97 research outputs found
Evaluation of a Planning Methodology: Integrating Land Use Information in Water Quality Planning
The case study investigated was the 208 water quality planning conducted in the Ashley Valley, around Vernal, Utah. The region is expected to urbanize rapidly due to energy development on adjacent state and federal land. The water quality planning was being conducted in the absence of substantial prior land use planning.
A method is developed in the thesis for evaluating plans and methodologies. The method utilizes preformulated evaluation criteria to analyze structure and function of the methdology, political context, informational inputs, limiting factors, trigger factors, causeeffect relationships, and impacts of methodology on planning recommendations. The criteria collected from the literature and agency guidelines are consolidated into an evaluation model. Data were collected through field interviews, on-site inspection, and examination of workplans, critical path charts and plan documents.
The planning was well conducted overall. However, the water quality planning methodology did not maximize the utilization of land use information, nor did it integrate the available land use information into the analysis as fully as possible. Utilization of land use information could have been increased through greater emphasis on land use in the original workplan, more guidance to staff through specification of land use analysis subtasks, tighter coordination of staff, and consideration of a broader range of alternative scenarios.
The cursory nature of the land use analysis limited the number of alternative land use patterns identified. This in turn limited the number of potential pollution sources identified. The local political context discouraged serious consideration of some alternative land use patterns, and the use of land use controls as a management strategy
Environmental Quality Management in a Region with External Development Pressures
The objective of this study was to examine the problems of managing residuals and environmental quality in a region facing potentially rapid growth as a consequence of externally made development decisions. The research adapted and applied the residuals environmental management concept which recognizes the need for an integration of physical methods, implementation incentives and institutional arrangements in controlling air, water and solid residuals. The area selected for study, the Uintah Basin in Southeastern utah, has the potential for extensive energy resource and mineral development and could experience a large population influx and accelerated economic growth as a result. in the face of a wide range of possible resource developments, the study used an alternative futures approach, in which combinations of exogenous events leading to different types and levels of economic activities and employment inpacts were identified. Economic and land use simulation models were applied to project the effects of the futures on the basin. Materials balances were then drawn up for major polluting activities to determine the residuals that would be produced and discharged to the environment if there were not controls. An environmental impact and management model, structured as al inear programming model, was used to evaluate environmental management strategies. The model incorporated various production processes and residuals treatment methods. Air and water quality simulation models were applied to assess environmental impacts and generate model constraints. Several dimesnsions of environmental management strategies were analyzed including alternative production processes, waste treatment methods, and various implementation incentives such as effluent charges, effluent standards and effects of legal restructions. This report was submitted in fulfillment of Contract No. R-803203 by the Utah Water Research Laboratory, Utah State University under the sponsorship of the U.S. Environmental Protection Agency. This report covers the period July 22, 1974 to january 31, 1977, and was completed as of February 21, 1977
The UbiI (VisC) aerobic ubiquinone synthase is required for expression of type 1 pili, biofilm formation, and pathogenesis in uropathogenic Escherichia coli
Uropathogenic Escherichia coli (UPEC), which causes the majority of urinary tract infections (UTI), uses pilus-mediated adherence to initiate biofilm formation in the urinary tract. Oxygen gradients within E. coli biofilms regulate expression and localization of adhesive type 1 pili. A transposon mutant screen for strains defective in biofilm formation identified the ubiI (formerly visC) aerobic ubiquinone synthase gene as critical for UPEC biofilm formation. In this study, we characterized a nonpolar ubiI deletion mutant and compared its behavior to that of wild-type bacteria grown under aerobic and anoxic conditions. Consistent with its function as an aerobic ubiquinone-8 synthase, deletion of ubiI in UPEC resulted in reduced membrane potential, diminished motility, and reduced expression of chaperone-usher pathway pili. Loss of aerobic respiration was previously shown to negatively impact expression of type 1 pili. To determine whether this reduction in type 1 pili was due to an energy deficit, wild-type UPEC and the ubiI mutant were compared for energy-dependent phenotypes under anoxic conditions, in which quinone synthesis is undertaken by anaerobic quinone synthases. Under anoxic conditions, the two strains exhibited wild-type levels of motility but produced diminished numbers of type 1 pili, suggesting that the reduction of type 1 pilus expression in the absence of oxygen is not due to a cellular energy deficit. Acute- and chronic-infection studies in a mouse model of UTI revealed a significant virulence deficit in the ubiI mutant, indicating that UPEC encounters enough oxygen in the bladder to induce aerobic ubiquinone synthesis during infection. IMPORTANCE The majority of urinary tract infections are caused by uropathogenic E. coli, a bacterium that can respire in the presence and absence of oxygen. The bladder environment is hypoxic, with oxygen concentrations ranging from 4% to 7%, compared to 21% atmospheric oxygen. This work provides evidence that aerobic ubiquinone synthesis must be engaged during bladder infection, indicating that UPEC bacteria sense and use oxygen as a terminal electron acceptor in the bladder and that this ability drives infection potential despite the fact that UPEC is a facultative anaerobe
The Insulin-Like Growth Factor System in the Long-Lived Naked Mole-Rat.
Naked mole-rats (Heterocephalus glaber) (NMRs) are the longest living rodents known. They show negligible senescence, and are resistant to cancers and certain damaging effects associated with aging. The insulin-like growth factors (IGFs) have pluripotent actions, influencing growth processes in virtually every system of the body. They are established contributors to the aging process, confirmed by the demonstration that decreased IGF signaling results in life-extending effects in a variety of species. The IGFs are likewise involved in progression of cancers by mediating survival signals in malignant cells. This report presents a full characterization of the IGF system in the NMR: ligands, receptors, IGF binding proteins (IGFBPs), and IGFBP proteases. A particular emphasis was placed on the IGFBP protease, pregnancy-associated plasma protein-A (PAPP-A), shown to be an important lifespan modulator in mice. Comparisons of IGF-related genes in the NMR with human and murine sequences indicated no major differences in essential parts of the IGF system, including PAPP-A. The protease was shown to possess an intact active site despite the report of a contradictory genome sequence. Furthermore, PAPP-A was expressed and translated in NMRs cells and retained IGF-dependent proteolytic activity towards IGFBP-4 and IGF-independent activity towards IGFBP-5. However, experimental data suggest differential regulatory mechanisms for PAPP-A expression in NMRs than those described in humans and mice. This overall description of the IGF system in the NMR represents an initial step towards elucidating the complex molecular mechanisms underlying longevity, and how these animals have evolved to ensure a delayed and healthy aging process
Comparing large lecture mechanics curricula using the Force Concept Inventory: A five thousand student study
The performance of over 5000 students in introductory calculus-based
mechanics courses at the Georgia Institute of Technology was assessed using the
Force Concept Inventory (FCI). Results from two different curricula were
compared: a traditional mechanics curriculum and the Matter & Interactions
(M&I) curriculum. Post-instruction FCI averages were significantly higher for
the traditional curriculum than for the M&I curriculum; the differences between
curricula persist after accounting for factors such as pre-instruction FCI
scores, grade point averages, and SAT scores. FCI performance on categories of
items organized by concepts was also compared; traditional averages were
significantly higher in each concept. We examined differences in student
preparation between the curricula and found that the relative fraction of
homework and lecture topics devoted to FCI force and motion concepts correlated
with the observed performance differences. Limitations of concept inventories
as instruments for evaluating curricular reforms are discussed.Comment: 21 pages, 4 figures, submitted to Am. J. Phys. arXiv admin note:
substantial text overlap with arXiv:1112.559
Can sacrificial feeding areas protect aquatic plants from herbivore grazing? Using behavioural ecology to inform wildlife management
Effective wildlife management is needed for conservation, economic and human well-being objectives. However, traditional population control methods are frequently ineffective, unpopular with stakeholders, may affect non-target species, and can be both expensive and impractical to implement. New methods which address these issues and offer effective wildlife management are required. We used an individual-based model to predict the efficacy of a sacrificial feeding area in preventing grazing damage by mute swans (Cygnus olor) to adjacent river vegetation of high conservation and economic value. The accuracy of model predictions was assessed by a comparison with observed field data, whilst prediction robustness was evaluated using a sensitivity analysis. We used repeated simulations to evaluate how the efficacy of the sacrificial feeding area was regulated by (i) food quantity, (ii) food quality, and (iii) the functional response of the forager. Our model gave accurate predictions of aquatic plant biomass, carrying capacity, swan mortality, swan foraging effort, and river use. Our model predicted that increased sacrificial feeding area food quantity and quality would prevent the depletion of aquatic plant biomass by swans. When the functional response for vegetation in the sacrificial feeding area was increased, the food quantity and quality in the sacrificial feeding area required to protect adjacent aquatic plants were reduced. Our study demonstrates how the insights of behavioural ecology can be used to inform wildlife management. The principles that underpin our model predictions are likely to be valid across a range of different resource-consumer interactions, emphasising the generality of our approach to the evaluation of strategies for resolving wildlife management problems
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