Model-based morphological segmentation and labeling of coronary angiograms.

PubMed

Haris, K; Efstratiadis, S N; Maglaveras, N; Pappas, C; Gourassas, J; Louridas, G

1999-10-01

A method for extraction and labeling of the coronary arterial tree (CAT) using minimal user supervision in single-view angiograms is proposed. The CAT structural description (skeleton and borders) is produced, along with quantitative information for the artery dimensions and assignment of coded labels, based on a given coronary artery model represented by a graph. The stages of the method are: 1) CAT tracking and detection; 2) artery skeleton and border estimation; 3) feature graph creation; and iv) artery labeling by graph matching. The approximate CAT centerline and borders are extracted by recursive tracking based on circular template analysis. The accurate skeleton and borders of each CAT segment are computed, based on morphological homotopy modification and watershed transform. The approximate centerline and borders are used for constructing the artery segment enclosing area (ASEA), where the defined skeleton and border curves are considered as markers. Using the marked ASEA, an artery gradient image is constructed where all the ASEA pixels (except the skeleton ones) are assigned the gradient magnitude of the original image. The artery gradient image markers are imposed as its unique regional minima by the homotopy modification method, the watershed transform is used for extracting the artery segment borders, and the feature graph is updated. Finally, given the created feature graph and the known model graph, a graph matching algorithm assigns the appropriate labels to the extracted CAT using weighted maximal cliques on the association graph corresponding to the two given graphs. Experimental results using clinical digitized coronary angiograms are presented.

Utility of Microbial Source-Tracking Markers for Assessing Fecal Contamination in the Portage River Watershed, Northwestern Ohio, 2008

USGS Publications Warehouse

Kephart, Christopher M.; Bushon, Rebecca N.

2010-01-01

An influx of concentrated animal feeding operations in northwest Ohio has prompted local agencies to examine the effects of these industrial farms on water quality in the upper Portage River watershed. The utility of microbial source-tracking (MST) tools as a means of characterizing sources of fecal contamination in the watershed was evaluated. From 2007 to 2008, scientists with the U.S. Geological Survey, Bowling Green State University, and the Wood County Health Department collected and analyzed 17 environmental samples and 13 fecal source samples for Bacteroides-based host-associated DNA markers. At many of the environmental sites tested, MST marker results corroborated the presumptive fecal contamination sources. Results from this demonstration study support the utility of using MST with host-specific molecular markers to characterize the sources of fecal contamination in the Portage River watershed.

Autonomous watersheds: Reducing flooding and stream erosion through real-time control

NASA Astrophysics Data System (ADS)

Kerkez, B.; Wong, B. P.

2017-12-01

We introduce an analytical toolchain, based on dynamical system theory and feedback control, to determine how many control points (valves, gates, pumps, etc.) are needed to transform urban watersheds from static to adaptive. Advances and distributed sensing and control stand to fundamentally change how we manage urban watersheds. In lieu of new and costly infrastructure, the real-time control of stormwater systems will reduce flooding, mitigate stream erosion, and improve the treatment of polluted runoff. We discuss the how open source technologies, in the form of wireless sensor nodes and remotely-controllable valves (open-storm.org), have been deployed to build "smart" stormwater systems in the Midwestern US. Unlike "static" infrastructure, which cannot readily adapt to changing inputs and land uses, these distributed control assets allow entire watersheds to be reconfigured on a storm-by-storm basis. Our results show how the control of even just a few valves within urban catchments (1-10km^2) allows for the real-time "shaping" of hydrographs, which reduces downstream erosion and flooding. We also introduce an equivalence framework that can be used by decision-makers to objectively compare investments into "smart" system to more traditional solutions, such as gray and green stormwater infrastructure.

A marker-based watershed method for X-ray image segmentation.

PubMed

Zhang, Xiaodong; Jia, Fucang; Luo, Suhuai; Liu, Guiying; Hu, Qingmao

2014-03-01

Digital X-ray images are the most frequent modality for both screening and diagnosis in hospitals. To facilitate subsequent analysis such as quantification and computer aided diagnosis (CAD), it is desirable to exclude image background. A marker-based watershed segmentation method was proposed to segment background of X-ray images. The method consisted of six modules: image preprocessing, gradient computation, marker extraction, watershed segmentation from markers, region merging and background extraction. One hundred clinical direct radiograph X-ray images were used to validate the method. Manual thresholding and multiscale gradient based watershed method were implemented for comparison. The proposed method yielded a dice coefficient of 0.964±0.069, which was better than that of the manual thresholding (0.937±0.119) and that of multiscale gradient based watershed method (0.942±0.098). Special means were adopted to decrease the computational cost, including getting rid of few pixels with highest grayscale via percentile, calculation of gradient magnitude through simple operations, decreasing the number of markers by appropriate thresholding, and merging regions based on simple grayscale statistics. As a result, the processing time was at most 6s even for a 3072×3072 image on a Pentium 4 PC with 2.4GHz CPU (4 cores) and 2G RAM, which was more than one time faster than that of the multiscale gradient based watershed method. The proposed method could be a potential tool for diagnosis and quantification of X-ray images. Copyright © 2014 Elsevier Ireland Ltd. All rights reserved.

Effects of floodgates operation on nitrogen transformation in a lake based on structural equation modeling analysis.

PubMed

Zhu, Longji; Zhou, Haixuan; Xie, Xinyu; Li, Xueke; Zhang, Duoying; Jia, Liming; Wei, Qingbin; Zhao, Yue; Wei, Zimin; Ma, Yingying

2018-08-01

Floodgates operation is one of the primary means of flood control in lake development. However, knowledge on the linkages between floodgates operation and nitrogen transformation during the flood season is limited. In this study, water samples from six sampling sites along Lake Xingkai watershed were collected before and after floodgates operation. The causal relationships between environmental factors, bacterioplankton community composition and nitrogen fractions were determined during flood season. We found that concentrations of nitrogen fractions decreased significantly when the floodgates were opened, while the concentrations of total nitrogen (TN) and NO 3 - increased when the floodgates had been shut for a period. Further, we proposed a possible mechanism that the influence of floodgates operation on nitrogen transformation was largely mediated through changes in dissolved organic matter, dissolved oxygen and bacterioplankton community composition as revealed by structural equation modeling (SEM). We conclude that floodgates operation has a high risk for future eutrophication of downstream watershed, although it can reduce nitrogen content temporarily. Therefore, the environmental impacts of floodgates operation should be carefully evaluated before the floodwaters were discharged into downstream watershed. Copyright © 2018. Published by Elsevier B.V.

Spatial and Temporal Scales of Surface Water-Groundwater Interactions

NASA Astrophysics Data System (ADS)

Boano, F.

2016-12-01

The interfaces between surface water and groundwater (i.e., river and lake sediments) represent hotspots for nutrient transformation in watersheds. This intense biochemical activity stems from the peculiar physicochemical properties of these interface areas. Here, the exchange of water and nutrients between surface and subsurface environments creates an ecotone region that can support the presence of different microbial species responsible for nutrient transformation. Previous studies have elucidated that water exchange between rivers and aquifers is organized in a complex system of nested flow cells. Each cell entails a range of residence timescales spanning multiple order of magnitudes, providing opportunities for different biochemical reactions to occur. Physically-bases models represent useful tools to deal with the wide range of spatial and temporal scales that characterize surface-subsurface water exchange. This contribution will present insights about how hydrodynamic processes control scale organization for surface water - groundwater interactions. The specific focus will be the influence of exchange processes on microbial activity and nutrient transformation, discussing how groundwater flow at watershed scale controls flow conditions and hence constrain microbial reactions at much smaller scales.

Automatic segmentation and classification of mycobacterium tuberculosis with conventional light microscopy

NASA Astrophysics Data System (ADS)

Xu, Chao; Zhou, Dongxiang; Zhai, Yongping; Liu, Yunhui

2015-12-01

This paper realizes the automatic segmentation and classification of Mycobacterium tuberculosis with conventional light microscopy. First, the candidate bacillus objects are segmented by the marker-based watershed transform. The markers are obtained by an adaptive threshold segmentation based on the adaptive scale Gaussian filter. The scale of the Gaussian filter is determined according to the color model of the bacillus objects. Then the candidate objects are extracted integrally after region merging and contaminations elimination. Second, the shape features of the bacillus objects are characterized by the Hu moments, compactness, eccentricity, and roughness, which are used to classify the single, touching and non-bacillus objects. We evaluated the logistic regression, random forest, and intersection kernel support vector machines classifiers in classifying the bacillus objects respectively. Experimental results demonstrate that the proposed method yields to high robustness and accuracy. The logistic regression classifier performs best with an accuracy of 91.68%.

Adaptive striping watershed segmentation method for processing microscopic images of overlapping irregular-shaped and multicentre particles.

PubMed

Xiao, X; Bai, B; Xu, N; Wu, K

2015-04-01

Oversegmentation is a major drawback of the morphological watershed algorithm. Here, we study and reveal that the oversegmentation is not only because of the irregular shapes of the particle images, which people are familiar with, but also because of some particles, such as ellipses, with more than one centre. A new parameter, the striping level, is introduced and the criterion for striping parameter is built to help find the right markers prior to segmentation. An adaptive striping watershed algorithm is established by applying a procedure, called the marker searching algorithm, to find the markers, which can effectively suppress the oversegmentation. The effectiveness of the proposed method is validated by analysing some typical particle images including the images of gold nanorod ensembles. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

Presumptive Sources of Fecal Contamination in Four Tributaries to the New River Gorge National River, West Virginia, 2004

USGS Publications Warehouse

Mathes, Melvin V.; O'Brien, Tara L.; Strickler, Kriston M.; Hardy, Joshua J.; Schill, William B.; Lukasik, Jerzy; Scott, Troy M.; Bailey, David E.; Fenger, Terry L.

2007-01-01

Several methods were used to determine the sources of fecal contamination in water samples collected during September and October 2004 from four tributaries to the New River Gorge National River -- Arbuckle Creek, Dunloup Creek, Keeney Creek, and Wolf Creek. All four tributaries historically have had elevated levels of fecal coliform bacteria. The source-tracking methods used yielded various results, possibly because one or more methods failed. Sourcing methods used in this study included the detection of several human-specific and animal-specific biological or molecular markers, and library-dependent pulsed-field gel electrophoresis analysis that attempted to associate Escherichia coli bacteria obtained from water samples with animal sources by matching DNA-fragment banding patterns. Evaluation of the results of quality-control analysis indicated that pulsed-field gel electrophoresis analysis was unable to identify known-source bacteria isolates. Increasing the size of the known-source library did not improve the results for quality-control samples. A number of emerging methods, using markers in Enterococcus, human urine, Bacteroidetes, and host mitochondrial DNA, demonstrated some potential in associating fecal contamination with human or animal sources in a limited analysis of quality-control samples. All four of the human-specific markers were detected in water samples from Keeney Creek, a watershed with no centralized municipal wastewater-treatment facilities, thus indicating human sources of fecal contamination. The human-specific Bacteroidetes and host mitochondrial DNA markers were detected in water samples from Dunloup Creek, Wolf Creek, and to a lesser degree Arbuckle Creek. Results of analysis for wastewater compounds indicate that the September 27 sample from Arbuckle Creek contained numerous human tracer compounds likely from sewage. Dog, horse, chicken, and pig host mitochondrial DNA were detected in some of the water samples with the exception of the October 5 sample from Dunloup Creek. Cow, white-tailed deer, and Canada goose DNA were not detected in any of the samples collected from the four tributaries, despite the presence of these animals in the watersheds. Future studies with more rigorous quality-control analyses are needed to investigate the potential applicability and use of these emerging methods. Because many of the detections for the various methods could vary over time and with flow conditions, repeated sampling during both base flow and storm events would be necessary to more definitively determine the sources of fecal contamination for each watershed.

Comparison of parameter-adapted segmentation methods for fluorescence micrographs.

PubMed

Held, Christian; Palmisano, Ralf; Häberle, Lothar; Hensel, Michael; Wittenberg, Thomas

2011-11-01

Interpreting images from fluorescence microscopy is often a time-consuming task with poor reproducibility. Various image processing routines that can help investigators evaluate the images are therefore useful. The critical aspect for a reliable automatic image analysis system is a robust segmentation algorithm that can perform accurate segmentation for different cell types. In this study, several image segmentation methods were therefore compared and evaluated in order to identify the most appropriate segmentation schemes that are usable with little new parameterization and robustly with different types of fluorescence-stained cells for various biological and biomedical tasks. The study investigated, compared, and enhanced four different methods for segmentation of cultured epithelial cells. The maximum-intensity linking (MIL) method, an improved MIL, a watershed method, and an improved watershed method based on morphological reconstruction were used. Three manually annotated datasets consisting of 261, 817, and 1,333 HeLa or L929 cells were used to compare the different algorithms. The comparisons and evaluations showed that the segmentation performance of methods based on the watershed transform was significantly superior to the performance of the MIL method. The results also indicate that using morphological opening by reconstruction can improve the segmentation of cells stained with a marker that exhibits the dotted surface of cells. Copyright © 2011 International Society for Advancement of Cytometry.

Method to transform algae, materials therefor, and products produced thereby

DOEpatents

Dunahay, T.G.; Roessler, P.G.; Jarvis, E.E.

1997-08-26

Disclosed is a method to transform chlorophyll C-containing algae. The method includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further, specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae. 2 figs.

Method to transform algae, materials therefor, and products produced thereby

DOEpatents

Dunahay, Terri Goodman; Roessler, Paul G.; Jarvis, Eric E.

1997-01-01

Disclosed is a method to transform chlorophyll C-containing algae which includes introducing a recombinant molecule comprising a nucleic acid molecule encoding a dominant selectable marker operatively linked to an algal regulatory control sequence into a chlorophyll C-containing alga in such a manner that the marker is produced by the alga. In a preferred embodiment the algal regulatory control sequence is derived from a diatom and preferably Cyclotella cryptica. Also disclosed is a chimeric molecule having one or more regulatory control sequences derived from one or more chlorophyll C-containing algae operatively linked to a nucleic acid molecule encoding a selectable marker, an RNA molecule and/or a protein, wherein the nucleic acid molecule does not normally occur with one or more of the regulatory control sequences. Further specifically disclosed are molecules pACCNPT10, pACCNPT4.8 and pACCNPT5.1. The methods and materials of the present invention provide the ability to accomplish stable genetic transformation of chlorophyll C-containing algae.

Dual nitrate isotopes clarify the role of biological processing and hydrologic flow paths on nitrogen cycling in subtropical low-gradient watersheds

DOE PAGES

Griffiths, Natalie A.; Jackson, C. Rhett; McDonnell, Jeffrey J.; ...

2016-02-08

Nitrogen (N) is an important nutrient as it often limits productivity but in excess can impair water quality. Most studies on watershed N cycling have occurred in upland forested catchments where snowmelt dominates N export; fewer studies have focused on low-relief watersheds that lack snow. We examined watershed N cycling in three adjacent, low-relief watersheds in the Upper Coastal Plain of the southeastern United States to better understand the role of hydrological flow paths and biological transformations of N at the watershed scale. Groundwater was the dominant source of nitrified N to stream water in two of the three watersheds,more » while atmospheric deposition comprised 28% of stream water nitrate in one watershed. The greater atmospheric contribution may have been due to the larger stream channel area relative to total watershed area or the dominance of shallow subsurface flow paths contributing to stream flow in this watershed. There was a positive relationship between temperature and stream water ammonium concentrations and a negative relationship between temperature and stream water nitrate concentrations in each watershed suggesting that N cycling processes (i.e., nitrification and denitrification) varied seasonally. However, there were no clear patterns in the importance of denitrification in different water pools possibly because a variety of factors (i.e., assimilatory uptake, dissimilatory uptake, and mixing) affected nitrate concentrations. In conclusion, together, these results highlight the hydrological and biological controls on N cycling in low-gradient watersheds and variability in N delivery flow paths among adjacent watersheds with similar physical characteristics.« less

INFLUENCES OF HYDROLOGY ON NUTRIENT DYNAMICS IN LAKE SUPERIOR COASTAL WETLANDS

EPA Science Inventory

Little is known about the role of the coastal wetlands (CWs) of Lake Superior in modifying or contributing to nutrient fluxes from watersheds to the lake. We are studying factors controlling nutrient retention and transformation of CWs in Western Lake Superior. CWs may be unique ...

Weeds of Hawaii’s lands devoted to watershed protection and biodiversity conservation: Role of biological control as the missing piece in an integrated pest management strategy

USGS Publications Warehouse

Medeiros, Arthur C.; Loope, L.L.

2011-01-01

Despite Hawaii’s reputation as an extinction icon, significant biological resources remain, especially in watersheds, natural areas, and specialized edaphic sites (e.g., lava dry forest, coastal). While direct habitat destruction by humans continues, human-facilitated biological invaders are currently the primary agents of continuing degradation. The ability of invasive plants to have prolific seed production, efficient dispersal systems, and to become established in dense vegetation, complicated by Hawaii’s rugged topography, appears to render mechanical and chemical control as mere holding actions. Costly, ‘environmentally unfriendly’, and often ineffective, strategies using chemical and mechanical control on a large scale, despite the most valiant of efforts, can be viewed simply as attempts to buy time. Without increased levels of safely tested biological control, the seemingly inevitable result is the landscape level transformation of native forests, with potentially catastrophic consequences to cultural, biological, water, and economic resources. Increased levels of effective biological control for certain intractable invasive species appear to comprise a conspicuous ‘missing piece’ in our efforts to protect Hawaiian watersheds and other conservation lands.

Modeled Watershed Runoff Associated with Variations in Precipitation Data with Implications for Contaminant Fluxes

EPA Science Inventory

Watershed-scale fate and transport models are important tools for estimating the sources, transformation, and transport of contaminants to surface water systems. Precipitation is one of the primary inputs to watershed biogeochemical models, influencing changes in the water budge...

Isolating the impact of septic systems on fecal pollution in streams of suburban watersheds in Georgia, United States.

PubMed

Sowah, Robert A; Habteselassie, Mussie Y; Radcliffe, David E; Bauske, Ellen; Risse, Mark

2017-01-01

The presence of multiple sources of fecal pollution at the watershed level presents challenges to efforts aimed at identifying the influence of septic systems. In this study multiple approaches including targeted sampling and monitoring of host-specific Bacteroidales markers were used to identify the impact of septic systems on microbial water quality. Twenty four watersheds with septic density ranging from 8 to 373 septic units/km 2 were monitored for water quality under baseflow conditions over a 3-year period. The levels of the human-associated HF183 marker, as well as total and ruminant Bacteroidales, were quantified using quantitative polymerase chain reaction. Human-associated Bacteroidales yield was significantly higher in high density watersheds compared to low density areas and was negatively correlated (r = -0.64) with the average distance of septic systems to streams in the spring season. The human marker was also positively correlated with the total Bacteroidales marker, suggesting that the human source input was a significant contributor to total fecal pollution in the study area. Multivariable regression analysis indicates that septic systems, along with forest cover, impervious area and specific conductance could explain up to 74% of the variation in human fecal pollution in the spring season. The results suggest septic system impact through contributions to groundwater recharge during baseflow or failing septic system input, especially in areas with >87 septic units/km 2 . This study supports the use of microbial source tracking approaches along with traditional fecal indicator bacteria monitoring and land use characterization in a tiered approach to isolate the influence of septic systems on water quality in mixed-use watersheds. Copyright © 2016 Elsevier Ltd. All rights reserved.

Rates of biotite weathering, and clay mineral transformation and neoformation, determined from watershed geochemical mass-balance methods for the Coweeta Hydrologic Laboratory, Southern Blue Ridge Mountains, North Carolina, USA

Treesearch

Jason R. Price; Michael A. Velbel

2013-01-01

Biotite is a common constituent of silicate bedrock. Its weathering releases plant nutrients and consumes atmospheric CO2. Because of its stoichiometric relationship with its transformational weathering product and sensitivity to botanical activity, calculating biotite weathering rates using watershed mass-balance methods has proven challenging....

A lagged variable model for characterizing temporally dynamic export of legacy anthropogenic nitrogen from watersheds to rivers.

PubMed

Chen, Dingjiang; Guo, Yi; Hu, Minpeng; Dahlgren, Randy A

2015-08-01

Legacy nitrogen (N) sources originating from anthropogenic N inputs (NANI) may be a major cause of increasing riverine N exports in many regions, despite a significant decline in NANI. However, little quantitative knowledge exists concerning the lag effect of NANI on riverine N export. As a result, the N leaching lag effect is not well represented in most current watershed models. This study developed a lagged variable model (LVM) to address temporally dynamic export of watershed NANI to rivers. Employing a Koyck transformation approach used in economic analyses, the LVM expresses the indefinite number of lag terms from previous years' NANI with a lag term that incorporates the previous year's riverine N flux, enabling us to inversely calibrate model parameters from measurable variables using Bayesian statistics. Applying the LVM to the upper Jiaojiang watershed in eastern China for 1980-2010 indicated that ~97% of riverine export of annual NANI occurred in the current year and succeeding 10 years (~11 years lag time) and ~72% of annual riverine N flux was derived from previous years' NANI. Existing NANI over the 1993-2010 period would have required a 22% reduction to attain the target TN level (1.0 mg N L(-1)), guiding watershed N source controls considering the lag effect. The LVM was developed with parsimony of model structure and parameters (only four parameters in this study); thus, it is easy to develop and apply in other watersheds. The LVM provides a simple and effective tool for quantifying the lag effect of anthropogenic N input on riverine export in support of efficient development and evaluation of watershed N control strategies.

Dam construction impacts on multiscale characterization of sediment discharge in two typical karst watersheds of southwest China

NASA Astrophysics Data System (ADS)

Li, Zhenwei; Xu, Xianli; Xu, Chaohao; Liu, Meixian; Wang, Kelin

2018-03-01

Southwest China, as one of the largest continuous karst areas in the world, is a severely eroded region due to its special geological condition. Thus, soil and water conservation measures such as dam construction have been extensively implemented in this region to control sediment delivery. However, it remains unclear how dam construction affects multiscale variability of sediment discharge (SD) and its potentially influential factors in southwest China. To assess this, annual SD, water discharge (WD), precipitation (PT), potential evapotranspiration (PET), and normalized differential vegetation index (NDVI) data from 1955 to 2015 were obtained from two karst watersheds of Liujiang (no large dams) and Hongshui (dam-controlled). These sites shared the similar climatic conditions. The Mann-Kendal test, Wilcoxon rank-sum test, and continuous wavelet transform analysis was used to detect the trends and periodicity in SD, and wavelet coherence analysis were employed to detect the temporal covariance between SD and WD, PT, PET, and NDVI. Results indicated that the multiscale variability of SD was strongly influenced by dam construction. The annual SD showed significant 4-year periodic oscillation in the Liujiang watershed, while no significant cycles were found in the Hongshui watershed. Dam construction exerted substantial influence on the multiscale correlations between SD and its associated factors. The time scales that the NDVI resonated with SD were concentrated on the periodicity of 2- and 3-year in the Liujiang watershed. In contrast, no significant periodicities were observed in the Hongshu watershed. This study yields a greater understanding of SD dynamics, and is helpful for better watershed management in karst areas of southwest China.

Uncertainty quantification of fiber orientation distribution measurements for long-fiber-reinforced thermoplastic composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Bhisham N.; Naragani, Diwakar; Nguyen, Ba Nghiep

We present a detailed methodology for experimental measurement of fiber orientation distribution (FOD) in injection-molded discontinuous fiber composites using the method of ellipses on 2D cross sections. Best practices to avoid biases occurring during surface preparation and optical imaging of carbon-fiber-reinforced thermoplastics are discussed. A marker-based watershed transform routine for efficient image segmentation and the separation of touching fiber ellipses is developed. The sensitivity of the averaged orientation tensor to the image sample size is studied for the case of long-fiber thermoplastics. A Mori-Tanaka implementation of the Eshelby model is then employed to quantify the sensitivity of elastic stiffness predictionsmore » to biases in the FOD measurements.« less

Uncertainty quantification of fiber orientation distribution measurements for long-fiber-reinforced thermoplastic composites

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sharma, Bhisham N.; Naragani, Diwakar; Nguyen, Ba Nghiep

Here, we present a detailed methodology for experimental measurement of fiber orientation distribution in injection-molded discontinuous fiber composites using the method of ellipses on two-dimensional cross sections. Best practices to avoid biases occurring during surface preparation and optical imaging of carbon-fiber-reinforced thermoplastics are discussed. We developed a marker-based watershed transform routine for efficient image segmentation and the separation of touching fiber ellipses. The sensitivity of the averaged orientation tensor to the image sample size is studied for the case of long-fiber thermoplastics. A Mori–Tanaka implementation of the Eshelby model is then employed to quantify the sensitivity of elastic stiffness predictionsmore » to biases in the fiber orientation distribution measurements.« less

Uncertainty quantification of fiber orientation distribution measurements for long-fiber-reinforced thermoplastic composites

DOE PAGES

Sharma, Bhisham N.; Naragani, Diwakar; Nguyen, Ba Nghiep; ...

2017-09-28

Here, we present a detailed methodology for experimental measurement of fiber orientation distribution in injection-molded discontinuous fiber composites using the method of ellipses on two-dimensional cross sections. Best practices to avoid biases occurring during surface preparation and optical imaging of carbon-fiber-reinforced thermoplastics are discussed. We developed a marker-based watershed transform routine for efficient image segmentation and the separation of touching fiber ellipses. The sensitivity of the averaged orientation tensor to the image sample size is studied for the case of long-fiber thermoplastics. A Mori–Tanaka implementation of the Eshelby model is then employed to quantify the sensitivity of elastic stiffness predictionsmore » to biases in the fiber orientation distribution measurements.« less

Three-dimensional reconstruction of teeth and jaws based on segmentation of CT images using watershed transformation.

PubMed

Naumovich, S S; Naumovich, S A; Goncharenko, V G

2015-01-01

The objective of the present study was the development and clinical testing of a three-dimensional (3D) reconstruction method of teeth and a bone tissue of the jaw on the basis of CT images of the maxillofacial region. 3D reconstruction was performed using the specially designed original software based on watershed transformation. Computed tomograms in digital imaging and communications in medicine format obtained on multispiral CT and CBCT scanners were used for creation of 3D models of teeth and the jaws. The processing algorithm is realized in the stepwise threshold image segmentation with the placement of markers in the mode of a multiplanar projection in areas relating to the teeth and a bone tissue. The developed software initially creates coarse 3D models of the entire dentition and the jaw. Then, certain procedures specify the model of the jaw and cut the dentition into separate teeth. The proper selection of the segmentation threshold is very important for CBCT images having a low contrast and high noise level. The developed semi-automatic algorithm of multispiral and cone beam computed tomogram processing allows 3D models of teeth to be created separating them from a bone tissue of the jaws. The software is easy to install in a dentist's workplace, has an intuitive interface and takes little time in processing. The obtained 3D models can be used for solving a wide range of scientific and clinical tasks.

An Automated Energy Detection Algorithm Based on Morphological Filter Processing with a Modified Watershed Transform

DTIC Science & Technology

2018-01-01

ARL-TR-8270 ● JAN 2018 US Army Research Laboratory An Automated Energy Detection Algorithm Based on Morphological Filter...Automated Energy Detection Algorithm Based on Morphological Filter Processing with a Modified Watershed Transform by Kwok F Tom Sensors and Electron...1 October 2016–30 September 2017 4. TITLE AND SUBTITLE An Automated Energy Detection Algorithm Based on Morphological Filter Processing with a

The construction and use of versatile binary vectors carrying pyrG auxotrophic marker and fluorescent reporter genes for Agrobacterium-mediated transformation of Aspergillus oryzae.

PubMed

Nguyen, Khuyen Thi; Ho, Quynh Ngoc; Pham, Thu Ha; Phan, Tuan-Nghia; Tran, Van-Tuan

2016-12-01

Aspergillus oryzae is a safe mold widely used in food industry. It is also considered as a microbial cell factory for production of recombinant proteins and enzymes. Currently, genetic manipulation of filamentous fungi is achieved via Agrobacterium tumefaciens-mediated transformation methods usually employing antibiotic resistance markers. These methods are hardly usable for A. oryzae due to its strong resistance to the common antifungal compounds used for fungal transformation. In this study, we have constructed two binary vectors carrying the pyrG gene from A. oryzae as a biochemical marker than an antibiotic resistance marker, and an expression cassette for GFP or DsRed reporter gene under control of the constitutive gpdA promoter from Aspergillus nidulans. All components of these vectors are changeable to generate new versions for specific research purposes. The developed vectors are fully functional for heterologous expression of the GFP and DsRed fluorescent proteins in the uridine/uracil auxotrophic A. oryzae strain. Our study provides a new approach for A. oryzae transformation using pyrG as the selectable auxotrophic marker, A. tumefaciens as the DNA transfer tool and fungal spores as the transformation material. The binary vectors constructed can be used for gene expression studies in this industrially important filamentous fungus.

Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

NASA Astrophysics Data System (ADS)

Jayakaran, A. D.; Williams, T. M.; Ssegane, H.; Amatya, D. M.; Song, B.; Trettin, C. C.

2014-03-01

Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal South Carolina watersheds in terms of streamflow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a reversal in relative streamflow difference between two paired watersheds, and to examine the selective impacts of a hurricane on the vegetative composition of the forest. We related these impacts to their potential contribution to change watershed hydrology through altered evapotranspiration processes. Using over 30 years of monthly rainfall and streamflow data we showed that there was a significant transformation in the hydrologic character of the two watersheds - a transformation that occurred soon after the hurricane's passage. We linked the change in the rainfall-runoff relationship to a catastrophic change in forest vegetation due to selective hurricane damage. While both watersheds were located in the path of the hurricane, extant forest structure varied between the two watersheds as a function of experimental forest management techniques on the treatment watershed. We showed that the primary damage was to older pines, and to some extent larger hardwood trees. We believe that lowered vegetative water use impacted both watersheds with increased outflows on both watersheds due to loss of trees following hurricane impact. However, one watershed was able to recover to pre hurricane levels of evapotranspiration at a quicker rate due to the greater abundance of pine seedlings and saplings in that watershed.

Hurricane impacts on a pair of coastal forested watersheds: implications of selective hurricane damage to forest structure and streamflow dynamics

NASA Astrophysics Data System (ADS)

Jayakaran, A. D.; Williams, T. M.; Ssegane, H.; Amatya, D. M.; Song, B.; Trettin, C. C.

2013-09-01

Hurricanes are infrequent but influential disruptors of ecosystem processes in the southeastern Atlantic and Gulf coasts. Every southeastern forested wetland has the potential to be struck by a tropical cyclone. We examined the impact of Hurricane Hugo on two paired coastal watersheds in South Carolina in terms of stream flow and vegetation dynamics, both before and after the hurricane's passage in 1989. The study objectives were to quantify the magnitude and timing of changes including a reversal in relative streamflow-difference between two paired watersheds, and to examine the selective impacts of a hurricane on the vegetative composition of the forest. We related these impacts to their potential contribution to change watershed hydrology through altered evapotranspiration processes. Using over thirty years of monthly rainfall and streamflow data we showed that there was a significant transformation in the hydrologic character of the two watersheds - a transformation that occurred soon after the hurricane's passage. We linked the change in the rainfall-runoff relationship to a catastrophic shift in forest vegetation due to selective hurricane damage. While both watersheds were located in the path of the hurricane, extant forest structure varied between the two watersheds as a function of experimental forest management techniques on the treatment watershed. We showed that the primary damage was to older pines, and to some extent larger hardwood trees. We believe that lowered vegetative water use impacted both watersheds with increased outflows on both watersheds due to loss of trees following hurricane impact. However, one watershed was able to recover to pre hurricane levels of canopy transpiration at a quicker rate due to the greater abundance of pine seedlings and saplings in that watershed.

Temporal Assessment of the Impact of Exposure to Cow Feces in Two Watersheds by Multiple Host-Specific PCR Assays

EPA Science Inventory

Exposure to feces in two watersheds with different management histories was assessed by tracking cattle feces bacterial populations using multiple host-specific PCR assays. In addition, environmental factors affecting the occurrence of these markers were identified. Each assay wa...

Temporal Assessment of the Impact of Exposure to Cow Feces inTwo Watersheds by Multiple Host-Specific PCR Assays

EPA Science Inventory

Fecal exposure in two watersheds with different management histories was assessed by tracking cattle fecal bacterial populations using multiple host-specific PCR assays. In addition, environmental factors affecting the occurrence of these markers were identified. Each assay was t...

Insulated piggyBac vectors for insect transgenesis

PubMed Central

Sarkar, Abhimanyu; Atapattu, Asela; Belikoff, Esther J; Heinrich, Jörg C; Li, Xuelei; Horn, Carsten; Wimmer, Ernst A; Scott, Maxwell J

2006-01-01

Background Germ-line transformation of insects is now a widely used method for analyzing gene function and for the development of genetically modified strains suitable for pest control programs. The most widely used transposable element for the germ-line transformation of insects is piggyBac. The site of integration of the transgene can influence gene expression due to the effects of nearby transcription enhancers or silent heterochromatic regions. Position effects can be minimized by flanking a transgene with insulator elements. The scs/scs' and gypsy insulators from Drosophila melanogaster as well as the chicken β-globin HS4 insulator function in both Drosophila and mammalian cells. Results To minimize position effects we have created a set of piggyBac transformation vectors that contain either the scs/scs', gypsy or chicken β-globin HS4 insulators. The vectors contain either fluorescent protein or eye color marker genes and have been successfully used for germ-line transformation of Drosophila melanogaster. A set of the scs/scs' vectors contains the coral reef fluorescent protein marker genes AmCyan, ZsGreen and DsRed that have not been optimized for translation in human cells. These marker genes are controlled by a combined GMR-3xP3 enhancer/promoter that gives particularly strong expression in the eyes. This is also the first report of the use of the ZsGreen and AmCyan reef fluorescent proteins as transformation markers in insects. Conclusion The insulated piggyBac vectors should protect transgenes against position effects and thus facilitate fine control of gene expression in a wide spectrum of insect species. These vectors may also be used for transgenesis in other invertebrate species. PMID:16776846

Downstream cumulative effects of land use on freshwater communities

NASA Astrophysics Data System (ADS)

Kuglerová, L.; Kielstra, B. W.; Moore, D.; Richardson, J. S.

2015-12-01

Many streams and rivers are subject to disturbance from intense land use such as urbanization and agriculture, and this is especially obvious for small headwaters. Streams are spatially organized into networks where headwaters represent the tributaries and provide water, nutrients, and organic material to the main stems. Therefore perturbations within the headwaters might be cumulatively carried on downstream. Although we know that the disturbance of headwaters in urban and agricultural landscapes poses threats to downstream river reaches, the magnitude and severity of these changes for ecological communities is less known. We studied stream networks along a gradient of disturbance connected to land use intensity, from urbanized watersheds to watersheds placed in agricultural settings in the Greater Toronto Area. Further, we compared the patterns and processes found in the modified watershed to a control watershed, situated in a forested, less impacted landscape. Preliminary results suggest that hydrological modifications (flash floods), habitat loss (drainage and sewer systems), and water quality issues of small streams in urbanized and agricultural watersheds represent major disturbances and threats for aquatic and riparian biota on local as well as larger spatial scales. For example, communities of riparian plants are dominated by species typical of the land use on adjacent uplands as well as the dominant land use on the upstream contributing area, instead of riparian obligates commonly found in forested watersheds. Further, riparian communities in disturbed environments are dominated by invasive species. The changes in riparian communities are vital for various functions of riparian vegetation. Bank erosion control is suppressed, leading to severe channel transformations and sediment loadings in urbanized watersheds. Food sources for instream biota and thermal regimes are also changed, which further triggers alterations of in-stream biological communities. These findings clearly demonstrate that in watersheds which are disturbed by intensive land use, the eco-hydrological linkages between biota and fluvial processes significantly differ from those in more natural and forested landscapes.

HydroGrid: Technologies for Global Water Quality and Sustainability

NASA Astrophysics Data System (ADS)

Yeghiazarian, L.

2017-12-01

Humans have been transforming planet Earth for millennia. We have recently come to understand that the collective impact of our decisions and actions has brought about severe water quality problems, which are likely to worsen in the light of rapid population growth to the projected nine billion by 2050. To sustainably manage our global water resources and possibly reverse these effects requires efforts in real-time monitoring of water contamination, analysis of monitoring data, and control of the state of water contamination. We develop technologies to address all three areas: monitoring, analysis and control. These efforts are carried out in the conceptual framework of the HydroGrid, an interconnected water system, which is (1) firmly rooted in the fundamental understanding of processes that govern microbial dynamics on multiple scales; and (2) used to develop watershed-specific management strategies. In the area of monitoring we are developing mobile autonomous sensors to detect surface water contamination, an effort supported by extensive materials research to provide multifunctional materials. We analyze environmental data within a stochastic modeling paradigm that bridges microscopic particle interactions to macroscopic manifestation of microbial population behavior in time and space in entire watersheds. These models are supported with laboratory and field experiments. Finally, we combine control and graph theories to derive controllability metrics of natural watersheds.

Assessment of fecal pollution sources in a small northern-plains watershed using PCR and phylogenetic analyses of Bacteroidetes 16S rRNA gene

USGS Publications Warehouse

Lamendella, R.; Domingo, J.W.S.; Oerther, D.B.; Vogel, J.R.; Stoeckel, D.M.

2007-01-01

We evaluated the efficacy, sensitivity, host-specificity, and spatial/temporal dynamics of human- and ruminant-specific 16S rRNA gene Bacteroidetes markers used to assess the sources of fecal pollution in a fecally impacted watershed. Phylogenetic analyses of 1271 fecal and environmental 16S rRNA gene clones were also performed to study the diversity of Bacteroidetes in this watershed. The host-specific assays indicated that ruminant feces were present in 28-54% of the water samples and in all sampling seasons, with increasing frequency in downstream sites. The human-targeted assays indicated that only 3-5% of the water samples were positive for human fecal signals, although a higher percentage of human-associated signals (19-24%) were detected in sediment samples. Phylogenetic analysis indicated that 57% of all water clones clustered with yet-to-be-cultured Bacteroidetes species associated with sequences obtained from ruminant feces, further supporting the prevalence of ruminant contamination in this watershed. However, since several clusters contained sequences from multiple sources, future studies need to consider the potential cosmopolitan nature of these bacterial populations when assessing fecal pollution sources using Bacteroidetes markers. Moreover, additional data is needed in order to understand the distribution of Bacteroidetes host-specific markers and their relationship to water quality regulatory standards. ?? 2006 Federation of European Microbiological Societies.

Does anthropogenic nitrogen enrichment increase organic nitrogen concentrations in runoff from forested and human-dominated watersheds?

USGS Publications Warehouse

Pellerin, B.A.; Kaushal, S.S.; McDowell, W.H.

2006-01-01

Although the effects of anthropogenic nitrogen (N) inputs on the dynamics of inorganic N in watersheds have been studied extensively, "the influence of N enrichment on organic N loss" is not as well understood. We compiled and synthesized data on surface water N concentrations from 348 forested and human-dominated watersheds with a range of N loads (from less than 100 to 7,100 kg N km-2 y-1) to evaluate the effects of N loading via atmospheric deposition, fertilization, and wastewater on dissolved organic N (DON) concentrations. Our results indicate that, on average, DON accounts for half of the total dissolved N (TDN) concentrations from forested watersheds, but it accounts for a smaller fraction of TDN in runoff from urban and agricultural watersheds with higher N loading. A significant but weak correlation (r 2 = 0.06) suggests that N loading has little influence on DON concentrations in forested watersheds. This result contrasts with observations from some plot-scale N fertilization studies and suggests that variability in watershed characteristics and climate among forested watersheds may be a more important control on DON losses than N loading from atmospheric sources. Mean DON concentrations were positively correlated, however, with N load across the entire land-use gradient (r 2 = 0.37, P < 0.01), with the highest concentrations found in agricultural and urban watersheds. We hypothesize that both direct contributions of DON from wastewater and agricultural amendments and indirect transformations of inorganic N to organic N represent important sources of DON to surface waters in human-dominated watersheds. We conclude that DON is an important component of N loss in surface waters draining forested and human-dominated watersheds and suggest several research priorities that may be useful in elucidating the role of N enrichment in watershed DON dynamics. ?? 2006 Springer Science+Business Media, Inc.

Image processing based detection of lung cancer on CT scan images

NASA Astrophysics Data System (ADS)

Abdillah, Bariqi; Bustamam, Alhadi; Sarwinda, Devvi

2017-10-01

In this paper, we implement and analyze the image processing method for detection of lung cancer. Image processing techniques are widely used in several medical problems for picture enhancement in the detection phase to support the early medical treatment. In this research we proposed a detection method of lung cancer based on image segmentation. Image segmentation is one of intermediate level in image processing. Marker control watershed and region growing approach are used to segment of CT scan image. Detection phases are followed by image enhancement using Gabor filter, image segmentation, and features extraction. From the experimental results, we found the effectiveness of our approach. The results show that the best approach for main features detection is watershed with masking method which has high accuracy and robust.

An automated approach to the segmentation of HEp-2 cells for the indirect immunofluorescence ANA test.

PubMed

Tonti, Simone; Di Cataldo, Santa; Bottino, Andrea; Ficarra, Elisa

2015-03-01

The automatization of the analysis of Indirect Immunofluorescence (IIF) images is of paramount importance for the diagnosis of autoimmune diseases. This paper proposes a solution to one of the most challenging steps of this process, the segmentation of HEp-2 cells, through an adaptive marker-controlled watershed approach. Our algorithm automatically conforms the marker selection pipeline to the peculiar characteristics of the input image, hence it is able to cope with different fluorescent intensities and staining patterns without any a priori knowledge. Furthermore, it shows a reduced sensitivity to over-segmentation errors and uneven illumination, that are typical issues of IIF imaging. Copyright © 2015 Elsevier Ltd. All rights reserved.

Dynamics of aerial and terrestrial populations of Phytophthora ramorum in a California watershed under different climatic conditions

Treesearch

Catherine A. Eyre; Melina Kozanitas; Matteo Garbelotto

2013-01-01

We present a study of the epidemiology of sudden oak death (SOD) in California within a watershed based on temporally and spatially replicated surveys of symptoms, viability of the pathogen from symptomatic leaves, and genetic analyses using polymorphic SSR markers.Phytophthora ramorum is sensitive to climate; its...

Tracing Nitrate Contributions to Streams During Varying Flow Regimes at the Sleepers River Research Watershed, Vermont, USA

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Boyer, E. W.; Ohte, N.; Doctor, D. H.; Kendall, C.

2003-12-01

Quantifying sources and transformations of nitrate in headwater catchments is fundamental to understanding the movement of nitrogen to streams. At the Sleepers River Research Watershed in northeastern Vermont (USA), we are using multiple chemical tracer and mixing model approaches to quantify sources and transport of nitrate to streams under varying flow regimes. We sampled streams, lysimeters, and wells at nested locations from the headwaters to the outlet of the 41 ha W-9 watershed under the entire range of flow regimes observed throughout 2002-2003, including baseflow and multiple events (stormflow and snowmelt). Our results suggest that nitrogen sources, and consequently stream nitrate concentrations, are rapidly regenerated during several weeks of baseflow and nitrogen is flushed from the watershed by stormflow events that follow baseflow periods. Both basic chemistry data (anions, cations, & dissolved organic carbon) and isotopic data (nitrate, dissolved organic carbon, and dissolved inorganic carbon) indicate that nitrogen source contributions vary depending upon the extent of saturation in the watershed, the initiation of shallow subsurface water inputs, and other hydrological processes. Stream nitrate concentrations typically peak with discharge and are higher on the falling than the rising limb of the hydrograph. Our data also indicate the importance of terrestrial and aquatic biogeochemical processes, in addition to hydrological connectivity in controlling how nitrate moves from the terrestrial landscape to streams. Our detailed sampling data from multiple flow regimes are helping to identify and quantify the "hot spots" and "hot moments" of biogeochemical and hydrological processes that control nitrogen fluxes in streams.

[Use of the hygromycin phosphotransferase gene as the dominant selective marker for Chlamydomonas reinhardtii transformation].

PubMed

Butanaev, A M

1994-01-01

The hygromycin phosphotransferase gene (hpt) from E. coli under the control of the SV40 early promoter was used as a dominant selectable marker for transformation of Chlamydomonas reinhardtii. Cells were transformed by electroporation (pulse length, 2 ms, field strength, 1 kV/cm). The culture growth phase was a crucial parameter for transformation (optimal density approximately 10(6) cells/ml). It was possible to obtain approximately 10(3) Hyg-resistant colonies under these conditions. Foreign DNA integrated into the Chlamydomonas genome was maintained for at least 8 months but the Hyg-resistant phenotype of the transformed clones was unstable. The frequency of codon usage in the hpt gene was compared with the one in Chlamydomonas nuclear genes. It is supposed that highly biased codon usage in Chlamydomonas does not preclude expression. Advantages of this selection system for studying Chlamydomonas transformation by heterologous genes are discussed.

piggybac- and PhiC31-Mediated Genetic Transformation of the Asian Tiger Mosquito, Aedes albopictus (Skuse)

PubMed Central

Labbé, Geneviève M. C.; Nimmo, Derric D.; Alphey, Luke

2010-01-01

Background The Asian tiger mosquito, Aedes albopictus (Skuse), is a vector of several arboviruses including dengue and chikungunya. This highly invasive species originating from Southeast Asia has travelled the world in the last 30 years and is now established in Europe, North and South America, Africa, the Middle East and the Caribbean. In the absence of vaccine or antiviral drugs, efficient mosquito control strategies are crucial. Conventional control methods have so far failed to control Ae. albopictus adequately. Methodology/Principal Findings Germline transformation of Aedes albopictus was achieved by micro-injection of embryos with a piggyBac-based transgene carrying a 3xP3-ECFP marker and an attP site, combined with piggyBac transposase mRNA and piggyBac helper plasmid. Five independent transgenic lines were established, corresponding to an estimated transformation efficiency of 2–3%. Three lines were re-injected with a second-phase plasmid carrying an attB site and a 3xP3-DsRed2 marker, combined with PhiC31 integrase mRNA. Successful site-specific integration was observed in all three lines with an estimated transformation efficiency of 2–6%. Conclusions/Significance Both piggybac- and site-specific PhiC31-mediated germline transformation of Aedes albopictus were successfully achieved. This is the first report of Ae. albopictus germline transformation and engineering, a key step towards studying and controlling this species using novel molecular techniques and genetic control strategies. PMID:20808959

A novel multiphoton microscopy images segmentation method based on superpixel and watershed.

PubMed

Wu, Weilin; Lin, Jinyong; Wang, Shu; Li, Yan; Liu, Mingyu; Liu, Gaoqiang; Cai, Jianyong; Chen, Guannan; Chen, Rong

2017-04-01

Multiphoton microscopy (MPM) imaging technique based on two-photon excited fluorescence (TPEF) and second harmonic generation (SHG) shows fantastic performance for biological imaging. The automatic segmentation of cellular architectural properties for biomedical diagnosis based on MPM images is still a challenging issue. A novel multiphoton microscopy images segmentation method based on superpixels and watershed (MSW) is presented here to provide good segmentation results for MPM images. The proposed method uses SLIC superpixels instead of pixels to analyze MPM images for the first time. The superpixels segmentation based on a new distance metric combined with spatial, CIE Lab color space and phase congruency features, divides the images into patches which keep the details of the cell boundaries. Then the superpixels are used to reconstruct new images by defining an average value of superpixels as image pixels intensity level. Finally, the marker-controlled watershed is utilized to segment the cell boundaries from the reconstructed images. Experimental results show that cellular boundaries can be extracted from MPM images by MSW with higher accuracy and robustness. © 2017 Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Export of Dissolved Organic Carbon following Prescribed Fire on Forested Watersheds: Implications for Watershed Management for Drinking Water Supply

NASA Astrophysics Data System (ADS)

Zhang, W.; Olivares, C. I.; Uzun, H.; Erdem, C. U.; Trettin, C.; Liu, Y.; Robinson, E. R.; Karanfil, T.; Chow, A. T.

2016-12-01

Detrital material in forest watersheds is the major terrestrial source of dissolved organic matter (DOM) and disinfection byproduct (DBP) precursors in surface source waters, but it is also the fuel for forest fires. Prescribed fire, as a fuel reduction technique is intended to reduce the amount of forest detritus, and therefore the risk of wildfire. Accordingly, periodic prescribed fire can reduce the accumulation of detritus on forest floor and the amount of DOM export after forest treatments. To evaluate the effects of prescribed fire on water quality, we conducted a controlled study on a paired first-order watershed system that includes a 160 ha treatment watershed (WS77) and 200 ha control watershed (WS80) on the Santee Experimental Forest, near Charleston South Carolina. WS77 has been used for prescribed fire research since the 1960's, the current experimental burn occurred on April, 2016. WS80 has not been managed or burned for at least 55 years. Gauging stations were equipped with in-situ TOC sensors and flow-proportional water samplers for monitoring temporal trends on water quality. Water samples taken from the first runoff event from both watersheds including rising limb, peak discharge, and falling limb were used for detailed chemical characterizations including DOC and nutrient concentrations, coagulation efficiency, and DBP formation such as trihalomethanes (THMs) and halocacetic acids (HAAs) from chlorination as well as N-nitrosodimethylamine (NDMA) from chlorination, and chemical formula assignment on DOM using Fourier Transform Ion Cyclotron Resonance Mass Spectrometry (FT-ICR-MS) before and after chlorination and chloramination. Preliminary FT-ICR-MS data shows that DOM chemical compositions are different between raw samples collected from WS77 and WS80. Chlorination resulted in a shift toward lower molecular mass compared to the raw materials. While chloramination did not cause a drastic mass shift, such a treatment also produced DOM moieties that are significantly different from the raw material. Based on our understanding, this watershed-scale study is the first field-scale study to evaluate the effects of prescribed fire on treatability of drinking water supplies.

A case study characterizing animal fecal sources in surface water using a mitochondrial DNA marker.

PubMed

Bucci, John P; Shattuck, Michelle D; Aytur, Semra A; Carey, Richard; McDowell, William H

2017-08-01

Water quality impairment by fecal waste in coastal watersheds is a public health issue. The present study provided evidence for the use of a mitochondrial (mtDNA) marker to detect animal fecal sources in surface water. The accurate identification of fecal pollution is based on the notion that fecal microorganisms preferentially inhabit a host animal's gut environment. In contrast, mtDNA host-specific markers are inherent to eukaryotic host cells, which offers the advantage by detecting DNA from the host rather than its fecal bacteria. The present study focused on sampling water presumably from non-point sources (NPS), which can increase bacterial and nitrogen concentrations to receiving water bodies. Stream sampling sites located within the Piscataqua River Watershed (PRW), New Hampshire, USA, were sampled from a range of sites that experienced nitrogen inputs such as sewer and septic systems and suburban runoff. Three mitochondrial (mtDNA) gene marker assays (human, bovine, and canine) were tested from surface water. Nineteen sites were sampled during an 18-month period. Analyses of the combined single and multiplex assay results showed that the proportion of occurrence was highest for bovine (15.6%; n = 77) compared to canine (5.6%; n = 70) and human (5.7%; n = 107) mtDNA gene markers. For the human mtDNA marker, there was a statistically significant relationship between presence vs. absence and land use (Fisher's test p = 0.0031). This result was evident particularly for rural suburban septic, which showed the highest proportion of presence (19.2%) compared to the urban sewered (3.3%), suburban sewered (0%), and agricultural (0%) as well as forested septic (0%) sites. Although further testing across varied land use is needed, our study provides evidence for using the mtDNA marker in large watersheds.

Rain Garden Research at EPA’s Urban Watershed Research Facility: Promoting Nitrate Removal through Rain Garden Design

EPA Science Inventory

Rain gardens are designed to infiltrate stormwater, capture suspended solids, sorb heavy metals and phosphorus, and transform nutrients through biological processes. Most studies have found a low capacity for stormwater nitrate removal. Research at the Urban Watershed Managemen...

Watershed Nitrogen Modeling: Benefits of Diverse Approaches Using a Case Study from New York State

EPA Science Inventory

Watershed-scale models have evolved as an important tool for estimating the sources, transformation, and transport of contaminants to surface water systems. A wide variety of modeling approaches exist for estimating inputs, fate, and transport of constituents but most are broadl...

Beaver Ponds: Resurgent Nitrogen Sinks for Rural Watersheds in the Northeastern United States.

PubMed

Lazar, Julia G; Addy, Kelly; Gold, Arthur J; Groffman, Peter M; McKinney, Richard A; Kellogg, Dorothy Q

2015-09-01

Beaver-created ponds and dams, on the rise in the northeastern United States, reshape headwater stream networks from extensive, free-flowing reaches to complexes of ponds, wetlands, and connecting streams. We examined seasonal and annual rates of nitrate transformations in three beaver ponds in Rhode Island under enriched nitrate-nitrogen (N) conditions through the use of N mass balance techniques on soil core mesocosm incubations. We recovered approximately 93% of the nitrate N from our mesocosm incubations. Of the added nitrate N, 22 to 39% was transformed during the course of the incubation. Denitrification had the highest rates of transformation (97-236 mg N m d), followed by assimilation into the organic soil N pool (41-93 mg N m d) and ammonium generation (11-14 mg N m d). Our denitrification rates exceeded those in several studies of freshwater ponds and wetlands; however, rates in those ecosystems may have been limited by low concentrations of nitrate. Assuming a density of 0.7 beaver ponds km of catchment area, we estimated that in nitrate-enriched watersheds, beaver pond denitrification can remove approximately 50 to 450 kg nitrate N km catchment area. In rural watersheds of southern New England with high N loading (i.e., 1000 kg km), denitrification from beaver ponds may remove 5 to 45% of watershed nitrate N loading. Beaver ponds represent a relatively new and substantial sink for watershed N if current beaver populations persist. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Comparison of two alternative dominant selectable markers for wine yeast transformation.

PubMed

Cebollero, Eduardo; Gonzalez, Ramon

2004-12-01

Genetic improvement of industrial yeast strains is restricted by the availability of selectable transformation markers. Antibiotic resistance markers have to be avoided for public health reasons, while auxotrophy markers are generally not useful for wine yeast strain transformation because most industrial Saccharomyces cerevisiae strains are prototrophic. For this work, we performed a comparative study of the usefulness of two alternative dominant selectable markers in both episomic and centromeric plasmids. Even though the selection for sulfite resistance conferred by FZF1-4 resulted in a larger number of transformants for a laboratory strain, the p-fluoro-DL-phenylalanine resistance conferred by ARO4-OFP resulted in a more suitable selection marker for all industrial strains tested. Both episomic and centromeric constructions carrying this marker resulted in transformation frequencies close to or above 10(3) transformants per microg of DNA for the three wine yeast strains tested.

Correlation of quantitative PCR for a poultry-specific brevibacterium marker gene with bacterial and chemical indicators of water pollution in a watershed impacted by land application of poultry litter.

PubMed

Weidhaas, Jennifer L; Macbeth, Tamzen W; Olsen, Roger L; Harwood, Valerie J

2011-03-01

The impact of fecal contamination from human and agricultural animal waste on water quality is a major public health concern. Identification of the dominant source(s) of fecal pollution in a watershed is necessary for assessing the safety of recreational water and protecting water resources. A field study was conducted using quantitative PCR (qPCR) for the 16S rRNA gene of Brevibacterium sp. LA35 to track feces-contaminated poultry litter in environmental samples. Based on sensitivity and specificity characteristics of the qPCR method, the Bayesian conditional probability that detection of the LA35 marker gene in a water sample represented a true-positive result was 93%. The marker's covariance with fecal indicator bacteria (FIB) and metals associated with poultry litter was also assessed in litter, runoff, surface water, and groundwater samples. LA35 was detected in water and soil samples collected throughout the watershed, and its concentration covaried with concentrations of Escherichia coli, enterococci, As, Cu, P, and Zn. Significantly greater concentrations of FIB, As, Cu, P, and Zn were observed in edge-of-field runoff samples in which LA35 was detected, compared to samples in which it was not detected. Furthermore, As, Cu, P, and Zn concentrations covaried in environmental samples in which LA35 was detected and typically did not in samples in which the marker gene was not detected. The covariance of the poultry-specific LA35 marker gene with these known contaminants from poultry feces provides further evidence that it is a useful tool for assessing the impact of poultry-derived fecal pollution in environmental waters.

Automated system for characterization and classification of malaria-infected stages using light microscopic images of thin blood smears.

PubMed

Das, D K; Maiti, A K; Chakraborty, C

2015-03-01

In this paper, we propose a comprehensive image characterization cum classification framework for malaria-infected stage detection using microscopic images of thin blood smears. The methodology mainly includes microscopic imaging of Leishman stained blood slides, noise reduction and illumination correction, erythrocyte segmentation, feature selection followed by machine classification. Amongst three-image segmentation algorithms (namely, rule-based, Chan-Vese-based and marker-controlled watershed methods), marker-controlled watershed technique provides better boundary detection of erythrocytes specially in overlapping situations. Microscopic features at intensity, texture and morphology levels are extracted to discriminate infected and noninfected erythrocytes. In order to achieve subgroup of potential features, feature selection techniques, namely, F-statistic and information gain criteria are considered here for ranking. Finally, five different classifiers, namely, Naive Bayes, multilayer perceptron neural network, logistic regression, classification and regression tree (CART), RBF neural network have been trained and tested by 888 erythrocytes (infected and noninfected) for each features' subset. Performance evaluation of the proposed methodology shows that multilayer perceptron network provides higher accuracy for malaria-infected erythrocytes recognition and infected stage classification. Results show that top 90 features ranked by F-statistic (specificity: 98.64%, sensitivity: 100%, PPV: 99.73% and overall accuracy: 96.84%) and top 60 features ranked by information gain provides better results (specificity: 97.29%, sensitivity: 100%, PPV: 99.46% and overall accuracy: 96.73%) for malaria-infected stage classification. © 2014 The Authors Journal of Microscopy © 2014 Royal Microscopical Society.

GFP as a marker for transient gene transfer and expression in Mycoplasma hyorhinis.

PubMed

Ishag, Hassan Z A; Liu, Maojun; Yang, Ruosong; Xiong, Qiyan; Feng, Zhixin; Shao, Guoqing

2016-01-01

Mycoplasma hyorhinis (M. hyorhinis) is an opportunistic pathogen of pigs and has been shown to transform cell cultures, which has increased the interest of researchers. The green florescence proteins (GFP) gene of Aquorea victoria, proved to be a vital marker to identify transformed cells in mixed populations. Use of GFP to observe gene transfer and expression in M. hyorhinis (strain HUB-1) has not been described. We have constructed a pMD18-O/MHRgfp plasmid containing the p97 gene promoter, origin of replication, tetracycline resistance marker and GFP gene controlled by the p97 gene promoter. The plasmid transformed into M. hyorhinis with a frequency of ~4 × 10(-3) cfu/µg plasmid DNA and could be detected by PCR amplification of the GFP gene from the total DNA of the transformant mycoplasmas. Analysis of a single clone grown on KM2-Agar containing tetracycline, showed a green fluorescence color. Conclusively, this report suggests the usefulness of GFP to monitor transient gene transfer and expression in M. hyorhinis, eventually minimizing screening procedures for gene transfer and expression.

Managing Watersheds as Couple Human-Natural Systems: A Review of Research Opportunities

NASA Astrophysics Data System (ADS)

Cai, X.

2011-12-01

Many watersheds around the world are impaired with severe social and environmental problems due to heavy anthropogenic stresses. Humans have transformed hydrological and biochemical processes in watersheds from a stationary to non-stationary status through direct (e.g., water withdrawals) and indirect (e.g., altering vegetation and land cover) interferences. It has been found that in many watersheds that socio-economic drivers, which have caused increasingly intensive alteration of natural processes, have even overcome natural variability to become the dominant factor affecting the behavior of watershed systems. Reversing this trend requires an understanding of the drivers of this intensification trajectory, and needs tremendous policy reform and investment. As stressed by several recent National Research Council (NRC) reports, watershed management will pose an enormous challenge in the coming decades. Correspondingly, the focus of research has started an evolution from the management of reservoir, stormwater and aquifer systems to the management of integrated watershed systems, to which policy instruments designed to make more rational economic use of water resources are likely to be applied. To provide a few examples: reservoir operation studies have moved from a local to a watershed scale in order to consider upstream best management practices in soil conservation and erosion control and downstream ecological flow requirements and water rights; watersheds have been modeled as integrated hydrologic-economic systems with multidisciplinary modeling efforts, instead of traditional isolated physical systems. Today's watershed management calls for a re-definition of watersheds from isolated natural systems to coupled human-natural systems (CHNS), which are characterized by the interactions between human activities and natural processes, crossing various spatial and temporal scales within the context of a watershed. The importance of the conceptual innovation has been evidenced by 1) institutional innovation for integrated watershed management; 2) real-world management practices involving multidisciplinary expertise; 3) growing role of economics in systems analysis; 4) enhanced research programs such as the CHNS program and Water, Sustainability and Climate (WSC) program at the US National Science Foundation (NSF). Furthermore, recent scientific and technological developments are expected to accommodate integrated watershed system analysis approaches, such as: 1) increasing availability of distributed digital datasets especially from remote sensing products (e.g. digital watersheds); 2) distributed and semi-distributed watershed hydrologic modeling; 3) enhanced hydroclimatic monitoring and forecast; 4) identified evidences of vulnerability and threshold behavior of watersheds; and 5) continuing improvements in computational and optimization algorithms. Managing watersheds as CHNS will be critical for watershed sustainability, which ensures that human societies will benefit forever from the watershed through development of harmonious relationships between human and natural systems. This presentation will provide a review of the research opportunities that take advantage of the concept of CHNS and associated scientific, technological and institutional innovations/developments.

Convergence and non-convergence in ecological, phenotypic, and genetic divergence across replicate population pairs of lake and stream stickleback

PubMed Central

Kaeuffer, Renaud; Peichel, Catherine L.; Bolnick, Daniel I.; Hendry, Andrew P.

2015-01-01

Convergent (or parallel) evolution provides strong evidence for a deterministic role of natural selection: similar phenotypes evolve when independent populations colonize similar environments. In reality, however, independent populations in similar environments always show some differences: some non-convergent evolution is present. It is therefore important to explicitly quantify the convergent and non-convergent aspects of trait variation, and to investigate the ecological and genetic explanations for each. We performed such an analysis for threespine stickleback (Gasterosteus aculeatus) populations inhabiting lake and stream habitats in independent watersheds. Morphological traits differed in the degree to which lake-stream divergence was convergent across watersheds. Some aspects of this variation were correlated with ecological variables related to diet, presumably reflecting the strength and specifics of divergent selection. Furthermore, a genetic scan revealed some markers that diverged between lakes and streams in many of the watersheds and some that diverged in only a few watersheds. Moreover, some of the lake-stream divergence in genetic markers was associated within some of the lake-stream divergence in morphological traits. Our results suggest that convergent evolution, and deviations from it, are primarily the result of natural selection, which corresponds in only some respect to the dichotomous habitat classifications frequently used in such studies. PMID:22276537

Molecular Investigations of Bacteroides as Microbial Source Tracking Tools in Southeast Louisiana Watersheds

NASA Astrophysics Data System (ADS)

Schulz, C. J.; Childers, G. W.; Engel, A. S.

2006-12-01

Microbial Source Tracking (MST) is a developing field that is gaining increased attention. MST refers to a host of techniques that discriminates among the origins of fecal material found in natural waters from different sources (e.g. human, livestock, and wildlife) by using microbial indicator species with specificity to only certain host organisms. The development of species-specific molecular markers would allow for better evaluation of public health risks and tracking of nutrient sources impacting a watershed. Although several MST methods have been reported with varying levels of success, few offer general applicability for natural waters due to spatial and temporal constraints associated with these methods. One group of molecular MST markers that show promise for broad environmental applications are molecular 16S rDNA probes for Bacteroides. This method is based on 16S rDNA detection directly from environmental samples without the need for a preliminary cultivation step. In this study we have expanded previous sampling efforts to compile a database of over 1000 partial 16S rRNA Bacteroides genes retrieved from the fecal material of 15 different host species (human, cat, dog, pig, kangaroo). To characterize survival of Bacteroides outside of the host, survival time of the Bacteroides marker was compared to that of E.coli under varying natural environmental conditions (temperature and salinity). Bacteroides displayed a survival curve with shouldering and tailing similar to that of E.coli, but log reduction times differed with treatment. In summary, MST marker stability was identified within host species and the overall Bacteroides community structure correlated to host diet, suggesting that detection of a Bacteroides community could confidently identify fecal contamination point sources. Natural water samples from southeast Louisiana were collected for MST including the Tangipahoa River watershed where the source of fecal contamination has been hotly debated. The Bacteroides tool repeatedly demonstrated the presence of cattle related Bacteroides markers and the absence of human markers.This study is now being expanded to include the entire Lake Pontchartrain Basin.

Microsatellite markers for the endangered Roanoke logperch, Percina rex (Percidae) and their potential utility for other darter species

USGS Publications Warehouse

Dutton, D.J.; Roberts, J.H.; Angermeier, P.L.; Hallerman, E.M.

2008-01-01

The Roanoke logperch (Percina rex Jordan and Evermann), an endangered fish, occurs in only six watersheds in the Roanoke and Chowan river drainages of Virginia, USA. The species' population genetic structure is poorly known. We developed 16 microsatellite markers that were reliably scorable and polymorphic P. rex. Markers were also screened in seven other darter species of the genus Percina. Most markers exhibited successful amplification and polymorphism in several species. These markers may therefore prove useful for population genetic studies in other darters, a diverse but highly imperiled group. ?? 2008 The Authors.

Runoff potentiality of a watershed through SCS and functional data analysis technique.

PubMed

Adham, M I; Shirazi, S M; Othman, F; Rahman, S; Yusop, Z; Ismail, Z

2014-01-01

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling.

Runoff Potentiality of a Watershed through SCS and Functional Data Analysis Technique

PubMed Central

Adham, M. I.; Shirazi, S. M.; Othman, F.; Rahman, S.; Yusop, Z.; Ismail, Z.

2014-01-01

Runoff potentiality of a watershed was assessed based on identifying curve number (CN), soil conservation service (SCS), and functional data analysis (FDA) techniques. Daily discrete rainfall data were collected from weather stations in the study area and analyzed through lowess method for smoothing curve. As runoff data represents a periodic pattern in each watershed, Fourier series was introduced to fit the smooth curve of eight watersheds. Seven terms of Fourier series were introduced for the watersheds 5 and 8, while 8 terms of Fourier series were used for the rest of the watersheds for the best fit of data. Bootstrapping smooth curve analysis reveals that watersheds 1, 2, 3, 6, 7, and 8 are with monthly mean runoffs of 29, 24, 22, 23, 26, and 27 mm, respectively, and these watersheds would likely contribute to surface runoff in the study area. The purpose of this study was to transform runoff data into a smooth curve for representing the surface runoff pattern and mean runoff of each watershed through statistical method. This study provides information of runoff potentiality of each watershed and also provides input data for hydrological modeling. PMID:25152911

Legacy nutrient dynamics and patterns of catchment response under changing land use and management

NASA Astrophysics Data System (ADS)

Attinger, S.; Van, M. K.; Basu, N. B.

2017-12-01

Watersheds are complex heterogeneous systems that store, transform, and release water and nutrients under a broad distribution of both natural and anthropogenic controls. Many current watershed models, from complex numerical models to simpler reservoir-type models, are considered to be well-developed in their ability to predict fluxes of water and nutrients to streams and groundwater. They are generally less adept, however, at capturing watershed storage dynamics. In other words, many current models are run with an assumption of steady-state dynamics, and focus on nutrient flows rather than changes in nutrient stocks within watersheds. Although these commonly used modeling approaches may be able to adequately capture short-term watershed dynamics, they are unable to represent the clear nonlinearities or hysteresis responses observed in watersheds experiencing significant changes in nutrient inputs. To address such a lack, we have, in the present work, developed a parsimonious modeling approach designed to capture long-term catchment responses to spatial and temporal changes in nutrient inputs. In this approach, we conceptualize the catchment as a biogeochemical reactor that is driven by nutrient inputs, characterized internally by both biogeochemical degradation and residence or travel time distributions, resulting in a specific nutrient output. For the model simulations, we define a range of different scenarios to represent real-world changes in land use and management implemented to improve water quality. We then introduce the concept of state-space trajectories to describe system responses to these potential changes in anthropogenic forcings. We also increase model complexity, in a stepwise fashion, by dividing the catchment into multiple biogeochemical reactors, coupled in series or in parallel. Using this approach, we attempt to answer the following questions: (1) What level of model complexity is needed to capture observed system responses? (2) How can we explain different patterns of nonlinearity in watershed nutrient dynamics? And finally, how does the accumulation of nutrient legacies within watersheds impact current and future water quality?

A Transforming Marker That Produces Merodiploids with High Efficiency and Stable Transformants with Low Efficiency in Streptococcus

PubMed Central

Ravin, Arnold W.; Ma, Michael

1975-01-01

A mutation (ery-r8) conferring a high level of resistance to erythromycin in the Challis strain of Streptoccus sanguis can be transferred to wild-type erythromycin-sensitive recipients via single molecules of donor DNA. The transformants thus produced are of two types: (1) cells slightly more resistant to erythromycin than wild-type and capable of segregating (at a frequency of 2 x 10-4/bacterium/generation) either wild-type or highly-resistant cells like the original donor type; (2) cells phenotypically and genotypically identical to the original donor type. The unstable diploids (ery-r8/+) occur with a frequency equivalent to that obtained with high-efficiency (HE) markers, whereas the stable donor-type (ery-r8) transformants occur with about five hundred times lower frequency. Penetration of the wild-type recipient by more than one molecule of DNA bearing the ery-r8 marker increases by as much as seven times the incidence of stable transformants. UV-irradiation of molecules bearing the ery-r8 marker diminishes their ability to cooperate in producing a stable transformant, although the UV sensitivity of stable transformant production by a single DNA molecule is not different from that of diploid production. Hence, stable transformants do not appear to be produced by a process typical of low efficiency (LE) markers, which are generally highly sensitive to ultraviolet irradiation. Moreover, stable ery-r8 transformants are produced with equally low frequencies in strains of S. pneumoniae that discriminate (hex+) and fail to discriminate (hex -) between HE and LE markers. We postulate that all transformations by the ery-r8 marker result in ery-r8/+ diploids, and that segregation results in the infrequent stable transformants of the original donor type. This hypothesis is supported by the observations that rifampin treatment of ery-r8/+ populations increases the frequency of segregation and similar treatment of wild-type recipients undergoing transformation by the ery-r8 marker increases the frequency of stable transformants.—In producing the ery-r8/+ transformant the r8 allele is integrated close to the site of its wild-type homolog, since single molecules of DNA from this transformant can be shown to carry both alleles. Segregation of either the ery-r8 or + allele is not detectably enhanced by acridine orange or thymidine deprivation.—The ery-r8 marker occurs close to a site of mutation (ery-r2) which confers erythromycin resistance upon ribosomes. When the r2 and r8 markers are jointly transferred, ery-r2-r8/+ genomes are produced in which the r2 marker is stably integrated but the r8 marker is unstably adjoined to its wild-type homolog. Thus, the duplicated region can be quite short. When the ery-r8 marker is stably integrated, the region of the marker is refractory to subsequent transformation. Markers with properties like ery-r8 are not particularly rare, being found with a frequency of about 4% among spontaneous mutations to erythromycin resistance. PMID:1232022

Effect of freshwater sediment characteristics on the persistence of fecal indicator bacteria and genetic markers within a Southern California Watershed.

EPA Science Inventory

In this study, the relative aging of FIB and genetic markers for Enterococcus spp. (ENT1A), general Bacteroides (GenBac3), and human-associated Bacteroides (HF183) in varying freshwater sediments was evaluated. Freshwater sediment was collected from four different sites within th...

A Cross-Site Comparison of Factors Influencing Soil Nitrification Rates in Northeastern USA Forested Watersheds

Treesearch

Donald S. Ross; Beverley C. Wemple; Austin E. Jamison; Guinevere Fredriksen; James B. Shanley; Gregory B. Lawrence; Scott W. Bailey; John L. Campbell

2009-01-01

Elevated N deposition is continuing on many forested landscapes around the world and our understanding of ecosystem response is incomplete. Soil processes, especially nitrification, are critical. Many studies of soil N transformations have focused on identifying relationships within a single watershed but these results are often not transferable. We studied 10 small...

Machine learning approach for automated screening of malaria parasite using light microscopic images.

PubMed

Das, Dev Kumar; Ghosh, Madhumala; Pal, Mallika; Maiti, Asok K; Chakraborty, Chandan

2013-02-01

The aim of this paper is to address the development of computer assisted malaria parasite characterization and classification using machine learning approach based on light microscopic images of peripheral blood smears. In doing this, microscopic image acquisition from stained slides, illumination correction and noise reduction, erythrocyte segmentation, feature extraction, feature selection and finally classification of different stages of malaria (Plasmodium vivax and Plasmodium falciparum) have been investigated. The erythrocytes are segmented using marker controlled watershed transformation and subsequently total ninety six features describing shape-size and texture of erythrocytes are extracted in respect to the parasitemia infected versus non-infected cells. Ninety four features are found to be statistically significant in discriminating six classes. Here a feature selection-cum-classification scheme has been devised by combining F-statistic, statistical learning techniques i.e., Bayesian learning and support vector machine (SVM) in order to provide the higher classification accuracy using best set of discriminating features. Results show that Bayesian approach provides the highest accuracy i.e., 84% for malaria classification by selecting 19 most significant features while SVM provides highest accuracy i.e., 83.5% with 9 most significant features. Finally, the performance of these two classifiers under feature selection framework has been compared toward malaria parasite classification. Copyright © 2012 Elsevier Ltd. All rights reserved.

A cross-site comparison of factors influencing soil nitrification rates in northeastern USA forested watersheds

USGS Publications Warehouse

Ross, D.S.; Wemple, B.C.; Jamison, A.E.; Fredriksen, G.; Shanley, J.B.; Lawrence, G.B.; Bailey, S.W.; Campbell, J.L.

2009-01-01

Elevated N deposition is continuing on many forested landscapes around the world and our understanding of ecosystem response is incomplete. Soil processes, especially nitrification, are critical. Many studies of soil N transformations have focused on identifying relationships within a single watershed but these results are often not transferable. We studied 10 small forested research watersheds in the northeastern USA to determine if there were common factors related to soil ammonification and nitrification. Vegetation varied between mixed northern hardwoods and mixed conifers. Watershed surface soils (Oa or A horizons) were sampled at grid or transect points and analyzed for a suite of chemical characteristics. At each sampling point, vegetation and topographic metrics (field and GIS-based) were also obtained. Results were examined by watershed averages (n = 10), seasonal/watershed averages (n = 28), and individual sampling points (n = 608). Using both linear and tree regression techniques, the proportion of conifer species was the single best predictor of nitrification rates, with lower rates at higher conifer dominance. Similar to other studies, the soil C/N ratio was also a good predictor and was well correlated with conifer dominance. Unlike other studies, the presence of Acer saccharum was not by itself a strong predictor, but was when combined with the presence of Betula alleghaniensis. Topographic metrics (slope, aspect, relative elevation, and the topographic index) were not related to N transformation rates across the watersheds. Although found to be significant in other studies, neither soil pH, Ca nor Al was related to nitrification. Results showed a strong relationship between dominant vegetation, soil C, and soil C/N. ?? 2008 Springer Science+Business Media, LLC.

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages

PubMed Central

Cao, Yiping; Raith, Meredith R.; Smith, Paul D.; Griffith, John F.; Weisberg, Stephen B.; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Gregory, Jason; Guzman, Joe; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-01-01

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool. PMID:28777324

Regional Assessment of Human Fecal Contamination in Southern California Coastal Drainages.

PubMed

Cao, Yiping; Raith, Meredith R; Smith, Paul D; Griffith, John F; Weisberg, Stephen B; Schriewer, Alexander; Sheldon, Andrew; Crompton, Chris; Amenu, Geremew G; Gregory, Jason; Guzman, Joe; Goodwin, Kelly D; Othman, Laila; Manasjan, Mayela; Choi, Samuel; Rapoport, Shana; Steele, Syreeta; Nguyen, Tommy; Yu, Xueyuan

2017-08-04

Host-associated genetic markers that allow for fecal source identification have been used extensively as a diagnostic tool to determine fecal sources within watersheds, but have not been used in routine monitoring to prioritize remediation actions among watersheds. Here, we present a regional assessment of human marker prevalence among drainages that discharge to the U.S. southern California coast. Approximately 50 samples were analyzed for the HF183 human marker from each of 22 southern California coastal drainages under summer dry weather conditions, and another 50 samples were targeted from each of 23 drainages during wet weather. The HF183 marker was ubiquitous, detected in all but two sites in dry weather and at all sites during wet weather. However, there was considerable difference in the extent of human fecal contamination among sites. Similar site ranking was produced regardless of whether the assessment was based on frequency of HF183 detection or site average HF183 concentration. However, site ranking differed greatly between dry and wet weather. Site ranking also differed greatly when based on enterococci, which do not distinguish between pollution sources, vs. HF183, which distinguishes higher risk human fecal sources from other sources, indicating the additional value of the human-associated marker as a routine monitoring tool.

Effect of promoter driving selectable marker on corn transformation.

PubMed

Prakash, N Shiva; Prasad, V; Chidambram, Thillai P; Cherian, Shoba; Jayaprakash, T L; Dasgupta, Santanu; Wang, Qi; Mann, Michael T; Spencer, T Michael; Boddupalli, Raghava S

2008-08-01

Identification of an appropriate selection agent and its corresponding selectable marker gene is one of the first steps in establishing a transformation protocol for a given plant species. As the promoter controls expression level of the genes, the promoter driving the selectable marker gene can affect transformation. However, investigations into the direct effect of promoters driving selectable marker on transformation are lacking in the literature though many reports of relative strengths of promoters driving reporter genes like GUS or CAT or GFP are available. In the present study, we have compared rice Actin1 and CaMV.35S (commonly used promoters in monocotyledonous plant transformation) promoters driving nptII for their effectiveness in paromomycin selection of transgenic corn events. To enable statistically meaningful analysis of the results, a large sample size of nearly 5,000 immature embryos (explants) was employed producing approximately 1,250 independent events from each of the two constructs in four independent experiments. The rate of appearance of resistant calli and percentage of resistant calli recovered was higher with P-Os.Actin1/nptII/nos3' as compared to P-CaMV.35S/nptII/nos3' in all four experiments. There was no appreciable difference either in the frequency of plant regeneration or in the morphological characteristics of plants recovered from the two constructs. Although the escape rate trended lower with P-Os.Actin1 as compared to P-CaMV.35S, the recovery of low copy events was significantly higher with P-CaMV.35S. The higher transformation frequency with P-Os.Actin1 could be related to the strength of this promoter as compared to P-CaMV.35S in the explants and/or calli. Based on these results, we infer that the promoter driving the selectable marker is an important factor to be considered while establishing a high throughput transformation protocol as it could not only influence the transformation frequency but also the copy number of the transgene in the recovered transgenics.

Aspects of Carbon and Sulfur Transformations in MOFEP Surface Soils

Treesearch

Henry G. Spratt

1997-01-01

Carbon and sulfur transformations were studied in surface soils from plots in MOFEP sites from August 1993 to May 1996 and in plots in watersheds ofMOFEP sites 1, 3, and 4 from May 1995 to May 1996. Element pools measured included total carbon, total sulfur, sulfate, and organic sulfur. Transformations quantified included lignocellulose mineralization and organic...

Real-time implementations of image segmentation algorithms on shared memory multicore architecture: a survey (Conference Presentation)

NASA Astrophysics Data System (ADS)

Akil, Mohamed

2017-05-01

The real-time processing is getting more and more important in many image processing applications. Image segmentation is one of the most fundamental tasks image analysis. As a consequence, many different approaches for image segmentation have been proposed. The watershed transform is a well-known image segmentation tool. The watershed transform is a very data intensive task. To achieve acceleration and obtain real-time processing of watershed algorithms, parallel architectures and programming models for multicore computing have been developed. This paper focuses on the survey of the approaches for parallel implementation of sequential watershed algorithms on multicore general purpose CPUs: homogeneous multicore processor with shared memory. To achieve an efficient parallel implementation, it's necessary to explore different strategies (parallelization/distribution/distributed scheduling) combined with different acceleration and optimization techniques to enhance parallelism. In this paper, we give a comparison of various parallelization of sequential watershed algorithms on shared memory multicore architecture. We analyze the performance measurements of each parallel implementation and the impact of the different sources of overhead on the performance of the parallel implementations. In this comparison study, we also discuss the advantages and disadvantages of the parallel programming models. Thus, we compare the OpenMP (an application programming interface for multi-Processing) with Ptheads (POSIX Threads) to illustrate the impact of each parallel programming model on the performance of the parallel implementations.

Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed

USDA-ARS?s Scientific Manuscript database

Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. These contaminants can be mobilized into the water column due to resuspension events, thus affecting overall water quality. Along with the contaminants, other markers such as microbia...

Microsatellite markers for the endangered Roanoke logperch, Percina rex (Percidae) and their potential utility for other darter species.

PubMed

Dutton, Daniel J; Roberts, James H; Angermeier, Paul L; Hallerman, Eric M

2008-07-01

The Roanoke logperch (Percina rex Jordan and Evermann), an endangered fish, occurs in only six watersheds in the Roanoke and Chowan river drainages of Virginia, USA. The species' population genetic structure is poorly known. We developed 16 microsatellite markers that were reliably scorable and polymorphic P. rex. Markers were also screened in seven other darter species of the genus Percina. Most markers exhibited successful amplification and polymorphism in several species. These markers may therefore prove useful for population genetic studies in other darters, a diverse but highly imperiled group. © 2008 The Authors. Journal compilation © 2008 Blackwell Publishing Ltd.

The assessment of land use change impact on watersheds runoff using SWAT: case study of Urmia Lake in Iran

NASA Astrophysics Data System (ADS)

Jabbari, Anahita; Jarihani, Ben; Rezaie, Hossein

2015-04-01

Lake Urmia, long counted among the world's largest saltwater lakes, contains only 5% of the amount of water it did just 20 years ago. The decline is generally blamed on a combination of drought, increased water diversion for irrigated agriculture within the lake's watershed and land use mismanagement. It has been believed that land use changes in Lake Urmia basin is one of the most important factors in shrinkage of Urmia Lake in recent decades. Transforming the traditional agricultural practices (i.e., wheat) to the more water consuming practices (i.e., apple orchards) is one of the most important reasons increased agricultural water consumption in the watershed. In this study we assessed the effect of the land use changes of watershed in hydrological runoff processing in the Nazloo chai watershed, one of the most important river basins of the Urmia Lake basin. Actually the rapid and at the same time unreasonable transformations of land use in farm lands of Urmia lake sub basins, extremely has been raised the amount of blue water (surface or groundwater) consumption in watershed which leads to dramatic decrement of watershed runoff amounts. One of the most unfavorable consequences of land use change was changing the blue and green (rainwater insofar as it does not become runoff) water usage patterns in watershed, in addition to water use increment. The soil and water assessment tool (SWAT), one of the most important and reliable models which was used to model the rainfall runoff, has been used in current study. The land use maps were extracted from Landsat images archives for the most severe turning points in respect of land use change in the recent 30 years. After calibrating the model, several land use patterns of historical data were used in the model to produce the runoff. The results showed the strong relation between land use change and runoff reduction in the Lake Urmia basin.

Complex Catchment Processes that Control Stream Nitrogen and Organic Matter Concentrations in a Northeastern USA Upland Catchment

NASA Astrophysics Data System (ADS)

Sebestyen, S. D.; Shanley, J. B.; Pellerin, B.; Saraceno, J.; Aiken, G. R.; Boyer, E. W.; Doctor, D. H.; Kendall, C.

2009-05-01

There is a need to understand the coupled biogeochemical and hydrological processes that control stream hydrochemistry in upland forested catchments. At watershed 9 (W-9) of the Sleepers River Research Watershed in the northeastern USA, we use high-frequency sampling, environmental tracers, end-member mixing analysis, and stream reach mass balances to understand dynamic factors affect forms and concentrations of nitrogen and organic matter in streamflow. We found that rates of stream nitrate processing changed during autumn baseflow and that up to 70% of nitrate inputs to a stream reach were retained. At the same time, the stream reach was a net source of the dissolved organic carbon (DOC) and dissolved organic nitrogen (DON) fractions of dissolved organic matter (DOM). The in-stream nitrate loss and DOM gains are examples of hot moments of biogeochemical transformations during autumn when deciduous litter fall increases DOM availability. As hydrological flowpaths changed during rainfall events, the sources and transformations of nitrate and DOM differed from baseflow. For example, during storm flow we measured direct inputs of unprocessed atmospheric nitrate to streams that were as large as 30% of the stream nitrate loading. At the same time, stream DOM composition shifted to reflect inputs of reactive organic matter from surficial upland soils. The transport of atmospheric nitrate and reactive DOM to streams underscores the importance of quantifying source variation during short-duration stormflow events. Building upon these findings we present a conceptual model of interacting ecosystem processes that control the flow of water and nutrients to streams in a temperate upland catchment.

Optimal land use management for soil erosion control by using an interval-parameter fuzzy two-stage stochastic programming approach.

PubMed

Han, Jing-Cheng; Huang, Guo-He; Zhang, Hua; Li, Zhong

2013-09-01

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 10(9) $ was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.

Optimal Land Use Management for Soil Erosion Control by Using an Interval-Parameter Fuzzy Two-Stage Stochastic Programming Approach

NASA Astrophysics Data System (ADS)

Han, Jing-Cheng; Huang, Guo-He; Zhang, Hua; Li, Zhong

2013-09-01

Soil erosion is one of the most serious environmental and public health problems, and such land degradation can be effectively mitigated through performing land use transitions across a watershed. Optimal land use management can thus provide a way to reduce soil erosion while achieving the maximum net benefit. However, optimized land use allocation schemes are not always successful since uncertainties pertaining to soil erosion control are not well presented. This study applied an interval-parameter fuzzy two-stage stochastic programming approach to generate optimal land use planning strategies for soil erosion control based on an inexact optimization framework, in which various uncertainties were reflected. The modeling approach can incorporate predefined soil erosion control policies, and address inherent system uncertainties expressed as discrete intervals, fuzzy sets, and probability distributions. The developed model was demonstrated through a case study in the Xiangxi River watershed, China's Three Gorges Reservoir region. Land use transformations were employed as decision variables, and based on these, the land use change dynamics were yielded for a 15-year planning horizon. Finally, the maximum net economic benefit with an interval value of [1.197, 6.311] × 109 was obtained as well as corresponding land use allocations in the three planning periods. Also, the resulting soil erosion amount was found to be decreased and controlled at a tolerable level over the watershed. Thus, results confirm that the developed model is a useful tool for implementing land use management as not only does it allow local decision makers to optimize land use allocation, but can also help to answer how to accomplish land use changes.

Hydrologic connectivity as a framework for understanding biogeochemical flux through watersheds and along fluvial networks

NASA Astrophysics Data System (ADS)

Covino, Tim

2017-01-01

Hydrologic connections can link hillslopes to channel networks, streams to lakes, subsurface to surface, land to atmosphere, terrestrial to aquatic, and upstream to downstream. These connections can develop across vertical, lateral, and longitudinal dimensions and span spatial and temporal scales. Each of these dimensions and scales are interconnected, creating a mosaic of nested hydrologic connections and associated processes. In turn, these interacting and nested processes influence the transport, cycling, and transformation of organic material and inorganic nutrients through watersheds and along fluvial networks. Although hydrologic connections span dimensions and spatiotemporal scales, relationships between connectivity and carbon and nutrient dynamics are rarely evaluated within this framework. The purpose of this paper is to provide a cross-disciplinary view of hydrologic connectivity - highlighting the various forms of hydrologic connectivity that control fluxes of organic material and nutrients - and to help stimulate integration across scales and dimensions, and collaboration among disciplines.

Effect of forest harvesting best management practices on coarse woody debris distribution in stream and riparian zones in three Appalachian watersheds

Treesearch

J. M. McClure; R. K. Kolka; A. White

2004-01-01

The distribution of coarse woody debris (CWD) was analyzed in three Appalachian watersheds in eastern Kentucky, eighteen years after harvest. The three watersheds included an unharvested control (Control), a second watershed with best management practices (BMPs) applied that included a 15.2 m unharvested zone near the stream (BMP watershed), and a third watershed that...

Sensors in the Stream: The High-Frequency Wave of the Present.

PubMed

Rode, Michael; Wade, Andrew J; Cohen, Matthew J; Hensley, Robert T; Bowes, Michael J; Kirchner, James W; Arhonditsis, George B; Jordan, Phil; Kronvang, Brian; Halliday, Sarah J; Skeffington, Richard A; Rozemeijer, Joachim C; Aubert, Alice H; Rinke, Karsten; Jomaa, Seifeddine

2016-10-04

New scientific understanding is catalyzed by novel technologies that enhance measurement precision, resolution or type, and that provide new tools to test and develop theory. Over the last 50 years, technology has transformed the hydrologic sciences by enabling direct measurements of watershed fluxes (evapotranspiration, streamflow) at time scales and spatial extents aligned with variation in physical drivers. High frequency water quality measurements, increasingly obtained by in situ water quality sensors, are extending that transformation. Widely available sensors for some physical (temperature) and chemical (conductivity, dissolved oxygen) attributes have become integral to aquatic science, and emerging sensors for nutrients, dissolved CO 2 , turbidity, algal pigments, and dissolved organic matter are now enabling observations of watersheds and streams at time scales commensurate with their fundamental hydrological, energetic, elemental, and biological drivers. Here we synthesize insights from emerging technologies across a suite of applications, and envision future advances, enabled by sensors, in our ability to understand, predict, and restore watershed and stream systems.

Automatic extraction of planetary image features

NASA Technical Reports Server (NTRS)

LeMoigne-Stewart, Jacqueline J. (Inventor); Troglio, Giulia (Inventor); Benediktsson, Jon A. (Inventor); Serpico, Sebastiano B. (Inventor); Moser, Gabriele (Inventor)

2013-01-01

A method for the extraction of Lunar data and/or planetary features is provided. The feature extraction method can include one or more image processing techniques, including, but not limited to, a watershed segmentation and/or the generalized Hough Transform. According to some embodiments, the feature extraction method can include extracting features, such as, small rocks. According to some embodiments, small rocks can be extracted by applying a watershed segmentation algorithm to the Canny gradient. According to some embodiments, applying a watershed segmentation algorithm to the Canny gradient can allow regions that appear as close contours in the gradient to be segmented.

Problems with the dating of sediment core using excess (210)Pb in a freshwater system impacted by large scale watershed changes.

PubMed

Baskaran, Mark; Nix, Joe; Kuyper, Clark; Karunakara, N

2014-12-01

Pb-210 dating of freshwater and coastal sediments have been extensively conducted over the past 40 years for historical pollution reconstruction studies, sediment focusing, sediment accumulation and mixing rate determination. In areas where there is large scale disturbance of sediments and the watershed, the vertical profiles of excess (210)Pb ((210)Pbxs) could provide erroneous or less reliable information on sediment accumulation rates. We analyzed one sediment core from Hendrix Lake in southwestern Arkansas for excess (210)Pb and (137)Cs. There is no decrease in excess (210)Pb activity with depth while the (137)Cs profile indicates sharp peak corresponding to 1963 and the (137)Cs penetration depth of (137)Cs corresponds to 1952. The historical data on the accelerated mercury mining during 1931-1944 resulted in large-scale Hg input to this watershed. Using the peak Hg activity as a time marker, the obtained sediment accumulation rates agree well with the (137)Cs-based rates. Four independent evidences (two-marker events based on (137)Cs and two marker events based on Hg mining activity) result in about the same sedimentation rates and thus, we endorse earlier suggestion that (210)Pb profile always needs to be validated with at least one another independent method. We also present a concise discussion on what important factors that can affect the vertical profiles of (210)Pbxs in relatively smaller lakes. Copyright © 2014 Elsevier Ltd. All rights reserved.

Physiography, geology, and land cover of four watersheds in eastern Puerto Rico: Chapter A in Water quality and landscape processes of four watersheds in eastern Puerto Rico

USGS Publications Warehouse

Murphy, Sheila F.; Stallard, Robert F.; Larsen, Matthew C.; Gould, William A.; Murphy, Sheila F.

2012-01-01

Four watersheds with differing geology and land cover in eastern Puerto Rico have been studied on a long-term basis by the U.S. Geological Survey to evaluate water, energy, and biogeochemical budgets. These watersheds are typical of tropical, island-arc settings found in many parts of the world. Two watersheds are located on coarse-grained granitic rocks that weather to quartz- and clay-rich, sandy soils, and two are located on fine-grained volcanic rocks and volcaniclastic sedimentary rocks that weather to quartz-poor, fine-grained soils. For each bedrock type, one watershed is covered with mature forest, and the other watershed, like most of Puerto Rico, has transformed from relatively undisturbed pre-European forest to intensive agriculture in the 19th and early 20th centuries, and further to ongoing reforestation that began in the middle of the 20th century. The comparison of water chemistry and hydrology in these watersheds allows an evaluation of the effects of land-use history and geology on hydrologic regimes and erosion rates. This chapter describes the physiography, geology, and land cover of the four watersheds and provides background information for the remaining chapters in this volume.

Stormwater Infrastructure Effects on Urban Nitrogen Budgets

NASA Astrophysics Data System (ADS)

Hale, R. L.; Turnbull, L.; Earl, S.; Moratto, S.; Shorts, D.; Grimm, N. B.

2012-12-01

The effects of urbanization on downstream ecosystems, particularly due to changes in nutrient inputs and altered hydrology are well studied. Less is known, however, about nutrient transport and processing within urban watersheds. Previous research has focused on the roles of land cover and land use but drainage system design and configuration also are apt to play a significant role in controlling the transport of water and nutrients downstream. Furthermore, variability in drainage systems within and between cities may lead to differences in the effects of urbanization on downstream ecosystems over time and space. We established a nested stormwater sampling network with 10 watersheds ranging in size from 5 to 22,000 ha in the Indian Bend Wash watershed in Scottsdale, AZ. Small (< 200ha) watersheds had uniform land cover (medium-density residential) but were drained by a variety of stormwater infrastructure including surface runoff, pipes, natural or engineered washes, and retention basins. We quantified discharge and precipitation at the outflow of each subwatershed and collected stormwater and rainfall samples for analyses of dissolved nitrogen species and δ15N, δ18O and Δ17O isotopes of nitrate (NO3) over two years. We also measured potential denitrification rates in washes and retention basins within our sites, and collected soil and pavement samples to describe pools of N within our watersheds. We used these data in combination with literature data on soil N transformations to construct N budgets for each watershed for a single event and at annual scales. We found that stormwater infrastructure type strongly affects N retention. Watersheds with surface or pipe drainage were sources of N downstream, whereas watersheds drained by washes or retention basins retained 70-99% of N inputs in rainfall. Event scale N retention was strongly correlated with hydrologic connectivity, as measured by runoff coefficients. Differences in δ15N, δ18O, and Δ17O isotopes of NO3 suggested that watersheds with decreased hydrologic connectivity were more biogeochemically active, that is, exported NO3 had less of an atmospheric signal than did NO3 exported from piped watersheds. Overall, we find that stormwater infrastructure significantly alters hydrologic connectivity and that these changes in hydrology are driving patterns in N export and retention.

Persistence of soil organic matter in eroding versus depositional landform positions

USGS Publications Warehouse

Berhe, Asmeret Asefaw; Harden, Jennifer W.; Torn, Margaret S.; Kleber, Markus; Burton, Sarah D.; Harte, John

2012-01-01

Soil organic matter (SOM) processes in dynamic landscapes are strongly influenced by soil erosion and sedimentation. We determined the contribution of physical isolation of organic matter (OM) inside aggregates, chemical interaction of OM with soil minerals, and molecular structure of SOM in controlling storage and persistence of SOM in different types of eroding and depositional landform positions. By combining density fractionation with elemental and spectroscopic analyses, we showed that SOM in depositional settings is less transformed and better preserved than SOM in eroding landform positions. However, which environmental factors exert primary control on storage and persistence of SOM depended on the nature of the landform position considered. In an annual grassland watershed, protection of SOM by physical isolation inside aggregates and chemical association of organic matter (complexation) with soil minerals, as assessed by correlation with radiocarbon concentration, were more effective in the poorly drained, lowest-lying depositional landform positions, compared to well-drained landform positions in the upper parts of the watershed. Results of this study demonstrated that processes of soil erosion and deposition are important mechanisms of long-term OM stabilization.

Conjunction of wavelet transform and SOM-mutual information data pre-processing approach for AI-based Multi-Station nitrate modeling of watersheds

NASA Astrophysics Data System (ADS)

Nourani, Vahid; Andalib, Gholamreza; Dąbrowska, Dominika

2017-05-01

Accurate nitrate load predictions can elevate decision management of water quality of watersheds which affects to environment and drinking water. In this paper, two scenarios were considered for Multi-Station (MS) nitrate load modeling of the Little River watershed. In the first scenario, Markovian characteristics of streamflow-nitrate time series were proposed for the MS modeling. For this purpose, feature extraction criterion of Mutual Information (MI) was employed for input selection of artificial intelligence models (Feed Forward Neural Network, FFNN and least square support vector machine). In the second scenario for considering seasonality-based characteristics of the time series, wavelet transform was used to extract multi-scale features of streamflow-nitrate time series of the watershed's sub-basins to model MS nitrate loads. Self-Organizing Map (SOM) clustering technique which finds homogeneous sub-series clusters was also linked to MI for proper cluster agent choice to be imposed into the models for predicting the nitrate loads of the watershed's sub-basins. The proposed MS method not only considers the prediction of the outlet nitrate but also covers predictions of interior sub-basins nitrate load values. The results indicated that the proposed FFNN model coupled with the SOM-MI improved the performance of MS nitrate predictions compared to the Markovian-based models up to 39%. Overall, accurate selection of dominant inputs which consider seasonality-based characteristics of streamflow-nitrate process could enhance the efficiency of nitrate load predictions.

[Decrease of spontaneous mutations in Haemophilus influenzae caused by transformation with its own DNA irradiated with near-ultraviolet light].

PubMed

Alarcón-Hernández, E; Cabrera-Juárez, E

1992-01-01

Transforming DNA containing the streptomycin resistance marker, was irradiated for 8 h with broad near ultraviolet light (325-400 nm) at pH 4.8, and the inactivation kinetics determined. After selection of streptomycin resistant transformants, they were grown until a turbidity of 150-200 Klett units. In these cultures we looked for new markers coming from the irradiated transforming DNA. We looked and found the novobiocin resistance marker and one that conveys to protoporphyrin IX utilization, measured as an increase in the mutation frequency of these markers in the streptomycin resistant population. In other experiments, we found a decline in spontaneous mutation frequency for the same markers in the cells transformed with irradiated DNA. This last finding rises the possibility of alterations on the mutator genes as a result of near ultraviolet irradiation.

Background, short-term and potential long-term denitrification capacity of soils in urbanized coastal watersheds on Kiawah Island, South Carolina, USA

Treesearch

S.R. Drescher; A.J. Lewitus; S.D. Brown

2006-01-01

Urbanization is escalating in many coastal areas of the US and is associated with deteriorating water quality. Often the associated changes in land use result in an overabundance of nutrients and other types of pollution entering ground and surface waters. It is important that we understand biogeochemical transformation processes on urbanizing watersheds if we are to...

Development of Genetic Markers for Environmental DNA (eDNA) Monitoring of Sturgeon

DTIC Science & Technology

2014-09-01

sturgeon markers were tested for specificity against a battery of 32 non-target fish species common to the Mississippi and Illinois River watersheds...techniques. Such methods, including fishing , netting, seining, and electrofishing, can often be logistically complex and require considerable outlays of... fish and amphibian community composition (Minamoto et al. 2012, Thomsen et al. 2012) and biomass estimation (Takahara et al. 2012). Sturgeon are taxa

Retrospective Review of Watershed Characteristics and a Framework for Future Research in the Sarasota Bay Watershed, Florida

USGS Publications Warehouse

Kish, George R.; Harrison, Arnell S.; Alderson, Mark

2008-01-01

The U.S. Geological Survey, in cooperation with the Sarasota Bay Estuary Program conducted a retrospective review of characteristics of the Sarasota Bay watershed in west-central Florida. This report describes watershed characteristics, surface- and ground-water processes, and the environmental setting of the Sarasota Bay watershed. Population growth during the last 50 years is transforming the Sarasota Bay watershed from rural and agriculture to urban and suburban. The transition has resulted in land-use changes that influence surface- and ground-water processes in the watershed. Increased impervious cover decreases recharge to ground water and increases overland runoff and the pollutants carried in the runoff. Soil compaction resulting from agriculture, construction, and recreation activities also decreases recharge to ground water. Conventional approaches to stormwater runoff have involved conveyances and large storage areas. Low-impact development approaches, designed to provide recharge near the precipitation point-of-contact, are being used increasingly in the watershed. Simple pollutant loading models applied to the Sarasota Bay watershed have focused on large-scale processes and pollutant loads determined from empirical values and mean event concentrations. Complex watershed models and more intensive data-collection programs can provide the level of information needed to quantify (1) the effects of lot-scale land practices on runoff, storage, and ground-water recharge, (2) dry and wet season flux of nutrients through atmospheric deposition, (3) changes in partitioning of water and contaminants as urbanization alters predevelopment rainfall-runoff relations, and (4) linkages between watershed models and lot-scale models to evaluate the effect of small-scale changes over the entire Sarasota Bay watershed. As urbanization in the Sarasota Bay watershed continues, focused research on water-resources issues can provide information needed by water-resources managers to ensure the future health of the watershed.

Targeting the Sources of Fecal Contamination using Dog-, Human-, and Ruminant- Specific Markers in the Lake Herrick Watershed, Georgia.

NASA Astrophysics Data System (ADS)

Saintil, T.; Radcliffe, D. E.; Rasmussen, T. C.; Habteselassie, M.; Sowah, R.; Kannan, A.

2016-12-01

The Lake Herrick Watershed is about 1.5 km2 and covers portions of the University of Georgia's East campus, the Oconee Forest, residential and commercial landuse. Lake Herrick, a recreational site on the University of Georgia campus, was closed in 2002 due to fecal contamination. Subsequent monitoring confirmed persistent contamination, which led to a permanent closure to swimming, boating, and fishing. While fecal coliform abundance is a standard metric for determining human health risks, Geldreich (1970) showed that fecal abundance does not necessarily correlate with the presence of pathogens. Nor does it identify pollution sources, which are needed to mitigate health risks. Two inflow tributaries and the outlet stream were monitored for discharge, fecal coliform, forms of nitrogen and phosphorus and other water-quality data to quantify lake influent and effluent bacteria loads. Fecal sources were identified using the human HF183 genetic marker (Seurinck et al., 2005), the ruminant BacR marker (Reischer et al., 2006), and the dog mitochondrial DNA (mtDNA) marker (Tambalo et al., 2012). Preliminary results confirm high concentrations of E. coli and Enterococci, above the State's limit of 124 MPN/100 mL, in both baseflows and stormflows. The findings also suggest that the E. coli and Enterococci loads from the inlet tributaries are on average higher compared to the bacteria loads coming out of the outlet stream. The human markers were detectable at all three sites but most of the samples were not quantifiable. The ruminant markers were quantifiable at both inlets but no ruminant markers were found at the outlet. The dog markers were detectable but not quantifiable at both inlets and no dog markers were detected at the outlet. Statistical analyses will be used to establish relationships between the nutrients data, the fecal concentrations, and the gene-specific markers.

Bladder segmentation in MR images with watershed segmentation and graph cut algorithm

NASA Astrophysics Data System (ADS)

Blaffert, Thomas; Renisch, Steffen; Schadewaldt, Nicole; Schulz, Heinrich; Wiemker, Rafael

2014-03-01

Prostate and cervix cancer diagnosis and treatment planning that is based on MR images benefit from superior soft tissue contrast compared to CT images. For these images an automatic delineation of the prostate or cervix and the organs at risk such as the bladder is highly desirable. This paper describes a method for bladder segmentation that is based on a watershed transform on high image gradient values and gray value valleys together with the classification of watershed regions into bladder contents and tissue by a graph cut algorithm. The obtained results are superior if compared to a simple region-after-region classification.

Sediment delivery to the Gulf of Alaska: source mechanisms along a glaciated transform margin

USGS Publications Warehouse

Dobson, M.R.; O'Leary, D.; Veart, M.

1998-01-01

Sediment delivery to the Gulf of Alaska occurs via four areally extensive deep-water fans, sourced from grounded tidewater glaciers. During periods of climatic cooling, glaciers cross a narrow shelf and discharge sediment down the continental slope. Because the coastal terrain is dominated by fjords and a narrow, high-relief Pacific watershed, deposition is dominated by channellized point-source fan accumulations, the volumes of which are primarily a function of climate. The sediment distribution is modified by a long-term tectonic translation of the Pacific plate to the north along the transform margin. As a result, the deep-water fans are gradually moved away from the climatically controlled point sources. Sets of abandoned channels record the effect of translation during the Plio-Pleistocene.

SFA 2.0- Watershed Structure and Controls

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Ken

2015-01-23

Berkeley Lab Earth Scientist Ken Williams explains the watershed research within the Sustainable Systems SFA 2.0 project—including identification and monitoring of primary factors that control watershed biogeochemical functioning.

Automatic segmentation of vessels in in-vivo ultrasound scans

NASA Astrophysics Data System (ADS)

Tamimi-Sarnikowski, Philip; Brink-Kjær, Andreas; Moshavegh, Ramin; Arendt Jensen, Jørgen

2017-03-01

Ultrasound has become highly popular to monitor atherosclerosis, by scanning the carotid artery. The screening involves measuring the thickness of the vessel wall and diameter of the lumen. An automatic segmentation of the vessel lumen, can enable the determination of lumen diameter. This paper presents a fully automatic segmentation algorithm, for robustly segmenting the vessel lumen in longitudinal B-mode ultrasound images. The automatic segmentation is performed using a combination of B-mode and power Doppler images. The proposed algorithm includes a series of preprocessing steps, and performs a vessel segmentation by use of the marker-controlled watershed transform. The ultrasound images used in the study were acquired using the bk3000 ultrasound scanner (BK Ultrasound, Herlev, Denmark) with two transducers "8L2 Linear" and "10L2w Wide Linear" (BK Ultrasound, Herlev, Denmark). The algorithm was evaluated empirically and applied to a dataset of in-vivo 1770 images recorded from 8 healthy subjects. The segmentation results were compared to manual delineation performed by two experienced users. The results showed a sensitivity and specificity of 90.41+/-11.2 % and 97.93+/-5.7% (mean+/-standard deviation), respectively. The amount of overlap of segmentation and manual segmentation, was measured by the Dice similarity coefficient, which was 91.25+/-11.6%. The empirical results demonstrated the feasibility of segmenting the vessel lumen in ultrasound scans using a fully automatic algorithm.

Alternative Regression Equations for Estimation of Annual Peak-Streamflow Frequency for Undeveloped Watersheds in Texas using PRESS Minimization

USGS Publications Warehouse

Asquith, William H.; Thompson, David B.

2008-01-01

The U.S. Geological Survey, in cooperation with the Texas Department of Transportation and in partnership with Texas Tech University, investigated a refinement of the regional regression method and developed alternative equations for estimation of peak-streamflow frequency for undeveloped watersheds in Texas. A common model for estimation of peak-streamflow frequency is based on the regional regression method. The current (2008) regional regression equations for 11 regions of Texas are based on log10 transformations of all regression variables (drainage area, main-channel slope, and watershed shape). Exclusive use of log10-transformation does not fully linearize the relations between the variables. As a result, some systematic bias remains in the current equations. The bias results in overestimation of peak streamflow for both the smallest and largest watersheds. The bias increases with increasing recurrence interval. The primary source of the bias is the discernible curvilinear relation in log10 space between peak streamflow and drainage area. Bias is demonstrated by selected residual plots with superimposed LOWESS trend lines. To address the bias, a statistical framework based on minimization of the PRESS statistic through power transformation of drainage area is described and implemented, and the resulting regression equations are reported. Compared to log10-exclusive equations, the equations derived from PRESS minimization have PRESS statistics and residual standard errors less than the log10 exclusive equations. Selected residual plots for the PRESS-minimized equations are presented to demonstrate that systematic bias in regional regression equations for peak-streamflow frequency estimation in Texas can be reduced. Because the overall error is similar to the error associated with previous equations and because the bias is reduced, the PRESS-minimized equations reported here provide alternative equations for peak-streamflow frequency estimation.

SAR image change detection using watershed and spectral clustering

NASA Astrophysics Data System (ADS)

Niu, Ruican; Jiao, L. C.; Wang, Guiting; Feng, Jie

2011-12-01

A new method of change detection in SAR images based on spectral clustering is presented in this paper. Spectral clustering is employed to extract change information from a pair images acquired on the same geographical area at different time. Watershed transform is applied to initially segment the big image into non-overlapped local regions, leading to reduce the complexity. Experiments results and system analysis confirm the effectiveness of the proposed algorithm.

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2012 CFR

2012-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2013 CFR

2013-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

40 CFR 141.716 - Source toolbox components.

Code of Federal Regulations, 2014 CFR

2014-07-01

... for Microbial Toolbox Components § 141.716 Source toolbox components. (a) Watershed control program. Systems receive 0.5-log Cryptosporidium treatment credit for implementing a watershed control program that meets the requirements of this section. (1) Systems that intend to apply for the watershed control...

Neoplastic transformation of SV40-immortalized human urinary tract epithelial cells by in vitro exposure to 3-methylcholanthrene.

PubMed

Reznikoff, C A; Loretz, L J; Christian, B J; Wu, S Q; Meisner, L F

1988-08-01

Normal human urinary tract epithelial cells (HUC) were neoplastically transformed in vitro using a step-wise strategy. First, a partially transformed non-virus-producing cell line was obtained after infection of HUC with simian virus 40 (SV40). This cell line (SV-HUC-1) was demonstrated to be clonal in origin, as 100% of cells contained at least five of seven marker chromosomes. Marker chromosomes were formed by balanced translocations resulting in a 'pseudodiploid' cell line. SV-HUC-1 showed altered growth properties in vitro (e.g. anchorage independent growth) but failed to form tumors in athymic nude mice, even after 3 years in culture (80 passages). In the studies reported here, SV-HUC-1 at early passages (P15-P19) were exposed to 3-methylcholanthrene (MCA) in three separate experiments. After a six-week post-treatment period of cell culture, cells were inoculated s.c. into athymic nude mice. In all experiments, MCA-treated SV-HUC-1 formed carcinomas in mice usually with a latent period of 5-8 weeks. These carcinomas showed heterogeneity with respect to histopathologies and growth properties in the mice and karyotypes. All the tumors retained SV-HUC-1 chromosome markers, but each independent transformant was aneuploid and contained unique new marker chromosomes. Chromosomes usually altered in tumor cells included numbers 3, 5, 6, 9, 11 and 13. Mutations in the ras family of cellular proto-oncogenes resulting in altered mobility of the p21 protein product were not detected in six cell lines established from independently derived tumors. It is not yet known whether other cellular proto-oncogenes are activated in these tumorigenic transformants. Neither control SV-HUC-1 (which were not exposed to MCA), nor early passage HUC exposed to MCA formed tumors when inoculated into mice. Thus, the tumorigenic transformation of HUC resulted from the combined actions of SV40 and MCA.

Chromosome Rearrangements Recovered following Transformation of Neurospora Crassa

PubMed Central

Perkins, D. D.; Kinsey, J. A.; Asch, D. K.; Frederick, G. D.

1993-01-01

New chromosome rearrangements were found in 10% or more of mitotically stable transformants. This was shown for transformations involving a variety of different markers, vectors and recipient strains. Breakpoints were randomly distributed among the seven linkage groups. Controls using untransformed protoplasts of the same strains contained almost no rearrangements. A study of molecularly characterized Am(+) transformants showed that rearrangements are frequent when multiple ectopic integration events have occurred. In contrast, rearrangements are absent or infrequent when only the resident locus is restored to am(+) by a homologous event. Sequences of the transforming vector were genetically linked to breakpoints in 6 of 10 translocations that were examined using Southern hybridization or colony blots. PMID:8349106

SFA 2.0- Watershed Structure and Controls

ScienceCinema

Williams, Ken

2018-05-23

Berkeley Lab Earth Scientist Ken Williams explains the watershed research within the Sustainable Systems SFA 2.0 project—including identification and monitoring of primary factors that control watershed biogeochemical functioning.

A new and efficient approach for construction of uridine/uracil auxotrophic mutants in the filamentous fungus Aspergillus oryzae using Agrobacterium tumefaciens-mediated transformation.

PubMed

Nguyen, Khuyen Thi; Ho, Quynh Ngoc; Do, Loc Thi Binh Xuan; Mai, Linh Thi Dam; Pham, Duc-Ngoc; Tran, Huyen Thi Thanh; Le, Diep Hong; Nguyen, Huy Quang; Tran, Van-Tuan

2017-06-01

Aspergillus oryzae is a filamentous fungus widely used in food industry and as a microbial cell factory for recombinant protein production. Due to the inherent resistance of A. oryzae to common antifungal compounds, genetic transformation of this mold usually requires auxotrophic mutants. In this study, we show that Agrobacterium tumefaciens-mediated transformation (ATMT) method is very efficient for deletion of the pyrG gene in different Aspergillus oryzae wild-type strains to generate uridine/uracil auxotrophic mutants. Our data indicated that all the obtained uridine/uracil auxotrophic transformants, which are 5- fluoroorotic acid (5-FOA) resistant, exist as the pyrG deletion mutants. Using these auxotrophic mutants and the pyrG selectable marker for genetic transformation via A. tumefaciens, we could get about 1060 transformants per 10 6 fungal spores. In addition, these A. oryzae mutants were also used successfully for expression of the DsRed fluorescent reporter gene under control of the A. oryzae amyB promoter by the ATMT method, which resulted in obvious red transformants on agar plates. Our work provides a new and effective approach for constructing the uridine/uracil auxotrophic mutants in the importantly industrial fungus A. oryzae. This strategy appears to be applicable to other filamentous fungi to develop similar genetic transformation systems based on auxotrophic/nutritional markers for food-grade recombinant applications.

An empirical assessment of which inland floods can be managed

USGS Publications Warehouse

Mogollón, Beatriz; Frimpong, Emmanuel A.; Hoegh, Andrew B.; Angermeier, Paul

2016-01-01

Riverine flooding is a significant global issue. Although it is well documented that the influence of landscape structure on floods decreases as flood size increases, studies that define a threshold flood-return period, above which landscape features such as topography, land cover and impoundments can curtail floods, are lacking. Further, the relative influences of natural versus built features on floods is poorly understood. Assumptions about the types of floods that can be managed have considerable implications for the cost-effectiveness of decisions to invest in transforming land cover (e.g., reforestation) and in constructing structures (e.g., storm-water ponds) to control floods. This study defines parameters of floods for which changes in landscape structure can have an impact. We compare nine flood-return periods across 31 watersheds with widely varying topography and land cover in the southeastern United States, using long-term hydrologic records (≥20 years). We also assess the effects of built flow-regulating features (best management practices and artificial water bodies) on selected flood metrics across urban watersheds. We show that landscape features affect magnitude and duration of only those floods with return periods ≤10 years, which suggests that larger floods cannot be managed effectively by manipulating landscape structure. Overall, urban watersheds exhibited larger (270 m3/s) but quicker (0.41 days) floods than non-urban watersheds (50 m3/s and 1.5 days). However, urban watersheds with more flow-regulating features had lower flood magnitudes (154 m3/s), but similar flood durations (0.55 days), compared to urban watersheds with fewer flow-regulating features (360 m3/s and 0.23 days). Our analysis provides insight into the magnitude, duration and count of floods that can be curtailed by landscape structure and its management. Our findings are relevant to other areas with similar climate, topography, and land use, and can help ensure that investments in flood management are made wisely after considering the limitations of landscape features to regulate floods.

Seasonal trends in eDNA detection and occupancy of bigheaded carps

USGS Publications Warehouse

Erickson, Richard A.; Merkes, Christopher; Jackson, Craig; Goforth, Reuben; Amberg, Jon J.

2017-01-01

Bigheaded carps, which include silver and bighead carp, are threatening to invade the Great Lakes. These species vary seasonally in distribution and abundance due to environmental conditions such as precipitation and temperature. Monitoring this seasonal movement is important for management to control the population size and spread of the species. We examined if environmental DNA (eDNA) approaches could detect seasonal changes of these species. To do this, we developed a novel genetic marker that was able to both detect and differentiate bighead and silver carp DNA. We used the marker, combined with a novel occupancy model, to study the occurrence of bigheaded carps at 3 sites on the Wabash River over the course of a year. We studied the Wabash River because of concerns that carps may be able to use the system to invade the Great Lakes via a now closed (ca. 2017) connection at Eagle Marsh between the Wabash River's watershed and the Great Lakes' watershed. We found seasonal trends in the probability of detection and occupancy that varied across sites. These findings demonstrate that eDNA methods can detect seasonal changes in bigheaded carps densities and suggest that the amount of eDNA present changes seasonally. The site that was farthest upstream and had the lowest carp densities exhibited the strongest seasonal trends for both detection probabilities and sample occupancy probabilities. Furthermore, other observations suggest that carps seasonally leave this site, and we were able to detect this with our eDNA approach.

A bifunctional aminoglycoside acetyltransferase/phosphotransferase conferring tobramycin resistance provides an efficient selectable marker for plastid transformation.

PubMed

Tabatabaei, Iman; Ruf, Stephanie; Bock, Ralph

2017-02-01

A new selectable marker gene for stable transformation of the plastid genome was developed that is similarly efficient as the aadA, and produces no background of spontaneous resistance mutants. More than 25 years after its development for Chlamydomonas and tobacco, the transformation of the chloroplast genome still represents a challenging technology that is available only in a handful of species. The vast majority of chloroplast transformation experiments conducted thus far have relied on a single selectable marker gene, the spectinomycin resistance gene aadA. Although a few alternative markers have been reported, the aadA has remained unrivalled in efficiency and is, therefore, nearly exclusively used. The development of new marker genes for plastid transformation is of crucial importance to all efforts towards extending the species range of the technology as well as to those applications in basic research, biotechnology and synthetic biology that involve the multistep engineering of plastid genomes. Here, we have tested a bifunctional resistance gene for its suitability as a selectable marker for chloroplast transformation. The bacterial enzyme aminoglycoside acetyltransferase(6')-Ie/aminoglycoside phosphotransferase(2″)-Ia possesses an N-terminal acetyltransferase domain and a C-terminal phosphotransferase domain that can act synergistically and detoxify aminoglycoside antibiotics highly efficiently. We report that, in combination with selection for resistance to the aminoglycoside tobramycin, the aac(6')-Ie/aph(2″)-Ia gene represents an efficient marker for plastid transformation in that it produces similar numbers of transplastomic lines as the spectinomycin resistance gene aadA. Importantly, no spontaneous antibiotic resistance mutants appear under tobramycin selection.

Retransformation of marker-free potato for enhanced resistance against fungal pathogens by pyramiding chitinase and wasabi defensin genes.

PubMed

Khan, Raham Sher; Darwish, Nader Ahmed; Khattak, Bushra; Ntui, Valentine Otang; Kong, Kynet; Shimomae, Kazuki; Nakamura, Ikuo; Mii, Masahiro

2014-09-01

Multi-auto-transformation vector system has been one of the strategies to produce marker-free transgenic plants without using selective chemicals and plant growth regulators and thus facilitating transgene stacking. In the study reported here, retransformation was carried out in marker-free transgenic potato CV. May Queen containing ChiC gene (isolated from Streptomyces griseus strain HUT 6037) with wasabi defensin (WD) gene (isolated from Wasabia japonica) to pyramid the two disease resistant genes. Molecular analyses of the developed shoots confirmed the existence of both the genes of interest (ChiC and WD) in transgenic plants. Co-expression of the genes was confirmed by RT-PCR, northern blot, and western blot analyses. Disease resistance assay of in vitro plants showed that the transgenic lines co-expressing both the ChiC and WD genes had higher resistance against the fungal pathogens, Fusarium oxysporum (Fusarium wilt) and Alternaria solani (early blight) compared to the non-transformed control and the transgenic lines expressing either of the ChiC or WD genes. The disease resistance potential of the transgenic plants could be increased by transgene stacking or multiple transformations.

Membrane lipid-protein interactions modify the regulatory role of adenosine-deaminase complexing protein: a phase fluorometry study of a malignancy marker

NASA Astrophysics Data System (ADS)

Parola, Abraham H.; Porat, Nurith; Caiolfa, Valeria R.; Gill, David; Kiesow, Lutz A.; Weisman, Mathew; Nemschitz, S.; Yaron, Dahlia; Singer, Karen; Solomon, Ethel

1990-05-01

The role of membrane lipid-protein interactions in malignant cell transformation was examined with adenosine deaminase (ADA) as a representative membrane protein. ADA's activity changes dramatically in transformed cells and accordingly it is a malignancy marker. Yet, the mechanisms controlling its variable activity are unknown. We undertook the spectroscopic deciphering of its interactions with its lipidic environment in normal and malignant cells. ADA exists in two interconvertible forms, small (45 KD) and large (21OKD). The large form consists of two small catalytic subunits (55-ADA) and a dimeric complexing protein ADCP. The physiological role of ADCP was not known either. Our studies were carried out at three levels.: 1. Solution enzyme kinetics, 2. The interaction of 55-ADA with ADCP reconstituted in liposomes: Effect of cholesterol and 3. Multifrequency phase modulation spectrofluorometry of pyrene-labeled 55-ADA bound to ADCP on the membranes of normal and RSV or RSV Ts68 transformed chick embryo fibroblasts. We found: 1. ADCP has an allosteric regulatory role on 55-ADA, which may be of physiological relevance: It inhibits 55-ADA activity at low physiological adenosine concentrations but accelerates deamination at high substrate concentration. 2. When reconstituted in DMPC liposomes, it retains 55-ADA activity (in its absence the activity is lost) and upon rigidification with cholesterol, a three fold increase in 55-ADA activity is attained, contrary to ADCP's regulatory activity when free of lipids. 3. The reduced ADA activity in transformed chick embryo fibroblasts is associated with increased membrane lipid fluidity (reduced order parameter), reduced accessibility of ADCP and increase rotational dynamics of the complex. We thus obtained spectroscopic deciphering of the vertical motion of ADCP, controlled by lipid-protein interaction, resulting in variable activity of this malignancy marker.

Linking fecal bacteria in rivers to landscape, geochemical, and hydrologic factors and sources at the basin scale

PubMed Central

Verhougstraete, Marc P.; Martin, Sherry L.; Kendall, Anthony D.; Hyndman, David W.; Rose, Joan B.

2015-01-01

Linking fecal indicator bacteria concentrations in large mixed-use watersheds back to diffuse human sources, such as septic systems, has met limited success. In this study, 64 rivers that drain 84% of Michigan’s Lower Peninsula were sampled under baseflow conditions for Escherichia coli, Bacteroides thetaiotaomicron (a human source-tracking marker), landscape characteristics, and geochemical and hydrologic variables. E. coli and B. thetaiotaomicron were routinely detected in sampled rivers and an E. coli reference level was defined (1.4 log10 most probable number⋅100 mL−1). Using classification and regression tree analysis and demographic estimates of wastewater treatments per watershed, septic systems seem to be the primary driver of fecal bacteria levels. In particular, watersheds with more than 1,621 septic systems exhibited significantly higher concentrations of B. thetaiotaomicron. This information is vital for evaluating water quality and health implications, determining the impacts of septic systems on watersheds, and improving management decisions for locating, constructing, and maintaining on-site wastewater treatment systems. PMID:26240328

Simulating mercury and methyl mercury stream concentrations at multiple scales in a wetland influenced coastal plain watershed (McTier Creek, SC, USA)

Treesearch

Chris Knightes; G.M. Davis; H.E. Golden; P.A. Conrads; P.M. Bradley; C.A. Journey

2016-01-01

Mercury (Hg) is the toxicant responsible for the most fish advisories across the United States, with 1.1 million river miles under advisory. The processes governing fate, transport, and transformation of mercury in streams and rivers are not well understood, in large part, because these systems are intimately linked with their surrounding watersheds and are often...

Quality assurance report - Loch Vale Watershed, 1999-2002

USGS Publications Warehouse

Botte, Jorin A.; Baron, Jill S.

2004-01-01

The National Park Service initiated the Loch Vale Watershed (LVWS) project in 1980 with funding from the Aquatic Effects Research Program of the National Acid Precipitation Assessment Program. Long-term ecological research and monitoring address watershed-scale ecosystem processes, particularly as they respond to atmospheric deposition and climate variability. Monitoring of meteorological, hydrologic, precipitation chemistry, and surface water quality parameters enable us to use long-term trends to distinguish natural from human-caused disturbances. Research into snow distribution, hydrologic flowpaths, vegetation responses to N deposition, isotopic transformations of N by forest and soil processes, trace metals, and aquatic ecological responses to disturbance enable us to understand processes that influence high elevation ecosystems.

Sources and transformations of nitrate from streams draining varying land uses: Evidence from dual isotope analysis

USGS Publications Warehouse

Burns, Douglas A.; Boyer, E.W.; Elliott, E.M.; Kendall, C.

2009-01-01

Knowledge of key sources and biogeochemical processes that affect the transport of nitrate (NO3-) in streams can inform watershed management strategies for controlling downstream eutrophication. We applied dual isotope analysis of NO3- to determine the dominant sources and processes that affect NO3- concentrations in six stream/river watersheds of different land uses. Samples were collected monthly at a range of flow conditions for 15 mo during 2004-05 and analyzed for NO3- concentrations, ?? 15NNO3, and ??18ONO3. Samples from two forested watersheds indicated that NO3- derived from nitrification was dominant at baseflow. A watershed dominated by suburban land use had three ??18ONO3 values greater than +25???, indicating a large direct contribution of atmospheric NO 3- transported to the stream during some high flows. Two watersheds with large proportions of agricultural land use had many ??15NNO3 values greater than +9???, suggesting an animal waste source consistent with regional dairy farming practices. These data showed a linear seasonal pattern with a ??18O NO3:??15NNO3 of 1:2, consistent with seasonally varying denitrification that peaked in late summer to early fall with the warmest temperatures and lowest annual streamflow. The large range of ?? 15NNO3 values (10???) indicates that NO 3- supply was likely not limiting the rate of denitrification, consistent with ground water and/or in-stream denitrification. Mixing of two or more distinct sources may have affected the seasonal isotope patterns observed in these two agricultural streams. In a mixed land use watershed of large drainage area, none of the source and process patterns observed in the small streams were evident. These results emphasize that observations at watersheds of a few to a few hundred km2 may be necessary to adequately quantify the relative roles of various NO 3- transport and process patterns that contribute to streamflow in large basins. Copyright ?? 2009 by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America. All rights reserved.

A vision-based automated guided vehicle system with marker recognition for indoor use.

PubMed

Lee, Jeisung; Hyun, Chang-Ho; Park, Mignon

2013-08-07

We propose an intelligent vision-based Automated Guided Vehicle (AGV) system using fiduciary markers. In this paper, we explore a low-cost, efficient vehicle guiding method using a consumer grade web camera and fiduciary markers. In the proposed method, the system uses fiduciary markers with a capital letter or triangle indicating direction in it. The markers are very easy to produce, manipulate, and maintain. The marker information is used to guide a vehicle. We use hue and saturation values in the image to extract marker candidates. When the known size fiduciary marker is detected by using a bird's eye view and Hough transform, the positional relation between the marker and the vehicle can be calculated. To recognize the character in the marker, a distance transform is used. The probability of feature matching was calculated by using a distance transform, and a feature having high probability is selected as a captured marker. Four directional signals and 10 alphabet features are defined and used as markers. A 98.87% recognition rate was achieved in the testing phase. The experimental results with the fiduciary marker show that the proposed method is a solution for an indoor AGV system.

Targeted Gene Deletion in Cordyceps militaris Using the Split-Marker Approach.

PubMed

Lou, HaiWei; Ye, ZhiWei; Yun, Fan; Lin, JunFang; Guo, LiQiong; Chen, BaiXiong; Mu, ZhiXian

2018-05-01

The macrofungus Cordyceps militaris contains many kinds of bioactive ingredients that are regulated by functional genes, but the functions of many genes in C. militaris are still unknown. In this study, to improve the frequency of homologous integration, a genetic transformation system based on a split-marker approach was developed for the first time in C. militaris to knock out a gene encoding a terpenoid synthase (Tns). The linear and split-marker deletion cassettes were constructed and introduced into C. militaris protoplasts by PEG-mediated transformation. The transformation of split-marker fragments resulted in a higher efficiency of targeted gene disruption than the transformation of linear deletion cassettes did. The color phenotype of the Tns gene deletion mutants was different from that of wild-type C. militaris. Moreover, a PEG-mediated protoplast transformation system was established, and stable genetic transformants were obtained. This method of targeted gene deletion represents an important tool for investigating the role of C. militaris genes.

Coupled Effects of Natural and Anthropogenic Controls on Seasonal and Spatial Variations of River Water Quality during Baseflow in a Coastal Watershed of Southeast China

PubMed Central

Huang, Jinliang; Huang, Yaling; Zhang, Zhenyu

2014-01-01

Surface water samples of baseflow were collected from 20 headwater sub-watersheds which were classified into three types of watersheds (natural, urban and agricultural) in the flood, dry and transition seasons during three consecutive years (2010–2012) within a coastal watershed of Southeast China. Integrating spatial statistics with multivariate statistical techniques, river water quality variations and their interactions with natural and anthropogenic controls were examined to identify the causal factors and underlying mechanisms governing spatiotemporal patterns of water quality. Anthropogenic input related to industrial effluents and domestic wastewater, agricultural activities associated with the precipitation-induced surface runoff, and natural weathering process were identified as the potential important factors to drive the seasonal variations in stream water quality for the transition, flood and dry seasons, respectively. All water quality indicators except SRP had the highest mean concentrations in the dry and transition seasons. Anthropogenic activities and watershed characteristics led to the spatial variations in stream water quality in three types of watersheds. Concentrations of NH4 +-N, SRP, K+, CODMn, and Cl− were generally highest in urban watersheds. NO3 –N Concentration was generally highest in agricultural watersheds. Mg2+ concentration in natural watersheds was significantly higher than that in agricultural watersheds. Spatial autocorrelations analysis showed similar levels of water pollution between the neighboring sub-watersheds exhibited in the dry and transition seasons while non-point source pollution contributed to the significant variations in water quality between neighboring sub-watersheds. Spatial regression analysis showed anthropogenic controls played critical roles in variations of water quality in the JRW. Management implications were further discussed for water resource management. This research demonstrates that the coupled effects of natural and anthropogenic controls involved in watershed processes, contribute to the seasonal and spatial variation of headwater stream water quality in a coastal watershed with high spatial variability and intensive anthropogenic activities. PMID:24618771

Integrating local research watersheds into hydrologic education: Lessons from the Dry Creek Experimental Watershed

NASA Astrophysics Data System (ADS)

McNamara, J. P.; Aishlin, P. S.; Flores, A. N.; Benner, S. G.; Marshall, H. P.; Pierce, J. L.

2014-12-01

While a proliferation of instrumented research watersheds and new data sharing technologies has transformed hydrologic research in recent decades, similar advances have not been realized in hydrologic education. Long-standing problems in hydrologic education include discontinuity of hydrologic topics from introductory to advanced courses, inconsistency of content across academic departments, and difficulties in development of laboratory and homework assignments utilizing large time series and spatial data sets. Hydrologic problems are typically not amenable to "back-of-the-chapter" examples. Local, long-term research watersheds offer solutions to these problems. Here, we describe our integration of research and monitoring programs in the Dry Creek Experimental Watershed into undergraduate and graduate hydrology programs at Boise State University. We developed a suite of watershed-based exercises into courses and curriculums using real, tangible datasets from the watershed to teach concepts not amenable to traditional textbook and lecture methods. The aggregation of exercises throughout a course or degree allows for scaffolding of concepts with progressive exposure of advanced concepts throughout a course or degree. The need for exercises of this type is growing as traditional lecture-based classes (passive learning from a local authoritative source) are being replaced with active learning courses that integrate many sources of information through situational factors.

The Search for Hydrologic Signatures: The Effect of Data Transformations on Bayesian Model Calibration

NASA Astrophysics Data System (ADS)

Sadegh, M.; Vrugt, J. A.

2011-12-01

In the past few years, several contributions have begun to appear in the hydrologic literature that introduced and analyzed the benefits of using a signature based approach to watershed analysis. This signature-based approach abandons the standard single criteria model-data fitting paradigm in favor of a diagnostic approach that better extracts the available information from the available data. Despite the prospects of this new viewpoint, rather ad-hoc criteria have hitherto been proposed to improve watershed modeling. Here, we aim to provide a proper mathematical foundation to signature based analysis. We analyze the information content of different data transformation by analyzing their convergence speed with Markov Chain Monte Carlo (MCMC) simulation using the Generalized Likelihood function of Schousp and Vrugt (2010). We compare the information content of the original discharge data against a simple square root and Box-Cox transformation of the streamflow data. We benchmark these results against wavelet and flow duration curve transformations that temporally disaggregate the discharge data. Our results conclusive demonstrate that wavelet transformations and flow duration curves significantly reduce the information content of the streamflow data and consequently unnecessarily increase the uncertainty of the HYMOD model parameters. Hydrologic signatures thus need to be found in the original data, without temporal disaggregation.

Hydrologic control of carbon cycling and aged carbon discharge in the Congo River basin

NASA Astrophysics Data System (ADS)

Schefuß, Enno; Eglinton, Timothy I.; Spencer-Jones, Charlotte L.; Rullkötter, Jürgen; de Pol-Holz, Ricardo; Talbot, Helen M.; Grootes, Pieter M.; Schneider, Ralph R.

2016-09-01

The age of organic material discharged by rivers provides information about its sources and carbon cycling processes within watersheds. Although elevated ages in fluvially transported organic matter are usually explained by erosion of soils and sedimentary deposits, it is commonly assumed that mainly young organic material is discharged from flat tropical watersheds due to their extensive plant cover and rapid carbon turnover. Here we present compound-specific radiocarbon data of terrigenous organic fractions from a sedimentary archive offshore the Congo River, in conjunction with molecular markers for methane-producing land cover reflecting wetland extent. We find that the Congo River has been discharging aged organic matter for several thousand years, with apparently increasing ages from the mid- to the Late Holocene. This suggests that aged organic matter in modern samples is concealed by radiocarbon from atmospheric nuclear weapons testing. By comparison to indicators for past rainfall changes we detect a systematic control of organic matter sequestration and release by continental hydrology, mediating temporary carbon storage in wetlands. As aridification also leads to exposure and rapid remineralization of large amounts of previously stored labile organic matter, we infer that this process may cause a profound direct climate feedback that is at present underestimated in carbon cycle assessments.

Long-term monitoring of molecular markers can distinguish different seasonal patterns of fecal indicating bacteria sources.

PubMed

Riedel, Timothy E; Thulsiraj, Vanessa; Zimmer-Faust, Amity G; Dagit, Rosi; Krug, Jenna; Hanley, Kaitlyn T; Adamek, Krista; Ebentier, Darcy L; Torres, Robert; Cobian, Uriel; Peterson, Sophie; Jay, Jennifer A

2015-03-15

Elevated levels of fecal indicator bacteria (FIB) have been observed at Topanga Beach, CA, USA. To identify the FIB sources, a microbial source tracking study using a dog-, a gull- and two human-associated molecular markers was conducted at 10 sites over 21 months. Historical data suggest that episodic discharge from the lagoon at the mouth of Topanga Creek is the main source of bacteria to the beach. A decline in creek FIB/markers downstream from upper watershed development and a sharp increase in FIB/markers at the lagoon sites suggest sources are local to the lagoon. At the lagoon and beach, human markers are detected sporadically, dog marker peaks in abundance mid-winter, and gull marker is chronically elevated. Varied seasonal patterns of FIB and source markers were identified showing the importance of applying a suite of markers over long-term spatial and temporal sampling to identify a complex combination of sources of contamination. Copyright © 2014 Elsevier Ltd. All rights reserved.

Agrobacterium tumefaciens-mediated transformation of oleaginous yeast Lipomyces species

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, Ziyu; Deng, Shuang; Culley, David E.

Background: Because of interest in the production of renewable bio-hydrocarbon fuels, various living organisms have been explored for their potential use in producing fuels and chemicals. The oil-producing (oleaginous) yeast Lipomyces starkeyi is the subject of active research regarding the production of lipids using a wide variety of carbon and nutrient sources. The genome of L. starkeyi has been published, which opens the door to production strain improvements using the tools of synthetic biology and metabolic engineering. However, using these tools for strain improvement requires the establishment of effective and reliable transformation methods with suitable selectable markers (antibiotic resistance ormore » auxotrophic marker genes) and the necessary genetic elements (promoters and terminators) for expression of introduced genes. Chemical-based methods have been published, but suffer from low efficiency or the requirement for targeting to rRNA loci. To address these problems, Agrobacterium-mediated transformation was investigated as an alternative method for L. starkeyi and other Lipomyces species. Results: In this study, Agrobacterium-mediated transformation was demonstrated to be effective in the transformation of both L. starkeyi and other Lipomyces species and that the introduced DNA can be reliably integrated into the chromosomes of these species. The gene deletion of Ku70 and Pex10 was also demonstrated in L. starkeyi. In addition to the bacterial antibiotic selection marker gene hygromycin B phosphotransferase, the bacterial -glucuronidase reporter gene under the control of L. starkeyi translation elongation factor 1 promoter was also stably expressed in seven different Lipomyces species. Conclusion: The results from this study clearly demonstrate that Agrobacterium-mediated transformation is a reliable genetic tool for gene deletion and integration and expression of heterologous genes in L. starkeyi and other Lipomyces species.« less

Transformation of apple (Malus × domestica) using mutants of apple acetolactate synthase as a selectable marker and analysis of the T-DNA integration sites.

PubMed

Yao, Jia-Long; Tomes, Sumathi; Gleave, Andrew P

2013-05-01

Apple acetolactate synthase mutants were generated by site-specific mutagenesis and successfully used as selection marker in tobacco and apple transformation. T-DNA/Apple genome junctions were analysed using genome-walking PCR and sequencing. An Agrobacterium-mediated genetic transformation system was developed for apple (Malus × domestica), using mutants of apple acetolactate synthase (ALS) as a selectable marker. Four apple ALS mutants were generated by site-specific mutagenesis and subsequently cloned under the transcriptional control of the CaMV 35S promoter and ocs 3' terminator, in a pART27-derived plant transformation vector. Three of the four mutations were found to confer resistance to the herbicide Glean(®), containing the active agent chlorsulfuron, in tobacco (Nicotiana tabacum) transformation. In apple transformation, leaf explants infected with Agrobacterium tumefaciens EHA105 containing one of the three ALS mutants resulted in the production of shoots on medium containing 2-8 μg L(-1) Glean(®), whilst uninfected wild-type explants failed to regenerate shoots or survive on medium containing 1 and 3 μg L(-1) Glean(®), respectively. Glean(®)-resistant, regenerated shoots were further multiplied and rooted on medium containing 10 μg L(-1) Glean(®). The T-DNA and apple genome-DNA junctions from eight rooted transgenic apple plants were analysed using genome-walking PCR amplification and sequencing. This analysis confirmed T-DNA integration into the apple genome, identified the genome integration sites and revealed the extent of any vector backbone integration, T-DNA rearrangements and deletions of apple genome DNA at the sites of integration.

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus.

PubMed

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic indicator in certain lesions.

Efficient and resilient governance of social-ecological systems.

PubMed

Erickson, Adam

2015-09-01

New institutions are critically needed to improve the resilience of social-ecological systems globally. Watershed management offers an important model due to its ability to govern mixed-ownership landscapes through common property regimes, translating national goals into local action. Here, I assess the efficacy of state watershed management institutions in the Pacific Northwest, based on their ability to support local watershed groups. I use document analysis to describe and compare state institutions in Washington, Oregon, Idaho, and California. Results indicate that state institutional efficiency and resilience are the key factors determining watershed group activity and stability. The primary drivers of institutional efficiency and resilience were institutional unification, robust funding portfolios, low agency conflict, and strong support for economic multiplier effects, creative partnerships, and scholarly research. My findings elucidate the critical role of institutional efficiency and resilience in governing dynamic and complex social-ecological systems, enabling the flexibility to address emergent transformations.

Development of a Candida glabrata dominant nutritional transformation marker utilizing the Aspergillus nidulans acetamidase gene (amdS).

PubMed

Fu, Jianmin; Blaylock, Morganne; Wickes, Cameron F; Welte, William; Mehrtash, Adrian; Wiederhold, Nathan; Wickes, Brian L

2016-05-01

The gene encoding Aspergillus nidulans acetamidase (amdS) was placed under control of Candida albicans ACT1 promoter and terminator sequences and then cloned into a plasmid containing C. glabrata ARS10,CEN8 or ARS10+CEN8 sequences. All plasmids transformed C. glabrata wild-type cells to acetamide+, with the ARS-only containing plasmid transforming cells at the highest frequencies (>1.0 × 10(4) transformants μg(-1)). Plasmids were rapidly lost under non-selective conditions with the frequency dependent on chromosomal element, thus recycling the acetamide- phenotype. The amdS plasmid was used to transform a set of clinical isolates resistant to a variety of antifungal drugs. All strains were successfully transformed to the acetamide+ phenotype at high frequency, confirming that this plasmid construct could be used as a simple dominant marker on virtually any strain. Gap repair experiments demonstrated that just as in Saccharomyces cerevisiae, gap repair functions efficiently inC. glabrata, suggesting that C. glabrata has numerous similarities toS. cerevisiae with regard to ease of molecular manipulation. The amdS system is inexpensive and efficient, and combined with existing C. glabrata plasmid elements, confers a high transformation frequency for C. glabrata with a phenotype that can be easily recycled. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Microbial Source Tracking in Adjacent Karst Springs.

PubMed

Ohad, Shoshanit; Vaizel-Ohayon, Dalit; Rom, Meir; Guttman, Joseph; Berger, Diego; Kravitz, Valeria; Pilo, Shlomo; Huberman, Zohar; Kashi, Yechezkel; Rorman, Efrat

2015-08-01

Modern man-made environments, including urban, agricultural, and industrial environments, have complex ecological interactions among themselves and with the natural surroundings. Microbial source tracking (MST) offers advanced tools to resolve the host source of fecal contamination beyond indicator monitoring. This study was intended to assess karst spring susceptibilities to different fecal sources using MST quantitative PCR (qPCR) assays targeting human, bovine, and swine markers. It involved a dual-time monitoring frame: (i) monthly throughout the calendar year and (ii) daily during a rainfall event. Data integration was taken from both monthly and daily MST profile monitoring and improved identification of spring susceptibility to host fecal contamination; three springs located in close geographic proximity revealed different MST profiles. The Giach spring showed moderate fluctuations of MST marker quantities amid wet and dry samplings, while the Zuf spring had the highest rise of the GenBac3 marker during the wet event, which was mirrored in other markers as well. The revelation of human fecal contamination during the dry season not connected to incidents of raining leachates suggests a continuous and direct exposure to septic systems. Pigpens were identified in the watersheds of Zuf, Shefa, and Giach springs and on the border of the Gaaton spring watershed. Their impact was correlated with partial detection of the Pig-2-Bac marker in Gaaton spring, which was lower than detection levels in all three of the other springs. Ruminant and swine markers were detected intermittently, and their contamination potential during the wet samplings was exposed. These results emphasized the importance of sampling design to utilize the MST approach to delineate subtleties of fecal contamination in the environment. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

Markers of the denormalisation of smoking and the tobacco industry.

PubMed

Chapman, S; Freeman, B

2008-02-01

In nations with histories of declining smoking prevalence and comprehensive tobacco control policies, smoking-positive cultures have been severely eroded. Smoking, smokers and the tobacco industry are today routinely depicted in everyday discourse and media representations in a variety of overwhelmingly negative ways. Several authors have invoked Erving Goffman's notions of stigmatization to describe the process and impact of this radical transformation, which importantly includes motivating smoking cessation. Efforts to describe nations' progress toward comprehensive tobacco control have hitherto taken little account of the role of cultural change to the meaning of smoking and the many ways in which it has become denormalised. This paper identifies a diversity of generally undocumented yet pervasive markers of the "spoiled identity" of smoking, smokers and the tobacco industry, illustrated with examples from Australia, a nation with advanced tobacco control. We caution about some important negative consequences arising from the stigmatization of smokers. We recommend that schemes rating the comprehensiveness of national tobacco control should be supplemented by documentation of markers of this denormalisation.

Using dual isotopes to evaluate sources and transformations of nitrate in the West Lake watershed, eastern China

NASA Astrophysics Data System (ADS)

Jin, Zanfang; Qin, Xue; Chen, Lingxiao; Jin, Mantong; Li, Feili

2015-06-01

The West Lake is a World Heritage site in the West Lake watershed in eastern China. In this study, the hydrogeological and dual isotopic approaches were integrated to evaluate the seasonal and spatial variations of nitrate (NO3-) in the West Lake watershed, and to characterize NO3- sources and transformations. The results revealed that the geochemical facies of the water samples were dominated by Ca2 + + Na+-HCO3- + SO42- in the surface water and transfer water, Ca2 + + Na+-HCO3- and Ca2 + + Na+-SO42 - in the groundwater, which most likely reflect natural reactions and anthropogenic inputs. About 13% of the groundwater samples containing NO3- exceeded the World Health Organization (WHO) standard of 10 mg N L- 1. NO3- was the dominant form of total nitrogen (TN) and was the main surface water contaminant in the West Lake watershed. The δ15NNO3 and δ18ONO3 values indicated that the dominant NO3- sources in surface water were soil nitrogen (soil N) and chemical fertilizers, while the main NO3- sources in groundwater were soil N from the forest, chemical fertilizers and manure in the tea garden, domestic sewage from the small, old residential area in the forest as well as urban areas. The distribution of NO3- in groundwater was strongly influenced by land use. Results also suggest that there was significant nitrification in surface water and groundwater in the West Lake watershed, and that there were also denitrification processes in groundwater. The annual net fluxes of TN, NO3-, and NH4+ into the West Lake were 2.0 × 104, 4.0 × 103, and 1.31 × 104 kg as N, respectively.

Characterization of sources and loadings of fecal pollutants using microbial source tracking assays in urban and rural areas of the Grand River Watershed, Southwestern Ontario.

PubMed

Lee, Dae-Young; Lee, Hung; Trevors, Jack T; Weir, Susan C; Thomas, Janis L; Habash, Marc

2014-04-15

Sources of fecal water pollution were assessed in the Grand River and two of its tributaries (Ontario, Canada) using total and host-specific (human and bovine) Bacteroidales genetic markers in conjunction with reference information, such as land use and weather. In-stream levels of the markers and culturable Escherichia coli were also monitored during multiple rain events to gain information on fecal loadings to catchment from diffuse sources. Elevated human-specific marker levels were accurately identified in river water impacted by a municipal wastewater treatment plant (WWTP) effluent and at a downstream site in the Grand River. In contrast, the bovine-specific marker showed high levels of cattle fecal pollution in two tributaries, both of which are characterized as intensely farmed areas. The bovine-specific Bacteroidales marker increased with rainfall in the agricultural tributaries, indicating enhanced loading of cattle-derived fecal pollutants to river from non-point sources following rain events. However, rain-triggered fecal loading was not substantiated in urban settings, indicating continuous inputs of human-originated fecal pollutants from point sources, such as WWTP effluent. This study demonstrated that the Bacteroidales source tracking assays, in combination with land use information and hydrological data, may provide additional insight into the spatial and temporal distribution of source-specific fecal contamination in streams impacted by varying land uses. Using the approach described in this study may help to characterize impacted water sources and to design targeted land use management plans in other watersheds in the future. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantitative identification of nitrate pollution sources and uncertainty analysis based on dual isotope approach in an agricultural watershed.

PubMed

Ji, Xiaoliang; Xie, Runting; Hao, Yun; Lu, Jun

2017-10-01

Quantitative identification of nitrate (NO 3 - -N) sources is critical to the control of nonpoint source nitrogen pollution in an agricultural watershed. Combined with water quality monitoring, we adopted the environmental isotope (δD-H 2 O, δ 18 O-H 2 O, δ 15 N-NO 3 - , and δ 18 O-NO 3 - ) analysis and the Markov Chain Monte Carlo (MCMC) mixing model to determine the proportions of riverine NO 3 - -N inputs from four potential NO 3 - -N sources, namely, atmospheric deposition (AD), chemical nitrogen fertilizer (NF), soil nitrogen (SN), and manure and sewage (M&S), in the ChangLe River watershed of eastern China. Results showed that NO 3 - -N was the main form of nitrogen in this watershed, accounting for approximately 74% of the total nitrogen concentration. A strong hydraulic interaction existed between the surface and groundwater for NO 3 - -N pollution. The variations of the isotopic composition in NO 3 - -N suggested that microbial nitrification was the dominant nitrogen transformation process in surface water, whereas significant denitrification was observed in groundwater. MCMC mixing model outputs revealed that M&S was the predominant contributor to riverine NO 3 - -N pollution (contributing 41.8% on average), followed by SN (34.0%), NF (21.9%), and AD (2.3%) sources. Finally, we constructed an uncertainty index, UI 90 , to quantitatively characterize the uncertainties inherent in NO 3 - -N source apportionment and discussed the reasons behind the uncertainties. Copyright © 2017 Elsevier Ltd. All rights reserved.

Using Microbial Source Tracking Markers to Predict Occurrence of Waterborne Pathogens in Urban and Agricultural Watershed

EPA Science Inventory

Runoff from agricultural fields and urban landscapes may carry a variety of microbial contaminants that compromises water quality and increases the possibility of human exposure to pathogenic microorganisms. Establishing the relationship between microbial source tracking (MST) ma...

Image segmentation for biomedical applications based on alternating sequential filtering and watershed transformation

NASA Astrophysics Data System (ADS)

Gorpas, D.; Yova, D.

2009-07-01

One of the major challenges in biomedical imaging is the extraction of quantified information from the acquired images. Light and tissue interaction leads to the acquisition of images that present inconsistent intensity profiles and thus the accurate identification of the regions of interest is a rather complicated process. On the other hand, the complex geometries and the tangent objects that very often are present in the acquired images, lead to either false detections or to the merging, shrinkage or expansion of the regions of interest. In this paper an algorithm, which is based on alternating sequential filtering and watershed transformation, is proposed for the segmentation of biomedical images. This algorithm has been tested over two applications, each one based on different acquisition system, and the results illustrate its accuracy in segmenting the regions of interest.

Application of wavelet-based multi-model Kalman filters to real-time flood forecasting

NASA Astrophysics Data System (ADS)

Chou, Chien-Ming; Wang, Ru-Yih

2004-04-01

This paper presents the application of a multimodel method using a wavelet-based Kalman filter (WKF) bank to simultaneously estimate decomposed state variables and unknown parameters for real-time flood forecasting. Applying the Haar wavelet transform alters the state vector and input vector of the state space. In this way, an overall detail plus approximation describes each new state vector and input vector, which allows the WKF to simultaneously estimate and decompose state variables. The wavelet-based multimodel Kalman filter (WMKF) is a multimodel Kalman filter (MKF), in which the Kalman filter has been substituted for a WKF. The WMKF then obtains M estimated state vectors. Next, the M state-estimates, each of which is weighted by its possibility that is also determined on-line, are combined to form an optimal estimate. Validations conducted for the Wu-Tu watershed, a small watershed in Taiwan, have demonstrated that the method is effective because of the decomposition of wavelet transform, the adaptation of the time-varying Kalman filter and the characteristics of the multimodel method. Validation results also reveal that the resulting method enhances the accuracy of the runoff prediction of the rainfall-runoff process in the Wu-Tu watershed.

Impact of water management interventions on hydrology and ecosystem services in Garhkundar-Dabar watershed of Bundelkhand region, Central India

NASA Astrophysics Data System (ADS)

Singh, Ramesh; Garg, Kaushal K.; Wani, Suhas P.; Tewari, R. K.; Dhyani, S. K.

2014-02-01

Bundelkhand region of Central India is a hot spot of water scarcity, land degradation, poverty and poor socio-economic status. Impacts of integrated watershed development (IWD) interventions on water balance and different ecosystem services are analyzed in one of the selected watershed of 850 ha in Bundelkhand region. Improved soil, water and crop management interventions in Garhkundar-Dabar (GKD) watershed of Bundelkhand region in India enhanced ET to 64% as compared to 58% in untreated (control) watershed receiving 815 mm annual average rainfall. Reduced storm flow (21% vs. 34%) along with increased base flow (4.5% vs. 1.2%) and groundwater recharge (11% vs. 7%) of total rainfall received were recorded in treated watershed as compared to untreated control watershed. Economic Water productivity and total income increased from 2.5 to 5.0 INR m-3 and 11,500 to 27,500 INR ha-1 yr-1 after implementing integrated watershed development interventions in GKD watershed, respectively. Moreover IWD interventions helped in reducing soil loss more than 50% compared to control watershed. The results demonstrated that integrated watershed management practices addressed issues of poverty in GKD watershed. Benefit to cost ratio of project interventions was found three and pay back period within four years suggest economic feasibility to scale-up IWD interventions in Bundelkhend region. Scaling-up of integrated watershed management in drought prone rainfed areas with enabling policy and institutional support is expected to promote equity and livelihood along with strengthening various ecosystem services, however, region-specific analysis is needed to assess trade-offs for downstream areas along with onsite impact.

Input-output budgets of selected nutrients on an experimental watershed near Parsons, West Virginia

Treesearch

J. D. Helvey; Samuel H. Kunkle; Samuel H. Kunkle

1986-01-01

A control watershed at the Fernow Experimental Watershed effectively neutralizes acids received in precipitation. However, sulfate input by precipitation greatly exceeds sulfate losses as streamflow and watershed acidification is a real concern.

Is a clean river fun for all? Recognizing social vulnerability in watershed planning.

PubMed

Cutts, Bethany B; Greenlee, Andrew J; Prochaska, Natalie K; Chantrill, Carolina V; Contractor, Annie B; Wilhoit, Juliana M; Abts, Nancy; Hornik, Kaitlyn

2018-01-01

Watershed planning can lead to policy innovation and action toward environmental protection. However, groups often suffer from low engagement with communities that experience disparate impacts from flooding and water pollution. This can limit the capacity of watershed efforts to dismantle pernicious forms of social inequality. As a result, the benefits of environmental changes often flow to more empowered residents, short-changing the power of watershed-based planning as a tool to transform ecological, economic, and social relationships. The objectives of this paper are to assess whether the worldview of watershed planning actors are sufficiently attuned to local patterns of social vulnerability and whether locally significant patterns of social vulnerability can be adequately differentiated using conventional data sources. Drawing from 35 in-depth interviews with watershed planners and community stakeholders in the Milwaukee River Basin (WI, USA), we identify five unique definitions of social vulnerability. Watershed planners in our sample articulate a narrower range of social vulnerability definitions than other participants. All five definitions emphasize spatial and demographic characteristics consistent with existing ways of measuring social vulnerability. However, existing measures do not adequately differentiate among the spatio-temporal dynamics used to distinguish definitions. In response, we develop two new social vulnerability measures. The combination of interviews and demographic analyses in this study provides an assessment technique that can help watershed planners (a) understand the limits of their own conceptualization of social vulnerability and (b) acknowledge the importance of place-based vulnerabilities that may otherwise be obscured. We conclude by discussing how our methods can be a useful tool for identifying opportunities to disrupt social vulnerability in a watershed by evaluating how issue frames, outreach messages, and engagement tactics. The approach allows watershed planners to shift their own culture in order to consider socially vulnerable populations comprehensively.

Is a clean river fun for all? Recognizing social vulnerability in watershed planning

PubMed Central

Greenlee, Andrew J.; Prochaska, Natalie K.; Chantrill, Carolina V.; Contractor, Annie B.; Wilhoit, Juliana M.; Abts, Nancy; Hornik, Kaitlyn

2018-01-01

Watershed planning can lead to policy innovation and action toward environmental protection. However, groups often suffer from low engagement with communities that experience disparate impacts from flooding and water pollution. This can limit the capacity of watershed efforts to dismantle pernicious forms of social inequality. As a result, the benefits of environmental changes often flow to more empowered residents, short-changing the power of watershed-based planning as a tool to transform ecological, economic, and social relationships. The objectives of this paper are to assess whether the worldview of watershed planning actors are sufficiently attuned to local patterns of social vulnerability and whether locally significant patterns of social vulnerability can be adequately differentiated using conventional data sources. Drawing from 35 in-depth interviews with watershed planners and community stakeholders in the Milwaukee River Basin (WI, USA), we identify five unique definitions of social vulnerability. Watershed planners in our sample articulate a narrower range of social vulnerability definitions than other participants. All five definitions emphasize spatial and demographic characteristics consistent with existing ways of measuring social vulnerability. However, existing measures do not adequately differentiate among the spatio-temporal dynamics used to distinguish definitions. In response, we develop two new social vulnerability measures. The combination of interviews and demographic analyses in this study provides an assessment technique that can help watershed planners (a) understand the limits of their own conceptualization of social vulnerability and (b) acknowledge the importance of place-based vulnerabilities that may otherwise be obscured. We conclude by discussing how our methods can be a useful tool for identifying opportunities to disrupt social vulnerability in a watershed by evaluating how issue frames, outreach messages, and engagement tactics. The approach allows watershed planners to shift their own culture in order to consider socially vulnerable populations comprehensively. PMID:29715285

[New paradigm for soil and water conservation: a method based on watershed process modeling and scenario analysis].

PubMed

Zhu, A-Xing; Chen, La-Jiao; Qin, Cheng-Zhi; Wang, Ping; Liu, Jun-Zhi; Li, Run-Kui; Cai, Qiang-Guo

2012-07-01

With the increase of severe soil erosion problem, soil and water conservation has become an urgent concern for sustainable development. Small watershed experimental observation is the traditional paradigm for soil and water control. However, the establishment of experimental watershed usually takes long time, and has the limitations of poor repeatability and high cost. Moreover, the popularization of the results from the experimental watershed is limited for other areas due to the differences in watershed conditions. Therefore, it is not sufficient to completely rely on this old paradigm for soil and water loss control. Recently, scenario analysis based on watershed modeling has been introduced into watershed management, which can provide information about the effectiveness of different management practices based on the quantitative simulation of watershed processes. Because of its merits such as low cost, short period, and high repeatability, scenario analysis shows great potential in aiding the development of watershed management strategy. This paper elaborated a new paradigm using watershed modeling and scenario analysis for soil and water conservation, illustrated this new paradigm through two cases for practical watershed management, and explored the future development of this new soil and water conservation paradigm.

Watershed Analysis of Nitrate Transport as a Result of Agricultural Inputs for Varying Land Use/Land Cover and Soil Type

NASA Astrophysics Data System (ADS)

Scott, M. E.; Sykes, J. F.

2006-12-01

The Grand River Watershed is one of the largest watersheds in southwestern Ontario with an area of approximately 7000 square kilometers. Ninety percent of the watershed is classified as rural, and 80 percent of the watershed population relies on groundwater as their source of drinking water. Management of the watershed requires the determination of the effect of agricultural practices on long-term groundwater quality and to identify locations within the watershed that are at a higher risk of contamination. The study focuses on the transport of nitrate through the root zone as a result of agricultural inputs with attenuation due to biodegradation. The driving force for transport is spatially and temporally varying groundwater recharge that is a function of land use/land cover, soil and meteorological inputs that yields 47,229 unique soil columns within the watershed. Fertilizer sources are determined from Statistics Canada's Agricultural Census and include livestock manure and a popular commercial fertilizer, urea. Accounting for different application rates yields 60,066 unique land parcels of which 22,809 are classified as croplands where manure and inorganic fertilizes are directly applied. The transport for the croplands is simulated over a 14-year period to investigate the impact of seasonal applications of nitrate fertilizers on the concentration leaching from the root zone to the water table. Based on land use/land cover maps, ArcView GIS is used to define the location of fertilizer applications within the watershed and to spatially visualize data and analyze results. The large quantity of input data is stored and managed using MS-Access and a relational database management system. Nitrogen transformations and ammonium and nitrate uptake by plants and transport through the soil column are simulated on a daily basis using Visual Basic for Applications (VBA) within MS-Access modules. Nitrogen transformations within the soil column were simplified using parameters that were obtained from literature or could be calculated from readily available soil information for the Grand River Watershed. Spatially and seasonally averaged results for the 14 year period indicate that nitrate leaching through the root zone does not exceed the maximum contaminant level (MCL) of 10 mg/l nitrate. However, in 1992, over 12 percent of the watershed area in crops exceeded the MCL during the winter season. The characteristically well drained soils of the central region of the watershed are more susceptible to groundwater contamination following autumn manure-N applications, as no crop-growth is present to remove excess nitrogen from the system. Therefore, farm best management practices do not ensure that groundwater contamination will not occur. This research is an important first step in developing agricultural contaminant loadings for a watershed scale surface water and groundwater model. Municipalities can utilize this model as a management tool to determine the extent of contamination and delineate site sensitive locations, such as well-head protection zones. Other applications of this model include risk assessments of contaminant migration due to climate change predictions, varying fertilizer application practices, modifications in crop management and changes in land use. The impact of climate change on recharge has been investigated.

Using Campylobacter spp. and Escherichia coli data and Bayesian microbial risk assessment to examine public health risks in agricultural watersheds under tile drainage management.

PubMed

Schmidt, P J; Pintar, K D M; Fazil, A M; Flemming, C A; Lanthier, M; Laprade, N; Sunohara, M D; Simhon, A; Thomas, J L; Topp, E; Wilkes, G; Lapen, D R

2013-06-15

Human campylobacteriosis is the leading bacterial gastrointestinal illness in Canada; environmental transmission has been implicated in addition to transmission via consumption of contaminated food. Information about Campylobacter spp. occurrence at the watershed scale will enhance our understanding of the associated public health risks and the efficacy of source water protection strategies. The overriding purpose of this study is to provide a quantitative framework to assess and compare the relative public health significance of watershed microbial water quality associated with agricultural BMPs. A microbial monitoring program was expanded from fecal indicator analyses and Campylobacter spp. presence/absence tests to the development of a novel, 11-tube most probable number (MPN) method that targeted Campylobacter jejuni, Campylobacter coli, and Campylobacter lari. These three types of data were used to make inferences about theoretical risks in a watershed in which controlled tile drainage is widely practiced, an adjacent watershed with conventional (uncontrolled) tile drainage, and reference sites elsewhere in the same river basin. E. coli concentrations (MPN and plate count) in the controlled tile drainage watershed were statistically higher (2008-11), relative to the uncontrolled tile drainage watershed, but yearly variation was high as well. Escherichia coli loading for years 2008-11 combined were statistically higher in the controlled watershed, relative to the uncontrolled tile drainage watershed, but Campylobacter spp. loads for 2010-11 were generally higher for the uncontrolled tile drainage watershed (but not statistically significant). Using MPN data and a Bayesian modelling approach, higher mean Campylobacter spp. concentrations were found in the controlled tile drainage watershed relative to the uncontrolled tile drainage watershed (2010, 2011). A second-order quantitative microbial risk assessment (QMRA) was used, in a relative way, to identify differences in mean Campylobacter spp. infection risks among monitoring sites for a hypothetical exposure scenario. Greater relative mean risks were obtained for sites in the controlled tile drainage watershed than in the uncontrolled tile drainage watershed in each year of monitoring with pair-wise posterior probabilities exceeding 0.699, and the lowest relative mean risks were found at a downstream drinking water intake reference site. The second-order modelling approach was used to partition sources of uncertainty, which revealed that an adequate representation of the temporal variation in Campylobacter spp. concentrations for risk assessment was achieved with as few as 10 MPN data per site. This study demonstrates for the first time how QMRA can be implemented to evaluate, in a relative sense, the public health implications of controlled tile drainage on watershed-scale water quality. Crown Copyright © 2013. Published by Elsevier Ltd. All rights reserved.

Dissolved Organic Matter Composition and Export from U.S. Rivers

NASA Astrophysics Data System (ADS)

Aiken, G.; Butman, D. E.; Spencer, R. G.; Raymond, P.

2012-12-01

Dissolved organic matter (DOM) chemistry and flux are potentially useful indicators of watershed characteristics, climate influences on watershed hydrology and soils, and changes associated with water and land resource management. Organic source materials, watershed geochemistry, oxidative processes and hydrology strongly influence the nature and reactivity of DOM in aquatic systems. The molecules that comprise DOM, in turn, control a number of environmental processes important for ecosystem function including light penetration and photochemistry, microbial activity, mineral dissolution/precipitation, and the transport and reactivity of hydrophobic compounds and metals. In particular, aromatic molecules derived from higher plants exert strong controls on aquatic photochemistry, and on the transport and biogeochemistry of metals. Assessment of DOM composition and transport, therefore, can provide a basis for understanding watershed processes and biogeochemistry of rivers and streams. Here we present results of a multi-year study designed to assess the seasonal and spatial variability of DOM quantity and quality for 15 large North American river basins. Samples were collected from the mouths of the rivers using a sampling program designed to capture hydrologic and seasonal variability of DOM export. DOM concentrations and composition, based on DOM fractionation on XAD resins, chromophoric dissolved organic matter (CDOM) parameters (ultraviolet /visible absorption and fluorescence spectroscopy), specific compound analyses, and DO14C content varied greatly both between sites and seasonally within a given site. DOM in these rivers exhibited a wide range of concentration and carbon specific ultra-violet absorbance at 254 nm (SUVA254), an optical measurement that is an indicator of DOM aromatic carbon content. In almost all systems, CDOM optical parameters correlated strongly with DOC concentration and hydrophobic organic acid (HPOA) content (aquatic humic substances). In particular, SUVA254 was found to correlate strongly with the proportion of HPOA and Δ14C. Relationships between dissolved organic carbon (DOC) concentration and absorbance for individual rivers were quite variable due to differences in the fraction of non-chromophoric DOM. Notably, the relationship between UV absorption coefficients and DOC concentration for four rivers that drain arid regions and/or are heavily influenced by impoundments were statistically weak.although similar trends for these rivers were not observed for Δ14C. Basins with high discharge, high density of vegetation cover, and low population densities exported younger, more aromatic DOM. Conversely, old DOM was exported from low discharge watersheds draining arid regions and watersheds impacted by high population densities. While individual watershed characteristics control DOC concentrations, CDOM parameters and DO14C content, overall discharge dominated the flux of both CDOM and DO14C to coastal waters. The link between the nature and reactivity of DOM and its optical properties can be exploited to provide powerful monitoring tools to assess the impacts of climate change, land-use change, and management practices on overall water quality and on DOM transport and transformation.

Relationships and trends of E. Coli, human-associated Bacteroides, and pathogens in the Proctor Creek Watershed

EPA Science Inventory

Urban surface waters can be impacted by anthropogenic sources such as impervious surfaces, sanitary and storm sewers, and failing infrastructure. Fecal indicator bacteria (FIB) and microbial source tracking (MST) markers are common gauges of stream water quality, however, little...

Investigating the Sources and Dynamics of Dissolved Organic Matter in an Agricultural Watershed in California (U.S.A.)

NASA Astrophysics Data System (ADS)

Dyda, R. Y.; Hernes, P. J.; Spencer, R. G.; Ingrum, T. D.; Pellerin, B. A.; Bergamaschi, B. A.

2007-12-01

Dissolved organic matter (DOM) is ubiquitous and plays critical roles in nutrient cycling, aquatic food webs and numerous other biogeochemical processes. Furthermore, various factors control the quality and quantity of DOM, including land use, soil composition, in situ production, microbial uptake and assimilation and hydrology. As a component of DOM, dissolved organic carbon (DOC) has been recently identified as a drinking water constituent of concern due to its propensity to form EPA-regulated carcinogenic compounds when disinfected for drinking water purposes. Therefore, understanding the sources, cycling and modification of DOC across various landscapes is of direct relevance to a wide range of studies. The Willow Slough watershed is located in the Central Valley of California (U.S.A.) and is characterized by both diverse geomorphology as well as land use. The watershed drains approximately 425 km2 and is bordered by Cache and Putah Creeks to the north and south. The study area in the watershed includes the eastern portion of the foothills of the inner Coast Range and the alluvial plain and encompasses diverse land uses, including orchards, viticulture, dairy, pasture and natural grasslands. The Willow Slough watershed represents a unique opportunity to examine DOC dynamics through multiple land uses and hydrologic flow paths that are common throughout California. Preliminary data show that DOC concentrations at the watershed mouth peak during winter storms and also increase gradually throughout the summer months during the agricultural irrigation season. The increasing DOC concentrations during the summer months may result from agricultural runoff and/or primary production in channel. In addition, initial results using the chromophoric DOM (CDOM) absorption coefficient and spectral slope parameters indicate seasonal differences in the composition of the DOM. Spectral slopes decreased during both the summer irrigation season and winter storms relative to winter base flow, consistent with an increase in terrestrial signature. Biomolecular markers such as lignin phenols provide diagnostic source information on DOM as they are derived uniquely from vascular plants. Lignin can be used to differentiate angiosperm and gymnosperm tissues, but more importantly for this study, carbon-normalized yields can help to constrain the proportions of the increasing DOC during irrigation that come from vascular plants versus in situ production. In addition to supplying useful source information, dissolved lignin phenols undergo rapid photodegradation when exposed to adequate solar radiation, and this process is "imprinted" through increases in the acidic components of lignin and decreases in the syringyl phenols, thus providing insight into DOM cycling in agriculture-dominated watersheds. Data will be presented highlighting the use of a range of analytical and spectrophotometric measurements including lignin phenols, 13C of DOC and CDOM in the Willow Slough watershed for investigating sources and dynamics of DOM throughout the watershed.

Transformation of Lesquerella fendleri with the new binary vector pGPro4-35S

USDA-ARS?s Scientific Manuscript database

Crop genetic engineering requires the use of various promoters to control the expression of introduced transgenes. Some of the binary vectors currently available for promoter characterization in dicotyledonous plants have pitfalls due to their construction, such as containing a selectable marker ca...

Simulation of daily pesticide concentrations from watershed characteristics and monthly climatic data

USGS Publications Warehouse

Vecchia, Aldo V.; Crawford, Charles G.

2006-01-01

A time-series model was developed to simulate daily pesticide concentrations for streams in the coterminous United States. The model was based on readily available information on pesticide use, climatic variability, and watershed charac-teristics and was used to simulate concentrations for four herbicides [atrazine, ethyldipropylthiocarbamate (EPTC), metolachlor, and trifluralin] and three insecticides (carbofuran, ethoprop, and fonofos) that represent a range of physical and chemical properties, application methods, national application amounts, and areas of use in the United States. The time-series model approximates the probability distributions, seasonal variability, and serial correlation characteristics in daily pesticide concentration data from a national network of monitoring stations. The probability distribution of concentrations for a particular pesticide and station was estimated using the Watershed Regressions for Pesticides (WARP) model. The WARP model, which was developed in previous studies to estimate the probability distribution, was based on selected nationally available watershed-characteristics data, such as pesticide use and soil characteristics. Normality transformations were used to ensure that the annual percentiles for the simulated concentrations agree closely with the percentiles estimated from the WARP model. Seasonal variability in the transformed concentrations was maintained by relating the transformed concentration to precipitation and temperature data from the United States Historical Climatology Network. The monthly precipitation and temperature values were estimated for the centroids of each watershed. Highly significant relations existed between the transformed concentrations, concurrent monthly precipitation, and concurrent and lagged monthly temperature. The relations were consistent among the different pesticides and indicated the transformed concentrations generally increased as precipitation increased but the rate of increase depended on a temperature-dependent growing-season effect. Residual variability of the transformed concentrations, after removal of the effects of precipitation and temperature, was partitioned into a signal (systematic variability that is related from one day to the next) and noise (random variability that is not related from one day to the next). Variograms were used to evaluate measurement error, seasonal variability, and serial correlation of the historical data. The variogram analysis indicated substantial noise resulted, at least in part, from measurement errors (the differences between the actual concen-trations and the laboratory concentrations). The variogram analysis also indicated the presence of a strongly correlated signal, with an exponentially decaying serial correlation function and a correlation time scale (the time required for the correlation to decay to e-1 equals 0.37) that ranged from about 18 to 66 days, depending on the pesticide type. Simulated daily pesticide concentrations from the time-series model indicated the simulated concentrations for the stations located in the northeastern quadrant of the United States where most of the monitoring stations are located generally were in good agreement with the data. The model neither consistently overestimated or underestimated concentrations for streams that are located in this quadrant and the magnitude and timing of high or low concentrations generally coincided reasonably well with the data. However, further data collection and model development may be necessary to determine whether the model should be used for areas for which few historical data are available.

Heterogeneity in Immune Marker Expression after Acquisition of Resistance to EGFR Kinase Inhibitors: Analysis of a Case with Small Cell Lung Cancer Transformation.

PubMed

Suda, Kenichi; Murakami, Isao; Yu, Hui; Kim, Jihye; Ellison, Kim; Rivard, Christopher J; Mitsudomi, Tetsuya; Hirsch, Fred R

2017-06-01

Expression of immune markers is of scientific interest because of their potential roles as predictive biomarkers for immunotherapy. Although the microenvironment of metastatic tumors and/or therapy-inducible histological transformation may affect the expression of these immune markers, there are few data regarding this context. A 76-year-old never-smoking female with EGFR-mutated lung adenocarcinoma (AC) acquired resistance to gefitinib. After her death, an autopsy revealed SCLC transformation and EGFR T790M secondary mutation (T790M) as mutually exclusive resistance mechanisms occurring differently in different metastases; two liver metastases (SCLC versus AC with T790M) and two lymph node metastases (SCLC versus AC with T790M) were analyzed to compare the expression status of immune markers by immunohistochemistry and by an immune oncology gene expression panel. Programmed death ligand 1 (PD-L1) protein was partially expressed in tumor cells with AC lesions (T790M) but not in tumor cells with SCLC transformation. The liver metastasis with SCLC transformation showed no stromal PD-L1 expression and scant tumor-infiltrating lymphocytes, whereas the other lesions demonstrated stromal PD-L1 staining and infiltration of CD8-positive T cells. Data generated using an immuno-oncology gene expression panel indicated a higher level of T-cell costimulatory molecules and lower expression of type I interferon-regulated genes in lesions with SCLC transformation. These data highlight the heterogeneity of expression of immune markers depending on the metastatic sites and histological transformation and indicate that the biopsy specimen from one lesion may not be representative of immune marker status for all lesions. Copyright © 2017 International Association for the Study of Lung Cancer. Published by Elsevier Inc. All rights reserved.

Restricted gene flow between resident Oncorhynchus mykiss and an admixed population of anadromous steelhead

USGS Publications Warehouse

Matala, Andrew P.; Allen, Brady; Narum, Shawn R.; Harvey, Elaine

2017-01-01

The species Oncorhynchus mykiss is characterized by a complex life history that presents a significant challenge for population monitoring and conservation management. Many factors contribute to genetic variation in O. mykiss populations, including sympatry among migratory phenotypes, habitat heterogeneity, hatchery introgression, and immigration (stray) rates. The relative influences of these and other factors are contingent on characteristics of the local environment. The Rock Creek subbasin in the middle Columbia River has no history of hatchery supplementation and no dams or artificial barriers. Limited intervention and minimal management have led to a dearth of information regarding the genetic distinctiveness of the extant O. mykiss population in Rock Creek and its tributaries. We used 192 SNP markers and collections sampled over a 5‐year period to evaluate the temporal and spatial genetic structures of O. mykissbetween upper and lower watersheds of the Rock Creek subbasin. We investigated potential limits to gene flow within the lower watershed where the stream is fragmented by seasonally dry stretches of streambed, and between upper and lower watershed regions. We found minor genetic differentiation within the lower watershed occupied by anadromous steelhead (FST = 0.004), and evidence that immigrant influences were prevalent and ubiquitous. Populations in the upper watershed above partial natural barriers were highly distinct (FST = 0.093) and minimally impacted by apparent introgression. Genetic structure between watersheds paralleled differences in local demographics (e.g., variation in size), migratory restrictions, and habitat discontinuity. The evidence of restricted gene flow between putative remnant resident populations in the upper watershed and the admixed anadromous population in the lower watershed has implications for local steelhead productivity and regional conservation.

[A comparison study of hpt and bar as selection marker gene of transgenic rice].

PubMed

Zhang, Chun-Yu; Li, Hong-Yu; Liu, Bin

2012-12-01

The decision of using selection marker is one of the key factors for success of plant genetic transformation and offspring screening. As two commonly used selection markers, hpt and bar genes are widely used in tissue culture-based rice transformation. To experimentally compare their performance, we investigated the efficiency of two transformation systems using Hygromycin and Bialaphos as the selection agents, respectively. The result indicated that the system using hpt gene as the selection marker saved 10 days and had double transformation efficiency and lower transgene copy number in comparison to the system using bar gene. Then, we assessed the feasibility of screening transgenic rice in the field by soaking the wild-type and transgenic seeds in a series of solutions containing step diluted hygromycin for two days. We targeted the suitable concentration for distinguishing the transgenic seeds from WT Kitaake seeds was 167 mg L(-1). However, the cost of screening by hygromycin is still much higher than that of Basta in field test. Therefore, this study experimentally demonstrated the advantages and disadvantages of the hpt and bar gene as the selection markers and thus provided a reference for choose of an appropriate selection marker according to the practical applications.

36 CFR 251.9 - Management of Municipal Watersheds.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Watersheds. 251.9 Section 251.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Natural Resources Control § 251.9 Management of Municipal Watersheds. (a) The Forest Service shall manage National Forest watersheds that supply municipal water under...

36 CFR 251.9 - Management of Municipal Watersheds.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Watersheds. 251.9 Section 251.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Natural Resources Control § 251.9 Management of Municipal Watersheds. (a) The Forest Service shall manage National Forest watersheds that supply municipal water under...

36 CFR 251.9 - Management of Municipal Watersheds.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Watersheds. 251.9 Section 251.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Natural Resources Control § 251.9 Management of Municipal Watersheds. (a) The Forest Service shall manage National Forest watersheds that supply municipal water under...

36 CFR 251.9 - Management of Municipal Watersheds.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Watersheds. 251.9 Section 251.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Natural Resources Control § 251.9 Management of Municipal Watersheds. (a) The Forest Service shall manage National Forest watersheds that supply municipal water under...

36 CFR 251.9 - Management of Municipal Watersheds.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Watersheds. 251.9 Section 251.9 Parks, Forests, and Public Property FOREST SERVICE, DEPARTMENT OF AGRICULTURE LAND USES Miscellaneous Land Uses Natural Resources Control § 251.9 Management of Municipal Watersheds. (a) The Forest Service shall manage National Forest watersheds that supply municipal water under...

Relationships and trends of E. Coli, human-associated bacteroides, and pathogens in the Proctor Creek watershed (GWRC 2017)

EPA Science Inventory

Urban surface waters can be impacted by anthropogenic sources such as impervious surfaces, sani-tary and storm sewers, and failing infrastructure. Fecal indicator bacteria (FIB) and microbial source tracking (MST) markers are common gauges of stream water qual-ity, however, litt...

Impacts of land management practices on stream microbial loading in Northeast GA

EPA Science Inventory

Identification of dominant source(s) of fecal pollution in a watershed is necessary for assessing the safety of recreational water and for protecting water resources. The objective of this study was to examine the relative abundance of molecular fecal markers from two cattle farm...

An empirical assessment of which inland floods can be managed.

PubMed

Mogollón, Beatriz; Frimpong, Emmanuel A; Hoegh, Andrew B; Angermeier, Paul L

2016-02-01

Riverine flooding is a significant global issue. Although it is well documented that the influence of landscape structure on floods decreases as flood size increases, studies that define a threshold flood-return period, above which landscape features such as topography, land cover and impoundments can curtail floods, are lacking. Further, the relative influences of natural versus built features on floods is poorly understood. Assumptions about the types of floods that can be managed have considerable implications for the cost-effectiveness of decisions to invest in transforming land cover (e.g., reforestation) and in constructing structures (e.g., storm-water ponds) to control floods. This study defines parameters of floods for which changes in landscape structure can have an impact. We compare nine flood-return periods across 31 watersheds with widely varying topography and land cover in the southeastern United States, using long-term hydrologic records (≥20 years). We also assess the effects of built flow-regulating features (best management practices and artificial water bodies) on selected flood metrics across urban watersheds. We show that landscape features affect magnitude and duration of only those floods with return periods ≤10 years, which suggests that larger floods cannot be managed effectively by manipulating landscape structure. Overall, urban watersheds exhibited larger (270 m(3)/s) but quicker (0.41 days) floods than non-urban watersheds (50 m(3)/s and 1.5 days). However, urban watersheds with more flow-regulating features had lower flood magnitudes (154 m(3)/s), but similar flood durations (0.55 days), compared to urban watersheds with fewer flow-regulating features (360 m(3)/s and 0.23 days). Our analysis provides insight into the magnitude, duration and count of floods that can be curtailed by landscape structure and its management. Our findings are relevant to other areas with similar climate, topography, and land use, and can help ensure that investments in flood management are made wisely after considering the limitations of landscape features to regulate floods. Copyright © 2015 Elsevier Ltd. All rights reserved.

Storage in alluvial deposits controls the timing of particle delivery from large watersheds, filtering upland erosional signals and delaying benefits from watershed best management practices

NASA Astrophysics Data System (ADS)

Pizzuto, J. E.; Skalak, K.; Karwan, D. L.

2017-12-01

Transport of suspended sediment and sediment-borne constituents (here termed fluvial particles) through large river systems can be significantly influenced by episodic storage in floodplains and other alluvial deposits. Geomorphologists quantify the importance of storage using sediment budgets, but these data alone are insufficient to determine how storage influences the routing of fluvial particles through river corridors across large spatial scales. For steady state systems, models that combine sediment budget data with "waiting time distributions" (to define how long deposited particles remain stored until being remobilized) and velocities during transport events can provide useful predictions. Limited field data suggest that waiting time distributions are well represented by power laws, extending from <1 to >104 years, while the probability of storage defined by sediment budgets varies from 0.1 km-1 for small drainage basins to 0.001 km-1 for the world's largest watersheds. Timescales of particle delivery from large watersheds are determined by storage rather than by transport processes, with most particles requiring 102 -104 years to reach the basin outlet. These predictions suggest that erosional "signals" induced by climate change, tectonics, or anthropogenic activity will be transformed by storage before delivery to the outlets of large watersheds. In particular, best management practices (BMPs) implemented in upland source areas, designed to reduce the loading of fluvial particles to estuarine receiving waters, will not achieve their intended benefits for centuries (or longer). For transient systems, waiting time distributions cannot be constant, but will vary as portions of transient sediment "pulses" enter and are later released from storage. The delivery of sediment pulses under transient conditions can be predicted by adopting the hypothesis that the probability of erosion of stored particles will decrease with increasing "age" (where age is defined as the elapsed time since deposition). Then, waiting time and age distributions for stored particles become predictions based on the architecture of alluvial storage and the tendency for erosional processes to preferentially remove younger deposits, improving assessment of watershed BMPs and other important applications.

Interacting With A Near Real-Time Urban Digital Watershed Using Emerging Geospatial Web Technologies

NASA Astrophysics Data System (ADS)

Liu, Y.; Fazio, D. J.; Abdelzaher, T.; Minsker, B.

2007-12-01

The value of real-time hydrologic data dissemination including river stage, streamflow, and precipitation for operational stormwater management efforts is particularly high for communities where flash flooding is common and costly. Ideally, such data would be presented within a watershed-scale geospatial context to portray a holistic view of the watershed. Local hydrologic sensor networks usually lack comprehensive integration with sensor networks managed by other agencies sharing the same watershed due to administrative, political, but mostly technical barriers. Recent efforts on providing unified access to hydrological data have concentrated on creating new SOAP-based web services and common data format (e.g. WaterML and Observation Data Model) for users to access the data (e.g. HIS and HydroSeek). Geospatial Web technology including OGC sensor web enablement (SWE), GeoRSS, Geo tags, Geospatial browsers such as Google Earth and Microsoft Virtual Earth and other location-based service tools provides possibilities for us to interact with a digital watershed in near-real-time. OGC SWE proposes a revolutionary concept towards a web-connected/controllable sensor networks. However, these efforts have not provided the capability to allow dynamic data integration/fusion among heterogeneous sources, data filtering and support for workflows or domain specific applications where both push and pull mode of retrieving data may be needed. We propose a light weight integration framework by extending SWE with open source Enterprise Service Bus (e.g., mule) as a backbone component to dynamically transform, transport, and integrate both heterogeneous sensor data sources and simulation model outputs. We will report our progress on building such framework where multi-agencies" sensor data and hydro-model outputs (with map layers) will be integrated and disseminated in a geospatial browser (e.g. Microsoft Virtual Earth). This is a collaborative project among NCSA, USGS Illinois Water Science Center, Computer Science Department at UIUC funded by the Adaptive Environmental Infrastructure Sensing and Information Systems initiative at UIUC.

Storm Event Suspended Sediment-Discharge Hysteresis and Controls in Agricultural Watersheds: Implications for Watershed Scale Sediment Management.

PubMed

Sherriff, Sophie C; Rowan, John S; Fenton, Owen; Jordan, Philip; Melland, Alice R; Mellander, Per-Erik; hUallacháin, Daire Ó

2016-02-16

Within agricultural watersheds suspended sediment-discharge hysteresis during storm events is commonly used to indicate dominant sediment sources and pathways. However, availability of high-resolution data, qualitative metrics, longevity of records, and simultaneous multiwatershed analyses has limited the efficacy of hysteresis as a sediment management tool. This two year study utilizes a quantitative hysteresis index from high-resolution suspended sediment and discharge data to assess fluctuations in sediment source location, delivery mechanisms and export efficiency in three intensively farmed watersheds during events over time. Flow-weighted event sediment export was further considered using multivariate techniques to delineate rainfall, stream hydrology, and antecedent moisture controls on sediment origins. Watersheds with low permeability (moderately- or poorly drained soils) with good surface hydrological connectivity, therefore, had contrasting hysteresis due to source location (hillslope versus channel bank). The well-drained watershed with reduced connectivity exported less sediment but, when watershed connectivity was established, the largest event sediment load of all watersheds occurred. Event sediment export was elevated in arable watersheds when low groundcover was coupled with high connectivity, whereas in the grassland watershed, export was attributed to wetter weather only. Hysteresis analysis successfully indicated contrasting seasonality, connectivity and source availability and is a useful tool to identify watershed specific sediment management practices.

Transformation of Sordaria macrospora to hygromycin B resistance: characterization of transformants by electrophoretic karyotyping and tetrad analysis.

PubMed

Walz, M; Kück, U

1995-12-01

The ascomycete Sordaria macrospora was transformed using different plasmid molecules containing the bacterial hygromycin B resistance gene (hph) under the control of different expression signals. The highest transformation frequency was obtained with vector pMW1. On this plasmid molecule, expression of the hph gene is directed by the upstream region of the isopenicillin N synthetase gene (pcbC) from the deuteromycete Acremonium chrysogenum. Southern analysis suggests that the vector copies are integrated as tandem repeats into the S. macrospora chromosomes and that duplicated sequences are most probably not inactivated by methylation during meiosis. Furthermore, the hygromycin B resistance (hygR) is not correlated with the number of integrated vector molecules. Electrophoretic karyotyping was used to further characterize S. macrospora transformants. Five chromosomal bands were separated by pulsed-field gel electrophoresis (PFGE) representing seven chromosomes with a total genome size of 39.5Mb. Hybridization analysis revealed ectopic integration of vector DNA into different chromosomes. In a few transformants, major rearrangements were detected. Transformants were sexually propagated to analyze the fate of the heterologous vector DNA. Although the hygR phenotype is stably maintained during mitosis, about a third of all lines tested showed loss of the resistance marker gene after meiosis. However, as was concluded from electrophoretic karyotyping, the resistant spores showed a Mendelian segregation of the integrated vector molecules in at least three consecutive generations. Our data indicate that heterologous marker genes can be used for transformation tagging, or the molecular mapping of chromosomal loci in S. macrospora.

Can forest transformation help reducing floods in forested watersheds? Certain aspects on soil hydraulics and organic matter properties

NASA Astrophysics Data System (ADS)

Wahl, N. A.; Wöllecke, B.; Bens, O.; Hüttl, R. F.

Former floodplains in many European countries increasingly suffer from serious floods due to intensified human activity. These floods have caused safety and ecological problems as well as they have resulted in economic losses in agricultural used watersheds. In this context, the influence of the management practice of forest transformation in forested areas on soil hydraulic properties is presented and discussed as a means of preventing such disasters at a reasonable cost and during a foreseeable period. Investigations were carried out in northeastern Germany on forest stands differing in tree populations and stand structure. It was found that infiltration capacity and hydraulic conductivity K exhibit overall low values nevertheless the tree species. This finding appears to be related to water repellency, the predominating texture, and a poor macroporosity. During the different stages of forest transformation, the type and amount of soil organic matter and humus in the litter layer change, leading to a decrease of the water capacity of the litter layer and the uppermost part of the mineral soil. Furthermore, these changes affect soil properties connected with water repellency. It is concluded that for the approximate duration of one century the practice of forest transformation does not contribute to flood prevention through enhanced infiltration capacity or water retention.

All Property is Riverfront Property: The Raindrop App and FLOW Project

NASA Astrophysics Data System (ADS)

Carter, T.; Miss, M.; Kirn, M.; Niyogi, D.; Bachta, E.; Steckel, J.

2011-12-01

Rivers in the United States are essential to sustain lives of both nonhuman species and of human societies. Urban areas rely heavily upon their nearby rivers and watersheds for their survival and yet citizens are often unaware of inextricable linkages between societal and river functions. One way to overcome this lack of awareness is by exploring new avenues for engagement with the general public. In this project, we use three fields for this engagement (science, art, and technology) to produce a river awareness tool that creates connections between citizens and their watersheds through visceral and technological interfaces. The target area is the White River watershed, which is entirely contained within the state of Indiana and encompasses nearly 30,000 km2 in the central and southern portions of the state including the metropolitan region of Indianapolis. We developed a mobile device application called "Raindrop" that uses geographic information systems (GIS) and mobile device GPS technology to map a raindrop's path from a user's home to the river and identifies the various flow paths and pollutant constituents transported by this water along the way. Physical markers along the White River designed by an artist on the project team allows for the virtual features of the application to be grounded in physical space. The use of Raindrop to connect users with their urban watershed is shown to have significant promise for widespread application. A number of key advantages of using this technology over traditional forms of outreach are enumerated below. First, by collaborating with a nationally renowned artist both in the design of the application and for physical markers, the audience for Raindrop is greatly expanded and interesting dynamics between the scientific and artist members of the general public are developed. Second, in urban areas the use of mobile devices and handheld Web technology are ubiquitous and thus the information can be conveyed to an audience in a form that is familiar and relevant. By pulling the mobile device users into physical spaces along the river, the experience is enhanced further. Finally, the ability to concisely display essential watershed, weather, and climate information using iconography, predefined data analysis, and dynamic programming allows for the application to run quickly and usability to be optimized. Future work will focus on end user evaluation and replicability in other urban watersheds around the country.

Predictive Understanding of Mountainous Watershed Hydro-Biogeochemical Function and Response to Perturbations

NASA Astrophysics Data System (ADS)

Hubbard, S. S.; Williams, K. H.; Agarwal, D.; Banfield, J. F.; Beller, H. R.; Bouskill, N.; Brodie, E.; Maxwell, R. M.; Nico, P. S.; Steefel, C. I.; Steltzer, H.; Tokunaga, T. K.; Wainwright, H. M.; Dwivedi, D.; Newcomer, M. E.

2017-12-01

Recognizing the societal importance, vulnerability and complexity of mountainous watersheds, the `Watershed Function' project is developing a predictive understanding of how mountainous watersheds retain and release downgradient water, nutrients, carbon, and metals. In particular, the project is exploring how early snowmelt, drought, floods and other disturbances will influence mountainous watershed dynamics at seasonal to decadal timescales. Located in the 300km2 East River headwater catchment of the Upper Colorado River Basin, the project is guided by several constructs. First, the project considers the integrated role of surface and subsurface flow and biogeochemical reactions - from bedrock to the top of the vegetative canopy, from terrestrial through aquatic compartments, and from summit to receiving waters. The project takes a system-of-systems perspective, focused on developing new methods to quantify the cumulative watershed hydrobiogeochemical response to perturbations based on information from select subsystems within the watershed, each having distinct vegetation-subsurface biogeochemical-hydrological characteristics. A `scale-adaptive' modeling capability, in development using adaptive mesh refinement methods, serves as the organizing framework for the SFA. The scale-adaptive approach is intended to permit simulation of system-within-systems behavior - and aggregation of that behavior - from genome through watershed scales. This presentation will describe several early project discoveries and advances made using experimental, observational and numerical approaches. Among others, examples may include:quantiying how seasonal hydrological perturbations drive biogeochemical responses across critical zone compartments, with a focus on N and C transformations; metagenomic documentation of the spatial variability in floodplain meander microbial ecology; 3D reactive transport simulations of couped hydrological-biogeochemical behavior in the hyporheic zone; and new characterization and inversion approaches to quantify co-variability between above and below ground dynamics and the susceptibility of vegetation to drought stress. More information is provided at: Watershed.lbl.gov

Efficient transformation and regeneration of transgenic cassava using the neomycin phosphotransferase gene as aminoglycoside resistance marker gene.

PubMed

Niklaus, Michael; Gruissem, Wilhelm; Vanderschuren, Hervé

2011-01-01

Cassava is one of the most important crops in the tropics. Its industrial use for starch and biofuel production is also increasing its importance for agricultural production in tropical countries. In the last decade cassava biotechnology has emerged as a valuable alternative to the breeding constraints of this highly heterozygous crop for improved trait development of cassava germplasm. Cassava transformation remains difficult and time-consuming because of limitations in selecting transgenic tissues and regeneration of transgenic plantlets. We have recently reported an efficient and robust cassava transformation protocol using the hygromycin phosphotransferase II (hptII) gene as selection marker and the aminoglycoside hygromycin at optimal concentrations to maximize the regeneration of transgenic plantlets. In the present work, we expanded the transformation protocol to the use of the neomycin phosphotransferase II (nptII) gene as selection marker. Several aminoglycosides compatible with the use of nptII were tested and optimal concentrations for cassava transformation were determined. Given its efficiency equivalent to hptII as selection marker with the described protocol, the use of nptII opens new possibilities to engineer transgenic cassava lines with multiple T-DNA insertions and to produce transgenic cassava with a resistance marker gene that is already deregulated in several commercial transgenic crops.

Evaluating the source of streamwater nitrate using δ15N and δ18O in nitrate in two watersheds in New Hampshire, USA

USGS Publications Warehouse

Pardo, Linda H.; Kendall, Carol; Pett-Ridge, Jennifer; Chang, Cecily C.Y.

2004-01-01

The natural abundance of nitrogen and oxygen isotopes in nitrate can be a powerful tool for identifying the source of nitrate in streamwater in forested watersheds, because the two main sources of nitrate, atmospheric deposition and microbial nitrification, have distinct δ18O values. Using a simple mixing model, we estimated the relative fractions in streamwater derived from these sources for two forested watersheds with markedly different streamwater nitrate outputs. In this study, we monitored δ15N and δ18O of nitrate biweekly in atmospheric deposition and in streamwater for 20 months at the Hubbard Brook Experimental Forest, New Hampshire, USA (moderate nitrogen export), and monthly in streamwater at the Bowl Research Natural Area, New Hampshire, USA (high nitrogen export). For rain, δ18O values ranged from +47 to +77‰ (mean: +58‰) and δ15N from −5 to +1‰ (mean: −3‰); for snow, δ18O values ranged from +52 to +75‰ (mean: +67‰) and δ15N from −3 to +2‰ (mean: −1‰). Streamwater nitrate, in contrast to deposition, had δ18O values between +12 and +33‰ (mean: +18‰) and δ15N between −3 and +6‰ (mean: 0‰). Since nitrate produced by nitrification typically has δ18O values ranging from −5 to +15‰, our field data suggest that most of the nitrate lost from the watersheds in streamflow was nitrified within the catchment. Our results confirm the importance of microbial nitrogen transformations in regulating nitrogen losses from forested ecosystems and suggest that hydrologic storage may be a factor in controlling catchment nitrate losses.

Estimates of diffuse phosphorus sources in surface waters of the United States using a spatially referenced watershed model

USGS Publications Warehouse

Alexander, R.B.; Smith, R.A.; Schwarz, G.E.

2004-01-01

The statistical watershed model SPARROW (SPAtially Referenced Regression On Watershed attributes) was used to estimate the sources and transport of total phosphorus (TP) in surface waters of the United States. We calibrated the model using stream measurements of TP from 336 watersheds of mixed land use and spatial data on topography, soils, stream hydrography, and land use (agriculture, forest, shrub/grass, urban). The model explained 87% of the spatial variability in log transformed stream TP flux (kg yr-1). Predictions of stream yield (kg ha-1 yr-1) were typically within 45% of the observed values at the monitoring sites. The model identified appreciable effects of soils, streams, and reservoirs on TP transport, The estimated aquatic rates of phosphorus removal declined with increasing stream size and rates of water flushing in reservoirs (i.e. areal hydraulic loads). A phosphorus budget for the 2.9 million km2 Mississippi River Basin provides a detailed accounting of TP delivery to streams, the removal of TP in surface waters, and the stream export of TP from major interior watersheds for sources associated with each land-use type. ?? US Government 2004.

The study of soils and vegetation transformation due fire disturbances in remote areas through scenario modelling of observed hydrological response to fire impact

NASA Astrophysics Data System (ADS)

Nesterova, Natalia; Semenova, Olga; Lebedeva, Luidmila

2015-04-01

Large territories of Siberia and Russian Far East are the subject to frequent forest fires. Often there is no information available about fire impact except its timing, areal distribution and qualitative characteristics of fire severity. Observed changes of hydrological response in burnt watersheds can be considered as indirect evidence of soil and vegetation transformation due to fire impact. In our study we used MODIS Fire products to detect spatial distribution of fires in Transbaikal and Far East regions of Russia in 2000 - 2012 period. Small and middle-size watersheds (with area up to 10000 km2) affected by extensive (burn area not less than 20 %) fires were chosen. We analyzed available hydrological data (measured discharges in watersheds outlets) for chosen basins. In several cases apparent hydrological response to fire was detected. To investigate main factors causing the change of hydrologic regime after fire several scenarios of soil and vegetation transformation were developed for each watershed under consideration. Corresponding sets of hydrological model parameters describing those transformations were elaborated based on data analysis and post-fire landscape changes as derived from a literature review. We implied different factors such as removal of organic layer, albedo changes, intensification of soil thaw (in presence of permafrost and seasonal soil freezing), reduction of infiltration rate and evapotranspiration, increase of upper subsurface flow fraction in summer flood events following the fire and others. We applied Hydrograph model (Russia) to conduct simulation experiments aiming to reveal which landscape changes scenarios were more plausible. The advantages of chosen hydrological model for this study are 1) that it takes into consideration thermal processes in soils which in case of permafrost and seasonal soil freezing presence can play leading role in runoff formation and 2) that observable vegetation and soil properties are used as its parameters allowing minimal resort to calibration. The model can use dynamic set of parameters performing preassigned abrupt and/or gradual changes of landscape characteristics. Interestingly, based on modelling results it can be concluded that depending on dominant landscape different aspects of soil and vegetation cover changes may influence runoff formation in contrasting way. The results of the study will be reported.

Tracking nonpoint source nitrogen pollution in human-impacted watersheds

USGS Publications Warehouse

Kaushal, Sujay S.; Groffman, Peter M; Band, Lawrence; Elliott, Emily M.; Shields, Catherine A.; Kendall, Carol

2011-01-01

Nonpoint source nitrogen (N) pollution is a leading contributor to U.S. water quality impairments. We combined watershed N mass balances and stable isotopes to investigate fate and transport of nonpoint N in forest, agricultural, and urbanized watersheds at the Baltimore Long-Term Ecological Research site. Annual N retention was 55%, 68%, and 82% for agricultural, suburban, and forest watersheds, respectively. Analysis of δ15N-NO3–, and δ18O-NO3– indicated wastewater was an important nitrate source in urbanized streams during baseflow. Negative correlations between δ15N-NO3– and δ18O-NO3– in urban watersheds indicated mixing between atmospheric deposition and wastewater, and N source contributions changed with storm magnitude (atmospheric sources contributed ∼50% at peak storm N loads). Positive correlations between δ15N-NO3– and δ18O-NO3– in watersheds suggested denitrification was removing septic system and agriculturally derived N, but N from belowground leaking sewers was less susceptible to denitrification. N transformations were also observed in a storm drain (no natural drainage network) potentially due to organic carbon inputs. Overall, nonpoint sources such as atmospheric deposition, wastewater, and fertilizer showed different susceptibility to watershed N export. There were large changes in nitrate sources as a function of runoff, and anticipating source changes in response to climate and storms will be critical for managing nonpoint N pollution.

Dominant selectable markers for Penicillium spp. transformation and gene function studies

USDA-ARS?s Scientific Manuscript database

Penicillium spp. has been genetically manipulated and gene function studies have utilized single gene deletion strains for phenotypic analysis. Fungal transformation experiments have relied on hygromycin and hygromycin phosphotransferase (hph) as the main dominant selectable marker (DSM) system in P...

Automated segmentation and isolation of touching cell nuclei in cytopathology smear images of pleural effusion using distance transform watershed method

NASA Astrophysics Data System (ADS)

Win, Khin Yadanar; Choomchuay, Somsak; Hamamoto, Kazuhiko

2017-06-01

The automated segmentation of cell nuclei is an essential stage in the quantitative image analysis of cell nuclei extracted from smear cytology images of pleural fluid. Cell nuclei can indicate cancer as the characteristics of cell nuclei are associated with cells proliferation and malignancy in term of size, shape and the stained color. Nevertheless, automatic nuclei segmentation has remained challenging due to the artifacts caused by slide preparation, nuclei heterogeneity such as the poor contrast, inconsistent stained color, the cells variation, and cells overlapping. In this paper, we proposed a watershed-based method that is capable to segment the nuclei of the variety of cells from cytology pleural fluid smear images. Firstly, the original image is preprocessed by converting into the grayscale image and enhancing by adjusting and equalizing the intensity using histogram equalization. Next, the cell nuclei are segmented using OTSU thresholding as the binary image. The undesirable artifacts are eliminated using morphological operations. Finally, the distance transform based watershed method is applied to isolate the touching and overlapping cell nuclei. The proposed method is tested with 25 Papanicolaou (Pap) stained pleural fluid images. The accuracy of our proposed method is 92%. The method is relatively simple, and the results are very promising.

Nitrogen cycling process rates across urban ecosystems.

PubMed

Reisinger, Alexander J; Groffman, Peter M; Rosi-Marshall, Emma J

2016-09-21

Nitrogen (N) pollution of freshwater, estuarine, and marine ecosystems is widespread and has numerous environmental and economic impacts. A portion of this excess N comes from urban watersheds comprised of natural and engineered ecosystems which can alter downstream N export. Studies of urban N cycling have focused on either specific ecosystems or on watershed-scale mass balances. Comparisons of specific N transformations across ecosystems are required to contextualize rates from individual studies. Here we reviewed urban N cycling in terrestrial, aquatic, and engineered ecosystems, and compared N processing in these urban ecosystem types to native reference ecosystems. We found that net N mineralization and net nitrification rates were enhanced in urban forests and riparian zones relative to reference ecosystems. Denitrification was highly variable across urban ecosystem types, but no significant differences were found between urban and reference denitrification rates. When focusing on urban streams, ammonium uptake was more rapid than nitrate uptake in urban streams. Additionally, reduction of stormwater runoff coupled with potential decreases in N concentration suggests that green infrastructure may reduce downstream N export. Despite multiple environmental stressors in urban environments, ecosystems within urban watersheds can process and transform N at rates similar to or higher than reference ecosystems. © FEMS 2016. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Increased salivary aldehyde dehydrogenase 1 in non-reticular oral lichen planus*

PubMed Central

Mansourian, Arash; Shanbehzadeh, Najmeh; Kia, Seyed Javad; Moosavi, Mahdieh-Sadat

2017-01-01

Background Oral lichen planus is a potentially malignant disorder. One of the malignant transformation markers is cancer stem cells. One of the proposed marker for the detection of cancer stem cells's in head and neck cancer is aldehyde dehydrogenase. Recently it is shown that aldehyde dehydrogenase 1 expression in tissue samples is associated with oral lichen planus malignant transformation. Objective This study evaluates salivary aldehyde dehydrogenase 1 in oral lichen planus. Method Thirty patients and 30 age and sex-matched healthy volunteers were recruited. Oral lichen planus was diagnosed based on the modified World Health Organization criteria. Subjects in the case group were divided into reticular and non-reticular forms. Unstimulated salivary samples were collected at 10-12 AM. Saliva concentrations of aldehyde dehydrogenase 1 were measured by ELISA. Results The differences between aldehyde dehydrogenase levels in the oral lichen planus group compared with the control group were not significant but aldehyde dehydrogenase in non-reticular oral lichen planus was significantly higher than that of the reticular form. Limitations of the study This is a cross-sectional study, thus longitudinal studies in oral lichen planus may present similar or different results. Conclusions The mechanism of malignant transformation in oral lichen planus is not defined. Previous analyses revealed that the aldehyde dehydrogenase 1 expression is significantly correlated with increased risk of transformation. This finding is consistent with our results because in the erosive and ulcerative forms of oral lichen planus, which have an increased risk of transformation, salivary aldehyde dehydrogenase 1 was overexpressed. A higher salivary aldehyde dehydrogenase level in non-reticular oral lichen planus can be a defensive mechanism against higher oxidative stress in these groups. Aldehyde dehydrogenase may be one of the malignant transformation markers in oral lichen planus. Further studies are needed for introducing aldehyde dehydrogenase as a prognostic indicator in certain lesions. PMID:28538873

Generation of Marker- and/or Backbone-Free Transgenic Wheat Plants via Agrobacterium-Mediated Transformation.

PubMed

Wang, Gen-Ping; Yu, Xiu-Dao; Sun, Yong-Wei; Jones, Huw D; Xia, Lan-Qin

2016-01-01

Horizontal transfer of antibiotic resistance genes to animals and vertical transfer of herbicide resistance genes to the weedy relatives are perceived as major biosafety concerns in genetically modified (GM) crops. In this study, five novel vectors which used gusA and bar as a reporter gene and a selection marker gene, respectively, were constructed based on the pCLEAN dual binary vector system. Among these vectors, 1G7B and 5G7B carried two T-DNAs located on two respective plasmids with 5G7B possessing an additional virGwt gene. 5LBTG154 and 5TGTB154 carried two T-DNAs in the target plasmid with either one or double right borders, and 5BTG154 carried the selectable marker gene on the backbone outside of the T-DNA left border in the target plasmid. In addition, 5BTG154, 5LBTG154, and 5TGTB154 used pAL154 as a helper plasmid which contains Komari fragment to facilitate transformation. These five dual binary vector combinations were transformed into Agrobacterium strain AGL1 and used to transform durum wheat cv Stewart 63. Evaluation of the co-transformation efficiencies, the frequencies of marker-free transgenic plants, and integration of backbone sequences in the obtained transgenic lines indicated that two vectors (5G7B and 5TGTB154) were more efficient in generating marker-free transgenic wheat plants with no or minimal integration of backbone sequences in the wheat genome. The vector series developed in this study for generation of marker- and/or backbone-free transgenic wheat plants via Agrobacterium -mediated transformation will be useful to facilitate the creation of "clean" GM wheat containing only the foreign genes of agronomic importance.

Geospatial tool-based morphometric analysis using SRTM data in Sarabanga Watershed, Cauvery River, Salem district, Tamil Nadu, India

NASA Astrophysics Data System (ADS)

Arulbalaji, P.; Gurugnanam, B.

2017-11-01

A morphometric analysis of Sarabanga watershed in Salem district has been chosen for the present study. Geospatial tools, such as remote sensing and GIS, are utilized for the extraction of river basin and its drainage networks. The Shuttle Radar Topographic Mission (SRTM-30 m resolution) data have been used for morphometric analysis and evaluating various morphometric parameters. The morphometric parameters of Sarabanga watershed have been analyzed and evaluated by pioneer methods, such as Horton and Strahler. The dendritic type of drainage pattern is draining the Sarabanga watershed, which indicates that lithology and gentle slope category is controlling the study area. The Sarabanga watershed is covered an area of 1208 km2. The slope of the watershed is various from 10 to 40% and which is controlled by lithology of the watershed. The bifurcation ratio ranges from 3 to 4.66 indicating the influence of geological structure and suffered more structural disturbances. The form factor indicates elongated shape of the study area. The total stream length and area of watershed indicate that mean annual rainfall runoff is relatively moderate. The basin relief expressed that watershed has relatively high denudation rates. The drainage density of the watershed is low indicating that infiltration is more dominant. The ruggedness number shows the peak discharges that are likely to be relatively higher. The present study is very useful to plan the watershed management.

Effects of prescribed fire on recruitment of Juniperus and Opuntia in a semiarid grassland watershed

Treesearch

Burton K. Pendleton; Rosemary L. Pendleton; Carleton S. White

2008-01-01

The Bernalillo Watershed Protection Project was begun in 1953 following catastrophic erosion and flooding of small communities below. Although erosion control features and protection from grazing successfully increased grass cover and stabilized watershed soils, the expansion of juniper woodland (Juniperus monosperma) into the grassland watershed...

Effects of watershed management practices on sediment concentrations in the southwestern United States: Management implications

Treesearch

Vicente L. Lopes; Peter F. Ffolliott; Malchus B. Baker

2000-01-01

Effects of watershed management practices on suspended sediment concentrations from ponderosa pine forests and pinyon-juniper woodlands in the Southwestern United States are examined. Completely cleared and strip-cut ponderosa pine watersheds produced higher sediment concentrations than the control. Likewise, cabled and herbicide-treated pinyon-juniper watersheds...

Traditional and Host-Associated Fecal Indicator Bacterial Patterns in Southern California Watersheds: Field Source Identification Studies and Laboratory Microcosms Investigating Presence and Persistence in Water and Sediments

NASA Astrophysics Data System (ADS)

Mika, Kathryn Beth

Overall, recreational beach water quality remains an issue of concern in Southern California and across the globe. Many factors come into play when determining water quality, including physical issues such as the myriad sources that contribute pollution to the site and financial and political issues that control the way water quality is monitored and determined. Current national regulations require the monitoring of fecal indicator bacteria in order to determine recreational water quality. However, it is also important to identify biological and geographical sources of pollution to consistently impaired locations. A commonly applied approach to meet the goals of source identification is to sample sites that have been high in FIB for further study. A tiered approach such as this, however, assumes a correlation between FIB and the sources of interest in the watershed. The research described in this dissertation tests this assumption in two Southern California watersheds, Santa Monica Canyon and Ventura Harbor. In both cases, a tiered approach to sampling using FIB as a first tier to guide sampling would have failed to identify sources of human fecal pollution (as identified by the presence of the human-associated Bacteroides marker HF183). Every watershed is a distinct environment that has different potential sources of bacteria and many factors contributing to the persistence of the bacteria. Rather than attempting to apply an indicator that has worked as a first tier in other watersheds, it would be better to have as a first tier an in-depth study of the watershed using historical data or local experts to provide information on the most likely sources of pollution in the watershed. Using this information it would be possible to design a study using FIB and one or more source-associated parameters to identify specific sources of pollution in the watershed. In addition, sampling FIB and other parameters such as HF183 allow the application of other microbial source tracking tools including indicator ratios and detection frequencies. Source identification studies do not necessarily have to be long-term to identify consistent sources of pollution. For example, within the first four months of sampling at Ventura, the increased frequency of detection of HF183 at the Marina Dock sample location was apparent, and a dry weather influx of HF183 was seen in the Keys channels. In addition to the many sources of FIB to the environment such as storm drains, leaking sewers, and wildlife, there are important environmental reservoirs such as sand and seaweed that can foster FIB growth and persistence in the environment. As such, it is important to understand the effect of different factors on the ability of bacteria to survive and persist in these reservoirs. Microcosm experiments conducted during the course of this dissertation research found that in dry beach sand (0.1% moisture), the addition of moisture was detrimental to the survival of the indicators studied (General Bacteroidales, E. coli, and enterococci). While increased moisture was not always detrimental to bacterial survival, these results point to the ability of bacteria to persist for long periods of time in beach environments under in-situ conditions (including dry sand). These findings point to the importance of understanding the behavior of indicator bacteria populations that have evolved to survive in environmental conditions so that their potential impact on overlying or adjacent water quality can be better understood. In summation, results from this research point to the importance of selecting indicators and sample locations that are most relevant to watershed concerns rather than using a first tier such as FIB to preferentially select sites for further analysis. Measuring a marker for human fecal pollution in both watershed studies provided useful information for potential human inputs that would have been missed if sites were chosen based on high FIB levels. In addition it is very important to understand the contribution of different reservoirs, such as sand, in the study area to the observed microbial pollution. Overall, these results point to the need for further examination of the ability of bacteria to survive under various environmental conditions in both water and sand, using both environmental microbial populations and populations from likely sources such as human sewage.

Testing a two-scale focused conservation strategy for reducing phosphorus and sediment loads from agricultural watersheds

USGS Publications Warehouse

Carvin, Rebecca; Good, Laura W.; Fitzpatrick, Faith A.; Diehl, Curt; Songer, Katherine; Meyer, Kimberly J.; Panuska, John C.; Richter, Steve; Whalley, Kyle

2018-01-01

This study tested a focused strategy for reducing phosphorus (P) and sediment loads in agricultural streams. The strategy involved selecting small watersheds identified as likely to respond relatively quickly, and then focusing conservation practices on high-contributing fields within those watersheds. Two 5,000 ha (12,360 ac) watersheds in the Driftless Area of south central Wisconsin, previously ranked in the top 6% of similarly sized Wisconsin watersheds for expected responsiveness to conservation efforts to reduce high P and sediment loads, were chosen for the study. The stream outlets from both watersheds were monitored from October of 2006 through September of 2016 for streamflow and concentrations of sediment, total P, and, beginning in October of 2009, total dissolved P. Fields and pastures having the highest potential P delivery to the streams in each watershed were identified using the Wisconsin P Index (Good et al. 2012). After three years of baseline monitoring (2006 to 2009), farmers implemented both field- and farm-based conservation practices in one watershed (treatment) as a means to reduce sediment and P inputs to the stream from the highest contributing areas, whereas there were no out-of-the-ordinary conservation efforts in the second watershed (control). Implementation occurred primarily in 2011 and 2012. In the four years following implementation of conservation practices (2013 through 2016), there was a statistically significant reduction in storm-event suspended sediment loads in the treatment watershed compared to the control watershed when the ground was not frozen (p = 0.047). While there was an apparent reduction in year-round suspended sediment event loads, it was not statistically significant at the 95% confidence level (p = 0.15). Total P loads were significantly reduced for runoff events (p < 0.01) with a median reduction of 50%. Total P and total dissolved P concentrations for low-flow conditions were also significantly reduced (p < 0.01) compared to the control watershed. This study demonstrated that a strategy that first identifies watersheds likely to respond to conservation efforts and then focuses implementation on relatively high-contributing fields within those watersheds can be successful in reducing stream P concentrations and loads.

Biogeochemical and Hydrological Controls on Mercury and Methylmercury in First Order Coastal Plain Watersheds of the Chesapeake Bay

NASA Astrophysics Data System (ADS)

Heyes, A.; Gilmour, C. C.; Bell, J. T.; Butera, D.; McBurney, A. W.

2015-12-01

Over the past 7 years we made use of the long-term research site at the Smithsonian Environmental Research Center (SERC) in central Maryland to study the fluxes of mercury (Hg) and methylmercury (MeHg) in three small first-order mid-Atlantic coastal plain watersheds. One watershed is entirely forested, one watershed is primarily agriculture with a forested stream buffer, and one watershed is mixed land use but contains a beaver produced wetland pond. Our initial goals were to assess watershed Hg yields in the mid-Atlantic and to establish a baseline prior to implementation of Hg emissions controls. All three studied watersheds produced relatively high yields of Hg, with the greatest yield coming from the forested watershed. Our initial evaluation of three watersheds showed that MeHg production and flux could also be high, but varied dramatically among watersheds and across years and seasons. During each year we observed episodic MeHg production in the spring and sometimes during prolonged high-flow storm events in the fall. The observed spring maxima of MeHg release coincided with development of anoxia in riparian groundwater. MeHg accumulation in riparian groundwater began once nitrate was depleted and either iron accumulation or sulfate depletion of groundwater began. We propose the presence of nitrate was modulating MeHg production through the suppression of sulfate and iron reducers and perhaps methanogens. As sulfate is not limiting in any of the watersheds owing to the sediments marine origin, we hypothesize the depletion of nitrate allows sulfate reducing bacteria to now utilize available carbon. Although wetlands are generally thought of as the primary zones of MeHg production in watersheds, shallow riparian groundwaters very close to the stream appear to play that role in SERC Coastal Plain watersheds. We hypothesize that the balance between nitrate, sulfate and other microbial electron acceptors in watersheds is a major control on MeHg production. Land management practices that change upset this balance by changing nitrate load and carbon quality will undoubtedly impact the cycling of Hg.

The ambiguity of "watershed": the politics of people and conservation in northern Thailand.

PubMed

Pinkaew Laungaramsri

2000-04-01

The current conflict over watershed management between the lowlanders and highlanders in Chomthong has unveiled various aspects of the politics of people versus nature conservation. What is important is that the conflict has exposed the shifting and inconsistent views of the Thai state towards the peripheral areas and its people. Thus, on the one hand, the official discourse on "watershed" was appropriated by the urban middle-class conservationists and lowlanders to legitimize their control of highland resources to the exclusion of the highland minorities. The two groups also used ethnic differences to justify their control over the highland resources. On the other hand, the conflict also showed that the control by the dominant power could never be absolute. Highlanders responded to the "watershed regime" by redefining watershed integrity, adapting to the state conservation pressure, and seeking and forming alliances with other groups.

Using dual isotopes to evaluate sources and transformations of nitrate in the West Lake watershed, eastern China.

PubMed

Jin, Zanfang; Qin, Xue; Chen, Lingxiao; Jin, Mantong; Li, Feili

2015-01-01

The West Lake is a World Heritage site in the West Lake watershed in eastern China. In this study, the hydrogeological and dual isotopic approaches were integrated to evaluate the seasonal and spatial variations of nitrate (NO3(-)) in the West Lake watershed, and to characterize NO3(-) sources and transformations. The results revealed that the geochemical facies of the water samples were dominated by Ca(2+)+Na(+)-HCO3(-)+SO4(2)(-) in the surface water and transfer water, Ca(2+)+Na(+)-HCO3(-) and Ca(2+)+Na(+)-SO4(2-) in the groundwater, which most likely reflect natural reactions and anthropogenic inputs. About 13% of the groundwater samples containing NO3(-) exceeded the World Health Organization (WHO) standard of 10 mg N L(-1). NO3(-) was the dominant form of total nitrogen (TN) and was the main surface water contaminant in the West Lake watershed. The δ(15)NNO3 and δ(18)ONO3 values indicated that the dominant NO3(-) sources in surface water were soil nitrogen (soil N) and chemical fertilizers, while the main NO3(-) sources in groundwater were soil N from the forest, chemical fertilizers and manure in the tea garden, domestic sewage from the small, old residential area in the forest as well as urban areas. The distribution of NO3(-) in groundwater was strongly influenced by land use. Results also suggest that there was significant nitrification in surface water and groundwater in the West Lake watershed, and that there were also denitrification processes in groundwater. The annual net fluxes of TN, NO3(-), and NH4(+) into the West Lake were 2.0×10(4), 4.0×10(3), and 1.31×10(4) kg as N, respectively. Copyright © 2015 Elsevier B.V. All rights reserved.

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2010 CFR

2010-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2011 CFR

2011-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2012 CFR

2012-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2014 CFR

2014-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

40 CFR 141.520 - Is my system subject to the updated watershed control requirements?

Code of Federal Regulations, 2013 CFR

2013-07-01

... AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People Additional Watershed Control...

Nutrient inputs from the watershed and coastal eutrophication in the Florida Keys

DOE Office of Scientific and Technical Information (OSTI.GOV)

LaPointe, B.E.; Clark, M.W.

1992-12-01

Widespread use of septic tanks in the Florida Keys increase the nutrient concentrations of limestone ground waters that discharge into shallow nearshore waters, resulting in coastal eutrophication. This study characterizes watershed nutrient inputs, transformations, and effects along a land-sea gradient stratified into four ecosystems that occur with increasing distance from land: manmade canal systems, seagrass meadows, patch reefs, and offshore bank reefs. Soluble reactive phosphorus (SRP), the primary limiting nutrient, was significantly elevated in canal systems, while dissolved inorganic nitrogen (DIN; NH[sub 4][sup =] and NO[sub 3][sup [minus

Whole-system phosphorus balances as a practical tool for lake management

Treesearch

Johanna Schussler; Lawrence A. Baker; Hugh Chester-Jones

2007-01-01

Controlling phosphorus (P) inputs to lakes remains a priority of lake management. This study develops watershed P balances for 11 recreational lakes in Minnesota. Areal P input rates to the watersheds ranged from 0.32 to 6.0 kg Pha-1 year-1 and was linearly related to the percentage of watershed in agriculture. Watershed P...

Generation of Trichoderma atroviride mutants with constitutively activated G protein signaling by using geneticin resistance as selection marker.

PubMed

Gruber, Sabine; Omann, Markus; Rodrìguez, Carolina Escobar; Radebner, Theresa; Zeilinger, Susanne

2012-11-17

Species of the fungal genus Trichoderma are important industrial producers of cellulases and hemicellulases, but also widely used as biocontrol agents (BCAs) in agriculture. In the latter function Trichoderma species stimulate plant growth, induce plant defense and directly antagonize plant pathogenic fungi through their mycoparasitic capabilities. The recent release of the genome sequences of four mycoparasitic Trichoderma species now forms the basis for large-scale genetic manipulations of these important BCAs. Thus far, only a limited number of dominant selection markers, including Hygromycin B resistance (hph) and the acetamidase-encoding amdS gene, have been available for transformation of Trichoderma spp. For more extensive functional genomics studies the utilization of additional dominant markers will be essential. We established the Escherichia coli neomycin phosphotransferase II-encoding nptII gene as a novel selectable marker for the transformation of Trichoderma atroviride conferring geneticin resistance. The nptII marker cassette was stably integrated into the fungal genome and transformants exhibited unaltered phenotypes compared to the wild-type. Co-transformation of T. atroviride with nptII and a constitutively activated version of the Gα subunit-encoding tga3 gene (tga3Q207L) resulted in a high number of mitotically stable, geneticin-resistant transformants. Further analyses revealed a co-transformation frequency of 68% with 15 transformants having additionally integrated tga3Q207L into their genome. Constitutive activation of the Tga3-mediated signaling pathway resulted in increased vegetative growth and an enhanced ability to antagonize plant pathogenic host fungi. The neomycin phosphotransferase II-encoding nptII gene from Escherichia coli proved to be a valuable tool for conferring geneticin resistance to the filamentous fungus T. atroviride thereby contributing to an enhanced genetic tractability of these important BCAs.

Hydrologic calibration of paired watersheds using a MOSUM approach

DOE PAGES

Ssegane, H.; Amatya, D. M.; Muwamba, A.; ...

2015-01-09

Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the calibration period and tests a change detection technique of moving sums of recursive residuals (MOSUM) to select calibration periods for each control-treatment watershed pair when the regression coefficients for daily water table elevation (WTE) were most stable to reduce regression model uncertainty. The control and treatment watersheds included 1–3 year intensively managedmore » loblolly pine ( Pinus taeda L.) with natural understory, same age loblolly pine intercropped with switchgrass ( Panicum virgatum), 14–15 year thinned loblolly pine with natural understory (control), and switchgrass only. Although monitoring during the calibration period spanned 2009 to 2012, silvicultural operational practices that occurred during this period such as harvesting of existing stand and site preparation for pine and switchgrass establishment may have acted as external factors, potentially shifting hydrologic calibration relationships between control and treatment watersheds. Results indicated that MOSUM was able to detect significant changes in regression parameters for WTE due to silvicultural operations. This approach also minimized uncertainty of calibration relationships which could otherwise mask marginal treatment effects. All calibration relationships developed using this MOSUM method were quantifiable, strong, and consistent with Nash–Sutcliffe Efficiency (NSE) greater than 0.97 for WTE and NSE greater than 0.92 for daily flow, indicating its applicability for choosing calibration periods of paired watershed studies.« less

Nutrient exports from watersheds with varying septic system densities in the North Carolina Piedmont.

PubMed

Iverson, G; Humphrey, C P; O'Driscoll, M A; Sanderford, C; Jernigan, J; Serozi, B

2018-04-01

Septic systems (SSs) have been shown to be a significant source of nitrogen and phosphorus to nutrient-sensitive coastal surface and groundwaters. However, few published studies have quantified the effects of SSs on nutrient inputs to water supply watersheds in the Piedmont region of the USA. This region consists of rolling hills at the surface underlain by clayey soils. There are nearly 1 million SSs in this region, which accounts for approximately 50% of all SSs in North Carolina. The goal of this study was to determine if significant differences in nutrient concentrations and exports exist between Piedmont watersheds with different densities of SSs. Water quality was assessed in watersheds with SSs (n = 11) and a sewer and a forested watershed, which were designated as controls. Stream flow and environmental readings were recorded and water samples were collected from the watersheds from January 2015-December 2016. Additional samples were collected from sand filter watersheds in April 2015-March 2016 to compare to septic and control watersheds. Samples were analyzed for total dissolved nitrogen (TDN) and orthophosphate (PO 4 -P). Results indicated that watersheds served by a high-density (HD) of SSs (4.9 kg-N yr -1 ha -1 ; 0.2 kg-P yr -1 ha -1 ) exported more than double the median masses of TDN and PO 4 -P, respectively, relative to low-density (1.0 kg-N yr -1 ha -1 ; <0.1 kg-P yr -1 ha -1 ) and control watersheds (1.4 kg-N yr -1 ha -1 ; <0.1 kg-P yr -1 ha -1 ) during baseflow. Isotopic analysis indicated that wastewater was the most likely source of nitrate-N in HD watersheds. In all other watersheds, isotopic results suggested non-wastewater sources as the dominant nitrate-N provider. These findings indicated that SS density was a significant factor in the delivery of septic-derived nutrients to these nutrient-sensitive, water supply watersheds of the North Carolina Piedmont. Copyright © 2018 Elsevier Ltd. All rights reserved.

Factors controlling the long-term temporal and spatial patterns of nitrate-nitrogen export in a dairy farming watershed.

PubMed

Jiang, Rui; Wang, Chun-ying; Hatano, Ryusuke; Kuramochi, Kanta; Hayakawa, Atsushi; Woli, Krishna P

2015-04-01

It is difficult to investigate the factors that control the riverine nitrate-nitrogen (NO3--N) export in a watershed which gains or losses groundwater. To control the NO3--N contamination in these watersheds, it is necessary to investigate the factors that are related to the export of NO3--N that is only produced by the watershed itself. This study was conducted in the Shibetsu watershed located in eastern Hokkaido, Japan, which gains external groundwater contribution (EXT) and 34% of the annual NO3--N loading occurs through EXT. The riverine NO3--N exports from 1980 to 2009 were simulated by the SWAT model, and the factors controlling the temporal and spatial patterns of NO3--N exports were investigated without considering the EXT. The results show that hydrological events control NO3--N export at the seasonal scale, while the hydrological and biogeochemical processes are likely to control NO3--N export at the annual scale. There was an integrated effect among the land use, topography, and soil type related to denitrification process, that regulated the spatial patterns of NO3--N export. The spatial distribution of NO3--N export from hydrologic response units (HRUs) identified the agricultural areas with surplus N that are vulnerable to nitrate contamination. A new standard for the N fertilizer application rate including manure application should be given to control riverine NO3--N export. This study demonstrates that applying the SWAT model is an appropriate method to determine the temporal and spatial patterns of NO3--N export from the watershed which includes EXT and to identify the crucial pollution areas within a watershed in which the management practices can be improved to more effectively control NO3--N export to water bodies.

Spatial characteristics of topography, energy exchange, and forest cover in a central Appalachian watershed

Treesearch

Stanislaw J. Tajchman; Hailiang Fu; James N. Kochenderfer; Pan Chunshen

1995-01-01

Spatial variation of topography, net radiation, evapotranspiration, and forest stand in the central Appalachian watershed is described. The study area is the control watershed 4 (39"20'N, 79"49"W) located in the Fernow Experimental Forest at Parsons, West Virginia. The watershed encompasses an area of 39.2 ha, it has a southeast orientation, and the...

Soil erosion and sediment production on watershed landscapes: Processes and control

Treesearch

Peter F. Ffolliott; Kenneth N. Brooks; Daniel G. Neary; Roberto Pizarro Tapia; Pablo Garcia-Chevesich

2013-01-01

Losses of the soil resources from otherwise productive and well functioning watersheds is often a recurring problem confronting hydrologists and watershed managers. These losses of soil have both on-site and off-site effects on the watershed impacted. In addition to the loss of inherent soil resources through erosion processes, on-site effects can include the breakdown...

Artificial watershed acidification on the Fernow Experimental Forest, USA

Treesearch

M.B. Adams; P.J. Edwards; F. Wood; J.N. Kochenderfer

1993-01-01

A whole-watershed manipulation project was begun on the Fernow Experimental Forest in West Virginia, USA, in 1987, with the objective of increasing understanding of the effects of acidic deposition on forest ecosystems. Two treatment watersheds (WS9 and WS3) and one control watershed (WS4) were included. Treatments were twice-ambient N and S deposition, applied via NH...

Spatially-Distributed Cost–Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution

PubMed Central

Geng, Runzhe; Wang, Xiaoyan; Sharpley, Andrew N.; Meng, Fande

2015-01-01

Best management practices (BMPs) for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P) index), model simulation techniques (Hydrological Simulation Program–FORTRAN), and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved) for four allocation approaches. Selection of a ‘‘best approach” depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001) decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program efficiency. The integrated model approach described that selects and places BMPs at varying levels of implementation, provides a new theoretical basis and technical guidance for diffuse pollution management in agricultural watersheds. PMID:26313561

Spatially-Distributed Cost-Effectiveness Analysis Framework to Control Phosphorus from Agricultural Diffuse Pollution.

PubMed

Geng, Runzhe; Wang, Xiaoyan; Sharpley, Andrew N; Meng, Fande

2015-01-01

Best management practices (BMPs) for agricultural diffuse pollution control are implemented at the field or small-watershed scale. However, the benefits of BMP implementation on receiving water quality at multiple spatial is an ongoing challenge. In this paper, we introduce an integrated approach that combines risk assessment (i.e., Phosphorus (P) index), model simulation techniques (Hydrological Simulation Program-FORTRAN), and a BMP placement tool at various scales to identify the optimal location for implementing multiple BMPs and estimate BMP effectiveness after implementation. A statistically significant decrease in nutrient discharge from watersheds is proposed to evaluate the effectiveness of BMPs, strategically targeted within watersheds. Specifically, we estimate two types of cost-effectiveness curves (total pollution reduction and proportion of watersheds improved) for four allocation approaches. Selection of a ''best approach" depends on the relative importance of the two types of effectiveness, which involves a value judgment based on the random/aggregated degree of BMP distribution among and within sub-watersheds. A statistical optimization framework is developed and evaluated in Chaohe River Watershed located in the northern mountain area of Beijing. Results show that BMP implementation significantly (p >0.001) decrease P loss from the watershed. Remedial strategies where BMPs were targeted to areas of high risk of P loss, deceased P loads compared with strategies where BMPs were randomly located across watersheds. Sensitivity analysis indicated that aggregated BMP placement in particular watershed is the most cost-effective scenario to decrease P loss. The optimization approach outlined in this paper is a spatially hierarchical method for targeting nonpoint source controls across a range of scales from field to farm, to watersheds, to regions. Further, model estimates showed targeting at multiple scales is necessary to optimize program efficiency. The integrated model approach described that selects and places BMPs at varying levels of implementation, provides a new theoretical basis and technical guidance for diffuse pollution management in agricultural watersheds.

Upper Washita River experimental watersheds: Sediment Database

USDA-ARS?s Scientific Manuscript database

Improving the scientific understanding of the effectiveness of watershed conservation practices and floodwater-retardation structures to control floods and soil erosion is one of the primary objectives for sediment studies in the upper Washita River Experimental Watersheds. This paper summarizes se...

Meta-analysis of the predictive value of DNA aneuploidy in malignant transformation of oral potentially malignant disorders.

PubMed

Alaizari, Nader A; Sperandio, Marcelo; Odell, Edward W; Peruzzo, Daiane; Al-Maweri, Sadeq A

2018-02-01

DNA aneuploidy is an imbalance of chromosomal DNA content that has been highlighted as a predictor of biological behavior and risk of malignant transformation. To date, DNA aneuploidy in oral potentially malignant diseases (OPMD) has been shown to correlate strongly with severe dysplasia and high-risk lesions that appeared non-dysplastic can be identified by ploidy analysis. Nevertheless, the prognostic value of DNA aneuploidy in predicting malignant transformation of OPMD remains to be validated. The aim of this meta-analysis was to assess the role of DNA aneuploidy in predicting malignant transformation in OPMD. The questions addressed were (i) Is DNA aneuploidy a useful marker to predict malignant transformation in OPMD? (ii) Is DNA diploidy a useful negative marker of malignant transformation in OPMD? These questions were addressed using the PECO method. Five studies assessing aneuploidy as a risk marker of malignant change were pooled into the meta-analysis. Aneuploidy was found to be associated with a 3.12-fold increased risk to progress into cancer (RR=3.12, 95% CI 1.86-5.24). Based on the five studies meta-analyzed, "no malignant progression" was more likely to occur in DNA diploid OPMD by 82% when compared to aneuploidy (RR=0.18, 95% CI 0.08-0.41). In conclusion, aneuploidy is a useful marker of malignant transformation in OPMD, although a diploid result should be interpreted with caution. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Construction of a Distributed-network Digital Watershed Management System with B/S Techniques

NASA Astrophysics Data System (ADS)

Zhang, W. C.; Liu, Y. M.; Fang, J.

2017-07-01

Integrated watershed assessment tools for supporting land management and hydrologic research are becoming established tools in both basic and applied research. The core of these tools are mainly spatially distributed hydrologic models as they can provide a mechanism for investigating interactions among climate, topography, vegetation, and soil. However, the extensive data requirements and the difficult task of building input parameter files for driving these distributed models, have long been an obstacle to the timely and cost-effective use of such complex models by watershed managers and policy-makers. Recently, a web based geographic information system (GIS) tool to facilitate this process has been developed for a large watersheds of Jinghe and Weihe catchments located in the loess plateau of the Huanghe River basin in north-western China. A web-based GIS provides the framework within which spatially distributed data are collected and used to prepare model input files of these two watersheds and evaluate model results as well as to provide the various clients for watershed information inquiring, visualizing and assessment analysis. This Web-based Automated Geospatial Watershed Assessment GIS (WAGWA-GIS) tool uses widely available standardized spatial datasets that can be obtained via the internet oracle databank designed with association of Map Guide platform to develop input parameter files for online simulation at different spatial and temporal scales with Xing’anjiang and TOPMODEL that integrated with web-based digital watershed. WAGWA-GIS automates the process of transforming both digital data including remote sensing data, DEM, Land use/cover, soil digital maps and meteorological and hydrological station geo-location digital maps and text files containing meteorological and hydrological data obtained from stations of the watershed into hydrological models for online simulation and geo-spatial analysis and provides a visualization tool to help the user interpret results. The utility of WAGWA-GIS in jointing hydrologic and ecological investigations has been demonstrated on such diverse landscapes as Jinhe and Weihe watersheds, and will be extended to be utilized in the other watersheds in China step by step in coming years

Characterizing relationships among fecal indicator bacteria, microbial source tracking markers, and associated waterborne pathogen occurrence in stream water and sediments in a mixed land use watershed

EPA Science Inventory

Bed sediments of streams and rivers may store high concentrations of fecal indicator bacteria (FIB) and pathogens. Due to resuspension events, these contaminants can be mobilized into the water column and affect overall water quality. Other bacterial indicators such as microbial ...

A BASIN-WIDE ANALYSIS OF THE DYNAMICS OF FECAL CONTAMINATION AND FECAL SOURCE IDENTIFICATION IN TILLAMOOK BAY, OREGON

EPA Science Inventory

The objectives of this study were to determine if spatial and temporal dynamics exist in source-specific Bacteroidales 16S rRNA genetic marker data across a watershed, to study these in relation to fecal indicator counts, general measurements of water quality, and climat...

Urban Streams as Transporters or Transformers of Carbon and Nutrients: Does Size Matter?

NASA Astrophysics Data System (ADS)

Wood, K. L.; Kaushal, S.

2017-12-01

Urbanization degrades water quality, channel form/ function, and related ecosystem services. Biological and hydrological responses to urbanization vary between sites potentially due to watershed size, channel size, and geomorphology along the broader urban watershed continuum. We investigated if/when the size of a stream can influence water quality in urban watersheds. We conducted high-frequency sampling of a small polluted headwater stream and a large restored stream in the Anacostia watershed, Washington D.C. metro area. Temperature, pH, conductivity, discharge, dissolved inorganic carbon (DIC), dissolved organic carbon (DOC) and total dissolved nitrogen (TDN) were measured 2-3 times a week at two locations near the University of Maryland campus. DOC showed strong positive linear relationships with discharge at both sites, but TDN showed significant but contrasting linear relationships in the small polluted headwater site vs. the larger restored stream. In the larger restored stream, TDN significantly decreased with increasing water temperatures, which potentially suggested biological uptake. In the headwater stream, TDN concentrations significantly increased with increasing temperature, which suggests a possible seasonal input from terrestrial or in-stream sources. Interestingly, there were significant relationships between DIC and DOC in the larger restored stream, which suggested that there may have been a biological coupling of carbon forms due to stream ecosystem metabolism. Differences in relationships between TDN, DIC, and DOC and discharge, pH, and water temperatures may indicate the effects of stream size and floodplain restoration on water chemistry responses to human inputs. Larger streams may show greater potential for biogeochemical transformations, and stream size may need to be better evaluated in efforts to prioritize restoration strategies.

Analysis of streamflow distribution of non-point source nitrogen export from long-term urban-rural catchments to guide watershed management in the Chesapeake Bay watershed

NASA Astrophysics Data System (ADS)

Duncan, J. M.; Band, L. E.; Groffman, P.

2017-12-01

Discharge, land use, and watershed management practices (stream restoration and stormwater control measures) have been found to be important determinants of nitrogen (N) export to receiving waters. We used long-term water quality stations from the Baltimore Ecosystem Study Long-Term Ecological Research (BES LTER) Site to quantify nitrogen export across streamflow conditions at the small watershed scale. We calculated nitrate and total nitrogen fluxes using methodology that allows for changes over time; weighted regressions on time, discharge, and seasonality. Here we tested the hypotheses that a) while the largest N stream fluxes occur during storm events, there is not a clear relationship between N flux and discharge and b) N export patterns are aseasonal in developed watersheds where sources are larger and retention capacity is lower. The goal is to scale understanding from small watersheds to larger ones. Developing a better understanding of hydrologic controls on nitrogen export is essential for successful adaptive watershed management at societally meaningful spatial scales.

Efficient Generation of Marker-Free Transgenic Rice Plants Using an Improved Transposon-Mediated Transgene Reintegration Strategy1

PubMed Central

Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong

2015-01-01

Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops. PMID:25371551

Efficient generation of marker-free transgenic rice plants using an improved transposon-mediated transgene reintegration strategy.

PubMed

Gao, Xiaoqing; Zhou, Jie; Li, Jun; Zou, Xiaowei; Zhao, Jianhua; Li, Qingliang; Xia, Ran; Yang, Ruifang; Wang, Dekai; Zuo, Zhaoxue; Tu, Jumin; Tao, Yuezhi; Chen, Xiaoyun; Xie, Qi; Zhu, Zengrong; Qu, Shaohong

2015-01-01

Marker-free transgenic plants can be developed through transposon-mediated transgene reintegration, which allows intact transgene insertion with defined boundaries and requires only a few primary transformants. In this study, we improved the selection strategy and validated that the maize (Zea mays) Activator/Dissociation (Ds) transposable element can be routinely used to generate marker-free transgenic plants. A Ds-based gene of interest was linked to green fluorescent protein in transfer DNA (T-DNA), and a green fluorescent protein-aided counterselection against T-DNA was used together with polymerase chain reaction (PCR)-based positive selection for the gene of interest to screen marker-free progeny. To test the efficacy of this strategy, we cloned the Bacillus thuringiensis (Bt) δ-endotoxin gene into the Ds elements and transformed transposon vectors into rice (Oryza sativa) cultivars via Agrobacterium tumefaciens. PCR assays of the transposon empty donor site exhibited transposition in somatic cells in 60.5% to 100% of the rice transformants. Marker-free (T-DNA-free) transgenic rice plants derived from unlinked germinal transposition were obtained from the T1 generation of 26.1% of the primary transformants. Individual marker-free transgenic rice lines were subjected to thermal asymmetric interlaced-PCR to determine Ds(Bt) reintegration positions, reverse transcription-PCR and enzyme-linked immunosorbent assay to detect Bt expression levels, and bioassays to confirm resistance against the striped stem borer Chilo suppressalis. Overall, we efficiently generated marker-free transgenic plants with optimized transgene insertion and expression. The transposon-mediated marker-free platform established in this study can be used in rice and possibly in other important crops. © 2015 American Society of Plant Biologists. All Rights Reserved.

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2013 CFR

2013-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2011 CFR

2011-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2012 CFR

2012-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2014 CFR

2014-07-01

... WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

[Transformation of Chlamydomonas reinhardtii CW-15 with the hygromycin phosphotransferase gene as a selective marker].

PubMed

Ladygin, V G; Butanaev, A M

2002-09-01

To transform Chlamydomonas reinhardtii Dang. Cells, plasmid pCTVHyg was constructed with the use of the Escherichia coli hygromycin phosphotransferase gene (hpt) controlled by the SV40 early promoter. Cells of the CW-15 mutant strain were transformed by electroporation, with the yield reaching 10(3) hygromycin-resistant (HygR) clones per 10(6) recipient cells. The exogenous DNA integrated in the Ch. reinhardtii nuclear genome showed stable transmission for approximately 350 cell generations, while hygromycin resistance was expressed as an unstable character. Codon usage was compared for the hpt gene and Ch. reinhardtii nuclear genes. The results testified that codon usage bias, which is characteristic of Ch. reinhardtii, is not the major factor affecting foreign gene expression. The advantages of the selective system for studying Ch. reinhardtii transformation with heterologous genes are discussed.

Tropical land-sea couplings: Role of watershed deforestation, mangrove estuary processing, and marine inputs on N fluxes in coastal Pacific Panama.

PubMed

Valiela, Ivan; Elmstrom, Elizabeth; Lloret, Javier; Stone, Thomas; Camilli, Luis

2018-07-15

We review data from coastal Pacific Panama and other tropical coasts with two aims. First, we defined inputs and losses of nitrogen (N) mediating connectivity of watersheds, mangrove estuaries, and coastal sea. N entering watersheds-mainly via N fixation (79-86%)-was largely intercepted; N discharges to mangrove estuaries (3-6%), small compared to N inputs to watersheds, nonetheless significantly supplied N to mangrove estuaries. Inputs to mangrove estuaries (including watershed discharges, and marine inputs during flood tides) were matched by losses (mainly denitrification and export during ebb tides). Mangrove estuary subsidies of coastal marine food webs take place by export of forms of N [DON (62.5%), PN (9.1%), and litter N (12.9%)] that provide dissimilative and assimilative subsidies. N fixation, denitrification, and tidal exchanges were major processes, and DON was major form of N involved in connecting fluxes in and out of mangrove estuaries. Second, we assessed effects of watershed forest cover on connectivity. Decreased watershed forest cover lowered N inputs, interception, and discharge into receiving mangrove estuaries. These imprints of forest cover were erased during transit of N through estuaries, owing to internal N cycle transformations, and differences in relative area of watersheds and estuaries. Largest losses of N consisted of water transport of energy-rich compounds, particularly DON. N losses were similar in magnitude to N inputs from sea, calculated without considering contribution by intermittent coastal upwelling, and hence likely under-estimated. Pacific Panama mangrove estuaries are exposed to major inputs of N from land and sea, which emphasizes the high degree of bi-directional connectivity in these coupled ecosystems. Pacific Panama is still lightly affected by human or global changes. Increased deforestation can be expected, as well as changes in ENSO, which will surely raise watershed-derived loads of N, as well as significantly change marine N inputs affecting coastal coupled ecosystems. Copyright © 2018 Elsevier B.V. All rights reserved.

Water balance of drained plantation watersheds in North Carolina

Treesearch

Johnny M. Grace; R. W. Skaggs

2006-01-01

A 3-year study to evaluate the effect of thinning on the hydrology of a drained loblolly pine (Pinus taeda L.) plantation was conducted in eastern North Carolina. The study utilized a paired watershed design with a 40-ha thinned watershed (WS5) and a 16-ha control watershed (WS2). Data from the field experiment conducted from 1999-2002 was used to...

Long-Term Observations of Nitrogen and Phosphorus Export in Paired-Agricultural Watersheds under Controlled and Conventional Tile Drainage.

PubMed

Sunohara, M D; Gottschall, N; Wilkes, G; Craiovan, E; Topp, E; Que, Z; Seidou, O; Frey, S K; Lapen, D R

2015-09-01

Controlled tile drainage (CTD) regulates water and nutrient export from tile drainage systems. Observations of the effects of CTD imposed en masse at watershed scales are needed to determine the effect on downstream receptors. A paired-watershed approach was used to evaluate the effect of field-to-field CTD at the watershed scale on fluxes and flow-weighted mean concentrations (FWMCs) of N and P during multiple growing seasons. One watershed (467-ha catchment area) was under CTD management (treatment [CTD] watershed); the other (250-ha catchment area) had freely draining or uncontrolled tile drainage (UCTD) (reference [UCTD] watershed). The paired agricultural watersheds are located in eastern Ontario, Canada. Analysis of covariance and paired tests were used to assess daily fluxes and FWMCs during a calibration period when CTD intervention on the treatment watershed was minimal (2005-2006, when only 4-10% of the tile-drained area was under CTD) and a treatment period when the treatment (CTD) watershed had prolific CTD intervention (2007-2011 when 82% of tile drained fields were controlled, occupying >70% of catchment area). Significant linear regression slope changes assessed using ANCOVA ( ≤ 0.1) for daily fluxes from upstream and downstream monitoring sites pooled by calibration and treatment period were -0.06 and -0.20 (stream water) (negative values represent flux declines in CTD watershed), -0.59 and -0.77 (NH-N), -0.14 and -0.15 (NO-N), -1.77 and -2.10 (dissolved reactive P), and -0.28 and 0.45 (total P). Total P results for one site comparison contrasted with other findings likely due to unknown in-stream processes affecting total P loading, not efficacy of CTD. The FWMC results were mixed and inconclusive but suggest physical abatement by CTD is the means by which nutrient fluxes are predominantly reduced at these scales. Overall, our study results indicate that CTD is an effective practice for reducing watershed scale fluxes of stream water, N, and P during the growing season. Copyright © by the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America, Inc.

Research on Coupling Method of Watershed Initial Water Rights Allocation in Daling River

NASA Astrophysics Data System (ADS)

Liu, J.; Fengping, W.

2016-12-01

Water scarcity is now a common occurrence in many countries. The situation of watershed initial water rights allocation has caused many benefit conflicts among regions and regional water sectors of domestic and ecology environment and industries in China. This study aims to investigate the method of watershed initial water rights allocation in the perspective of coupling in Daling River Watershed taking provincial initial water rights and watershed-level governmental reserved water as objects. First of all, regarding the allocation subsystem of initial water rights among provinces, this research calculates initial water rights of different provinces by establishing the coupling model of water quantity and quality on the principle of "rewarding efficiency and penalizing inefficiency" based on the two control objectives of water quantity and quality. Secondly, regarding the allocation subsystem of watershed-level governmental reserved water rights, the study forecasts the demand of watershed-level governmental reserved water rights by the combination of case-based reasoning and water supply quotas. Then, the bilaterally coupled allocation model on water supply and demand is designed after supply analysis to get watershed-level governmental reserved water rights. The results of research method applied to Daling River Watershed reveal the recommended scheme of watershed initial water rights allocation based on coordinated degree criterion. It's found that the feasibility of the iteration coupling model and put forward related policies and suggestions. This study owns the advantages of complying with watershed initial water rights allocation mechanism and meeting the control requirements of water quantity, water quality and water utilization efficiency, which help to achieve the effective allocation of water resources.

Agrobacterium tumefaciens-mediated transformation of oleaginous yeast Lipomyces species.

PubMed

Dai, Ziyu; Deng, Shuang; Culley, David E; Bruno, Kenneth S; Magnuson, Jon K

2017-08-01

Interest in using renewable sources of carbon, especially lignocellulosic biomass, for the production of hydrocarbon fuels and chemicals has fueled interest in exploring various organisms capable of producing hydrocarbon biofuels and chemicals or their precursors. The oleaginous (oil-producing) yeast Lipomyces starkeyi is the subject of active research regarding the production of triacylglycerides as hydrocarbon fuel precursors using a variety of carbohydrate and nutrient sources. The genome of L. starkeyi has been published, which opens the door to production strain improvements through the development and use of the tools of synthetic biology for this oleaginous species. The first step in establishment of synthetic biology tools for an organism is the development of effective and reliable transformation methods with suitable selectable marker genes and demonstration of the utility of the genetic elements needed for expression of introduced genes or deletion of endogenous genes. Chemical-based methods of transformation have been published but suffer from low efficiency. To address these problems, Agrobacterium-mediated transformation was investigated as an alternative method for L. starkeyi and other Lipomyces species. In this study, Agrobacterium-mediated transformation was demonstrated to be effective in the transformation of both L. starkeyi and other Lipomyces species. The deletion of the peroxisomal biogenesis factor 10 gene was also demonstrated in L. starkeyi. In addition to the bacterial antibiotic selection marker gene hygromycin B phosphotransferase, the bacterial β-glucuronidase reporter gene under the control of L. starkeyi translation elongation factor 1α promoter was also stably expressed in six different Lipomyces species. The results from this study demonstrate that Agrobacterium-mediated transformation is a reliable and effective genetic tool for homologous recombination and expression of heterologous genes in L. starkeyi and other Lipomyces species.

Wildfire Effects on In-stream Nutrient Processing and Hydrologic Transport

NASA Astrophysics Data System (ADS)

Rhea, A.; Covino, T. P.; Rhoades, C.; Fegel, T.

2017-12-01

In many forests throughout the Western U.S., drought, climate change, and growing fuel loads are contributing to increased fire frequency and severity. Wildfires can influence watershed nutrient retention as they fundamentally alter the biological composition and physical structure in upland landscapes, riparian corridors, and stream channels. While numerous studies have documented substantial short-term increases in stream nutrient concentrations and export (particularly reactive nitrogen, N) following forest fires, the long-term implications for watershed nutrient cycling remain unclear. For example, recent work indicates that nitrate concentrations and export can remain elevated for a decade or more following wildfire, yet the controls on these processes are unknown. In this research, we use empirical observations from nutrient tracer injections, nutrient diffusing substrates, and continuous water quality monitoring to isolate biological and physical controls on nutrient export across a burn-severity gradient. Tracer results demonstrate substantial stream-groundwater exchange, but little biological nutrient uptake in burned streams. This in part explains patterns of elevated nutrient export. Paired nutrient diffusing substrate experiments allow us to further investigate shifts in N, phosphorus, and carbon limitation that may suppress post-fire stream nutrient uptake. By isolating the mechanisms that reduce the capacity of fire-affected streams to retain and transform nutrient inputs, we can better predict dynamics in post-fire water quality and help prioritize upland and riparian restoration.

Virtual Sensors in a Web 2.0 Digital Watershed

NASA Astrophysics Data System (ADS)

Liu, Y.; Hill, D. J.; Marini, L.; Kooper, R.; Rodriguez, A.; Myers, J. D.

2008-12-01

The lack of rainfall data in many watersheds is one of the major barriers for modeling and studying many environmental and hydrological processes and supporting decision making. There are just not enough rain gages on the ground. To overcome this data scarcity issue, a Web 2.0 digital watershed is developed at NCSA(National Center for Supercomputing Applications), where users can point-and-click on a web-based google map interface and create new precipitation virtual sensors at any location within the same coverage region as a NEXRAD station. A set of scientific workflows are implemented to perform spatial, temporal and thematic transformations to the near-real-time NEXRAD Level II data. Such workflows can be triggered by the users' actions and generate either rainfall rate or rainfall accumulation streaming data at a user-specified time interval. We will discuss some underlying components of this digital watershed, which consists of a semantic content management middleware, a semantically enhanced streaming data toolkit, virtual sensor management functionality, and RESTful (REpresentational State Transfer) web service that can trigger the workflow execution. Such loosely coupled architecture presents a generic framework for constructing a Web 2.0 style digital watershed. An implementation of this architecture at the Upper Illinois Rive Basin will be presented. We will also discuss the implications of the virtual sensor concept for the broad environmental observatory community and how such concept will help us move towards a participatory digital watershed.

Optimization Tool For Allocation Of Watershed Management Practices For Sediment And Nutrient Control

EPA Science Inventory

Implementation of conservation programs are perceived as being crucial for restoring and protecting waters and watersheds from nonpoint source pollution. Success of these programs depends to a great extent on planning tools that can assist the watershed management process. Herein...

Improvement of tissue culture, genetic transformation, and applications of biotechnology to Brassica.

PubMed

Ravanfar, Seyed Ali; Orbovic, Vladimir; Moradpour, Mahdi; Abdul Aziz, Maheran; Karan, Ratna; Wallace, Simon; Parajuli, Saroj

2017-04-01

Development of in vitro plant regeneration method from Brassica explants via organogenesis and somatic embryogenesis is influenced by many factors such as culture environment, culture medium composition, explant sources, and genotypes which are reviewed in this study. An efficient in vitro regeneration system to allow genetic transformation of Brassica is a crucial tool for improving its economical value. Methods to optimize transformation protocols for the efficient introduction of desirable traits, and a comparative analysis of these methods are also reviewed. Hence, binary vectors, selectable marker genes, minimum inhibitory concentration of selection agents, reporter marker genes, preculture media, Agrobacterium concentration and regeneration ability of putative transformants for improvement of Agrobacterium-mediated transformation of Brassica are discussed.

Hydrologic response to stormwater control measures in urban watersheds

NASA Astrophysics Data System (ADS)

Bell, Colin D.; McMillan, Sara K.; Clinton, Sandra M.; Jefferson, Anne J.

2016-10-01

Stormwater control measures (SCMs) are designed to mitigate deleterious effects of urbanization on river networks, but our ability to predict the cumulative effect of multiple SCMs at watershed scales is limited. The most widely used metric to quantify impacts of urban development, total imperviousness (TI), does not contain information about the extent of stormwater control. We analyzed the discharge records of 16 urban watersheds in Charlotte, NC spanning a range of TI (4.1-54%) and area mitigated with SCMs (1.3-89%). We then tested multiple watershed metrics that quantify the degree of urban impact and SCM mitigation to determine which best predicted hydrologic response across sites. At the event time scale, linear models showed TI to be the best predictor of both peak unit discharge and rainfall-runoff ratios across a range of storm sizes. TI was also a strong driver of both a watershed's capacity to buffer small (e.g., 1-10 mm) rain events, and the relationship between peak discharge and precipitation once that buffering capacity is exceeded. Metrics containing information about SCMs did not appear as primary predictors of event hydrologic response, suggesting that the level of SCM mitigation in many urban watersheds is insufficient to influence hydrologic response. Over annual timescales, impervious surfaces unmitigated by SCMs and tree coverage were best correlated with streamflow flashiness and water yield, respectively. The shift in controls from the event scale to the annual scale has important implications for water resource management, suggesting that overall limitation of watershed imperviousness rather than partial mitigation by SCMs may be necessary to alleviate the hydrologic impacts of urbanization.

Suitability of non-lethal marker and marker-free systems for development of transgenic crop plants: present status and future prospects.

PubMed

Manimaran, P; Ramkumar, G; Sakthivel, K; Sundaram, R M; Madhav, M S; Balachandran, S M

2011-01-01

Genetically modified crops are one of the prudent options for enhancing the production and productivity of crop plants by safeguarding from the losses due to biotic and abiotic stresses. Agrobacterium-mediated and biolistic transformation methods are used to develop transgenic crop plants in which selectable marker genes (SMG) are generally deployed to identify 'true' transformants. The commonly used SMG obtained from prokaryotic sources when employed in transgenic plants pose risks due to their lethal nature during selection process. In the recent past, some non-lethal SMGs have been identified and used for selection of transformants with increased precision and high selection efficiency. Considering the concerns related to bio-safety of the environment, it is desirable to remove the SMG in order to maximize the commercial success through wide adoption and public acceptance of genetically modified (GM) food crops. In this review, we examine the availability, and the suitability of wide range of non-lethal selection markers and elimination of SMG methods to develop marker-free transgenics for achieving global food security. As the strategies for marker-free plants are still in proof-of-concept stage, adaptation of new genomics tools for identification of novel non-lethal marker systems and its application for developing marker-free transgenics would further strengthen the crop improvement program. Copyright © 2011 Elsevier Inc. All rights reserved.

Application of advanced remote sensing techniques to improve modeling estuary water quality

USDA-ARS?s Scientific Manuscript database

Estuaries, the interface between terrestrial and coastal waters are an important component of complex and dynamic coastal watersheds. They are usually characterized by abrupt chemical gradients and complex dynamics, which can result in major transformations in the amount, chemical nature and timing ...

[Regulation framework of watershed landscape pattern for non-point source pollution control based on 'source-sink' theory: A case study in the watershed of Maluan Bay, Xiamen City, China].

PubMed

Huang, Ning; Wang, Hong Ying; Lin, Tao; Liu, Qi Ming; Huang, Yun Feng; Li, Jian Xiong

2016-10-01

Watershed landscape pattern regulation and optimization based on 'source-sink' theory for non-point source pollution control is a cost-effective measure and still in the exploratory stage. Taking whole watershed as the research object, on the basis of landscape ecology, related theories and existing research results, a regulation framework of watershed landscape pattern for non-point source pollution control was developed at two levels based on 'source-sink' theory in this study: 1) at watershed level: reasonable basic combination and spatial pattern of 'source-sink' landscape was analyzed, and then holistic regulation and optimization method of landscape pattern was constructed; 2) at landscape patch level: key 'source' landscape was taken as the focus of regulation and optimization. Firstly, four identification criteria of key 'source' landscape including landscape pollutant loading per unit area, landscape slope, long and narrow transfer 'source' landscape, pollutant loading per unit length of 'source' landscape along the riverbank were developed. Secondly, nine types of regulation and optimization methods for different key 'source' landscape in rural and urban areas were established, according to three regulation and optimization rules including 'sink' landscape inlay, banding 'sink' landscape supplement, pollutants capacity of original 'sink' landscape enhancement. Finally, the regulation framework was applied for the watershed of Maluan Bay in Xiamen City. Holistic regulation and optimization mode of watershed landscape pattern of Maluan Bay and key 'source' landscape regulation and optimization measures for the three zones were made, based on GIS technology, remote sensing images and DEM model.

The Water Erosion Prediction Project (WEPP) model for saturation excess conditions: application to an agricultural and a forested watershed.

NASA Astrophysics Data System (ADS)

Crabtree, B.; Brooks, E.; Ostrowski, K.; Elliot, W. J.; Boll, J.

2006-12-01

We incorporated saturation excess overland flow processes in the Water Erosion Prediction Project (WEPP) model for the evaluation of human disturbances in watersheds. In this presentation, we present results of the modified WEPP model to two watersheds: an agricultural watershed with mixed land use, and a forested watershed. The agricultural watershed is Paradise Creek, an intensively monitored watershed with continuous climate, flow and sediment data collection at multiple locations. Restoration efforts in Paradise Creek watershed include changing to minimal tillage or no-tillage sytems, and implementation of structural practices. The forested watershed is the 28 km2 Mica Creek Experimental Watershed (MCEW) where disturbances include clear and partial cutting, and road building. The MCEW has a nested study design, which allows for the analysis of cumulative effects as well as the traditional comparison of treatment versus control. Mica Creek watershed is a high elevation watershed where streamflow is generated mostly by snowmelt. Treatments include road building in 1997, and clearcut and partial-cut logging in 2001. Our results include the simulation of streamflow and sediment delivery at multiple locations within each watershed, and evaluation of the human disturbances.

WATERSHED LEVEL RISK ASSESSMENT OF NITROGEN AND PHOSPHOROUS EXPORT

EPA Science Inventory

The distribution of different types of land cover across a watershed is a principal factor in controlling the amount of nitrogen and phosphorous exported from a watershed. A well developed literature of nutrient export coefficients by land-cover class was used to model t...

Comparison of radar and gauge precipitation data in watershed models across varying spatial and temporal scales

EPA Science Inventory

Precipitation is a key control on watershed hydrologic modelling output, with errors in rainfall propagating through subsequent stages of water quantity and quality analysis. Most watershed models incorporate precipitation data from rain gauges; higher-resolution data sources are...

Drainage basin control of acid loadings to two Adirondack lakes

NASA Astrophysics Data System (ADS)

Booty, W. G.; Depinto, J. V.; Scheffe, R. D.

1988-07-01

Two adjacent Adirondack Park (New York) calibrated watersheds (Woods Lake and Cranberry Pond), which receive identical atmospheric inputs, generate significantly different unit area of watershed loading rates of acidity to their respective lakes. A watershed acidification model is used to evaluate the watershed parameters which are responsible for the observed differences in acid loadings to the lakes. The greater overall mean depth of overburden on Woods Lake watershed, which supplies a greater buffer capacity as well as a longer retention time of groundwater, appears to be the major factor responsible for the differences.

Development of a Gene Cloning System in Methanogens.

DTIC Science & Technology

1987-03-27

Genetic transfer via DNA-dependent natural transformation was achieved for two markers, 5-fluorouracil-resistance, and 6- mercaptopurine resistance...resistance genes, and genes coding for enzymes that produce colored products will be tested as markers for plasmid transformation. A functional plasmid...clones, which include resistances to mercaptopurine , azahypoxanthine, diazauracil, kanamycin, mitomycin C, and fluorouracil- mercaptopurine and

Reservoir sedimentation rates in the Little Washita River experimental watershed, Oklahoma: measurement and controlling factors

USDA-ARS?s Scientific Manuscript database

Forty-five flood control reservoirs, authorized in the United States Flood Control Act of 1936, were installed between 1969 and 1982 in the Little Washita River Experimental Watershed (LWREW), located in central Oklahoma. Over time, these reservoirs have lost water storage capacity due to sedimentat...

Pretence and Deception: One Cognitive Watershed or Two?

ERIC Educational Resources Information Center

Peskin, Joan

A total of 48 Canadian, middle-class 3-year-olds participated in a study of their abilities to predict the actions of a story character with a false belief and a story character engaged in pretence. In the experimental situation, a red puppet with pen-markers for legs left an "inky trail" to the location of a hidden treasure in one of…

Hydrologic calibration of paired watersheds using a MOSUM approach

Treesearch

H. Ssegane; Devendra Amatya; A. Muwamba; G. M. Chescheir; T. Appelboom; E. W. Tollner; J. E. Nettles; M. A. Youssef; F. Birgand; R. W. Skaggs

2015-01-01

Paired watershed studies have historically been used to quantify hydrologic effects of land use and management practices by concurrently monitoring two neighboring watersheds (a control and a treatment) during the calibration (pre-treatment) and post-treatment periods. This study characterizes seasonal water table and flow response to rainfall during the...

Metal and Nutrient Distribution and Fractionation in Managed Urban Watersheds Across the US Southwest

NASA Astrophysics Data System (ADS)

Papelis, C.; Williams, A. C.; Boettcher, T. M.

2008-12-01

Metals, metalloids, and nutrients are common contaminants of concern in arid and semi-arid watersheds in the Southwestern U.S. Because of the dramatic population growth in this part of the U.S., the potential for contamination of urban watersheds has also increased over the last few decades. Streams in urban watersheds receive storm water, urban runoff, shallow groundwater, and treated wastewater, among other sources. In addition, urban watersheds are often heavily managed to mitigate flood events and sediment- related impacts. Sediment transport can have a profound effect on the water quality of affected bodies of water. However, differences in geology, hydrogeology, and land use may have dramatic effects on the distribution of nutrients and metals in different urban watersheds. To test these effects, aqueous and sediment samples were collected above and below erosion control and other structures along two heavily managed urban watersheds, namely the Las Vegas Wash in the Las Vegas Valley Watershed, Nevada, and the Rio Salado (Salt River) in the Phoenix Metropolitan Area, Arizona. The construction of such control structures has the potential to alter the distribution of metals and metalloids in bodies of water used by wildlife. In this study, all sediments were characterized by particle size distribution, specific surface area, mineralogical composition, and scanning electron microscopy. The results of total arsenic, boron, and phosphorus extractions will be discussed, as a function of sediment characteristics. Significant differences exist between the two U.S. Southwest watersheds studied, including land use, water sources, sediment characteristics, nutrient and metal distribution, and overall system complexity. These differences lead to significant variations in metalloid and nutrient distributions in the two watersheds. Differences and similarities in the two systems will be explained as a function of sediment characteristics and watershed properties.

A novel genomic signature with translational significance for human idiopathic pulmonary fibrosis.

PubMed

Bauer, Yasmina; Tedrow, John; de Bernard, Simon; Birker-Robaczewska, Magdalena; Gibson, Kevin F; Guardela, Brenda Juan; Hess, Patrick; Klenk, Axel; Lindell, Kathleen O; Poirey, Sylvie; Renault, Bérengère; Rey, Markus; Weber, Edgar; Nayler, Oliver; Kaminski, Naftali

2015-02-01

The bleomycin-induced rodent lung fibrosis model is commonly used to study mechanisms of lung fibrosis and to test potential therapeutic interventions, despite the well recognized dissimilarities to human idiopathic pulmonary fibrosis (IPF). Therefore, in this study, we sought to identify genomic commonalities between the gene expression profiles from 100 IPF lungs and 108 control lungs that were obtained from the Lung Tissue Research Consortium, and rat lungs harvested at Days 3, 7, 14, 21, 28, 42, and 56 after bleomycin instillation. Surprisingly, the highest gene expression similarity between bleomycin-treated rat and IPF lungs was observed at Day 7. At this point of maximal rat-human commonality, we identified a novel set of 12 disease-relevant translational gene markers (C6, CTHRC1, CTSE, FHL2, GAL, GREM1, LCN2, MMP7, NELL1, PCSK1, PLA2G2A, and SLC2A5) that was able to separate almost all patients with IPF from control subjects in our cohort and in two additional IPF/control cohorts (GSE10667 and GSE24206). Furthermore, in combination with diffusing capacity of carbon monoxide measurements, four members of the translational gene marker set contributed to stratify patients with IPF according to disease severity. Significantly, pirfenidone attenuated the expression change of one (CTHRC1) translational gene marker in the bleomycin-induced lung fibrosis model, in transforming growth factor-β1-treated primary human lung fibroblasts and transforming growth factor-β1-treated human epithelial A549 cells. Our results suggest that a strategy focused on rodent model-human disease commonalities may identify genes that could be used to predict the pharmacological impact of therapeutic interventions, and thus facilitate the development of novel treatments for this devastating lung disease.

A Novel Genomic Signature with Translational Significance for Human Idiopathic Pulmonary Fibrosis

PubMed Central

Tedrow, John; de Bernard, Simon; Birker-Robaczewska, Magdalena; Gibson, Kevin F.; Guardela, Brenda Juan; Hess, Patrick; Klenk, Axel; Lindell, Kathleen O.; Poirey, Sylvie; Renault, Bérengère; Rey, Markus; Weber, Edgar; Nayler, Oliver; Kaminski, Naftali

2015-01-01

The bleomycin-induced rodent lung fibrosis model is commonly used to study mechanisms of lung fibrosis and to test potential therapeutic interventions, despite the well recognized dissimilarities to human idiopathic pulmonary fibrosis (IPF). Therefore, in this study, we sought to identify genomic commonalities between the gene expression profiles from 100 IPF lungs and 108 control lungs that were obtained from the Lung Tissue Research Consortium, and rat lungs harvested at Days 3, 7, 14, 21, 28, 42, and 56 after bleomycin instillation. Surprisingly, the highest gene expression similarity between bleomycin-treated rat and IPF lungs was observed at Day 7. At this point of maximal rat–human commonality, we identified a novel set of 12 disease-relevant translational gene markers (C6, CTHRC1, CTSE, FHL2, GAL, GREM1, LCN2, MMP7, NELL1, PCSK1, PLA2G2A, and SLC2A5) that was able to separate almost all patients with IPF from control subjects in our cohort and in two additional IPF/control cohorts (GSE10667 and GSE24206). Furthermore, in combination with diffusing capacity of carbon monoxide measurements, four members of the translational gene marker set contributed to stratify patients with IPF according to disease severity. Significantly, pirfenidone attenuated the expression change of one (CTHRC1) translational gene marker in the bleomycin-induced lung fibrosis model, in transforming growth factor-β1–treated primary human lung fibroblasts and transforming growth factor-β1–treated human epithelial A549 cells. Our results suggest that a strategy focused on rodent model–human disease commonalities may identify genes that could be used to predict the pharmacological impact of therapeutic interventions, and thus facilitate the development of novel treatments for this devastating lung disease. PMID:25029475

Comparison of Osteogenic and Chondrogenic Differentiation Ability of Buccal Fat Pad Derived Mesenchymal Stem Cells and Gingival Derived Cells.

PubMed

Ghaderi, Hamid; Razmkhah, Mahboobeh; Kiany, Farin; Chenari, Nooshafarin; Haghshenas, Mohammad Reza; Ghaderi, Abbas

2018-06-01

One major goal of tissue engineering and regenerative medicine is to find an appropriate source of mesenchymal stem cells (MSCs) with higher differentiation ability. In this experimental study, the osteogenic and chondrogenic differentiation ability of buccal fat pad derived MSCs (BFP-MSCs) with gingival derived cells (GDCs) were compared. BFP-MSCs and GDCs were cultured enzymatically and expanded. The expanded cells were analyzed for membrane-associated markers, using flow cytometry. Then the ability of these cells to differentiate into osteocyte and chondrocyte was assessed morphologically and by mRNA expression of collagen I (COLL), BGLA and bone morphogenetic protein 2 (BMP2) using qRT-PCR. Flow cytometry analysis showed that both BFP-MSCs and GDCs expressed the characteristic stem cell markers such as CD73, CD44, and CD90, whereas they did not express hematopoietic markers. Mineralized calcium deposition was observed apparently in BFP-MSCs cultured in osteogenic medium but GDCs showed fewer mineralized nodules. The mRNA expression levels of BGLA and BMP2 showed 7×105 and 733-fold more mRNA expression in BFP-MSCs treated with differentiation media compared to the control group. In chondrogenic differentiation, BFP-MSCs transformed from a spindle to a cuboidal shape while GDCs showed only a slight transformation. In addition, mRNA expression of COLL showed 282-fold higher expression in BFP-MSCs in comparison to the control group. Such significant difference in mRNA expression of BGLA, BMP2, and COLL was not observed in GDCs compared to their corresponding controls. Based on the present results, BFP yields a greater proportion of stem cells compared to gingiva. Therefore, this tissue can be introduced as an easily available source for the treatment of periodontal defects and other maxillofacial injuries.

Innovative Approaches for Urban Watershed Wet-Weather Flow Management and Control

EPA Science Inventory

The “Innovative Approaches for Urban Watershed Wet-Weather Flow Management and Control: State of the Technology” project investigated a range of innovative technology and management strategies emerging outside the normal realm of business within the continental United States, fo...

Simulating Multi-Scale Mercury Fate and Transport in a Coastal Plain Watershed

EPA Science Inventory

Mercury is the toxicant responsible for the largest number of fish advisories across the United States, with 1.1 million river miles under advisory. The processes governing fate, transport, and transformation of mercury in streams and rivers are not well understood, in large part...

A Decision Support Tool to Evaluate Sources and Sinks of Nitrogen within a Watershed Framework

EPA Science Inventory

Human transformation of the nitrogen (N) cycle is causing a number of environmental and human health problems. Federal, state and local authorities focusing on management of N loadings face both technical and non-technical challenges. One technical issue is that we need a bette...

Aquatic Ecosystem Exposure Associated with Atmospheric Mercury Deposition: Importance of Watershed and Water Body Hot Spots and Hot Moments

EPA Science Inventory

Atmospheric deposition of divalent mercury (Hg(II)) is often the primary driving force for mercury contamination in fish tissue, resulting in mercury exposure to wildlife and humans. Transport and transformation of the deposited mercury into the environmentally relevant form, met...

Development of a Plant Transformation Selection System Based on Expression of Genes Encoding Gentamicin Acetyltransferases

PubMed Central

Hayford, Maria B.; Medford, June I.; Hoffman, Nancy L.; Rogers, Stephen G.; Klee, Harry J.

1988-01-01

The development of selectable markers for transformation has been a major factor in the successful genetic manipulation of plants. A new selectable marker system has been developed based on bacterial gentamicin-3-N-acetyltransferases [AAC(3)]. These enzymes inactivate aminoglycoside antibiotics by acetylation. Two examples of AAC(3) enzymes have been manipulated to be expressed in plants. Chimeric AAC(3)-III and AAC(3)-IV genes were assembled using the constitutively expressed cauliflower mosaic virus 35S promoter and the nopaline synthase 3′ nontranslated region. These chimeric genes were engineered into vectors for Agrobacterium-mediated plant transformation. Petunia hybrida and Arabidopsis thaliana tissue transformed with these vectors grew in the presence of normally lethal levels of gentamicin. The transformed nature of regenerated Arabidopsis plants was confirmed by DNA hybridization analysis and inheritance of the selectable phenotype in progeny. The chimeric AAC(3)-IV gene has also been used to select transformants in several additional plant species. These results show that the bacterial AAC(3) genes will serve as useful selectable markers in plant tissue culture. Images Fig. 3 Fig. 4 Fig. 5 PMID:16666057

Development of a multiobjective optimization tool for the selection and placement of best management practices for nonpoint source pollution control

NASA Astrophysics Data System (ADS)

Maringanti, Chetan; Chaubey, Indrajeet; Popp, Jennie

2009-06-01

Best management practices (BMPs) are effective in reducing the transport of agricultural nonpoint source pollutants to receiving water bodies. However, selection of BMPs for placement in a watershed requires optimization of the available resources to obtain maximum possible pollution reduction. In this study, an optimization methodology is developed to select and place BMPs in a watershed to provide solutions that are both economically and ecologically effective. This novel approach develops and utilizes a BMP tool, a database that stores the pollution reduction and cost information of different BMPs under consideration. The BMP tool replaces the dynamic linkage of the distributed parameter watershed model during optimization and therefore reduces the computation time considerably. Total pollutant load from the watershed, and net cost increase from the baseline, were the two objective functions minimized during the optimization process. The optimization model, consisting of a multiobjective genetic algorithm (NSGA-II) in combination with a watershed simulation tool (Soil Water and Assessment Tool (SWAT)), was developed and tested for nonpoint source pollution control in the L'Anguille River watershed located in eastern Arkansas. The optimized solutions provided a trade-off between the two objective functions for sediment, phosphorus, and nitrogen reduction. The results indicated that buffer strips were very effective in controlling the nonpoint source pollutants from leaving the croplands. The optimized BMP plans resulted in potential reductions of 33%, 32%, and 13% in sediment, phosphorus, and nitrogen loads, respectively, from the watershed.

Variable Streamflow Contributions in Nested Subwatersheds of a US Midwestern Urban Watershed

DOE PAGES

Wei, Liang; Hubbart, Jason A.; Zhou, Hang

2017-09-09

Quantification of runoff is critical to estimate and control water pollution in urban regions, but variation in impervious area and land-use type can complicate the quantification of runoff. We quantified the streamflow contributions of subwatersheds and the historical changes in streamflow in a flood prone urbanizing watershed in US Midwest to guide the establishment of a future pollution-control plan. Streamflow data from five nested hydrological stations enabled accurate estimations of streamflow contribution from five subwatersheds with variable impervious areas (from 0.5% to 26.6%). We corrected the impact of Missouri river backwatering at the most downstream station by comparing its streamflowmore » with an upstream station using double-mass analysis combined with Bernaola-Galvan Heuristic Segmentation approach. We also compared the streamflow of the urbanizing watershed with seven surrounding rural watersheds to estimate the cumulative impact of urbanization on the streamflow regime. The two most urbanized subwatersheds contributed >365 mm streamflow in 2012 with 657 mm precipitation, which was more than fourfold greater than the two least urbanized subwatersheds. Runoff occurred almost exclusively over the most urbanized subwatersheds during the dry period. The frequent floods occurred and the same amount of precipitation produced ~100 mm more streamflow in 2008–2014 than 1967–1980 in the urbanizing watershed; such phenomena did not occur in surrounding rural watersheds. Our approaches provide comprehensive information for planning on runoff control and pollutant reduction in urban watersheds.« less

Variable Streamflow Contributions in Nested Subwatersheds of a US Midwestern Urban Watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wei, Liang; Hubbart, Jason A.; Zhou, Hang

Quantification of runoff is critical to estimate and control water pollution in urban regions, but variation in impervious area and land-use type can complicate the quantification of runoff. We quantified the streamflow contributions of subwatersheds and the historical changes in streamflow in a flood prone urbanizing watershed in US Midwest to guide the establishment of a future pollution-control plan. Streamflow data from five nested hydrological stations enabled accurate estimations of streamflow contribution from five subwatersheds with variable impervious areas (from 0.5% to 26.6%). We corrected the impact of Missouri river backwatering at the most downstream station by comparing its streamflowmore » with an upstream station using double-mass analysis combined with Bernaola-Galvan Heuristic Segmentation approach. We also compared the streamflow of the urbanizing watershed with seven surrounding rural watersheds to estimate the cumulative impact of urbanization on the streamflow regime. The two most urbanized subwatersheds contributed >365 mm streamflow in 2012 with 657 mm precipitation, which was more than fourfold greater than the two least urbanized subwatersheds. Runoff occurred almost exclusively over the most urbanized subwatersheds during the dry period. The frequent floods occurred and the same amount of precipitation produced ~100 mm more streamflow in 2008–2014 than 1967–1980 in the urbanizing watershed; such phenomena did not occur in surrounding rural watersheds. Our approaches provide comprehensive information for planning on runoff control and pollutant reduction in urban watersheds.« less

Characterization and evaluation of controls on post-fire streamflow response across western US watersheds

NASA Astrophysics Data System (ADS)

Saxe, Samuel; Hogue, Terri S.; Hay, Lauren

2018-02-01

This research investigates the impact of wildfires on watershed flow regimes, specifically focusing on evaluation of fire events within specified hydroclimatic regions in the western United States, and evaluating the impact of climate and geophysical variables on response. Eighty-two watersheds were identified with at least 10 years of continuous pre-fire daily streamflow records and 5 years of continuous post-fire daily flow records. Percent change in annual runoff ratio, low flows, high flows, peak flows, number of zero flow days, baseflow index, and Richards-Baker flashiness index were calculated for each watershed using pre- and post-fire periods. Independent variables were identified for each watershed and fire event, including topographic, vegetation, climate, burn severity, percent area burned, and soils data. Results show that low flows, high flows, and peak flows increase in the first 2 years following a wildfire and decrease over time. Relative response was used to scale response variables with the respective percent area of watershed burned in order to compare regional differences in watershed response. To account for variability in precipitation events, runoff ratio was used to compare runoff directly to PRISM precipitation estimates. To account for regional differences in climate patterns, watersheds were divided into nine regions, or clusters, through k-means clustering using climate data, and regression models were produced for watersheds grouped by total area burned. Watersheds in Cluster 9 (eastern California, western Nevada, Oregon) demonstrate a small negative response to observed flow regimes after fire. Cluster 8 watersheds (coastal California) display the greatest flow responses, typically within the first year following wildfire. Most other watersheds show a positive mean relative response. In addition, simple regression models show low correlation between percent watershed burned and streamflow response, implying that other watershed factors strongly influence response. Spearman correlation identified NDVI, aridity index, percent of a watershed's precipitation that falls as rain, and slope as being positively correlated with post-fire streamflow response. This metric also suggested a negative correlation between response and the soil erodibility factor, watershed area, and percent low burn severity. Regression models identified only moderate burn severity and watershed area as being consistently positively/negatively correlated, respectively, with response. The random forest model identified only slope and percent area burned as significant watershed parameters controlling response. Results will help inform post-fire runoff management decisions by helping to identify expected changes to flow regimes, as well as facilitate parameterization for model application in burned watersheds.

Critical zone structure controls concentration-discharge relationships and solute generation in forested tropical montane watersheds

NASA Astrophysics Data System (ADS)

Wymore, Adam S.; Brereton, Richard L.; Ibarra, Daniel E.; Maher, Kate; McDowell, William H.

2017-07-01

Concentration-discharge (C-Q) relationships are poorly known for tropical watersheds, even though the tropics contribute a disproportionate amount of solutes to the global ocean. The Luquillo Mountains in Puerto Rico offer an ideal environment to examine C-Q relationships across a heterogeneous tropical landscape. We use 10-30 years of weekly stream chemistry data across 10 watersheds to examine C-Q relationships for weathering products (SiO2(aq), Ca2+, Mg2+, and Na+) and biologically controlled solutes (dissolved organic carbon [DOC], dissolved organic nitrogen [DON], NH4+, NO3-, PO43-, K+, and SO42-). We analyze C-Q relationships using power law equations and a solute production model and use principal component analysis to test hypotheses regarding how the structure of the critical zone controls solute generation. Volcaniclastic watersheds had higher concentrations of weathering solutes and smaller tributaries were approximately threefold more efficient at generating these solutes than larger rivers. Lithology and vegetation explained a significant amount of variation in the theoretical maximum concentrations of weathering solutes (r2 = 0.43-0.48) and in the C-Q relationships of PO43- (r2 = 0.63) and SiO2(aq) (r2 = 0.47). However, the direction and magnitude of these relationships varied. Across watersheds, various forms of N and P displayed variable C-Q relationships, while DOC was consistently enriched with increasing discharge. Results suggest that PO43- may be a useful indicator of watershed function. Relationships between C-Q and landscape characteristics indicate the extent to which the structure and function of the Critical zone controls watershed solute fluxes.

Watershed analysis of the Salmon River watershed, Washington : hydrology

USGS Publications Warehouse

Bidlake, William R.

2003-01-01

The U.S. Geological Survey analyzed selected hydrologic conditions as part of a watershed analysis of the Salmon River watershed, Washington, conducted by the Quinault Indian Nation. The selected hydrologic conditions were analyzed according to a framework of hydrologic key questions that were identified for the watershed. The key questions were posed to better understand the natural, physical, and biological features of the watershed that control hydrologic responses; to better understand current streamflow characteristics, including peak and low flows; to describe any evidence that forest harvesting and road construction have altered frequency and magnitude of peak and low flows within the watershed; to describe what is currently known about the distribution and extent of wetlands and any impacts of land management activities on wetlands; and to describe how hydrologic monitoring within the watershed might help to detect future hydrologic change, to preserve critical ecosystem functions, and to protect public and private property.

A paired-watershed budget study to quantify interbasin groundwater flow in a lowland rain forest, Costa Rica

NASA Astrophysics Data System (ADS)

Genereux, David P.; Jordan, Michael T.; Carbonell, David

2005-04-01

A paired-watershed budget study was used to quantify the annual water and major ion (sodium, potassium, magnesium, calcium, chloride, and sulfate) budgets of two adjacent lowland rain forest watersheds in Costa Rica. Interbasin groundwater flow (IGF) accounted for about two thirds of the water input and about 97% of the solute input (an average over the six major ions) to one watershed but little or none of the inputs to the adjacent watershed in which IGF was at most marginally distinguishable from zero. Results underscore the significance of IGF as a potential control on the hydrology and water quality of lowland watersheds, the spatial complexity of its occurrence in lowlands (where its influence may range from dominating to negligible on adjacent watersheds), and the importance of accounting for IGF in the design and execution of watershed studies and in water management.

Plant genetic transformation efficiency of selected Malaysian rice based on selectable marker gene (hptII).

PubMed

Htwe, Nwe Nwe; Ling, Ho Chai; Zaman, Faridah Qamaruz; Maziah, Mahmood

2014-04-01

Rice is one of the most important cereal crops with great potential for biotechnology progress. In transformation method, antibiotic resistance genes are routinely used as powerful markers for selecting transformed cells from surrounding non-transformed cells. In this study, the toxicity level of hygromycin was optimized for two selected mutant rice lines, MR219 line 4 and line 9. The mature embryos were isolated and cultured on an MS medium with different hygromycin concentrations (0, 20, 40, 60, 80 and 100 mg L(-1)). Evidently, above 60 mg L(-1) was effective for callus formation and observed completely dead. Further there were tested for specific concentration (0-60). Although, 21.28% calli survived on the medium containing 45 mg L(-1) hygromycin, it seemed suitable for the identification of putative transformants. These findings indicated that a system for rice transformation in a relatively high frequency and the transgenes are stably expressed in the transgenic plants. Green shoots were regenerated from the explant under hygromycin stress. RT-PCR using hptII and gus sequence specific primer and Southern blot analysis were used to confirm the presence of the transgene and to determine the transformation efficiency for their stable integration in regenerated plants. This study demonstrated that the hygromycin resistance can be used as an effective marker for rice transformation.

SCIENCE OF INTEGRATED WATERSHED MANAGEMENT: LINKING POLLUTANT CONTROL PRACTICES WITH WATER QUALITY

EPA Science Inventory

SCIENCE OF INTEGRATED WATERSHED MANAGEMENT: LINKING POLLUTANT CONTROL PRACTICES WITH WATER QUALITY M. Morrison (NRMRL), C. Nietch (NRMRL), 1. Schubauer-Berigan (NRMRL), M. Hantush (NRMRL), D. Lai (NRMRL), B. Daniel (NERL), M. Griffith (NCEA) Science Questions LTG 3. MYP Sc...

Generation of marker-free Bt transgenic indica rice and evaluation of its yellow stem borer resistance.

PubMed

Kumar, S; Arul, L; Talwar, D

2010-01-01

We report on generation of marker-free (‘clean DNA’) transgenic rice (Oryza sativa), carrying minimal gene-expression-cassettes of the genes of interest, and evaluation of its resistance to yellow stem borer Scirpophaga incertulas (Lepidoptera: Pyralidae). The transgenic indica rice harbours a translational fusion of 2 different Bacillus thuringiensis (Bt) genes, namely cry1B-1Aa, driven by the green-tissue-specific phosphoenol pyruvate carboxylase (PEPC) promoter. Mature seed-derived calli of an elite indica rice cultivar Pusa Basmati-1 were co-bombarded with gene-expression-cassettes (clean DNA fragments) of the Bt gene and the marker hpt gene, to generate marker-free transgenic rice plants. The clean DNA fragments for bombardment were obtained by restriction digestion and gel extraction. Through biolistic transformation, 67 independent transformants were generated. Transformation frequency reached 3.3%, and 81% of the transgenic plants were co-transformants. Stable integration of the Bt gene was confirmed, and the insert copy number was determined by Southern analysis. Western analysis and ELISA revealed a high level of Bt protein expression in transgenic plants. Progeny analysis confirmed stable inheritance of the Bt gene according to the Mendelian (3:1) ratio. Insect bioassays revealed complete protection of transgenic plants from yellow stem borer infestation. PCR analysis of T2 progeny plants resulted in the recovery of up to 4% marker-free transgenic rice plants.

Revealing the Role of Microbes in Controlling Contaminants

ScienceCinema

Williams, Kenneth Hurst

2018-05-11

In Rifle, Colorado, Berkeley Lab earth scientist, Kenneth Hurst Williams, highlights the role subsurface microbial communities can play in controlling the flow of contaminants in groundwater. The DOE Joint Genome Institute is a key collaborator in the research. Williams is Component Lead of Watershed Structure and Controls within Berkeley Lab's Genomes-to-Watershed Scientific Focus Area.

Revealing the Role of Microbes in Controlling Contaminants

DOE Office of Scientific and Technical Information (OSTI.GOV)

Williams, Kenneth Hurst

2015-04-02

In Rifle, Colorado, Berkeley Lab earth scientist, Kenneth Hurst Williams, highlights the role subsurface microbial communities can play in controlling the flow of contaminants in groundwater. The DOE Joint Genome Institute is a key collaborator in the research. Williams is Component Lead of Watershed Structure and Controls within Berkeley Lab's Genomes-to-Watershed Scientific Focus Area.

Changes of Photochemical Properties of Dissolved Organic Matter During a Hydrological Year

NASA Astrophysics Data System (ADS)

Porcal, P.; Dillon, P. J.

2009-05-01

The fate of dissolved organic matter (DOM) in lakes and streams is significantly affected by photochemical transformation of DOM. A series of laboratory photochemical experiments has been conducted to describe long term changes in photochemical properties of DOM. The stream samples used in this study originated from three different watersheds in Dorset area (Ontario, Canada), the first watershed has predominantly coniferous cove, the second one is dominated by maple and birch, and a large wetland dominates to the third one. The first order kinetic constant rate was used as a suitable characteristic of photochemical properties of DOM. The higher rates were observed in samples from watershed dominated by coniferous forest while the lower rates were determined in deciduous forest. Kinetic rates from all three watersheds showed sinusoidal pattern during the hydrological year. The rates increased steadily during autumn and winter and decreased during spring and summer. The highest values were observed during the spring melt events when the fresh DOM was flushed out from terrestrial sources. The minimum rate constants were in summer when the discharge was lower. The photochemical properties of DOM changes during the hydrological year and correspond to the seasonal cycles of terrestrial organic matter.

Evaluating sources and processing of nonpoint source nitrate in a small suburban watershed in China

NASA Astrophysics Data System (ADS)

Han, Li; Huang, Minsheng; Ma, Minghai; Wei, Jinbao; Hu, Wei; Chouhan, Seema

2018-04-01

Identifying nonpoint sources of nitrate has been a long-term challenge in mixed land-use watershed. In the present study, we combine dual nitrate isotope, runoff and stream water monitoring to elucidate the nonpoint nitrate sources across land use, and determine the relative importance of biogeochemical processes for nitrate export in a small suburban watershed, Longhongjian watershed, China. Our study suggested that NH4+ fertilizer, soil NH4+, litter fall and groundwater were the main nitrate sources in Longhongjian Stream. There were large changes in nitrate sources in response to season and land use. Runoff analysis illustrated that the tea plantation and forest areas contributed to a dominated proportion of the TN export. Spatial analysis illustrated that NO3- concentration was high in the tea plantation and forest areas, and δ15N-NO3 and δ18O-NO3 were enriched in the step ponds. Temporal analysis showed high NO3- level in spring, and nitrate isotopes were enriched in summer. Study as well showed that the step ponds played an important role in mitigating nitrate pollution. Nitrification and plant uptake were the significant biogeochemical processes contributing to the nitrogen transformation, and denitrification hardly occurred in the stream.

The development of a 3D mesoscopic model of metallic foam based on an improved watershed algorithm

NASA Astrophysics Data System (ADS)

Zhang, Jinhua; Zhang, Yadong; Wang, Guikun; Fang, Qin

2018-06-01

The watershed algorithm has been used widely in the x-ray computed tomography (XCT) image segmentation. It provides a transformation defined on a grayscale image and finds the lines that separate adjacent images. However, distortion occurs in developing a mesoscopic model of metallic foam based on XCT image data. The cells are oversegmented at some events when the traditional watershed algorithm is used. The improved watershed algorithm presented in this paper can avoid oversegmentation and is composed of three steps. Firstly, it finds all of the connected cells and identifies the junctions of the corresponding cell walls. Secondly, the image segmentation is conducted to separate the adjacent cells. It generates the lost cell walls between the adjacent cells. Optimization is then performed on the segmentation image. Thirdly, this improved algorithm is validated when it is compared with the image of the metallic foam, which shows that it can avoid the image segmentation distortion. A mesoscopic model of metallic foam is thus formed based on the improved algorithm, and the mesoscopic characteristics of the metallic foam, such as cell size, volume and shape, are identified and analyzed.

Applying soil property information for watershed assessment.

NASA Astrophysics Data System (ADS)

Archer, V.; Mayn, C.; Brown, S. R.

2017-12-01

The Forest Service uses a priority watershed scheme to guide where to direct watershed restoration work. Initial assessment was done across the nation following the watershed condition framework process. This assessment method uses soils information for a three step ranking across each 12 code hydrologic unit; however, the soil information used in the assessment may not provide adequate detail to guide work on the ground. Modern remote sensing information and terrain derivatives that model the environmental gradients hold promise of showing the influence of soil forming factors on watershed processes. These small scale data products enable the disaggregation of coarse scale soils mapping to show continuous soil property information across a watershed. When this information is coupled with the geomorphic and geologic information, watershed specialists can more aptly understand the controlling influences of drainage within watersheds and focus on where watershed restoration projects can have the most success. A case study on the application of this work shows where road restoration may be most effective.

Stable plastid transformation in Scoparia dulcis L.

PubMed

Muralikrishna, Narra; Srinivas, Kota; Kumar, Kalva Bharath; Sadanandam, Abbagani

2016-10-01

In the present investigation we report stable plastid transformation in Scoparia dulcis L., a versatile medicinal herb via particle gun method. The vector KNTc, harbouring aadA as a selectable marker and egfp as a reporter gene which were under the control of synthetic promoter pNG1014a, targets inverted repeats, trnR / t rnN of the plastid genome. By use of this heterologous vector, recovery of transplastomic lines with suitable selection protocol have been successfully established with overall efficiency of two transgenic lines for 25 bombarded leaf explants. PCR and Southern blot analysis demonstrated stable integration of foreign gene into the target sequences. The results represent a significant advancement of the plastid transformation technology in medicinal plants, which relevantly implements a change over in enhancing and regulating of certain metabolic pathways.

Hydrologic processes of forested headwater watersheds across a physiographaic gradient in the southeastern United States

Treesearch

Ge Sun; Johnny Boggs; Steven G. McNulty; Devendra M. Amatya; Carl C. Trettin; Zhaohua Dai; James M. Vose; Ileana B. La Torre Torres; Timothy Callahan

2008-01-01

Understanding the hydrologic processes is the first step in making sound watershed management decisions including designing Best Management Practices for nonpoint source pollution control. Over the past fifty years, various forest experimental watersheds have been instrumented across the Carolinas through collaborative studies among federal, state, and private...

MODELING PROCESSES CONTROLLING MERCURY FATE IN WATERSHEDS RECEIVING ATMOSPHERIC DEPOSITION - COMPARISON OF FIELD SCALE GLEAMS AND WATERSHED SCALE WCS-GBMM

EPA Science Inventory

Long-term simulations of mercury fate in watersheds are needed to support regulations such as TMDLs and to predict the effectiveness of regulatory proposals, such as the Clean Air Mercury Rule (CAMR). Scientific uncertainties in mercury fate process descriptions combined with in...

Recovery of decomposition and soil microarthropod communities in an Appalachian watershed two decades after a clearcut

Treesearch

Liam Heneghan; Alissa Salmore; D.A. Crossley

2004-01-01

We examined decomposition rates of three substrates (Quercus prinus L., Acer rubrum L., and Cornus florida L.) in a watershed 21 years after it had been clearcut, and compared them to an adjacent control watershed. Previous investigations at these sites had shown that microarthropod populations, important...

Differentiating impacts of land use changes from pasture management in a CEAP watershed using the SWAT model

USDA-ARS?s Scientific Manuscript database

Due to intensive farm practices, nonpoint-source (NPS) pollution has become one of the most challenging environmental problems in agricultural and mixed land use watersheds. Usually, various conservation practices are implemented in the watershed to control the NPS pollution problem. However, land u...

A COMPREHENSIVE NONPOINT SOURCE FIELD STUDY FOR SEDIMENT, NUTRIENTS, AND PATHOGENS IN THE SOUTH FORK BROAD RIVER WATERSHED IN NORTHEAST GEORGIA

EPA Science Inventory

This technical report provides a description of the field project design, quality control, the sampling protocols and analysis methodology used, and standard operating procedures for the South Fork Broad River Watershed (SFBR) Total Maximum Daily Load (TMDL) project. This watersh...

Consistency of Hydrologic Relationships of a Paired Watershed Approach

Treesearch

Herbert Ssegane; Devendra M. Amatya; George M. Chescheir; Wayne R. Skaggs; Ernest W. Tollner; Jami E. Nettles

2013-01-01

Paired watershed studies are used around the world to evaluate and quantify effects of forest and water management practices on hydrology and water quality. The basic concept uses two neighboring watersheds (one as a control and another as a treatment), which are concurrently monitored during calibration (pre-treatment) and post-treatment periods. A statistically...

40 CFR 141.71 - Criteria for avoiding filtration.

Code of Federal Regulations, 2011 CFR

2011-07-01

... PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Filtration and Disinfection § 141.71... water. (2) The public water system must maintain a watershed control program which minimizes the... determine whether the watershed control program is adequate to meet this goal. The adequacy of a program to...

Monitoring wetland inundation dynamics in response to weather variability in the Chesapeake Bay watershed

USDA-ARS?s Scientific Manuscript database

Wetlands provide a broad range of ecosystem services, including flood control, water purification, groundwater replenishment, and biodiversity support. The provision of these services, which are especially valued in the Chesapeake Bay Watershed, is largely controlled by varying levels of wetness. ...

40 CFR 141.522 - How does the State determine whether my system's watershed control requirements are adequate?

Code of Federal Regulations, 2010 CFR

2010-07-01

... Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000 People... has maximized land ownership and/or controlled land use within the watershed. Disinfection Profile ...

Are watershed and lacustrine controls on planktonic N2 fixation hierarchically structured?

PubMed

Scott, J Thad; Doyle, Robert D; Prochnow, Shane J; White, Joseph D

2008-04-01

N2 fixation can be an important source of N to limnetic ecosystems and can influence the structure of phytoplankton communities. However, watershed-scale conditions that favor N2 fixation in lakes and reservoirs have not been well studied. We measured N2 fixation and lacustrine variables monthly over a 19-month period in Waco Reservoir, Texas, USA, and linked these data with nutrient-loading estimates from a physically based watershed model. Readily available topographic, soil, land cover, effluent discharge, and climate data were used in the Soil and Water Assessment Tool (SWAT) to derive watershed nutrient-loading estimates. Categorical and regression tree (CART) analysis revealed that lacustrine and watershed correlates of N2 fixation were hierarchically structured. Lacustrine conditions showed greater predictive capability temporally. For instance, low NO3(-) concentration (<25 microg N/L) and high water temperatures (>27 degrees C) in the reservoir were correlated with the initiation of N2 fixation seasonally. When lacustrine conditions were favorable for N2 fixation, watershed conditions appeared to influence spatial patterns of N2 fixation within the reservoir. For example, spatially explicit patterns of N2 fixation were correlated with the ratio of N:P in nutrient loadings and the N loading rate, which were driven by anthropogenic activity in the watershed and periods of low stream flow, respectively. Although N2 fixation contributed <5% of the annual N load to the reservoir, 37% of the N load was derived from atmospheric N2 fixation during summertime when stream flow in the watershed was low. This study provides evidence that watershed anthropogenic activity can exert control on planktonic N2 fixation, but that temporality is controlled by lacustrine conditions. Furthermore, this study also supports suggestions that reduced inflows may increase the propensity of N2-fixing cyanobacterial blooms in receiving waters of anthropogenically modified landscapes.

Electrotransformation and expression of bacterial genes encoding hygromycin phosphotransferase and beta-galactosidase in the pathogenic fungus Histoplasma capsulatum.

PubMed

Woods, J P; Heinecke, E L; Goldman, W E

1998-04-01

We developed an efficient electrotransformation system for the pathogenic fungus Histoplasma capsulatum and used it to examine the effects of features of the transforming DNA on transformation efficiency and fate of the transforming DNA and to demonstrate fungal expression of two recombinant Escherichia coli genes, hph and lacZ. Linearized DNA and plasmids containing Histoplasma telomeric sequences showed the greatest transformation efficiencies, while the plasmid vector had no significant effect, nor did the derivation of the selectable URA5 marker (native Histoplasma gene or a heterologous Podospora anserina gene). Electrotransformation resulted in more frequent multimerization, other modification, or possibly chromosomal integration of transforming telomeric plasmids when saturating amounts of DNA were used, but this effect was not observed with smaller amounts of transforming DNA. We developed another selection system using a hygromycin B resistance marker from plasmid pAN7-1, consisting of the E. coli hph gene flanked by Aspergillus nidulans promoter and terminator sequences. Much of the heterologous fungal sequences could be removed without compromising function in H. capsulatum, allowing construction of a substantially smaller effective marker fragment. Transformation efficiency increased when nonselective conditions were maintained for a time after electrotransformation before selection with the protein synthesis inhibitor hygromycin B was imposed. Finally, we constructed a readily detectable and quantifiable reporter gene by fusing Histoplasma URA5 with E. coli lacZ, resulting in expression of functional beta-galactosidase in H. capsulatum. Demonstration of expression of bacterial genes as effective selectable markers and reporters, together with a highly efficient electrotransformation system, provide valuable approaches for molecular genetic analysis and manipulation of H. capsulatum, which have proven useful for examination of targeted gene disruption, regulated gene expression, and potential virulence determinants in this fungus.

Developing a geomorphic approach for ranking watersheds for rehabilitation, Zuni Indian Reservation, New Mexico

USGS Publications Warehouse

Gellis, A.C.; Cheama, A.; Lalio, S.M.

2001-01-01

As a result of past erosion problems on the Zuni Indian Reservation in western New Mexico, the US Congress in 1990 authorized the Zuni Tribe to begin a program for watershed rehabilitation. This paper describes an approach to rank the most appropriate watersheds for rehabilitation for the Zuni Reservation. The approach was based on data collected during a 3-year study on geomorphic and anthropogenic characteristics of the Rio Nutria Watershed, including data on (i) arroyo cross-sectional changes, (ii) erosion-control structures, and (iii) sheetwash erosion. Results of this 3-year study indicated that 61 of 85 channel cross-sections aggraded and channels with lower width-to-depth ratios eroded. Results on assessment of erosion-control structures, some dating back to the 1930's, indicated that 60% of earthen dams and 22% of rock-and-brush structures were breached or flanked in the Rio Nutria Watershed. Sheetwash erosion measured on five land-cover sites (sagebrush, pasture, chained pin??on and juniper, unchained pin??on and juniper, and ponderosa pine) indicated chained pin??on and juniper sites and pasture sites had the highest volume-weighted sediment concentrations of 13,000 and 9970 ppm, respectively. Based on interpretations of the 3-year study in the Rio Nutria Watershed, a two-stage approach was developed to rank the most appropriate watersheds for rehabilitation on the Zuni Reservation. In the first stage, the reservation was divided into eight major watersheds, which were ranked according to the most potential for erosion. In the second stage, the watershed with the most potential for erosion was divided into sub-basins, which were ranked according to the most potential for erosion. Quantitative and qualitative information on physical and anthropogenic factors were used at each stage to rank the watersheds. Quantitative physical data included headcut density, percentage of bare ground, percentage of chained area, channel width-to-depth ratio, change in channel density from 1934 to 1988, and sheetwash erosion rates. Qualitative physical data included erosion rankings on the main channels, tributaries, and entire basins. Anthropogenic data included density of dirt roads and condition of erosion-control structures. A community survey and agricultural acreage were also used in the selection process. The first stage analysis resulted in the selection of the Rio Nutria Watershed as the most appropriate major watershed for rehabilitation. In the second stage, the Rio Nutria Watershed was divided into 15 sub-basins; the analysis indicated the highest priority sub-basins for rehabilitation were Benny Draw, Coal Mine Canyon Draw, and Garcia Draw.

Generation of composite Persea americana (Mill.) (avocado) plants: A proof-of-concept-study.

PubMed

Prabhu, S Ashok; Ndlovu, Buyani; Engelbrecht, Juanita; van den Berg, Noëlani

2017-01-01

Avocado (Persea americana (Mill.)), an important commercial fruit, is severely affected by Phytophthora Root Rot in areas where the pathogen is prevalent. However, advances in molecular research are hindered by the lack of a high-throughput transient transformation system in this non-model plant. In this study, a proof-of-concept is demonstrated by the successful application of Agrobacterium rhizogenes-mediated plant transformation to produce composite avocado plants. Two ex vitro strategies were assessed on two avocado genotypes (Itzamna and A0.74): In the first approach, 8-week-old etiolated seedlings were scarred with a sterile hacksaw blade at the base of the shoot, and in the second, inch-long incisions were made at the base of the shoot (20-week-old non-etiolated plants) with a sterile blade to remove the cortical tissue. The scarred/wounded shoot surfaces were treated with A. rhizogenes strains (K599 or ARqua1) transformed with or without binary plant transformation vectors pRedRootII (DsRed1 marker), pBYR2e1-GFP (GFP- green fluorescence protein marker) or pBINUbiGUSint (GUS- beta-glucuronidase marker) with and without rooting hormone (Dip 'N' Grow) application. The treated shoot regions were air-layered with sterile moist cocopeat to induce root formation. Results showed that hormone application significantly increased root induction, while Agrobacterium-only treatments resulted in very few roots. Combination treatments of hormone+Agrobacterium (-/+ plasmids) showed no significant difference. Only the ARqua1(+plasmid):A0.74 combination resulted in root transformants, with hormone+ARqua1(+pBINUbiGUSint) being the most effective treatment with ~17 and 25% composite plants resulting from strategy-1 and strategy-2, respectively. GUS- and GFP-expressing roots accounted for less than 4 and ~11%, respectively, of the total roots/treatment/avocado genotype. The average number of transgenic roots on the composite plants was less than one per plant in all treatments. PCR and Southern analysis further confirmed the transgenic nature of the roots expressing the screenable marker genes. Transgenic roots showed hyper-branching compared to the wild-type roots but this had no impact on Phytophthora cinnamomi infection. There was no difference in pathogen load 7-days-post inoculation between transformed and control roots. Strategy-2 involving A0.74:ARqua1 combination was the best ex vitro approach in producing composite avocado plants. The approach followed in this proof-of-concept study needs further optimisation involving multiple avocado genotypes and A. rhizogenes strains to achieve enhanced root transformation efficiencies, which would then serve as an effective high-throughput tool in the functional screening of host and pathogen genes to improve our understanding of the avocado-P. cinnamomi interaction.

Generation of composite Persea americana (Mill.) (avocado) plants: A proof-of-concept-study

PubMed Central

Prabhu, S. Ashok; Ndlovu, Buyani; Engelbrecht, Juanita

2017-01-01

Avocado (Persea americana (Mill.)), an important commercial fruit, is severely affected by Phytophthora Root Rot in areas where the pathogen is prevalent. However, advances in molecular research are hindered by the lack of a high-throughput transient transformation system in this non-model plant. In this study, a proof-of-concept is demonstrated by the successful application of Agrobacterium rhizogenes-mediated plant transformation to produce composite avocado plants. Two ex vitro strategies were assessed on two avocado genotypes (Itzamna and A0.74): In the first approach, 8-week-old etiolated seedlings were scarred with a sterile hacksaw blade at the base of the shoot, and in the second, inch-long incisions were made at the base of the shoot (20-week-old non-etiolated plants) with a sterile blade to remove the cortical tissue. The scarred/wounded shoot surfaces were treated with A. rhizogenes strains (K599 or ARqua1) transformed with or without binary plant transformation vectors pRedRootII (DsRed1 marker), pBYR2e1-GFP (GFP- green fluorescence protein marker) or pBINUbiGUSint (GUS- beta-glucuronidase marker) with and without rooting hormone (Dip 'N' Grow) application. The treated shoot regions were air-layered with sterile moist cocopeat to induce root formation. Results showed that hormone application significantly increased root induction, while Agrobacterium-only treatments resulted in very few roots. Combination treatments of hormone+Agrobacterium (-/+ plasmids) showed no significant difference. Only the ARqua1(+plasmid):A0.74 combination resulted in root transformants, with hormone+ARqua1(+pBINUbiGUSint) being the most effective treatment with ~17 and 25% composite plants resulting from strategy-1 and strategy-2, respectively. GUS- and GFP-expressing roots accounted for less than 4 and ~11%, respectively, of the total roots/treatment/avocado genotype. The average number of transgenic roots on the composite plants was less than one per plant in all treatments. PCR and Southern analysis further confirmed the transgenic nature of the roots expressing the screenable marker genes. Transgenic roots showed hyper-branching compared to the wild-type roots but this had no impact on Phytophthora cinnamomi infection. There was no difference in pathogen load 7-days-post inoculation between transformed and control roots. Strategy-2 involving A0.74:ARqua1 combination was the best ex vitro approach in producing composite avocado plants. The approach followed in this proof-of-concept study needs further optimisation involving multiple avocado genotypes and A. rhizogenes strains to achieve enhanced root transformation efficiencies, which would then serve as an effective high-throughput tool in the functional screening of host and pathogen genes to improve our understanding of the avocado-P. cinnamomi interaction. PMID:29053757

Statistical analysis of cyprinid ethoxyresorufin-O-deethylase data in a large French watershed.

PubMed

Flammarion, P; Migeon, B; Garric, J

1998-01-01

A comparison of ethoxyresorufin-O-deethylase (EROD) data collected in 1995 in various sites in the Rhône watershed (France) was carried out to quantify the influence of factors such as contamination and biological parameters on EROD levels and within-group variabilities. Three species of cyprinids were collected and fish chemical contamination was measured. A log transformation of EROD data provided both normalization and homogeneity of variances. The influence of female sexual maturation on the variability and EROD dimorphism was quantified. A relationship with contaminant bioaccumulation was observed. A comparison with EROD data collected during previous studies by the same laboratory was made to validate the results.

Development of Protoporphyrinogen Oxidase as an Efficient Selection Marker for Agrobacterium tumefaciens-Mediated Transformation of Maize

PubMed Central

Li, Xianggan; Volrath, Sandy L.; Nicholl, David B.G.; Chilcott, Charles E.; Johnson, Marie A.; Ward, Eric R.; Law, Marcus D.

2003-01-01

In this article, we report the isolation of plant protoporphyrinogen oxidase (PPO) genes and the isolation of herbicide-tolerant mutants. Subsequently, an Arabidopsis double mutant (Y426M + S305L) was used to develop a selectable marker system for Agrobacterium tumefaciens-mediated transformation of maize (Zea mays) and to obtain multiple events tolerant to the PPO family of herbicides. Maize transformants were produced via butafenacil selection using a flexible light regime to increase selection pressure. Butafenacil selection per se did not change transgene copy number distribution relative to other selectable marker systems, but the most tolerant events identified in the greenhouse were more likely to contain multiple copies of the introduced mutant PPO gene. To date, more than 2,500 independent transgenic maize events have been produced using butafenacil selection. The high frequency of A. tumefaciens-mediated transformation via PPO selection enabled us to obtain single-copy transgenic maize lines tolerant to field levels of butafenacil. PMID:12972658

Light-inducible genetic engineering and control of non-homologous end-joining in industrial eukaryotic microorganisms: LML 3.0 and OFN 1.0.

PubMed

Zhang, Lei; Zhao, Xihua; Zhang, Guoxiu; Zhang, Jiajia; Wang, Xuedong; Zhang, Suping; Wang, Wei; Wei, Dongzhi

2016-02-09

Filamentous fungi play important roles in the production of plant cell-wall degrading enzymes. In recent years, homologous recombinant technologies have contributed significantly to improved enzymes production and system design of genetically manipulated strains. When introducing multiple gene deletions, we need a robust and convenient way to control selectable marker genes, especially when only a limited number of markers are available in filamentous fungi. Integration after transformation is predominantly nonhomologous in most fungi other than yeast. Fungal strains deficient in the non-homologous end-joining (NHEJ) pathway have limitations associated with gene function analyses despite they are excellent recipient strains for gene targets. We describe strategies and methods to address these challenges above and leverage the power of resilient NHEJ deficiency strains. We have established a foolproof light-inducible platform for one-step unmarked genetic modification in industrial eukaryotic microorganisms designated as 'LML 3.0', and an on-off control protocol of NHEJ pathway called 'OFN 1.0', using a synthetic light-switchable transactivation to control Cre recombinase-based excision and inversion. The methods provide a one-step strategy to sequentially modify genes without introducing selectable markers and NHEJ-deficiency. The strategies can be used to manipulate many biological processes in a wide range of eukaryotic cells.

[Temporal-spatial distribution of agricultural diffuse nitrogen pollution and relationship with soil respiration and nitrification].

PubMed

Wei, Ouyang; Cai, Guan-Qing; Huang, Hao-Bo; Geng, Xiao-Jun

2014-06-01

The soil respiration, nitrification and denitrification processes play an important role on soil nitrogen transformation and diffuse nitrogen loading. These processes are also the chains for soil circle. In this study, the Zhegao watershed located north of Chaohu Lake was selected to explore the interactions of these processes with diffuse nitrogen pollution. The BaPS (Barometric Process Separation) was applied to analyze the soil respiration, nitrification and denitrification processes in farmland and forest. The SWAT (Soil and Water Assessment Tool) simulated the temporal and spatial pattern of diffuse nitrogen loading. As the expanding of farmland and higher level of fertilization, the yearly mean loading of diffuse nitrogen increased sustainably from 1980-1995 to 1996-2012. The monthly loading in 1996-2012 was also higher than that in the period of 1980-1995, which closely related to the precipitation. The statistical analysis indicated that there was a significant difference between two periods. The yearly averaged loading of the whole watershed in 1996-2012 was 10.40 kg x hm(-2), which was 8.10 kg x hm(-2) in 1980-1995. The variance analysis demonstrated that there was also a big difference between the spatial distributions of two periods. The forest soil had much higher soil respiration than the farmland soil. But the farmland had higher nitrification and denitrification rates. The more intensive nitrogen transformation in the farmland contributed to the less diffuse nitrogen loading. As the nitrification rate of farmland was higher than denitrification rate, agricultural diffuse nitrate nitrogen loading would increase and organic nitrogen loading would reduce. The analysis of soil respiration, nitrification and denitrification is helpful for the study of soil nitrogen circle form the aspect of soil biology, which also benefits the control of agricultural diffuse nitrogen pollution.

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2010 CFR

2010-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2012 CFR

2012-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2014 CFR

2014-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2013 CFR

2013-07-01

... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL PRIMARY DRINKING WATER REGULATIONS Enhanced Filtration and Disinfection-Systems Serving Fewer Than 10,000... oocysts in the source water. Your system's watershed control program must, for Cryptosporidium: (a...

Controls of event-based nutrient transport within nested headwater agricultural watersheds of the western Lake Erie basin

USDA-ARS?s Scientific Manuscript database

Understanding the processes controlling nutrient delivery in headwater agricultural watersheds is essential for predicting and mitigating eutrophication and harmful algal blooms in receiving surface waters. The objective of this study was to elucidate nutrient transport pathways and examine key comp...

Watershed Land Use and Seasonal Variation Constrain the Influence of Riparian Canopy Cover on Stream Ecosystem Metabolism

EPA Science Inventory

While watershed and local scale controls on stream metabolism have been independently investigated, little is known about how controls exerted at these different scales interact to determine stream metabolic rates, or how these interactions vary across seasons. To address this ...

Object-based methods for individual tree identification and tree species classification from high-spatial resolution imagery

NASA Astrophysics Data System (ADS)

Wang, Le

2003-10-01

Modern forest management poses an increasing need for detailed knowledge of forest information at different spatial scales. At the forest level, the information for tree species assemblage is desired whereas at or below the stand level, individual tree related information is preferred. Remote Sensing provides an effective tool to extract the above information at multiple spatial scales in the continuous time domain. To date, the increasing volume and readily availability of high-spatial-resolution data have lead to a much wider application of remotely sensed products. Nevertheless, to make effective use of the improving spatial resolution, conventional pixel-based classification methods are far from satisfactory. Correspondingly, developing object-based methods becomes a central challenge for researchers in the field of Remote Sensing. This thesis focuses on the development of methods for accurate individual tree identification and tree species classification. We develop a method in which individual tree crown boundaries and treetop locations are derived under a unified framework. We apply a two-stage approach with edge detection followed by marker-controlled watershed segmentation. Treetops are modeled from radiometry and geometry aspects. Specifically, treetops are assumed to be represented by local radiation maxima and to be located near the center of the tree-crown. As a result, a marker image was created from the derived treetop to guide a watershed segmentation to further differentiate overlapping trees and to produce a segmented image comprised of individual tree crowns. The image segmentation method developed achieves a promising result for a 256 x 256 CASI image. Then further effort is made to extend our methods to the multiscales which are constructed from a wavelet decomposition. A scale consistency and geometric consistency are designed to examine the gradients along the scale-space for the purpose of separating true crown boundary from unwanted textures occurring due to branches and twigs. As a result from the inverse wavelet transform, the tree crown boundary is enhanced while the unwanted textures are suppressed. Based on the enhanced image, an improvement is achieved when applying the two-stage methods to a high resolution aerial photograph. To improve tree species classification, we develop a new method to choose the optimal scale parameter with the aid of Bhattacharya Distance (BD), a well-known index of class separability in traditional pixel-based classification. The optimal scale parameter is then fed in the process of a region-growing-based segmentation as a break-off value. Our object classification achieves a better accuracy in separating tree species when compared to the conventional Maximum Likelihood Classification (MLC). In summary, we develop two object-based methods for identifying individual trees and classifying tree species from high-spatial resolution imagery. Both methods achieve promising results and will promote integration of Remote Sensing and GIS in forest applications.

[Study on transformation of P-dissolving Penicillium oxalicum P8 with double-marker vector expressing green fluorescent protein and hygromycin B resistance].

PubMed

Zhang, Lei; Fan, Bing-Quan; Huang, Wei-Yi

2005-12-01

P-dissolving Penicillium oxalicum P8 was isolated previously in this lab which has a considerable ability to dissolve many kinds of inorganic phosphorus and improve crop growth. In order to study rhizosphere colonization of plants by Penicillium oxalicum P8, protoplasts were transformed with a double-marker expression vector of green fluorescent protein and hygromycin B resistance. Some transformants were selected which expressed both the GFP and hygromycin B phosphotransferase and did not show significant morphological or physiological differences as compared to wild-type strain. Southern blot analysis confirmed the heterogeneous genomic integration of the vector DNA into the transformants.

Transport and transformation of nutrients and sediment in two agricultural watersheds in northeast Arkansas

USDA-ARS?s Scientific Manuscript database

Agriculture is vital to Arkansas economy as it contributes $20 billion annually, double the average national contribution to the state GDP. Arkansas is ranked in the top 5 in rice, cotton seed and sorghum, and top 20 in soybean, corn for grain, and wheat production nationally. Despite the importance...

Modeling Mercury Exposure at Different Scales in the McTier Creek Watershed and Edisto River Basin, SC USA

EPA Science Inventory

Mercury is the toxicant responsible for the largest number of fish advisories across the United States, with 1.25 million miles of rivers under advisory. The processes governing fate, transport, and transformation of mercury in lotic ecosystems are not well-understood, in large p...

Modeling Mercury Exposure at Different Scales in the McTier Creek Watershed and Edisto River Basin SC USA

EPA Science Inventory

Mercury (Hg) is the toxicant responsible for the largest number of fish advisories across the United States, with 1.25 million river miles under advisory. The processes governing fate, transport, and transformation of Hg in lotic ecosystems are not well-understood, in large part...

Assessments of urban growth in the Tampa Bay watershed using remote sensing data

USGS Publications Warehouse

Xian, G.; Crane, M.

2005-01-01

Urban development has expanded rapidly in the Tampa Bay area of west-central Florida over the past century. A major effect associated with this population trend is transformation of the landscape from natural cover types to increasingly impervious urban land. This research utilizes an innovative approach for mapping urban extent and its changes through determining impervious surfaces from Landsat satellite remote sensing data. By 2002, areas with subpixel impervious surface greater than 10% accounted for approximately 1800 km2, or 27 percent of the total watershed area. The impervious surface area increases approximately three-fold from 1991 to 2002. The resulting imperviousness data are used with a defined suite of geospatial data sets to simulate historical urban development and predict future urban and suburban extent, density, and growth patterns using SLEUTH model. Also examined is the increasingly important influence that urbanization and its associated imperviousness extent have on the individual drainage basins of the Tampa Bay watershed.

Effect of historic land cover change on runoff curve number estimation in Iowa

USGS Publications Warehouse

Wehmeyer, Loren L.; Weirich, Frank H.

2010-01-01

Within three decades of European-descended settlers arriving in Iowa, much of the land cover across the state was transformed from prairie and forest to farmland, patches of forest, and urbanized areas. Between 1832 and 1859, the General Land Office surveyed the state of Iowa to aid in the disbursement of land. In 1875, an illustrated atlas of the State of Iowa was published. Using these two data resources for classifying land cover, the hydrologic impact of the land cover change resulting from the first three decades of settlement is presented in terms of the effect on the area-weighted average curve number, a term commonly used to predict runoff from rainstorms. In the four watersheds studied, the area-weighted average curve number increased by a mean of 16.4 from 61.4 to 77.8 with the greatest magnitude of change occurring in the two western Iowa watersheds as opposed to the two more heavily forested eastern Iowa watersheds.

Algorithm to calculate proportional area transformation factors for digital geographic databases

DOE Office of Scientific and Technical Information (OSTI.GOV)

Edwards, R.

1983-01-01

A computer technique is described for determining proportionate-area factors used to transform thematic data between large geographic areal databases. The number of calculations in the algorithm increases linearly with the number of segments in the polygonal definitions of the databases, and increases with the square root of the total number of chains. Experience is presented in calculating transformation factors for two national databases, the USGS Water Cataloging Unit outlines and DOT county boundaries which consist of 2100 and 3100 polygons respectively. The technique facilitates using thematic data defined on various natural bases (watersheds, landcover units, etc.) in analyses involving economicmore » and other administrative bases (states, counties, etc.), and vice versa.« less

Segmentation of the glottal space from laryngeal images using the watershed transform.

PubMed

Osma-Ruiz, Víctor; Godino-Llorente, Juan I; Sáenz-Lechón, Nicolás; Fraile, Rubén

2008-04-01

The present work describes a new method for the automatic detection of the glottal space from laryngeal images obtained either with high speed or with conventional video cameras attached to a laryngoscope. The detection is based on the combination of several relevant techniques in the field of digital image processing. The image is segmented with a watershed transform followed by a region merging, while the final decision is taken using a simple linear predictor. This scheme has successfully segmented the glottal space in all the test images used. The method presented can be considered a generalist approach for the segmentation of the glottal space because, in contrast with other methods found in literature, this approach does not need either initialization or finding strict environmental conditions extracted from the images to be processed. Therefore, the main advantage is that the user does not have to outline the region of interest with a mouse click. In any case, some a priori knowledge about the glottal space is needed, but this a priori knowledge can be considered weak compared to the environmental conditions fixed in former works.

Evaluation of spatial plan in controlling stream flow rate in Wakung Watershed, Pemalang, Central Java, Indonesia

NASA Astrophysics Data System (ADS)

Anwar, Y.; Setyasih, I.; Setiawan, M. A.; Christanto, N.

2018-04-01

Evaluation study for such a regional spatial plan (RTRW) in Indonesia has not been evaluated for its effectiveness in controlling the surface run off that contributed to streamflow. This necessity can be accomplishsed by applying a modeling approach, such as Soil Water Assessment Tool (SWAT). The objectives of this research are 1) to simulate the streamflow of Wakung watershed based on actual landuse, 2) to predict streamflow of Wakung watershed based on RTRW, and 3) to evaluate the effectiveness of the RTRW of Pemalang District in controling streamflow rate at Wakung Watershed. ArcSWAT model was used to determine the erosion rate prediction. The model was then calibrated by using SWATCUP. Model performance were tested by using R2 and ENS. The calibration and validation results showed that R2 and ENS (monthly) > 0.5. The result of SWAT simulation in Wakung sub-watershed reaching 161 - 4950 m3/s/years for W-A scenario (actual landuse and weather data of 2013), for scenario W-R (RTRW and weather data of 2013), 330 - 4919 m3/s/year. The comparison between actual and spatial plan land use data for stream flow is showing that the W-A scenario is lower than the W-R scenario in 19 sub watersheds. This is because there are many plans for adding land use for urban and intensive horticulture land in areas with steep slopes (> 25%). This condition is caused by the demands of fulfilling the needs of settlement and food for people in the Wakung watershed.

Water-quality characteristics of six small, semiarid watersheds in the Green River coal region of Colorado

USGS Publications Warehouse

Turk, John T.; Parker, Randolph S.

1982-01-01

Analysis of major and trace constituents in streams flowing through six semiarid watersheds indicates that the stream chemistry is characterized by saturation with respect to common carbonate minerals (calcium, magnesium, iron, manganese, and lead). The solubility of the carbonate minerals may be a major control on the absolute and relative concentrations of calcium, magnesium, bicarbonate, iron, manganese, and lead; however, other mechanisms probably control the concentrations of cadmium and zinc. Statistical analyses indicate that the mean concentrations of the major ions in the two climatic areas studied are significantly (P=0.05) different from one another, with larger mean concentrations in the more arid area. Trace-metal concentrations were similar from one area to another and indistinguishable from site to site (P=0.05) for lead, cadmium, and zinc. Linear regressions of major ion concentration to specific conductance are similar in both areas for sodium, bicarbonate, sulfate, and chloride. Results of the study may be useful in providing a first approximation of stream chemistry in other watersheds with the same geologic setting, determining watersheds with similar geochemical controls, and determining future changes in stream chemistry in the watersheds studied. (USGS)

31. View of mezzanine floor level in transmitter building no. ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

31. View of mezzanine floor level in transmitter building no. 102 showing various electronic central indicator panel to control building air conditioning, steam pressure, supply temperature, discharge temperature, supply pressure, transformer vault status, and radome conditioning system. - Clear Air Force Station, Ballistic Missile Early Warning System Site II, One mile west of mile marker 293.5 on Parks Highway, 5 miles southwest of Anderson, Anderson, Denali Borough, AK

Conservation Management of Agriculture Land using Geospatial Approach (A Case Study in the Bone Watershed, Gorontalo Province, Indonesia)

NASA Astrophysics Data System (ADS)

Maryati, Sri; Eraku, Sunarty; Kasim, Muh

2018-02-01

Bone Watershed is one of the major watersheds in Gorontalo Province. Bone watershed has a very important role for the people of Gorontalo Province. The role of Bone Watershed is mainly related to the providing clean water, producing oxygen, controlling flood, providing habitat for endemic flora fauna and other environmental functions. The role of Bone Watershed for the community's economic sector is also very important, the Bone watershed provides livelihood for surrounding communities includes fertile land resources for agriculture and plantations, forest products, and livestock feed. This research is important considering the Bone watershed has limited availability of land for agriculture and the high risk of natural disasters such as floods and landslides. Geospatial data includes topography map, landform map, soil map, integrated with field survey results and soil properties were analized to determine conservation management of agriculture land in the Bone Watershed, Gorontalo Province, Indonesia. The result of this study shows that based on soil properties and physical land characteristics, land use for agriculture should consider appropriate conservation techniques, land capability and respect to local wisdom.

Watershed System Model: The Essentials to Model Complex Human-Nature System at the River Basin Scale

NASA Astrophysics Data System (ADS)

Li, Xin; Cheng, Guodong; Lin, Hui; Cai, Ximing; Fang, Miao; Ge, Yingchun; Hu, Xiaoli; Chen, Min; Li, Weiyue

2018-03-01

Watershed system models are urgently needed to understand complex watershed systems and to support integrated river basin management. Early watershed modeling efforts focused on the representation of hydrologic processes, while the next-generation watershed models should represent the coevolution of the water-land-air-plant-human nexus in a watershed and provide capability of decision-making support. We propose a new modeling framework and discuss the know-how approach to incorporate emerging knowledge into integrated models through data exchange interfaces. We argue that the modeling environment is a useful tool to enable effective model integration, as well as create domain-specific models of river basin systems. The grand challenges in developing next-generation watershed system models include but are not limited to providing an overarching framework for linking natural and social sciences, building a scientifically based decision support system, quantifying and controlling uncertainties, and taking advantage of new technologies and new findings in the various disciplines of watershed science. The eventual goal is to build transdisciplinary, scientifically sound, and scale-explicit watershed system models that are to be codesigned by multidisciplinary communities.

Controlling factors of soil selenium distribution in a watershed in Se-enriched and longevity region of South China.

PubMed

Shao, Ya; Cai, Chongfa; Zhang, Haitao; Fu, Wei; Zhong, Xuemei; Tang, Shen

2018-05-10

Selenium (Se) is an essential nutritional element for human beings. Many studies have been conducted on concentration and distribution patterns of soil Se in low Se, Se-enriched, and selenosis areas; however, soil Se has not been systematically studied in a watershed, especially in Se-enriched longevity region and karst area in South China. This study is carried out to explore the controlling factors of Se-enriched soils in Baishou river tributary watershed, where soils are Se-enriched, and local people have the phenomenon of longevity. The area-weighted average rock Se concentration in the watershed is 0.054 mg/kg, and there are no significant differences in rock Se concentration between different strata and between different lithological rocks. The area-weighted average concentration of Se in soils (0-20 cm) is 0.80 mg/kg, and the soil Se concentration is of high level in the watershed. Soil Se concentration decreases from upstream to downstream in the watershed, and significantly correlated with elevation. Climate is the main factor causing high content of soil Se in the watershed which lacks black rock series. The difference of clastic and carbonate parent materials in soil forming process and the physical and chemical properties (pH, OM, etc.) are the main reasons for the spatial variation of Se distribution in the watershed. The research will be beneficial to the development and utilization of Se-enriched soil in Se-enriched area.

Removal of Woody Riparian Vegetation Substantially Altered a Stream Ecosystem in an Otherwise Undisturbed Grassland Watershed

DOE PAGES

Larson, Danelle M.; Dodds, Walter K.; Veach, Allison M.

2018-04-23

Riparian zones are key interfaces between stream and terrestrial ecosystems. Yet, we know of no whole-watershed experiments that cut only woody vegetation in the riparian zone in an otherwise intact watershed to isolate the role of riparian zones on stream ecology. We removed all of the woody riparian vegetation (from 10- and 30-m-wide buffers in headwaters and main channels, respectively) for 5 km of stream in a single watershed while leaving the remainder of the grassland watershed un-impacted. We assessed water chemistry changes 3 years before and 3 years after riparian wood removal and in two neighboring control watersheds withmore » a before–after, control-impact design and analysis. Riparian woody removal caused 10–100-fold increases in mean stream water nitrate concentrations and pulses of high nitrate for 3 years thereafter. Other nutrients and total suspended solids increased 2–25 times for the 3 years of post-removal. In-stream rates of gross primary production, ecosystem respiration, and net ecosystem production had large treatment effect sizes but also high variance among samples. Past studies of whole-watershed deforestations showed similar water quality responses to our riparian deforestation. Riparian zones of grassland streams are sensitive to disturbance and likely impart relatively greater influence on stream structure and function than the upslope of the watershed. Finally, our results further emphasize the role of riparian zones in biogeochemically linking aquatic and terrestrial habitats.« less

Removal of Woody Riparian Vegetation Substantially Altered a Stream Ecosystem in an Otherwise Undisturbed Grassland Watershed

DOE Office of Scientific and Technical Information (OSTI.GOV)

Larson, Danelle M.; Dodds, Walter K.; Veach, Allison M.

Riparian zones are key interfaces between stream and terrestrial ecosystems. Yet, we know of no whole-watershed experiments that cut only woody vegetation in the riparian zone in an otherwise intact watershed to isolate the role of riparian zones on stream ecology. We removed all of the woody riparian vegetation (from 10- and 30-m-wide buffers in headwaters and main channels, respectively) for 5 km of stream in a single watershed while leaving the remainder of the grassland watershed un-impacted. We assessed water chemistry changes 3 years before and 3 years after riparian wood removal and in two neighboring control watersheds withmore » a before–after, control-impact design and analysis. Riparian woody removal caused 10–100-fold increases in mean stream water nitrate concentrations and pulses of high nitrate for 3 years thereafter. Other nutrients and total suspended solids increased 2–25 times for the 3 years of post-removal. In-stream rates of gross primary production, ecosystem respiration, and net ecosystem production had large treatment effect sizes but also high variance among samples. Past studies of whole-watershed deforestations showed similar water quality responses to our riparian deforestation. Riparian zones of grassland streams are sensitive to disturbance and likely impart relatively greater influence on stream structure and function than the upslope of the watershed. Finally, our results further emphasize the role of riparian zones in biogeochemically linking aquatic and terrestrial habitats.« less

Glacier loss and emerging hydrologic vulnerabilities in the Peruvian Andes

NASA Astrophysics Data System (ADS)

Mark, B. G.; McKenzie, J. M.; Baraer, M.; Lagos, P.; Lautz, L.; Carey, M.; Bury, J.; Crumley, R.; Wigmore, O.; Somers, L. D.

2015-12-01

Accelerating glacier recession in the tropical Andes is transforming downstream hydrology, while increasing demands for water by end-users (even beyond the watershed limits) is complicating the assessment of vulnerability. Future scenarios of hydro-climatic vulnerability require a better understanding of coupled hydrologic and human systems, involving both multiscale process studies and more robust models of glacier-climate interactions. We synthesize research in two proglacial valleys of glacierized mountain ranges in different regions of Peru that are both in proximity to growing water usage from urban sectors, agriculture, hydroelectric generation, and mining. In both the Santa River watershed draining the Cordillera Blanca and the Shullcas River watershed below Hyuatapallana Mountain in Junin, glaciers have receded over 25% since the 1980s. Historical runoff and glacier data, combined with glacier-climate modeling, show a long-term decrease in discharge resulting from a net loss of stored water. We find evidence that this altered hydrology is transforming proglacial wetland ecology and water quality, even while water resource use has intensified. Beyond glaciers, our results show that over 60% of the dry season base flow in each watershed is groundwater sourced from heterogeneous aquifers. Municipal water supply in Huancayo already relies on 18 groundwater wells. Perceptions of water availability and actual water use practices remain relatively divorced from the actual water resources provided from each mountain range. Critical changes in glacier volume and water supply are not perceived or acknowledged consistently amongst different water users, nor reflected in water management decisions. In order to identify, understand, model, and adapt to climate-glacier-water changes, it is vital to integrate the analysis of water availability and groundwater processes (the domain of hydrologists) with that of water use (the focus for social scientists). Attention must be drawn to evaluating risks and adaptation options with rigorous, data-based scenario evaluations of how management decisions impact all end users.

A Comparison of Erosion and Water Pollution Control Strategies for an Agricultural Watershed

NASA Astrophysics Data System (ADS)

Prato, Tony; Shi, Hongqi

1990-02-01

The effectiveness and efficiency of two erosion control strategies and one water pollution control (riparian) strategy are compared for Idaho's Tom Beall watershed. Erosion control strategies maximize annualized net returns per hectare on each field and restrict field erosion rates to no more than 11.2 or 16.8 tons per hectare. The riparian strategy uses good vegetative cover on all fields adjacent to the creek and in noncropland areas and the resource management system that maximizes annualized net returns per hectare on remaining fields. The Agricultural Nonpoint Source Pollution model is used to simulate the levels and concentrations of sediment, nitrogen, phosphorus, and chemical oxygen demand at the outlet of the watershed. Erosion control strategies generate less total erosion and water pollution but are less efficient than the riparian strategy. The riparian strategy is less equitable for farmers than the erosion control strategies.

[The balance of markers of regulation vascular tone and fibrinogen in the prognosis of hemorrhagic transformation and fatal outcome in the acute period of ischemic stroke].

PubMed

Liang, O V; Kochetov, A G; Arkhipkin, A A; Novozhenova, Iu V; Shamalov, N A; Ramazanov, G R; Chuĭko, M R; Ogurtsov, P P; Skvortsova, V I

2012-01-01

The markers of regulation vascular tone, such as rennin, endothelin-1, and C-type natriuretic peptide, are of great value for prognosis of hemorrhagic transformation and fatal outcome of ischemic stroke. A change in the vascular tone in case of hemorrhagic transformation at the affected site precedes activation of the coagulation component of hemostasis as a mechanism preventing blood loss and increasing fibrinogen level. This work was aimed to study the balance of the above markers and fibrinogen in the prognosis of hemorrhagic transformation and fatal outcome in the acute period of ischemic stroke. It included 62 patients receiving no thrombolytic therapy. It was shown that symptomatic hemorrhagic transformation was associated with elevated rennin levels without a marked fall in the level of C-type natriuretic peptide and asymptomatic hemorrhagic transformation with elevated endothelin-1 levels and decreased concentration of natriuretic peptide. Fibrinogen level on day 4 of the observation proved to be a reliable predictor of negative prognosis. Asymptomatic hemorrhagic transformation without fatal outcome was associated with systemic and local vasoconstriction and inhibition of local vasodilation. Symptomatic hemorrhagic transformation with the fatal outcome was accompanied by dysregulation of vascular tone in the form of activation of systemic and local vasoconstriction, insufficient inhibition of local vasodilation and compensatory reaction in the form of activation of hemostatic mechanisms manifest as elevated fibrinogen levels on day 4. The lethal outcome without hemorrhagic transformation was associated with systemic vasoconstriction, activation of local vasodilation and vasoconstriction leading to local "biochemical paralysis" of vascular tone regulation.

Effect of Photochemical Transformation on Dissolved Organic Carbon Concentration and Bioavailability from Watersheds with Varying Landcover

NASA Astrophysics Data System (ADS)

Vermilyea, A.; Sanders, A.; Vazquez, E.

2017-12-01

The transformation of freshwater dissolved organic carbon (DOC) can have important implications for water quality, aquatic ecosystem health, and our climate. DOC is an important nutrient for heterotrophic microorganisms near the base of the aquatic food chain and the extent of conversion of DOC to CO2 is a critical piece of the global carbon cycle. Photochemical pathways have the potential to transform recalcitrant DOC into more labile forms that can then be converted to smaller DOC molecules and eventually be completely mineralized to CO2. This may lead to a DOC pool with different bioavailability depending on the structural composition of the original DOC pool and the mechanistic pathways undergone during transformation. This study aimed to measure the changes in DOC concentration and bioavailability due solely to photochemical processes in three watersheds of northern Vermont, USA that have varied land cover, land use (LCLU) attributes. Our hypothesis was that photochemical transformations will lead to (1) an overall loss of DOC due to mineralization to CO2 and (2) a relative increase in the bioavailable fraction of DOC. Additionally, the influence of LCLU and base flow versus storm flow on both mineralization rates and changes in DOC bioavailability was investigated. Irradiation of filtered samples in quartz vessels under sunlight led to small changes in DOC concentration over time, but significant changes in DOC bioavailability. In general, fluorescence excitation-emission matrices (EEMs) showed a shift from an initially more humic-like DOC pool, to a more protein-like (bioavailable) DOC pool. Specific UV index (SUVA) along with bioavailable DOC (BDOC) incubations were also used to characterize DOC and its bioavailability. There were only small differences in the DOC transformation that took place among sites, possibly due to only small differences in the initial bioavailability and fluorescent properties between water samples. Photochemical transformation appears to play an important role in the transformation of a more recalcitrant (humic) pool of DOC into a more bioavailable DOC pool that can then be utilized by aquatic heterotrophs and ultimately be converted to CO2.

Resesrvoir sedimentation rates in the Little Washita River experimental watershed, Oklahoma

USDA-ARS?s Scientific Manuscript database

The Washita River Basin (WRB) was one of eleven pilot watershed projects selected for construction of flood control reservoirs around the country as a result of the Flood Control Act of 1936. These reservoirs were implemented to prevent and manage soil erosion and flooding. A total of 45 reservoirs ...

Invasive Species Guidebook for Department of Defense Installations in the Chesapeake Bay Watershed: Identification, Control, and Restoration

DTIC Science & Technology

2007-11-01

INSTALLATIONS IN THE CHESAPEAKE BAY WATERSHED IDENTIFICATION AND CONTROL METHODS Cogongrass ( Imperata cylindrica ) Description & Biology – A large...Crown vetch Coronilla varia MD, VA 14 Leafy spurge Euphorbia esula VA 15 Ground ivy Glechoma hederacea DC, MD, PA, VA, WV 17 Cogongrass Imperata

Reference interval computation: which method (not) to choose?

PubMed

Pavlov, Igor Y; Wilson, Andrew R; Delgado, Julio C

2012-07-11

When different methods are applied to reference interval (RI) calculation the results can sometimes be substantially different, especially for small reference groups. If there are no reliable RI data available, there is no way to confirm which method generates results closest to the true RI. We randomly drawn samples obtained from a public database for 33 markers. For each sample, RIs were calculated by bootstrapping, parametric, and Box-Cox transformed parametric methods. Results were compared to the values of the population RI. For approximately half of the 33 markers, results of all 3 methods were within 3% of the true reference value. For other markers, parametric results were either unavailable or deviated considerably from the true values. The transformed parametric method was more accurate than bootstrapping for sample size of 60, very close to bootstrapping for sample size 120, but in some cases unavailable. We recommend against using parametric calculations to determine RIs. The transformed parametric method utilizing Box-Cox transformation would be preferable way of RI calculation, if it satisfies normality test. If not, the bootstrapping is always available, and is almost as accurate and precise as the transformed parametric method. Copyright © 2012 Elsevier B.V. All rights reserved.

Using host-associated genetic markers to investigate sources of fecal contamination in two Vermont streams

USGS Publications Warehouse

Medalie, Laura; Matthews, Leslie J.; Stelzer, Erin A.

2011-01-01

The use of host-associated Bacteroidales-based 16S ribosomal ribonucleic acid genetic markers was investigated as a tool for providing information to managers on sources of bacterial impairment in Vermont streams. The study was conducted during 2009 in two watersheds on the U.S. Environmental Protection Agency's 303(d) List of Impaired Waters, the Huntington and the Mettawee Rivers. Streamwater samples collected during high-flow and base-flow conditions were analyzed for concentrations of Escherichia coli (E. coli) and Bacteroidales genetic markers (General AllBac, Human qHF183 and BacHum, Ruminant BoBac, and Canid BacCan) to identify humans, ruminants, and canids as likely or unlikely major sources of fecal contamination. Fecal reference samples from each of the potential source groups, as well as from common species of wildlife, were collected during the same season and from the same watersheds as water samples. The results were combined with data from other states to assess marker cross reaction and to relate marker results to E. coli, the regulated water-quality parameter, with a higher degree of statistical significance. Results from samples from the Huntington River collected under different flow conditions on three dates indicated that humans were unlikely to be a major source of fecal contamination, except for a single positive result at one station that indicated the potential for human sources. Ruminants (deer, moose, cow, or sheep) were potential sources of fecal contamination at all six stations on the Huntington River during one high-flow event and at all but two stations during the other high-flow event. Canids were potential sources of fecal contamination at some stations during two high-flow events, with genetic-marker concentrations in samples from two of the six stations showing consistent positive results for canids for both storm dates. A base-flow sample showed no evidence of major fecal contamination in the Huntington River from humans, ruminants, or canids. Results from samples from the Mettawee River watershed collected during high-flow conditions (12 storm samples on 2 dates at 6 stations) indicated that there was no evidence of fecal contamination from humans in seven samples and possible evidence in five samples. Results for humans were positive for only one station during both storm events. For two of the five samples with evidence for human fecal contamination, results for two different human genetic markers agreed, but results from three samples were inconsistent. In samples from five of the six Mettawee stations, ruminants were a potential source of fecal contamination on at least one of the three sampled dates, including three positive results for the base-flow sample. Yet samples from all of the stations that showed positive results for ruminants did so for only one or two of the three sampled dates. Samples from only one of the six stations gave consistent results, which were negative for ruminants for all three dates. In the Mettawee River base-flow sample, humans were an unlikely source of major fecal contamination. Factors that may influence results and conclusions include the timing of sample collection relative to the storm event; variability of E. coli and Bacteroidales concentrations in fecal reference samples and in water; sampling and analytical errors; the potential cross reactivity of host-associated genetic markers; and different persistence and survival rates of E. coli bacteria and Bacteroidales genetic markers on land, in water, and by season. These factors interfere with the ability to directly relate Bacteroidales concentrations to E. coli concentrations in river samples. It must be recognized that while use of Bacteroidales genetic markers as a source tracking tool coupled with the interpretive approach described in this report cannot be used quantitatively to pinpoint sources, it can be used to exclude potential sources as major contributors to fecal contamination.

Timber harvest and logging plan for the South Fork of the Caspar Creek watershed

Treesearch

Anonymous

1970-01-01

The Caspar Creek Watershed Study was initiated in 1960 to study large differences between conditions of stream flow and sedimentation, fish life and fish habitat between paired watersheds, one of which will be carefully logged while the other is left undisturbed as a control. This study will not compare differences in types of logging practices.

Internet of People: Opportunities and challenges for engaging stakeholders in watershed planning via the Web

NASA Astrophysics Data System (ADS)

Babbar-Sebens, M.

2016-12-01

Social computing technologies are transforming the way our society interacts and generates content on the Web via collective intelligence. Previously unimagined possibilities have arisen for using these technologies to engage stakeholders and involve them in policy making and planning efforts. While the Internet has been used in the past to support education and communication endeavors, we have developed a novel, web-based, interactive planning tool that engages the community in using science-based methods for the design of potential conservation practices on their landscape, and thereby, reducing undesirable impacts of extreme hydroclimatic events. The tool, Watershed REstoration using Spatio-Temporal Optimization of Resources (WRESTORE), uses a democratic voting process coupled with visualization interfaces, computational simulation and optimization models, and user modeling techniques to support a human-centered design approach. This human-centered design approach, which is reinforced by use of Web 2.0 technologies, has the potential to enable policy makers to connect to a larger community of stakeholders and directly engage them in environmental stewardship efforts. Additionally, the design framework can be used by watershed groups to plug-in their own hydrologic models, climate observations and forecasts, and various other simulation models unique to their watersheds. In this presentation, we will demonstrate the effectiveness of WRESTORE for designing alternatives of conservation practices in a HUC-11 Midwestern watershed, results of various experiments with a diverse set of test users and stakeholders, and discuss potential for future developments.

Watershed-Scale Heterogeneity of the Biophysical Controls on Soil Respiration

NASA Astrophysics Data System (ADS)

Riveros, D. A.; Pacific, V. J.; McGlynn, B. L.; Welsch, D. L.; Epstein, H. E.; Muth, D. J.; Marshall, L.; Wraith, J.

2006-12-01

Large gaps exist in our understanding of the variability of soil respiration response to changing hydrologic conditions across spatial and temporal scales. Determining the linkages between the hydrologic cycle and the biophysical controls of soil respiration from the local point, to the plot, to the watershed scale is critical to understanding the dynamics of net ecosystem CO2 exchange (NEE). To study the biophysical controls of soil respiration, we measured soil CO2 concentration, soil CO2 flux, dissolved CO2 in stream water, soil moisture, soil temperature, groundwater dynamics, and precipitation at 20-minute intervals throughout the growing season at 4 sites and at weekly intervals at 62 sites covering the range of topographic position, slope, aspect, land cover, and upslope accumulated area conditions in a 555-ha subalpine watershed in central Montana. Our goal was to quantify watershed-scale heterogeneity in soil CO2 concentrations and surface efflux and gain understanding of the biophysical controls on soil respiration. We seek to improve our ability to evaluate and predict soil respiration responses to a dynamic hydrologic cycle across multiple temporal and spatial scales. We found that time lags between biophysical controls and soil respiration can occur from hourly to daily scales. The sensitivity of soil respiration to changes in environmental conditions is controlled by the antecedent soil moisture and by topographic position. At the watershed scale, significant differences in soil respiration exist between upland (dry) and lowland (wet) sites. However, differences in the magnitude and timing of soil respiration also exist within upland settings due to heterogeneity in soil temperature, soil moisture, and soil organic matter. Finally, we used a process-based model to simulate respiration at different times of the year across spatial locations. Our simulations highlight the importance of autotrophic and heterotrophic respiration (production) over diffusivity and soil physical properties (transport). Our work begins to address the disconnect between point, footprint, watershed scale estimates of ecosystem respiration and the role of a dynamic hydrologic cycle.

Hydrologic resilience of a Canadian Foothills watershed to forest harvest

NASA Astrophysics Data System (ADS)

Goodbrand, Amy; Anderson, Axel

2016-04-01

Recent investigations of long-term hydrometeorological, groundwater, and streamflow data from watersheds on the eastern slopes of the Canadian Rocky Mountains showed the streamflow regime was resilient to forest harvest. These watersheds had low levels of harvest relative to their size and a large area of sparsely vegetated alpine talus slopes and exposed bedrock; an area shown to generate the majority of runoff for streamflow. In contrast, watersheds located in the foothills of the Rocky Mountains are of lower relief and typically have harvestable timber throughout the watershed; therefore, these watersheds may be more sensitive to forest disturbance and have increased potential for streamflow response. This project assesses the hydrologic resilience of an Alberta Foothills watershed to forest harvest using a 23-year dataset from the Tri-Creeks Experimental Watershed (Tri-Creeks). Tri-Creeks has been the site of intensive streamflow, groundwater, snow accumulation, and precipitation observations from 1967 - 1990. During the early 1980s, forestry experiments were conducted to compare the effects of timber harvest and riparian buffers, and the effectiveness of timber harvesting ground rules in protecting fisheries and maintaining water resources within three sub-watersheds: Eunice (16.8 km2; control); Deerlick (15.2 km2; 36% streamside timber removal); and, Wampus (28.3 km2; 37% clear-cut). Statistical analyses were used to compare the pre-and post-harvest ratios of treatment to control sub-watershed runoff for: water year, monthly (April - October), snowmelt peak flow, and low flow (10th percentile streamflow) periods as an assessment of hydrologic resilience to forest harvest. The only significant post-harvest change was an increase in water yield during May at Wampus (Mann-Whitney (MW), p<0.05) and Deerlick (MW, p<0.1) Creeks. The lack of change in snowmelt peak flow timing or magnitude was not expected, particularly in Deerlick, which had 36% streamside timber removal. The streamflow regime of Tri-Creeks displayed remarkable resilience to forest harvest. We hypothesize on the processes and characteristics that result in this watershed to exhibit greater resilience compared to other forested watersheds.

Model analysis of check dam impacts on long-term sediment and water budgets in southeast Arizona, USA

USGS Publications Warehouse

Norman, Laura M.; Niraula, Rewati

2016-01-01

The objective of this study was to evaluate the effect of check dam infrastructure on soil and water conservation at the catchment scale using the Soil and Water Assessment Tool (SWAT). This paired watershed study includes a watershed treated with over 2000 check dams and a Control watershed which has none, in the West Turkey Creek watershed, Southeast Arizona, USA. SWAT was calibrated for streamflow using discharge documented during the summer of 2013 at the Control site. Model results depict the necessity to eliminate lateral flow from SWAT models of aridland environments, the urgency to standardize geospatial soils data, and the care for which modelers must document altering parameters when presenting findings. Performance was assessed using the percent bias (PBIAS), with values of ±2.34%. The calibrated model was then used to examine the impacts of check dams at the Treated watershed. Approximately 630 tons of sediment is estimated to be stored behind check dams in the Treated watershed over the 3-year simulation, increasing water quality for fish habitat. A minimum precipitation event of 15 mm was necessary to instigate the detachment of soil, sediments, or rock from the study area, which occurred 2% of the time. The resulting watershed model is useful as a predictive framework and decision-support tool to consider long-term impacts of restoration and potential for future restoration.

Multi-year microbial source tracking study characterizing fecal contamination in an urban watershed

USGS Publications Warehouse

Bushon, Rebecca N.; Brady, Amie M. G.; Christensen, Eric D.; Stelzer, Erin A.

2017-01-01

Microbiological and hydrological data were used to rank tributary stream contributions of bacteria to the Little Blue River in Independence, Missouri. Concentrations, loadings and yields of E. coli and microbial source tracking (MST) markers, were characterized during base flow and storm events in five subbasins within Independence, as well as sources entering and leaving the city through the river. The E. coli water quality threshold was exceeded in 29% of base-flow and 89% of storm-event samples. The total contribution of E. coli and MST markers from tributaries within Independence to the Little Blue River, regardless of streamflow, did not significantly increase the median concentrations leaving the city. Daily loads and yields of E. coli and MST markers were used to rank the subbasins according to their contribution of each constituent to the river. The ranking methodology used in this study may prove useful in prioritizing remediation in the different subbasins.

Spreadsheet WATERSHED modeling for nonpoint-source pollution management in a Wisconsin basin

USGS Publications Warehouse

Walker, J.F.; Pickard, S.A.; Sonzogni, W.C.

1989-01-01

Although several sophisticated nonpoint pollution models exist, few are available that are easy to use, cover a variety of conditions, and integrate a wide range of information to allow managers and planners to assess different control strategies. Here, a straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.A straightforward pollutant input accounting approach is presented in the form of an existing model (WATERSHED) that has been adapted to run on modern electronic spreadsheets. As an application, WATERSHED is used to assess options to improve the quality of highly eutrophic Delavan Lake in Wisconsin. WATERSHED is flexible in that several techniques, such as the Universal Soil Loss Equation or unit-area loadings, can be used to estimate nonpoint-source inputs. Once the model parameters are determined (and calibrated, if possible), the spreadsheet features can be used to conduct a sensitivity analysis of management options. In the case of Delavan Lake, it was concluded that, although some nonpoint controls were cost-effective, the overall reduction in phosphorus would be insufficient to measurably improve water quality.

Stormwater management network effectiveness and implications for urban watershed function: A critical review

USGS Publications Warehouse

Jefferson, Anne J.; Bhaskar, Aditi S.; Hopkins, Kristina G.; Fanelli, Rosemary; Avellaneda, Pedro M.; McMillan, Sara K.

2017-01-01

Deleterious effects of urban stormwater are widely recognized. In several countries, regulations have been put into place to improve the conditions of receiving water bodies, but planning and engineering of stormwater control is typically carried out at smaller scales. Quantifying cumulative effectiveness of many stormwater control measures on a watershed scale is critical to understanding how small-scale practices translate to urban river health. We review 100 empirical and modelling studies of stormwater management effectiveness at the watershed scale in diverse physiographic settings. Effects of networks with stormwater control measures (SCMs) that promote infiltration and harvest have been more intensively studied than have detention-based SCM networks. Studies of peak flows and flow volumes are common, whereas baseflow, groundwater recharge, and evapotranspiration have received comparatively little attention. Export of nutrients and suspended sediments have been the primary water quality focus in the United States, whereas metals, particularly those associated with sediments, have received greater attention in Europe and Australia. Often, quantifying cumulative effects of stormwater management is complicated by needing to separate its signal from the signal of urbanization itself, innate watershed characteristics that lead to a range of hydrologic and water quality responses, and the varying functions of multiple types of SCMs. Biases in geographic distribution of study areas, and size and impervious surface cover of watersheds studied also limit our understanding of responses. We propose hysteretic trajectories for how watershed function responds to increasing imperviousness and stormwater management. Even where impervious area is treated with SCMs, watershed function may not be restored to its predevelopment condition because of the lack of treatment of all stormwater generated from impervious surfaces; non-additive effects of individual SCMs; and persistence of urban effects beyond impervious surfaces. In most cases, pollutant load decreases largely result from run-off reductions rather than lowered solute or particulate concentrations. Understanding interactions between natural and built landscapes, including stormwater management strategies, is critical for successfully managing detrimental impacts of stormwater at the watershed scale.

Mercury cycling in peatland watersheds. Chapter 11.

Treesearch

Randall K. Kolka; Carl P.J. Mitchell; Jeffrey D. Jeremiason; Neal A. Hines; David F. Grigal; Daniel R. Engstrom; Jill K. Coleman-Wasik; Edward A. Nater; Edward B. Swain; Bruce A. Monson; Jacob A. Fleck; Brian Johnson; James E. Almendinger; Brian A. Branfireun; Patrick L. Brezonik; James B. Cotner

2011-01-01

Mercury (Hg) is of great environmental concern due to its transformation into the toxic methylmercury (MeHg) form that bioaccumulates within the food chain and causes health concerns for both humans and wildlife (U.S. Environmental Protection Agency 2002). Mercury can affect neurological development in fetuses and young children. In adults, exposure to Hg can lead to...

"Connecting with Courage," An Outward Bound Program for Adolescent Girls.

ERIC Educational Resources Information Center

Porter, Terry

Research on girls' development has found that girls see the world that coheres through human relationships rather than through systems of rules, and that 12 or 13 is a watershed age for girls, a time of "central relational crisis." As their bodies enter the physiological transformations that culminate in womanhood, they face an onslaught…

An unconventional approach to ecosystem unit classification in western North Carolina, USA

Treesearch

W. Henry McNab; Sara A. Browning; Steven A. Simon; Penelope E. Fouts

1999-01-01

The authors used an unconventional combination of data transformation and multivariate analyses to reduce subjectivity in identification of ecosystem units in a mountainous region of western North Carolina, USA. Vegetative cover and environmental variables were measured on 79 stratified, randomly located, 0.1 ha sample plots in a 4000 ha watershed. Binary...

[Production of marker-free plants expressing the gene of the hepatitis B virus surface antigen].

PubMed

Rukavtsova, E B; Gaiazova, A R; Chebotareva, E N; Bur'ianova, Ia I

2009-08-01

The pBM plasmid, carrying the gene of hepatitis B virus surface antigen (HBsAg) and free of any selection markers of antibiotic or herbicide resistance, was constructed for genetic transformation of plants. A method for screening transformed plant seedlings on nonselective media was developed. Enzyme immunoassay was used for selecting transgenic plants with HBsAg gene among the produced regenerants; this method provides for a high sensitivity detection of HBsAg in plant extracts. Tobacco and tomato transgenic lines synthesizing this antigen at a level of 0.01-0.05% of the total soluble protein were obtained. The achieved level of HBsAg synthesis is sufficient for preclinical trials of the produced plants as a new generation safe edible vaccine. The developed method for selecting transformants can be used for producing safe plants free of selection markers.

Relationship of field and LiDAR estimates of forest canopy cover with snow accumulation and melt

Treesearch

Mariana Dobre; William J. Elliot; Joan Q. Wu; Timothy E. Link; Brandon Glaza; Theresa B. Jain; Andrew T. Hudak

2012-01-01

At the Priest River Experimental Forest in northern Idaho, USA, snow water equivalent (SWE) was recorded over a period of six years on random, equally-spaced plots in ~4.5 ha small watersheds (n=10). Two watersheds were selected as controls and eight as treatments, with two watersheds randomly assigned per treatment as follows: harvest (2007) followed by mastication (...

Watershed response and recovery from the Will Fire: ten years of observations

Treesearch

Kenneth B. Roby

1989-01-01

Watershed response and recovery from a wildfire which burned 95 percent of the Williams Creek watershed in 1979 were monitored. Ground cover reduced to 11 percent by the fire increased to 80 percent by 1983. Grasses seeded for erosion control provided less than 10 percent cover until 3 years following the fire, and no significant difference in ground cover was found...

Effects of forest cover and environmental variables on snow accumulation and melt

Treesearch

Mariana Dobre; William J. Elliot; Joan Q. Wu; Timothy E. Link; Ina S. Miller

2011-01-01

The goal of this study was to assess the effects of topography and forest cover resulting from different treatments on snow accumulation and melt in small watersheds in the western United States. A paired-watershed study was implemented at the Priest River Experimental Forest, Idaho, where 10 small watersheds with an average area of 4.5 ha were treated by: 1) control (...

Honey Creek Watershed Project Tillage Demonstration Results 1981.

DTIC Science & Technology

1982-01-01

previous levels of water quality. Of these nonpoint sources, nutrient runoff from agricultural watersheds is most significant. This publication reports...return to previous levels of water quality. Of these nonpoint sources, nu- trient runoff from agricultural watersheds is most significent. How, though...was the Corps, experienced as civil engineers, to address nutrient runoff and erosion control in farm areas? Their answer to this question was to ask

DNA transformations of Candida tropicalis with replicating and integrative vectors.

PubMed

Sanglard, D; Fiechter, A

1992-12-01

The alkane-assimilating yeast Candida tropicalis was used as a host for DNA transformations. A stable ade2 mutant (Ha900) obtained by UV-mutagenesis was used as a recipient for different vectors carrying selectable markers. A first vector, pMK16, that was developed for the transformation of C. albicans and carries an ADE2 gene marker and a Candida autonomously replicating sequence (CARS) element promoting autonomous replication, was compatible for transforming Ha900. Two transformant types were observed: (i) pink transformants which easily lose pMK16 under non-selective growth conditions; (ii) white transformants, in which the same plasmid exhibited a higher mitotic stability. In both cases pMK16 could be rescued from these cells in Escherichia coli. A second vector, pADE2, containing the isolated C. tropicalis ADE2, gene, was used to transform Ha900. This vector integrated in the yeast genome at homologous sites of the ade2 locus. Different integration types were observed at one or both ade2 alleles in single or in tandem repeats.

Physio-climatic controls on vulnerability of watersheds to climate and land use change across the U. S.

NASA Astrophysics Data System (ADS)

Deshmukh, Ankit; Singh, Riddhi

2016-11-01

Understanding how a watershed's physio-climatic characteristics affect its vulnerability to environmental (climatic and land use) change is crucial for managing these complex systems. In this study, we combine the strengths of recently developed exploratory modeling frameworks and comparative hydrology to quantify the relationship between watershed's vulnerability and its physio-climatic characteristics. We propose a definition of vulnerability that can be used by a diverse range of water system managers and is useful in the presence of large uncertainties in drivers of environmental change. This definition is related to adverse climate change and land use thresholds that are quantified using a recently developed exploratory modeling approach. In this way, we estimate the vulnerability of 69 watersheds in the United States to climate and land use change. We explore definitions of vulnerability that describe average or extreme flow conditions, as well as others that are relevant from the point of view of instream organisms. In order to understand the dominant controls on vulnerability, we correlate these indices with watershed's characteristics describing its topography, geology, drainage, climate, and land use. We find that mean annual flow is more vulnerable to reductions in precipitation in watersheds with lower average soil permeability, lower baseflow index, lower forest cover, higher topographical wetness index, and vice-versa. Our results also indicate a potential mediation of climate change impacts by regional groundwater systems. By developing such relationships across a large range of watersheds, such information can potentially be used to assess the vulnerability of ungauged watersheds to uncertain environmental change.

Dissolved organic matter composition of Arctic rivers: Linking permafrost and parent material to riverine carbon

USGS Publications Warehouse

O’Donnell, Jonathan A.; Aiken, George R.; Swanson, David K.; Santosh, Panda; Butler, Kenna D.; Baltensperger, Andrew P.

2016-01-01

Recent climate change in the Arctic is driving permafrost thaw, which has important implications for regional hydrology and global carbon dynamics. Permafrost is an important control on groundwater dynamics and the amount and chemical composition of dissolved organic matter (DOM) transported by high-latitude rivers. The consequences of permafrost thaw for riverine DOM dynamics will likely vary across space and time, due in part to spatial variation in ecosystem properties in Arctic watersheds. Here we examined watershed controls on DOM composition in 69 streams and rivers draining heterogeneous landscapes across a broad region of Arctic Alaska. We characterized DOM using bulk dissolved organic carbon (DOC) concentration, optical properties, and chemical fractionation and classified watersheds based on permafrost characteristics (mapping of parent material and ground ice content, modeling of thermal state) and ecotypes. Parent material and ground ice content significantly affected the amount and composition of DOM. DOC concentrations were higher in watersheds underlain by fine-grained loess compared to watersheds underlain by coarse-grained sand or shallow bedrock. DOC concentration was also higher in rivers draining ice-rich landscapes compared to rivers draining ice-poor landscapes. Similarly, specific ultraviolet absorbance (SUVA254, an index of DOM aromaticity) values were highest in watersheds underlain by fine-grained deposits or ice-rich permafrost. We also observed differences in hydrophobic organic acids, hydrophilic compounds, and DOM fluorescence across watersheds. Both DOC concentration and SUVA254 were negatively correlated with watershed active layer thickness, as determined by high-resolution permafrost modeling. Together, these findings highlight how spatial variations in permafrost physical and thermal properties can influence riverine DOM.

DOC Dynamics in Small Headwater Streams: the Role of Hydrology, Climate, and Land Management

NASA Astrophysics Data System (ADS)

Lajtha, K.; Lee, B. S.; Jones, J. A.

2015-12-01

Dissolved organic carbon (DOC) is a critical component of the carbon (C) cycle of both terrestrial and aquatic systems. For small headwater allochthonous streams, terrestrial C delivery fuels the metabolism of receiving waters and significantly influences biotic diversity and function. While nutrient fluxes in streams have long been used as indicators of terrestrial ecosystem processes, less attention has been given to terrestrial controls on DOC export. We used the long-term stream chemistry records from the H.J. Andrews Forest LTER to examine forest management, climatic, and hydrologic controls on both seasonal and annual DOC fluxes. Within a watershed, annual DOC flux was highly related to annual discharge (Q), although considerable variability in higher discharge years suggested a role for indices of storminess, especially early in the water year. Among watersheds, younger, previously harvested watersheds generally had significantly lower DOC fluxes for a given Q than old-growth watersheds, even 4+ decades after harvest. The exception to this pattern was a harvested watershed that had significant downed wood retained on site, and had densities of coarse woody debris (CWD) close to that of the old-growth watersheds even though live tree biomass was similar to the other harvested watersheds. Other climatic factors did not appear to have significant roles in predicting either seasonal or annual fluxes of DOC. This is in sharp contrast to fluxes of nitrate at our site, which appears to be related most significantly to the presence of alder within the watershed. Taken together, our data suggest a persistent and cascading role for CWD in old-growth forest ecosystems.

Quantification of BMPs Selection and Spatial Placement Impact on Water Quality Controlling Plans in Lower Bear River Watershed, Utah

NASA Astrophysics Data System (ADS)

Salha, A. A.; Stevens, D. K.

2016-12-01

The aim of the watershed-management program in Box Elder County, Utah set by Utah Division of Water Quality (UDEQ) is to evaluate the effectiveness and spatial placement of the implemented best-management practices (BMP) for controlling nonpoint-source contamination at watershed scale. The need to evaluate the performance of BMPs would help future policy and program decisions making as desired end results. The environmental and costs benefits of BMPs in Lower Bear River watershed have seldom been measured beyond field experiments. Yet, implemented practices have rarely been evaluated at the watershed scale where the combined effects of variable soils, climatic conditions, topography and land use/covers and management conditions may significantly change anticipated results and reductions loads. Such evaluation requires distributed watershed models that are necessary for quantifying and reproducing the movement of water, sediments and nutrients. Soil and Water Assessment Tool (SWAT) model is selected as a watershed level tool to identify contaminant nonpoint sources (critical zones) and areas of high pollution risks. Water quality concerns have been documented and are primarily attributed to high phosphorus and total suspended sediment concentrations caused by agricultural and farming practices (required load is 460 kg/day of total phosphorus based on 0.075 mg/l and an average of total suspended solids of 90 mg/l). Input data such as digital elevation model (DEM), land use/Land cover (LULC), soils, and climate data for 10 years (2000-2010) is utilized along with observed water quality at the watershed outlet (USGS) and some discrete monitoring points within the watershed. Statistical and spatial analysis of scenarios of management practices (BMP's) are not implemented (before implementation), during implementation, and after BMP's have been studied to determine whether water quality of the two main water bodies has improved as required by the LBMR watershed's TMDL and if the BMPs are cost-effectively targeting the critical zones.

Mathematical morphology for automated analysis of remotely sensed objects in radar images

NASA Technical Reports Server (NTRS)

Daida, Jason M.; Vesecky, John F.

1991-01-01

A symbiosis of pyramidal segmentation and morphological transmission is described. The pyramidal segmentation portion of the symbiosis has resulted in low (2.6 percent) misclassification error rate for a one-look simulation. Other simulations indicate lower error rates (1.8 percent for a four-look image). The morphological transformation portion has resulted in meaningful partitions with a minimal loss of fractal boundary information. An unpublished version of Thicken, suitable for watersheds transformations of fractal objects, is also presented. It is demonstrated that the proposed symbiosis works with SAR (synthetic aperture radar) images: in this case, a four-look Seasat image of sea ice. It is concluded that the symbiotic forms of both segmentation and morphological transformation seem well suited for unsupervised geophysical analysis.

Hydro-Geomorphic Connectivity in Arid Watershed: Anthropogenic Effects and Extreme Flash flood

NASA Astrophysics Data System (ADS)

Egozi, Roey

2017-04-01

Arid watersheds are excellent settings to study water and sediment connectivity because of spars vegetation and the possibility to make clearer links between climate parameters and topographical changes. However different flood event magnitudes may result in different degrees of connectivity. This even gets more complicated when man made modifications to the drainage system are done without considering the outcomes in terms of the potential of flood damage and risks, i.e. in the case of extreme flash floods. Herein we report on the results from two studies conducted in two different small catchments along the dead sea rift: Wadi A Dalia and Wadi Ras Moakif. The studies conducted as part of a larger project aimed at investigating the floods and damages triggered by a rare storm event occurred at the end of October 2015. This storm event covered all of Israel and characterized with rare rainfall depths and intensities as well as floods with rare pick discharges. Observations and field measurements of bed material, river cross sections and water elevation markers were done and statistical analysis has been performed to estimate the exceed probability of the different measured and estimated hydro-climatic values. In Wadi-A-Dalia the coupling of rare rainfall depths over the watershed area which itself was bare due to over grazing result in a major flood. The severe damage caused by this flood was intensified due to the increase of structural hydrologic connectivity, i.e. flood protection canal discharged higher volumes of water collected from small Wadi systems at the same time. In Wadi Ras Moakif the rainfall cells did not produced rare rainfall, but still a major flood occurred over a very short distance of the main channel transporting huge amount of bed material deposited and blocked the main road along the dead sea western coast. In this case the cause was similar - a modification to the drainage system result in increase structural hydrologic connectivity lead to runoff concentration and higher stream power value. The results suggest that in arid watersheds flood protection measures that involve modifications to the drainage system such that the structural hydrologic connectivity improves with the aim to conduit the volume of water away may fail to provide the protection planned and may cause higher damage to infrastructures. Therefore, hydrologic connectivity should become a parameter in flood control design. Moreover, studying hydrologic connectivity in natural landscapes may provide valid solutions for flood control design projects.

Enhanced proliferation of primary rat type II pneumocytes by Jaagsiekte sheep retrovirus envelope protein

DOE Office of Scientific and Technical Information (OSTI.GOV)

Johnson, Chassidy; Jahid, Sohail; Voelker, Dennis R.

Jaagsiekte sheep retrovirus (JSRV) is the causative agent of a contagious lung cancer in sheep. The envelope protein (Env) is the oncogene, as it can transform cell lines in culture and induce tumors in animals, although the mechanisms for transformation are not yet clear because a system to perform transformation assays in differentiated type II pneumocytes does not exist. In this study we report culture of primary rat type II pneumocytes in conditions that favor prolonged expression of markers for type II pneumocytes. Env-expressing cultures formed more colonies that were larger in size and were viable for longer periods ofmore » time compared to vector control samples. The cells that remained in culture longer were confirmed to be derived from type II pneumocytes because they expressed surfactant protein C, cytokeratin, displayed alkaline phosphatase activity and were positive for Nile red. This system will be useful to study JSRV Env in the targets of transformation.« less

[Coupling SWAT and CE-QUAL-W2 models to simulate water quantity and quality in Shanmei Reservoir watershed].

PubMed

Liu, Mei-Bing; Chen, Dong-Ping; Chen, Xing-Wei; Chen, Ying

2013-12-01

A coupled watershed-reservoir modeling approach consisting of a watershed distributed model (SWAT) and a two-dimensional laterally averaged model (CE-QUAL-W2) was adopted for simulating the impact of non-point source pollution from upland watershed on water quality of Shanmei Reservoir. Using the daily serial output from Shanmei Reservoir watershed by SWAT as the input to Shanmei Reservoir by CE-QUAL-W2, the coupled modeling was calibrated for runoff and outputs of sediment and pollutant at watershed scale and for elevation, temperature, nitrate, ammonium and total nitrogen in Shanmei Reservoir. The results indicated that the simulated values agreed fairly well with the observed data, although the calculation precision of downstream model would be affected by the accumulative errors generated from the simulation of upland model. The SWAT and CE-QUAL-W2 coupled modeling could be used to assess the hydrodynamic and water quality process in complex watershed comprised of upland watershed and downstream reservoir, and might further provide scientific basis for positioning key pollution source area and controlling the reservoir eutrophication.

Assessing the Role of Land Use in Watershed Nitrate Export Using Triple Oxygen Isotopes

NASA Astrophysics Data System (ADS)

Bostic, J.; Nelson, D. M.; Eshleman, K. N.

2017-12-01

Quantifying the influence of land-use patterns on the amount and source(s) of nitrate (NO3) exported from watersheds is critical for understanding and mitigating the effects of nutrient pollution on downstream waterbodies. The isotopic composition of NO3 is valuable for fingerprinting of NO3 sources, including manure and atmospheric nitrate. To assess loads, sources, and potential transformations of NO3 in the Chesapeake Bay (CB) watershed, stream samples from fourteen sub-watersheds of the CB were collected semi-monthly and during multiple storm events from October 2015-September 2016 (Water Year 2016). The watersheds range in size (500 - 127,900 ha) and in dominant land-use (forest, urban, agriculture). The samples were analyzed for nitrate concentrations and isotopes (δ15N, as well as the triple oxygen isotope composition, defined as Δ17O ≅ δ17O - 0.52 x δ18O). Stream loads of nitrate were estimated using WRTDS (Weighted Regressions on Time, Discharge, and Season). NO3 deposition (dry and wet) was fairly uniform across all watersheds (2.1 - 3.0 kg NO3-N ha-1), whereas stream NO3 varied greatly (0.6 - 11.8 kg NO3-N ha-1). Stream loads of NO3 were positively related to the percent of agricultural land (r2 = 0.67, p < 0.005) and negatively related to the percent of forested land (r2 = 0.61, p < 0.005). Preliminary isotope data indicate a positive relationship between δ15NNO3 and the proportion of agricultural land (r2 = 0.48, p < 0.0001), which suggests that nitrate inputs in predominantly agricultural watersheds are manure or pools of partially denitrified fertilizer. A positive relationship between Δ17ONO3 and the percent of forested land (r2 = 0.19, p < 0.005) suggests that forests export a greater proportion of atmospheric nitrate than other systems. Full NO3 isotope data for Water Year 2016 ( 400 samples) will be presented from all watersheds to elucidate the amount and sources of NO3 exported from a variety of land-uses.

Controls on mercury and methylmercury deposition for two watersheds in Acadia National Park, Maine.

PubMed

Johnson, K B; Haines, T A; Kahl, J S; Norton, S A; Amirbahman, Aria; Sheehan, K D

2007-03-01

Throughfall and bulk precipitation samples were collected for two watersheds at Acadia National Park, Maine, from 3 May to 16 November 2000, to determine which landscape factors affected mercury (Hg) deposition. One of these watersheds, Cadillac Brook, burned in 1947, providing a natural experimental design to study the effects of forest type on deposition to forested watersheds. Sites that face southwest received the highest Hg deposition, which may be due to the interception of cross-continental movement of contaminated air masses. Sites covered with softwood vegetation also received higher Hg deposition than other vegetation types because of the higher scavenging efficiency of the canopy structure. Methyl mercury (MeHg) deposition was not affected by these factors. Hg deposition, as bulk precipitation and throughfall was lower in Cadillac Brook watershed (burned) than in Hadlock Brook watershed (unburned) because of vegetation type and watershed aspect. Hg and MeHg inputs were weighted by season and vegetation type because these two factors had the most influence on deposition. Hg volatilization was not determined. The total Hg deposition via throughfall and bulk precipitation was 9.4 microg/m(2)/year in Cadillac Brook watershed and 10.2 microg/m(2)/year in Hadlock Brook watershed. The total MeHg deposition via throughfall and bulk precipitation was 0.05 microg/m(2)/year in Cadillac Brook watershed and 0.10 microg/m(2)/year in Hadlock Brook watershed.

Identifying nitrate sources and transformations in surface water by combining dual isotopes of nitrate and stable isotope mixing model in a watershed with different land uses and multi-tributaries

NASA Astrophysics Data System (ADS)

Wang, Meng; Lu, Baohong

2017-04-01

Nitrate is essential for the growth and survival of plants, animals and humans. However, excess nitrate in drinking water is regarded as a health hazard as it is linked to infant methemoglobinemia and esophageal cancer. Revealing nitrate characteristics and identifying its sources are fundamental for making effective water management strategies, but nitrate sources in multi-tributaries and mixed land covered watersheds remain unclear. It is difficult to determine the predominant NO3- sources using conventional water quality monitoring techniques. In our study, based on 20 surface water sampling sites for more than two years' monitoring from April 2012 to December 2014, water chemical and dual isotopic approaches (δ15N-NO3- and δ18O-NO3-) were integrated for the first time to evaluate nitrate characteristics and sources in the Huashan watershed, Jianghuai hilly region, East China. The results demonstrated that nitrate content in surface water was relatively low in the downstream (<10 mg/L), but spatial heterogeneities were remarkable among different sub-watersheds. Extremely high nitrate was observed at the source of the river in one of the sub-watersheds, which exhibited an exponential decline along the stream due to dilution, absorption by aquatic plants, and high forest cover. Although dramatically decline of nitrate occurred along the stream, denitrification was not found in surface water by analyzing δ15N-NO3- and δ18O-NO3- relationship. Proportional contributions of five potential nitrate sources (i.e., precipitation; manure and sewage; soil nitrogen; nitrate fertilizer; nitrate derived from ammonia fertilizer and rainfall) were estimated using a Bayesian isotope mixing model. Model results indicated nitrate sources varied significantly among different rainfall conditions, land use types, as well as anthropologic activities. In summary, coupling dual isotopes of nitrate (δ15N-NO3- and δ18O-NO3-, simultaneously) with a Bayesian isotope mixing model offers a useful and practical way to qualitatively analyze nitrate sources and transformations as well as quantitatively estimate the contributions of potential nitrate sources in surface water. With the assessment of nitrate sources and characteristics, effective management strategies can be implemented to reduce N export and improve water quality in this region.

Quantifying the Spatial and Seasonal Hydrodynamics of Subsurface Soil Salinity and Selenium Mobilization in the Pariette Watershed, Uintah Basin, UT

NASA Astrophysics Data System (ADS)

Amakor, X. N.; Jacobson, A. R.; Cardon, G. E.; Grossl, P. R.

2011-12-01

A recent water quality report recognized concentrations of salts and selenium above total maximum daily loads (TMDLs) in the Pariette Wetlands located in the Uintah Basin, Utah. Since the wetlands are located in the Pacific Migratory Flyway and frequented by numerous water fowl, the elevated levels of total dissolved solids and Se are of concern. To determine whether it possible to manage the mobilization of salts and associated contaminants through the watershed soils into the Pariette Wetlands, knowledge of the spatio-temporal dynamics and distribution of these contaminants is required. Thus, the objective of this study is to characterize the spatio-temporal mobilization of salts and total selenium in the Pariette Draw watershed. Intensive soil information is being collected along the streams feeding the wetlands from fields representing the dominant land-uses in the watershed (irrigated agricultural fields, fallow salt-crusted fields, oil and natural gas extraction fields) using both the noninvasive electromagnetic induction (EMI) sensing technique (EM38DD) and the invasive time-domain reflectometry (TDR). At each site, ground truth samples were collected from optimally determined points generated using the ESAP-RSSD program based on the bulk soil electrical conductivity survey information. Stable soil properties affecting the measurement of salinity (e.g., clay content, organic matter content, cation exchange capacity, bulk density) were also characterized at these points. Parameters affected by fluctuations in soil moisture content (e.g., pH, electrical conductivity of saturation paste extract (ECe), dissolved organic carbon (DOC), and total selenium in the dissolved saturation extract) are being measured repeatedly over a minimum of 1 year. Based on regression models of collocated EMI, TDR and ECe measurements, the dense survey data are transformed into ECe. Geostatistical kriging methods are applied to the transformed ECe and volumetric water content to reveal the complex spatio-temporal patterns of salinity, water content, and total selenium (based on the association between ECe and total Se) across portions of the watershed. Temporal changes are being compared using the paired t-test. Here we present the spatio-temporal correlations among the properties and over the sampling times for the 2011 summer and fall seasons with an initial evaluation of the underlying processes contributing to the elevated contaminant loads at the wetlands. Additional measurements will be made in 2012 to capture the effects of early spring snowmelt and runoff.

Light-inducible genetic engineering and control of non-homologous end-joining in industrial eukaryotic microorganisms: LML 3.0 and OFN 1.0

PubMed Central

Zhang, Lei; Zhao, Xihua; Zhang, Guoxiu; Zhang, Jiajia; Wang, Xuedong; Zhang, Suping; Wang, Wei; Wei, Dongzhi

2016-01-01

Filamentous fungi play important roles in the production of plant cell-wall degrading enzymes. In recent years, homologous recombinant technologies have contributed significantly to improved enzymes production and system design of genetically manipulated strains. When introducing multiple gene deletions, we need a robust and convenient way to control selectable marker genes, especially when only a limited number of markers are available in filamentous fungi. Integration after transformation is predominantly nonhomologous in most fungi other than yeast. Fungal strains deficient in the non-homologous end-joining (NHEJ) pathway have limitations associated with gene function analyses despite they are excellent recipient strains for gene targets. We describe strategies and methods to address these challenges above and leverage the power of resilient NHEJ deficiency strains. We have established a foolproof light-inducible platform for one-step unmarked genetic modification in industrial eukaryotic microorganisms designated as ‘LML 3.0’, and an on-off control protocol of NHEJ pathway called ‘OFN 1.0’, using a synthetic light-switchable transactivation to control Cre recombinase-based excision and inversion. The methods provide a one-step strategy to sequentially modify genes without introducing selectable markers and NHEJ-deficiency. The strategies can be used to manipulate many biological processes in a wide range of eukaryotic cells. PMID:26857594

Modelling of the estimated contributions of different sub-watersheds and sources to phosphorous export and loading from the Dongting Lake watershed, China.

PubMed

Hou, Ying; Chen, Weiping; Liao, Yuehua; Luo, Yueping

2017-11-03

Considerable growth in the economy and population of the Dongting Lake watershed in Southern China has increased phosphorus loading to the lake and resulted in a growing risk of lake eutrophication. This study aimed to reveal the spatial pattern and sources of phosphorus export and loading from the watershed. We applied an export coefficient model and the Dillon-Rigler model to quantify contributions of different sub-watersheds and sources to the total phosphorus (TP) export and loading in 2010. Together, the upper and lower reaches of the Xiang River watershed and the Dongting Lake Area contributed 60.9% of the TP exported from the entire watershed. Livestock husbandry appeared to be the largest anthropogenic source of TP, contributing more than 50% of the TP exported from each secondary sub-watersheds. The actual TP loading to the lake in 2010 was 62.9% more than the permissible annual TP loading for compliance with the Class III water quality standard for lakes. Three primary sub-watersheds-the Dongting Lake Area, the Xiang River, and the Yuan River watersheds-contributed 91.2% of the total TP loading. As the largest contributor among all sources, livestock husbandry contributed nearly 50% of the TP loading from the Dongting Lake Area and more than 60% from each of the other primary sub-watersheds. This study provides a methodology to identify the key sources and locations of TP export and loading in large lake watersheds. The study can provide a reference for the decision-making for controlling P pollution in the Dongting Lake watershed.

Morphogenetic and chemical stability of long-term maintained Agrobacterium-mediated transgenic Catharanthus roseus plants.

PubMed

Verma, Priyanka; Sharma, Abhishek; Khan, Shamshad Ahmad; Mathur, Ajay Kumar; Shanker, Karuna

2015-01-01

Transgenic Catharanthus roseus plants (transgenic Dhawal [DT] and transgenic Nirmal [NT]) obtained from the Agrobacterium tumefaciens and Agrobacterium rhizognenes-mediated transformations, respectively, have been maintained in vitro for 5 years. Plants were studied at regular intervals for various parameters such as plant height, leaf size, multiplication rate, alkaloid profile and presence of marker genes. DT plant gradually lost the GUS gene expression and it was not detected in the fifth year while NT plant demonstrated the presence of genes rolA, rolB and rolC even in the fifth year, indicating the more stable nature of Ri transgene. Vindoline content in the DT was two times more than in non-transformed control plants. Alkaloid and tryptophan profiles were almost constant during the 5 years. The cluster analysis revealed that the DT plant is more close to the control Nirmal plant followed by NT plant.

Sediment Management at the Watershed Level

DTIC Science & Technology

2012-08-01

al. 2005). Trimble examined ten river basins (1,000 to 7,500 mi2 ) and found that the sediment yield averaged about six percent. He attributed the...importance of storage and remobilization in controlling sediment yield from the 139 mi2 Coon Creek watershed in Wisconsin. Trimble prepared sediment...Federal government in 1984, DHP activities targeted sixteen watersheds comprising 2,625 mi2 within the Yazoo River Basin in the Lower Mississippi

Evaluation of five microbial and four mitochondrial DNA markers for tracking human and pig fecal pollution in freshwater

PubMed Central

He, Xiwei; Liu, Peng; Zheng, Guolu; Chen, Huimei; Shi, Wei; Cui, Yibin; Ren, Hongqiang; Zhang, Xu-Xiang

2016-01-01

This study systematically evaluated five microbial and four mitochondrial DNA (mtDNA) markers, including sensitivities and specificities under PCR method, and fecal concentrations and decay rates in water under qPCR method. The microbial DNA markers were the three human-associated (BacH, HF183 and B.adolescentis) and two pig-associated (Pig-2-Bac and L.amylovorus), while the mtDNA ones were two human- (H-ND6 and H-ND5) and two pig-associated (P-CytB and P-ND5). All the mtDNA markers showed higher sensitivity (100%) than the microbial ones (84.0–88.8%) except Pig-2-Bac (100%). Specificities of the human mtDNA markers (99.1 and 98.1%) were higher than those of the human-associated microbial ones (57.0–88.8%). But this pattern was not observed in the pig-associated markers where Pig-2-Bac had 100% specificity. The reliability of H-ND6 and H-ND5 was further evidenced to identify locations of the most polluted within the Taihu Lake watershed of China. In general, the microbial DNA markers demonstrated a higher fecal concentration than the mtDNA ones; increasing temperature and sunlight exposure accelerated significantly the decay of all the DNA markers. Results of this study suggest that DNA markers H-ND6, H-ND5, and Pig-2-Bac may be among the best for fecal source tracking in water. PMID:27734941

Evaluation of five microbial and four mitochondrial DNA markers for tracking human and pig fecal pollution in freshwater

NASA Astrophysics Data System (ADS)

He, Xiwei; Liu, Peng; Zheng, Guolu; Chen, Huimei; Shi, Wei; Cui, Yibin; Ren, Hongqiang; Zhang, Xu-Xiang

2016-10-01

This study systematically evaluated five microbial and four mitochondrial DNA (mtDNA) markers, including sensitivities and specificities under PCR method, and fecal concentrations and decay rates in water under qPCR method. The microbial DNA markers were the three human-associated (BacH, HF183 and B.adolescentis) and two pig-associated (Pig-2-Bac and L.amylovorus), while the mtDNA ones were two human- (H-ND6 and H-ND5) and two pig-associated (P-CytB and P-ND5). All the mtDNA markers showed higher sensitivity (100%) than the microbial ones (84.0-88.8%) except Pig-2-Bac (100%). Specificities of the human mtDNA markers (99.1 and 98.1%) were higher than those of the human-associated microbial ones (57.0-88.8%). But this pattern was not observed in the pig-associated markers where Pig-2-Bac had 100% specificity. The reliability of H-ND6 and H-ND5 was further evidenced to identify locations of the most polluted within the Taihu Lake watershed of China. In general, the microbial DNA markers demonstrated a higher fecal concentration than the mtDNA ones; increasing temperature and sunlight exposure accelerated significantly the decay of all the DNA markers. Results of this study suggest that DNA markers H-ND6, H-ND5, and Pig-2-Bac may be among the best for fecal source tracking in water.

Use of an alpha-galactosidase gene as a food-grade selection marker for Streptococcus thermophilus.

PubMed

Labrie, S; Bart, C; Vadeboncoeur, C; Moineau, S

2005-07-01

The alpha-galactosidase gene (aga) of Lactococcus raffinolactis ATCC 43920 was previously shown to be an efficient food-grade selection marker in Lactococcus lactis and Pediococcus acidilactici but not in Streptococcus thermophilus. In this study, we demonstrated that the alpha-galactosidase of L. raffinolactis is thermolabile and inoperative at 42 degrees C, the optimal growth temperature of S. thermophilus. An in vitro assay indicated that the activity of this alpha-galactosidase at 42 degrees C was only 3% of that at 30 degrees C, whereas the enzyme retained 23% of its activity at 37 degrees C. Transformation of Strep. thermophilus RD733 with the shuttle-vector pNZ123 bearing the aga gene of L. raffinolactis (pRAF301) generated transformants that were stable and able to grow on melibiose and raffinose at 37 degrees C or below. The transformed cells possessed 6-fold more alpha-galactosidase activity after growth on melibiose than cells grown on lactose. Slot-blot analyses of aga mRNA indicated that repression by lactose occurred at the transcriptional level. The presence of pRAF301 did not interfere with the lactic acid production when the transformed cells of Strep. thermophilus were grown at the optimal temperature in milk. Using the recombinant plasmid pRAF301, which carries a chloramphenicol resistance gene in addition to aga, we showed that both markers were equally efficient at differentiating transformed from nontransformed cells. The aga gene of L. raffinolactis can be used as a highly efficient selection marker in Strep. thermophilus.

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuse sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

MANAGING MICROBIAL CONTAMINATION IN URBAN WATERSHEDS

EPA Science Inventory

This paper presents different approaches for controlling pathogen contamination in urban watersheds for contamination resulting from point and diffuses sources. Point sources of pathogens can be treated by a disinfection technology of known effectiveness, and a desired reduction ...

Watershed Characteristics and Land Management in the Nonpoint-Source Evaluation Monitoring Watersheds in Wisconsin

USGS Publications Warehouse

Rappold, K.F.; Wierl, J.A.; Amerson, F.U.

1997-01-01

In 1992, the Wisconsin Department of Natural Resources, in cooperation with the U.S. Geological Survey, began a land-use inventory to identify sources of contaminants and track the land-management changes for eight evaluation monitoring watersheds in Wisconsin. An important component of the land-use inventory has been developing descriptions and preliminary assessments for the eight watersheds. These descriptions establish a baseline for future data analysis. The watershed descriptions include sections on location, reference watersheds, climate, land use, soils and topography, and surface-water resources. The land-management descriptions include sections on objectives, sources of nonpoint contamination and goals of contaminant reduction, and implementation of best-management practices. This information was compiled primarily from the nonpoint-source control plans, county soil surveys, farm conservation plans, Federal and State agency data reports, and data collected through the land-use inventory.

A longitudinal study of atrazine and 2,4-D exposure and oxidative stress markers among Iowa corn farmers

PubMed Central

Lerro, Catherine C.; Beane Freeman, Laura E.; Portengen, Lützen; Kang, Daehee; Lee, Kyoungho; Blair, Aaron; Lynch, Charles F.; Bakke, Berit; De Roos, Anneclaire J.; Vermeulen, Roel C.H.

2018-01-01

Reactive oxygen species, potentially formed through environmental exposures, can overwhelm an organism’s antioxidant capabilities resulting in oxidative stress. Long-term oxidative stress is linked with chronic diseases. Pesticide exposures have been shown to cause oxidative stress in vivo. We utilized a longitudinal study of corn farmers and non-farming controls in Iowa to examine the impact of exposure to the widely used herbicides atrazine and 2,4-dichlorophenoxyacetic acid (2,4-D) on markers of oxidative stress. 225 urine samples were collected during five agricultural time periods (pre-planting, planting, growing, harvest, off-season) for 30 farmers who applied pesticides occupationally and 10 controls who did not; all were non-smoking men ages 40–60. Atrazine mercapturate (atrazine metabolite), 2,4-D, and oxidative stress markers (malondialdehyde [MDA], 8-hydroxy-2′-deoxyguanosine [8-OHdG], and 8-isoprostaglandin-F2α [8-isoPGF]) were measured in urine. We calculated β estimates and 95% confidence intervals (95%CI) for each pesticide-oxidative stress marker combination using multivariate linear mixed-effect models for repeated measures. Farmers had higher urinary atrazine mercapturate and 2,4-D levels compared to controls. In regression models, after natural log transformation, 2,4-D was associated with elevated levels of 8-OHdG (β=0.066, 95%CI=0.008–0.124) and 8-isoPGF (β=0.088, 95%CI=0.004–0.172). 2,4-D may be associated with oxidative stress because of modest increases in 8-OHdG, a marker of oxidative DNA damage, and 8-isoPGF, a product of lipoprotein peroxidation, with recent 2,4-D exposure. Future studies should investigate the role of 2,4-D-induced oxidative stress in the pathogenesis of human diseases. PMID:28116766

Establishment of rat pancreatic endocrine cell lines by infection with simian virus 40.

PubMed Central

Niesor, E J; Wollheim, C B; Mintz, D H; Blondel, B; Renold, A E; Weil, R

1979-01-01

The feasibility of infection and transformation by SV40 (simian virus 40) of primary cell cultures derived from newborn-rat pancreas was investigated. As judged by the presence of intranuclear SV40 T-antigen, exposure to the virus resulted specifically in infection and transformation of epithelioid (predominantly endocrine) cells. The transformed cells were subcultured (more than 64 passages) and cloned. Culture medium and acid/ethanol extracts of the cells did not contain detectable amounts of immunoreactive insulin after the third subculture. However, inoculation of such SV40-transformed pancreatic cells into immunodeficient rats results in tumours in which insulin production was partially restored through the passage in vivo, since the tumour cells contained and synthesized small amounts of immunoreactive insulin which co-migrated with an insulin marker on gel chromatography. Interestingly, the transformed cells maintained under tissue-culture conditions produced a protein immunologically related to insulin, soluble in aqueous buffer but insoluble in acid/ethanol. This 3000-dalton protein is too large to be a translation product of the rat preproinsulin 9S mRNA. SV40-transformed pancreatic cells might prove useful in the investigation of the factors controlling and maintaining insulin biosynthesis. Images Fig. 1. PMID:222255

Detection of Oil Palm Root Penetration by Agrobacterium-Mediated Transformed Ganoderma boninense, Expressing Green Fluorescent Protein.

PubMed

Govender, Nisha; Wong, Mui-Yun

2017-04-01

A highly efficient and reproducible Agrobacterium-mediated transformation protocol for Ganoderma boninense was developed to facilitate observation of the early stage infection of basal stem rot (BSR). The method was proven amenable to different explants (basidiospore, protoplast, and mycelium) of G. boninense. The transformation efficiency was highest (62%) under a treatment combination of protoplast explant and Agrobacterium strain LBA4404, with successful expression of an hyg marker gene and gus-gfp fusion gene under the control of heterologous p416 glyceraldehyde 3-phosphate dehydrogenase promoter. Optimal transformation conditions included a 1:100 Agrobacterium/explant ratio, induction of Agrobacterium virulence genes in the presence of 250 μm acetosyringone, co-cultivation at 22°C for 2 days on nitrocellulose membrane overlaid on an induction medium, and regeneration of transformants on potato glucose agar prepared with 0.6 M sucrose and 20 mM phosphate buffer. Evaluated transformants were able to infect root tissues of oil palm plantlets with needle-like microhyphae during the penetration event. The availability of this model pathogen system for BSR may lead to a better understanding of the pathogenicity factors associated with G. boninense penetration into oil palm roots.

Increased variability of watershed areas in patients with high-grade carotid stenosis.

PubMed

Kaczmarz, Stephan; Griese, Vanessa; Preibisch, Christine; Kallmayer, Michael; Helle, Michael; Wustrow, Isabel; Petersen, Esben Thade; Eckstein, Hans-Henning; Zimmer, Claus; Sorg, Christian; Göttler, Jens

2018-03-01

Watershed areas (WSAs) of the brain are most susceptible to acute hypoperfusion due to their peripheral location between vascular territories. Additionally, chronic WSA-related vascular processes underlie cognitive decline especially in patients with cerebral hemodynamic compromise. Despite of high relevance for both clinical diagnostics and research, individual in vivo WSA definition is fairly limited to date. Thus, this study proposes a standardized segmentation approach to delineate individual WSAs by use of time-to-peak (TTP) maps and investigates spatial variability of individual WSAs. We defined individual watershed masks based on relative TTP increases in 30 healthy elderly persons and 28 patients with unilateral, high-grade carotid stenosis, being at risk for watershed-related hemodynamic impairment. Determined WSA location was confirmed by an arterial transit time atlas and individual super-selective arterial spin labeling. We compared spatial variability of WSA probability maps between groups and assessed TTP differences between hemispheres in individual and group-average watershed locations. Patients showed significantly higher spatial variability of WSAs than healthy controls. Perfusion on the side of the stenosis was delayed within individual watershed masks as compared to a watershed template derived from controls, being independent from the grade of the stenosis and collateralization status of the circle of Willis. Results demonstrate feasibility of individual WSA delineation by TTP maps in healthy elderly and carotid stenosis patients. Data indicate necessity of individual segmentation approaches especially in patients with hemodynamic compromise to detect critical regions of impaired hemodynamics.

Urban base flow with low impact development

USGS Publications Warehouse

Bhaskar, Aditi; Hogan, Dianna M.; Archfield, Stacey A.

2016-01-01

A novel form of urbanization, low impact development (LID), aims to engineer systems that replicate natural hydrologic functioning, in part by infiltrating stormwater close to the impervious surfaces that generate it. We sought to statistically evaluate changes in a base flow regime because of urbanization with LID, specifically changes in base flow magnitude, seasonality, and rate of change. We used a case study watershed in Clarksburg, Maryland, in which streamflow was monitored during whole-watershed urbanization from forest and agricultural to suburban residential development using LID. The 1.11-km2 watershed contains 73 infiltration-focused stormwater facilities, including bioretention facilities, dry wells, and dry swales. We examined annual and monthly flow during and after urbanization (2004–2014) and compared alterations to nearby forested and urban control watersheds. We show that total streamflow and base flow increased in the LID watershed during urbanization as compared with control watersheds. The LID watershed had more gradual storm recessions after urbanization and attenuated seasonality in base flow. These flow regime changes may be because of a reduction in evapotranspiration because of the overall decrease in vegetative cover with urbanization and the increase in point sources of recharge. Precipitation that may once have infiltrated soil, been stored in soil moisture to be eventually transpired in a forested landscape, may now be recharged and become base flow. The transfer of evapotranspiration to base flow is an unintended consequence to the water balance of LID.

GIS-based spatial regression and prediction of water quality in river networks: A case study in Iowa

USGS Publications Warehouse

Yang, X.; Jin, W.

2010-01-01

Nonpoint source pollution is the leading cause of the U.S.'s water quality problems. One important component of nonpoint source pollution control is an understanding of what and how watershed-scale conditions influence ambient water quality. This paper investigated the use of spatial regression to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration in the Cedar River Watershed, Iowa. An Arc Hydro geodatabase was constructed to organize various datasets on the watershed. Spatial regression models were developed to evaluate the impacts of watershed characteristics on stream NO3NO2-N concentration and predict NO3NO2-N concentration at unmonitored locations. Unlike the traditional ordinary least square (OLS) method, the spatial regression method incorporates the potential spatial correlation among the observations in its coefficient estimation. Study results show that NO3NO2-N observations in the Cedar River Watershed are spatially correlated, and by ignoring the spatial correlation, the OLS method tends to over-estimate the impacts of watershed characteristics on stream NO3NO2-N concentration. In conjunction with kriging, the spatial regression method not only makes better stream NO3NO2-N concentration predictions than the OLS method, but also gives estimates of the uncertainty of the predictions, which provides useful information for optimizing the design of stream monitoring network. It is a promising tool for better managing and controlling nonpoint source pollution. ?? 2010 Elsevier Ltd.

Seasonal changes in the chemical quality and biodegradability of dissolved organic matter exported from soils to streams in coastal temperate rainforest watersheds

Treesearch

Jason B. Fellman; Eran Hood; David V. D' Amore; Richard T. Edwards; Dan White

2009-01-01

The composition and biodegradability of streamwater dissolved organic matter (DOM) varies with source material and degree of transformation. We combined PARAFAC modeling of fluorescence excitation-emission spectroscopy and biodegradable dissolved organic carbon (BDOC) incubations to investigate seasonal changes in the lability of DOM along a soil-stream continuum in...

Climate, water use, and land surface transformation in an irrigation intensive watershed - streamflow responses from 1950 through 2010

USGS Publications Warehouse

Dale, Joseph; Zou, Chris B.; Andrews, William J.; Long, James M.; Liang, Ye; Qiao, Lei

2015-01-01

Climatic variability and land surface change have a wide range of effects on streamflow and are often difficult to separate. We analyzed long-term records of climate, land use and land cover, and re-constructed the water budget based on precipitation, groundwater levels, and water use from 1950 through 2010 in the Cimarron–Skeleton watershed and a portion of the Cimarron–Eagle Chief watershed in Oklahoma, an irrigation-intensive agricultural watershed in the Southern Great Plains, USA. Our results show that intensive irrigation through alluvial aquifer withdrawal modifies climatic feedback and alters streamflow response to precipitation. Increase in consumptive water use was associated with decreases in annual streamflow, while returning croplands to non-irrigated grasslands was associated with increases in streamflow. Along with groundwater withdrawal, anthropogenic-induced factors and activities contributed nearly half to the observed variability of annual streamflow. Streamflow was more responsive to precipitation during the period of intensive irrigation between 1965 and 1984 than the period of relatively lower water use between 1985 and 2010. The Cimarron River is transitioning from a historically flashy river to one that is more stable with a lower frequency of both high and low flow pulses, a higher baseflow, and an increased median flow due in part to the return of cropland to grassland. These results demonstrated the interrelationship among climate, land use, groundwater withdrawal and streamflow regime and the potential to design agricultural production systems and adjust irrigation to mitigate impact of increasing climate variability on streamflow in irrigation intensive agricultural watershed.

Influence of land use on water quality in a tropical landscape: a multi-scale analysis

PubMed Central

Yackulic, Charles B.; Lim, Yili; Arce-Nazario, Javier A.

2015-01-01

There is a pressing need to understand the consequences of human activities, such as land transformations, on watershed ecosystem services. This is a challenging task because different indicators of water quality and yield are expected to vary in their responsiveness to large versus local-scale heterogeneity in land use and land cover (LUC). Here we rely on water quality data collected between 1977 and 2000 from dozens of gauge stations in Puerto Rico together with precipitation data and land cover maps to (1) quantify impacts of spatial heterogeneity in LUC on several water quality indicators; (2) determine the spatial scale at which this heterogeneity influences water quality; and (3) examine how antecedent precipitation modulates these impacts. Our models explained 30–58% of observed variance in water quality metrics. Temporal variation in antecedent precipitation and changes in LUC between measurements periods rather than spatial variation in LUC accounted for the majority of variation in water quality. Urbanization and pasture development generally degraded water quality while agriculture and secondary forest re-growth had mixed impacts. The spatial scale over which LUC influenced water quality differed across indicators. Turbidity and dissolved oxygen (DO) responded to LUC in large-scale watersheds, in-stream nitrogen concentrations to LUC in riparian buffers of large watersheds, and fecal matter content and in-stream phosphorus concentration to LUC at the sub-watershed scale. Stream discharge modulated impacts of LUC on water quality for most of the metrics. Our findings highlight the importance of considering multiple spatial scales for understanding the impacts of human activities on watershed ecosystem services. PMID:26146455

State factor relationships of dissolved organic carbon and nitrogen losses from unpolluted temperate forest watersheds

USGS Publications Warehouse

Perakis, S.S.; Hedin, L.O.

2007-01-01

We sampled 100 unpolluted, old-growth forested watersheds, divided among 13 separate study areas over 5 years in temperate southern Chile and Argentina, to evaluate relationships among dominant soil-forming state factors and dissolved carbon and nitrogen concentrations in watershed streams. These watersheds provide a unique opportunity to examine broad-scale controls over carbon (C) and nitrogen (N) biogeochemistry in the absence of significant human disturbance from chronic N deposition and land use change. Variations in the ratio dissolved organic carbon (DOC) to nitrogen (DON) in watershed streams differed by underlying soil parent material, with average C:N = 29 for watersheds underlain by volcanic ash and basalt versus C:N = 73 for sedimentary and metamorphic parent materials, consistent with stronger adsorption of low C:N hydrophobic materials by amorphous clays commonly associated with volcanic ash and basalt weathering. Mean annual precipitation was related positively to variations in both DOC (range: 0.2-9.7 mg C/L) and DON (range: 0.008-0.135 mg N/L) across study areas, suggesting that variations in water volume and concentration may act synergistically to influence C and N losses across dry to wet gradients in these forest ecosystems. Dominance of vegetation by broadleaf versus coniferous trees had negligible effects on organic C and N concentrations in comparison to abiotic factors. We conclude that precipitation volume and soil parent material are important controls over chemical losses of dissolved organic C and N from unpolluted temperate forest watersheds. Our results raise the possibility that biotic imprints on watershed C and N losses may be less pronounced in naturally N-poor forests than in areas impacted by land use change and chronic N deposition. Copyright 2007 by the American Geophysical Union.

Climate Change Impacts on Sediment Transport In a Lowland Watershed System: Controlling Processes and Projection

NASA Astrophysics Data System (ADS)

al Aamery, N. M. H.; Mahoney, D. T.; Fox, J.

2017-12-01

Future climate change projections suggest extreme impacts on watershed hydrologic systems for some regions of the world including pronounced increases in surface runoff and instream flows. Yet, there remains a lack of research focused on how future changes in hydrologic extremes, as well as relative hydrologic mean changes, impact sediment redistribution within a watershed and sediment flux from a watershed. The authors hypothesized that variations in mean and extreme changes in turn may impact sediments in depositional and erosional dominance in a manner that may not be obvious to the watershed manager. Therefore, the objectives of this study were to investigate the inner processes connecting the combined effect of extreme climate change projections on the vegetation, upland erosion, and instream processes to produce changes in sediment redistribution within watersheds. To do so, research methods were carried out by the authors including simulating sediment processes in forecast and hindcast periods for a lowland watershed system. Publically available climate realizations from several climate factors and the Soil Water Assessment Tool (SWAT) were used to predict hydrologic conditions for the South Elkhorn Watershed in central Kentucky, USA to 2050. The results of the simulated extreme and mean hydrological components were used in simulating upland erosion with the connectivity processes consideration and thereafter used in building and simulating the instream erosion and deposition of sediment processes with the consideration of surface fine grain lamina (SFGL) layer controlling the benthic ecosystem. Results are used to suggest the dominance of erosional and depositional redistribution of sediments under different scenarios associated with extreme and mean hydrologic forecasting. The results are discussed in reference to the benthic ecology of the stream system providing insight on how water managers might consider sediment redistribution in a changing climate.

The Impact of Drainage Network Structure on Flooding in a Small Urban Watershed in Metropolitan Baltimore, MD

NASA Astrophysics Data System (ADS)

Meierdiercks, K. L.; Smith, J. A.; Miller, A. J.

2006-12-01

The impact of urban development on watershed-scale hydrology is examined in a small urban watershed in the Metropolitan Baltimore area. Analyses focus on Dead Run, a 14.3 km2 tributary of the Gwynns Falls, which is the principal study watershed of the Baltimore Ecosystem Study. Field observations of rainfall and discharge have been collected for storms occurring in the 2003, 2004, and 2005 warm seasons including the flood of record for the USGS Dead Run at Franklintown gage (7 July 2004), in which 5 inches of rain fell in less than 4 hours. Dead Run has stream gages at 6 locations with drainage areas ranging from 1.2 to 14.3 km2. Hydrologic response to storm events varies greatly in each of the subwatersheds due to the diverse development types located there. These subwatersheds range in land use from medium-density residential, with and without stormwater management control, to commercial/light industrial with large impervious lots and an extensive network of stormwater management ponds. The unique response of each subwatershed is captured using field observations in conjunction with the EPA Stormwater Management Model (SWMM), which routes storm runoff over the land surface and through the drainage network of a watershed. Of particular importance to flood response is the structure of the drainage network (both surface channels and storm drain network) and its connectivity to preferential flow paths within the watershed. The Dead Run drainage network has been delineated using geospatial data derived from aerial photography and engineering planning drawings. Model analyses are used to examine the characteristics of flow paths that control flood response in urban watersheds. These analyses aim to identify patterns in urban flow pathways and use those patterns to predict response in other urban watersheds.

UNCERTAINTIES IN NITROGEN MASS LOADINGS IN COASTAL WATERSHEDS

EPA Science Inventory

With the increasing reduction of nutrients for coastal eutrophication control, the importance of well defined nitrogen mass balance becomes paramount. imited number of attempts have been made to quantify inputs and outputs within major coastal ecosystems including its watersheds....

Is Soil Development Controlling Ecohydrologic Response to Climate Change in the Southern Cascade and Sierra Nevada Watersheds, CA, USA?

NASA Astrophysics Data System (ADS)

Devine, S.; O'Geen, A. T.; Dahlke, H. E.

2016-12-01

Understanding climate change impacts on hydrology is especially relevant to areas already dealing with water scarcity, common in Mediterranean regions such as California (CA). For instance, warming is expected to drive up evapotranspiration (ET) fluxes from vegetation, which could impact runoff (Q) and water supply by up to 30% from CA's Sierra Nevadas by 2100. In this study, we hypothesize that the 1-2 oC increase during the 20th and early 21st centuries should have resulted in a trend of decreasing Q for a given amount of precipitation (P) due to increasing ET through time. We also hypothesize that any observed differences in watershed ET response to warming could be explained by soil controls, since Mediterranean biomes require soil moisture storage to endure dry summers. We analyzed unimpaired runoff from 10 major CA watersheds relative to P over a 110 year record and found trends of increasing P minus Q in the northern watersheds, supporting the hypothesis of mountain Q vulnerability to warming but not in the central and southern watersheds. This may be partly due to the faster rates of summertime warming we observed in the northern watersheds when potential ET is highest. Analysis of several soil investigations in the study area on bioclimosequences suggests that these inter-watershed differences in P minus Q may also be due to soils. Soils formed from volcanic rocks, which are more prevalent in the northern watersheds, tend to have higher clay contents and water holding capacity. Moreover, the higher elevation central and southern watersheds were more widely glaciated throughout the Pleistocene, resulting in a wider extent of scoured landscapes and soils shallow to hard bedrock. Thus, the northern watershed ET flux could have previously been temperature constrained with untapped soil moisture storage. Going forward, an analysis is planned to quantify the extent of various soil-vegetation-climate zones. For each zone, we will build simple water balance models to estimate watershed ET response sensitivity. This should help resolve whether or not soil development is regulating hydrologic response to climate change. However, from an ecological resilience point of view, the southern watersheds may be the most sensitive. Lack of hydrologic response suggests that an upward biome shift may be ongoing or imminent there.

Effects of thinning on hydrology and water quality of a drained pine forest in coastal North Carolina

Treesearch

D.M. Amatya; R.W. Skaggs

2008-01-01

A study was conducted to examine the effects of commercial thinning on hydrology and water quality of a 28-year old (in 2002) drained loblolly pine (Pinus taeda L.) plantation watershed (D3) using another adjacent watershed (D1) as a control. A paired watershed approach was used with data from two periods (1988-90 and 2000-02) for calibration and data from 2002-07 as...

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed.

PubMed

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-03-03

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world.

Identifying and Classifying Pollution Hotspots to Guide Watershed Management in a Large Multiuse Watershed

PubMed Central

Su, Fangli; Kaplan, David; Li, Lifeng; Li, Haifu; Song, Fei; Liu, Haisheng

2017-01-01

In many locations around the globe, large reservoir sustainability is threatened by land use change and direct pollution loading from the upstream watershed. However, the size and complexity of upstream basins makes the planning and implementation of watershed-scale pollution management a challenge. In this study, we established an evaluation system based on 17 factors, representing the potential point and non-point source pollutants and the environmental carrying capacity which are likely to affect the water quality in the Dahuofang Reservoir and watershed in northeastern China. We used entropy methods to rank 118 subwatersheds by their potential pollution threat and clustered subwatersheds according to the potential pollution type. Combining ranking and clustering analyses allowed us to suggest specific areas for prioritized watershed management (in particular, two subwatersheds with the greatest pollution potential) and to recommend the conservation of current practices in other less vulnerable locations (91 small watersheds with low pollution potential). Finally, we identified the factors most likely to influence the water quality of each of the 118 subwatersheds and suggested adaptive control measures for each location. These results provide a scientific basis for improving the watershed management and sustainability of the Dahuofang reservoir and a framework for identifying threats and prioritizing the management of watersheds of large reservoirs around the world. PMID:28273834

Effect of subsurface drainage on runoff and sediment yield from an agricultural watershed in western Oregon, U.S.A.

NASA Astrophysics Data System (ADS)

Istok, J. D.; Kling, G. F.

1983-09-01

Rainfall, watershed runoff and suspended-sediment concentrations for three small watersheds (0.46, 1.4 and 6.0 ha in size) were measured continuously for four winter rainfall seasons. The watersheds were fall-planted to winter wheat and were located on the hilly western margins of the Willamette Valley, Oregon. Following two rainfall seasons of data collection, a subsurface drainage system (consisting of a patterned arrangement of 10-cm plastic tubing at a depth of 1.0 m and a spacing of 12 m) was installed on the 1.4-ha watershed (watershed 2). Perched water tables were lowered and seepage was reduced on watershed 2 following the installation of the drainage system. The reductions were quantified with a water-table index (cumulative integrated excess). Watershed runoff and sediment yield from watershed 2 were decreased by ˜65 and ˜55%, respectively. These reductions were estimated from double mass curves and by statistical regression on a set of hydrograph variables. Maximum flow and average flow rates were decreased and the time from the beginning of a storm to the peak flow (lag time) increased. It is concluded that subsurface drainage can be an effective management practice for erosion control in western Oregon.

The USA Nr Inventory: Dominant Sources and Primary Transport Pathways

NASA Astrophysics Data System (ADS)

Sabo, R. D.; Clark, C.; Sobota, D. J.; Compton, J.; Cooter, E. J.; Schwede, D. B.; Bash, J. O.; Rea, A.; Dobrowolski, J. P.

2016-12-01

Efforts to mitigate the deleterious effects of excess reactive nitrogen (Nr) on human health and ecosystem goods and service while ensuring food, biofuel, and fiber availability, is one of the most pressing environmental management challenges of this century. Effective management of Nr requires up to date inventories that quantitatively characterize the sources, transport, and transformation of Nr through the environment. The inherent complexity of the nitrogen cycle, however, through multiple exchange points across air, water, and terrestrial media, renders such inventories difficult to compile and manage. Previous Nr Inventories are for 2002 and 2007, and used data sources that have since been improved. Thus, this recent inventory will substantially advance the methodology across many sectors of the inventory (e.g. deposition and biological fixation in crops and natural systems) and create a recent snapshot that is sorely needed for policy planning and trends analysis. Here we use a simple mass balance approach to estimate the input-output budgets for all United States Geologic Survey Hydrologic Unit Code-8 watersheds. We focus on a recent year (i.e. 2012) to update the Nr Inventory, but apply the analytical approach for multiple years where possible to assess trends through time. We also compare various sector estimates using multiple methodologies. Assembling datasets that account for new Nr inputs into watersheds (e.g., atmospheric NOy deposition, food imports, biologic N fixation) and internal fluxes of recycled Nr (e.g., manure, Nr emmissions/volatilization) provide an unprecedented, data driven computation of N flux. Input-output budgets will offer insight into 1) the dominant sources of Nr in a watershed (e.g., food imports, atmospheric N deposition, or fertilizer), 2) the primary loss pathways for Nr (e.g., crop N harvest, volatilization/emissions), and 3) what watersheds are net sources versus sinks of Nr. These insights will provide needed clarity for managers looking to minimize the loss of Nr to atmospheric and aquatic compartments, while also providing a foundational database for researchers assessing the dominant controls of N retention and loss in natural and anthropogenically dominated ecosystems. Disclaimer: Views expressed are the authors' and not views or polices of the U.S.EPA.

Disrupted carbon cycling in restored and unrestored urban streams: Critical timescales and controls

USGS Publications Warehouse

Larsen, L. G.; Harvey, Judson

2017-01-01

Carbon fixation and respiration in flowing waterways play significant roles in global and regional carbon budgets, yet how land use and watershed management interact with temporal disturbances (storms) to influence metabolism remains poorly understood. Here, we combine long-term with synoptic sampling of metabolism and its variable controls in neighboring watersheds of the Chesapeake Bay to resolve limiting factors and critical timescales associated with recovery from disturbance. We found that, relative to predictions of the river continuum concept, focal streams have “disrupted” carbon cycles, with carbon balances closer to zero, and, in some cases, tighter coupling between gross primary production (GPP) and ecosystem respiration (ER), attributable to carbon limitation. Carbon became limiting to ER where flashy storm hydrographs and simplified channel geomorphology inhibited accumulation of fine sediment. Shannon entropy analysis of timescales revealed that fine sediment served as a time-release capsule for nutrients and carbon over 4–6 months, fueling biogeochemical transformations. Loss of fines through hydraulic disturbance had up to 30-d impacts on GPP and 50-d impacts on ER in the stream with carbon limitation. In contrast, where GPP and ER were not tightly coupled, recovery occurred within 1 d. Results suggest that a complex interplay between nutrient and carbon limitation and mechanical and chemical disturbance governs patterns and consequences of disrupted carbon cycling in urban streams. Carbon limitation and tight GPP/ER coupling enhance the vulnerability of stream ecosystem functions, but best management practices that target stormflow reduction and channel geomorphic diversity can break that coupling and minimize carbon cycle disruptions.

Segmentation of DTI based on tensorial morphological gradient

NASA Astrophysics Data System (ADS)

Rittner, Leticia; de Alencar Lotufo, Roberto

2009-02-01

This paper presents a segmentation technique for diffusion tensor imaging (DTI). This technique is based on a tensorial morphological gradient (TMG), defined as the maximum dissimilarity over the neighborhood. Once this gradient is computed, the tensorial segmentation problem becomes an scalar one, which can be solved by conventional techniques, such as watershed transform and thresholding. Similarity functions, namely the dot product, the tensorial dot product, the J-divergence and the Frobenius norm, were compared, in order to understand their differences regarding the measurement of tensor dissimilarities. The study showed that the dot product and the tensorial dot product turned out to be inappropriate for computation of the TMG, while the Frobenius norm and the J-divergence were both capable of measuring tensor dissimilarities, despite the distortion of Frobenius norm, since it is not an affine invariant measure. In order to validate the TMG as a solution for DTI segmentation, its computation was performed using distinct similarity measures and structuring elements. TMG results were also compared to fractional anisotropy. Finally, synthetic and real DTI were used in the method validation. Experiments showed that the TMG enables the segmentation of DTI by watershed transform or by a simple choice of a threshold. The strength of the proposed segmentation method is its simplicity and robustness, consequences of TMG computation. It enables the use, not only of well-known algorithms and tools from the mathematical morphology, but also of any other segmentation method to segment DTI, since TMG computation transforms tensorial images in scalar ones.

Transformation of follicular lymphoma - Why does it happen and can it be prevented?

PubMed

Link, Brian K

2018-03-01

Follicular lymphoma is a clinical disease with a multitude of presentations and behaviors. Although infrequent, transformation of follicular lymphoma to a more aggressive behaving subtype - prototypically diffuse large B-cell lymphoma - confers a substantially adverse prognosis. There is no consensus for optimal management after transformation is recognized. Historically considered a distinct clinical event, this review highlights the multiple subclinical transformational events that either variably or cumulatively result in clinical recognition of transformed follicular lymphoma. Known and suspected events include genetic and epigenetic perturbations, metabolomic changes, and alterations in the microenvironment. This diverse spectrum of pathways leads to heterogeneous clinical presentations and outcomes of transformed follicular lymphoma. Current options for prevention of transformation are limited to known strategies of managing follicular lymphoma before the transformation is recognized. Although most retrospectively analyzed studies suggest an association of lower transformation rates with early systemic therapy, specific components of therapy such as anti-CD20 antibodies, anthracyclines, or purine analogues are less strongly associated with "preventative' value. Thus, the goal of preventing transformation is of limited value among all factors that go into decisions on early management of follicular lymphoma. Future opportunities to prevent clinical evidence of transformation will benefit from early detection of markers of subclinical transformation and development of therapies to specifically target the biology implied by those markers. Copyright © 2017. Published by Elsevier Ltd.

Development of a Model of Nitrogen Cycling in Stormwater Control Measures and Application of the Model at the Watershed Scale

NASA Astrophysics Data System (ADS)

Bell, C.; Tague, C.; McMillan, S. K.

2016-12-01

Stormwater control measures (SCMs) create ecosystems in urban watersheds that store water and promote nitrogen (N) retention and removal. This work used computer modeling at two spatial scales (the individual SCM and watershed scale) to quantify how SCMs affect runoff and nitrogen export in urban watersheds. First, routines that simulate the dynamic hydrologic and water quality processes of an individual wet pond SCM were developed and applied to quantify N processing under different environmental and design scenarios. Results showed that deeper SCMs have greater inorganic N removal efficiencies because they have more stored volume of relatively N-deplete water, and therefore have a greater capacity to dilute relatively N-rich inflow. N removal by the SCM was more sensitive to this design parameter than it was to variations in air temperature, inflow N concentrations, and inflow volume. Next, these SCM model routines were used to simulate processes of a suburban watershed in Charlotte, NC with 16 SCMs. The watershed configuration was varied to simulate runoff under different scenarios of impervious surface connectivity to SCMs with the goal of developing a simple predictive relationship between watershed condition and N loads. We used unmitigated imperviousness (UI), percent of the impervious area that is unmitigated by SCMs, to quantify watershed condition. Results showed that as SCM mitigation decreased, or as UI increased from 3% to 15%, runoff ratios and loads of nitrite and total dissolved N increased by 26% (21-32%), 14% (3-26%) and 13% (2-25%), respectively. The shape of the relationship between these response variables and UI was linear, which indicates that mitigation of any impervious surfaces will result in proportional reductions. However, the range of UI included in this study is on the low end of urban watersheds and future work will assess the behavior of this relationship at higher TI and UI levels.

Hydrologic effects of large southwestern USA wildfires significantly increase regional water supply: fact or fiction?

NASA Astrophysics Data System (ADS)

Wine, M. L.; Cadol, D.

2016-08-01

In recent years climate change and historic fire suppression have increased the frequency of large wildfires in the southwestern USA, motivating study of the hydrological consequences of these wildfires at point and watershed scales, typically over short periods of time. These studies have revealed that reduced soil infiltration capacity and reduced transpiration due to tree canopy combustion increase streamflow at the watershed scale. However, the degree to which these local increases in runoff propagate to larger scales—relevant to urban and agricultural water supply—remains largely unknown, particularly in semi-arid mountainous watersheds co-dominated by winter snowmelt and the North American monsoon. To address this question, we selected three New Mexico watersheds—the Jemez (1223 km2), Mogollon (191 km2), and Gila (4807 km2)—that together have been affected by over 100 wildfires since 1982. We then applied climate-driven linear models to test for effects of fire on streamflow metrics after controlling for climatic variability. Here we show that, after controlling for climatic and snowpack variability, significantly more streamflow discharged from the Gila watershed for three to five years following wildfires, consistent with increased regional water yield due to enhanced infiltration-excess overland flow and groundwater recharge at the large watershed scale. In contrast, we observed no such increase in discharge from the Jemez watershed following wildfires. Fire regimes represent a key difference between the contrasting responses of the Jemez and Gila watersheds with the latter experiencing more frequent wildfires, many caused by lightning strikes. While hydrologic dynamics at the scale of large watersheds were previously thought to be climatically dominated, these results suggest that if one fifth or more of a large watershed has been burned in the previous three to five years, significant increases in water yield can be expected.

Differential DNA methylation profile of key genes in malignant prostate epithelial cells transformed by inorganic arsenic or cadmium.

PubMed

Pelch, Katherine E; Tokar, Erik J; Merrick, B Alex; Waalkes, Michael P

2015-08-01

Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10μM Cd for 11weeks (CTPE) or 5μM iAs for 29weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1) were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (>25-fold) and S100P (>40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (>15-fold) and NTM (>1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. Published by Elsevier Inc.

Chemomics-based marker compounds mining and mimetic processing for exploring chemical mechanisms in traditional processing of herbal medicines, a continuous study on Rehmanniae Radix.

PubMed

Zhou, Li; Xu, Jin-Di; Zhou, Shan-Shan; Shen, Hong; Mao, Qian; Kong, Ming; Zou, Ye-Ting; Xu, Ya-Yun; Xu, Jun; Li, Song-Lin

2017-12-29

Exploring processing chemistry, in particular the chemical transformation mechanisms involved, is a key step to elucidate the scientific basis in traditional processing of herbal medicines. Previously, taking Rehmanniae Radix (RR) as a case study, the holistic chemome (secondary metabolome and glycome) difference between raw and processed RR was revealed by integrating hyphenated chromatographic techniques-based targeted glycomics and untargeted metabolomics. Nevertheless, the complex chemical transformation mechanisms underpinning the holistic chemome variation in RR processing remain to be extensively clarified. As a continuous study, here a novel strategy by combining chemomics-based marker compounds mining and mimetic processing is proposed for further exploring the chemical mechanisms involved in herbal processing. First, the differential marker compounds between raw and processed herbs were rapidly discovered by untargeted chemomics-based mining approach through multivariate statistical analysis of the chemome data obtained by integrated metabolomics and glycomics analysis. Second, the marker compounds were mimetically processed under the simulated physicochemical conditions as in the herb processing, and the final reaction products were chemically characterized by targeted chemomics-based mining approach. Third, the main chemical transformation mechanisms involved were clarified by linking up the original marker compounds and their mimetic processing products. Using this strategy, a set of differential marker compounds including saccharides, glycosides and furfurals in raw and processed RR was rapidly found, and the major chemical mechanisms involved in RR processing were elucidated as stepwise transformations of saccharides (polysaccharides, oligosaccharides and monosaccharides) and glycosides (iridoid glycosides and phenethylalcohol glycosides) into furfurals (glycosylated/non-glycosylated hydroxymethylfurfurals) by deglycosylation and/or dehydration. The research deliverables indicated that the proposed strategy could advance the understanding of RR processing chemistry, and therefore may be considered a promising approach for delving into the scientific basis in traditional processing of herbal medicines. Copyright © 2017 Elsevier B.V. All rights reserved.

Urban Watershed Research Facility at Edison Environmental Center

EPA Science Inventory

The Urban Watershed Research Facility (UWRF) is an isolated, 20-acre open space within EPA’s 200 acre Edison facility established to develop and evaluate the performance of stormwater management practices under controlled conditions. The facility includes greenhouses that allow ...

Effects of Urban Stormwater Infrastructure and Spatial Scale on Nutrient Export and Runoff from Semi-Arid Urban Catchments

NASA Astrophysics Data System (ADS)

Hale, R. L.; Turnbull, L.; Earl, S.; Grimm, N. B.

2011-12-01

There has been an abundance of literature on the effects of urbanization on downstream ecosystems, particularly due to changes in nutrient inputs as well as hydrology. Less is known, however, about nutrient transport processes and processing in urban watersheds. Engineered drainage systems are likely to play a significant role in controlling the transport of water and nutrients downstream, and variability in these systems within and between cities may lead to differences in the effects of urbanization on downstream ecosystems over time and space. We established a nested stormwater sampling network with 12 watersheds ranging in scale from 5 to 17000 ha in the Indian Bend Wash watershed in Scottsdale, AZ. Small (<200ha) watersheds had uniform land cover (medium density residential), but were drained by a variety of stormwater infrastructure including surface runoff, pipes, natural or modified washes, and retention basins. At the outlet of each of these catchments we monitored rainfall and discharge, and sampled stormwater throughout runoff events for dissolved nitrogen (N), phosphorus (P), and organic carbon (oC). Urban stormwater infrastructure is characterized by a range of hydrologic connectivity. Piped watersheds are highly connected and runoff responds linearly to rainfall events, in contrast to watersheds drained with retention basins and washes, where runoff exhibits a nonlinear threshold response to rainfall events. Nutrient loads from piped watersheds scale linearly with total storm rainfall. Because of frequent flushing, nutrient concentrations from these sites are lower than from wash and retention basin drained sites and total nutrient loads exhibit supply limitation, e.g., nutrient loads are poorly predicted by storm rainfall and are strongly controlled by factors that determine the amount of nutrients stored within the watershed, such as antecedent dry days. In contrast, wash and retention basin-drained watersheds exhibit transport limitation. These watersheds flow less frequently than pipe-drained sites and therefore stormwater has higher concentrations of nutrients, although total loads are significantly lower. Nonlinearities in cross-storm rainfall-nutrient loading relationships for the wash and retention basin watersheds suggest that these systems may become supply limited during large rain events. Results show that characteristics of the hydrologic network such as hydrologic connectivity mediate terrestrial-aquatic linkages. Specifically, we see that increased hydrologic connectivity, as in the piped watershed, actually decreases the predictive power of storm size with regard to nutrient export, whereas nutrient loads from poorly connected watersheds are strongly predicted by storm size.

Agrobacterium-mediated transformation of maize (Zea mays) with Cre-lox site specific recombination cassettes in BIBAC vectors.

PubMed

Vega, Juan M; Yu, Weichang; Han, Fangpu; Kato, Akio; Peters, Eric M; Zhang, Zhanyuan J; Birchler, James A

2008-04-01

The Cre/loxP site-specific recombination system has been applied in various plant species including maize (Zea mays) for marker gene removal, gene targeting, and functional genomics. A BIBAC vector system was adapted for maize transformation with a large fragment of genetic material including a herbicide resistance marker gene, a 30 kb yeast genomic fragment as a marker for fluorescence in situ hybridization (FISH), and a 35S-lox-cre recombination cassette. Seventy-five transgenic lines were generated from Agrobacterium-mediated transformation of a maize Hi II line with multiple B chromosomes. Eighty-four inserts have been localized among all 10 A chromosome pairs by FISH using the yeast DNA probe together with a karyotyping cocktail. No inserts were found on the B chromosomes; thus a bias against the B chromosomes by the Agrobacterium-mediated transformation was revealed. The expression of a cre gene was confirmed in 68 of the 75 transgenic lines by a reporter construct for cre/lox mediated recombination. The placement of the cre/lox site-specific recombination system in many locations in the maize genome will be valuable materials for gene targeting and chromosome engineering.

Upland and in-stream controls on baseflow nutrient dynamics in tile-drained agroecosystem watersheds

NASA Astrophysics Data System (ADS)

Ford, William I.; King, Kevin; Williams, Mark R.

2018-01-01

In landscapes with low residence times (e.g., rivers and reservoirs), baseflow nutrient concentration dynamics during sensitive timeframes can contribute to deleterious environmental conditions downstream. This study assessed upland and in-stream controls on baseflow nutrient concentrations in a low-gradient, tile-drained agroecosystem watershed. We conducted time-series analysis using Empirical mode decomposition of seven decade-long nutrient concentration time-series in the agricultural Upper Big Walnut Creek watershed (Ohio, USA). Four tributaries of varying drainage areas and three main-stem sites were monitored, and nutrient grab samples were collected weekly from 2006 to 2016 and analyzed for dissolved reactive phosphorus (DRP), nitrate-nitrogen (NO3-N), total nitrogen (TN), and total phosphorus (TP). Statistically significant seasonal fluctuations were compared with seasonality of baseflow, watershed characteristics (e.g., tile-drain density), and in-stream water quality parameters (pH, DO, temperature). Findings point to statistically significant seasonality of all parameters with peak P concentrations in summer and peak N in late winter-early spring. Results suggest that upland processes exert strong control on DRP concentrations in the winter and spring months, while coupled upland and in-stream conditions control watershed baseflow DRP concentrations during summer and early fall. Conversely, upland flow sources driving streamflow exert strong control on baseflow NO3-N, and in-stream attenuation through transient and permanent pathways impacts the magnitude of removal. Regarding TN and TP, we found that TN was governed by NO3-N, while TP was governed by DRP in summer and fluvial erosion of P-rich benthic sediments during higher baseflow conditions. Findings of the study highlight the importance of coupled in-stream and upland management for mitigating eutrophic conditions during environmentally sensitive timeframes.

Federal Facility Agreement Annual Progress Report for Fiscal Year 1999 Oak Ridge, Tennessee

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bechtel Jacobs Company LLC

2000-01-01

The U.S. Department of Energy-Oak Ridge Operations (DOE-ORO) EM Program adopted a watershed approach for performing Remedial Investigations (RIs) and characterizations for ORR because it is an effective system for determining the best methods for protecting and restoring aquatic ecosystems and protecting human health. The basic concept is that water quality and ecosystem problems are best solved at the watershed level rather than at the individual water-body or discharger level. The watershed approach requires consideration of all environmental concerns, including needs to protect public health, critical habitats such as wetlands, biological integrity, and surface and ground waters. The watershed approachmore » provides an improved basis for management decisions concerning contaminant sources and containment. It allows more direct focus by stakeholders on achieving ecological goals and water quality standards rather than a measurement of program activities based on numbers of permits or samples. The watershed approach allows better management strategies for investigations, therefore maximizing the utilization of scarce resources. Feasibility studies (FSs) evaluate various alternatives in terms of environmental standards, the protection of human health and the environment, and the costs of implementation to find the optimum solution among them. Society has to decide how much it is willing to spend to meet the standards and to be protective. Conducting FSs is the process of trading off those criteria to pick that optimum point that society wants to achieve. Performing this analysis at the watershed scale allows those trade-offs to be made meaningfully. In addition, a Land Use Control Assurance Plan for the ORR was prepared to identify the strategy for assuring the long-term effectiveness of land use controls. These land use controls will be relied upon to protect human health and the environment at areas of the ORR undergoing remediation pursuant to the Comprehensive Environmental Response, Compensation, and Liability Act and/or the Resource Conservation and Recovery Act. This plan will be implemented by means of a Memorandum of Understanding (MOU) incorporating its terms with the United States EPA and TDEC. The majority of projects described in this report are grouped into five watersheds. They are the East Tennessee Technical Park (ETTP) Watershed (formerly the K-25 Site), the Melton Valley (MV) and Bethel Valley (BV) Watersheds at the Oak Ridge National Laboratory (ORNL), and the Bear Creek Valley (BCV) and Upper East Fork Poplar Creek (UEFPC) Watersheds at the Y-12 Plant.« less

A science-based, watershed strategy to support effective remediation of abandoned mine lands

USGS Publications Warehouse

Buxton, Herbert T.; Nimick, David A.; Von Guerard, Paul; Church, Stan E.; Frazier, Ann G.; Gray, John R.; Lipin, Bruce R.; Marsh, Sherman P.; Woodward, Daniel F.; Kimball, Briant A.; Finger, Susan E.; Ischinger, Lee S.; Fordham, John C.; Power, Martha S.; Bunch, Christine M.; Jones, John W.

1997-01-01

A U.S. Geological Survey Abandoned Mine Lands Initiative will develop a strategy for gathering and communicating the scientific information needed to formulate effective and cost-efficient remediation of abandoned mine lands. A watershed approach will identify, characterize, and remediate contaminated sites that have the most profound effect on water and ecosystem quality within a watershed. The Initiative will be conducted during 1997 through 2001 in two pilot watersheds, the Upper Animas River watershed in Colorado and the Boulder River watershed in Montana. Initiative efforts are being coordinated with the U.S. Forest Service, Bureau of Land Management, National Park Service, and other stakeholders which are using the resulting scientific information to design and implement remediation activities. The Initiative has the following eight objective-oriented components: estimate background (pre-mining) conditions; define baseline (current) conditions; identify target sites (major contaminant sources); characterize target sites and processes affecting contaminant dispersal; characterize ecosystem health and controlling processes at target sites; develop remediation goals and monitoring network; provide an integrated, quality-assured and accessible data network; and document lessons learned for future applications of the watershed approach.

Estimating soil erosion risk and evaluating erosion control measures for soil conservation planning at Koga watershed in the highlands of Ethiopia

NASA Astrophysics Data System (ADS)

Molla, Tegegne; Sisheber, Biniam

2017-01-01

Soil erosion is one of the major factors affecting sustainability of agricultural production in Ethiopia. The objective of this paper is to estimate soil erosion using the universal soil loss equation (RUSLE) model and to evaluate soil conservation practices in a data-scarce watershed region. For this purpose, soil data, rainfall, erosion control practices, satellite images and topographic maps were collected to determine the RUSLE factors. In addition, measurements of randomly selected soil and water conservation structures were done at three sub-watersheds (Asanat, Debreyakob and Rim). This study was conducted in Koga watershed at upper part of the Blue Nile basin which is affected by high soil erosion rates. The area is characterized by undulating topography caused by intensive agricultural practices with poor soil conservation practices. The soil loss rates were determined and conservation strategies have been evaluated under different slope classes and land uses. The results showed that the watershed is affected by high soil erosion rates (on average 42 t ha-1 yr-1), greater than the maximum tolerable soil loss (18 t ha-1 yr-1). The highest soil loss (456 t ha-1 yr-1) estimated from the upper watershed occurred on cultivated lands of steep slopes. As a result, soil erosion is mainly aggravated by land-use conflicts and topographic factors and the rugged topographic land forms of the area. The study also demonstrated that the contribution of existing soil conservation structures to erosion control is very small due to incorrect design and poor management. About 35 % out of the existing structures can reduce soil loss significantly since they were constructed correctly. Most of the existing structures were demolished due to the sediment overload, vulnerability to livestock damage and intense rainfall. Therefore, appropriate and standardized soil and water conservation measures for different erosion-prone land uses and land forms need to be implemented in Koga watershed.

Composition of water and suspended sediment in streams of urbanized subtropical watersheds in Hawaii

USGS Publications Warehouse

De Carlo, E. H.; Beltran, V.L.; Tomlinson, M.S.

2004-01-01

Urbanization on the small subtropical island of Oahu, Hawaii provides an opportunity to examine how anthropogenic activity affects the composition of material transferred from land to ocean by streams. This paper investigates the variability in concentrations of trace elements (Pb, Zn, Cu, Ba, Co, As, Ni, V and Cr) in streams of watersheds on Oahu, Hawaii. The focus is on water and suspended particulate matter collected from the Ala Wai Canal watershed in Honolulu and also the Kaneohe Stream watershed. As predicted, suspended particulate matter controls most trace element transport. Elements such as Pb, Zn, Cu, Ba and Co exhibit increased concentrations within urbanized portions of the watersheds. Particulate concentrations of these elements vary temporally during storms owing to input of road runoff containing elevated concentrations of elements associated with vehicular traffic and other anthropogenic activities. Enrichments of As in samples from predominantly conservation areas are interpreted as reflecting agricultural use of fertilizers at the boundaries of urban and conservation lands. Particulate Ni, V and Cr exhibit distributions during storm events that suggest a mineralogical control. Principal component analysis of particulate trace element concentrations establishes eigenvalues that account for nearly 80% of the total variance and separates trace elements into 3 factors. Factor 1 includes Pb, Zn, Cu, Ba and Co, interpreted to represent metals with an urban anthropogenic enrichment. Factor 2 includes Ni, V and Cr, elements whose concentrations do not appear to derive from anthropogenic activity and is interpreted to reflect mineralogical control. Another, albeit less significant, anthropogenic factor includes As, Cd and U and is thought to represent agricultural inputs. Samples collected during a storm derived from an offshore low-pressure system suggest that downstream transport of upper watershed material during tradewind-derived rains results in a 2-3-fold dilution of the particulate concentrations of Pb, Zn and Cu in the Ala Wai canal watershed. ?? 2004 Elsevier Ltd. All rights reserved.

The Role of Frozen Soil in Groundwater Discharge Predictions for Warming Alpine Watersheds

NASA Astrophysics Data System (ADS)

Evans, Sarah G.; Ge, Shemin; Voss, Clifford I.; Molotch, Noah P.

2018-03-01

Climate warming may alter the quantity and timing of groundwater discharge to streams in high alpine watersheds due to changes in the timing of the duration of seasonal freezing in the subsurface and snowmelt recharge. It is imperative to understand the effects of seasonal freezing and recharge on groundwater discharge to streams in warming alpine watersheds as streamflow originating from these watersheds is a critical water resource for downstream users. This study evaluates how climate warming may alter groundwater discharge due to changes in seasonally frozen ground and snowmelt using a 2-D coupled flow and heat transport model with freeze and thaw capabilities for variably saturated media. The model is applied to a representative snowmelt-dominated watershed in the Rocky Mountains of central Colorado, USA, with snowmelt time series reconstructed from a 12 year data set of hydrometeorological records and satellite-derived snow covered area. Model analyses indicate that the duration of seasonal freezing in the subsurface controls groundwater discharge to streams, while snowmelt timing controls groundwater discharge to hillslope faces. Climate warming causes changes to subsurface ice content and duration, rerouting groundwater flow paths but not altering the total magnitude of future groundwater discharge outside of the bounds of hydrologic parameter uncertainties. These findings suggest that frozen soil routines play an important role for predicting the future location of groundwater discharge in watersheds underlain by seasonally frozen ground.

Use of USLE/GIS methodology for predicting soil loss in a semiarid agricultural watershed.

PubMed

Erdogan, Emrah H; Erpul, Günay; Bayramin, Ilhami

2007-08-01

The Universal Soil Loss Equation (USLE) is an erosion model to estimate average soil loss that would generally result from splash, sheet, and rill erosion from agricultural plots. Recently, use of USLE has been extended as a useful tool predicting soil losses and planning control practices in agricultural watersheds by the effective integration of the GIS-based procedures to estimate the factor values in a grid cell basis. This study was performed in the Kazan Watershed located in the central Anatolia, Turkey, to predict soil erosion risk by the USLE/GIS methodology for planning conservation measures in the site. Rain erosivity (R), soil erodibility (K), and cover management factor (C) values of the model were calculated from erosivity map, soil map, and land use map of Turkey, respectively. R values were site-specifically corrected using DEM and climatic data. The topographical and hydrological effects on the soil loss were characterized by LS factor evaluated by the flow accumulation tool using DEM and watershed delineation techniques. From resulting soil loss map of the watershed, the magnitude of the soil erosion was estimated in terms of the different soil units and land uses and the most erosion-prone areas where irreversible soil losses occurred were reasonably located in the Kazan watershed. This could be very useful for deciding restoration practices to control the soil erosion of the sites to be severely influenced.

The role of frozen soil in groundwater discharge predictions for warming alpine watersheds

USGS Publications Warehouse

Evans, Sarah G.; Ge, Shemin; Voss, Clifford I.; Molotch, Noah P.

2018-01-01

Climate warming may alter the quantity and timing of groundwater discharge to streams in high alpine watersheds due to changes in the timing of the duration of seasonal freezing in the subsurface and snowmelt recharge. It is imperative to understand the effects of seasonal freezing and recharge on groundwater discharge to streams in warming alpine watersheds as streamflow originating from these watersheds is a critical water resource for downstream users. This study evaluates how climate warming may alter groundwater discharge due to changes in seasonally frozen ground and snowmelt using a 2‐D coupled flow and heat transport model with freeze and thaw capabilities for variably saturated media. The model is applied to a representative snowmelt‐dominated watershed in the Rocky Mountains of central Colorado, USA, with snowmelt time series reconstructed from a 12 year data set of hydrometeorological records and satellite‐derived snow covered area. Model analyses indicate that the duration of seasonal freezing in the subsurface controls groundwater discharge to streams, while snowmelt timing controls groundwater discharge to hillslope faces. Climate warming causes changes to subsurface ice content and duration, rerouting groundwater flow paths but not altering the total magnitude of future groundwater discharge outside of the bounds of hydrologic parameter uncertainties. These findings suggest that frozen soil routines play an important role for predicting the future location of groundwater discharge in watersheds underlain by seasonally frozen ground.

Approach and case-study of green infrastructure screening analysis for urban stormwater control.

PubMed

Eaton, Timothy T

2018-03-01

Urban stormwater control is an urgent concern in megacities where increased impervious surface has disrupted natural hydrology. Water managers are increasingly turning to more environmentally friendly ways of capturing stormwater, called Green Infrastructure (GI), to mitigate combined sewer overflow (CSO) that degrades local water quality. A rapid screening approach is described to evaluate how GI strategies can reduce the amount of stormwater runoff in a low-density residential watershed in New York City. Among multiple possible tools, the L-THIA LID online software package, using the SCS-CN method, was selected to estimate relative runoff reductions expected with different strategies in areas of different land uses in the watershed. Results are sensitive to the relative areas of different land uses, and show that bioretention and raingardens provide the maximum reduction (∼12%) in this largely residential watershed. Although commercial, industrial and high-density residential areas in the watershed are minor, larger runoff reductions from disconnection strategies and porous pavement in parking lots are also possible. Total stormwater reductions from various combinations of these strategies can reach 35-55% for individual land uses, and between 23% and 42% for the entire watershed. Copyright © 2017. Published by Elsevier Ltd.

Myoglobin as marker in meat adulteration: a UPLC method for determining the presence of pork meat in raw beef burger.

PubMed

Giaretta, Nicola; Di Giuseppe, Antonella M A; Lippert, Martina; Parente, Augusto; Di Maro, Antimo

2013-12-01

The identification of meat animal species used in raw burgers is very important with respect to economic and religious considerations. Therefore, international supervisory bodies have implemented procedures to control the employed meat species. In this paper we propose myoglobin as a powerful molecular marker to evaluate the presence of non-declared meat addition in raw beef burgers by using ultra-performance liquid chromatography (UPLC) for the separation and identification of edible animal species (beef, chicken, horse, ostrich, pig and water buffalo). Meat samples were pre-treated with sodium nitrite to transform oxymyoglobin and deoxymyoglobin to the more stable metmyoglobin. The developed method was validated, preparing mixtures with different percentages of pork and beef minced meat. The obtained results show that using myoglobin as marker, 5% (25 mg/500 mg) of pork or beef meat can be detected in premixed minced meat samples. Copyright © 2013 Elsevier Ltd. All rights reserved.

Watershed Management Tool for Selection and Spacial Allocation of Non-Point Source Pollution Control Practices

EPA Science Inventory

Distributed-parameter watershed models are often utilized for evaluating the effectiveness of sediment and nutrient abatement strategies through the traditional {calibrate→ validate→ predict} approach. The applicability of the method is limited due to modeling approximations. In ...

Quantification of pathogens and markers of fecal contamination during storm events along popular surfing beaches in San Diego, California.

PubMed

Steele, Joshua A; Blackwood, A Denene; Griffith, John F; Noble, Rachel T; Schiff, Kenneth C

2018-06-01

Along southern California beaches, the concentrations of fecal indicator bacteria (FIB) used to quantify the potential presence of fecal contamination in coastal recreational waters have been previously documented to be higher during wet weather conditions (typically winter or spring) than those observed during summer dry weather conditions. FIB are used for management of recreational waters because measurement of the bacterial and viral pathogens that are the potential causes of illness in beachgoers exposed to stormwater can be expensive, time-consuming, and technically difficult. Here, we use droplet digital Polymerase Chain Reaction (digital PCR) and digital reverse transcriptase PCR (digital RT-PCR) assays for direct quantification of pathogenic viruses, pathogenic bacteria, and source-specific markers of fecal contamination in the stormwater discharges. We applied these assays across multiple storm events from two different watersheds that discharge to popular surfing beaches in San Diego, CA. Stormwater discharges had higher FIB concentrations as compared to proximal beaches, often by ten-fold or more during wet weather. Multiple lines of evidence indicated that the stormwater discharges contained human fecal contamination, despite the presence of separate storm sewer and sanitary sewer systems in both watersheds. Human fecal source markers (up to 100% of samples, 20-12440 HF183 copies per 100 ml) and human norovirus (up to 96% of samples, 25-495 NoV copies per 100 ml) were routinely detected in stormwater discharge samples. Potential bacterial pathogens were also detected and quantified: Campylobacter spp. (up to 100% of samples, 16-504 gene copies per 100 ml) and Salmonella (up to 25% of samples, 6-86 gene copies per 100 ml). Other viral human pathogens were also measured, but occurred at generally lower concentrations: adenovirus (detected in up to 22% of samples, 14-41 AdV copies per 100 ml); no enterovirus was detected in any stormwater discharge sample. Higher concentrations of avian source markers were noted in the stormwater discharge located immediately downstream of a large bird sanctuary along with increased Campylobacter concentrations and notably different Campylobacter species composition than the watershed that had no bird sanctuary. This study is one of the few to directly measure an array of important bacterial and viral pathogens in stormwater discharges to recreational beaches, and provides context for stormwater-based management of beaches during high risk wet-weather periods. Furthermore, the combination of culture-based and digital PCR-derived data is demonstrated to be valuable for assessing hydrographic relationships, considering delivery mechanisms, and providing foundational exposure information for risk assessment. Copyright © 2018 Elsevier Ltd. All rights reserved.

Implementation of a watershed algorithm on FPGAs

NASA Astrophysics Data System (ADS)

Zahirazami, Shahram; Akil, Mohamed

1998-10-01

In this article we present an implementation of a watershed algorithm on a multi-FPGA architecture. This implementation is based on an hierarchical FIFO. A separate FIFO for each gray level. The gray scale value of a pixel is taken for the altitude of the point. In this way we look at the image as a relief. We proceed by a flooding step. It's like as we immerse the relief in a lake. The water begins to come up and when the water of two different catchment basins reach each other, we will construct a separator or a `Watershed'. This approach is data dependent, hence the process time is different for different images. The H-FIFO is used to guarantee the nature of immersion, it means that we need two types of priority. All the points of an altitude `n' are processed before any point of altitude `n + 1'. And inside an altitude water propagates with a constant velocity in all directions from the source. This operator needs two images as input. An original image or it's gradient and the marker image. A classic way to construct the marker image is to build an image of minimal regions. Each minimal region has it's unique label. This label is the color of the water and will be used to see whether two different water touch each other. The algorithm at first fill the hierarchy FIFO with neighbors of all the regions who are not colored. Next it fetches the first pixel from the first non-empty FIFO and treats this pixel. This pixel will take the color of its neighbor, and all the neighbors who are not already in the H-FIFO are put in their correspondent FIFO. The process is over when the H-FIFO is empty. The result is a segmented and labeled image.

Epstein-Barr virus recombinants from overlapping cosmid fragments.

PubMed

Tomkinson, B; Robertson, E; Yalamanchili, R; Longnecker, R; Kieff, E

1993-12-01

Five overlapping type 1 Epstein-Barr virus (EBV) DNA fragments constituting a complete replication- and transformation-competent genome were cloned into cosmids and transfected together into P3HR-1 cells, along with a plasmid encoding the Z immediate-early activator of EBV replication. P3HR-1 cells harbor a type 2 EBV which is unable to transform primary B lymphocytes because of a deletion of DNA encoding EBNA LP and EBNA 2, but the P3HR-1 EBV can provide replication functions in trans and can recombine with the transfected cosmids. EBV recombinants which have the type 1 EBNA LP and 2 genes from the transfected EcoRI-A cosmid DNA were selectively and clonally recovered by exploiting the unique ability of the recombinants to transform primary B lymphocytes into lymphoblastoid cell lines. PCR and immunoblot analyses for seven distinguishing markers of the type 1 transfected DNAs identified cell lines infected with EBV recombinants which had incorporated EBV DNA fragments beyond the transformation marker-rescuing EcoRI-A fragment. Approximately 10% of the transforming virus recombinants had markers mapping at 7, 46 to 52, 93 to 100, 108 to 110, 122, and 152 kbp from the 172-kbp transfected genome. These recombinants probably result from recombination among the transfected cosmid-cloned EBV DNA fragments. The one recombinant virus examined in detail by Southern blot analysis has all the polymorphisms characteristic of the transfected type 1 cosmid DNA and none characteristic of the type 2 P3HR-1 EBV DNA. This recombinant was wild type in primary B-lymphocyte infection, growth transformation, and lytic replication. Overall, the type 1 EBNA 3A gene was incorporated into 26% of the transformation marker-rescued recombinants, a frequency which was considerably higher than that observed in previous experiments with two-cosmid EBV DNA cotransfections into P3HR-1 cells (B. Tomkinson and E. Kieff, J. Virol. 66:780-789, 1992). Of the recombinants which had incorporated the marker-rescuing cosmid DNA fragment and the fragment encoding the type 1 EBNA 3A gene, most had incorporated markers from at least two other transfected cosmid DNA fragments, indicating a propensity for multiple homologous recombinations. The frequency of incorporation of the nonselected transfected type 1 EBNA 3C gene, which is near the end of two of the transfected cosmids, was 26% overall, versus 3% in previous experiments using transfections with two EBV DNA cosmids. In contrast, the frequency of incorporation of a 12-kb EBV DNA deletion which was near the end of two of the transfected cosmids was only 13%.(ABSTRACT TRUNCATED AT 400 WORDS)

The role of headwater streams in downstream water quality

USGS Publications Warehouse

Alexander, R.B.; Boyer, E.W.; Smith, R.A.; Schwarz, G.E.; Moore, R.B.

2007-01-01

Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and 40% in fourth- and higher-order rivers that include navigable waters and their tributaries. These results underscore the profound influence that headwater areas have on shaping downstream water quantity and water quality. The results have relevance to water-resource management and regulatory decisions and potentially broaden understanding of the spatial extent of Federal CWA jurisdiction in U.S. waters. ?? 2007 American Water Resources Association.

The Role of Headwater Streams in Downstream Water Quality1

PubMed Central

Alexander, Richard B; Boyer, Elizabeth W; Smith, Richard A; Schwarz, Gregory E; Moore, Richard B

2007-01-01

Knowledge of headwater influences on the water-quality and flow conditions of downstream waters is essential to water-resource management at all governmental levels; this includes recent court decisions on the jurisdiction of the Federal Clean Water Act (CWA) over upland areas that contribute to larger downstream water bodies. We review current watershed research and use a water-quality model to investigate headwater influences on downstream receiving waters. Our evaluations demonstrate the intrinsic connections of headwaters to landscape processes and downstream waters through their influence on the supply, transport, and fate of water and solutes in watersheds. Hydrological processes in headwater catchments control the recharge of subsurface water stores, flow paths, and residence times of water throughout landscapes. The dynamic coupling of hydrological and biogeochemical processes in upland streams further controls the chemical form, timing, and longitudinal distances of solute transport to downstream waters. We apply the spatially explicit, mass-balance watershed model SPARROW to consider transport and transformations of water and nutrients throughout stream networks in the northeastern United States. We simulate fluxes of nitrogen, a primary nutrient that is a water-quality concern for acidification of streams and lakes and eutrophication of coastal waters, and refine the model structure to include literature observations of nitrogen removal in streams and lakes. We quantify nitrogen transport from headwaters to downstream navigable waters, where headwaters are defined within the model as first-order, perennial streams that include flow and nitrogen contributions from smaller, intermittent and ephemeral streams. We find that first-order headwaters contribute approximately 70% of the mean-annual water volume and 65% of the nitrogen flux in second-order streams. Their contributions to mean water volume and nitrogen flux decline only marginally to about 55% and 40% in fourth- and higher-order rivers that include navigable waters and their tributaries. These results underscore the profound influence that headwater areas have on shaping downstream water quantity and water quality. The results have relevance to water-resource management and regulatory decisions and potentially broaden understanding of the spatial extent of Federal CWA jurisdiction in U.S. waters. PMID:22457565

Water quality functions of riparian forest buffers in Chesapeake bay watersheds

USGS Publications Warehouse

Lowrance, R.; Altier, L.S.; Newbold, J.D.; Schnabel, R.R.; Groffman, P.M.; Denver, J.M.; Correll, D.L.; Gilliam, J.W.; Robinson, J.L.; Brinsfield, R.B.; Staver, K.W.; Lucas, W.; Todd, A.H.

1997-01-01

Maryland, Virginia, and Pennsylvania, USA, have agreed to reduce nutrient loadings to Chesapeake Bay by 40% by the year 2000. This requires control of nonpoint sources of nutrients much of which comes from agriculture. Riparian forest buffer systems (RFBS) provide effective control of nonpoint source (NPS) pollution in some types of agricultural watersheds. Control of NPS pollution is dependent on the type of pollutant and the hydrologic connection between pollution sources, the RFBS, and the stream. Water quality improvements are most likely in areas of where most of the excess precipitation moves across, in, or near the root zone of the RFBS. In areas such as the Inner Coastal Plain and Piedmont watersheds with thin soils RFBS should retain 50%-90% of the total loading of nitrate in shallow groundwater sediment in surface runoff and total N in born surface runoff and groundwater. Retention of phosphorus is generally much less. In regions with deeper soils and/or greater regional groundwater recharge (such as parts of the Piedmont and the Valley and Ridge), RFBS water quality improvements are probably much less. The expected levels of pollutant control by RFBS are identified for each of nine physiographic provinces of the Chesapeake Bay Watershed. Issues related to of establishment sustainability, and management are also discussed.

Impacts of fertilization on water quality of a drained pine plantation: a worst case scenario.

PubMed

Beltran, Bray J; Amatya, Devendra M; Youssef, Mohamed; Jones, Martin; Callahan, Timothy J; Skaggs, R Wayne; Nettles, Jami E

2010-01-01

Intensive plantation forestry will be increasingly important in the next 50 yr to meet the high demand for domestic wood in the United States. However, forest management practices can substantially influence downstream water quality and ecology. This study analyses, the effect of fertilization on effluent water quality of a low gradient drained coastal pine plantation in Carteret County, North Carolina using a paired watershed approach. The plantation consists of three watersheds, two mature (31-yr) and one young (8-yr) (age at treatment). One of the mature watersheds was commercially thinned in 2002. The mature unthinned watershed was designated as the control. The young and mature-thinned watersheds were fertilized at different rates with Arborite (Encee Chemical Sales, Inc., Bridgeton, NC), and boron. The outflow rates and nutrient concentrations in water drained from each of the watersheds were measured. Nutrient concentrations and loadings were analyzed using general linear models (GLM). Three large storm events occurred within 47 d of fertilization, which provided a worst case scenario for nutrient export from these watersheds to the receiving surface waters. Results showed that average nutrient concentrations soon after fertilization were significantly (alpha = 0.05) higher on both treatment watersheds than during any other period during the study. This increase in nutrient export was short lived and nutrient concentrations and loadings were back to prefertilization levels as soon as 3 mo after fertilization. Additionally, the mature-thinned watershed presented higher average nutrient concentrations and loadings when compared to the young watershed, which received a reduced fertilizer rate than the mature-thinned watershed.

Tracking Nonpoint Source Nitrogen and Carbon in Watersheds of Chesapeake Bay

NASA Astrophysics Data System (ADS)

Kaushal, S.; Pennino, M. J.; Duan, S.; Blomquist, J.

2012-12-01

Humans have altered nitrogen and carbon cycles in rivers regionally with important impacts on coastal ecosystems. Nonpoint source nitrogen pollution is a leading contributor to coastal eutrophication and hypoxia. Shifts in sources of carbon impact downstream ecosystem metabolism and fate and transport of contaminants in coastal zones. We used a combination of stable isotopes and optical tracers to investigate fate and transport of nitrogen and carbon sources in tributaries of the largest estuary in the U.S., the Chesapeake Bay. We analyzed isotopic composition of water samples from major tributaries including the Potomac River, Susquehanna River, Patuxent River, and Choptank River during routine and storm event sampling over multiple years. A positive correlation between δ15N-NO3- and δ18O-NO3- in the Potomac River above Washington D.C. suggested denitrification or biological uptake in the watershed was removing agriculturally-derived N during summer months. In contrast, the Patuxent River in Maryland showed elevated δ15N-NO3- (5 - 12 per mil) with no relationship to δ18O-NO3- suggesting the importance of wastewater sources. From the perspective of carbon sources, there were distinct isotopic values of the δ13C-POM of particulate organic matter and fluorescence excitation emission matrices (EEMS) for rivers influenced by their dominant watershed land use. EEMS showed that there were increases in the humic and fulvic fractions of dissolved organic matter during spring floods, particularly in the Potomac River. Stable isotopic values of δ13C-POM also showed rapid depletion suggesting terrestrial carbon "pulses" in the Potomac River each spring. The δ15N-POM peaked to 10 - 15 per mil each spring suggested a potential manure source or result of biological processing within the watershed. Overall, there were considerable changes in sources and transformations of nitrogen and carbon that varied across rivers and that contribute to nitrogen and carbon loads. Anticipating changes in sources and transformations will be critical for effectively managing nonpoint pollution and ecosystem services such as drinking water quality and coastal habitat.

Can warmwater streams be rehabilitated using watershed-scale standard erosion control measures alone?

PubMed

Shields, F Douglas; Knight, Scott S; Cooper, Charles M

2007-07-01

Degradation of warmwater streams in agricultural landscapes is a pervasive problem, and reports of restoration effectiveness based on monitoring data are rare. Described is the outcome of rehabilitation of two deeply incised, unstable sand-and-gravel-bed streams. Channel networks of both watersheds were treated using standard erosion control measures, and aquatic habitats within 1-km-long reaches of each stream were further treated by addition of instream structures and planting woody vegetation on banks ("habitat rehabilitation"). Fish and their habitats were sampled semiannually during 1-2 years before rehabilitation, 3-4 years after rehabilitation, and 10-11 years after rehabilitation. Reaches with only erosion control measures located upstream from the habitat measure reaches and in similar streams in adjacent watersheds were sampled concurrently. Sediment concentrations declined steeply throughout both watersheds, with means > or = 40% lower during the post-rehabilitation period than before. Physical effects of habitat rehabilitation were persistent through time, with pool habitat availability much higher in rehabilitated reaches than elsewhere. Fish community structure responded with major shifts in relative species abundance: as pool habitats increased after rehabilitation, small-bodied generalists and opportunists declined as certain piscivores and larger-bodied species such as centrarchids and catostomids increased. Reaches without habitat rehabilitation were significantly shallower, and fish populations there were similar to the rehabilitated reaches prior to treatment. These findings are applicable to incised, warmwater streams draining agricultural watersheds similar to those we studied. Rehabilitation of warmwater stream ecosystems is possible with current knowledge, but a major shift in stream corridor management strategies will be needed to reverse ongoing degradation trends. Apparently, conventional channel erosion controls without instream habitat measures are ineffective tools for ecosystem restoration in incised, warmwater streams of the Southeastern U.S., even if applied at the watershed scale and accompanied by significant reductions in suspended sediment concentration.

Evaluation of Two Library-Independent Microbial Source Tracking Methods To Identify Sources of Fecal Contamination in French Estuaries▿

PubMed Central

Gourmelon, Michèle; Caprais, Marie Paule; Ségura, Raphaël; Le Mennec, Cécile; Lozach, Solen; Piriou, Jean Yves; Rincé, Alain

2007-01-01

In order to identify the origin of the fecal contamination observed in French estuaries, two library-independent microbial source tracking (MST) methods were selected: (i) Bacteroidales host-specific 16S rRNA gene markers and (ii) F-specific RNA bacteriophage genotyping. The specificity of the Bacteroidales markers was evaluated on human and animal (bovine, pig, sheep, and bird) feces. Two human-specific markers (HF183 and HF134), one ruminant-specific marker (CF193′), and one pig-specific marker (PF163) showed a high level of specificity (>90%). However, the data suggest that the proposed ruminant-specific CF128 marker would be better described as an animal marker, as it was observed in all bovine and sheep feces and 96% of pig feces. F RNA bacteriophages were detected in only 21% of individual fecal samples tested, in 60% of pig slurries, but in all sewage samples. Most detected F RNA bacteriophages were from genotypes II and III in sewage samples and from genotypes I and IV in bovine, pig, and bird feces and from pig slurries. Both MST methods were applied to 28 water samples collected from three watersheds at different times. Classification of water samples as subject to human, animal, or mixed fecal contamination was more frequent when using Bacteroidales markers (82.1% of water samples) than by bacteriophage genotyping (50%). The ability to classify a water sample increased with increasing Escherichia coli or enterococcus concentration. For the samples that could be classified by bacteriophage genotyping, 78% agreed with the classification obtained from Bacteroidales markers. PMID:17557850

Applying the Manning equation to determine the critical distance in non-point source pollution using remotely sensed data and cartographic modelling

NASA Astrophysics Data System (ADS)

de Oliveira, Lília M.; Santos, Nádia A. P.; Maillard, Philippe

2013-10-01

Non-point source pollution (NPSP) is perhaps the leading cause of water quality problems and one of the most challenging environmental issues given the difficulty of modeling and controlling it. In this article, we applied the Manning equation, a hydraulic concept, to improve models of non-point source pollution and determine its influence as a function of slope - land cover roughness for runoff to reach the stream. In our study the equation is somewhat taken out of its usual context to be applies to the flow of an entire watershed. Here a digital elevation model (DEM) from the SRTM satellite was used to compute the slope and data from the RapidEye satellite constellation was used to produce a land cover map later transformed into a roughness surface. The methodology is applied to a 1433 km2 watershed in Southeast Brazil mostly covered by forest, pasture, urban and wetlands. The model was used to create slope buffer of varying width in which the proportions of land cover and roughness coefficient were obtained. Next we correlated these data, through regression, with four water quality parameters measured in situ: nitrate, phosphorous, faecal coliform and turbidity. We compare our results with the ones obtained by fixed buffer. It was found that slope buffer outperformed fixed buffer with higher coefficients of determination up to 15%.

Cre/lox system to develop selectable marker free transgenic tobacco plants conferring resistance against sap sucking homopteran insect.

PubMed

Chakraborti, Dipankar; Sarkar, Anindya; Mondal, Hossain A; Schuermann, David; Hohn, Barbara; Sarmah, Bidyut K; Das, Sampa

2008-10-01

A binary expression vector was constructed containing the insecticidal gene Allium sativum leaf agglutinin (ASAL), and a selectable nptII marker gene cassette, flanked by lox sites. Similarly, another binary vector was developed with the chimeric cre gene construct. Transformed tobacco plants were generated with these two independent vectors. Each of the T(0) lox plants was crossed with T(0) Cre plants. PCR analyses followed by the sequencing of the target T-DNA part of the hybrid T(1) plants demonstrated the excision of the nptII gene in highly precised manner in certain percentage of the T(1) hybrid lines. The frequency of such marker gene excision was calculated to be 19.2% in the hybrids. Marker free plants were able to express ASAL efficiently and reduce the survivability of Myzus persiceae, the deadly pest of tobacco significantly, compared to the control tobacco plants. Results of PCR and Southern blot analyses of some of the T(2) plants detected the absence of cre as well as nptII genes. Thus, the crossing strategy involving Cre/lox system for the excision of marker genes appears to be very effective and easy to execute. Documentation of such marker excision phenomenon in the transgenic plants expressing the important insecticidal protein for the first time has a great significance from agricultural and biotechnological points of view.

A watershed-based adaptive knowledge system for developing ecosystem stakeholder partnerships

NASA Astrophysics Data System (ADS)

Lin, Hebin; Thornton, Jeffrey A.; Shadrin, Nickolai

2015-11-01

This study proposes a Watershed-based Adaptive Knowledge System (WAKES) to consistently coordinate multiple stakeholders in developing sustainable partnerships for ecosystem management. WAKES is extended from the institutional mechanism of Payments for Improving Ecosystem Services at the Watershed-scale (PIES-W). PIES-W is designed relating to the governance of ecosystem services fl ows focused on a lake as a resource stock connecting its infl owing and outfl owing rivers within its watershed. It explicitly realizes the values of conservation services provided by private land managers and incorporates their activities into the public organizing framework for ecosystem management. It implicitly extends the "upstream-to-downstream" organizing perspective to a broader vision of viewing the ecosystems as comprised of both "watershed landscapes" and "marine landscapes". Extended from PIES-W, WAKES specifies two corresponding feedback: Framework I and II. Framework I is a relationship matrix comprised of three input-output structures of primary governance factors intersecting three subsystems of a watershed with regard to ecosystem services and human stakeholders. Framework II is the Stakeholder-and-Information structure channeling five types of information among four stakeholder groups in order to enable the feedbacks mechanism of Framework I. WAKES identifies the rationales behind three fundamental information transformations, illustrated with the Transboundary Diagnostic Analysis and the Strategic Action Program of the Bermejo River Binational Basin. These include (1) translating scientific knowledge into public information within the Function-and-Service structure corresponding to the ecological subsystem, (2) incorporating public perceptions into political will within the Service- and- Value structure corresponding to the economic subsystem, and (3) integrating scientific knowledge, public perceptions and political will into management options within the Value-and-Stakeholder structure corresponding to the social subsystem. This study seeks to share a vision of social adaptation for a global sustainable future through developing a network to adopt contributions from and forming partnerships among all ecosystem stakeholders.

Modeling nutrient in-stream processes at the watershed scale using Nutrient Spiralling metrics

NASA Astrophysics Data System (ADS)

Marcé, R.; Armengol, J.

2009-01-01

One of the fundamental problems of using large-scale biogeochemical models is the uncertainty involved in aggregating the components of fine-scale deterministic models in watershed applications, and in extrapolating the results of field-scale measurements to larger spatial scales. Although spatial or temporal lumping may reduce the problem, information obtained during fine-scale research may not apply to lumped categories. Thus, the use of knowledge gained through fine-scale studies to predict coarse-scale phenomena is not straightforward. In this study, we used the nutrient uptake metrics defined in the Nutrient Spiralling concept to formulate the equations governing total phosphorus in-stream fate in a watershed-scale biogeochemical model. The rationale of this approach relies on the fact that the working unit for the nutrient in-stream processes of most watershed-scale models is the reach, the same unit used in field research based on the Nutrient Spiralling concept. Automatic calibration of the model using data from the study watershed confirmed that the Nutrient Spiralling formulation is a convenient simplification of the biogeochemical transformations involved in total phosphorus in-stream fate. Following calibration, the model was used as a heuristic tool in two ways. First, we compared the Nutrient Spiralling metrics obtained during calibration with results obtained during field-based research in the study watershed. The simulated and measured metrics were similar, suggesting that information collected at the reach scale during research based on the Nutrient Spiralling concept can be directly incorporated into models, without the problems associated with upscaling results from fine-scale studies. Second, we used results from our model to examine some patterns observed in several reports on Nutrient Spiralling metrics measured in impaired streams. Although these two exercises involve circular reasoning and, consequently, cannot validate any hypothesis, this is a powerful example of how models can work as heuristic tools to compare hypotheses and stimulate research in ecology.

Headwater Influences on Downstream Water Quality

PubMed Central

Oakes, Robert M.

2007-01-01

We investigated the influence of riparian and whole watershed land use as a function of stream size on surface water chemistry and assessed regional variation in these relationships. Sixty-eight watersheds in four level III U.S. EPA ecoregions in eastern Kansas were selected as study sites. Riparian land cover and watershed land use were quantified for the entire watershed, and by Strahler order. Multiple regression analyses using riparian land cover classifications as independent variables explained among-site variation in water chemistry parameters, particularly total nitrogen (41%), nitrate (61%), and total phosphorus (63%) concentrations. Whole watershed land use explained slightly less variance, but riparian and whole watershed land use were so tightly correlated that it was difficult to separate their effects. Water chemistry parameters sampled in downstream reaches were most closely correlated with riparian land cover adjacent to the smallest (first-order) streams of watersheds or land use in the entire watershed, with riparian zones immediately upstream of sampling sites offering less explanatory power as stream size increased. Interestingly, headwater effects were evident even at times when these small streams were unlikely to be flowing. Relationships were similar among ecoregions, indicating that land use characteristics were most responsible for water quality variation among watersheds. These findings suggest that nonpoint pollution control strategies should consider the influence of small upland streams and protection of downstream riparian zones alone is not sufficient to protect water quality. PMID:17999108

Watershed Scale Impacts of Stormwater Green Infrastructure ...

EPA Pesticide Factsheets

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3− and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger

An Extended Spectral-Spatial Classification Approach for Hyperspectral Data

NASA Astrophysics Data System (ADS)

Akbari, D.

2017-11-01

In this paper an extended classification approach for hyperspectral imagery based on both spectral and spatial information is proposed. The spatial information is obtained by an enhanced marker-based minimum spanning forest (MSF) algorithm. Three different methods of dimension reduction are first used to obtain the subspace of hyperspectral data: (1) unsupervised feature extraction methods including principal component analysis (PCA), independent component analysis (ICA), and minimum noise fraction (MNF); (2) supervised feature extraction including decision boundary feature extraction (DBFE), discriminate analysis feature extraction (DAFE), and nonparametric weighted feature extraction (NWFE); (3) genetic algorithm (GA). The spectral features obtained are then fed into the enhanced marker-based MSF classification algorithm. In the enhanced MSF algorithm, the markers are extracted from the classification maps obtained by both SVM and watershed segmentation algorithm. To evaluate the proposed approach, the Pavia University hyperspectral data is tested. Experimental results show that the proposed approach using GA achieves an approximately 8 % overall accuracy higher than the original MSF-based algorithm.

CONTROLS ON NUTRIENT LOSSES FROM A FORESTED BASIN IN THE OREGON COAST RANGE

EPA Science Inventory

Although conceptual models of watershed biogeochemistry emphasize the movement of materials from the land to the sea, important transfers occur in the reverse direction in coastal watersheds through salt spray deposition and returning anadromous fish. To understand the connectio...

WATERSHED MANIPULATION PROJECT: QUALITY ASSURANCE IMPLEMENTATION PLAN FOR 1986-1989

EPA Science Inventory

The Watershed Manipulation Project (WMP) was implemented by EPA to: identify and quantify the relative importance of various processes in controlling surface water acidification with particular emphasis on the role of sulfate adsorption and base cation supply in the long-term wat...

Cytogenetic and molecular markers for detecting Aegilops uniaristata chromosomes in a wheat background.

PubMed

Gong, Wenping; Li, Guangrong; Zhou, Jianping; Li, Genying; Liu, Cheng; Huang, Chengyan; Zhao, Zhendong; Yang, Zujun

2014-09-01

Aegilops uniaristata has many agronomically useful traits that can be used for wheat breeding. So far, a Triticum turgidum - Ae. uniaristata amphiploid and one set of Chinese Spring (CS) - Ae. uniaristata addition lines have been produced. To guide Ae. uniaristata chromatin transformation from these lines into cultivated wheat through chromosome engineering, reliable cytogenetic and molecular markers specific for Ae. uniaristata chromosomes need to be developed. Standard C-banding shows that C-bands mainly exist in the centromeric regions of Ae. uniaristata but rarely at the distal ends. Fluorescence in situ hybridization (FISH) using (GAA)8 as a probe showed that the hybridization signal of chromosomes 1N-7N are different, thus (GAA)8 can be used to identify all Ae. uniaristata chromosomes in wheat background simultaneously. Moreover, a total of 42 molecular markers specific for Ae. uniaristata chromosomes were developed by screening expressed sequence tag - sequence tagged site (EST-STS), expressed sequence tag - simple sequence repeat (EST-SSR), and PCR-based landmark unique gene (PLUG) primers. The markers were subsequently localized using the CS - Ae. uniaristata addition lines and different wheat cultivars as controls. The cytogenetic and molecular markers developed herein will be helpful for screening and identifying wheat - Ae. uniaristata progeny.

pKWmEB: integration of Kruskal-Wallis test with empirical Bayes under polygenic background control for multi-locus genome-wide association study.

PubMed

Ren, Wen-Long; Wen, Yang-Jun; Dunwell, Jim M; Zhang, Yuan-Ming

2018-03-01

Although nonparametric methods in genome-wide association studies (GWAS) are robust in quantitative trait nucleotide (QTN) detection, the absence of polygenic background control in single-marker association in genome-wide scans results in a high false positive rate. To overcome this issue, we proposed an integrated nonparametric method for multi-locus GWAS. First, a new model transformation was used to whiten the covariance matrix of polygenic matrix K and environmental noise. Using the transferred model, Kruskal-Wallis test along with least angle regression was then used to select all the markers that were potentially associated with the trait. Finally, all the selected markers were placed into multi-locus model, these effects were estimated by empirical Bayes, and all the nonzero effects were further identified by a likelihood ratio test for true QTN detection. This method, named pKWmEB, was validated by a series of Monte Carlo simulation studies. As a result, pKWmEB effectively controlled false positive rate, although a less stringent significance criterion was adopted. More importantly, pKWmEB retained the high power of Kruskal-Wallis test, and provided QTN effect estimates. To further validate pKWmEB, we re-analyzed four flowering time related traits in Arabidopsis thaliana, and detected some previously reported genes that were not identified by the other methods.

Physicochemical assessment criteria for high-voltage pulse capacitors

NASA Astrophysics Data System (ADS)

Darian, L. A.; Lam, L. Kh.

2016-12-01

In the paper, the applicability of decomposition products of internal insulation of high-voltage pulse capacitors is considered (aging is the reason for decomposition products of internal insulation). Decomposition products of internal insulation of high-voltage pulse capacitors can be used to evaluate their quality when in operation and in service. There have been three generations of markers of aging of insulation as in the case with power transformers. The area of applicability of markers of aging of insulation for power transformers has been studied and the area can be extended to high-voltage pulse capacitors. The research reveals that there is a correlation between the components and quantities of markers of aging of the first generation (gaseous decomposition products of insulation) dissolved in insulating liquid and the remaining life of high-voltage pulse capacitors. The application of markers of aging to evaluate the remaining service life of high-voltage pulse capacitor is a promising direction of research, because the design of high-voltage pulse capacitors keeps stability of markers of aging of insulation in high-voltage pulse capacitors. It is necessary to continue gathering statistical data concerning development of markers of aging of the first generation. One should also carry out research aimed at estimation of the remaining life of capacitors using markers of the second and the third generation.

Gene disruption in Trichoderma atroviride via Agrobacterium-mediated transformation.

PubMed

Zeilinger, Susanne

2004-02-01

A modified Agrobacterium-mediated transformation method for the efficient disruption of two genes encoding signaling compounds of the mycoparasite Trichoderma atroviride is described, using the hph gene of Escherichia coli as selection marker. The transformation vectors contained about 1 kb of 5' and 3' non-coding regions from the tmk1 (encoding a MAP kinase) or tga3 (encoding an alpha-subunit of a heterotrimeric G protein) target loci flanking a selection marker. Transformation of fungal conidia and selection on hygromycin-containing media applying an overlay-based procedure, which overcomes the lack of formation of distinct single colonies by the fungus, led to stable clones for both disruption constructs. Southern and PCR analyses proved gene disruption by single-copy homologous integration with a frequency of approximately 60% for both genes; and the loss of tmk1 and tga3 transcript formation in the disruptants was demonstrated by RT-PCR.

An efficient and high-throughput protocol for Agrobacterium-mediated transformation based on phosphomannose isomerase positive selection in Japonica rice (Oryza sativa L.).

PubMed

Duan, Yongbo; Zhai, Chenguang; Li, Hao; Li, Juan; Mei, Wenqian; Gui, Huaping; Ni, Dahu; Song, Fengshun; Li, Li; Zhang, Wanggen; Yang, Jianbo

2012-09-01

A number of Agrobacterium-mediated rice transformation systems have been developed and widely used in numerous laboratories and research institutes. However, those systems generally employ antibiotics like kanamycin and hygromycin, or herbicide as selectable agents, and are used for the small-scale experiments. To address high-throughput production of transgenic rice plants via Agrobacterium-mediated transformation, and to eliminate public concern on antibiotic markers, we developed a comprehensive efficient protocol, covering from explant preparation to the acquisition of low copy events by real-time PCR analysis before transplant to field, for high-throughput production of transgenic plants of Japonica rice varieties Wanjing97 and Nipponbare using Escherichia coli phosphomannose isomerase gene (pmi) as a selectable marker. The transformation frequencies (TF) of Wanjing97 and Nipponbare were achieved as high as 54.8 and 47.5%, respectively, in one round of selection of 7.5 or 12.5 g/L mannose appended with 5 g/L sucrose. High-throughput transformation from inoculation to transplant of low copy events was accomplished within 55-60 days. Moreover, the Taqman assay data from a large number of transformants showed 45.2% in Wanjing97 and 31.5% in Nipponbare as a low copy rate, and the transformants are fertile and follow the Mendelian segregation ratio. This protocol facilitates us to perform genome-wide functional annotation of the open reading frames and utilization of the agronomically important genes in rice under a reduced public concern on selectable markers. We describe a comprehensive protocol for large scale production of transgenic Japonica rice plants using non-antibiotic selectable agent, at simplified, cost- and labor-saving manners.

Recent patents on biosafety strategies of selectable marker genes in genetically modified crops.

PubMed

Jiang, Yiming; Hu, Xiaoning; Huang, Haiying

2014-01-01

Genetically modified crops (GMCs) have been planted world wide since 1990s, but the potential insecurity of selectable marker genes raises the questions about GMC safety. Therefore, several researches have been conducted on marker gene safety issues and recently several patents have been issued on this subject. There are two main approaches to achieve this goal: seeking the biosafety selectable marker and eliminating these insecure marker genes after transformation. Results show that these two systems are quite effective. Recent patents on the two ways are discussed in this review.

Managing Microbial Risks from Indirect Wastewater Reuse for Irrigation in Urbanizing Watersheds.

PubMed

Verbyla, Matthew E; Symonds, Erin M; Kafle, Ram C; Cairns, Maryann R; Iriarte, Mercedes; Mercado Guzmán, Alvaro; Coronado, Olver; Breitbart, Mya; Ledo, Carmen; Mihelcic, James R

2016-07-05

Limited supply of clean water in urbanizing watersheds creates challenges for safely sustaining irrigated agriculture and global food security. On-farm interventions, such as riverbank filtration (RBF), are used in developing countries to treat irrigation water from rivers with extensive fecal contamination. Using a Bayesian approach incorporating ethnographic data and pathogen measurements, quantitative microbial risk assessment (QMRA) methods were employed to assess the impact of RBF on consumer health burdens for Giardia, Cryptosporidium, rotavirus, norovirus, and adenovirus infections resulting from indirect wastewater reuse, with lettuce irrigation in Bolivia as a model system. Concentrations of the microbial source tracking markers pepper mild mottle virus and HF183 Bacteroides were respectively 2.9 and 5.5 log10 units lower in RBF-treated water than in the river water. Consumption of lettuce irrigated with river water caused an estimated median health burden that represents 37% of Bolivia's overall diarrheal disease burden, but RBF resulted in an estimated health burden that is only 1.1% of this overall diarrheal disease burden. Variability and uncertainty associated with environmental and cultural factors affecting exposure correlated more with QMRA-predicted health outcomes than factors related to disease vulnerability. Policies governing simple on-farm interventions like RBF can be intermediary solutions for communities in urbanizing watersheds that currently lack wastewater treatment.

Effects of future urban and biofuel crop expansions on the riverine export of phosphorus to the Laurentian Great Lakes

USGS Publications Warehouse

LaBeau, Meredith B.; Robertson, Dale M.; Mayer, Alex S.; Pijanowski, Bryan C.; Saad, David A.

2013-01-01

Increased phosphorus (P) loadings threaten the health of the world’s largest freshwater resource, the Laurentian Great Lakes (GL). To understand the linkages between land use and P delivery, we coupled two spatially explicit models, the landscape-scale SPARROW P fate and transport watershed model and the Land Transformation Model (LTM) land use change model, to predict future P export from nonpoint and point sources caused by changes in land use. According to LTM predictions over the period 2010–2040, the GL region of the U.S. may experience a doubling of urbanized areas and agricultural areas may increase by 10%, due to biofuel feedstock cultivation. These land use changes are predicted to increase P loadings from the U.S. side of the GL basin by 3.5–9.5%, depending on the Lake watershed and development scenario. The exception is Lake Ontario, where loading is predicted to decrease by 1.8% for one scenario, due to population losses in the drainage area. Overall, urban expansion is estimated to increase P loadings by 3.4%. Agricultural expansion associated with predicted biofuel feedstock cultivation is predicted to increase P loadings by an additional 2.4%. Watersheds that export P most efficiently and thus are the most vulnerable to increases in P sources tend to be found along southern Lake Ontario, southeastern Lake Erie, western Lake Michigan, and southwestern Lake Superior where watershed areas are concentrated along the coastline with shorter flow paths. In contrast, watersheds with high soil permeabilities, fractions of land underlain by tile drains, and long distances to the GL are less vulnerable.

Gene transfer and expression in plants.

PubMed

Lorence, Argelia; Verpoorte, Robert

2004-01-01

Until recently, agriculture and plant breeding relied solely on the accumulated experience of generations of farmers and breeders that is, on sexual transfer of genes between plant species. However, recent developments in plant molecular biology and genomics now give us access to knowledge and understanding of plant genomes and the possibility of modifying them. This chapter presents an updated overview of the two most powerful technologies for transferring genetic material (DNA) into plants: Agrobacterium-mediated transformation and microparticle bombardment (biolistics). Some of the topics that are discussed in detail are the main variables controlling the transformation efficiency that can be achieved using each one of these approaches; the advantages and limitations of each methodology; transient versus stable transformation approaches; the potential of some in planta transformation systems; alternatives to developing transgenic plants without selection markers; the availability of diverse genetic tools generated as part of the genome sequencing of different plant species; transgene expression, gene silencing, and their association with regulatory elements; and prospects and ways to possibly overcome some transgene expression difficulties, in particular the use of matrix-attachment regions (MARs).

Multiple lines of evidence to identify sewage as the cause of water quality impairment in an urbanized tropical watershed.

PubMed

Kirs, Marek; Kisand, Veljo; Wong, Mayee; Caffaro-Filho, Roberto A; Moravcik, Philip; Harwood, Valerie J; Yoneyama, Bunnie; Fujioka, Roger S

2017-06-01

Indicator bacteria, which are conventionally used to evaluate recreational water quality, can originate from various non-human enteric and extra-enteric sources, hence they may not be indicative of human health risk nor do they provide information on the sources of contamination. In this study we utilized traditional (enterococci and Escherichia coli) and alternative (Clostridium perfringens) indicator bacteria, F + -specific coliphage, molecular markers for microorganisms associated with human sewage (human-associated Bacteroides and polyomaviruses), and microbial community analysis tools (16S rRNA gene fragment amplicon sequencing), to identify and evaluate human sewage-related impact in the Manoa watershed in Honolulu, Hawaii. Elevated concentrations of enterococci (geometric mean ranging from 1604 to 2575 CFU 100 mL -1 ) and C. perfringens (45-77 CFU 100 mL -1 ) indicated impairment of the urbanized section of the stream, while indicator bacteria concentrations decreased downstream in the tidally influenced Ala Wai Canal. The threshold values triggering water quality violation notifications in Hawaii were exceeded in 33.3-75.0% of samples collected at sites in the urbanized section of Manoa Stream, but were not exceeded in any of the samples collected at an upstream site located in a forested area. Correlation between indicator bacteria concentrations and rainfall amounts was weak to moderate but significant (E. coli R = 0.251, P = 0.009; enterococci R = 0.369, P < 0.001; C. perfringens R = 0.343, P < 0.001), while concentrations of human fecal-associated molecular markers were not significantly correlated with rainfall (human-associated Bacteroides, R = 0.131, P = 0.256; human-associated polyomaviruses, R = 0.213, P = 0.464). Presence of human sewage was confirmed by detection of human-associated Bacteroides and human polyomavirus in the urbanized section of Manoa Stream (83.3-100% and 41.7-66.7% positive samples respectively). It was further confirmed by microbial community analyses which suggested that an average 2.4-3.4% of the total bacterial population in this section was associated with sewage. Microbial community profiles were significantly influenced by rainfall (R 2  = 0.4390, P < 0.001), pH (R 2  = 0.3077, P = 0.006), salinity (R 2  = 0.2614, P = 0.038), and conductivity (R 2  = 0.2676, P = 0.031). Although microbial diversity fluctuated throughout the watershed, it was lower in the impaired section. Leaking sewer systems and illegal cross-connections are implicated in the impairment of the watershed, hence both the sewer and the storm water lines should be routinely inspected. Collectively, our data suggest that information derived from the analysis of microbial communities complements current marker-based microbial source tracking techniques and environmental monitoring programs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Behavior of Agricultural water users induced hydro-climatic cycle change in Heihe River Basin, in the northwest of china

NASA Astrophysics Data System (ADS)

Wu, F.; Deng, X.; Cai, X.; Zhang, X.; Zhang, Q.

2017-12-01

Water allocation unbalance is the most important driving force of ecological degradation in the Heihe River Basin, where it seems the lifeblood of environment and human society. Water commute complex and frequent in soil, atmosphere, surface and ground face. The balance analysis of Water's transformation based on the WRF (Weather Research Forecasting) and SWAT (Soil and Water Assessment Tool) simulations, puts forward the application of land governance in arid and semi-arid region. In this study, we designed an irrigation scheme using local field experiences and incorporated the irrigation scheme into WRF/Noah-MP model. Then, to test the effects of irrigation scheme on performance of WRF/Noah-MP model, we carried out two simulations with the Heihe watershed, Northwest China, as a case study area. Firstly, the irrigation simulation is meanly about 860 mm across all of 671 cropland grid cells within the Heihe watershed and gradually increases from about 500 mm nearby the foot of Qilian Mountain to the maximum about 1500 mm in the middle and lower reach of Heihe River. Both of regional mean value and spatial heterogeneity are close to ground measurements. Secondly, the irrigation simulation dramatically reduced the mean bias of specified humidity to -0.47 g kg-1 (accounting for 6.0% of observation) and RMSE of temperature to 0.47 °C, respectively, since the irrigation enhanced the surface latent heat and weakened sensible heat to atmosphere. Thirdly, Across the 8 agricultural sites, the correlation coefficient and RMSE increased from 0.75 to 0.80. Finally, we found the surface runoff will increase by 0.46% with SWAT model at irrigation months. Therefore, the irrigation may led to expansion of cultivated land through transformation from groundwater to surface water at some degree. Water authorities should strengthen the tough water management measures to implement measures of total quantity control and raise the efficiency of water resources.

Analysis of the High-Frequency Content in Human QRS Complexes by the Continuous Wavelet Transform: An Automatized Analysis for the Prediction of Sudden Cardiac Death.

PubMed

García Iglesias, Daniel; Roqueñi Gutiérrez, Nieves; De Cos, Francisco Javier; Calvo, David

2018-02-12

Fragmentation and delayed potentials in the QRS signal of patients have been postulated as risk markers for Sudden Cardiac Death (SCD). The analysis of the high-frequency spectral content may be useful for quantification. Forty-two consecutive patients with prior history of SCD or malignant arrhythmias (patients) where compared with 120 healthy individuals (controls). The QRS complexes were extracted with a modified Pan-Tompkins algorithm and processed with the Continuous Wavelet Transform to analyze the high-frequency content (85-130 Hz). Overall, the power of the high-frequency content was higher in patients compared with controls (170.9 vs. 47.3 10³nV²Hz -1 ; p = 0.007), with a prolonged time to reach the maximal power (68.9 vs. 64.8 ms; p = 0.002). An analysis of the signal intensity (instantaneous average of cumulative power), revealed a distinct function between patients and controls. The total intensity was higher in patients compared with controls (137.1 vs. 39 10³nV²Hz -1 s -1 ; p = 0.001) and the time to reach the maximal intensity was also prolonged (88.7 vs. 82.1 ms; p < 0.001). The high-frequency content of the QRS complexes was distinct between patients at risk of SCD and healthy controls. The wavelet transform is an efficient tool for spectral analysis of the QRS complexes that may contribute to stratification of risk.

Problems in determining the return of a watershed to pretreatment conditions: techniques applied to a study at Caspar Creek, California

Treesearch

Robert B. Thomas

1990-01-01

Using a previously treated basin as a control in subsequent paired watershed studies requires the control to be stable. Basin stability can be assessed in many ways, some of which are investigated for the South Fork of Caspar Creek in northern California. This basin is recovering from logging and road building in the early 1970s. Three storm-based discharge...

How lithology and climate affect REE mobility and fractionation along a shale weathering transect of the Susquehanna Shale Hills Critical Zone Observatory

NASA Astrophysics Data System (ADS)

Ma, L.; Jin, L.; Dere, A. L.; White, T.; Mathur, R.; Brantley, S. L.

2012-12-01

Shale weathering is an important process in global elemental cycles. Accompanied by the transformation of bedrock into regolith, many elements including rare earth elements (REE) are mobilized primarily by chemical weathering in the Critical Zone. Then, REE are subsequently transported from the vadose zone to streams, with eventual deposition in the oceans. REE have been identified as crucial and strategic natural resources; and discovery of new REE deposits will be facilitated by understanding global REE cycles. At present, the mechanisms and environmental factors controlling release, transport, and deposition of REE - the sources and sinks - at Earth's surface remain unclear. Here, we present a systematic study of soils, stream sediments, stream waters, soil water and bedrock in six small watersheds that are developed on shale bedrock in the eastern USA to constrain the mobility and fractionation of REE during early stages of chemical weathering. The selected watersheds are part of the shale transect established by the Susquehanna Shale Hills Observatory (SSHO) and are well suited to investigate weathering on shales of different compositions or within different climate regimes but on the same shale unit. Our REE study from SSHO, a small gray shale watershed in central Pennsylvania, shows that up to 65% of the REE (relative to parent bedrock) is depleted in the acidic and organic-rich soils due to chemical leaching. Both weathering soil profiles and natural waters show a preferential removal of middle REE (MREE: Sm to Dy) relative to light REE (La to Nd) and heavy REE (Ho to Lu) during shale weathering, due to preferential release of MREE from a phosphate phase (rhabdophane). Strong positive Ce anomalies observed in the regolith and stream sediments point to the fractionation and preferential precipitation of Ce as compared to other REE, in the generally oxidizing conditions of the surface environments. One watershed developed on the Marcellus black shale in Pennsylvania allows comparison of behaviors of REE in the organic-rich vs. organic-poor end members under the same climate conditions. Our study shows that black shale bedrock has much higher REE contents compared to the Rose Hill gray shale. The presence of reactive phases such as organic matter, carbonates and sulfides in black shale and their alteration greatly enhance the release of REE and other metals to surface environments. This observation suggests that weathering of black shale is thus of particular importance in the global REE cycles, in addition to other heavy metals that impact the health of terrestrial and aquatic ecosystems. Finally, our ongoing investigation of four more gray shale watersheds in Virginia, Tennessee, Alabama, and Puerto Rico will allow for a comparison of shale weathering along a climosequence. Such a systematic study will evaluate the control of air temperature and precipitation on REE release from gray shale weathering in eastern USA.

Use of a fluoride channel as a new selection marker for fission yeast plasmids and application to fast genome editing with CRISPR/Cas9

PubMed Central

Fernandez, Ronan; Berro, Julien

2017-01-01

Fission yeast is a powerful model organism that has provided insights into important cellular processes thanks to the ease of its genome editing by homologous recombination. However, creation of strains with a large number of targeted mutations or containing plasmids has been challenging because only a very small number of selection markers is available in Schizosaccharomyces pombe. In this paper, we identify two fission yeast fluoride exporter channels (Fex1p and Fex2p) and describe the development of a new strategy using Fex1p as a selection marker for transformants in rich media supplemented with fluoride. To our knowledge this is the first positive selection marker identified in S. pombe that does not use auxotrophy or drug resistance and that can be used for plasmids transformation or genomic integration in rich media. We illustrate the application of our new marker by significantly accelerating the protocol for genome edition using CRISPR/Cas9 in S. pombe. PMID:27327046

Using geophysical images of a watershed subsurface to predict soil textural properties

USDA-ARS?s Scientific Manuscript database

Subsurface architecture, in particular changes in soil type across the landscape, is an important control on the hydrological and ecological function of a watershed. Traditional methods of mapping soils involving subjective assignment of soil boundaries are inadequate for studies requiring a quantit...

IS IT NECESSARY TO CONTROL POTENTIALLY INFECTIOUS MICROORGANISMS IN ANIMAL WASTES?

EPA Science Inventory

This presentation will begin with a holistic view of the watershed; considering microbiological water quality needs and how they are influenced by activities in the watershed. It will look at the current indicators of microbiological water quality and their usefulness and then id...

Toward understanding mechanisms controlling urea delivery in a coastal plain watershed

USDA-ARS?s Scientific Manuscript database

Improved understanding of nutrient mobilization and delivery to surface waters is critical to protecting water quality in agricultural watersheds. Urea, a form of organic nitrogen, is a common nutrient found in fertilizers, manures, and human waste, and is gaining recognition as an important driver ...

Morphological operation based dense houses extraction from DSM

NASA Astrophysics Data System (ADS)

Li, Y.; Zhu, L.; Tachibana, K.; Shimamura, H.

2014-08-01

This paper presents a method of reshaping and extraction of markers and masks of the dense houses from the DSM based on mathematical morphology (MM). Houses in a digital surface model (DSM) are almost joined together in high-density housing areas, and most segmentation methods cannot completely separate them. We propose to label the markers of the buildings firstly and segment them into masks by watershed then. To avoid detecting more than one marker for a house or no marker at all due to its higher neighbour, the DSM is morphologically reshaped. It is carried out by a MM operation using the certain disk shape SE of the similar size to the houses. The sizes of the houses need to be estimated before reshaping. A granulometry generated by opening-by-reconstruction to the NDSM is proposed to detect the scales of the off-terrain objects. It is a histogram of the global volume of the top hats of the convex objects in the continuous scales. The obvious step change in the profile means that there are many objects of similar sizes occur at this scale. In reshaping procedure, the slices of the object are derived by morphological filtering at the detected continuous scales and reconstructed in pile as the dome. The markers are detected on the basis of the domes.

Cereal transformation through particle bombardment

NASA Technical Reports Server (NTRS)

Casas, A. M.; Kononowicz, A. K.; Bressan, R. A.; Hasegawa, P. M.; Mitchell, C. A. (Principal Investigator)

1995-01-01

The review focuses on experiments that lead to stable transformation in cereals using microprojectile bombardment. The discussion of biological factors that affect transformation examines target tissues and vector systems for gene transfer. The vector systems include reporter genes, selectable markers, genes of agronomic interest, and vector constructions. Other topics include physical parameters that affect DNA delivery, selection of stably transformed cells and plant regeneration, and analysis of gene expression and transmission to the progeny.

The importance of the riparian zone and in-stream processes in nitrate attenuation in undisturbed and agricultural watersheds – a review of the scientific literature

USGS Publications Warehouse

Ranalli, Anthony J.; Macalady, Donald L.

2010-01-01

We reviewed published studies from primarily glaciated regions in the United States, Canada, and Europe of the (1) transport of nitrate from terrestrial ecosystems to aquatic ecosystems, (2) attenuation of nitrate in the riparian zone of undisturbed and agricultural watersheds, (3) processes contributing to nitrate attenuation in riparian zones, (4) variation in the attenuation of nitrate in the riparian zone, and (5) importance of in-stream and hyporheic processes for nitrate attenuation in the stream channel. Our objectives were to synthesize the results of these studies and suggest methodologies to (1) monitor regional trends in nitrate concentration in undisturbed 1st order watersheds and (2) reduce nitrate loads in streams draining agricultural watersheds. Our review reveals that undisturbed headwater watersheds have been shown to be very retentive of nitrogen, but the importance of biogeochemical and hydrological riparian zone processes in retaining nitrogen in these watersheds has not been demonstrated as it has for agricultural watersheds. An understanding of the role of the riparian zone in nitrate attenuation in undisturbed watersheds is crucial because these watersheds are increasingly subject to stressors, such as changes in land use and climate, wildfire, and increases in atmospheric nitrogen deposition. In general, understanding processes controlling the concentration and flux of nitrate is critical to identifying and mapping the vulnerability of watersheds to water quality changes due to a variety of stressors. In undisturbed and agricultural watersheds we propose that understanding the importance of riparian zone processes in 2nd order and larger watersheds is critical. Research is needed that addresses the relative importance of how the following sources of nitrate along any given stream reach might change as watersheds increase in size and with flow: (1) inputs upstream from the reach, (2) tributary inflow, (3) water derived from the riparian zone, (4) groundwater from outside the riparian zone (intermediate or regional sources), and (5) in-stream (hyporheic) processes.

Correlation of crAssphage-based qPCR markers with culturable and molecular indicators of human fecal pollution in an impacted urban watershed.

PubMed

Stachler, Elyse; Akyon, Benay; Aquino de Carvalho, Nathalia; Ference, Christian; Bibby, Kyle

2018-06-06

Environmental waters are monitored for fecal pollution to protect public health. Many previously developed human-specific fecal pollution indicators lack adequate sensitivity to be reliably detected in environmental waters or do not correlate well with viral pathogens. Recently, two novel human sewage-associated source tracking qPCR markers were developed based on the bacteriophage crAssphage, CPQ_056 and CPQ_064. These assays are highly human specific, abundant in sewage, and are viral-based, suggesting great promise for environmental application as human fecal pollution indicators. A 30-day sampling study was conducted in an urban stream impacted by combined sewer overflows to evaluate the crAssphage markers' performance in an environmental system. The crAssphage markers were present at concentrations of 4.02-6.04 log10 copies/100 mL throughout the study period, indicating their high abundance and ease of detection in polluted environmental waters. In addition, the crAssphage assays were correlated with rain events, molecular markers for human polyomavirus and HF183, as well as culturable E. coli, enterococci, and somatic coliphage. The CPQ_064 assay correlated strongly to a greater number of biological indicators than the CPQ_056 assay. This study is the first to evaluate both crAssphage qPCR assays in an extended environmental application of crAssphage markers for monitoring of environmental waters. It is also the first study to compare crAssphage marker concentration with other viral-based indicators.

Mapping technological and biophysical capacities of watersheds to regulate floods

USGS Publications Warehouse

Mogollón, Beatriz; Villamagna, Amy M.; Frimpong, Emmanuel A.; Angermeier, Paul

2016-01-01

Flood regulation is a widely valued and studied service provided by watersheds. Flood regulation benefits people directly by decreasing the socio-economic costs of flooding and indirectly by its positive impacts on cultural (e.g., fishing) and provisioning (e.g., water supply) ecosystem services. Like other regulating ecosystem services (e.g., pollination, water purification), flood regulation is often enhanced or replaced by technology, but the relative efficacy of natural versus technological features in controlling floods has scarcely been examined. In an effort to assess flood regulation capacity for selected urban watersheds in the southeastern United States, we: (1) used long-term flood records to assess relative influence of technological and biophysical indicators on flood magnitude and duration, (2) compared the widely used runoff curve number (RCN) approach for assessing the biophysical capacity to regulate floods to an alternative approach that acknowledges land cover and soil properties separately, and (3) mapped technological and biophysical flood regulation capacities based on indicator importance-values derived for flood magnitude and duration. We found that watersheds with high biophysical (via the alternative approach) and technological capacities lengthened the duration and lowered the peak of floods. We found the RCN approach yielded results opposite that expected, possibly because it confounds soil and land cover processes, particularly in urban landscapes, while our alternative approach coherently separates these processes. Mapping biophysical (via the alternative approach) and technological capacities revealed great differences among watersheds. Our study improves on previous mapping of flood regulation by (1) incorporating technological capacity, (2) providing high spatial resolution (i.e., 10-m pixel) maps of watershed capacities, and (3) deriving importance-values for selected landscape indicators. By accounting for technology that enhances or replaces natural flood regulation, our approach enables watershed managers to make more informed choices in their flood-control investments.

Hydrology and water quality in two mountain basins of the northeastern US: Assessing baseline conditions and effects of ski area development

USGS Publications Warehouse

Wemple, B.; Shanley, J.; Denner, J.; Ross, D.; Mills, K.

2007-01-01

Mountain regions throughout the world face intense development pressures associated with recreational and tourism uses. Despite these pressures, much of the research on bio-geophysical impacts of humans in mountain regions has focused on the effects of natural resource extraction. This paper describes findings from the first 3 years of a study examining high elevation watershed processes in a region undergoing alpine resort development. Our study is designed as a paired-watershed experiment. The Ranch Brook watershed (9.6 km2) is a relatively pristine, forested watershed and serves as the undeveloped 'control' basin. West Branch (11.7 km2) encompasses an existing alpine ski resort, with approximately 17% of the basin occupied by ski trails and impervious surfaces, and an additional 7% slated for clearing and development. Here, we report results for water years 2001-2003 of streamflow and water quality dynamics for these watersheds. Precipitation increases significantly with elevation in the watersheds, and winter precipitation represents 36-46% of annual precipitation. Artificial snowmaking from water within West Branch watershed currently augments annual precipitation by only 3-4%. Water yield in the developed basin exceeded that in the control by 18-36%. Suspended sediment yield was more than two and a half times greater and fluxes of all major solutes were higher in the developed basin. Our study is the first to document the effects of existing ski area development on hydrology and water quality in the northeastern US and will serve as an important baseline for evaluating the effects of planned resort expansion activities in this area.

Forecasting the remaining reservoir capacity in the Laurentian Great Lakes watershed

NASA Astrophysics Data System (ADS)

Alighalehbabakhani, Fatemeh; Miller, Carol J.; Baskaran, Mark; Selegean, James P.; Barkach, John H.; Dahl, Travis; Abkenar, Seyed Mohsen Sadatiyan

2017-12-01

Sediment accumulation behind a dam is a significant factor in reservoir operation and watershed management. There are many dams located within the Laurentian Great Lakes watershed whose operations have been adversely affected by excessive reservoir sedimentation. Reservoir sedimentation effects include reduction of flood control capability and limitations to both water supply withdrawals and power generation due to reduced reservoir storage. In this research, the sediment accumulation rates of twelve reservoirs within the Great Lakes watershed were evaluated using the Soil and Water Assessment Tool (SWAT). The estimated sediment accumulation rates by SWAT were compared to estimates relying on radionuclide dating of sediment cores and bathymetric survey methods. Based on the sediment accumulation rate, the remaining reservoir capacity for each study site was estimated. Evaluation of the anthropogenic impacts including land use change and dam construction on the sediment yield were assessed in this research. The regression analysis was done on the current and pre-European settlement sediment yield for the modeled watersheds to predict the current and natural sediment yield in un-modeled watersheds. These eleven watersheds are in the state of Indiana, Michigan, Ohio, New York, and Wisconsin.

Summary of the land-use inventory for the nonpoint-source evaluation monitoring watersheds in Wisconsin

USGS Publications Warehouse

Wierl, J.A.; Rappold, K.F.; Amerson, F.U.

1996-01-01

In 1992, the Wisconsin Department of Natural Resources (WDNR) in cooperation with the U.S. Geological Survey initiated a land-use inventory to identify sources of pollutants and track the land-management changes for eight evaluation monitoring watersheds established as part of the WDNR's Nonpoint Source Program. Each evaluation monitoring watershed is within a WDNR priority watershed. The U.S. Geological Survey is responsible for collection of water-quality data in the evaluation monitoring watersheds. An initial inventory was completed for each of the WDNR priority watersheds before nonpoint-source plans were developed for the control of nonpoint pollution. The land-use inventory described in this report expands upon the initial inventory by including nonpoint pollution sources that were not identified and also by updating changes in landuse and land-management practices. New sources of nonpoint pollution, not identified in the initial inventory, could prove to be important when monitored and modeled data are analyzed. This effort to inventory the evaluation monitoring watersheds will help with the interpretation of future land-use and water-quality data. This report describes landuse inventory methods, presents results of the inventory, and lists proposed future activities.

Hydrology of C-3 watershed, Seney National Wildlife Refuge, Michigan

USGS Publications Warehouse

Sweat, Michael J.

2001-01-01

Proposed changes to watershed management practices near C-3 Pool at Seney National Wildlife Refuge will affect surface-water flow patterns, ground-water levels, and possibly local plant communities. Data were collected between fall 1998 and spring 2000 to document existing conditions and to assess potential changes in hydrology that might occur as a consequence of modifications to water management practices in C-3 watershed.Minimum and maximum measured inflows and outflows for the study period are presented in light of proposed management changes to C-3 watershed. Streamflows ranged from 0 to 8.61 cubic meters per second. Low or zero flow was generally measured in late summer and early fall, and highest flows were measured during spring runoff and winter rain events. Ground-water levels varied by about a half meter, with levels closest to or above the land surface during spring runoff into the early summer, and with levels generally below land surface during late fall into early winter.A series of optional management practices that could conserve and restore habitat of the C-3 watershed is described. Modifications to the existing system of a drainage ditch and control structures are examined, as are the possibilities of reconnecting streams to their historical channels and the construction of additional or larger control structures to further manage the distribution of water in the watershed. The options considered could reduce erosion, restore presettlement streamflow conditions, and modify the ground-water gradient.

Comparison of sediment and nutrient export and runoff characteristics from watersheds with centralized versus distributed stormwater management

USGS Publications Warehouse

Hopkins, Kristina G.; Loperfido, J.V.; Craig, Laura S.; Noe, Gregory; Hogan, Dianna

2017-01-01

Stormwater control measures (SCMs) are used to retain stormwater and pollutants. SCMs have traditionally been installed in a centralized manner using detention to mitigate peak flows. Recently, distributed SCM networks that treat runoff near the source have been increasingly utilized. The aim of this study was to evaluate differences among watersheds that vary in SCM arrangement by assessing differences in baseflow nutrient (NOx-N and PO4−) concentrations and fluxes, stormflow export of suspended sediments and particulate phosphorus (PP), and runoff characteristics. A paired watershed approach was used to compare export between 2004 and 2016 from one forested watershed (For-MD), one suburban watershed with centralized SCMs (Cent-MD), and one suburban watershed with distributed SCMs (Dist-MD). Results indicated baseflow nitrate (NOx-N) concentrations typically exceeded 1 mg-N/L in all watersheds and were highest in Dist-MD. Over the last 10 years in Dist-MD, nitrate concentrations in both stream baseflow and in a groundwater well declined as land use shifted from agriculture to suburban. Baseflow nitrate export temporarily increased during the construction phase of SCM development in Dist-MD. This temporary pulse of nitrate may be attributed to the conversion of sediment control facilities to SCMs and increased subsurface flushing as infiltration SCMs came on line. During storm flow, Dist-MD tended to have less runoff and lower maximum specific discharge than Cent-MD for small events (<1.3 cm), but runoff responses became increasingly similar to Cent-MD with increasing precipitation (>1.3 cm). Mass export estimated during paired storm events indicated Dist-MD exported 30% less sediment and 31% more PP than Cent-MD. For large precipitation events, export of sediment and PP was similar among all three watersheds. Results suggest that distributed SCMs can reduce runoff and sediment loads during small rain events compared to centralized SCMs, but these differences become less evident for large events when peak discharge likely leads to substantial bank erosion.

Long-term ionic increases from a central Appalachian forested watershed

Treesearch

Pamela J. Edwards; J. David Helvey

1991-01-01

The electrical conductivity of stream water draining from an unmanaged and undisturbed control watershed has been increasing rather steadily, about 0.03 mS m-1 yr-1, since 1971. During this period, NO–3 and Ca2+ concentrations increased and were shown to...

Modeling pesticide diuron loading from the San Joaquin watershed into the Sacramento-San Joaquin Delta using SWAT

USDA-ARS?s Scientific Manuscript database

Quantitative information on pesticide loading into the Sacramento-San Joaquin Delta waterways of northern California is critical for water resource management in the region, and potentially useful for biological weed control planning. The San Joaquin watershed, an agriculturally intensive area, is a...

Watershed Restoration in the Northern Sierra Nevada: A Biotechnical Approach

Treesearch

Donna S. Lindquist; Linton Y. Bowie

1989-01-01

A cooperative erosion control project was initiated in 1985 for the North Fork Feather River watershed in California's northern Sierra Nevada due to widespread accelerated erosion. Resulting sedimentation problems have impacted fish, wildlife and livestock resources, and have created operational concerns for hydroelectric facilities located downstream. In response...

Regional ecological risk assessment for the introduction of Gambusia affinis (western mosquitofish) into Montana watersheds

Treesearch

Jerome J. Schleier; Sing Sharlene E.; Robert K. D. Peterson

2008-01-01

Qualitative risk assessment methodologies were used to assess the risk of establishment and consequent impacts on native minnows and species of concern (SOC) associated with the intentional or unintentional introduction of the mosquito biological control agent, Gambusia affinis, to various Montana watersheds. Gambusia affinis...

Temporal and spatial variation of nitrogen transformations in nitrogen-saturated soils of a central Appalachian hardwood forest

Treesearch

Frank S. Gilliam; Bradley M. Yurish; Mary Beth Adams

2001-01-01

We studied temporal and spatial patterns of soil nitrogen (N) dynamics from 1993 to 1995 in three watersheds of Fernow Experimental Forest, W.V.: WS7 (24-year-old, untreated); WS4 (mature, untreated); and WS3 (24- year-old, treated with (NH4)2SO4 since 1989 at the rate of 35 kg N·ha–1...

Breast tumor segmentation in high resolution x-ray phase contrast analyzer based computed tomography.

PubMed

Brun, E; Grandl, S; Sztrókay-Gaul, A; Barbone, G; Mittone, A; Gasilov, S; Bravin, A; Coan, P

2014-11-01

Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer based phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure's possible applications. A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.

Using trainable segmentation and watershed transform for identifying unilocular and multilocular cysts from ultrasound images of ovarian tumour

NASA Astrophysics Data System (ADS)

Ibrahim, Dheyaa Ahmed; Al-Assam, Hisham; Du, Hongbo; Jassim, Sabah

2017-05-01

Ovarian masses are categorised into different types of malignant and benign. In order to optimize patient treatment, it is necessary to carry out pre-operational characterisation of the suspect ovarian mass to determine its category. Ultrasound imaging has been widely used in differentiating malignant from benign cases due to its safe and non-intrusive nature, and can be used for determining the number of cysts in the ovary. Presently, the gynaecologist is tasked with manually counting the number of cysts shown on the ultrasound image. This paper proposes, a new approach that automatically segments the ovarian masses and cysts from a static B-mode image. Initially, the method uses a trainable segmentation procedure and a trained neural network classifier to accurately identify the position of the masses and cysts. After that, the borders of the masses can be appraised using watershed transform. The effectiveness of the proposed method has been tested by comparing the number of cysts identified by the method against the manual examination by a gynaecologist. A total of 65 ultrasound images were used for the comparison, and the results showed that the proposed solution is a viable alternative to the manual counting method for accurately determining the number of cysts in a US ovarian image.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Brun, E., E-mail: emmanuel.brun@esrf.fr; Grandl, S.; Sztrókay-Gaul, A.

Purpose: Phase contrast computed tomography has emerged as an imaging method, which is able to outperform present day clinical mammography in breast tumor visualization while maintaining an equivalent average dose. To this day, no segmentation technique takes into account the specificity of the phase contrast signal. In this study, the authors propose a new mathematical framework for human-guided breast tumor segmentation. This method has been applied to high-resolution images of excised human organs, each of several gigabytes. Methods: The authors present a segmentation procedure based on the viscous watershed transform and demonstrate the efficacy of this method on analyzer basedmore » phase contrast images. The segmentation of tumors inside two full human breasts is then shown as an example of this procedure’s possible applications. Results: A correct and precise identification of the tumor boundaries was obtained and confirmed by manual contouring performed independently by four experienced radiologists. Conclusions: The authors demonstrate that applying the watershed viscous transform allows them to perform the segmentation of tumors in high-resolution x-ray analyzer based phase contrast breast computed tomography images. Combining the additional information provided by the segmentation procedure with the already high definition of morphological details and tissue boundaries offered by phase contrast imaging techniques, will represent a valuable multistep procedure to be used in future medical diagnostic applications.« less

Combined effects of climate and land management on watershed vegetation dynamics in an arid environment.

PubMed

Liu, Peilong; Hao, Lu; Pan, Cen; Zhou, Decheng; Liu, Yongqiang; Sun, Ge

2017-07-01

Leaf area index (LAI) is a key parameter to characterize vegetation dynamics and ecosystem structure that determines the ecosystem functions and services such as clean water supply and carbon sequestration in a watershed. However, linking LAI dynamics and environmental controls (i.e., coupling biosphere, atmosphere, and anthroposphere) remains challenging and such type of studies have rarely been done at a watershed scale due to data availability. The present study examined the spatial and temporal variations of LAI for five ecosystem types within a watershed with a complex topography in the Upper Heihe River Basin, a major inland river in the arid and semi-arid western China. We integrated remote sensing-based GLASS (Global Land Surface Satellite) LAI products, interpolated climate data, watershed characteristics, and land management records for the period of 2001-2012. We determined the relationships among LAI, topography, air temperature and precipitation, and grazing history by five ecosystem types using several advanced statistical methods. We show that long-term mean LAI distribution had an obvious vertical pattern as controlled by precipitation and temperature in a hilly watershed. Overall, watershed-wide mean LAI had an increasing trend overtime for all ecosystem types during 2001-2012, presumably as a result of global warming and a wetting climate. However, the fluctuations of observed LAI at a pixel scale (1km) varied greatly across the watershed. We classified the vegetation changes within the watershed as 'Improved', 'Stabilized', and 'Degraded' according their respective LAI changes. We found that climate was not the only driver for temporal vegetation changes for all land cover types. Grazing partially contributed to the decline of LAI in some areas and masked the positive climate warming effects in other areas. Extreme weathers such as cold spells and droughts could substantially affect inter-annual variability of LAI dynamics. We concluded that temporal and spatial LAI dynamics were rather complex and were affected by both climate variations and human disturbances in the study basin. Future monitoring studies should focus on the functional interactions among vegetation dynamics, climate variations, land management, and human disturbances. Published by Elsevier B.V.

Effects of Complementary Combination Therapy of Korean Red Ginseng and Antiviral Agents in Chronic Hepatitis B.

PubMed

Choi, Seung-Hwa; Yang, Keum-Jin; Lee, Dong-Soo

2016-12-01

Chronic hepatitis B management is commonly targeted at reducing viral replication. However, the currently available antiviral therapies are associated with some problems, including resistance and numerous adverse effects. Ginseng has been reported to be effective for treating viral infections such as influenza and human immunodeficiency virus. However, there are currently few studies on the effects of ginseng in chronic hepatitis B. Thus, this study investigated the effects of ginseng together with antiviral agents in chronic hepatitis B. This was a prospective, single-blinded, randomized controlled trial, and single-center study. Thirty-eight patients were enrolled. The control group (n = 19) was administered antiviral agents alone. The experimental group (n = 19) was administered antiviral agents along with Korean Red Ginseng powder capsules (each dose is 1 gram (two capsules), a one-day dose is 3 grams). The baseline characteristics did not differ between the two groups. Differences in several non-invasive fibrosis serologic markers (type IV collagen, hyaluronic acid, transforming growth factor-β) and in the hepatitis B virus DNA levels were compared between the groups. The non-invasive fibrosis serologic markers were further decreased in the experimental group, with significant differences after treatment observed for hyaluronic acid (p = 0.032) and transforming growth factor-β (p = 0.008), but not for type IV collagen (p = 0.174). This study suggests the possibility of Korean Red Ginseng as a complementary therapy for chronic hepatitis B.

Retrofitting for watershed drainage

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bennett, D.B.; Heaney, J.P.

1991-09-01

Over the past 8 years, degradation in Florida's Indian River Lagoon has taken the form of fish kills, reduced viable recreational and commercial fisheries, and loss of seagrass beds. Stormwater drainage practices in the watershed have been identified as the primary culprit in the slow demise of the lagoon. Specific drainage problems include an increased volume of freshwater runoff to the estuarine receiving water and deposition of organic sediments, reduced water clarity because of increased discharge of suspended solids and tea colored' groundwater - a result of drainage-canal-induced land dewatering, and eutrophication caused by nutrient loadings. In addition, poor flushingmore » in lagoon segments makes runoff impacts even more damaging to the ecosystem. Recently, the lagoon has received national, regional, state, and local attention over its degradation and citizens' action and multi-agency efforts to restore it. To mitigate damage to the Indian River lagoon, agencies are considering alternatives such as retrofitting to reduce pollutant loads and implementing a more comprehensive watershed approach to stormwater management instead of individual controls on new development currently widely practiced. A comprehensive, long-term watershed control approach avoids unnecessary construction expenses, encourages cost-effective tradeoffs based on specific objectives, facilities performance monitoring, and accounts for cumulative impacts of continued growth in the watershed.« less

Modeling of phosphorus fluxes produced by wild fires at watershed scales.

NASA Astrophysics Data System (ADS)

Matyjasik, M.; Hernandez, M.; Shaw, N.; Baker, M.; Fowles, M. T.; Cisney, T. A.; Jex, A. P.; Moisen, G.

2017-12-01

River runoff is one of the controlling processes in the terrestrial phosphorus cycle. Phosphorus is often a limiting factor in fresh water. One of the factors that has not been studied and modeled in detail is phosporus flux produced from forest wild fires. Phosphate released by weathering is quickly absorbed in soils. Forest wild fires expose barren soils to intensive erosion, thus releasing relatively large fluxes of phosphorus. Measurements from three control burn sites were used to correlate erosion with phosphorus fluxes. These results were used to model phosphorus fluxes from burned watersheds during a five year long period after fires occurred. Erosion in our model is simulated using a combination of two models: the WEPP (USDA Water Erosion Prediction Project) and the GeoWEPP (GIS-based Water Erosion Prediction Project). Erosion produced from forest disturbances is predicted for any watershed using hydrologic, soil, and meteorological data unique to the individual watersheds or individual slopes. The erosion results are modified for different textural soil classes and slope angles to model fluxes of phosphorus. The results of these models are calibrated using measured concentrations of phosphorus for three watersheds located in the Interior Western United States. The results will help the United States Forest Service manage phosporus fluxes in national forests.

Cations and microbial indicators: strong relationships in waters of urban/mixed land use watersheds of Southwest, VA

NASA Astrophysics Data System (ADS)

Steele, M.; Badgley, B.

2016-12-01

Background The salinity and composition of salts in freshwater streams, rivers, and waterbodies varies substantially, often impacted by human urban, agricultural, and mining land uses. While extreme fluctuations in salinity have been shown to influence both microbial communities and biogeochemical cycles, the differential effects of specific ion species at low salinity levels is poorly understood. The objective of this study was to examine the relationship between water chemistry and microbial water quality indicators. We collected weekly grab samples from nine sub-watersheds in Southwest Virginia. Samples were measured for standard physical and chemical properties: dissolved oxygen, temperature, specific conductance, pH, calcium, magnesium, potassium, chloride, fluoride, sulfate, nitrogen species, phosphorus, and dissolved organic carbon. In addition, three types of microbial fecal indicators were measured: total coliforms, E. coli, and HF183 (a human specific genomic marker). Results The relationships within and between water chemistry and water quality indicators are complex and frequently co-correlated. Concentrations of traditional biogeochemical elements (N, P, C) were less strongly related to water quality indicators than were Ca, Mg, Na in watersheds. Ca and Mg were strongly correlated with total coliforms, r2 = 0.88 and r2 = 0.86 respectively. While potassium is very strongly related to E. coli (r2 = 0.96). Currently, we cannot reasonably explain these relationships by the land use composition or common sources within the landscape. The human specific fecal indicator was not well correlated with other microbial water quality indicators, and yet found ubiquitously across the developed watersheds and most strongly correlated with sodium concentrations (r2 = 0.84). The results suggest that 1) wastewater via subsurface flowpaths may more broadly impact surface water chemistry and quality than expected, and 2) that cation chemistry may influence the microbial community and serve as a mediator of watershed biogeochemical cycling.

Minimally invasive screening for colitis using attenuated total internal reflectance Fourier transform infrared spectroscopy

PubMed Central

Titus, Jitto; Viennois, Emilie; Merlin, Didier; Perera, A. G. Unil

2016-01-01

This article describes a rapid, simple and cost-effective technique that could lead to a screening method for colitis without the need for biopsies or in vivo measurements. This screening technique includes the testing of serum using Attenuated Total Reflectance Fourier Transform Infrared (ATR-FTIR) spectroscopy for the colitis-induced increased presence of mannose. Chronic (Interleukin 10 knockout) and acute (Dextran Sodium Sulphate-induced) models for colitis are tested using the ATR-FTIR technique. Arthritis (Collagen Antibody Induced Arthritis) and metabolic syndrome (Toll like receptor 5 knockout) models are also tested as controls. The marker identified as mannose uniquely screens and distinguishes the colitic from the non-colitic samples and the controls. The reference or the baseline spectrum could be the pooled and averaged spectra of non-colitic samples or the subject's previous sample spectrum. This shows the potential of having individualized route maps of disease status, leading to personalized diagnosis and drug management. PMID:27094092

A Newly Identified Role of the Deciduous Forest Floor in the Timing of Green-Up

NASA Astrophysics Data System (ADS)

Lapenis, Andrei G.; Lawrence, Gregory B.; Buyantuev, Alexander; Jiang, Shiguo; Sullivan, Timothy J.; McDonnell, Todd C.; Bailey, Scott

2017-11-01

Plant phenology studies rarely consider controlling factors other than air temperature. We evaluate here the potential significance of physical and chemical properties of soil (edaphic factors) as additional important controls on phenology. More specifically, we investigate causal connections between satellite-observed green-up dates of small forest watersheds and soil properties in the Adirondack Mountains of New York, USA. Contrary to the findings of previous studies, where edaphic controls of spring phenology were found to be marginal, our analyses show that at least three factors manifest themselves as significant controls of seasonal patterns of variation in vegetated land surfaces observed from remote sensing: (1) thickness of the forest floor, (2) concentration of exchangeable soil potassium, and (3) soil acidity. For example, a thick forest floor appears to delay the onset of green-up. Watersheds with elevated concentrations of potassium are associated with early surface greening. We also found that trees growing in strongly acidified watersheds demonstrate delayed green-up dates. Overall, our work demonstrates that, at the scale of small forest watersheds, edaphic factors can explain a significant percentage of the observed spatial variation in land surface phenology that is comparable to the percentage that can be explained by climatic and landscape factors. We conclude that physical and chemical properties of forest soil play important roles in forest ecosystems as modulators of climatic drivers controlling the rate of spring soil warming and the transition of trees out of winter dormancy.

Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls.

PubMed

Staley, Zachery R; Grabuski, Josey; Sverko, Ed; Edge, Thomas A

2016-11-01

Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log 10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log 10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log 10 CFU/100 ml, and 7.65 log 10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can potentially degrade water quality and pose risks to human and ecosystem health. Therefore, identifying fecal contamination in storm water runoff and outfalls is essential for remediation efforts to reduce risks to public health. This study employed multiple methods of identifying levels and sources of fecal contamination in both river and storm water outfall sites, evaluating the efficacy of using culture-based enumeration of E. coli, molecular methods of determining the source(s) of contamination, and CST markers as indicators of fecal contamination. The results identified pervasive human sewage contamination in storm water outfalls and throughout an urban watershed and highlight the utility of using both MST and CST to identify raw sewage contamination. © Crown copyright 2016.

Comparison of Microbial and Chemical Source Tracking Markers To Identify Fecal Contamination Sources in the Humber River (Toronto, Ontario, Canada) and Associated Storm Water Outfalls

PubMed Central

Grabuski, Josey; Sverko, Ed; Edge, Thomas A.

2016-01-01

ABSTRACT Storm water runoff is a major source of pollution, and understanding the components of storm water discharge is essential to remediation efforts and proper assessment of risks to human and ecosystem health. In this study, culturable Escherichia coli and ampicillin-resistant E. coli levels were quantified and microbial source tracking (MST) markers (including markers for general Bacteroidales spp., human, ruminant/cow, gull, and dog) were detected in storm water outfalls and sites along the Humber River in Toronto, Ontario, Canada, and enumerated via endpoint PCR and quantitative PCR (qPCR). Additionally, chemical source tracking (CST) markers specific for human wastewater (caffeine, carbamazepine, codeine, cotinine, acetaminophen, and acesulfame) were quantified. Human and gull fecal sources were detected at all sites, although concentrations of the human fecal marker were higher, particularly in outfalls (mean outfall concentrations of 4.22 log10 copies, expressed as copy numbers [CN]/100 milliliters for human and 0.46 log10 CN/100 milliliters for gull). Higher concentrations of caffeine, acetaminophen, acesulfame, E. coli, and the human fecal marker were indicative of greater raw sewage contamination at several sites (maximum concentrations of 34,800 ng/liter, 5,120 ng/liter, 9,720 ng/liter, 5.26 log10 CFU/100 ml, and 7.65 log10 CN/100 ml, respectively). These results indicate pervasive sewage contamination at storm water outfalls and throughout the Humber River, with multiple lines of evidence identifying Black Creek and two storm water outfalls with prominent sewage cross-connection problems requiring remediation. Limited data are available on specific sources of pollution in storm water, though our results indicate the value of using both MST and CST methodologies to more reliably assess sewage contamination in impacted watersheds. IMPORTANCE Storm water runoff is one of the most prominent non-point sources of biological and chemical contaminants which can potentially degrade water quality and pose risks to human and ecosystem health. Therefore, identifying fecal contamination in storm water runoff and outfalls is essential for remediation efforts to reduce risks to public health. This study employed multiple methods of identifying levels and sources of fecal contamination in both river and storm water outfall sites, evaluating the efficacy of using culture-based enumeration of E. coli, molecular methods of determining the source(s) of contamination, and CST markers as indicators of fecal contamination. The results identified pervasive human sewage contamination in storm water outfalls and throughout an urban watershed and highlight the utility of using both MST and CST to identify raw sewage contamination. PMID:27542934

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pelch, Katherine E.; Tokar, Erik J.; Merrick, B. Alex

Previous work shows altered methylation patterns in inorganic arsenic (iAs)- or cadmium (Cd)-transformed epithelial cells. Here, the methylation status near the transcriptional start site was assessed in the normal human prostate epithelial cell line (RWPE-1) that was malignantly transformed by 10 μM Cd for 11 weeks (CTPE) or 5 μM iAs for 29 weeks (CAsE-PE), at which time cells showed multiple markers of acquired cancer phenotype. Next generation sequencing of the transcriptome of CAsE-PE cells identified multiple dysregulated genes. Of the most highly dysregulated genes, five genes that can be relevant to the carcinogenic process (S100P, HYAL1, NTM, NES, ALDH1A1)more » were chosen for an in-depth analysis of the DNA methylation profile. DNA was isolated, bisulfite converted, and combined bisulfite restriction analysis was used to identify differentially methylated CpG sites, which was confirmed with bisulfite sequencing. Four of the five genes showed differential methylation in transformants relative to control cells that was inversely related to altered gene expression. Increased expression of HYAL1 (> 25-fold) and S100P (> 40-fold) in transformants was correlated with hypomethylation near the transcriptional start site. Decreased expression of NES (> 15-fold) and NTM (> 1000-fold) in transformants was correlated with hypermethylation near the transcriptional start site. ALDH1A1 expression was differentially expressed in transformed cells but was not differentially methylated relative to control. In conclusion, altered gene expression observed in Cd and iAs transformed cells may result from altered DNA methylation status. - Highlights: • Cd and iAs are known human carcinogens, yet neither appears directly mutagenic. • Prior data suggest epigenetic modification plays a role in Cd or iAs induced cancer. • Altered methylation of four misregulated genes was found in Cd or iAs transformants. • The resulting altered gene expression may be relevant to cellular transformation.« less

Effects of Nitrogen Inputs and Watershed Characteristics on ...

EPA Pesticide Factsheets

Nitrogen (N) inputs to the landscape have been linked previously to N loads exported from watersheds at the national scale; however, stream N concentration is arguably more relevant than N load for drinking water quality, freshwater biological responses and establishment of nutrient criteria. In this study, we combine national-scale anthropogenic N input data, including synthetic fertilizer, crop biological N fixation, manure applied to farmland, atmospheric N deposition, and point source inputs, with data from the 2008-09 National Rivers and Streams Assessment to quantify the relationship between N inputs and in-stream concentrations of total N (TN), dissolved inorganic N (DIN), and total organic N (TON) (calculated as TN – DIN). In conjunction with simple linear regression, we use multiple regression to understand how watershed and stream reach attributes modify the effect of N inputs on N concentrations. Median TN was 0.50 mg N L-1 with a maximum of 25.8 mg N L-1. Total N inputs to the watershed ranged from less than 1 to 196 kg N ha-1 y-1, with a median of 14.4 kg N ha-1 y-1. Atmospheric N deposition was the single largest anthropogenic N source in the majority of sites, but, agricultural sources generally dominate total N inputs in sites with elevated N concentrations. The sum of all N inputs were positively correlated with concentrations of all forms of N [r2 = 0.44, 0.43, and 0.18 for TN, DIN, and TON, respectively (all log-transformed), n = 1112], indi

Retention of Afforestation Areas as Part of Flood Protection - Research Site and Methodology for Headwater Watershad in Poland / Retencja Leśna Zlewni Jako Element Ochrony Przeciwpowodziowej

NASA Astrophysics Data System (ADS)

Orczykowski, Tomasz; Tiukało, Andrzej

2016-03-01

Land use is considered as a non-structural, ecologically beneficial flood protection measure. Forest as one of the land use types has many useful applications which can be observed in detail on www.nwrm.eu website project. It is scientifically proved that afforestation influences flood events with high probability of occurrence. However, it is still to be argued how to measure land use impact on the hydrological response of watershed and how it should be measured in an efficient and quantifiable way. Having the tool for such an impact measurement, we can build efficient land management strategies. It is difficult to observe the impact of land use on flood events in the field.Therefore, one of the possible solutions is to observe this impact indirectly by means of hydrological rainfall-runoff models as a proxy for the reality. Such experiments were conducted in the past. Our study aims to work on the viability assessment, methodology and tools that allow to observe this impact with use of selected hydrological models and readily available data in Poland. Our first reaserch site is located within headwaters of the Kamienna river watershed. This watershed has been affected by ecological disaster, which resulted in loss of 65% of forest coverage. Our proposed methodology is to observe this transformation and its effect on the watershed response to heavy precipitation and therefore change in the flood risk.

Using Eco-hydrologic modeling in the Penobscot River Watershed to explore the role of climate and land use change on DOC concentration and flux

NASA Astrophysics Data System (ADS)

Rouhani, S. F. B. B.; Schaaf, C.; Douglas, E. M.; Huntington, T. G.; Kim, J.

2017-12-01

Dissolved Organic Carbon leaches from the terrestrial watersheds to serve as one of the largest sources of marine DOC. Runoff, slope, soil organic matter and land cover characteristics are the primary spatial factors controlling the variability of fluvial Dissolved Organic Carbon fluxes through the catchment. In large, more heterogeneous catchments, streamflow dissolved organic carbon dynamics are regulated by the combined effect of hydrological mechanisms and the proportion of major landscape elements, such as wetland and forested areas. A number of studies have demonstrated that the amount of wetlands, especially peatlands, controls the watershed level transport of DOC in streams.The Penobscot River Watershed is located in north-central Maine and drains into the Gulf of Maine. It is the second largest watershed in New England. The Penobscot River Watershed is primarily forested but also contains extensive bogs, marshes, and wooded swamps.Studying the spatial and temporal changes in DOC export in the Penobscot River Watershed allows us to better understand and detect carbon sinks to carbon source shifts (or vice versa) in northern forested ecosystems.The Regional Hydro-Ecological Simulation System, is a physical process based terrestrial model that has the ability to simulate both the source and transportation of DOC by combining both hydrological and ecological processes. The study is focused on simulating the DOC concentration and flux with RHESSys in the Penobscot River Watershed. The simulated results are compared with field measurements of DOC from the watershed and the model results from the LOADEST and the temporal DOC export patterns are explored. Future changes in the amount of streamflow DOC will also be investigated by using projected land cover and climate change scenarios. Incremental increases in the loss of wetland areas have been implemented to explore the sensitivity of this watershed to wetland loss and progressive changes in forested land cover have been implemented to understand the role of vegetation types to the DOC flux.The simulated daily streamflow for the period of 2004-2013 corresponded well with observed daily streamflowat USGS gauge station. in addition, the simulated DOC flux and concentration values matched well with observed data and LODEST model results.

A novel transformation system using a bleomycin resistance marker with chemosensitizers for Aspergillus oryzae.

PubMed

Suzuki, Satoshi; Tada, Sawaki; Fukuoka, Mari; Taketani, Hiroko; Tsukakoshi, Yoshiki; Matsushita, Mayumi; Oda, Kosuke; Kusumoto, Ken-Ichi; Kashiwagi, Yutaka; Sugiyama, Masanori

2009-05-22

Aspergillus oryzae is resistant to many kinds of antibiotics, which hampers their use to select transformants. In fact, the fungus is resistant to over 200microg/ml of bleomycin (Bm). By enhancing the susceptibility of A. oryzae to Bm using Triton X-100 as a detergent and an ATP-binding cassette (ABC) pump inhibitor, chlorpromazine, to the growing medium, we established a novel transformation system by Bm selection for A. oryzae. In a medium containing these reagents, A. oryzae showed little growth even in the presence of 30microg Bm/ml. Based on these findings, we constructed a Bm-resistance expression cassette (BmR), in which blmB encoding Bm N-acetyltransferase from Bm-producing Streptomyces verticillus was expressed under the control of a fungal promoter. We obtained a gene knockout mutant efficiently by Bm selection, i.e., the chromosomal ligD coding region was successfully replaced by BmR using ligD disruption cassette consisted of ligD flanking sequence and BmR through homologous recombination.

Transformation of the Fungal Soybean Pathogen Cercospora kikuchii with the Selectable Marker bar

PubMed Central

Upchurch, Robert G.; Meade, Maura J.; Hightower, Robin C.; Thomas, Robert S.; Callahan, Terrence M.

1994-01-01

An improved transformation protocol, utilizing selection for resistance to the herbicide bialaphos, has been developed for the plant pathogenic fungus Cercospora kikuchii. Stable, bialaphos-resistant transformants are recovered at frequencies eight times higher than those achieved with the previous system that was based on selection for benomyl resistance. In addition to C. kikuchii, this improved method can also be used to transform other species of Cercospora. Images PMID:16349469

Understanding Metal Sources and Transport Processes in Watersheds: a Hydropedologic Approach (Invited)

NASA Astrophysics Data System (ADS)

Bullen, T. D.; Bailey, S. W.; McGuire, K. J.; Brousseau, P.; Ross, D. S.; Bourgault, R.; Zimmer, M. A.

2010-12-01

Understanding the origin of metals in watersheds, as well as the transport and cycling processes that affect them is of critical importance to watershed science. Metals can be derived both from weathering of minerals in the watershed soils and bedrock and from atmospheric deposition, and can have highly variable residence times in the watershed due to cycling through plant communities and retention in secondary mineral phases prior to release to drainage waters. Although much has been learned about metal cycling and transport through watersheds using simple “box model” approaches that define unique input, output and processing terms, the fact remains that watersheds are inherently complex and variable in terms of substrate structure, hydrologic flowpaths and the influence of plants, all of which affect the chemical composition of water that ultimately passes through the watershed outlet. In an effort to unravel some of this complexity at a watershed scale, we have initiated an interdisciplinary, hydropedology-focused study of the hydrologic reference watershed (Watershed 3) at the Hubbard Brook Experimental Forest in New Hampshire, USA. This 41 hectare headwater catchment consists of a beech-birch-maple-spruce forest growing on soils developed on granitoid glacial till that mantles Paleozoic metamorphic bedrock. Soils vary from lateral spodosols downslope from bedrock exposures near the watershed crest to vertical and bi-modal spodosols along hillslopes to umbrepts at toe-slope positions and inferred hydrologic pinch points created by bedrock and till structure. Using a variety of chemical and isotope tracers (e.g., K/Na, Ca/Sr, Sr/Ba, Fe/Mn, 87Sr/86Sr, Ca-Sr-Fe stable isotopes) on water, soil and plant samples in an end-member mixing analysis approach, we are attempting to discretize the watershed according to soil types encountered along determined hydrologic flowpaths in order better constrain the various biogeochemical processes that control the delivery of metals to the watershed outlet. Our initial results reveal that along the numerous first-order streams that drain the watershed, chemical and Sr isotope compositions are highly variable from sample point to sample point on a given day and from season to season, reflecting the complex nature of hydrologic flowpaths that deliver water to the streams and hinting at the importance of groundwater seeps that appear to concentrate along the central axis of the watershed.

Phosphoproteins in extracellular vesicles as candidate markers for breast cancer

PubMed Central

Chen, I-Hsuan; Xue, Liang; Hsu, Chuan-Chih; Paez, Juan Sebastian Paez; Pan, Li; Andaluz, Hillary; Wendt, Michael K.; Iliuk, Anton B.; Tao, W. Andy

2017-01-01

The state of protein phosphorylation can be a key determinant of cellular physiology such as early-stage cancer, but the development of phosphoproteins in biofluids for disease diagnosis remains elusive. Here we demonstrate a strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs isolated from small volumes of plasma samples. Using label-free quantitative phosphoproteomics, we identified 144 phosphoproteins in plasma EVs that are significantly higher in patients diagnosed with breast cancer compared with healthy controls. Several biomarkers were validated in individual patients using paralleled reaction monitoring for targeted quantitation. This study demonstrates that the development of phosphoproteins in plasma EV as disease biomarkers is highly feasible and may transform cancer screening and monitoring. PMID:28270605

Phosphoproteins in extracellular vesicles as candidate markers for breast cancer.

PubMed

Chen, I-Hsuan; Xue, Liang; Hsu, Chuan-Chih; Paez, Juan Sebastian Paez; Pan, Li; Andaluz, Hillary; Wendt, Michael K; Iliuk, Anton B; Zhu, Jian-Kang; Tao, W Andy

2017-03-21

The state of protein phosphorylation can be a key determinant of cellular physiology such as early-stage cancer, but the development of phosphoproteins in biofluids for disease diagnosis remains elusive. Here we demonstrate a strategy to isolate and identify phosphoproteins in extracellular vesicles (EVs) from human plasma as potential markers to differentiate disease from healthy states. We identified close to 10,000 unique phosphopeptides in EVs isolated from small volumes of plasma samples. Using label-free quantitative phosphoproteomics, we identified 144 phosphoproteins in plasma EVs that are significantly higher in patients diagnosed with breast cancer compared with healthy controls. Several biomarkers were validated in individual patients using paralleled reaction monitoring for targeted quantitation. This study demonstrates that the development of phosphoproteins in plasma EV as disease biomarkers is highly feasible and may transform cancer screening and monitoring.

Water quality degradation effects on freshwater availability: Impacts to human activities

USGS Publications Warehouse

Peters, N.E.; Meybeck, Michel

2000-01-01

The quality of freshwater at any point on the landscape reflects the combined effects of many processes along water pathways. Human activities on all spatial scales affect both water quality and quantity. Alteration of the landscape and associated vegetation has not only changed the water balance, but typically has altered processes that control water quality. Effects of human activities on a small scale are relevant to an entire drainage basin. Furthermore, local, regional, and global differences in climate and water flow are considerable, causing varying effects of human activities on land and water quality and quantity, depending on location within a watershed, geology, biology, physiographic characteristics, and climate. These natural characteristics also greatly control human activities, which will, in turn, modify (or affect) the natural composition of water. One of the most important issues for effective resource management is recognition of cyclical and cascading effects of human activities on the water quality and quantity along hydrologic pathways. The degradation of water quality in one part of a watershed can have negative effects on users downstream. Everyone lives downstream of the effects of some human activity. An extremely important factor is that substances added to the atmosphere, land, and water generally have relatively long time scales for removal or clean up. The nature of the substance, including its affinity for adhering to soil and its ability to be transformed, affects the mobility and the time scale for removal of the substance. Policy alone will not solve many of the degradation issues, but a combination of policy, education, scientific knowledge, planning, and enforcement of applicable laws can provide mechanisms for slowing the rate of degradation and provide human and environmental protection. Such an integrated approach is needed to effectively manage land and water resources.

Effectiveness of barnyard best management practices in Wisconsin

USGS Publications Warehouse

Stuntebeck, Todd D.; Bannerman, Roger T.

1998-01-01

In 1978, the Wisconsin Legislature committed to protecting water quality by enacting the Nonpoint Source Water Pollution Abatement Program. Through this program, cost-share money is provided within priority watersheds to control sources of nonpoint pollution. Most of the cost-share dollars for rural watersheds have been used to implement barnyard Best Management Practices (BMPs) because barnyards are believed to be a major source of pollutants, most notably phosphorus. Reductions in phosphorus loads of as much as 95 percent have been predicted for the barnyard BMPs recommended for priority watersheds.

GIS Based Distributed Runoff Predictions in Variable Source Area Watersheds Employing the SCS-Curve Number

NASA Astrophysics Data System (ADS)

Steenhuis, T. S.; Mendoza, G.; Lyon, S. W.; Gerard Marchant, P.; Walter, M. T.; Schneiderman, E.

2003-04-01

Because the traditional Soil Conservation Service Curve Number (SCS-CN) approach continues to be ubiquitously used in GIS-BASED water quality models, new application methods are needed that are consistent with variable source area (VSA) hydrological processes in the landscape. We developed within an integrated GIS modeling environment a distributed approach for applying the traditional SCS-CN equation to watersheds where VSA hydrology is a dominant process. Spatial representation of hydrologic processes is important for watershed planning because restricting potentially polluting activities from runoff source areas is fundamental to controlling non-point source pollution. The methodology presented here uses the traditional SCS-CN method to predict runoff volume and spatial extent of saturated areas and uses a topographic index to distribute runoff source areas through watersheds. The resulting distributed CN-VSA method was incorporated in an existing GWLF water quality model and applied to sub-watersheds of the Delaware basin in the Catskill Mountains region of New York State. We found that the distributed CN-VSA approach provided a physically-based method that gives realistic results for watersheds with VSA hydrology.

Chloride cycling in two forested lake watersheds in the west-central Adirondack Mountains, New York, U.S.A.

USGS Publications Warehouse

Peters, N.E.

1991-01-01

The chemistry of precipitation, throughfall, soil water, ground water, and surface water was evaluated in two forested lake-watersheds over a 4-yr period to assess factors controlling C1- cycling. Results indicate that C1- cycling in these watersheds is more complex than the generally held view of the rapid transport of atmospherically derived C1- through the ecosystem. The annual throughfall Cl- flux for individual species in the northern hardwood forest was 2 to 5 times that of precipitation (56 eq ha-1), whereas the Na+ throughfall flux, in general, was similar to the precipitation flux. Concentrations of soil-water Cl- sampled from ceramic tension lysimeters at 20 cm below land surface generally exceeded the Na+ concentrations and averaged 31 ??eq L-1, the highest of any waters sampled in the watersheds, except throughfall under red spruce which averaged 34 ??eq L-1. Chloride was concentrated prior to storms and mobilized rapidly during storms as suggested by increases in streamwater Cl- concentrations with increasing flow. Major sources of Cl- in both watersheds are the forest floor and hornblende weathering in the soils and till. In the Panther Lake watershed, which contains mainly thick deposits of till( > 3 m), hornblende weathering results in a net Cl- flux 3 times greater than that in the Woods Lake watershed, which contains mainly thin deposits of till. The estimated accumulation rate of Cl- in the biomass of the two watersheds was comparable to the precipitation Cl- flux.The chemistry of precipitation, throughfall, soil water, ground water, and surface water was evaluated in two forested lake-watersheds over a 4-yr period to assess factors controlling Cl- cycling. Results indicate that Cl- cycling in these watersheds is more complex than the generally held view of the rapid transport of atmospherically derived Cl- through the excosystem. The annual throughfall Cl- flux for individual species in the northern hardwood forest was 2 to 5 times that of precipitation (56 eq ha-1), whereas the Na+ throughfall flux, in general, was similar to the precipitation flux. Concentrations of soil-water Cl- sampled from ceramic tension lysimeters at 20 cm below land surface generally exceeded the Na+ concentrations and averaged 31 ??eq L-1, the highest of any waters sampled in the watersheds, except throughfall under red spruce which averaged 34 ??eq L-1. Chloride was concentrated prior to storms and mobilized rapidly during storms as suggested by increases in streamwater Cl- concentrations with increasing flow. Major sources of Cl- in both watersheds are the forest floor and hornblende weathering in the soils and till. In the Panther Lake watershed, which contains mainly thick deposits of till (> 3 m), hornblende weathering results in a net Cl- flux 3 times greater than that in the Woods Lake watershed, which contains mainly thin deposits of till. The estimated accumulation rate of Cl- in the biomass of the two watersheds was comparable to the precipitation Cl- flux.

Distribution and abundance of human-specific Bacteroides and relation to traditional indicators in an urban tropical catchment

PubMed Central

Nshimyimana, J P; Ekklesia, E; Shanahan, P; Chua, L H C; Thompson, J R

2014-01-01

Aims The study goals were to determine the relationship between faecal indicator bacteria (FIB), the HF183 marker and land use, and the phylogenetic diversity of HF183 marker sequences in a tropical urban watershed. Methods and Results Total coliforms, Escherichia coli, and HF183 were quantified in 81 samples categorized as undeveloped, residential and horticultural from the Kranji Reservoir and Catchment in Singapore. Quantitative-PCR for HF183 followed by analysis of variance indicated that horticultural areas had significantly higher geometric means for marker levels (4·3 × 104 HF183-GE 100 ml−1) than nonhorticultural areas (3·07 × 103 HF183-GE 100 ml−1). E. coli and HF183 were moderately correlated in horticultural areas (R = 0·59, P = 0·0077), but not elsewhere in the catchment. Initial upstream surveys of candidate sources revealed elevated HF183 in a wastewater treatment effluent but not in aquaculture ponds. The HF183 marker was cloned, sequenced and determined by phylogenetic analysis to match the original marker description. Conclusion We show that quantification of the HF183 marker is a useful tool for mapping the spatial distribution and potential sources of human sewage contamination in tropical environments such as Singapore. Significance and Impact A major challenge for assessment of water quality in tropical environments is the natural occurrence and nonconservative behaviour of FIB. The HF183 marker has been employed in temperate environments as an alternative indicator for human sewage contamination. Our study supports the use of the HF183 marker as an indicator for human sewage in Singapore and motivates further work to determine HF183 marker levels that correspond to public health risk in tropical environments. PMID:24460587

Watershed Scale Impacts of Stormwater Green Infrastructure on Hydrology, Nitrogen Fluxes, and Combined Sewer Overflows in the Baltimore, MD and Washington, DC area

NASA Astrophysics Data System (ADS)

Jaffe, P. R.; Pennino, M. J.; McDonald, R.

2016-12-01

Despite the increasing use of urban stormwater green infrastructure (SGI), including detention ponds and rain gardens, few studies have quantified the cumulative effects of multiple SGI projects on hydrology and water quality at the watershed scale. To assess the effects of SGI, Baltimore County, MD, Montgomery County, MD, and Washington, DC, were selected based on the availability of data on SGI, water quality, and stream flow. The watershed scale impact of SGI was evaluated by assessing how increased spatial density of SGI correlates with stream hydrology and nitrogen exports over space and time. The most common SGI types were detention ponds (58%), followed by marshes (12%), sand filters (9%), wet ponds (7%), infiltration trenches (4%), and rain gardens (2%). When controlling for watersheds size and percent impervious surface cover, watersheds with greater amounts of SGI (>10% SGI) have 44% lower peak runoff, 26% less frequent runoff events, and 26% less variable runoff than watersheds with lower SGI. Watersheds with more SGI also show 44% less NO3- and 48% less total nitrogen exports compared to watersheds with minimal SGI. There was no significant reduction in combined sewer overflows in watersheds with greater SGI. Based on specific SGI types, infiltration trenches (R2 = 0.35) showed the strongest correlation with hydrologic metrics, likely due to their ability to attenuate flow, while bioretention (R2 = 0.19) and wet ponds (R2 = 0.12) showed stronger relationships with nitrogen compared to other SGI types, possibly due to greater denitrification in these sites. When comparing individual watersheds over time, increases in SGI corresponded to non-significant reductions in hydrologic flashiness and combined sewer overflows compared to watersheds with no change in SGI. This study shows that while implementation of SGI is ongoing, some regions are beginning to have enough SGI to see significant impacts on hydrology and water quality at the watershed scale.

A study of dissolved organic carbon and nitrate export in Catskill Mountain watersheds

NASA Astrophysics Data System (ADS)

Son, K.; Moore, K. E.; Lin, L.; Schneiderman, E. M.; Band, L. E.

2016-12-01

Watersheds in the Catskill Mountain region of New York State have historically experienced soil and stream acidification due to deposition of acidic compounds created from atmospheric SO2 and NOx. Recent studies in this region, and elsewhere in North America and Europe, have shown increases in dissolved organic carbon (DOC) in streams and lakes. Watersheds in the Catskills are the major source of drinking water for New York City and other communities in the region. Due to use of chlorine for disinfection, there is potential for the increase in DOC to lead to increased levels of disinfection byproducts in treated drinking water. Therefore, developing an improved understanding of the sources, fate and transport mechanisms, and export patterns for nitrate and DOC is important for informing watershed and water supply management. In this study, we analyzed the relationships between watershed characteristics, nitrate, and DOC for 12 gauged streams in the Neversink River watershed. Watershed characteristics included topography (elevation, slope, topographic wetness index), vegetation (leaf area index, species composition), soil (soil hydraulic parameters, soil carbon, wetland soil), atmospheric deposition (SO2, NOx), and climate (precipitation, temperature). Our preliminary analysis showed that both watershed slope and baseflow ratio are negatively correlated with annual median DOC concentration. At Biscuit Brook in the Neversink watershed, annual precipitation explained about 25% of annual DOC median concentration. DOC concentration was highly correlated with storm runoff in spring, summer, and fall, but stream nitrate concentration was weakly correlated with storm runoff in most seasons except summer when it was highly correlated with baseflow. We also applied a process-based ecohydrologic model (Regional Hydrologic Ecologic System Simulation, RHESSys) to the Biscuit Brook watershed to explore sources of nitrate and DOC and their movement within the watershed. We expect that this study will increase our understanding of how, when, and where DOC and nitrate are stored and transported to streams, as well as give insights into the key controls on nitrate and DOC processes in Catskill Mountain watersheds.

Hydrostratigraphic and structural controls on streamflow generation in the Chuska Mountains, Navajo Nation, AZ/NM

NASA Astrophysics Data System (ADS)

Tsinnajinnie, L.; Frisbee, M. D.; Wilson, J. L.

2017-12-01

A conceptual model of hydrostratigraphic and structural influences on 3D streamflow generation processes is tested in the Whiskey Creek watershed located in the Chuska Mountains of the Navajo Nation along the northern NM/AZ border. The role of hydrostratigraphy and structure in groundwater processes has been well studied. However, influences of heterogeneity due to geologic structure and stratigraphy of mountain blocks on 3D streamflow generation has received less attention. Three-dimensional flow in mountainous watersheds, such as Saguache Creek (CO) and Rio Hondo (NM), contributes significant amounts of groundwater from deep circulation to streamflow. This fully 3D conceptual model is fundamentally different than watersheds characterized as 2D, those dominated by surface and shallow subsurface runoff, because 3D watersheds can have much longer flowpaths and mean residence times (up to 1000s of years). In contrast to Saguache Creek (volcanic bedrock) and Rio Hondo (crystalline metamorphic), the bedrock geology of the watersheds draining the Chuska Mountains is primarily comprised of sedimentary bedrock capped by extrusive volcanics. We test this conceptual model using a combination of stream gauging, tritium analyses, and endmember mixing analysis (EMMA) on the general ion chemistry and stable isotope composition of water samples collected in 2013-2016. Springs that emerge from the Chuska Sandstone are tritium dead indicative of a large component of pre-bomb pulse water in discharge and deeper 3D flow. EMMA indicates that most streamflow is generated from groundwater emerging from the Chuska Sandstone. Gaining/losing conditions in Whiskey Creek are strongly related to hydrostratigraphy as evidenced by a transition from gaining conditions largely found in the Chuska Sandstone to losing conditions where the underlying Chinle Formation outcrops. Although tritium in Whiskey Creek suggests 3D interactions are present, hydrostratigraphic and structural controls may limit the occurrence of longer residence times and longer flow paths. Mountainous watersheds similar to the 3D hydrostratigraphic and structurally controlled models will exhibit different responses to perturbations, such as climate change, than watersheds that fit existing 2D and 3D conceptual models.

Gene inactivation in the plant pathogen Glomerella cingulata: three strategies for the disruption of the pectin lyase gene pnlA.

PubMed

Bowen, J K; Templeton, M D; Sharrock, K R; Crowhurst, R N; Rikkerink, E H

1995-01-20

The feasibility of performing routine transformation-mediated mutagenesis in Glomerella cingulata was analysed by adopting three one-step gene disruption strategies targeted at the pectin lyase gene pnlA. The efficiencies of disruption following transformation with gene replacement- or gene truncation-disruption vectors were compared. To effect replacement-disruption, G. cingulata was transformed with a vector carrying DNA from the pnlA locus in which the majority of the coding sequence had been replaced by the gene for hygromycin B resistance. Two of the five transformants investigated contained an inactivated pnlA gene (pnlA-); both also contained ectopically integrated vector sequences. The efficacy of gene disruption by transformation with two gene truncation-disruption vectors was also assessed. Both vectors carried at 5' and 3' truncated copy of the pnlA coding sequence, adjacent to the gene for hygromycin B resistance. The promoter sequences controlling the selectable marker differed in the two vectors. In one vector the homologous G. cingulata gpdA promoter controlled hygromycin B phosphotransferase expression (homologous truncation vector), whereas in the second vector promoter elements were from the Aspergillus nidulans gpdA gene (heterologous truncation vector). Following transformation with the homologous truncation vector, nine transformants were analysed by Southern hybridisation; no transformants contained a disrupted pnlA gene. Of nineteen heterologous truncation vector transformants, three contained a disrupted pnlA gene; Southern analysis revealed single integrations of vector sequence at pnlA in two of these transformants. pnlA mRNA was not detected by Northern hybridisation in pnlA- transformants. pnlA- transformants failed to produce a PNLA protein with a pI identical to one normally detected in wild-type isolates by silver and activity staining of isoelectric focussing gels. Pathogenesis on Capsicum and apple was unaffected by disruption of the pnlA gene, indicating that the corresponding gene product, PNLA, is not essential for pathogenicity. Gene disruption is a feasible method for selectively mutating defined loci in G. cingulata for functional analysis of the corresponding gene products.

Interpolation of Water Quality Along Stream Networks from Synoptic Data

NASA Astrophysics Data System (ADS)

Lyon, S. W.; Seibert, J.; Lembo, A. J.; Walter, M. T.; Gburek, W. J.; Thongs, D.; Schneiderman, E.; Steenhuis, T. S.

2005-12-01

Effective catchment management requires water quality monitoring that identifies major pollutant sources and transport and transformation processes. While traditional monitoring schemes involve regular sampling at fixed locations in the stream, there is an interest synoptic or `snapshot' sampling to quantify water quality throughout a catchment. This type of sampling enables insights to biogeochemical behavior throughout a stream network at low flow conditions. Since baseflow concentrations are temporally persistence, they are indicative of the health of the ecosystems. A major problem with snapshot sampling is the lack of analytical techniques to represent the spatially distributed data in a manner that is 1) easily understood, 2) representative of the stream network, and 3) capable of being used to develop land management scenarios. This study presents a kriging application using the landscape composition of the contributing area along a stream network to define a new distance metric. This allows for locations that are more `similar' to stay spatially close together while less similar locations `move' further apart. We analyze a snapshot sampling campaign consisting of 125 manually collected grab samples during a summer recession flow period in the Townbrook Research Watershed. The watershed is located in the Catskill region of New York State and represents the mixed forest-agriculture land uses of the region. Our initial analysis indicated that stream nutrients (nitrogen and phosphorus) and chemical (major cations and anions) concentrations are controlled by the composition of landscape characteristics (landuse classes and soil types) surrounding the stream. Based on these relationships, an intuitively defined distance metric is developed by combining the traditional distance between observations and the relative difference in composition of contributing area. This metric is used to interpolate between the sampling locations with traditional geostatistic techniques (semivariograms and ordinary kriging). The resulting interpolations provide continuous stream nutrient and chemical concentrations with reduced kriging RMSE (i.e., the interpolation fits the actual data better) performed without path restriction to the stream channel (i.e., the current default for most geostatistical packages) or performed with an in-channel, Euclidean distance metric (i.e., `as the fish swims' distance). In addition to being quantifiably better, the new metric also produces maps of stream concentrations that match expected continuous stream concentrations based on expert knowledge of the watershed. This analysis and its resulting stream concentration maps provide a representation of spatially distributed synoptic data that can be used to quantify water quality for more effective catchment management that focuses on pollutant sources and transport and transformation processes.

Physicochemical assessment criteria for high-voltage pulse capacitors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Darian, L. A., E-mail: LDarian@rambler.ru; Lam, L. Kh.

In the paper, the applicability of decomposition products of internal insulation of high-voltage pulse capacitors is considered (aging is the reason for decomposition products of internal insulation). Decomposition products of internal insulation of high-voltage pulse capacitors can be used to evaluate their quality when in operation and in service. There have been three generations of markers of aging of insulation as in the case with power transformers. The area of applicability of markers of aging of insulation for power transformers has been studied and the area can be extended to high-voltage pulse capacitors. The research reveals that there is amore » correlation between the components and quantities of markers of aging of the first generation (gaseous decomposition products of insulation) dissolved in insulating liquid and the remaining life of high-voltage pulse capacitors. The application of markers of aging to evaluate the remaining service life of high-voltage pulse capacitor is a promising direction of research, because the design of high-voltage pulse capacitors keeps stability of markers of aging of insulation in high-voltage pulse capacitors. It is necessary to continue gathering statistical data concerning development of markers of aging of the first generation. One should also carry out research aimed at estimation of the remaining life of capacitors using markers of the second and the third generation.« less

Advancement in Watershed Modelling Using Dynamic Lateral and Longitudinal Sediment (Dis)connectivity Prediction

NASA Astrophysics Data System (ADS)

Mahoney, D. T.; al Aamery, N. M. H.; Fox, J.

2017-12-01

The authors find that sediment (dis)connectivity has seldom taken precedence within watershed models, and the present study advances this modeling framework and applies the modeling within a bedrock-controlled system. Sediment (dis)connectivity, defined as the detachment and transport of sediment from source to sink between geomorphic zones, is a major control on sediment transport. Given the availability of high resolution geospatial data, coupling sediment connectivity concepts within sediment prediction models offers an approach to simulate sediment sources and pathways within a watershed's sediment cascade. Bedrock controlled catchments are potentially unique due to the presence of rock outcrops causing longitudinal impedance to sediment transport pathways in turn impacting the longitudinal distribution of the energy gradient responsible for conveying sediment. Therefore, the authors were motivated by the need to formulate a sediment transport model that couples sediment (dis)connectivity knowledge to predict sediment flux for bedrock controlled catchments. A watershed-scale sediment transport model was formulated that incorporates sediment (dis)connectivity knowledge collected via field reconnaissance and predicts sediment flux through coupling with the Partheniades equation and sediment continuity model. Sediment (dis)connectivity was formulated by coupling probabilistic upland lateral connectivity prediction with instream longitudinal connectivity assessments via discretization of fluid and sediment pathways. Flux predictions from the upland lateral connectivity model served as an input to the instream longitudinal connectivity model. Disconnectivity in the instream model was simulated via the discretization of stream reaches due to barriers such as bedrock outcroppings and man-made check dams. The model was tested for a bedrock controlled catchment in Kentucky, USA for which extensive historic water and sediment flux data was available. Predicted sediment flux was validated via sediment flux measurements collected by the authors. Watershed configuration and the distribution of lateral and longitudinal impedances to sediment transport were found to have significant influence on sediment connectivity and thus sediment flux.

Evaluation on the effectiveness of 2-deoxyglucose-6-phosphate phosphatase (DOGR1) gene as a selectable marker for oil palm (Elaeis guineensis Jacq.) embryogenic calli transformation mediated by Agrobacterium tumefaciens

PubMed Central

Izawati, Abang Masli Dayang; Masani, Mat Yunus Abdul; Ismanizan, Ismail; Parveez, Ghulam Kadir Ahmad

2015-01-01

DOGR1, which encodes 2-deoxyglucose-6-phosphate phosphatase, has been used as a selectable marker gene to produce transgenic plants. In this study, a transformation vector, pBIDOG, which contains the DOGR1 gene, was transformed into oil palm embryogenic calli (EC) mediated by Agrobacterium tumefaciens strain LBA4404. Transformed EC were exposed to 400 mg l-1 2-deoxyglucose (2-DOG) as the selection agent. 2-DOG resistant tissues were regenerated into whole plantlets on various regeneration media containing the same concentration of 2-DOG. The plantlets were later transferred into soil and grown in a biosafety screenhouse. PCR and subsequently Southern blot analyses were carried out to confirm the integration of the transgene in the plantlets. A transformation efficiency of about 1.0% was obtained using DOGR1 gene into the genome of oil palm. This result demonstrates the potential of using combination of DOGR1 gene and 2-DOG for regenerating transgenic oil palm. PMID:26442041

Mitochondrial Genome Sequencing and Development of Genetic Markers for the Detection of DNA of Invasive Bighead and Silver Carp (Hypophthalmichthys nobilis and H. molitrix) in Environmental Water Samples from the United States

PubMed Central

Farrington, Heather L.; Edwards, Christine E.; Guan, Xin; Carr, Matthew R.; Baerwaldt, Kelly; Lance, Richard F.

2015-01-01

Invasive Asian bighead and silver carp (Hypophthalmichthys nobilis and H. molitrix) pose a substantial threat to North American aquatic ecosystems. Recently, environmental DNA (eDNA), genetic material shed by organisms into their environment that can be detected by non-invasive sampling strategies and genetic assays, has gained recognition as a tool for tracking the invasion front of these species toward the Great Lakes. The goal of this study was to develop new species-specific conventional PCR (cPCR) and quantitative (qPCR) markers for detection of these species in North American surface waters. We first generated complete mitochondrial genome sequences from 33 bighead and 29 silver carp individuals collected throughout their introduced range. These sequences were aligned with those from other common and closely related fish species from the Illinois River watershed to identify and design new species-specific markers for the detection of bighead and silver carp DNA in environmental water samples. We then tested these genetic markers in the laboratory for species-specificity and sensitivity. Newly developed markers performed well in field trials, did not have any false positive detections, and many markers had much higher detection rates and sensitivity compared to the markers currently used in eDNA surveillance programs. We also explored the use of multiple genetic markers to determine whether it would improve detection rates, results of which showed that using multiple highly sensitive markers should maximize detection rates in environmental samples. The new markers developed in this study greatly expand the number of species-specific genetic markers available to track the invasion front of bighead and silver carp and will improve the resolution of these assays. Additionally, the use of the qPCR markers developed in this study may reduce sample processing time and cost of eDNA monitoring for these species. PMID:25706532

Mitochondrial genome sequencing and development of genetic markers for the detection of DNA of invasive bighead and silver carp (Hypophthalmichthys nobilis and H. molitrix) in environmental water samples from the United States.

PubMed

Farrington, Heather L; Edwards, Christine E; Guan, Xin; Carr, Matthew R; Baerwaldt, Kelly; Lance, Richard F

2015-01-01

Invasive Asian bighead and silver carp (Hypophthalmichthys nobilis and H. molitrix) pose a substantial threat to North American aquatic ecosystems. Recently, environmental DNA (eDNA), genetic material shed by organisms into their environment that can be detected by non-invasive sampling strategies and genetic assays, has gained recognition as a tool for tracking the invasion front of these species toward the Great Lakes. The goal of this study was to develop new species-specific conventional PCR (cPCR) and quantitative (qPCR) markers for detection of these species in North American surface waters. We first generated complete mitochondrial genome sequences from 33 bighead and 29 silver carp individuals collected throughout their introduced range. These sequences were aligned with those from other common and closely related fish species from the Illinois River watershed to identify and design new species-specific markers for the detection of bighead and silver carp DNA in environmental water samples. We then tested these genetic markers in the laboratory for species-specificity and sensitivity. Newly developed markers performed well in field trials, did not have any false positive detections, and many markers had much higher detection rates and sensitivity compared to the markers currently used in eDNA surveillance programs. We also explored the use of multiple genetic markers to determine whether it would improve detection rates, results of which showed that using multiple highly sensitive markers should maximize detection rates in environmental samples. The new markers developed in this study greatly expand the number of species-specific genetic markers available to track the invasion front of bighead and silver carp and will improve the resolution of these assays. Additionally, the use of the qPCR markers developed in this study may reduce sample processing time and cost of eDNA monitoring for these species.

Effects of poultry manure, compost, and biochar amendments on soil nitrogen dynamics in maize production systems

NASA Astrophysics Data System (ADS)

Ryals, R.; Tang, J.; Hastings, M. G.; Dell, C. J.; Sims, T.

2013-12-01

Intensification of animal agriculture has profound impacts on the global and local biogeochemistry of nitrogen (N), resulting in consequences to environmental and human health. In the Chesapeake Bay watershed, intensive agriculture is the primary contributor to N pollution, with animal manure comprising more than half of N from agriculture. Management interventions may play an important role in mitigating reactive N pollution in the Bay watershed. The objective of our research was to test management strategies that maximize benefits of poultry manure as an agricultural resource while minimizing it as a source of reactive nitrogen to the atmosphere and ground and surface waters. We conducted field experiments in two agricultural regions of the Chesapeake Bay watershed (Georgetown, Delaware and State College, Pennsylvania) to explore the effects of poultry manure amendments on gaseous N losses and soil N transformations. Treatments were applied at rates needed to meet the plant N demand at each site and included unfertilized controls, fertilizer N (urea), and raw, composted, or and biocharred poultry manure. The fate of the N from all sources was followed throughout the growing season. Global greenhouse gases emitted from soil (nitrous oxide [N2O] and carbon dioxide [CO2]) and regional air pollutants (nitrogen oxides [NOx] and ammonia [NH3]) were measured. Gas measurements were coupled with data on treatment effects on temperature, moisture, and concentrations of nitrate (NO3¬-) and ammonium (NH4+) in surface soils (0-10 cm). Soil NO3- and NH4+ were also measured approximately monthly in the soil profile (0-10, 10-30, 30-50, 50-70, and 70-100 cm) as an index of leaching potential. Plant N uptake and grain production were also quantified to quantify crop N use efficiency and compare measured N losses for each N source. Our results suggest that the form of poultry manure amendments can affect the magnitude of reactive N losses to the environment.

40 CFR 141.521 - What updated watershed control requirements must my unfiltered system implement to continue to...

Code of Federal Regulations, 2011 CFR

2011-07-01

...) Identify watershed characteristics and activities which may have an adverse effect on source water quality; and (b) Monitor the occurrence of activities which may have an adverse effect on source water quality. ... Protection of Environment ENVIRONMENTAL PROTECTION AGENCY (CONTINUED) WATER PROGRAMS (CONTINUED) NATIONAL...

Ecosystem processes at the watershed scale: mapping and modeling ecohydrological controls

Treesearch

Lawrence E. Band; T. Hwang; T.C. Hales; James Vose; Chelcy Ford

2012-01-01

Mountain watersheds are sources of a set of valuable ecosystem services as well as potential hazards. The former include high quality freshwater, carbon sequestration, nutrient retention, and biodiversity, whereas the latter include flash floods, landslides and forest fires. Each of these ecosystem services and hazards represents different elements of the integrated...

Spatial and temporal controls on watershed ecohydrology in the northern Rocky Mountains

Treesearch

Ryan E. Emanuel; Howard E. Epstein; Brian L. McGlynn; Daniel L. Welsch; Daniel J. Muth; Paulo D& #65533; fOdorico

2010-01-01

Vegetation water stress plays an important role in the movement of water through the soil�]plant�]atmosphere continuum. However, the effects of water stress on evapotranspiration (ET) and other hydrological processes at the watershed scale remain poorly understood due in part to spatially and temporally heterogeneous conditions within the...

Evaluating mountain meadow groundwater response to pinyon-juniper and temperature in a great basin watershed

USDA-ARS?s Scientific Manuscript database

Expansion of deeply-rooted Pinyon-Juniper (PJ) has altered water partitioning and reduced water availability to discharging meadows. Research highlights the development and application of GSFLOW to a semi-arid, snow-dominated watershed in the Great Basin to evaluate PJ and temperature controls on mo...

Thinking outside of the Lake: Can controls on nutrient inputs into Lake Erie benefit stream conservation in its watershed?

USDA-ARS?s Scientific Manuscript database

Investment in agricultural conservation practices (CPs) to address Lake Erie's re-eutrophication may offer benefits that extend beyond the lake, such as improved habitat conditions for fish communities throughout the watershed. If such conditions are not explicitly considered in Lake Erie nutrient ...

MEETING IN PHILADELPHIA: NUTRIENT CONCENTRATIONS IN FLOWING WATERS OF THE SOUTH FORK BROAD RIVER, GEORGIA WATERSHED

EPA Science Inventory

The objective of this poster is by comparing nutrient and DOM concentrations in small and large streams, we hope to better understand: (1) watershed controls on stream nutrient and DOM concentrations; and (2) the variability of nutrient and DOM concentrations within a river netwo...

Interactive influences of ozone and climate on streamflow of forested watersheds

Treesearch

Ge Sun; Samuel B. Mclaughlin; John H. Porter; Johan Uddling; Patrick J. Mulholland; Mary B. Adams; Neil Pederson

2012-01-01

The capacity of forests tomitigate global climate change can be negatively influenced by tropospheric ozone that impairs both photosynthesis and stomatal control of plant transpiration, thus affecting ecosystem productivity and watershed hydrology. We have evaluated individual and interactive effects of ozone and climate on late season streamflow for six forested...

Post-disturbance sediment recovery: Implications for watershed resilience

Treesearch

Sara L. Rathburn; Scott M. Shahverdian; Sandra E. Ryan

2017-01-01

Sediment recovery following disturbances is a measure of the time required to attain pre-disturbance sediment fluxes. Insight into the controls on recovery processes and pathways builds understanding of geomorphic resilience.We assess post-disturbance sediment recovery in three small (1.5-100 km2), largely unaltered watersheds within the northern Colorado...