Potential of Marine Reserves to Cause Community-Wide Changes beyond Their Boundaries

Abstract:  Fishing and other human activities can alter the abundances, size structure, and behavior of species playing key roles in shaping marine communities (e.g., keystone predators), which may in turn cause ecosystem shifts. Despite extensive evidence that cascading trophic interactions can underlie community-wide recovery inside no-take marine reserves by protecting high-level predators, the spatial extent of these effects into adjacent fished areas is unknown. I examined the potential for community-wide changes (i.e., the transition from overgrazed coralline barrens to macroalgal beds) in temperate rocky reefs within and around a no-take marine reserve. For this purpose I assessed distribution patterns of predatory fishes, sea urchins, and barrens across the reserve boundaries. Predatory fishes were significantly more abundant within the reserve than in adjacent locations, with moderate spillover across the reserve edges. In contrast, community-wide changes of benthic assemblages were apparent well beyond the reserve boundaries, which is consistent with temporary movements of predatory fishes (e.g., foraging migration) from the reserve to surrounding areas. My results suggest that no-take marine reserves can promote community-wide changes beyond their boundaries.     

Detection of fetal structural abnormalities at the 11–14 week ultrasound scan

The aim of this study was to evaluate the detection of fetal structural abnormalities by the 11–14 week scan. 2853 pregnant women were submitted to a routine ultrasound scan between the 11th and 14th week and the fetal skull, brain, spine, abdominal wall, limbs, stomach and bladder were examined. Following the scans the patientes were examined in the second or third trimester of pregnancy. An isolated increased nuchal translucency was not considered an abnormality. However, these patients had an early echocardiography assessment. Fetal structural abnormalities were classified as major or minor and of early or late onset. A total of 130 (4.6%) defects were identified and 29 (22.3%) of these were diagnosed at the 11–14 week scan, including nine cardiac defects associated with increased nuchal translucency. The antenatal ultrasound detection rate was 71.5%, and 31.2% were detected in the first-trimester assessment. 78.8% of the major defects were diagnosed by the prenatal scan and 37.8% by the 11–14 week scan. Fetal structural abnormalities at the 11–14 week scan were detected in approximately 22.3% of the cases, therefore, a second-trimester anomaly scan is important in routine antenatal care to increase the prenatal detection of fetal defects. Copyright © 2002 John Wiley & Sons, Ltd.     

Population Dynamics of Forest Voles (Clethrionomys,Rodentia) in Northern European Russia

Long-term data sets on the population dynamics of forest voles in northern European Russia were analyzed. Eastward and northward trends in changes of the ratio between model species and the degree of their dominance were revealed. In virtually all sites studied, the numbers of the northern red-backed and bank voles changed synchronously; however, the population dynamics became less synchronous as the distance between study areas increased.     

不同气候情景下甘肃草地碳收支时空模拟与预测

在碳达峰、碳中和的背景下,草地碳汇是实现碳中和的关键路径.基于第六次国际耦合模式比较计划（CMIP6）气候情景数据,运用Daycent模型对甘肃草地2015~2100年碳收支进行模拟,并利用趋势分析法研究未来78 a草地碳收支的时空变化规律.结果表明,SSP245未来气候情景下,净生态系统生产力（NEP）呈不显著波动下降趋势,速率（以C计,下同）达-0.20 g ·（m² ·a）^-1,且该情景下草地碳汇处于下降状态;SSP585未来气候情景下,草地NEP以1.36 g ·（m² ·a）^-1的速率呈显著波动上升趋势,草地碳汇逐渐增加;草地碳收支的空间分布由西北向东南递增;SSP585气候情景下的温度和降水的增幅高于SSP245的气候情景,且草地碳收支与降水量的变动具有一致性,与温度的变化呈反向关系.研究明确了在不同气候情景下甘肃草地的碳汇强度,对有效固碳有参考和促进作用.     

电场对污泥堆肥富里酸结构特征的影响

为了研究电场对污泥堆肥富里酸结构特征及电子转移能力(ETC)的影响,以市政污泥和米糠为原料,设置施加5V的直流电场(T1)和不施加电场(CK)的两个堆肥进行对比实验.通过三维荧光-平行因子分析(EEM-PARAFAC)、紫外可见光谱(UV-vis)、傅里叶红外光谱(FTIR)结合二维相关光谱(2DCOS)分析堆肥过程中富里酸结构和组成变化.通过电化学方法测定了堆肥富里酸的电子接受能力(EAC)和电子供给能力(EDC).结果表明,类色氨酸、类富里酸和类胡敏酸是堆肥FA的主要组分,随着堆肥的进行,FA中类色氨酸物质减少,类富里酸和类胡敏酸含量增加,电场能够促进FA在堆肥过程中类色氨酸的降解和类胡敏酸的形成,提高了FA的芳香性、分子量和腐殖化程度.电化学分析结果表明,FA的ETC呈现先增后减的趋势.相比CK处理,施加电场降低了FA的EDC,但同时增强了其EAC,使得堆肥后期的FA具有更强的ETC.结果将有助于进一步了解污泥堆肥过程中FA的形成过程及其氧化还原特性.     

温度梯度下钛合金热防护结构的导波特性研究

目的 实现可重复使用钛合金热防护结构的导波健康监测。方法 针对钛合金热防护结构,提出热–力–电多物理场耦合导波传播建模仿真分析方法,研究温度梯度下钛合金热防护结构中导波的传播特性,以及在温度梯度和裂纹损伤耦合作用下导波的传播特性。结果 20~500 ℃的温度梯度会导致钛合金结构中导波的群速度降低、幅值衰减降低,裂纹损伤使得钛合金结构中导波的群速度、幅值降低,且损伤越大,影响越明显。裂纹扩展至20 mm时,S0模式群速度降低了1.5%,A0模式群速度降低了2%。结论 此模型可为大范围的温度梯度条件下,钛合金热防护结构上传感器优化布置以及导波监测方法的研究提供指导。     

2015~2019年南京北郊碳质气溶胶组成变化

碳质气溶胶是大气细颗粒物的重要组成,对空气质量、人体健康和气候变化有着重要影响.为了探究碳质气溶胶在减排背景下的长期变化,本研究测定了南京北郊5 a（2014年12月17日至2020年1月5日） PM_2.5样品的有机碳（OC）和元素碳（EC）浓度.结果表明,ρ（OC）和ρ（EC）5a平均值分别为（10.2±5.3）μg·m^-3和（1.6±1.1）μg·m^-3,其中OC占PM_2.5的31.1%,EC占PM_2.5的5.2%.OC和EC均呈现出冬高夏低的季节特征.通过非参数的Mann-Kendall检验和Sen’s斜率发现,OC和PM_2.5的浓度整体呈显著下降趋势[OC:P<0.000 1,-0.79μg·（m³·a）^-1,-0.29%·a^-1; PM_2.5:P<0.000 1,-4.59μg·（m³·a）^-1,-1.5...     

河流底泥DOM、营养盐与重金属空间分异特征及响应关系

为探究河流底泥中的溶解性有机物(DOM)和营养盐对重金属迁移转化的影响,以沈阳市新穆河、南小河和老背河为研究对象,利用三维荧光光谱,结合平行因子(PARAFAC)、主成分分析(PCA)和结构方程模型(SEM)研究了底泥中的DOM、营养盐与重金属的空间分异特征及DOM与营养盐对重金属的响应关系.结果表明,3条河流底泥中的总氮(TN)和总磷(TP)呈重度污染状态.南小河底泥中的ω(Zn)、ω(As)、ω(Cu)、ω(Ni)和ω(Cd)分别是辽宁省土壤背景值的2.48、 1.02、 3.45、 3.00和39.05倍,老背河的ω(Zn)、ω(Cu)和ω(Cd)分别是背景值的2.56、 1.92和8.00倍,新穆河的ω(Zn)和ω(Cu)分别是背景值的1.40和1.10倍,总体上3条河流均存在重金属累积现象,累积严重程度为：南小河>老背河>新穆河,其中南小河和老背河Cd污染严重.应用PARAFAC共解析出5类DOM组分,分别为类色氨酸、酚类络合物、微生物代谢产物、类富里酸和类胡敏酸,其中类富里酸和类胡敏酸丰度较高;基于PCA分析,新穆河底泥污染的主控因子为TN、 TP、类富里酸和类...     

生物锰氧化物对4种重金属的吸附特性研究

通过培养锰氧化细菌Sphingopyxis sp.4-15,制备生物锰氧化物,研究了生物锰氧化物的结构性质及其在不同影响因素下对4种重金属Cu、Zn、Cr和As的吸附特性。结果表明该生物锰氧化物中含有MnO₂、Mn₃O₄和MnO等晶体锰氧化物,包裹在菌体细胞表面呈现出规则的花球状。其锰主要以高价态的Mn⁴⁺和Mn³⁺形式存在,平均孔径为35.56 nm,比表面积为41.49 m²/g。锰氧化物对重金属的吸附过程受pH值影响,最适pH值为4~6;离子强度对吸附过程干扰较小;升高温度有利于其对Cu和Zn的吸附,而对As的吸附产生抑制;锰氧化物对Cu(Ⅱ)、Zn(Ⅱ)、As(Ⅲ)的吸附在反应360 min时可达到平衡,对Cr(Ⅲ)的吸附在反应5 min内达到平衡;在4种重金属最大初始浓度下,生物锰氧化物对Cu(Ⅱ)、Zn(Ⅱ)、Cr(Ⅲ)、As(Ⅲ)的吸附量依次为:70.184、15.140、9.141、0.089 mg/g,具有较大的重金属吸附容量。     

基于SEM的城市突发事件现场应急指挥能力影响因素分析

为提升城市突发事件现场应急指挥能力,通过分析城市现场应急指挥能力影响因素,构建城市现场应急指挥能力影响因素与突发事件应急指挥效果结构方程模型,并采用SPSS和AMOS软件对北京市现场应急指挥能力进行研究。结果表明:应急指挥统筹决策对应急指挥能力影响相对较大,应急指挥对象影响相对较小;应急指挥体系建设对应急指挥统筹决策影响相对最大,其次是应急信息平台系统。城市应综合考虑各因素间相关关系,有针对性地提高应急指挥能力。