bluuebunny/crossref_metadata_2025 huggingface dataset:
Design of Engineered Cyclodextrin Derivatives for Spontaneous Coating of Highly Porous Metal-Organic Framework Nanoparticles in Aqueous Media
Authors: Cutrone Giovanna , Li Xue , Casas-Solvas Juan M. , Menendez-Miranda Mario , Qiu Jingwen , Benkovics Gábor , Constantin Doru , Malanga Milo , Moreira-Alvarez Borja , Costa-Fernandez José M. , García-Fuentes Luis , Gref Ruxandra , Vargas-Berenguel Antonio
Published: August 2019

Nanosized metal-organic frameworks (nanoMOFs) MIL-100(Fe) are highly porous and biodegradable materials that have emerged as promising drug nanocarriers. A challenging issue concerns their surface functionalization in order to evade the immune system and to provide molecular recognition ability, so that they can be used for specific targeting. A convenient method for their coating with tetraethylene glycol, polyethylene glycol, and mannose residues is reported herein. The method consists of the organic solvent-free self-assembly on the nanoMOFs of building blocks based on β-cyclodextrin facially derivatized with the referred functional moieties, and multiple phosphate groups to anchor to the nanoparticles’ surface. The coating of nanoMOFs with cyclodextrin phosphate without further functional groups led to a significant decrease of macrophage uptake, slightly improved by polyethylene glycol or mannose-containing cyclodextrin phosphate coating. More notably, nanoMOFs modified with tetraethylene glycol-containing cyclodextrin phosphate displayed the most efficient “stealth” effect. Mannose-coated nanoMOFs displayed a remarkably enhanced binding affinity towards a specific mannose receptor, such as Concanavalin A, due to the multivalent display of the monosaccharide, as well as reduced macrophage internalization. Coating with tetraethylente glycol of nanoMOFs after loading with doxorubicin is also described. Therefore, phosphorylated cyclodextrins offer a versatile platform to coat nanoMOFs in an organic solvent-free, one step manner, providing them with new biorecognition and/or “stealth” properties.
Association of Lifelong Intake of Barley Diet with Healthy Aging: Changes in Physical and Cognitive Functions and Intestinal Microbiome in Senescence-Accelerated Mouse-Prone 8 (SAMP8)
Authors: Shimizu Chikako , Wakita Yoshihisa , Kihara Makoto , Kobayashi Naoyuki , Tsuchiya Youichi , Nabeshima Toshitaka
Published: August 2019

Barley intake reportedly reduces the risk of cardiovascular disease, but effects on the systemic phenotypes during healthy aging have not yet been examined. Therefore, we examined the effects of barley on the lifespan; behavioral phenotypes, such as locomotor activity, and cognitive functions, and intestinal microbiome in the senescence-accelerated mouse-prone 8 (SAMP8) mouse. We prepared two mild high-fat diets by adding lard, in which the starch components of AIN-93G were replaced by rice or barley “Motchiriboshi.” SAMP8 (four weeks old, male) mice were fed AIN-93G until eight weeks old, and then rice (rice group) or barley diet (rice: barley = 1:4, barley group) until death. Changes in aging-related phenotypes, object and spatial recognition, locomotor and balancing activities, and the intestinal microbiome were recorded. Moreover, plasma cholesterol levels were analyzed at 16 weeks old. Barley intake prolonged the lifespan by approximately four weeks, delayed locomotor atrophy, and reduced balancing ability and spatial recognition. Barley intake significantly increased the medium and small particle sizes of high-density lipoprotein (HDL) cholesterol, which is associated with a reduced risk of total stroke. The Bacteroidetes to Firmicutes ratio in the barley group was significantly higher than that in the rice group during aging. Thus, lifelong barley intake may have positive effects on healthy aging.
Milk and Dairy Products and Their Nutritional Contribution to the Average Polish Diet
Authors: Górska-Warsewicz Hanna , Rejman Krystyna , Laskowski Wacław , Czeczotko Maksymilian
Published: August 2019

The main aim of this study was to identify the dairy sources of energy and 44 nutrients in the average Polish diet. Our research included: carbohydrates, protein, total fat, saturated fatty acids (SFA), monounsaturated fatty acids (MUFA), polyunsaturated fatty acids (PUFA), cholesterol, 18 amino acids, 9 minerals, and 10 vitamins. The analysis was conducted based on the data from the 2016 Household Budget Survey, a representative sample of the Polish population (i.e., 36,886 households). The category of milk and dairy products was divided into three main groups (i.e., milk, cheeses, and yoghurts, milk drinks and other dairy products) and seven sub-groups (i.e., whole milk, reduced fat milk, condensed and powdered milk, ripened and melted cheese, cottage cheese, yoghurts, milk drinks and other dairy products). Milk and dairy products provided 9.1% of the total energy supply. A high share (above 20%) in the supply of nutrients was noted in the case of calcium (54.7%), riboflavin (28.1%), vitamin B12 (26.1%), and phosphorus (24.6%). Supply at the level of 10–20% was observed for protein, SFA, zinc, total fat, cholesterol, potassium, magnesium, and vitamin A. Of the amino acids, the share above 20% from dairy category was recorded in the case of 6 amino acids (proline, tyrosine, serine, lysine, valine, and leucine) and at the level of 10–20% for 10 amino acids (isoleucine, histidine, threonine, tryptophan, phenylalanine, methionine, glutamic acid, aspartic acid, alanine, and arginine).
Hydrodynamics of Intravitreal Injections into Liquid Vitreous Substitutes
Authors: Henein Christin , Awwad Sahar , Ibeanu Nkiruka , Vlatakis Stavros , Brocchini Steve , Tee Khaw Peng , Bouremel Yann
Published: August 2019

Intravitreal injections have become the cornerstone of retinal care and one of the most commonly performed procedures across all medical specialties. The impact of hydrodynamic forces of intravitreal solutions when injected into vitreous or vitreous substitutes has not been well described. While computational models do exist, they tend to underestimate the starting surface area of an injected bolus of a drug. Here, we report the dispersion profile of a dye bolus (50 µL) injected into different vitreous substitutes of varying viscosities, surface tensions, and volumetric densities. A novel 3D printed in vitro model of the vitreous cavity of the eye was designed to visualize the dispersion profile of solutions when injected into the following vitreous substitutes—balanced salt solution (BSS), sodium hyaluronate (HA), and silicone oils (SO)—using a 30G needle with a Reynolds number (Re) for injection ranging from approximately 189 to 677. Larger bolus surface areas were associated with faster injection speeds, lower viscosity of vitreous substitutes, and smaller difference in interfacial surface tensions. Boluses exhibited buoyancy when injected into standard S1000. The hydrodynamic properties of liquid vitreous substitutes influence the initial injected bolus dispersion profile and should be taken into account when simulating drug dispersion following intravitreal injection at a preclinical stage of development, to better inform formulations and performance.
Scale-Up Synthesis and In Vivo Anti-Tumor Activity of Curcumin Diethyl Disuccinate, an Ester Prodrug of Curcumin, in HepG2-Xenograft Mice
Authors: Muangnoi Chawanphat , Ratnatilaka Na Bhuket Pahweenvaj , Jithavech Ponsiree , Wichitnithad Wisut , Srikun Onsiri , Nerungsi Chakkrapan , Patumraj Suthiluk , Rojsitthisak Pornchai
Published: August 2019

Previously, we synthesized curcumin and a succinate ester prodrug of curcumin namely curcumin diethyl disuccinate (CurDD) in the lab scale, which yielded hundred milligrams to few grams of the compounds. CurDD was found to be more stable in a phosphate buffer pH 7.4 and exhibited better cytotoxicity against Caco-2 cells than curcumin. Here, the one-pot syntheses of curcumin and CurDD were scaled up to afford multigram quantities of both compounds for preclinical studies using a 10-L chemical reactor. The key steps for the synthesis of curcumin were the formation of boron-acetylacetone complex and the decomplexation of boron-curcumin complex. The synthesis of CurDD could be achieved via a one-step esterification between curcumin and succinic acid monoethyl ester chloride using 4-(N,N-dimethylamino)pyridine as a catalyst. The synthesized curcumin and CurDD were then investigated and compared for an anti-tumor activity in HepG2-xenograft mice. CurDD could reduce the tumor growth in HepG2-xenograft mice better than curcumin. CurDD also exerted the stronger inhibition on VEGF secretion, COX-2 and Bcl-2 expression and induced higher Bax expression in comparison with curcumin. The results suggest that CurDD is a promising prodrug of curcumin and has a potential to be further developed as a therapeutic agent or an adjuvant for the treatment of hepatocellular carcinoma.
Topical Inserts: A Versatile Delivery Form for HIV Prevention
Authors: Peet M. Melissa , Agrahari Vivek , Anderson Sharon M. , Hanif Homaira , Singh Onkar N. , Thurman Andrea R. , Doncel Gustavo F. , Clark Meredith R.
Published: August 2019

The development of topical inserts for the prevention of sexually transmitted infections (STIs), particularly human immunodeficiency virus (HIV), represents a promising alternative to oral and parenteral pre-exposure prophylaxis (PrEP) dosage forms. They may be used for vaginal and/or rectal administration of a variety of agents with antiviral activity. Topical inserts deliver drugs to the portal of viral entry, i.e., the genital or rectal mucosa, with low systemic exposure, and therefore are safer and have fewer side effects than systemic PrEP agents. They may dissolve fast, releasing the active drugs within minutes of insertion, or slowly for long-acting drug delivery. Furthermore, they are user-friendly being easy to administer, discreet and highly portable. They are also economical and easy to manufacture at scale and to distribute, with excellent stability and shelf-life. Altogether, topical inserts represent a particularly promising form of drug delivery for HIV and STI prevention. Highlighted within this review are end-user acceptability research dedicated to understanding preferred attributes for this form of drug delivery, advantages and disadvantages of the formulation platform options, considerations for their development, clinical assessment of select placebo prototypes, future directions, and the potential impact of this dosage form on the HIV prevention landscape.
Mediality, Temporality, Social Cognition, and Evolution
Authors: Blanco Rivero José Javier
Published: August 2019

In the literature of Media Studies, the word mediality has emerged as an expression of the concern about the specificity of media and their link to time, experience, technology and social change. However, mediality is not yet a concept, since the description of the function of media as mediation and transmission has become an obstacle to achieve further developments. In light of these remarks, this paper proposes a theoretical arrangement that gives meaning to mediality by connecting the word into a network of concepts, such as social cognition, evolution, temporality, synchronization and double closure. In order to achieve this goal, the author designs a theoretical apparatus consisting of the self-referential coupling between N. Luhmann’s systems theory, H. von Foerster’s second order cybernetics, R. Harris’ integration linguistics, and A. Clark’s extended cognition. A consistent integration and interpretation of the sketched theory, allows us to draw the conclusion that in order to comprehend mediality, it is crucial to understand the relationship between information, double closure, social cognition and evolution, while questions regarding human cognition do not be to be involved; and if that should be the case, research should depart from the problem of the structural coupling between human and social cognition.
Study on the Anticondensation Characteristics of Liquid Silicone Rubber Temperature-Control Coatings
Authors: Guo Juyi , Wang Xilin , Wang Jun , Chen Chuan , Liu Yu , Fan Weinan , Jia Zhidong
Published: August 2019

Metal cabinets such as switch cabinets and ring network cabinets have the advantages of small footprints and good protection for equipment and offer neat and orderly protection. They are widely used in power systems. In a hot and humid environment, condensation can easily cause equipment to age and even cause insulation failure. Therefore, research on reliable anticondensation methods is of great significance for the safe operation of power equipment. In this study, phase change capsules with phase transition temperatures of 22 and 32 °C were used as fillers and liquid silicone rubber was used as a matrix to prepare liquid silicone rubber composites filled with phase change capsules for a temperature-control coating. Studies have shown that liquid silicone rubber coatings containing phase change capsules can significantly enhance the anticondensation performance of metal cabinets. By using a temperature-control coating on the surface where the cabinet experiences condensation, the temperature difference between the surface and the dew point is reduced, thereby slowing down the condensation rate and even preventing condensation.
Urea Formaldehyde Resin Resultant Plywood with Rapid Formaldehyde Release Modified by Tunnel-Structured Sepiolite
Authors: Li Xiaona , Gao Qiang , Xia Changlei , Li Jianzhang , Zhou Xiaoyan
Published: August 2019

In order to reduce the cost of plywood and save edible resources (wheat flour), a cheap and resourceful clay, sepiolite, was used to modify urea formaldehyde (UF) resin. The performances of filler-filled UF resins were characterized by measuring the thermal behavior, cross section, and functional groups. Results showed that cured UF resin with SEP (sepiolite) formed a toughened fracture surface, and the wet shear strength of the resultant plywood was maximum improved by 31.4%. The tunnel structure of SEP was beneficial to the releasing of formaldehyde, as a result, the formaldehyde emission of the plywood bonded by UF resin with SEP declined by 43.7% compared to that without SEP. This study provided a new idea to reduce the formaldehyde emission, i.e., accelerating formaldehyde release before the product is put into use.
Numerical and Analytical Investigation of an Unsteady Thin Film Nanofluid Flow over an Angular Surface
Authors: Rasheed Haroon , Khan Zeeshan , Khan Ilyas , Ching Dennis , Nisar Kottakkaran
Published: August 2019

In the present study, we examine three-dimensional thin film flow over an angular rotating disk plane in the presence of nanoparticles. The governing basic equations are transformed into ordinary differential equations by using similarity variables. The series solution has been obtained by the homotopy asymptotic method (HAM) for axial velocity, radial velocity, darning flow, induced flow, and temperature and concentration profiles. For the sake of accuracy, the results are also clarified numerically with the help of the BVPh2- midpoint method. The effect of embedded parameters such as the Brownian motion parameter Nb, Schmidt number Sc, thermophoretic parameter and Prandtl number Pr are explored on velocity, temperature and concentration profiles. It is observed that with the increase in the unsteadiness factor S, the thickness of the momentum boundary layer increases, while the Sherwood number Sc, with the association of heat flow from sheet to fluid, reduces with the rise in S and results in a cooling effect. It is also remarkable to note that the thermal boundary layer increases with the increase of the Brownian motion parameter Nb and Prandtl number Pr, hindering the cooling process resulting from heat transfer.
Experimental Study on Precipitation Behavior of Spinels in Stainless Steel-Making Slag under Heating Treatment
Authors: Li Jianli , Mou Qiqiang , Zeng Qiang , Yu Yue
Published: August 2019

The stability of chromium in stainless steel slag has a positive correlation with spinel particle size and a negative correlation with the calcium content of the spinel. The effect of heating time on the precipitation of spinel crystals in the CaO-SiO2-MgO-Al2O3-Cr2O3-FeO system was investigated in the laboratory. Scanning electron microscopy with energy-dispersive and X-ray diffraction were adopted to observe the microstructure, test the chemical composition, and determine the mineral phases of synthetic slags, and FactSage7.1 was applied to calculate the crystallization process of the molten slag. The results showed that the particle size of the spinel crystals increased from 9.42 to 10.73 μm, the calcium content in the spinel crystals decreased from 1.38 at% to 0.78 at%, and the content of chromium in the spinel crystal increased from 16.55 at% to 22.78 at% with an increase in the heating time from 0 min to 120 min at 1450 °C. Furthermore, the species of spinel minerals remained constant. Therefore, an extension in the heating time is beneficial for improving the stability of chromium in stainless steel slag.
Economic Viability and Environmental Efficiency Analysis of Hydrogen Production Processes for the Decarbonization of Energy Systems
Authors: Xu Li , Wang Ying , Shah Syed Ahsan Ali , Zameer Hashim , Solangi Yasir Ahmed , Walasai Gordhan Das , Siyal Zafar Ali
Published: August 2019

The widespread penetration of hydrogen in mainstream energy systems requires hydrogen production processes to be economically competent and environmentally efficient. Hydrogen, if produced efficiently, can play a pivotal role in decarbonizing the global energy systems. Therefore, this study develops a framework which evaluates hydrogen production processes and quantifies deficiencies for improvement. The framework integrates slack-based data envelopment analysis (DEA), with fuzzy analytical hierarchy process (FAHP) and fuzzy technique for order of preference by similarity to ideal solution (FTOPSIS). The proposed framework is applied to prioritize the most efficient and sustainable hydrogen production in Pakistan. Eleven hydrogen production alternatives were analyzed under five criteria, including capital cost, feedstock cost, O&M cost, hydrogen production, and CO2 emission. FAHP obtained the initial weights of criteria while FTOPSIS determined the ultimate weights of criteria for each alternative. Finally, slack-based DEA computed the efficiency of alternatives. Among the 11, three alternatives (wind electrolysis, PV electrolysis, and biomass gasification) were found to be fully efficient and therefore can be considered as sustainable options for hydrogen production in Pakistan. The rest of the eight alternatives achieved poor efficiency scores and thus are not recommended.
Investigating the Dynamic Impact of CO2 Emissions and Economic Growth on Renewable Energy Production: Evidence from FMOLS and DOLS Tests
Authors: Khan Muhammad Waris Ali , Panigrahi Shrikant Krupasindhu , Almuniri Khamis Said Nasser , Soomro Mujeeb Iqbal , Mirjat Nayyar Hussain , Alqaydi Eisa Salim
Published: August 2019

Understanding the dynamic nexus between CO2 emissions and economic growth in the sustainable environment helps the economies in developing resources and formulating apposite energy policies. In the recent past, various studies have explored the nexus between CO2 emissions and economic growth. This study, however, investigates the nexus between renewable energy production, CO2 emissions, and economic growth over the period from 1995 to 2016 for seven Association of Southeast Asian Nations (ASEAN) countries. Fully Modified Ordinary Least Square (FMOLS) and Dynamic Ordinary Least Square (DOLS) methodologies were used to estimate the long- and short-run relationships. The panel results revealed that renewable energy production has a significant long term effect on CO2 emissions for Vietnam (t = −2.990), Thailand (t = −2.505), and Indonesia (t = −2.515), and economic growth impact for Malaysia (t = 2.050), Thailand (t = −2.001), and the Philippines (t = −2.710). It is, therefore, vital that the ASEAN countries implement policies and strategies that ensure energy saving and continuous economic growth without forsaking the environment. This study, as such, recommends that ASEAN countries should take measures to decrease the reliance on fossil fuels for achieving these objectives. Future research should consider the principles of circular economy and clean energy development mechanisms integrated with renewable energy technologies.
The Impact of Open Access on Teaching—How Far Have We Come?
Authors: Gadd Elizabeth , Morrison Chris , Secker Jane
Published: August 2019

This article seeks to understand how far the United Kingdom higher education (UK HE) sector has progressed towards open access (OA) availability of the scholarly literature it requires to support courses of study. It uses Google Scholar, Unpaywall and Open Access Button to identify OA copies of a random sample of articles copied under the Copyright Licensing Agency (CLA) HE Licence to support teaching. The quantitative data analysis is combined with interviews of, and a workshop with, HE practitioners to investigate four research questions. Firstly, what is the nature of the content being used to support courses of study? Secondly, do UK HE establishments regularly incorporate searches for open access availability into their acquisition processes to support teaching? Thirdly, what proportion of content used under the CLA Licence is also available on open access and appropriately licenced? Finally, what percentage of content used by UK HEIs under the CLA Licence is written by academics and thus has the potential for being made open access had there been support in place to enable this? Key findings include the fact that no interviewees incorporated OA searches into their acquisitions processes. Overall, 38% of articles required to support teaching were available as OA in some form but only 7% had a findable re-use licence; just 3% had licences that specifically permitted inclusion in an ‘electronic course-pack’. Eighty-nine percent of journal content was written by academics (34% by UK-based academics). Of these, 58% were written since 2000 and thus could arguably have been made available openly had academics been supported to do so.
A Sinicized World Religion?: Chinese Christianity at the Contemporary Moment of Globalization
Authors: Cao Nanlai
Published: August 2019

This essay explores the rise of Protestant Christianity at the contemporary stage of China’s globalization as a unique social and cultural phenomenon. Globalization can be seen as not only a homogenization process in political and economic terms, but also a process in which religious ideas and moral principles spread around the world. While in an earlier phase of globalization lack of Christianity was once constructed as a moral argument to ban Chinese migration to the Christian West, in the current context of China’s aggressive business outreach and mass emigration Christianity has become a vital social force and moral resource in binding Chinese merchants and traders in diaspora. By linking the rise of a sinicized version of Christianity in secular Europe with China’s present-day business globalization, I hope to suggest a new transnational framework for studying Chinese Christianity, which has often been examined in the nation-based political context of church-state relations, and for rethinking it beyond the static, decontextualized system of world religions.
Habermas, Taylor, and Connolly on Secularism, Pluralism, and the Post-Secular Public Sphere
Authors: Kaltsas Spyridon
Published: August 2019

The main purpose of this paper is to explore and understand the relationships between secularism, pluralism, and the post-secular public sphere in the thought of Jürgen Habermas, Charles Taylor, and William Connolly. The three authors develop a thorough critique of secularism which implies a radical break with the dogmatic idea of removing religion from the public sphere. My main objective is to show that this critique is related to a normative understanding of our post-secular situation and requires a rethinking of the boundaries of the public sphere in relation to the predicament of pluralism. Arguing against the post-metaphysical conception of secularism, Taylor develops a critique of Habermas’s “institutional translation proviso”, and Connolly stresses the agonistic dimension of the post-secular public sphere. I take these criticisms into account, while arguing that Taylor and Connolly are unable to provide a sound basis for the legitimacy of our institutional settings. In contrast to Taylor and Connolly, I propose a reading of Habermas’s theory based on the internal relationship between universal justification and the everyday contexts of pre-political solidarity. I conclude with a focus on the need to take into account the agonistic dimension of the post-secular public sphere.
Can we Monitor Height of Native Grasslands in Uruguay with Earth Observation?
Authors: Tiscornia Guadalupe , Baethgen Walter , Ruggia Andrea , Do Carmo Martín , Ceccato Pietro
Published: August 2019

In countries where livestock production based on native grasslands is an important economic activity, information on structural characteristics of forage is essential to support national policies and decisions at the farm level. Remote sensing is a good option for quantifying large areas in a relative short time, with low cost and with the possibility of analyzing annual evolution. This work aims at contributing to improve grazing management, by evaluating the ability of remote sensing information to estimate forage height, as an estimator of available biomass. Field data (forage height) of 20 commercial paddocks under grazing conditions (322 samples), and their relation to MODIS data (FPAR, LAI, MIR, NIR, Red, NDVI and EVI) were analyzed. Correlations between remote sensing information and field measurements were low, probably due to the extremely large variability found within each paddock for field observations (CV: Around 75%) and much lower when considering satellite information (MODIS: CV: 4%–6% and Landsat:CV: 12%). Despite this, the red band showed some potential (with significant correlation coefficient values in 41% of the paddocks) and justifies further exploration. Additional work is needed to find a remote sensing method that can be used to monitor grasslands height.
A Model-Dependent Method for Monitoring Subtle Changes in Vegetation Height in the Boreal–Alpine Ecotone Using Bi-Temporal, Three Dimensional Point Data from Airborne Laser Scanning
Authors: Næsset Erik , Gobakken Terje , McRoberts Ronald E.
Published: August 2019

The boreal tree line is in many places expected to advance upwards into the mountains due to climate change. This study aimed to develop a general method for estimation of vegetation height change in general, and change in tree height more specifically, for small geographical domains utilizing bi-temporal airborne laser scanner (ALS) data. The domains subject to estimation may subsequently be used to monitor vegetation and tree height change with detailed temporal and geographical resolutions. A method was developed with particular focus on statistically rigorous estimators of uncertainty for change estimates. The method employed model-dependent statistical inference. The method was demonstrated in a 12 ha study site in a boreal–alpine tree line in southeastern Norway, in which 316 trees were measured on the ground in 2006 and 2012 and ALS data were acquired in two temporally coincident campaigns. The trees ranged from 0.11 m to 5.20 m in height. Average growth in height was 0.19 m. Regression models were used to predict and estimate change. By following the area-based approach, predictions were produced for every individual 2 m2 population element that tessellated the study area. Two demonstrations of the method are provided in which separate height change estimates were calculated for domains of size 1.5 ha or greater. Differences in height change estimates among such small domains illustrate how change patterns may vary over the landscape. Model-dependent mean square error estimates for the height change estimators that accounted for (1) model parameter uncertainty, (2) residual variance, and (3) residual covariance are provided. Findings suggested that the two latter sources of uncertainty could be ignored in the uncertainty analysis. The proposed estimators are likely to work well for estimation of differences in height change along a gradient of small monitoring units, like the 1.5 ha cells used for demonstration purposes, and thus may potentially be used to monitor tree line migration over time.
Dissecting Performances of PERSIANN-CDR Precipitation Product over Huai River Basin, China
Authors: Sun Shanlei , Zhou Shujia , Shen Huayu , Chai Rongfan , Chen Haishan , Liu Yibo , Shi Wanrong , Wang Jia , Wang Guojie , Zhou Yang
Published: August 2019

Satellite-based precipitation products, especially those with high temporal and spatial resolution, constitute a potential alternative to sparse rain gauge networks for multidisciplinary research and applications. In this study, the validation of the 30-year Precipitation Estimation from Remotely Sensed Information using Artificial Neural Networks-Climate Data Record (PERSIANN-CDR) daily precipitation dataset was conducted over the Huai River Basin (HRB) of China. Based on daily precipitation data from 182 rain gauges, several continuous and categorical validation statistics combined with bias and error decomposition techniques were employed to quantitatively dissect the PERSIANN-CDR performance on daily, monthly, and annual scales. With and without consideration of non-rainfall data, this product reproduces adequate climatologic precipitation characteristics in the HRB, such as intra-annual cycles and spatial distributions. Bias analyses show that PERSIANN-CDR overestimates daily, monthly, and annual precipitation with a regional mean percent total bias of 11%. This is related closely to the larger positive false bias on the daily scale, while the negative non-false bias comes from a large underestimation of high percentile data despite overestimating lower percentile data. The systematic sub-component (error from high precipitation), which is independent of timescale, mainly leads to the PERSIANN-CDR total Mean-Square-Error (TMSE). Moreover, the daily TMSE is attributed to non-false error. The correlation coefficient (R) and Kling–Gupta Efficiency (KGE) respectively suggest that this product can well capture the temporal variability of precipitation and has a moderate-to-high overall performance skill in reproducing precipitation. The corresponding capabilities increase from the daily to annual scale, but decrease with the specified precipitation thresholds. Overall, the PERSIANN-CDR product has good (poor) performance in detecting daily low (high) rainfall events on the basis of Probability of Detection, and it has a False Alarm Ratio of above 50% for each precipitation threshold. The Equitable Threat Score and Heidke Skill Score both suggest that PERSIANN-CDR has a certain ability to detect precipitation between the second and eighth percentiles. According to the Hanssen–Kuipers Discriminant, this product can generally discriminate rainfall events between two thresholds. The Frequency Bias Index indicates an overestimation (underestimation) of precipitation totals in thresholds below (above) the seventh percentile. Also, continuous and categorical statistics for each month show evident intra-annual fluctuations. In brief, the comprehensive dissection of PERSIANN-CDR performance reported herein facilitates a valuable reference for decision-makers seeking to mitigate the adverse impacts of water deficit in the HRB and algorithm improvements in this product.
The Depths of Cast Shadow
Authors: Cameron Mark , Kumar Lalit
Published: August 2019

To improve the accuracy of analysis outputs from remotely sensed images, shadow and illumination effects need to be minimised or removed. Shadow behaviour at different spectral wavelengths needs to be understood to quantify shadow accurately. This study examined whether a normalised spectral signature of shadow is invariant to sun–object–sensor geometry and can be used to quantify shadow depth. A “FieldSpec® Pro FR” Spectroradiometer and a Canon 450D digital SLR camera were used to measure signatures of cast shadow. Our field-based experiment used an occulter to cast shadow onto a ‘Spectralon’ white plate at six incremental zenith angles and evaluated shadow behaviour within and between varying footprints. A white-balanced image of each shadow zenith was taken by the Canon 450D. The FR Spectroradiometer signatures were normalised to unit vector form and compared to longitudinal transect profiles of shadow from normalised camera images using a scattering index (SI). The normalised signatures show that shadow depth is darker and more ‘blue’ at the proximal areas and conversely that image brightness values increases towards distal areas. Since image brightness is a result of sun–object–sensor geometry, we conclude that a normalised spectral signature is invariant to geometry and can be used to quantify shadow depth.
Are There Sufficient Landsat Observations for Retrospective and Continuous Monitoring of Land Cover Changes in China?
Authors: Zhou Yan , Dong Jinwei , Liu Jiyuan , Metternicht Graciela , Shen Wei , You Nanshan , Zhao Guosong , Xiao Xiangming
Published: August 2019

Unprecedented human-induced land cover changes happened in China after the Reform and Opening-up in 1978, matching with the era of Landsat satellite series. However, it is still unknown whether Landsat data can effectively support retrospective analysis of land cover changes in China over the past four decades. Here, for the first time, we conduct a systematic investigation on the availability of Landsat data in China, targeting its application for retrospective and continuous monitoring of land cover changes. The latter is significant to assess impact of land cover changes, and consequences of past land policy and management interventions. The total and valid observations (excluding clouds, cloud shadows, and terrain shadows) from Landsat 5/7/8 from 1984 to 2017 were quantified at pixel scale, based on the cloud computing platform Google Earth Engine (GEE). The results show higher intensity of Landsat observation in the northern part of China as compared to the southern part. The study provides an overall picture of Landsat observations suitable for satellite-based annual land cover monitoring over the entire country. We uncover that two sub-regions of China (i.e., Northeast China-Inner Mongolia-Northwest China, and North China Plain) have sufficient valid observations for retrospective analysis of land cover over 30 years (1987–2017) at an annual interval; whereas the Middle-Lower Yangtze Plain (MLYP) and Xinjiang (XJ) have sufficient observations for annual analyses for the periods 1989–2017 and 2004–2017, respectively. Retrospective analysis of land cover is possible only at a two-year time interval in South China (SC) for the years 1988–2017, Xinjiang (XJ) for the period 1992–2003, and the Tibetan Plateau (TP) during 2004–2017. For the latter geographic regions, land cover dynamics can be analyzed only at a three-year interval prior to 2004. Our retrospective analysis suggest that Landsat-based analysis of land cover dynamics at an annual interval for the whole country is not feasible; instead, national monitoring at two- or three-year intervals could be achievable. This study provides a preliminary assessment of data availability, targeting future continuous land cover monitoring in China; and the code is released to the public to facilitate similar data inventory in other regions of the world.
Estimating Leaf Area Index with a New Vegetation Index Considering the Influence of Rice Panicles
Authors: He Jiaoyang , Zhang Ni , Su Xi , Lu Jingshan , Yao Xia , Cheng Tao , Zhu Yan , Cao Weixing , Tian Yongchao
Published: August 2019

The emergence of rice panicle substantially changes the spectral reflectance of rice canopy and, as a result, decreases the accuracy of leaf area index (LAI) that was derived from vegetation indices (VIs). From a four-year field experiment with using rice varieties, nitrogen (N) rates, and planting densities, the spectral reflectance characteristics of panicles and the changes in canopy reflectance after panicle removal were investigated. A rice “panicle line”—graphical relationship between red-edge and near-infrared bands was constructed by using the near-infrared and red-edge spectral reflectance of rice panicles. Subsequently, a panicle-adjusted renormalized difference vegetation index (PRDVI) that was based on the “panicle line” and the renormalized difference vegetation index (RDVI) was developed to reduce the effects of rice panicles and background. The results showed that the effects of rice panicles on canopy reflectance were concentrated in the visible region and the near-infrared region. The red band (670 nm) was the most affected by panicles, while the red-edge bands (720–740 nm) were less affected. In addition, a combination of near-infrared and red-edge bands was for the one that best predicted LAI, and the difference vegetation index (DI) (976, 733) performed the best, although it had relatively low estimation accuracy (R2 = 0.60, RMSE = 1.41 m2/m2). From these findings, correcting the near-infrared band in the RDVI by the panicle adjustment factor (θ) developed the PRDVI, which was obtained while using the “panicle line”, and the less-affected red-edge band replaced the red band. Verification data from an unmanned aerial vehicle (UAV) showed that the PRDVI could minimize the panicle and background influence and was more sensitive to LAI (R2 = 0.77; RMSE = 1.01 m2/m2) than other VIs during the post-heading stage. Moreover, of all the assessed VIs, the PRDVI yielded the highest R2 (0.71) over the entire growth period, with an RMSE of 1.31 (m2/m2). These results suggest that the PRDVI is an efficient and suitable LAI estimation index.
A Study of Vertical Structures and Microphysical Characteristics of Different Convective Cloud–Precipitation Types Using Ka-Band Millimeter Wave Radar Measurements
Authors: Zheng Jiafeng , Zhang Peiwen , Liu Liping , Liu Yanxia , Che Yuzhang
Published: August 2019

Millimeter wave cloud radar (MMCR) is one of the primary instruments employed to observe cloud–precipitation. With appropriate data processing, measurements of the Doppler spectra, spectral moments, and retrievals can be used to study the physical processes of cloud–precipitation. This study mainly analyzed the vertical structures and microphysical characteristics of different kinds of convective cloud–precipitation in South China during the pre-flood season using a vertical pointing Ka-band MMCR. Four kinds of convection, namely, multi-cell, isolated-cell, convective–stratiform mixed, and warm-cell convection, are discussed herein. The results show that the multi-cell and convective–stratiform mixed convections had similar vertical structures, and experienced nearly the same microphysical processes in terms of particle phase change, particle size distribution, hydrometeor growth, and breaking. A forward pattern was proposed to specifically characterize the vertical structure and provide radar spectra models reflecting the different microphysical and dynamic features and variations in different parts of the cloud body. Vertical air motion played key roles in the microphysical processes of the isolated- and warm-cell convections, and deeply affected the ground rainfall properties. Stronger, thicker, and slanted updrafts caused heavier showers with stronger rain rates and groups of larger raindrops. The microphysical parameters for the warm-cell cloud–precipitation were retrieved from the radar data and further compared with the ground-measured results from a disdrometer. The comparisons indicated that the radar retrievals were basically reliable; however, the radar signal weakening caused biases to some extent, especially for the particle number concentration. Note that the differences in sensitivity and detectable height of the two instruments also contributed to the compared deviation.
Tracking Control of a Maglev Vibration Isolation System Based on a High-Precision Relative Position and Attitude Model
Authors: Wu Qianqian , Liu Bilong , Cui Ning , Zhao Sifang
Published: August 2019

The maglev vibration isolation system exhibits excellent micro-vibration isolation performance (0.01 Hz to 100 Hz band) in the space environment. However, a collision between the base and the floating platform may occur in an ultra-low frequency range (≤0.01 Hz). To avoid collision, the relative position and attitude between the base and the floating platform needs to be accurately tracked and controlled. In this study, a novel measurement method with four groups of two-dimensional position-sensitive detectors equipped with four laser light sources was proposed. A high-precision relative position and attitude measurement model was established based on the geometric relationship of space coordinates. A proportional-differential (PD) fixed-point control algorithm was adopted to realize tracking control. The control performance of the system was evaluated through simulation. Experiments were also carried out to verify the stability of the system and the precision of the control algorithm. A maglev vibration isolation system prototype was constructed and a test system was established. The proposed relative position and attitude measurement model was verified and the six degrees of freedom relative position and attitude response of the system was tested. Based on the measurement model, the tracking control of the system was proven to have high precision.
Very Low Resource Digital Implementation of Bioimpedance Analysis
Authors: Soulier Fabien , Lamlih Achraf , Kerzérho Vincent , Bernard Serge , Rouyer Tristan
Published: August 2019

Bioimpedance spectroscopy consists of measuring the complex impedance of biological tissues over a large frequency domain. This method is particularly convenient for physiological studies or health monitoring systems. For a wide range of applications, devices need to be portable, wearable or even implantable. Next generation of bioimpedance sensing systems thus require to be implemented with power and resource savings in mind. Impedance measurement methods are divided into two main categories. Some are based on “single-tone” signals while the others use “multi-tone” signals. The firsts benefit from a very simple analysis that may consist of synchronous demodulation. However, due to necessary frequency sweep, the total measurement may take a long time. On the other hand, generating a multi-frequency signal allows the seconds to cover the whole frequency range simultaneously. This is at the cost of a more complex analysis algorithm. This makes both approaches hardly suitable for embedded applications. In this paper, we propose an intermediate approach that combines the speed of multi-tone systems with a low-resource analysis algorithm. This results in a minimal implementation using only adders and synchronous adc. For optimal performances, this small footprint digital processing can be synthesized and embedded on a mixed-mode integrated circuit together with the analog front-end. Moreover, the proposed implementation is easily scalable to fit an arbitrary frequency range. We also show that the resulting impact on noise sensitivity can be mitigated.
Study of Data Transfer in a Heterogeneous LoRa-Satellite Network for the Internet of Remote Things
Authors: Lysogor Ivan , Voskov Leonid , Rolich Alexey , Efremov Sergey
Published: August 2019

In the absence of traditional communication infrastructures, the choice of available technologies for building data collection and control systems in remote areas is very limited. This paper reviews and analyzes protocols and technologies for transferring Internet of Things (IoT) data and presents an architecture for a hybrid IoT-satellite network, which includes a long range (LoRa) low power wide area network (LPWAN) terrestrial network for data collection and an Iridium satellite system for backhaul connectivity. Simulation modelling, together with a specialized experimental stand, allowed us to study the applicability of different methods of information presentation for the case of transmitting IoT data over low-speed satellite communication channels. We proposed a data encoding and packaging scheme called GDEP (Gateway Data Encoding and Packaging). It is based on the combination of data format conversion at the connection points of a heterogeneous network and message packaging. GDEP enabled the reduction of the number of utilized Short Burst Data (SBD) containers and the overall transmitted data size by almost five times.
Chipless-RFID: A Review and Recent Developments
Authors: Herrojo Cristian , Paredes Ferran , Mata-Contreras Javier , Martín Ferran
Published: August 2019

In this paper, a review of the state-of-the-art chipless radiofrequency identification (RFID) technology is carried out. This recent technology may provide low cost tags as long as these tags are not equipped with application specific integrated circuits (ASICs). Nevertheless, chipless-RFID presents a series of technological challenges that have been addressed by different research groups in the last decade. One of these challenges is to increase the data storage capacity of tags, in order to be competitive with optical barcodes, or even with chip-based RFID tags. Thus, the main aim of this paper is to properly clarify the advantages and disadvantages of chipless-RFID technology. Moreover, since the coding information is an important aspect in such technology, the different coding techniques, as well as the main figures of merit used to compare different chipless-RFID tags, will be analyzed.
How Do People Become Foster Carers in Portugal? The Process of Building the Motivation
Authors: Diogo Elisete , Branco Francisco
Published: August 2019

Act no. 142/2015 highlights the importance of children out-of-home being placed in a family context. However, foster care continues to be an almost absent component in the Portuguese childcare system. In 2017, it corresponded to just 3% of out-of-home care. This research aims to contribute to the understanding of the reasons for becoming a foster family. It adopted a qualitative approach, using carers’ narrative interviews and practitioners semi-structured interviews, inspired by grounded theory. Foster family motivation is rooted in altruism, affection for children and sensitivity to maltreatment. These factors, as well as personal life course and contact with out-of-home care, induce a predisposition to become a foster family. The quality of the support services and the care professionals’ performance also reveal key elements.