bluuebunny/crossref_metadata_2025 huggingface dataset:
In Vitro Polyploidization of Brassolaeliocattleya Hybrid Orchid
Authors: Vilcherrez-Atoche Joe Abdul , Silva Jéssica Coutinho , Clarindo Wellington Ronildo , Mondin Mateus , Cardoso Jean Carlos
Published: January 2023

The Cattleya (Orchidaceae–Laeliinae subtribe) intergeneric hybrids, such as Brassolaeliocattleya (Blc.), have great ornamental value, due to their compact-size, with large and high color diversity of flowers. Artificial induction of polyploidy brings agronomic, ornamental and genetic benefits to plants. Polyploidization efficiency depends on factors, such as the type of antimitotic, polyploidization method, concentrations, exposure times and type of explant. This study aimed to develop a protocol to polyploidize Blc. orchids, by testing two types of explants (seeds and protocorms), concentrations and exposure times to colchicine. The effects of colchicine on the in vitro development of explants were also investigated. The responses of explants to colchicine depended on the concentrations, exposure time and the interaction of these factors. Flow cytometric analysis evidenced high endopolyploidy and allowed the separation of polyploidized (4C, 8C and 16C peaks) from non-polyploidized (only 2C and 4C peaks) plants. The highest percentage of polyploid plants was regenerated from protocorms (16.4%) treated with colchicine instead of seeds (3.2%). Protocorms treated with colchicine at 500–750 μM for 18 h resulted in the best percentage of polyploidization. Additionally, in vitro natural polyploidization using protocorms was reported (11.5%). Cytological analyses allowed an estimation of the number of chromosomes of the parents (≡70), polyploidized (≡140) and non-polyploidized progeny (≡70).
Density-Dependent Effects of Simultaneous Root and Floral Herbivory on Plant Fitness and Defense
Authors: Aguirrebengoa Martin , Müller Caroline , Hambäck Peter A. , González-Megías Adela
Published: January 2023

Plants are attacked by multiple herbivores, and depend on a precise regulation of responses to cope with a wide range of antagonists. Simultaneous herbivory can occur in different plant compartments, which may pose a serious threat to plant growth and reproduction. In particular, plants often face co-occurring root and floral herbivory, but few studies have focused on such interactions. Here, we investigated in the field the combined density-dependent effects of root-chewing cebrionid beetle larvae and flower-chewing pierid caterpillars on the fitness and defense of a semiarid Brassicaceae herb. We found that the fitness impact of both herbivore groups was independent and density-dependent. Increasing root herbivore density non-significantly reduced plant fitness, while the relationship between increasing floral herbivore density and the reduction they caused in both seed number and seedling emergence was non-linear. The plant defensive response was non-additive with regard to the different densities of root and floral herbivores; high floral herbivore density provoked compensatory investment in reproduction, and this tolerance response was combined with aboveground chemical defense induction when also root herbivore density was high. Plants may thus prioritize specific trait combinations in response to varying combined below- and aboveground herbivore densities to minimize negative impacts on fitness.
Annotation of the Turnera subulata (Passifloraceae) Draft Genome Reveals the S-Locus Evolved after the Divergence of Turneroideae from Passifloroideae in a Stepwise Manner
Authors: Henning Paige M. , Roalson Eric H. , Mir Wali , McCubbin Andrew G. , Shore Joel S.
Published: January 2023

A majority of Turnera species (Passifloraceae) exhibit distyly, a reproductive system involving both self-incompatibility and reciprocal herkogamy. This system differs from self-incompatibility in Passiflora species. The genetic basis of distyly in Turnera is a supergene, restricted to the S-morph, and containing three S-genes. How supergenes and distyly evolved in Turnera, and the other Angiosperm families exhibiting distyly remain largely unknown. Unraveling the evolutionary origins in Turnera requires the generation of genomic resources and extensive phylogenetic analyses. Here, we present the annotated draft genome of the S-morph of distylous Turnera subulata. Our annotation allowed for phylogenetic analyses of the three S-genes’ families across 56 plant species ranging from non-seed plants to eudicots. In addition to the phylogenetic analysis, we identified the three S-genes’ closest paralogs in two species of Passiflora. Our analyses suggest that the S-locus evolved after the divergence of Passiflora and Turnera. Finally, to provide insights into the neofunctionalization of the S-genes, we compared expression patterns of the S-genes with close paralogs in Arabidopsis and Populus trichocarpa. The annotation of the T. subulata genome will provide a useful resource for future comparative work. Additionally, this work has provided insights into the convergent nature of distyly and the origin of supergenes.
Application of Baltic Pine (Pinus sylvestris) Needle Extract as a Gut Microbiota-Modulating Feed Supplement for Domestic Chickens (Gallus gallus)
Authors: Rubens Juris , Kibilds Juris , Jansons Martins , Piginka-Vjaceslavova Inga , Barene Ilze , Daberte Irena , Liepa Laima , Malniece Aija , Rubens Arturs , Starkute Vytaute , Zokaityte Egle , Ruzauskas Modestas , Bartkiene Elena , Bartkevics Vadims , Pugajeva Iveta
Published: January 2023

The valorization of wood industry residues is very desirable from a circular economy perspective. Pine needle extracts are known for their health-promoting properties and therefore can be used as herbal remedies and nutritional supplements. Since the withdrawal of antibiotics as growth promoters in the European Union, natural feed additives that improve poultry health and production are needed. It was proposed that pine needle extract could be a good alternative to antibiotic usage at sub-therapeutic concentrations. The results relevant to our assumption could be obtained by using domestic chickens as an in vivo model for the evaluation of gut microbiota-altering properties of pine needle extract as an herbal supplement. We tested the antimicrobial effects of Baltic pine (Pinus sylvestris) needle extract. Then, we used chicken (Gallus gallus) that received feed supplemented with two different concentrations of the extract for 40 days to evaluate the changes in gut microbiota using 16S rRNA gene sequencing. This preliminary study demonstrated trends toward dose-dependent desirable changes in broiler microbiome, such as a reduction in the relative abundance of Campylobacter.
Exogenous SA Applications Alleviate Salinity Stress via Physiological and Biochemical changes in St John’s Wort Plants
Authors: Kwon Eun-Hae , Adhikari Arjun , Imran Muhammad , Lee Da-Sol , Lee Chung-Yeol , Kang Sang-Mo , Lee In-Jung
Published: January 2023

The plant St. John’s wort contains high levels of melatonin, an important biochemical that has both beneficial and adverse effects on stress. Therefore, a method for increasing melatonin levels in plants without adversely affecting their growth is economically important. In this study, we investigated the regulation of melatonin levels in St. John’s wort by exposing samples to salinity stress (150 mM) and salicylic acid (0.25 mM) to augment stress tolerance. The results indicated that salinity stress significantly reduced the plant chlorophyll content and damaged the photosystem, plant growth and development. Additionally, these were reconfirmed with biochemical indicators; the levels of abscisic acid (ABA) and proline were increased and the activities of antioxidants were reduced. However, a significant increase was found in melatonin content under salinity stress through upregulation in the relative expression of tryptophan decarboxylase (TDC), tryptamine 5-hydroxylase (T5H), serotonin N-acetyltransferase (SNAT), and N-acetylserotonin methyltransferase (ASMT). The salicylic acid (SA) treatment considerably improved their photosynthetic activity, the maximum photochemical quantum yield (133%), the potential activity of PSⅡ (294%), and the performance index of electron flux to the final PS I electron acceptors (2.4%). On the other hand, SA application reduced ABA levels (32%); enhanced the activity of antioxidant enzymes, such as superoxide dismutase (SOD) (15.4%) and 2,2-diphenyl-1-picrylhydrazyl (DPPH) (120%); and increased polyphenol (6.4%) and flavonoid (75.4%) levels in salinity-stressed St. John’s wort plants. Similarly, SA application under NaCl stress significantly modulated the melatonin content in terms of ion balance; the level of melatonin was reduced after SA application on salt-treated seedlings but noticeably higher than on only SA-treated and non-treated seedlings. Moreover, the proline content was reduced considerably and growth parameters, such as plant biomass, shoot length, and chlorophyll content, were enhanced following treatment of salinity-stressed St. John’s wort plants with salicylic acid. These findings demonstrate the beneficial impact of salt stress in terms of a cost-effective approach to extract melatonin in larger quantities from St. John’s wort. They also suggest the efficiency of salicylic acid in alleviating stress tolerance and promoting growth of St. John’s wort plants.
Can Direct Subsidies or Tax Incentives Improve the R&D Efficiency of the Manufacturing Industry in China?
Authors: Liu Zhen , Zhou Xijun
Published: January 2023

The understanding of the impact of different government support methods on R&D efficiency is of great significance for evaluating the performance of innovation policies in various countries. We selected 31 manufacturing industries in China from 2009 to 2015, used the stochastic frontier analysis (SFA) method to measure R&D efficiency, and used tobit regression method to examine the relationship between direct government subsidies and preferential tax policies and manufacturing R&D efficiency. The results reveal that the overall R&D efficiency of China’s manufacturing industry was low, but it has been steadily increasing, and the R&D efficiency of emerging industries was significantly higher than that of traditional industries. Tax incentives played a stable and significant role in promoting R&D efficiency in manufacturing. Affected by factors such as the government’s long-term preference and information asymmetry, direct subsidies had no significant impact on the current R&D efficiency of the manufacturing industry, and began to play a positive role after a two-year lag. Based on the above research findings, this paper suggests that progressive preferential tax rates can be designed according to the “base + increment” approach for tax preferential policies. At the same time, different proportions of tax cuts should be set for enterprises of different sizes and levels of innovation, and the focus should be on small and medium-sized enterprises and emerging industries. In terms of direct funding subsidies, the government should not only increase the support for basic research, but also give more preference to enterprises that receive tax incentives for research and development, so as to enhance the complementary effect of the two types of subsidy policies. The marginal contribution of this paper mainly includes three aspects: First, based on the Chinese situation, the impact of direct government subsidies and tax incentives on the R&D efficiency of the manufacturing industry is tested. Second, we present the evidence that direct government funding subsidies “crowd out” enterprise R&D funds. Thirdly, we describe the influence of enterprise scale, innovation level, ownership, and management ability on R&D efficiency of the manufacturing industry, and put forward the possible influence mechanism.
Establishment and Application of a Novel Four-Dimensional Model for Simulation of a Natural Water Flooding Reservoir—A Case Study of Nanpu No. 2 Structure in the BHW Basin
Authors: Duan Jian , Zhu Lu , Luo Wanjing
Published: January 2023

Long-term development of fluvial reservoirs causes regular changes in the microscopic pore-throat structure, physical properties and phase permeability curves of the reservoirs, and the evolution history of different oil layer varies. These effects can be explored using a four-dimensional (4D) model of the maturing field. The logging curves of 89 sand bodies of the Nanpu No. 2 structure in the Bohai Bay Basin were restored to the non-water flooded state based on the changing status of water flooding layers at different stages and levels, and an original geological model was established by combining data for the old wells. The time-varying relationship was incorporated in the dynamic model with surface flux as the variable, and the numerical simulation analysis was conducted based on the reservoir time-varying characteristics. The results showed that ① the logging data of the water-flooded layer significantly affected the simulation results of the geological model and can only be used for the establishment of the initial geological model after repositioning of time and space; ② the time variation of reservoir properties and relative permeability markedly affected the simulation results of the remaining oil. Reservoir parameters and fluid properties simulated by the 4D model were consistent with the data of water flooded layers in new wells during different periods; ③ the novel method significantly improved the fitting rate of the dynamic model, and the model was used to quantitatively describe the morphology of dominant seepage channels and reservoir variation parameters. The novel idea of ‘retreat as progress’ and ‘bring in to solve’ achieved the solution of the dynamic and static parameters of the 4D model according to each time step of space-time evolution. The results provide a guide for comprehensive adjustment and evaluation of Nanpu Oilfield for 52 well-times with an oil increase of 1.68 × 104 tons for the different stages.
Dynamic Signature Verification Technique for the Online and Offline Representation of Electronic Signatures in Biometric Systems
Authors: Huang Juanjuan , Xue Yuhang , Liu Linhui
Published: January 2023

Biometric systems input physical or personal human characteristics for identification, authentication, and security purposes. With the advancement in communication and intelligent security systems, biometrics are programmed to validate electronic signatures (E-signatures) for online and offline authentication. This article introduces a dynamic signature verification technique (DSVT) using mutual compliance (MC) between the security system and the biometric device. The security system is responsible for online and offline signature approval using personal inputs from humans. This personal verification is related to the stored online/offline signatures using certificates provided for authentication. The certificate-based authentication is valid within a session for online representation. Contrarily, this authentication is valid for persons under offline conditions. In this mode of segregation, application-level authentication verification is performed. A conventional tree classifier for dynamic signature verification is used for differentiating online and offline signatures. Moreover, the security metrics—such as signing bit, key, and size—are verified for both modes using classifier learning. For the segregated mode, the validation of the above is required to be unanimous to accelerate the dynamicity. The proposed technique’s performance is analyzed using the authentication success rate, verification failing ratio, verification time, and complexity.
Synthesis of 2-DOF Decoupled Rotation Stage with FEA-Based Neural Network
Authors: Ye Tingting , Li Yangmin
Published: January 2023

Transfer printing technology has developed rapidly in the last decades, offering a potential demand for 2-DOF rotation stages. In order to remove decoupling modeling, improve motion accuracy, and simplify the control method, the 2-DOF decoupled rotation stages based on compliant mechanisms present notable merits. Therefore, a novel 2-DOF decoupled rotation stage is synthesized of which the critical components of decoupling are the topological arrangement and a novel decoupled compound joint. To fully consider the undesired deformation of rigid segments, an FEA-based neural network model is utilized to predict the rotation strokes and corresponding coupling ratios, and optimize the structural parameters. Then, FEA simulations are conducted to investigate the static and dynamic performances of the proposed 2-DOF decoupled rotation stage. The results show larger rotation strokes of 4.302 mrad in one-axis actuation with a 1.697% coupling ratio, and 4.184 and 4.151 mrad in two-axis actuation with undesired Rz rotation of 0.014 mrad with fewer actuators than other works. In addition, the first natural frequency of 2151 Hz is also higher, enabling a wider working frequency range.
Is Industry 5.0 a Human-Centred Approach? A Systematic Review
Authors: Alves Joel , Lima Tânia M. , Gaspar Pedro D.
Published: January 2023

Industry 5.0 presents itself as a strategy that puts the human factor at the centre of production, where the well-being of the worker is prioritized, as well as more sustainable and resilient production systems. For human centricity, it is necessary to empower human beings and, respectively, industrial operators, to improve their individual skills and competences in collaboration or cooperation with digital technologies. This research’s main purpose and distinguishing point are to determine whether Industry 5.0 is truly human-oriented and how human centricity can be created with Industry 5.0 technologies. For that, this systematic literature review article analyses and clarifies the concepts and ideologies of Industry 5.0 and its respective technologies (Artificial Intelligence, Robotics, Human-robot collaboration, Digitalization), as well as the strategies of human centricity, with the aim of achieving sustainable and resilient systems, especially for the worker.
Life Cycle Assessment and Its Application in Wastewater Treatment: A Brief Overview
Authors: Rashid Siti Safirah , Harun Siti Norliyana , Hanafiah Marlia M. , Razman Khalisah K. , Liu Yong-Qiang , Tholibon Duratul Ain
Published: January 2023

This paper provides a brief review on wastewater treatment system and the application of life cycle assessment (LCA) for assessing its environmental performance. An extensive review regarding the geographical relevance of LCA for WWTPs, and the evaluation of sustainable wastewater treatment by LCA in both developed and developing countries are also discussed. The objective of the review is to identify knowledge gap, for the improvement of the LCA application and methodology to WWTPs. A total of 35 published articles related to wastewater treatment (WWT) and LCA from international scientific journals were studied thoroughly and summarised from 2006 to 2022. This review found that there is lack of studies concerning LCA of WWTPs that consider specific local criteria especially in the developing countries. Thus, it is important to: (1) assess the influence of seasonality (i.e., dry and wet seasons) on the environmental impact of WWT, (2) investigate environmental impacts from WWTPs in developing countries focusing on the site-specific inventory data, and (3) evaluate environmental sustainability of different processes for upgrading the wastewater treatment system. The environmental impact and cost assessment aspects are crucial for the sustainable development of WWTP. Therefore, environmental impacts must be thoroughly assessed to provide recommendation for future policy and for the water industry in determining environmental trade-offs toward sustainable development.
The Need for Biomarkers in the ALS–FTD Spectrum: A Clinical Point of View on the Role of Proteomics
Authors: Vignaroli Francesca , Mele Angelica , Tondo Giacomo , De Giorgis Veronica , Manfredi Marcello , Comi Cristoforo , Mazzini Letizia , De Marchi Fabiola
Published: January 2023

Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are severely debilitating and progressive neurodegenerative disorders. A distinctive pathological feature of several neurodegenerative diseases, including ALS and FTD, is the deposition of aberrant protein inclusions in neuronal cells, which leads to cellular dysfunction and neuronal damage and loss. Despite this, to date, the biological process behind developing these protein inclusions must be better clarified, making the development of disease-modifying treatment impossible until this is done. Proteomics is a powerful tool to characterize the expression, structure, functions, interactions, and modifications of proteins of tissue and biological fluid, including plasma, serum, and cerebrospinal fluid. This protein-profiling characterization aims to identify disease-specific protein alteration or specific pathology-based mechanisms which may be used as markers of these conditions. Our narrative review aims to highlight the need for biomarkers and the potential use of proteomics in clinical practice for ALS–FTD spectrum disorders, considering the emerging rationale in proteomics for new drug development. Certainly, new data will emerge in the near future in this regard and support clinicians in the development of personalized medicine.
Models of Humanism in Ancient China: An Explanation Centered on Early Confucian Ethics
Authors: Rošker Jana S.
Published: January 2023

In China, humanism, especially within the framework of Confucian ethics, developed quite differently from humanist discourses in Europe. Therefore, it is important to understand the origins and development of Confucian ideas that place human beings at the center of culture and the cosmos. Through the lens of the cultural particularities of humanism, this knowledge can help us gain a more complex and multi-layered insight into the universal factors that make up human nature. This paper critically examines the foundations, development, and distinctive features of traditional Chinese humanism, which emerged within the framework of classical Confucian teachings. Beginning with an analysis of the Confucian view of the relationship between the individual and society, the author explains the conceptual origin and historical development of various models of humanism in the Chinese tradition. The paper then sheds light on the reasons for the transition from religions to humanities that took place in China during the Axial Age, and highlights various implications of this transition manifested in Confucian ethics and its search for a better social order.
Religious Symbolism and the Experience of Life as Meaningful: Addition, Enhancement, or Both?
Authors: Barrett Nathaniel F.
Published: January 2023

This paper explores the question of how religious symbolism functions to provide a more meaningful or enriched experience of life. It examines a common and highly influential view, referred to here as the “source model”, for which this function requires the addition to experience of transcendent meanings generated by rituals and other specially adapted kinds of symbolic activity. Using Robert Bellah’s Religion in Human Evolution and Clifford Geertz’s “Religion as a Cultural System” as representative examples, I critique a key premise of the source model, namely that the meaning-making function of religious symbolism evolved in response to a universal experience of life as problematic. I argue that the experience of life as problematic is a product of symbolism, not a precondition. Moreover, with respect to this experience, I propose that symbolism functions not to add meaning but to enhance meanings that are vaguely discerned in everyday life. I close with the suggestion that an enhanced experience of life as problematic is itself a kind of enriched meaning and an important source of the affective power of religious practice.
Risk Measures in Simulation-Based Business Valuation: Classification of Risk Measures in Risk Axiom Systems and Application in Valuation Practice
Authors: Ernst Dietmar
Published: January 2023

Simulation-based company valuations are based on an analysis of the risks in the company to be valued. This means that risk analysis is decisively important in a simulation-based business valuation. The link between risk measures, risk conception and risk axiom systems has not yet been sufficiently elaborated for simulation-based business valuations. The aim of this study was to determine which understanding of risk underlies simulation-based business valuations and how this can be implemented via suitable risk measures in simulation-based business valuations. The contribution of this study is providing guidance for the methodologically correct selection of appropriate risk measures. This will help with avoiding valuation errors. To this end, the findings were combined from risk axiom systems with the valuation equations of simulation-based business valuations. Only position-invariant risk measures are suitable for simulation-based business valuations.
Analysis of Yields and Their Determinants in the European Corporate Green Bond Market
Authors: Grishunin Sergei , Bukreeva Alesya , Suloeva Svetlana , Burova Ekaterina
Published: January 2023

The green bond market helps to mobilize financial sources toward sustainable investments. Green bonds are similar to conventional bonds but are specifically designed to raise money to finance environmental projects. The feature of green bonds is the existence of greenium, or the lower yield compared to “conventional” bonds of the same risk. The relevance of the paper is underpinned by the mixed evidence on the existence of ‘greenium’, especially in corporate green bond markets; there has been limited research on the topic and a narrow focus on global, US, or Chinese green bond markets. Instead, the greenium in European debt markets remains underexplored. The objective of this study is to investigate the existence of greenium and its key determinants in European corporate debt capital markets, including the local markets of the United Kingdom (UK), France, Netherlands, and Germany. The sample included 3851 corporate bonds, both green and conventional ones, between 2007 and 2021 from 33 European countries. Linear regression was applied for the analysis. The results show that the climate corporate bonds in Europe are priced at a discount to the same-risk conventional corporate bonds. The magnitude of greenium is around 3 bps. Determinants of greenium include the presence of an ESG rating and belonging to the utility and financial industry. The remaining drivers of bond yields in the European corporate debt market are the credit quality (expressed by the level of credit rating), the coupon size, the bond tenor, the market liquidity, and macroeconomic variables (growth of gross domestic product and consumer price index). For the local corporate debt markets, our results are controversial. In all markets under consideration except for the UK and the Netherlands, we did not find sustainable evidence of greenium. The results of the research lead to a better understanding of the green bond market for investors, researchers, regulators, and potential issuing companies.
High-Resolution Humidity Observations Based on Commercial Microwave Links (CML) Data—Case of Tel Aviv Metropolitan Area
Authors: Rubin Yoav , Sohn Shira , Alpert Pinhas
Published: January 2023

The humidity in the atmosphere plays a crucial role in a wide range of atmospheric processes determined by the water-vapor concentration in the air. The accuracy of weather forecasts is largely dictated by the humidity field measured at low atmospheric levels. At the near-surface level, the absolute humidity variations can be large due to the variability of land cover (LC). Cities are one of the primary LCs which have a substantial impact on the humidity field. Large urban areas are expanding, causing a significant change in the near-surface humidity field. Current measurement tools, however, do not satisfactorily assess the cities’ effects on the humidity field. This paper presents an innovative method for high-resolution humidity measurements based on the cellular network. Here, the humidity field around Tel Aviv was retrieved from the cellular network during the summer of 2017. The results show a well-noticed impact of the city and other LC types on the humidity field over the Tel Aviv metropolitan area. The method presented here can offer an improved description of the humidity field at the city-canopy level and therefore provide a better assessment of the urban/LC effects on the environment, atmospheric modeling, and particularly on clouds/rain development.
Estimating Nighttime PM2.5 Concentration in Beijing Based on NPP/VIIRS Day/Night Band
Authors: Deng Jianqiong , Qiu Shi , Zhang Yu , Cui Haodong , Li Kun , Cheng Hongjia , Liu Zhaoyan , Dou Xianhui , Qian Yonggang
Published: January 2023

Nighttime PM2.5 detection by remote sensing can expand understanding of PM2.5 spatiotemporal patterns due to wider coverage compared to ground monitors and by supplementing traditional daytime detection. However, using remote sensing data to invert PM2.5 at night is still challenging. Compared with daytime detection, which operates on sunlight, nighttime detection operates on much weaker moonlight and artificial light sources, complicating signal extraction. Moreover, as the attempts to sense PM2.5 remotely using satellite data are relatively recent, the existing nighttime models are still not mature, overlooking many important factors such as stray light, seasonality in meteorological effects, and observation angle. This paper attempts to improve the accuracy of nighttime PM2.5 detection by proposing an inversion model that takes these factors into consideration. The Visible Infrared Imaging Radiometer Suite/Day/Night Band (VIIRS/DNB) on board the polar-orbiting Suomi National Polar-orbiting Partnership (Suomi NPP) and National Oceanic Atmospheric Administration-20 (NOAA-20) was used to establish a nighttime PM2.5 inversion model in the Beijing area from 1 March 2018 to 28 February 2019. The model was designed by first studying the effects of these factors through a stepwise regression, then building a multivariate regression model to compensate for these effects. The results showed that the impact of satellite viewing zenith angle (VZA) was strongest, followed by seasonality and moonlight. Total accuracy was measured using correlation coefficient (R) compared to ground measurements, achieving 0.87 over the urban area and 0.74 over the suburbs. Specifically, the proposed method works efficiently at subsatellite points, which in this case correspond to VZA from 0 and 5°. In spring, summer, autumn, and winter, the R reached 0.95, 0.93, 0.94, and 0.97 at subsatellite points in the urban area, while it was 0.88, 0.82, 0.85, and 0.77 in the suburbs.
Spatiotemporal Characteristics of the Mud Receiving Area Were Retrieved by InSAR and Interpolation
Authors: Hu Bo , Qiao Zhongya
Published: January 2023

The mud receiving area is an important sand storage area for dredging sea sand reclamation and sand-dumping in the waterway. The sediment accumulation area generated in the process of sand dumping and sand storage has an impact on the surrounding transportation facilities and the normal use of the entire sand storage area. From 6 August 2021 to 9 May 2022, The Sentinel-1A 24-view SLC data covering the sludge area were used to monitor the safety around the seawall road by InSAR technology. Synthetic aperture radar differential interferometry (Differential InSAR, D-InSAR) technology can obtain surface micro deformation information through single-time differential interference processing, mainly used for sudden surface deformation. D-InSAR technology detected five accumulation areas with a thickness of more than 10 cm near the seawall road, earth embankment, and cofferdam, and TS-InSAR (Time series InSAR) technology was used to retrieve the deformation of the surrounding road. The road settlement is a slight settlement distributed between ±5 mm/a. This paper uses the leveling results combined with variance analysis to verify the fusion of different TS-InSAR methods while considering the area of data loss due to causes such as loss of coherence. This paper also considers the common ground continuity and uses the adjacent interpolation and bilinear interpolation algorithm to improve knowledge of the study area seawall road and the surrounding soil embankment deformation data of the road. Compared with the leveling data, the difference between the missing data and the leveling data after interpolation is stable at about 1–7 mm, which increases the risk level of part of the road which needs to be maintained. It provides a reference method to make up for the missing data caused by ground incoherence.
Forcing Mechanisms of the Interannual Sea Level Variability in the Midlatitude South Pacific during 2004–2020
Authors: Germineaud C. , Volkov D. L. , Cravatte S. , Llovel W.
Published: January 2023

Over the past few decades, the global mean sea level rise and superimposed regional fluctuations of sea level have exerted considerable stress on coastal communities, especially in low-elevation regions such as the Pacific Islands in the western South Pacific Ocean. This made it necessary to have the most comprehensive understanding of the forcing mechanisms that are responsible for the increasing rates of extreme sea level events. In this study, we explore the causes of the observed sea level variability in the midlatitude South Pacific on interannual time scales using observations and atmospheric reanalyses combined with a 1.5 layer reduced-gravity model. We focus on the 2004–2020 period, during which the Argo’s global array allowed us to assess year-to-year changes in steric sea level caused by thermohaline changes in different depth ranges (from the surface down to 2000 m). We find that during the 2015–2016 El Niño and the following 2017–2018 La Niña, large variations in thermosteric sea level occurred due to temperature changes within the 100–500 dbar layer in the midlatitude southwest Pacific. In the western boundary region (from 30°S to 40°S), the variations in halosteric sea level between 100 and 500 dbar were significant and could have partially balanced the corresponding changes in thermosteric sea level. We show that around 35°S, baroclinic Rossby waves forced by the open-ocean wind-stress forcing account for 40 to 75% of the interannual sea level variance between 100°W and 180°, while the influence of remote sea level signals generated near the Chilean coast is limited to the region east of 100°W. The contribution of surface heat fluxes on interannual time scales is also considered and shown to be negligible.
Remote Sensing in Field Crop Monitoring: A Comprehensive Review of Sensor Systems, Data Analyses and Recent Advances
Authors: Omia Emmanuel , Bae Hyungjin , Park Eunsung , Kim Moon Sung , Baek Insuck , Kabenge Isa , Cho Byoung-Kwan
Published: January 2023

The key elements that underpin food security require the adaptation of agricultural systems to support productivity increases while minimizing inputs and the adverse effects of climate change. The advances in precision agriculture over the past few years have substantially enhanced the efficiency of applying spatially variable agronomic inputs for irrigation, such as fertilizers, pesticides, seeds, and water, and we can attribute them to the increasing number of innovations that utilize new technologies that are capable of monitoring field crops for varying spatial and temporal changes. Remote sensing technology is the primary driver of success in precision agriculture, along with other technologies, such as the Internet of Things (IoT), robotic systems, weather forecasting technology, and global positioning systems (GPSs). More specifically, multispectral imaging (MSI) and hyperspectral imaging (HSI) have made the monitoring of the field crop health to aid decision making and the application of spatially and temporally variable agronomic inputs possible. Furthermore, the fusion of remotely sensed multisource data—for instance, HSI and LiDAR (light detection and ranging) data fusion—has even made it possible to monitor the changes in different parts of an individual plant. To the best of our knowledge, in most reviews on this topic, the authors focus on specific methods and/or technologies, with few or no comprehensive reviews that expose researchers, and especially students, to the vast possible range of remote sensing technologies used in agriculture. In this article, we describe/evaluate the remote sensing (RS) technologies for field crop monitoring using spectral imaging, and we provide a thorough and discipline-specific starting point for researchers of different levels by supplying sufficient details and references. We also high light strengths and drawbacks of each technology, which will help readers select the most appropriate method for their intended uses.
First-Break Picking of Large-Offset Seismic Data Based on CNNs with Weighted Data
Authors: Yin Yuchen , Han Liguo , Zhang Pan , Lu Zhanwu , Shang Xujia
Published: January 2023

Deep reflection seismic data are usually accompanied by large-offset data, and the accurate and rapid identification of the first arrivals of seismic records plays an important role in eliminating the effects of topography and other factors that increase with the increasing offsets. In this paper, we propose a method based on convolutional neural networks (CNNs) that can accurately identify the first arrivals of large-offset seismic data. A time window for linear dynamic correction was established to convert the raw seismic data into rectangular images so as to reduce the amount of invalid sample data and improve the training efficiency. In order to enhance the prediction effect of the far-offset first arrivals, we propose the strategy of adjusting the weight of the far-offset data to increase the weight of the far-offset data in the training dataset and, thus, to improve the first arrival accuracy. The manually picked first arrivals are used as labels and the input to the CNNs for training, and the full-offset first arrivals are the output. The travel time tomography velocity is modeled and compared based on the first arrivals obtained through manual picking, industrial software automatic picking, and CNN prediction. The results show that the application of CNNs to large-offset seismic datasets can help researchers to obtain the first arrivals at different offsets, while the inclusion of far-offset weights can effectively improve the modeling depth of the tomography inversion, and the accuracy of the results is high.
Study on the Quantitative Precipitation Estimation of X-Band Dual-Polarization Phased Array Radar from Specific Differential Phase
Authors: Zhao Guo , Huang Hao , Yu Ye , Zhao Kun , Yang Zhengwei , Chen Gang , Zhang Yu
Published: January 2023

In this study, the quantitative precipitation estimation (QPE) capability of three X-band dual-polarization phased array radars (PAR) in Guangzhou, South China, was demonstrated, with an S-band operational dual-polarization radar as the benchmark. Rainfall rate (R) estimators based on the specific differential phase (KDP) for summer precipitation for both X-band and S-band radars were derived from the raindrop size distributions (DSDs) observed by a 2-dimensional video disdrometer (2DVD) in South China. Rainfall estimates from the radars were evaluated with gauge observations in three events, including pre-summer rainfall, typhoon precipitation, and local severe convective precipitation. Observational results showed that radar echoes from the X-band PARs suffered much more severely from attenuation than those from the S-band radar. Compared to S-band observations, the X-band echoes can disappear when the signal-to-noise ratio drops to a certain level due to severe attenuation, resulting in different estimated rainfall areas for X- and S-band radars. The attenuation corrected by KDP had good consistency with S-band observations, but the accuracy of attenuation correction was affected by DSD uncertainty and may vary in different types of precipitation. The QPE results demonstrated that the R(KDP) estimator produced better rainfall accumulations from the X-band PAR observations compared to the S-band observations. For both the X-band and S-band radars, the estimates of hourly accumulated rainfall became more accurate in heavier rainfall, due to the decreases of both the DSD uncertainty and the impact of measurement errors. In the heavy precipitation area, the estimation accuracy of the X-band radar was high, and the overestimation of the S-band radar was obvious. Through the analysis of the ZH-ZDR distribution in the three weather events, it was found that the X-band PAR with the capability of high spatiotemporal observations can capture minute-level changes in the microphysical characteristics, which help improve the estimation accuracy of ground rainfall.
Automatic Detection of Subglacial Water Bodies in the AGAP Region, East Antarctica, Based on Short-Time Fourier Transform
Authors: Hao Tong , Jing Liwen , Liu Jiashu , Wang Dailiang , Feng Tiantian , Zhao Aiguo , Li Rongxing
Published: January 2023

Subglacial water bodies are critical components in analyzing the instability of the Antarctic ice sheet. Their detection and identification normally rely on geophysical and remote sensing methods such as airborne radar echo sounding (RES), ground seismic, and satellite/airborne altimetry and gravity surveys. In particular, RES surveys are able to detect basal terrain with a relatively high accuracy that can assist with the mapping of subglacial hydrology systems. Traditional RES processing methods for the identification of subglacial water bodies mostly rely on their brightness in radargrams and hydraulic flatness. In this study, we propose an automatic method with the main objective to differentiate the basal materials by quantitatively evaluating the shape of the A-scope waveform near the basal interface in RES radargrams, which has been seldom investigated. We develop an automatic algorithm mainly based on the traditional short-time Fourier transform (STFT) to quantify the shape of the A-scope waveform in radargrams. Specifically, with an appropriate window width applied on the main peak of each A-scope waveform in the RES radargram, STFT shows distinct and contrasting frequency responses at the ice-water interface and ice-rock interface, which is largely dependent upon their different reflection characteristics at the basal interface. We apply this method on 882 RES radargrams collected in the Antarctic’s Gamburtsev Province (AGAP) in East Antarctica. There are 8822 identified A-scopes with the calculated detection value larger than the set threshold, out of the overall 1,515,065 valid A-scopes in these 882 RES radargrams. Although these identified A-scopes only takes 0.58% of the overall A-scope population, they show exceptionally continuous distribution to represent the subglacial water bodies. Through a comprehensive comparison with existing inventories of subglacial lakes, we successfully verify the validity and advantages of our method in identifying subglacial water bodies using the detection probability for other basal materials of theoretically the highest along-track resolution. The frequency signature obtained by the proposed joint time–frequency analysis provides a new corridor of investigation that can be further expanded to multivariable deep learning approaches for subglacial and englacial material characterization, as well as subglacial hydrology mapping.
Observation of Near-Inertial Internal Gravity Waves in the Southern South China Sea
Authors: Liu Qian , Cui Jian , Shang Xiaodong , Xie Xiaohui , Wu Xiangbai , Gao Junliang , Mei Huan
Published: January 2023

Two sets of more than 850 days of mooring records and satellite altimeter data are used to explore the features and spatiotemporal evolution of near-inertial waves (NIWs) near Nansha Island in the southern South China Sea (SCS). The observed NIWs are dominated by clockwise (downward energy propagation) motions and show a clear blue shift with a distinct peak frequency of 1.09 f during two large NIW events. The near-inertial kinetic energy (NIKE) is primarily concentrated in the upper layer and radiated downward. The largest value of depth-integrated NIKE reaches 3.5 KJ/m2. Besides, the NIWs are dominated by the first three modes, which account for 80% of the total NIKE. Moreover, the depth-integrated NIKE exhibits an apparent seasonal variation, with the largest NIKE in winter, which is almost three times larger than that in other seasons. Every large NIKE event is attributed to the passage of storms and is dominated by mode-2 NIWs. The dominance of the mode-2 NIWs is likely caused by the interaction between NIWs and mesoscale eddies.
Calibration of the Greenhouse Gas Monitoring Instrument (GMI) Based on a Digital Calibration Field Network
Authors: Shi Hailiang , Li Zhiwei , Ye Hanhan , Luo Haiyan , Wang Xianhua , Xiong Wei
Published: January 2023

The Greenhouse Gas Monitoring Instrument (GMI), carried by Gaofen 5 (GF5-01), and the Hyperspectral Observation Satellite (GF5-02) were successfully launched on 9 May 2018, and September 7, 2021, respectively, and are the only passive greenhouse gas payloads in China that can regularly obtain effective detection data in-orbit at this stage. Before launch, the research team carried out much laboratory calibration work and designed an on-board calibration system based on solar radiation sources which guarantees the quantitative accuracy of the payload data to the greatest extent. In order to more effectively meet the high frequency calibration requirements over the whole life cycle of the payload, the research team carried out research using the on-track site calibration method based on digital calibration field network technology, and the obtained calibration coefficient effectively complements the laboratory and on-board calibration results. The working principle of the GMI is quite different from that of a traditional imaging payload. Spatial heterodyne spectroscopy (SHS) is used to detect the absorption spectrum of greenhouse gases, has a large field of view and is non-imaging and hyperspectral. The existing fixed-site alternative calibration methods cannot fully meet the requirements of calibration tasks. In this paper, we propose a set of global digital calibration radiation field screening criteria that can meet the characteristics of the GMI and design a method to calculate the site calibration coefficients of non-absorption spectral channels according to the characteristics of hyperspectral data. Based on the historical observation data of the GMI, the initial calibration calculation of the payload launch was carried out, and the calibration results of four spectral channels of the GMI were obtained: The calibration coefficient range of the O2 channel is 1.05–1.15, the mean value is 1.10 and the standard deviation is 2.72%; the calibration coefficient of the CO2-1 channel is 1.05–1.13, the mean value is 1.09 and the standard deviation is 2.64%; the calibration coefficient of the CH4 channel is 1.08–1.10, the mean value is 1.11 and the standard deviation is 2.73%; the calibration coefficient of the CO2-2 channel is 1.09–1.14, the mean value is 1.12 and the standard deviation is 2.93%. The above results show that the radiation performance of each channel of the GMI shows no significant attenuation during this period, that the site calibration coefficient has no significant fluctuation and that the in-orbit operation state is stable.