bluuebunny/crossref_metadata_2025 huggingface dataset:
Morphological description of the first protozoeal stage of the deep-sea shrimps Aristeus antennatus and Gennadas elegans, with a key
Authors: Carreton Marta , Dos Santos Antonina , De Sousa Lígia Faria , Rotllant Guiomar , Company Joan B.
Published: July 2020

Accurate information on commercial marine species larvae is key to fisheries science, as their correct identification is the first step towards studying the species’ connectivity patterns. In this study, we provide a complete morphological description of the first protozoeal stage of the valued deep-sea blue and red shrimpAristeus antennatusand of the small mesopelagic shrimpGennadas elegans. These two larval morphologies previously posed a risk of misidentification, thus hindering the study ofA. antennatuslarval ecology and dynamics in the context of fisheries science. Using specimens caught in the plankton at various locations in the Northwestern Mediterranean Sea and identification confirmed by molecular methods, the larvae ofA. antennatusandG. elegansare distinguished from each other by the ornamentation of the antennula. A possible confusion in previous descriptions of Aristeidae larvae is addressed and a new key for the identification of Dendrobranchiata larvae provided.
MTFMT deficiency correlates with reduced mitochondrial integrity and enhanced host susceptibility to intracellular infection
Authors: Seo Jung-Hwa , Hwang Cheol-Sang , Yoo Joo-Yeon
Published: July 2020

Mitochondria behave as functional and structural hubs for innate defense against intracellular infection. While the mitochondrial membrane serves as a platform for the assembly of signaling complexes activated by intracellular infection, various danger molecules derived from impaired mitochondria activate innate signaling pathways. Using methionyl-tRNA formyl transferase (MTFMT)-deficient cells, which exhibit impaired mitochondrial activity, we examined the role of mitochondrial integrity in regulating innate defense against infection. Since MTFMT functions at the early steps of mitochondrial translation, its loss was expected to cause defects in mitochondrial activity. Under transient MTFMT gene silencing conditions, we observed shortened mitochondria along with reduced activity. MTFMT-silenced cells were more susceptible to intracellular infection, as examined by infection with RNA viruses and the intracellular bacterium Shigella flexneri. In support of this observation, MTFMT-silenced cells possessed lowered basal NF-κB activity, which remained low after S. flexneri infection. In addition, the mitochondrial accumulation of evolutionarily conserved signaling intermediate in Toll pathway (ECSIT), an adaptor protein for NF-κB activation, was significantly decreased in MTFMT-silenced cells, explaining the reduced NF-κB activity observed in these cells. Since impaired mitochondria likely release mitochondrial molecules, we evaluated the contribution of mitochondrial N-formyl peptides to the regulation of bacterial infection. Transient transfection of mitochondrial-derived N-formyl peptides favored S. flexneri infection, which was accompanied by enhanced bacterial survival, but did not affect host cell viability. However, transient transfection of mitochondrial-derived N-formyl peptides did not affect basal NF-κB activity. Altogether, these data suggest that the integrity of mitochondria is essential to their proper function in protecting against infection, as intact mitochondria not only block the release of danger molecules but also serve as signaling hubs for the downstream NF-κB pathway.
Tumor microenvironment characterization in head and neck cancer identifies prognostic and immunotherapeutically relevant gene signatures
Authors: Huo Mengqi , Zhang Ying , Chen Zhong , Zhang Suxin , Bao Yang , Li Tianke
Published: July 2020

The tumor microenvironment (TME) is of great clinical significance for predicting the therapeutic effect of tumors. Nonetheless, there was no systematic analysis of cellular interactions in the TME of head and neck cancer (HNSC). This study used gene expression data from 816 patients with HNSC to analyze the scores of 22 immune cells. On this basis, we have established a novel TMEscore-based prognostic risk model. The relationship between TMEscore and clinical and genomic characteristics was analyzed. The sample was divided into risk-H and risk-L groups based on the prognosis risk model of TMEscore, with significant differences in overall survival between the two groups (log rank p < 0.001). In terms of clinical features, the TMEscore is closely related to the T staging, Grade, and HPV. As for genomic characteristics, the genomic features of the Risk-H samples are a low expression of immune-related genes and high-frequency mutations of TP53 and CEP152. This model was validated in an external test set, in which the prognosis for Risk-H group and Risk-L group was also significantly different (log rank p = 0.017). A quantitative method of TME infiltration pattern is established, which may be a potential predictor of HNSC prognosis.
Humanized GPRC6AKGKY is a gain-of-function polymorphism in mice
Authors: Pi Min , Xu Fuyi , Ye Ruisong , Nishimoto Satoru K. , Kesterson Robert A. , Williams Robert W. , Lu Lu , Quarles L. Darryl
Published: July 2020

GPRC6A is proposed to regulate energy metabolism in mice, but in humans a KGKY polymorphism in the third intracellular loop (ICL3) is proposed to result in intracellular retention and loss-of-function. To test physiological importance of this human polymorphism in vivo, we performed targeted genomic humanization of mice by using CRISPR/Cas9 (clustered regularly interspaced short palindromic repeats-CRISPR associated protein 9) system to replace the RKLP sequence in the ICL3 of the GPRC6A mouse gene with the uniquely human KGKY sequence to create Gprc6a-KGKY-knockin mice. Knock-in of a human KGKY sequence resulted in a reduction in basal blood glucose levels and increased circulating serum insulin and FGF-21 concentrations. Gprc6a-KGKY-knockin mice demonstrated improved glucose tolerance, despite impaired insulin sensitivity and enhanced pyruvate-mediated gluconeogenesis. Liver transcriptome analysis of Gprc6a-KGKY-knockin mice identified alterations in glucose, glycogen and fat metabolism pathways. Thus, the uniquely human GPRC6A-KGKY variant appears to be a gain-of-function polymorphism that positively regulates energy metabolism in mice.
Sodium ions allosterically modulate the M2 muscarinic receptor
Authors: Friedman Sheli , Tauber Merav , Ben-Chaim Yair
Published: July 2020

G protein coupled receptors (GPCRs) play a key role in the vast majority of cellular signal transduction processes. Previous experimental evidence has shown that sodium ion (Na+) allosterically modulate several class A GPCRs and theoretical studies suggested that the same also holds true for muscarinic receptors. Here we examined, using Xenopus oocytes as an expression system, the effect of Na+ on a prototypical GPCR, the M2 muscarinic receptor (M2R). We found that removal of extracellular Na+ resulted in a decrease in the potency of ACh toward the M2R and that a conserved aspartate in transmembrane domain 2 is crucial for this effect. We further show that this allosteric effect of Na+ does not underlie the voltage-dependence of this receptor.
Combinational therapy with antibiotics and antibiotic-loaded adipose-derived stem cells reduce abscess formation in implant-related infection in rats
Authors: Yoshitani Junya , Kabata Tamon , Arakawa Hiroshi , Kato Yukio , Nojima Takayuki , Hayashi Katsuhiro , Tokoro Masaharu , Sugimoto Naotoshi , Kajino Yoshitomo , Inoue Daisuke , Ueoka Ken , Yamamuro Yuki , Tsuchiya Hiroyuki
Published: July 2020

Implant-related infection is difficult to treat without extended antibiotic courses. However, the long-term use of antibiotics has led to the development of multidrug- and methicillin-resistant Staphylococcusaureus. Thus, alternatives to conventional antibiotic therapy are needed. Recently, mesenchymal stem cells have been shown to have antimicrobial properties. This study aimed to evaluate the antimicrobial activity and therapeutic effect of local treatment with antibiotic-loaded adipose-derived stem cells (ADSCs) plus an antibiotic in a rat implant-associated infection model. Liquid chromatography/tandem mass spectrometry revealed that ADSCs cultured in the presence of ciprofloxacin for 24 h showed time-dependent antibiotic loading. Next, we studied the therapeutic effects of ADSCs and ciprofloxacin alone or in combination in an implant-related infection rat model. The therapeutic effects of ADSCs plus antibiotics, antibiotics, and ADSCs were compared with no treatment as a control. Rats treated with ADSCs plus ciprofloxacin had the lowest modified osteomyelitis scores, abscess formation, and bacterial burden on the implant among all groups (P < 0.05). Thus, local treatment with ADSCs plus an antibiotic has an antimicrobial effect in implant-related infection and decrease abscess formation. Thus, our findings indicate that local administration of ADSCs with antibiotics represents a novel treatment strategy for implant-associated osteomyelitis.
A time-dependent diffusion MRI signature of axon caliber variations and beading
Authors: Lee Hong-Hsi , Papaioannou Antonios , Kim Sung-Lyoung , Novikov Dmitry S. , Fieremans Els
Published: July 2020

MRI provides a unique non-invasive window into the brain, yet is limited to millimeter resolution, orders of magnitude coarser than cell dimensions. Here, we show that diffusion MRI is sensitive to the micrometer-scale variations in axon caliber or pathological beading, by identifying a signature power-law diffusion time-dependence of the along-fiber diffusion coefficient. We observe this signature in human brain white matter and identify its origins by Monte Carlo simulations in realistic substrates from 3-dimensional electron microscopy of mouse corpus callosum. Simulations reveal that the time-dependence originates from axon caliber variation, rather than from mitochondria or axonal undulations. We report a decreased amplitude of time-dependence in multiple sclerosis lesions, illustrating the potential sensitivity of our method to axonal beading in a plethora of neurodegenerative disorders. This specificity to microstructure offers an exciting possibility of bridging across scales to image cellular-level pathology with a clinically feasible MRI technique.
A mitochondria-targeted anticancer nanoplatform with deep penetration for enhanced synergistic sonodynamic and starvation therapy
Authors: Zhang Ruo , Zhang Liang , Ran Haitao , Li Pan , Huang Ju , Tan Mixiao , Yang Yang , Wang Zhigang
Published: July 2020

Sonodynamic therapy (SDT), as an emerging technique, gives rise to reactive oxygen species (ROS)-induced apoptosis of tumor cells.
Recent advances: peptides and self-assembled peptide-nanosystems for antimicrobial therapy and diagnosis
Authors: Zou Pengfei , Chen Wen-Ting , Sun Tongyi , Gao Yuanyuan , Li Li-Li , Wang Hao
Published: July 2020

Bacterial infections, especially the refractory treatment of drug-resistant bacteria, are one of the greatest threats to human health. Self-assembling peptide-based strategies can specifically detect the bacteria at the site of infection in the body and kill it.
Broad spectrum antibacterial photodynamic and photothermal therapy achieved with indocyanine green loaded SPIONs under near infrared irradiation
Authors: Bilici K. , Atac N. , Muti A. , Baylam I. , Dogan O. , Sennaroglu A. , Can F. , Yagci Acar H.
Published: July 2020

Antimicrobial photodynamic therapy (aPDT) and antimicrobial photothermal therapy (aPTT) are promising local and effective alternative therapies for antibiotic resistant bacterial infections and biofilms.
Hydrothermal polymerization towards fully biobased polyazomethines
Authors: Li Guotai , Yu Kui , Noordijk Jurrie , Meeusen-Wierts Monique H. M. , Gebben Bert , oude Lohuis Petra A. M. , Schotman Anton H. M. , Bernaerts Katrien V.
Published: July 2020

Hydrothermal polymerization and biobased building blocks enable a green route towards aromatic polyazomethines.
Selective DCP detection with xanthene derivatives by carbonyl phosphorylation
Authors: Behera Kanhu Charan , Bag Bamaprasad
Published: July 2020

Dual mode signalling for DCP detection with rhodamine-6G derivatives through phosphorylation at the spirocyclic carbonyl end.
Effects of polydopamine-passivation on the optical properties of carbon dots and its potential use in vivo
Authors: Pappalardo Juan Sebastian , Macairan Jun-Ray , Macina Alexia , Poulhazan Alexandre , Quattrocchi Valeria , Marcotte Isabelle , Naccache Rafik
Published: July 2020

Passivation of carbon dots via heteroatom doping has been shown to enhance their optical properties and tune their fluorescence signature.
Hydrogen bonds and halogen bonds in complexes of carbones L→C←L as electron donors to HF and ClF, for L = CO, N2, HNC, PH3, and SH2
Authors: Del Bene Janet E. , Alkorta Ibon , Elguero José
Published: July 2020

MP2 and EOM-CCSD calculations have been carried out to determine the structures, binding energies, and spin-spin coupling constants of carbone complexes L→C←L with the carbone the electron donor to HF or ClF, for L = CO, N2, HNC, PH3, and SH2.
Structure of water and polymer at the buried polymer/water interface unveiled using heterodyne-detected vibrational sum frequency generation
Authors: Myalitsin Anton , Ghosh Sanat , Urashima Shu-hei , Nihonyanagi Satoshi , Yamaguchi Shoichi , Aoki Takashi , Tahara Tahei
Published: July 2020

Heterodyne-detected vibrational sum frequency generation reveals the molecular-level structure of the polymer/water interface that is different from what has been argued.
Insights into C–O insertion in a carbene/alkyne metathesis cascade reaction catalyzed by Rh2(OAc)4: a DFT study
Authors: Zhang Yan , Yang Yongsheng , Xue Ying
Published: July 2020

The mechanism and selectivities of C–O insertion in the carbene/alkyne metathesis of diazo compounds catalyzed by Rh2(OAc)4 are studied with DFT calculations.
Intertwined chemistry of hydroxyl hydrogen-bond donors, epoxides and isocyanates in the organocatalytic synthesis of oxazolidinones versus isocyanurates: rational catalytic investigation and mechanistic understanding
Authors: Yingcharoen Prapussorn , Natongchai Wuttichai , Poater Albert , D' Elia Valerio
Published: July 2020

The efficiency and chemoselectivity of the cycloaddition of isocyanates to epoxides to afford oxazolidinones were investigated using hydroxyl hydrogen-bond donors as organocatalysts.
Photoresponsive Zn2+-specific metallohydrogels coassembled from imidazole containing phenylalanine and arylazopyrazole derivatives
Authors: Sallee Ashanti , Ghebreyessus Kesete
Published: July 2020

Stimuli-responsive supramolecular gels and metallogels have been widely explored in the past decade, but the fabrication of metallogels with reversible photoresponsive properties remains largely unexplored.
Ultrathin Bi2O2S nanosheet near-infrared photodetectors
Authors: Chitara Basant , Limbu Tej B. , Orlando Jason D. , Tang Yongan , Yan Fei
Published: July 2020

Solution-processed Bi2O2S nanosheets demonstrate high-efficiency NIR photodetection with a responsivity of 4 A/W, an external quantum efficiency of 630%, and a normalized photocurrent-to-dark-current ratio of 1.3 × 1010 per watt.
Thioglycoligation of aromatic thiols using a natural glucuronide donor
Authors: Kurdziel Martyna , Kopeć Magdalena , Pâris Arnaud , Lewiński Krzysztof , Lafite Pierre , Daniellou Richard
Published: July 2020

This is the first example of a thioglycoligase that is able to catalyse the formation of S-glucuronides using aromatic thiols and a natural glucuronide donor.
Tellurophene-containing π-conjugated polymers with unique heteroatom–heteroatom interactions by post-element-transformation of an organotitanium polymer
Authors: Nishiyama Hiroki , Zheng Feng , Inagi Shinsuke , Fueno Hiroyuki , Tanaka Kazuyoshi , Tomita Ikuyoshi
Published: July 2020

A unique π-conjugated tellurophene-containing polymer that possesses fully coplanar ring units through a tellurium–oxygen interaction, was prepared by the post-element-transformation of a titanacyclopentadiene-containing reactive precursor.
Advances in ligand-unsupported argentophilic interactions in crystal engineering: an emerging platform for supramolecular architectures
Authors: Jassal Amanpreet Kaur
Published: July 2020

Ligand-unsupported argentophilic interactions are described, emphasizing reticular design and recent developments in advanced synthetic strategies, and highlighting diverse interactions that are useful for the construction of unmitigated networks.
Carbon nanotube impregnated anthracite (An/CNT) as a superior sorbent for azo dye removal
Authors: Mohamed Fathy M. , Li Zhaohui , Zayed Ahmed M.
Published: July 2020

Raw anthracite was impregnated with a minute amount of multi-walled carbon-nanotubes at a solid/solid ratio of 50 : 1 via calcination at 950 °C for 2 h to produce anthracite/carbon nanotube (An/CNT) composite with superior sorption efficiency.
Physical vapor deposited organic ferroelectric diisopropylammonium bromide film and its self-powered photodetector characteristics
Authors: Priya K Shanmuga , Kola Lakshmi , Pal Subhajit , Biswas Pranab Parimal , Murugavel P.
Published: July 2020

Organic diisopropylammonium bromide (DIPAB) ferroelectric thin film and its application potential in photodetectors.
Influence of precursor ratio and dopant concentration on the structure and optical properties of Cu-doped ZnCdSe-alloyed quantum dots
Authors: Ca N. X. , Van H. T. , Do P. V. , Thanh L. D. , Tan P. M. , Truong N. X. , Oanh V. T. K. , Binh N. T. , Hien N. T.
Published: July 2020

Tunable copper doped Zn1−xCdxS alloy quantum dots (QDs) were successfully synthesized by the wet chemical method.
Covalent polymer functionalized graphene oxide/poly(ether ether ketone) composites for fused deposition modeling: improved mechanical and tribological performance
Authors: Yang Cheng , Xu Jing , Xing Yue , Hao Sijia , Ren Zhidong
Published: July 2020

A polymer “bridge” was designed to connect graphene oxide and poly(ether ether ketone), making stronger and tougher composites.
Nucleation and growth behavior of Er3+ doped oxyfluorophosphate glasses
Authors: Ojha N. , Szczodra A. , Boetti N. G. , Massera J. , Petit L.
Published: July 2020

The nucleation and growth behavior of glasses with the composition (75 NaPO3-25 CaF2)100−x–(TiO2/ZnO/MgO)x, with x = 0 and x = 1.5 (in mol%) is investigated.
A naringenin-based benzoxazine with an intramolecular hydrogen bond as both a thermal latent polymerization additive and property modifier for epoxy resins
Authors: Hao Boran , Yang Rui , Zhang Kan
Published: July 2020

A naringenin-based benzoxazine containing a latent catalytic system was designed and successfully synthesized and it can be used as both a thermal latent polymerization additive and a beneficial property modifier for epoxy resins.
Theoretical study on aromatic and open-shell characteristics of carbon nanobelts composed of indeno[1,2-b]fluorene units: dependence on the number of units and charge states
Authors: Kishi Ryohei , Yamane Masaki , Sugiura Ryosuke , Yoshida Wataru , Shimizu Yosuke , Nakano Masayoshi
Published: July 2020

Dependence of aromatic and open-shell characteristics on the number of units and charged states was theoretically investigated for carbon nanobelts composed of indeno[1,2-b]fluorene units by using quantum chemical calculations.
Structural and optical properties of langbeinite-related red-emitting K2Sc2(MoO4)(PO4)2:Eu phosphors
Authors: Terebilenko Kateryna V. , Nedilko Serhii G. , Chornii Vitalii P. , Prokopets Vadym M. , Slobodyanik Mykola S. , Boyko Volodymyr V.
Published: July 2020

The luminescence properties of K2Sc2(MoO4)(PO4)2:Eu indicate that these ceramics can be potential candidates for UV-based lighting applications as red phosphors.
Synthesis and anti-osteoporosis activity of novel Teriparatide glycosylation derivatives
Authors: Wang Nan , Li Jingyang , Song Hui , Liu Chao , Hu Honggang , Liao Hongli , Cong Wei
Published: July 2020

N-Acetyl glucosamine glycosylation of Teriparatide achieves enhanced helicity, greater protease stability and increased osteoblast differentiation promoting ability.
Lilypad aggregation: localised self-assembly and metal sequestration at a liquid–vapour interface
Authors: Jones Christopher D. , Lewis Aled R. , Jones Daniel. R. , Ottley Christopher J. , Liu Kaiqiang , Steed Jonathan W.
Published: July 2020

Lilypad aggregates are localised spheroidal soft materials formed by the non-equilibrium self-assembly of colloids at a liquid–vapour interface.
Reductive radical-initiated 1,2-C migration assisted by an azidyl group
Authors: Zhang Xueying , Zhang Zhansong , Song Jin-Na , Wang Zikun
Published: July 2020

We report here a novel reductive radical-polar crossover reaction that is a reductive radical-initiated 1,2-C migration of 2-azido allyl alcohols enabled by an azidyl group.
Sustainable development of vanadium pentoxide carbon composites derived from Hibiscus sabdariffa family for application in supercapacitors
Authors: Ngom B. D. , Ndiaye N. M. , Sylla N. F. , Mutuma B. K. , Manyala N.
Published: July 2020

For the future development of environmentally friendly and sustainable electrode materials, herein, novel orthorhombic vanadium pentoxide@carbon composites (V2O5@C–WHS, V2O5@C–R1HS and V2O5@C–R2HS) were synthesized via a green solvothermal process.
Disposable multiplexed electrochemical sensors based on electro-triggered selective immobilization of probes for simultaneous detection of DNA and proteins
Authors: Fan Jinlong , Tang Ying , Yang Weiwei , Yu Yongsheng
Published: July 2020

Electrically addressable covalent immobilization of probes on a multiplexed electrode for the simultaneous detection of multiple targets within the same sample.
A highly sensitive piezoresistive sensor with interlocked graphene microarrays for meticulous monitoring of human motions
Authors: Cheng Lin , Qian Wei , Wei Lei , Zhang Hengjie , Zhao Tingyu , Li Ming , Liu Aiping , Wu Huaping
Published: July 2020

A flexible piezoresistive sensor based on interlocked graphene microarrays displays adjustable piezoresistance by changing the contact way of the graphene microarrays.
Circular RNA circFGD4 suppresses gastric cancer progression via modulating miR-532-3p/APC/β-catenin signalling pathway
Authors: Dai Xinglong , Liu Jianjun , Guo Xiong , Cheng Anqi , Deng Xiaoya , Guo Liqun , Wang Ziwei
Published: July 2020

Background: Mounting evidence has displayed critical roles of circular RNAs (circRNAs) in multiple cancers. The underlying mechanisms by which circFGD4 contributed to gastric cancer (GC) are still unclear.

Methods: The levels and clinical values of circFGD4 in GC patients were detected and analysed by quantitative real-time PCR. The biological roles of circFGD4 in GC were assessed in vitro and in vivo experiments. Dual-luciferase reporter, fluorescence in situ hybridization, RNA immunoprecipitation, biotin-coupled RNA pull-down, and TOP/Flash and FOP/Flash reporter gene assays were employed to evaluate the effects of circFGD4 on miR-532-3p-mediated adenomatous polyposis coli (APC)/β-catenin signalling in GC cells.

Results: circFGD4 expression was down-regulated the most in human GC tissues and cell lines. Low expression of circFGD4 was correlated with poor tumour differentiation, lymphatic metastasis, and poor prognosis of GC patients. circFGD4 suppressed GC cell viability, colony formation, migration, induced epithelial–mesenchymal transition (EMT), and tumorigenesis and metastasis in vivo. Next, we validated that circFGD4 acted as a sponge of miR-532-3p to relieve the tumour-promoting effects of miR-532-3p on its target APC. The mechanistic analysis demonstrated that the circFGD4 suppressed GC cell viability, migration, and EMT by modulating the miR-532-3p/APC axis to inactivate the β-catenin signalling.

Conclusion: circFGD4 suppressed GC progression through sponging miR-532-3p and enhancing APC expression to inactivate the β-catenin signalling. Thus circFGD4 provides a novel potential biomarker and valuable therapeutic strategy for GC.
Vision‐based map building and path planning method in unmanned air/ground vehicle cooperative systems
Authors: a'Xing Xi , Jin Zhao , Haolong Fu , Tao Zhou , Dongjie Liu
Published: July 2020

To reduce the casualties and improve the efficiency of robot, unmanned air/ground vehicle (UAV/UGV) cooperative systems are proposed. In this study, mathematical algorithms are applied in a typical‐rescue scenario. As a ‘flying eye’, the UAV provided the global information by vision sensor. Then, the images were processed with SURF algorithm and image binarisation to model the environment. Based on the UAV's information, the optimised A* algorithm was proposed. Finally, a feasible path was designed for UGV to rescue. Experiments are performed to evaluate the performances of the proposed method. Results show that SURF algorithm and image binarisation can realise the accuracy and robustness of map building. The optimised A* algorithm can provide a real‐time and feasible path.
Chinese cursive character detection method
Authors: Qin Xiao , Jiang Jianhui , Fan Wei , Yuan Changan
Published: July 2020

Chinese is a widely used language in the world. Chinese cursive script is one of the most distinctive calligraphy art and traditional cultures of China. However, for its connected writing, there is a lack of research on text recognition for cursive images. Here, the authors construct a small cursive image dataset named as Chinese Cursive and there are 523 images in this dataset. It contains continuous strokes text, recognises difficulty etc. Each cursive character is corresponded to a label. The authors proposed a cursive detection method named as SE‐seglink for the dataset. The SE‐seglink further enhances the image feature extraction. Compared to the existing methods, the SE‐seglink performs better in recognising cursive scripts and improves the precision of text detection in cursive images. After multiple sets of comparative experiments, the effectiveness of the SE‐seglink method was evaluated by the experiment on the benchmark image dataset ICDAR2015.
Broad-line type Ic SN 2020bvc
Authors: Izzo L. , Auchettl K. , Hjorth J. , De Colle F. , Gall C. , Angus C. R. , Raimundo S. I. , Ramirez-Ruiz E.
Published: July 2020

Long-duration gamma-ray bursts (GRBs) are almost unequivocally associated with very energetic, broad-line supernovae of Type Ic-BL. While the gamma-ray emission is emitted in narrow jets, the SN emits radiation isotropically. Therefore, it has been hypothesized that some SN Ic-BL not associated with GRBs arise from events with inner engines such as off-axis GRBs or choked jets. Here we present observations of the nearby (d = 120 Mpc) SN 2020bvc (ASAS-SN 20bs) that support this scenario.Swift-UVOT observations reveal an early decline (up to two days after explosion), while optical spectra classify it as a SN Ic-BL with very high expansion velocities (≈70 000 km s−1), similar to that found for the jet-cocoon emission in SN 2017iuk associated with GRB 171205A. Moreover, theSwiftX-Ray Telescope and CXO X-ray Observatory detected X-ray emission only three days after the SN and decaying onward, which can be ascribed to an afterglow component. Cocoon and X-ray emission are both signatures of jet-powered GRBs. In the case of SN 2020bvc, we find that the jet is off axis (by ≈23 degrees), as also indicated by the lack of early (≈1 day) X-ray emission, which explains why no coincident GRB was detected promptly or in archival data. These observations suggest that SN 2020bvc is the first orphan GRB detected through its associated SN emission.
The flux-weighted gravity-luminosity relation of Galactic classical Cepheids
Authors: Groenewegen M. A. T.
Published: July 2020

The flux-weighted gravity-luminosity relation (FWGLR) is investigated for a sample of 477 classical Cepheids (CCs), including stars that have been classified in the literature as such but are probably not. The luminosities are taken from the literature, based on the fitting of the spectral energy distributions (SEDs) assuming a certain distance and reddening. The flux-weighted gravity (FWG) is taken from gravity and effective temperature determinations in the literature based on high-resolution spectroscopy. There is a very good agreement between the theoretically predicted and observed FWG versus pulsation period relation that could serve in estimating the FWG (and log g) in spectroscopic studies with a precision of 0.1 dex. As was known in the literature, the theoretically predicted FWGLR relation for CCs is very tight and is not very sensitive to metallicity (at least for LMC and solar values), rotation rate, and crossing of the instability strip. The observed relation has a slightly different slope and shows more scatter (0.54 dex). This is due both to uncertainties in the distances and to the pulsation phase averaged FWG values. Data from future Gaia data releases should reduce these errors, and then the FWGLR could serve as a powerful tool in Cepheid studies.
A hydrodynamical halo model for weak-lensing cross correlations
Authors: Mead A. J. , Tröster T. , Heymans C. , Van Waerbeke L. , McCarthy I. G.
Published: July 2020

On the scale of galactic haloes, the distribution of matter in the cosmos is affected by energetic, non-gravitational processes, the so-called baryonic feedback. A lack of knowledge about the details of how feedback processes redistribute matter is a source of uncertainty for weak-lensing surveys, which accurately probe the clustering of matter in the Universe over a wide range of scales. We developed a cosmology-dependent model for the matter distribution that simultaneously accounts for the clustering of dark matter, gas, and stars. We informed our model by comparing it to power spectra measured from theBAHAMASsuite of hydrodynamical simulations. In addition to considering matter power spectra, we also considered spectra involving the electron-pressure field, which directly relates to the thermal Sunyaev-Zel’dovich (tSZ) effect. We fitted parameters in our model so that it can simultaneously model both matter and pressure data and such that the distribution of gas as inferred from tSZ has an influence on the matter spectrum predicted by our model. We present two variants, one that matches the feedback-induced suppression seen in the matter–matter power spectrum at the percent level and a second that matches the matter–matter data to a slightly lesser degree (≃2%). However, the latter is able to simultaneously model the matter–electron pressure spectrum at the ≃15% level. We envisage our models being used to simultaneously learn about cosmological parameters and the strength of baryonic feedback using a combination of tSZ and lensing auto- and cross-correlation data.
A dynamical and radiation semi-analytical model of pulsar-star colliding winds along the orbit: Application to LS 5039
Authors: Molina E. , Bosch-Ramon V.
Published: July 2020

Context.Gamma-ray binaries are systems that emit nonthermal radiation peaking at energies above 1 MeV. One proposed scenario to explain their emission consists of a pulsar orbiting a massive star, with particle acceleration taking place in shocks produced by the interaction of the stellar and pulsar winds.

Aims.We develop a semi-analytical model of the nonthermal emission of the colliding-wind structure, which includes the dynamical effects of orbital motion. We apply the model to a general case and to LS 5039.

Methods.The model consists of a one-dimensional emitter, the geometry of which is affected by Coriolis forces owing to orbital motion. Two particle accelerators are considered: one at the two-wind standoff location and the other one at the turnover produced by the Coriolis force. Synchrotron and inverse Compton emission is studied taking into account Doppler boosting and absorption processes associated to the massive star.

Results.If both accelerators are provided with the same energy budget, most of the radiation comes from the region of the Coriolis turnover and beyond, up to a few orbital separations from the binary system. Significant orbital changes of the nonthermal emission are predicted in all energy bands. The model allows us to reproduce some of the LS 5039 emission features, but not all of them. In particular, the MeV radiation is probably too high to be explained by our model alone, the GeV flux is recovered but not its modulation, and the radio emission beyond the Coriolis turnover is too low. The predicted system inclination is consistent with the presence of a pulsar in the binary.

Conclusions.The model is quite successful in reproducing the overall nonthermal behavior of LS 5039. Some improvements are suggested to better explain the phenomenology observed in this source, such as accounting for particle reacceleration beyond the Coriolis turnover, unshocked pulsar wind emission, and the three-dimensional extension of the emitter.
A proto-helium white dwarf stripped by a substellar companion via common-envelope ejection
Authors: Irrgang A. , Geier S. , Heber U. , Kupfer T. , El-Badry K. , Bloemen S.
Published: July 2020

In the past, SDSS J160429.12+100002.2 wass spectroscopically classified as a blue horizontal branch (BHB) star. Assuming a luminosity that is characteristic of BHB stars, the object’s radial velocity and proper motions from Gaia Early Data Release 3 would imply that its Galactic rest-frame velocity exceeds its local escape velocity. Consequently, the object would be considered a hypervelocity star, which would prove particularly interesting because its Galactic trajectory points in our direction. However, based on the spectroscopic analysis of follow-up observations, we show that the object is actually a short-period (P ≈ 3.4 h) single-lined spectroscopic binary system with a visible B-type star (effective temperature Teff = 15 840 ± 160 K and surface gravity log(g) = 4.86 ± 0.04) that is less luminous than typical BHB stars. Accordingly, the distance of the system is lower than originally thought, which renders its Galactic orbit bound to the Galaxy. Nevertheless, it is still an extreme halo object on a highly retrograde orbit. The abundances of He, C, N, O, Ne, Mg, Al, Si, S, and Ca are subsolar by factors from 3 to more than 100, while Fe is enriched by a factor of about 6. This peculiar chemical composition pattern is most likely caused by atomic diffusion processes. Combining constraints from astrometry, orbital motion, photometry, and spectroscopy, we conclude that the visible component is an unevolved proto-helium white dwarf with a thin hydrogen envelope that was stripped by a substellar companion through common-envelope ejection. Its unique configuration renders the binary system an interesting test bed for stellar binary evolution in general and common-envelope evolution in particular.
Local feedback stabilization of time-periodic evolution equations by finite dimensional controls
Authors: Badra Mehdi , Mitra Debanjana , Ramaswamy Mythily , Raymond Jean-Pierre
Published: July 2020

We study the feedback stabilization around periodic solutions of parabolic control systems with unbounded control operators, by controls of finite dimension. We prove that the stabilization of the infinite dimensional system relies on the stabilization of a finite dimensional control system obtained by projection and next transformedviaits Floquet-Lyapunov representation. We emphasize that this approach allows us to define feedback control laws by solving Riccati equations of finite dimension. This approach, which has been developed in the recent years for the boundary stabilization of autonomous parabolic systems, seems to be totally new for the stabilization of periodic systems of infinite dimension. We apply results obtained for the linearized system to prove a local stabilization result, around periodic solutions, of the Navier-Stokes equations, by finite dimensional Dirichlet boundary controls.
Aeolus L2 Activities at KNMI
Authors: Donovan D. P. , Marseille Gert-Jan , de Kloe Jos , Stoffelen Ad
Published: July 2020

KNMI has had a long involvement with the recently launched Aeolus mission. Aeolus is an ESA Earth-Explorer mission and embarks the Atmospheric Laser Doppler Instrument (ALADIN). ALADIN is the first space-borne Doppler Wind Lidar (DWL) and was successfully launched in late August 2018. KNMI has had a long association with this mission and is sharing the software development of the L2B processor used to generate L2B wind products at ECMWF, develops related scene classification algorithms and performs calibration/validation activities. In addition, KNMI conducts more fundamental work for improving the retrieval of atmosphere optical properties, taking into account multiple scattering effects.
ESA’s Lidar Missions Aeolus and EarthCARE
Authors: Kanitz Thomas , Ciapponi Alessandra , Mondello Alessia , D’Ottavi Alessandro , Mateo Ana Baselga , Straume Anne-Grete , Voland Christoph , Bon Didier , Checa Elena , Alvarez Emilio , Bellucci Ida , Do Carmo Joao Pereira , Brewster John , Marshall Jon , Schillinger Marc , Hannington Mark , Rennie Michael , Reitebuch Oliver , Lecrenier Olivier , Bravetti Paolo , Sacchieri Valentina , De Sanctis Valeria , Lefebvre Alain , Parrinello Tommaso , Wernham Denny
Published: July 2020

ESAs Earth Explorer Aeolus was launched in August 2018. Aboard the first spaceborne wind lidar ALADIN (Atmospheric LAser Doppler INstrument) was switched on in early September 2018 and demonstrated the capability to provide atmospheric wind profiles globally from particle and molecular backscatter. In doing so, it will contribute to the improvement in numerical weather prediction (NWP) and the understanding of global dynamics. At the same, it is a major step for powerful and frequency stabilized ultraviolet (UV) lasers for space applications. In parallel, ESA and its partners continue the development of this technology by setting up further ground tests based on Aeolus, and preparing the next milestone with ATLID (ATmospheric LIDar) for the Earth Cloud, Aerosol and Radiation Explorer (EarthCARE) mission. ATLID is currently fully integrated and getting prepared for its on-ground testing.
Laser Remote Sensors for NASA’s Future Earth and Space Science Missions
Authors: Singh Upendra N.
Published: July 2020

Active optical (Laser/Lidar) measurement techniques are critical for the future National Aeronautics and Space Administration (NASA) Earth, Planetary Science, Exploration, and Aeronautics measurements. The latest science decadal surveys recommend a number of missions requiring active optical systems to meet the science measurement objectives and the aeronautics community continues to use Laser/Lidar technologies to meet the aeronautics measurement objectives. This presentation will provide an overview of NASA efforts in developing and maturing state-of-the-art advanced solid-state flight laser/lidar systems for airborne and space-borne remote sensing measurements. The presentation will also provide details of a strategic approach for active optical technologies and techniques to meet the NASA’s future Earth and Space Science measurements/missions needs and requirements for space-based applications.
Lidar Concept of “Guanlan” Mission for Space Oceanography
Authors: Wu Songhua , Chen Weibiao , Tang Junwu , Zhao Chaofang , Chen Ge
Published: July 2020

Among the various challenges in spaceborne radar observation of the ocean, the following two issues are probably of a higher priority: inadequate dynamic resolution, and ineffective vertical penetration. Two highly anticipated breakthroughs in the coming decade are likely to be associated with radar interferometry and ocean lidar technology, which are expected to make a substantial contribution to a sub-mesoscale-resolving and depth-resolving observation of the ocean. The planned “Guanlan” science mission comprises a dual-frequency (Ku and Ka) interferometric altimetry (IA) and a near-nadir pointing ocean lidar (OL). The spaceborne active OL will ensure a deeper penetration depth and an all-time detection which leads to a layered characterization of the optical properties of the subsurface ocean. The simultaneous functioning of the OL and a dual-frequency (Ku and Ka) interferometric altimetry system will allow an enhanced understanding of contributions of the atmosphere and the air-sea interface which in turn considerably reduce the error budgets of the two sensors. The OL payload is expected to partially reveal the marine food chain and ecosystem with 10-m vertical interval in the euphotic layer, moving a significant step down to the oceanic mixed layer both dynamically and bio-optically.
MCT APD Detection System for Atmospheric Profiling Applications Using Two-Micron Lidar
Authors: Refaat Tamer F. , Petros Mulugeta , Remus Ruben , Singh Upendra N.
Published: July 2020

An advanced detection system, based on mercury cadmium telluride avalanche photodiodes array, was implemented within a 2-μm lidar. Detection system characterization was conducted for performance evaluation including settling time, noise-equivalent-power (NEP) and dynamic range. Results indicated an average NEP of 1.4 fW/Hz1/2 per pixel. Lidar range resolved profiling demonstrated the dynamic range capability by measuring near-field aerosol scattering and far-field clouds reflection simultaneously.
Particulate Optical Properties in the Mediterranean and Black Seas Through Calipso Spaceborne Lidar Measurements
Authors: Dionisi Davide , Brando Vittorio , Volpe Gianluca , Colella Simone , Santoleri Rosalia
Published: July 2020

New applications on global-scale plankton retrievals using the CALIOP (Cloud-Aerosol Lidar with orthogonal Polarization) lidar measurements on the CALIPSO (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations) satellite recently suggested that space-based lidars could provide information about the depth distribution of optical scattering. Assessing the oceanic surface layer’s optical properties through CALIOP is one of the reasons of the extension of the CALIOP mission for another 3 years (2018-2020). The objective of this work is the evaluation of the potential CALIOP ocean products in the Mediterranean and Black seas using the ocean color products provided by the Copernicus Marine Environment Monitoring Systems (CMEMS).
Rayleigh Wind Retrieval for the Aladin Airborne Demonstrator of the Aeolus Mission Using Simulated Response Calibration
Authors: Zhai Xiaochun , Marksteiner Uwe , Weiler Fabian , Lemmerz Christian , Lux Oliver , Witschas Benjamin , Reitebuch Oliver
Published: July 2020

Aeolus, launched on 22 August 2018, is the first ever satellite to directly observe wind information from space on a global scale. An airborne prototype called ALADIN Airborne Demonstrator (A2D) was developed at the German Aerospace Center (DLR) for validating the Aeolus measurement principle based on realistic atmospheric signals. However, atmospheric and instrumental variability currently limit the reliability and repeatability of the A2D instrument response calibration. In this study, a simulated Rayleigh response calibration (SRRC) is presented for resolving the limitations of A2D instrument response calibration.
Research on the Control Point Extraction Method of Chinese Gaofen 7 Satellite Using Altimeter and Footprint Camera
Authors: Li Binbin , Xie Huan , Tong Xiaohua , Cai Yinqiao , Zhang Zhijie
Published: July 2020

Satellite laser altimetry is one of the most advanced information acquisition technologies in Earth observation system. It can provide high-accuracy elevation information, however, due to the lack of detail intensity information, its planimetric accuracy is usually worse than the elevation accuracy. Gaofen 7 (GF-7) satellite scheduled for launch in 2019 will be equipped with laser altimeter, footprint camera, stereo mapping camera, etc. The laser altimeter together with the footprint camera was designed to provide high accuracy ground control point of satellite mapping. The laser altimeter can provide the high-accuracy elevation information and the joint processing of footprint camera and stereo mapping camera can provide high-accuracy planimetric information. Therefore, this paper mainly studies the technology of extracting high-accuracy control points based on GF-7 satellite’s altimeter, footprint camera and stereo mapping camera using a simulated dataset extracted from Quickbird image and ICESat altimetric data.
Aerosol Investigation During the Arctic Haze Season of 2018: Optical and Hygroscopic Properties
Authors: Müller Kim Janka , Ritter Christoph , Nakoudi Konstantina
Published: July 2020

In the beginning of March 2018, Lidar measurements were performed on Svalbard, Arctic Ocean, in order to analyse the optical and hygroscopic properties of Arctic aerosol. In this study, aerosol backscatter showed signiﬁcant higher values in lower altitudes. The analysis of the Colour Ratio (CR) revealed smaller particles in lower altitudes, with larger particles appearing only above Investigation of the hygroscopic character was done by applying the growth parameter introduced by Gassó et al. (2000). It was found that the method of Zieger et.al. (2010) can be successfully extended to backscatter and CR data from Lidar measurements. Ice nucleation was examined in ice supersaturation conditions, with no ice cloud formation observed. This indicated that the role of Arctic aerosol as ice nuclei is still a poorly understood issue.
Airborne Pollen Observed by PollyXT Raman Lidar at Finokalia, Crete
Authors: Shang Xiaoxia , Bohlmann Stephanie , Filioglou Maria , Giannakaki Elina , Pitkänen Mikko R.A. , Saarto Annika , Amiridis Vassilis , Kanakidou Maria , Komppula Mika
Published: July 2020

In order to document and study airborne pollen in the Mediterranean region, a pollen measurement campaign was performed during February-May 2018, at the Finokalia station in Crete. A ground-based multi-wavelength Raman polarization lidar PollyXT performed continuous measurements, together with a Hirst-type Burkard pollen sampler. The optical properties of pollen layers with presence of airborne pollen are retrieved and presented. Dust-free condition is applied for pollen study, using the dust models.
Analysis of a Pollution Transmission Process in Hefei City Based on Mobile Lidar
Authors: Zhang Shuai , Zhou Zhaoming , Ye Conglei , Shi Jibing , Wang Peng , Liu Dong
Published: July 2020

The air pollution has been regional in China with the development of economy. To monitoring the air pollution transmission, a new technique, mobile lidar system (GBQ-S01), was introduced. In this paper, a pollution transmission process happened on October 26th, 2017, was analyzed with the use of mobile lidar, air quality monitoring stations data, and Hysplit backward trajectories. The results showed that the polluted air mass was transferred from northeast under the force of air pressure. Under the influences of air pollution transmission and bad meteorological diffusion conditions, The PM10 quality concentrations in Hefei increased a lot within 5 hours; among all the 10 national air quality monitoring stations, the Luyang District (the northernmost one) and Changjiang Middle Road (the easternmost one) received the most serious impact with PM10 concentration reached up to 252 μg/m3 and 219 μg/m3 at 22:00 (Beijing Time).
Application of Regularization Algorithm to HSRL-2 Observations During Oracles Campaign: Comparison of Retrieved and In Situ Particle Size Distributions and Single Scattering Albedo
Authors: Kolgotin Alexei , Veselovskii Igor , Korenskiy Mikhail , Müller Detlef
Published: July 2020

Data obtained from HSRL-2 observations carried out on 20 September 2016 during the ORACLES campaign are publicly accessible. In our presentation we invert 3β+2α data into (1) particle size distributions with a regularization algorithm, and subsequently compute (2) single scattering albedo. We carry out a first comparison to the same particle characteristics measured with airborne in-situ instruments. We find good agreement of the data products. However, a more detailed study is needed as correction factors and sources of retrieval and measurement uncertainties need to be tested.