change characteristics
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2022 ◽  
Author(s):  
Yi-Xuan Shan ◽  
Hui-Lan Yang ◽  
Hong-Bin Wang ◽  
Shuai Zhang ◽  
Ying Li ◽  
...  

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


2022 ◽  
Vol 14 (1) ◽  
pp. 465
Author(s):  
Yumeng Wang ◽  
Jingyan Ma ◽  
Lijuan Zhang ◽  
Yutao Huang ◽  
Xihui Guo ◽  
...  

In this study, on the basis of the temperature data collected at 612 meteorological stations in China from 1961 to 2019, cold regions were defined using three indicators: an average temperature of <−3.0 °C during the coldest month; less than five months with an average temperature of >10 °C; and an annual average temperature of ≤5 °C. Spatial interpolation, spatial superposition, a trend analysis, and a spatial similarity analysis were used to obtain the spatial distribution of the cold regions in China from 1961 to 2019. Then, the areas of the cold regions and the spatial change characteristics were analyzed. The results reveal that the average area of the cold regions in China from 1961 to 2019 was about 427.70 × 104 km2, accounting for about 44.5% of the total land area. The rate of change of the area of the cold regions from 1961 to 2019 was −14.272 × 104 km2/10 a, exhibiting a very significant decreasing trend. On the basis of the changes between 1991–2019 and 1961–1990, the area of China’s cold regions decreased by 49.32 × 104 km2. The findings of this study provide references for studying changes in the natural environment due to climate change, as well as for studying changes on a global scale.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Hexia Yao ◽  
Mohd Dahlan Hj. A. Malek

College students’ employment is affected by many factors such as economy and policy, which makes the prediction error of college students’ employment rate large. In order to solve this problem, a prediction method of college students’ employment rate based on the gray system is designed. Firstly, it analyzes the current research status of college students’ employment rate prediction, finds out the causes of errors, then collects the historical data of college students’ employment rate, fits the change characteristics of college students’ employment rate through the gray system, and establishes the prediction model of college students’ employment rate. Finally, the simulation test is realized by using the employment rate data of college students. The results show that the gray system can reflect the change characteristics of college students’ employment rate and obtain high-precision college students’ employment rate prediction results. The prediction error is less than that of other college students’ employment rate prediction methods. We achieved an average accuracy of 95.22% as compared to 92.3% and 87.7% of other proposed systems. The prediction results can provide some reference information for the university employment management department.


2021 ◽  
Vol 13 (23) ◽  
pp. 4879
Author(s):  
Luguang Jiang ◽  
Ye Liu ◽  
Si Wu ◽  
Cheng Yang

In recent years, much attention has been given to the current situation and trend regarding economic development in the Democratic People’s Republic of Korea (DPRK), of which urbanization is an important indicator. In the present study, (i) the urbanized area is estimated using DMSP/OLS and NPP/VIIRS, (ii) the current spatial pattern and the change characteristics of typical cities are revealed, and (iii) the scale and developmental stage of major cities in the DPRK are judged through comparison. Although the DPRK is relatively closed, the financial crisis in 2008 indirectly affected its economic development, and a large gap remains between the urbanization level of the DPRK and that of China and the Republic of Korea. The large cities in the DPRK are located mainly in its eastern coastal areas and western plains, and there has been no significant expansion in Pyongyang, Chungjin, and Hamhung in the past 28 years. Although economic construction has begun again recently in the DPRK, further reform and opening are required. As the DPRK’s relations with its neighbors and countries around the world improve, its economic development and urban construction will present a new pattern.


2021 ◽  
Vol 17 (2) ◽  
pp. 094-105
Author(s):  
Domenico Prisa

The Opuntia genus, belonging to the Cactaceae family, has about 300 species, of which Opuntia ficus indica, or Prickly Pear, is considered the best known and most significant. Opuntia ficus indica have been used in Mexico and Latin America since pre-hispanic times as a food and medicinal resource. In recent years, prickly pear cultivation has increased mainly because this plant used for food, medicinal and livestock purposes is able to withstand extreme drought conditions in relatively poor soils. The fruits of the prickly pear are of various colours such as yellow, orange, purple and white, and when ripe their sweet pulp is characterised by a low acidity. It possesses numerous nutritional and therapeutic virtues such as richness in carbohydrates, vitamins, minerals and considerable antioxidant, anti-diabetes, anti-cancer fruit activity. Opuntia also has laxative properties due to its soluble fibres and mucilage. The infusion of the harvested and dried flowers has a depurative effect; it has a mild, gentle diuretic and relaxing action on the renal excretory system. Opuntias are also exploited as an alternative and cheap source of source of food for animals and as an ornamental plant. Opuntia ficus indica is grown in subtropical, tropical and warm-temperature areas; it is mainly cultivated in Tunisia, Libya and Egypt. The Prickly Pear finds a particularly favourable habitat in Sardinia, Calabria, Apulia and Sicily, where it is also cultivated, as well as in Spain and North Africa, for the exploitation of its edible fruit, with its delicately sweet pulp, rich in minerals, especially calcium and phosphorus, and vitamin C. In this review, the characteristics, cultivation methods, main uses of the plant and fruits, market and adversities of Opuntia ficus indica are described.


2021 ◽  
Author(s):  
◽  
Judith Helen Lawrence

<p>The ability of decision makers to respond to climate change impacts such as sea-level rise and increased flood frequency is challenged by uncertainty about scale, timing, dynamic changes that could lead to regime shifts, and by societal changes. Climate change adaptation decision making needs to be robust and flexible across a range of possible futures, to provide sufficient certainty for investment decisions in the present, without creating undue risks and liabilities for the near and long-term futures. A country’s governance and regulatory institutions set parameters for such decisions. The decision-making challenge is, therefore, a function of the uncertainty and dynamic characteristics of climate change, a country’s institutional framework, and the ways in which actual decision-making practice delivers on the intention of the framework.  My research asks if the current decision-making framework, at national and sub-national scales, and practices under it are adequate to enable decision makers to make climate change adaptation decisions that sufficiently address the constraints posed by climate change uncertainty and dynamic change. The focus is on New Zealand’s multi-scale governance and institutional framework with its high level of devolution to the local level, the level assumed as the most appropriate for climate change adaptation decisions. Empirical information was collected from a sample of agencies and actors, at multiple governance scales reflecting the range of geographical characteristics, governance types, organisational functions and actor disciplines. Data were collected using a mix of workshops, interviews and document analyses. The adequacy of the institutional framework and practice was examined using 12 criteria derived from the risk-based concepts of precaution, risk management, adaptive management and transformational change, with respect to; a) understanding and representing uncertainty and dynamic climate change; b) governance and regulations; and c) organisations and actors.  The research found that the current decision-making framework has many elements that could, in principle, address uncertainty and dynamic climate change. It enables long-term considerations and emphasises precaution and risk-based decision making. However, adaptive and transformational objectives are largely absent, coordination across multiple levels of government is constrained and timeframes are inconsistent across statutes. Practice shows that climate risk has been entrenched by misrepresentation of climate change characteristics. The resulting ambiguity is compounded at different governance scales, by gaps in the use of national and regional instruments and consequent differences in judicial decisions. Practitioners rely heavily upon static, time-bound treatments of risk, which reinforce unrealistic community expectations of ongoing protections, even as the climate continues to change, and makes it difficult to introduce transformational measures. Some efforts to reflect changing risk were observed but are, at best, transitional measures. Some experimentation was found in local government practice and boundary organisations were used as change-agents. Any potential improvements to both the institutional framework and to practices that could enable flexible and robust adaptation to climate change, would require supporting policies and adaptive governance to leverage them and to sustain decision making through time.  This thesis contributes to understanding how uncertainty and dynamic climate change characteristics matter for adaptation decision making by examining both a country-level institutional framework and practice under it. The adequacy analysis offers a new way of identifying institutional barriers, enablers and entry points for change in the context of decision making under conditions of uncertainty and dynamic climate change.</p>


2021 ◽  
Author(s):  
◽  
Judith Helen Lawrence

<p>The ability of decision makers to respond to climate change impacts such as sea-level rise and increased flood frequency is challenged by uncertainty about scale, timing, dynamic changes that could lead to regime shifts, and by societal changes. Climate change adaptation decision making needs to be robust and flexible across a range of possible futures, to provide sufficient certainty for investment decisions in the present, without creating undue risks and liabilities for the near and long-term futures. A country’s governance and regulatory institutions set parameters for such decisions. The decision-making challenge is, therefore, a function of the uncertainty and dynamic characteristics of climate change, a country’s institutional framework, and the ways in which actual decision-making practice delivers on the intention of the framework.  My research asks if the current decision-making framework, at national and sub-national scales, and practices under it are adequate to enable decision makers to make climate change adaptation decisions that sufficiently address the constraints posed by climate change uncertainty and dynamic change. The focus is on New Zealand’s multi-scale governance and institutional framework with its high level of devolution to the local level, the level assumed as the most appropriate for climate change adaptation decisions. Empirical information was collected from a sample of agencies and actors, at multiple governance scales reflecting the range of geographical characteristics, governance types, organisational functions and actor disciplines. Data were collected using a mix of workshops, interviews and document analyses. The adequacy of the institutional framework and practice was examined using 12 criteria derived from the risk-based concepts of precaution, risk management, adaptive management and transformational change, with respect to; a) understanding and representing uncertainty and dynamic climate change; b) governance and regulations; and c) organisations and actors.  The research found that the current decision-making framework has many elements that could, in principle, address uncertainty and dynamic climate change. It enables long-term considerations and emphasises precaution and risk-based decision making. However, adaptive and transformational objectives are largely absent, coordination across multiple levels of government is constrained and timeframes are inconsistent across statutes. Practice shows that climate risk has been entrenched by misrepresentation of climate change characteristics. The resulting ambiguity is compounded at different governance scales, by gaps in the use of national and regional instruments and consequent differences in judicial decisions. Practitioners rely heavily upon static, time-bound treatments of risk, which reinforce unrealistic community expectations of ongoing protections, even as the climate continues to change, and makes it difficult to introduce transformational measures. Some efforts to reflect changing risk were observed but are, at best, transitional measures. Some experimentation was found in local government practice and boundary organisations were used as change-agents. Any potential improvements to both the institutional framework and to practices that could enable flexible and robust adaptation to climate change, would require supporting policies and adaptive governance to leverage them and to sustain decision making through time.  This thesis contributes to understanding how uncertainty and dynamic climate change characteristics matter for adaptation decision making by examining both a country-level institutional framework and practice under it. The adequacy analysis offers a new way of identifying institutional barriers, enablers and entry points for change in the context of decision making under conditions of uncertainty and dynamic climate change.</p>


2021 ◽  
Vol 13 (22) ◽  
pp. 4514
Author(s):  
Sixue Shi ◽  
Yu Chang ◽  
Yuehui Li ◽  
Yuanman Hu ◽  
Miao Liu ◽  
...  

Wetlands, as the most essential ecosystem, are degraded throughout the world. Wetlands in Zhenlai county, with the Momoge National Nature Reserve, which was included on the Ramsar list, have degraded by nearly 30%. Wetland degradation is a long-term continuous process with annual or interannual changes in water area, water level, or vegetation presence and growth. Therefore, it requires sufficiently frequent and high-spatial-resolution data to represent its dynamics. This study mapped yearly land-use maps with 30-m resolution from 1985 to 2018 using Landsat data in Google Earth Engine (GEE) to explore the wetland degradation process and mapped 12-day interval land-use maps with 15-m resolution using the Sentinel-1B and Sentinel-2 data in GEE and other assistant platforms to study the characteristics of wetland dynamics in 2018. Four sets of maps were generated using Sentinel-1B (S1), Sentinel-2 (S2), the combination of Sentinel-1B and Sentinel-2 (S12), and S12 with multitemporal remote sensing (S12’). All of the classifications were performed in the Random Forest Classification (RFC) method using remote sensing indicators. The results indicate that S12’ was the most accurate. Then, the impact of the historic land-use degradation process on current wetland change dynamics was discussed. Stable, degradation, and restoration periods were identified according to the annual changes in wetlands. The degraded, stable, restored, and vulnerable zones were assessed based on the transformation characteristics among wetlands and other land-use types. The impact of historical land-use trajectories on wetland change characteristics nowadays is diverse in land-use types and distributions, and the ecological environment quality is the comprehensive result of the effect of historical land-use trajectories and the amount of rainfall and receding water from paddy fields. This study offers a new method to map high-spatiotemporal-resolution land-use (S12’) and addresses the relationship between historic wetland change characteristics and its status quo. The findings are also applicable to wetland research in other regions. This study could provide more detailed scientific guidance for wetland managers by quickly detecting wetland changes at a finer spatiotemporal resolution.


2021 ◽  
Vol 2121 (1) ◽  
pp. 012039
Author(s):  
Tengfei Zhao ◽  
Yongjie Nie ◽  
Min Cao

Abstract The cross-linked polyethylene cable will undergo thermal aging during service, which will seriously affect the service life of the cable. The current integration method can analyze the charge injection and conduction parameters from the dynamic change rate of the charge over time, and then analyze the insulation state of the polymer. Aiming at the field 10KV fault breakdown cable, this paper uses the current integration method to compare the dynamic change characteristics of the charge of the faulty cable and the new cable, and uses the ratio of Q(t) at t=600s and t=4s to study Charge injection and accumulation situation. Through analysis, it is found that the fault breakdown of the cable, the maximum charge accumulation under high voltage is 9000 Q/nC, the charge change rate is about 2, and the dielectric constant is 3.1, which is much greater than that of the new cable, indicating that the breakdown of the three-phase cable is mainly caused by the cable. It is caused by aging and eventually leads to insulation deterioration and breakdown.


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