncogenic potential. Real-time PCR and immunohistochemical staining were performed in 174 primary bladder cancer specimens and 21 normal bladder mucosae to evaluate these genes. FOXO1 and FOXG1 mRNA expression in cancer tissues were higher than in normal mucosae (each P<0.001). FOXO1 mRNA levels were significantly higher in samples of non-progressed patients (P<0.001), but FOXG1 were enhanced in those of progressed patients (P=0.019). On univariate analysis, FOXO1 mRNA expression was significantly associated with grade, stage, recurrence, progression and survival (each P<0.05). On multivariate analysis, increased FOXO1 mRNA expression was associated with both reduced disease progression (odds ratio [OR], 0.367; 95% confidence interval [CI], 0.163-0.826, P=0.015) and enhanced disease-free survival (OR, 3.262; 95% CI, 1.361-7.820, P=0.008). At a median follow-up of 33 months (range 2 to 156), the patients with a high FOXO1 mRNA expression had a significantly prolonged survival (P=0.001). Immunohistochemical findings of FOXO1 were generally concordant with mRNA expression levels. In conclusion, FOXO1 may be a promising marker for predicting progression in human bladder cancers

    Ictal time-irreversible intracranial EEG signals as markers of the epileptogenic zone.

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    OBJECTIVE: To show that time-irreversible EEG signals recorded with intracranial electrodes during seizures can serve as markers of the epileptogenic zone. METHODS: We use the recently developed method of mapping time series into directed horizontal graphs (dHVG). Each node of the dHVG represents a time point in the original intracranial EEG (iEEG) signal. Statistically significant differences between the distributions of the nodes' number of input and output connections are used to detect time-irreversible iEEG signals. RESULTS: In 31 of 32 seizure recordings we found time-irreversible iEEG signals. The maximally time-irreversible signals always occurred during seizures, with highest probability in the middle of the first seizure half. These signals spanned a large range of frequencies and amplitudes but were all characterized by saw-tooth like shaped components. Brain regions removed from patients who became post-surgically seizure-free generated significantly larger time-irreversibilities than regions removed from patients who still had seizures after surgery. CONCLUSIONS: Our results corroborate that ictal time-irreversible iEEG signals can indeed serve as markers of the epileptogenic zone and can be efficiently detected and quantified in a time-resolved manner by dHVG based methods. SIGNIFICANCE: Ictal time-irreversible EEG signals can help to improve pre-surgical evaluation in patients suffering from pharmaco-resistant epilepsies.K.S. gratefully acknowledges support by the Swiss National Science Foundation (SNF 32003B_155950). H.G. gratefully acknowledges support by a Research Grant of the Inselspital Bern. R.G.A. acknowledges funding from the Volkswagen foundation and was supported by the Spanish Ministry of Economy and Competitiveness (Grant FIS2014-54177- R). This project has received funding from the European Union’s Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 642563 (R.G.A.). MG gratefully acknowledges the financial support of the EPSRC via grant EP/N014391/1, funding from Epilepsy Research UK via grant number A1007 and was generously supported by a Wellcome Trust Institutional Strategic Support Award (WT105618MA)

    Mechanism of cigarette smoke condensate-induced acute inflammatory response in human bronchial epithelial cells

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    BACKGROUND: To demonstrate the involvement of tobacco smoking in the pathophysiology of lung disease, the responses of pulmonary epithelial cells to cigarette smoke condensate (CSC) — the particulate fraction of tobacco smoke — were examined. METHODS: The human alveolar epithelial cell line A549 and normal human bronchial epithelial cells (NHBEs) were exposed to 0.4 μg/ml CSC, a concentration that resulted in >90% cell survival and <5% apoptosis. Changes in gene expression and signaling responses were determined by RT-PCR, western blotting and immunocytofluorescence. RESULTS: NHBEs exposed to CSC showed increased expression of the inflammatory mediators sICAM-1, IL-1β, IL-8 and GM-CSF, as determined by RT-PCR. CSC-induced IL-1β expression was reduced by PD98059, a blocker of mitogen-actived protein kinase (MAPK) kinase (MEK), and by PDTC, a NFκB inhibitor. Analysis of intracellular signaling pathways, using antibodies specific for phosphorylated MAPKs (extracellular signal-regulated kinase [ERK]-1/2), demonstrated an increased level of phosphorylated ERK1/2 with increasing CSC concentration. Nuclear localization of phosphorylated ERK1/2 was seen within 30 min of CSC exposure and was inhibited by PD98059. Increased phosphorylation and nuclear translocation of IκB was also seen after CSC exposure. A549 cells transfected with a luciferase reporter plasmid containing a NFκB-inducible promoter sequence and exposed to CSC (0.4 μg/ml) or TNF-α (50 ng/ml) had an increased reporter activity of approximately 2-fold for CSC and 3.5-fold for TNF-α relative to untreated controls. CONCLUSION: The acute phase response of NHBEs to cigarette smoke involves activation of both MAPK and NFκB

    Fibroblasts from different sites may promote or inhibit recruitment of flowing lymphocytes by endothelial cells

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    We examined the hypothesis that stromal fibroblasts modulate the ability of endothelial cells (EC) to recruit lymphocytes in a site-specific manner. PBL were perfused over HUVEC that had been cultured with fibroblasts isolated from the inflamed synovium or the skin of patients with rheumatoid arthritis or osteoarthritis, or from normal synovium, with or without exposure to the inflammatory cytokines TNF-a+IFN-c. Fibroblasts from inflamed synovium, but no others, caused unstimulated HUVEC to bind flowing lymphocytes. This adhesion was supported by a4b1-VCAM-1 interaction and stabilised by activation of PBL through CXCR4–CXCL12. Antibody neutralisation of IL-6 during co-culture effectively abolished the ability of EC to bind lymphocytes. Cytokine-stimulated EC supported high levels of lymphocyte adhesion, through the presentation of VCAM-1, E-selectin and chemokine(s) acting through CXCR3. Interestingly, co-culture with dermal fibroblasts caused a marked reduction in cytokine-induced adhesion, while synovial fibroblasts had variable effects depending on their source. In the dermal co-cultures, neutralisation of IL-6 or TGF-b caused partial recovery of cytokine-induced lymphocyte adhesion; this was complete when both were neutralised. Exogenous IL-6 was also found to inhibit response to TNF-a+IFN-c. Normal stromal fibroblasts appear to regulate the cytokine-sensitivity of vascular endothelium, while fibroblasts associated with chronic inflammation bypass this and develop a directly inflammatory phenotype. Actions of IL-6 might be pro-inflammatory or anti-inflammatory, depending on the local milieu

    Venglustat, a novel glucosylceramide synthase inhibitor, in patients at risk of rapidly progressing ADPKD: primary results of a double-blind, placebo-controlled, phase 2/3 randomized clinical trial

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    RATIONALE AND OBJECTIVE: Autosomal dominant polycystic kidney disease (ADPKD) is characterized by the formation of multiple kidney cysts that leads to growth in total kidney volume (TKV) and progression to kidney failure. Venglustat is a glucosylceramide synthase inhibitor that has been shown to inhibit cyst growth and reduce kidney failure in preclinical models of ADPKD. STUDY DESIGN: STAGED-PKD was a two-stage, multicenter, double-blind, randomized, placebo-controlled Phase 2/3 study in adults with ADPKD at risk of rapidly progressive disease, selected based on Mayo Kidney Volume Class 1C-1E and an estimated glomerular filtration rate (eGFR) of 30-89.9 mL/min/1.73 m2. SETTING AND PARTICIPANTS: Enrollment included 236 and 242 patients in Stages 1 and 2, respectively. INTERVENTION(S): In Stage 1, patients were randomized 1:1:1 to venglustat 8 mg or 15 mg, or placebo. In Stage 2, patients were randomized 1:1 to venglustat 15 mg (highest dose identified as safe and well tolerated in Stage 1) or placebo. OUTCOMES: Primary endpoints were rate of change in TKV over 18 months in Stage 1 and eGFR slope over 24 months in Stage 2. Secondary endpoints were eGFR slope over 18 months (Stage 1), rate of change in TKV (Stage 2), and safety/tolerability, pain, and fatigue (Stages 1 and 2). RESULTS: A prespecified interim futility analysis showed that venglustat treatment had no effect on the annualized rate of change in TKV over 18 months (Stage 1) and had a faster rate of decline in eGFR slope over 24 months (Stage 2). Due to this lack of efficacy, the study was terminated early. LIMITATIONS: The short follow-up after end-of-treatment and limited generalizability of findings. CONCLUSIONS: In patients with rapidly progressing ADPKD, treatment with venglustat at either 8 mg or 15 mg showed no change in the rate of change in TKV and a faster rate of eGFR decline in the STAGED-PKD trial despite a dose-dependent decrease in plasma glucosylceramide (GL-1) levels
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