Synchronous Changes Research Articles

Spatial Heterogeneity of PM2.5 Concentration in Response to Land Use/Cover Conversion in the Yangtze River Delta Region

The sustainable management direction of PM2.5 concentrations in the Yangtze River Delta region remains unclear due to regional spatial effects. This study combined the random forest model, spatial econometric model, and multi-scale geographically weighted regression model (MGWR) to explore the multi-scale spatial response of PM2.5 concentration to land use/cover conversion. The results show that:① PM2.5 concentrations in the Yangtze River Delta region from 2000 to 2018 showed four types of spatial-temporal patterns of spatially continuous aggregation, with strong regional synchronous changes. ② The relative influence of land conversion on PM2.5 concentrations showed a complex performance, and the source-sink effect of cultivated land and forest land was obvious. Neighborhood analysis indicated that the effect of surrounding aggregated land use conversion was generally more significant than that of single cells on PM2.5 concentration change, and the spatial effect was obvious. ③ PM2.5 concentration changes were mostly significantly negatively correlated with forest land and grassland conversion types and significantly positively correlated with conversion types between cropland, construction land, and water bodies. The importance ranking of the random forest model and correlation coefficient intensity indicated that the conversion between cropland-cropland (29.65%; 0.650), forest land-forest land (26.98%; 0.726), construction land-cropland (22.57%; 0.519), cropland-forestland (17.84%; 0.602), and cropland-construction land (16.34%; 0.424) contributed more to the variation in PM2.5 concentration. The spatial Durbin model revealed a significant spatial dependence of the change in PM2.5 concentration and a strong spatial spillover effect. ④ The MGWR model revealed the scale effects and non-stationary characteristics of the spatial relationships between different land use conversions acting on PM2.5 concentration change, and its spatial relationship showed strong differences in transfer types. However, the multi-models revealed that different land conversions drove the PM2.5 concentration change in different ways, so it is necessary to formulate targeted joint management strategies in a categorical and hierarchical manner.

Ionospheric Disturbances Possibly Associated with Yangbi Ms6.4 and Maduo Ms7.4 Earthquakes in China from China Seismo Electromagnetic Satellite

In this paper, the data of electron density, electron temperature and ion compositions detected by the China seismo-electromagnetic satellite (CSES) before Yangbi Ms6.4 and Maduo Ms7.4 earthquakes in China during 21–22 May 2021 are analyzed by using the algorithms of moving average to get the high frequency perturbations, revisited orbit comparison to construct the normal background, and wavelet transform to obtain the spectrum characteristics. Most of the parameters we studied were characterized by synchronous changes and similar frequencies, and even have symmetrical structures in the seismogenic zone, suggesting that they may originate from the same disturbing source. The research results also demonstrated that the electron density and electron temperature forms changed from relatively stable to unstable about 40 days before the earthquakes, and then gradually recovered after the earthquakes. Meanwhile, the disturbances are concentrated near the epicenter. As the earthquakes approach, the number of disturbances gradually becomes more frequent. Based on those observational facts, we suggest that the Yangbi and Maduo earthquakes may have affected the ionosphere through the ionosphere and magnetosphere branch and thermal branch of the lithosphere atmosphere ionosphere coupling model mechanism.

Annual dynamics of eukaryotic and bacterial communities revealed by 18S and 16S rRNA metabarcoding in the coastal ecosystem of Sagami Bay, Japan

Sagami Bay, Japan is influenced by both the warm Kuroshio Current and the cold Oyashio Current and rich nutrients are supplied from multiple river sources and the deep-sea, forming a dynamic ecosystem. The aim of the present study was to investigate eukaryotic and bacterial communities in the coastal waters of Sagami Bay, using 16S rRNA and 18S rRNA sequencing and to assess the seasonal and vertical dynamics in relation to physicochemical and biological conditions. Eukaryotic and bacterial communities showed synchronous seasonal and vertical changes along with environmental variability. Diversity of plankton community suspended in the surface was lower than those at the subsurface layers in both the eukaryotes and bacteria communities; however, community diversity showed different characteristics in the subsurface where the eukaryotic community at the deeper layer (100 m) was as low as the surface and highest in intermediate depth layers (10–50 m), while that of bacterial community was highest in the deeper layer (100 m). The annual variability of the coastal microbial communities was driven, not only by the seasonal changes of abiotic and biotic factors and short-term rapid changes by river water inflow and phytoplankton blooms, but also largely influenced by deep-seawater upwellings due to the unique seafloor topography.

Contiguous Governance of Synchronic and Diachronic Changes for the Use of Genome Editing Technologies

Genome editing technologies are increasingly coming under scrutiny, based on various social value judgments in biomedical research, clinical care, and public health. A central cause of this sociotechnical tension is that these technologies are capable of precisely and easily creating genome-modified organisms and human cells and tissues. To exemplify a general framework for a national governance system of genome editing technologies, we first look at the regulatory dynamics in Japan. Second, we expose the potential tension between national and international debates and directions for the global harmonization of genome editing technologies. Third, underpinning these two perspectives, we propose contiguous governance as a novel model of the governance of emerging biotechnologies from both synchronic and diachronic perspectives. These perspectives, derived from genome editing technologies, can contribute to a better understanding and consideration of future regulations and governance systems.

Human practices behind the aquatic and terrestrial ecological decoupling to climate change in the tropical Andes

Anthropogenic climate change and landscape alteration are two of the most important threats to the terrestrial and aquatic ecosystems of the tropical Americas, thus jeopardizing water and soil resources for millions of people in the Andean nations. Understanding how aquatic ecosystems will respond to anthropogenic stressors and accelerated warming requires shifting from short-term and static to long-term, dynamic characterizations of human-terrestrial-aquatic relationships. Here we use sediment records from Lake Llaviucu, a tropical mountain Andean lake long accessed by Indigenous and post-European societies, and hypothesize that under natural historical conditions (i.e., low human pressure) vegetation and aquatic ecosystems' responses to change are coupled through indirect climate influences—that is, past climate-driven vegetation changes dictated limnological trajectories. We used a multi-proxy paleoecological approach including drivers of terrestrial vegetation change (pollen), soil erosion (Titanium), human activity (agropastoralism indicators), and aquatic responses (diatoms) to estimate assemblage-wide rates of change and model their synchronous and asynchronous (lagged) relationships using Generalized Additive Models. Assemblage-wide rate of change results showed that between ca. 3000 and 400 calibrated years before present (cal years BP) terrestrial vegetation, agropastoralism and diatoms fluctuated along their mean regimes of rate of change without consistent periods of synchronous rapid change. In contrast, positive lagged relationships (i.e., asynchrony) between climate-driven terrestrial pollen changes and diatom responses (i.e., asynchrony) were in operation until ca. 750 cal years BP. Thereafter, positive lagged relationships between agropastoralism and diatom rates of changes dictated the lake trajectory, reflecting the primary control of human practices over the aquatic ecosystem prior European occupation. We interpret that shifts in Indigenous practices (e.g., valley terracing) curtailed nutrient inputs into the lake decoupling the links between climate-driven vegetation changes and the aquatic community. Our results demonstrate how rates of change of anthropogenic and climatic influences can guide dynamic ecological baselines for managing water ecosystem services in the Andes.

An XML Privacy-Preserving Data Disclosure Decision Scheme

In order to protect the sensitive data represented as XML documents in a trusted collaborative system where sensitive data are not shared, an XML privacy-preserving data disclosure decision scheme was proposed under the assumption of a trusted server. This scheme is inspired by the idea of separating storage structure and content. Temporary access matrix is used to represent structure authorization and the vector represents the content authorization of leaf node. According to the conversion rules, access matrix not only represents access authorization of all nodes but also keeps the main structure of the XML document. With the combination of the vector and matrix, it can provide different access views for different group users with different purposes. In addition, start-end encoding is used to encode all the nodes for locating nodes and the content; privilege matrix solves the problem of privacy synchronization change for all users. At the same time, authentication polynomials are used to verify different users and improve the security level. The experimental results show that the scheme not only effectively protects XML sensitive data but also reduces the storage pressure on the server side; at the same time, from the response time, we know that it is beneficial for the rapid search and information positioning.

Chromium isotope evidence for oxygenation events in the Ediacaran ocean

Pulses of the Ediacaran ocean oxygenation were inferred from strong enrichments of redox-sensitive elements (RSEs; particularly Mo, V, U, Re) and negative pyrite sulfur isotopes (δ34Spy) in black shales of the Doushantuo Formation in South China. These oceanic oxygenation events (OOEs) have been challenged by the lack of comparable RSE enrichments in correlative strata of northwestern Canada. Here we report four positive chromium isotope (δ53Cr) excursions with peak values (+0.79 ± 0.03‰ to +1.45 ± 0.06‰; 2SD) close to the average δ53Cr value of the modern ocean (+1.0 ± 0.3‰) at the intervals of OOEs, which are separated by low δ53Cr values close to that of the bulk silicate Earth (BSE, −0.124 ± 0.101‰). The positive δ53Cr excursions could be explained by episodic input of oxygenated water from the open ocean to the restricted Nanhua basin, or pulses of ocean oxygenation during the Ediacaran-early Cambrian. The two interpretations can explain the majority of the geochemical data available from the Wuhe section, but both have limitations. The first interpretation implies that the open ocean was more oxygenated than the Nanhua basin during the entire Ediacaran-early Cambrian period, which is not supported by the currently available data from other Ediacaran successions. The second interpretation has difficulties to explain the thallium isotope (ε205Tl) data from the same section, pending confirmation of the OOEs from other successions globally. The data from the Wuhe section highlight the complexity of interpreting the redox history of the global ocean from geochemical results of a single section. Nonetheless, the synchronous changes of multiproxy records—including positive δ53Cr excursions, RSE peaks, negative δ34Spy and molybdenum isotope (δ98Mo) excursions—at the same stratigraphic intervals do support a more oxygenated ocean at ~635 Ma, ~580 Ma, ~560 Ma, and early Cambrian, regardless of the degree of restriction of the Nanhua basin from the open ocean.

Spatiotemporal patterns of population response in the visual cortex under isoflurane: from wakefulness to loss of consciousness.

Anesthetic drugs are widely used in medicine and research to mediate loss of consciousness (LOC). Isoflurane is a commonly used anesthetic drug; however, its effects on cortical sensory processing, in particular around LOC, are not well understood. Using voltage-sensitive dye imaging, we measured visually evoked neuronal population response from the visual cortex in awake and anesthetized mice at 3 increasing concentrations of isoflurane, thus controlling the level of anesthesia from wakefulness to deep anesthesia. At low concentration of isoflurane, the effects on neuronal measures were minor relative to the awake condition. These effects augmented with increasing isoflurane concentration, while around LOC point, they showed abrupt and nonlinear changes. At the network level, we found that isoflurane decreased the stimulus-evoked intra-areal spatial spread of local neural activation, previously reported to be mediated by horizontal connections, and also reduced intra-areal synchronization of neuronal population. The synchronization between different visual areas decreased with higher isoflurane levels. Isoflurane reduced the population response amplitude and prolonged their latencies while higher visual areas showed increased vulnerability to isoflurane concentration. Our results uncover the changes in neural activity and synchronization at isoflurane concentrations leading to LOC and suggest reverse hierarchical shutdown of cortical areas.

Phase-dependent local brain states determine the impact of image-guided transcranial magnetic stimulation on motor network electroencephalographic synchronization.

Recent studies have synchronized transcranial magnetic stimulation (TMS) application with pre-defined brain oscillatory phases showing how brain response to perturbation depends on the brain state. However, none have investigated whether phase-dependent TMS can possibly modulate connectivity with homologous distant brain regions belonging to the same network. In the framework of network-targeted TMS, we investigated whether stimulation delivered at a specific phase of ongoing brain oscillations might favour stronger cortico-cortical (c-c) synchronization of distant network nodes connected to the stimulation target. Neuronavigated TMS pulses were delivered over the primary motor cortex (M1) during ongoing electroencephalography recording in 24 healthy individuals over two repeated sessions 1month apart. Stimulation effects were analysed considering whether the TMS pulse was delivered at the time of a positive (peak) or negative (trough) phase of μ-frequency oscillation, which determines c-c synchrony within homologous areas of the sensorimotor network. Diffusion weighted imaging was used to study c-c connectivity within the sensorimotor network and identify contralateral regions connected with the stimulation spot. Depending on when during the μ-activity the TMS-pulse was applied (peak or trough), its impact on inter-hemispheric network synchrony varied significantly. Higher M1-M1 phase-lock synchronization after the TMS-pulse (0-200ms) in the μ-frequency band was found for trough compared to peak stimulation trials in both study visits. Phase-dependent TMS delivery might be crucial not only to amplify local effects but also to increase the magnitude and reliability of the response to the external perturbation, with implications for interventions aimed at engaging more distributed functional brain networks. KEY POINTS: Synchronized transcranial magnetic stimulation (TMS) pulses with pre-defined brain oscillatory phases allow evaluation of the impact of brain states on TMS effects. TMS pulses over M1 at the negative peak of the μ-frequency band induce higher phase-lock synchronization with interconnected contralateral homologous regions. Cortico-cortical synchronization changes are linearly predicted by the fibre density and cross-section of the white matter tract that connects the two brain regions. Phase-dependent TMS delivery might be crucial not only to amplify local effects but also to increase the magnitude and reliability of within-network synchronization.

Symmetrically Controlled Design of Twin Alumina-Co Composite Thin Films

Self-assembled dual-working electrode electrolytic cells were designed to produce twin alumina-Co composite films with highly symmetrical microstructures using a deflected electric field-assisted alternating current electrodeposition method. The results show that the deposition current density, microstructure, and optical and magnetic properties of the twin composite films exhibit a high degree of symmetry. The distribution of magnetic Co particles in the alumina nanopores can be changed by adjusting the magnitude of the deflected electric field, resulting in a synchronous symmetrical change in the microstructure of the composite films, which enables the fine-tuning of the magneto-optical properties of the twin alumina-Co composite films at the microscopic scale. The current density distribution on the surface of the twin composite films along the direction of the deflected electric field was quantitatively analyzed by theoretical calculations and numerical simulations. The results show that the deposition current density gradually increases from 0.024 A/m2 in region C to 0.056 A/m2 in region A at 6 V deflection voltage. The saturation magnetization intensity gradually increases along the radial direction, which is 118, 130, and 150 kA/m, respectively

Magnetostriction and damping of forced vibrations in Fe-Cr-Mo-Al alloy

The magnetostriction, damping capacity and mechanical properties of a Fe-Cr-Mo-Al alloy are studied and compared with binary Fe-Cr and Fe-Al alloys. Synchronous change in magnetostriction and damping in Fe-16Cr-0.6Mo-0.6Al alloy: the maximum magnetostriction strain and damping capacity are obtained after annealing at 900 °C followed by air cooling. Frequency dependence of damping in subresonance range is analyzed and interpreted in terms of variations in relaxation time and stiffness of DMA.

Developing a national indicator of functional connectivity

Habitat loss is a significant driver of biodiversity loss, causing fragmentation into small, isolated patches of suitable land cover. This reduces the permeability of landscapes to the movement of individuals and reduces the likelihood of metapopulation persistence. Quantifying functional connectivity, the ability of a focal species to move between resource patches, is therefore essential for conservation management. There is substantial evidence supporting a technique based on ‘population synchrony’- the degree of correlation in time-series of annual population growth rates between different long-term monitoring sites, to provide a measure of functional connectivity. However, synchronised population dynamics are not only driven by the movement of individuals between sites, but also shared environmental conditions which must be accounted for. Here, we use species survey data from over four decades to investigate average levels and temporal trends in population synchrony for 58 British bird and butterfly species. We first show that population synchrony is significantly associated with synchrony in some seasonal climatic variables. Once we accounted for spatiotemporal climatic patterns, we found that synchrony in butterflies declined over time by 71% between 1985 and 2000 but increased by 64% in recent years. Synchrony in birds showed some decline between 1999 and 2005, after which there appears to being recovery, however most species (74%) show no significant overall change in synchrony. Our proposed indicator provides a ‘species-eye-view’ of functional connectivity using widely available abundance data. Developing such indicators of functional connectivity, which can be updated annually, is crucial to improve the effectiveness of land management strategies for conservation under increasing environmental change.

Motif Transition Intensity: A Novel Network-Based Early Warning Indicator for Financial Crises

Financial crisis, rooted in a lack of system resilience and robustness, is a particular type of critical transition that may cause grievous economic and social losses and should be warned against as early as possible. Regarding the financial system as a time-varying network, researchers have identified early warning signals from the changing dynamics of network motifs. In addition, network motifs have many different morphologies that unveil high-order correlation patterns of a financial system, whose synchronous change represents the dramatic shift in the financial system’s functionality and may indicate a financial crisis; however, it is less studied. This paper proposes motif transition intensity as a novel method that quantifies the synchronous change of network motifs in detail. Applying this method to stock networks, we developed three early warning indicators. Empirically, we conducted a horse race to predict ten global crises during 1991–2020. The results show evidence that the proposed indicators are more efficient than the VIX and the other 39 network-based indicators. In a detailed analysis, the proposed indicators send sensitive and comprehensible warning signals, especially for the U.S. subprime mortgage crisis and the European sovereign debt crisis. Furthermore, the proposed method provides a new perspective to detect critical signals and may be extended to predict other crisis events in natural and social systems.

Functional network connectivity and topology during naturalistic stimulus is altered in first-episode psychosis

BackgroundPsychotic disorders have been suggested to derive from dysfunctional integration of signaling between brain regions. Earlier studies have found several changes in functional network synchronization as well as altered network topology in patients with psychotic disorders. However, studies have used mainly resting-state that makes it more difficult to link functional alterations to any specific stimulus or experience. We set out to examine functional connectivity as well as graph (topological) measures and their association to symptoms in first-episode psychosis patients during movie viewing. Our goal was to understand whole-brain functional dynamics of complex naturalistic information processing in psychosis and changes in brain functional organization related to symptoms. Methods71 first-episode psychosis patients and 57 control subjects watched scenes from the movie Alice in Wonderland during 3 T fMRI. We compared functional connectivity and graph measures indicating integration, segregation and centrality between groups, and examined the association between topology and symptom scores in the patient group. ResultsWe identified a subnetwork with predominantly decreased links of functional connectivity in first-episode psychosis patients. The subnetwork was mainly comprised of nodes of and links between the cingulo-opercular, sensorimotor and default-mode networks. In topological measures, we observed between-group differences in properties of centrality. ConclusionsFunctional brain networks are affected during naturalistic information processing already in the early stages of psychosis, concentrated in salience- and cognitive control-related hubs and subnetworks. Understanding these aberrant dynamics could add to better targeted cognitive and behavioral interventions in the early stages of psychotic disorders.

Assessment of the psychological qualities of a paramedic’s personality

The purpose of the study is to identify professionally significant psychological qualities of a paramedic ‘s personality. Results. The presence of synchronous changes in indicators for each characteristic of the paramedic’s personality, both male and female, was revealed; the most pronounced psychological qualities of the personality of professional paramedics were: developed visual-imaginative thinking, caution and prudence, suspicion; the most pronounced psychological qualities of the personality of medical students were the same qualities as those of professional paramedics with the inclusion of markedly pronounced conservatism. Conclusion. When comparing the psychograms of professional paramedics and medical students, psychological characteristics that are subject to correction were identified: emotional instability, dominance, suspicion and relaxation.

Evidence that modern fires may be unprecedented during the last 3400 years in permafrost zone of Central Siberia, Russia

Recent climate change in Siberia is increasing the probability of dangerous forest fires. The development of effective measures to mitigate and prevent fires is impossible without an understanding of long-term fire dynamics. This paper presents the first multi-site palaeo-fire reconstruction based on macroscopic charcoal data from peat and lake sediment cores located in different landscapes across the permafrost area of central Siberia. The obtained results show similar temporal patterns of charcoal accumulation rates in the cores under study, and near synchronous changes in fire regimes. The paleo-fire record revealed moderate biomass burning between 3.4 and 2.6 ka BP, followed by the period of lower burning occurring from 2.6 to 1.7 ka BP that coincided with regional climate cooling and moistening. Minimal fire activity was also observed during the Little Ice Age (0.7–0.25 ka BP). Fire frequencies increased during the interval from 1.7 to 0.7 ka BP and appears to be partly synchronous with climate warming during the Medieval Climate Anomaly. Regional reconstructions of long-term fire history show that recent fires are unprecedented during the late Holocene, with modern high biomass burning lying outside millennial and centennial variability of the last 3400 years.

Infrared radiation quantification of rock damage and its constitutive modeling under loading

The root cause of the infrared radiation (IR) change in rock is the failure of microelements during its evolution. However, the quantified relationship between the two parameters remains unclear. This paper, therefore, presents a quantification approach to investigate the internal damage evolution of loading rock through the surface IR. Multiparameter observation experiments were conducted primarily in coal rock samples. The change in related parameters within the rock sample during the evolution of the damage was recorded. The IR noise from the reference (unloaded) samples was taken as the threshold of the sudden change in the IR temperature. Thus, the noise signal and the sudden change in IR temperature were separated through these threshold values. On this basis, a quantitative index of infrared radiation, the IR counts was adopted. It was found that there was a synchronous sudden change between the IR and Acoustic ringing counts. According to the occurrence of sudden change in the IR counts and the differential infrared radiant thermal image sequence at the corresponding time, the damaged area of the rock can be accurately determined. Taking the IR counts as the characterization parameter of the rock damage variable, the quantitative characterization method of the evolution of coal-rock damage by IR and the stress-strain constitutive model was established. The IR calculated stress (σIR) can reflect the failure process of rock transition from the linear elastic to the plastic deformation stage.

Effect of astrocyte on synchronization of thermosensitive neuron-astrocyte minimum system

Astrocytes have a regulatory function on the central nervous system (CNS), especially in the temperature-sensitive hippocampal region. In order to explore the thermosensitive dynamic mechanism of astrocytes in the CNS, we establish a neuron–astrocyte minimum system to analyze the synchronization change characteristics based on the Hodgkin–Huxley model, in which a pyramidal cell and an interneuron are connected by an astrocyte. The temperature range is set as 0 °C–40 °C to juggle between theoretical calculation and the reality of a brain environment. It is shown that the synchronization of thermosensitive neurons exhibits nonlinear behavior with changes in astrocyte parameters. At a temperature range of 0 °C–18 °C, the effects of the astrocyte can provide a tremendous influence on neurons in synchronization. We find the existence of a value for inositol triphosphate (IP3) production rate and feedback intensities of astrocytes to neurons, which can ensure the weak synchronization of two neurons. In addition, it is revealed that the regulation of astrocytes to pyramidal cells is more sensitive than that to interneurons. Finally, it is shown that the synchronization and phase transition of neurons depend on the change in Ca2+ concentration at the temperature of weak synchronization. The results in this paper provide some enlightenment on the mechanism of cognitive dysfunction and neurological disorders with astrocytes.

An increase in circulating levels of branched-chain amino acids during hemodialysis with regard to protein breakdown: three case reports

BackgroundHemodialysis (HD) is a protein catabolic event. However, the amino acid (AA) kinetics during HD sessions involved in protein breakdown have not been well investigated in patients with and without diabetes mellitus (DM).Case presentationThree patients (two patients with DM and one patient without DM) underwent fasting HD. Plasma levels of branched-chain AAs (BCAA; leucine, isoleucine, and valine), major non-essential AAs (alanine and glutamine, including glutamate), insulin, and ketone bodies were measured every hour during each HD session. After the start of the HD session, the plasma levels of insulin and all BCAAs dropped simultaneously. There was a significant subsequent increase in the plasma level of leucine and isoleucine levels, while valine levels remained constant. However, the recovery in levels of BCAAs during HD indicated a profound amount of BCAAs entering the blood from body tissues such as muscles. BCAAs may have surpassed their removal by HD. Ketone body levels increased continuously from the start of the sessions and reached high values in patients with DM. Synchronous changes in insulin depletion and an increase in the levels of ketone bodies may indicate disruption of energy metabolism.ConclusionsThis is the first report to demonstrate the time course of the changes in circulating levels of BCAAs and related metabolites in energy homeostasis during HD. An increase in BCAA levels during HD was found to be due to their transfer from the body tissue which suggested protein breakdown.

Synchronic changes of lake organic and inorganic carbon burial in response to catchment development over the past century: A case study of Shilin Karst area

有机碳和无机碳的流域输出是湖泊碳埋藏的重要驱动因子, 而喀斯特地区无机碳循环具有反应迅速且对人类活动影响敏感的特点. 在流域开发持续增强的背景下, 喀斯特地区湖泊有机碳和无机碳的来源、含量与埋藏通量可能会出现同步变化的协同模式. 本文以云南省石林喀斯特地区流域土地利用类型不同的两个中型湖泊(长湖、月湖)开展对比分析, 通过对沉积物钻孔的土壤侵蚀强度(磁化率)、流域外源输入(C∶N比值)、水动力(粒度)、营养盐(总氮、总磷)、藻类生产力(叶绿素色素)等代用指标的分析, 结合监测数据和历史资料重建了两个湖泊环境变化的近百年历史, 并定量识别了有机碳和无机碳埋藏响应流域开发的变化特征与协同模式. 沉积物磁化率和C∶N比值结果揭示了流域地表侵蚀和外源输入的阶段性特征, 同时总氮和总磷含量记录了长湖和月湖营养水平上升的长期模式. 在流域森林覆被较高(33.43%)的长湖中, 全岩和有机质C∶N比值分别与磁化率信号呈显著正相关(r=0.95和0.89, P＜0.001), 且与无机碳和有机碳含量呈显著负相关(r=-0.94, P＜0.001和r=-0.52, P=0.01), 反映了森林植被退化时流域碳输出的减少对沉积物碳含量的影响. 而在流域耕地覆被为主(60.98%)的月湖中, 全岩和有机质C∶N比值与磁化率信号呈显著负相关(r=-0.54, P＜0.01和r=-0.67, P＜0.001), 且全岩C∶N比值与无机碳含量(P=0.15)无显著关系, 反映了耕作强度的增加可能促进了水体富营养化和内源输入的增强. 在两个湖泊中, 营养水平的上升和内源生产力的增加促进了有机碳含量的快速增加. 进一步分析表明, 近百年来长湖有机碳与无机碳含量变化的同步性明显(r=0.54, P＜0.001)而在月湖中无显著关系(P=0.20, P>0.05). 两个湖泊中沉积通量的变化均与全岩C∶N比值呈显著正相关(r=0.48和0.45, P≤0.001), 且有机碳与无机碳埋藏通量均呈现同步变化的显著特征(r=0.72和0.85, P＜0.001). 其中长湖的无机碳埋藏通量显著高于有机碳埋藏通量, 而月湖的有机碳埋藏通量略高于无机碳埋藏通量, 反映了岩溶地区流域外源输入和水体富营养化的差异性驱动影响. 在流域开发增强的梯度下, 森林退化会降低流域碳输出的负荷, 而农业扩张和水体富营养化会促进藻类生长和内源有机碳的累积. 因此, 流域土地利用和水体营养水平对湖泊无机碳和有机碳埋藏变化的长期轨迹和协同模式产生了重要影响, 对喀斯特地区的碳库评估需要考虑无机碳循环的重要性.;Catchment-scale exports of organic and inorganic carbon plays an important role in affecting the lake sediment carbon burial. Inorganic carbon cycling in Karst landscapes is sensitive to human activities due to the rapid kinetics of carbonate dissolution. As with intensive watershed development, the source, content and burial loading of organic and inorganic carbon in Karst region may show a synchronous change. This study selected two medium-sized lakes (Lake Changhu and Lake Yuehu) with contrasting land uses patterns in the Shilin Karst area of central Yunnan for sediment surveys. With the proxies analyses for soil erosion (i.e. magnetic susceptibility (MS)), catchment allochthonous input (C∶N ratio), lake hydrology (particle size), nutrient levels (total phosphorus and nitrogen) and primary production (i.e. algal pigments), together with monitoring data and historical records, the history of limnological changes and catchment development over the last century for both lakes were reconstructed. Furthermore, long-term variation and synchronic pattern of sediment organic carbon (OC) and inorganic carbon (IC) burial in the context of catchment development were quantified. The sediment MS signal recorded the fluctuation in soil erosion intensity and a general pattern of long-term nutrient enrichment in both lakes. In Lake Changhu, with a higher land cover of forest (33.43%), the bulk and organic C∶N ratios were positively related with the MS signal (r=0.95 and 0.89, P < 0.001) but showed a negative relationship with sediment inorganic and organic carbon content (r=-0.94, P < 0.001 and -0.52, P=0.01), respectively, reflecting a significant impact of catchment carbon input. In Lake Yuehu, with a current land cover dominated by the cropland (60.98%), the bulk and organic C∶N ratios were negatively related with the MS signal (r=-0.54, P < 0.01 and -0.67, P < 0.001) and the bulk C∶N ratio showed no relationship with the sediment inorganic content (P=0.15), reflecting that the cropland expansion may have enhanced lake eutrophication and autochthonous input. In both lakes, nutrient enrichment and algal production enhanced the rapid OC accumulation. Additional analyses showed that there existed a significantly synchronous change between OC and IC content in Lake Changhu (r=0.54, P < 0.001) but not in Lake Yuehu (P=0.20, P>0.05). In both lakes, sediment loading was positively related with bulk C∶N ratio (r=0.48 and 0.45, P≤0.001), and there also existed a significantly synchronous change between OC and IC loadings (r=0.72 and 0.85, P < 0.001). Furthermore, the IC burial rate was significantly higher than that of OC in Lake Changhu, while IC consistently lower than OC in the nutrient-rich Lake Yuehu, reflecting differential forcing of vegetation degradation and lake eutrophication. With the intensive development in watershed, forest degradation can reduce the loading of catchment carbon export, while agricultural expansion and eutrophication would promote the growth of algae and the OC accumulation rate. Therefore, land use and lake nutrient levels can significantly impact the long-term trajectory and synchronic variation of sediment OC and IC burial. Thus, IC cycling should be considered in the regional assessment of carbon stock in karst areas.