On the Multidimensional Augmentation of Fingerprint Data for Indoor Localization in A Large-Scale Building Complex Based on Multi-Output Gaussian Process

Wi-Fi fingerprinting becomes a dominant solution for large-scale indoor localization due to its major advantage of not requiring new infrastructure and dedicated devices. The number and the distribution of Reference Points (RPs) for the measurement of localization fingerprints like RSSI during the offline phase, however, greatly affects the localization accuracy; for instance, the UJIIndoorLoc is known to have the issue of uneven spatial distribution of RPs over buildings and floors. Data augmentation has been proposed as a feasible solution to not only improve the smaller number and the uneven distribution of RPs in the existing fingerprint databases but also reduce the labor and time costs of constructing new fingerprint databases. In this paper, we propose the multidimensional augmentation of fingerprint data for indoor localization in a large-scale building complex based on Multi-Output Gaussian Process (MOGP) and systematically investigate the impact of augmentation ratio as well as MOGP kernel functions and models with their hyperparameters on the performance of indoor localization using the UJIIndoorLoc database and the state-of-the-art neural network indoor localization model based on a hierarchical RNN. The investigation based on experimental results suggests that we can generate synthetic RSSI fingerprint data up to ten times the original data -- i.e., the augmentation ratio of 10 -- through the proposed multidimensional MOGP-based data augmentation without significantly affecting the indoor localization performance compared to that of the original data alone, which extends the spatial coverage of the combined RPs and thereby could improve the localization performance at the locations that are not part of the test dataset.Comment: 10 pages, 6 figures, under review for journal publicatio

Biomarkers of Systemic Inflammation in Ugandan Infants and Children Hospitalized With Respiratory Syncytial Virus Infection

Background: Optimizing outcomes in respiratory syncytial virus (RSV) pneumonia requires accurate diagnosis and determination of severity that, in resource-limited settings, is often based on clinical assessment alone. We describe host inflammatory biomarkers and clinical outcomes among children hospitalized with RSV lower respiratory tract infection (LRTI) in Uganda and controls with rhinovirus and pneumococcal pneumonia. Methods: 58 children hospitalized with LRTI were included. We compared 37 patients with RSV, 10 control patients with rhinovirus and 11 control patients with suspected pneumococcal pneumonia. Results: Patients in the RSV group had significantly lower levels of C-reactive protein (CRP) and chitinase-3-like protein 1 (CHI3L1) than the pneumococcal pneumonia group (P < 0.05 for both). Among children with RSV, higher admission levels of CRP predicted prolonged time to resolution of tachypnea, tachycardia and fever. Higher levels of CHI3L1 were associated with higher composite clinical severity scores and predicted prolonged time to resolution of tachypnea and tachycardia, time to wean oxygen and time to sit. Higher levels of lipocalin-2 (LCN2) predicted prolonged time to resolution of tachypnea, tachycardia and time to feed. Higher admission levels of all 3 biomarkers were predictive of a higher total volume of oxygen administered during hospitalization (P < 0.05 for all comparisons). Of note, CHI3L1 and LCN2 appeared to predict clinical outcomes more accurately than CRP, the inflammatory biomarker most widely used in clinical practice. Conclusions: Our findings suggest that CHI3L1 and LCN2 may be clinically informative biomarkers in childhood RSV LRTI in low-resource settings

Energy-Efficient Message Bundling with Delay and Synchronization Constraints in Wireless Sensor Networks

In a wireless sensor network (WSN), reducing the energy consumption of battery-powered sensor nodes is key to extending their operating duration before battery replacement is required. Message bundling can save on the energy consumption of sensor nodes by reducing the number of message transmissions. However, bundling a large number of messages could increase not only the end-to-end delays and message transmission intervals, but also the packet error rate (PER). End-to-end delays are critical in delay-sensitive applications, such as factory monitoring and disaster prevention. Message transmission intervals affect time synchronization accuracy when bundling includes synchronization messages, while an increased PER results in more message retransmissions and, thereby, consumes more energy. To address these issues, this paper proposes an optimal message bundling scheme based on an objective function for the total energy consumption of a WSN, which also takes into account the effects of packet retransmissions and, thereby, strikes the optimal balance between the number of bundled messages and the number of retransmissions given a link quality. The proposed optimal bundling is formulated as an integer nonlinear programming problem and solved using a self-adaptive global-best harmony search (SGHS) algorithm. The experimental results, based on the Cooja emulator of Contiki-NG, demonstrate that the proposed optimal bundling scheme saves up to 51.8% and 8.8% of the total energy consumption with respect to the baseline of no bundling and the state-of-the-art integer linear programming model, respectively

A new approach to high resolution, high contrast electron microscopy of macromolecular block copolymer assemblies

Determining the structure of macromolecular samples is vital for understanding and adapting their function. Transmission electron microscopy (TEM) is widely used to achieve this, but, owing to the weak electron scattering cross-section of carbon, TEM images of macromolecular samples are generally low contrast and low resolution. Here we implement a fast and practically simple routine to achieve high-contrast imaging of macromolecular samples using exit wave reconstruction (EWR), revealing a new level of structural detail. This is only possible using ultra-low contrast supports such as the graphene oxide (GO) used here and as such represents a novel application of these substrates. We apply EWR on GO membranes to study self-assembled block copolymer structures, distinguishing not only the general morphology or nanostructure, but also evidence for the substructure (i.e. the polymer chains) which gives insight into their formation mechanisms and functional properties

High myopia induced by form deprivation is associated with altered corneal biomechanical properties in chicks

The cornea is a soft, transparent, composite organic tissue, which forms the anterior outer coat of the eyeball. Although high myopia is increasing in prevalence worldwide and is known to alter the structure and biomechanical properties of the sclera, remarkably little is known about its impact on the biomechanics of the cornea. We developed and validated a novel optical-coherence-tomography-indentation probe–to measure corneal biomechanical properties in situ, in chicks having experimentally-induced high myopia, while maintaining intraocular pressure at levels covering the physiological range. We found that the cornea of highly myopic chicks was more steeply curved and softer, at all tested intraocular pressures, than that in contralateral, non-myopic eyes, or in age-matched normal, untreated eyes. These results indicate that the biomechanical properties of the cornea are altered in chicks developing experimentally-induced myopia

Extreme Asymmetry in the Disk of V1247 Ori

We present the first near-infrared scattered-light detection of the transitional disk around V1247 Ori, which was obtained using high-resolution polarimetric differential imaging observations with Subaru/HiCIAO. Our imaging in the H band reveals the disk morphology at separations of ~0.14"-0.86" (54-330 au) from the central star. The polarized intensity (PI) image shows a remarkable arc-like structure toward the southeast of the star, whereas the fainter northwest region does not exhibit any notable features. The shape of the arm is consistent with an arc of 0.28" $\pm$ 0.09" in radius (108 au from the star), although the possibility of a spiral arm with a small pitch angle cannot be excluded. V1247 Ori features an exceptionally large azimuthal contrast in scattered, polarized light; the radial peak of the southeastern arc is about three times brighter than the northwestern disk measured at the same distance from the star. Combined with the previous indication of an inhomogeneous density distribution in the gap at $\lesssim$46 au, the notable asymmetry in the outer disk suggests the presence of unseen companions and/or planet-forming processes ongoing in the arc.Comment: 21 pages, 5 figures, accepted for publication in PAS

Dysregulation of angiopoietin-Tie-2 axis in ugandan children hospitalized with pneumonia

Objective Pneumonia is the leading cause of death in children under 5, with the highest burden in resource-limited countries. Endothelial activation occurs in pneumonia and can be assessed using quantitative levels of biomarkers angiopoietin (Ang)-1 and Ang-2. We examined admission levels of Ang-1 and Ang-2 in pediatric pneumonia and their association with disease severity and outcome. Methods Prospective cohort study of children with hypoxemic pneumonia admitted to two hospitals in Uganda. Clinical, radiographic, and microbiologic characteristics were measured at admission. Disease severity was assessed using the Respiratory Index of Severity in Children (RISC). Plasma levels of Ang-1 and Ang-2 were quantified by enzyme-linked immunosorbent assay. Vital signs, oxygen supplementation, and mortality were assessed prospectively. Results We included 65 patients (43% female) with median age 19 months (IQR 8–24). Admission Ang-2/Ang-1 ratio directly correlated with RISC (ρ = 0.32, p = 0.008) and lactate level (ρ = 0.48, p 0.084) was associated with prolonged tachypnea (HR 0.50 (95%CI 0.29–0.87), p = 0.02), fever (HR 0.56 (95%CI 0.33 to 0.96), p = 0.02), longer duration of oxygen therapy (HR 0.59 (95%CI 0.35–0.99), p = 0.04), and hospital stay (HR 0.43 (95%CI 0.25–0.74), p = 0.001). The Ang-2/Ang-1 ratio at admission was higher in fatal cases relative to survivors (0.36 [IQR: 0.17–0.58] vs. 0.077 [IQR: 0.025–0.19]; p = 0.05) Conclusion Endothelial activation in hypoxemic pediatric pneumonia, reflected by high plasma Ang-2/Ang-1 ratio, is associated with disease severity, prolonged recovery time, and mortality

Community-wide assessment of GPCR structure modelling and ligand docking: GPCR Dock 2008

Recent breakthroughs in the determination of the crystal structures of G protein-coupled receptors (GPCRs) have provided new opportunities for structure-based drug design strategies targeting this protein family. With the aim of evaluating the current status of GPCR structure prediction and ligand docking, a community-wide, blind prediction assessment - GPCR Dock 2008 - was conducted in coordination with the publication of the crystal structure of the human adenosine A2Areceptor bound to the ligand ZM241385. Twenty-nine groups submitted 206 structural models before the release of the experimental structure, which were evaluated for the accuracy of the ligand binding mode and the overall receptor model compared with the crystal structure. This analysis highlights important aspects for success and future development, such as accurate modelling of structurally divergent regions and use of additional biochemical insight such as disulphide bridges in the extracellular loops