Rapid Decrease Research Articles

Timing of nitrogen fertilization and shading affect the transition of nitrogen metabolism in senescing leaves of ripening wheat (Triticum aestivum L.)

ABSTRACT The grain yield and protein content of wheat is influenced by the transition of nitrogen metabolism in senescing leaves from pre-anthesis to maturity. To characterize the biochemical processes of the transition, we here analyzed the interactions among greenness, soluble protein, amino acid and protease activity in the flag and second leaves of ripening wheat plants. Nitrogen regimes were adjusted by intensive nitrogen applications in the early (IN (E)) or late stages (IN (L)) along with or without top-dressing at anthesis (±TD). The progress of leaf nitrogen metabolism towards terminal senescence appeared to be split into two phases: the first phase (from pre-anthesis to about 15 days after anthesis (DAA), when leaf greenness did not change appreciably) was characterized by a decrease in soluble protein, and the second phase (after 15 DAA) was characterized by drastic increases in the protease activity followed by a rapid decrease in leaf greenness. The decrease in soluble proteins during the first phase was not accompanied by a rise in protease activity. The rise in protease activity during the second phase was most apparent in the IN (E)-TD plants that were likely under the most severe nitrogen starvation among the treatments. The IN (L) and TD were effective to defer the leaf senescence processes. The shading treatment delayed the rise in protease activity and decrease in leaf greenness. This study suggests that the terminal leaf senescence proceeds in two phases, and the transition between these was accelerated by low nitrogen and slowed by mild shading.

Numerical Investigation of Pore Characteristics in Compacted Sand Layers—Physical Interpretation of Applicability of Kozeny-Carman Equation

Accurate evaluation of permeability in subsurface media is essential for solving problems in various fields, such as environmental and petroleum engineerings. This study aims to numerically investigate the pore characteristics of spherical particle beds imitating compacted sandstones for the physical understanding of the permeability change with porosity. In this study, the structures of monodisperse and polydisperse particle beds are simulated and the pore regions are extracted using various numerical methods. The pore characteristics such as effective porosity, tortuosity, and specific surface area in the bed are quantified. The permeability is then calculated by substituting them into the Kozeny-Carman equation. The obtained permeability is compared with measurement results from actual sandstones. The respective pore characteristics are also evaluated against findings from previous studies. The role of pore characteristics in influencing permeability is investigated to examine changes in permeability in compacted sandstones. Consequently, the respective pore characteristics are modeled as functions of porosity. The effective porosity and tortuosity obtained from the present analysis aligns with both experimental results and the physical models proposed in previous studies. The specific surface area also agrees with the previous experimental results. However, the model proposed in the previous research does not match the experimental and present numerical results at low porosity. Therefore, we develop a new geometric model for specific surface area under low porosity conditions. Based on the numerical results, we assess the applicability of the original Kozeny-Carman equation to actual sandstones composed of deformed particles and analyze its physical interpretation. The results suggest that the rapid increase in tortuosity and the rapid decrease in specific surface area with decreasing porosity cause the Kozeny-Carman equation to maintain its original form even in compacted sandstones.

Rapid Decrease in Dextrose Concentration After Intra-Articular Knee Injection: Implications for Mechanism of Action of Dextrose Prolotherapy

Background: D-glucose (dextrose) is used as a 5000–25,000 mg% solution in the injection-based pain therapy known as dextrose prolotherapy (DPT). The number of peer-reviewed clinical trials supporting its use is growing. However, the mechanism of action is unknown, limiting further research. A commonly expressed theory is that hyperosmotic dextrose injection induces inflammation, initiating a healing-specific inflammatory cascade. In vitro study models have used continuous exposure to high concentration dextrose. But the rate of dextrose clearance after intra-articular injection, and, therefore, the duration of exposure of tissues to any particular dextrose concentration, remains unknown. We therefore determined the rate of dextrose concentration diminution in one human participant’s knees after intra-articular dextrose knee injection. Method: In this pre–post N-of-1 study, the first author (KDR), a well 70-year-old male without knee-related pathology, injected his own knees with 30 mL of 12,500 mg% dextrose on three occasions; performed serial aspirations of 1.2 mL of intra-articular fluid from 7 to 360 min post-injection; and assessed synovial dextrose concentration. Dextrose clearance kinetics were determined using Minitab and GraphPad Prism software. Results: Dextrose concentration dropped rapidly in all three trials, approximating an exponential or steep S curve. A third order chemical reaction pattern was found, suggesting factors other than dilution or glucose transporter activity, such as rapid diffusion of dextrose across the synovial membrane, may have contributed to the rapid drop in dextrose concentration. Conclusion: This pre-post N-of-1 study shows that, after intraarticular injection of 30 mL of 12,500 mg% dextrose injection into a well knee, the concentration of dextrose diminished rapidly, suggesting that intra-articular cells, tissue, and anatomic structures are exposed to an initially high dextrose concentration for a very short time. This likely affects the mechanism of action of DPT and should inform in vitro study methods.

Comparison of the Effectiveness and Hypocalcemia Risk of Antiresorptive Agents in Patients with Hypercalcemia of Malignancy.

Hypercalcemia of malignancy (HCM), a major metabolic complication of cancer, is often managed with bisphosphonates (BP) and, increasingly, with denosumab. We aimed to compare the effectiveness and safety of denosumab with that of BP, with or without calcitonin, in treating HCM. This retrospective cohort study was conducted at a tertiary hospital from 2017 to 2022 and included 317 patients treated for HCM. Participants were divided into three treatment groups: denosumab, intravenous (IV) BP only, and IV BP combined with calcitonin. The primary outcomes measured were changes in calcium levels and the incidence of hypocalcemia. Analysis of covariance was used to adjust for age, sex, body mass index, creatinine level, type of malignancy, and the use of furosemide and steroids. The mean participant age was 65 years, and 37.5% were female. After adjustment, both denosumab and IV BPs were found to effectively lower calcium levels. Denosumab led to a decrease of 2.0 mg/dL (-15.9%), while IV BP alone resulted in a reduction of 1.8 mg/dL (-13.9%). The largest reduction, of 2.7 mg/dL (-20.9%), occurred with IV BP and calcitonin. Both denosumab and IV BP+calcitonin yielded their lowest calcium levels within 48 hours, whereas the IV BP only group reached a nadir within 72 hours. Despite these differences in treatment effectiveness, hypocalcemia occurred significantly less frequently in the denosumab group compared to the other groups. Denosumab and IV BP were similarly effective in reducing calcium levels. However, IV BP combined with calcitonin yielded a more rapid and pronounced decrease.

Thermally-Stable Temperature-Independent Tunneling Magnetoresistance in all van der Waals Fe3GaTe2/GaSe/Fe3GaTe2 Magnetic Tunnel Junctions.

Thermal stability is of great significance for the next-generation two-dimensional (2D) non-volatile spintronic devices. Typically, as the temperature increases, the spin polarization of materials decreases rapidly following the Bloch 𝑇3/2 law in low-temperature regions, resulting in a rapid decrease in the tunneling magnetoresistance (TMR) of the magnetic tunnel junction (MTJ). Owing to the thermal effects induced by current during the writing processes, even small temperature fluctuations can result in significant variations in the TMR of MTJs, hindering their practical applications. In this paper, all-van der Waals Fe3GaTe2/GaSe/Fe3GaTe2 (FGaT/GaSe/FGaT) MTJ devices are constructed, achieving a TMR ratio of 47% at low temperatures and 17% at room temperature. Importantly, the TMR ratio remains stable within a temperature range from 2 to 160 K, breaking the Bloch 𝑇3/2 law. The temperature-independent TMR is highly related to the enhanced perpendicular magnetic anisotropy (PMA) with reduced dimensionality is demonstrated. This work paves a promising path to achieve high-performance, thermally stable 2D spintronic memory chips.

Electro-chemo-mechanical deterioration of high-dose electron irradiated Li1.3Al0.3Ti1.7(PO4)3 electrolyte

Solid-state electrolytes (SSEs) hold promises for aerospace and satellite applications, owing to their high-voltage and low-temperature stability. However, concerns about electrochemical degradation under high-energy radiation hinder their widespread use in space. To this end, a NASICON-type Li1.3Al0.3Ti1.7(PO4)3 (LATP) electrolyte with high ionic conductivity at room temperature was selected, and the effects of high-dose electron irradiation on the microstructure as well as electrochemical and mechanical properties of electrolyte were investigated by using neutron powder diffraction (NPD), NPD stress analysis, micro-computed tomography, nanoindentation, and XRD residual stress test. It was confirmed that LATP SSEs held good resistance to irradiation at absorbed doses of 1 and 2 MGy with negligibly performance degradation, while irradiation at high doses induced a rapid decrease in the Young modulus and hardness of SSEs and introduced a tensile stress of 65.79 MPa at up to 10 MGy absorbed dose, which increased the cracking tendency and the risk of lithium dendrite growth in the solid-state electrolyte. NPD revealed that the reduction of lithium vacancies at the M1 site of the irradiated SSEs was the critical factor for the ion transport performance degradation. This is evidenced by a significant increase in impedance, up to 453 Ω, and an increase in the activation energy for ion transport to 0.501 eV.

Structural and functional responses of soil fungal and bacterial communities to a lithium contamination gradient.

The use of lithium (Li) in decarbonization strategies has positioned it as a central component of modern technological advances, particularly in battery applications. However, the increasing demand for Li has raised concerns about its environmental consequences, which are poorly documented. This study aimed to fill this knowledge gap by examining the impact of Li on soil bacterial/fungal communities. Using a microcosm approach, we explored the impacts of increasing Li concentrations on both microbial community structure and activities. Our results revealed significant changes in bacterial/fungal communities, particularly in the bacterial communities. Most of the indicator species were negatively correlated with the Li gradient, reinforcing the harmful effect of Li. Proteobacteria dominated at low concentrations, whereas Firmicutes were the most abundant at high concentrations. OTUs affiliated with the genus Alicyclobacillus represented >29% of the total affiliated OTUs at the highest Li concentrations. Moreover, Alicyclobacillus fastidiosus showed resilience and specific adaptation to Li. Fungal communities showed less pronounced changes, with Mucoromycota remaining the dominant phylum at all concentrations. Nevertheless, some genera presented correlations with Li concentration, particularly the plant mutualists Leptodontidium, Oidiodendron, and Solicoccozyma. In addition, rapid decreases in several enzymatic activities crucial for the functioning of the carbon, nitrogen and phosphorus cycles were noted. Accordingly, microbial respiration was also impacted by high Li concentrations. Finally, a correlative analysis linked the decreases in enzyme activity to decreases in the abundances of both Proteobacteria and Ascomycota. These results underline the multiple impacts of Li on bacterial/fungal communities, highlighting both structural alterations and changes in microbial activities.

Quartz textures, trace elements, fluid inclusions, and in situ oxygen isotopes from Aktogai porphyry Cu deposit, Kazakhstan

Abstract The Paleozoic Aktogai Group in Kazakhstan ranks among the 30 largest porphyry Cu deposits globally. The Aktogai deposit is the largest one in the Aktogai Group and is characterized by intensive potassic alteration where the dominant orebody occurred. However, its mineralization processes still need to be clarified. Our investigation focused on the texture, trace elements, fluid inclusions, and in situ oxygen isotopes of the quartz from the ore-related tonalite porphyry and associated potassic alteration at Aktogai to trace the deposit’s mineralization processes. Ti-in-quartz thermobarometry, fluid inclusion microthermometry, and geological characteristics indicate that the ore-related magma at Aktogai originated from a shallow magma chamber at ∼1.9 ± 0.5 kbar (∼7.2 ± 1.9 km) and intruded as the tonalite porphyry stock at ∼1.7–2.4 km. The potassic alteration and associated Cu mineralization comprise five types of veins (A1, A2, B1, B2, and C) and two types of altered rocks (biotite and K-feldspar). Among them, nine types of hydrothermal quartz were identified from early to late: (1) VQA1 in A1 veins and RQbt in biotite-altered rocks; (2) VQA2 in A2 veins and RQkfs in K-feldspar altered rocks; (3) VQB1 in B1 veins and VQB2E in B2 veins; and (4) quartz associated with Cu-Fe sulfides (VQB2L, VQBC, and VQC) in B and C veins. Titanium contents of the quartz decreased, while Al/Ti ratios increased from early to late. Fluid inclusion microthermometry and mineral thermometers reveal that VQA1, RQbt, and hydrothermal biotite formed under high-temperature (∼470–560 °C) and ductile conditions. VQA2, RQkfs, VQB1, and hydrothermal K-feldspar formed during the transition stage from ductile to brittle, with temperatures of ∼350–540 °C. The rapid decrease in pressure from lithostatic to hydrostatic pressure led to fluid boiling and minor involvement of meteoric water (∼11–14%) in the mineralizing fluid. Extensive recrystallization in VQA1 to VQB1 was associated with repeated cleavage and healing of the intrusion. With cooling, K-feldspar decomposition and hydrolysis increased. Fluid cooling and water-rock reactions resulted in the co-precipitation of Cu-Fe sulfides, white mica, chlorite, VQBC, and VQC at temperatures of ∼275–370 °C and brittle conditions. The Paleozoic Aktogai deposit exhibits formation depths and fluid evolution processes similar to Mesozoic and Cenozoic porphyry Cu deposits worldwide. The close association between Cu-Fe sulfides and later quartz formed under intermediate-temperature conditions at Aktogai implies that Cu-Fe sulfides are not precipitated under early high-temperature conditions in porphyry Cu deposits.

An analytical model for predicting the shear fracture behavior of discontinuities with multi-scale asperities incorporating the damage element method

Asperities within discontinuities play a critical role in contributing to shear resistance. However, their influence on the shear fracture behavior of discontinuities is constrained by size effects. Revealing and predicting the fracture process of discontinuities with multi-scale asperities is crucial for guiding engineering stability assessment. In this study, PFC2D was employed to simulate the microscopic fracture process of discontinuities with multi-scale asperities under shear loading conditions. The simulation revealed that first-order asperities predominantly experience wear failure, whereas second-order asperities primarily undergo shear failure. Based on these findings, the damage evolution equation for the microscopic elements of first-order asperities was formulated using classical wear theory, while the equation for second-order asperities employed Weibull distribution statistical theory. Consequently, an analytical model was developed that considers the influence of multi-scale asperities on the shear behavior of discontinuities incorporating the damage element method. Subsequently, this analytical model was validated against experimental data and numerical results, demonstrating its capability to accurately predict the rapid stress decrease following the peak point. Finally, the sensitivity of the model parameters was discussed.

Abstract TP356: Nucleocytoplasmic shuttling of Sirt1 and Sirt2 during cerebral ischemia

Background and Rationale: Acute hyperglycemia caused by cerebral ischemia occurs when there is a lack of oxygen, resulting in anaerobic glycolysis. The Sirt1 and Sirt2 initiate the influence on glucose metabolism and cellular homeostasis through nucleocytoplasmic shuttling. We observed nuclear-cytoplasmic translocation of Sirt1 and Sirt2 during anaerobic glycolysis in the brain. Methods: We investigated differences between young and aged mice in a non-fasting group of cerebral ischemia model. Young mice were subjected to time-dependently ischemia induction (0, 1, 2, or 3 h) without reperfusion, and aged mice underwent ischemia for 1 h. All mice measured relative cerebral blood flow using a Laser Doppler. To evaluate the cerebral cortex was separated from nuclear and cytoplasmic fractions by Western blotting. Results: Aged mice had a more rapid and dramatic decrease in relative cerebral blood flow compared to young mice. Cytoplasmic-Sirt1 was elevated and cytoplasmic-Sirt2 did not change in young mice. In both young and aged mice in the ipsilateral cerebral cortex during 1 h ischemia, Sirt1 activity shifted from the nucleus to the cytoplasm, and Sirt2 activity shifted from the cytoplasm to the nucleus. Conclusion: Cellular senescence can contribute to the accelerating glucose metabolism and aging processes in cerebral ischemia. We demonstrated that ischemia accelerates aging-like processes in the brain. These processes are mediated through the upregulation of the cytoplasmic-Sirt1 and nuclear-Sirt2 pathways. Key words: Stroke, Ischemia, middle cerebral artery occlusion, nucleocytoplasmic shuttling, Sirt1, Sirt2

Effects of hyperglycemia on neuronal network function in an in vitro model of the ischemic penumbra

IntroductionHyperglycemia is common in acute ischemic stroke, and associated with unfavorable outcome. However, the optimal glucose level is not known and cellular effects of hyperglycemia under hypoxia are largely unclear. We assessed how the extracellular glucose concentration affects cultured neuronal networks under experimental in vitro conditions, to provide a starting point for assessment of mechanisms at the neuronal network and cellular levels. MethodsWe used in vitro cultured rat neuronal networks on micro-electrode arrays (MEAs) and glass coverslips. Twenty-four hours of controlled hypoxia was induced. We measured neuronal network activity during baseline (normoxia, 6 h), 24 h of hypoxia, and 6 h after reoxygenation, defined as the summed number of action potentials in 1 h bins. Apoptosis was determined intermittently with caspase 3/7 staining and microscopy. We compared groups of networks under glucose concentrations of 5.0 mmol/L, 7.0 mmol/L, 9.0 mmol/L, and 12.0 mmol/L. ResultsOverall, during hypoxia, a gradual decrease in neuronal network activity and increase in apoptosis was found. There were faster decrease in activity (p < 0.01) and more apoptosis after 24 h of hypoxia under glucose levels of 12 mmol/L in a single-well MEA set-up (p < 0.05), and more apoptosis in glass coverslips with glucose levels of 12.0 mmol/L in comparison with 5 mmol/L (p = 0.03). These differences were not observed in multi-well MEAs, in which effects of hypoxia were much smaller than in single-well MEAs. ConclusionHyperglycemia was associated with a more rapid decrease of neuronal network activity during and more apoptosis after 24 h of hypoxia in cultured neuronal networks. Loss of neuronal activity and apoptosis probably play a role in poorer outcomes of stroke patients under hyperglycemia. Our model provides a starting point for further assessment of pathomechanisms.

Proteomic insights into dual-species biofilm formation of E. coli and E. faecalis on urinary catheters

Infections associated with urinary catheters are often caused by biofilms composed of various bacterial species that form on the catheters’ surfaces. In this study, we investigated the intricate interplay between Escherichia coli and Enterococcus faecalis during biofilm formation on urinary catheter segments using a dual-species culture model. We analyzed biofilm formation and global proteomic profiles to understand how these bacteria interact and adapt within a shared environment. Our findings demonstrated dynamic population shifts within the biofilms, with E. coli initially thriving in the presence of E. faecalis, then declining during biofilm development. E. faecalis exhibited a rapid decrease in cell numbers after 48 h in both single- and dual-species biofilms. Interestingly, the composition of the dual-species biofilms was remarkably diverse, with some predominantly composed of E. coli or of E. faecalis; others showed a balanced ratio of both species. Notably, elongated E. faecalis cells were observed in dual-species biofilms, a novel finding in mixed-species biofilm cultures. Proteomic analysis revealed distinct adaptive strategies E. coli and E. faecalis employed within biofilms. E. coli exhibited a more proactive response, emphasizing motility, transcription, and protein synthesis for biofilm establishment; whereas E. faecalis displayed a more reserved strategy, potentially downregulating metabolic activity, transcription, and translation in response to cohabitation with E. coli. Both E. coli and E. faecalis displayed significant downregulation of virulence-associated proteins when coexisting in dual-species biofilms. By delving deeper into these dynamics, we can gain a more comprehensive understanding of challenging biofilm-associated infections, paving the way for novel strategies to combat them.

Nanoconfinement-Driven Energy-Efficient CO2 Capture and Release at High Pressures on a Unique Large-Pore Mesoporous Carbon.

Although microporous carbons can perform well for CO2 separations under high pressure conditions, their energy-demanding regeneration may render them a less attractive material option. Here, we developed a large-pore mesoporous carbon with pore sizes centered around 20-30 nm using a templated technical lignin. During the soft-templating process, unique cylindrical supramolecular assemblies form from the copolymer template. This peculiar nanostructuring takes place due to the presence of polyethylene glycol (PEG) segments on both the Pluronic® template and the PEG-grafted lignin derivative (glycol lignin). A large increase in CO2 uptake occurs on the resulting large-pore mesoporous carbon at 270 K close to the saturation pressure (3.2 MPa), owing to capillary condensation. This phenomenon enables a CO2/CH4 selectivity(SCO2/CH4,mol/mol) of 3.7 at 270 K and 3.1 MPa absolute pressure, and a swift pressure swing regeneration process with desorbed CO2 per unit pressure far outperforming a benchmark activated carbon (i.e., notably rapid decrease in the amount of adsorbed CO2 with decreasing pressure). We propose large-pore mesoporous carbons as a novel family of CO2 capture adsorbents, based on the phase-transition behavior shift of CO2 in the nanoconfined environment. This novel material concept may open new horizons for physisorptive CO2 separations with energy-efficient regeneration options.

Optimization of the Geometric Characteristics of Damping Layers for Acoustic Black Hole Beams Based on the Backpropagation Algorithm

In real-world scenarios, it is common to apply a damping layer of a specific thickness to the surface of an acoustic black hole (ABH) beam to boost its energy dissipation capacity. However, it has become apparent that excessive damping layers might result in negative consequences. The present study suggests employing the backpropagation (BP) algorithm to refine the positioning, thickness, and contour of the damping layer for optimal results. This study begins with the derivation of a semi-analytical solution for the vibration characteristics of an ABH beam under a harmonic load using the Gaussian expansion method (GEM). This process results in the preliminary identification of a thickness profile for the damping layer that exhibits significant potential for energy dissipation. Subsequently, a BP neural network is trained on the data produced by the semi-analytical solution to further optimize this thickness variation function. The findings reveal that the geometry of the damping layer has a more complex influence on performance than previously recognized. The optimization guided by the BP neural network suggests that achieving a strong ABH effect does not require uniform application of the damping layer across the entire ABH section. Rather, the most effective approach is to concentrate the damping layer thickness at the ABH tip, with a rapid decrease in thickness as one moves away from this point. It is also determined that applying a damping layer in areas far from the tip is unnecessary. Additionally, an innovative strategy is proposed to enhance the system’s energy dissipation capabilities without changing the truncation thickness of the ABH beam. This research contributes to a deeper understanding of how the damping layer affects the energy dissipation performance of ABH beams.

Multifaceted changes in water availability with a warmer climate

Climate warming alters spatial and seasonal patterns of surface water availability (P-E), affecting runoff and terrestrial water storage. However, a comprehensive assessment of these changes across various hydroclimates remains lacking. We develop a multi-model ensemble approach to classify global terrestrial hydroclimate into four distinct regimes based on the mean and seasonality of P-E. P-E is projected to become increasingly variable across space and time. Wet regions with low and high seasonality are likely to experience more concentrated increases in wet-season runoff by up to 20%, highlighting potential increases in flood-related vulnerability. Low-seasonality regions exhibit faster wet-season increases and more rapid dry-season decreases in soil moisture, heightening the likelihood of water scarcity and drought. Conversely, dry regions with high seasonality are less sensitive to climate change. These findings underscore the multifaceted impacts of climate change on global water resources, necessitating the need for tailored adaptation strategies for different hydroclimate regimes.

The Impact of Adverse Childhood Experiences on the Development of Adolescent Risk-Taking: The Mediating Effect of Self-Control and Moderating Effect of Genetic Variations.

Risk-taking is a concerning yet prevalent issue during adolescence and can be life-threatening. Examining its etiological sources and evolving pathways helps inform strategies to mitigate adolescents' risk-taking behavior. Studies have found that unfavorable environmental factors, such as adverse childhood experiences (ACEs), are associated with momentary levels of risk-taking in adolescents, but little is known about whether ACEs shape the developmental trajectory of risk-taking. Even less research has investigated the underlying mechanisms. Drawing on the self-regulation theory, this study examined the associations between ACEs and the developmental trajectory of adolescent risk-taking. Moreover, it also explored self-control as a mediator and genetic variations as a moderator from a "gene × environment" approach. Participants were 564 Chinese adolescents (48.40% males, Mage = 14.20 years, SD = 1.52). Adolescents reported their ACEs and self-control at T1 and risk-taking three times, with a six-month interval between each time point. Adolescents' saliva was collected at T1 for genetic extraction, and polygenetic index was created based on the gene-by-environment interaction between SNPs and ACEs for self-control via the leave-one-out machine learning approach. Findings of latent growth modeling revealed that adolescents' risk-taking decreased over time. ACEs were directly and indirectly through self-control associated with high initial levels of, and a rapid decrease in, risk-taking, especially for those with a higher polygenetic index compared to those with a lower polygenetic index. Theoretically, these results suggest a tripartite model of adolescent risk-taking, such that risk-taking is the combined function of adverse experiences in early years, low self-control, and carriage of sensitive genes. Practically, intervention strategies should reduce childhood adversities, build up self-control, and consider the potential impacts of genetic plasticity.

Monitoring changes and multi-scenario simulations of land use and ecosystem service values in coastal cities: A case study of Qingdao, China.

The study of land cover dynamics and the valuation of ecosystem services in coastal cities is pivotal for guiding sustainable urban development and conserving natural resources amidst the unique challenges posed by their geographical and ecological contexts. This study utilizes a 30m × 30m land use/cover change (LUCC) dataset to elucidate the spatiotemporal evolution of LUCC and ecosystem service value (ESV) and the trade-offs and synergistic relationships among ecosystem services in the coastal city of Qingdao under three different scenarios over the past 35years and in the future based on the dual perspective of the past-future by using the equivalent factor approach (EFA), the PLUS model, and Spearman's rank correlation coefficient. The findings reveal a pronounced expansion in built-up areas in Qingdao from 1985 to 2020, with a concomitant significant reduction in cropland, leading to a fluctuation in the total ESV, which initially increased and then declined. This indicates the intense pressure Qingdao faces in terms of agricultural development and ecological conservation. By 2030, under scenarios of natural development, cropland protection, and ecological protection, Qingdao is projected to experience varied degrees of ESV decline, amounting to 1.989 billion, 0.803 billion, and 0.142 billion yuan respectively, with the natural development scenario showing a rapid decrease in ESV around the Jiaozhou Bay area. The spatial ESV patterns under the cropland protection and ecological protection scenarios remain largely consistent with those of 2020, as does the spatial configuration of land use across all scenarios. The ecological protection scenario, demonstrating the least reduction in ESV, emerges as the optimal strategy for balancing urban development with ecological sustainability, advocating it as the preferred pathway for Qingdao's future urban planning. Over the past 35 years, Qingdao's ecosystem services have primarily exhibited synergies, although significant trade-offs remain between agricultural expansion and water supply. Additionally, there are some trade-offs between gas regulation and nutrient cycling with water supply. Under different scenarios for 2030, while the trade-off between agricultural output and water resource conservation persists, the ecologicalprotection scenario significantly enhances synergies among all service categories. This study provides an EFA-PLUS-ESV framework that offers innovations for modeling future ecosystem service values and their trade-offs and synergistic relationships.

A Multi-Regime Car-Following Model Capturing Traffic Breakdown

Traffic breakdown refers to the first-order transition from free flow to synchronized flow. It is characterized by a rapid decrease in speed, suddenly increasing density, and abruptly plummeting capacity in most of the relevant observations. To understand its cause and model its empirical observations, a multi-regime car-following model is proposed, which classifies the car-following state into four regimes, i.e., Free driving, High-speed following, Low-speed following, and Emergency. Simulation results demonstrate that traffic breakdown and spontaneous jam formation can be reproduced simultaneously by the new model. Experimental verification has shown that the new model can successfully simulate the observed concave growth pattern of traffic oscillations.

Increasing temporal stability of global tropical cyclone precipitation

Tropical cyclone (TC) precipitation has led to escalating urban flooding and transportation disruptions in recent years. The volatility of the TC rain rate (RR) over short periods complicates accurate forecasting. Here, we use satellite-based observational rainfall datasets from 1998 to 2019 to calculate changes in TC 24-h RR and quantify the temporal stability of TC precipitation. We demonstrate a significant global increase in the annual temporal stability of TC RR across the total rainfall area, inner-core, and rainband areas. Specifically, the probabilities of rapid RR increase and decrease events in the TC total rainfall area decreased at rates of –1.74 ± 0.57% per decade and –2.23 ± 0.55% per decade, respectively. Based on the reanalysis dataset, we propose that the synergistic effects of increased atmospheric stability and total column water vapor—both resulting from anthropogenic warming at low latitudes—are potentially associated with this trend.

Transcriptomic Insights into Post-Spawning Death and Muscle Atrophy in Ayu (Plecoglossus altivelis).

In semelparous species like the ayu (Plecoglossus altivelis), spawning is followed by rapid physiological decline and death; yet, the underlying molecular mechanisms remain largely unexplored. This study examines transcriptomic changes in ayu skeletal muscle before and after spawning, with a focus on key genes and pathways contributing to muscle atrophy and metabolic dysfunction. Through RNA sequencing and DEG analysis, we identified over 3000 DEGs, and GSEA and KEGG pathway analysis revealed significant downregulation of energy metabolism and protein degradation. In post-spawning ayu, a rapid decrease in body weight was observed, accompanied by a decline in the expression of myosin heavy chain genes, which are major muscle protein genes, and gene expression changes indicative of muscle atrophy. Decreased expression of AP-1 transcription factors associated with muscle development and aging was also evident. PPI network analysis identified carbohydrate catabolism protein gapdh may be the key factor that led to muscle atrophy and accelerated aging in ayu. Our study revealed that after spawning, the ayu muscle tissue undergoes strong metabolic disorders and cellular stress responses, providing special insights into the mechanisms through the post-spawning death of ayu.