bluuebunny/crossref_metadata_2025 huggingface dataset:
Butyric Acid and Leucine Induce α-Defensin Secretion from Small Intestinal Paneth Cells
Authors: Takakuwa Akiko , Nakamura Kiminori , Kikuchi Mani , Sugimoto Rina , Ohira Shuya , Yokoi Yuki , Ayabe Tokiyoshi
Published: November 2019

The intestine not only plays a role in fundamental processes in digestion and nutrient absorption, but it also has a role in eliminating ingested pathogenic bacteria and viruses. Paneth cells, which reside at the base of small intestinal crypts, secrete α-defensins and contribute to enteric innate immunity through potent microbicidal activities. However, the relationship between food factors and the innate immune functions of Paneth cells remains unknown. Here, we examined whether short-chain fatty acids and amino acids induce α-defensin secretion from Paneth cells in the isolated crypts of small intestine. Butyric acid and leucine elicit α-defensin secretion by Paneth cells, which kills Salmonella typhimurium. We further measured Paneth cell secretion in response to butyric acid and leucine using enteroids, a three-dimensional ex vivo culture system of small intestinal epithelial cells. Paneth cells expressed short-chain fatty acid receptors, Gpr41, Gpr43, and Gpr109a mRNAs for butyric acid, and amino acid transporter Slc7a8 mRNA for leucine. Antagonists of Gpr41 and Slc7a8 inhibited granule secretion by Paneth cells, indicating that these receptor and transporter on Paneth cells induce granule secretion. Our findings suggest that Paneth cells may contribute to intestinal homeostasis by secreting α-defensins in response to certain nutrients or metabolites.
Cholesterol Disturbances and the Role of Proper Nutrition in CKD Patients
Authors: Gluba-Brzozka Anna , Franczyk Beata , Rysz Jacek
Published: November 2019

Chronic kidney disease (CKD) is a widespread disease with increasing prevalence in the modern society. Lipid disturbances are common in this group of patients. In most patients with CKD atherogenic dyslipidemia is observed. Dyslipidemia in patients with renal diseases increases the risk of cardiovascular diseases and it accelerates the progression of chronic kidney disease to its end stage. The amelioration of dyslipidemia and the lowering of oxidative stress, inflammatory processes, insulin sensitivity and remnant lipoproteins levels may lead to the reduction in cardiovascular burden. Nutritional interventions can strengthen the beneficial effect of treatment and they play an important role in the preservation of overall well-being of the patients with CKD since the aim of appropriate diet is to reduce the risk of cardiovascular events, prevent malnutrition, and hamper the progression of kidney disease. The management of dyslipidemia, regardless of the presence of chronic kidney disease, should be initiated by the introduction of therapeutic lifestyle changes. The introduction of diet change was shown to exert beneficial effect on the lipid level lowering that reaches beyond pharmacological therapy. Currently available evidence give the impression that data on dietary interventions in CKD patients is not sufficient to make any clinical practice guidelines and is of low quality.
LmxM.22.0250-Encoded Dual Specificity Protein/Lipid Phosphatase Impairs Leishmania mexicana Virulence In Vitro
Authors: Kraeva Natalya , Leštinová Tereza , Ishemgulova Aygul , Majerová Karolina , Butenko Anzhelika , Vaselek Slavica , Bespyatykh Julia , Charyyeva Arzuv , Spitzová Tatiana , Kostygov Alexei Yu. , Lukeš Julius , Volf Petr , Votýpka Jan , Yurchenko Vyacheslav
Published: November 2019

Protein phosphorylation/dephosphorylation is an important regulatory mechanism that controls many key physiological processes. Numerous pathogens successfully use kinases and phosphatases to internalize, replicate, and survive, modifying the host′s phosphorylation profile or signal transduction pathways. Multiple phosphatases and kinases from diverse bacterial pathogens have been implicated in human infections before. In this work, we have identified and characterized the dual specificity protein/lipid phosphatase LmDUSP1 as a novel virulence factor governing Leishmania mexicana infection. The LmDUSP1-encoding gene (LmxM.22.0250 in L. mexicana) has been acquired from bacteria via horizontal gene transfer. Importantly, its orthologues have been associated with virulence in several bacterial species, such as Mycobacterium tuberculosis and Listeria monocytogenes. Leishmania mexicana with ablated LmxM.22.0250 demonstrated severely attenuated virulence in the experimental infection of primary mouse macrophages, suggesting that this gene facilitates Leishmania pathogenicity in vertebrates. Despite significant upregulation of LmxM.22.0250 expression in metacyclic promastigotes, its ablation did not affect the ability of mutant cells to differentiate into virulent stages in insects. It remains to be further investigated which specific biochemical pathways involve LmDUSP1 and how this facilitates the parasite′s survival in the host. One of the interesting possibilities is that LmDUSP1 may target host′s substrate(s), thereby affecting its signal transduction pathways.
Biological Evaluation of Arylsemicarbazone Derivatives as Potential Anticancer Agents
Authors: Nascimento da Cruz Anne Cecília , Brondani Dalci José , I´talo de Santana Temístocles , Oliveira da Silva Lucas , da Oliveira Borba Elizabeth Fernanda , de Faria Antônio Rodolfo , Ferreira Cavalcanti  de Albuquerque Julianna , Piessard Sylvie , Matos Ximenes Rafael , Baratte Blandine , Bach Stéphane , Ruchaud Sandrine , Bezerra Mendonça Junior Francisco Jaime , Bazin Marc-Antoine , Montenegro Rabello Marcelo , Hernandes Marcelo Zaldini , Marchand Pascal , Gonçalves da Silva Teresinha
Published: November 2019

Fourteen arylsemicarbazone derivatives were synthesized and evaluated in order to find agents with potential anticancer activity. Cytotoxic screening was performed against K562, HL-60, MOLT-4, HEp-2, NCI-H292, HT-29 and MCF-7 tumor cell lines. Compounds 3c and 4a were active against the tested cancer cell lines, being more cytotoxic for the HL-60 cell line with IC50 values of 13.08 μM and 11.38 μM, respectively. Regarding the protein kinase inhibition assay, 3c inhibited seven different kinases and 4a strongly inhibited the CK1δ/ε kinase. The studied kinases are involved in several cellular functions such as proliferation, migration, cell death and cell cycle progression. Additional analysis by flow cytometry revealed that 3c and 4a caused depolarization of the mitochondrial membrane, suggesting apoptosis mediated by the intrinsic pathway. Compound 3c induced arrest in G1 phase of the cell cycle on HL-60 cells, and in the annexin V assay approximately 50% of cells were in apoptosis at the highest concentration tested (26 μM). Compound 4a inhibited cell cycle by accumulation of abnormal postmitotic cells at G1 phase and induced DNA fragmentation at the highest concentration (22 μM).
Efficient Delivery of Therapeutic siRNA by Fe3O4 Magnetic Nanoparticles into Oral Cancer Cells
Authors: Jin Lili , Wang Qiuyu , Chen Jiayu , Wang Zixiang , Xin Hongchuan , Zhang Dianbao
Published: November 2019

The incidence of oral cancer is increasing due to smoking, drinking, and human papillomavirus (HPV) infection, while the current treatments are not satisfactory. Small interfering RNA (siRNA)-based therapy has brought hope, but an efficient delivery system is still needed. Here, polyethyleneimine (PEI)-modified magnetic Fe3O4 nanoparticles were prepared for the delivery of therapeutic siRNAs targeting B-cell lymphoma-2 (BCL2) and Baculoviral IAP repeat-containing 5 (BIRC5) into Ca9-22 oral cancer cells. The cationic nanoparticles were characterized by transmission electronic microscopy (TEM), scanning electronic microscopy (SEM), dynamic light scattering (DLS), and vibrating sample magnetometer (VSM). By gel retardation assay, the nanoparticles were found to block siRNA in a concentration-dependent manner. The cellular uptake of the nanoparticle/siRNA complexes under a magnetic field was visualized by Perl’s Prussian blue staining and FAM labeling. High gene silencing efficiencies were determined by quantitative real-time PCR and western blotting. Furthermore, the nanoparticle-delivered siRNAs targeting BCL2 and BIRC5 were found to remarkably inhibit the viability and migration of Ca9-22 cells, by cell counting kit-8 assay and transwell assay. In this study, we have developed a novel siRNA-based therapeutic strategy targeting BCL2 and BIRC5 for oral cancer.
Be Aggressive! Amorphous Excipients Enabling Single-Step Freeze-Drying of Monoclonal Antibody Formulations
Authors: Haeuser Christina , Goldbach Pierre , Huwyler Joerg , Friess Wolfgang , Allmendinger Andrea
Published: November 2019

Short freeze-drying cycles for biopharmaceuticals are desirable. Formulations containing an amorphous disaccharide, such as sucrose, are prone to collapse upon aggressive primary drying at higher shelf temperature. We used 2-hydroxypropyl-betacyclodextrin (HPBCD) in combination with sucrose and polyvinylpyrrolidone (PVP) to develop an aggressive lyophilization cycle for low concentration monoclonal antibody (mAb) formulations. Glass transition temperature and collapse temperature of the formulations were determined, and increasingly aggressive cycle parameters were applied. Using a shelf temperature of +30 °C during primary drying, the concept of combining sublimation and desorption of water in a single drying step was investigated. Cake appearance was evaluated visually and by micro-computed tomography. Lyophilisates were further analyzed for reconstitution time, specific surface area, residual moisture, and glass transition temperature. We demonstrated the applicability of single-step freeze-drying, shortening the total cycle time by 50% and providing elegant lyophilisates for pure HPBCD and HPBCD/sucrose formulations. HPBCD/PVP/sucrose showed minor dents, while good mAb stability at 10 mg/mL was obtained for HPBCD/sucrose and HPBCD/PVP/sucrose when stored at 40 °C for 3 months. We conclude that HPBCD-based formulations in combination with sucrose are highly attractive, enabling aggressive, single-step freeze-drying of low concentration mAb formulations, while maintaining elegant lyophilisates and ensuring protein stability at the same time.
A Systematic Review of Models Used and Preferences for Continuing Education and Continuing Professional Development of Pharmacists
Authors: Micallef Ricarda , Kayyali Reem
Published: November 2019

Continuing Education (CE) or Continuing Professional Development (CPD) are used by pharmacists globally to maintain up-to-date knowledge and skills throughout their careers. The primary aim of this study was to identify the formats or models used by pharmacists for CE and CPD globally. The secondary aim was to identify preferences of pharmacists, in relation to the variety of formats or models used to fulfil mandatory requirements, in order to support future planning of lifelong learning events. A systematic review was performed using PubMed, Science Direct, and Web of Science covering a time period from 1995 until March 2018. Searches were conducted in English, with studies on undergraduate studies being excluded. Eighteen papers from an initial search of 4561 were included from 2004 to 2014. All studies focused on pharmacists. Three studies identified face-to-face learning as a preference, with six studies identifying a positive impact of interactive learning. All four identified studies focusing on online provision were linked to CE. One study highlighted the benefits of blended learning. Two studies identified concluded that no one size fits all. A clear structure of event was highlighted in three studies. Three studies highlighted the relevance of topics to practice, and two studies showed the need for opportunities to apply knowledge. Due to the variety of formats and no consistent model, no perfect model or activity has been identified. However, CPD showed increased practice outcomes versus CE. Although an increasing amount of technology is being utilized, face-to-face learning is still preferred. Interactive, multiple-format learning should be used where possible, to reflect preferences of different learners. There is a need for a structured approach to the planning and learning event itself to support CE and CPD.
Assessment of Genetic Diversity for Drought, Heat and Combined Drought and Heat Stress Tolerance in Early Maturing Maize Landraces
Authors: Nelimor Charles , Badu-Apraku Baffour , Tetteh Antonia Y. , N’guetta Assanvo S. P.
Published: November 2019

Climate change is expected to aggravate the effects of drought, heat and combined drought and heat stresses. An important step in developing ‘climate smart’ maize varieties is to identify germplasm with good levels of tolerance to the abiotic stresses. The primary objective of this study was to identify landraces with combined high yield potential and desirable secondary traits under drought, heat and combined drought and heat stresses. Thirty-three landraces from Burkina Faso (6), Ghana (6) and Togo (21), and three drought-tolerant populations/varieties from the Maize Improvement Program at the International Institute of Tropical Agriculture were evaluated under three conditions, namely managed drought stress, heat stress and combined drought and heat stress, with optimal growing conditions as control, for two years. The phenotypic and genetic correlations between grain yield of the different treatments were very weak, suggesting the presence of independent genetic control of yield to these stresses. However, grain yield under heat and combined drought and heat stresses were highly and positively correlated, indicating that heat-tolerant genotypes would most likely tolerate combined drought and stress. Yield reduction averaged 46% under managed drought stress, 55% under heat stress, and 66% under combined drought and heat stress, which reflected hypo-additive effect of drought and heat stress on grain yield of the maize accessions. Accession GH-3505 was highly tolerant to drought, while GH-4859 and TZm-1353 were tolerant to the three stresses. These landrace accessions can be invaluable sources of genes/alleles for breeding for adaptation of maize to climate change.
A Novel Hybrid Foaming Method for Low-Pressure Microcellular Foam Production of Unfilled and Talc-Filled Copolymer Polypropylenes
Authors: Llewelyn Gethin , Rees Andrew , Griffiths Christian A. , Jacobi Martin
Published: November 2019

Unfilled and talc-filled Copolymer Polypropylene (PP) samples were produced through low-pressure foam-injection molding (FIM). The foaming stage of the process has been facilitated through a chemical blowing agent (C6H7NaO7 and CaCO3 mixture), a physical blowing agent (supercritical N2) and a novel hybrid foaming (combination of said chemical and physical foaming agents). Three weight-saving levels were produced with the varying foaming methods and compared to conventional injection molding. The unfilled PP foams produced through chemical blowing agent exhibited the strongest mechanical characteristics due to larger skin wall thicknesses, while the weakest were that of the talc-filled PP through the hybrid foaming technique. However, the hybrid foaming produced superior microcellular foams for both PPs due to calcium carbonate (CaCO3) enhancing the nucleation phase.
Dispersed-Monolayer Graphene-Doped Polymer/Silica Hybrid Mach-Zehnder interferometer (MZI) Thermal Optical Switch with Low-Power Consumption and Fast Response
Authors: Cao Yue , Zhang Daming , Yang Yue , Lin Baizhu , Lv Jiawen , Yang Xianwang , Zhao Haowen , Wang Fei , Li Baohua , Yi Yunji
Published: November 2019

This article demonstrates a dispersed-monolayer graphene-doped polymer/silica hybrid Mach–Zehnder interferometer (MZI) thermal optical switch with low-power consumption and fast response. The polymer/silica hybrid MZI structure reduces the power consumption of the device as a result of the large thermal optical coefficient of the polymer material. To further decrease the response time of the thermal optical switch device, a polymethyl methacrylate, doped with monolayer graphene as a cladding material, has been synthesized. Our study theoretically analyzed the thermal conductivity of composites using the Lewis–Nielsen model. The predicted thermal conductivity of the composites increased by 133.16% at a graphene volume fraction of 0.263 vol %, due to the large thermal conductivity of graphene. Measurements taken of the fabricated thermal optical switch exhibited a power consumption of 7.68 mW, a rise time of 40 μs, and a fall time of 80 μs at a wavelength of 1550 nm.
Fabrication of a Large-Area, Fused Polymer Micromold Based on Electric-Field-Driven (EFD) μ-3D Printing
Authors: Peng Zilong , Gou Nairui , Wei Zilong , Zhao Jiawei , Wang Fei , Yang Jianjun , Li Yinan , Lan Hongbo
Published: November 2019

An electric-field-driven (EFD), μ-3D printed, fused polymer technique has been developed for the fabrication of large-area microscale prototype molds using typical polymer materials, including microcrystalline wax (MC-wax), polycaprolactone (PCL), and polymathic methacrylate (PMMA). This work proposes an alternative for large area microscale modes and overcomes the limitation of high cost in the traditional mold manufacturing industry. The EFD principle enables printing of fused polymers materials more than one order of magnitude lower than the nozzle diameter, contributing to the necking effect of the Taylor cone jet, which is the key factor to achieve the microscale manufacturing. Numerical simulation of electric field distribution between the meniscus and substrate was carried out to elucidate the dependence of electric field distribution on the meniscus condition of three types of polymers under printable voltage, and the electrical field parameters for the EFD μ-3D printing were determined. A number of experiments were printed successfully using a large range of viscosity materials, ranging from tens of mPa·s to hundreds of thousands of mPa·s of PCL and PMMA. The differences in parameters of different materials, such as viscosity, tensile properties, and surface energy, were studied to assess their use in different fields. Using proper process parameters and a nozzle with an inner diameter of 200 μm, three different application cases were completed, including a Wax microarray and microchannel with a minimum dot diameter of 20 μm, a PCL mesh structure with a minimum line width of 5 μm, and a PMMA large-area mold with a maximum aspect ratio of 0.8. Results show that the EFD μ-3D printing has the outstanding advantages of high printing resolution and polymer material universality.
Green Synthesized Silver Nanoparticles of Myrtus communis L (AgMC) Extract Inhibits Cancer Hallmarks via Targeting Aldose Reductase (AR) and Associated Signaling Network
Authors: Ali Abuderman Abdulwahab , Syed Rabbani , A. Alyousef Abdullah , S. Alqahtani Mohammed , Shamsul Ola Mohammad , Malik Abdul
Published: November 2019

In this current study, we demonstrated the green synthesis and characterization of silver nanoparticles using Myrtus communis L. plant extract (Ag-MC) and its evaluation of anticancer and antimicrobial activities. The green synthesis of (Ag-MC), was assessed by numerous characterization techniques such as ultraviolet-visible spectroscopy (UV-VIS), Fourier-transform infrared spectroscopy (FT-IR), X-ray powder diffraction (XRD) transmission electron microscopy (TEM) and energy dispersive x-ray spectroscopy (EDX). The anti-cancer activity of the green synthesized silver nanoparticles was evaluated by the median inhibitory dose (IC50) on human liver carcinoma cell lines (HepG2). These results suggested that SN-NPs can be used as effective anticancer cell lines, as well as antibacterial and antiseptic agents in the medical field. This study showed that overexpression of aldose reductase (AR) in the human liver carcinoma cell line, HepG2, was down regulated by administration of SN-MC. The down regulation of AR was associated with abrogation of Pl3k/Akt, ERK and NF-kB pathways and the inhibition of cancer hallmarks, however, the target molecule for Ag-MC was not practically established. Thus it is still unknown if the consequences were due to AR inhibition or direct Ag-MC interaction with AR.
Evaluation and Application of Multi-Source Satellite Rainfall Product CHIRPS to Assess Spatio-Temporal Rainfall Variability on Data-Sparse Western Margins of Ethiopian Highlands
Authors: Belay Ashebir Sewale , Fenta Ayele Almaw , Yenehun Alemu , Nigate Fenta , Tilahun Seifu A. , Moges Michael M. , Dessie Mekete , Adgo Enyew , Nyssen Jan , Chen Margaret , Griensven Ann Van , Walraevens Kristine
Published: November 2019

The spatio-temporal characteristic of rainfall in the Beles Basin of Ethiopia is poorly understood, mainly due to lack of data. With recent advances in remote sensing, satellite derived rainfall products have become alternative sources of rainfall data for such poorly gauged areas. The objectives of this study were: (i) to evaluate a multi-source rainfall product (Climate Hazards Group Infrared Precipitation with Stations: CHIRPS) for the Beles Basin using gauge measurements and (ii) to assess the spatial and temporal variability of rainfall across the basin using validated CHIRPS data for the period 1981–2017. Categorical and continuous validation statistics were used to evaluate the performance, and time-space variability of rainfall was analyzed using GIS operations and statistical methods. Results showed a slight overestimation of rainfall occurrence by CHIRPS for the lowland region and underestimation for the highland region. CHIRPS underestimated the proportion of light daily rainfall events and overestimated the proportion of high intensity daily rainfall events. CHIRPS rainfall amount estimates were better in highland regions than in lowland regions, and became more accurate as the duration of the integration time increases from days to months. The annual spatio-temporal analysis result using CHIRPS revealed: a mean annual rainfall of the basin is 1490 mm (1050–2090 mm), a 50 mm increase of mean annual rainfall per 100 m elevation rise, periodical and persistent drought occurrence every 8 to 10 years, a significant increasing trend of rainfall (~5 mm year−1), high rainfall variability observed at the lowland and drier parts of the basin and high coefficient of variation of monthly rainfall in March and April (revealing occurrence of bimodal rainfall characteristics). This study shows that the performance of CHIRPS product can vary spatially within a small basin level, and CHIRPS can help for better decision making in poorly gauged areas by giving an option to understand the space-time variability of rainfall characteristics.
Subfootprint Variability of Sea Surface Salinity Observed during the SPURS-1 and SPURS-2 Field Campaigns
Authors: Bingham Frederick M.
Published: November 2019

Subfootprint variability (SFV), variability within the footprint of a satellite measurement, is a source of error associated with the validation process, especially for a satellite measurement with a large footprint such as those measuring sea surface salinity (SSS). This type of error has not been adequately quantified in the past. In this study, I have examined SFV using in situ ocean data from the SPURS-1 (Salinity Processes in the Upper ocean Regional Studies-1) and SPURS-2 field campaigns in the subtropical North Atlantic and eastern tropical North Pacific respectively. I computed SFV from these data over two one-year periods of intense sampling. The results show that SFV is highly seasonal. I have computed SFV errors in several different forms, a median value of the weekly snapshot error, a total snapshot error, an absolute error of the Aquarius and SMAP (Soil Moisture Active Passive) measurement, a part of that error associated with SFV and a bias due to the skewness of the distribution of SSS. These results are characteristic only of the particular regions studied. However, comparison of the results with high resolution models, and in situ data from moorings gives the possibility of getting global estimates of SFV from these other more common sources of SSS data.
Fine-Grained Classification of Hyperspectral Imagery Based on Deep Learning
Authors: Chen Yushi , Huang Lingbo , Zhu Lin , Yokoya Naoto , Jia Xiuping
Published: November 2019

Hyperspectral remote sensing obtains abundant spectral and spatial information of the observed object simultaneously. It is an opportunity to classify hyperspectral imagery (HSI) with a fine-grained manner. In this study, the fine-grained classification of HSI, which contains a large number of classes, is investigated. On one hand, traditional classification methods cannot handle fine-grained classification of HSI well; on the other hand, deep learning methods have shown their powerfulness in fine-grained classification. So, in this paper, deep learning is explored for HSI supervised and semi-supervised fine-grained classification. For supervised HSI fine-grained classification, densely connected convolutional neural network (DenseNet) is explored for accurate classification. Moreover, DenseNet is combined with pre-processing technique (i.e., principal component analysis or auto-encoder) or post-processing technique (i.e., conditional random field) to further improve classification performance. For semi-supervised HSI fine-grained classification, a generative adversarial network (GAN), which includes a discriminative CNN and a generative CNN, is carefully designed. The GAN fully uses the labeled and unlabeled samples to improve classification accuracy. The proposed methods were tested on the Indian Pines data set, which contains 33,3951 samples with 52 classes. The experimental results show that the deep learning-based methods provide great improvements compared with other traditional methods, which demonstrate that deep models have huge potential for HSI fine-grained classification.
The Influence of Heterogeneity on Lunar Irradiance Based on Multiscale Analysis
Authors: Zeng Xiangzhao , Li Chuanrong
Published: November 2019

The Moon is a stable light source for the radiometric calibration of satellite sensors. It acts as a diffuse panel that reflects sunlight in all directions, however, the lunar surface is heterogeneous due to its topography and different mineral content and chemical composition at different locations, resulting in different optical properties. In order to perform radiometric calibration using the Moon, a lunar irradiance model using different observation geometry is required. Currently, two lunar irradiance models exist, namely, the Robotic Lunar Observatory (ROLO) and the Miller and Turner 2009 (MT2009). The ROLO lunar irradiance model is widely used as the radiometric standard for on-orbit sensors. The MT2009 lunar irradiance model is popular for remote sensing at night, however, the original version of the MT2009 lunar irradiance model takes less consideration of the heterogeneous lunar surface and lunar topography. Since the heterogeneity embedded in the lunar surface is the key to the improvement of the lunar irradiance model, this study analyzes the influence of the heterogeneous surface on the irradiance of moonlight based on model data at different scales. A heterogeneous correction factor is defined to describe the impact of the heterogeneous lunar surface on lunar irradiance. On the basis of the analysis, the following conclusions can be made. First, the influence of heterogeneity in the waning hemisphere is greater than that in waxing hemisphere under all 32 wavelengths of the ROLO filters. Second, the influence of heterogeneity embedded in the lunar surface exerts less impact on lunar irradiance at lower resolution. Third, the heterogeneous correction factor is scale independent. Finally, the lunar irradiance uncertainty introduced by topography is very small and decreases as the resolution of model data decreases due to the loss of topographic information.
Integrating LiDAR, Multispectral and SAR Data to Estimate and Map Canopy Height in Tropical Forests
Authors: Fagua J. Camilo , Jantz Patrick , Rodriguez-Buritica Susana , Duncanson Laura , Goetz Scott J.
Published: November 2019

Developing accurate methods to map vegetation structure in tropical forests is essential to protect their biodiversity and improve their carbon stock estimation. We integrated LIDAR (Light Detection and Ranging), multispectral and SAR (Synthetic Aperture Radar) data to improve the prediction and mapping of canopy height (CH) at high spatial resolution (30 m) in tropical forests in South America. We modeled and mapped CH estimated from aircraft LiDAR surveys as a ground reference, using annual metrics derived from multispectral and SAR satellite imagery in a dry forest, a moist forest, and a rainforest of tropical South America. We examined the effect of the three forest types, five regression algorithms, and three predictor groups on the modelling and mapping of CH. Our CH models reached errors ranging from 1.2–3.4 m in the dry forest and 5.1–7.4 m in the rainforest and explained variances from 94–60% in the dry forest and 58–12% in the rainforest. Our best models show higher accuracies than previous works in tropical forests. The average accuracy of the five regression algorithms decreased from dry forests (2.6 m +/− 0.7) to moist (5.7 m +/− 0.4) and rainforests (6.6 m +/− 0.7). Random Forest regressions produced the most accurate models in the three forest types (1.2 m +/− 0.05 in the dry, 4.9 m +/− 0.14 in the moist, and 5.5 m +/− 0.3 the rainforest). Model performance varied considerably across the three predictor groups. Our results are useful for CH spatial prediction when GEDI (Global Ecosystem Dynamics Investigation lidar) data become available.
Image Formation of Azimuth Periodically Gapped SAR Raw Data with Complex Deconvolution
Authors: Qian Yulei , Zhu Daiyin
Published: November 2019

The phenomenon of periodical gapping in Synthetic Aperture Radar (SAR), which is induced in various ways, creates challenges in focusing raw SAR data. To handle this problem, a novel method is proposed in this paper. Complex deconvolution is utilized to restore the azimuth spectrum of complete data from the gapped raw data in the proposed method. In other words, a new approach is provided by the proposed method to cope with periodically gapped raw SAR data via complex deconvolution. The proposed method provides a robust implementation of deconvolution for processing azimuth gapped raw data. The proposed method mainly consists of phase compensation and recovering the azimuth spectrum of raw data with complex deconvolution. The gapped data become sparser in the range of the Doppler domain after phase compensation. Then, it is feasible to recover the azimuth spectrum of the complete data from gapped raw data via complex deconvolution in the Doppler domain. Afterwards, the traditional SAR imaging algorithm is capable of focusing the reconstructed raw data in this paper. The effectiveness of the proposed method was validated via point target simulation and surface target simulation. Moreover, real SAR data were utilized to further demonstrate the validity of the proposed method.
The Radiative Transfer Characteristics of the O2 Infrared Atmospheric Band in Limb-Viewing Geometry
Authors: He Weiwei , Wu Kuijun , Feng Yutao , Fu Di , Chen Zhenwei , Li Faquan
Published: November 2019

The O2(a1Δg) emission near 1.27 μm provides an important means to remotely sense the thermal characteristics, dynamical features, and compositional structures of the upper atmosphere because of its photochemistry and spectroscopic properties. In this work, an emission–absorption transfer model for limb measurements was developed to calculate the radiation and scattering spectral brightness by means of a line-by-line approach. The nonlocal thermal equilibrium (non-LTE) model was taken into account for accurate calculation of the O2(a1Δg) emission by incorporating the latest rate constants and spectral parameters. The spherical adding and doubling methods were used in the multiple scattering model. Representative emission and absorption line shapes of the O 2 ( a 1 Δ g , υ ′ = 0 ) → O 2 ( X Σ g 3 , υ ″ = 0 ) band and their spectral behavior varying with altitude were examined. The effects of solar zenith angle, surface albedo, and aerosol loading on the line shapes were also studied. This paper emphasizes the advantage of using infrared atmospheric band for remote sensing of the atmosphere from 20 up to 120 km, a significant region where the strongest coupling between the lower and upper atmosphere occurs.
RDTS-Based Two-Dimensional Temperature Monitoring with High Positioning Accuracy Using Grid Distribution
Authors: Zhang Can , Jin ZhongXie
Published: November 2019

A novel two-dimensional (2D) positioning method based on Raman distributed temperature sensing (RDTS) has been reported to dramatically improve positioning accuracy. Using a well-designed 2D distribution of optical fiber and corresponding algorithms, the heat source can be accurately located without crosstalk; however, there is a tradeoff between sensing distance and positioning accuracy. In our experiments, an RDTS system with a spatial resolution of 0.8 m along a 3 km multimode fiber (MMF) is used with specific 2D routing rules and corresponding algorithms. A positioning accuracy of about 0.1 m is obtained without hardware modification, which could be improved through the dense arrangement of fiber; however, this would sacrifice the sensing length. This solution can be used for both flat surfaces and curved surfaces such as pipes or tank surfaces. This scheme can also be extended to three-dimensional positioning using a delicate routing design of sensing fiber.
Towards Point-of-Care Heart Failure Diagnostic Platforms: BNP and NT-proBNP Biosensors
Authors: Alawieh Hussein , El Chemaly Trishia , Alam Samir , Khraiche Massoud
Published: November 2019

Heart failure is a class of cardiovascular diseases that remains the number one cause of death worldwide with a substantial economic burden of around $18 billion incurred by the healthcare sector in 2017 due to heart failure hospitalization and disease management. Although several laboratory tests have been used for early detection of heart failure, these traditional diagnostic methods still fail to effectively guide clinical decisions, prognosis, and therapy in a timely and cost-effective manner. Recent advances in the design and development of biosensors coupled with the discovery of new clinically relevant cardiac biomarkers are paving the way for breakthroughs in heart failure management. Natriuretic neurohormone peptides, B-type natriuretic peptide (BNP) and N-terminal prohormone of BNP (NT-proBNP), are among the most promising biomarkers for clinical use. Remarkably, they result in an increased diagnostic accuracy of around 80% owing to the strong correlation between their circulating concentrations and different heart failure events. The latter has encouraged research towards developing and optimizing BNP biosensors for rapid and highly sensitive detection in the scope of point-of-care testing. This review sheds light on the advances in BNP and NT-proBNP sensing technologies for point-of-care (POC) applications and highlights the challenges of potential integration of these technologies in the clinic. Optical and electrochemical immunosensors are currently used for BNP sensing. The performance metrics of these biosensors—expressed in terms of sensitivity, selectivity, reproducibility, and other criteria—are compared to those of traditional diagnostic techniques, and the clinical applicability of these biosensors is assessed for their potential integration in point-of-care diagnostic platforms.
Multi-Sensor Fusion and Error Compensation of Attitude Measurement System for Shaft Boring Machine
Authors: Wang Xinliang , Liu Jiangong , Liu Yang , Fu Wenjun , Zhu Lei
Published: November 2019

To ensure that the shaft boring machine (SBM) runs along the pre-designed axis steadily, the role of the attitude measurement system is essential, but its accuracy and reliability cannot be guaranteed. Currently, there is no effective technology to meet the actual requirements, and there is a lack of relevant theoretical research in this field. Through further study of the attitude analysis method and multi-sensor fusion technology, this paper presents a dual coordinate method, which can be used to describe the attitude characteristics of the SBM. Moreover, this paper discusses the relationships between the attitude changes and the values of the angle as well as displacement and analyzes the implementation complexity and computational efficiency of related algorithms in software and hardware. According to the working characteristics of the SBM, the hardware design and the reasonable layout of the attitude measurement system are provided. Based on multi-sensor data, this paper puts forward an improved method combining a complementary filter with an extended Kalman filter (EKF) for attitude estimation and error compensation. The simulation experiments of different working processes verify the steady-state response and dynamic response performance of the method. Experimental results show that the dual coordinate method and the proposed filter are more suitable for attitude estimation of the SBM compared to other methods.
A Differential Resonant Voltage Sensor Consisting of Piezo Bimorph and Quartz Crystal Double-Ended Tuning Fork Resonators
Authors: Huang Zijun , Bian Leixiang
Published: November 2019

A differential resonant voltage sensor with frequency output was developed by bonding two quartz crystal double-ended tuning forks (DETFs) on both sides of a piezo bimorph. The applied voltage induced tensile and compression deformation in the upper and bottom layers of the piezo bimorph, which caused the resonant frequency of the dual DETFs to increase and decrease, respectively. In this case, the differential output of the resonance frequencies of the dual DETFs greatly reduced the effect of temperature drift. In addition, the input resistance of the piezo bimorph reached a few hundred GΩ, which caused almost no influence on the DC voltage under test. The fabricated device showed a linear characteristic over its measurement range of ±700 V with a sensitivity of 0.75 Hz/V, a resolution of 0.007% (0.1 V) and hysteresis of 0.76% of the full range. The quality factor of the DETFs was about 3661 (in air). This novel resonant voltage sensor with its extremely low power consumption is promising for measuring or monitoring DC voltage in various fields.
Gendered Career Pathways among Doctoral Graduates in the United Kingdom
Authors: Peri-Rotem Nitzan
Published: November 2019

While women form about half of PhD students in Western countries, previous studies have shown that female doctoral graduates are underrepresented in senior positions and have lower earnings compared to their male counterparts within and outside academia. Less is known however about the role of gender in determining the odds of securing a permanent position among doctorate recipients. In this study, we use data from the UK Doctoral Impact and Career Tracking Survey from 2013 to explore the career trajectories of doctoral graduates within seven to nine years after earning their degree. We find that in every observed time point following graduation (0.5, 3.5, and 7–9 years), men are significantly more likely to work in a permanent job than women are. Furthermore, gender gaps in permanent employment are particularly pronounced in the private sector and in non-academic occupations. Using a nested logistic regression model, we find that the higher propensity of female doctoral graduates to work in part-time employment compared to their male counterparts, in combination with other differential employment characteristics has cumulative negative implications on their likelihood of securing a permanent position.
SwimBIT: A Novel Approach to Stroke Analysis During Swim Training Based on Attitude and Heading Reference System (AHRS)
Authors: Ramos Félix Eduardo , da Silva Hugo Plácido , Olstad Bjørn Harald , Cabri Jan , Lobato Correia Paulo
Published: November 2019

In a world where technology is assuming a pervasive role, sports sciences are also increasingly exploiting the possibilities opened by advanced sensors and intelligent algorithms. This paper focuses on the development of a convenient, practical, and low-cost system, SwimBIT, which is intended to help swimmers and coaches in performance evaluation, improvement, and injury reduction. Real-world data were collected from 13 triathletes (age 20.8 ± 3.5 years, height 173.7 ± 5.3 cm, and weight 63.5 ± 6.3 kg) with different skill levels in performing the four competitive styles of swimming in order to develop a representative database and allow assessment of the system’s performance in swimming conditions. The hardware collects a set of signals from swimmers based on an attitude and heading reference system (AHRS), and a machine learning workflow for data analysis is used to extract a selection of indicators that allows analysis of a swimmer’s performance. Based on the AHRS data, three novel indicators are proposed: trunk elevation, body balance, and body rotation. Experimental evaluation has shown promising results, with a 100% accuracy in swim lap segmentation, a precision of 100% in the recognition of backstroke, and a precision of 89.60% in the three remaining swimming techniques (butterfly, breaststroke, and front crawl). The performance indicators proposed here provide valuable information for both swimmers and coaches in their quest for enhancing performance and preventing injuries.
Vitamin D Status Differs by Sex, Sport-Season, and Skin Pigmentation among Elite Collegiate Basketball Players
Authors: Fields Jennifer B. , Payne Daniel C. , Gallo Sina , Busteed Deanna R. , Jones Margaret T.
Published: November 2019

Vitamin D plays a key role in bone health, musculoskeletal function, and sport performance. Collegiate athletes competing in indoor sports may be at greater risk of vitamin D deficiency due to limited outdoor time. Therefore, the purpose was to assess 25-hydroxyvitamin D (25(OH)D) concentrations among collegiate men and women basketball (MBB, WBB) athletes. National Collegiate Athletic Association Division I men (MBB, n = 11) and women (WBB, n = 9) were tested during the off-season (T1; July) and pre-season (T2; October). Measurements included serum 25(OH)D; skin pigmentation, bone mineral density, and daily sun exposure (self-reported). Paired t-tests determined changes in 25(OH)D by sport-season and sex. Pearson correlations examined relationships between outcome variables. MBB athletes (mean ± SD; 19.6 ± 1.3 years) showed a reduction in 25(OH)D (T1: 64.53 nmol·L−1 ± 11.96) (T2: 56.11 nmol·L−1 ± 7.90) (p = 0.001). WBB (20.1 ± 1.1 years) had no change in 25(OH)D (T1: 99.07 nmol·L−1 ± 49.94. T2: 97.56 nmol·L−1 ± 36.47, p = 0.848). A positive association between 25(OH)D and skin pigmentation was observed (r = 0.47, p = 0.038). 25(OH)D was inversely correlated with lean body mass (LBM), body mass (BM), and bone mineral density (BMD), while a positive association was seen between 25(OH)D and skin pigmentation. In summary, 25(OH)D insufficiency was prevalent amongst male collegiate basketball athletes, with 25(OH)D levels being lower in the pre-season (October) than the off-season (July). Furthermore, darker skin pigmentation significantly correlated with 25(OH)D, indicating that individuals with darker skin tones may be at a greater risk of insufficiency/deficiency. More research is needed to examine the relationships between 25(OH)D and bone health in athletes.
A Framework to Assess the Sustainability of Platform Economy: The Case of Barcelona Ecosystem
Authors: Fuster Morell Mayo , Espelt Ricard
Published: November 2019

This article presents a framework for evaluating the sustainability qualities of Platform Economy initiatives. It takes into account governance, economic model, technology, data policies, social responsibility and impact. The framework has been tested empirically in a sample of one hundred commons-based peer-to-peer production cases identified in Barcelona. Data collection was based on online ethnography and structured interviews. The results reveal the different levels and tendencies of pro-democratization. It appears that the cases that are more sustainable are also sustainable in other dimensions. The analysis found a correlation between governance and technology and data models, and it further demonstrated that governance is correlated with the economic model. Both results together indicate that the governance of a platform plays a central role in its overall approach.
Personalized Evaporative Cooler to Reduce Energy Consumption and Improve Thermal Comfort in Free-Running Spaces
Authors: Tejero-González Ana , Esquivias Paula M.
Published: November 2019

The need to reduce energy consumption in buildings is imperative, but we must maintain individual thermal comfort of the occupants to ensure their well-being and productivity. Personal conditioning systems (PCS) have been suggested as a strategy to achieve both energy efficiency and thermal comfort, as they are considered to be low-energy consumers, allow increasing set-point temperatures, and give occupants the chance to control their own personal environment. While most warm-environment PCS are based on air-movement devices, the potential of using desk direct evaporative coolers (dDEC) has been scarcely explored. This work presents the results of the characterization of a dDEC and its potential for improving the indoor temperature and thermal comfort in a free-running office space. The study proposes adapted corrective power (CPa) and cooling fan efficiency for evaporative systems (CFEe) indexes. Results show that the dDEC achieves thermal comfort with a local effect, and it is recommended to be positioned directly on the desk surface, orientated to the occupant, and at a certain distance. Under these conditions, the CPa reaches −2.8 °C, involving better CFEe than the desk fans studied in the literature. Speed has little effect on the local air conditions, though it does improve the perception of thermal comfort. The relative humidity of the air does not exceed the recommendable limits, but renovation of the indoor air enables better conditions.
Occurrence Characteristic and Mining Technology of Ultra-thick Coal Seam in Xinjiang, China
Authors: Qin Dongdong , Wang Xufeng , Zhang Dongsheng , Guan Weiming , Zhang Lei , Xu Mengtang
Published: November 2019

The scientific and efficient mining of ultra-thick coal seam in Xinjiang, China is faced with the problems of low exploration level and lack of theoretical research on underground mining. This paper studied occurrence characteristic of ultra-thick coal seams in Xinjiang, using field investigation and drilling exploration. Based on the variation law of support load under different roof bearing structure form and development height in multi-layer mining, classification method and mining technology selection of ultra-thick coal seam were put forward. The results indicate that: (1) The ultra-thick coal seams in Xinjiang have a distribution characteristic of more north and less south, more east and less west, mainly concentrate in East Junggar and Turpan-Harmi coalfields. The form of the ultra-thick coal seam has the remarkable characteristic of coal seams merging and bifurcating. (2) The mechanical model of the relationship between the support and surrounding rock under different roof bearing structures is established. At the early stage of multi-layer mining, the support load includes the load caused by rotary subsidence of the blocks that formed the near-stope roof bearing structure and the gravity load of rock blocks under roof bearing structure. At the later stage, the support load is mainly gravity load of loose blocks below the far-stope roof bearing structure. (3) According the roof bearing structure form, ultra-thick coal seam can be divided into three types: no stable bearing structure, (higher) beam bearing structure and arch bearing structure. In order to ensure the stability of near-stope roof bearing structure, backfill mining, longwall mining, and longwall mining early and backfill mining later should be adopted in three types ultra-thick coal seams mining respectively.