3,805 research outputs found
Low flow hydraulics in alluvial channels
The investigation of the low flow condition has become important in recent years as a means of determining critical levels of water pollution, aquatic habitat and instream flow needs. To assess these critical conditions, it is necessary to predict the hydraulic response of a river system to a given low flow discharge. Conventional flow models, however, are often inaccurate at low discharges due to the geometric and hydraulic channel features peculiar to these flow conditions. The dominant channel feature at low stages is the pool-riffle sequence, where pools are distinguished by deep, slow moving water and riffles by shallow, relatively rapid moving flow. Conventional flow models have difficulty effectively representing the highly nonprismatic channel geometry, the rapidly changing flow hydraulics, and the dominating influence of flow resistance characteristic of pool-riffle sequences. In this research, a one-dimensional mathematical model has been developed to simulate accurately channel characteristics under low flow conditions. For a given steady discharge, channel geometry, and channel bed particle size distribution, the model predicts the flow depth, the mean velocity, and the flow resistance. Energy losses are assumed to result from flow resistance, as well as from local losses generated by the contractions and expansions occurring through the pool-riffle sequence. The model has been verified using field data, as well as laboratory data collected in conjunction with the project.U.S. Department of the InteriorU.S. Geological SurveyOpe
A Creek in Need: A Water Chemistry Analysis of a Stream Slated for Restoration (Line Creek, Schoharie County, NY)
Surface water quality may directly impact human health and the survival of aquatic life. Schoharie County is a unique laboratory for studying surface water chemistry because many creeks and streams were ravaged by large scale flooding events associated with Hurricane Irene and Tropical Storm Lee in 2011. Currently, one of the largest stream restoration projects in the US is being conducted in the Schoharie Creek watershed. One damaged stream is Line Creek, which is a small first order stream in that watershed. Line Creek was tested for sodium, chloride, alkalinity (HCO3-), hardness (CaCO3), iron, nitrite (NO2-N), nitrate (NO3-N), total and dissolved phosphorous (PO4-P), ammonia (NH3-N) and coliform bacteria. The aforementioned parameters were measured at two sites between February and May 2014 and were compared to earlier data. Data for 2014 (upstream/downstream; all values are mg/L unless otherwise noted) are: sodium 3.18/4.46; chloride 13.5/22.5; alkalinity 29.2/55.0; hardness 40.8/58.8; iron 0.296/0.354; nitrite 0.011/0.014; nitrate 0.122/0.149; total phosphorous 0.002/0.043; dissolved phosphorous 0/0.015; ammonia 0.597/0.639; coliform bacteria(CFU) 16/42. While many parameters fell within EPA guidelines for human consumption or within an accepted range for survival of aquatic life, some like iron, were too high by EPA standards, while alkalinity was too low for aquatic life to properly develop essential hard/bony body structures. This work will be discussed with respect to the larger Schoharie Creek watershed. The broad implications of the data with respect to human and aquatic life will be discussed
Physiological and Behavioral Differences in Sensory Processing: A Comparison of Children with Autism Spectrum Disorder and Sensory Modulation Disorder
A high incidence of sensory processing difficulties exists in children with Autism Spectrum Disorder (ASD) and children with Sensory Modulation Disorder (SMD). This is the first study to directly compare and contrast these clinical disorders. Sympathetic nervous system markers of arousal and reactivity were utilized in a laboratory paradigm that administered a series of sensory challenges across five sensory domains. The Short Sensory Profile, a standardized parent-report measure, provided a measure of sensory-related behaviors. Physiological arousal and sensory reactivity were lower in children with ASD whereas reactivity after each sensory stimulus was higher in SMD, particularly to the first stimulus in each sensory domain. Both clinical groups had significantly more sensory-related behaviors than typically developing children, with contrasting profiles. The ASD group had more taste/smell sensitivity and sensory under-responsivity while the SMD group had more atypical sensory seeking behavior. This study provides preliminary evidence distinguishing sympathetic nervous system functions and sensory-related behaviors in Autism Spectrum Disorder and Sensory Modulation Disorder. Differentiating the physiology and sensory symptoms in clinical groups is essential to the provision of appropriate interventions
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Gene expression differs in susceptible and resistant amphibians exposed to Batrachochytrium dendrobatidis.
Chytridiomycosis, the disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has devastated global amphibian biodiversity. Nevertheless, some hosts avoid disease after Bd exposure even as others experience near-complete extirpation. It remains unclear whether the amphibian adaptive immune system plays a role in Bd defence. Here, we describe gene expression in two host species-one susceptible to chytridiomycosis and one resistant-following exposure to two Bd isolates that differ in virulence. Susceptible wood frogs (Rana sylvatica) had high infection loads and mortality when exposed to the more virulent Bd isolate but lower infection loads and no fatal disease when exposed to the less virulent isolate. Resistant American bullfrogs (R. catesbeiana) had high survival across treatments and rapidly cleared Bd infection or avoided infection entirely. We found widespread upregulation of adaptive immune genes and downregulation of important metabolic and cellular maintenance components in wood frogs after Bd exposure, whereas American bullfrogs showed little gene expression change and no evidence of an adaptive immune response. Wood frog responses suggest that adaptive immune defences may be ineffective against virulent Bd isolates that can cause rapid physiological dysfunction. By contrast, American bullfrogs exhibited robust resistance to Bd that is likely attributable, at least in part, to their continued upkeep of metabolic and skin integrity pathways as well as greater antimicrobial peptide expression compared to wood frogs, regardless of exposure. Greater understanding of these defences will ultimately help conservationists manage chytridiomycosis
Archeological Testing and Monitoring of the Proposed Roma Visitor Complex, City of Roma, Starr County, Texas
In February and March 2003, staff from the Center for Archaeological Research (CAR) of The University of Texas at San Antonio conducted archeological testing and monitoring within the boundaries of the National Historic Landmark District of Roma, Texas. This work was conducted in partial fulfillment of the requirement of the Programmatic Agreement of the Statewide Transportation Enhancement Program, Section 106 of the National Historic Preservation Act, and the Texas Antiquities Code. The archeological services were conducted under contract with Kell Muñoz Architects of San Antonio and in coordination with the City of Roma and the Pharr District of the Texas Department of Transportation. The sites examined included 41SR210 (Antonia Sáenz Residence), 41SR211 (Stone Cottage), 41SR212 (Rafael García-Ramirez House and Store), 41SR215 (Ramirez Hospital), and 41SR337 (The Coffee Pot Café). This report presents the results of archeological testing and monitoring of areas to be impacted by improvements. The improvements include stabilization of historic building walls, installation of utility lines, and the construction of an amphitheater located in the courtyard. This work supported the information concerning the dates of occupation and construction at each site. The cultural materials found were a mixture of artifacts that likely date to before, during, and after the period of construction of each of the buildings. Because these artifacts were not preserved in an archeological context that dates to a particular historical period of Roma and none were recovered from distinct archeological features from such a time period, none of the archeological deposits investigated can be considered to be National Register of Historic Places (NRHP) eligible. Overall, it is the conclusion of CAR that the substantial construction-related impacts related to the Roma Visitor Complex project will not impact intact cultural deposits. Even areas within the National Historic Landmark District that will be subject to relatively shallow, subsurface disturbances retain no intact cultural deposits that would be eligible for nomination to the NRHP or may be contributing to the existing National Historic Landmark properties. Finally, the one area where cultural materials with limited research value may be encountered will not be adversely impacted by construction activities.
These archeological investigations were conducted under Texas Antiquities Permit No. 3052, with Dr. Steve A. Tomka, CAR Director, serving as Principal Investigator. All cultural materials to be curated were prepared in accordance with federal regulation 36 CFR part 79. All collected artifacts and project-related documents will be permanently curated at the Center for Archaeological Research
The Missouri phosphorus index (2007)
Phosphorus (P) is the nutrient limiting algal production in many Missouri streams and lakes. Water quality deteriorates when too much phosphorus enters a stream or lake, a process called eutrophication. Excess phosphorus also can reduce water clarity, cause fish kills, increase drinking water treatment costs and reduce the quality of drinking waterNew 11/007/W
Development and initial testing of the self‐care of chronic illness inventory
Aim
The aim was to develop and psychometrically test the self‐care of chronic illness Inventory, a generic measure of self‐care.
Background
Existing measures of self‐care are disease‐specific or behaviour‐specific; no generic measure of self‐care exists.
Design
Cross‐sectional survey.
Methods
We developed a 20‐item self‐report instrument based on the Middle Range Theory of Self‐Care of Chronic Illness, with three separate scales measuring Self‐Care Maintenance, Self‐Care Monitoring, and Self‐Care Management. Each of the three scales is scored separately and standardized 0–100 with higher scores indicating better self‐care. After demonstrating content validity, psychometric testing was conducted in a convenience sample of 407 adults (enrolled from inpatient and outpatient settings at five sites in the United States and ResearchMatch.org). Dimensionality testing with confirmatory factor analysis preceded reliability testing.
Results
The Self‐Care Maintenance scale (eight items, two dimensions: illness‐related and health‐promoting behaviour) fit well when tested with a two‐factor confirmatory model. The Self‐Care Monitoring scale (five items, single factor) fitted well. The Self‐Care Management scale (seven items, two factors: autonomous and consulting behaviour), when tested with a two‐factor confirmatory model, fitted adequately. A simultaneous confirmatory factor analysis on the combined set of items supported the more general model.
Conclusion
The self‐care of chronic illness inventory is adequate in reliability and validity. We suggest further testing in diverse populations of patients with chronic illnesses
Survey of Blueberry (\u3ci\u3eVaccinium\u3c/i\u3e spp.) Problems in the Gulf South
The blueberry (Vaccinium) industry in Mississippi has been steadily increasing since the early 1980s, but some plants in older fields are now in decline. The root rot pathogen, Phytophthora cinnamomi, is endemic in the southeastern United States and has caused severe losses to blueberries in North Carolina and Arkansas. Because the warm, humid climate of Mississippi, with periods of high precipitation, provides a favorable environment for Phytophthora root rot disease, it was suspected to be the cause of plant decline in older blueberry fields. Members of the Gulf South Blueberry Growers Association were mailed surveys to determine cultural practices and the extent of losses in their blueberry fields. The survey was written in partial, open-ended question format with 33 questions pertaining to cultivars, number of hectares planted, cultural practices, overall health of the blueberry plants, and losses due to diseases, insects, or other problems. Fifty-eight of 146 surveys (40%) were completed and returned. 89% of respondents grew rabbiteye (Vaccinium ashei) cultivars and the balance grew southern highbush (V. corymbosum hybrids) cultivars. The average number of plants per hectare was 1523 with the majority of plants 10 - 20 years old. 79% of the growers described the overall condition of their plants as average, healthy, or vigorous. The most common cause of plant death cited was environmental with damage caused by the 2004 and 2005 hurricanes at the top of the list. No major diseases were reported by 36% of the respondents, while mummy berry (Monilinia vaccinii-corymbosi [Reade] Honey), leaf spots (many causal organisms), and root rot (Phytophthora cinnamomi Rands) were noted as problems by 22, 15, and 10% of the growers, respectively. Phytophthora species were isolated from root and soil samples collected from symptomatic plants on three farms. Weeds were listed as problems on 100% of the surveys. 47% of the respondents plan to increase their blueberry plantings mainly with rabbiteye cultivars
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