KD-EKF: A Consistent Cooperative Localization Estimator Based on Kalman Decomposition

In this paper, we revisit the inconsistency problem of EKF-based cooperative localization (CL) from the perspective of system decomposition. By transforming the linearized system used by the standard EKF into its Kalman observable canonical form, the observable and unobservable components of the system are separated. Consequently, the factors causing the dimension reduction of the unobservable subspace are explicitly isolated in the state propagation and measurement Jacobians of the Kalman observable canonical form. Motivated by these insights, we propose a new CL algorithm called KD-EKF which aims to enhance consistency. The key idea behind the KD-EKF algorithm involves perform state estimation in the transformed coordinates so as to eliminate the influencing factors of observability in the Kalman observable canonical form. As a result, the KD-EKF algorithm ensures correct observability properties and consistency. We extensively verify the effectiveness of the KD-EKF algorithm through both Monte Carlo simulations and real-world experiments. The results demonstrate that the KD-EKF outperforms state-of-the-art algorithms in terms of accuracy and consistency

Characterization of Correlated Calcium Dynamics in Astrocytes in PCL Scaffold: Application of Wavelet Transform Coherence

While 2D culture models have been used extensively to elucidate the cell-to-cell communication, they do not recapitulate fully the 3D characteristics of microenvironment in vivo, e.g., polarized cell attachment and generally confer a considerably stiffer substrate than the endogenous extracellular matrix. Development of fibrous scaffolds that can better mimic the native microenvironment and improve the spatial arrangement of seeded cells should foster experimental strategies to monitor and determine the 3D cell-to-cell communication. In this study, poly(ε- caprolactone) (PCL) fibers were fabricated in different sizes using a microfluidic platform and spatially arranged to create a suitable 3D microenvironment in order to investigate the cell viability and calcium signaling in mouse astrocytes. A powerful algorithm, referred to as wavelet transform coherence (WTC), was applied to establish the correlation between astrocytes that were seeded on the PCL fiber. As expected, two astrocytes that appeared to be in physical contact showed high correlation, whereas two astrocytes seeded within a few cell lengths but not in physical contact showed negligible correlation. The WTC correlation analysis of a cluster of six astrocytes seeded on a single PCL fiber led to surprising results that the cells can communicate over many cell lengths without being in physical contact. More systematic studies using spatially controlled 3D microenvironment will likely help unravel the intricate cell communication mechanisms

Effects of natural products on skin inflammation caused by abnormal hormones secreted by the adrenal gland

The cortex of adrenal gland produces glucocorticoid, mineralocorticoid, and androgen. The medulla of adrenal gland secrets catecholamines. These hormones play an important role in regulating blood pressure, metabolism, and homeostasis of glucose or electrolytes. Hypersecretion or hyposecretion by the adrenal gland will cause a complex cascade of hormone effects and lead to diseases, including Addison’s disease, Cushing’s syndrome, and congenital adrenal cortical hyperplasia. Skin is the largest organ of body. It provides protection and acts as a barrier against external damage factors like infectious organisms, chemicals, and allergens. Endocrinologic disorders often induce cutaneous abnormalities. According to the previous evidences, natural products have the potential properties for attenuating skin disorders and improving dermatologic symptoms by inhibiting inflammation through MAPK or PI3K/AKT-dependent NF-κB pathways. The natural products may also promote skin wound healing by inhibiting the production of matrix metalloproteinase-9. We systematically searched the relevant articles from databases, including PubMed, Embase, and Cochrane library databases, to review the effects of natural products on skin disorders. This article summarized the effects of natural products on skin inflammation caused by abnormal hormone secreted by adrenal gland. And the published papers indicated that natural products might be a potential source for treating skin diseases

Neural networks to predict radiographic brain injury in pediatric patients treated with Extracorporeal Membrane Oxygenation

Brain injury is a significant source of morbidity and mortality for pediatric patients treated with Extracorporeal Membrane Oxygenation (ECMO). Our objective was to utilize neural networks to predict radiographic evidence of brain injury in pediatric ECMO-supported patients and identify specific variables that can be explored for future research. Data from 174 ECMO-supported patients were collected up to 24 h prior to, and for the duration of, the ECMO course. Thirty-five variables were collected, including physiological data, markers of end-organ perfusion, acid-base homeostasis, vasoactive infusions, markers of coagulation, and ECMO-machine factors. The primary outcome was the presence of radiologic evidence of moderate to severe brain injury as established by brain CT or MRI. This information was analyzed by a neural network, and results were compared to a logistic regression model as well as clinician judgement. The neural network model was able to predict brain injury with an Area Under the Curve (AUC) of 0.76, 73% sensitivity, and 80% specificity. Logistic regression had 62% sensitivity and 61% specificity. Clinician judgment had 39% sensitivity and 69% specificity. Sequential feature group masking demonstrated a relatively greater contribution of physiological data and minor contribution of coagulation factors to the model\u27s performance. These findings lay the foundation for further areas of research directions

A Pilot Study Identifying Brain-Targeting Adaptive Immunity in Pediatric Extracorporeal Membrane Oxygenation Patients with Acquired Brain Injury

OBJECTIVES: Extracorporeal membrane oxygenation provides short-term cardiopulmonary life support, but is associated with peripheral innate inflammation, disruptions in cerebral autoregulation, and acquired brain injury. We tested the hypothesis that extracorporeal membrane oxygenation also induces CNS-directed adaptive immune responses which may exacerbate extracorporeal membrane oxygenation-associated brain injury. DESIGN: A single center prospective observational study. SETTING: Pediatric and cardiac ICUs at a single tertiary care, academic center. PATIENTS: Twenty pediatric extracorporeal membrane oxygenation patients (0-14 yr; 13 females, 7 males) and five nonextracorporeal membrane oxygenation Pediatric Logistic Organ Dysfunction score matched patients. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: Venous blood samples were collected from the extracorporeal membrane oxygenation circuit at day 1 (10-23 hr), day 3, and day 7 of extracorporeal membrane oxygenation. Flow cytometry quantified circulating innate and adaptive immune cells, and CNS-directed autoreactivity was detected using an in vitro recall response assay. Disruption of cerebral autoregulation was determined using continuous bedside near-infrared spectroscopy and acquired brain injury confirmed by MRI. Extracorporeal membrane oxygenation patients with acquired brain injury (n = 9) presented with a 10-fold increase in interleukin-8 over extracorporeal membrane oxygenation patients without brain injury (p \u3c 0.01). Furthermore, brain injury within extracorporeal membrane oxygenation patients potentiated an inflammatory phenotype in adaptive immune cells and selective autoreactivity to brain peptides in circulating B cell and cytotoxic T cell populations. Correlation analysis revealed a significant relationship between adaptive immune responses of extracorporeal membrane oxygenation patients with acquired brain injury and loss of cerebral autoregulation. CONCLUSIONS: We show that pediatric extracorporeal membrane oxygenation patients with acquired brain injury exhibit an induction of pro-inflammatory cell signaling, a robust activation of adaptive immune cells, and CNS-targeting adaptive immune responses. As these patients experience developmental delays for years after extracorporeal membrane oxygenation, it is critical to identify and characterize adaptive immune cell mechanisms that target the developing CNS

Pore structure and fractal characteristics of Wufeng–Longmaxi formation shale in northern Yunnan–Guizhou, China

In this study, the microscopic pore characteristics of shale in marine strata are evaluated. Based on field emission scanning electron microscopy (FE-SEM), low-temperature N2 adsorption (LT-N2GA), low-pressure CO2 adsorption (LP-CO2GA) and high-pressure methane adsorption (HPMA) experiments, the pore characteristics of 12 shales from the Wufeng–Longmaxi Formations in northern Yunnan and Guizhou are characterized qualitatively and quantitatively. Fractal Frenkel–Halsey–Hill (FHH) theory is used to analyse the fractal characteristics, and the adsorption pore characteristics of shale are discussed. The correlation between the fractal dimension and pore structure and adsorption performance is determined. The results show that the total organic carbon (TOC) contents of the 12 shales are in the middle–low level, ranging from 0.43% to 5.42%, and the shales are generally in the highly mature to overmaturity stage (vitrinite reflectance (Ro) values between 1.80% and 2.51%). The mineral composition is mainly quartz and clay minerals. The average clay mineral content is 40.98% (ranging from 24.7% to 63.3%), and the average quartz content is 29.03% (ranging from 16.8% to 39.6%), which are consistent with those of marine shale in the Sichuan Basin. FE-SEM and LT-N2GA isotherms reveal a complex shale pore structure and open pore style, mainly ink bottle-shaped and parallel plate-like pores. The total pore volumes (PVs) range from 0.012–0.052 cm3/g, and the specific surface area (SSA) values range from 18.112–38.466 m2/g. All shale samples have abundant micropores and mesopores, accounting for >90% of the total SSA. The fractal dimensions, D1 and D2, were obtained from N2 adsorption data, with different adsorption characteristics at 0–0.5 and 0.5–1.0 relative pressures. The fractal dimensions increase with increasing BJH PV and BET SSA and decrease with decreasing average pore diameter (APD). The fractal dimensions are positively correlated with the TOC and clay mineral contents and negatively correlated with the quartz content. The fractal dimension can be used to evaluate the methane adsorption capacity; the larger the fractal dimension is, the larger the methane adsorption capacity is. Fractal analysis is helpful to better understand the pore structure and adsorption capacity of shale gas reservoirs

System-level biological effects of extremely low-frequency electromagnetic fields: an in vivo experimental review

During the past decades, the potential effects of extremely low-frequency electromagnetic fields (ELF-EMFs) on human health have gained great interest all around the world. Though the International Commission on Non-Ionizing Radiation Protection recommended a 100 μT, and then a 200 μT magnetic field limit, the long-term effects of ELF-EMFs on organisms and systems need to be further investigated. It was reported that both electrotherapy and possible effects on human health could be induced under ELF-EM radiation with varied EM frequencies and fields. This present article intends to systematically review the in vivo experimental outcome and the corresponding mechanisms to shed some light on the safety considerations of ELF-EMFs. This will further advance the subsequent application of electrotherapy in human health