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1.
An integrated model describing hydrology, hydrodynamics, salt dynamics and vegetation was developed to predict the evolution of the Ciénega de Santa Clara, a non-tidal, anthropogenic wetland located in the Colorado River Delta. The Ciénega, an important part of the Delta ecosystem, is supported by saline groundwater from the U.S. that is sent to Mexico to control salinity in the U.S. The future of this water source is uncertain, and thus, the model was developed to predict how the Ciénega would respond to changes in the quantity and salinity of its inflow. Over the calibration period, 1993–2007, modeled results of wetland surface area, the fraction of the wetland covered in vegetation and salinity concentrations compare well to actual data. The model shows that between 1993 and 2007 evapotranspiration rates range from 0 to 8 mm/day, wetland surface area increases 44% from 4500 to 6500 ha, the fraction of the wetland covered in vegetation decreases slightly from 0.92 to 0.88, and the mean salinity concentration in the wetland increases from 3100 to 6700 ppm. The model was used to run nine hypothetical scenarios, representing the range of inflow quantity and salinity to the Ciénega that could occur if the source of the inflow is altered, including the possible re-opening of the Yuma Desalting plant. Model results show that the Ciénega ecosystem is more sensitive to changes in salinity than to changes in flow. However, in almost all cases, an increase in salinity and/or a decrease in flow would cause a significant decrease in vegetation cover, compromising a large portion of the habitat currently available to wildlife at the Ciénega.  相似文献   

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This research aimed to investigate the applicability of an integrated constructed wetland system for P removal from low-strength wastewaters. The integrated system consisted of a constructed wetland and a post-filter unit, in series; both units were packed with oyster shells (OS) as adsorption and filtration media. Based on 1 year of operation under the overall hydraulic retention time of 3.5 days, the integrated system was found to be highly effective in removing BOD5 (92.3%), N (85.7%), P (98.3%) and total suspended solids (TSS) (94.4%) compounds, in which the constructed wetland unit was responsible for most of the treatment performance, while the post-filter unit served as a polishing unit, especially in the removal of the remaining N, P and TSS. To simulate heavy rainfall conditions, the integrated system was tested under hydraulic shock loading at the overall hydraulic retention time of 0.7 day for 14 days that represented the extreme period of high drainage flows. There were some increases of P concentrations in the post-filter effluent during the 14 days of operation up to about 5 mg/l, but these P concentrations were later decreased to about 1 mg/L after the shock loading period. These experimental results suggested the applicability of the integrated constructed wetland system which used oyster shells as adsorption and filtration media for P removal which should help to minimize eutrophication problems in receiving waters.  相似文献   

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Conventional Orthognathic surgery (OGS) planning involves cephalometric analyses and dental casts to be mounted on an articulator. Dental segments are subsequently identified, cut and repositioned to allow the fabrication of intraoral wafers that guide the positioning of the osteotomy bone segments. This conventional planning introduces many inaccuracies that affect the post-surgery outcomes. Although computer technologies have advanced computational tools for OGS planning, they have failed in providing a practical solution. Many focuses only on some specific stages of the planning process, and their ability to transfer preoperative planning data to the operating room is limited. This paper proposes a new integrated haptic-enabled virtual reality (VR) system for OGS planning. The system incorporates CAD tools and haptics to facilitate a complete planning process and is able to automatically generate preoperative plans. A clinical pre-diagnosis is also provided automatically by the system based on the patient’s digital data. A functional evaluation based on a real patient case study demonstrates that the proposed virtual OGS planning method is feasible and more effective than the traditional approach at increasing the intuitiveness and reducing errors and planning times.  相似文献   

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This paper presents an operations planning scheme based on mathematical programming models (specifically, Mixed-Integer Linear Programming (MILP) models) integrated into a web-enabled Advanced Planning and Scheduling System (APS), developed for and implemented in an engine assembler that supplies the car industry. One objective of this paper is to provide empirical insights into some operations planning characteristics in the automotive industry. The other main objective is to show MILP models and their use to create plans that enable the coordination of different planning levels (mid-term and short-term) and planning domains (procurement, production and distribution). The APS fulfills the requirements of an engine assembler in the automotive sector (namely lean-type constraints and objectives). The system is based on two MILP models, which have been purposely developed together along with their relations. The models presented herein provide a solution that considers supply chain objectives and constraints, and are integrated by means of data and constraints which have proven sufficient to fulfill users?? and stakeholders?? requirements. This case study presents the models?? most relevant aspects and their implementation.  相似文献   

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We present a synoptic assessment intended to maximize the benefits to wetland species biodiversity gained through Clean Water Act regulatory efforts within 225 sub-basins in Missouri, Iowa, Nebraska and Kansas (US Environmental Protection Agency, Region 7), USA. Our assessment provides a method for prioritizing sub-basins potentially critical for supporting wetland species biodiversity and may assist environmental managers and conservationists constrained by limited resources. We prioritize sub-basins based on the projected increase in the risk of wetland species extirpation across Region 7 that would be avoided by applying a unit of regulatory protection effort within a sub-basin. Because the projected increase in risk avoided per unit effort has not been directly measured, we represent this quantity with an index of indicators drawn from readily available data. A conceptual model incorporating landscape and anthropogenic factors guides index development via a series of simple benefit-cost equations. We rank and map the final index scores to show the relative priority among sub-basins for protection effort. High priority sub-basins appear to be concentrated along the major river systems within the region, where sensitive wetland species and intensive agriculture tend to coincide. Protection of wetland species biodiversity is an important, but not exclusive, attribute around which priorities should be set. Nevertheless, incorporation of our results into management strategies should allow managers to cast their local decisions in the context of regional scale maintenance of wetland species biodiversity, increasing ecological benefits for a given protection effort.  相似文献   

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Coastal wetlands are considered to be amongst the most productive ecosystems and can provide invaluable ecological services. However, coastal wetlands are listed amongst the most threatened ecosystems suffering from anthropogenic activities. The loss or degradation of coastal wetlands has drawn a high level of attention to wetland restoration. Improvement of the structure and function of degraded, damaged and destroyed wetlands may be achieved through ecological restoration. Large numbers of restoration projects have been conducted worldwide based on different restoration goals and different methods. It is undoubtedly important to evaluate whether coastal wetland restoration is successful. However, coastal wetland restoration assessment has become challenging because of current disagreement on definitions and concepts of restoration evaluation. We reviewed the methodology of coastal wetland restoration and criteria for success evaluation, and then summarized the issues for current wetland restoration and success evaluation based on literature review. Moreover, we used an estuarine wetland affected by urbanization as a sample to demonstrate how to establish a success indicator system for guiding wetland restoration and evaluating the success of wetland restoration.  相似文献   

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Over the last three decades, Cryo-TEM has developed into a powerful technique for high-resolution imaging of biological macromolecules in their native vitrified state. However, the method for vitrifying specimens onto EM grids is essentially unchanged - application of ~3 μL sample to a grid, followed by blotting and rapid plunge freezing into liquid ethane. Several trials are often required to obtain suitable thin (few hundred nanometers or less) vitrified layers amenable for cryo-TEM imaging, which results in waste of precious sample and resources. While commercially available instruments provide some level of automation to control the vitrification process in an effort to increase quality and reproducibility, obtaining satisfactory vitrified specimens remains a bottleneck in the Cryo-TEM pipeline. We describe here a completely novel method for EM specimen preparation based on small volume (picoliter to nanoliter) dispensing using inkjet technology. A first prototype system (Spotiton v0.5) demonstrates feasibility of this new approach for specimen vitrification. A piezo-electric inkjet dispenser is integrated with optical real-time cameras (100 Hz frame rate) to analyze picoliter to nanoliter droplet profiles in-flight and spreading dynamics on the grid, and thus provides a method to optimize timing of the process. Using TEM imaging and biochemical assays we demonstrate that the piezo-electric inkjet mechanism does not disrupt the structural or functional integrity of macromolecules. These preliminary studies provide insight into the factors and components that will need further development to enable a robust and repeatable technique for specimen vitrification using this novel approach.  相似文献   

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Pathways database system: an integrated system for biological pathways   总被引:1,自引:0,他引:1  
MOTIVATION: During the next phase of the Human Genome Project, research will focus on functional studies of attributing functions to genes, their regulatory elements, and other DNA sequences. To facilitate the use of genomic information in such studies, a new modeling perspective is needed to examine and study genome sequences in the context of many kinds of biological information. Pathways are the logical format for modeling and presenting such information in a manner that is familiar to biological researchers. RESULTS: In this paper we present an integrated system, called Pathways Database System, with a set of software tools for modeling, storing, analyzing, visualizing, and querying biological pathways data at different levels of genetic, molecular, biochemical and organismal detail. The novel features of the system include: (a) genomic information integrated with other biological data and presented from a pathway, rather than from the DNA sequence, perspective; (b) design for biologists who are possibly unfamiliar with genomics, but whose research is essential for annotating gene and genome sequences with biological functions; (c) database design, implementation and graphical tools which enable users to visualize pathways data in multiple abstraction levels, and to pose predetermined queries; and (d) an implementation that allows for web(XML)-based dissemination of query outputs (i.e. pathways data) to researchers in the community, giving them control on the use of pathways data. AVAILABILITY: Available on request from the authors.  相似文献   

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This study reports on the response of a tidal, freshwater forested wetland ecosystem to long-term input of secondarily treated municipal effluent from the City of Mandeville, LA. Measurements of hydrology, nutrients, and aboveground net primary productivity were made from September 1998 through March 2002. Accretion measurements were made in October 2000 and October 2004. The major hydrologic inputs to the system were the effluent, precipitation, and back water flooding from Lake Pontchartrain. Nutrient levels were generally low except in the immediate vicinity of the outfall. Mean net primary production of the freshwater forest system was significantly higher downstream of the effluent discharge (1202 g m−2 yr−1) compared to the control site (799 g m−2 yr−1). Downstream of the outfall, accretion rates were double the rate of relative sea level rise in the area. Removal efficiencies of N and P were as high as 75% and 95%, respectively. The relatively constant flow of secondarily treated municipal effluent buffered the downstream area from salinity intrusion during a region-wide drought. Re-direction of nutrient-enhanced effluents from open water bodies to wetland ecosystems can maintain plant productivity, sequester carbon, and maintain coastal wetland elevations in response to sea-level rise in addition to improving overall surface water quality, reducing energy use, and increasing financial savings.  相似文献   

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A self-organizing map (SOM) model was applied as a prediction tool for the performance of an integrated constructed wetland (ICW) agroecosystem treating agricultural runoff to protect receiving watercourses. By utilizing the SOM model, the time-consuming to measure expensive biochemical oxygen demand outflow concentrations were predicted well by other inexpensive variables, which were quicker and easier to measure. Correct predictions for the outflow biochemical oxygen demand concentrations were between 89% and 100%. This novel approach allows for the real time control of the outflow water quality of the ICW and potentially also of other treatment system applications. Moreover, the missing values and outliers from the large but incomplete ICW data set were replaced accurately by most likely values determined by the SOM model. This was important because the proportions of unusable entries for chemical oxygen demand, suspended solids and biochemical oxygen demand were very high: 41%, 54%, and 61%, respectively.  相似文献   

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MPSS: an integrated database system for surveying a set of proteins   总被引:3,自引:0,他引:3  
SUMMARY: We design and implement an integrated database system called 'multi-protein survey system' (MPSS), which provides a platform to retrieve information about many proteins at a time. This system integrates several important and widely used databases including SwissProt, TrEMBL, PDB and InterPro, plus useful references such as GO and KEGG to other databases. Users may submit a group of protein IDs, entry names, SwissProt/TrEMBL accession numbers or GenBank GIs through MPSS' web interface, and obtain protein annotation information from public databases and pre-computed molecular properties speedily. MPSS can also supply comprehensive information about query proteins, including 3D structures, domains, pathway, gene ontology and visual presentation of mapping to the GO tree and KEGG pathway, to provide an up-to-date view of available knowledge with regard to the structures and molecular functions of proteins under study. AVAILABILITY: MPSS is freely accessible at http://www.scbit.org/mpss/  相似文献   

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A micro analysis system for the electrochemical determination of the activity of protease along with pH sensing was fabricated aiming for its use in telemetric micro analysis systems targeting the testing of the stomach and intestines. The system consisted of a pH-sensing site and two protease assay sites formed in polydimethylsiloxane (PDMS) micro flow channels. To introduce sample solutions, valves were formed with gold electrodes in the inlets, which functioned on the basis of electrowetting. An external sample solution could be introduced into the sensing sites by switching on the valves at appropriate times. In the pH-sensing site, a pH-indicator electrode changed its electrode potential immediately after a sample solution reached an internal liquid-junction reference electrode. The slope of the calibration plot was -74.5 mVpH(-1). Bovine serum albumin (BSA) was used as the substrate for the enzyme and was spotted on the wall of the flow channel that faced the pH-indicator electrode of the protease assay sites. The release of protons accompanying the hydrolysis of BSA by the enzyme was detected using the pH-indicator electrode. When trypsin was contained in the sample solution as a test enzyme, a distinct decrease in pH, which was dependent on the trypsin activity, was observed, indicating that enzymatic hydrolysis was proceeding. The initial rate of potential change varied in proportion to the activity in a range between 1.0 and 51.7 Uml(-1). The integration of the microfluidic and sensing functions provides significant advantages for the use of this system as an isolated telemetric micro system that might operate with small batteries.  相似文献   

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The success of an ecosystems approach to river basin management depends greatly on the integration ofa wide range of information concerning the various components of the ecosystem, the formulation of realisticsolutions to complex problems, and finally, the support of all interested parties throughout the implementation phase:integrated State-of-Environment Reporting (SOER) can be an effective tool for meeting these challenges. Theecosystems approach is critical to the St. Lawrence Action Plan, a Canadian program which focuses on the protectionand conservation of the St. Lawrence River. The St. Lawrence Centre of Environment Canada not only acts asa catalyst in developing environmental partnerships among segments of the population, but synthesizes the resultsof these collective efforts. Its detailed evaluations on the state of the river environment perhaps best illustrate thenature of this task, because these reports must meet the particular environmental informational needs of many targetaudiences, which range from the general public to corporate decision-makers. SOER's practical nature facilitatesthe collection of data and the establishment of analysis targets and SOE indicators used in environmental monitoring.The integrated SOER framework developed at the St. Lawrence Centre represents a major challenge in the collection,integration, dissemination and use of environmental information. This framework is based in three majorobjectives: (1) information and education; (2) trend analysis and prediction; and (3) influence. Integrated SOER canbe a powerful tool: decision-makers will find it useful for designing action plans, while the general public can useit for assessing the state of the environment and the success of water management plans. Lastly, integrated SOERis also central to increasing public participation in the management of the environment, a factor essential to thesuccessful application of the ecosystems approach to water management.  相似文献   

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