A retrospective analysis of the influencing factors of nucleic acid CT value fluctuation in COVID-19 patients infected with Omicron variant virus in Changchun city.

Objective: This study aimed to determine the risk factors associated with fluctuations in nucleic acid CT values in patients infected with the Omicron variant during an outbreak at a hospital in Changchun city. Methods: A retrospective analysis was conducted on general information, medical history, vaccination history, and laboratory test data of COVID-19 patients infected with the Omicron variant and admitted to the hospital in Changchun from March 2022 to April 2022. The study aimed to explore the factors influencing nucleic acid CT value fluctuations in COVID-19 patients infected with the Omicron variant in Changchun city. Results: Fluctuations in nucleic acid CT values were significantly correlated with occupation composition (p = 0.030), hospital stay duration (p = 0.000), heart rate (p = 0.026), creatinine (p = 0.011), platelet count (p = 0.000), glutamic-pyruvic transaminase (p = 0.045), and glutamic oxaloacetic transaminase (p = 0.017). Binary logistic regression analysis revealed significant correlations between hospital stay duration (p = 0.000), platelet count (p = 0.019), heart rate (p = 0.036), and nucleic acid CT value fluctuations (p < 0.05), indicating that they were independent risk factors. Red blood cell count was identified as a factor influencing nucleic acid CT value fluctuations in Group A patients. Occupation composition, direct bilirubin, and platelet count were identified as factors influencing nucleic acid CT value fluctuations in Group B patients. Further binary logistic regression analysis indicated that occupational composition and direct bilirubin are significant independent factors for nucleic acid CT value fluctuations in Group B patients, positively correlated with occupational risk and negatively correlated with direct bilirubin. Conclusion: Therefore, enhancing patients' immunity, increasing physical exercise to improve myocardial oxygen consumption, reducing the length of hospital stays, and closely monitoring liver function at the onset of hospitalization to prevent liver function abnormalities are effective measures to control fluctuations in nucleic acid CT values.

Compressed intracellular motility via non-uniform temporal sampling in dynamic optical coherence tomography.

Significance: Optical coherence tomography has great utility for capturing dynamic processes, but such applications are particularly data-intensive. Samples such as biological tissues exhibit temporal features at varying time scales, which makes data reduction challenging. Aim: We propose a method for capturing short- and long-term correlations of a sample in a compressed way using non-uniform temporal sampling to reduce scan time and memory overhead. Approach: The proposed method separates the relative contributions of white noise, fluctuating features, and stationary features. The method is demonstrated on mammary epithelial cell spheroids in three-dimensional culture for capturing intracellular motility without loss of signal integrity. Results: Results show that the spatial patterns of motility are preserved and that hypothesis tests of spheroids treated with blebbistatin, a motor protein inhibitor, are unchanged with up to eightfold compression. Conclusions: The ability to measure short- and long-term correlations compressively will enable new applications in (3+1)D imaging and high-throughput screening.

Relationship between Abnormal Spontaneous Brain Activity and Altered Neuromuscular Activation of Lumbar Paraspinal Muscles in Chronic Low Back Pain.

OBJECTIVE: To investigate the neural mechanism underlying functional reorganization and motor coordination strategies in patients with chronic low back pain (cLBP). DESIGN: A case-control study based on data collected during routine clinical practice. SETTING: This study was conducted at the the First Affiliated Hospital of Sun Yat-sen University. PARTICIPANTS: Fifteen patients with cLBP and fifteen healthy controls. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Whole brain blood oxygen level-dependent signals were measured using functional magnetic resonance imaging and amplitude of low-frequency fluctuation (ALFF) method to identify pain-induced changes in regional spontaneous brain activity. A novel approach based on the surface electromyography (EMG) system and fine-wire electrodes was used to record EMG signals in the deep multifidus, superficial multifidus, and erector spinae. RESULTS: In cLBP, compared with healthy groups, ALFF was higher in the medial prefrontal, primary somatosensory, primary motor, and inferior temporal cortices, whereas it was lower in the cerebellum and anterior cingulate and posterior cingulate cortices. Furthermore, the decrease in the average EMG activity of three lumbar muscles in the cLBP group was positively correlated with the ALFF values of the primary somatosensory cortex, motor cortex, precuneus, and middle temporal cortex but significantly negatively correlated with the ALFF values of the medial prefrontal and inferior temporal cortices. Interestingly, the correlation between the functional activity in the cerebellum and the EMG activity varied in the lumbar muscles. CONCLUSIONS: These findings suggest a functional association between changes in spontaneous brain activity and altered voluntary neuromuscular activation patterns of the lumbar paraspinal muscles, providing new insights into the mechanisms underlying pain chronicity as well as important implications for developing novel therapeutic targets of cLBP.

[The relationship between intraocular pressure and age-related variations in ocular rigidity]. / Vzaimosvyaz' vnutriglaznogo davleniya s involyutsionnymi kolebaniyami rigidnosti glaza.

PURPOSE: This study aimed to identify the correlation between age-related fluctuations in the average values of rigidity of the fibrous tunic of the eye (FTE) and corresponding ranges of true intraocular pressure (IOP) in healthy eyes and eyes with open-angle glaucoma (OAG); using the identified ranges of FTE rigidity, to establish the appropriate IOP zones for healthy and glaucomatous eyes, taking into account the aging periods as classified by the World Health Organization (WHO). MATERIAL AND METHODS: Ocular-Response Analyzer tonometry was used according to the Koshits-Svetlova dynamic diagnostic method to examine 674 patients with healthy eyes and 518 patients with glaucomatous eyes, aged 18 to 90 years, classified according to the WHO aging periods, and a theoretical analysis was conducted to estimate clinical values of FTE rigidity, the current level of true IOP, and the calculated individual IOP level in a patient's eye during youth. RESULTS: The following IOP level zones were identified for patients with healthy and glaucomatous eyes: low IOP zone (≤13 mm Hg); medium IOP zone (14-20 mm Hg); elevated IOP zone (21-26 mm Hg); high IOP zone (27-32 mm Hg); subcompensated IOP zone (33-39 mm Hg); and decompensated IOP zone (≥40 mm Hg). CONCLUSION: The fundamental physiological criterion "rigidity" does not depend on central corneal thickness and consistently reflects the current level of true IOP. In all examined patients, both with healthy and glaucomatous eyes, healthy and glaucoma eyes with the same level of current rigidity had the same level of IOP. The ability to assign a given healthy or glaucomatous eye to a specific individual IOP zone is particularly important for the polyclinic system.

Shallow groundwater table fluctuations promote the accumulation and loss of phosphorus from surface soil to deeper soil in croplands around plateau lakes in Southwest China.

The continuous excessive application of phosphorus (P) fertilizers in intensive agricultural production leads to a large accumulation of P in surface soils, increasing the risk of soil P loss by runoff and leaching. However, there are few studies on the accumulation and loss of P from surface soil to deep soil profiles driven by shallow groundwater table (SGT) fluctuations. This study used the intensive cropland around 7 plateau lakes in Yunnan Province as an example and conducted in situ monitoring of P storage in the soil profile and SGT during the rainy season (RS) and dry season (DS) as well as simulation experiments on soil P loss. The aim was to study the spatiotemporal variation in P accumulation in the soil profile of cropland driven by SGT fluctuations in the RS and DS and estimate the P loss in the soil profile driven by SGT fluctuations. The results showed that fluctuations in the SGT promoted P accumulation from the surface soil to deeper soil. The proportions of P stored in various forms in the 30-60 cm and 60-100 cm soil layers in the RS were greater than those in the DS, while the average proportion in the 0-30 cm soil layer in the DS was as high as 48%. Compared with those in the DS, the maximum decreases in the proportion of P stored as TP and Olsen-P in the 0-100 cm soil layer in the RS were 16% and 58%, respectively, due to the rise in the SGT (SGT <30 cm), while the soil TP storage decreased by only 1% when the SGT was maintained at 60-100 cm. The critical thresholds for soil Olsen-P and TP gradually decreased with increasing soil depth, and the risk of P loss in deeper soil increased. The loss of soil P was increased by fluctuations in the SGT. Based on the cropland area around the 7 plateau lakes, P storage, and SGT fluctuations, the average loss intensity and loss amount of TP in the 0-100 cm soil layer around the 7 plateau lakes were estimated to be 25 kg/ha and 56 t, respectively. Therefore, reducing exogenous P inputs, improving soil endogenous P utilization efficiency and maintaining deep soil P retention are the basic strategies for preventing and controlling P accumulation and loss in deep soil caused by SGT fluctuations.

Pd/Pa fluctuation with continuous ATP administration indicates inaccurate FFR measurement caused by insufficient hyperemia.

Continuous intravenous adenosine triphosphate (ATP) administration is the standard method for inducing maximal hyperemia in fractional flow reserve (FFR) measurements. Several cases have demonstrated fluctuations in the ratio of mean distal coronary pressure to mean arterial pressure (Pd/Pa) value during ATP infusion, which raised our suspicions of FFR value inaccuracy. This study aimed to investigate our hypothesis that Pd/Pa fluctuations may indicate inaccurate FFR measurements caused by insufficient hyperemia. We examined 57 consecutive patients with angiographically intermediate coronary lesions who underwent fractional flow reverse (FFR) measurements in our hospital between November 2016 and September 2018. Pd/Pa was measured after continuous ATP administration (150 µg/kg/min) via a peripheral forearm vein for 5 min (FFRA); and we analyzed the FFR value variation in the final 20 s of the 5 min, defining 'Fluctuation' as variation range > 0.03. Then, 2 mg of nicorandil was administered into the coronary artery during continued ATP infusion, and the Pd/Pa was remeasured (FFRA+N). Fluctuations were observed in 23 of 57 patients. The cases demonstrating discrepancies of > 0.05 between FFRA and FFRA+N were observed more frequently in the fluctuation group than in the non-fluctuation group (12/23 vs. 1/34; p < 0.0001). The discrepancy between FFRA and FFRA+N values was smaller in the non-fluctuation group (mean difference ± SD; -0.00026 ± 0.04636 vs. 0.02608 ± 0.1316). Pd/Pa fluctuation with continuous ATP administration could indicate inaccurate FFR measurements caused by incomplete hyperemia. Additional vasodilator administration may achieve further hyperemia when Pd/Pa fluctuations are observed.

Prediction of Sudden Cardiac Death With Ultra-Short-Term Heart Rate Fluctuations.

BACKGROUND: Conventional measures of heart rate variability (HRV) have shown only modest associations with sudden cardiac death (SCD). Detrended fluctuation analysis (DFA), with novel methodological developments to evaluate the short-term scaling exponent, is a potentially superior method compared to conventional HRV tools. OBJECTIVES: In this study, the authors studied the analysis of the association between DFA and SCD. METHODS: The investigators studied the predictive value of ultra-short-term heart rate fluctuations (1-minute electrocardiogram samples) with DFA at rest and during different stages of physical exertion for incident SCD among 2,794 participants undergoing clinical exercise testing in the prospective FINCAVAS (Finnish Cardiovascular Study). The novel key DFA measure, the short-scale scaling exponent computed with second-order detrending (DFA2 α1), was the main exposure variable. SCDs were defined by American Heart Association/European Society of Cardiology criteria using death certificates with written accounts of the events. RESULTS: During a median follow-up of 8.3 years (Q1-Q3: 6.4-10.5), 83 SCDs occurred. DFA2 α1 measured at rest (but not in exercise) associated highly significantly with the risk of SCD, with 1-SD lower values associating with a 2.4-fold (Q1-Q3: 2.0-3.0) risk (P < 0.001). The results persisted when adjusting for other major risk factors for SCD, including age, cardiovascular morbidities, cardiorespiratory fitness, heart rate reduction, and left ventricular ejection fraction. Associations between conventional HRV parameters (measured at any stage of exercise or at rest) and SCD were substantially weaker and statistically nonsignificant after adjusting for other risk factors. CONCLUSIONS: Ultra-short-term DFA2 α1, when measured at rest, is a powerful and independent predictor of SCD. The association between DFA2 α1 and SCD is modified by physical exertion.

Fluctuation Theorems for Heat Exchanges between Passive and Active Baths.

In addition to providing general constraints on probability distributions, fluctuation theorems allow us to infer essential information on the role played by temperature in heat exchange phenomena. In this numerical study, we measure the temperature of an out-of-equilibrium active bath using a fluctuation theorem that relates the fluctuations in the heat exchanged between two baths to their temperatures. Our setup consists of a single particle moving between two wells of a quartic potential accommodating two different baths. The heat exchanged between the two baths is monitored according to two definitions: as the kinetic energy carried by the particle whenever it jumps from one well to the other and as the work performed by the particle on one of the two baths when immersed in it. First, we consider two equilibrium baths at two different temperatures and verify that a fluctuation theorem featuring the baths temperatures holds for both heat definitions. Then, we introduce an additional Gaussian coloured noise in one of the baths, so as to make it effectively an active (out-of-equilibrium) bath. We find that a fluctuation theorem is still satisfied with both heat definitions. Interestingly, in this case the temperature obtained through the fluctuation theorem for the active bath corresponds to the kinetic temperature when considering the first heat definition, while it is larger with the second one. We interpret these results by looking at the particle jump phenomenology.

Dependent Competing Failure Processes in Reliability Systems.

This paper deals with a reliability system hit by three types of shocks ranked as harmless, critical, or extreme, depending on their magnitudes, being below H1, between H1 and H2, and above H2, respectively. The system's failure is caused by a single extreme shock or by a total of N critical shocks. In addition, the system fails under occurrences of M pairs of shocks with lags less than some δ (δ-shocks) in any order. Thus, the system fails when one of the three named cumulative damages occurs first. Thus, it fails due to the competition of the three associated shock processes. We obtain a closed-form joint distribution of the time-to-failure, shock count upon failure, δ-shock count, and cumulative damage to the system on failure, to name a few. In particular, the reliability function directly follows from the marginal distribution of the failure time. In a modified system, we restrict δ-shocks to those with small lags between consecutive harmful shocks. We treat the system as a generalized random walk process and use an embellished variant of discrete operational calculus developed in our earlier work. We demonstrate analytical tractability of our formulas which are also validated, through Monte Carlo simulation.

On Casimir and Helmholtz Fluctuation-Induced Forces in Micro- and Nano-Systems: Survey of Some Basic Results.

Fluctuations are omnipresent; they exist in any matter, due either to its quantum nature or to its nonzero temperature. In the current review, we briefly cover the quantum electrodynamic Casimir (QED) force as well as the critical Casimir (CC) and Helmholtz (HF) forces. In the QED case, the medium is usually a vacuum and the massless excitations are photons, while in the CC and HF cases the medium is usually a critical or correlated fluid and the fluctuations of the order parameter are the cause of the force between the macroscopic or mesoscopic bodies immersed in it. We discuss the importance of the presented results for nanotechnology, especially for devising and assembling micro- or nano-scale systems. Several important problems for nanotechnology following from the currently available experimental findings are spelled out, and possible strategies for overcoming them are sketched. Regarding the example of HF, we explicitly demonstrate that when a given integral quantity characterizing the fluid is conserved, it has an essential influence on the behavior of the corresponding fluctuation-induced force.

Fault Diagnosis of Wind Turbine Gearbox Based on Modified Hierarchical Fluctuation Dispersion Entropy of Tan-Sigmoid Mapping.

Vibration monitoring and analysis are important methods in wind turbine gearbox fault diagnosis, and determining how to extract fault characteristics from the vibration signal is of primary importance. This paper presents a fault diagnosis approach based on modified hierarchical fluctuation dispersion entropy of tan-sigmoid mapping (MHFDE_TANSIG) and northern goshawk optimization-support vector machine (NGO-SVM) for wind turbine gearboxes. The tan-sigmoid (TANSIG) mapping function replaces the normal cumulative distribution function (NCDF) of the hierarchical fluctuation dispersion entropy (HFDE) method. Additionally, the hierarchical decomposition of the HFDE method is improved, resulting in the proposed MHFDE_TANSIG method. The vibration signals of wind turbine gearboxes are analyzed using the MHFDE_TANSIG method to extract fault features. The constructed fault feature set is used to intelligently recognize and classify the fault type of the gearboxes with the NGO-SVM classifier. The fault diagnosis methods based on MHFDE_TANSIG and NGO-SVM are applied to the experimental data analysis of gearboxes with different operating conditions. The results show that the fault diagnosis model proposed in this paper has the best performance with an average accuracy rate of 97.25%.

Seasonal Dynamics of Fruit Flies (Diptera: Drosophilidae) in Natural Parks of Moscow City, Russia.

The insect fauna of natural parks in large cities has not been sufficiently studied in Russia. This study represents the first investigation of the seasonal dynamics and species diversity of Drosophilidae in Moscow city. Traps with fermenting liquid were placed on the ground under trees to collect flies from four natural park sites between early May and late September from 2021 to 2023. A total of 26,420 individuals belonging to 11 genera and 33 drosophilid species were identified, with 21 species from 6 genera being new to the fauna of Moscow. Drosophila obscura Fll., D. phalerata Mg., and D. testacea Roser were the most abundant species in the traps. Peaks in the abundance of drosophilids varied between years, but the lowest abundance was always observed in May. In 2022, the highest number of flies was collected (9604 specimens), with slightly fewer in 2023 (8496 specimens), and even fewer in 2021 (8320 specimens). In 2022, the highest species diversity of drosophilids was also recorded-33 species-while 28 species were found in both 2021 and 2023. The high variability in the abundance of individual drosophila species obscures the differences between the studied years due to the effects of the "Month" and "Site" factors. The diversity metrics exhibit similar patterns among drosophila communities inhabiting comparable biotopes. Specific climatic factors, such as the temperature and precipitation, impact the species abundance and community diversity indices primarily through their effects on the preimaginal stages of drosophila development. For several species, the population dynamics in the spring, post-hibernation, are influenced by the conditions preceding winter.

Analysis of Arc/Arg3.1 Oligomerization In Vitro and in Living Cells.

Arc (also known as Arg3.1) is an activity-dependent immediate early gene product enriched in neuronal dendrites. Arc plays essential roles in long-term potentiation, long-term depression, and synaptic scaling. Although its mechanisms of action in these forms of synaptic plasticity are not completely well established, the activities of Arc include the remodeling of the actin cytoskeleton, the facilitation of AMPA receptor (AMPAR) endocytosis, and the regulation of the transcription of AMPAR subunits. In addition, Arc has sequence and structural similarity to retroviral Gag proteins and self-associates into virus-like particles that encapsulate mRNA and perhaps other cargo for intercellular transport. Each of these activities is likely to be influenced by Arc's reversible self-association into multiple oligomeric species. Here, we used mass photometry to show that Arc exists predominantly as monomers, dimers, and trimers at approximately 20 nM concentration in vitro. Fluorescence fluctuation spectroscopy revealed that Arc is almost exclusively present as low-order (monomer to tetramer) oligomers in the cytoplasm of living cells, over a 200 nM to 5 µM concentration range. We also confirmed that an α-helical segment in the N-terminal domain contains essential determinants of Arc's self-association.

Investigation of dosimetric effect of beam current fluctuations in synchrotron-based proton PBS continuous scanning.

Objective.In proton pencil beam scanning (PBS) continuous delivery, the beam is continuously delivered without interruptions between spots. For synchrotron-based systems, the extracted beam current exhibits a spill structure, and recent publications on beam current measurements have demonstrated significant fluctuations around the nominal values. These fluctuations potentially lead to dose deviations from those calculated assuming a stable beam current. This study investigated the dosimetric implications of such beam current fluctuations during proton PBS continuous scanning.Approach.Using representative clinical proton PBS plans, we performed simulations to mimic a worst-case clinical delivery environment with beam current varies from 50% to 250% of the nominal values. The simulations used the beam delivery parameters optimized for the best beam delivery efficiency of the upcoming particle therapy system at Mayo Clinic Florida. We reconstructed the simulated delivered dose distributions and evaluated the dosimetric impact of beam current fluctuations.Main results.Despite significant beam current fluctuations resulting in deviations at each spot level, the overall dose distributions were nearly identical to those assuming a stable beam current. The 1 mm/1% Gamma passing rate was 100% for all plans. Less than 0.2% root mean square error was observed in the planning target volume dose-volume histogram. Minimal differences were observed in all dosimetric evaluation metrics.Significance.Our findings demonstrate that with our beam delivery system and clinical planning practice, while significant beam current fluctuations may result in large local move monitor unit deviations at each spot level, the overall impact on the dose distribution is minimal.

Altered Intrinsic Brain Activity in Ischemic Stroke Patients Assessed Using the Percent Amplitude of a Fluctuation Method.

Ischemic stroke is a vascular disease that may cause cognitive and behavioral abnormalities. This study aims to assess abnormal brain function in ischemic stroke patients using the percent amplitude of fluctuation (PerAF) method and further explore the feasibility of PerAF as an imaging biomarker for investigating ischemic stroke pathophysiology mechanisms. Sixteen ischemic stroke patients and 22 healthy controls (HCs) underwent resting state functional magnetic resonance imaging (rs-fMRI) scanning, and the resulting data were analyzed using PerAF. Then a correlation analysis was conducted between PerAF values and Mini-Mental State Examination (MMSE) and Montreal Cognitive Assessment (MoCA) scores. Finally, the abnormal PerAF values were extracted and defined as features for support vector machine (SVM) analysis. Compared with HCs, ischemic stroke patients showed decreased PerAF in the bilateral cuneus, left middle frontal gyrus, precuneus and right inferior temporal gyrus, and increased PerAF in the bilateral orbital part of middle frontal gyrus and right orbital part of superior frontal gyrus. Correlation analyses revealed that PerAF values in the left orbital part of middle frontal gyrus was negatively correlated with the MoCA scores. The SVM classification of the PerAF values achieved an area under the curve (AUC) of 0.98 and an accuracy of 94.74%. Abnormal brain function has been found among ischemic stroke patients, which may be correlated with visual impairment, attention deficits, and dysregulation of negative emotions following a stroke. Our findings may support the potential of PerAF as a sensitive biomarker for investigating the underlying mechanisms of ischemic stroke.

Transdiagnostic markers across the psychosis continuum: a systematic review and meta-analysis of resting state fMRI studies.

Psychotic symptoms are among the most debilitating and challenging presentations of severe psychiatric diseases, such as schizophrenia, schizoaffective, and bipolar disorder. A pathophysiological understanding of intrinsic brain activity underlying psychosis is crucial to improve diagnosis and treatment. While a potential continuum along the psychotic spectrum has been recently described in neuroimaging studies, especially for what concerns absolute and relative amplitude of low-frequency fluctuations (ALFF and fALFF), these efforts have given heterogeneous results. A transdiagnostic meta-analysis of ALFF/fALFF in patients with psychosis compared to healthy controls is currently lacking. Therefore, in this pre-registered systematic review and meta-analysis PubMed, Scopus, and Embase were searched for articles comparing ALFF/fALFF between psychotic patients and healthy controls. A quantitative synthesis of differences in (f)ALFF between patients along the psychotic spectrum and healthy controls was performed with Seed-based d Mapping, adjusting for age, sex, duration of illness, clinical severity. All results were corrected for multiple comparisons by Family-Wise Error rates. While lower ALFF and fALFF were detected in patients with psychosis in comparison to controls, no specific finding survived correction for multiple comparisons. Lack of this correction might explain the discordant findings highlighted in previous literature. Other potential explanations include methodological issues, such as the lack of standardization in pre-processing or analytical procedures among studies. Future research on ALFF/fALFF differences for patients with psychosis should prioritize the replicability of individual studies. Systematic review registration: https://osf.io/, identifier (ycqpz).

The pypadf package: computing the pair angle distribution function from fluctuation scattering data.

The pair angle distribution function (PADF) is a three- and four-atom correlation function that characterizes the local angular structure of disordered materials, particles or nanocrystalline materials. The PADF can be measured using X-ray or electron fluctuation diffraction data, which can be collected by scanning or flowing a structurally disordered sample through a focused beam. It is a natural generalization of established pair distribution methods, which do not provide angular information. The software package pypadf provides tools to calculate the PADF from fluctuation diffraction data. The package includes tools for calculating the intensity correlation function, which is a necessary step in the PADF calculation and also the basis for other fluctuation scattering analysis techniques.

Assessing leaf physiological traits in response to flooding among dominant riparian herbs along the Three Gorges Dam in China.

Dams worldwide have significantly altered the composition of riparian forests. However, research on the functional traits of dominant herbs experiencing flooding stress due to dam impoundment remains limited. Given the high plasticity of leaf traits and their susceptibility to environmental influences, this study focuses on riparian herbs along the Three Gorges Hydro-Fluctuation Zone (TGHFZ). Specifically, it investigates how six leaf physiological traits of leading herbs-carbon, nitrogen, phosphorus, and their stoichiometric ratios-adapt to periodic flooding in the TGHFZ using cluster analysis, one-way analysis of variance (ANOVA), multiple comparisons, Pearson correlation analysis, and principal component analysis (PCA). We categorized 25 dominant herb species into three plant functional types (PFTs), noting that species from the same family tended to fall into the same PFT. Notably, leaf carbon content (LCC) exhibited no significant differences across various PFTs or altitudes. Within riparian forests, different PFTs employ distinct adaptation strategies: PFT-I herbs invest in structural components to enhance stress resistance; PFT-II, mostly comprising gramineous plants, responds to prolonged flooding by rapid growth above the water; and PFT-III, encompassing nearly all Compositae and annual plants, responds to prolonged flooding with vigorous rhizome growth and seed production. Soil water content (SWC) emerges as the primary environmental factor influencing dominant herb growth in the TGHFZ. By studying the response of leaf physiological traits in dominant plants to artificial flooding, we intend to reveal the survival mechanisms of plants under adverse conditions and lay the foundation for vegetation restoration in the TGHFZ.

Influence of anti-seasonal inundation on geochemical processes of arsenic speciation in the water-level-fluctuation zone soil of the Three Gorges Reservoir, China.

Since the completion of Three Gorges Dam, the water-level-fluctuation zone (WLFZ) of the Three Gorges Reservoir (TGR) experiences the periodic anti-seasonal inundation. However, knowledge for mechanisms of mobilization and transformation of arsenic (As) in WLFZ soils of the TGR remains scarce. To address this gap, a combination of field observation and simulated flooding experiments attempts to illustrate the As mobilization, the transformation between As(V) and As(III), and the factors driving these processes. The study revealed that anti-seasonal inundation (with a temperature at 13 â„ƒ) mitigated As release from submerged soils. Interestingly, the total As and ratio of As(III) (the more toxic form of As) concentrations in porewater at 13 â„ƒ was lower, and the prevalence of As(III) occurred later than those at 32 °C (imitate the seasonal inundation condition). The results indicated that the As reduction and the corresponding toxic risks in submerged soils were alleviated under anti-seasonal inundation. The study proposes the reduction of As-bearing manganese (Mn) mineral assemblages and competitive adsorption of dissolved organic carbon (DOC) as primary mechanisms for As mobilization. Furthermore, microorganism-mediated detoxification/reduction processes involving DOC, nitrogen, and Mn (oxyhydr)oxides were identified as central pathways for As(III) enrichment under anti-seasonal inundation. This study enhances understandings of the biogeochemical processes and fate of As in WLFZ soils influenced by artificial regulation of the reservoir.

From lake to fisheries: Interactive effect of climate and landuse changes hit on lake fish catch?

Global warming and unpredictable nature possess a negative impact on fisheries and the daily activities of other habitats. GIS and remote sensing approach is an effective tool to determine the morphological characteristics of the lake. The present study addresses the interactive effect of climate and landuse changes hit on fish catch in lake fisheries. We used a combination of the landscape disturbance index, vulnerability index, and loss index to construct a complete ecological risk assessment framework based on the landscape structure of regional ecosystems. The results indicate an increase from around 45%-76% in the percentage of land susceptible to moderate to ecological severe risk in the landscape from 2004 to 2023. Since 1950, temperature changes have increased by 0.4%, precipitation has decreased by 6%, and water levels have decreased by 4.2%, based on the results. The results indicate that landuse, water temperature, precipitation, and water depth significantly impact the aquaculture system. The findings strongly suggest integrating possible consequences of environmental change on fish yield for governance modeling techniques to minimize their effects.