构建基于儿童经验生长的教学问题“生态链”——以大班科学活动“春天的鸟声”问题设计为例

儿童的经验生长离不开问题的支持,集体教学活动中的问题设计应基于幼儿的原有经验并能最大程度地支持幼儿新经验的生长。本文围绕一节幼儿园科学领域活动设计,尝试通过"由问题引发问题""由谈话解决问题""由问题衍生问题"这一课堂问题"生态链"的构建,从哲学角度探寻集体教学活动中高质量问题的设计与运用。

高校“互联网+课程思政”体系建设与实践路径探索

课程思政有利于构建专业课程与思想政治课程的协同效应,但在网络普及和新媒体发展的时代背景下,课程思政的实施与发展面临新的挑战,例如文化冲击、受教育者的信仰缺失等。高校在构建“互联网+课程思政”体系前需要优先做好教育理念概念、网络教育资源开发、课程思政资源配套建设。在此基础上尝试运用大数据技术分析学生需求,设计更能吸引学生的课程思政教学内容;构建专业课程思政云平台,汇聚集体的智慧高效发展课程思政内容与方法体系;同时利用网络拓展课程思政的“生态链”,有效拓展课程思政的时空范围。

Telomeres:Linking stress and survival,ecology and evolution

Telomeres are protective structures at the ends of eukaryotic chromosomes. The loss of telomeres through cell division and oxidative stress is related to cellular aging, organismal growth and disease. In this way, telomeres link molecular and cellular mechanisms with organismal processes, and may explain variation in a number of important life-history traits. Here, we discuss how telomere biology relates to the study of physiological ecology and life history evolution. We emphasize current knowledge on how telomeres may relate to growth, survival and lifespan in natural populations. We finish by examining interest- ing new connections between telomeres and the glucocorticoid stress response. Glucocorticoids are often employed as indices of physiological condition, and there is evidence that the glucocorticoid stress response is adaptive. We suggest that one way that glucocorticoids impact organismal survival is through elevated oxidative stress and telomere loss. Future work needs to establish and explore the link between the glucocorticoid stress response and telomere shortening in natural populations. If a link is found, it provides an explanatory mechanism by which environmental perturbation impacts life history trajectories [Current Zoology 56 （6）： 714-727, 2010].

根植核心素养 践行“三生”教育

近些年来,幼儿传统文化教育呈现出多元化和丰富化特征。幼儿园开展传统文化教育,主要在"五大领域"中融合蒙学,而园外机构实施传统文化教育,则主要通过"传统文化教育+"形式,即传统文化教育融合其他领域。目前幼儿传统文化教育的目标尚未明确与清晰,教育内容亟待重新梳理与系统研发、设计,幼儿教师传统文化素养亟待提升。传统蒙学需要在教育目标、教育内容、教学方法与教师教育等方面加强活化与转化,以适应现代幼儿教育体系,促进幼儿健康发展。

Morphological and Thermal Properties of Starches Isolated from White and Pigmented Sorghum Landraces Grown in Hyper Arid Regions

The starches were isolated by alkaline extraction from white and red sorghum, predominant cultivars in the Sahara of Algeria. Morphological, thermal properties and amylose content of isolated starches were examined. The starches of two sorghum landraces of white and pigmented kernels growing in hyper arid environmental conditions showed significant differences in granule size, amylose content and thermal behavior which ultimately affect the physicochemical and functional properties. When observed using environmental scanning electron microscopy （ESEM）. The starch granules showed polyhedral shape. Some of them showed pinholes. The granular size ranged between 6.325-39.905 μm and 7.096-44.774 μm, respectively for white and red sorghum starches. The granule size distribution was unimodal. The amylose content in white sorghum starch （27.1%） was higher than that in red sorghum （24.8%）. Differential scanning calorimetry （DSC） analysis revealed that sorghum starches present higher temperatures at the peak （70.60℃ and 72.28℃ for white and red sorghum starches, respectively） and lower gelatinization enthalpies （9.087 J/g and 8.270 J/g for white and red sorghum starches, respectively） than other cereal starches. The determination of these properties is relevant to the comprehension of starch and starch-based foods digestibility in order to direct them towards the specific applications in food and nonfood sectors.

Persistence and Impact of a PGPR on Microbial Communities of Biosolids and Soil Amended with Them

Survival of the plant-growth promoting rhizobacteria （PGPR） strain Pseudomonasfluorescens 92 in two batches ofbiosolids and soil amended with them and functional and structural shifts occurring in the resident bacterial communities were assessed. Viability of the rifampicin resistant gfp-tagged P. fluorescens 92RTcgfp, inoculated in microcosms consisting of biosolids, soil amended with biosolids and soil, drastically decreased 3-7 days after inoculation in treatments containing biosolids and soil amended with them. The PGPR counts in biosolids were always lower than in soil throughout the experiment whereas, in soil amended with biosolids, were similar or higher depending on the batch of biosolid. Analysis of the community-level physiological profiling （CLPP） revealed a strong impact of the strain on the metabolic activities, as seen in a general uniformity of the inoculated microcosms profiles. According to single-strand conformation polymorphism （SSCP） analysis, the presence of the PGPR had no effect on the resident soil and biosolid eubacterial population, whereas it induced a transient shift in the composition of the resident pseudomonads. In conclusion, biosolids themselves are not suitable as inoculum vehicle for the PGPR nevertheless, their combined incorporation into soil increases the inoculum survival and buffers the competition effects with the resident communities.

Seasonal Community Structure of Mesozooplankton in the Daya Bay,South China Sea

Mesozooplankton are key components of coastal ecosystems,linking the microbial food web to the classic food chain.In this study,species composition and abundance of mesozooplankton is studied for the Daya Bay in April(spring) and October(fall),2006.A total of 27 species of mesozooplankton were identified in spring and 58 species in fall.Dominant species were Oithona tenuis,Flaccisagitta enflata,Penilia avirostris and Centropages tenuiremis in spring,shifting to Microsetella norvegica,Oithona tenuis and Parvocalanus crassirostris in fall.Higher mesozooplankton abundance was found at Aotou Cove and Dapeng'ao Cove compared to other stations,indicating the influence of eutrophication on mesozooplankton community in the Daya Bay.The outbreak of Noctiluca scintillans bloom in spring reduced the species diversity and abundance of mesozooplankton.

Index system for assessing ecological stability of circular economy industrial chain of electronic industry and its empirical study

With the development of science and technology and the rapid growth of productive forees new and high technology industries have. For example, computer, mobile phone, etc. are increasingly popular, especially hi-tech products updating more and more quickly, which has initiated some problems： resources depletion, environmental pollution, ecosystems damage, etc. While people are enjoying convenient and comfortable life from hi-tech, they are worrying about quantities of e-wastes discharged.In order to reduce the amount and harm of e-wastes, this paper starts from the connotation of the ecological stability of circular economy electronics industry chain （CEEIC, for shorO, uses the food chain principle for reference to describe the links and connection of the electronics industry chain, and selects factors from the three link： production, consumption and recycle to construct indexes system based on their characteristics, with which a scientific evaluation is carried on for CEEIC by using fuzzy comprehensive evaluation.

DNA-assisted rational design of BaF_2 linear and erythrocyteshaped nanocrystals

The synthesis of inorganic materials with special morphologies with the assistance of biological molecules is a potential development in the field of controllable growth and assembly of nanomaterials. In this paper, BaF2 nanocrystals in patterns of well-defined linear and erythrocyte-shaped structure were synthesized with the assistance of Escherichia coil DNA. Morphology and the arrangement of BaF2 particles on DNA were controllable by altering the reaction condition. Square nanoparticles arranged in linear chains were gained with the assistance of normal DNA; while, erythrocyte-shaped BaF2 nanospheres were synthesized with the assistance of denatured DNA. Besides, the influences of solvent, reaction temperature, concentration of reactants and the heating time on the morphology of the BaF2 particles were studied.

A Population Morphologically Structured Model for Microscopic Growth of Filamentous Microorganism

The growth of filamentous microorganism is contributed by tip extension and branching. The microscopic growth of filamentous microorganism means the growth process from one or a few spores. In order to describe the microscopic process, a population morphologically structured model is proposed, in which three morphological compartment and their interactions were considered, and the heterogeneity of hyphal growth was included. The model was applied to describe the microscopic growth of Streptomyces tendae and Geotrichum candidum with good agreement. From model prediction, it is concluded that if the number of hyphae is large enough (macroscopic growth), the specific growth rate of filamentous microorganism and the ratio of morphological forms in hyphae will become constant.

Belowground Tritrophic Food Chain Modulates Soil Respiration in Grasslands

Edaphic biota significantly affects several essential ecological functions such as C-storage, nutrient turnover, and productivity.However, it is not completely understood how belowground animal contribution to these functions changes in grasslands subject to different land use types. A microcosm experiment was carried out to test the effect of a tritrophic food chain on CO_2 release from grassland soils. Soil was collected from three differently managed grassland systems(meadow, pasture, and mown pasture) located in three distinct German regions that cover a north-south gradient of approximately 500 km. The tritrophic food chain comprised natural edaphic microflora, nematodes, and predatory gamasid mites. The experimental design involved a full factorial combination of the presence and absence of nematodes and gamasid mites. Nematodes significantly increased the CO_2 emissions in most treatments,but the extent of this effect varied with land use type. The fact that grazing by nematodes stimulated the metabolic activity of the edaphic microflora over a wide range of grassland soils highlighted the critical impact of the microfauna on ecosystem services associated with soil organic matter dynamics. Gamasids slightly amplified the effect of nematodes on microbial metabolic activity,but only in the pastures. This effect was most probably due to the control of nematode abundance. The fact that gamasid addition also augmented the impact of environmental conditions on nematode-induced modulation of soil respiration highlighted the need for including land use differences while evaluating soil fauna contribution to soil processes. To conclude, the differential response of the investigated tritrophic food chain to different grassland management systems suggests that adverse effects of land use intensification on important soil processes such as atmospheric C-release could potentially be reduced by using management methods that preserve essential features of the belowground food web.

ROLE OF DIFFERENT SYSTEM DELAYS ON ECOLOGICAL FOOD CHAIN DYNAMICS:MATHEMATICAL MODELLING AND ANALYSIS

This paper studies a three tier ecological food chain model consisting of nutrient,autotroph,and herbivore populations.Regeneration of nutrient from dead autotroph and herbivore biomass bydecomposers present in the soil is included.The time required for maturation of the herbivore populationis incorporated as a distributed time delay.Next,the authors introduce the time lag requiredfor regeneration of nutrient from the dead herbivore as a discrete time delay.Stability and bifurcationbehavior of the one-and two-delay models are carried out and a comparative study of the significanceof these delays in controlling the system dynamics is performed.Numerical simulations are done tojustify analytical results.

Compound-specific hydrogen isotopes of long-chain n-alkanes extracted from topsoil under a grassland ecosystem in northern China

To investigate characteristics of H isotope variation in long-chain n-alkanes （δDn-alkanes） from higher plants in surface soils under a single ecosystem, 12 samples from a basalt regolith were randomly collected from Damaping in Wanquan County of Zhangjiakou in North China. Molecular distribution and C （δ^13Cn-alkanes） and H isotopes of long-chain n-alkanes, as well as C isotopes of TOC （δ^13CTOC）, were analyzed. Both δ^13CTOC and δ^13Cn-alkanes values from four representative dominant long-chain n-alkanes （n-C27, n-C29, n-C31, n-C33） derived from terrestrial higher plants show minor variations among the 12 samples, indicating the major contributor is from local grasses with a uniform C3 photosynthetic pathway. In contrast, variations in δ^13Cn-alkanes values of the four long-chain n-alkanes are relatively large, with the more abundant homologs generally showing more negative δDn-alkanes values and less variation. However, variation of 〈30‰ among weighted averaged δDn-alkanes values of the four long-chain n-alkanes is not only less than that among δDn-alkanes values for different modern terrestrial C3 grasses from the specific locations, but also less than the literature values of δDn-alkanes of long-chain n-alkanes for single species over different seasons. Thus, because the sources of long-chain n-alkanes in surface soils and sediments are similarly from multiple individual plants, our results are significant in confirming that paleoclimatic, paleoenvironmental and paleohydrological information can be interpreted more accurately from δDn-alkanes values of long-chain n-alkanes from sediments, particularly terrestrial sediments with organic matter derived from in-situ plants.