3,660 research outputs found

    Laboratory Quality Control Report: Why is it Important?

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    The Arkansas Water Resources Center (AWRC) maintains a fee-based water quality lab that is certified through the Arkansas Department of Environmental Quality (ADEQ). The AWRC Water Quality Lab analyzes water samples for a variety of constituents, using standard methods for the analysis of water samples (APHA 2012). Whether you have one or several water samples tested, the lab generates a report of values for each parameter that you have analyzed, which is provided to the client. Included with every water quality report is a Lab Quality Control (QC) report for each of the parameters analyzed within the package. The Lab QC report provides important information about the performance of the methods used to test your water sample(s)

    The bacterial microflora of fish, revised

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    The results of numerous studies indicate that fish possess bacterial populations on or in their skin, gills, digestive tract, and light-emitting organs. In addition, the internal organs (kidney, liver, and spleen) of healthy fish may contain bacteria, but there is debate about whether or not muscle is actually sterile. Using traditional culture-dependent techniques, the numbers and taxonomic composition of the bacterial populations generally reflect those of the surrounding water. More modern culture-independent approaches have permitted the recognition of previously uncultured bacteria. The role of the organisms includes the ability to degrade complex molecules (therefore exercising a potential benefit in nutrition), to produce vitamins and polymers, and to be responsible for the emission of light by the light-emitting organs of deep-sea fish. Taxa, including Pseudomonas, may contribute to spoilage by the production of histamines in fish tissue

    Taxonomy of bacterial fish pathogens

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    Bacterial taxonomy has progressed from reliance on highly artificial culture-dependent techniques involving the study of phenotype (including morphological, biochemical and physiological data) to the modern applications of molecular biology, most recently 16S rRNA gene sequencing, which gives an insight into evolutionary pathways (= phylogenetics). The latter is applicable to culture-independent approaches, and has led directly to the recognition of new uncultured bacterial groups, i.e. "Candidatus", which have been associated as the cause of some fish diseases, including rainbow trout summer enteritic syndrome. One immediate benefit is that 16S rRNA gene sequencing has led to increased confidence in the accuracy of names allocated to bacterial pathogens. This is in marked contrast to the previous dominance of phenotyping, and identifications, which have been subsequently challenged in the light of 16S rRNA gene sequencing. To date, there has been some fluidity over the names of bacterial fish pathogens, with some, for example Vibrio anguillarum, being divided into two separate entities (V. anguillarum and V. ordalii). Others have been combined, for example V. carchariae, V. harveyi and V. trachuri as V. harveyi. Confusion may result with some organisms recognized by more than one name; V. anguillarum was reclassified as Beneckea and Listonella, with Vibrio and Listonella persisting in the scientific literature. Notwithstanding, modern methods have permitted real progress in the understanding of the taxonomic relationships of many bacterial fish pathogens

    Spatial summation of individual cones in human color vision.

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    The human retina contains three classes of cone photoreceptors each sensitive to different portions of the visual spectrum: long (L), medium (M) and short (S) wavelengths. Color information is computed by downstream neurons that compare relative activity across the three cone types. How cone signals are combined at a cellular scale has been more difficult to resolve. This is especially true near the fovea, where spectrally-opponent neurons in the parvocellular pathway draw excitatory input from a single cone and thus even the smallest stimulus projected through natural optics will engage multiple color-signaling neurons. We used an adaptive optics microstimulator to target individual and pairs of cones with light. Consistent with prior work, we found that color percepts elicited from individual cones were predicted by their spectral sensitivity, although there was considerable variability even between cones within the same spectral class. The appearance of spots targeted at two cones were predicted by an average of their individual activations. However, two cones of the same subclass elicited percepts that were systematically more saturated than predicted by an average. Together, these observations suggest both spectral opponency and prior experience influence the appearance of small spots

    Stream Water Quality to Support HUC 12 Prioritization in the Lake Wister Watershed, Oklahoma: August 2017 through May 2019

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    Nonpoint source pollution associated with human land use (agriculture and urbanization) is one of the leading causes of impairment to waterways in the United States (EPA 2000). The primary pollutants associated with agricultural and urban land use are sediment and nutrients which enter nearby streams during rain events and are then carried downstream. These sediments and nutrients may result in water quality issues in the downstream water bodies like increased algal growth or decreased water clarity (e.g. Smith et al., 1999). Best management practices (BMPs) are often used to mitigate the effects of nonpoint source pollution in the watershed. Practices such as riparian buffers installed along the edge of field and conservation tillage (e.g., no-till, spring-till, and cover crops) slow overland flow, reducing erosion and nutrient loss from the landscape (Schoumans et al. 2014). Installing BMPs throughout the entire watershed would have the greatest effect at reducing nonpoint source pollution; however, this is not socially or economically feasible. Targeting critical source areas or priority watersheds for BMPs installation, optimizes the benefits while reducing the overall (Sharpley et al. 2000)

    Watershed Investigative Support to the Poteau Valley Improvement Authority: Stream Water Quality to Support HUC 12 Prioritization in the Lake Wister Watershed, Oklahoma

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    Nonpoint source pollution associated with human land use (agriculture and urbanization) is one of the leading causes of impairment to waterways in the United States (EPA, 2000). The primary pollutants associated with agricultural and urban land use are sediment and nutrients which enter nearby streams during rain events and are then carried downstream. These sediments and nutrients may result in water quality issues in the downstream water bodies like increased algal growth or decreased water clarity (e.g. Smith et al., 1999)

    An Investigation into the Accessibility of AP Calculus

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    This is a mixed methods ethnographic study conducted to determine what obstacles students face when approaching AP Calculus. I focused my study on home economics, peer pressure, ELL status and home support. Overall, I found that being a student who is ELL (hereafter defined as a student who was or currently is required to take ACCESS testing) had the most negative effect of the previously listed factors. Home economics and peer pressure were inconclusive or often had no effect. Finally, having a supportive home life in the form of parents who value education, encourage goal-setting, and set high expectations had a positive effect in accessing AP Calculus. These findings allow me to focus my future work to mitigate the negative and foster the positive influences

    Cognitively Engineering a Virtual Collaboration Environment for Crisis Response

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    Crisis response situations require collaboration across many different organizations with different backgrounds, training, procedures, and goals. The Indian Ocean Tsunami in 2004 and the Hurricane Katrina relief efforts in 2005 emphasized the importance of effective communication and collaboration. In the former, the Multinational Planning Augmentation Team (MPAT) supported brokering of requests for assistance with offers of help from rapidly deployed military and humanitarian assistance facilities. In the aftermath of Hurricane Katrina, the National Guard Soldiers and active component Army Soldiers assisted other state, federal, and non-government organizations with varying degrees of efficiency and expediency. Compounding the challenges associated with collaboration during crisis situations is the distributed nature of the supporting organizations and the lack of a designated leader across these military, government, nongovernment organizations. The Army Research Laboratory is collaborating with the University of Edinburgh, University o

    DIVING INTO ONE’S PAINFUL PAST AND DARKEST INTERNAL FEARS: THE DEVELOPMENTAL PROCESS OF THE THREAD THAT SNAPPED

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    AN ABSTRACT OF THE THESIS OFAustin Harrison, for the Master of Fine Arts degree in Theatre, presented on April 10, 2020, at Southern Illinois University Carbondale. TITLE: DIVING INTO ONE’S PAINFUL PAST AND DARKEST INTERNAL FEARS: THE DEVELOPMENTAL PROCESS OF THE THREAD THAT SNAPPEDMAJOR PROFESSOR: Dr. Jacob Juntunen This thesis details the development of my full-length play The Thread That Snapped from its early conception in 2019 to full production at Southern Illinois University Department of Theatre’s Christian H. Moe Theatre’s space in March 2020. In writing The Thread That Snapped, I was inspired by traumatic chapters within my life that shaped me as a human. This play, therefore, examines the unpredictable ways in which an individual is driven to insanity and the delicate thread that separates sanity and insanity. From this play comes a study into the human condition and how society and relationships shape who we become n life. Chapter One includes a statement of the project, the origin, and development of the script, initial structure and plot considerations for the script, research that impacted the creation of the script, character development, and tools for self-evaluation. Chapter Two covers the pre-writing process, feedback from my writing partner, notes from my advisor, Jacob Juntunen, and the director, Susan Patrick Benson, about the script’s development and an overall description of the play’s progression through drafts. Chapter Three describes the design meetings held in preparation for the production of The Thread That Snapped. Chapter Four details the audition and casting process as well as rehearsals for the piece. Chapter Five evaluates The Thread That Snapped’s production, describes ideas for future productions of the piece as well as possible revisions. Chapter Six concludes the thesis by tracking my progression in the playwriting program over the past three years. It includes my writing growth in terms of structure and developing my artistic voice. It also discusses my professional development over the time in the program, as well as the evolution of my teaching practice. I have also included in the thesis the production script of The Thread That Snapped

    Water Quality Reporting Limits, Method Detection Limits, and Censored Values: What Does It All Mean?

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    The Arkansas Water Resources Center (AWRC) maintains a fee-based water-quality lab that is certified by the Arkansas Department of Environmental Quality (ADEQ). The AWRC Water Quality Lab analyzes water samples for a variety of constituents, using standard methods for the analysis of water samples (APHA 2012). The lab generates a report on the analysis, which is provided to clientele, and reports the concentrations or values as measured. Often times the concentrations or values might be very small, even zero as reported by the lab – what does this mean? How should we use this information? This document is intended to help our clientele understand the analytical report, the values, and how one might interpret information near the lower analytical limits. Every client wants the analysis of their water sample(s) to be accurate and precise, but what do we really mean when we say those two words? These words are often used synonymously or thought of as being the same, but the two words mean two different things. Both are equally important when analyzing water samples for constituent concentrations
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