Coral communities of Biscayne Bay,Florida and adjacent offshore areas: diversity,abundance, distribution,and environmental correlates

• 1. Hardbottom habitats of Biscayne Bay, a shallow lagoon adjacent to the city of Miami, Florida, USA, contain a limited number of coral species that represent a small subset of the species found at nearby offshore hardbottom and reef habitats of the Florida Reef Tract. Although the physical characteristics of this basin make it a marginal environment for coral growth, the presence of dense populations of Siderastrea radians and Porites furcata indicate that these, as well as other corals that are found at lower densities, are able to tolerate extreme and fluctuating conditions. Three factors, temperature, sedimentation, and salinity, appear to limit coral abundance, diversity, and distribution within Biscayne Bay.
• 2. Temperatures exhibit high frequencies of extreme high and low values known to cause coral stress and mortality elsewhere. Similarly, sedimentation rates are very high and sediment resuspension caused by currents, storms and boating activities commonly bury corals under sediment layers. Sediment burial was shown experimentally to influence growth and mortality of S. radians.
• 3. The salinity of Biscayne Bay is influenced by freshwater inputs from canal, sheetflow and groundwater sources that create a near‐shore environment with low mean salinity and high salinity fluctuation. Coral communities along this western margin have the lowest coral density and species richness. Chronic exposure to low salinity was shown experimentally to cause a decrease in the growth of S. radians.
• 4. The location of Biscayne Bay, downstream of a large restoration effort planned for the Everglades watershed, highlights the need to understand the relationship between the physical environment and the health of benthic communities. The data presented here provide the type of scientific information needed so that management decisions can take into account the potential impacts of human activities on the health of coral populations that are already near their tolerance limits for temperature, salinity, and sedimentation.

Copyright © 2003 John Wiley & Sons, Ltd.     

Eroding diversity away: Impacts of a tetrapod breakwater on a subtropical coral reef

1. Artificial barriers for coastal protection have been deployed across numerous tropical and subtropical islands in the Pacific, including Okinawa Island, southern Japan, where artificial defences have been installed along a large part of the coastline.
2. Although artificial barriers can lead to beach narrowing or loss and can exacerbate erosion, their effects on coral reef ecosystems remain understudied.
3. This study investigated the impact of a tetrapod breakwater in Ogimi Village, Okinawa Island, Japan, comparing the area affected by the presence of the barrier with a nearby natural coastline, and examining differences in physical parameters (depth profiles, sediment granulometry, and erosion on plaster balls) and benthic community composition.
4. Significant differences in depth profiles, sediment granulometry, and erosion were found, suggestive of alterations in water energy levels (lower than controls on the landward side of the barrier, and higher on the seaward side).
5. The benthic community was also clearly affected, with almost no living corals growing over the blocks or in their proximity.
6. Overall, the data show how breakwaters can affect the physical environment and benthic communities in a subtropical coral reef ecosystem, with negative consequences for coral survival.

     

陕西关中小麦全麦粉SDS沉淀值与膨胀体积的遗传研究

为了给小麦品质育种早代选择指标的确定提供理论依据．选用5个品质性状不同的陕西关中小麦品种及其双列杂交的F1为材料，分析了全麦粉SDS沉淀值和膨胀体积的遗传特性。全麦粉SDS沉淀值和膨胀体积的平均值分别为67．66ml和6．09ml／g．其中沉淀值变异幅度较大，变异系数较高．而膨胀体积变异幅度较小，变异系数较低。SDS沉淀值的广义遗传力和狭义遗传力分别为98、42％和97．06％；膨胀体积的广义遗传力和狭义遗传力分别为54．75％和10．82％。对陕西关中小麦品质育种配制的组合而言，全麦粉SDS沉淀值可作为小麦育种分离早代蛋白质品质选择的指标，而全麦粉膨胀体积最好在育种高代进行选择。     

甬江口及附近海域冲淤变化研究分析

利用1935年、1962年、1979年、2004年这四个年份的海图资料,建立了甬江口及附近海域的数字高程模型（DEM）,进而定量计算了不同时段的海床平面冲淤变化、海岸演变和滩槽平面变化。结果表明,在1935-2004年间,甬江口及附近海域总体上以轻微淤积为主,年均淤积速率4.24 cm/a;岸线持续向海推进,潮滩呈淤涨态势,而深槽则趋于萎缩。但冲淤性质在不同时段有所不同,呈现出由冲转淤的调整趋势,这种趋势主要是人为因素作用的结果。     

垂向异重流式分离鳃在动水中的集成试验研究

通过集成垂向异重流式混合流体水沙分离鳃的动水沉降试验,分析了沉淀时间、进流速度与溢流浓度的关系,并对溢流液体进行了颗分试验。试验表明,通过控制进流速度,可以调节溢流浓度的大小。动水沉降试验在一定程度上可以达到泥沙在静水沉降时的效果,对加速水沙分离的效果明显。     

Experimental Investigation of Ultrafiltration Membrane With Different Pretreatment technology for Lake Water

In order to solve the problems that the exiting technologies do not adapt to the deterioration of the water quality in the water plant, the ultrafiltration was used to treat water respectively from ozone biological activated carbon pool (process 1), sand filtration pool (process 2) and sedimentation tank (process 3) in the region of river network of southern China.It is found that the average DOC removal rate were 33.08%, 23.60%, and 18.55%, and the average alga removal are 98.71%, 97.84%, and 98.13% in the process 1, process2 and process3, respectively.The turbidity of the effluent is lower than 0.1 NTU, and the particles with their size bigger than 2 μm were lower than 20 per milliliter in all the three process.The trans membrane pressure increased by 6.59% and the water production rate of the UF membrane was 98.02% during 45 days pilot experiment in the process 1.When 0.65mg/L chlorine was added before ultrafiltration membrane, the trans membrane pressure was recovered effectively after hydraulic flush.And the trans membrane pressure increased by 2.91% and the water production rate of the UF membrane was 97.63% during 10 days pilot experiment in the process 2.The trans membrane pressure increased by 13.52% and the water production rate of the UF membrane was 97.01% during 20 days pilot experiment in the process 3.     

Direct numerical simulation of sedimentation of rectangular particle with ALE method

The settling behaviors of rectangular particles with different initial orientation angles, aspect ratios and Reynolds numbers are simulated by using finite element arbitrary Lagrangian Eulerian domain method. The results show that the settling behaviors of the rectangular particle are affected significantly by the initial orientation angle under certain Reynolds number. With the increasing initial orientation angle, the fluctuation of the orientation angle, setting velocity,rotation velocity and lateral drifting velocity all increase. The impact of aspect ratio on the process of settlement has a strong relationship with the magnitudes of length and width. However, regardless of the magnitudes of length and width, when aspect ratio increased, final settling velocity decreases accordingly. Reynolds number of particle deposition process has a great impact on sedimentation process as well. If the Reynolds number is below a critical value, the particle eventually settles steadily. At larger Reynolds number,the oscillation of lateral motion and orientation angle become persistent. An inverted T structure forms due to the interaction between particles when many particles fall in the channel, and particles tend to horizontally positioned when the time span increases.     

单克隆抗体纯化的研究进展

单克隆抗体在现代生物检测领域和医疗领域起着越来越重要的作用。而不管是何种抗体,来源于哪种形式,在用于检测和治疗之前都需进行纯化,纯化的方法因抗体种类和用途不同而不同。大致可分为沉淀法和色谱法两大类,作者就各种不同方法的应用范围及纯化结果的纯度、活性回收率、纯化周期、每批可纯化样品量、纯化成本等方面进行了比较和讨论。     

中药复方总化学成分(浸膏)提取工艺研究

本研究旨在提高白花蛇舌草、金银花、黄芪、甘草组成的中药复方的临床疗效和抗病毒作用机理研究,为复方剂型改革和工业化生产提供科学依据。采用正交设计结合单因素考察,对复方水提和醇沉工艺进行优化:以水提后的浸膏重量为考察指标,选用L₉(3⁴)正交表设计试验,对浸泡时间、用水量、煎煮时间、煎煮次数4个因素进行优化;采用HPLC法测定复方浸膏中的甘草酸含量作为醇沉优化指标,选用L₉(3⁴)正交表设计试验,对乙醇浓度、乙醇用量、醇沉时间3个因素进行优化。结果得到复方水提最佳工艺:浸泡1 h、12倍加水量、煎煮4次、煎煮时间1.5 h;浸膏醇沉最佳工艺:80%乙醇浓度、4倍乙醇量、醇沉16 h。结合实际生产和成本因素,确定中药复方水提和醇沉工艺为:浸泡0.5 h、12倍加水量、煎煮3次、煎煮时间1 h,65%乙醇浓度、3倍乙醇量、醇沉16 h,水提浸膏收率为57.2%,醇沉浸膏甘草酸含量为0.42%,均接近正交方案中的最高值。     

Diphasic sedimentation technique complemented by a statistical approach as a useful tool to the quantification and the determination of dynamics of eggs produced by adult monogenean parasitizing groupers,Epinephelus marginatus (Lowe, 1834), in captivity

Monogenean parasites create problems in confined fish, such as at aquaculture and aquariums facilities. Strategic timing of antihelminthic treatments should be based on the dynamics of monogenean egg production which requires egg quantification, but there is no standardized analytical method. The WHO diphasic sedimentation method for helminth quantification of eggs was applied in samples with tetrahedral and fusiform monogenean eggs from six specimens of confined groupers (Epinephelus marginatus) (31 m³ sea water tank; water temperature 21.1–14.4°C; photoperiod 9:53–15 h light; November 2011 to June 2012). Helminth eggs remain in the pellet, while most organic matter was removed forming a cap. In contrast, monogenean eggs are distributed within both the pellet and cap. The diphasic sedimentation method is suitable to quantify tetrahedral and total egg number by counting those eggs in the pellet and incorporing water temperature data to obtain a statistically significant model expression (R² = 0.943; R² = 0.809), while this approach only weakly predicted fusiform egg numbers (R² = 0.297). Fusiform egg numbers declined along November–December, and increased in February–March, until June. Tetrahedral eggs decreased in November–December, but did not increase until March. The trend of egg populations and best time for antihelminthic treatment application can be set by WHO technique with the statistical approach proposed.