Search Results (159)

This research presents a novel approach to 28 $\mathrm{GHz}$ impulse radio ultra-wideband (IR-UWB) transmission using pulse position modulation (PPM) over an analog radio-over-fiber (ARoF) link, investigating the impact of fiber-based fronthaul on the overall performance of the communication system. In this setup, an arbitrary waveform generator (AWG) is employed for PPM signal generation, while demodulation is performed with a commercial time-to-digital converter (TDC) based on an event timer. To enhance the reliability of transmitted reference PPM (TR-PPM) signals, the transmission system integrates Gray coding and Consultative Committee for Space Data Systems (CCSDS)-standard-compliant Reed-Solomon (RS) error correcting code (ECC). System performance was evaluated by transmitting pseudorandom binary sequences (PRBSs) and measuring the bit error ratio (BER) across a 5-m wireless link between two 20 $\mathrm{d}\mathrm{B}\mathrm{i}$ gain horn (Ka-band) antennas, with and without a 20 $\mathrm{k}\mathrm{m}$ single-mode optical fiber (SMF) link in transmitter side and ECC at the receiver side. The system achieved a BER of less than 8.17 × 10⁻⁷, using a time bin duration of 200 $\mathrm{p}\mathrm{s}$ and a pulse duration of 100 $\mathrm{p}\mathrm{s}$, demonstrating robust performance and significant potential for space-to-ground telecommunication applications. Full article

SYPRO^® Orange (SyO) is a zwitterionic dye that is used for protein gel staining, for thermal melt assays of proteins, and as a marker for misfolded proteins. However, while widely utilized, much of SyOs’ photophysics remains unexplored. We studied the effect of pH on the photophysical properties of SyO in aqueous solution and found two well-defined transitions in the 0 to 10 pH range between three SyO species with distinct absorption and fluorescence properties. The first transition occurs around pH 1.5 and appears to be a coupled deprotonation–aggregation event. The second transition occurs between pH 4 and 5, and its pK_a depends on the concentration of SyO. A link between the concentration dependence of the pK_a of the second pH transition and the aggregation behavior of SyO at neutral pH is discussed, and aggregation equilibrium titrations are presented that suggest that SyO forms multimeric aggregates at neutral pH containing ten or more SyO molecules. Full article

Episodic sedimentary processes with significant changes in sedimentation rate have occurred on the East Hainan Coast, the inner shelf of the South China Sea, since the Last Glacial Maximum. In particular, the early-Holocene (~11.5–8.7 ka) rapid sedimentation at a mean rate of ~4.90 m/ka is crucial to understand the processes of terrigenous input to the ocean, carbon cycling and climate control in coastal-neritic sedimentary evolution. However, the chronological framework and the detailed environmental evolution remain uncertain. In this study, core sediments collected from the East Hainan Coast (code: NH01) were used to revisit the characteristics of luminescence signals by comparing the dating results using the blue-light stimulated luminescence (blue-OSL) ages and previously published post-infrared blue-light stimulated luminescence (pIR-blue OSL) ages. The results showed that both the ages agreed with each other for the fine-grained quartz fraction. The refined chronology of the early-Holocene deposits on the East Hainan Coast with higher resolution suggested that the sedimentation rate was ~0.60 m/ka before 10.97 ka, while it increased abruptly to ~5.89 m/ka during the period of 10.97–9.27 ka. According to the refined OSL chronology and the high-resolution (~2.5 cm) titanium intensity using X-ray fluorescence (XRF) scanning, the rapid sedimentation during the early Holocene was likely controlled by increased terrigenous input. The variation in Ti flux reflected the differential response between two meltwater pulse (MWP) events under the combined effects of enhanced early-Holocene monsoons and localized freshwater input. These findings highlight the compound controls of global ice-volume change, monsoon dynamics and coastal geomorphic evolution on sedimentary processes. Full article

This study presents the first direct cosmogenic ³⁶Cl-based chronology of landscape evolution and ground deformation in the Ionian Islands, focusing on the Thinia Valley in northern Kefalonia, western Greece. At the Zola site, exposure ages indicate that the eastern limb of the associated anticline has undergone intermittent deformation since at least 34 ka, with ongoing exhumation still occurring today. Variability in erosion rates suggests a complex deformation history, with lower-elevation samples exhuming faster than those at higher elevations. The findings highlight the role of progressive landslide activity rather than a single catastrophic failure. The compression-induced asymmetry of the Zola anticline, along with regional seismicity, appears to control slope instability. The exposure ages at the SK site reveal a surface that reached steady-state long before 20 ka, with a uniform erosion rate of 47.72 ± 0.82 m·Ma⁻¹, consistent with regional estimates. Additionally, a prehistoric earthquake—dated at 4.8 ± 0.14 ka—has been identified, with a planar surface exhumed in a single slip event. These findings emphasize the tectonic mobility of the region, with deformation processes persisting since the Middle Pleistocene. The results contribute to a broader understanding of fault-controlled slope instability and have direct implications for seismic hazard assessment in actively deforming terrains. Full article

Invertase (INV, EC3.2.1.26) is widely recognized as an indispensable enzyme for catalyzing sucrose degradation and plays a central role in plant growth as well as fruit quality improvement. However, no systematic study has been performed in kiwifruit. Here, we identified 102 AaINV genes in the Actinidia arguta “M1” genome. Their physical and chemical properties, subcellular localizations, phylogenetic relationships and expression profiles were characterized. Phylogenetic analysis showed that the INV members were clustered into three groups (vacuole invertases (VINVs) and cell wall invertases (CWINVs) in Group I, alkaline/neutral invertase (NINVs) in Group II and Group III), demonstrating evolutionary conservation in the INV family across Arabidopsis and Actinidia species. Gene replication analysis revealed that many AaINV genes were derived from gene duplication events. Molecular evolution analysis based on Ka/Ks ratios indicated that the INV members have experienced extensive purifying selection during evolution. To explore the potential gene functions, we integrated RNA-seq and metabolomics to analyze AaINV gene expression patterns and sugar accumulation in three A. arguta varieties (“Kukuwa”, “Qinhuang”, “Xianziguang”), respectively. The expression analysis of the 102 genes showed that the expression patterns varied among the three kiwifruit varieties at fruit maturity stage. The expression levels of AaINVs were also investigated via qRT-PCR in these varieties. Specifically, we constructed a complex regulatory network that regulates sugar metabolism in kiwifruit based on the correlation between 42 AaINV genes and 14 sugar metabolites. These findings provide insights into physiological functions of AaINVs in kiwifruit, especially roles in governing sugars accumulation in fruits. Full article

The total organic carbon (TOC) content in lake sediments is an effective archive indicating past climate changes. However, the resolution of the TOC record has generally been limited by factors such as subsampling intervals, hampering further comprehension of past climate change. Recently, hyperspectral imaging technology has been increasingly employed to scan lake sediment cores, presenting new opportunities to reconstruct high-resolution sequences, but the reconstruction of long-term high-resolution TOC records using hyperspectral imaging and the climate implications have not been well studied. In this study, we scanned sedimentary cores from Wudalianchi Crater Lake in northeast China with a spatial resolution of 400 × 400 μm, utilizing visible and near-infrared (VNIR) hyperspectral imaging technology. Then, a partial least-squares regression (PLSR) model was constructed by comparing eight different preprocessing methods and optimally selecting the best spectral subset combined with a genetic algorithm (GA). Our analysis demonstrates that the PLSR model, constructed using 62 relevant bands selected by the Savitzky–Golay second derivative (D2) preprocessing method and GA, was the most reliable, with the validation set’s R-value reaching a high of 0.91 and RMSE as low as 1.18%. Notably, the spectral range of 656–669 nm showed a strong positive correlation with measured TOC, indicating its sensitivity for TOC estimation. Given this advantage, we reconstructed the TOC records of sediments from the Wudalianchi Crater Lake during the 38–13 ka BP period, which exhibited significant millennial-scale fluctuation events. These corresponded well with the millennial-scale events in pollen and TOC from Lake Sihailongwan, δ¹⁸O records of Greenland ice cores, and δ¹⁸O records from Asian stalagmites. Thus, the combination of hyperspectral imaging and the PLSR model is effective in reconstructing high-resolution TOC changes in lake sediments, which is essential for understanding climate change as well as carbon burial in lakes. Full article

Gene duplication, as a prevalent phenomenon in the tree of life, provides a potential substrate for evolution. However, its role in the Aurantioideae remains unclear. In this study, we systematically identified, for the first time, a comprehensive landscape of five types of gene duplication in the genomes of 26 species within Aurantioideae, focusing on dissecting the duplication patterns, their potential evolutionary significance, and their impact on gene function and expression. Our results showed that the tandem duplication (TD) was a predominant duplication type and confirmed a shared ancient whole-genome duplication (γWGD) event within Aurantioideae. Ka/Ks indicated that all duplication types are under purifying selection pressure, with TD and proximal duplication (PD) undergoing rapid functional divergence. Gene Ontology (GO) enrichment analysis revealed functional specialization among different duplication types, collectively contributing to genome evolution. In addition, comparing the gene expression differentiation of the five gene duplication types between the outer and inner pericarps of Citrus maxima ‘Huazhouyou’, it was found that the proportion of gene expression differentiation in the exocarp was generally higher, suggesting tissue-specific functional roles for duplicated genes in the peel. Furthermore, gene conversion events revealed that Citrus sinensis and Citrus maxima ‘Huazhouyou’ experienced more gene conversion events, supporting that C. sinensis originated through hybridization with C. maxima as the maternal parent. Finally, the comparative analysis of gene families among 26 species in Aurantioideae revealed that small gene families (1–3 members) accounted for a substantial proportion in all species, indicating a lack of recent large-scale genome duplication events in this subfamily. These findings fill a gap in the understanding of gene duplication in Aurantioideae and provide a theoretical foundation for exploring the evolutionary mechanisms and breeding improvements within this group. Additionally, our study offers new insights into the contribution of gene duplication to functional diversification and ecological adaptation in other plants. Full article

Histone methyltransferases (SDGs) and demethylases (JMJs) are well-established regulators of transcriptional responses in plants under adverse conditions. This study characterized SDG and JMJ enzymes in the cowpea (Vigna unguiculata) genome and analyzed their expression patterns under various stress conditions, including root dehydration and mechanical injury followed by CABMV or CPSMV inoculation. A total of 47 VuSDG genes were identified in the cowpea genome and classified into seven distinct classes: I, II, III, IV, V, VI, and VII. Additionally, 26 VuJMJ-coding genes were identified and categorized into their respective groups: Jmj-only, JMJD6, KDM3, KDM5, and KDM4. Analysis of gene expansion mechanisms for the studied loci revealed a predominance of dispersed duplication and WGD/segmental duplication events, with Ka/Ks ratios indicating that all WGD/segmental duplications are under purifying selection. Furthermore, a high degree of conservation was observed for these loci across species, with legumes displaying the highest conservation rates. Cis-Regulatory Element analysis of VuSDG and VuJMJ gene promoters revealed associations with Dof-type and bZIP transcription factors, both of which are known to play roles in plant stress responses and developmental processes. Differential expression patterns were observed for VuSDG and VuJMJ genes under the studied stress conditions, with the highest number of upregulated transcripts detected during the root dehydration assay. Our expression data suggest that as the referred stress persists, the tolerant cowpea accession decreases methylation activity on target histones and shifts towards enhanced demethylation. This dynamic balance between histone methylation and demethylation may regulate the expression of genes linked to dehydration tolerance. During the mechanical injury and viral inoculation assays, VuSDG and VuJMJ transcripts were upregulated exclusively within 60 min after the initial mechanical injury combined with CABMV or CPSMV inoculation, indicating an early role for these enzymes in the plant’s defense response to pathogen exposure. The current study presents a detailed analysis of histone modifiers in cowpea and indicates their role as important epigenetic regulators modulating stress tolerance. Full article

The mitochondrial genome of Spartina alterniflora, an invasive species with significant ecological and economic impacts, was analyzed to provide a theoretical basis for understanding its phylogenetic relationships and molecular biology. Mitochondrial genome sequences of S. alterniflora and 23 related species from NCBI were utilized for bioinformatics and comparative genomic analyses. A sliding window analysis identified three genes (rps2, atp9, and nad6) as potential DNA barcodes for species identification. Intracellular gene transfer (IGT) events between mitochondrial and chloroplast genome were detected, highlighting the dynamic nature of genomic evolution. A selective pressure analysis revealed that most protein-coding genes (PCGs) underwent purifying selection (K_a/K_s < 1), while the nad2 and ccmB genes showed signs of positive selection pressure (K_a/K_s > 1), indicating their role in adaptation. A phylogenetic analysis demonstrated a close relationship between S. alterniflora and Eleusine indica, supported by a collinearity analysis, which suggests environmental convergence. This study provides novel insights into the structural and evolutionary characteristics of the S. alterniflora mitochondrial genome, offering valuable genomic resources for future research on invasive species management and evolutionary biology. Full article

Transient analysis in power systems is essential for identifying deficiencies in the system, as well as for the protection and design of equipment. Transients can arise from natural events or network operations; in either case, they have the potential to cause significant damage to transmission lines, protection devices, generators, or transformers. This study examines a 20 kA, 1.2/50 µs lightning strike on a distributed-parameter transmission line connected to a power transformer. The voltage distributions across the winding sections on the neutral grounded high-voltage side of a disc-structured power transformer were obtained using the state-space method. An equivalent circuit for the state-space model was also developed in the Alternative Transients Program–Electromagnetic Transients Program (ATP-EMTP), and the results from both methods were compared. Both approaches revealed that the voltage waveforms in the transformer’s winding sections were consistent, with the voltage distribution decreasing linearly. Additionally, the voltage–current waves reached the transformer with a specific delay, depending on the characteristics of the transmission line and the location of the lightning strike. The impact of an increase in the grounding resistance value on the high-voltage side of the transformer on voltage distribution and peak voltage levels was examined. The proposed method effectively captures the voltage–current behavior of the transmission line and transformer windings during transient conditions. It is concluded that the state-space method serves as a viable alternative for transient analysis in power systems and can enhance the design of protection equipment and winding insulation studies. Full article

α-Synuclein (α-Syn) is implicated in the pathophysiology of Parkinson’s disease (PD) and plays a significant role in neuronal degeneration. Iron response proteins (IRPs) bind to iron response elements (IREs) found in the 5′-untranslated regions (5′-UTRs) of the messenger RNA that encode the α-Syn gene. This study used multi-spectroscopic approach techniques to investigate the impact of iron on α-Syn IRE RNA binding to IRP1. The formation of a stable complex between α-Syn RNA and IRP1 was suggested by fluorescence quenching results. Fluorescence measurements showed that α-Syn RNA and IRP1 had a strong interaction, with a binding constant (K_a) of 21.0 × 10⁶ M⁻¹ and 1:1 binding stoichiometry. About one binding site per IRP1 molecule was suggested by the α-Syn RNA binding. The K_a for α-Syn RNA•IRP1 with added Fe²⁺ (50 μM) was 6.4 μM⁻¹. When Fe²⁺ was added, the K_a of α-Syn RNA•IRP1 was reduced by 3.3 times. These acquired K_a values were used to further understand the thermodynamic characteristics of α-Syn RNA•IRP1 interactions. The thermodynamic properties clearly suggested that α-Syn RNA binding to IRP1 was an entropy-favored and enthalpy-driven event, with significant negative ΔH and small positive ΔS. For α-Syn RNA•IRP1, the Gibbs free energy (ΔG) was −43.7 ± 2.7 kJ/mol, but in the presence of Fe²⁺, it was −36.3 ± 2.1 kJ/mol. These thermodynamic calculations indicated that hydrogen bonding as well as van der Waals interactions might help to stabilize the complex formation. Additionally, far-UV CD spectra verified α-Syn RNA•IRP1 complex formation, and α-Syn RNA and Fe²⁺ induce secondary structural alteration of IRP1. According to our findings, iron alters the hydrogen bonding in α-Syn RNA•IRP1 complexes and induces a structural change in IRP1. This suggests that iron selectively affects the thermodynamics of these RNA–protein interactions. Full article

This essay explores the mid-eighteenth-century travel experience of Scottish writer Anne Macvicar Grant [1775–1838]. Grant is perhaps best known for her late eighteenth- and early nineteenth-century travel writing and anthropological discourse focussed primarily upon the Scottish Highlands. Yet, the majority of Grant’s childhood was spent in Albany, New York. After she had established herself as a writer and published various texts dealing with her more recent experience in the Scottish Highlands, in 1808, Grant published Memoirs of an American Lady, a semi-biographical account of her childhood spent in the multicultural contact zone of a British military outpost. There are two key issues that this essay explores. First, I discuss the process of memory. Unlike intentional travelogues of the time, Grant’s text was not compiled with the aid of a diary or ledger. Grant’s entire account comprises memories of events that occurred over forty years in the past. Part of this essay then discusses the potential fallibilities of the fragility of human memory upon the traveller. While it may be anticipated that this first issue is detrimental to the account of the traveller, the second key issue that I explore is arguably advantageous to Grant’s account. The extent to which Grant, throughout her life, immersed herself within various marginalised communities undoubtedly allows for the production of a more nuanced and balanced account of external cultures than was the custom at the time. What complicates this account is the mixing of memory and cultural immersion. In her writing around the Scottish Highlands, Grant frequently relies upon her experience of certain cultures as a child to explain and convey her understanding of the different marginalised communities she encounters as an adult. Integral to this essay is the fact that this mixing of memory and cultural exposure also occurs the opposite way around. In the Memoirs, the writer’s recollections of the Mohawk or the Kanien’kehà:ka people and colonial Dutch communities as a child seem to be coloured and subjected by her more recent experience of the Highland people. Full article

As a subfamily of the PD-(D/E)XK nuclease superfamily, DUF506 family shows great potential in abiotic stress responding of higher plant, yet its clues of structure, evolution and functions remain largely unexplored due to their distant phylogenetic relationship with other nuclease families, especially in Triticum aestivum. In this study, 26 T. aestivum DUF506 genes (TaDUF506) were identified from genome-wide level through bioinformatic techniques. Phylogenetic and structural analyses revealed that TaDUF506 genes exhibit conserved motif and gene structure patterns intra-phylogenetic clusters but display significant divergence inter-clusters. Gene duplication identification showed that whole-genome duplication event (WGD) was the primary driver of TaDUF506 family expansion, while Ka/Ks analysis indicated that whole TaDUF506 family experienced purifying selection generally. Gene ontology analysis and protein-protein interaction prediction suggested that DUF506 plays a potential role in transcription regulation and nucleotide-excision generally. Promoter analyses highlighted an enrichment of hormone-responsive elements linked to salt stress in TaDUF1.3-3D TaDUF5.1-3A, with expression analysis demonstrated their significant upregulation under salt stress, suggesting the potential roles in stress responses. Altogether, our study advances the understanding of DUF506 gene family in higher plant from structural, evolutional and functional aspects, and thereby provides a foundation for the development of salt-tolerant wheat varieties. Full article

Sewer infrastructure is vital for flood prevention, environmental protection, and public health. As part of sewer infrastructure, sewer systems are prone to degradation. Traditional maintenance methods for sewer systems are largely manual and reactive and rely on inconsistent data, leading to inefficient maintenance. The KaSyTwin research project addresses the urgent need for efficient and resilient sewer system management methods in Germany, aiming to develop a methodology for the semi-automated development and utilization of digital twins of sewer systems to enhance data availability and operational resilience. Using advanced multi-sensor robotic platforms equipped with scanning and imaging systems, i.e., laser scanners and cameras, as well as artificial intelligence (AI), the KaSyTwin research project focuses on generating digital twin-enabled representations of sewer systems in real time. As a project report, this work outlines the research framework and proposed methodologies in the KaSyTwin research project. Digital twins of sewer systems integrated with AI technologies are expected to facilitate proactive maintenance, resilience forecasting against extreme weather events, and real-time damage detection. Furthermore, the KaSyTwin research project aspires to advance the digital management of sewer systems, ensuring long-term functionality and public welfare via on-demand structural health monitoring and non-destructive testing. Full article

The ability to track moisture content using soil moisture sensors in green stormwater infrastructure (GSI) systems allows us to understand the system’s water management capacity and recovery. Soil moisture sensors have been used to quantify infiltration and evapotranspiration in GSI practices both preceding, during, and following storm events. Although useful, soil-specific calibration is often needed for soil moisture sensors, as small measurement variations can result in misinterpretation of the water budget and associated GSI performance. The purpose of this research is to quantify the uncertainties that cause discrepancies between default (factory general) sensor soil moisture measurements versus calibrated sensor soil moisture measurements within a subsurface layer of GSI systems. The study uses time domain reflectometry soil moisture sensors based on the ambient soil’s dielectric properties under different soil setups in the laboratory and field. The default ‘loam’ calibration was compared to soil-specific (loamy sand) calibrations developed based on laboratory and GSI field data. The soil-specific calibration equations used a correlation between dielectric properties (real dielectric: ε_r, and apparent dielectric: K_a) and the volumetric water content from gravimetric samples. A paired t-test was conducted to understand any statistical significance within the datasets. Between laboratory and field calibrations, it was found that field calibration was preferred, as there was less variation in the factory general soil moisture reading compared to gravimetric soil moisture tests. Real dielectric permittivity (ε_r) and apparent permittivity (K_a) were explored as calibration options and were found to have very similar calibrations, with the largest differences at saturation. The ε_r produced a 6% difference while the K_a calibration produced a 3% difference in soil moisture measurement at saturation. K_a was chosen over ε_r as it provided an adequate representation of the soil and is more widely used in soil sensor technology. With the implemented field calibration, the average desaturation time of the GSI was faster by an hour, and the recovery time was quicker by a day. GSI recovery typically takes place within 1–4 days, such that an extension of a day in recovery could result in the conclusion that the system is underperforming, rather than it being the result of a limitation of the soil moisture sensors’ default calibrations. Full article