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1.
J Environ Manage ; 370: 122487, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39288489

RESUMO

Income group heterogeneity and transboundary food-related water footprints are essential for water resource management. Previous studies have not fully characterized the transboundary food-related water footprints by regional income groups. Taking Guangdong as an example, this study calculates the local and transboundary food-related water footprints by income groups and explores relevant socioeconomic factors during 2007-2017. Results show that the proportion of transboundary food-related water footprints by income groups has increased during 2007-2017. By 2017, nearly half of food-related water footprints of income groups happened in external regions. In particular, the high-income groups of Guangdong transferred large amounts of food-related water footprints to specific northern regions (e.g., Heilongjiang and Jilin). However, socioeconomic changes of these northern regions contributed to the increase of food-related water footprints by income groups. Fortunately, the transitions of food consumption structures of income groups helped to reduce the external food-related water footprints. We also observed that the effects of dietary behavior changes were group heterogeneous. The findings of this study can provide scientific foundations for group-targeted dietary behavior optimization to reduce water footprints, as well as interregional collaboration for sustainable food and water resource management.

2.
BMC Res Notes ; 17(1): 262, 2024 Sep 12.
Artigo em Inglês | MEDLINE | ID: mdl-39267197

RESUMO

OBJECTIVES: The Social Accounting Matrix (SAM) is an extension of Input-Output tables that records macro and meso-economic accounts of a socio-economic system. Its main objective is to provide a comprehensive understanding of the interrelationships among different economic sectors and agents. The SAM can be used for various purposes, including economic analysis, policy evaluation, and economic modelling. It allows policymakers to make more informed decisions, understand potential consequences of different policy options and serve as the foundation for constructing Computable General Equilibrium (CGE) models. DATA DESCRIPTION: The SAM for Germany is a comprehensive source of data that reveals the incomes and expenditures of 163 different production sectors, along with data on factors of production, households, corporations, government, and external accounts with the rest of the world. Additionally, it provides information on gross fixed capital formation, changes in inventories, and natural capital accounts. This SAM was compiled by extending the EXIOBASE Input-Output (IO) accounts with data from the Federal Statistical Office of Germany. Balancing items were also used to ensure that the Total Income and Total Expenditure of the main transactors are in balance.


Assuntos
Renda , Alemanha , Humanos , Renda/estatística & dados numéricos , Modelos Econômicos , Contabilidade/métodos , Fatores Socioeconômicos
3.
Front Public Health ; 12: 1386826, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39234076

RESUMO

Healthcare is a major generator of greenhouse gases, so consideration of this contribution to climate change needs to be quantified in ways that can inform models of care. Given the availability of activity-based financial data, environmentally-extended input-output (EEIO) analysis can be employed to calculate systemic carbon footprints for healthcare activities, allowing comparison of different patient care pathways. We thus quantified and compared the carbon footprint of two common care pathways for patients with stable coronary artery disease, with similar clinical outcomes: coronary stenting and coronary artery bypass surgery (CABG). Healthcare cost data for these two pathways were disaggregated and the carbon footprint associated with this expenditure was calculated by connecting the flow of money within the economy to the greenhouse gases emitted to support the full range of associated activities. The systemic carbon footprint associated with an average stable patient CABG pathway, at a large tertiary referral hospital in Sydney, Australia in 2021-22, was 11.5 tonnes CO2-e, 4.9 times greater than the 2.4 tonnes CO2-e footprint of an average comparable stenting pathway. These data suggest that a stenting pathway for stable coronary disease should be preferred on environmental grounds and introduces EEIO analysis as a practical tool to assist in health-care related carbon footprinting.


Assuntos
Pegada de Carbono , Ponte de Artéria Coronária , Doença da Artéria Coronariana , Stents , Humanos , Doença da Artéria Coronariana/cirurgia , Austrália , Custos de Cuidados de Saúde
4.
J Environ Manage ; 370: 122509, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39293113

RESUMO

Promoting good health and ensuring responsible production and consumption are essential components of the Sustainable Development Goals (SDGs) established by of the United Nations, as well as the goals of beautiful China. While the health impacts of air pollution have garnered significant attention, there remains a paucity of studies comparing the disparities in responsibility arising from production versus consumption. This paper integrates the Weather Research and Forecasting - Comprehensive Air Quality Model with Extensions (WRF-CAMx) model, the multiregional input‒output (MRIO) model, and the global exposure mortality model (GEMM) to assess the extent of PM2.5-related premature deaths caused by production and consumption activities in 30 Chinese provinces. The findings reveal a spatial mismatch in health burdens between production and consumption. Considering pollutant emissions and their transfer only through the supply chain leads to the finding that the net outflow of emissions from producers is mainly located in most of the northern provinces of China. However, when atmospheric transport and health impacts are included, the producing provinces are mainly located in central China, while the consuming provinces are located in the southeastern coastal and remote western and northern regions. Additionally, the long-range impact of consumption provinces with respect to the health burden is more than twice as large as that of production provinces, and its potential impact on the health burden cannot be ignored. From a sectoral perspective, production emissions from the non-electricity industry and services sectors contribute to 60% of the health burden, while their consumption emissions contribute to over 80% of the health burden. Furthermore, consumption activities in the non-electricity industry and services sectors significantly influence production emissions in the transport, agriculture, and electricity sectors. The geographical separation of consumption and production regions facilitated by trade is a critical yet often overlooked aspect in current regional air quality planning in China. A more comprehensive analysis of life-cycle emissions driven by final consumption could yield greater reductions compared to direct production reductions.

5.
Environ Sci Technol ; 58(37): 16570-16577, 2024 Sep 17.
Artigo em Inglês | MEDLINE | ID: mdl-39231004

RESUMO

In this study, the fluxes of microplastics (mp) were quantified during a 12-month period for three rural headwater lake catchments in Muskoka-Haliburton, south-central Ontario, Canada. A novel catchment particle balance approach was used, incorporating inputs from atmospheric deposition and stream inflows against lake outflow and sedimentation. This approach provides the first reported observation-based estimates of microplastic residence time in freshwater lakes. Atmospheric deposition had the highest daily microplastic flux (3.95-8.09 mp/m2/day), compared to the inflow streams (2.21-2.34 mp/m2/day), suggesting that it is the dominant source of microplastics to rural regions. Approximately 44-71% of the deposited microplastics were retained in the terrestrial catchments and 30-49% of the microplastics in the stream inflows were retained in the study lakes. Given that output fluxes ranged from 0.72-3.76 mp/m2/day in the sediment and 1.18-1.66 mp/m2/day in the lake outflows, the microplastic residence time was estimated to be between 3 and 12 years, suggesting that lakes are an important reservoir for microplastics. Fibers were the dominant shape in atmospheric deposition, streamwater, and lake water; however, in lake sediment, there was a higher proportion of fragments. Across all media, poly(ethylene terephthalate) was the dominant polymer identified (23%).


Assuntos
Lagos , Microplásticos , Poluentes Químicos da Água , Microplásticos/análise , Poluentes Químicos da Água/análise , Ontário , Monitoramento Ambiental
6.
Cell Syst ; 15(9): 808-823.e6, 2024 Sep 18.
Artigo em Inglês | MEDLINE | ID: mdl-39243757

RESUMO

The regulation of genes can be mathematically described by input-output functions that are typically assumed to be time invariant. This fundamental assumption underpins the design of synthetic gene circuits and the quantitative understanding of natural gene regulatory networks. Here, we found that this assumption is challenged in mammalian cells. We observed that a synthetic reporter gene can exhibit unexpected transcriptional memory, leading to a shift in the dose-response curve upon a second induction. Mechanistically, we investigated the cis-dependency of transcriptional memory, revealing the necessity of promoter DNA methylation in establishing memory. Furthermore, we showed that the synthetic transcription factor's effective DNA binding affinity underlies trans-dependency, which is associated with its capacity to undergo biomolecular condensation. These principles enabled modulating memory by perturbing either cis- or trans-regulation of genes. Together, our findings suggest the potential pervasiveness of transcriptional memory and implicate the need to model mammalian gene regulation with time-varying input-output functions. A record of this paper's transparent peer review process is included in the supplemental information.


Assuntos
Metilação de DNA , Regulação da Expressão Gênica , Regiões Promotoras Genéticas , Fatores de Transcrição , Transcrição Gênica , Metilação de DNA/genética , Regiões Promotoras Genéticas/genética , Humanos , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Regulação da Expressão Gênica/genética , Animais , Transcrição Gênica/genética , Redes Reguladoras de Genes/genética , Mamíferos/genética
7.
Heliyon ; 10(17): e36738, 2024 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-39319131

RESUMO

China is one of the largest volatile organic compounds (VOCs) emitters worldwide. The emission levels of and harm caused by VOCs have attracted much attention. China has implemented multiple policies for VOCs prevention and control but lacks economic control measures for VOCs In this study, the input-output (IO) price model was used to simulate and analyze the emission reduction and economic effects resulting from the imposition of a VOCs environmental protection tax (EPT) in 31 provinces in China. The results show that, first, the collection of a VOCs-EPT can achieve not only VOCs emission reductions but also the synergistic emission reductions of other major pollutants. Second, the collection of a VOCs-EPT could have a negative impact on the macroeconomy, i.e., the greater the tax scope and the higher the tax rate are, the greater the negative economic impact. Third, differences in the level of economic development, the structure of pollution emissions and the stringency of tax policies among regions would cause the emission reduction effect and related negative economic impact to vary across regions. Finally, the collection of a VOCs-EPT could have heterogeneous impacts on various industries, as high-emission industries would suffer greater negative impacts. Therefore, each region should set tax rates that match its provincial economic and environmental development levels. Furthermore, a VOCs-EPT can be levied on key industries, and reasonable preferential tax policies can be formulated to reduce negative macroeconomic benefits.

8.
Environ Sci Pollut Res Int ; 31(45): 56660-56684, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39279022

RESUMO

Global Value Chains (GVCs) significantly influence international trade and environmental outcomes. Despite the economic benefits of GVCs, their impact on the environment remains under-examined. This study  analyzes the effects of GVC participation (considering forward and backward positions) on total carbon emissions embodied in exports (TEEE) and imports (TEEI). Utilizing panel data from 65 economies spanning 1995 to 2018, we apply input-output matrices and the system generalized method of moments (GMM-SYS) approach. Our results indicate that GVC participation generally is associated with reductions in TEEI and increases in TEEE, with backward participation exerting a more substantial impact. Furthermore, we observed asymmetrical impacts of GVC participation between developed and developing countries. Developed nations tend to reap greater benefits from GVC in terms of diminished CO2 emissions associated with imports, as well as notable CO2 reductions in both exports and imports, particularly when forward participation is the focal point. Conversely, developing countries grapple with heightened environmental burdens stemming from their engagement in backward linkages.


Assuntos
Comércio , Dióxido de Carbono/análise , Carbono , Países em Desenvolvimento
9.
Environ Res ; 263(Pt 1): 120018, 2024 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-39293752

RESUMO

Realizing a synergistic reduction of air pollutant and CO2 emissions (APCE) is an important approach to promote a green socio-economic transformation in China, and it can provide a solid foundation for the achievement of clean energy production and climate action under a sustainable development goal framework. The objective of this study is to explore the quantitative relationship and evolution of synergies between APCE in industrial sectors driven by different socio-economic effects from 2007 to 2020 in China. The results indicated that the main sectors of pollutant emissions had consistency, however, large differences in the reduction efficiency of emissions exist among pollutants. The efficiency in reducing CO2 emissions was about 48% lower when compared with reductions of SO2 (95%), NOx (86%), and smoke and dust (83%) emissions from 2007 to 2020. The effects of improved technology were the main contributor to a reduction in pollutant emissions, but the synergies between APCE driving by it were not achieved. While the synergies between APCE driven by structure and final demand effects were significant. The synergies between NOx and CO2 emissions were stronger driven by final demand structure and type effects, with correlation coefficients of 1.06 and 1.13, respectively. Besides, the degree of synergistic reduction between APCE in most industrial sectors was around zero. Therefore, the efficiency of synergistic pollution reduction should be improved with the development of a synergistic governance system for industrial sectors. The structural decomposition analysis based on input-output model combined with the cross-elasticity analysis method to quantitively synergies between APCE from the consumption (demand) perspective, considering the connections between industrial sectors with socio-economic developing, which would contribute to the industrial synergistic reduction and green transformation as the consumption driven gradually increasing.

10.
Sci Total Environ ; 951: 175539, 2024 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-39151613

RESUMO

Agricultural product demand driven by population and economic growth poses challenges to water, land, and energy utilization, and this increasing local demand is largely met through trade. However, the efficiency and nexus pattern of the water, land, and energy embodied in agricultural trade are not well understood. This study uses the multi-regional input-output framework to analyze agricultural water, land, and energy utilization efficiency of resource footprints per unit economic output as well as their transfer and nexus pattern in global agricultural trade for 1995-2019. The results show that many international agricultural trade paths are inefficient in the water, land, and energy resource use because the agricultural products in these paths are exported from relatively low- to high-efficiency economies/regions. However, these inefficient transfer paths show an increasing trend over the study period. Regarding the water-land-energy nexus, conflicts are prevalent in land-energy and water-energy couplings. Most trade paths are conducted to alleviate the pressure on a specific resource, inadvertently increasing the pressure on other resources. Although agricultural trade is important for meeting global food demands, it is not consistently beneficial to the local environment when considering agricultural resources use efficiency. This study is expected to improve our understanding of agricultural trade impacts to the agricultural resources and support the sustainable development of global agriculture.

11.
Pflugers Arch ; 2024 Aug 09.
Artigo em Inglês | MEDLINE | ID: mdl-39162833

RESUMO

Neurons in central nervous systems receive multiple synaptic inputs and transform them into a largely standardized output to their target cells-the action potential. A simplified model posits that synaptic signals are integrated by linear summation and passive propagation towards the axon initial segment, where the threshold for spike generation is either crossed or not. However, multiple lines of research during past decades have shown that signal integration in individual neurons is much more complex, with important functional consequences at the cellular, network, and behavioral-cognitive level. The interplay between concomitant excitatory and inhibitory postsynaptic potentials depends strongly on the relative timing and localization of the respective synapses. In addition, dendrites contain multiple voltage-dependent conductances, which allow scaling of postsynaptic potentials, non-linear input processing, and compartmentalization of signals. Together, these features enable a rich variety of single-neuron computations, including non-linear operations and synaptic plasticity. Hence, we have to revise over-simplified messages from textbooks and use simplified computational models like integrate-and-fire neurons with some caution. This concept article summarizes the most important mechanisms of dendritic integration and highlights some recent developments in the field.

12.
Huan Jing Ke Xue ; 45(8): 4520-4528, 2024 Aug 08.
Artigo em Chinês | MEDLINE | ID: mdl-39168672

RESUMO

To deepen the recognition of changes in industrial water use with socio-economic development, a "double-layer nested" structural decomposition analysis has been proposed to decompose the influence of the drivers of industrial water use change by sectors in China from 2002 to 2020. The results showed that the scale expansion factors represented by consumption, investment, and export were the main factors for the growth of industrial water use in different sectors, among which the expansion effect of per capita consumption grew faster. Additionally, there were obvious differences in the major drivers of industrial scale expansion between different sectors, which directly drove the industrial structure change. The production process water use effect and water reuse effect were the main factors to curb the growth of industrial water use. The accumulation of both had completely offset the positive effect of industrial scale expansion during the period, reducing industrial water consumption by 11.2 billion m3. However, the production process water use changes in metal extraction, smelting, and processing and energy processing sectors such as electric power had a smaller negative effect, leading to the potential for improving industrial water efficiency solely through a relatively small improvement in water resource reuse. Therefore, it is necessary to strengthen industrial water conservation management based on the differences in the impact of various sectors to promote the transformation and upgradation of industrial production and consumption structures, and to avoid another increase in industrial water use in China.

13.
J Neurophysiol ; 2024 Aug 28.
Artigo em Inglês | MEDLINE | ID: mdl-39196985

RESUMO

The manner in which motoneurons respond to excitatory and inhibitory inputs depends strongly on how their intrinsic properties are influenced by the neuromodulators serotonin and noradrenaline. These neuromodulators enhance the activation of voltage­gated channels that generate persistent (long-lasting) inward sodium and calcium currents (PICs) into the motoneurons. PICs are crucial for initiating, accelerating, and maintaining motoneuron firing. A greater accessibility to state-of-the-art techniques that allows both the estimation and examination of PIC modulation in tens of motoneurons in vivo has rapidly evolved our knowledge of how motoneurons amplify and prolong the effects of synaptic input. We are now in a position to gain substantial mechanistic insight into the role of PICs in motor control at an unprecedented pace. The present review briefly describes the effects of PICs on motoneuron firing and the methods available for estimating them before presenting the emerging evidence of how PICs can be modulated in health and disease. Our rapidly developing knowledge of the potent effects of PICs on motoneuron firing has the potential to improve our understanding of how we move, and points to new approaches to improve motor control. Finally, gaps in our understanding are highlighted and methodological advancements suggested to encourage readers to explore outstanding questions to further elucidate PIC physiology.

14.
J Environ Manage ; 367: 121990, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-39094411

RESUMO

Dual control policies aim to effectively reduce energy consumption and carbon emission by setting targets for total volume and intensity control. With global climate change becoming increasingly serious. China, as a large energy-consuming and carbon-emitting country, faces a huge challenge to reduce carbon emissions. The transition from the "dual control of energy consumption" to the "dual control of carbon emissions" in China is necessary to optimize energy structures, promote energy conservation, reduce carbon emissions, and reach carbon neutrality. This study utilizes multi-regional input-output models to evaluate the results toward both goals from production-based, consumption-based, and income-based perspectives. The findings indicate that "dual control of carbon emissions" is a more precise approach than "dual control of energy consumption". Some provinces have met the latter goal while still falling short of the former. Provinces having met their production-based energy intensity and carbon emission intensity targets, but having failed their consumption-based and income-based targets, are identified to develop a comprehensive and accurate assessment of these targets. A net outflow of embodied energy and carbon emissions is observed among provinces in less-developed central and southern regions to more-developed eastern and northern regions. Suggestions and policy implications based on these findings include establishing a comprehensive evaluation of energy and carbon intensity, considering both consumption-based and income-based perspectives, as well as facilitating enhanced cooperation among developed and developing provinces.


Assuntos
Carbono , Mudança Climática , China
15.
ISA Trans ; 153: 143-154, 2024 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-39069453

RESUMO

The optimal control design of the boiler-turbine system is vital to ensure feasibility and high responsiveness over desired load variations. Using the traditional linear control techniques realization of this task is difficult, as the boiler-turbine mechanism has strong nonlinearities. Besides, environmental and economic concerns have replaced existing tracking control ones as the primary concerns of advanced power plants. Thus, this study proposes an optimal economic model predictive controller (EMPC) scheme for this unit on the basis of the input/output feedback linearization (IOFL) method. By employing the IOFL method, this unit is decoupled into a new linearized model that is utilized for developing the suggested optimal IOFL EMPC technique. The proposed control scheme is formulated in an economic quadratic programming form that considers the input-rate and input limits of the unit for optimal economic performance. In addition, an adaptive iterative algorithm is utilized for constraints mapping with guaranteeing a feasible solution in a finite number of steps without violation of original constraints over the entire predictive horizon. The outcomes of the simulation show that the suggested optimal IOFL EMPC scheme offers an improved dynamic and economic output performance over fuzzy hierarchical MPC, fuzzy EMPC, and nonlinear EMPC techniques during various load variations.

16.
Lancet Reg Health West Pac ; 48: 101115, 2024 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-39006230

RESUMO

Background: Health systems have a dual imperative to take action on climate change. First, they must develop climate resilient health services in response to the direct and indirect impacts of climate change on health. Second, they must reduce their own carbon footprint since health systems are a significant contributor to global greenhouse gas emissions. Methods: An environmentally-extended multi-region input-output analysis was carried out, incorporating National Accounts data for Australia and annual expenditure data from WA Health for financial year 2019-20. Expenditure data were categorised to one of 344 economic sectors and by location of the provider of goods or services purchased. Findings: WA Health contributes 8% of WA's total carbon footprint, driven by expenditure on chemicals (23.8% of total), transport (20.2% of total), and electricity supply (19.7% of total). These 3 sectors represent 63.7% of WA Health's carbon footprint, but only 10.8% of its total expenditure. Interpretation: Reducing emissions related to health service provision in WA will require a holistic approach that leverages carbon footprinting insights and integrates them into organisational decision-making across all health programs. The high carbon-intensity of the transport and chemicals sectors supports previous research calling for a reduction in unnecessary pathology testing and the transition to delivery of non-urgent health care via sustainable models of telehealth. The impact of WA's size and location presents challenges, with a predominantly non-renewable energy supply and reliance on transport and supply chains from other states adding significantly to emissions. Funding: The study received funding from the Australian Research Council, The University of Sydney, and the WA Department of Health. The full list of funding information can be found in Acknowledgements.

17.
Sci Total Environ ; 948: 174863, 2024 Oct 20.
Artigo em Inglês | MEDLINE | ID: mdl-39038675

RESUMO

Grain production consumes a large amount of water and is affected by the degree of water scarcity and participation in the grain trade in various regions. The grain trade has changed the food security risks in regions where grain exports and imports. Therefore, it is crucial to consider regional water scarcity to understand food security risks from the grain trade network. Here, we construct a new framework for measuring regional food security risks associated with water scarcity, grain production, and grain trade based on a cross-city grain trade network combined with virtual water flows to evaluate the regional food security risks in the Yangtze River Delta region (YRD) of China in 2017. The results show that under the current domestic grain trade pattern in China, the YRD and its four provincial-level administrative regions are in a net grain import state. The grain trade within the YRD is concentrated in exports from the two major grain-producing areas of Anhui and Jiangsu to Zhejiang and Shanghai, especially from northern Jiangsu to southeastern Zhejiang. The net import results of virtual blue water in most cities indicate that the YRD has shifted its water resource pressure to other grain exporting regions in China, with Shanghai and Zhejiang being the greatest beneficiaries. Extreme risk only exists in Shanghai, and severe and moderate risks are concentrated in Jiangsu. The current grain trade has reduced the overall food security risk in the YRD by 1.3 % but increased the risks in Shanghai and Zhejiang by 2.1 % and 0.8 % respectively. This study highlights the potential risks that excessive production of food in water-scarce areas in the grain trade system may bring to a stable food supply, providing useful information for a comprehensive understanding of the food and water security situation and for future trade-offs.

18.
Sci Total Environ ; 947: 174552, 2024 Oct 15.
Artigo em Inglês | MEDLINE | ID: mdl-39002578
19.
Sci Total Environ ; 945: 174153, 2024 Oct 01.
Artigo em Inglês | MEDLINE | ID: mdl-38906292

RESUMO

Water scarcity, land pollution, and global warming are serious challenges and crises facing the development of sustainable or green agriculture and need to be addressed using efficient and environmentally friendly management strategies. This paper proposed an integrated framework appropriate for agricultural green total factor productivity (AGTFP) assessment coupled with microscopic and mesoscopic perspectives under water-energy-food (WEF) nexus, which generated scientific and reasonable strategies for green and low-carbon agriculture from internal core factors and peripheral environmental impacts to improve green agricultural production sustainability. Taking the Lianshui irrigation district (LID) with three sub-areas as the object, internal core factors were explored by partial least squares regression (PLSR) and the external impact path through partial least squares structural equation modeling (PLS-SEM). Results indicated that AGTFP in LID was the smallest (0.818) compared to the three sub-areas and was in a fluctuating state. Meanwhile, AGTFP which was calculated considering undesirable outputs, was closer to tangible productivity. Resource endowments and technical facilities will promote agricultural production, desirable outputs will stimulate green production, and undesirable outputs can inhibit green production. The external influence pathway was shown to be primary environment - > secondary environment - > economic aspects - > social aspects - > AGTFP. The innovative perspectives presented in this study can facilitate preferable decisions and avoid unintended consequences for human-natural systems.


Assuntos
Agricultura , Conservação dos Recursos Naturais , Agricultura/métodos , Conservação dos Recursos Naturais/métodos , Desenvolvimento Sustentável , China , Humanos , Irrigação Agrícola/métodos
20.
Philos Trans R Soc Lond B Biol Sci ; 379(1906): 20230235, 2024 Jul 29.
Artigo em Inglês | MEDLINE | ID: mdl-38853561

RESUMO

Which proportion of the long-term potentiation (LTP) expressed in the bulk of excitatory synapses is postsynaptic and which presynaptic remains debatable. To understand better the possible impact of either LTP form, we explored a realistic model of a CA1 pyramidal cell equipped with known membrane mechanisms and multiple, stochastic excitatory axo-spinous synapses. Our simulations were designed to establish an input-output transfer function, the dependence between the frequency of presynaptic action potentials triggering probabilistic synaptic discharges and the average frequency of postsynaptic spiking. We found that, within the typical physiological range, potentiation of the postsynaptic current results in a greater overall output than an equivalent increase in presynaptic release probability. This difference grows stronger at lower input frequencies and lower release probabilities. Simulations with a non-hierarchical circular network of principal neurons indicated that equal increases in either synaptic fidelity or synaptic strength of individual connections also produce distinct changes in network activity, although the network phenomenology is likely to be complex. These observations should help to interpret the machinery of LTP phenomena documented in situ. This article is part of a discussion meeting issue 'Long-term potentiation: 50 years on'.


Assuntos
Potenciação de Longa Duração , Modelos Neurológicos , Sinapses , Potenciação de Longa Duração/fisiologia , Sinapses/fisiologia , Células Piramidais/fisiologia , Animais , Simulação por Computador , Potenciais de Ação/fisiologia , Região CA1 Hipocampal/fisiologia
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