Heterogeneity of mature oligodendrocytes in the central nervous system

Mature oligodendrocytes form myelin sheaths that are crucial for the insulation of axons and efficient signal transmission in the central nervous system.Recent evidence has challenged the classical view of the functionally static mature oligodendrocyte and revealed a gamut of dynamic functions such as the ability to modulate neuronal circuitry and provide metabolic support to axons.Despite the recognition of potential heterogeneity in mature oligodendrocyte function,a comprehensive summary of mature oligodendrocyte diversity is lacking.We delve into early 20th-century studies by Robertson and Río-Hortega that laid the foundation for the modern identification of regional and morphological heterogeneity in mature oligodendrocytes.Indeed,recent morphologic and functional studies call into question the long-assumed homogeneity of mature oligodendrocyte function through the identification of distinct subtypes with varying myelination preferences.Furthermore,modern molecular investigations,employing techniques such as single cell/nucleus RNA sequencing,consistently unveil at least six mature oligodendrocyte subpopulations in the human central nervous system that are highly transcriptomically diverse and vary with central nervous system region.Age and disease related mature oligodendrocyte variation denotes the impact of pathological conditions such as multiple sclerosis,Alzheimer's disease,and psychiatric disorders.Nevertheless,caution is warranted when subclassifying mature oligodendrocytes because of the simplification needed to make conclusions about cell identity from temporally confined investigations.Future studies leveraging advanced techniques like spatial transcriptomics and single-cell proteomics promise a more nuanced understanding of mature oligodendrocyte heterogeneity.Such research avenues that precisely evaluate mature oligodendrocyte heterogeneity with care to understand the mitigating influence of species,sex,central nervous system region,age,and disease,hold promise for the development of therapeutic interventions targeting varied central nervous system pathology.

Carbon storage of a subtropical forest ecosystem: a case study of the Jinggang Mountain National Nature Reserve in south-eastern China

The carbon cycle of forest ecosystems plays a key role in regulating CO2 concentrations in the atmosphere. Research on carbon storage estimation of forest ecosystems has become a major research topic. However, carbon budgets of subtropical forest ecosystems have received little attention. Reports of soil carbon storage and topographic heterogeneity of carbon storage are limited. This study focused on the Jinggang Mountain National Nature Reserve as an example of a mid-subtropical forest and evaluated soil and vegetation carbon storage by field sampling combined with GIS, RS and GPS technology. We classified the forest into nine forest types using ALOS high-resolution remote sensing images. The evergreen broad-leaved forest has the largest area, occupying 26.5% of the total area, followed by coniferous and broad-leaved mixed forests and warm temperate coniferous forest, occupying 24.2 and 22.9%, respectively. The vegetation and soil carbon storage of the whole forest ecosystem were 1,692,344 and 5,514,707 t, with a carbon density of 7.4 and 24.2 kg/m^2, respectively, which suggests that the ecosystem has great carbon storage capacity. The topographic heterogeneity of the carbon storage was also analysed. The largest vegetation storage and soil storage is at 700–800 and 1000–1100 m, respectively. The vegetation carbon storage is highest in the southeast, south and southwest.

The Function and Value of Water Conservation of Forest Ecosystem in Gongbo Nature Reserve of Tibet

Gongbo Nature Reserve, located in Nyingchi of Tibet, is by far the largest construction project of forest reserves that China approves and invests in. This article adopts the shadow project method, and estimates the water conservation function of forest ecosystem of Gongbo Nature Reserve based on the Specifications for Assessment of Forest Ecosystem Services in China promulgated by State Forestry Administration of China. The results show that the total value of water conservation of forest ecosystem in Gongbo Nature Reserve is 8.485 billion yuan, while the function of water conservation is a small fraction of ecological service function, indicating that there is great ecological value in service function of forest ecosystem in Gongbo Nature Reserve, that is, Gongbo Nature Reserve has vital ecological value.

Non-use value assessment for wetland ecosystem service of Hongxing National Nature Reserve in northeast China

By the contingent value method, we studied the non-use value of wetland ecosystem service of Hongxing National Nature Reserve （HNNR） in Heilongjiang Pro- vince, northeast China. The proportion of respondents willing to pay （WTP） for protection of HNNR was 63 %. The WTP ratio was affected by geographical area, contact nature, personal preferences, and familiar degree of the respondents. The WTP value was affected by age, education level and career of the respondents. The mainly reasons for people rejecting to pay for protecting HNNR were ＂I am not familiar to HNNR＂ and ＂I had no capacity for additional spending because of low income＂. Weighted average individual WTP value was CNY 59.26 Yuan ind.^-1 year^-1 for all the respondents with WTP. The total non-use ecosystem service value of HNNR was CNY 1430 million Yuan in 2013. The heritage value was highest followed by existence value and option value. From the high ecosystem service value in HNNR, it is very important to construct nature reserve for protecting natural ecosystems and human sustainable use of natural resources.

Spatial variations of Pb in the vertical zone of the soil-plant system in the Changbai Mountain National Nature Reserve

The characteristics of vertical and horizontal variations of lead element(Pb) in soil plant system of vertical zone in Changbai Mountain National Nature Reserve(CNNR) were studied. The results showed that Pb concentrations in soils of vertical zone are all above 25 mg/kg, and the average Pb concentration of each soil zone negatively correlates its degree of variation, i.e. brown coniferous forest soil zone has the lowest average Pb concentration of four soil zones, and the highest horizontal variation; however, mountain soddy forest soil has the highest average Pb concentration, and the lowest horizontal variation; the average concentration of plant Pb of each plant zone is lower than the worldwide average level of Pb in plant(Clarke), respectively, and plant Pb content order is consistent with soil Pb content order, but their horizontal variations are different from those in soil zones, the variation of mountain tundra forest zone is highest, but Betula ermanii forest zone the lowest. Vertical variation of plant Pb is obviously higher than that in soils with variation coefficient of 89.76%; the enrichment capability of plant for Pb is depended on the plant types and the different organs of plant; parent material and parent rock, pH values, soil organic matter and soil particle fraction etc. are the main factors influencing variations of Pb content in soil plant system of vertical zone in CNNR.

Simulation of the Ecosystem Productivity Responses to Aerosol Diffuse Radiation Fertilization Effects over the Pan-Arctic during 2001–19

The pan-Arctic is confronted with air pollution transported from lower latitudes.Observations have shown that aerosols help increase plant photosynthesis through the diffuse radiation fertilization effects(DRFEs).While such DRFEs have been explored at low to middle latitudes,the aerosol impacts on pan-Arctic ecosystems and the contributions by anthropogenic and natural emission sources remain less quantified.Here,we perform regional simulations at 0.2o×0.2ousing a well-validated vegetation model(Yale Interactive terrestrial Biosphere,YIBs)in combination with multi-source of observations to quantify the impacts of aerosol DRFEs on the net primary productivity(NPP)in the pan-Arctic during 2001-19.Results show that aerosol DRFEs increase pan-Arctic NPP by 2.19 Pg C(12.8%)yr^(-1)under clear-sky conditions,in which natural and anthropogenic sources contribute to 8.9% and 3.9%,respectively.Under all-sky conditions,such DRFEs are largely dampened by cloud to only 0.26 Pg C(1.24%)yr^(-1),with contributions of 0.65% by natural and 0.59% by anthropogenic species.Natural aerosols cause a positive NPP trend of 0.022% yr^(-1)following the increased fire activities in the pan-Arctic.In contrast,anthropogenic aerosols induce a negative trend of-0.01% yr^(-1)due to reduced emissions from the middle latitudes.Such trends in aerosol DRFEs show a turning point in the year of 2007 with more positive NPP trends by natural aerosols but negative NPP trends by anthropogenic aerosols thereafter.Though affected by modeling uncertainties,this study suggests a likely increasing impact of aerosols on terrestrial ecosystems in the pan-Arctic under global warming.

Developing phase of China's system of nature reserves in perspective

Up until 2009, 2541 nature reserves had been established in China. However, the process of developing this system of nature reserves was not quite smooth. Various kinds of information related to nature reserves, such as annual growth, the type of nature reserves established, motives behind building a nature reserve, legal instructions and the constitution of government sectors, were collected and analyzed in order to highlight the characteristics of the development of our nature reserve system. As a result, we identify three phases and their characteristics, i.e., the initial phase from 1956 to 1978, the establishment phase from 1979 to 1996 and the management standardization phase from 1997 to 2009, could be clearly identified. It is suggested that since the establishment of this comprehensive structural framework in China, the system should be entering a new developing phase. We recommend that more attentions should be paid on how to guarantee effective management and how nature reserves are able to maintain their value and fulfill their objectives in the future.

Emergy Evaluation of a Village Ecosystem in Wolong Nature Reserve in China

Due to historic reasons, there are several human settlements in nature reserves and national parks, which may constitute a threat to biodiversity. Establishment of nature reserves may however generate constraints for development of local communities residing in these reserves. The village ecosystem of Zhuanjinglou Village in Wolong Nature Reserve includes population, farming and livestock (domestic and alpine) and forest ecosystem. An emergy analysis of agro-ecosystem (including the farming and livestock ecosystem) and energy consumption in Zhuanjinglou Village indicates that livestock ecosystem plays an important role in village ecosystem, which may be the source of great pressure on the state of the local environment. The increasing ratio of electricity in energy consumption may play a positive role for environmental conservation. Despite some successful experiences, there are some remaining issues that need to be addressed in the ecological rehabilitation of the village ecosystem.

Change of Forest Ecosystem Service Function and Its Value in Kanas Nature Reserve

In order to clarify the service function and value of forest ecosystem in Kanas Nature Reserve, the ecological service function and its value of forest ecosystem in Kanas Nature Reserve in 2009 and 2014 were evaluated by using the method of Specifications for Assessment of Forest Ecosystem Services in China(LY/T 1721-2008). The results showed that in 2014, the total value of forest ecosystem service function in Kanas Nature Reserve increased by 7.34% compared with that in 2009, and the value of water conservation and biodiversity accounted for the largest proportion. The increasing rate of functional value of shrub forest land was obviously higher than that of coniferous forest land and broad-leaf forest land. The service function and value of different forest types were obviously different.

Valuation on Forest Ecosystem Services of Nanling National Nature Reserve

The forest ecological system fulfills many important ecological functions. Researches on the analysis and valuation on forest ecosystem services are at the cutting edge of current ecology and ecological economics. Based on the calculation method of service value of forest ecosystem, 7 forest ecosystem services of Nanling National Nature Reserve were valued, totaling 703.48 million yuan/year. In terms of the contribution size of the service value of forest ecosystem, carbon fixation and oxygen release came as the greatest one, followed by conservation of soil, purification of the air, biodiversity conservation, conservation of water, accumulation of nutrients, and forest recreation. With its value of 208.46 million yuan, carbon fixation and oxygen release ranked first, accounting for 29.63% of the total value; conservation of soil of 24.67% service value took the second place; purification of the air came in third in the value rankings, representing 22.55% of the total value; the fourth one was biodiversity conservation, whose service value came up to 14.51%. Those 4 services made up 91.36% of the total value while other 3 services ranging from conservation of water, accumulation of nutrients to forest recreation were merely a small proportion. This is because the Nanling National Nature Reserve is essentially a large oxygen bar. The above-mentioned ecosystem valuation method contributes to the understanding of the overall value of the forest ecosystem as well as the implementation and advancement in the regional sustainable development strategy.

Protected Areas, Subsistence Farming Systems and Nature Conservation

The preservation of the traditional subsistence farming systems and the conservation of natural values （habitats, fauna and flora）, in articulation with local development, was the key issues in this paper. The farmers have been able to manage the systems so as to cope with adverse conditions, but their future is quite uncertain. The methodology included： （1） field observation visits and cartographic information analysis of land use; （2） structured interviews with animal production and agro-forestry specialists; and （3） meetings with the participation of stakeholders. The paper concludes that depopulation is responsible for the increasing decline of agriculture and livestock. The decrease in agricultural activity in general and the consequent practices and traditional systems of agriculture causes changes in the landscape and has negative effects on nature conservation and biodiversity. Thus, we believe that the preservation and development of traditional economic activities linked to agriculture, agro-forestry and food processing are essential to maintain the typical landscape and to preserve natural values of Montemuro Site. The paper shows that in mountain areas, particularly those classified as nature network sites, farming, economic development and nature conservation are not antagonistic objectives.

Measurement System of Landscape Fragmentation in National Nature Reserves:A Case Study of Dinghu Mountain National Nature Reserve,Guangdong Province

With the advancement of industrialization and urbanization,the natural landscape has been destroyed to varying degrees,presenting the trend of landscape fragmentation and ecosystem degradation.Taking Dinghu Mountain National Nature Reserve as an example,a three-dimension measurement system of separation degree,fractal dimension and interference intensity for landscape fragmentation is established and verified by collecting survey data through questionnaires.The research results will provide a theoretical reference for landscape conservation and sustainable development of national nature reserves.

Entropy Production in a Non-Isolated Thermodynamic System Taking into Account Regular Factors of Nonrandom Nature

The work illustrates the impossibility of decreasing entropy in a strictly random thermodynamic process in a non-isolated system using the example of heating a planet by solar radiation flux without and taking into account its rotation around its own axis. That is, the second law of thermodynamics formulated for isolated systems continues to govern such systems. We have shown that in order to achieve a stationary state at lower values of temperature and entropy far from thermodynamic equilibrium at a maximum of temperature and entropy, it is necessary to have regular factors of nonrandom nature, one of which in this example is the rotation of the planet around its own axis. This means that the reason for the appearance of ordered structured objects in non-isolated thermodynamic systems is not the random process itself, but the action of dynamic control mechanisms, such as periodic external influences, nonlinear elements with positive feedback, catalysts for chemical reactions, etc. We present the plots with dependences of temperature and entropy versus time in non-isolated systems with purely random processes and in the presence of a control factor of non-random nature-rotation.

The Macrolichens of Barluk Mountain National Nature Reserve, Xinjiang Province, China

A checklist of the macrolichens (foliose, fruticose & squamulose) of Barluk Mountain National Nature Reserve located in northwestern China is presented. It was derived from 47 inventories of preserved and undeveloped areas which yielded more than 670 collections containing 102 taxa (99 species, 1 subspecies, 2 varieties). Eight species were found that were new to Xinjiang, China. Twenty-eight species and 2 varieties were found on rock, 31 species on bark of deciduous and coniferous trees, 26 species on soil and 14 species and 1 subspecies over mosses. Foliose lichens were dominant with 76 species, followed by 16 species of squamulose lichens and 7 species of fruticose lichens.

Valuation of Forest Ecosystem Services of the Kanas Nature Reserve in Xinjiang

Based on field surveys,typical sample-plot experiments,and long-term observation of ecological stations,the main species of trees in the Kanas Nature Reserve in Xinjiang were studied,and the value of their 7 kinds of services including water conservation,soil conservation,carbon fixation and oxygen release,accumulation of nutrients,air purification,biodiversity conservation,and forest recreation was evaluated in 2014.The results showed that:the total value of forest ecosystem services provided by the Kanas Nature Reserve in Xinjiang was 4.314 billion yuan/a,and the value of ecosystem services per unit area was 69,600 yuan/(hm^2·a).The value of forest ecosystem services were as follows:forest recreation(1,458,000,000 yuan/a) > water conservation(1,423,630,000 yuan/a) > biodiversity conservation(544,820,000 yuan/a) > carbon fixation and oxygen release(367,590,000 yuan/a) > air purification(258,830,000 yuan/a) > accumulation of nutrients(141,590,000 yuan/a) > soil conservation(119,270,000 yuan/a).According to the valuation of ecosystem services excluding forest recreation provided by 7 types of forests in the reserve,the value of ecosystem services per unit area of Pinus sibirica(Loud.) Mayr forest,Abies sibirica Ledeb.forest,Larix sibirica Ledeb.forest,Betula pendula Roth.forest,Populus davidiana Dode forest,shrubbery,and Picea obovata Ledeb.forest was 71,500,66,500,54,400,44,200,40,500,36,700,and 32,900 yuan/(hm^2·a),respectively.

博士后对学术职业环境满意吗?——基于Nature全球博士后调查数据比较分析

本研究基于已有成果,将博士后学术职业环境划分为学术资源、职业保障、组织管理、科研强度四个维度。利用2020年Nature全球博士后教育调查数据,通过比较分析博士后对学术职业环境的感知与评价。研究发现,相比较国外发达国家博士后而言,我国接近四成博士后对学术职业环境感到满意。为了优化博士后学术职业环境,大学需强化对博士后科研资金的支持力度,保障博士后科研参与机会,减少非学术事务对博士后科研时间的挤占,规范导师指导;大学不断调适大学基层学术组织治理模式,优化院系对博士后学术职业发展的组织支持与服务质量;大学与博士后建立稳定性雇佣关系,不断提升工资薪酬水平,疏通博士后学术职业晋升渠道,营造良好的工作环境;高校实行服务型、便捷式的科研管理方式,制定灵活多元的学术评价机制,破除博士后对“学术GDP主义”的崇拜。

Nature's disguise:Empirical demonstration of dead-leaf masquerade in Kallima butterflies

Animals deploy diverse color-based defenses against predators,including crypsis,mimicry,aposematism,and masquerade.While crypsis,mimicry,aposematism have been extensively studied,the strategy of masquerade-where organisms imitate inedible or inanimate objects such as leaves,twigs,stones,and bird droppings-remains comparatively underexplored,particularly in adult butterflies.The Indian oakleaf butterfly(Kallima inachus)exemplifies this phenomenon,with its wings resembling dead leaves,providing a classic example of natural selection.Although it has long been postulated that these butterflies evade predation by being misidentified as dead leaves,direct experimental evidence is lacking.In the current study,using domestic chicks as predators,we manipulated their prior experience with dead leaves(model objects)while maintaining constant exposure to butterflies to test whether dead-leaf masquerade provides a protective advantage by preventing recognition.Results showed a marked delay in the initiation of attacks by chicks familiar with dead leaves compared to those with no prior exposure or those exposed to visually altered leaves.Chicks with prior dead-leaf experience required a similar amount of time to attack the butterflies as they did to attack dead leaves.These findings provide the first empirical demonstration of dead-leaf masquerade in Kallima butterflies,shedding light on its evolutionary significance.Our study highlights the effectiveness of masquerade in inducing the misclassification of butterflies as inanimate objects,showcasing the precise mimicry achieved by these organisms when viewed in isolation from the model objects.This study advances our understanding of the evolution of masquerade and its role as a potent antipredator strategy in nature.

Zhang Jiebin-Master of the School of Tonifying with Medicinals Warm in Nature

Zhang Jiebin,also known as Zhang Huiqing and Zhang Jingyue(1563-1640 AD)was from Shanyin(today's Shaoxing,Zhejing Province).People usually call him Zhang Jingyue.He was a famous medical theorist,clinician and the representative personage of the School of Tonifying with Medicinals Warm in Nature.He is the author of The Classified Classic(Lei Jing),Jingyue's Complete Works(Jing Yue Quan Shu),etc.

Research on Automatic Test System of Engine Blade Natural Frequency

Blades are one of the important components on aircraft engines.If they break due to vibration failure,the normal operation of the entire engine will be offected.Therefore,it is necessary to measure their natural frequency before installing them on the engine to avoid resonance.At present,most blade vibration testing systems require manual operation by operators,which has high requirements for operators and the testing process is also very cumbersome.Therefore,the testing efficiency is low and cannot meet the needs of efficient testing.To solve the current problems of low testing efficiency and high operational requirements,a high-precision and high-efficiency automatic test system is designed.The testing accuracy of this system can reach ±1%,and the testing efficiency is improved by 37% compared to manual testing.Firstly,the influence of compression force and vibration exciter position on natural frequency test is analyzed by amplitude-frequency curve,so as to calibrate servo cylinder and fourdimensional motion platform.Secondly,the sine wave signal is used as the excitation to sweep the blade linearly,and the natural frequency is determined by the amplitude peak in the frequency domain.Finally,the accuracy experiment and efficiency experiment are carried out on the developed test system,whose results verify its high efficiency and high precision.

Adaptive Network Sustainability and Defense Based on Artificial Bees Colony Optimization Algorithm for Nature Inspired Cyber Security

Cyber Defense is becoming a major issue for every organization to keep business continuity intact.The presented paper explores the effectiveness of a meta-heuristic optimization algorithm-Artificial Bees Colony Algorithm(ABC)as an Nature Inspired Cyber Security mechanism to achieve adaptive defense.It experiments on the Denial-Of-Service attack scenarios which involves limiting the traffic flow for each node.Businesses today have adapted their service distribution models to include the use of the Internet,allowing them to effectively manage and interact with their customer data.This shift has created an increased reliance on online services to store vast amounts of confidential customer data,meaning any disruption or outage of these services could be disastrous for the business,leaving them without the knowledge to serve their customers.Adversaries can exploit such an event to gain unauthorized access to the confidential data of the customers.The proposed algorithm utilizes an Adaptive Defense approach to continuously select nodes that could present characteristics of a probable malicious entity.For any changes in network parameters,the cluster of nodes is selected in the prepared solution set as a probable malicious node and the traffic rate with the ratio of packet delivery is managed with respect to the properties of normal nodes to deliver a disaster recovery plan for potential businesses.