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111.
Phylogenetic relationships within the copepod family Euchaetidae and between representatives of three copepod orders (Calanoida,
Harpacticoida, and Poecilostomatoida) were investigated using partial nucleotide sequences of the mitochondrial 16S rRNA and
the nuclear 28S rRNA genes. DNA isolation, polymerase chain reaction, cloning, and DNA sequencing techniques were customized
for these crustaceans. Our results support the monophyly of each copepod order, but in contrast to traditional morphology-based
phylogenies of copepod orders, the Poecilostomatoida are basal to the Calanoida and Harpacticoida on our DNA-based phylogenetic
tree. Phylogenetic trees generated by maximum parsimony, neighbor-joining, and maximum-likelihood analyses support the classification
of the genera Euchaeta and Paraeuchaeta in the family Euchaetidae; results, however, suggest that Euchaetaacuta Giesbrecht is more closely related to species of the genus Paraeuchaeta than to those of Euchaeta, although limited taxon sampling may be partially responsible for this result. Phylogenetic mapping using the most parsimonious
16S tree suggests that the morphological synapomorphies distinguishing the genus Euchaeta evolved independently twice during the history of the Euchaetidae. Further, phylogenetic mapping suggests that the most recent
common ancestor of the Euchaetidae and the Aetideidae was a deep-living, vertically migrating copepod, and that a bathypelagic,
vertically migrating lifestyle characteristic of Paraeuchaeta is an ancestral trait of the family Euchaetidae which was lost apomorphically by Euchaeta. The application of a molecular clock suggests that the sibling species Euchaeta rimana Bradford and Euchaeta marina (Prestandrea) diverged due to the emergence of the Panamanian land bridge.
Received: 9 October 1997 / Accepted: 5 August 1998 相似文献
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113.
A. F. M. Kisters F. M. Meyer I. B. Seravkin S. E. Znamensky A. M. Kosarev R. G. W. Ertl 《Geologische Rundschau》1999,87(4):603-616
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117.
Gödeke S Richnow HH Weiss H Fischer A Vogt C Borsdorf H Schirmer M 《Journal of contaminant hydrology》2006,87(3-4):211-236
At the Centre for Environmental Research Leipzig-Halle (UFZ) research site in Zeitz, Germany, benzene contaminates the lower of two aquifers with concentrations of up to 20 mg/l. Since the benzene plume has a minimum length of approximately 1 km, enhanced natural attenuation measures are being considered as a remediation strategy. This study describes the performance and evaluation of a multi-species reactive tracer test using the tracers fluorescein and bromide as conservative tracers and toluene as reactive tracer. Sampling was performed over a period of six months using a detailed network of multilevel sampling wells. Toluene was only slightly retarded in comparison to bromide, whereas fluorescein was retarded considerably stronger. Therefore, it was not possible to use fluorescein as an in situ tracer for the determination of groundwater velocities. The ionic nature of fluorescein is assumed to be the major reason for its retardation. The results show that the infiltration conditions were suitable to produce a wide spreading of the tracer front along the full thickness of the aquifer. Thus, a large aquifer volume can be treated in future enhanced bioremediation measures. The total quantity of infiltrated toluene (24 l) was degraded under sulfate-reducing conditions over a flow path of 50 m. Benzylsuccinate was identified as a metabolite of toluene degradation under sulfate-reducing conditions at this site. The modelling results show that toluene degradation was described more accurately using Monod kinetics than first-order kinetics. Since toluene was only slightly retarded in comparison to bromide, sorption and desorption processes were considered to be negligible. 相似文献
118.
Soil erosion and nutrient losses are great concerns following forest wildfires. Biosolids application might enhance revegetation efforts while reducing soil erodibility. Consequently, we applied Denver Metro Wastewater District composted biosolids at rates of 0, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to increase plant cover and growth. Soils were classified as Ustorthents, Ustochrepts, and Haploborols. Simulated rainfall was applied for 30 min at a rate of 100 mm h(-1) to 3- x 10-m paired plots. Biosolids application rates did not significantly affect mean total runoff (p < 0.05). Sediment concentrations were significantly greater (p < 0.05) from the control plots compared with the plots that had received the 80 Mg biosolids ha(-1) rate. Biosolids application rate had mixed effects on water-quality constituents; however, concentrations of all runoff constituents for all treatment rates were below levels recommended for drinking water standards, except Pb. Biosolids application to this site increased plant cover, which should provide erosion control. 相似文献
119.
Petersdorff C Boermans T Harnisch J 《Environmental science and pollution research international》2006,13(5):350-358
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Goal Scope and Background. The European Directive on Energy Performance of Buildings which came into force 16 December 2002 will be implemented in the legislation of Member States by 4 January 2006. In addition to the aim of improving the overall energy efficiency of new buildings, large existing buildings will become a target for improvement, as soon as they undergo significant renovation. The building sector is responsible for about 40% of Europe's total end energy consumption and hence this Directive is an important step for the European Union in order that it should reach the level of saving required by the Kyoto Agreement. In this the EU is committed to reduce CO2 emissions relative to the base year of 1990 by 8 per cent, by 2010. But what will be the impact of the new Directive, how large could be the impacts of extending the obligation for energy efficiency retrofitting towards smaller buildings? Can improvement of the insulation offset or reduce the growing energy consumption from the increasing installation of cooling installations? EURIMA, the European Insulation Manufacturers Association and EuroACE, the European Alliance of Companies for Energy Efficiency in Buildings, asked Ecofys to address these questions.Methods
The effect of the EPB Directive on the emissions associated with the heating energy consumption of the total EU 15 building stock has been examined in a model calculation, using the Built Environment Analysis Model (BEAM), which was developed by Ecofys to investigate energy saving measures in the building stock. The great complexity of the EU-15 building stock had to be simplified by examining five standard buildings with eight insulation standards, which are assigned to building age and renovation status. Furthermore, three climatic regions (cold, moderate, warm) were distinguished for the calculation of the heating energy demand. This gave a basic 210 building types for which the heating energy demand and CO2 emissions from heating were calculated according to the principles of the European Norm EN 832.Results and Discussion
The model calculations demonstrates that the main contributor to the total heating related CO2 emissions of 725 Mt/a from the EU building stock in 2002 is the residential sector (77%) while the remaining 23% originates from non-residential buildings. In the residential sector, single-family houses represent the largest group responsible for 60% of the total CO2 emissions equivalent to 435 Mt/a.-
- The technical potential: If all retrofit measures in the scope of the Directive were realised immediately for the complete residential and non-residential building stock the overall CO2 emission savings would add up to 82 Mt/a. An additional saving potential compared to the Directive of 69 Mt/a would be created if the scope of the Directive was extended to cover retrofit measures in multi-family dwellings (200-1000m2) and non-residential buildings smaller than 1000m2 used floor space. In addition including the large group of single-family dwellings would lead to a potential for additional CO2 emission reductions compared to the Directive of 316 Mt/a.-
- Temporal mobilization of the potential: Calculations based on the building stock as it develops over time with average retrofit rates demonstrated that regulations introduced following the EPB Directive result in a CO2 emissions decrease of 34 Mt/a by the year 2010 compared to the business as usual scenario. Extending the scope of the EPB Directive to all residential buildings (including single and multi-family dwellings), the CO2 emission savings potential over the 'business as usual' scenario could be doubled to 69 Mt/a in the year 2010. This creates an additional saving potential compared to the Directive of 36 Mt/a.-
- Cooling demand: The analysis demonstrated that in warm climatic zones the cooling demand can be reduced drastically by a combination of lowering the internal heat loads and by improved insulation. With the reduction of the heat loads to a moderate level the cooling demand, e.g. of a terraced house located in Madrid, can be reduced by an additional 85% if the insulation level is improved appropriately.Conclusions
This study demonstrates that the European Directive on Energy Performance of Buildings will have a significant impact on the CO2 emissions of the European building stock. The main saving potential lies in insulation of the existing building stock. Beyond this, CO2 emissions could, however, be greatly reduced if the scope of the Directive were to be extended to include retrofit of smaller buildings.Recommendation and Perspective
The reductions should be seen in relation to the remaining gap of 190 Mt CO2 eq. per annum between the current emission levels of EU-15 and the target under the Kyoto-Protocol for the year 2010. The energy and industrial sector will probably contribute only a fraction of this reduction via the newly established EU emissions trading scheme and connected projects under the flexible mechanism. In addition, the traffic sector is likely to continue its growth path leading to a widening of the gap. Thus, there is likely to be considerable pressure on the EU building sector to contribute to the EU climate targets beyond what will be achieved by means of the current EPB Directive. Legislators on the EU and national level are therefore advised to take accelerated actions to tap the very significant emission reduction potentials available in the EU building stock. 相似文献120.
Meyer VF Redente EF Barbarick KA Brobst RB Paschke MW Miller AL 《Journal of environmental quality》2004,33(3):873-881
Soil stability and revegetation is a great concern following forest wildfires. Biosolids application might enhance revegetation efforts and enhance soil stability. In May 1997, we applied Metro Wastewater Reclamation District (Denver, CO, USA) composted biosolids at rates of 0, 5, 10, 20, 40, and 80 Mg ha(-1) to a severely burned, previously forested site near Buffalo Creek, CO to improve soil C and N levels and help establish eight native, seeded grasses. The soils on the site belong to the Sphinx series (sandy-skeletal, mixed, frigid, shallow Typic Ustorthents). Vegetation and soils data were collected for four years following treatment. During the four years following treatment, total plant biomass ranged from approximately 50 to 230 g m(-2) and generally increased with increasing biosolids application. The percentage of bare ground ranged from 4 to 58% and generally decreased with increasing biosolids rate. Higher rates of biosolids application were associated with increased concentrations of N, P, and Zn in tissue of the dominant plant species, streambank wheatgrass [Elymus lanceolatus (Scribn. & J.G. Sm) Gould subsp. lanceolatus], relative to the unamended, unfertilized control. At two months following biosolids application (1997), total soil C and N at soil depths of 0 to 7.5, 7.5 to 15, and 15 to 30 cm showed significant (P < 0.05) linear increases (r2 > 0.88) as biosolids rate increased. The surface soil layer also showed this effect one year after application (1998). For Years 2 through 4 (1999-2001) following treatment, soil C and N levels declined but did not show consistent trends. The increase in productivity and cover resulting from the use of biosolids can aid in the rehabilitation of wildfire sites and reduce soil erosion in ecosystems similar to the Buffalo Creek area. 相似文献