城市雨洪管控需要生态智慧的引领

针对频繁发生的城市洪涝,我国提出了建设海绵城市的策略,然而海绵城市建设能否解决当今城市面临的困境仍然存在许多不确定性。本文从城市雨洪的两面性、城市洪涝灾害形成之根源、城市规划者的责任、生态智慧在城市雨洪管控中的重要性和海绵城市建设等方面做了深入阐述,希望在海绵城市建设中运用生态智慧去实现管控城市洪涝和雨洪资源开发利用的目的。     

基于韧性理念的中国城市雨洪管理研究热点与趋势

在中国洪涝灾害频发的背景下,海绵城市等雨洪管理实践有助于灾害的缓解,提高城市应对雨洪的“韧性”。韧性城市作为应对灾害风险的城市规划理念,已被应用于一些国家的雨洪风险管理中。本文基于韧性理念,运用科学计量分析工具CiteSpace梳理中国雨洪研究现状,从生态、工程、社会雨洪韧性3方面分析了雨洪管理热点与相关技术,发现在跨领域的雨洪系统管理、区域到街区间不同空间尺度用地调蓄管理方面存在不足,提出未来应构建以“生态-工程-社会”为核心,涵盖“区域-城市-街区”尺度,多技术集成为支撑的自适应韧性雨洪管理体系。     

黄河流域城市生态韧性时空演变及其影响因素

城市作为最复杂的社会生态系统,在经历经济快速积累、城镇化加快推进的同时,面临着资源短缺、环境污染、生物多样性锐减等生态环境挑战,增强城市生态韧性对城市可持续发展至关重要。从韧性的内涵角度评估城市生态韧性水平,探究城市防范内外生态风险能力的时空特征,剖析城市生态韧性差异的影响机制,对实施城市生态文明建设与风险防控具有指导意义。基于"演化韧性"视角从"抵抗-响应-转型"三个能力构建城市生态韧性指标体系,以黄河流域七大城市群59个地级市2011-2020年面板数据为例,运用熵权-逼近理想解排序法(熵权-TOPSIS法)、传统和空间马尔可夫链,在对黄河流域城市生态韧性进行定量测算的基础上,分析其时空特征。最后利用面板分位数回归深入探索黄河流域城市生态韧性影响因素的分段效应,提高对城市生态韧性影响机制的认识。结果表明:(1)2011-2020年,城市生态韧性均值在(0.092,0.125)范围内,呈现缓慢增长态势;离散程度呈倒"U"型变化特征趋势;空间上,城市生态韧性表现为"下游强、上中游弱",城市群内部以省会城市为核心向外围地级市递减,"中心-外围"的分布格局明显。(2)城市生态韧性主要在相邻等级之间进行递次转移,仍未实现跨等级转移,具有"路径依赖"和"自身锁定"特征;地理空间背景在城市生态韧性动态演变过程中发挥着重要作用,表现为"强强联合、低低临近"的集聚效应。(3)影响因素方面,经济发展水平、科技创新对城市生态韧性具有显著促进作用;产业结构对城市生态韧性表现为显著抑制作用,人口密度和环境规制对城市生态韧性不同分位点的影响作用存在显著的异质性。研究结果可为黄河流域全面推进生态保护与建设"韧性城市"提供一定的科学参考和理论依据。     

生态智慧引导下的太原市棕地修复逻辑与策略

城市生态系统是一个复杂的人工系统,城市经过快速掠夺式的发展已经造成绿地生态空间锐减,水体资源缺乏且污染严重,热岛效应突出和城市棕地面积大且污染严重等一系列生态问题。以资源枯竭型城市内大量存在的棕地为研究对象,认为城市棕地的修复需要生态智慧的引导,在建立生态智慧引导的城市棕地修复逻辑和框架的基础上,结合太原市棕地生态修复实践,建立从棕地安全性修复、棕地功能修复和棕地景观修复的综合修复框架,提出分期分类多元化再生,分类利用城市功能活化,去棕还绿抗污染植物配置棕地修复的生态智慧策略。     

城市生态韧性水平空间评估及其驱动力——以北京市通州区为例

随着城镇化水平的提高、城镇化进程的发展,城市生态系统逐渐变得脆弱不堪,增强城市生态韧性水平对城市发展起关键性作用。以韧性的核心内涵为基础评估城市生态韧性水平,探究城市防范化解生态风险能力在空间上的差异,从而制定分区生态治理制度,是提升城市防范化解生态风险能力的有效办法。从抵抗力、适应力和恢复力三方面构建了城市生态韧性水平空间评估模型,以2020年北京市通州区行政边界、土地利用、重点排污单位、人口等数据为例,评估了2020年北京市通州区生态韧性空间格局,并利用空间自相关模型对其分区生态治理进行研究。最后利用地理加权回归分析模型（Geographical weighted regression,GWR）进行驱动力分析,探讨社会经济层面对城市生态韧性水平空间的影响,并提出建设性建议。主要得到以下结论：（1）在空间结构上,通州区生态韧性低值区域最多,占比为52.80%,主要分布于通州区北部、东北部、中部偏西及东南部;高值区域最少,占比0.83%,零星分布于偏西部地区和偏南部地区。通州区由于缺乏相对适宜的整体规划和统筹安排,使城市生态系统的循环体系受到了负面影响,从而导致东南地区抵抗力弱。同时,近年来降水点的南移使得大量水资源在城市热岛效应的作用下流失,通州区东南部及通州大运河沿线区域内恢复力呈现出大范围低值水平。（2）通州区中心偏西北地区为副中心的核心地带,呈现低韧性水平-高排污企业密度的集聚分布情况,且生态韧性低值区域主要集聚于新华街、中仓街、玉桥街等区域,说明这些区域的环境生态风险防范化解能力比较低,需要因地制宜地对生态危机做出可持续的分区生态治理,增强区域对生态风险的调节能力。（3）结合GWR模型的驱动力分析,城市生态韧性水平主要被城市功能多样性驱动,且城市功能多样性越强,城市生态韧性水平越低,在通州区西北部的城市副中心负向影响最为显著。研究结果为城市生态韧性水平发展优化提供了理论依据,为促进国土空间合理利用和有效保护发挥积极作用。     

基于“潜力-弹性-稳定性”模型的温州市生态韧性时空变化及影响因素研究

城市生态韧性为城市应对长期发展积累的内在压力,以及外界不确定性风险的冲击提供了新思路,对城市的可持续发展具有重要意义。基于城市生态学视角,从生态韧性的抵御力、恢复力及适应力三个方面特性,构建基于"潜力-弹性-稳定性"的生态韧性评价模型,分析了1990-2020年温州市生态韧性时空变化特征,并运用时空地理加权回归模型(GTWR),探究了生态韧性影响因素的时空异质性。结果表明:(1)1990-2020年,温州城市生态韧性指数总体呈现先上升后下降的趋势,潜力、弹性、稳定性呈现出相似的变化趋势,研究后期稳定性的提升使生态韧性的下降得到短暂缓解。(2)温州市东部沿海地区生态韧性较差,西部与北部山地生态韧性较好;低韧性水平区呈现出区域中心韧性水平降低,并且向外围扩张的趋势。(3)温州市城市生态韧性影响因素之间存在显著的时空差异,空间上也存在波动方向与强度的差异,这种差异性集中分布于城市边缘县(区)。研究以期为温州市及沿海同等级城市,提升城市生态韧性、促进区域可持续发展决策提供参考。     

城市生态韧性时空变化及情景模拟研究——以杭州市为例

从韧性的特征角度研究城市生态韧性水平的变化机制,探究城市防范化解生态风险能力的时空差异,以此明确城市分区生态治理的重要任务,是实现韧性城市生态风险防控的有利途径。从抵抗力、适应力和恢复力3个方面构建了城市生态韧性评估模型,并以杭州为例,评估了其1995—2015年城市生态韧性时空变化格局,再者利用空间自相关模型对2015年杭州生态韧性分区管理模式进行了探究。最后,基于FLUS模型模拟了2035年基准和创新创业导向的两种情景下的城市土地利用空间格局,并评估了不同城市发展情景下的生态韧性水平空间分布情况。基于以上研究得到以下结论:(1)1995—2005年,生态韧性低值区域向东北和东南方向扩张,而生态韧性高值水平区域明显减少。2005—2015年,杭州西北部和西部原本存在的中等韧性水平区域也转为低等水平。(2)2015年,城市东北区域呈现低韧性水平-高排污企业密度的集聚分布,说明该区域环境生态风险防范化解能力比较低,需要加大环境监测和生态治理的资金投入,严防重大环境污染事件的发生。(3)创新创业导向的"创新天堂"城市发展情景比基准情景下2035年杭州整体生态韧性水平更高,主要影响因素在于前...     

基于“风险-连通性-潜力”的南昌市生态韧性评估

随着城市建设的快速发展，建设用地持续扩张，生态用地不断缩减，城市生态系统出现了各种风险和退化现象，故对城市生态韧性进行评估尤为重要。本研究从城市化进程带来的景观地类变化视角出发，通过“风险-连通性-潜力”模型、空间自相关模型及核密度评估等方法对南昌市2005—2020年生态韧性水平进行评估，并探究其时空演化特征。结果表明：2005—2020年，研究区风险、连通性和潜力各子系统空间格局稳定，但差异显著，其中，生态风险呈中部高、东西两侧低的特征，连通性和生态潜力的空间分布则与生态风险相反，呈中部低、东西两端高的格局。南昌市生态韧性整体水平不高，以中、较低韧性水平为主体，低等级持续增长，高值水平区域逐渐减少。生态韧性的“高-高”集聚类型不断减小，“低-低”集聚类型逐步增加。核密度评估表明，南昌市整体韧性水平变化不大，空间差异明显。应根据南昌市不同区域的生态韧性水平特征，结合城市规划布局调整不同景观类型的数量与分布，改变不同景观类型空间分布的连通性和集聚性，实现区域整体生态韧性水平的优化提升。研究结果可为城市空间规划布局提供理论依据。     

基于传统生态智慧的江南水网空间韧性机制及实践启示

传统江南水网空间是一种典型的社会—生态系统,人文社会系统和自然生态系统之间的良性互动对于其韧性构建有着重要的积极作用。基于柯林斯等人提出的压力—冲击动态（PPD）模型,以平江府为典型代表,研究传统江南水网空间如何通过生态系统服务的桥梁搭建水网物质空间与人类社区发展之间的联系,从而厘清社会—生态系统在此过程中如何培育、优化和提升江南水网空间韧性。在此基础上,创新性地从生态系统服务供需关系的角度提出社会—生态韧性构建的生态智慧,并倡导以恢复力、适应力与变革力韧性机制培育为导向的、江南地区构建现代社区实践的若干启示,旨在引导江南水网空间实现具有韧性的社会—生态系统转型发展。     

城市雨洪管理实践需要生态实践智慧的引导

生态实践智慧是人类(个人、人群乃至社会)在对人与自然互利共生关系深刻感悟的基础上、成功从事生态实践的能力,是一种选择"正确的"生态知识成功进行"为善的"生态实践的能力。生态知识只有通过成功的生态实践,才可能转化为生态实践智慧。生态实践智慧通过巧妙连接各类生态知识与整体实践行动,不仅自古以来就引导着人类应对雨洪管理实践,还成就了众多造福万代的雨洪管理工程。在当下我国城市雨洪管理的实践中,它应该而且能够继续成为有效的引导者。     

Reconstitution de la végétation et du paléoclimat à partir de charbons de bois prélevés sur les sites du Paléolithique dans la région de Jungwon en Corée

Hundreds samples of the charcoals and waterlogged woods excavated from three late Paleolithic sites (Suyanggae, Gunang-gul and Sorori) in the Jungwon Region in Korea were analyzed to reconstruct the vegetation and paleoclimate in the region. Analyzed charcoal samples from the Suyanggae site show that the climate was cold in the lower part and it became more warm and dry in the upper part. From the Gunang-gul site, only Picea spp. was identified, indicating cool climates. From the Sorori site, two species were found; Alnus spp. (95%) and Ulmus spp. (5%). No conifers were discovered. The species composition indicates that the climate condition of central Korean peninsula around 8,800 BP was little cooler and wetter condition.     

Characterization and functional analysis of hsp21.8b: An orthologous small heat shock protein gene in Tribolium castaneum

Small heat shock proteins (sHSPs) act as molecular chaperones and are widely distributed in all kinds of organisms. Comparative analysis revealed that an orthologous shsp was present during insect evolution. Here, hsp21.8b, one insect orthologous shsp, had been identified in Tribolium castaneum. Quantitative real‐time PCR illustrated that Tchsp21.8b was expressed in all developmental stages, along with the lowest expression at early embryonic stage and relative high expression at other stages especially in late eggs and late pupae. In the adult period, Tchsp21.8b exhibited the highest expression level in central nervous system and followed in elytron, epidermis, ovary and fat body. Moreover, it was upregulated 3.39‐fold in response to enhanced heat stress (45°C) for 4 hr but not to cold stress (4°C) and was upregulated by 1.73‐ to 1.94‐fold under ultraviolet (UV) exposure during 4–6 hr. It was also downregulated by 20.8%–41.8% under starvation in 3 days and had a “down‐up‐down” trend under the pathogen stresses. Larval RNA interference of Tchsp21.8b caused 40.6% insects mortality and reduced the oviposition amount by 66.0% and only 21.0% of the ds‐Tchsp21.8b eggs could hatch into larvae. These results suggested that as an orthologous shsp, Tchsp21.8b not only plays important roles in the growth, development and fecundity of T. castaneum but with the competence to resist the environment stresses, although the response is relatively weak compared to other hsps. Results from this study also uncovered the functions of the orthologous shsp in the development and anti‐stresses ability of T. castanuem. It provided more scientific evidence for revealing the physiological mechanisms of shsps of the insects and enhanced the capabilities to control different pests.     

La stratigraphie du Pléistocène supérieur et le Paléolithique en Corée

In Korea, Quaternary deposits are characterized by marine and fluvial terrace deposits, commonly found in the coastal areas and at the sides of river valleys. The major terraces are classified into 5 different levels, i.e., alluvial plain (3-5 m asl), lower terrace (10-25 m asl), middle terrace (33-50 m asl), high terrace (55-85 m asl), and highest terrace (90-160 m asl). They were formed by the repetition of sedimentation and erosion due to sea level fluctuation and uplifting along the coastal areas during Quaternary period. The formation age of the lower marine terraces at the level of 10-20 m is interpreted to be the last interglacial (75-125 Ka, MIS = 5a-5e). The middle coastal terrace gravels distributed at the level of about 33-45 m above mean sea level and are to be formed before the last interglacial. Above coastal terrace deposits, slope deposits and paleosol layers are overlain and freezing and thawing crackings were developed in them. Major prehistory archaeological sites in the coastal areas are found in the slope deposits formed during last glaciations. The upper parts of the slope deposits are typified by paleosol layers with typical frost cracks (soil wedges) and frangipanes. As geochronological bases for subdividing Paleolithic cultures, two typical paleosol layers are useful because they are mostly found and imprinted with several horizons of frost cracks or soil wedges. The uppermost crack structures were formed under the boreal-periglacial climatic regime during the last glacial period of extremely cold-dry climate in Korea. The upper pedogenetic sediments containing frost cracks or soil wedges were formed between 24 and 17 Ka in many Paleolithic profiles. The lowermost paleosol layer with frost cracks (soil wedge), strongly attacked into hillslope sediments or last interglacial saprolite layers on the weathered basement rocks, were detected at least as old as 59-74,000 Ka. Lastly upper Paleolithic cultural layers were found in the young fluvial deposits, which had been formed since the Last Glacial Maximum (LGM). Some of them were particularly continued as late as the Pleistocene-Holocene Transition Period.     

Évolution des grands Carnivores au Plio Pléistocène en Afrique et en Europe occidentale

This paper provides an overview of current knowledge of Plio Pleistocene Carnivora from Africa and Europe. In Plio Pleistocene times, many genera extend their ranges in Africa and Eurasia but their evolution are quite distinct in the two continents. In Africa, the modern carnivoran guild of sub saharian Africa originated in the early Pleistocene when took place extinction of archaic species. The north African fossil record is far from complete until the middle Pleistocene. In the middle and late Pleistocene, the modern carnivoran guild is associated with other elements: the simian jackal Canis simensis and two species of ursids Ursus arctos and Ursus deningeri which evolved towards Ursus spelaeus. Western European carnivore faunas show due to migration a constant turn-over of the species. Among felids, Panthera schaubi described by Viret (1954) and attributed to the genus Puma by Hemmer et al. (2004), is morphologically close to the snow leopard Panthera (Uncia) uncia. Canis etruscus is the sister group pf the clade including wolf and coyote and Canis arnensis is close to the African jackals. Ursus deningeri appears in the early Pleistocene together with two arctoid forms Ursus rodei and Ursus dolinensis that may be synonymous to Ursus arctos. The genus Hyaena is present in Europe in the middle and late Pleistocene.     

« Flûte » et pointes de la Grosse Badlhöhle, Autriche

The Grosse Badlhöhle (Austria, Steiermark) is the origin of one of the most perfect bone points of the early Aurignacian and one of the best perforated femurs of the same period, which can be regarded as musical instruments. Two other fragments of points raise intriguing questions on the first Homo sapiens sapiens which cannot be solved today but will contribute to future research. A review on the debate of Palaeolithic flutes will follow with experimental proofs of boring artificial holes with high quality pictures on the blow-hole and the lack of gnawing traces on the opposite face. The musical possibility of an instrument with only one hole is discussed with ethnographic analogies. Hafting, optimal conditions of strength and possible use of arrows will close the discussion on the Badlhöhle bone artefacts.     

Dynamic data replacement and adaptive scheduling policies in spark

Improper data replacement and inappropriate selection of job scheduling policy are important reasons for the degradation of Spark system operation speed, which directly causes the performance degradation of Spark parallel computing. In this paper, we analyze the existing caching mechanism of Spark and find that there is still more room for optimization of the existing caching policy. For the task structure analysis, the key information of Spark tasks is taken out to obtain the data and memory usage during the task runtime, and based on this, an RDD weight calculation method is proposed, which integrates various factors affecting the RDD usage and establishes an RDD weight model. Based on this model, a minimum weight replacement algorithm based on RDD structure analyzing is proposed. The algorithm ensure that the relatively more valuable data in the data replacement process can be cached into memory. In addition, the default job scheduling algorithm of the Spark framework considers a single factor, which cannot form effective scheduling for jobs and causes a waste of cluster resources. In this paper, an adaptive job scheduling policy based on job classification is proposed to solve the above problem. The policy can classify job types and schedule resources more effectively for different types of jobs. The experimental results show that the proposed dynamic data replacement algorithm effectively improves Spark's memory utilization. The proposed job classification-based adaptive job scheduling algorithm effectively improves the system resource utilization and shortens the job completion time.

     

Estimation de la distensibilité aortique à partir de séquences d’images de résonance magnétique « steady-state free-precession » et « contraste de phase »

Objective

To investigate the accuracy in the estimation of the aortic lumen area and distensibility obtained from Steady-State Free-Precession (SSFP) and Phase Contrast (PC) MR sequences.

Subjects and methods

Systolic and diastolic aortic lumen of the ascending and descending aorta of 50 subjects, collected with both acquisition sequences, were extracted using a 2D + t automated segmentation method.

Results

While the statistical study indicated very similar lumen areas for SSFP and PC data (slope = 1, r = 0.99), the corresponding distensibility values were less correlated (r = 0.54). Comparison between distensibility values in the ascending and descending aorta and study of these values with aging indicated a greater coherence with expected physiological behavior of the aorta when using SSFP images.

Discussion

Flow artifacts were more severe in PC images and could explain the better results obtained when using SSFP sequences.

Conclusion

A more accurate local assessment of the aortic stiffness is obtained from SSFP image sequences than from PC image sequences.     

Ndst1, a heparan sulfate modification enzyme, regulates neuroectodermal patterning by enhancing Wnt signaling in Xenopus

Neural tissue is derived from three precursor regions: neural plate, neural crest, and preplacodal ectoderm. These regions are determined by morphogen-mediated signaling. Morphogen distribution is generally regulated by binding to an extracellular matrix component, heparan sulfate (HS) proteoglycan. HS is modified by many enzymes, such as N-deacetyl sulfotransferase 1 (Ndst1), which is highly expressed in early development. However, functions of HS modifications in ectodermal patterning are largely unknown. In this study, we analyzed the role of Ndst1 using Xenopus embryos. We found that ndst1 was expressed in anterior neural plate and the trigeminal region at the neurula stage. ndst1 overexpression expanded the neural crest (NC) region, whereas translational inhibition reduced not only the trigeminal region, but also the adjacent NC region, especially the anterior part. At a later stage, ndst1 knocked-down embryos showed defects in cranial ganglion formation. We also found that Ndst1 activates Wnt signaling pathway at the neurula stage. Taken together, our results suggest that N-sulfonated HS accumulates Wnt ligand and activates Wnt signaling in ndst1-expressing cells, but that it inhibits signaling in non-ndst1-expressing cells, leading to proper neuroectodermal patterning.     

Le Magdalénien de la grotte « Grappin » à Arlay (Jura, France) : nouveaux regards

The “Grappin” or “Saint-Vincent's” cave, on the western slope of Jura, East of France, has been explored since 1889. From then to 1960, it has yielded substantial material dated to middle “à navettes” Magdalenian developing during the late Pleniglacial. The study of this settlement, although often mentioned, was never dealt with comprehensively until now. Due to its scientific importance for the middle Magdalenian of western Europe, the site is to be reinvestigated through a global interdisciplinary project entitled “The Tardiglacial and the start of Holocene in the Jura and its margins”. This paper will review our present knowledge of the site, radiocarbon dates and archaeological data. It also focuses on ornaments and engraved mobile art.     

Resolution-optimized NMR measurement of <Superscript>1</Superscript>D<Subscript>CH</Subscript>, <Superscript>1</Superscript>D<Subscript>CC</Subscript> and <Superscript>2</Superscript>D<Subscript>CH</Subscript> residual dipolar couplings in nucleic acid bases

New methods are described for accurate measurement of multiple residual dipolar couplings in nucleic acid bases. The methods use TROSY-type pulse sequences for optimizing resolution and sensitivity, and rely on the E.COSY principle to measure the relatively small two-bond ²D_CH couplings at high precision. Measurements are demonstrated for a 24-nt stem-loop RNA sequence, uniformly enriched in ¹³C, and aligned in Pf1. The recently described pseudo-3D method is used to provide homonuclear ¹H-¹H decoupling, which minimizes cross-correlation effects and optimizes resolution. Up to seven ¹H-¹³C and ¹³C-¹³C couplings are measured for pyrimidines (U and C), including ¹D_C5H5, ¹D_C6H6, ²D_C5H6, ²D_C6H5, ¹D_C5C4, ¹D_C5C6, and ²D_C4H5. For adenine, four base couplings (¹D_C2H2, ¹D_C8H8, ¹D_C4C5, and ¹D_C5C6) are readily measured whereas for guanine only three couplings are accessible at high relative accuracy (¹D_C8H8, ¹D_C4C5, and ¹D_C5C6). Only three dipolar couplings are linearly independent in planar structures such as nucleic acid bases, permitting cross validation of the data and evaluation of their accuracies. For the vast majority of dipolar couplings, the error is found to be less than ±3% of their possible range, indicating that the measurement accuracy is not limiting when using these couplings as restraints in structure calculations. Reported isotropic values of the one- and two-bond J couplings cluster very tightly for each type of nucleotide.