城市新陈代谢视角下的城市公共健康风险

城市公共健康风险是当代城市研究的一个重要主题,在中国人文地理学界尚未得到充分关注。国内既有研究主要集中在两个维度——健康城市建设和城市风险治理,然而这些研究受到城市/自然二元论的影响。自20世纪90年代以来,城市政治生态学在西方人文地理学界迅速崛起,提出了以社会关系为核心的城市新陈代谢理论,在空间和联系两个层面将社会与自然,人类行为体与非人类行为体联系起来,实现了对二元论的超越。基于这一理论,本文从空间和联系层面对城市公共健康风险的具体形式进行分析,指出在空间层面上,存在空间流转和重叠的公共健康风险和空间生产和再生产活动的公共健康风险;就联系层面而言,存在“新陈代谢断裂”的公共健康风险和公众认知的公共健康风险。     

高黎贡山不同土地类型土壤中微生物的生化活性

从高黎贡山不同土地类型土壤的理化特性及微生物特性,探讨了不同土地类型生态因子的变化及其对微生物生长代谢的作用,以及人类活动对微生物的影响。     

杂交鲷和黑鲷幼鱼的代谢率及排泄率比较

杂交鲷是以真鲷为母本,黑鲷为父本的杂交F1代品种,为了比较杂交鲷与黑鲷的代谢特征,采用静水密闭式呼吸仪测定了13、18、23、28、33℃（32℃）5个温度下杂交鲷和黑鲷幼鱼的代谢率及排泄率.结果表明：13~28℃温度下,杂交鲷和黑鲷幼鱼的代谢率、排泄率均随温度的升高而升高,28℃时杂交鲷和黑鲷幼鱼的代谢率、排泄率分别为14.22±0.95、0.39±0.02 J/（g.h）和17.47±0.14、0.43±0.02 J/（.gh）,分别是其13℃时的5.69、4.05倍和4.01、3.73倍;且各温度下黑鲷的代谢率始终高于杂交鲷,前者是后者的1.23~1.73倍;杂交鲷和黑鲷幼鱼分别在32℃和33℃时代谢率比28℃下跌了22.23%和3.83%,证明该温度已分别超出了这2种幼鱼的最高适温;杂交鲷和黑鲷幼鱼28℃时的窒息点溶解氧含量分别为1.94、1.40 mg/dm3,低于真鲷21℃时的窒息点溶解氧含量（2.30 mg/dm3）;O∶N原子比值结果显示,28℃时蛋白质供能比最低,生长积累速度最快,是2种幼鱼的最适温度.综合分析认为,杂交鲷幼鱼具有代谢率显著低于亲本的优点,也继承了父本耐低温的特点,但同时失去了亲本耐高温、耐低氧的特点,并出现了应激反应大等不良性状.     

Effects of ration, temperature and body weight on metabolism in young black porgy

ＩＮＴＲＯＤＵＣＴＩＯＮＴｈｅｍｅｔａｂｏｌｉｓｍｉｎｆｉｓｈｉｎｃｌｕｄｅｓｓｔａｎｄａｒｄｍｅｔａｂｏｌｉｓｍ(ＲＳ)ｒｏｕｔｉｎｅｍｅｔａｂｏｌｉｓｍ(ＲＲ),ｓｐｅｃｉｆｉｃｄｙｎａｍｉｃａｃｔｉｏｎ(ＳＤＡ)ａｎｄａｃｔｉｖｅｍｅｔａｂｏｌｉｓｍ(ＲＡ),ｒｅｌａｔｅｄａｓ:　　ＲＴ=ＲＳ ＲＲ ＳＤＡ ＲＡｗｈｅｒｅＲＳｉｓｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈｅｆｉｓｈａｔｒｅｓｔ;ＲＲｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈｅｒｏｕｔｉｎｅｌｙａｃｔｉｖｅｆｉｓｈ;ＳＤＡｔｈｅｍｅｔａｂｏｌｉｓｍｏｆｔｈ…     

深海生物原位实验与生态监测研究进展

深海在黑暗、高静水压、低温(黑烟囱等热液系统除外)和寡营养的极端环境下形成了特殊的生境。对深海生物/微生物的研究,不仅可以揭示各种深海生物的生理代谢特性和动态变化规律,而且有助于深海生物资源的开发利用,特别是深海微生物碳循环机制的相关研究可为全球实现碳中和目标提供新的路线图。研究深海生物的首要条件是获得大量保持原位特性的样本,然而传统深海采样手段的局限可能导致深海相关研究结果无法反映深海环境下真实的生命过程,亟需发展满足深海生物原位研究的采样方法和生态监测技术。本文对深海生物研究现状,相关科学问题和原位组学研究进展,以及原位生态监测装备研发和应用进行综述,并对深海原位生物实验室进行了展望。     

太平洋牡蛎三倍体与二倍体特殊动力代谢的比较

采用耗氧强度测定法 ,对太平洋牡蛎三倍体和二倍体代谢进行比较研究。结果表明 ,在不同温度下 ,2n标准代谢 (StM)占常规代谢 (有饵料条件下 ,RfM)的比例平均为 85 7%( 82 6%— 91 % ) ,高于 3n的 78 4% ( 72 %— 84 3% ) ;2n因摄食所耗机械代谢变动于RfM的2 6%— 6 7% ,平均值为 4 3% ,低于 3n的 8% ( 4 9%— 1 3 6% ) ;同时 ,2n用于消化、吸收食物的代谢平均约占RfM的 9 98% ,低于 3n的均值 1 2 6%。经协方差分析检验 ,倍性对标准代谢、消化和吸收代谢及摄食代谢虽未表现出显著作用 ,但在不同生理状况下 ,2n耗氧率的均值都高于 3n。在 2 0℃下 ,对太平洋牡蛎 2n和 3n标准代谢和常规代谢 (无饵料条件下 ,RM)的昼夜周期性比较表明 ,3n的特殊动力代谢 (SDA)峰值略高于 2n,SDA持续时间和总耗能分别为 2n的 1 3倍和 0 80倍。实验还表明 ,2n和 3n在停食后 2 8h和 2 4h分别达到其排氨率的高峰 ,两者的排氨率差异虽不显著 ,但排氨率均值 3n高于 2n。     

盐酸甜菜碱对短盖巨脂鲤脂肪代谢的影响

采用现场实验的方法，以短盖巨脂鲤为对象进行了60天养殖实验，探讨盐酸甜菜碱对其脂肪代谢作用机理。结果表明，盐酸甜菜碱使整鱼水分和含脂量呈下降趋势，鱼肌肉含水量下降，肝脂量极显著降低；肌肉和肝脏中游离肉碱、酸不溶肉碱含量和酸不溶肉碱与游离肉碱的比例极显著提高；血清总胆固醇和甘油三酯极显著下降，脂肪酶活性呈升高趋势；甜菜碱对肠系膜脂肪酶活力产生影响，使鱼肌肉肌问脂肪分布发生明显变化。实验结果提示：甜菜碱可改善肉质，它参与机体代谢活动，使肝脏和肌肉中甲基化产物(肉碱)含量增加，影响肠系膜脂肪酶活力，改变体脂和鱼肉脂肪酸组成，进行体脂重分配。     

The PROWQM physical–biological model with benthic–pelagic coupling applied to the northern North Sea

PROWQM, a 1-D depth resolving model which couples physical and microbiological processes in the water column with sedimentation/resuspension and benthic mineralisation processes, has been used to simulate seasonal changes of chlorophyll, nutrients and oxygen at the PROVESS north site (59°20′N 1°00′E) in the North Sea. PROWQM is derived from the 3-D model COHERENS, and improves COHEREN's benthic and pelagic biology.The physical sub-model of PROWQM implicitly solves turbulence closure equations forced by climatological, or realistic high-frequency, meteorological and tidal data. The pelagic biological sub-model 2MPPD includes a ‘diatomy’ microplankton (mp1) and a ‘flagellatey’ (or microbial loop) microplankton (mp2), the cycling of silicon and nitrogen, slow-sinking detritus, and fast-sinking phytodetritus. Phytodetritus is formed by shear-driven aggregation of particulate material, using a simple algorithm for bulk processes that is derived by considering the interactions of single cells. The microplankton compartments include heterotrophic bacteria and protozoa as well as phytoplankton, and most microplankton rates are specified with the aid of a ‘heterotroph fraction’ parameter, which was 0.125 for mp1 and 0.6 for mp2. The microbiological system is closed by mesozooplankton grazing pressures imposed as time varying series determined from observed zooplankton abundance. The benthic boundary sub-model includes a superficial fluff layer and a nutrient element reservoir in the consolidated sediment. Particulate material in the fluff layer can be resuspended (in response to bed stress by near-bed flows), mineralised or carried by bioturbation into the underlying, consolidated, sediment, where it is mineralised and its nutrients returned to the water-column at rates mainly dependent on (implicit) macrobenthic pumping. Benthic denitrification can occur when mineralisation rates exceed oxygen supply.Verification of the PROWQM numerical implementation used test cases and checks for nutrient element conservation. Simulations with realistic forcing, for a range of parameter values, were compared with historic observations in the NOWESP data set and during FLEX76, and with those made during the PROVESS cruises in autumn 1998. PROWQM provided a good simulation of the seasonal succession from a diatom-dominated spring bloom to summer dominance by small flagellates. The simulations included sedimentation of organic matter from the spring bloom, and qualitatively realistic behaviour of the fluff layer, but decay rates were too slow and there was almost no denitrification. The simulated surface mixed layer was too shallow during the summer. Simulated annual net microplankton primary production was in between 59 and 91 g C m⁻² y⁻¹. A large proportion of mineralisation, 28–47% of nitrogen and 40–67% of silicon mineralisation, took place as a result of the decay of sinking and resuspended detritus whilst in the water column.PROWQM is discussed in relation to other models that have been used to simulate this part of the North Sea, in particular the simpler ECOHAM1 and the more complex ERSEM, and in relation to PROWQM's evolution from COHERENS.     

Latitudinal Differences in the Planktonic Biomass and Community Structure Down to the Greater Depths in the Western North Pacific

As part of the research program WEST-COSMIC Phase I (1997–2001), vertical profiles down to the greater depths (0–2000 m or 5800 m) of the plankton community structure composed of heterotrophic bacteria, phytoplankton, protozooplankton and metazooplankton were studied at one station in each subarctic (44°N) and in transitional region (39°N), and two stations in subtropical region (30°N and 25°N); all in 137–155°E in the western North Pacific Ocean. The biomass of all four taxonomic groups decreased rapidly with increasing depths at all stations, although the magnitude of depth-related decrease differed among the groups. As plankton community structure, metazooplankton biomass and bacterial biomass occupied >50% of the total in 0–2000 and 2000–4000 or 5000 m strata, respectively, at subarctic and transitional stations, while bacterial biomass contributed to >50% of the total consistently from 0 through 4800 or 5800 m at subtropical stations. Metazooplankton biomass integrated over the greater depths exhibited a clear latitudinal pattern (high north and low south), but this was not the case for those of the other taxonomic groups. As a component of metazooplankton, an appreciable contribution of diapausing copepods to the metazooplankton was noted at subarctic and transitional stations, but they were few or nil at subtropical stations. As protozooplankton assemblages, heterotrophic microflagellates (HMF) and dinoflagellates were two major components at subarctic and transitional stations, but were only HMF predominated at subtropical stations. From biomass ratios between heterotrophic bacteria, HMF and dinoflagellates, “sinking POC-DOC-heterotrophic bacteria-HMF-heterotrophic dinoflagellates” link was proposed as a microbial food chain operative in the deep layer of the western North Pacific. All results are discussed in the light of latitudinal differences in the structure and functioning of plankton community contributing to the ‘biological pump’ in the western North Pacific Ocean. This revised version was published online in July 2006 with corrections to the Cover Date.     

深圳湾浮游生物和底栖动物现状调查研究

对深圳湾浮游植物、浮游动物和底栖动物的种类、数量及分布现状进行了研究。结果表明 ,淡水种类占绝对优势 ,藻类5门32属45种 ,其中硅藻12属18种 ,绿藻1属15种 ,蓝藻7属10种 ,裸藻、金藻各1属1种 ;浮游动物共计37种 ,其中原生动物9种,轮虫14种 ,枝角类2种 ,桡足类8种 ,浮游幼虫及其它4种 ;底栖动物20种 ,分别为环节动物的多毛类7种 ,寡毛类2种 ,软体动物8种 ,甲壳动物2种 ,鱼类1种。浮游生物和底栖动物数量和分布的特征是 :藻类细胞密度为2.4×106～1.4×107个/L ,平均6.43×106 个/L。浮游动物为514.0～8049.2个/L,平均1690.8个/L。底栖动物个体数为180～8860个/m2,平均为2364个/m2。这三类生物的种类和数量分布与距深圳河河口的距离有密切关系。因此 ,三类生物多样性指数湾内段与湾口段差异明显,且平均值偏低 ,说明深圳湾水体有一定程度的污染