bluuebunny/crossref_metadata_2025 huggingface dataset:
U-Pb Age Dating and Geochemistry of Soft-Sediment Deformation Structure-Bearing Late Cretaceous Volcano-Sedimentary Basins in the SW Korean Peninsula and Their Tectonic Implications
Authors: Ko Kyoungtae , Kim Sungwon , Gihm Yongsik
Published: May 2021

Cretaceous volcano-sedimentary basins and successions in the Korean Peninsula are located along NE-SW- and NNE-SSW-trending sinistral strike–slip fault systems. Soft-sediment deformation structures (SSDS) of lacustrine sedimentary strata occur in the Wido, Buan, and Haenam areas of the southwestern Korean Peninsula. In this study, systematic geological, geochronological, and geochemical investigations of the volcanic-sedimentary successions were conducted to constrain the origin and timing of SSDS-bearing lacustrine strata. The SSDS-bearing strata is conformably underlain and overlain by volcanic rocks, and it contains much volcaniclastic sediment and is interbedded with tuffs. The studied SSDSs were interpreted to have formed by ground shaking during syndepositional earthquakes. U-Pb zircon ages of volcanic and volcaniclastic rocks within the studied volcano-sedimentary successions were ca. 87–84 Ma, indicating that active volcanism was concurrent with lacustrine sedimentation. Geochemical characteristics indicate that these mostly rhyolitic rocks are similar to subduction-related calc-alkaline volcanic rocks from an active continental margin. This suggests that the SSDSs in the study area were formed by earthquakes related to proximal volcanic activity due to the oblique subduction of the Paleo-Pacific Plate during the Late Cretaceous.
Metal Doped PVA Films for Opto-Electronics-Optical and Electronic Properties, an Overview
Authors: Bulinski Mircea
Published: May 2021

Polyvinyl alcohol is unique among polymers. Apart from its preparation, it is not built up in polymerization reactions from monomers, unlike most vinyl-polymers, and it is biodegradable in the presence of suitably acclimated microorganisms. It is an environmentally friendly material for a wide range of applications, from medical ones, based on its biocompatibility, to integrated optics. This paper reviews, in addition to the preparation and optimization of films of polyvinyl alcohol doped with different metal species, the role of dopants and doping technologies in the involved electronic mechanism. The optical properties were studied by UV-VIS-IR, Mössbauer spectroscopy, and other measurement techniques, with applications such as real-time holography, microlasers, optical sensors or nanophotonics in mind.
Preparation of Fe3O4-Ag Nanocomposites with Silver Petals for SERS Application
Authors: Nguyen Thi Thuy , Mammeri Fayna , Ammar Souad , Nguyen Thi Bich Ngoc , Nguyen Trong Nghia , Nghiem Thi Ha Lien , Thuy Nguyen Thi , Ho Thi Anh
Published: May 2021

The formation of silver nanopetal-Fe3O4 poly-nanocrystals assemblies and the use of the resulting hetero-nanostructures as active substrates for Surface Enhanced Raman Spectroscopy (SERS) application are here reported. In practice, about 180 nm sized polyol-made Fe3O4 spheres, constituted by 10 nm sized crystals, were functionalized by (3-aminopropyl)triethoxysilane (APTES) to become positively charged, which can then electrostatically interact with negatively charged silver seeds. Silver petals were formed by seed-mediated growth in presence of Ag+ cations and self-assembly, using L-ascorbic acid (L-AA) and polyvinyl pyrrolidone (PVP) as mid-reducing and stabilizing agents, respectively. The resulting plasmonic structure provides a rough surface with plenty of hot spots able to locally enhance significantly any applied electrical field. Additionally, they exhibited a high enough saturation magnetization with Ms = 9.7 emu g−1 to be reversibly collected by an external magnetic field, which shortened the detection time. The plasmonic property makes the engineered Fe3O4-Ag architectures particularly valuable for magnetically assisted ultra-sensitive SERS sensing. This was unambiguously established through the successful detection, in water, of traces, (down to 10−10 M) of Rhodamine 6G (R6G), at room temperature.
A Comprehensive Study of Drug Loading in Hollow Mesoporous Silica Nanoparticles: Impacting Factors and Loading Efficiency
Authors: Guo Lanying , Ping Jiantao , Qin Jinglei , Yang Mu , Wu Xi , You Mei , You Fangtian , Peng Hongshang
Published: May 2021

Although hollow mesoporous silica nanoparticles (HMSNs) have been intensively studied as nanocarriers, selecting the right HMSNs for specific drugs still remains challenging due to the enormous diversity in so far reported HMSNs and drugs. To this end, we herein made a comprehensive study on drug loading in HMSNs from the viewpoint of impacting factors and loading efficiency. Specifically, two types of HMSNs with negative and positive zeta potential were delicately constructed, and three categories of drugs were selected as delivery targets: highly hydrophobic and lipophobic (oily), hydrophobic, and hydrophilic. The results indicated that (i) oily drugs could be efficiently loaded into both of the two HMSNs, (ii) HMSNs were not good carriers for hydrophobic drugs, especially for planar drugs, (iii) HMSNs had high loading efficiency towards oppositely charged hydrophilic drugs, i.e., negatively charged HMSNs for cationic molecules and vice versa, (iv) entrapped drugs would alter zeta potential of drug-loaded HMSNs. This work may provide general guidelines about designing high-payload HMSNs by reference to the physicochemical property of drugs.
Effect of Nano Silica Particles on Impact Resistance and Durability of Concrete Containing Coal Fly Ash
Authors: Zhang Peng , Sha Dehao , Li Qingfu , Zhao Shikun , Ling Yifeng
Published: May 2021

In this study, the effect of adding nano-silica (NS) particles on the properties of concrete containing coal fly ash were explored, including the mechanical properties, impact resistance, chloride penetration resistance, and freezing–thawing resistance. The NS particles were added into the concrete at 1%, 2%, 3%, 4%, and 5% of the binder weight. The behavior under an impact load was measured using a drop weight impact method, and the number of blows and impact energy difference was used to assess the impact resistance of the specimens. The durability of the concrete includes its chloride penetration and freezing–thawing resistance; these were calculated based on the chloride diffusion coefficient and relative dynamic elastic modulus (RDEM) of the samples after the freezing–thawing cycles, respectively. The experimental results showed that the addition of NS can considerably improve the mechanical properties of concrete, along with its freezing–thawing resistance and chloride penetration resistance. When NS particles were added at different replacement levels, the compressive, flexural, and splitting tensile strengths of the specimens were increased by 15.5%, 27.3%, and 19%, respectively, as compared with a control concrete. The addition of NS enhanced the impact resistance of the concrete, although the brittleness characteristics of the concrete did not change. When the content of the NS particles was 2%, the number of first crack impacts reached a maximum of 37, 23.3% higher compared with the control concrete. Simultaneously, the chloride penetration resistance and freezing–thawing resistance of the samples increased dramatically. The optimal level of cement replacement by NS in concrete for achieving the best impact resistance and durability was 2–3 wt%. It was found that when the percentage of the NS in the cement paste was excessively high, the improvement from adding NS to the properties of the concrete were reduced, and could even lead to negative impacts on the impact resistance and durability of the concrete.
Applications and Properties of Magnetic Nanoparticles
Authors: Arosio Paolo
Published: May 2021

In the last few decades, magnetic nanoconstructs have attracted increasing attention due to, among others, their specific magnetic properties and huge number of applications in completely different fields [...]
Gene-Directed Enzyme Prodrug Therapy by Dendrimer-Like Mesoporous Silica Nanoparticles against Tumor Cells
Authors: Candela-Noguera Vicente , Vivo-Llorca Gema , Díaz de Greñu Borja , Alfonso María , Aznar Elena , Orzáez Mar , Marcos María Dolores , Sancenón Félix , Martínez-Máñez Ramón
Published: May 2021

We report herein a gene-directed enzyme prodrug therapy (GDEPT) system using gated mesoporous silica nanoparticles (MSNs) in an attempt to combine the reduction of side effects characteristic of GDEPT with improved pharmacokinetics promoted by gated MSNs. The system consists of the transfection of cancer cells with a plasmid controlled by the cytomegalovirus promoter, which promotes β-galactosidase (β-gal) expression from the bacterial gene lacZ (CMV-lacZ). Moreover, dendrimer-like mesoporous silica nanoparticles (DMSNs) are loaded with the prodrug doxorubicin modified with a galactose unit through a self-immolative group (DOXO-Gal) and modified with a disulfide-containing polyethyleneglycol gatekeeper. Once in tumor cells, the reducing environment induces disulfide bond rupture in the gatekeeper with the subsequent DOXO-Gal delivery, which is enzymatically converted by β-gal into the cytotoxic doxorubicin drug, causing cell death. The combined treatment of the pair enzyme/DMSNs-prodrug are more effective in killing cells than the free prodrug DOXO-Gal alone in cells transfected with β-gal.
High-Performance On-Chip Silicon Beamsplitter Based on Subwavelength Metamaterials for Enhanced Fabrication Tolerance
Authors: Fernández de Cabo Raquel , González-Andrade David , Cheben Pavel , Velasco Aitor V.
Published: May 2021

Efficient power splitting is a fundamental functionality in silicon photonic integrated circuits, but state-of-the-art power-division architectures are hampered by limited operational bandwidth, high sensitivity to fabrication errors or large footprints. In particular, traditional Y-junction power splitters suffer from fundamental mode losses due to limited fabrication resolution near the junction tip. In order to circumvent this limitation, we propose a new type of high-performance Y-junction power splitter that incorporates subwavelength metamaterials. Full three-dimensional simulations show a fundamental mode excess loss below 0.1 dB in an ultra-broad bandwidth of 300 nm (1400–1700 nm) when optimized for a fabrication resolution of 50 nm, and under 0.3 dB in a 350 nm extended bandwidth (1350–1700 nm) for a 100 nm resolution. Moreover, analysis of fabrication tolerances shows robust operation for the fundamental mode to etching errors up to ±20 nm. A proof-of-concept device provides an initial validation of its operation principle, showing experimental excess losses lower than 0.2 dB in a 195 nm bandwidth for the best-case resolution scenario (i.e., 50 nm).
A New Nanomaterial Based Biosensor for MUC1 Biomarker Detection in Early Diagnosis, Tumor Progression and Treatment of Cancer
Authors: Ulucan-Karnak Fulden , Akgöl Sinan
Published: May 2021

Early detection of cancer disease is vital to the successful treatment, follow-up and survival of patients, therefore sensitive and specific methods are still required. Mucin 1 (MUC1) is a clinically approved biomarker for determining the cancer that is a type I transmembrane protein with a dense glycosylated extracellular domain extending from the cell surface to 200–500 nm. In this study, nanopolymers were designed with a lectin affinity-based recognition system for MUC1 detection as a bioactive layer on electrochemical biosensor electrode surfaces. They were synthesized using a mini emulsion polymerization method and derivatized with triethoxy-3-(2-imidazolin-1-yl) propylsilane (IMEO) and functionalized with Concanavalin a Type IV (Con A) lectin. Advanced characterization studies of nanopolymers were performed. The operating conditions of the sensor system have been optimized. Biosensor validation studies were performed. Real sample blood serum was analyzed and this new method compared with a commercially available medical diagnostic kit (Enzyme-Linked ImmunoSorbent Assay-ELISA). The new generation nanopolymeric material has been shown to be an affordable, sensitive, reliable and rapid device with 0.1–100 U/mL linear range and 20 min response time.
Tinzaparin vs. Nadroparin Safety and Efficacy in Neurosurgery
Authors: Wilhelmy Florian , Hantsche Annika , Gaier Michael , Kasper Johannes , Fehrenbach Michael Karl , Oesemann Rene , Meixensberger Jürgen , Lindner Dirk
Published: May 2021

Background: An outbreak of African swine fever (ASF) in China in 2020 has led to an unprecedented shortage of nadroparin. Most patients, especially those kept in hospital for surgery, are currently treated with prophylactic anticoagulation (AC). In search of alternatives for nadroparin (fraxiparine), we found no sufficient data on alternatives for neurosurgical patients, such as tinzaparin of European origin. We compared nadroparin and tinzaparin concerning adverse events (bleeding versus thromboembolic events) in neurosurgical patients. Methods: Between 2012 and 2018, 517 neurosurgical patients with benign and malignant brain tumors as well as 297 patients with subarachnoid hemorrhage (SAH) were treated in the Department of Neurosurgery, University Hospital Leipzig, receiving prophylactic anticoagulation within 48 h. In 2015, prophylactic anticoagulation was switched from nadroparin to tinzaparin throughout the university hospital. In a retrospective manner, the frequency and occurrence of adverse events (rebleeding and thromboembolic events) in connection with the substance used were analyzed. Statistical analysis was performed using Fisher’s exact test and the chi-squared test. Results: Rebleeding rates were similar in both nadroparin and tinzaparin cohorts in patients being treated for meningioma, glioma, and SAH combined (8.8% vs. 10.3%). Accordingly, the rates of overall thromboembolic events were not significantly different (5.5% vs. 4.3%). The severity of rebleeding did not vary. There was no significant difference among subgroups when compared for deep vein thrombosis (DVT) or pulmonary embolism (PE). Conclusion: In this retrospective study, tinzaparin seems to be a safe alternative to nadroparin for AC in patients undergoing brain tumor surgery or suffering from SAH.
Microstructure/Mechanical Characterization of Plasma Nitrided Fine-Grain Austenitic Stainless Steels in Low Temperature
Authors: Farghali Abdelrahman , Aizawa Tatsuhiko , Yoshino Tomoaki
Published: May 2021

Fine-grained austenitic stainless steels (FGSS) were plasma nitrided below 700 K to describe their microstructure evolution during the nitrogen supersaturation process and to investigate the post-stressing effect on the microstructure and mechanical properties of nitrided FGSS. Normal- and fine-grained AISI304 plates were nitrided at 623 K and 673 K to investigate the grain size effect on the nitrogen supersaturation process as well as the microstructure evolution during the nitriding process. Fine-grained AISI316 (FGSS316) wires were nitrided at 623 K to demonstrate that their outer surfaces were uniformly nitrided to have the same two-phase, refined microstructure with high nitrogen solute content. This nitrided FGSS316 wire had a core structure where the original FGSS316 core matrix was bound by the nitrided FGSS316 layer. The nitrided wire had higher stiffness, ultimate strength, and elongation in the uniaxial tensile testing than its un-nitrided wires. The core microstructure was refined and homogenized by this applied loading together with an increase of nitrided layer hardness.
Selenium as a Bioactive Micronutrient in the Human Diet and Its Cancer Chemopreventive Activity
Authors: Radomska Dominika , Czarnomysy Robert , Radomski Dominik , Bielawska Anna , Bielawski Krzysztof
Published: May 2021

This review answers the question of why selenium is such an important trace element in the human diet. Daily dietary intake of selenium and its content in various food products is discussed in this paper, as well as the effects of its deficiency and excess in the body. Moreover, the biological activity of selenium, which it performs mainly through selenoproteins, is discussed. These specific proteins are responsible for thyroid hormone management, fertility, the aging process, and immunity, but their key role is to maintain a redox balance in cells. Furthermore, taking into account world news and the current SARS-CoV-2 virus pandemic, the impact of selenium on the course of COVID-19 is also discussed. Another worldwide problem is the number of new cancer cases and cancer-related mortality. Thus, the last part of the article discusses the impact of selenium on cancer risk based on clinical trials (including NPC and SELECT), systematic reviews, and meta-analyses. Additionally, this review discusses the possible mechanisms of selenium action that prevent cancer development.
Inhibitory Effect of Apomorphine on Focal and Nonfocal Plasticity in the Human Motor Cortex
Authors: Fresnoza Shane M. , Batsikadze Giorgi , Müller Lynn Elena , Rost Constanze , Chamoun Michael , Paulus Walter , Kuo Min-Fang , Nitsche Michael A.
Published: May 2021

Dopamine is crucial for neuroplasticity, which is considered to be the neurophysiological foundation of learning and memory. The specific effect of dopamine on plasticity such as long-term potentiation (LTP) and long-term depression (LTD) is determined by receptor subtype specificity, concentration level, and the kind of plasticity induction technique. In healthy human subjects, the dopamine precursor levodopa (L-DOPA) exerts a dosage-dependent non-linear effect on motor cortex plasticity. Low and high dosage L-DOPA impaired or abolished plasticity, while medium-dose preserved and reversed plasticity in previous studies. Similar dosage-dependent effects were also observed for selective D1-like and D2-like receptor activation that favor excitatory and inhibitory plasticity, respectively. However, such a dosage-dependent effect has not been explored for a nonselective dopamine agonist such as apomorphine in humans. To this aim, nonfocal and focal motor cortex plasticity induction using paired associative stimulation (PAS) and transcranial direct current stimulation (tDCS) were performed respectively in healthy participants under 0.1, 0.2, 0.3 mg apomorphine or placebo drug. Transcranial magnetic stimulation-elicited motor-evoked potentials were used to monitor motor cortical excitability alterations. We hypothesized that, similar to L-DOPA, apomorphine will affect motor cortex plasticity. The results showed that apomorphine with the applied dosages has an inhibitory effect for focal and nonfocal LTP-like and LTD-like plasticity, which was either abolished, diminished or reversed. The detrimental effect on plasticity induction under all dosages of apomorphine suggests a predominantly presynaptic mechanism of action of these dosages.
On the Post-Processing of 3D-Printed ABS Parts
Authors: Khosravani Mohammad Reza , Schüürmann Jonas , Berto Filippo , Reinicke Tamara
Published: May 2021

Application of Additive Manufacturing (AM) has significantly increased in the past few years. AM also known as three-dimensional (3D) printing has been currently used in fabrication of prototypes and end-use products. Considering the new applications of additively manufactured components, it is necessary to study structural details of these parts. In the current study, influence of a post-processing on the mechanical properties of 3D-printed parts has been investigated. To this aim, Acrylonitrile Butadiene Styrene (ABS) material was used to produce test coupons based on the Fused Deposition Modeling (FDM) process. More in deep, a device was designed and fabricated to fix imperfection and provide smooth surfaces on the 3D-printed ABS specimens. Later, original and treated specimens were subjected to a series of tensile loads, three-point bending tests, and water absorption tests. The experimental tests indicated fracture load in untreated dog-bone shaped specimen was 2026.1 N which was decreased to 1951.7 N after surface treatment. Moreover, the performed surface treatment was lead and decrease in tensile strength from 29.37 MPa to 26.25 MPa. Comparison of the results confirmed effects of the surface modification on the fracture toughness of the examined semi-circular bending components. Moreover, a 3D laser microscope was used for visual investigation of the specimens. The documented results are beneficial for next designs and optimization of finishing processes.
Combination of Corn Pith Fiber and Biobased Flame Retardant: A Novel Method toward Flame Retardancy, Thermal Stability, and Mechanical Properties of Polylactide
Authors: Yang Yunxian , Wang De-Yi , Haurie Laia , Liu Zhiqi , Zhang Lu
Published: May 2021

Some crop by-products are considered to be promising materials for the development of novel biobased products for industrial applications. The flammability of these alternatives to conventional materials is a constraint to expanded applications. Polylactide (PLA) composites containing a combination of oxidized corn pith fiber (OCC) and a biobased flame retardant (PA-THAM) have been prepared via an in situ modification method. SEM/EDS, FTIR and TGA were performed to establish that PA-THAM was coated onto the surface of OCC. The mechanical properties, thermal stability and fire behavior of PLA-based biocomposites were investigated. The incorporation of 5 phr PA-THAM imparted biocomposite good interfacial adhesion and increased decomposition temperature at 10% mass loss by 50 °C. The flame retardant properties were also improved, as reflected by an increased LOI value, a UL-94 V-2 rating, reduction of PHRR, and increased formation of char residue. Therefore, the introduction of 5 phr PA-THAM can maintain a good balance between flame retardancy and mechanical properties of this PLA/OCC system.
Theory of Mind Ability and Socioeconomic Status, a Study of Street-Connected Children and Adolescents in Ecuador
Authors: Pluck Graham
Published: May 2021

Family socioeconomic status (SES) is closely associated with cognitive ability in children and adolescents. However, most of the research has come from high-income countries. There is only limited research on ‘street children’, who represent an aspect of low-SES particularly associated with low- and middle-income counties. The current research in Quito, Ecuador, compared a group of street-connected youth with a not street-connected control group on two different measures of theory of mind ability and verbal comprehension. Initial analysis revealed that the street-connected sample scored significantly below the level of the control sample for verbal comprehension. For the main analysis, street-connected youth were matched to control participants for age, sex, and verbal comprehension scores. The street-connected sample was found to perform significantly below the control sample on both measures of theory of mind. Furthermore, worse performance appeared to be linked to severity of symptoms of post-traumatic stress disorder (PTSD) within the street-connected sample. In conclusion, the association of relatively poor verbal comprehension with street-connectedness is consistent with existing research from high-income countries on SES gradients and cognitive development. In contrast, theory of mind ability, a core aspect of social cognition, may be particularly linked to the street-connectedness form of low SES that exists in many low- and middle-income countries.
Near-Ultraviolet to Near-Infrared Band Thresholds Cloud Detection Algorithm for TANSAT-CAPI
Authors: Ding Ning , Shao Jianbing , Yan Changxiang , Zhang Junqiang , Qiao Yanfeng , Pan Yun , Yuan Jing , Dong Youzhi , Yu Bo
Published: May 2021

Cloud and aerosol polarization imaging detector (CAPI) is one of the important payloads on the China Carbon Dioxide Observation Satellite (TANSAT), which can realize multispectral polarization detection and accurate on-orbit calibration. The main function of the instrument is to identify the interference of clouds and aerosols in the atmospheric detection path and to improve the retrieval accuracy of greenhouse gases. Therefore, it is of great significance to accurately identify the clouds in remote sensing images. However, in order to meet the requirement of lightweight design, CAPI is only equipped with channels in the near-ultraviolet to near-infrared bands. It is difficult to achieve effective cloud recognition using traditional visible light to thermal infrared band spectral threshold cloud detection algorithms. In order to solve the above problem, this paper innovatively proposes a cloud detection method based on different threshold tests from near ultraviolet to near infrared (NNDT). This algorithm first introduces the 0.38 μm band and the ratio of 0.38 μm band to 1.64 μm band, to realize the separation of cloud pixels and clear sky pixels, which can take advantage of the obvious difference in radiation characteristics between clouds and ground objects in the near-ultraviolet band and the advantages of the band ratio in identifying clouds on the snow surface. The experimental results show that the cloud recognition hit rate (PODcloud) reaches 0.94 (ocean), 0.98 (vegetation), 0.99 (desert), and 0.86 (polar), which therefore achieve the application standard of CAPI data cloud detection The research shows that the NNDT algorithm replaces the demand for thermal infrared bands for cloud detection, gets rid of the dependence on the minimum surface reflectance database that is embodied in traditional cloud recognition algorithms, and lays the foundation for aerosol and CO2 parameter inversion.
46-Year (1973–2019) Permafrost Landscape Changes in the Hola Basin, Northeast China Using Machine Learning and Object-Oriented Classification
Authors: Șerban Raul-David , Șerban Mihaela , He Ruixia , Jin Huijun , Li Yan , Li Xinyu , Wang Xinbin , Li Guoyu
Published: May 2021

Land use and cover changes (LUCC) in permafrost regions have significant consequences on ecology, engineered systems, and the environment. Obtaining more details about LUCC is crucial for sustainable development, land conservation, and environment management. The Hola Basin (957 km2) in the northernmost part of Northeast China, a boreal forest landscape underlain by discontinuous, sporadic, and isolated permafrost, was selected for the case study. The LUCC was analyzed using the Landsat archive of satellite images from 1973 to 2019. A thematic change detection analysis was performed by combining the object-based image analysis (OBIA) and the Support Vector Machine (SVM) algorithm. Four types of LUCC (forest, grass, water, and anthropic) were extracted with an overall accuracy of 80% for 1973 and >90% for 1986, 2000, and 2019. Forest, the dominant class (750 km2 in 1973), declined by 88 km2 (11.8%) from 1973 to 1986 but had a recovery of 78 km2 (12.5%) from 2000 to 2019. Grass, the second-largest class (187 km2 in 1973), increased by 86 km2 (46.5%) between 1973 and 1986 and decreased by 90 km2 (40%) between 2000 and 2019. The anthropic class continuously increased from 10 km2 (1973) to 37 km2 (2019). Major features in LUCC are attributed to rapid population growth, resource exploitation, agriculture intensification, economic development, and frequent forest fires. Under a pronounced climate warming, these drivers have been accelerating the degradation of permafrost, subsequently triggering natural hazards and deteriorating the ecological environment. This study represents a benchmark for sustainable LUCC management in the Hola Basin, Northeast China.
Rich CNN Features for Water-Body Segmentation from Very High Resolution Aerial and Satellite Imagery
Authors: Zhang Zhili , Lu Meng , Ji Shunping , Yu Huafen , Nie Chenhui
Published: May 2021

Extracting water-bodies accurately is a great challenge from very high resolution (VHR) remote sensing imagery. The boundaries of a water body are commonly hard to identify due to the complex spectral mixtures caused by aquatic vegetation, distinct lake/river colors, silts near the bank, shadows from the surrounding tall plants, and so on. The diversity and semantic information of features need to be increased for a better extraction of water-bodies from VHR remote sensing images. In this paper, we address these problems by designing a novel multi-feature extraction and combination module. This module consists of three feature extraction sub-modules based on spatial and channel correlations in feature maps at each scale, which extract the complete target information from the local space, larger space, and between-channel relationship to achieve a rich feature representation. Simultaneously, to better predict the fine contours of water-bodies, we adopt a multi-scale prediction fusion module. Besides, to solve the semantic inconsistency of feature fusion between the encoding stage and the decoding stage, we apply an encoder-decoder semantic feature fusion module to promote fusion effects. We carry out extensive experiments in VHR aerial and satellite imagery respectively. The result shows that our method achieves state-of-the-art segmentation performance, surpassing the classic and recent methods. Moreover, our proposed method is robust in challenging water-body extraction scenarios.
A Novel Approach to Obtain PAR with a Multi-Channel Spectral Microsensor, Suitable for Sensor Node Integration
Authors: Bäumker Eiko , Zimmermann Daniel , Schierle Stefan , Woias Peter
Published: May 2021

We propose a novel approach to measure photosynthetically active radiation (PAR ) in the form of photosynthetic photon flux density with an inexpensive, small multi-channel spectrometer sensor, with integrated optical filters and analog-to-digital converter. Our experiments prove that the combination of eight spectral channels with different optical sensitivities, such as the sensorchip in use (AS7341, ams), derive the PAR with an accuracy of 14/m2/s. Enabled by the sensor architecture, additional information about the light quality can be retrieved which is expressed in the RLQI. A calibration method is proposed, and exemplary measurements are performed. Moreover, the integration in a solar-powered wireless sensor node is outlined, which enables long-term field experiments with high sensor densities and may be used to obtain important indexes, such as the GPP.
Balanced Distribution Adaptation for Metal Oxide Semiconductor Gas Sensor Array Drift Compensation
Authors: Jiang Zongze , Xu Peng , Du Yongbin , Yuan Feng , Song Kai
Published: May 2021

Drift compensation is an important issue for metal oxide semiconductor (MOS) gas sensor arrays. General machine learning methods require constant calibration and a large amount of label gas data. At the same time, recalibration will cause a lot of costs, and label gas is difficult to obtain in practice. In this paper, a novel drift compensation method based on balanced distribution adaptation (BDA) is proposed. First, the BDA drift compensation method can adjust the conditional distribution and marginal distribution between the two domains through the weight balance factor, thereby more effectively reducing the mismatch between the two domains. When the BDA method performs classification tasks through machine learning, no labeled data is required in the target domain. Then, the particle swarm optimization algorithm is used to improve the accuracy of drift compensation. Individuals in the population are initialized randomly, and their fitness values are calculated. Iterative optimization of the population individuals is conducted until the optimal weight balance factor parameters are calculated. Finally, the BDA method is experimentally verified on the public gas sensor drift data set. Experimental results showed that the BDA method was significantly better than the existing joint distribution adaptation (JDA) method and other standard drift compensation methods such as K-Nearest Neighbor (KNN). In the two setting groups, the recognition accuracy was 4.54% and 1.62% ahead of the JDA method, and 12.23% and 15.83% ahead of the KNN method.
Hybrid Imitation Learning Framework for Robotic Manipulation Tasks
Authors: Jung Eunjin , Kim Incheol
Published: May 2021

This study proposes a novel hybrid imitation learning (HIL) framework in which behavior cloning (BC) and state cloning (SC) methods are combined in a mutually complementary manner to enhance the efficiency of robotic manipulation task learning. The proposed HIL framework efficiently combines BC and SC losses using an adaptive loss mixing method. It uses pretrained dynamics networks to enhance SC efficiency and performs stochastic state recovery to ensure stable learning of policy networks by transforming the learner’s task state into a demo state on the demo task trajectory during SC. The training efficiency and policy flexibility of the proposed HIL framework are demonstrated in a series of experiments conducted to perform major robotic manipulation tasks (pick-up, pick-and-place, and stack tasks). In the experiments, the HIL framework showed about a 2.6 times higher performance improvement than the pure BC and about a four times faster training time than the pure SC imitation learning method. In addition, the HIL framework also showed about a 1.6 times higher performance improvement and about a 2.2 times faster training time than the other hybrid learning method combining BC and reinforcement learning (BC + RL) in the experiments.
Next-Generation Dried Blood Spot Samplers for Protein Analysis: Describing Trypsin-Modified Smart Sampling Paper
Authors: Pizzi Eleonora , Halvorsen Trine Grønhaug , Koehler Christian J. , Reubsaet Léon
Published: May 2021

This paper describes smart sampling paper to be used for bottom-up protein analysis. Four different manners to immobilize trypsin on cellulose were evaluated. Untreated paper, potassium-periodate-functionalized paper (with and without post-immobilization reduction) and 2-hydroxyethyl methacrylate (HEMA)/2-vinyl-4,4-dimethylazlactone (VDM)-functionalized paper were all used to immobilize trypsin. For the evaluation, Coomassie Brilliant Blue staining of proteins on paper and the BAEE trypsin activity assay needed to be modified. These methods allowed, together with data from mass spectrometric analysis of cytochrome C digestions, us to acquire fundamental insight into protein binding, and trypsin action and activity on paper. All functionalized discs bind more protein than the untreated discs. Protein binding to functionalized discs is based on both adsorption and covalent binding. Trypsin immobilized on potassium-periodate-functionalized discs exhibits the highest trypsin activity when using cytochrome C as substrate. It is proven that it is trypsin attached to paper (and not desorbed trypsin) which is responsible for the enzyme activity. The use of discs on complex biological samples shows that all functionalized discs are able to digest diluted serum; for the best-performing disc, HEMA-VDM functionalized, up to 200 high-confidence proteins are qualified, showing its potential.
Specification of Glazings for Façades Based on Spectrophotometric Characterization of Transmittance
Authors: Sacht Helenice Maria , Bragança Luís , Almeida Manuela , Caram Rosana
Published: May 2021

The correct specification of glazings for façades can reduce the energy consumption in buildings. The heat exchange occurs through transparent surfaces and radiation reaches the building as light and heat. Therefore, glazings significantly contribute to the heat transfer between outdoor and indoor spaces and act directly on daylighting and thermal comfort. This paper reports on the spectrophotometric characterization of glazings transmittance for the study of components of a modular façade system and its suitability for the climate of Portugal (temperate climate). The study focused on results of spectrophotometric measurements of optical properties, specifically the transmittance of some types of glazings (solar control, self-cleaning, low-e, float, and extra-clear) and two types of double glazings. The results show the percentage of transmission to ultraviolet, visible, and near-infrared regions and its importance, which enabled the analysis of the glazing efficiency regarding daylighting and the correlation to thermal performance. Subsidies and indications for the specification and adequate uses of transparent surfaces have been presented and complemented the datasheets available from the manufactures.
Black Soldier Fly Larvae Meal as Alternative to Fish Meal for Aquaculture Feed
Authors: Oteri Marianna , Di Rosa Ambra Rita , Lo Presti Vittorio , Giarratana Filippo , Toscano Giovanni , Chiofalo Biagina
Published: May 2021

Hermetia illucens meal (HIM) as ingredient in feed represents a way to achieve more sustainable food production. The aim was to characterize the chemical, microbiological and organoleptic characteristics of four diets for Sparus aurata, isoenergetic and isoproteic, containing 0%, 25%, 35% and 50% of HIM in substitution of fish meal (FM). Analyses were carried out using gas chromatography for fatty acids and amino acids, ICP-OES for minerals and liquid chromatography for aflatoxins and following International Organization for Standardization methods for microbial flora. E-sensing analysis of the diets was evaluated using an artificial sensory platform (E-eye, E-nose and E-tongue). The chemical results were submitted to a one-way ANOVA while Principal Component Analysis (PCA) of the e-sensing data was performed. No significant differences were observed for polyunsaturated fatty acids, thrombogenic and peroxidation indices among the diets. The replacement of FM with HIM increased the content of lysine, methionine, isoleucine, leucine, threonine and valine, while phosphorus, calcium and sodium content decreased (p < 0.01) as the percentage of HIM increased. Lead was significantly below the maximum level set by the EU regulation. The diets showed good hygienic and sanitary quality. The artificial senses permitted distinguishing color, odor and taste among the diets. Data allow considering Hermetia illucens as alternative protein source in fish nutrition.
Exploring Countermeasures from a Psychological Perspective to Create a Safe Driving Environment for Personal Mobility Devices
Authors: Kim Suk-Hee , Lim Hyejin , Kim Junghwa
Published: May 2021

The personal mobility device (E-Powered Personal Mobility Vehicle) has recently been attracting attention as a viable method of transportation for first and last mile travel, primarily due to its portability and ease of mobility. Although the size of its market is increasing rapidly, the number of accidents is also increasing rapidly. Suwon city, in particular, has the highest rate of traffic accidents linked with personal mobility among all of the local governments in the Gyeonggi Province in Korea, as of 2019. The annual average rate of increase has been as high as 151.7% over the past three years. The objective of this study was to analyze the usage of personal mobility devices among Suwon citizens through a questionnaire, which was then analyzed using partial least square structural equation modeling (PLS-SEM). We then examined the impact of psychological attitudes on the future use of personal mobility, and then derived future policy directions from all of the gathered data. According to a survey of Suwon citizens, the ratio of users who had no experience in using the devices was higher than that of those who had some experience in using them. The results of the survey on citizens’ satisfaction with the driving environment revealed that their overall satisfaction level was low, while the response rate regarding the need for safety equipment and systems was high, confirming that the current system had poor safety levels, which results in a very high risk of accidents. However, given that there were many positive responses regarding the users’ intentions to use personal mobility devices in the future, it seems that it is necessary to establish a safer driving environment in order to better incorporate these personal mobility devices into the city.
The Initial Training of Science Teachers in African Countries: A Systematic Literature Review
Authors: Soares Diana , Lopes Betina , Abrantes Isabel , Watts Mike
Published: May 2021

This study presents a systematic literature review (SLR) on the initial training of science teachers in Africa based on selected research articles, in the period 2000–2020, that emphasize the importance of surveying knowledge that goes beyond those that historically have a longer path in the building of scientific knowledge, such as that of European or North American countries. The analysis included a total of 31 articles from the Web of Science (WoS) and Scopus databases. The findings indicate a lack of knowledge, or at least visibility, considering the initial training of African teachers, particularly in developing countries. South Africa leads the number of publications. Within the five African countries implied in the SLR the following outputs were identified: (i) a division between teacher education research that is ‘place-based’ and one that uses (only) ‘universal theories’ (such as Vygotsky and Bandura); (ii) a tension between the application of student-centered learning and teaching models and more traditional classroom practices. Finally, the majority of articles highlight the importance of investing in further research around teacher education. Based on these outputs the importance of international cooperation in teacher education research articulating theory and practice to ensure a global and local perspective towards sustainable development is reinforced.
Strategic Management for Community-Based Markets: From Consumers’ Perspectives and Experiences
Authors: Chen Chao-Jung R. , Yu Tun-Hsiang Edward , Fu Rachel J. C.
Published: May 2021

This study used a consumer survey to identify resources and services that are important to farmers’ market (FM) shoppers. The questionnaire was distributed onsite in six FMs in Tennessee, and a total of 506 FM shoppers responded. The most important resources and services in terms of a shopper’s decision to visit a FM are identified as supporting local food, quality, friendly, and diverse vendors, and food origin. Multivariate analysis of variance (MANOVA) reveals that convenience and close to home are more important to women; price is more important to younger and lower-income shoppers, while quality, convenience, interaction with farmers/producers, and food origin are more important to older shoppers. Content analysis indicated that FM shoppers were impressed with FM atmosphere and liked the quality, variety, and convenience provided by FMs, but disliked not having clear information such as product labels and websites.
An Analysis of the Influencing Factors of Study Engagement and Its Enlightenment to Education: Role of Perceptions of School Climate and Self-Perception
Authors: Zhou Aibao , Guan Xiangli , Ahmed Md Zahir , Ahmed Oli , Jobe Mary C. , Hiramoni Fatema Akhter
Published: May 2021

Predominantly, a school provides pedagogical support to its students, though perceptions about the school’s internal environment can incessantly influence a student’s aggregated learning experience. The present study aims to investigate the impact of the campus environment on students’ study engagement and the roles of self-concept clarity and intentional self-regulation on this association. A hypothetical model about the relationship between campus perception, self-concept clarity, intentional self-regulation, and study engagement was tested. A total of 1597 students from Gansu Province, China, selected through a convenience sampling technique, were surveyed utilizing self-rated scales. Data were collected utilizing the Study Engagement Scale, Perceptions of School Climate Scale, Intentional Self-Regulation Scale and Self-Concept Clarity Scale. Results showed lower to moderate positive correlations between study variables. Students’ campus environment perceptions positively predicted adolescents’ study engagement. This association was also mediated by self-concept clarity and intentional self-regulation. All of these factors explained 41.26% variability of the study engagement. These findings show how the learning environment can impact students. Specifically, these results help demonstrate that self-concept clarity and intentional self-regulation have academic importance to optimize students’ study engagement that in turn promotes quality learning.
The Experience of Place in the Annual Festival Held in an Amazigh Village in Southern Tunisia
Authors: Kitagawa Tamaki
Published: May 2021

The phenomenological meaning of place argued by Yi-Fu Tuan and Edward Relph involves multiple disciplines, including religious studies. Based on the idea of experience of place, the study examines the structural contrast between the inner village and the outside suburbs. Focusing on the representation of the contrast of places in the festival of southern Tunisia, it also discusses the inner and the outer experience of the human existence that such contrast implies. In this regard, interviews with the local people in the village and observation of rituals and festivals were implemented. The traditional rituals designate the contrast of the human realm and the untamed nature, which has been shaped by environmental and historical factors. Their ambivalent ontological orientations toward usefulness/controllability and toward sacredness/uncontrollability are reconciled by the experience of the festival. The dynamism of the inside and the outside in the form of olives, a bride, or a palanquin enables people to realize the source of new lives and experience the essential meaning of generation. In spite of recent political and exhibitionistic tendencies, the Mahrajān represents the universal structure of festivals in which arbitrariness is periodically broken down by introducing the external sacredness into the inner human realm.
Inversion of Tridiagonal Matrices Using the Dunford-Taylor’s Integral
Authors: Caratelli Diego , Ricci Paolo Emilio
Published: May 2021

We show that using Dunford-Taylor’s integral, a classical tool of functional analysis, it is possible to derive an expression for the inverse of a general non-singular complex-valued tridiagonal matrix. The special cases of Jacobi’s symmetric and Toeplitz (in particular symmetric Toeplitz) matrices are included. The proposed method does not require the knowledge of the matrix eigenvalues and relies only on the relevant invariants which are determined, in a computationally effective way, by means of a dedicated recursive procedure. The considered technique has been validated through several test cases with the aid of the computer algebra program Mathematica©.
Changes in the Risk of Stroke in Dialysis Patients: A Retrospective Analysis over the Last 40 Years
Authors: Aono Toshiya , Shinya Yuki , Miyawaki Satoru , Sugiyama Takehiro , Kumagai Isao , Takenobu Atsumi , Shin Masahiro , Saito Nobuhito , Teraoka Akira
Published: May 2021

The stroke incidence in hemodialysis (HD) patients is high, but the associated factors remain largely unknown. This study aimed to analyze stroke incidence in HD patients and changes in risk factors. Data of 291 patients were retrospectively analyzed. The cumulative stroke incidences were 21.6% at 10 years and 31.5% at 20. Diabetic nephropathy (DN) significantly increased overall stroke (hazard ratio (HR), 2.24; 95% confidence interval (CI), 1.21–4.12; p = 0.001) and ischemic stroke (HR, 2.16; 95% CI, 1.00–4.64; p = 0.049). Patients treated with online HDF were less likely to have overall stroke (HR, 0.13; 95% CI, 0.03–0.56; p = 0.006) and ischemic stroke (HR, 0.08; 95% CI, 0.01–0.60; p = 0.014). DN (HR, 1.56; 95% CI, 1.08–2.27; p = 0.019) and age >80 years at HD initiation (20–49 years old; HR 0.13, 95% CI, 0.05-0.35, p < 0.001 and age 50–79 years; HR 0.42, 95% CI, 0.26–0.66, p < 0.001 (reference: age >80 years)) were significantly associated with stroke and/or death events. Over time, stroke risk increased in HD patients, due to the increasing number of DN. Although dialysis technology has advanced over time, these advances could not overcome other risk factors for stroke. Further increase in stroke and mortality due to aging remains a concern.