Search Results (121)

Understanding root decomposition dynamics is essential to address declining carbon sequestration and nutrient imbalances in monoculture plantations. This study elucidates how forest gaps regulate Pinus massoniana root decomposition through comparative methodological analysis, providing theoretical foundations for near-natural forest management and carbon–nitrogen cycle optimization in plantations. The results showed the following: (1) Root decomposition was significantly accelerated by the in situ soil litterbag method (ISLM) versus the traditional litterbag method (LM) (decomposition rate (k) = 0.459 vs. 0.188), reducing the 95% decomposition time (T_0.95) by nearly nine years (6.53 years vs. 15.95 years). ISLM concurrently elevated the root potassium concentration and reconfigured the relationships between root decomposition and soil nutrients. (2) Lower-order roots (orders 1–3) decomposed significantly faster than higher-order roots (orders 4–5) (k = 0.455 vs. 0.193). This disparity was amplified under ISLM (lower-/higher-order root k ratio = 4.1) but diminished or reversed under LM (lower-/higher-order root k ratio = 0.8). (3) Forest gaps regulated decomposition through temporal phase interactions, accelerating decomposition initially (0–360 days) while inhibiting it later (360–720 days), particularly for higher-order roots. Notably, forest gap effects fundamentally reversed between methodologies (slight promotion under LM vs. significant inhibition under ISLM). Our study reveals that conventional LM may obscure genuine ecological interactions during root decomposition, confirms lower-order roots as rapid nutrient-cycling pathways, provides crucial methodological corrections for plantation nutrient models, and advances theoretical foundations for precision management of P. massoniana plantations. Full article

Plant-specific WUSCHEL (WUS)-related homeobox (WOX) family of transcription factors are involved in apical meristem maintenance, embryogenesis, lateral organ development, and hormone signaling. Among the members of this family, WOX1 is known to play essential roles in many species. However, the function of the peony ‘Feng Dan’ (Paeonia ostii L.) WOX1 (PoWOX1) remains unknown. The initial bioinformatic analysis revealed that PoWOX1 belongs to the modern clade of the WOX gene family and has a highly conserved homeodomain (HD), the WUS motif, the STF-box, and the MAEWEST/WOX4-box. Subsequent heterologous overexpression in Arabidopsis thaliana revealed that PoWOX1 promotes root growth, early shoot initiation, and flowering. The root vascular tissues, especially the arrangement and size of xylem cells, were different between the PoWOX1-overexpressing transgenics and the wild-type plants, and the pericycle cells adjacent to the xylem divided more easily in the transgenics than in the wild type. Furthermore, under in vitro conditions, the transgenic leaf explants exhibited more callus induction and differentiation than the wild-type leaf explants. Thus, the study’s findings provide novel insights into the role of PoWOX1 in promoting root development and callus tissue induction and differentiation, serving as a reference for developing an efficient regeneration system for the peony. Full article

Investigating the contribution and interaction of water transport pathways in plant roots is important for understanding the functioning of the root hydraulic system. In this study, the real-time dynamics of lateral water transport along the cell-to-cell pathway and the diffusional water permeability of cells in the root suction zone of whole maize plants were investigated non-invasively by spin-echo NMR in response to rapid blockage of root apoplast. Apoplast blockage was carried out by insoluble precipitates using an original approach based on alternate incubation of whole plant roots in aqueous solutions of K₄[Fe(CN)₆] and CuSO₄. In the first stage after the apoplast blockage, the water transport along the cell-to-cell pathway and the diffusional water permeability of root cells was decreased 2.5 times. Using inhibitory analysis and gene expression analysis, it was shown that root aquaporins are involved in the decrease in cell-to-cell water transport in response to apoplast blockage. After an initial decrease, the cell-to-cell water transport was restored to initial values. At the same time, there was a partial compensation of the transpiration loss caused by the apoplast blockage. It is assumed that the apoplastic water flow in plant roots can modulate the cell-to-cell water transport and functional activity of aquaporins. Full article

The landmark Philippine Supreme Court case Llorente vs. Llorente illuminates the complex intersections of transnational migration, inheritance law, and colonial legacies in the Philippines. The case centers on Lorenzo Llorente, a Filipino US Navy serviceman whose estate became the subject of a fifteen-year legal battle between his first wife Paula and his second wife Alicia. Lorenzo returned from the battles of World War II to find his wife in Nabua living with his brother and pregnant with his brother’s child. Lorenzo obtained a divorce in California in 1952. He later returned to the Philippines and married Alicia, naming her and their three adopted children as heirs in his will. Upon his death in 1985, Paula challenged the validity of the US divorce and claimed rights to Lorenzo’s estate under Philippine succession laws. While lower courts initially favored Paula’s claims by rigidly applying Philippine laws that are rooted in the colonial era and privileged blood relations, the Supreme Court ultimately upheld Lorenzo’s will in 2000, recognizing his right to divorce as a US citizen. This case reveals how postcolonial Philippine legal frameworks, still heavily influenced by Spanish colonial law, often fail to accommodate the complex realities of transnational families and diverse kinship practices, instead imposing rigid interpretations that fracture rather than heal family relations. Inheritance, previously a highly shared and negotiated process mediated by the elders, can now escalate to family disputes which play out in the impersonal space of the courtroom. Full article

This paper introduces a method of monitoring infrared channel calibration stability through direct comparison of calibrated radiances by two Advanced Baseline Imager (ABI) on two geostationary (GEO) platforms. This GEO-GEO comparison is based on radiances in the overlapping area observed by the two ABIs, pixel by pixel, at approximately the same time, location, spectrum, and viewing zenith angle. It was initially developed for GOES-17 and subsequent GOES missions to validate the ABI’s calibration around its local midnight—a subject of particular interest for instruments on three-axis stabilized geostationary satellites. With the cryocooler anomaly of the GOES-17 ABI, however, the GEO-GEO comparison became an indispensable tool to characterize GOES-17 ABI infrared (IR) channel calibration with high frequency, low uncertainty, and in near real time, providing critical feedback to root cause investigation and mitigation options. Later, the GEO-GEO comparison was applied to the GOES-18 ABI as originally intended and was proved successful. It confirms that, with few exceptions, radiometric calibration for all ABIs is stable to within 0.1 K when the radiance fluctuation is converted to the brightness temperature at 300 K. Full article

Understanding the mechanisms of converting plant residue carbon (C) into soil C is important for managing the soil C pool and improving soil fertility. However, little is known yet about how the heterogeneous C from the plant residues, e.g., from the various plant parts, is bound in the aggregates of soil with different initial fertility. To address this, an incubating experiment was carried out through the addition of the ¹³C-labelled aboveground (stems and leaves) and belowground (roots) residue of maize into Mollisols with high and low fertility. Soil aggregates (> 250 μm and < 250 μm) were sieved, and their δ¹³C of soil organic carbon (SOC) was quantified. The amino sugar content (calculating for microbial residue C, MRC) and the contribution of MRC to the SOC pool (MRC/SOC) were calculated. The results showed that the SOC and maize residue-derived carbon (MDC) concentrations decreased quickly at the beginning, and then, the decrease slowed down until reaching a relatively constant level, and the two stages corresponded to two main microbial anabolism processes, which were entailing synthesizing living microbial biomass and producing microbial residues, respectively. During the beginning period, limited priming effects were observed, but this priming effect is stronger in the macroaggregates of high-fertility soil. The study further proved the existing conclusion that soil fertility and maize residue quality both influenced the C sequestration in the short term but not in the long term in macroaggregates. In the microaggregates, however, only maize residue quality influenced the C sequestration in the long term. In addition, the microaggregates exhibited higher MDC and SOC concentration, and reached a steady state for the MRC/SOC dynamics later than the macroaggregates. These indicated that the microaggregates had a larger C sequestrating capacity than the macroaggregates. The results suggest that soil aggregates are a major factor influencing exogenous C sequestration, even regulating the effective duration of soil fertility and plant quality. Full article

The application of an environmentally friendly plant growth regulator to regulate plant growth and development represents a promising strategy for sustainable agriculture. Thymol is a kind of plant-derived natural compound. We have found that thymol is a potential biostimulant with the capability to trigger plant defense against abiotic stresses. Little is known about whether and how thymol modulates plant root system architecture. In this study, physiological, histochemical, and molecular approaches were applied to identify the role of thymol in promoting lateral root development in watermelon seedlings. Thymol significantly promoted LRP (lateral root primordia) initiation and lateral root formation. Rboh (respiratory burst oxidase homolog)-dependent reactive oxygen species (ROS) generation was involved in thymol-promoted lateral root development from LRP. Then, the Rboh gene family with nine members (ClRboh1–ClRboh9) was identified from watermelon genome. Thymol significantly induced the expression of a set of ClRbohs in roots. These results suggested that thymol was able to stimulate lateral root formation by triggering Rboh-dependent ROS production. These findings may help understand the biological function of thymol as an elicitor of lateral root in both applied and fundamental study. Full article

Background: Pathogenic variants within the gene encoding transforming growth factor β (TGF-β) are responsible for Loeys-Dietz syndrome (LDS), a heritable thoracic aortic disease sharing clinical features with Marfan syndrome, including craniofacial and skeletal abnormalities as well as aortic root aneurysms and dissections. In contrast to Marfan syndrome patients, who rarely develop aneurysms or dissections beyond the aortic root, LDS patients frequently exhibit vessel aneurysms in locations other than the aortic root. Here, we report the case of a 61-year-old patient who initially presented with marfanoid characteristics and an aortic root aneurysm and was presumed to have Marfan syndrome two decades ago. Later, the patient developed an abdominal aorta aneurysm, necessitating endovascular repair and stent placement. That fact raised doubts regarding the initial diagnosis of Marfan syndrome, and we decided to investigate the genetic cause of the disorder. Methods: Genetic testing was performed using WES analysis and Sanger sequencing. Results: The genetic analysis detected a de novo heterozygous pathogenic variant c.896G>A in exon 5 of the TGFB2 gene, resulting in the amino acid substitution p. Arg299Gln that has devastating destabilizing structural effects on 3D folding of the protein, as demonstrated by the molecular modeling study we performed. This variant is pathogenic for LDS type 4, partially consistent with the patient’s clinical presentation. Conclusions: Our case emphasizes the significance of precise clinical assessment and genetic verification in patients exhibiting marfanoid characteristics. Furthermore, our findings contribute to the understanding of the diverse clinical spectrum associated with this specific pathogenic variant of TGFB2, underscoring the importance of detailed clinical assessment in expanding knowledge of genotype-phenotype correlations. Accurate diagnosis is crucial for tailored and appropriate management of individuals with heritable thoracic aortic diseases. Full article

Background and Clinical Significance: Dental implants are widely used; however, tooth extraction often results in alveolar bone loss and gingival recession, necessitating bone and connective tissue reconstruction, especially in the esthetic anterior regions. To address these issues, implants are occasionally connected to adjacent teeth, but this remains controversial, as complications (e.g., intrusion of natural teeth) have been observed. This report demonstrates the long-term success of implants replaced after removing maxillary bilateral central incisors and connecting them to lateral incisors with reduced supportive bone due to periodontitis. Case Presentation: A 57-year-old woman with root fractures in maxillary bilateral central incisors, periodontitis, and malocclusion was treated with connecting implants and natural teeth. Bone levels surrounding maxillary bilateral lateral incisors were diminished due to root fractures in adjacent central incisors and periodontitis. After initial periodontal therapy, hopeless maxillary central incisors were extracted, replaced with implants using a digitally simulated surgical guide, and guided bone regeneration and connective tissue grafting were performed. Implants were connected to lateral incisors with provisional restorations, and orthodontic treatment was initiated following digital set-ups incorporating implants into the overall strategy. Final porcelain-fused-to-zirconia restorations were placed after orthodontic treatment. At the 5-year follow-up, gingival morphology, coloration, and position of lateral incisors remained stable. Conclusions: This case demonstrates that connecting implants to natural teeth in the anterior region can effectively maintain periodontal tissues around natural teeth and allow for minimally invasive, short-term, and esthetic treatment. However, careful long-term observation through maintenance is necessary due to limited evidence for this approach in the anterior region. Full article

Mei (Prunus mume Sieb. et Zucc.) is a rare woody species that flowers in winter, yet its large-scale propagation is limited by the variable ability of cuttings to form adventitious roots (ARs). In this study, two cultivars were compared: P. mume ‘Xiangxue Gongfen’ (GF), which roots readily, and P. mume ‘Zhusha Wanzhaoshui’ (ZS), which is more recalcitrant. Detailed anatomical observations revealed that following cutting, the basal region expanded within 7 days, callus tissues had appeared by 14 days, and AR primordia emerged between 28 and 35 days. Notably, compared to the recalcitrant cultivar ZS, the experimental cultivar GF exhibited significantly enhanced callus tissue formation and AR primordia differentiation. Physiological analyses showed that the initial IAA concentration was highest at day 0, whereas cytokinin (tZR) and gibberellin (GA1) levels peaked at 14 days, with ABA gradually decreasing over time, resulting in increased IAA/tZR and IAA/GA1 ratios during the rooting process. Transcriptomic profiling across these time points identified significant upregulation of key genes (e.g., PmPIN3, PmLOG2, PmCKX5, PmIAA13, PmLAX2, and PmGA2OX1) and transcription factors (PmWOX4, PmSHR, and PmNAC071) in GF compared to ZS. Moreover, correlation analyses revealed that PmSHR expression is closely associated with IAA and tZR levels. Overexpression of PmSHR in tobacco further validated its role in enhancing lateral root formation. Together, these findings provide comprehensive insights into the temporal, hormonal, and genetic regulation of AR formation in P. mume, offering valuable strategies for improving its propagation. Full article

In the field of liquid composite moulding (LCM) simulations, a long-standing assumption has dominated–the belief in constant resin viscosity. While effective in many cases, this assumption may not hold for the infusion process, which lasts for an extended period. This impacts the mechanical properties of the cured epoxy, which are crucial for load transfer in polymer structures. The majority of epoxy resins operate on a bipartite foundation, wherein their viscosity undergoes dynamic alterations during the process of cross-linking. Temperature and cross-linking intricately interact, with elevated temperatures initially reducing viscosity due to kinetic energy but later increasing it as cross-linking accelerates. This interplay significantly influences the efficiency of the infusion process, especially in large and intricate moulds. This article explores the significant temperature dependence of epoxy resin viscosity, proposing an accurate model rooted in its non-linear evolution. This model aligns with empirical evidence, offering insights into determining the optimal starting temperature for efficient mould filling. This study presents an advanced infusion model that extends existing non-linear dual-split viscosity approaches by incorporating the experimental validation of viscosity variations. Unlike previous models that primarily focus on theoretical or numerical frameworks, this work integrates experimental insights to optimize infusion temperature for efficient resin infusion in large and complex parts. Building on these findings, a novel mould-filling technique is proposed to enhance efficiency and reduce material waste. Full article

The root system of clonal rootstocks has been poorly studied, despite its crucial importance. Roots not only provide support and nutrition to the plant but also contribute to tolerance to pests, diseases and environmental stresses, in addition to optimizing yields. Although the initial cost of clonal rootstocks is higher, the investment is offset by the reduction in phytosanitary treatments, greater longevity of the trees and a lower mortality rate. The aim of this research was to quantify the root system growth of five clonally propagated dwarf and normal avocado genotypes evaluated in rhizotrons, with the perspective of identifying distinctive characteristics suitable for their possible use in container culture. The avocado clonal plants to be evaluated were placed in rhizotrons and evaluated for six months, where 35 growth variables were evaluated with the aid of a root analyzer program. A randomized complete block design with five treatments (genotypes) and three replications was used under greenhouse conditions. Analysis of variance, variable purge and multivariate analysis were performed. It was found that ‘Duke 7’ and ‘San Martín’ were statistically different for most of variables, with ‘San Martín’ showing less root growth and ‘Duke 7’ showing remarkable lateral growth. The adventitious root system’s growth depends on the genotype, and the use of rhizotrons allows its study, which proved to be a useful methodology for this type of evaluation since it allows the visualization and adequate quantification of root growth. Genotypes with less root growth may be suitable for use in container culture, and roots with extensive lateral growth may be useful in shallow soils. Full article

In the field of multi-robot cooperative localization and task planning, traditional filtering algorithms encounter synchronization and consistency issues during multi-source data fusion. These challenges result in cumulative localization errors and inefficient information sharing, which limits the system’s collaborative capabilities and control accuracy. To overcome these limitations, a distributed cooperative navigation strategy is introduced. Initially, a Distributed Adaptive Extended Kalman Filter (DAEKF) is implemented, which adaptively adjusts the noise covariance matrix to effectively manage nonlinearities and multi-source noise conditions. Subsequently, a Distributed Model Predictive Control (DMPC) framework is introduced. This framework predicts and optimizes each robot’s kinematic model, thereby improving the system’s collaborative operations and dynamic decision-making capabilities. Finally, the efficacy of this strategy is confirmed through detailed simulations and robotic experiments. The simulation results for cooperative localization demonstrate that DAEKF outperforms Kalman Filter (KF) and Extended Kalman Filter (EKF) in terms of localization accuracy. In the straight-line path-tracking experiments, DAEKF effectively reduced both lateral and heading errors for both robots. For Robot 1, DAEKF reduced the lateral error Root Mean Squared Error (RMSE) by 68.87%, 27.80%, and 25.76%, compared to No Filtering, KF, and EKF. In heading error, DAEKF reduced the RMSE by 52.29%, 41.89%, and 36.47%. For Robot 2, DAEKF reduced the lateral error RMSE by 51.30%, 22.88%, and 11.60%, compared to No Filtering, KF, and EKF. In heading error, DAEKF reduced the RMSE by 39.55%, 37.15%, and 26.00%. In the curved path-tracking experiments, both robots demonstrated high trajectory conformity while traveling along a predefined path combining straight-line and circular arc segments, with lateral errors in the straight-line segments all below 0.05 m. The strategy proposed in this study significantly enhanced the precision and stability of multi-robot collaborative navigation, demonstrating strong practicality and scalability. Full article

The root system plays an important role in the efficient absorption of nitrogen (N), but there is limited understanding of the growth characteristics of maize roots of different genotypes and their dynamic response to N supply. In this study, landraces in the 1950s and modern hybrids, modern hybrids and their parents, inbred lines with different N efficiency and standard inbred line B73 were used, combined with the dynamic culture method, to observe the dynamic changes in root growth under long-term N stress conditions. The results showed that there were genotypic differences in the response of maize roots to low N. Low N enhances root growth earlier than the increases in shoot-to-root dry matter allocation. With the extension of low N stress, the root biomass of each genotype basically increased significantly from 3 to 6 days and then was gradually reversed by high N on the 12th day. As for shoot biomass, 11 genotypes began to decrease significantly from 6 to 9 days after low-N stress. The total axial root length, primary root length, seminal root length, and the first and second whorl crown root length of seven genotypes were increased more or less under low N. With the extension of N stress, the number of third and fourth whorl crown roots decreased significantly, which indicated that regulation of root elongation is earlier than that of crown root initiation. As the degree of low-N stress increased, the trend of total lateral root length changes in different genotypes could be divided into three categories, indicating that the response of lateral root growth to low-N stress is genotype-dependent. With the advancement of the breeding process, the roots of modern hybrids become smaller but more responsive to low-N stress. The root phenotypes of Zhengdan958 and Xianyu335 come from different genetic models. Compared with embryonic roots, the crown roots of B73 have a more active role in adapting to low-N stress. Shoot N concentration may reflect plant internal N status, which plays a regulatory role in root morphogenesis. Full article

γ-Aminobutyric acid (GABA), an endogenous amino acid widely found in living organisms, has important functions in plants such as regulating growth and development, maintaining carbon and nitrogen nutrient balance, and coping with adversity. In this study, we investigated the effects of exogenous 0.5 mmol/L GABA on the growth, antioxidant metabolism, and GABA shunt metabolism of tall fescue under 20 μmol/L Cd stress, using tall fescue (Festuca arundinacea) ‘Ruby II’ under hydroponics conditions. The results showed that (1) applying GABA for 3, 7, 11, and 15 d under Cd stress inhibited Cd transport from roots to leaves and promoted plant height, alleviating the effects of Cd stress on plant growth. (2) Exogenous 0.5 mmol/L GABA had an interesting regulatory effect on the activation of the antioxidant enzyme system induced by stress at different stages, which was accompanied by a decrease in malondialdehyde (MDA) contents and alleviated the degree of cell membrane lipid peroxidation under cadmium stress. Specifically, peroxidase (POD) enzyme activity reactions initially responded on the 3rd and 7th days of stress, and the changes in catalase (CAT) enzyme activities concentrated on the 11th and 15th days of the later stage. Ascorbate peroxidase (APX) enzyme was active throughout the whole stress period in the roots. Multiple factorial analyses further proved that the antioxidant pathway strongly influenced the survival and growth of tall fescue under stress in the presence of GABA. (3) Application of exogenous GABA activated the branching pathway for GABA synthesis from Glu decarboxylation (GABA shunt) with a higher contribution in the leaves, which induced changes in glutamate content, and plants maintained a higher endogenous GABA content and signal to regulate the plant antioxidant system and reduce cell membrane damage, thus improving the tolerance of plants to Cd stress. Full article