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1.
Ecol Eng ; 129: 123-133, 2019 Apr 01.
Article in English | MEDLINE | ID: mdl-32982067

ABSTRACT

Restoration and reconnection of floodplain systems provide multiple societal and ecosystem benefits, while providing municipalities the opportunity to attempt alternative approaches to maintain infrastructure protection and function. In some restored floodplains, treated wastewater effluent discharge is redirected over land instead of directly into rivers to allow natural flow and infiltration, to facilitate restoration designs such as levee setback, and to provide additional freshwater to floodplain ecosystems. However, indirect discharge of treated effluent over land may pose risks to surface and groundwater when pollutants like excess nutrients enter the floodplain and undergo transformation. We investigated the consequences for groundwater and surface water quality when effluent was redirected as open water channels over a floodplain surface. In this study, seasonal floodplain nutrient concentrations in groundwater and surface water were observed for more than 5 years as a floodplain and wastewater treatment plant underwent a major restoration project that included river-floodplain reconnection with levee setback and redirection of effluent discharge from a river channel to open flow across the restored floodplain. Nutrient loading to the surrounding floodplain groundwater and surface water was observed, but based on measures of hydrological connectivity, groundwater flow paths, and biogeochemistry, nutrients from the effluent moved within the floodplain with minimal effect to the surrounding floodplain water quality. We did not find evidence of substantial additional processing that could replace advanced nutrient treatment in this system, however we did observe evidence of diverse nutrient processes that may support enhanced retention if treatment channels were designed to enhance these processes. We suggest that indirect discharge of high quality treated effluent in a restored floodplain is a viable alternative to direct discharge into a river when groundwater flow directs that discharge to habitats where minimal nutrient sensitivity is expected.

2.
J Am Water Resour Assoc ; 55(2): 497-510, 2019 Apr 05.
Article in English | MEDLINE | ID: mdl-32704230

ABSTRACT

A total maximum daily load for the Chesapeake Bay requires reduction in pollutant load from sources within the Bay watersheds. The Conestoga River watershed has been identified as a major source of sediment load to the Bay. Upland loads of sediment from agriculture are a concern; however, a large proportion of the sediment load in the Conestoga River has been linked to scour of legacy sediment associated with historic millpond sites. Clarifying this distinction and identifying specific segments associated with upland vs. channel sources has important implications for future management. In order to address this important question, we combined the strengths of two widely accepted watershed management models - Soil and Water Assessment Tool (SWAT) for upland agricultural processes, and Hydrologic Simulation Program FORTRAN (HSPF) for instream fate and transport - to create a novel linked modeling system to predict sediment loading from critical sources in the watershed including upland and channel sources, and to aid in targeted implementation of management practices. The model indicates approximately 66% of the total sediment load is derived from instream sources, in agreement with other studies in the region and can be used to support identification of these channel source segments vs. upland source segments, further improving targeted management. The innovated linked SWAT-HSPF model implemented in this study is useful for other watersheds where both upland agriculture and instream processes are important sources of sediment load.

3.
Ecol Eng ; 116: 110-120, 2018.
Article in English | MEDLINE | ID: mdl-31908361

ABSTRACT

Hyporheic exchange between a river channel and its floodplain region assists in mediating processes such as nutrient removal and temperature regulation. Floodplain restoration in the form of levee setbacks are often carried out to improve the hyporheic exchange. In this study Light Detection and Ranging (LiDAR) data were used along with the head data from observation wells and stage data from rivers to setup and calibrate a groundwater model for 458 km2 of area within Gap to Gap reach of the Yakima River, WA. This area has witnessed several efforts of floodplain restoration in the form of levee setbacks. The groundwater model was used to quantify hyporheic flow emerging from the Yakima River in steady and transient states during pre-restoration (using LiDAR data of 2008) and post-restoration period (after levee setback using LiDAR data of 2013). The comparison of results from the model runs during pre and post-restoration periods showed that the length of the pathlines increased after levee setback for both steady and transient state model simulations. The largest increase of about 62 m was noticed in the month of September 2014 (pre: 398 m and post: 460 m). The study also showed that the direction of the flow changed following levee setback, expanding the area for hyporheic flux exchange between surface and groundwater. The model run during transient state also suggested that pathlines were longer during drier months compared to wet months. Overall, the study showed that levee setbacks improved the hyporheic connection between surface and groundwater in the Yakima floodplain which demonstrates that levee setback can provide a valuable hydrologic tool to restore ecosystem processes in previously leveed rivers.

4.
Environ Sci Technol ; 47(16): 9324-31, 2013 Aug 20.
Article in English | MEDLINE | ID: mdl-23869402

ABSTRACT

qPCR methods are able to analyze DNA from microbes within hours of collecting water samples, providing the promptest notification and public awareness possible when unsafe pathogenic levels are reached. Health risk, however, may be overestimated by the presence of extracellular DNA (eDNA) that is corecovered by the filtration procedure which is the most commonly used method to concentrate target microbes from environmental waters. Using C. parvum 18S rRNA gene fragment as a representative of eDNA, we examined the impact of filters (types and pore sizes) and physiochemical properties of surface water samples on the recovery of spiked DNA. Our results indicated that binding affinities of various filter membranes were quantifiably different for eDNA fragments with the polycarbonate (PC) binding the least and mixed cellulose acetate and cellulose nitrate (MCE) binding the most as evidenced by up to 16% recovery of the spiked plasmid DNA with a pore size of 0.2 µm. Water quality parameters also had a distinct influence on the recovery of eDNA which was enhanced by the presence of high total suspended solid (TSS) concentrations and reduced pH. At pH 5.5, with 150 mg/L of clay, DNA recovery was increased to as much as 18%. By shielding the negative charge, thus increasing the interaction of DNA and colloids, the increase of Na(+) and Ca(2+) concentrations resulted in more DNA binding and consequently more recovery from environmental water samples. Therefore, in addition to analytical uncertainties, potential differences in qPCR data from filtered waters characterized with low pH and high TSS and ionic strength should be considered in pollution assessments.


Subject(s)
DNA, Protozoan/isolation & purification , RNA, Ribosomal, 18S/genetics , Cryptosporidium parvum/genetics , Filtration , Hydrogen-Ion Concentration , Membranes, Artificial , Osmolar Concentration , Water Quality
5.
Water Res ; 46(18): 5941-53, 2012 Nov 15.
Article in English | MEDLINE | ID: mdl-22980572

ABSTRACT

Purified oocysts of Cryptosporidium parvum were used to evaluate the applicability of two quantitative PCR (qPCR) viability detection methods in raw surface water and disinfection treated water. Propidium monoazide-qPCR targeting hsp70 gene was compared to reverse transcription (RT)-qPCR heat induced hsp70 mRNA in water samples spiked with oocysts. Changes in viability of flow cytometry sorted fresh and oocysts having undergone various aging periods (up to 48 months at 4 °C) were evaluated by Ct values obtained from the qPCR before and after disinfection scenarios involving ammonia or hydrogen peroxide. Both qPCR methods achieved stability in dose dependent responses by hydrogen peroxide treatment in distilled water that proved their suitability for the viability evaluations. Oocysts exposed to 3% hydrogen peroxide were inactivated at a rate of 0.26 h(-1) and 0.93 h(-1), as measured by the mRNA assay and the PMA-DNA assay, respectively. In contrast, the PMA-DNA assay was not as sensitive as the mRNA assay in detecting viability alterations followed by exposure to ammonia or after a long-term storage in 4 °C in distilled water since no dose response dependency was achieved. Surface water concentrates containing enhanced suspendable solids determined that changes in viability were frequently detected only by the mRNA method. Failure of, or inconsistency in the detection of oocysts viability with the PMA-DNA method, apparently resulted from solids that might have reduced light penetration through the samples, and thus inhibited the cross-linking step of PMA-DNA assay.


Subject(s)
Azides/pharmacology , Cryptosporidium/drug effects , Disinfection/methods , Oocysts/drug effects , Propidium/analogs & derivatives , Ammonia/pharmacology , Cryptosporidium/genetics , Hydrogen Peroxide/pharmacology , Polymerase Chain Reaction , Propidium/pharmacology , Reverse Transcriptase Polymerase Chain Reaction
6.
J Nurs Educ ; 51(2): 111-4, 2012 Feb.
Article in English | MEDLINE | ID: mdl-22148934

ABSTRACT

Mental health nursing faculty are challenged to connect with students on an affective level in their courses. One important strategy to promote affective learning is to understand the experience of the family caregiver. There is relatively little student access to family caregivers of individuals who are identified as severely and persistently mentally ill. Consequently, nursing students may not appreciate the myriad psychosocial challenges and adaptations that family caregivers of these individuals are forced to make, often for a lifetime. This article describes a unique teaching strategy that promotes cognitive and affective learning while also providing students with a clear window into the dynamics of families of people with mental illness.


Subject(s)
Caregivers/psychology , Education, Nursing , Empathy , Mental Disorders/nursing , Problem-Based Learning , Professional-Family Relations , Humans , Nursing Assessment , Social Support , United States
7.
Appl Environ Microbiol ; 77(18): 6476-85, 2011 Sep.
Article in English | MEDLINE | ID: mdl-21803904

ABSTRACT

Extraction of high-quality mRNA from Cryptosporidium parvum is a key step in PCR detection of viable oocysts in environmental samples. Current methods for monitoring oocysts are limited to water samples; therefore, the goal of this study was to develop a rapid and sensitive procedure for Cryptosporidium detection in soil samples. The efficiencies of five RNA extraction methods were compared (mRNA extraction with the Dynabeads mRNA Direct kit after chemical and physical sample treatments, and total RNA extraction methods using the FastRNA Pro Soil-Direct, PowerSoil Total RNA, E.Z.N.A. soil RNA, and Norgen soil RNA purification kits) for the direct detection of Cryptosporidium with oocyst-spiked sandy, loamy, and clay soils by using TaqMan reverse transcription-PCR. The study also evaluated the presence of inhibitors by synthesis and incorporation of an internal positive control (IPC) RNA into reverse transcription amplifications, used different facilitators (bovine serum albumin, yeast RNA, salmon DNA, skim milk powder, casein, polyvinylpyrrolidone, sodium hexametaphosphate, and Salmonella enterica serovar Typhi) to mitigate RNA binding on soil components, and applied various treatments (ß-mercaptoethanol and bead beating) to inactivate RNase and ensure the complete lysis of oocysts. The results of spiking studies showed that Salmonella cells most efficiently relieved binding of RNA. With the inclusion of Salmonella during extraction, the most efficient mRNA method was Dynabeads, with a detection limit of 6 × 10(2) oocysts g(-1) of sandy soil. The most efficient total RNA method was PowerSoil, with detection limits of 1.5 × 10(2), 1.5 × 10(3), and 1.5 × 10(4) C. parvum oocysts g(-1) soil for sandy, loamy, and clay samples, respectively.


Subject(s)
Cryptosporidium parvum/isolation & purification , Cryptosporidium parvum/physiology , HSP70 Heat-Shock Proteins/genetics , Real-Time Polymerase Chain Reaction/methods , Reverse Transcriptase Polymerase Chain Reaction/methods , Soil/parasitology , Cell Survival , Cryptosporidium parvum/genetics , Oocysts/physiology , Polymerase Chain Reaction , RNA, Messenger/analysis , RNA, Messenger/genetics , RNA, Protozoan/analysis , RNA, Protozoan/genetics , Time Factors
8.
J Nurs Scholarsh ; 42(1): 83-91, 2010 Mar.
Article in English | MEDLINE | ID: mdl-20487190

ABSTRACT

PURPOSE: To explain how baccalaureate-prepared acute care nurses understand, adapt to, and negotiate challenge and change in acute care settings in the context of social and structural features and consequently develop career persistence there. DESIGN: Grounded theory method based on the research of Strauss and Corbin. METHODS: A research team conducted open-ended interviews with a theoretic sample of 19 new and experienced baccalaureate-prepared (BSN) nurses in the southeast United States during 2007 and 2008 until saturation was achieved. Interviews were audiotaped and transcribed verbatim. Constant comparative method was used to analyze data to three increasingly abstract levels culminating in theory emergence. A diagram was developed to better understand relationships and processes. FINDINGS: A central category, building professional resilience, emerged as the central social process with three core processes of verifying fit, stage setting, and optimizing the environment contributing to career persistence in acute care. Core processes include skills and practices nurses have learned to negotiate changing acute care environments while sustaining patient advocacy. Definitions, properties, and dimensions of each were established. CONCLUSIONS: The study offers a systematic framework for understanding and promoting career persistence for acute care nurses. Findings broaden theories of resilience to the unique settings of acute care nursing and further extend theoretical understanding of the nursing shortage and market issues of supply and demand. CLINICAL RELEVANCE: A middle range theory of professional resilience and career persistence makes visible skills and practices acute-care nurses use to weather continuous change and challenge in health care. Teachable practices can be integrated into nursing education and staff development to improve professional career longevity of experienced nurses at the bedside.


Subject(s)
Burnout, Professional/prevention & control , Education, Nursing, Baccalaureate , Nursing Staff, Hospital , Personnel Management , Adult , Female , Humans , Male , Middle Aged , Models, Theoretical , Nursing Staff, Hospital/education , Nursing Staff, Hospital/psychology , Nursing Staff, Hospital/supply & distribution , Personnel Turnover , Resilience, Psychological , Southeastern United States , Staff Development
9.
Nurs Educ Perspect ; 29(2): 80-9, 2008.
Article in English | MEDLINE | ID: mdl-18459622

ABSTRACT

New nurses typically begin their practice in acute care settings in hospitals, where their work is characterized by time constraints, high safety risks for patients, and layers of complexity and difficult problems. Retention of experienced nurses is an issue central to patient safety. The purpose of this qualitative study was to explore the nature of professional resilience in new baccalaureate-prepared nurses in acute care settings and to extrapolate pedagogical strategies that can be developed to support resilience and career longevity. Findings revealed a common process of evolving resilience among participants. New nurses spend a significant amount of time learning their place in the social structure. With positive experiences, they begin to feel more competent with skills and relationships and become increasingly aware of discrepancies between their ideas of professional nursing and their actual experiences in the work setting. The risk of new nurses leaving their practice is constantly present during these struggles. Acceptable compromises yield a reconciliation of the current crisis, typically occurring long after formal precepting has ended. Personal growth is evident by the evolving clarity of professional identity, an edifying sense of purpose, and energy resources to move forward. For new nurses, professional resilience yields the capacity for self-protection, risk taking, and moving forward with reflective knowledge of self.


Subject(s)
Adaptation, Psychological , Education, Nursing, Baccalaureate , Nursing Staff, Hospital/psychology , Adult , Humans , Inservice Training , Nurse-Patient Relations , Nursing Staff, Hospital/education , Personnel Administration, Hospital , Southeastern United States
10.
Water Res ; 42(10-11): 2803-13, 2008 May.
Article in English | MEDLINE | ID: mdl-18367230

ABSTRACT

Relative changes in the microbial quality of Lake Texoma, on the border of Texas and Oklahoma, were investigated by monitoring protozoan pathogens, fecal indicators, and factors influencing the intensity of the microbiological contamination of surface water reservoirs. The watershed serves rural agricultural communities active in cattle ranching, recreation, and is a potential drinking water source. A total of 193 surface water samples were tested over a 27-month period to determine levels of parasite contamination. The overall occurrence of Cryptosporidium oocysts was higher in both frequency and concentration than Giardia cysts. Cryptosporidium oocysts were found in 99% and Giardia cysts in 87% of the samples. Although Cryptosporidium and Giardia occurrence were significantly but not strongly correlated, all other correlation coefficients including turbidity and total dissolved solids were non-significant. Statistically supportable seasonal variations were found suggesting that Cryptosporidium and Giardia were higher in summer and fall than in other seasons of the year. While Cryptosporidium levels were correlated with rainfall, this was not the case with Giardia. The maximum numbers for both protozoan parasites were detected from a site impacted by cattle ranching during calving season. Restriction fragment length polymorphism analysis was used for confirmation of Cryptosporidium in surface waters influenced by agricultural discharges. As we had expected, oocysts were of the bovine type indicating that the Cryptosporidium parvum detected in surface waters perhaps came from cattle living in the watershed.


Subject(s)
Agriculture , Eukaryota/isolation & purification , Water Supply/analysis , Animals , Cryptosporidium/genetics , Cryptosporidium/isolation & purification , Enterobacteriaceae/isolation & purification , Geography , Giardia/genetics , Giardia/isolation & purification , Nephelometry and Turbidimetry , Oocysts , Rain , Seasons
11.
Environ Sci Technol ; 41(15): 5299-305, 2007 Aug 01.
Article in English | MEDLINE | ID: mdl-17822094

ABSTRACT

A field study was conducted to evaluate the performance of a ferrous iron based in situ redox zone for the treatment of a dissolved phase Cr(VI) plume at a former industrial site. The ferrous iron based in situ redox zone was created by injecting a blend of 0.2 M ferrous sulfate and 0.2 M sodium dithionite into the path of a dissolved Cr(VI) plume within a shallow medium to fine sand unconfined aquifer formation. Monitoring data collected over a period of 1020 days after more than 100 m of linear groundwater flow through the treatment zone indicated sustained treatment of dissolved phase Cr(VI) from initial concentrations between 4 and 8 mg/L to less than 0.015 mg/L. Sustained treatment is assumed to be primarily due to the reduction of Cr(VI) to Cr(III) by ferrous iron adsorbed to, precipitated on, and/or incorporated into aquifer iron (hydr)oxide solid surfaces within the treatment zone. Precipitated phases likely include FeCO3 and FeS based on saturation index considerations and SEM/EDS analysis. The detection of solid phase sulfites and thiosulfates in aquifer sediments collected from the treatment zone more than 2 years following injection suggests dithionite decomposition products may also play a significant role in the long-term treatment of the dissolved phase Cr(VI).


Subject(s)
Chromium/chemistry , Dithionite/chemistry , Ferrous Compounds/chemistry , Fresh Water/chemistry , Soil/analysis , Iron/analysis , Microscopy, Electron, Scanning , Oxidation-Reduction , Reducing Agents/chemistry
12.
J Nurs Educ ; 44(12): 548-54, 2005 Dec.
Article in English | MEDLINE | ID: mdl-16402737

ABSTRACT

New nurses seem unable to find a means of flourishing professionally in acute care practice and, consequently, exit far earlier than expected. Worldviews of baccalaureate students have changed from previous generations; yet, the approaches to nursing education remain essentially the same. Just as clinical settings benefit from nursing theory as the basis for nursing practice and scientific inquiry, the science of nursing education would benefit from nursing theory as a basis for guiding educational practice. Parse's human science theory, the Human Becoming School of Thought, is a fitting theoretical framework for a model of teaching-learning for undergraduate baccalaureate nursing education. In addition, as a theory of dynamic relational synchrony, Parse's work provides an appropriate framework with which to promote professional resilience and career longevity by purposefully engaging students within student-faculty dyads to explore personal meanings and philosophies of caring, and to create strong professional identities.


Subject(s)
Adaptation, Psychological , Education, Nursing, Baccalaureate/organization & administration , Human Development , Models, Educational , Models, Nursing , Professional Competence/standards , Attitude of Health Personnel , Career Mobility , Empathy , Faculty, Nursing , Health Knowledge, Attitudes, Practice , Humans , Interprofessional Relations , Mentors/psychology , Models, Psychological , Nursing Education Research , Philosophy, Nursing , Problem-Based Learning , Psychology, Educational , Social Identification , Socialization , Students, Nursing/psychology , Thinking
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