Principles of Lake Quality Management

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The Effects of Artificial Destratification on the Water Quality and Microbial Populations of Hyrum Reservoir

Artificial destratification is being increasingly used in attempts to improve water quality and control eutrophication. Most of the artificial destratification efforts are being conducted by public water supply utilities in efforts to improve reservoir water quality for culinary purposes. At present, artificial destratification is being conducted without a complete understanding of the process or its effects on the reservoir. Whether or not artificial destratification can control algal growth and other microbial processes is a controversial question. The effect of artificial destratification on the microbial flora must be understood if it is to be used effectively as a management tool in the control of water quality. In recent years a blue-green algal bloom has developed during the summer in Hyrum Reservoir. The massive bloom of Aphanizomenon jlos-aquae presents esthetic problems to those using the reservoir for recreational purposes. These esthetic problems have reduced the use of the reservoir for swimming, water skiing, and fishing. It is believed that artificial de stratification, or the destruction of natural stratification obtained through diffused-air aeration, will improve the water quality of the reservoir

Water Quality Analysis Laboratory Procedures Syllabus

Introduction: The 1976 edition of Methods of Chemical Analysis of Water and Wastes describes chemical analytical procedures to be sued in Water Quality Office (WQO) laboratoires. The methods were chose through the combined efforts of the Regional Analytical Quality Control (AQC) Coordinators, Laboratory Quality Control Officers, and other senior chemicsts in both federal and state laboratories. Method selection was based on the following criteria: 1. The method should measure the desired constitutent with precision and accuracy suffiecient to meet the data needs of WQO in the presence of the interferences normally encountered in polluted waters. 2. The procedures should utilize the equipment and skillso normally available in the typical water pollution control laboratory. 3. The selected methods are in use in many laboraties or have been sufficiently tested to establish their validity. 4. The mthods should be sufficiently rapid to permit routine use for the examination of a large number of samples. Except where noted under scope and Application for each constituent, the methods can be used for the measurement of the indicated constituent in both water and wastewaters and in oboth saline and fresh water samples. Instrumental methods have been selected in preference to manual procedures because of the improved speed, precision, and accuracy. Procedures for the Technicon AutoAnalyzer have been included for laboratories having this equipment available. Precision and accuracy statements have been derived from interlaboratory studies conducted by the Methods and Performance Activity, Analytical Quality Control Laboratory, WQO; the American Society for Testing Materials; or the Analytical Reference Service of the Public Health Service, DHEW. Specific instructions for the handling and preservation of samples cannot be given because of the wide variability in types of samples and local sampling situations. However, certain general principles should be followed. Wherever possible, the sampling program should be designed to provide for the shortest possible interval between sample collection and analysis. Positive steps should be taken to maintain both the concentration and the physical state of the constituents to be measureed

Effects of Temperature on the Toxicity to the Aquatic Biota of Waste Discharges - A Compilation of the Literature

An extensive compiliation and general evaluation of the literature is presented which describes the temperature interaction with toxicity. Recent literature is summarized and made accessible along with a few generalized relationships such that researchers may design studies in a manner that will increase the utility of their results. A detailed indexing system is employed which makes the information contained in the report accessible by author, toxicant, and text organism. Summary tables of the most pertinent literature are also presented for easy subject retrieval. It was concluded that very little uniformity in experimental design is found between experiments on temperature-toxicity relationships, and a generalized summary of the results presented in th eliterature is essentially impossible because of the inconsistencies in experimental designs. The utilization of standard bioassay procedures is highly recommened, and these procedures should be applied to experimental designs which allow the estimation of parameters related to the theoretical effects of temperature

Nutrient Dynamics and Gas Production in Aquatic Ecosystems: The Effects and Utilization of Mercury and Nitrogen in Sediment-Water Microcosms

Sixteen sediment-water microcosms designed to allow complete gas, liquid, and solid mass balances of gases, nutrients, and mercury were studies under dark conditions or varying light intensity for a period of 189 days. Results indicated that the microcosm technique is a very sensitive method of analyzing microbial dynamics in sediment water systems. Gas quantity and composition changes were easy to monitor and were especially sensitive to light and nutrient variations. Nitrogen fixation occurred in all lighted systems (blue-green algae nitrogen fixers, Anabaena, and others) and was adequate to insure that no nitrogen limitation occurred even though nitrogen limitation was imposed on the system. Sediments apparently did not act as a significant source of nitrogen. Iron and phosphorus were in excess and as such were closely linked as would be predicted on the basis of chemical equilibria. Non-equilibrium chemical behavior of such elements would apparently result only when appreciable amounts of the compound or element is utilized in growth

Exposure-Dependent Control of Malaria-Induced Inflammation in Children

In malaria-naïve individuals, Plasmodium falciparum infection results in high levels of parasite-infected red blood cells (iRBCs) that trigger systemic inflammation and fever. Conversely, individuals in endemic areas who are repeatedly infected are often asymptomatic and have low levels of iRBCs, even young children. We hypothesized that febrile malaria alters the immune system such that P. falciparum re-exposure results in reduced production of pro-inflammatory cytokines/chemokines and enhanced anti-parasite effector responses compared to responses induced before malaria. To test this hypothesis we used a systems biology approach to analyze PBMCs sampled from healthy children before the six-month malaria season and the same children seven days after treatment of their first febrile malaria episode of the ensuing season. PBMCs were stimulated with iRBC in vitro and various immune parameters were measured. Before the malaria season, children's immune cells responded to iRBCs by producing pro-inflammatory mediators such as IL-1β, IL-6 and IL-8. Following malaria there was a marked shift in the response to iRBCs with the same children's immune cells producing lower levels of pro-inflammatory cytokines and higher levels of anti-inflammatory cytokines (IL-10, TGF-β). In addition, molecules involved in phagocytosis and activation of adaptive immunity were upregulated after malaria as compared to before. This shift was accompanied by an increase in P. falciparum-specific CD4+Foxp3- T cells that co-produce IL-10, IFN-γ and TNF; however, after the subsequent six-month dry season, a period of markedly reduced malaria transmission, P. falciparum-inducible IL-10 production remained partially upregulated only in children with persistent asymptomatic infections. These findings suggest that in the face of P. falciparum re-exposure, children acquire exposure-dependent P. falciparum-specific immunoregulatory responses that dampen pathogenic inflammation while enhancing anti-parasite effector mechanisms. These data provide mechanistic insight into the observation that P. falciparum-infected children in endemic areas are often afebrile and tend to control parasite replication

Malaria-associated atypical memory B cells exhibit markedly reduced B cell receptor signaling and effector function

Protective antibodies in Plasmodium falciparum malaria are only acquired after years of repeated infections. Chronic malaria exposure is associated with a large increase in atypical memory B cells (MBCs) that resemble B cells expanded in a variety of persistent viral infections. Understanding the function of atypical MBCs and their relationship to classical MBCs will be critical to developing effective vaccines for malaria and other chronic infections. We show that VH gene repertoires and somatic hypermutation rates of atypical and classical MBCs are indistinguishable indicating a common developmental history. Atypical MBCs express an array of inhibitory receptors and B cell receptor (BCR) signaling is stunted in atypical MBCs resulting in impaired B cell responses including proliferation, cytokine production and antibody secretion. Thus, in response to chronic malaria exposure, atypical MBCs appear to differentiate from classical MBCs becoming refractory to BCR-mediated activation and potentially interfering with the acquisition of malaria immunity. DOI: http://dx.doi.org/10.7554/eLife.07218.00

Treatment of Chronic Asymptomatic Plasmodium falciparum Infection Does Not Increase the Risk of Clinical Malaria Upon Reinfection.

: Chronic asymptomatic Plasmodium falciparum infections are common in endemic areas and are thought to contribute to the maintenance of malaria immunity. Whether treatment of these infections increases the subsequent risk of clinical episodes of malaria is unclear. : In a 3-year study in Mali, asymptomatic individuals with or without P. falciparum infection at the end of the 6-month dry season were identified by polymerase chain reaction (PCR), and clinical malaria risk was compared during the ensuing 6-month malaria transmission season. At the end of the second dry season, 3 groups of asymptomatic children were identified: (1) children infected with P. falciparum as detected by rapid diagnostic testing (RDT) who were treated with antimalarials (n = 104), (2) RDT-negative children whose untreated P. falciparum infections were detected retrospectively by PCR (n = 55), and (3) uninfected children (RDT/PCR negative) (n = 434). Clinical malaria risk during 2 subsequent malaria seasons was compared. Plasmodium falciparum-specific antibody kinetics during the dry season were compared in children who did or did not harbor asymptomatic P. falciparum infections. : Chronic asymptomatic P. falciparum infection predicted decreased clinical malaria risk during the subsequent malaria season(s); treatment of these infections did not alter this reduced risk. Plasmodium falciparum-specific antibodies declined similarly in children who did or did not harbor chronic asymptomatic P. falciparum infection during the dry season. : These findings challenge the notion that chronic asymptomatic P. falciparum infection maintains malaria immunity and suggest that mass drug administration during the dry season should not increase the subsequent risk of clinical malaria.<br/

Index Construction for Multiple Objective Analysis of Land and Water Use in a High Mountain Watershed

Comprehensive planning is an elusive ideal. The practical planner must sort the relevant information from the vast amounts of data that modern technology can collect. The objective of this study was to use the Upper Blackfoot watershed in the mountains of Southeastern Idaho as an arena for developing methods for construction, refinement, and application of indices needed to design land and water management schemes, compare alternatives, and influence the public in their uses of the area. A total of 21 uses were examined on 242 land units of a 160 square-mile area ranging in elevation from 6300 to 9000 feet and where the principal activities of grazing, lumbering, mining, and recreation can only be undertaken in the summer after the snow has melted. The indices considered were a reasonability index for screening out unreasonable uses at the start of the planning process, an index of use intensity for estimating an amount for reasonable uses, and an index for estimating the utility of the amount of use made from the public viewpoint. Data were collected on 42 attributes for the 343 land units and used in a linear programming model to maximize 1) economic benefits from use of the area and 2) minimize environmental disturbance. The resolution in the available use data limited the model solution to allocating uses among 18 larger land units. The primary factor limiting the modeling, however, was the lack of information for defining the interactions among the uses. The analysis provides a framework for classifying and identifying interactions beginning with the simplest case of simultaneous use by two uses in near proximity. The contribution of the study was a framework for analysis and the identification of the needs for research on the physical interactions among simultaneous uses, the perceived interactions of simultaneous users, and characterization of attributes for defining the quality of an area for a use

Comparative Pathogenesis of Three Human and Zoonotic SARS-CoV Strains in Cynomolgus Macaques

The severe acute respiratory syndrome (SARS) epidemic was characterized by increased pathogenicity in the elderly due to an early exacerbated innate host response. SARS-CoV is a zoonotic pathogen that entered the human population through an intermediate host like the palm civet. To prevent future introductions of zoonotic SARS-CoV strains and subsequent transmission into the human population, heterologous disease models are needed to test the efficacy of vaccines and therapeutics against both late human and zoonotic isolates. Here we show that both human and zoonotic SARS-CoV strains can infect cynomolgus macaques and resulted in radiological as well as histopathological changes similar to those seen in mild human cases. Viral replication was higher in animals infected with a late human phase isolate compared to a zoonotic isolate. While there were significant differences in the number of host genes differentially regulated during the host responses between the three SARS-CoV strains, the top pathways and functions were similar and only apparent early during infection with the majority of genes associated with interferon signaling pathways. This study characterizes critical disease models in the evaluation and licensure of therapeutic strategies against SARS-CoV for human use