The Effects of Fatigue on Balance in Individuals with Parkinson\u27s Disease: Influence of Medication and Brain-Derived Neurotrophic Factor Genotype

Background and Purpose: The purpose was to investigate the effects of fatigue on balance in individuals with Parkinson’s disease (PD). Because falls in this population can have deleterious consequences, it is important to understand the influence of fatigue and PD medications on balance. Additionally, since brain-derived neurotrophic factor (BDNF) has been shown to be related to motor performance, we explored its role in balance fatigue. Participants: 27 individuals (age= 65.4±8.1; males= 14, females= 13) with neurologist-diagnosed PD. Of the 27, 13 were genotyped for BDNF as Val/Val, 11 as Val/Met, 2 as Met/Met, and one refused genotyping. Methods: Participants were tested twice, first on medication and second off medication, one week apart. On both days, participants completed the following tests before and after a fatiguing condition: mini-Balance Evaluation Systems Test (mini-BESTest), computerized dynamic posturography (sensory orientation and motor control), functional reach, and gait spatial-temporal parameters at preferred gait speed across an instrumented walking mat. To address the primary aim of the study, a 2 (condition: pre and post) X 2 (medication: on and off) factorial ANOVA was performed for each outcome variable in each of the following domains: 1. anticipatory postural response; 2. adaptive postural responses; 3. Dynamic balance; 4. sensory orientation; and, 5. gait characteristics. For the exploratory aim, independent t-tests were conducted to compare both pre- and post-fatigue states, and on and of medication states for all of the aforementioned balance domains. Results: There were no statistically significant interactions between time (pre and post) and medication (on and off) for anticipatory postural responses, adaptive postural responses, dynamic balance, sensory orientation, or gait characteristics (ps≥.187). Participants with BDNF Met alleles were not significantly different from Val/Val participants in balance or gait (ps≥.111) and response to a fatiguing condition (ps≥.070). Discussion: The results of this study suggest that fatigue does not have a detrimental effect on balance and gait in individuals with PD. Likewise, our results were also in line with other studies that suggest that PD medications are not effective for decreasing risk of falls due to postural instability. Lastly, these results also indicate that individuals with a BDNF Met allele are not at an increased fall risk after a fatiguing condition compared to those with the Val/Val genotype

Solar heating of wastewater stabilization ponds

March 1983.Includes bibliographical references.Project A-046-COLO; partially funded by the U.S. Dept. of the Interior, as authorized by the Water Research and Development Act of 1978

An evaluation of oxygen-hydrogen propulsion systems for the Space Station

Conceptual designs for O2/H2 chemical and resistojet propulsion systems for the space station was developed and evaluated. The evolution of propulsion requirements was considered as the space station configuration and its utilization as a space transportation node change over the first decade of operation. The characteristics of candidate O2/H2 auxiliary propulsion systems are determined, and opportunities for integration with the OTV tank farm and the space station life support, power and thermal control subsystems are investigated. OTV tank farm boiloff can provide a major portion of the growth station impulse requirements and CO2 from the life support system can be a significant propellant resource, provided it is not denied by closure of that subsystem. Waste heat from the thermal control system is sufficient for many propellant conditioning requirements. It is concluded that the optimum level of subsystem integration must be based on higher level space station studies

Evaluating Water Reuse Alternatives in Water Resources Planning

Water reuse is a recognized option for augmenting water supplies to provide for expanded water needs. A methodology is developed for examining optimal strategies for water reuse within the context of the total water resources system, including both the provision of water supplies for various uses and management of wastewaters. A model of the water resources system is formulated as a “transportation “ or “transshipment” problem in linear programming depicting the possible sources of supply, including effluent sources available for reuse, which can be used to satisfy the requirements of various water users. The optimizing objective in the model is to minimize the cost of meeting water supply requirements and of wastewater treatment to satisfy water quality standards. The Lower Jordan River Basin, which encompasses the Salt Lake City, Utah, metropolitan area, is used as a case study for applying and testing the model. Optimally allocation were obtained for low, middle, and high forecasts of future water requirements roughly corresponding to a fifty-year time horizon. Four alternatives for regional wastewater treatment were also analyzed considering possibilities for reuse. Assessment capabilities of the model include examining redistribution of supplies, time-staging of supplies and related treatment facilities, and analyzing sensitivity of allocations to change in costs

Optimization of Water Allocation, Wastewater Treatment, and Reuse Considering Nonlinear Costs, Seasonal Variations, and Stochastic Supplies

Two significant, interrelated water resources problems are: (1) efficiently salvaging and reusing effluent water in order to augment limited water supplies; and (2) economically managing and treating wastewater to meet water quality standards. Using systems engineering and operations research techniques, the report focuses on the optimal management and use of water of impaired quality in a water resources system, including utilization or irrigation return flows and other poor quality water, water quantity and quality management systems, and wastewater reclamation opportunities. The study develops a mathematical programming transportation or transshipment model formulated for the Lower Jordan River Basin in Utah. The model incorporated all “possible” water resources (including sequential and recycled reuse of water)to supply spatially separated multi-sector water users considering non-linear costs with economies of scale for water supply and wastewater treatment, temporal aspects of seasonality and stochastic nature of water supply and demand, and the system effects of higher wastewater treatment levels. The results of the model runs give specific allocations of waste from the available sources to meet use sector requirements over a planning horizon from 1975 to 2020. The total minimum cost of water supply and wastewater treatment allocation is reduced by considering seasonality of water requirements. Stochasticity of supply and water treatment requirements increase total allocation costs. The comparison of results from the model can be used to analyze the interdependence of water supply, water pollution control, options for water salvage and reuse in order to better plan public investment in water and wastewater management facilities

Energy Development vs Water Quality in the Upper Colorado and Upper Missouri River Basins

This report examines the relationship between energy development and water quality in the Upper Colorado and Upper Missouri River Basins. The location and type of energy resources and present and possible future developments are identified relative to the water resource systems. Impacts from energy developments are discussed in terms of the various pollutants generated by energy extraction and processing activities, and the pollution transport mechanisms and pathways by which they can enter surface and groundwater. The report discusses the implications for energy development of the water quality aspects of legislative requirements and regulations. These include the Federal Water Pollution Control Act Amendments, the Safe Drinking Water Act, the Surface Mining Control and Reclamation Act, the Resource Conservation and Recovery Act, and the Toxic Substances Control Act. Many of the potential water pollution problems associated with energy development will occur through the transport of pollutants from air pollution and solid waste disposal. The consumptive use of all water withdrawn for energy processing as a pollution control measure raises three important issues--each of which represents a potential conflict between energy developers' compliance with the legislation and western water law: (1) junior rights and water transfer, (2) the beneficial use question, and (3) the reasonable use measure of certain water quality practices

Estimación a corto plazo de la temperatura del agua. Aplicación en sistemas de producción en medio acuático

[ES] El control y la predicción de parámetros físico-químicos del agua en tanques de cultivo de plantas de producción en medio acuático es un aspecto fundamental del buen funcionamiento de este tipo de instalaciones. En este trabajo se propone la estimación de la temperatura del agua en las próximas 24 horas en una planta de producción de anguilas europeas de carácter intensivo mediante regresiones múltiples y modelos univariantes de series temporales (modelos de suavizado y ARIMA). Se cuenta con datos de las temperaturas diarias en distintas series de tanques correspondientes a los años 1997 al 2001. Los modelos se calibran considerando exclusivamente la relación de los datos presentes y pasados de la temperatura, asumiéndose de esta forma que la variabilidad de otros factores que pueden influir en este parámetro está contenida en la propia serie de datos. Las mejores validaciones proporcionan niveles de varianza explicada en la mayor parte de los casos superiores al 95% y errores en la predicción inferiores a 1º C.Gutiérrez Estrada, JC.; De Pedro Sanz, E.; López Luque, R.; Pulido Calvo, I. (2005). Estimación a corto plazo de la temperatura del agua. Aplicación en sistemas de producción en medio acuático. Ingeniería del agua. 12(1):77-92. https://doi.org/10.4995/ia.2005.2553OJS7792121Alcaraz, G. y S. Espina (1995) Acute toxicity of nitrite in juvenile grass carp modified by weight and temperature. Bulletin of Environmental Contamination and Toxicology, 55: 473-478.Allan, G.L. y G.B. Maguire (1991) Lethal levels of low dissolved oxygen and effects of short-term oxygen stress on subsequent growth of juvenile Panaeus monodon. Aquaculture, 94: 27-37.Bejda, A.J., B.A. Phelan y A.l. Studholme (1992) The effect of dissolved oxygen on the growth of young-of-the-year winter flounder, Pseudopleuronectes americanus. 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Aquacultural Engineering (en prensa)Hair, J.F., R.E. Anderson, R.l. Tatham y W.C. Black (1999) Análisis multivariante. Edita: Pretince Hall. Madrid.Hart, P.R. y G.R. Purser (1995). Effects of salinity and temperature on eggs and yolk sac larvae of the greenback flounder (Rhombosolea tapirina Günther, 1862). Aquaculture, 136: 221-230.Hart, P.R., W.G. Hutchinson y G.J. Purser (1996) Effects fo photoperiod, temperature and salinity on hatcheryreared larvae of the greenback flounder (Rhombosolea tapirina Günther, 1862). Aquaculture, 144: 303-311.Holton-Wilson, J. y B. Keating (1996) Previsiones en los negocios. Edita: IRWIN. Illinois.Junttila, J. (2001) Structural breaks, ARIMA model and finnish inflation forecasts. International Journal of Forecasting, 17: 203-230.Kitanidis, P.K. y R.L. Bras (1980) Real time forecasting with a conceptual hydrological model. 2. Applications and results. Water Resources Research, 16: 1034-1044.Klemetson, S.L. y G.L. Rogers (1985) Aquaculture pond temperature modeling. Aquaculture Engineering, 4: 191-208.Madenjian, C.P., G.L. Rogers y A.W. Fast (1987) Predicting night time dissolved oxygen loss in prawn ponds of Hawaii: Part II. A new method. Aquaculture Engineering, 6: 209-225.Marceau, P., D. Cluis y G. Morin (1986) Comparaison des performances relatives à un modèle déterministe et à un modèle stochastique de température de l'eau en rivière. Canadian Journal of Civil Engineering, 13(3): 352-364.Meyer, D. y D.E. Brune (1982) Computer simulation of the diurnal oxygen levels in a stillwater aquaculture pond. Aquaculture Engineering, 1: 245-261.Moreu, P. (1999) Estadística Informatizada. Edita: Paraninfo. Madrid.Otnes, R.K. y L. Enochson (1978) Applied time series analysis. Edita: Wiley Interscience. New York.Park, H.H. (1998) Analysis and prediction of walleye pollock (Theragra chalcogramma) landings in Korea by time series analysis. Fisheries Research, 38: 1-7.Prybotuk, V.R., Y. Junsub y D. Mitchell (2000) Comparison of neural models with ARIMA and regression models for prediction of Houston's daily maximum ozone concentrations. European Journal of Operational Research, 122: 31-40.Pulido-Calvo, I. (2001) Diseño y gestión óptimos de sistemas de impulsión y de almacenamiento de agua para riego. Tesis Doctoral. Universidad de Córdoba.Pulido-Calvo, I., J. Roldán, R. López-Luque y J.C. Gutiérrez-Estrada (2002) Técnicas de predicción a corto plazo de la demanda de agua. Aplicación al uso agrícola. Ingeniería del Agua, 9(3): 319-331.Pulido-Calvo, I., J. Roldán, R. López-Luque y J.C. Gutiérrez-Estrada (2003) Demand forecasting for irrigation water distribution systems. Journal of Irrigation and Drainage Engineering, 129(6): 422-431.QI, M. y G.P. Zhang (2001) An investigation of model selection criteria for neural network time series forecasting. European Journal of Operational Research, 132: 666-680.Romaire, R.P. y C.E. 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(1991) Ecology of teleost fishes. Edita: Chapman and Hall. Londres.Yang, C.C., S.O. Prasher, R. Lacroix, S. Sreekanth, N.K. Patni y L. Masse (1997) Artificial neural network model for subsurface-drained farmlands. Journal of Irrigation and Drainage Engineering, 123(4): 285-292

Chemical and ultrasonic conditioning of water treatment plant coagulant sludges

The objective of this investigation was to evaluate the use of ultrasonic energy, pH adjustment, and addition of polyelectrolytes in dewatering coagulant sludges. Emphasis was placed on the effects of the ultrasonic power output level and period of conditioning, the chemical conditioning of the sludge, and the type and origin of the sludge. Dewatering is thought to be the most practical approach for reducing the volume of coagulant sludges and efforts are being made to improve their dewatering characteristics. An experimental system consisting of a magnetically stirred sludge reservoir, sonifier and reaction chamber, polymer feeder, and collection cylinder was developed for this study. The dewaterability of 3 conditioned sludges, 2 alum and 1 iron, before and after sonification was evaluated by vacuum filtration, centrifugation, and settling tests; and specific resistance, TS, and turbidity served as control parameters. Chemical conditioning of all sludges significantly improved their dewatering characteristics, and further improvement was possible by the use of ultrasonic conditioning; the effect of treatment was greater on alum sludge than it was on iron sludge. Conditioning for vacuum filtration required a lower ultrasonic power input over a shorter period of time than did treatment for centrifugation and settling; however, the resulting improvement in dewaterability when compared to the unsonified sample was less --Abstract, page ii