bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Anticoagulant Activity and Active Components of Safflower Injection
Authors: Wang Kai-Hong , Li Shi-Fei , Zhao Yi , Li Hong-Xia , Zhang Li-Wei
Published: January 2018

Safflower injection is well-known as a traditional Chinese medicine used to improve the blood circulation. In this study, seven safflower injection samples from different companies were evaluated for their in vitro anticoagulant activity by measuring their activated partial thromboplastin time (APTT) and prothrombin time (PT) against human plasma. The screening results suggested that the safflower injections exhibited a significant prolonging influence on APTT (p < 0.05 vs. the control group), but not on prolonging PT (p > 0.05 vs. the control group). The safflower injection was separated into four fractions, and among them, fraction four demonstrated the most anticoagulant activity, with an APTT of 95.4 ± 1.4 s at a concentration of 4.0 μg/μL (p < 0.01 vs. control group). In addition, three active components, p-hydroxybenzaldehyde, p-hydroxy-cinnamic acid, and (8Z)-decaene-4,6-diyne-1-O-β-d-glucopyranoside were isolated from fraction four with Sephadex LH-20 and C18 column chromatography. All three active components showed significant prolonging of APTT (p < 0.05 vs. control group). Among them, p-hydroxy-cinnamic acid exhibited the most activity (p < 0.01 vs. control group). The results indicated that safflower injection strongly affects the intrinsic coagulation system, and we suggest that this might be the mechanism by which the safflower injection activates and promotes blood circulation.
Generating CRISPR/Cas9-Derived Mutant Mice by Zygote Cytoplasmic Injection Using an Automatic Microinjector
Authors: Doe Brendan , Brown Ellen , Boroviak Katharina
Published: January 2018

Clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) assisted generation of mutant animals has become the method of choice for the elucidation of gene function in development and disease due to the shortened timelines for generation of a desired mutant, the ease of producing materials in comparison to other methodologies (such as embryonic stem cells, ESCs) and the ability to simultaneously target multiple genes in one injection session. Here we describe a step by step protocol, from preparation of materials through to injection and validation of a cytoplasmic injection, which can be used to generate CRISPR mutants. This can be accomplished from start of injection to completion within 2–4 h with high survival and developmental rates of injected zygotes and offers significant advantages over pronuclear and other previously described methodologies for microinjection.
Engineering Ru@Pt Core-Shell Catalysts for Enhanced Electrochemical Oxygen Reduction Mass Activity and Stability
Authors: Jackson Ariel , Strickler Alaina , Higgins Drew , Jaramillo Thomas
Published: January 2018

Improving the performance of oxygen reduction reaction (ORR) electrocatalysts is essential for the commercial efficacy of many renewable energy technologies, including low temperature polymer electrolyte fuel cells (PEFCs). Herein, we report highly active and stable carbon-supported Ru@Pt core-shell nanoparticles (Ru@Pt/C) prepared by a wet chemical synthesis technique. Through rotating disc electrode testing, the Ru@Pt/C achieves an ORR Pt mass-based activity of 0.50 A mgPt−1 at 0.9 V versus the reversible hydrogen electrode (RHE), which exceeds the activity of the state-of-the-art commercial Pt/C catalyst as well as the Department of Energy 2020 PEFC electrocatalyst activity targets for transportation applications. The impact of various synthetic parameters, including Pt to Ru ratios and catalyst pretreatments (i.e., annealing) are thoroughly explored. Pt-based mass activity of all prepared Ru@Pt/C catalysts was found to exceed 0.4 mgPt−1 across the range of compositions investigated, with the maximum activity catalyst having a Ru:Pt ratio of 1:1. This optimized composition of Ru@Pt/C catalyst demonstrated remarkable stability after 30,000 accelerated durability cycles (0.6 to 1.0 V vs. RHE at 125 mV s−1), maintaining 85% of its initial mass activity. Scanning transmission electron microscopy energy dispersive spectroscopy (STEM-EDS) analysis at various stages of electrochemical testing demonstrated that the Pt shell can provide sufficient protection against the dissolution of the otherwise unstable Ru core.
Crystallization of TiO2 Nanotubes by In Situ Heating TEM
Authors: Casu Alberto , Lamberti Andrea , Stassi Stefano , Falqui Andrea
Published: January 2018

The thermally-induced crystallization of anodically grown TiO2 amorphous nanotubes has been studied so far under ambient pressure conditions by techniques such as differential scanning calorimetry and in situ X-ray diffraction, then looking at the overall response of several thousands of nanotubes in a carpet arrangement. Here we report a study of this phenomenon based on an in situ transmission electron microscopy approach that uses a twofold strategy. First, a group of some tens of TiO2 amorphous nanotubes was heated looking at their electron diffraction pattern change versus temperature, in order to determine both the initial temperature of crystallization and the corresponding crystalline phases. Second, the experiment was repeated on groups of few nanotubes, imaging their structural evolution in the direct space by spherical aberration-corrected high resolution transmission electron microscopy. These studies showed that, differently from what happens under ambient pressure conditions, under the microscope’s high vacuum (p < 10−5 Pa) the crystallization of TiO2 amorphous nanotubes starts from local small seeds of rutile and brookite, which then grow up with the increasing temperature. Besides, the crystallization started at different temperatures, namely 450 and 380 °C, when the in situ heating was performed irradiating the sample with electron beam energy of 120 or 300 keV, respectively. This difference is due to atomic knock-on effects induced by the electron beam with diverse energy.
Detection of ZrO2 Nanoparticles in Lung Tissue Sections by Time-of-Flight Secondary Ion Mass Spectrometry and Ion Beam Microscopy
Authors: Veith Lothar , Böttner Julia , Vennemann Antje , Breitenstein Daniel , Engelhard Carsten , Meijer Jan , Estrela-Lopis Irina , Wiemann Martin , Hagenhoff Birgit
Published: January 2018

The increasing use of nanoparticles (NP) in commercial products requires elaborated techniques to detect NP in the tissue of exposed organisms. However, due to the low amount of material, the detection and exact localization of NP within tissue sections is demanding. In this respect, Time-of-Flight Secondary Ion Mass Spectrometry (ToF-SIMS) and Ion Beam Microscopy (IBM) are promising techniques, because they both offer sub-micron lateral resolutions along with high sensitivities. Here, we compare the performance of the non-material-consumptive IBM and material-consumptive ToF-SIMS for the detection of ZrO2 NP (primary size 9–10 nm) in rat lung tissue. Unfixed or methanol-fixed air-dried cryo-sections were subjected to IBM using proton beam scanning or to three-dimensional ToF-SIMS (3D ToF-SIMS) using either oxygen or argon gas cluster ion beams for complete sample sputtering. Some sample sites were analyzed first by IBM and subsequently by 3D ToF-SIMS, to compare results from exactly the same site. Both techniques revealed that ZrO2 NP particles occurred mostly agglomerated in phagocytic cells with only small quantities being associated to the lung epithelium, with Zr, S, and P colocalized within the same biological structures. However, while IBM provided quantitative information on element distribution, 3D ToF-SIMS delivered a higher lateral resolution and a lower limit of detection under these conditions. We, therefore, conclude that 3D ToF-SIMS, although not yet a quantitative technique, is a highly valuable tool for the detection of NP in biological tissue.
Infant Development at the Age of 6 Months in Relation to Feeding Practices, Iron Status, and Growth in a Peri-Urban Community of South Africa
Authors: Rothman Marinel , Faber Mieke , Covic Namukolo , Matsungo Tonderayi , Cockeran Marike , Kvalsvig Jane , Smuts Cornelius
Published: January 2018

Background: Evidence on the association between feeding practices, iron deficiency, anaemia, stunting, and impaired psychomotor development during infancy is limited. This study assessed the association between psychomotor development with early feeding practices, growth, iron status, and anaemia. Methods: This was cross-sectional baseline data of a randomised controlled trial which included 6-month-old infants and their mothers or primary caregivers (n = 750) in a peri-urban community in the North West province of South Africa. The Kilifi Developmental Inventory and a parent rating scale were used to assess psychomotor development. Feeding practices and anthropometric measurements were based on the World Health Organisation (WHO) guidelines. Anaemia and iron status were determined by blood sample analysis. Results: Prevalence of anaemia and stunting for the infants were 36.4% and 28.5%, respectively. Multiple regression analysis showed that birth weight was related to combined psychomotor scores (β = −3.427 (−4.603, 1.891), p < 0.001), as well as parent rating scores (β = −0.843 (−1.507, −0.180), p = 0.013). Length-for-age z-scores were associated with combined psychomotor scores (β = −1.419 (−2.466, 0.373), p = 0.008), as well as parent rating scores (β = −0.747 (−1.483, −0.010), p = 0.047). Conclusions: In this setting, with high prevalence of anaemia and stunting, important associations between lower psychomotor development scores and birthweight as well as length-for-age z-scores in 6-month-old infants were found. These findings warrant further investigation to develop a greater understanding of factors influencing the association between child growth and psychomotor development within the first 1000 days of life.
Low-Carbohydrate, High-Protein, High-Fat Diets Rich in Livestock, Poultry and Their Products Predict Impending Risk of Type 2 Diabetes in Chinese Individuals that Exceed Their Calculated Caloric Requirement
Authors: Shan Ruiqi , Duan Wei , Liu Lei , Qi Jiayue , Gao Jian , Zhang Yunlong , Du Shanshan , Han Tianshu , Pang Xiuyu , Sun Changhao , Wu Xiaoyan
Published: January 2018

The evidence on the association between long-term low-carbohydrate, high-fat and high-protein diets and type 2 diabetes (T2D) is controversial. Until now, data is limited for Chinese populations, especially in considering the influence of extra energy intake. In this paper, we aimed to investigate the association of low-carbohydrate, high-fat and high-protein diets with type 2 diabetes (T2D) risk in populations consuming extra calories and those with normal caloric intake, We also determined whether the association is mediated by insulin resistance (IR) or β-cell dysfunction. A total of 3644 subjects in the Harbin People’s Health Study (Cohort 1, 2008–2012) and 7111 subjects in the Harbin Cohort Study on Diet, Nutrition and Chronic Non-Communicable Diseases (Cohort 2, 2010–2015) were analyzed, with a median follow-up of 4.2 and 5.3 years, respectively. Multivariate relative risks (RRs) and their 95% confidence intervals (95% CIs) were calculated to estimate the association between low-carbohydrate, high-fat and high-protein diet and T2D in logistic regression models. The multivariate RRs (95% CIs) were 1.00, 2.24 (1.07, 4.72) and 2.29 (1.07, 4.88) (Ptrend = 0.04), and 1.00, 1.45 (0.91, 2.31) and 1.64 (1.03, 2.61) (Ptrend = 0.04) across tertiles of low-carbohydrate, high-fat and high-protein diet scores in the population consuming extra calories in Cohort 1 and Cohort 2, respectively. The association was no longer significant after adjustment for livestock and its products, or poultry and its products. The mediation analysis discovered that this association in the population consuming extra calories was insulin resistance mediated, in both Cohort 1 and Cohort 2. However, the association was not significant among participants overall and participants with normal caloric intake. Our results indicated that long-term low-carbohydrate, high-fat and high-protein diets were associated with increased T2D risk among the population consuming extra calories, which may be caused by higher intake of animal-origin fat and protein as well as lower intake of vegetables, fruit and fiber. Additionally, the association was mediated by IR. In the population consuming extra calories, reducing the intake of livestock, poultry and their products and increasing the intake of vegetables, fruit and fiber might protect this population from developing T2D.
Rational Management of Iron-Deficiency Anaemia in Inflammatory Bowel Disease
Authors: Nielsen Ole , Soendergaard Christoffer , Vikner Malene , Weiss Günter
Published: January 2018

Anaemia is the most frequent, though often neglected, comorbidity of inflammatory bowel disease (IBD). Here we want to briefly present (1) the burden of anaemia in IBD, (2) its pathophysiology, which mostly arises from bleeding-associated iron deficiency, followed by (3) diagnostic evaluation of anaemia, (4) a balanced overview of the different modes of iron replacement therapy, (5) evidence for their therapeutic efficacy and subsequently, (6) an updated recommendation for the practical management of anaemia in IBD. Following the introduction of various intravenous iron preparations over the last decade, questions persist about when to use these preparations as opposed to traditional and other novel oral iron therapeutic agents. At present, oral iron therapy is generally preferred for patients with quiescent IBD and mild iron-deficiency anaemia. However, in patients with flaring IBD that hampers intestinal iron absorption and in those with inadequate responses to or side effects with oral preparations, intravenous iron supplementation is the therapy of choice, although information on the efficacy of intravenous iron in patients with active IBD and anaemia is scare. Importantly, anaemia in IBD is often multifactorial and a careful diagnostic workup is mandatory for optimized treatment. Nevertheless, limited information is available on optimal therapeutic start and end points for treatment of anaemia. Of note, neither oral nor intravenous therapies seem to exacerbate the clinical course of IBD. However, additional prospective studies are still warranted to determine the optimal therapy in complex conditions such as IBD.
Coffee Intake and Liver Steatosis: A Population Study in a Mediterranean Area
Authors: Veronese Nicola , Notarnicola Maria , Cisternino Anna , Reddavide Rosa , Inguaggiato Rosa , Guerra Vito , Rotolo Ornella , Zinzi Iris , Leandro Gioacchino , Correale Mario , Tutino Valeria , Misciagna Giovanni , Osella Alberto , Bonfiglio Caterina , Giannelli Gianluigi , Gabriella Caruso Maria ,   For the MICOL Group
Published: January 2018

Coffee drinking seems to have several beneficial effects on health outcomes. However, the effect on hepatic steatosis, depending on a high alcohol consumption (AFLD, alcoholic fatty liver disease) or on metabolic factors (non-alcoholic fatty liver disease, NAFLD), is still equivocal. Thus, we aimed to explore the potential association between coffee consumption and the presence and severity of hepatic steatosis in people with NAFLD or AFLD. In this cross-sectional study, coffee drinking was recorded using a semi-quantitative food frequency questionnaire, and categorized as yes vs. no and as 0, 1, 2, ≥3. The degree of fatty liver was assessed through a standardized ultrasound examination (score 0 to 6, with higher values reflecting higher severity). Liver steatosis was classified as NAFLD or AFLD on daily alcohol intake >30 g/day for men and >20 g/day for women. This study included 2819 middle-aged participants; the great majority were coffee drinkers (86.1%). After adjusting for 12 potential confounders, drinking coffee was not associated with decreased odds for NAFLD (n = 916) (odds ratio, OR = 0.93; 95% confidence intervals, CI: 0.72–1.20) or AFLD (n = 276) (OR = 1.20; 95% CI: 0.66–2.0). The consumption of coffee (categorized as yes vs. no), or an increased consumption of coffee were not associated with the presence of mild, moderate or severe liver steatosis in either NAFLD or AFLD. In conclusion, coffee intake was not associated with any lower odds of hepatic steatosis in either non-alcoholic or alcoholic forms in this large cohort of South Italian individuals.
Deciphering the Evolution and Development of the Cuticle by Studying Lipid Transfer Proteins in Mosses and Liverworts
Authors: Salminen Tiina , Eklund D. , Joly Valentin , Blomqvist Kristina , Matton Daniel , Edqvist Johan
Published: January 2018

When plants conquered land, they developed specialized organs, tissues, and cells in order to survive in this new and harsh terrestrial environment. New cell polymers such as the hydrophobic lipid-based polyesters cutin, suberin, and sporopollenin were also developed for protection against water loss, radiation, and other potentially harmful abiotic factors. Cutin and waxes are the main components of the cuticle, which is the waterproof layer covering the epidermis of many aerial organs of land plants. Although the in vivo functions of the group of lipid binding proteins known as lipid transfer proteins (LTPs) are still rather unclear, there is accumulating evidence suggesting a role for LTPs in the transfer and deposition of monomers required for cuticle assembly. In this review, we first present an overview of the data connecting LTPs with cuticle synthesis. Furthermore, we propose liverworts and mosses as attractive model systems for revealing the specific function and activity of LTPs in the biosynthesis and evolution of the plant cuticle.
Plasma: An International Open Access Journal for All of Plasma Science
Authors: Gates David
Published: January 2018

Plasma is an open access, cross-disciplinary scholarly journal of scientific studies related to all aspects of plasma science, such as plasma physics, plasma chemistry and space plasma[...]
Acknowledgement to Reviewers of Polymers in 2017
Authors:   Polymers Editorial Office
Published: January 2018

Peer review is an essential part in the publication process, ensuring that Polymers maintains high quality standards for its published papers.[...]
Colloidal Dispersion of a Perfluorosulfonated Ionomer in Water–Methanol Mixtures
Authors: Li Sinan , Terao Ken , Sato Takahiro
Published: January 2018

We have investigated the dispersion state of a perfluorosulfonated ionomer (PFSI; Nafion®) in aqueous dispersion and the effect of methanol (MeOH) added to the aqueous dispersion by small-angle X-ray scattering (SAXS) as well as static and dynamic light scattering (SLS and DLS, respectively). Although both electrostatic and hydrophobic interactions of PFSI are expected to be strong in the dispersions, SAXS profiles obtained were satisfactorily fitted by the spherical particle model of a bimodal molar mass distribution. The rod-like aggregate model proposed in previous papers was denied at least for the present PFSI dispersion. Although the SAXS profiles exhibited a weak peak and the auto-correlation functions of DLS showed a log-time decay by the “repulsive cage effect” due to the long-ranged electrostatic interaction among PFSI particles, the concentration dependence of SLS results was probably normal because the cancellation of the electrostatic and hydrophobic interactions. The addition of MeOH into the aqueous dispersion of PFSI weakened both the hydrophobic and electcrostatic interactions of PFSI, and it is rather difficult to classify whether MeOH is a good or poor solvent (dispersant) for PFSI.
Theory of the Flower Micelle Formation of Amphiphilic Random and Periodic Copolymers in Solution
Authors: Sato Takahiro
Published: January 2018

The mixing Gibbs energy Δgm for the flower-micelle phase of amphiphilic random and periodic (including alternating) copolymers was formulated on the basis of the lattice model. The formulated Δgm predicts (1) the inverse proportionality of the aggregation number to the degree of polymerization of the copolymer, (2) the increase of the critical micelle concentration with decreasing the hydrophobe content, and (3) the crossover from the micellization to the liquid–liquid phase separation as the hydrophobe content increases. The transition from the uni-core flower micelle to the multi-core flower necklace as the degree of polymerization increases was also implicitly indicated by the theory. These theoretical results were compared with experimental results for amphiphilic random and alternating copolymers reported so far.
Mechanical Properties and Wear Resistance of Sulfonated Graphene/Waterborne Polyurethane Composites Prepared by In Situ Method
Authors: Feng Jianyan , Wang Xuechuan , Guo Peiying , Wang Yujie , Luo Xiaomin
Published: January 2018

In order to improve the dispensability of graphene oxide (GO) in waterborne polyurethane (WPU), sulfonated graphene (SGO) with superior dispersity was prepared by modifying graphene oxide with sodium 2-chloroethane sulfonate to introduce hydrophilic sulfonic groups into the structure. SGO/WPU composites were prepared using isophorone diisocyanate (IPDI), polytetramethylene ether glycol (PTMEG 2000), dimethylolpropionic acid (DMPA) and SGO as raw materials. The influence of SGO content on composite properties were investigated. The structure and morphology of SGO and SGO/WPU composites were characterized by infrared spectroscopy, X-ray diffractometry and transmission electron microscopy etc. Their mechanical properties and wear resistance were analyzed as well. The experimental results showed that SGO was successfully grafted onto polyurethane macromolecule by an in situ method and, with the introduction of sulfonic groups, the interfacial compatibility of GO and PU was improved significantly so that SGO evenly dispersed into WPU. The SGO that was grafted onto WPU macromolecules exhibited layered morphology with nanometers in the WPU matrix. With increasing SGO content, the tensile strength and the wear resistance of the film increased, but the addition of more than 0.8 wt % SGO yielded unfavorable results. When the added amount of SGO was 0.8 wt % of WPU, the tensile strength of the composite film was 46.53% higher than that of the blank group, and the wear resistance of the film was remarkably improved, which was due to a strong interaction between the SGO and WPU phases. Thus, the conclusion can be drawn that appropriate amount of SGO addition can enhance the mechanical properties of SGO/WPU composite film.
A Comparative Study on Micellar and Solubilizing Behavior of Three EO-PO Based Star Block Copolymers Varying in Hydrophobicity and Their Application for the In Vitro Release of Anticancer Drugs
Authors: Vyas Bijal , Pillai Sadafara , Bahadur Anita , Bahadur Pratap
Published: January 2018

The temperature and pH dependent self-assembly of three star shaped ethylene oxide-propylene oxide (EO-PO) block copolymers (Tetronics® 304, 904 and 908) with widely different hydrophobicity was examined in aqueous solutions. Physico-chemical methods viz. viscosity, cloud point, solubilization along with thermal, scattering and spectral techniques shows strongly temperature and salt dependent solution behavior. T304 possessing low molecular weight did not form micelles; moderately hydrophilic T904 remained as micelles at ambient temperature and showed micellar growth while very hydrophilic T908 formed micelles at elevated temperatures. The surface activity/micellization/solubilization power was favored in the presence of salt. The copolymers turn more hydrophilic in acidic pH due to protonation of central ethylene diamine moiety that hinders micelle formation. The solubilization of a model insoluble azo dye 1-(o-Tolylazo)-2-naphthol (Orange OT) and hydrophobic drugs (quercetin and curcumin) for copolymer solutions in aqueous and salt solutions are also reported. Among the three copolymers, T904 showed maximum solubility of dye and drugs, hence the in vitro release of drugs from T904 micelles was estimated and the effect on cytotoxicity of loading the drugs in T904 micelles was compared with the cytotoxicity of free drugs on the CHO-K1 cells. The results from the present work provide a better insight in selection of Tetronics® for their application in different therapeutic applications.
Diversity without Pluralism: Religious Landscape in Mainland China
Authors: Liang Yongjia
Published: January 2018

The paper explores religious diversity and pluralism in the religioscape of mainland China with three examples. While religious diversity is de facto practice, “religious pluralism” is not socially recognised, culturally legitimised, or discursively institutionalised. On the one hand, state co-option of religious groups is achieved through particular definition of “religion” without the conceptualisation of pluralism, leaving undefined religious activities to cultural policy or national security measures. On the other hand, practices that might be identified as religious elsewhere does not usually self-identified as such, not to say seek for the right of religious freedom. To explain the absence of articulated/institutionalised “religious pluralism” in China, the paper provides three examples—civil activism against tomb-levelling campaign, “the Society of Disciples” (mentuhui), and a ritual service provider. The paper argues that the religioscape of mainland China is one with de facto religious diversity without the ideology of religious pluralism, because the diverse religious practices do not make a conscious reference to pluralism, remain non-institutional, disinterested in religious freedom, and, most important of all, below the state’s radar.
Acknowledgement to Reviewers of Risks in 2017
Authors:   Risks Editorial Office
Published: January 2018

n/a
Vegetation Changes along the Qinghai-Tibet Plateau Engineering Corridor Since 2000 Induced by Climate Change and Human Activities
Authors: Song Yi , Jin Long , Wang Haibo
Published: January 2018

The Qinghai-Tibet (QT) Plateau Engineering Corridor is located in the hinterland of the QT Plateau, which is highly sensitive to global climate change. Climate change causes permafrost degradation, which subsequently affects vegetation growth. This study focused on the vegetation dynamics and their relationships with climate change and human activities in the region surrounding the QT Plateau Engineering Corridor. The vegetation changes were inferred by applying trend analysis, the Mann-Kendall trend test and abrupt change analysis. Six key regions, each containing 40 nested quadrats that ranged in size from 500 × 500 m to 20 × 20 km, were selected to determine the spatial scales of the impacts from different factors. Cumulative growing season integrated enhanced vegetation index (CGSIEVI) values were calculated for each of the nested quadrats of different sizes to indicate the overall vegetation state over the entire year at different spatial scales. The impacts from human activities, a sudden increase in precipitation and permafrost degradation were quantified at different spatial scales using the CGSIEVI values and meteorological data based on the double mass curve method. Three conclusions were derived. First, the vegetation displayed a significant increasing trend over 23.6% of the study area. The areas displaying increases were mainly distributed in the Hoh Xil. Of the area where the vegetation displayed a significant decreasing trend, 72.4% was made up of alpine meadows. Second, more vegetation, especially the alpine meadows, has begun to degenerate or experience more rapid degradation since 2007 due to permafrost degradation and overgrazing. Finally, an active layer depth of 3 m to 3.2 m represents a limiting depth for alpine meadows.
Remote Sensing and Cropping Practices: A Review
Authors: Bégué Agnès , Arvor Damien , Bellon Beatriz , Betbeder Julie , De Abelleyra Diego , P. D. Ferraz Rodrigo , Lebourgeois Valentine , Lelong Camille , Simões Margareth , R. Verón Santiago
Published: January 2018

For agronomic, environmental, and economic reasons, the need for spatialized information about agricultural practices is expected to rapidly increase. In this context, we reviewed the literature on remote sensing for mapping cropping practices. The reviewed studies were grouped into three categories of practices: crop succession (crop rotation and fallowing), cropping pattern (single tree crop planting pattern, sequential cropping, and intercropping/agroforestry), and cropping techniques (irrigation, soil tillage, harvest and post-harvest practices, crop varieties, and agro-ecological infrastructures). We observed that the majority of the studies were exploratory investigations, tested on a local scale with a high dependence on ground data, and used only one type of remote sensing sensor. Furthermore, to be correctly implemented, most of the methods relied heavily on local knowledge on the management practices, the environment, and the biological material. These limitations point to future research directions, such as the use of land stratification, multi-sensor data combination, and expert knowledge-driven methods. Finally, the new spatial technologies, and particularly the Sentinel constellation, are expected to improve the monitoring of cropping practices in the challenging context of food security and better management of agro-environmental issues.
Design of a Novel Spectral Albedometer for Validating the MODerate Resolution Imaging Spectroradiometer Spectral Albedo Product
Authors: Zhou Hongmin , Wang Jindi , Liang Shunlin
Published: January 2018

Land surface shortwave broadband albedo is a key parameter in general circulation models and surface energy budget models. Multispectral satellite data are typically used to generate broadband albedo products in a three-step process: atmospheric correction, for converting the top-of-atmosphere observations to surface directional reflectance; angular modeling, for converting the surface directional reflectance to spectral albedo of each individual band; and finally, narrowband-to-broadband conversion, for transforming the spectral albedos to broadband albedos. Spectroradiometers can be used for validating surface directional reflectance products and pyranometers or broadband albedometers, for validating broadband albedo products, but spectral albedo products are rarely validated using ground measurements. In this study, we designed a new type of albedometer that can measure spectral albedos. It consists of multiple interference filters and a silicon detector, for measuring irradiance from 400–1100 nm. The linearity of the sensors is 99%, and the designed albedometer exhibits consistency up to 0.993, with a widely-used commercial instrument. A field experiment for measuring spectral albedo of grassland using this new albedometer was conducted in Yudaokou, China and the measurements are used for validating the MODerate Resolution Imaging Spectroradiometer (MODIS) spectral albedos. The results show that the biases of the MODIS spectral albedos of the first four bands are −0.0094, 0.0065, 0.0159, and −0.0001, respectively. This new instrument provides an effective technique for validating spectral albedos of any satellite sensor in this spectral range, which is critical for improving satellite broadband albedo products.
Acknowledgement to Reviewers of Remote Sensing in 2017
Authors:   Remote Sensing Editorial Office
Published: January 2018

Peer review is an essential part in the publication process, ensuring that Remote Sensing maintains high quality standards for its published papers.[...]
Knowledge-Based Generalized Side-Lobe Canceller for Ionospheric Clutter Suppression in HFSWR
Authors: Zhang Xin , Yao Di , Yang Qiang , Dong Yingning , Deng Weibo
Published: January 2018

High frequency surface wave radar (HFSWR) has been successfully developed for early warning and remote sensing. However, the ionospheric clutter is a difficult challenge that can make HFSWR system inefficient. The Generalized Side-lobe Canceller (GSC) has been proved to be an effective algorithm for clutter suppression in theory, but it suffers from the performance degradation for some non-ideal conditions in practice. The most intolerable shortcoming is the signal to noise ratio (SNR) loss caused by the residual signal in the secondary data. In this paper, a knowledge-based GSC (KB-GSC) method has been proposed via an adaptive single notch filter design to reject the residual signal for reducing the SNR loss. The feasibility and availability has been demonstrated by measured data.
Disaggregation of Landsat-8 Thermal Data Using Guided SWIR Imagery on the Scene of a Wildfire
Authors: Cho Kangjoon , Kim Yonghyun , Kim Yongil
Published: January 2018

Thermal data products derived from remotely sensed data play significant roles as key parameters for biophysical phenomena. However, a trade-off between spatial and spectral resolutions has existed in thermal infrared (TIR) remote sensing systems, with the end product being the limited resolution of the TIR sensor. In order to treat this problem, various disaggregation methods of TIR data, based on the indices from visible and near-infrared (VNIR), have been developed to sharpen the coarser spatial resolution of TIR data. Although these methods were reported to exhibit sufficient performance in each study, preservation of thermal variation in the original TIR data is still difficult, especially in fire areas due to the distortion of the VNIR reflectance by the impact of smoke. To solve this issue, this study proposes an efficient and improved disaggregation algorithm of TIR imagery on wildfire areas using guided shortwave infrared (SWIR) band imagery via a guided image filter (GF). Radiometric characteristics of SWIR wavelengths could preserve spatially high frequency temperature components in flaming combustion, and the GF preserved thermal variation of the original TIR data in the disaggregated result. The proposed algorithm was evaluated using Landsat-8 operational land imager (OLI) and thermal infrared sensor (TIRS) images on wildfire areas, and compared with other algorithms based on a vegetation index (VI) originating from VNIR. In quantitative analysis, the proposed disaggregation method yielded the best values of root mean square error (RMSE), mean absolute error (MAE), correlation coefficient (CC), erreur relative globale adimensionelle de synthèse (ERGAS), and universal image quality index (UIQI). Furthermore, unlike in other methods, the disaggregated temperature map in the proposed method reflected the thermal variation of wildfire in visual analysis. The experimental results showed that the proposed algorithm was successfully applied to the TIR data, especially to wildfire areas in terms of quantitative and visual assessments.
Incorporating Satellite Precipitation Estimates into a Radar-Gauge Multi-Sensor Precipitation Estimation Algorithm
Authors: He Yuxiang , Zhang Yu , Kuligowski Robert , Cifelli Robert , Kitzmiller David
Published: January 2018

This paper presents a new and enhanced fusion module for the Multi-Sensor Precipitation Estimator (MPE) that would objectively blend real-time satellite quantitative precipitation estimates (SQPE) with radar and gauge estimates. This module consists of a preprocessor that mitigates systematic bias in SQPE, and a two-way blending routine that statistically fuses adjusted SQPE with radar estimates. The preprocessor not only corrects systematic bias in SQPE, but also improves the spatial distribution of precipitation based on SQPE and makes it closely resemble that of radar-based observations. It uses a more sophisticated radar-satellite merging technique to blend preprocessed datasets, and provides a better overall QPE product. The performance of the new satellite-radar-gauge blending module is assessed using independent rain gauge data over a five-year period between 2003–2007, and the assessment evaluates the accuracy of newly developed satellite-radar-gauge (SRG) blended products versus that of radar-gauge products (which represents MPE algorithm currently used in the NWS (National Weather Service) operations) over two regions: (I) Inside radar effective coverage and (II) immediately outside radar coverage. The outcomes of the evaluation indicate (a) ingest of SQPE over areas within effective radar coverage improve the quality of QPE by mitigating the errors in radar estimates in region I; and (b) blending of radar, gauge, and satellite estimates over region II leads to reduction of errors relative to bias-corrected SQPE. In addition, the new module alleviates the discontinuities along the boundaries of radar effective coverage otherwise seen when SQPE is used directly to fill the areas outside of effective radar coverage.
The Effect of Three Different Data Fusion Approaches on the Quality of Soil Moisture Retrievals from Multiple Passive Microwave Sensors
Authors: Van der Schalie Robin , De Jeu Richard , Parinussa Robert , Rodríguez-Fernández Nemesio , Kerr Yann , Al-Yaari Amen , Wigneron Jean-Pierre , Drusch Matthias
Published: January 2018

Long-term climate records of soil moisture are of increased importance to climate researchers. In this study, we aim to evaluate the quality of three different fusion approaches that combine soil moisture retrieval from multiple satellite sensors. The arrival of L-band missions has led to an increased focus on the integration of L-band-based soil moisture retrievals in climate records, emphasizing the need to improve our understanding based on its added value within a multi-sensor framework. The three evaluated approaches were developed on 10-year passive microwave data (2003–2013) from two different satellite sensors, i.e., SMOS (2010–2013) and AMSR-E (2003–2011), and are based on a neural network (NN), regressions (REG), and the Land Parameter Retrieval Model (LPRM). The ability of the different approaches to best match AMSR-E and SMOS in their overlapping period was tested using an inter-comparison exercise between the SMOS and AMSR-E datasets, while the skill of the individual soil moisture products, based on anomalies, was evaluated using two verification techniques; first, a data assimilation technique that links precipitation information to the quality of soil moisture (expressed as the Rvalue), and secondly the triple collocation analysis (TCA). ASCAT soil moisture was included in the skill evaluation, representing the active microwave-based counterpart of soil moisture retrievals. Besides a semi-global analysis, explicit focus was placed on two regions that have strong land–atmosphere coupling, the Sahel (SA) and the central Great Plains (CGP) of North America. The NN approach gives the highest correlation coefficient between SMOS and AMSR-E, closely followed by LPRM and REG, while the absolute error is approximately the same for all three approaches. The Rvalue and TCA show the strength of using different satellite sources and the impact of different merging approaches on the skill to correctly capture soil moisture anomalies. The highest performance is found for AMSR-E over sparse vegetation, for SMOS over moderate vegetation, and for ASCAT over dense vegetation cover. While the two SMOS datasets (L3 and LPRM) show a similar performance, the three AMSR-E datasets do not. The good performance for AMSR-E over spare vegetation is mainly perceived for AMSR-E LPRM, benefiting from the physically based model, while AMSR-E NN shows improved skill in densely vegetated areas, making optimal use of the SMOS L3 training dataset. AMSR-E REG has a reasonable performance over sparsely vegetated areas; however, it quickly loses skill with increasing vegetation density. The findings over the SA and CGP mainly reflect results that are found in earlier sections. This confirms that historical soil moisture datasets based on a combination of these sources are a valuable source of information for climate research.
Band Subset Selection for Hyperspectral Image Classification
Authors: Yu Chunyan , Song Meiping , Chang Chein-I
Published: January 2018

This paper develops a new approach to band subset selection (BSS) for hyperspectral image classification (HSIC) which selects multiple bands simultaneously as a band subset, referred to as simultaneous multiple band selection (SMMBS), rather than one band at a time sequentially, referred to as sequential multiple band selection (SQMBS), as most traditional band selection methods do. In doing so, a criterion is particularly developed for BSS that can be used for HSIC. It is a linearly constrained minimum variance (LCMV) derived from adaptive beamforming in array signal processing which can be used to model misclassification errors as the minimum variance. To avoid an exhaustive search for all possible band subsets, two numerical algorithms, referred to as sequential (SQ) and successive (SC) algorithms are also developed for LCMV-based SMMBS, called SQ LCMV-BSS and SC LCMV-BSS. Experimental results demonstrate that LCMV-based BSS has advantages over SQMBS.
Underwater Object Segmentation Based on Optical Features
Authors: Chen Zhe , Zhang Zhen , Bu Yang , Dai Fengzhao , Fan Tanghuai , Wang Huibin
Published: January 2018

Underwater optical environments are seriously affected by various optical inputs, such as artificial light, sky light, and ambient scattered light. The latter two can block underwater object segmentation tasks, since they inhibit the emergence of objects of interest and distort image information, while artificial light can contribute to segmentation. Artificial light often focuses on the object of interest, and, therefore, we can initially identify the region of target objects if the collimation of artificial light is recognized. Based on this concept, we propose an optical feature extraction, calculation, and decision method to identify the collimated region of artificial light as a candidate object region. Then, the second phase employs a level set method to segment the objects of interest within the candidate region. This two-phase structure largely removes background noise and highlights the outline of underwater objects. We test the performance of the method with diverse underwater datasets, demonstrating that it outperforms previous methods.
Preparation of Cu2O-Reduced Graphene Nanocomposite Modified Electrodes towards Ultrasensitive Dopamine Detection
Authors: He Quanguo , Liu Jun , Liu Xiaopeng , Li Guangli , Deng Peihong , Liang Jing
Published: January 2018

Cu2O-reduced graphene oxide nanocomposite (Cu2O-RGO) was used to modify glassy carbon electrodes (GCE), and applied for the determination of dopamine (DA). The microstructure of Cu2O-RGO nanocomposite material was characterized by scanning electron microscope. Then the electrochemical reduction condition for preparing Cu2O-RGO/GCE and experimental conditions for determining DA were further optimized. The electrochemical behaviors of DA on the bare electrode, RGO- and Cu2O-RGO-modified electrodes were also investigated using cyclic voltammetry in phosphate-buffered saline solution (PBS, pH 3.5). The results show that the oxidation peaks of ascorbic acid (AA), dopamine (DA), and uric acid (UA) could be well separated and the peak-to-peak separations are 204 mV (AA-DA) and 144 mV (DA-UA), respectively. Moreover, the linear response ranges for the determination of 1 × 10−8 mol/L~1 × 10−6 mol/L and 1 × 10−6 mol/L~8 × 10−5 mol/L with the detection limit 6.0 × 10−9 mol/L (S/N = 3). The proposed Cu2O-RGO/GCE was further applied to the determination of DA in dopamine hydrochloride injections with satisfactory results.
Performance Analysis of Millimeter-Wave Multi-hop Machine-to-Machine Networks Based on Hop Distance Statistics
Authors: Jung Haejoon , Lee In-Ho
Published: January 2018

As an intrinsic part of the Internet of Things (IoT) ecosystem, machine-to-machine (M2M) communications are expected to provide ubiquitous connectivity between machines. Millimeter-wave (mmWave) communication is another promising technology for the future communication systems to alleviate the pressure of scarce spectrum resources. For this reason, in this paper, we consider multi-hop M2M communications, where a machine-type communication (MTC) device with the limited transmit power relays to help other devices using mmWave. To be specific, we focus on hop distance statistics and their impacts on system performances in multi-hop wireless networks (MWNs) with directional antenna arrays in mmWave for M2M communications. Different from microwave systems, in mmWave communications, wireless channel suffers from blockage by obstacles that heavily attenuate line-of-sight signals, which may result in limited per-hop progress in MWNs. We consider two routing strategies aiming at different types of applications and derive the probability distributions of their hop distances. Moreover, we provide their baseline statistics assuming the blockage-free scenario to quantify the impact of blockages. Based on the hop distance analysis, we propose a method to estimate the end-to-end performances (e.g., outage probability, hop count, and transmit energy) of the mmWave MWNs, which provides important insights into mmWave MWN design without time-consuming and repetitive end-to-end simulation.
Calculation and Identification of the Aerodynamic Parameters for Small-Scaled Fixed-Wing UAVs
Authors: Shen Jieliang , Su Yan , Liang Qing , Zhu Xinhua
Published: January 2018

The establishment of the Aircraft Dynamic Model (ADM) constitutes the prerequisite for the design of the navigation and control system, but the aerodynamic parameters in the model could not be readily obtained especially for small-scaled fixed-wing UAVs. In this paper, the procedure of computing the aerodynamic parameters is developed. All the longitudinal and lateral aerodynamic derivatives are firstly calculated through semi-empirical method based on the aerodynamics, rather than the wind tunnel tests or fluid dynamics software analysis. Secondly, the residuals of each derivative are proposed to be identified or estimated further via Extended Kalman Filter(EKF), with the observations of the attitude and velocity from the airborne integrated navigation system. Meanwhile, the observability of the targeted parameters is analyzed and strengthened through multiple maneuvers. Based on a small-scaled fixed-wing aircraft driven by propeller, the airborne sensors are chosen and the model of the actuators are constructed. Then, real flight tests are implemented to verify the calculation and identification process. Test results tell the rationality of the semi-empirical method and show the improvement of accuracy of ADM after the compensation of the parameters.
Development of an Internal Real-Time Wireless Diagnostic Tool for a Proton Exchange Membrane Fuel Cell
Authors: Lee Chi-Yuan , Chen Chia-Hung , Tsai Chao-Hsuan , Wang Yu-Syuan
Published: January 2018

To prolong the operating time of unmanned aerial vehicles which use proton exchange membrane fuel cells (PEMFC), the performance of PEMFC is the key. However, a long-term operation can make the Pt particles of the catalyst layer and the pollutants in the feedstock gas bond together (e.g., CO), so that the catalyst loses reaction activity. The performance decay and aging of PEMFC will be influenced by operating conditions, temperature, flow and CO concentration. Therefore, this study proposes the development of an internal real-time wireless diagnostic tool for PEMFC, and uses micro-electro-mechanical systems (MEMS) technology to develop a wireless and thin (<50 μm) flexible integrated (temperature, flow and CO) microsensor. The technical advantages are (1) compactness and three wireless measurement functions; (2) elastic measurement position and accurate embedding; (3) high accuracy and sensitivity and quick response; (4) real-time wireless monitoring of dynamic performance of PEMFC; (5) customized design and development. The flexible integrated microsensor is embedded in the PEMFC, three important physical quantities in the PEMFC, which are the temperature, flow and CO, can be measured simultaneously and instantly, so as to obtain the authentic and complete reaction in the PEMFC to enhance the performance of PEMFC and to prolong the service life.