bluuebunny/crossref_metadata_2025 huggingface dataset:
Overexpression of CDC42SE1 in A431 Cells Reduced Cell Proliferation by Inhibiting the Akt Pathway
Authors: Kalailingam Pazhanichamy , Tan Hui Bing , Pan Jiun Yit , Tan Suat Hoon , Thanabalu Thirumaran
Published: February 2019

Cell division cycle 42 (CDC42), a small Rho GTPase, plays a critical role in many cellular processes, including cell proliferation and survival. CDC42 interacts with the CRIB (Cdc42- and Rac-interactive binding) domain of CDC42SE1, a small effector protein of 9 kDa. We found that the expression of CDC42SE1 was reduced in human skin cancer samples relative to matched perilesional control. Exogenous expression of CDC42SE1 but not CDC42SE1H38A (mutation within CRIB domain) in A431 cells (A431SE1, A431SE1-H38A) reduced cell proliferation. Antibody microarray analysis of A431Ctrl and A431SE1 lysate suggested that reduced A431SE1 cells proliferation was due to inhibition of Akt pathway, which was confirmed by the reduced P-Akt and P-mTOR levels in A431SE1 cells compared to A431Ctrl cells. This suggests that CDC42SE1 modulates the CDC42-mediated Akt pathway by competing with other effector proteins to bind CDC42. A431SE1 cells formed smaller colonies in soft agar compared to A431Ctrl and A431SE1-H38A cells. These findings correlate with nude mice xenograft assays, where A431SE1 cells formed tumors with significantly-reduced volume compared to the tumors formed by A431Ctrl cells. Our results suggest that CDC42SE1 is downregulated in skin cancer to promote tumorigenesis, and thus CDC42SE1 might be an important marker of skin cancer progression.
Host-Cell Type Dependent Features of Recombinant Human Aquaporin-4 Orthogonal Arrays of Particles—New Insights for Structural and Functional Studies
Authors: Pisani Francesco , Simone Laura , Mola Maria Grazia , De Bellis Manuela , Mastrapasqua Maria , Ruggieri Maddalena , Trojano Maria , Nicchia Grazia Paola , Svelto Maria , Frigeri Antonio
Published: February 2019

The CNS plasma-membrane water channel aquaporin-4 (AQP4) is expressed as two major isoforms able to aggregate into supramolecular assemblies known as ‘orthogonal arrays of particles’ (OAPs). OAP subnanometric features are largely unknown mainly because a method for the expression, isolation, and crystallization of integral human OAPs has not been developed. Here, the human OAP-forming isoform M23-AQP4 was expressed in insect and mammalian cell lines and AQP4 and OAP features evaluated. Native size exclusion chromatography was employed to isolate and analyze authentically folded OAPs, and neuromyelitis optica (NMO)-specific sandwich ELISA was developed to test OAP-integrity. The results demonstrate that in insect cells most AQP4 remains intracellular and unfolded and that OAPs are largely disassembled after the detergent extraction step. In mammalian cells, AQP4 showed regular plasma membrane targeting and OAPs exhibited strong post-extraction stability. Starting from the mammalian cell expression system, we isolated authentically folded OAPs. Together these data suggest a new strategy for expressing and isolating integral recombinant human OAPs and providing new insights into the cell-type dependent OAP-assembly and post-extraction stability, potentially useful to design new approaches for structural and functional studies of OAP and for other plasma membrane proteins organized into supramolecular structures.
MicroRNAs at the Interface between Osteogenesis and Angiogenesis as Targets for Bone Regeneration
Authors: Fröhlich Leopold
Published: February 2019

Bone formation and regeneration is a multistep complex process crucially determined by the formation of blood vessels in the growth plate region. This is preceded by the expression of growth factors, notably the vascular endothelial growth factor (VEGF), secreted by osteogenic cells, as well as the corresponding response of endothelial cells, although the exact mechanisms remain to be clarified. Thereby, coordinated coupling between osteogenesis and angiogenesis is initiated and sustained. The precise interplay of these two fundamental processes is crucial during times of rapid bone growth or fracture repair in adults. Deviations in this balance might lead to pathologic conditions such as osteoarthritis and ectopic bone formation. Besides VEGF, the recently discovered important regulatory and modifying functions of microRNAs also support this key mechanism. These comprise two principal categories of microRNAs that were identified with specific functions in bone formation (osteomiRs) and/or angiogenesis (angiomiRs). However, as hypoxia is a major driving force behind bone angiogenesis, a third group involved in this process is represented by hypoxia-inducible microRNAs (hypoxamiRs). This review was focused on the identification of microRNAs that were found to have an active role in osteogenesis as well as angiogenesis to date that were termed “CouplingmiRs (CPLGmiRs)”. Outlined representatives therefore represent microRNAs that already have been associated with an active role in osteogenic-angiogenic coupling or are presumed to have its potential. Elucidation of the molecular mechanisms governing bone angiogenesis are of great relevance for improving therapeutic options in bone regeneration, tissue-engineering, and the treatment of bone-related diseases.
Protective Features of Autophagy in Pulmonary Infection and Inflammatory Diseases
Authors: Wang Kui , Chen Yi , Zhang Pengju , Lin Ping , Xie Na , Wu Min
Published: February 2019

Autophagy is a highly conserved catabolic process involving autolysosomal degradation of cellular components, including protein aggregates, damaged organelles (such as mitochondria, endoplasmic reticulum, and others), as well as various pathogens. Thus, the autophagy pathway represents a major adaptive response for the maintenance of cellular and tissue homeostasis in response to numerous cellular stressors. A growing body of evidence suggests that autophagy is closely associated with diverse human diseases. Specifically, acute lung injury (ALI) and inflammatory responses caused by bacterial infection or xenobiotic inhalation (e.g., chlorine and cigarette smoke) have been reported to involve a spectrum of alterations in autophagy phenotypes. The role of autophagy in pulmonary infection and inflammatory diseases could be protective or harmful dependent on the conditions. In this review, we describe recent advances regarding the protective features of autophagy in pulmonary diseases, with a focus on ALI, idiopathic pulmonary fibrosis (IPF), chronic obstructive pulmonary disease (COPD), tuberculosis, pulmonary arterial hypertension (PAH) and cystic fibrosis.
Signal Transduction across the Nuclear Envelope: Role of the LINC Complex in Bidirectional Signaling
Authors: Hieda Miki
Published: February 2019

The primary functions of the nuclear envelope are to isolate the nucleoplasm and its contents from the cytoplasm as well as maintain the spatial and structural integrity of the nucleus. The nuclear envelope also plays a role in the transfer of various molecules and signals to and from the nucleus. To reach the nucleus, an extracellular signal must be transmitted across three biological membranes: the plasma membrane, as well as the inner and outer nuclear membranes. While signal transduction across the plasma membrane is well characterized, signal transduction across the nuclear envelope, which is essential for cellular functions such as transcriptional regulation and cell cycle progression, remains poorly understood. As a physical entity, the nuclear envelope, which contains more than 100 proteins, functions as a binding scaffold for both the cytoskeleton and the nucleoskeleton, and acts in mechanotransduction by relaying extracellular signals to the nucleus. Recent results show that the Linker of Nucleoskeleton and Cytoskeleton (LINC) complex, which is a conserved molecular bridge that spans the nuclear envelope and connects the nucleoskeleton and cytoskeleton, is also capable of transmitting information bidirectionally between the nucleus and the cytoplasm. This short review discusses bidirectional signal transduction across the nuclear envelope, with a particular focus on mechanotransduction.
Application of Mathematical Modelling to Reducing and Minimising Energy Requirement for Oxygen Transfer in Batch Stirred Tank Bioreactors
Authors: Fitzpatrick John J. , Gloanec Franck , Michel Elisa , Blondy Johanna , Lauzeral Anais
Published: February 2019

In this study, microbial kinetic and oxygen transfer modelling coupled with energy analysis was applied to investigate how manipulation and control of agitator power input and air flowrate can reduce and minimise the total energy requirement in a batch aerobic bioprocess subject to constraints. The study showed that major energy savings can be made by appropriate selection of these variables and how they are controlled throughout a bioprocess. In many bioprocesses, the oxygen concentration in the liquid is controlled at a constant value. This may be achieved by maintaining the agitator power at a constant value and varying the air flowrate or vice versa, or by continuously varying both. The modelling showed that the minimum or near-minimum total energy requirement occurred when operating at the onset of impeller flooding throughout the bioprocess by continuously varying both impeller power and air flowrate over the bioprocess time. Operating at the onset of flooding may not be practical to implement in practice. However, the minimum energy can be approached by dividing the bioprocess time into a small number of time segments with appropriately chosen constant agitator powers and varying the air flowrate within each segment. This is much more practical to implement.
Use of Lisdexamfetamine to Treat Obesity in an Adolescent with Severe Obesity and Binge Eating
Authors: Srivastava Gitanjali , O’Hara Valerie , Browne Nancy
Published: February 2019

Approximately two-thirds of US children and adolescents have either obesity or overweight status, with almost 24% of adolescents (ages 12–19 years) afflicted with severe obesity, defined as >1.2 × the 95th BMI percentile for age/gender. Despite the increasing disproportionate rise in severe or extreme childhood obesity, many children in weight management programs do not achieve a healthy weight. Most often, these patients will go on to require metabolic and bariatric surgery (MBS), but challenges and limitations may prohibit MBS on adolescents. Thus, tertiary care pediatric weight management centers are compelled to treat select pediatric obesity subtypes presenting with disease progression and disability with the available adult FDA-approved therapeutic modalities, specifically pharmacotherapy, in order to alleviate the disease state and provide relief to the patient. Here, we describe a case of severe pediatric obesity where a dedicated multidisciplinary pediatric weight management team at a tertiary care center utilizes a progressive pharmacotherapeutic approach with enormous benefits to the patient, highlighting the urgent gap and clinical care needs of this special population niche of severe adolescent obesity.
A Proposed Exogenous Cause of the Global Temperature Hiatus
Authors: Treloar Norman C.
Published: February 2019

Since 1850, the rise in global mean surface temperatures (GMSTs) from increasing atmospheric concentrations of greenhouse gases (GHGs) has exhibited three ~30-year hiatus (surface cooling) episodes. The current hiatus is often thought to be generated by similar cooling episodes in Pacific or Atlantic ocean basins. However, GMSTs as well as reconstructed Atlantic and Pacific ocean basin surface temperatures show the presence of similar multidecadal components generated from a three-dimensional analysis of differential gravitational (tidal) forcing from the sun and moon. This paper hypothesizes that these episodes are all caused by external tidal forcing that generates alternating ~30-year zonal and meridional circulation regimes, which respectively increase and decrease GMSTs through tidal effects on sequestration (deep ocean heat storage) and energy redistribution. Hiatus episodes consequently coincide with meridional regimes. The current meridional regime affecting GMSTs is predicted to continue to the mid-2030s but have limited tendency to decrease GMSTs from sequestration because of continuing increases in radiative forcing from increasing atmospheric GHGs. The tidal formulation also generates bidecadal oscillations, which may generate shorter ~12-year hiatus periods in global and ocean basin temperatures. The formulation appears to assimilate findings from disciplines as disparate as geophysics and biology.
Effect of Graphene on Flame Retardancy of Graphite Doped Intumescent Flame Retardant (IFR) Coatings: Synergy or Antagonism
Authors: Wang Yachao , Zhao Jiangping
Published: February 2019

A comparative study between graphene and modified graphene oxide (mGO) on the flame retardancy of graphite doped intumescent flame retardant (IFR) coatings is preliminarily investigated by cone calorimeter (CC), XRD, and SEM, with the final aim of clarifying the interactions between different graphenes and graphite doped coatings (polyester resin-ammonium polyphosphate-urea-pentaerythritol). The CC results determine that graphene exerts an obviously antagonistic effect on flame resistance, evidenced by the increased peak heat release rate (p-HRR) of 56.9 kW·m−2 for SD8+graphene (sample coating contains graphite with a particle size of 8 μm and 0.5 wt.% graphene as dopant), which increased by 80.6% compared with SD8 (coating contains graphite with a particle size of 8 μm); substitution with graphene or mGO imparts an acceleration of fire growth, because graphene inertness improves the viscosity of melting system, evidenced by the cracked appearance and porous structure of SD8+graphene. However, the higher reactivity of mGO favors the combustion; the barrier effect inhibits the transfer of mass and heat simultaneously, leading to a slight influence on flame retarding efficiency.
Colloidal Metal Oxide Nanoparticles Prepared by Laser Ablation Technique and Their Antibacterial Test
Authors: Duque Johan S. , Madrigal Brayan M. , Riascos Henry , Avila Yenny P.
Published: February 2019

In this article we report the production of metal oxide (TiFe2O4, ZnFe2O4) nanoparticles by pulsed laser ablation technique in a liquid environment. We used nanosecond Nd: YAG laser systems working at 532 nm and 1064 nm of wavelength and the energy of the laser beam was kept constant at 80 mJ. Absorbance spectra, surface plasmon resonance, optical band-gap, and nanoparticle morphology were investigated using ultraviolet-visible (UV-Vis) spectroscopy, Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM). Changing the wavelength of the laser for growth, nanoparticles showed shift between the absorbance and surface plasmon resonance peaks in their UV-Vis spectra, which implies that the optical properties of the colloid nanoparticles depend on laser parameters. This was confirmed with the variation of the band gap energy. Furthermore, redshift for the absorbance peak was observed for samples as-grown at 532 nm around 150 nm as a function of time preparation. Conversely, for the samples as-grown at 1064 nm there was no shift in the absorbance spectra, which could be due to agglomeration and formation of larger particles. The characterization results showed appropriate plasmonic photo-catalysts properties of the particles, hence the photoactivation of the nanoparticles was examined on antibacterial effect using colonies of Staphylococcus aureus and Escherichia coli.
Probabilistic Fatigue Life Prediction of Dissimilar Material Weld Using Accelerated Life Method and Neural Network Approach
Authors: Ahmad Hafiz Waqar , Hwang Jeong Ho , Javed Kamran , Chaudry Umer Masood , Bae Dong Ho
Published: February 2019

Welding alloy 617 with other metals and alloys has been receiving significant attention in the last few years. It is considered to be the benchmark for the development of economical hybrid structures to be used in different engineering applications. The differences in the physical and metallurgical properties of dissimilar materials to be welded usually result in weaker structures. Fatigue failure is one of the most common failure modes of dissimilar material welded structures. In this study, fatigue life prediction of dissimilar material weld was evaluated by the accelerated life method and artificial neural network approach (ANN). The accelerated life testing approach was evaluated for different distributions. Weibull distribution was the most appropriate distribution that fits the fatigue data very well. Acceleration of fatigue life test data was attained with 95% reliability for Weibull distribution. The probability plot verified that accelerating variables at each level were appropriate. Experimental test data and predicted fatigue life were in good agreement with each other. Two training algorithms, Bayesian regularization (BR) and Levenberg–Marquardt (LM), were employed for training ANN. The Bayesian regularization training algorithm exhibited a better performance than the Levenberg–Marquardt algorithm. The results confirmed that the assessment methods are effective for lifetime prediction of dissimilar material welded joints.
Automated Hints Generation for Investigating Source Code Plagiarism and Identifying The Culprits on In-Class Individual Programming Assessment
Authors: Budiman Ariel Elbert , Karnalim Oscar
Published: February 2019

Most source code plagiarism detection tools only rely on source code similarity to indicate plagiarism. This can be an issue since not all source code pairs with high similarity are plagiarism. Moreover, the culprits (i.e., the ones who plagiarise) cannot be differentiated from the victims even though they need to be educated further on different ways. This paper proposes a mechanism to generate hints for investigating source code plagiarism and identifying the culprits on in-class individual programming assessment. The hints are collected from the culprits’ copying behaviour during the assessment. According to our evaluation, the hints from source code creation process and seating position are 76.88% and at least 80.87% accurate for indicating plagiarism. Further, the hints from source code creation process can be helpful for indicating the culprits as the culprits’ codes have at least one of our predefined conditions for the copying behaviour.
A Lumped-Parameter Equivalent Circuit Modeling for S-Shaped I–V Kinks of Organic Solar Cells
Authors: Wei Tiankuo , Xu Chuanzhong , Lin Wei , Huang Gongyi , Yu Fei
Published: February 2019

We propose an improved lumped-parameter equivalent circuit model to describe S-shaped I–V kinks observed from organic solar cells. Firstly, to predict the S-shaped I–V kinks accurately in both the first and fourth quadrants, a shunt resistor in parallel with extraction diode is added to our previous model. Secondly, based on the Newton–Raphson method, we derive a solution to our improved circuit. Thirdly, our solution is verified by the method of least squares and experiments. Finally, compared with our previous work, the improved circuit has higher accuracy in demonstrating S-shaped I–V kinks in the first and fourth quadrants. Such an improved model is suitable for circuit simulations of organic solar cells.
High-Temperature Cooperative Spin Crossover Transitions and Single-Crystal Reflection Spectra of [FeIII(qsal)2](CH3OSO3) and Related Compounds
Authors: Takahashi Kazuyuki , Yamamoto Kaoru , Yamamoto Takashi , Einaga Yasuaki , Shiota Yoshihito , Yoshizawa Kazunari , Mori Hatsumi
Published: February 2019

New Fe(III) compounds from qsal ligand, [Fe(qsal)2](CH3OSO3) (1) and [Fe(qsal)2](CH3SO3)·CH3OH (3), along with known compound, [Fe(qsal)2](CF3SO3) (2), were obtained as large well-shaped crystals (Hqsal = N-(8-quinolyl)salicylaldimine). The compounds 1 and 2 were in the low-spin (LS) state at 300 K and exhibited a cooperative spin crossover (SCO) transition with a thermal hysteresis loop at higher temperatures, whereas 3 was in the high-spin (HS) state below 300 K. The optical conductivity spectra for 1 and 3 were calculated from the single-crystal reflection spectra, which were, to the best of our knowledge, the first optical conductivity spectra of SCO compounds. The absorption bands for the LS and HS [Fe(qsal)2] cations were assigned by time-dependent density functional theory calculations. The crystal structures of 1 and 2 consisted of a common one-dimensional (1D) array of the [Fe(qsal)2] cation, whereas that of 3 had an unusual 1D arrangement by π-stacking interactions which has never been reported. The crystal structures in the high-temperature phases for 1 and 2 indicate that large structural changes were triggered by the motion of counter anions. The comparison of the crystal structures of the known [Fe(qsal)2] compounds suggests the significant role of a large non-spherical counter-anion or solvate molecule for the total lattice energy gain in the crystal of a charged complex.
(2E)-2-[1-(1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]-N-(2-chlorophenyl)hydrazine carboxamide: Synthesis, X-ray Structure, Hirshfeld Surface Analysis, DFT Calculations, Molecular Docking and Antifungal Profile
Authors: Al-Wabli Reem I. , Al-Ghamdi Alwah R. , Aswathy Suchindra Amma Vijayakumar , Ghabbour Hazem A. , Al-Agamy Mohamed H. , Hubert Joe Issac , Attia Mohamed I.
Published: February 2019

Life-threatening fungal infections accounts for a major global health burden especially for individuals suffering from cancer, acquired immune deficiency syndrome (AIDS), or autoimmune diseases. (2E)-2-[1-(1,3-Benzodioxol-5-yl)-3-(1H-imidazol-1-yl)propylidene]-N-(2-chlorophenyl)hydrazinecarboxamide has been synthesized and characterized using various spectroscopic tools to be evaluated as a new antifungal agent. The (E)-configuration of the imine moiety of the title molecule has been unequivocally identified with the aid of single crystal X-ray analysis. The molecular structure of compound 4 was crystallized in the monoclinic, P21/c, a = 8.7780 (6) Å, b = 20.5417 (15) Å, c = 11.0793 (9) Å, β = 100.774 (2)°, V = 1962.5 (3) Å3, and Z = 4. Density functional theory computations have thoroughly explored the electronic characteristics of the title molecule. Moreover, molecular docking studies and Hirshfeld surface analysis were also executed on the title compound 4. The in vitro antifungal potential of the target compound was examined against four different fungal strains.
A Water-Stable Organic-Inorganic Hybrid Perovskite for Solar Cells by Inorganic Passivation
Authors: Tai Edward Guangqing , Wang Ryan Taoran , Chen Jason Yuanzhe , Xu Gu
Published: February 2019

Organic-inorganic hybrid halide perovskite solar cells (PSCs) have been a trending topic in recent years. Significant progress has been made to increase their power conversion efficiency (PCE) to more than 20%. However, the poor stability of PSCs in both working and non-working conditions results in rapid degradation through multiple environmental erosions such as water, heat, and UV light. Attempts have been made to resolve the rapid-degradation problems, including formula changes, transport layer improvements, and encapsulations, but none of these have effectively resolved the dilemma. This paper reports our findings on adding inorganic films as surface-passivation layers on top of the hybrid perovskite materials, which not only enhance stability by eliminating weak sites but also prevent water penetration by using a water-stable layer. The surface-passivated hybrid perovskite layer indicates a slight increase of bandgap energy (Eg = 1.76 eV), compared to the original methylammonium lead iodide (MAPbI3, Eg = 1.61 eV) layer, allowing for more stable perovskite layer with a small sacrifice in the photoluminescence property, which represents a lower charge diffusion rate and higher bandgap energy. Our finding offers an alternative approach to resolving the low stability issue for PSC fabrication.
The Relationship between Walking Speed and Step Length in Older Aged Patients
Authors: Morio Yuji , Izawa Kazuhiro P. , Omori Yoshitsugu , Katata Hironobu , Ishiyama Daisuke , Koyama Shingo , Yamano Yoshihisa
Published: February 2019

Compared with elderly people who have not experienced falls, those who have were reported to have a shortened step length, large fluctuations in their pace, and a slow walking speed. The purpose of this study was to elucidate the step length required to maintain a walking speed of 1.0 m/s in patients aged 75 years or older. We measured the 10 m maximum walking speed in patients aged 75 years or older and divided them into the following two groups: Those who could walk 1.0 m/s or faster (fast group) and those who could not (slow group). Step length was determined from the number of steps taken during the 10 m-maximum walking speed test, and the step length-to-height ratio was calculated. Isometric knee extension muscle force (kgf), modified functional reach (cm), and one-leg standing time (s) were also measured. We included 261 patients (average age: 82.1 years, 50.6% men) in this study. The fast group included 119 participants, and the slow group included 142 participants. In a regression logistic analysis, knee extension muscle force (p = 0.03) and step length-to-height ratio (p < 0.01) were determined as factors significantly related to the fast group. As a result of ROC curve analysis, a step length-to-height ratio of 31.0% could discriminate between the two walking speed groups. The results suggest that the step length-to-height ratio required to maintain a walking speed of 1.0 m/s is 31.0% in patients aged 75 years or older.
Evaluation of Different Dentifrice Compositions for Increasing the Hardness of Demineralized Enamel: An in Vitro Study
Authors: Oliveira Pedro Henrique Cabral , Oliveira Marcia Regina Cabral , Oliveira Luiz Henrique Cabral , Sfalcin Ravana Angelini , Pinto Marcelo Mendes , Rosa Ellen Perin , Deana Alessandro Melo , Horliana Anna Carolina Ratto Tempestini , César Paulo Francisco , Bussadori Sandra Kalil
Published: February 2019

This study aimed to evaluate microhardness of a dentifrice containing fluoride and arginine compared to a positive control (fluoride only) and a negative control (no fluoride) on sound and demineralized bovine enamel surfaces. Specimens were randomly assigned to different treatments that included daily pH cycling and brushing three times a day with one of the following dentifrices (n = 8): Neutraçucar (arginine and fluoride), Colgate Total 12 (fluoride) and My First Colgate (no fluoride). Enamel carious lesions were artificially created one week before the beginning of these treatments (demineralized bovine enamel (DE) groups). The same groups were also tested in sound enamel (sound bovine enamel (SE) groups). Microhardness was measured at baseline and after one, two, and five weeks of treatment using a Knoop indenter. Statistical analysis involved two-way Analysis of Variance (ANOVA) and Tukey’s test. After five weeks, both Total 12 and Neutraçucar had increased the microhardness of DE specimens (p < 0.05). Only Neutraçucar had increased the microhardness of the sound enamel after five weeks of treatment. Thus, it could be concluded that arginine-based dentifrices increase the microhardness of sound and demineralized bovine enamel surfaces.
A Comparative Study of Markerless Systems Based on Color-Depth Cameras, Polymer Optical Fiber Curvature Sensors, and Inertial Measurement Units: Towards Increasing the Accuracy in Joint Angle Estimation
Authors: Valencia-Jimenez Nicolas , Leal-Junior Arnaldo , Avellar Leticia , Vargas-Valencia Laura , Caicedo-Rodríguez Pablo , Ramírez-Duque Andrés A. , Lyra Mariana , Marques Carlos , Bastos Teodiano , Frizera Anselmo
Published: February 2019

This paper presents a comparison between a multiple red green blue-depth (RGB-D) vision system, an intensity variation-based polymer optical fiber (POF) sensor, and inertial measurement units (IMUs) for human joint angle estimation and movement analysis. This systematic comparison aims to study the trade-off between the non-invasive feature of a vision system and its accuracy with wearable technologies for joint angle measurements. The multiple RGB-D vision system is composed of two camera-based sensors, in which a sensor fusion algorithm is employed to mitigate occlusion and out-range issues commonly reported in such systems. Two wearable sensors were employed for the comparison of angle estimation: (i) a POF curvature sensor to measure 1-DOF angle; and (ii) a commercially available IMUs MTw Awinda from Xsens. A protocol to evaluate elbow joints of 11 healthy volunteers was implemented and the comparison of the three systems was presented using the correlation coefficient and the root mean squared error (RMSE). Moreover, a novel approach for angle correction of markerless camera-based systems is proposed here to minimize the errors on the sagittal plane. Results show a correlation coefficient up to 0.99 between the sensors with a RMSE of 4.90 ∘ , which represents a two-fold reduction when compared with the uncompensated results (10.42 ∘ ). Thus, the RGB-D system with the proposed technique is an attractive non-invasive and low-cost option for joint angle assessment. The authors envisage the proposed vision system as a valuable tool for the development of game-based interactive environments and for assistance of healthcare professionals on the generation of functional parameters during motion analysis in physical training and therapy.
Retrieval of Three-Dimensional Surface Deformation Using an Improved Differential SAR Tomography System
Authors: Wang Zhigui , Liu Mei , Lv Kunfeng
Published: February 2019

Conventional differential synthetic aperture radar tomography (D-TomoSAR) can only capture the scatterers’ one-dimensional (1-D) deformation information along the line of sight (LOS) of the synthetic aperture radar (SAR), which means that it cannot retrieve the three-dimensional (3-D) movements of the ground surface. To retrieve the 3-D deformation displacements, several methods have been proposed; the performance is limited due to the insufficient sensitivity for retrieving the North-South motion component. In this paper, an improved D-TomoSAR model is established by introducing the scatterers’ 3-D deformation parameters in slant range, azimuth, and elevation directions into the traditional D-TomoSAR model. The improved D-TomoSAR can be regarded as a multi-component two-dimensional (2-D) polynomial phase signal (PPS). Then, an effective algorithm is proposed to retrieve the 3-D deformation parameters of the ground surface by the 2-D product high-order ambiguity function (PHAF) with the relax (RELAX) algorithm. The estimation performance is investigated and compared with the traditional algorithm. Simulations and experimental results with semi-real data verify the effectiveness of the proposed signal model and algorithm.
Finite-Time Stabilization for Stochastic Interval Systems with Time Delay and Application to Energy-Storing Electrical Circuits
Authors: Chen Guici , Wei Fei , Wang Wenbo
Published: February 2019

In this paper, the problem of stochastic finite-time stabilization is investigated for stochastic delay interval systems. A nonlinear state feedback controller with input-to-state delay is introduced. By employing the Lyapunov–Krasovskii functional method, some sufficient conditions on stochastic finite-time stabilization are derived for closed-loop stochastic delay interval systems using the I t o ^ ’s differential formula. Suitable nonlinear state feedback controllers can be designed in terms of linear matrix inequalities. The obtained results are finally applied to an energy-storing electrical circuit to illustrate the effectiveness of the proposed method.
An Optimized Methodology for a Hybrid Photo-Voltaic and Energy Storage System Connected to a Low-Voltage Grid
Authors: Hussain Nengroo Sarvar , Umair Ali Muhammad , Zafar Amad , Hussain Sadam , Murtaza Tahir , Junaid Alvi Muhammad , Raghavendra K.V.G. , Jee Kim Hee
Published: February 2019

The growing human population and the increasing energy needs have produced a serious energy crisis, which has stimulated researchers to look for alternative energy sources. The diffusion of small-scale renewable distributed generations (DG) with micro-grids can be a promising solution to meet the environmental obligations. The uncertainty and sporadic nature of renewable energy sources (RES) is the main obstacle to their use as autonomous energy sources. In order to overcome this, a storage system is required. This paper proposes an optimized strategy for a hybrid photovoltaic (PV) and battery storage system (BSS) connected to a low-voltage grid. In this study, a cost function is formulated to minimize the net cost of electricity purchased from the grid. The charging and discharging of the battery are operated optimally to minimize the defined cost function. Half-hourly electricity consumer load data and solar irradiance data collected from the United Kingdom (UK) for a whole year are utilized in the proposed methodology. Five cases are discussed for a comparative cost analysis of the electricity imported and exported. The proposed scheme provides a techno-economic analysis of the combination of a BSS with a low-voltage grid, benefitting from the feed-in tariff (FIT) scheme.
On the Design of Low-Cost IoT Sensor Node for e-Health Environments
Authors: Petrellis Nikos , Birbas Michael , Gioulekas Fotios
Published: February 2019

The proliferation of Internet of Things (IoT) devices for patient monitoring has gained much attention in clinical care performance, proficient chronic disease management, and home caregiving. This work presents the design of efficient medical IoT sensor nodes (SNs) in terms of low-cost, low power-consumption, and increased data accuracy based on open-source platforms. The method utilizes a Sensor Controller (SC) within the IoT SN, which is capable of performing medical checks supporting a broad coverage of medical uses. A communication protocol has been developed for data and command exchange among SC, local gateways, and physicians’ or patients’ mobile devices (tablets, smart phones). The SC supports moving average window (MAW) and principle component analysis (PCA) filtering algorithms to capture data from the attached low-cost body sensors of different sampling profiles. Significant extensions in SN’s portability is achieved through energy consumption minimization based on the idle time gaps between sensors’ activations. SN’s components are either deactivated or set to low activity operation during these idle intervals. A medical case study is presented and the evaluated results show that the proposed SN can be incorporated into e-health platforms since it achieves comparable accuracy to its certified and high-cost commercial counterparts.
A Current Reconstruction at Parallel Three Phase Inverters Using Two Current Sensors
Authors: Kim Jeongwoo , Han Yu , Wang Shanshan , Wang Yihe , Cho Younghoon
Published: February 2019

In this paper, a current restoration method which can be applied to three phase parallel interleaved inverters (TPPII) using two current sensors has been proposed. In the proposed current reconstruction method, the branch current and the phase current of the two phases of the TPPII are sampled concurrently at the peak and valley of the pulse width modulation (PWM) carrier using two hall-effect sensors. Then, the phase current of each inverter is reconstructed by analyzing the sensed current with the current conduction path information according to the switch state in the peak and valley of the PWM carrier. This paper additionally analyzes the characteristics of the offset occurring in the detection process of two current sensors and it proposes a compensation method to reduce the offset on-line. In order to at once reduce the offset of the three-phase recovery current caused by the DC offset of the sensor, a coordinate conversion method and a low pass are used. To verify the performance of the proposed current recovery method and real-time offset compensation method, a simulation using PSIM software was performed, and experiments were conducted using a three phase parallel inverter composed of insulated gate bipolar transistor (IGBT) modules. In particular, the AC offset that occurred in the sampling process during the experiment was analyzed and modeled, and it was reduced by simple calculation.
A Mixed Deep Recurrent Neural Network for MEMS Gyroscope Noise Suppressing
Authors: Jiang Changhui , Chen Yuwei , Chen Shuai , Bo Yuming , Li Wei , Tian Wenxin , Guo Jun
Published: February 2019

Currently, positioning, navigation, and timing information is becoming more and more vital for both civil and military applications. Integration of the global navigation satellite system and /inertial navigation system is the most popular solution for various carriers or vehicle positioning. As is well-known, the global navigation satellite system positioning accuracy will degrade in signal challenging environments. Under this condition, the integration system will fade to a standalone inertial navigation system outputting navigation solutions. However, without outer aiding, positioning errors of the inertial navigation system diverge quickly due to the noise contained in the raw data of the inertial measurement unit. In particular, the micromechanics system inertial measurement unit experiences more complex errors due to the manufacturing technology. To improve the navigation accuracy of inertial navigation systems, one effective approach is to model the raw signal noise and suppress it. Commonly, an inertial measurement unit is composed of three gyroscopes and three accelerometers, among them, the gyroscopes play an important role in the accuracy of the inertial navigation system’s navigation solutions. Motivated by this problem, in this paper, an advanced deep recurrent neural network was employed and evaluated in noise modeling of a micromechanics system gyroscope. Specifically, a deep long short term memory recurrent neural network and a deep gated recurrent unit–recurrent neural network were combined together to construct a two-layer recurrent neural network for noise modeling. In this method, the gyroscope data were treated as a time series, and a real dataset from a micromechanics system inertial measurement unit was employed in the experiments. The results showed that, compared to the two-layer long short term memory, the three-axis attitude errors of the mixed long short term memory–gated recurrent unit decreased by 7.8%, 20.0%, and 5.1%. When compared with the two-layer gated recurrent unit, the proposed method showed 15.9%, 14.3%, and 10.5% improvement. These results supported a positive conclusion on the performance of designed method, specifically, the mixed deep recurrent neural networks outperformed than the two-layer gated recurrent unit and the two-layer long short term memory recurrent neural networks.
Preliminary Design for Wave Run-Up in Offshore Wind Farms: Comparison between Theoretical Models and Physical Model Tests
Authors: Luengo Frades Jorge , Negro Vicente , García Barba Javier , Martín-Antón Mario , López-Gutiérrez José Santos , Esteban M. Dolores , Moreno Blasco Luis J.
Published: February 2019

Estimation of wave run-up has been of increasing concern for offshore wind structures and a critical aspect for designers. The highly nonlinear phenomenon makes the study difficult. That is the reason for the very few design rules and experimental data available to estimate it. Actual wave run-up is greater than commonly predicted. The goal of this research is to benchmark the theoretical formulations with the results of the physical model tests performed by Deltares in the field of crest elevation, run-up, forces and pressures. The laboratory reproduced in a wave tank (75 m length; 8.7 m width; 1 m depth; and a 1:60 scale, with Froude similarity) an offshore power converter platform located at intermediate water depths (25–43.80 m) in the Southern North Sea, designed by the Norwegian company Aibel. The purpose of this research is to offer a preliminary design guide for wave run–up using theoretical expressions both for cylinders and gravity based structures (GBS), leaning on the cited laboratory tests to validate the results obtained by such theoretical models.
Spiders in the Web: Understanding the Evolution of REDD+ in Southwest Ghana
Authors: den Besten Jan Willem , Arts Bas , Behagel Jelle
Published: February 2019

The implementation of the global programme on Reducing Emissions from Deforestation and Forest Degradation in developing countries, and the role of Conservation, Sustainable Management of Forests and Enhancement of Forest Carbon Stocks (REDD+) is lacks a robust financial mechanism and is widely criticized for producing too little positive impact for climate, nature, and people. In many countries with tropical forests however, a variety of REDD+ projects continue to develop on the ground. This paper fills in some of the gaps in our understanding of the dynamic relation between global policymaking and implementation of REDD+ on the ground. Using the introduction of REDD+ in Southwest Ghana as an example, we apply a practice-based approach to analyze the different roles that local actors and global-local intermediaries played in the introduction of REDD+. Our results show a more balanced picture than polarized debates at the global levels suggest. The logic of practice explains how REDD+ was translated to the local situation. Global actors took a lead but depended on local actors to make REDD+ work. Together, they integrated elements of existing practices that helped REDD+ ‘land’ locally but also transformed REDD+ globally to resemble such local practices. REDD+ initiatives absorbed elements from established community-based conservation, forest restoration, and sustainable agro-forestry practices. The evolution of REDD+ in Ghana reflects global trends to integrate REDD+ with landscape approaches.
Adaptability of Populus to Physiography and Growing Conditions in the Southeastern USA
Authors: Ghezehei Solomon B. , Nichols Elizabeth G. , Maier Christopher A. , Hazel Dennis W.
Published: February 2019

Populus species have a high productivity potential as short-rotation woody crops, provided that site-suitable varieties are planted. The Coastal Plain, the Piedmont, and the Blue Ridge Mountains make up a significant part of the eastern and southeastern USA, and an insight into poplar productivity and adaptability will be valuable for the successful implementation of large-scale poplar stands in these regions. The objectives of this study were to examine the green wood biomass (hereafter biomass), biomass allocation, and wood properties of poplars in relation to growing conditions, physiography, and topography. The biomass of 4-year-old poplars was estimated using an equation derived through destructive sampling. Biomass-based clonal rankings were compared across the various site conditions (fertility, irrigation, land marginality, soil preparation, and topography) and the three physiographic provinces. Although not all clonal differences in biomass were significant, growing conditions, physiography, and soil preparation affected the clonal rankings and the significance of the clonal differences. Biomass changes due to physiography and land conditions were more structured at the genomic-group level. A higher-altitude physiography led to greater biomass increases in Populus trichocarpa × Populus deltoids (TD) clones than in P. deltoids × P. deltoids (DD) clones and vice versa. Favorable soil quality or management generally led to greater biomass of DD clones than of TD and P. deltoids × Populus maximowiczii (DM) clones. Weather-related variables were not clearly correlated with biomass, while land aspect was a significant influence on the biomass of genomic groups and clones. The site significantly affected wood density, moisture content, and carbon and nitrogen concentrations, while the clonal effects on wood composition and the clonal and site effects on biomass allocation were insignificant. Although clones showing greater biomass responses to growing conditions generally belonged to the same genomic group, clone-level selection could produce greater biomass gains than selection at the genomic-group level.
Fine Root Biomass Mediates Soil Fauna Community in Response to Nitrogen Addition in Poplar Plantations (Populus deltoids) on the East Coast of China
Authors: Bian Haixue , Geng Qinghong , Xiao Hanran , Shen Caiqin , Li Qian , Cheng Xiaoli , Luo Yiqi , Ruan Honghua , Xu Xia
Published: February 2019

Soil fauna is critical for maintaining ecosystem functioning, and its community could be significantly impacted by nitrogen (N) deposition. However, our knowledge of how soil-faunal community composition responds to N addition is still limited. In this study, we simulated N deposition (0, 50, 100, 150, and 300 kg N ha−1 year−1) to explore the effects of N addition on the total and the phytophagous soil fauna along the soil profile (0–10, 10–25, and 25–40 cm) in poplar plantations (Populus deltoids) on the east coast of China. Ammonium nitrate (NH4NO3) was dissolved in water and sprayed evenly under the canopy with a backpack sprayer to simulate N deposition. Our results showed that N addition either significantly increased or decreased the density (D) of both the total and the phytophagous soil fauna (Dtotal and Dp) at low or high N addition rates, respectively, indicating the existence of threshold effects over the range of N addition. However, N addition had no significant impacts on the number of groups (G) and diversity (H) of either the total or the phytophagous soil fauna (Gtotal, Gp and Htotal, Hp). With increasing soil depth, Dtotal, Dp, Gtotal, and Gp largely decreased, showing that the soil fauna have a propensity to aggregate at the soil surface. Htotal and Hp did not significantly vary along the soil profile. Importantly, the threshold effects of N addition on Dtotal and Dp increased from 50 and 100 to 150 kg N ha−1 year−1 along the soil profile. Fine root biomass was the dominant factor mediating variations in Dtotal and Dp. Our results suggested that N addition may drive changes in soil-faunal community composition by altering belowground food resources in poplar plantations.
Size-Dependent Patterns of Seed Rain in Gaps in Temperate Secondary Forests, Northeast China
Authors: Yan Qiaoling , Gang Qun , Zhu Jiaojun
Published: February 2019

Secondary forests have become the major forest type worldwide, and are experiencing various disturbances and exhibiting obvious vegetation degradation (e.g., reduced biodiversity and decreased productivity) compared with primary forests. Forest gap is a common small-scale disturbance in secondary forests. Promoting natural regeneration under gap disturbance is an important approach to recover biodiversity and ecosystem services for temperate secondary forests. The gap size is the crucial characteristic controlling natural regeneration of many tree species. However, little is known about the spatiotemporal pattern of seed rain for gravity-dispersed and wind-dispersed tree species in gaps of varying sizes. The objectives of this study were to determine how seed rain of dominant tree species depend on gap size, and consequently, to explore some gap-based silviculture solutions for restoring secondary forests from the view of seed dispersal. The spatial distribution of seed rain in gaps with three sizes (large gaps of 250–350 m2, medium gaps of 150–250 m2, and small gaps of <150 m2), the temporal dynamics of seed rain over three years, and the relationship between seed rain and soil seed banks were explored in temperate secondary forests. The results showed that more than 90% of the seeds in seed rain were wind-dispersed, and their seed rain density and the contribution of seed rain to soil seed bank in medium gaps reached the highest (p = 0.03). The results suggest that establishing medium-sized gaps (i.e., gap size with 150–250 m2) in the secondary forests is more favorable for improving the natural regeneration potential (arrival of seeds and forming soil seed bank) of gap-dependent and wind-dispersed species (e.g., Acer mono) in gaps.