The application prospects of robot pose estimation technology: exploring new directions based on YOLOv8-ApexNet.

Introduction: Service robot technology is increasingly gaining prominence in the field of artificial intelligence. However, persistent limitations continue to impede its widespread implementation. In this regard, human motion pose estimation emerges as a crucial challenge necessary for enhancing the perceptual and decision-making capacities of service robots. Method: This paper introduces a groundbreaking model, YOLOv8-ApexNet, which integrates advanced technologies, including Bidirectional Routing Attention (BRA) and Generalized Feature Pyramid Network (GFPN). BRA facilitates the capture of inter-keypoint correlations within dynamic environments by introducing a bidirectional information propagation mechanism. Furthermore, GFPN adeptly extracts and integrates feature information across different scales, enabling the model to make more precise predictions for targets of various sizes and shapes. Results: Empirical research findings reveal significant performance enhancements of the YOLOv8-ApexNet model across the COCO and MPII datasets. Compared to existing methodologies, the model demonstrates pronounced advantages in keypoint localization accuracy and robustness. Discussion: The significance of this research lies in providing an efficient and accurate solution tailored for the realm of service robotics, effectively mitigating the deficiencies inherent in current approaches. By bolstering the accuracy of perception and decision-making, our endeavors unequivocally endorse the widespread integration of service robots within practical applications.

MsHDZ23, a Novel Miscanthus HD-ZIP Transcription Factor, Participates in Tolerance to Multiple Abiotic Stresses.

The homeodomain-leucine zipper (HD-ZIP) transcription factors, representing one of the largest plant-specific superfamilies, play important roles in the response to various abiotic stresses. However, the functional roles of HD-ZIPs in abiotic stress tolerance and the underlying mechanisms remain relatively limited in Miscanthus sinensis. In this study, we isolated an HD-ZIP TF gene, MsHDZ23, from Miscanthus and ectopically expressed it in Arabidopsis. Transcriptome and promoter analyses revealed that MsHDZ23 responded to salt, alkali, and drought treatments. The overexpression (OE) of MsHDZ23 in Arabidopsis conferred higher tolerance to salt and alkali stresses compared to wild-type (WT) plants. Moreover, MsHDZ23 was able to restore the hb7 mutant, the ortholog of MsHDZ23 in Arabidopsis, to the WT phenotype. Furthermore, MsHDZ23-OE lines exhibited significantly enhanced drought stress tolerance, as evidenced by higher survival rates and lower water loss rates compared to WT. The improved drought tolerance may be attributed to the significantly smaller stomatal aperture in MsHDZ23-OE lines compared to WT. Furthermore, the accumulation of the malondialdehyde (MDA) under abiotic stresses was significantly decreased, accompanied by dramatically enhanced activities in several antioxidant enzymes, including superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in the transgenic plants. Collectively, these results demonstrate that MsHDZ23 functions as a multifunctional transcription factor in enhancing plant resistance to abiotic stresses.

Physical layer encryption for coherent PDM system based on polarization perturbations using a digital optical polarization scrambler.

In this paper, a security enhanced physical layer encryption scheme is proposed for coherent optical polarization division multiplexing (PDM) systems. The concept of a digital optical polarization scrambler (DOPS) is introduced to apply high speed rotation of state of polarization (RSOP) to the transmitted signal, which enables encryption based on polarization perturbations and offers superior flexibility in polarization management. By utilizing different combinations of digital polarization device matrices and adjusting their key parameters, four encryption modes are designed. The proposed encryption scheme is successfully implemented in a PDM-QPSK system at the data rate of 32 Gbps. Experimental results demonstrate that authorized users can successfully decrypt the received signal, while the eavesdroppers cannot derive useful information with a bit error rate (BER) at approximately 0.5. To enhance system security, a 5-D chaotic system is introduced with superior properties of high sensitivity to initial values and improved uniform distribution, which guarantees the large entropy and further the system's security. This scheme can effectively prevent against brute attacks with the expanded key space of 1060.

Fine-tuning brassinosteroid biosynthesis via 3'UTR-dependent decay of CPD mRNA modulates wood formation in Populus.

Brassinosteroids (BRs) are plant hormones that regulate wood formation in trees. Currently, little is known about the post-transcriptional regulation of BR synthesis. Here, we show that during wood formation, fine-tuning BR synthesis requires 3'UTR-dependent decay of Populus CONSTITUTIVE PHOTOMORPHOGENIC DWARF 1 (PdCPD1). Overexpression of PdCPD1 or its 3' UTR fragment resulted in a significant increase of BR levels and inhibited secondary growth. In contrast, transgenic poplars repressing PdCPD1 3' UTR expression displayed moderate levels of BR and promoted wood formation. We show that the Populus GLYCINE-RICH RNA-BINDING PROTEIN 1 (PdGRP1) directly binds to a GU-rich element in 3' UTR of PdCPD1, leading to its mRNA decay. We thus provide a post-transcriptional mechanism underlying BRs synthesis during wood formation, which may be useful for genetic manipulation of wood biomass in trees.

Efficient Accumulation of Amylopectin and Its Molecular Mechanism in the Submerged Duckweed Mutant.

Large-scale use of fossil fuels has brought about increasingly serious problems of environmental pollution, development and utilization of renewable energy is one of the effective solutions. Duckweed has the advantages of fast growth, high starch content and no occupation of arable land, so it is a promising starchy energy plant. A new submerged duckweed mutant (sub-1) with abundant starch accumulation was obtained, whose content of amylopectin accounts for 84.04% of the starch granules. Compared with the wild type (Lemna aequinoctialis), the branching degree of starch in sub-1 mutant was significantly increased by 19.6%. Chain length DP 6-12, DP 25-36 and DP > 36 of amylopectin significantly decreased, while chain length DP 13-24 significantly increased. Average chain length of wild-type and sub-1 mutant starches were greater than DP 22. Moreover, the crystal structure and physical properties of starch have changed markedly in sub-1 mutant. For example, the starch crystallinity of sub-1 mutant was only 8.94%, while that of wild-type was 22.3%. Compared with wild type, water solubility of starch was significantly reduced by 29.42%, whereas swelling power significantly increased by 97.07% in sub-1 mutant. In order to further analyze the molecular mechanism of efficient accumulation of amylopectin in sub-1 mutant, metabolome and transcriptome were performed. The results showed that glucose accumulated in sub-1 mutant, then degradation of starch to glucose mainly depends on α-amylase. At night, the down-regulated ß-amylase gene resulted in the inhibition of starch degradation. The starch and sucrose metabolism pathways were significantly enriched. Up-regulated expression of SUS, AGPase2, AGPase3, PYG, GPI and GYS provide sufficient substrate for starch synthesis in sub-1 mutant. From the 0H to 16H light treatment, granule-bound starch synthase (GBSS1) gene was inhibited, on the contrary, the starch branching enzyme (SBE) gene was induced. Differential expression of GBSS1 and SBE may be an important reason for the decrease ratio of amylose/amylopectin in sub-1 mutant. Taken together, our results indicated that the sub-1 mutant can accumulate the amylopectin efficiently, potentially through altering the differential expression of AGPase, GBSS1, SBE, and BAM. This study also provides theoretical guidance for creating crop germplasm with high amylopectin by means of synthetic biology in the future.

Influence of instability training on balance and coordination in tennis players / Influência do treinamento com instabilidade sobre o equilíbrio e a coordenação nos jogadores de tênis / Influencia del entrenamiento de inestabilidad sobre el equilibrio y la coordinación en jugadores de tenis

ABSTRACT Introduction: Corporal balance and psychomotor coordination are factors of extreme importance in the physical fitness of tennis players. It is believed that implementing training with instability in training can have repercussions in a better capacity of action influencing positively in the sports practice. Objective: Explore whether the addition of instability training to daily training can influence the physical fitness of tennis players. Methods: For this experiment, 100 national secondary professional tennis players were selected as volunteers, and divided equally into experimental and control groups. The experimental group received 12 weeks of additional intervention with instability training, while the control group remained with standard training. Pertinent data were collected before and after the intervention, statistically analyzed, and compared to the literature. Results: Anterior motion range of motion in the experimental group increased from 28.965 ± 0.418 to 39.357 ± 0.25; anterior motion accuracy increased from 26.258 ± 2.239 to 34.608 ± 0.342. Posterior stroke range of motion increased from 25.026 ± 2.136 to 34.528 ± 0.10, and posterior motion accuracy increased from 18.230 ± 1.096 to 28.225 ± 0.261. The data in the control group did not show significant changes. Conclusion: Instability training added to tennis players' daily training may influence tennis players' balance ability and movement coordination, positively impacting tennis players' fitness. Level of evidence II; Therapeutic studies -investigation of treatment outcomes.

RESUMO Introdução: O equilíbrio corporal e a coordenação psicomotora são fatores de extrema importância na aptidão física dos tenistas. Acredita-se que a implementação de treinamentos com instabilidade no treinamento possa repercutir em uma melhor capacidade de ação influenciando positivamente na prática esportiva. Objetivo: Explorar se o acréscimo do treinamento com instabilidade ao treino diário pode influenciar a aptidão física dos jogadores de tênis. Métodos: Para este experimento, 100 tenistas profissionais secundários nacionais foram selecionados como voluntários, divididos igualmente em grupo experimental e controle. O grupo experimental recebeu 12 semanas de intervenção adicional com o treinamento com instabilidade, enquanto o grupo de controle permaneceu com o treinamento padrão. Os dados pertinentes foram coletados antes e após a intervenção, analisados estatisticamente e comparados à literatura. Resultados: A abrangência do movimento anterior no grupo experimental aumentou de 28,965 ± 0,418 para 39,357 ± 0,25; a precisão do movimento anterior elevou-se de 26,258 ± 2,239 para 34,608 ± 0,342, a abrangência do curso posterior aumentou de 25,026 ± 2,136 para 34,528 ± 0,10, e a precisão do movimento posterior aumentou de 18,230 ± 1,096 para 28,225 ± 0,261. Os dados no grupo controle não apresentaram alterações significativas. Conclusão: O treinamento com instabilidade adicionado ao treinamento diário dos tenistas pode influenciar a capacidade de equilíbrio e a coordenação de movimentos dos tenistas, impactando positivamente a aptidão física dos jogadores de tênis. Nível de evidência II; Estudos terapêuticos - investigação dos resultados do tratamento.

RESUMEN Introducción: El equilibrio corporal y la coordinación psicomotriz son factores de suma importancia en la aptitud física de los tenistas. Se cree que la implementación de entrenamiento con inestabilidad en el entrenamiento puede repercutir en una mejor capacidad de acción influyendo positivamente en la práctica deportiva. Objetivo: Explorar si la adición del entrenamiento con inestabilidad al entrenamiento diario puede influir en la aptitud física de los tenistas. Métodos: Para este experimento, se seleccionaron como voluntarios 100 tenistas profesionales de nivel secundario nacional, divididos equitativamente en grupo experimental y grupo de control. El grupo experimental recibió 12 semanas de intervención adicional con entrenamiento de inestabilidad, mientras que el grupo de control permaneció con el entrenamiento estándar. Se recogieron datos pertinentes antes y después de la intervención, se analizaron estadísticamente y se compararon con la bibliografía. Resultados: La amplitud del movimiento anterior en el grupo experimental aumentó de 28,965 ± 0,418 a 39,357 ± 0,25; la precisión del movimiento anterior se elevó de 26,258 ± 2,239 a 34,608 ± 0,342, la amplitud del movimiento posterior aumentó de 25,026 ± 2,136 a 34,528 ± 0,10, y la precisión del movimiento posterior se elevó de 18,230 ± 1,096 a 28,225 ± 0,261. Los datos del grupo de control no mostraron cambios significativos. Conclusión: El entrenamiento de inestabilidad añadido al entrenamiento diario de los tenistas puede influir en la capacidad de equilibrio y la coordinación de movimientos de los tenistas, lo que repercute positivamente en la forma física de los tenistas. Nivel de evidencia II; Estudios terapéuticos - investigación de los resultados del tratamiento.

A piecewise sine waveguide for terahertz traveling wave tube.

In this paper, a piecewise sine waveguide (PWSWG) is proposed as the slow-wave structure (SWS) to develop high-power terahertz (THz) traveling wave tubes (TWTs). The PWSWG is an improvement over the rectangular waveguide wherein its two E-planes simultaneously oscillate up and down along the longitudinal direction. The oscillation curve in the H-plane is a piecewise sine curve formed by inserting line segments into the peaks and troughs of the sine curve. The simulation analysis and experimental verification show that the PWSWG offers the advantages of large interaction impedance and excellent electromagnetic transmission performance. Furthermore, the calculation results of beam-wave interaction show that the TWT based on PWSWG SWS can generate a radiated power of 253.1 W at the typical frequency of 220 GHz, corresponding to a gain of 37.04 dB and an interaction efficiency of 6.92%. Compared with the conventional SWG TWTs, the PWSWG TWT has higher interaction efficiency and shorter saturation tube length. In conclusion, the PWSWG proposed in this paper can be considered a suitable SWS for high-power THz radiation sources.

Ubiquitinated DA1 negatively regulates vascular cambium activity through modulating the stability of WOX4 in Populus.

Activity of the vascular cambium gives rise to secondary xylem for wood formation in trees. The transcription factor WUSCHEL-related HOMEOBOX4 (WOX4) is a central regulator downstream of the hormone and peptide signaling pathways that maintain cambial activity. However, the genetic regulatory network underlying WOX4-mediated wood formation at the post-transcriptional level remains to be elucidated. In this study, we identified the ubiquitin receptor PagDA1 in hybrid poplar (Populus alba × Populus glandulosa clone 84K) as a negative regulator of wood formation, which restricts cambial activity during secondary growth. Overexpression of PagDA1 in poplar resulted in a relatively reduced xylem due to decreased cambial cell division. By contrast, mutation of PagDA1 by CRISPR/Cas9 resulted in an increased cambial cell activity and promoted xylem formation. Genetic analysis demonstrated that PagDA1 functions antagonistically in a common pathway as PagWOX4 to regulate cambial activity. We propose that PagDA1 physically associates with PagWOX4 and modulates the degradation of PagWOX4 by the 26S proteasome. Moreover, genetic analysis revealed that PagDA1 exerts its negative effect on cambial development by modulating the stability of PagWOX4 in a ubiquitin-dependent manner mediated by the E3 ubiquitin ligase PagDA2. In sum, we have identified a cambial regulatory protein complex, PagDA1-PagWOX4, as a potential target for wood biomass improvement.

Metabolome and transcriptome analyses of the flavonoid biosynthetic pathway for the efficient accumulation of anthocyanins and other flavonoids in a new duckweed variety (68-red).

Duckweed is a kind of aquatic plant with the characteristics of high nutritional value and medicinal benefits. However, most researches focused on the natural germplasms. The underlying metabolic pathway remains to be systematically elaborated in duckweed. In our laboratory, one reddish-purple mutant with high-flavonoids was screened from a mutant library of Spirodela polyrhiza 6068, named 68-red. The content of anthocyanins and proanthocyanidins in 68-red mutant increased by 563.47% and 231.19%, respectively, compared to wild type. It is interesting that cynaroside and orientin content were significantly increased, in contrast, apigetrin and vitexin were decreased in 68-red mutant. Considering this, metabolome and transcriptome were employed to explore the flavonoids biosynthetic pathway. Here, a total of 734 metabolites were identified in the wild type and 68-red mutant. Among which, cyanidin-3-O-glucoside, cyanidin-3-O-galactoside, pelargonidin-3-O-glucoside and pelargonidin-3-O-(6″-O-malonyl)glucoside were significantly accumulated, which were positively correlated with deep reddish-purple of 68-red mutant. In addition, proanthocyanidins (B1, B2, B3, B4, C1, C2), flavonoid and its glycosides (11 luteolin and its glycosides, 14 quercetin and its glycosides, 14 kaempferol and its glycosides, 2 apigenin glycosides) were significantly accumulated, 2 apigenin glycosides were down-regulated in 68-red mutant. The transcriptome data and qRT-PCR indicated that 16 enzyme genes in flavonoids biosynthetic pathway (PAL, C4H, CHSs, F3H, ANS, ANR, F3'Hs, DFRs, LAR, GT1, BZ1) were significantly up-regulated in 68-red mutant. Correlation analysis found that three copies of F3'H gene play important roles in the synthesis of anthocyanins, luteolin and apigenin glycosides. In conclusion, the 68-red mutant is a high quality germplasm resources for food and medical industry. Metabolome and transcriptome provide new insight for exploring the enzyme genes and functional metabolites in duckweed.

Exploring a blue-light-sensing transcription factor to double the peak productivity of oil in Nannochloropsis oceanica.

Oleaginous microalgae can produce triacylglycerol (TAG) under stress, yet the underlying mechanism remains largely unknown. Here, we show that, in Nannochloropsis oceanica, a bZIP-family regulator NobZIP77 represses the transcription of a type-2 diacylgycerol acyltransferase encoding gene NoDGAT2B under nitrogen-repletion (N+), while nitrogen-depletion (N-) relieves such inhibition and activates NoDGAT2B expression and synthesis of TAG preferably from C16:1. Intriguingly, NobZIP77 is a sensor of blue light (BL), which reduces binding of NobZIP77 to the NoDGAT2B-promoter, unleashes NoDGAT2B and elevates TAG under N-. Under N+ and white light, NobZIP77 knockout fully preserves cell growth rate and nearly triples TAG productivity. Moreover, exposing the NobZIP77-knockout line to BL under N- can double the peak productivity of TAG. These results underscore the potential of coupling light quality to oil synthesis in feedstock or bioprocess development.

MYB42 inhibits hypocotyl cell elongation by coordinating brassinosteroid homeostasis and signalling in Arabidopsis thaliana.

BACKGROUND AND AIMS: The precise control of brassinosteroid (BR) homeostasis and signalling is a prerequisite for hypocotyl cell elongation in plants. Arabidopsis MYB42 and its paralogue MYB85 were previously identified to be positive regulators of secondary cell wall formation during mature stages. Here, we aim to reveal the role of MYB42 and MYB85 in hypocotyl elongation during the seedling stage and clarify how MYB42 coordinates BR homeostasis and signalling to regulate this process. METHODS: Histochemical analysis of proMYB42-GUS transgenic plants was used for determination of the MYB42 expression pattern. The MYB42, 85 overexpression, double mutant and some crossing lines were generated for phenotypic observation and transcriptome analysis. Transcription activation assays, quantitative PCR (qPCR), chromatin immunoprecipitation (ChIP)-qPCR and electrophoretic mobility shift assays (EMSAs) were conducted to determine the relationship of MYB42 and BRASSINAZOLE-RESISTANT 1 (BZR1), a master switch activating BR signalling. KEY RESULTS: MYB42 and MYB85 redundantly and negatively regulate hypocotyl cell elongation. They function in hypocotyl elongation by mediating BR signalling. MYB42 transcription was suppressed by BR treatment or in bzr1-1D (a gain-of-function mutant of BZR1), and mutation of both MYB42 and MYB85 enhanced the dwarf phenotype of the BR receptor mutant bri1-5. BZR1 directly repressed MYB42 expression in response to BR. Consistently, hypocotyl length of bzr1-1D was increased by simultaneous mutation of MYB42 and MYB85, but was reduced by overexpression of MYB42. Expression of a number of BR-regulated BZR1 (non-)targets associated with hypocotyl elongation was suppressed by MYB42, 85. Furthermore, MYB42 enlarged its action in BR signalling through feedback repression of BR accumulation and activation of DOGT1/UGT73C5, a BR-inactivating enzyme. CONCLUSIONS: MYB42 inhibits hypocotyl elongation by coordinating BR homeostasis and signalling during primary growth. The present study shows an MYB42, 85-mediated multilevel system that contributes to fine regulation of BR-induced hypocotyl elongation.

The BZR1-EDS1 module regulates plant growth-defense coordination.

Plants have developed sophisticated strategies to coordinate growth and immunity, but our understanding of the underlying mechanism remains limited. In this study, we identified a novel molecular module that regulates plant growth and defense in both compatible and incompatible infections. This module consisted of BZR1, a key transcription factor in brassinosteroid (BR) signaling, and EDS1, an essential positive regulator of plant innate immunity. We found that EDS1 interacts with BZR1 and suppresses its transcriptional activities. Consistently, upregulation of EDS1 function by a virulent Pseudomonas syringae strain or salicylic acid treatment inhibited BZR1-regulated expression of BR-responsive genes and BR-promoted growth. Furthermore, we showed that the cytoplasmic fraction of BZR1 positively regulates effector-triggered immunity (ETI) controlled by the TIR-NB-LRR protein RPS4, which is attenuated by BZR1's nuclear translocation. Mechanistically, cytoplasmic BZR1 facilitated AvrRps4-triggered dissociation of EDS1 and RPS4 by binding to EDS1, thus leading to efficient activation of RPS4-controlled ETI. Notably, transgenic expression of a mutant BZR1 that accumulates exclusively in the cytoplasm improved pathogen resistance without compromising plant growth. Collectively, these results shed new light on plant growth-defense coordination and reveal a previously unknown function for the cytoplasmic fraction of BZR1. The BZR1-EDS1 module may be harnessed for the simultaneous improvement of crop productivity and pathogen resistance.

Physical layer encryption scheme based on cellular automata and DNA encoding by hyper-chaos in a CO-OFDM system.

This study proposes an encryption scheme combining cellular automata (CA) and DNA encoding to improve security of a coherent optical orthogonal frequency division multiplexing (CO-OFDM) system, wherein key sequences are generated with good randomness and unpredictability by a 4-dimensional hyper-chaotic system. A base scrambling pseudo random binary sequence (PRBS) generated by the CA is introduced, which results in better scrambling effect and randomness in the conventional complex DNA encoding. The randomness, complexity and security of the system is enhanced due to 6 variable keys (key space of ∼10138). An experiment conducted in a 40 GHz 16QAM CO-OFDM system over an 80 km standard single mode fiber (SSMF) shows that the authorized user can successfully decrypt the received signal, while the eavesdroppers cannot derive useful information with bit error rate (BER) at approximately 0.5. An allowable optical signal to noise ratio (OSNR) penalty of 0.5 dB will be introduced to achieve same BER before and after encryption due to the error propagation of cellular automata.

ERF4 and MYB52 transcription factors play antagonistic roles in regulating homogalacturonan de-methylesterification in Arabidopsis seed coat mucilage.

Homogalacturonan (HG), a component of pectin, is synthesized in the Golgi apparatus in its fully methylesterified form. It is then secreted into the apoplast where it is typically de-methylesterified by pectin methylesterases (PME). Secretion and de-esterification are critical for normal pectin function, yet the underlying transcriptional regulation mechanisms remain largely unknown. Here, we uncovered a mechanism that fine-tunes the degree of HG de-methylesterification (DM) in the mucilage that surrounds Arabidopsis thaliana seeds. We demonstrate that the APETALA2/ETHYLENE RESPONSE FACTOR (AP2/ERF) transcription factor (TF) ERF4 is a transcriptional repressor that positively regulates HG DM. ERF4 expression is confined to epidermal cells in the early stages of seed coat development. The adhesiveness of the erf4 mutant mucilage was decreased as a result of an increased DM caused by a decrease in PME activity. Molecular and genetic analyses revealed that ERF4 positively regulates HG DM by suppressing the expression of three PME INHIBITOR genes (PMEIs) and SUBTILISIN-LIKE SERINE PROTEASE 1.7 (SBT1.7). ERF4 shares common targets with the TF MYB52, which also regulates pectin DM. Nevertheless, the erf4-2 myb52 double mutant seeds have a wild-type mucilage phenotype. We provide evidence that ERF4 and MYB52 regulate downstream gene expression in an opposite manner by antagonizing each other's DNA-binding ability through a physical interaction. Together, our findings reveal that pectin DM in the seed coat is fine-tuned by an ERF4-MYB52 transcriptional complex.

A High-Throughput Screening System for Populus Wood-Associated Transcription Factors and Its Application to Lignin Regulation.

Wood formation of trees is a complex and costly developmental process, whose regulatory network is involved in the protein-protein and protein-DNA interactions. To detect such interactions in wood development, we developed a high-throughput screening system with 517 Gal4-AD-wood-associated transcription factors (TFs) library from Populus alba × P. glandulosa cv "84K." This system can be used for screening the upstream regulators and interacting proteins of targets by mating-based yeast-one hybrid (Y1H) and yeast-two-hybrid (Y2H) method, respectively. Multiple regulatory modules of lignin biosynthesis were identified based on this Populus system. Five TFs interacted with the 500-bp promoter fragment of PHENYLALANINE AMMONIA-LYASE 2 (PAL2), the first rate-limiting enzyme gene in the lignin biosynthesis pathway, and 10 TFs interacted with PaMYB4/LTF1, a key regulator of lignin biosynthesis. Some of these interactions were further validated by EMSA and BiFC assays. The TF-PaPAL2 promoter interaction and TF-PaMYB4 interaction revealed a complex mechanism governing the regulation of lignin synthesis in wood cells. Our high-throughput Y1H/Y2H screening system may be an efficient tool for studying regulatory network of wood formation in tree species.

Brassinosteroid Signaling Converges With Auxin-Mediated C3H17 to Regulate Xylem Formation in Populus.

Brassinosteroid (BR) signaling has long been reported to have an effect on xylem development, but the detailed mechanism remains unclear, especially in tree species. In this study, we find PdC3H17, which was demonstrated to mediate xylem formation driven by auxin in our previous report, is also involved in BR-promoted xylem development. Y1H analysis, EMSA, and transcription activation assay confirmed that PdC3H17 was directly targeted by PdBES1, which is a key transcriptional regulator in BR signaling. Tissue specificity expression analysis and in situ assay revealed that PdC3H17 had an overlapping expression profile with PdBES1. Hormone treatment examinations verified that xylem phenotypes in PdC3H17 transgenic plants, which were readily apparent in normal condition, were attenuated by treatment with either brassinolide or the BR biosynthesis inhibitor propiconazole. The subsequent quantitative real-time polymerase chain reaction (qRT-PCR) analyses further revealed that BR converged with PdC3H17 to influence transcription of downstream xylem-related genes. Additionally, the enhancement of xylem differentiation by auxin in PdC3H17 overexpression plants was significantly attenuated compared with wild-type and dominant negative plants due to BR deficiency, which suggested that the BR- and auxin-responsive gene PdC3H17 acted as an mediation of these two hormones to facilitate xylem development. Taken together, our results demonstrate that BR signaling converges with auxin-mediated PdC3H17 to regulate xylem formation in Populus and thus provide insight into the regulation mechanism of BRs and the crosstalk with auxin signaling on xylem formation.

Multisensor decentralized nonlinear fusion using adaptive cubature information filter.

In nonlinear multisensor system, abrupt state changes and unknown variance of measurement noise are very common, which challenges the majority of the previously developed models for precisely known multisensor fusion techniques. In terms of this issue, an adaptive cubature information filter (CIF) is proposed by embedding strong tracking filter (STF) and variational Bayesian (VB) method, and it is extended to multi-sensor fusion under the decentralized fusion framework with feedback. Specifically, the new algorithms use an equivalent description of STF, which avoid the problem of solving Jacobian matrix during determining strong trace fading factor and solve the interdependent problem of combination of STF and VB. Meanwhile, A simple and efficient method for evaluating global fading factor is developed by introducing a parameter variable named fading vector. The analysis shows that compared with the traditional information filter, this filter can effectively reduce the data transmission from the local sensor to the fusion center and decrease the computational burden of the fusion center. Therefore, it can quickly return to the normal error range and has higher estimation accuracy in response to abrupt state changes. Finally, the performance of the developed algorithms is evaluated through a target tracking problem.

Symmetric spin splitting of elliptically polarized vortex beams reflected at air-gold interface via pseudo-Brewster angle.

A simple expression of the transverse spatial spin splitting of light-carrying intrinsic orbital angular momentum (IOAM) is theoretically derived for reflections at strong absorbing media surfaces. By introducing an asymmetric spin splitting (ASS) factor, the transverse spatial symmetric spin splitting (SSS) and ASS of an arbitrary polarized vortex beam can be distinguished. Here, the transverse spatial SSS of an elliptically polarized vortex beam with a phase difference of 90° is predicted when the incident angle is close to the pseudo-Brewster angle. Remarkably, the larger transverse spatial SSS reaches 1100 nm for the incident circularly polarized LG beam with l=3. It is noteworthy that the transverse spatial SSS can be flexibly manipulated by changing the polarized angle, meaning it is theoretically possible to realize fully polarization-controllable transverse spatial SSS for elliptically polarized incident vortex beams. These results could potentially be applied to precision polarization metrology and edge-enhanced imaging.

Dual regulation of xylem formation by an auxin-mediated PaC3H17-PaMYB199 module in Populus.

Wood (secondary xylem) formation in tree species is dependent on auxin-mediated vascular cambium activity in stems. However, the complex regulatory networks underlying xylem formation remain elusive. Xylem development in Populus was characterized based on microscopic observations of stem sections in transgenic plants. Transcriptomic, quantitative real-time PCR, chromatin immunoprecipitation PCR, and electrophoretic mobility shift assay analyses were conducted to identify target genes involved in xylem development. Yeast two-hybrid, pull-down, bimolecular fluorescence complementation, and co-immunoprecipitation assays were used to validate protein-protein interactions. PaC3H17 and its target PaMYB199 were found to be predominantly expressed in the vascular cambium and developing secondary xylem in Populus stems and play opposite roles in controlling cambial cell proliferation and secondary cell wall thickening through an overlapping pathway. Further, PaC3H17 interacts with PaMYB199 to form a complex, attenuating PaMYB199-driven suppression of its xylem targets. Exogenous auxin application enhances the dual control of the PaC3H17-PaMYB199 module during cambium division, thereby promoting secondary cell wall deposition. Dual regulation of xylem formation by an auxin-mediated PaC3H17-PaMYB199 module represents a novel regulatory mechanism in Populus, increasing our understanding of the regulatory networks involved in wood formation.

Micro-fiber Mach-Zehnder interferometer based on ring-core fiber.

A micro-fiber Mach-Zehnder interferometer (MZI), with a thousands-µm-long ring-core fiber (RCF), is demonstrated, and its performance investigation is also implemented. In this paper, the proposed MZI is manufactured by ends-splicing the short RCF segment with single-mode fiber (SMF-28), respectively. The scheme of the MZI is a typically core-mismatch structure, which has the advantages of miniaturization and simplification. Due to the core mismatch between RCF and SMF, the light from the SMF can be well separated into ring core (RC) and silica center (SC) of the RCF at the first splicing point. After transmitting through the RC and SC, the two separated light beams encounter each other and interfere at the second splicing point. Different from conventional micro-fiber MZIs using SMFs or few-mode fibers, the RCF has a higher numerical aperture, which can generate a larger optical path-length difference with a short length fiber, accumulates a higher extinction ratio and suppresses the crosstalk between the core and cladding modes. Therefore, our proposed MZI is more stable and the best extinction ratios can reach up to 18.2 dB. Meanwhile, owing to the core structure of RCF (where SC is surrounded by high-index ring core), the power propagating through low-index area of RCF is mostly confined into SC (termed the silica-center modes). These characteristics would lead to the lower sensitivity to external disturbances.