Explore the vast range of titles available.

The phytohormone auxin and microRNA-mediated regulation of gene expressions are key regulators of plant growth and development at both optimal and under low-temperature stress conditions. However, the mechanistic link between microRNA and auxin in regulating plant cold stress response remains elusive. To better understand the role of microRNA (miR) in the crosstalk between auxin and cold stress responses, we took advantage of the mutants of Arabidopsis thaliana with altered response to auxin transport and signal. Screening of the mutants for root growth recovery after cold stress at 4 °C revealed that the auxin signaling mutant, solitary root 1 (slr1; mutation in Aux/IAA14), shows a hypersensitive response to cold stress. Genome-wide expression analysis of miRs in the wild-type and slr1 mutant roots using next-generation sequencing revealed 180 known and 71 novel cold-responsive microRNAs. Cold stress also increased the abundance of 26–31 nt small RNA population in slr1 compared with wild type. Comparative analysis of microRNA expression shows significant differential expression of 13 known and 7 novel miRs in slr1 at 4 °C compared with wild type. Target gene expression analysis of the members from one potential candidate miR, miR169, revealed the possible involvement of miR169/NF-YA module in the Aux/IAA14-mediated cold stress response. Taken together, these results indicate that SLR/IAA14, a transcriptional repressor of auxin signaling, plays a crucial role in integrating miRs in auxin and cold responses.

The objective of this study is to manage the initial excess reactivity of the VVER-1200 reactor through different approaches, including the use of burnable absorbers and control rods in fuel assemblies with varying enrichments (from 4.95 wt.% to 2.0 wt.%) by using the Monte Carlo code Serpent. It is found that 30 integrated burnable absorbers (IBAs) rods are required to reduce the infinite multiplication factor (k inf ) from 1.32408 to 1.06983 in assemblies containing 4.95 wt.% enriched fuel. On the other hand, assemblies with enrichment below 2.5 wt.% do not require any IBA rods. Control rods (CRs) can also effectively reduce excess reactivity at the beginning of life (BOL), provided they are inserted more than 80% of the assembly’s height. When fully inserted, the CRs provide a reactivity worth of 85.5 pcm/cm in 4.95 wt.% enriched assemblies at BOL. Fuel enrichment has a significant impact on delayed neutron fraction as well as the FTC, and MTC. While the effect of IBA rods on these parameters is found to be insignificant; however they do harden the neutron spectrum at the BOL due to the thermal neutron absorption by isotopes 155 Gd and 157 Gd.

The focus of this work is to analyse the suitability of two-group diffusion coefficients and macro constants generated from SERPENT using out-scattering approximation (OSA), transport correction (TRC) and cumulative migration methods (CMM) for fuel and non-fuel materials. For this purpose, various assembly and core models of ACP-100 SMR were designed. Assessment of these constants was conducted using COMSOL Multiphysics. For six distinct fuels, the best models were proposed with the least error margin in k eff . Fuel material affects the group constants of non-fuel components except for radial reflectors. The sufficiency of two-group calculation was justified through spectrum analysis. Additional analysis revealed that MOX-RG has the hardest spectrum among all the fuels. Moreover, the effectiveness of boric acid to control excess reactivity was observed. Subcriticality was achieved for all fuel types except MOX-RG at a boric acid concentration of 4500 ppm. The influence of variation of boric acid concentrations on group constants was investigated using TRC and OSA. The reactivity difference between SERPENT and COMSOL was determined. It was found that OSA generates the most accurate results for MOX-RG with maximum 863 pcm error, while TRC produces higher accuracy with maximum error of approximately 250 pcm for other fuels.

Background Necrotizing enterocolitis (NEC) is an inflammatory gastrointestinal disease primarily affecting preterm neonates. Neonates with NEC suffer from a degree of neurodevelopmental delay that is not explained by prematurity alone. There is a need to understand the pathogenesis of neurodevelopmental delay in NEC. In this study, we assessed the macroscopic and microscopic changes that occur to brain cell populations in specific brain regions in a neonatal mouse model of NEC. Moreover, we investigated the role of intestinal inflammation as part of the mechanism responsible for the changes observed in the brain of pups with NEC. Methods Brains of mice were assessed for gross morphology and cerebral cortex thickness (using histology). Markers for mature neurons, oligodendrocytes, neural progenitor cells, microglia, and astrocytes were used to quantify their cell populations in different regions of the brain. Levels of cell apoptosis in the brain were measured by Western blotting and immunohistochemistry. Endoplasmic reticulum (ER) stress markers and levels of pro-inflammatory cytokines (in the ileum and brain) were measured by RT-qPCR and Western blotting. A Pearson test was used to correlate the levels of cytokines (ELISA) in the brain and ileum and to correlate activated microglia and astrocyte populations to the severity of NEC. Results NEC pups had smaller brain weights, higher brain-to-body weight ratios, and thinner cortices compared to control pups. NEC pups had increased levels of apoptosis and ER stress. In addition, NEC was associated with a reduction in the number of neurons, oligodendrocytes, and neural progenitors in specific regions of the brain. Levels of pro-inflammatory cytokines and the density of activated microglia and astrocytes were increased in the brain and positively correlated with the increase in the levels pro-inflammatory cytokines in the gut and the severity of NEC damage respectively. Conclusions NEC is associated with severe changes in brain morphology, a pro-inflammatory response in the brain that alters cell homeostasis and density of brain cell populations in specific cerebral regions. We show that the severity of neuroinflammation is associated with the severity of NEC. Our findings suggest that early intervention during NEC may reduce the chance of acute neuroinflammation and cerebral damage.

This article presents a novel perspective on plant embryogenesis, fundamentally differentiating it from the animal embryo model upon which plant models have long been based to discern the genetic and molecular mechanisms. We propose a plant embryonic body plan that aligns developmental and evolutionary insights across all five embryophyte groups (bryophytes, lycophytes, monilophytes, gymnosperms, and angiosperms). This conceptual model is grounded in a Reprogramming Potential (RP) involving an activation (RP1+) -suppression (RP1-) switch (RP1+/RP1-), which integrates embryonic development in a stepwise manner across diverse embryophytes. We further explore the evolutionary trajectory of this body plan, tracing the gradual assembly of the embryophyte genetic toolkit from bryophytes to angiosperms. Key developmental processes, such as the emergence of shoot and root meristems, vascular tissues, and seeds, are also examined within an evo-devo framework. Plant phenotypic plasticity, fundamental to their adaptation and survival, is manifested in two key hallmarks: (A) the iterative, modular growth of shoot and root units, and (B) their remarkable regenerative potential. While traditionally viewed as separate phenomena, we propose a novel, integrative model that connects these hallmarks within the context of plant embryogenesis. Our “proposed universal plant embryonic body plan” reconciles the genetic and molecular mechanisms of Arabidopsis thaliana embryogenesis with the contrasting developmental patterns observed in monocots. This unified model also integrates the concept of root founder cells and collet (shoot-root junction) into an embryonic framework facilitating the study of gene regulatory networks that underpin root evolution and its architecture.

The primary goal of enhancing automatic generation control (AGC) in interconnected multi-area power systems is to ensure high-quality power generation and reliable distribution during emergencies. These systems still struggle with consistent stability and effective response under dynamic load conditions despite technological advancements. This research introduces a secondary controller designed for load frequency control (LFC) to maintain stability during unexpected load changes by optimally tuning the parameters of a Proportional–Integral–Derivative (PID) controller using pelican optimization algorithm (POA). An interconnected power system for ith multi-area is modeled in this study; meanwhile, for determining the optimal PID gain settings, a four-area interconnected power system is developed consisting of thermal, reheat thermal, hydroelectric, and gas turbine units based on the ith area model. A sensitivity analysis was conducted to validate the proposed controller’s robustness under different load conditions (1%, 2%, and 10% step load perturbation) and adjusting nominal parameters (R, Tp, and Tij) within a range of ±25% and ±50%. The performance response indicates that the POA-optimized PID controller achieves superior performance in frequency stabilization and oscillation reduction, with the lowest integral time absolute error (ITAE) value showing improvements of 7.01%, 7.31%, 45.97%, and 50.57% over gray wolf optimization (GWO), Moth Flame Optimization Algorithm (MFOA), Particle Swarm Optimization (PSO), and Harris Hawks Optimization (HHO), respectively.

In this study, a simplified computational model of the blanket mock-up is created using the SERPENT Monte Carlo Code. The nuclear data is obtained from the enriched ENDF/B.VII.1 data library to conduct this study. The model is validated, as the error percentage for 63 Cu(n,2n) 62 Cu and 65 Cu(n,2n) 64 Cu reactions is less than 10% when compared to experimental results. The computational model is used to calculate the tritium production rate in different lithium zones with various neutron multipliers (U, Pb) and without any multipliers. The results show that the tritium production rate with a uranium multiplier is 86% higher than with a lead multiplier and 238% higher than with no multiplier. The neutron energy spectrum shows a peak in the 0.1 MeV to 10 MeV energy range for every case. This study also examines the effects of fusion neutrons on different isotopes, providing valuable data on how materials behave under high-speed neutron exposure.

The plant cell wall is a dynamic structure that changes in response to developmental and environmental cues through poorly understood signaling pathways. We identified two Leu-rich repeat receptor-like kinases in Arabidopsis thaliana that play a role in regulating cell wall function. Mutations in these FEI1 and FEI2 genes (named for the Chinese word for fat) disrupt anisotropic expansion and the synthesis of cell wall polymers and act additively with inhibitors or mutations disrupting cellulose biosynthesis. While FEI1 is an active protein kinase, a kinase-inactive version of FEI1 was able to fully complement the fei1 fei2 mutant. The expansion defect in fei1 fei2 roots was suppressed by inhibition of 1-aminocyclopropane-1-carboxylic acid (ACC) synthase, an enzyme that converts Ado-Met to ACC in ethylene biosynthesis, but not by disruption of the ethylene response pathway. Furthermore, the FEI proteins interact directly with ACC synthase. These results suggest that the FEI proteins define a novel signaling pathway that regulates cell wall function, likely via an ACC-mediated signal.

PurposeThis study aims to investigate the role of the components of intellectual capital (IC) on entrepreneurial opportunity recognition among small and medium enterprises (SMEs) in the Sultanate of Oman. The interrelationships of these components are also examined.Design/methodology/approachThe study used quantitative research methods. Data were collected using structured questionnaires from a sample of 347 respondents from SMEs operating in Oman. Structural equation modeling was employed to examine the hypotheses using partial least square technique.FindingsThe analysis results demonstrate that structural capital, relational capital and spiritual capital have significant relationships with entrepreneurial opportunity recognition. Meanwhile, human capital has no relationship with either entrepreneurial opportunity recognition or spiritual capital. Intriguingly, significant interrelationships are observed among IC's components.Practical implicationsThis study offers useful managerial implications for the related parties: firms, public institutions and other stakeholders. The findings could be a guideline for SME managers/owners to recognize the right entrepreneurial opportunity.Originality/valueTo the best of our knowledge, this study is the first to reveal the relationships between the tripartite model of IC and entrepreneurial opportunity recognition. This study is also the first to test the interrelationship of spiritual capital on other intellectual components.

Women entrepreneurs in the Middle Eastern region, particularly in the United Arab Emirates (UAE), face several challenges (e.g., cultural) coupled with the recent transformation of the digital economy. This issue poses a significant challenge for financing the business operations. Thus, this study aims to find the relationship between prior family business exposure, growth intention, motivation, and financial bootstrapping with the mediating role of prior experiences among women entrepreneurs in the UAE. A quantitative survey questionnaire method was used to collect responses from 318 women business owners in different regions of the UAE. The findings of the study suggest that there is a positive relationship between prior family business exposure and financial bootstrapping and growth intention and financial bootstrapping, and prior experience plays a mediating role among all exogenous variables. The study offers a unique perspective on the intersection between prior family business exposure, growth intention, motivation, and financial bootstrapping, highlighting the mediating role of prior experience in a demographical and geographic context (e.g., UAE) that is under-researched regarding financial strategies.