Using triple oxygen isotopes and oxygen-argon ratio to quantify ecosystem production in the mixed layer of northern South China Sea slope region

Quantifying the gross and net production is an essential component of carbon cycling and marine ecosystem studies.Triple oxygen isotope measurements and the O_(2)/Ar ratio are powerful indices in quantifying the gross primary production and net community production of the mixed layer zone,respectively.Although there is a substantial advantage in refining the gas exchange term and water column vertical mixing calibration,application of mixed layer depth history to the gas exchange term and its contribution to reducing indices error are unclear.Therefore,two cruises were conducted in the slope regions of the northern South China Sea in October 2014(autumn)and June 2015(spring).Discrete water samples at Station L07 in the upper 150 m depth were collected for the determination ofδ^(17)0,δ^(18)O,and the O_(2)/Ar ratio of dissolved gases.Gross oxygen production(GOP)was estimated using the triple oxygen isotopes of the dissolved O_(2),and net oxygen production(NOP)was calculated using O_(2)/Ar ratio and O_(2)concentration.The vertical mixing effect in NOP was calibrated via a N_(2)O based approach.GOP for autumn and spring was(169±23)mmol/(m^(2)·d)(by O_(2))and(189±26)mmol/(m^(2)·d)(by O_(2)),respectively.While NOP was 1.5 mmol/(m^(2)·d)(by O_(2))in autumn and 8.2 mmol/(m^(2)·d)(by O_(2))in spring.Application of mixed layer depth history in the gas flux parametrization reduced up to 9.5%error in the GOP and NOP estimations.A comparison with an independent O_(2)budget calculation in the diel observation indicated a26%overestimation in the current GOP,likely due to the vertical mixing effect.Both GOP and NOP in June were higher than those in October.Potential explanations for this include the occurrence of an eddy process in June,which may have exerted a submesoscale upwelling at the sampling station,and also the markedly higher terrestrial impact in June.

A Survey on the Continuing Education Status and Demand of Nurses in Chongqing Grass-Root Medical Institutions

Background: With the increased aging of population, the continuous increase in the morbidity of chronic diseases, and the issuance of universal two-child policy, the grass-root medical teams become more and more important. Objective: To investigate the continuing education status and demand of nurses in the grass-root medical institutions and thus provide a reference for optimizing the continuing education plan. Methods: From October 2018 to May 2019, a survey of 270 nurses from 28 grass-root medical institutions in Tongliang District of Chongqing was performed using a self-designed questionnaire. Results: In the grass-root medical institutions, the major continuing education pattern of nurses was hospital training and distance education;the continuing education focused on new basic theoretical knowledge and new nursing techniques, and its satisfaction was 67.8%. About 20.6% questionnaire answerers never had received continuing nursing education. As shown by one-way analysis of variance (ANOVA) and binary logistic regression analysis, the following factors were associated with the continuing education participation in the past three years: work unit, organizational affiliation, age, professional title and hospital policies. There were 93.0% questionnaire answerers reflecting that it was necessary to participate in the continuing education and wishing the conformance between the pattern and contents of continuing nursing education and the actual implementation status. Conclusion: The continuing education demand of nurses in the grass-root medical institutions is basic but diverse, and the organizations shall provide effective policy support for continuing education and make the diversified training plan by combining Internet technology, so as to realize the maximization of continuing education participation and keep improving the overall service quality of gross-root nurses.

Catalog of operational taxonomic units and unified amplicon sequencing data for the microbiomes of medicinal plant roots

China has a rich history of cultivating medicinal plants,whose root microbial communities closely interact with the medicinal plants,thereby influencing their growth,health,and medicinal properties.Currently,researchers widely use 16S rRNA gene amplicon sequencing to study these root microbial communities.However,publicly available sequence datasets often lack essential sample information or contain errors,impeding the reuse of the datasets in the future.In this study,we aimed to create a united,reliable,and readily usable source of 16S rRNA gene sequences for medicinal plant root microbiomes.We compiled a catalog of 1392 microbiome samples for 58 medicinal plants from 58 studies,and manually provided essential sample information based on the experimental setup described in the associated papers.We then processed the sequences using a custom pipeline,generating a united catalog of operational taxonomic units(OTUs)and conducting taxonomic classification.We also pre-dicted the ecological functions of the communities for each sample.Finally,we used this dataset,to compare the rhizosphere bacterial communities of Pseudostellaria heterophylla from Fujian and Guizhou Provinces,revealing significant differences in the community composition of the same plant from different geographic locations.By providing a comprehensive and united catalog of amplicon sequences and OTUs for medicinal plant root bacterial communities,this study offers an invaluable resource for future comparative studies and data mining.

全球旱地饱和水汽压差和根区土壤水分变化对植被生产力的影响及其成因

旱地约占全球陆地面积的40%,而水分是旱地植被生长的一大限制要素。尽管土壤水分与饱和水汽压差对植被生长的重要性已经得到了广泛证实,然而目前二者对植被生产力影响的空间异质性及其形成因素仍未得到深入研究,这对研究旱地生态系统对气候变化的响应带来了挑战。为了填补这一认知空白,研究收集了多源气象、根区土壤含水率和总初级生产力产品,基于随机森林算法量化了植被总初级生产力对根区土壤含水率和饱和水汽压差的敏感性,结合土地覆盖数据和分档平均方法分析了敏感性空间异质性的形成机制。结果表明:全球旱地饱和水汽压差与植被生产力总体呈显著上升趋势;根区土壤水分对植被生长的影响以正效应主导,饱和水汽压差对植被生长的影响以负效应主导;相较于森林和灌木,饱和水汽压差对植被生长的负效应及根区土壤含水率对植被生长的正效应在农田、草地和苔原及半干旱区更为强烈;植被生产力对饱和水汽压差和根区土壤水分的敏感性在数量上总体呈显著的线性负相关性。综上,植被种类和气候条件是导致全球旱地植被生产力对土壤水分和饱和水汽压差敏感性空间异质性的重要因素。

Different mechanisms underlying divergent responses of autotrophic and heterotrophic respiration to long-term throughfall reduction in a warm-temperate oak forest

Background:There are many studies on disentangling the responses of autotrophic(AR)and heterotrophic(HR)respiration components of soil respiration(SR)to long-term drought,but few studies have focused on the mechanisms underlying its responses.Methods:To explore the impact of prolonged drought on AR and HR,we conducted the 2-year measurements on soil CO_(2) effluxes in the 7th and 8th year of manipulated throughfall reduction(TFR)in a warm-temperate oak forest.Results:Our results showed long-term TFR decreased HR,which was positively related to bacterial richness.More importantly,some bacterial taxa such as Novosphingobium and norank Acidimicrobiia,and fungal Leptobacillium were identified as major drivers of HR.In contrast,long-term TFR increased AR due to the increased fine root biomass and production.The increased AR accompanied by decreased HR appeared to counteract each other,and subsequently resulted in the unchanged SR under the TFR.Conclusions:Our study shows that HR and AR respond in the opposite directions to long-term TFR.Soil microorganisms and fine roots account for the respective mechanisms underlying the divergent responses of HR and AR to long-term TFR.This highlights the contrasting responses of AR and HR to prolonged drought should be taken into account when predicting soil CO_(2) effluxes under future droughts.

Community Structure, Diversity, Biomass and Net Production in a Rehabilitated Subtropical Forest in North India

Gangetic alluvial plain in north India constitutes significant proportions of barren sodic lands. A representative site, where afforestation was carried out during 1960s to rehabilitate the site under forest ecosystem, was selected to assess the restoration success. Three stands (S1, S2, and S3) were selected in a semi-natural subtropical forest at Banthra, Lucknow (26°45’ N, 80°53’ E) on the basis of different vegetation morphology and basal area gradient. Species composition and their growth forms were studied in overstory, understory and ground layer vegetation, in which dominants were assorted. Among the dominants few species were common in the three stands as also in different strata, which perhaps indicate their natural regeneration. Classification of individuals among the different size classes indicated ‘L’ shape distribution in which most of the individuals remained confined in younger groups. Biomass increased from the stand S1 to S3 stand in overstory, and vise versa for understory. Stand S2 consisted of predominance of ground layer biomass over the other stands. Biomass allocation in different plant components differed significantly between the overstory and understory for aerial woody components (stem and branch). Annual litter fall did not differ significantly among the stands, where as fine root biomass (up to 45 cm soil depth) decreased from S1 to S3 stands. Rainy and summer seasons contributed to two-third proportion of total annual fine root production. The state of this rehabilitated forest when compared with the degraded and reference forest of the region indicated that structural complexity, biomass and production levels have been achieved to 70% of the reference forest site even after having a different species composition.

Root Exudation of Organic Acids of Herbaceous Pioneer Plants and Their Growth in Sterile and Non-Sterile Nutrient-Poor,Sandy Soils from Post-Mining Sites

Nutrient-poor, sandy soils form the prevailing substrate at post-mining sites of the Lusatian region(Brandenburg, Germany) and present a challenge for vegetation development. We studied the organic acid quantity and composition of three commonly occurring pioneer plant species, the legumes Lotus corniculatus L. and Trifolium arvense L. and the grass Calamagrostis epigeios(L.) Roth, to determine if plant growth and exudation differed with(non-sterilized soil) and without(sterilized soil) an indigenous soil microbial community. We investigated whether organic acids were found in the rhizosphere and surrounding soil and whether this influenced nutrient mobilization. This study consists of linked field investigations and a greenhouse experiment. Plants were grown in the greenhouse in either sterilized or non-sterilized sandy soil from a reclamation site in the Lusatian mining landscape(Welzow Su¨d, East Germany). After seven months, the plant biomass, root morphology, organic acids, and water-soluble nutrients and root colonization with arbuscular mycorrhizal fungi(AMF) and dark septate endophytes(DSE) were analyzed. Roots of all three plants in the field and greenhouse experiments were highly colonized with AMF. Calamagrostis epigeios and T. arvense had a significantly higher colonization frequency with DSE than L. corniculatus. The quantity and composition of organic acids strongly differed among plant species, with the highest number of organic acids found for L. corniculatus and lowest for C. epigeios. The quantity of organic acids was greatly reduced in all plants under sterilized soil conditions. However, the composition of organic acids and plant growth in sterilized soil were reduced for both legumes, but not for C. epigeios, which had a higher biomass under sterilized conditions. Changes in nutrient concentrations in the field rhizosphere soil relative to those in the control were measurable after seven months. While the spectrum of organic acids and the growth of legumes seemed to be dependent on a highly diverse soil microbial community and a symbiotic partner, the grass C. epigeios appeared capable of mobilizing enough nutrients without an indigenous microbial community, and might be more competitive on sites where soil microbial diversity and activity are low.

两种沙性栽培基质下柳枝稷根系生长对施氮水平的响应

为研究柳枝稷根系各生长指标在粗沙土与河沙两种栽培基质上对不同梯度氮肥的响应,在PVC管内开展了柳枝稷氮肥效应试验。结果表明:施用不同浓度的氮肥对不同土层柳枝稷的根长、根表面积、根体积、根平均直径、根干重均有显著性影响(P<0.05)。在粗沙土和河沙两种栽培基质中,在不同土层,柳枝稷的根长、根表面积、根体积和根干重最大值分别出现在N3和N4处理下;根平均直径则随着施氮水平的升高而降低。

土地整治公众参与机制中的社会资本及其作用

研究目的:分析土地整治公众参与机制中的社会资本内涵、表现形式及其作用于土地整治的实现途径。研究方法:文献资料法,归纳分析法,实证分析法。研究结果:厘清了土地整治公众参与机制中社会资本的概念及层次内涵,阐述了社会资本作用于土地整治的两种实现途径。研究结论:(1)社会资本是农民之间合作的基础,体现在以信任、互惠、规范和合作为基本特征而构建的社会参与网络;(2)土地整治公众参与机制中的社会资本在农村基层组织中得以显化,是建立和优化土地整治公众参与机制的充分必要条件;(3)社会资本与农村土地制度变迁相互影响相互作用。

基层特警基础体能训练的探讨

运用文献资料法、特尔斐法、测试法,对普通基层特警队员系统体能训练前后的体能指标进行跟踪测试。结果显示:经过系统体能训练后特警队员的大部分体能指标均有所提高,并呈显著性差异。提示:系统的体能训练方法对提高特警队员的体能是可行的,在原有体能项目考核基础上,制定适用于普通基层特警队员的体能考核标准。

沿海沙地竹林细根分解过程中的能量变化

对沿海沙地竹林细根在分解过程中的干质量热值和能量现存量以及释放量进行了研究。结果表明:竹林细根在分解过程中,其干质量热值大体呈现先降后升的变化规律,分解到180 d时下降到最低点。分解时间对其干质量热值影响达到极显著水平。花吊丝竹的干质量热值与月平均气温、月降雨量具有显著的线性相关(P<0.05)。除绿竹外,沿海沙地竹林各竹种能量现存量1 a内波动较大,黄甜竹的年平均能量现存量最高,达2.67×103kJ.m-2;台湾桂竹最低,为1.63×103kJ.m-2;绿竹变化较为稳定,集中在1.72×103kJ.m-2左右。细根在分解过程中,能量是逐渐损失释放的,在分解300 d后能量损失率均在68%以上,高节竹能量损失率最大,达77.74%。总体上,各竹种细根分解能量平均损失率随分解时间的延长而增大,分解完毕时能量平均损失率达73.96%;各竹种在分解初期能量损失差异较大,随着分解时间的延长,差异越来越小。

农村基层组织人员贪污贿赂犯罪立法解释适用问题研究

村民委员会、村党组织、村经济组织的成员和村小组长、村民委员会下设各委员会委员等在农村基层组织中担任一定的职务、履行一定的职责的人都是"村民委员会等农村基层组织人员",其构成贪污贿赂犯罪必然发生在协助人民政府从事行政管理工作的过程中,具有时间性。而对如何认定协助行政管理行为的完成,论文提供了一种路径,即假设不存在村基层组织的协助管理行为,由人民政府直接完成现实中由村基层组织协助完成的行政管理工作,那么在假设条件下,认定人民政府某些具体行政管理工作完成所采用的标准,应适用于村基层组织人员协助管理工作完成的认定。

新医改背景下构建公立医院与基层医疗机构分工协作机制探讨

通过对目前公立医院与基层医疗机构分工协作现有的合作、托管、重组、联合体、集团和院办院管等模式的系统归纳和描述,并针对这些分工协作模式在运行过程中存在的法规制度不协调和利益冲突,以及管理制度不完善等问题的分析,提出在分工协作机制的构建上,应统筹规划,并以政府为主导,明确权责,建立利益平衡机制,完善分级医疗制度,建立质量控制和监督机制等政策建议。

我国对外贸易促进GDP增长的实证分析

近三十年来,我国GDP增长迅速,其中对外贸易的蓬勃发展作出了重要贡献。为探索对外贸易与GDP增长之间的关系,根据1978—2007年我国经济发展数据,综合运用单位根检验、协整检验、格兰杰因果检验、方差分解等方法进行计量分析,发现出口贸易对我国GDP增长影响显著,进口贸易则间接对我国GDP增长作出了贡献。

混交林杉木观光木细根分解过程能量变化

对福建三明杉木观光木混交林中杉木和观光木细根分解过程中干质量热值、能量残留率、能量年归还量及释放量进行了系统的研究,结果表明,细根在分解过程中干质量热值呈递减趋势变化.同一树种细根径级越小其能量残留率也越小.杉木细根的年能量归还量为2.8184×106J.m-2,观光木细根的能量年归还量为0.6435×106J.m-2,在不同径级细根能量年归还量组成中,两个树种的<0.5 mm径级细根的能量年归还量均占60%以上,表明在细根的能量流动中,<0.5 mm细根起着重要的作用.杉木细根的能量年释放量为1.8187×106J.m-2,观光木细根的能量年释放量为0.5864×106J.m-2.

加强和创新基层思想政治工作的途径与方法

思想政治工作必须适应新形势方有强大的生命力。要适应就必须在内容、形式、方法、手段、机制等方面努力创新和改进。特别要在增强时代感,加强针对性、实效性、主动性上下功夫。

传统与现代:基层纠纷解决机制的法社会学分析

基层社会群体冲突事件的逐年上升,一定程度地体现了当代纠纷解决机制在基层运行的失灵。纠纷解决机制在基层何以失灵?透过云南7.19孟连群体事件,从法律社会学的角度分析传统纠纷解决机制向现代化转型过程中的困境与机遇。

差分方程在概率计算中的应用

给出全概率公式,介绍差分方程的定义及解法,总结归纳出了全概率公式与差分方程之间的关系,利用差分方程简化应用全概率公式在解决某些实际问题中的复杂繁琐性。

四川农业总产值的预测与分析

本文验证了四川农业总产值序列是一个单位根过程,在此基础上对其差分序列建立自回归模型进行预测;通过分析影响四川农业总产值多年来升降的原因,发现四川农业总产值的增长主要受外部因素的影响。

农村基层组织功能发挥探析

探索农村基层组织的有效形式,充分发挥农村基层组织的有效功能,是建设社会主义新农村的关键。要充分发挥农村基层组织的功能,最基本的是以人及村干部队伍建设为关键要素,以党的组织建设为核心系统,以村民自治组织为框架,建立健全村治环境下的多种多样的组织形式,形成一个合理分工、团结协调、相互监督、有序运作的组织体系。