bluuebunny/crossref_metadata_2025 huggingface dataset:
Mechanisms Involved in the Relationship between Low Calcium Intake and High Blood Pressure
Authors: Villa-Etchegoyen Cecilia , Lombarte Mercedes , Matamoros Natalia , Belizán José M. , Cormick Gabriela
Published: May 2019

There is increasing epidemiologic and animal evidence that a low calcium diet increases blood pressure. The aim of this review is to compile the information on the link between low calcium intake and blood pressure. Calcium intake may regulate blood pressure by modifying intracellular calcium in vascular smooth muscle cells and by varying vascular volume through the renin–angiotensin–aldosterone system. Low calcium intake produces a rise of parathyroid gland activity. The parathyroid hormone increases intracellular calcium in vascular smooth muscles resulting in vasoconstriction. Parathyroidectomized animals did not show an increase in blood pressure when fed a low calcium diet as did sham-operated animals. Low calcium intake also increases the synthesis of calcitriol in a direct manner or mediated by parathyroid hormone (PTH). Calcitriol increases intracellular calcium in vascular smooth muscle cells. Both low calcium intake and PTH may stimulate renin release and consequently angiotensin II and aldosterone synthesis. We are willing with this review to promote discussions and contributions to achieve a better understanding of these mechanisms, and if required, the design of future studies.
Identification of Education Models to Improve Health Outcomes in Arab Women with Pre-Diabetes
Authors: Al-Hamdan Rasha , Avery Amanda , Salter Andrew , Al-Disi Dara , Al-Daghri Nasser M. , McCullough Fiona
Published: May 2019

Few evaluations of interventions to delay or prevent type 2 diabetes mellitus (T2DM) in Saudi Arabia (SA) have been undertaken. The present study evaluates the impact of a 6-month intensive lifestyle modification intervention delivered in primary care. Females from SA with prediabetes, aged 18–55 years, were recruited with 190 participants eligible following screening and randomly allocated to receive a 3-month one-on-one, intensive lifestyle modification (intervention group (IG) n = 95) or standard guidance (control group (CG) n = 95). Participants completed questionnaires including demographic, dietary and physical activity data. Blood samples were collected at baseline, 3 and 6 months. A total of 123 (74 IG (age 40.6 ± 9.8 years; body mass index (BMI) 31.2 ± 7.0 kg/m2) and 49 CG (age 40.6 ± 12.7 years; BMI 32.3 ± 5.4 kg/m2)) participants completed the study. After 6 months, haemoglobin A1c (HbA1c; primary endpoint) significantly improved in the IG than CG completers in between-group comparisons (p < 0.001). Comparison between groups showed significant improvements in overall energy intake, total and high density lipoprotein (HDL)-cholesterol in favour of IG (p-values < 0.001, 0.04 and <0.001, respectively). BMI and weight change were not clinically significant in between group comparisons. A 6-month, intense one-on-one intervention in lifestyle modification significantly improves glycaemic and cardio metabolic profile of females living in SA with pre-diabetes delivered in a primary care setting. Longer duration studies, using the same intervention, may determine whether a meaningful weight loss secondary to improved diet can be achieved.
High Adherence to the Nordic Diet Is Associated with Lower Levels of Total and Platelet-Derived Circulating Microvesicles in a Norwegian Population
Authors: Chiva-Blanch Gemma , Laake Kristian , Myhre Peder , Bratseth Vibeke , Arnesen Harald , Solheim Svein , Badimon Lina , Seljeflot Ingebjørg
Published: May 2019

Circulating microvesicles (cMV) are small phospholipid-rich blebs shed from the membrane of activated vascular cells that contribute to vascular disease progression. We aimed to investigate whether the quality of the Nordic diet is associated with the degree of blood and vascular cell activation measured by MV shedding in elderly patients after an acute myocardial infarction (AMI). One-hundred and seventy-four patients aged 70–82 years were included in this cross-sectional study. Fasting blood samples were taken within 2 to 8 weeks after an AMI. Annexin V (AV)+ cMV derived from blood and vascular cells were measured through flow cytometry. A patient’s usual diet was recorded with the SmartDiet® questionnaire. Patients with higher adherence to the Nordic diet (highest diet score) had lower levels of total AV+ and platelet-derived (CD61+/AV+ and CD31+/AV+) cMV. Dietary habits influence cellular activation. A high adherence to the Nordic diet (assessed by the SmartDiet® score) in elderly post-AMI patients was associated with lower levels of platelet activation, which was reflected by a lesser release of MV carrying platelet-derived epitopes, potentially contributing to an explanation of the cardioprotective effects of the Nordic diet.
Dietary Walnut Supplementation Alters Mucosal Metabolite Profiles During DSS-Induced Colonic Ulceration
Authors: Nakanishi Masako , Matz Alyssa , Klemashevich Cory , Rosenberg Daniel W.
Published: May 2019

Walnuts contain a complex array of natural compounds and phytochemicals that exhibit a wide range of health benefits, including protection against inflammation and colon cancer. In this study, we assess the effects of dietary supplementation with walnuts on colonic mucosal injury induced in mice by the ulcerogenic agent, dextran sodium sulfate (DSS). C57Bl/6J mice were started on the Total Western Diet supplemented with freshly-ground whole walnuts (0, 3.5, 7 and 14% g/kg) 2 weeks prior to a 5-day DSS treatment and walnut diets were continued throughout the entire experimental period. Mice were examined at 2 days or 10 days after withdrawal of DSS. In a separate study, a discovery-based metabolite profiling analysis using liquid chromatography tandem mass spectrometry (LC-MS/MS) was performed on fecal samples and colonic mucosa following two weeks of walnut supplementation. Dietary walnut supplementation showed significant effects in the 10-day post-DSS recovery-phase study, in which the extent of ulceration was significantly reduced (7.5% vs. 0.3%, p < 0.05) with 14% walnuts. In the metabolite-profiling analysis, walnuts caused a significant increase in several polyunsaturated fatty acids (PUFAs), including docosahexaenoic acid (DHA) and 9-oxo-10(E),12(E)-octadecadienoic acid (9-oxoODA), as well as kynurenic acid. In colon tissue samples, walnuts caused a significant increase in the levels of S-adenosylhomocysteine (SAH) and betaine, important components of fatty acid β-oxidation. These metabolite changes may contribute in part to the observed protection against DSS-induced inflammatory tissue injury.
Effect of Weight Loss after Bariatric Surgery on Thyroid-Stimulating Hormone Levels in Euthyroid Patients with Morbid Obesity
Authors: Juiz-Valiña Paula , Outeiriño-Blanco Elena , Pértega Sonia , Varela-Rodriguez Bárbara María , García-Brao María , Mena Enrique , Pena-Bello Lara , Cordido María , Sangiao-Alvarellos Susana , Cordido Fernando
Published: May 2019

Obesity is associated with several endocrine abnormalities, including thyroid dysfunction. The objective of this study was to investigate the effect of weight loss after bariatric surgery on thyroid-stimulating hormone (TSH) levels in euthyroid patients with morbid obesity. We performed an observational study, evaluating patients with morbid obesity submitted to bariatric surgery. We included 129 patients (92 women) and 31 controls (21 women). Clinical, anthropometric, biochemical, and hormonal parameters were evaluated. The primary endpoint was circulating TSH (µU/mL). Fasting TSH levels were higher in the obese group (3.3 ± 0.2) than in the control group (2.1 ± 0.2). The mean excessive body mass index (BMI) loss (EBMIL) 12 months after bariatric surgery was 72.7 ± 2.1%. TSH levels significantly decreased in the obese patients after surgery; 3.3 ± 0.2 vs. 2.1 ± 0.2 before and 12 months after surgery, respectively. Free thyroxine (T4) (ng/dL) levels significantly decreased in the obese patients after surgery; 1.47 ± 0.02 vs. 1.12 ± 0.02 before and 12 months after surgery, respectively. TSH decreased significantly over time, and the decrement was associated with the EBMIL. In euthyroid patients with morbid obesity, weight loss induced by bariatric surgery promotes a significant decline of the increased TSH levels. This decrement of TSH is progressive over time after surgery and significantly associated with excess BMI loss.
The Lipid and Glyceride Profiles of Infant Formula Differ by Manufacturer, Region and Date Sold
Authors: Furse Samuel , Koulman Albert
Published: May 2019

We tested the hypothesis that the lipid composition of infant formula is consistent between manufacturers, countries and target demographic. We developed techniques to profile the lipid and glyceride fraction of milk and formula in a high throughput fashion. Formula from principal brands in the UK (2017–2019; bovine-, caprine-, soya-based), the Netherlands (2018; bovine-based) and South Africa (2018; bovine-based) were profiled along with fresh British animal and soya milk and skimmed milk powder. We found that the lipid and glyceride composition of infant formula differed by region, manufacturer and date of manufacture. The formulations within some brands, aimed at different target age ranges, differed considerably where others were similar across the range. Soya lecithin and milk lipids had characteristic phospholipid profiles. Particular sources of fat, such as coconut oil, were also easy to distinguish. Docosahexaenoic acid is typically found in triglycerides rather than phospholipids in formula. The variety by region, manufacturer, date of manufacture and sub-type for target demographics lead to an array of lipid profiles in formula. This makes it impossible to predict its molecular profile. Without detailed profile of the formula fed to infants, it is difficult to characterise the relationship between infant nutrition and their growth and development.
Magnetic Graphene Oxide Nanocarrier for Targeted Delivery of Cisplatin: A Perspective for Glioblastoma Treatment
Authors: Makharza Sami A. , Cirillo Giuseppe , Vittorio Orazio , Valli Emanuele , Voli Florida , Farfalla Annafranca , Curcio Manuela , Iemma Francesca , Nicoletta Fiore Pasquale , El-Gendy Ahmed A. , Goya Gerardo F. , Hampel Silke
Published: May 2019

Selective vectorization of Cisplatin (CisPt) to Glioblastoma U87 cells was exploited by the fabrication of a hybrid nanocarrier composed of magnetic γ-Fe2O3 nanoparticles and nanographene oxide (NGO). The magnetic component, obtained by annealing magnetite Fe3O4 and characterized by XRD measurements, was combined with NGO sheets prepared via a modified Hummer’s method. The morphological and thermogravimetric analysis proved the effective binding of γ-Fe2O3 nanoparticles onto NGO layers. The magnetization measured under magnetic fields up to 7 Tesla at room temperature revealed superparamagnetic-like behavior with a maximum value of MS = 15 emu/g and coercivity HC ≈ 0 Oe within experimental error. The nanohybrid was found to possess high affinity towards CisPt, and a rather slow fractional release profile of 80% after 250 h. Negligible toxicity was observed for empty nanoparticles, while the retainment of CisPt anticancer activity upon loading into the carrier was observed, together with the possibility to spatially control the drug delivery at a target site.
Photonic Crystal Circular Defect (CirD) Laser
Authors: Xiong Yifan , Ye Hanqiao , Umeda Takuma , Mizoguchi Shun , Morifuji Masato , Kajii Hirotake , Maruta Akihiro , Kondow Masahiko
Published: May 2019

We describe the design of photonic crystal circular defect (CirD) lasers to construct a compact optical module with a wavelength division multiplexing function for the application of inter-chip or intra-chip optical interconnects. Subsequently, we investigated the characteristics of CirD lasers including the quality factor of the cavity, the lasing threshold, and the modulation speed with a three-dimensional finite-difference time-domain method and two-dimensional rate equations. Finally, we demonstrated the single mode lasing and wavelength tuning behaviors of the CirD lasers using optical pumping technology under room-temperature continuous-wave conditions.
Hydrosilylation of Reactive Quantum Dots and Siloxanes for Stable Quantum Dot Films
Authors: Lee Changmin , Nam Eunhee , Lee Woosuk , Chae Heeyeop
Published: May 2019

The reactive acrylate-terminated CdZnSeS/ZnS quantum dots (QDs) were designed and prepared by the effective synthetic route to bond with a siloxane matrix via hydrosilylation. The conventional QD with oleic acid ligands does not have any reactivity, so the QDs were functionalized to assign reactivity for the QDs by the ligand modification of two step reactions. The oleic acid of the QDs was exchanged for hydroxyl-terminated ligands as an intermediate product by one-pot reaction. The hydroxyl-terminated QDs and acrylate-containing isocyanates were combined by nucleophilic addition reaction with forming urethane bonds and terminal acrylate groups. No degradation in quantum yield was observed after ligand exchange, nor following the nucleophilic addition reaction. The modification reactions of ligands were quantitatively controlled and their molecular structures were precisely confirmed by FT-IR and 1H-NMR. The QDs with acrylate ligands were then reacted with hydride-terminated polydimethylsiloxane (H-PDMS) to form a QD-siloxane matrix by thermal curing via hydro-silylation for the first time. The covalent bonding between the QDs and the siloxane matrix led to improvements in the stability against oxygen and moisture. Stability at 85 °C and 85% relative humidity (RH) were both improved by 22% for the QD-connected siloxane QD films compared with the corresponding values for conventional QD-embedded poly(methylmethacrylate) (PMMA) films. The photo-stability of the QD film after 26 h under a blue light-emitting diode (LED) was also improved by 45% in comparison with those of conventional QD-embedded PMMA films.
Enhanced Stability and Driving Performance of GO–Ag-NW-based Ionic Electroactive Polymer Actuators with Triton X-100-PEDOT:PSS Nanofibrils
Authors: Park Minjeong , Yoo Seokju , Bae Yunkyeong , Kim Seonpil , Jeon Minhyon
Published: May 2019

Ionic electroactive polymers (IEAPs) have received considerable attention for their flexibility, lightweight composition, large displacement, and low-voltage activation. Recently, many metal–nonmetal composite electrodes have been actively studied. Specifically, graphene oxide–silver nanowire (GO–Ag NW) composite electrodes offer advantages among IEAPs with metal–nonmetal composite electrodes. However, GO–Ag NW composite electrodes still show a decrease in displacement owing to low stability and durability during driving. Therefore, the durability and stability of the IEAPs with metal–nonmetal composite electrodes must be improved. One way to improve the device durability is coating the electrode surface with a protective layer. This layer must have enough flexibility and suitable electrical properties such that it does not hinder the IEAPs’ driving. Herein, a poly(3,4-ethylenedioxythiophene)–poly(styrenesulfonate) (PEDOT:PSS) protective layer and 4-(1,1,3,3-tetramethylbutyl)phenyl-polyethylene glycol (Triton X-100) are applied to improve driving performance. Triton X-100 is a nonionic surfactant that transforms the PEDOT:PSS capsule into a nanofibril structure. In this study, a mixed Triton X-100/PEDOT:PSS protective layer at an optimum weight ratio was coated onto the GO–Ag NW composite-electrode-based IEAPs under various conditions. The IEAP actuators based on GO–Ag NW composite electrodes with a protective layer of PEDOT:PSS treated with Triton X-100 showed the best stability and durability.
Synthetized Potato Starch—A New Eco Sizing Agent for Cotton Yarns
Authors: Kovačević Stana , Schwarz Ivana , Đorđević Suzana , Đorđević Dragan
Published: May 2019

The objective of this research was to verify the feasibility of the use of newly synthesized biopolymer materials for sizing cotton yarns based on the basic principles of chemical modification. Research included acid hydrolysis of potato starch up to controlled molar masses together with graft-polymerization and methacrylic acid onto hydrolyzed starch to improve hydrophilicity and solubility, to increase the capability of film forming, to increase adhesive potential and to avoid retrogradation phenomena. Research objectives were primarily focused on finding an appropriate, environmentally-friendly and productive sizing agent for cotton yarns via the analysis and systematization of a large number of synthesis methods in conjunction with the characterization and properties of graft-copolymers. The research results showed that potassium persulfate initiator was most efficient in grafting of methacrylic acid onto hydrolyzed starch, while azobisisobutyronitrile (AIBIN) initiator was most efficient in grafting of acrylic acid (AC). FTIR analysis confirmed that new and efficient products for sizing cotton yarns from synthetized potato starch were obtained. Research on rheological properties of copolymers shows a higher viscosity of grafted products indicating the good stability of potential starches. Ecological improvements have been established through high desizing degree as well as improvements in physical-mechanical properties of yarn, abrasion resistance and decrease in yarn surface hairiness were noticed. The use of new derivatives of potato starch, especially of hydrolyzed starch grafted with methacrylic acid (MAA), potassium persulfate (KPS) as initiator, was confirmed. Anova statistical analysis determined the influence of the entire sizing process on individual yarn parameters.
The Role of Surfaces in Gas Transport Through Polymer Membranes
Authors: Firpo Giuseppe , Angeli Elena , Guida Patrizia , Pezzuoli Denise , Repetto Diego , Repetto Luca , Valbusa Ugo
Published: May 2019

This paper describes a procedure to measure the permeability P, diffusivity D, and rate of adsorption k1, thus determining the solubility S and rate of desorption k2 of He, N2, O2, CH4, and CO2 on a polydimethylsiloxane (PDMS) membrane. The described procedure is able to determine experimentally all the physical quantities that characterize the gas transport process through a thin rubber polymer membrane. The experiments were carried out at room temperature and at a transmembrane pressure of 1 atm. The results are in good agreement with the available data in the literature and offer an evaluation of k1 and k2.
The Sound of the Unsayable: Jewish Secular Culture in Arnold Schönberg and Aharon Appelfeld
Authors: Ben-Horin Michal
Published: May 2019

This article examines the use of central elements of the Jewish religious repertoire and transcendental realm, such as prophecy or revelation, within the aesthetic secular realm of musical avant-garde and modern Hebrew literature. By focusing on two case studies, I attempt to shed new light on the question of Jewish secular culture. Arnold Schoenberg (1874–1951), an Austrian Jewish composer, was born into an assimilated Viennese family and converted to Protestantism before returning to Judaism in the 1930s while escaping to the United States. Aharon Appelfeld (1932–2018), an Israeli Jewish writer, was born in Czernowitz to assimilated German-speaking parents, survived the Holocaust and emigrated to Israel in 1946. My claim is that in their works both composer and author testify to traumatic experiences that avoid verbal representation by: (1) subverting and transgressing conventional aesthetic means and (2) alluding to sacred tropes and theological concepts. In exploring Schoenberg’s opera Moses und Aron and Appelfeld’s Journey into Winter among others, this article shows how the transcendent sphere returns within the musical and poetic avant-garde (musical prose, 12-tone composition, prose poem, non-semantic or semiotic fiction) as a “sound” of old traditions that can only be heard through the voices of a new Jewish culture.
Space- and Ground-Based Geophysical Data Tracking of Magma Migration in Shallow Feeding System of Mount Etna Volcano
Authors: Laiolo Marco , Ripepe Maurizio , Cigolini Corrado , Coppola Diego , Della Schiava Massimo , Genco Riccardo , Innocenti Lorenzo , Lacanna Giorgio , Marchetti Emanuele , Massimetti Francesco , Silengo Maria Cristina
Published: May 2019

After a month-long increase in activity at the summit craters, on 24 December 2018, the Etna volcano experienced a short-lived lateral effusive event followed by a rapid resumption of low-level explosive and degassing activity at the summit vents. By combining space (Moderate Resolution Imaging Spectroradiometer; MODIS and SENTINEL-2 images) and ground-based geophysical data, we track, in near real-time, the thermal, seismic and infrasonic changes associated with Etna’s activity during the September–December 2018 period. Satellite thermal data reveal that the fissural eruption was preceded by a persistent increase of summit activity, as reflected by overflow episodes in New SouthEast Crater (NSE) sector. This behavior is supported by infrasonic data, which recorded a constant increase both in the occurrence and in the energy of the strombolian activity at the same crater sectors mapped by satellite. The explosive activity trend is poorly constrained by the seismic tremor, which shows instead a sudden increase only since the 08:24 GMT on the 24 December 2018, almost concurrently with the end of the infrasonic detections occurred at 06:00 GMT. The arrays detected the resumption of infrasonic activity at 11:13 GMT of 24 December, when tremors almost reached the maximum amplitude. Infrasound indicates that the explosive activity was shifting from the summit crater along the flank of the Etna volcano, reflecting, with the seismic tremor, the intrusion of a gas-rich magma batch along a ~2.0 km long dyke, which reached the surface generating an intense explosive phase. The dyke propagation lasted for almost 3 h, during which magma migrated from the central conduit system to the lateral vent, at a mean speed of 0.15–0.20 m s−1. Based on MODIS and SENTINEL 2 images, we estimated that the summit outflows erupted a volume of lava of 1.4 Mm3 (±0.5 Mm3), and that the lateral effusive episode erupted a minimum volume of 0.85 Mm3 (±0.3 Mm3). The results presented here outline the support of satellite data on tracking the evolution of volcanic activity and the importance to integrate satellite with ground-based geophysical data in improving assessments of volcanic hazard during eruptive crises.
Quantitative Assessment of the Impact of Physical and Anthropogenic Factors on Vegetation Spatial-Temporal Variation in Northern Tibet
Authors: Ran Qinwei , Hao Yanbin , Xia Anquan , Liu Wenjun , Hu Ronghai , Cui Xiaoyong , Xue Kai , Song Xiaoning , Xu Cong , Ding Boyang , Wang Yanfen
Published: May 2019

The alpine grassland on the Qinghai-Tibet Plateau covers an area of about 1/3 of China’s total grassland area and plays a crucial role in regulating grassland ecological functions. Both environmental changes and irrational use of the grassland can result in severe grassland degradation in some areas of the Qinghai-Tibet Plateau. However, the magnitude and patterns of the physical and anthropogenic factors in driving grassland variation over northern Tibet remain debatable, and the interactive influences among those factors are still unclear. In this study, we employed a geographical detector model to quantify the primary and interactive impacts of both the physical factors (precipitation, temperature, sunshine duration, soil type, elevation, slope, and aspect) and the anthropogenic factors (population density, road density, residential density, grazing density, per capita GDP, and land use type) on vegetation variation from 2000 to 2015 in northern Tibet. Our results show that the vegetation index in northern Tibet significantly decreased from 2000 to 2015. Overall, the stability of vegetation types was sorted as follows: the alpine scrub > the alpine steppe > the alpine meadow. The physical factors, rather than the anthropogenic factors, have been the primary driving factors for vegetation dynamics in northern Tibet. Specifically, meteorological factors best explained the alpine meadow and alpine steppe variation. Precipitation was the key factor that influenced the alpine meadow variation, whereas temperature was the key factor that contributed to the alpine steppe variation. The anthropogenic factors, such as population density, grazing density and per capita GDP, influenced the alpine scrub variation most. The influence of population density is highly similar to that of grazing density, which may provide convenient access to simplify the study of the anthropogenic activities in the Tibet plateau. The interactions between the driving factors had larger effects on vegetation than any single factor. In the alpine meadow, the interaction between precipitation and temperature can explain 44.6% of the vegetation variation. In the alpine scrub, the interaction between temperature and GDP was the highest, accounting for 27.5% of vegetation variation. For the alpine steppe, the interaction between soil type and population density can explain 29.4% of the vegetation variation. The highest value of vegetation degradation occurred in the range of 448–469 mm rainfall in the alpine meadow, 0.61–1.23 people/km2 in the alpine scrub and –0.83–0.15 °C in the alpine steppe, respectively. These findings could contribute to a better understanding of degradation prevention and sustainable development of the alpine grassland ecosystem in northern Tibet.
Variability of the Suspended Particle Cross-Sectional Area in the Bohai Sea and Yellow Sea
Authors: Tang Qiong , Wang Shengqiang , Qiu Zhongfeng , Sun Deyong , Bilal Muhammad
Published: May 2019

A cross-sectional area (CSA) is a key element in the optical properties of suspended particles. The seasonal evolution of CSA has great potential for use in mapping total suspended particles, and such mapping plays an important role in water quality monitoring. In this study, the spatiotemporal variations in CSA in the Bohai Sea and the Yellow Sea were studied using temperature, salinity and chlorophyll-a data collected by four cruises. The CSA field data covered a wide range of spatiotemporal variabilities in the Bohai Sea and the Yellow Sea. The results revealed that the largest CSA (>2 m−1) was found in the coastal area, while the CSA (≤1 m−1) on the outer shelf was much smaller. Large values of CSA (>15 m−1) were observed in winter, whereas the smallest values of CSA (0~2 m−1) were observed in summer. These results suggest that vertical mixing and ocean stratification might be important physical mechanisms that influences the CSA seasonal distribution in the surface layer. The results also showed that phytoplankton played an important role in the CSA, with an R2 value of 0.601. The seasonal patterns of CSA documented in this study provide a fundamental theory for research on optical properties, mapping transparency, and photosynthetically active radiation.
Non-Rigid Vehicle-Borne LiDAR-Assisted Aerotriangulation
Authors: Zheng Li , Li Yuhao , Sun Meng , Ji Zheng , Yu Manzhu , Shu Qingbo
Published: May 2019

VLS (Vehicle-borne Laser Scanning) can easily scan the road surface in the close range with high density. UAV (Unmanned Aerial Vehicle) can capture a wider range of ground images. Due to the complementary features of platforms of VLS and UAV, combining the two methods becomes a more effective method of data acquisition. In this paper, a non-rigid method for the aerotriangulation of UAV images assisted by a vehicle-borne light detection and ranging (LiDAR) point cloud is proposed, which greatly reduces the number of control points and improves the automation. We convert the LiDAR point cloud-assisted aerotriangulation into a registration problem between two point clouds, which does not require complicated feature extraction and match between point cloud and images. Compared with the iterative closest point (ICP) algorithm, this method can address the non-rigid image distortion with a more rigorous adjustment model and a higher accuracy of aerotriangulation. The experimental results show that the constraint of the LiDAR point cloud ensures the high accuracy of the aerotriangulation, even in the absence of control points. The root-mean-square error (RMSE) of the checkpoints on the x, y, and z axes are 0.118 m, 0.163 m, and 0.084m, respectively, which verifies the reliability of the proposed method. As a necessary condition for joint mapping, the research based on VLS and UAV images in uncontrolled circumstances will greatly improve the efficiency of joint mapping and reduce its cost.
Recalibration of over 35 Years of Infrared and Water Vapor Channel Radiances of the JMA Geostationary Satellites
Authors: Tabata Tasuku , John Viju O. , Roebeling Rob A. , Hewison Tim , Schulz Jörg
Published: May 2019

Infrared sounding measurements of the Infrared Atmospheric Sounding Interferometer (IASI), Atmospheric Infrared Sounder (AIRS), and High-resolution Infrared Radiation Sounder/2 (HIRS/2) instruments are used to recalibrate infrared (IR; ~11 µm) channels and water vapor (WV; ~6 µm) channels of the Visible and Infrared Spin Scan Radiometer (VISSR), Japanese Advanced Meteorological Imager (JAMI), and IMAGER instruments onboard the historical geostationary satellites of the Japan Meteorological Agency (JMA). The recalibration was performed using a common recalibration method developed by European Organization for the Exploitation of Meteorological Satellites (EUMETSAT), which can be applied to the historical geostationary satellites to produce Fundamental Climate Data Records (FCDR). Pseudo geostationary imager radiances were computed from the infrared sounding measurements and regressed against the radiances from the geostationary satellites. Recalibration factors were computed from these pseudo imager radiance pairs. This paper presents and evaluates the result of recalibration of longtime-series of IR (1978–2016) and WV (1995–2016) measurements from JMA’s historical geostationary satellites. For the IR data of the earlier satellites (Geostationary Metrological Satellite (GMS) to GMS-4) significant seasonal variations in radiometric biases were observed. This suggests that the sensors on GMS to GMS-4 were strongly affected by seasonal variations in solar illumination. The amplitudes of these seasonal variations range from 3 K for the earlier satellites to <0.4 K for the recent satellites (GMS-5, Geostationary Operational Environmental Satellite-9 (GOES-9), Multi-functional Transport Satellite-1R (MTSAT-1R) and MTSAT-2). For the WV data of GOES-9, MTSAT-1R and MTSAT-2, no seasonal variations in radiometric biases were observed. However, for GMS-5, the amplitude of seasonal variation in bias was about 0.5 K. Overall, the magnitude of the biases for GMS-5, MTSAT-1R and MTSAT-2 were smaller than 0.3 K. Finally, our analysis confirms the existence of errors due to atmospheric absorption contamination in the operational Spectral Response Function (SRF) of the WV channel of GMS-5. The method used in this study is based on the principles developed within Global Space-based Inter-calibration System (GSICS). Moreover, presented results contribute to the Inter-calibration of imager observations from time-series of geostationary satellites (IOGEO) project under the umbrella of the World Meteorological Organization (WMO) initiative Sustained and Coordinated Processing of Environmental Satellite data for Climate Monitoring (SCOPE-CM).
Moving Target Detection with Modified Logarithm Background Subtraction and Its Application to the GF-3 Spotlight Mode
Authors: Shen Wenjie , Hong Wen , Han Bing , Wang Yanping , Lin Yun
Published: May 2019

Spaceborne spotlight SAR mode has drawn attention due to its high-resolution capability, however, the studies about moving target detection with this mode are less. The paper proposes an image sequence-based method entitled modified logarithm background subtraction to detect ground moving targets with Gaofen-3 Single Look Complex (SLC) spotlight SAR images. The original logarithm background subtraction method is designed by our team for airborne SAR. It uses the subaperture image sequence to generate a background image, then detects moving targets by using image sequence to subtract background. When we apply the original algorithm to the spaceborne spotlight SAR data, a high false alarm problem occurs. To tackle the high false alarm problem due to the target’s low signal-to-noise-ratio (SNR) in spaceborne cases, several improvements are made. First, to preserve most of the moving target signatures, a low threshold CFAR (constant false alarm rate) detector is used to get the coarse detection. Second, because the moving target signatures have higher density than false detections in the coarse detection, a modified DBSCAN (density-based spatial-clustering-of-applications-with-noise) clustering method is then adopted to reduce false alarms. Third, the Kalman tracker is used to exclude the residual false detections, due to the real moving target signature having dynamic behavior. The proposed method is validated by real data, the shown results also prove the feasibility of the proposed method for both Gaofen-3 and other spaceborne systems.
Analysis of Vegetation Red Edge with Different Illuminated/Shaded Canopy Proportions and to Construct Normalized Difference Canopy Shadow Index
Authors: Xu Nianxu , Tian Jia , Tian Qingjiu , Xu Kaijian , Tang Shaofei
Published: May 2019

Shadows exist universally in sunlight-source remotely sensed images, and can interfere with the spectral morphological features of green vegetations, resulting in imprecise mathematical algorithms for vegetation monitoring and physiological diagnoses; therefore, research on shadows resulting from forest canopy internal composition is very important. Red edge is an ideal indicator for green vegetation’s photosynthesis and biomass because of its strong connection with physicochemical parameters. In this study, red edge parameters (curve slope and reflectance) and the normalized difference vegetation index (NDVI) of two species of coniferous trees in Inner Mongolia, China, were studied using an unmanned aerial vehicle’s hyperspectral visible-to-near-infrared images. Positive correlations between vegetation red edge slope and reflectance with different illuminated/shaded canopy proportions were obtained, with all R2s beyond 0.850 (p < 0.01). NDVI values performed steadily under changes of canopy shadow proportions. Therefore, we devised a new vegetation index named normalized difference canopy shadow index (NDCSI) using red edge’s reflectance and the NDVI. Positive correlations (R2 = 0.886, p < 0.01) between measured brightness values and NDCSI of validation samples indicated that NDCSI could differentiate illumination/shadow circumstances of a vegetation canopy quantitatively. Combined with the bare soil index (BSI), NDCSI was applied for linear spectral mixture analysis (LSMA) using Sentinel-2 multispectral imaging. Positive correlations (R2 = 0.827, p < 0.01) between measured brightness values and fractional illuminated vegetation cover (FIVC) demonstrate the capacity of NDCSI to accurately calculate the fractional cover of illuminated/shaded vegetation, which can be utilized to calculate and extract the illuminated vegetation canopy from satellite images.
A New Retracking Algorithm for Retrieving Sea Ice Freeboard from CryoSat-2 Radar Altimeter Data during Winter–Spring Transition
Authors: Shen Xiaoyi , Similä Markku , Dierking Wolfgang , Zhang Xi , Ke Changqing , Liu Meijie , Wang Manman
Published: May 2019

A new method called Bézier curve fitting (BCF) for approximating CryoSat-2 (CS-2) SAR-mode waveform is developed to optimize the retrieval of surface elevation of both sea ice and leads for the period of late winter/early spring. We found that the best results are achieved when the retracking points are fixed on positions at which the rise of the fitted Bézier curve reaches 70% of its peak in case of leads, and 50% in case of sea ice. In order to evaluate the proposed retracking algorithm, we compare it to other empirically-based methods currently reported in the literature, namely the threshold first-maximum retracker algorithm (TFMRA) and the European Space Agency (ESA) CS-2 in-depth Level-2 algorithm (L2I). The results of the retracking procedure for the different algorithms are validated using data of the Operation Ice Bridge (OIB) airborne mission. For two OIB campaign periods in March 2015 and April 2016, the mean absolute differences between freeboard values retrieved from CS-2 and OIB data were 9.22 and 7.79 cm when using the BCF method, 10.41 cm and 8.16 cm for TFMRA, and 10.01 cm and 8.42 cm for L2I. This suggests that the sea ice freeboard data can be obtained with a higher accuracy when using the proposed BCF method instead of the TFMRA or the CS-2 L2I algorithm.
Machine Learning Approaches for Detecting Tropical Cyclone Formation Using Satellite Data
Authors: Kim Minsang , Park Myung-Sook , Im Jungho , Park Seonyoung , Lee Myong-In
Published: May 2019

This study compared detection skill for tropical cyclone (TC) formation using models based on three different machine learning (ML) algorithms-decision trees (DT), random forest (RF), and support vector machines (SVM)-and a model based on Linear Discriminant Analysis (LDA). Eight predictors were derived from WindSat satellite measurements of ocean surface wind and precipitation over the western North Pacific for 2005–2009. All of the ML approaches performed better with significantly higher hit rates ranging from 94 to 96% compared with LDA performance (~77%), although false alarm rate by MLs is slightly higher (21–28%) than that by LDA (~13%). Besides, MLs could detect TC formation at the time as early as 26–30 h before the first time diagnosed as tropical depression by the JTWC best track, which was also 5 to 9 h earlier than that by LDA. The skill differences across MLs were relatively smaller than difference between MLs and LDA. Large yearly variation in forecast lead time was common in all models due to the limitation in sampling from orbiting satellite. This study highlights that ML approaches provide an improved skill for detecting TC formation compared with conventional linear approaches.
Forest Stand Species Mapping Using the Sentinel-2 Time Series
Authors: Grabska Ewa , Hostert Patrick , Pflugmacher Dirk , Ostapowicz Katarzyna
Published: May 2019

Accurate information regarding forest tree species composition is useful for a wide range of applications, both for forest management and scientific research. Remote sensing is an efficient tool for collecting spatially explicit information on forest attributes. With the launch of the Sentinel-2 mission, new opportunities have arisen for mapping tree species owing to its spatial, spectral, and temporal resolution. The short revisit cycle (five days) is crucial in vegetation mapping because of the reflectance changes caused by phenological phases. In our study, we evaluated the utility of the Sentinel-2 time series for mapping tree species in the complex, mixed forests of the Polish Carpathian Mountains. We mapped the following nine tree species: common beech, silver birch, common hornbeam, silver fir, sycamore maple, European larch, grey alder, Scots pine, and Norway spruce. We used the Sentinel-2 time series from 2018, with 18 images included in the study. Different combinations of Sentinel-2 imagery were selected based on mean decrease accuracy (MDA) and mean decrease Gini (MDG) measures, in addition to temporal phonological pattern analysis. Tree species discrimination was performed using the Random Forest classification algorithm. Our results showed that the use of the Sentinel-2 time series instead of single date imagery significantly improved forest tree species mapping, by approximately 5–10% of overall accuracy. In particular, combining images from spring and autumn resulted in better species discrimination.
Editorial for the Special Issue “Solar Radiation, Modeling, and Remote Sensing”
Authors: Kaskaoutis Dimitris , Polo Jesús
Published: May 2019

Surface-solar radiation is of vital importance for life on Earth, radiation–energy balance, photosynthesis, and photochemical reactions, meteorological and climatic conditions, and the water cycle. Solar radiation measurements are growing in quality and density but they are still scarce enough to properly explain the spatial and temporal variability. As a consequence, great efforts are still being devoted to improving modeling and retrievals of solar radiation data. This Special Issue reviews techniques for solar radiation modeling and remote sensing using satellite and advanced statistical techniques for solar radiation. Satellite remote sensing of solar radiation provides better spatial coverage, and various methods have been presented on this issue covering several aspects: updated models for solar radiation modeling under clear sky conditions, new approaches for retrieving solar radiation from satellite imagery and validation against ground data, forecasting solar radiation, and modeling photosynthetically active radiation.
Changes in SO2 Flux Regime at Mt. Etna Captured by Automatically Processed Ultraviolet Camera Data
Authors: Delle Donne Dario , Aiuppa Alessandro , Bitetto Marcello , D’Aleo Roberto , Coltelli Mauro , Coppola Diego , Pecora Emilio , Ripepe Maurizio , Tamburello Giancarlo
Published: May 2019

We used a one-year long SO2 flux record, which was obtained using a novel algorithm for real-time automatic processing of ultraviolet (UV) camera data, to characterize changes in degassing dynamics at the Mt. Etna volcano in 2016. These SO2 flux records, when combined with independent thermal and seismic evidence, allowed for capturing switches in activity from paroxysmal explosive eruptions to quiescent degassing. We found SO2 fluxes 1.5–2 times higher than the 2016 average (1588 tons/day) during the Etna’s May 16–25 eruptive paroxysmal activity, and mild but detectable SO2 flux increases more than one month before its onset. The SO2 flux typically peaked during a lava fountain. Here, the average SO2 degassing rate was ~158 kg/s, the peak emission was ~260 kg/s, and the total released SO2 mass was ~1700 tons (in 3 h on 18 May, 2016). Comparison between our data and prior (2014–2015) results revealed systematic SO2 emission patterns prior to, during, and after an Etna’s paroxysmal phases, which allows us to tentatively identify thresholds between pre-eruptive, syn-eruptive, and post-eruptive degassing regimes.
Debonding Damage Detection in CFRP Plate-Strengthened Steel Beam Using Electromechanical Impedance Technique
Authors: Wang Bin , Sun Yongfeng , Li Yunzhang , Zhang Chuan
Published: May 2019

Carbon fiber reinforced polymer materials are widely applied in structure strengthened engineering because of the many advantages of carbon fiber reinforced polymer. However, the debonding damage between the carbon fiber reinforced polymer and host structures occurs frequently, which might lead to the brittle failure of structure components, especially flexural ones. In this paper, an electromechanical impedance-based method, an important technique in structural health monitoring, was adopted to detect the debonding damage of carbon fiber reinforced polymer plate-strengthened steel beam by using lead zirconate titanate (PZT) transducers. A carbon fiber reinforced polymer plate-strengthened steel beam specimen was fabricated in the laboratory and two PZT sensors were attached at different locations on the carbon fiber reinforced polymer plate. The impedance signatures with variation of the different degrees of the debonding damage were measured by an impedance analyzer. The root-mean-square deviation method and the cross-correlation coefficient method were used to quantify the correlation between the electromechanical impedance and the debonding damage degree. The results reflect that an electromechanical impedance-based structural health monitoring technique can serve as a good method to detect the debonding damage of carbon fiber reinforced polymer plate-strengthened steel structures.
Patient Mobility Support for Indoor Non-Directed Optical Body Area Networks
Authors: Dhatchayeny Durai Rajan , Arya Sudhanshu , Chung Yeon Ho
Published: May 2019

In this paper, a patient mobility support scheme for indoor non-directed optical body area networks (OBAN) is presented. The OBAN is an optical healthcare system where medical sensors are installed on various parts of the patient’s body and are connected to an optical coordinator for transmitting the physiological signals via optical wireless links. In the proposed scheme, a white light-emitting diode (LED) was employed as the optical coordinator that was mounted on the patient body, while a photodetector (PD) was used as the receiver installed at the ceiling. We considered three practical mobility scenarios in terms of the location of the coordinator: (i) Shoulder, (ii) wrist, and (iii) both shoulder and wrist. The analytical channel model for multiple reflections in a non-directed OBAN was developed and validated in the form of simulations. In addition, experiments were carried out to verify the effectiveness of the proposed mobility scheme. It was found that the third scenario (shoulder and wrist) performed best, showing a bit error rate (BER) of 1.2 × 10−6 at a distance of 1.25 m. The experimental results demonstrated that the proposed mobility support scheme in the OBAN added an additional degree of freedom to patients with reliable performances.
A Low-Cost IoT-Based System to Monitor the Location of a Whole Herd
Authors: Maroto-Molina Francisco , Navarro-García Jorge , Príncipe-Aguirre Karen , Gómez-Maqueda Ignacio , Guerrero-Ginel José E. , Garrido-Varo Ana , Pérez-Marín Dolores C.
Published: May 2019

Animal location technologies have evolved considerably in the last 60 years. Nowadays, animal tracking solutions based on global positioning systems (GPS) are commercially available. However, existing devices have several constraints, mostly related to wireless data transmission and financial cost, which make impractical the monitorization of all the animals in a herd. The main objective of this work is to develop a low-cost solution to enable the monitorization of a whole herd. An IoT-based system, which requires some animals of the herd being fitted with GPS collars connected to a Sigfox network and the rest with low-cost Bluetooth tags, has been developed. Its performance has been tested in two commercial farms, raising sheep and beef cattle, through the monitorization of 50 females in each case. Several collar/tag ratios, which define the cost per animal of the solution, have been simulated. Results demonstrate that a low collar/tag ratio enable the monitorization of a whole sheep herd. A larger ratio is needed for beef cows because of their grazing behavior. Nevertheless, the optimal ratio depends on the purpose of location data. Large variability has been observed for the number of hourly and daily messages from collars and tags. The system effectiveness for the monitorization of all the animals in a herd has been certainly proved.