Low Accumulation Research Articles

Interplay between a polerovirus and a closterovirus decreases aphid transmission of the polerovirus.

Multi-infection of plants by viruses is very common and can change drastically infection parameters such as virus accumulation, distribution, and vector transmission. Sugar beet is an important crop that is frequently co-infected by the polerovirus beet chlorosis virus (BChV) and the closterovirus beet yellows virus (BYV), both vectored by the green peach aphid (Myzus persicae). These phloem-limited viruses are acquired while aphids ingest phloem sap from infected plants. Here we found that co-infection decreased transmission of BChV by ~50% but had no impact on BYV transmission. The drastic reduction of BChV transmission was due to neither lower accumulation of BChV in co-infected plants nor reduced phloem sap ingestion by aphids from these plants. Using the signal amplification by exchange reaction fluorescent in situ hybridization technique on plants, we observed that 40% of the infected phloem cells were co-infected and that co-infection caused redistribution of BYV in these cells. The BYV accumulation pattern changed from distinct intracellular spherical inclusions in mono-infected cells to a diffuse form in co-infected cells. There, BYV co-localized with BChV throughout the cytoplasm, indicative of virus-virus interactions. We propose that BYV-BChV interactions could restrict BChV access to the sieve tubes and reduce its accessibility for aphids and present a model of how co-infection could alter BChV intracellular movement and/or phloem loading and reduce BChV transmission.IMPORTANCEMixed viral infections in plants are understudied yet can have significant influences on disease dynamics and virus transmission. We investigated how co-infection with two unrelated viruses, BChV and BYV, affects aphid transmission of the viruses in sugar beet plants. We show that co-infection reduced BChV transmission by about 50% without affecting BYV transmission, despite similar virus accumulation rates in co-infected and mono-infected plants. Follow-up experiments examined the localization and intracellular distribution of the viruses, leading to the discovery that co-infection caused a redistribution of BYV in the phloem vessels and altered its repartition pattern within plant cells, suggesting virus-virus interactions. In conclusion, the interplay between BChV and BYV affects the transmission of BChV but not BYV, possibly through direct or indirect virus-virus interactions at the cellular level. Understanding these interactions could be crucial for managing virus propagation in crops and preventing yield losses.

An Investigation of Thermomechanical Behavior in Laser Hot Wire Directed Energy Deposition of NAB: Finite Element Analysis and Experimental Validation

Laser Hot Wire (LHW) Directed Energy Deposition (DED) Additive Manufacturing (AM) processes are capable of manufacturing parts with a high deposition rate. There is a growing research interest in replacing large cast Nickel Aluminum Bronze (NAB) components using LHW DED processes for maritime applications. Understanding thermomechanical behavior during LHW DED of NAB is a critical step towards the production of high-quality NAB parts with desired performance and properties. In this paper, finite element simulations are first used to predict the thermomechanical time histories during LHW DED of NAB test coupons with an increasing geometric complexity, including single-layer and multilayer depositions. Simulation results are experimentally validated through in situ measurements of temperatures at multiple locations in the substrate as well as displacement at the free end of the substrate during and immediately following the deposition process. The results in this paper demonstrate that the finite element predictions have good agreement with the experimental measurements of both temperature and distortion history. The maximum prediction error for temperature is 5% for single-layer samples and 6% for multilayer samples, while the distortion prediction error is about 12% for single-layer samples and less than 4% for multilayer samples. In addition, this study shows the effectiveness of including a stress relaxation temperature at 500 °C during FE modeling to allow for better prediction of the low cross-layer accumulation of distortion in multilayer deposition of NAB.

ARR1 and ARR12 modulate arsenite toxicity responses in Arabidopsis roots by transcriptionally controlling the actions of NIP1;1 and NIP6;1.

Cytokinin is central to coordinating plant adaptation to environmental stresses. Here, we first demonstrated the involvement of cytokinin in Arabidopsis responses to arsenite [As(III)] stress. As(III) treatment reduced cytokinin contents, while cytokinin treatment repressed further primary root growth in Arabidopsis plants under As(III) stress. Subsequently, we revealed that the cytokinin signaling members ARR1 and ARR12, the type-B ARABIDOPSIS RESPONSE REGULATORs, participate in cytokinin signaling-mediated As(III) responses in plants as negative regulators. A comprehensive transcriptome analysis of the arr1 and arr12 single and arr1,12 double mutants was then performed to decipher the cytokinin signaling-mediated mechanisms underlying plant As(III) stress adaptation. Results revealed important roles for ARR1 and ARR12 in ion transport, nutrient responses, and secondary metabolite accumulation. Furthermore, using hierarchical clustering and regulatory network analyses, we identified two NODULIN 26-LIKE INTRINSIC PROTEIN (NIP)-encoding genes, NIP1;1 and NIP6;1, potentially involved in ARR1/12-mediated As(III) uptake and transport in Arabidopsis. By analyzing various combinations of arr and nip mutants, including high-order triple and quadruple mutants, we demonstrated that ARR1 and ARR12 redundantly function as negative regulators of As(III) tolerance by acting upstream of NIP1;1 and NIP6;1 to modulate their function in arsenic accumulation. ChIP-qPCR, EMSA, and transient dual-LUC reporter assays revealed that ARR1 and ARR12 transcriptionally activate the expression of NIP1;1 and NIP6;1 by directly binding to their promoters and upregulating their expression, leading to increased arsenic accumulation under As(III) stress. These findings collectively provide insights into cytokinin signaling-mediated plant adaptation to excessive As(III), contributing to the development of crops with low arsenic accumulation.

7005 Characterization of Clinical Candidate Miricorilant in Preclinical Models for NASH

Abstract Disclosure: T.J. Moll: None. E.M. Viho: None. M. Gentenaar: None. H. Hunt: Employee; Self; Corcept Therapeutics. O.C. Meijer: Grant Recipient; Self; Corcept Therapeutics. J. Kroon: Research Investigator; Self; Corcept Therapeutics. Background and aim: Miricorilant (CORT118335) is a selective glucocorticoid receptor (GR) modulator that is under clinical development for the treatment of non-alcohol steatohepatitis (NASH). It was previously shown that miricorilant treatment effectively lowers hepatic lipid content in mouse models of NASH. The aim of this study is to further characterize the effects of miricorilant in the mouse liver and in human liver tissue. Methods: In mouse liver tissue, we investigated the agonistic and antagonistic properties of miricorilant on GR activity. Eight-week-old male C57BL/6J mice were fed with a control diet or miricorilant-supplemented diet (resulting in an estimated dose of 60 mg/kg/day) for 6 days and 1.5 mg/kg corticosterone was injected to monitor the effects of miricorilant on GR-responsive gene expression. We next accessed the time-dependency of the lipid-lowering effects of miricorilant in the mouse liver. Mice were fed with a high-fat, high-fructose diet (HFHFD) for 3 weeks before treatment with 60 mg/kg/day miricorilant for one, three or six days by oral gavage, and triglyceride content in the liver was measured at endpoint. In human liver tissue, we investigated the effects of miricorilant on precision-cut liver slices (PCLS) obtained from two independent donors with pre-existing steatosis. PCLS were cultured for a total of 168 hours in the presence of 100 nM hydrocortisone, and with or without an exogenous lipid challenge. PCLS were treated with 200-600 nM miricorilant for 96 hours before triglyceride content was measured. RNA-sequencing was performed on PCLS after 24 hours of 200-400 nM miricorilant exposure. Results: In the mouse liver, miricorilant exhibited a unique combination of agonistic and antagonistic properties on GR-responsive gene expression. Miricorilant effectively lowered HFHFD-induced lipid accumulation in the mouse liver as soon as three days after treatment. In human PCLS, miricorilant treatment lowered triglyceride content in both donors. RNA-sequencing revealed respectively 40 and 128 differentially expressed genes after 200 and 400 nM miricorilant treatment. Pathway analysis revealed very-low-density lipoprotein (VLDL) particle remodeling as a significant enriched pathway, providing a possible explanation for the lowered triglyceride content upon miricorilant treatment. Conclusion: Miricorilant rapidly and effectively lowers hepatic lipid content in the mouse liver and in human PCLS, possibly via modulation of VLDL remodeling. Presentation: 6/2/2024

Noise reducing elements filled with laminated safety glass (LSG) for use along railway lines

The main purpose of noise barriers is to shield the environment from unwanted sound. Along railway lines, noise barriers must also meet strict requirements for structural integrity, usability and fatigue safety. Furthermore, noise barriers should satisfy aesthetic criteria. Transparent noise barriers have less impact on the environment and are more widely accepted by the public. In Germany, PMMA (acrylic glass) is currently the only transparent material approved for railway noise reducing elements. Laminated safety glass (LSG) could be a viable alternative due to its high rigidity and transparency, comparatively low dirt accumulation and high chemical and physical resistance. However, it still needs to be demonstrated that LSG meets the strict requirements for use along railway lines. LSG is a type of laminated glass that has a splitter-binding intermediate layer of plastics. The multi-layered structure presents challenges regarding the proof of usability. MFPA Leipzig GmbH was commissioned by the German Centre for Rail Traffic Research at the Federal Railway Authority to develop and evaluate possible methods to prove the usability of LSG for noise barriers along railway lines. The paper presents the structure of the project, the main findings until now and the open challenges to be addressed.

Comprehensive stable-isotope tracing of glucose and amino acids identifies metabolic by-products and their sources in CHO cell culture

Mammalian cell culture processes are widely utilized for biotherapeutics production, disease diagnostics, and biosensors, and hence, should be optimized to support robust cell growth and viability. However, toxic by-products accumulate in cultures due to inefficiencies in metabolic activities and nutrient utilization. In this study, we applied comprehensive 13C stable-isotope tracing of amino acids and glucose to two Immunoglobulin G (IgG) producing Chinese Hamster Ovary (CHO) cell lines to identify secreted by-products and trace their origins. CHO cells were cultured in media formulations missing a single amino acid or glucose supplemented with a 13C-tracer of the missing substrate, followed by gas chromatography-mass spectrometry (GC-MS) analysis to track labeled carbon flows and identify by-products. We tracked the sources of all secreted by-products and verified the identity of 45 by-products, majority of which were derived from glucose, leucine, isoleucine, valine, tyrosine, tryptophan, methionine, and phenylalanine. In addition to by-products identified previously, we identified several metabolites including 2-hydroxyisovaleric acid, 2-aminobutyric acid, L-alloisoleucine, ketoisoleucine, 2-hydroxy-3-methylvaleric acid, desmeninol, and 2-aminobutyric acid. When added to CHO cell cultures at different concentrations, certain metabolites inhibited cell growth while others including 2-hydroxy acids, surprisingly, reduced lactate accumulation. In vitro enzymatic analysis indicated that 2-hydroxy acids were metabolized by lactate dehydrogenase suggesting a possible mechanism for lowered lactate accumulation, e.g., competitive substrate inhibition. The 13C-labeling assisted metabolomics pipeline developed and the metabolites identified will serve as a springboard to reduce undesirable by-products accumulation and alleviate inefficient substrate utilization in mammalian cultures used for biomanufacturing and other applications through altered media formulations and pathway engineering strategies.

Enhancement of exercise-induced fatigue alleviation and liver selenium regulation through in situ nanoselenium synthesis by Lactobacillus rhamnosus cells, empowered by Ganoderma lucidum spore loading.

Given the increasing awareness of the negative effects of fatigue on daily activities, mental health, and quality of life, antifatigue supplements are becoming increasingly popular among consumers. Selenium has been found to have antifatigue potential in high dosage, but may cause toxicity effects to the body. In this study, inorganic selenium was first converted to nanoselenium particles via in situ synthesis by Lactobacillus rhamnosus SHA113 (Se-LRS), and then loaded by Ganoderma lucidum spores (GLS). The resulting products were not only assessed for their antioxidant activities, but also the antifatigue potential in mice. As a result, both Se-LRS and the Se-LRS/GLS complex exhibited higher antioxidant and antibacterial activities in simulated gastrointestinal fluids compared to isolated selenium nanoparticles. The Se-LRS/GLS complex demonstrated sustained release of selenium in simulated gastrointestinal fluids and showed significant alleviation of exercise-induced fatigue indicators, but relatively lower liver selenium accumulation in the mice, surpassing the effects of isolated nanoselenium. No toxicity was found to Caco-2 cells for Se-LRS/GLS complex at 2µg/mL. This is a novel approach to enhance the antifatigue potential of selenium without causing extra toxicity.

Effect of magnetic powder (Fe3O4) on heterotrophic-sulfur autotrophic denitrification efficiency and electron transport system activity for marine recirculating aquacultural wastewater treatment

As an efficient nitrogen removal process, heterotrophic-sulfur autotrophic denitrification (HSAD) has attracted extensive attention in wastewater treatment. However, the effects of magnetic powder (Fe3O4) on the electron transport activity in HSAD process remain unclear. Therefore, in this study, a heterotrophic-sulfur autotrophic denitrification system was established to remove nitrogen from marine recirculating aquacultural wastewater for evaluating the effects of Fe3O4. At the optimal Fe3O4 concentration of 50 mg/L, the nitrogen removal efficiency reached 100% with lower sulfate accumulation, and the start-up time was shortened. The assays of denitrifying enzymes and electron transport system activity showed that Fe3O4 improved the activities of nitrate and nitrite reductases, and increased the efficiency of electron transport. Microbial community analysis revealed that Fe3O4 enriched heterotrophic denitrifier Thauera and sulfur autotrophic denitrifier Canditatus Thiobios, and thus enhanced denitrification efficiencies. This study demonstrated that Fe3O4 is an efficient denitrification accelerator in HSAD for treating marine recirculating aquacultural wastewater.

Greater lactate accumulation does not alter peripheral concentrations of key appetite-regulating neuropeptides.

The potential mechanisms involved in lactate's role in exercise-induced appetite suppression requires further examination. We used sodium bicarbonate (NaHCO3) supplementation in a double-blind, placebo controlled, randomized crossover design to explore lactate's role on neuropeptide Y (NPY), agouti-related peptide (AgRP), and alpha-melanocyte stimulating hormone (α-MSH) concentrations. Twelve adults (7 males; 24.2±3.4 kg‧m-2; 42.18±8.56 mL‧kg-1‧min-1) completed two identical high-intensity interval training sessions following ingestion of NaHCO3 (BICARB) or sodium chloride (PLACEBO) pre-exercise. Blood lactate, acylated ghrelin, NPY, AgRP, α-MSH, and appetite perceptions were measured pre-exercise, 0-, 30-, 60-, and 90-min post-exercise. Free-living energy intake (electronic food diaries) was measured the day before, of, and after each experimental session. In BICARB, blood lactate was greater post-exercise (p<0.002, d>0.70) though acylated ghrelin was similar (p=0.075, =0.206) at all time-points post-exercise (p>0.034, d<0.22). NPY (p=0.006, >0.509) and AgRP (p<0.001, >0.488) had main effects of time increasing following exercise and returning to baseline, with no differences between sessions (NPY: p=0.0.192, =0.149; AgRP: p=0.422, =0.060). α-MSH had no main effect of time (p=0.573, =0.063) or session (p=0.269, =0.110). Appetite perceptions were similar during BICARB and PLACEBO (p=0.007, d=0.28) increasing in both sessions post-exercise (p<0.088, d>0.57). Energy intake had a main effect of day (p=0.025, =0.825), where the experimental session day was greater than the day before (p=0.010, d=0.59) with no other differences between days (p>0.260, d<0.38). The lower accumulation of lactate than our previous work did not generate exercise-induced appetite suppression as there were no differences in acylated ghrelin, appetite perceptions, or peripheral concentrations of neuropeptides.

A model framework for atmosphere–snow water vapor exchange and the associated isotope effects at Dome Argus, Antarctica – Part 1: The diurnal changes

Abstract. Ice-core water isotopes contain valuable information on past climate changes. However, such information can be altered by post-depositional processing after snow deposition. Atmosphere–snow water vapor exchange is one such process, but its influence remains poorly constrained. Here we constructed a box model to quantify the atmosphere–snow water vapor exchange fluxes and the associated isotope effects at sites with low snow accumulation rates, where the effects of atmosphere–snow water vapor exchange are suspected to be large. The model reproduced the observed diurnal variations in δ18O, δD, and deuterium excess (d-excess) in water vapor at Dome C, East Antarctica. According to the same model framework, we found that under average summer clear-sky conditions, atmosphere–snow water vapor exchange at Dome A can cause diurnal variations in atmospheric water vapor δ18O and δD of 4.8 ‰ ± 2.6 ‰ and 29 ‰ ± 19 ‰, with corresponding diurnal variations in surface snow δ18O and δD of 0.80 ‰ ± 0.35 ‰ and 1.6 ‰ ± 2.7 ‰. The modeled results under summer cloudy conditions display similar patterns to those under clear-sky conditions but with much smaller magnitudes of diurnal variations. However, under winter conditions at Dome A, the model predicts few to no diurnal changes in snow isotopes, consistent with the stable boundary condition in winter that inhibits effective vapor exchange between the atmosphere and snow. In addition, after 24 h and continuous simulations of 11 d, the model predicts significant enrichments in snow isotopes under summer conditions, while in winter, the depletions also accumulate after each 24 h simulation but with a much smaller magnitude of change compared to the results from summer simulations. If the modeled snow isotope enrichments in summer conditions and the depletions in winter conditions represent the general situation at Dome A, this likely suggests that atmosphere–snow water vapor exchange tends to increase snow isotope seasonality, and the annual net effect would be overall enrichments in snow isotopes since the effects in summer appear to be greater than those in winter. This trend will need to be further explored in the future with more comprehensive model studies and/or field observations and experiments.

Landslides and flood hazard mapping using geomorphological methods in Santa Ana, Costa Rica

This study addresses the critical need for comprehensive hazard maps to guide urban and periurban risk management in Santa Ana, Costa Rica. Located near the capital, San Jose, Santa Ana is a rapidly developing municipality characterized by high-value properties, commercial zones, luxury housing, agricultural, and protected areas. However, it faces significant challenges from landslides and floods. Despite its vulnerability, the municipality lacks detailed, holistic hazard assessments. To bridge this gap, we employed geomorphological methods, including morphometry and morphogenetics, integrated with geographic information systems (GIS), historical data, and on-site validation. Our analysis identified that slopes exceeding 20° are particularly susceptible to landslides, with valleys and unstable hillslopes being critical zones for seismic and water-induced destabilization. For flood hazards, areas with low slope and high flow accumulation, such as alluvial fans and flood plains, were found to be highly susceptible. Field and mapping validation against the DesInventar disaster database confirmed the accuracy of our hazard zones. These findings provide essential geospatial insights for effective risk management, decision-making, and territorial planning, enabling proactive and adaptive responses to natural hazards in Santa Ana. While this study does not present radical methodological innovations, its main contribution lies in demonstrating how easy-access and practical geomorphological tools can be used to generate valuable information on risk zoning in regions with limited resources. Furthermore, the methodology and insights from this study are applicable to other urban and periurban regions facing similar geomorphic hazards, highlighting its broader relevance.

The trophodynamics of polycyclic aromatic hydrocarbons in marine food webs: The importance of trophic level span from insights into Liaodong Bay (China).

The occurrence and trophic transfer of polycyclic aromatic hydrocarbons (PAHs) in aquatic ecosystems is vital to assess ecological risks. PAHs concentrations were analyzed in seawater, sediment, plankton, and marine species (15 fish species, 8 invertebrate species, 3 marine mammals), collected from Liaodong Bay (China). Bioaccumulation and biomagnification were calculated to demonstrate the biotransfer pattern of PAHs from the environmental matrix to high-level predators through the food web. Total PAHs concentrations ranged from 81.2 to 197.6 ng/L in seawater, 51.4 to 304.8 ng/g (dw) in sediment, and 65.3 to 28,885 ng/g (lw) in all biota samples. Three- and four-ring PAHs constituted major components (> 81% in each case) of PAH congener profiles. Lower biota-sediment accumulation factors (BSAFs) and bioaccumulation factors (BAFs) values indicated limited bioaccumulation of PAHs within marine organisms. Also, 77% of biomagnification factors (BMFTL) values of PAHs in spotted seal and finless porpoise were >1, whereas opposite transfer patterns of PAHs were observed in food webs with trophic values of 1.5-3.5 and 3.0-4.0; that is, trophic dilution (trophic magnification factor (TMF) <1) and trophic magnification (TMF >1), respectively. This study provides novel insights into the importance of TL span for trophodynamics of PAHs within food webs.

Understanding the anti-browning mechanism and physicochemical properties in potato pulp during the magnetic field processing

To reduce the detrimental effects of enzymatic-browning on potato pulp quality, this study investigated the anti-browning potential of magnetic field at varying intensities. The magnetic field (4 mT) enhanced the structural integrity of potato pulp cells, with the highest hardness (119.37 g). Furthermore, the potato pulp subjected to a magnetic field treatment of 4 mT for 60 min at a temperature of 32 °C (PP-MF-4) shown an orderly macromolecular aggregation, increased viscoelastic properties of potato pulp. The PP-MF-4 demonstrated excellent anti-browning capability, as evidenced by the highest L⁎ value (59.18), reduced browning index, and lower accumulation of browning-products. Furthermore, the PP-MF-4 exhibited a significant reduction in oxidative damage, attributed to enhanced antioxidant activity and total phenolic content. Besides, the PP-MF-4 inhibited browning enzymes and improved the molecular structure orderliness. Consequently, magnetic field presents a viable approach for mitigating enzymatic-browning in potato pulp, offering a promising methods for preserving its quality.

Growth and Depuration of Off‐Flavors in Rainbow Trout Oncorhynchus Mykiss in a Partial Recirculating Aquaculture System (PRAS)

ABSTRACTIn recirculating aquaculture systems (RAS), off‐flavours accumulated in fish muscle tissue can be problematic in terms of consumer acceptance and the reputation of farmed fish products. Off‐flavours often give fish earthy, muddy, or other undesirable flavours. Typically, off‐flavours are removed during a depuration period in which fish are fasted and held in clean water. Unfortunately, this causes additional costs and delayed sales, while fish lose weight and show a decrease in lipid content. First, we studied fish growth in a partial RAS (PRAS) where the conditions are very similar to those in depuration with a water exchange rate of 4000 L kg−1 feed, compared to RAS with a 650‐L water kg−1 feed. Rainbow trout (Oncorhynchus mykiss) was reared in both systems. Our aim was to combine the benefits of a higher water exchange rate: the lack of need for biofilters and a lower accumulation of off‐flavours while obtaining stable rearing conditions. Additionally, we studied the effects of moderate feeding and H2O2 addition during depuration. The fish grew faster in a PRAS than in a RAS when fed ad libitum. Thirteen off‐flavour compounds were found in the fish flesh and 11 in the circulating water. The H2O2 addition led to decreased levels of off‐flavours in the tank water and in fish muscle. The results showed no significant differences in off‐flavours between the fed and not‐fed systems, showing that moderate feeding did not prevent a good depuration result. However, the lipid content and the overall fish weight were higher in the fed systems, which suggests more effective depuration. Increased depuration efficiency can be an important tool when considering ways to improve the profitability of production.

Low soil pH enhances fruit acidity by inhibiting citric acid degradation in lemon (Citrus lemon L.)

Fruit acidity significantly influences fruit flavor, but the specific impact of soil pH on fruit acidity remains unclear. This study investigated the effects of various soil pH levels on fruit acidity and citric acid (CA) metabolism in lemon (Citrus limon L.). High soil pH (pH 8) decreased total soluble solids concentrations in lemon fruits, while low soil pH (pH 4) increased titratable acid and CA concentrations. Although low soil pH reduced the synthesis of CA due to the decreased citrate synthase and phosphoenolpyruvate carboxylase activities, the elevated fruit acidity under low soil pH conditions is not directly related to CA synthesis. Instead, low soil pH was found to suppress the activity of cytosolic aconitase (Cyt-ACO), an iron-dependent enzyme, indicating a potential role for CA degradation inhibition in low soil pH-induced CA accumulation. Furthermore, low soil pH significantly reduced cytosolic iron (Cyt-Fe) concentration, which was positively correlated with Cyt-ACO activity. In conclusion, low soil pH contributes to increasing fruit acidity in lemon, partially by inhibiting CA degradation due to the reduced Cyt-Fe concentrations. Our work unravels the influence of soil pH on CA accumulation and provides important clues for modulating CA levels through microelement fertilization in citrus.

Heavy metals in homestead soil: Metal fraction contents, bioaccessibility, and risk assessment

Rapid urbanization in China has led to the disappearance of countless villages and the transformation of homestead land into cultivated land or grassland. The quality of homestead soil (HS) plays a pivotal role in land-use conversion and reuse strategies, so the current state of heavy metal pollution in HS deserves attention. This study determined the fraction contents, bioaccessibility, risks, and affecting factors of Hg, As, Cd, Pb, Cu, and Zn in HS by comparing them with soil in cultivated land (CS), grassland (GS), homestead-converted cultivated land (HCS), and homestead-converted grassland (HGS). Results demonstrate that the contents of the six metals exceed background values, especially for Cd and Hg, resulting in significant pollution and elevated ecological risk. Distinct from the dominant residual fraction of other metals, the extractable fraction of Cd shows the highest proportion, which also contributes most to the high values of the Risk Assessment Code and extreme pollution conditions in HS, GS, and CS. Moreover, pH shows predominantly negative relations with the effective available and potentially available contents, while the effects of organic carbon fractions are notably the opposite. Furthermore, CS and GS suggest higher non-carcinogenic and carcinogenic risks than in the converted soil. This study indicates that HS has a lower metal accumulation risk compared with cultivated land and grassland, and homestead conversion seems to restrict the bioaccessibility of metals in soil.

Functional Analysis of Human GBA1 Missense Mutations in Drosophila: Insights into Gaucher Disease Pathogenesis and Phenotypic Consequences.

The human GBA1 gene encodes lysosomal acid β-glucocerebrosidase, whose activity is deficient in Gaucher disease (GD). In Drosophila, there are two GBA1 orthologs, Gba1a and Gba1b, and Gba1b is the bona fide GCase encoding gene. Several fly lines with different deletions in the Gba1b were studied in the past. However, since most GD-associated GBA1 mutations are point mutations, we created missense mutations homologous to the two most common GD mutations: the mild N370S mutation (D415S in Drosophila) and the severe L444P mutation (L494P in Drosophila), using the CRISPR-Cas9 technology. Flies homozygous for the D415S mutation (dubbed D370S hereafter) presented low GCase activity and substrate accumulation, which led to lysosomal defects, activation of the Unfolded Protein Response (UPR), inflammation/neuroinflammation, and neurodegeneration along with earlier death compared to control flies. Surprisingly, the L494P (called L444P hereafter) flies presented higher GCase activity with fewer lysosomal defects and milder disease in comparison to that presented by the D370S homozygous flies. Treatment with ambroxol had a limited effect on all homozygous fly lines tested. Overall, our results underscore the differences between the fly and human GCase enzymes, as evidenced by the distinct phenotypic outcomes of mutations in flies compared to those observed in human GD patients.

Fire history in northern Sierra Nevada mixed conifer forests across a distinct gradient in productivity

BackgroundUnderstanding the role of fire in forested landscapes is fundamental to fire reintroduction efforts, yet few studies have examined how fire dynamics vary in response to interactions between local conditions, such as soil productivity, and more broadscale changes in climate. In this study, we examined historical fire frequency, seasonality, and spatial patterning in mixed conifer forests across a distinct gradient of soil productivity in the northern Sierra Nevada. We cross-dated 46 different wood samples containing 377 fire scars from 6 paired sites, located on and off of ultramafic serpentine soils. Forests on serpentine-derived soils have slower growth rates, lower biomass accumulation, and patchier vegetation than adjacent, non-serpentine sites. Due to these differences, we hypothesized that historical fire frequency and spatial extent would be reduced in mixed conifer forests growing on serpentine soils.ResultsFire scars revealed a history of frequent fire at all of our sites (median composite interval: 6–22.5 years) despite clear differences in soil productivity. Fire frequency was slightly shorter in more productive non-serpentine sites, but this difference was not consistently significant within our sample pairs. While fires were frequent, both on and off of serpentine, they were also highly asynchronous, and this was largely driven by differing climate–fire relationships. Fires in more productive sites were strongly associated with drought conditions in the year of the fire, while fires in less productive serpentine sites appeared to be more dependent on a cycle of wet and dry conditions in the years preceding the fire. Widespread fires that crossed the boundary between serpentine and non-serpentine were associated with drier than normal years.ConclusionsIn our study, fine-scale variation in historical fire regime attributes was linked to both bottom-up and top-down controls. Understanding how these factors interact to create variation in fire frequency, timing, and spatial extent can help managers more effectively define desired conditions, develop management objectives, and identify management strategies for fire reintroduction and forest restoration projects.

Determination of Bisphenol Compounds and the Bioaccumulation after Co-Exposure with Polyethylene Microplastics in Zebrafish.

Knowledge regarding the combined toxicity mechanism of bisphenol compounds and microplastics (MPs) on organisms remains limited. In this study, we first developed an accurate and sensitive method to simultaneously quantify two bisphenol compounds and evaluate their accumulation and tissue distribution after co-exposure with MPs in zebrafish. Then, we determined the bioaccumulation potential of bisphenol A (BPA) and bisphenol S (BPS) in adult zebrafish in the absence and presence of MPs. Bisphenol compounds were found to accumulate in different tissues of zebrafish, with BPS showing lower accumulation levels compared to BPA. Importantly, we discovered that the presence of MPs could exacerbate the accumulation of bisphenol compounds in biological tissues. These findings highlight the enhanced bioavailability and risk posed by the co-exposure of bisphenol compounds and MPs, underscoring the need for further investigation into their combined environmental and biological health impacts.

Functional analysis of LdPMAT1, a positive regulator that promotes drought tolerance in Lilium distic hum nakai

Abiotic stress has become a major challenge for lily crop growth, development, yield and quality under irregular climate and precipitation trends. Molecular breeding is one of the most effective methods for developing highly stress-resistant cultivars. Previous studies revealed that miR396b and its target gene LdPMAT1 are involved in drought resistance, and in lily silencing miR396b significantly enhances drought resistance and LdPMAT1 expression. However, the function of LdPMAT1 in the lily response to abiotic stress is unclear. In this study, GUS activity tests and dual luciferase reporter gene assays (LUC) confirmed that LdPMAT1 is a novel miR396b target. The LdPMAT1 transcription level was greater in the roots and leaves and increased significantly within 7 days of drought stress. Stable LdPMAT1 overexpression significantly reduced leaf wilting and enhanced cell membrane stability by affecting osmoregulatory substance accumulation, improving plant drought resistance. Additionally, LdPMAT1 overexpression significantly increased the expression levels of LdCAT3 and SOD2, which encode superoxide dismutase (SOD) and catalase (CAT), respectively, as well as SOD and CAT enzyme activities. In contrast, reactive oxygen species (ROS) accumulated at high levels in the leaves and roots of the silenced plants, and the degree of damage was significantly greater than that in the wild type plants. Under conditions of 1% NaCl and 42 °C, plants overexpressing LdPMAT1 exhibited similar characteristic s of high stress resistance, with less wilting and lower ROS accumulation. This study provides a theoretical basis for cultivating new highly resistant lily cultivars and accelerating germplasm innovation to produce high-quality lilies worldwide.