Showing papers on "Water environment published in 1996"

Effectiveness of Water Exercise on Postural Mobility in the Well Elderly: An Experimental Study on Balance Enhancement

Abstract: BACKGROUND The fear of falling may cause elderly people to limit their movement. As movement errors are known to facilitate the acquisition of motor skills, the elderly may inadvertently cause the loss of postural skills by constraining their movements, and hence avoid potential movement errors. It was hypothesized that by having elderly individuals exercise in a risk-free environment-water was utilized in this experiment-their postural capabilities would improve. METHODS Four groups of elderly subjects (80 +/- 5.8 years old) were placed into four groups: Water Exercisers; Land Exercisers; Water Sitters; and Land Sitters. Each group met twice per week for 45 minutes for 5 weeks of simple exercises or socializing in the designated medium. The distance each individual could reach (Functional Reach, FR) was measured at the end of each week. RESULTS Initially, each group was at risk (FR < 10 inches) for falling Statistical testing showed that the Water Exercisers (WE) increased their FR almost every week; the Land Exercisers (LE) increased only during the first week; and the Water Sitters (WS) and Land Sitters (LS) did not increase at all. The FRs after 5 weeks were 13.4 +/- 1.6 (WE), 11.3 +/- 1.5 (LE), 9.6 +/- 1.3 (WS), and 9.3 +/- 0.71 (LS) inches for each group, respectively. CONCLUSIONS The data showed that the postural capabilities in these elderly people, as measured by the FR, were enhanced by the production of movement errors that was facilitated in a water environment (in the case of the Water groups) or the initiation of a novel exercise program (Land Exercisers). Alternative explanations, and implication of these results, are discussed.

Changing river channels

Abstract: Partial table of contents: Changing River Channels: The Geographical Tradition (G. Petts). TEMPORAL AND SPATIAL DIMENSIONS. Changes of River Channels in Europe During the Holocene (L. Starkel). Channel Networks: Progress in the Study of Spatial and Temporal Variations of Drainage Density (V. Gardiner). Channel Cross-Sectional Change (C. Park). PROCESSES OF CHANGE. Bedload Transport and Changing Grain Size Distributions (B. Gomez). Catchment Sediment Budgets and Change (S. Trimble). INFORMATION FOR THE MANAGEMENT OF CHANGE. Information Flow for Channel Management (M. Clark). Information from Topographic Survey (S. Downward). Information from Channel Geometry-Discharge Relations (G. Wharton). MANAGEMENT FOR CHANGE. River Channel Restoration: Theory and Practice (A. Brookes). Towards a Sustainable Water Environment (J. Gardiner). Index.

Pathogenic agents in freshwater resources

Abstract: Numerous pathogenic agents have been found in freshwaters used as sources for water supplies, recreational bathing and irrigation. These agents include bacterial pathogens, enteric viruses, several protozoans and parasitic worms more common to tropical waters. Although infected humans are a major source of pathogens, farm animals (cattle, sheep, pigs), animal pets (dogs, cats) and wildlife serve as significant reservoirs and should not be ignored. The range of infected individuals within a given warm-blooded animal group (humans included) may range from 1 to 25%. Survival times for pathogens in the water environment may range from a few days to as much as a year (Ascaris, Taenia eggs), with infective dose levels varying from one viable cell for several primary pathogenic agents to many thousands of cells for a given opportunistic pathogen. As pathogen detection in water is complex and not readily incorporated into routine monitoring, a surrogate is necessary. In general, indicators of faecal contamination provide a positive correlation with intestinal pathogen occurrences only when appropriate sample volumes are examined by sensitive methodology. Pathways by which pathogens reach susceptible water users include ingestion of contaminated water, body contact with polluted recreational waters and consumption of salad crops irrigated by polluted freshwaters. Major contributors to the spread of various water-borne pathogens are sewage, polluted surface waters and stormwater runoff. All of these contributions are intensified during periods of major floods. Several water-borne case histories are cited as examples of breakdowns in public health protection related to water supply, recreational waters and the consumption of contaminated salad crops. In the long term, water resource management must focus on pollution prevention from point sources of waste discharges and the spread of pathogens in watershed stormwater runoff.

Analysis of the Virulence Characteristics of Bacteria Isolated from Bottled, Water Cooler, and Tap Water

Abstract: A study was conducted to determine the numbers and types of bacteria found in three water sources—bottled water, water cooler water, and tap water—and to determine their virulence characteristics. A wide variety of water types were collected and each was analysed for Heterotrophic Plate Count (HPC) bacteria, Pseudomonas aeruginosa , and total coliforms. For each isolate, virulence characteristics were determined by enzyme analysis (10 associated with virulence), antibiotic susceptibility testing (natural and semi-synthetic antibiotics), acid lability (survival at pH 3-5), and cytotoxicity testing (HEp-2 cells). Results showed that all water sources had a normal bacterial content. Only 2 per cent of bottled water sources had P. aeruginosa . Total coliforms were isolated only from bottled water that used mixed (water alternating with milk) filling lines. Environmental bacteria did not produce significant enzymes associated with virulence, were not acid resistant, were susceptible to semi-synthetic antibiotics, and did not produce appreciable cytotoxicity. These natural aqueous bacteria were adopted to a water environment, did not grow well at conditions analogous to the human host, and did not have the characteristics associated with virulence. Future drinking water revisions and changes to the treatment processes should be directed towards the elimination of specific pathogens and to the prevention of exogenous sources of contamination rather than the elimination of natural water microbial populations. Keywords: virulence factors, drinking water, health risk, heterotrophic bacteria, water regulations.

Aquatic exercise device

Abstract: An aquatic exercise device which is to be used within a body of water such as a pool has an element which can be engaged by the foot or hand of an individual, which element is linked to a piston-cylinder combination so that as the user engagement element is moved by the user the piston rides in the cylinder. At the head end of the cylinder there is an opening which provides communication between the cylinder chamber and the water environment. As the piston moves back and forth water is either pushed out of the chamber through that opening or drawn into the chamber through that opening. The size of the opening, which may be selected by the user, determines the degree of resistance to the user's movement against the user engagement element.

Microcystin levels during 1992-95 for Lakes Sagami and Tsukui-Japan.

Abstract: Toxic cyanobacterial blooms have been frequently observed in Lakes Sagami and Tsukui, Kanagawa Prefecture, Japan, which are used as drinking and recreational water sources. As the first step toward the control and removal of cyanobacterial toxins, the present study evaluated the microcystin level in these lakes. Our established method using HPLC and LC/MS to pursue trace amounts of microcystins was applied to the determination of microcystins within cyanobacteria cells and in water. We could determine precisely the intracellular and extracellular microcystin level in the water environment during 1992-95. Microcystins RR, LR, and YR were detected at 0.02-2.64 micrograms/L in cell-free water and at 0.02-378 micrograms/L in the cells. Although there were many cases in which microcystin concentrations in the cells exceeded the proposed guideline level (1 microgram/L), there was only one example of this happening in cell-free water samples. Because the present monitoring indicated that the amount of microcystins detected in water was much less than that estimated in cells, the release of microcystins from the cells and their stability in lake water were examined in the dark. The resulting toxins persisted at the same concentration level for 14 days and the microcystin concentrations steadily declined, showing that biodegradation using aquatic natural bacterial flora is an effective detoxification process under natural conditions.

Water environment and nanostructural network in a reactive powder concrete

Abstract: A Reactive Powder Concrete (RPC) with an average compressive strength of 230 MPa was studied by diffuse reflectance infrared Fourier transformed spectroscopy (DRIFTS), controlled rate thermal analysis (CRTA) and low temperature nitrogen adsorption-desorption volumetry. Different water environments are observed by DRIFTS. The CRTA experiments coupled to mass spectrometric analyses allow us to differentiate various gases corresponding to adsorbed molecules and to the pyrolysis of different species. In particular the organic species added during processing can be observed. Adsorption experiments reveal a low specific surface area showing an intimate reaction between the starting components during processing. Furthermore, they show that the RPC can be considered as an open network of pores of various diameters.

Method and apparatus for treating meat products with ultrasonic energy in an ozonated water environment

Abstract: A process and apparatus for treating meat products with ultrasonic energy in an ozonated water environment to eradicate harmful pathopens from the surface of the meat products.

The journey from Arusha to Seychelles - successes and failures of integrated coastal zone management in Eastern Africa and island states

Abstract: The report is the outcome of the Second Policy Conference on Integrated Coastal Zone Management in Eastern Africa and Island States, and builds on the perception that economic opportunities in the region abound, stemming from tourism, largely based along the coast. This has translated into a growing number of coastal fishing activities, evolving into larger scale ventures, through destructive fishing methods; not surprisingly, resulting in fewer catches. Furthermore, due to the tourism expansion in the region, infrastructure is undergoing large scale development along the coastal zone, adversely affecting the environment due to wastes, improper sewage treatment, and soil erosion. In 1993, the environmental, and natural resource ministers of the region met in Arusha, Tanzania, to address these problems at a regional level, and endorsed a Resolution on coastal zone management recommendations. The report discusses the successes, and failures since then, reviewing overall trends on the coastal zone, through case studies, particularly focusing on the institutional, and legal framework, indicating the need to comply, and enforce regulations. The revision for new legislation is suggested, recommending stakeholders participation to help reduce environmental regulations' violations. The use of expertise, and training should be optimized, public awareness promoted, and capacity building developed.

Geographic information systems

Abstract: Geographic Information Systems (GIS) and relational database management system technology have increasingly provided a foundation for integration and analyses of water environment data in context with other geographically related data.. While large scale GIS projects can pose expensive undertakings, an ever-widening variety of applications are enhancing the understanding and management of natural and human-made systems and the relationships and impacts to each other. The degree of data diversity within a geographic framework employed in many water environment applications today extend to include economic, ecological, physical, political and hydrological, to name a few examples. Technical tools, such as global positioning system (GPS) technology, satellite remote sensing and modeling integration, has allowed GIS to con tinue to expand beyond digital mapping to embrace a growing number of water resource protection and management domains.

Risk Assessment for Pesticides and Their Metabolites in Water

Abstract: A method based on Hasse diagram is adopted to detect priority pesticides among the 130 most used in Europe. Hasse diagrams rank pesticides in groups of potential hazard to the water environment, according to pesticide properties (water solubility, vapour pressure and persistence in soil) and usages. The procedure is applied on a territorial scale, selecting Germany, U.K. and Italy as case studies, and validated with the experimental results of monitoring programs. Most of the pesticides ranked as a first priority by the model and analyzed for in water were effectively found. The percentage of positive findings decreases from class 1 to 6 of priority in agreement with the theoretical predictions. The model suggests that each country must develop its own analytical protocol addressed to the detection of the most “probable” pesticides. Pesticide metabolities of Italian priority pesticides are appraised in detail and their risk is assessed according to their occurrence in surface and groundwater, per...

Threshold stress intensity factor in soda-lime silicate glass by interrupted static fatigue test

Abstract: The measurement of the threshold stress intensity factor Kth for sub-critical crack growth of soda-lime glass in a water environment was performed using the interrupted static fatigue test. The experimental procedures suggested in a previous paper by the current authors were followed. In the first approach, Kth was calculated as the stress intensity factor at which half of the specimens fail during the constant stress phase of the test. In the second approach, the fatigue limit was determined from the stress intensity factor applied to the weakest surviving sample during the stress hold. For both cases, values of the stress intensity factor were obtained for increasing hold times, which ranged from 1 hour to 20 days. The estimated Kth values decrease with holding time but are expected to reach a limiting value, equivalent to the true threshold at long times. For holding times of 20 days, values of 0.16 and 0.15 M Pa m 1 2 were obtained by using the two different approaches. For the current test, the necessary limit in the estimated Kth values was not obtained, suggesting that if a threshold exists, it must be equal to or less than these values. These values are significantly lower than previous Kth estimates that were obtained by extrapolation from crack velocity and time-to-failure measurements (0.2 – 0.4 M Pa m 1 2 ).

Data management related to the application of two crop-water-environment- models in Argentina and Egypt

Abstract: In a study of the transportability and intercomparison of models, the on-farm soil water balance models SWAP and BIWASA were applied with data collected in Lavalle (Argentina) and Zenkalon (Egypt). It is concluded that the one-dimensional SWAP model does not predict the water and salt balances worse than the two-dimensional model. The era of model development should bend towards quality and quantity of input and output data, rather than towards further extending the arena of models.

An electron nuclear double resonance and electron spin resonance study of isotropic CO2- and SO2- radicals in natural carbonates

Abstract: Natural samples often exhibit isotropic electron spin resonance (ESR) signals at g=2.0006, (CO2-) and g=2.0057 (SO2-). Electron nuclear double resonance (ENDOR) data were collected for various calcitic or aragonitic samples of marine origin. The small and isotropic H-1 hyperfine ENDOR splitting (250-350 kHz) is explained by a locally disordered water environment for these species. As for the isotropic CO2- and CO3- radicals in synthetic monohydrocalcite and apatite, the radicals are most probably located in the occluded water embedded in these samples, and not in the crystal matrix.

Cadmium removal from water environment by a fungus Volveriella volvacea

Abstract: Biosorption technique was used for removal of cadmium under different conditions from water environment using a biosorbent, Volveriella volvaceas, locally growing fruit bodies of mushroom. Effects of different parameters like pH, sorbent concentration, ionic strength on the removal efficiency of cadmium by V. volvacea were carried out in continuation with adsorption kinetics and equilibrium isotherm experiments. From the kinetics studies it was found that nearly 95% of the total cadmium removal was achieved from cadmium spiked distilled water within first 15 minutes. Isotherm data was best fitted to linearised Langmuir equation and the sorption capacity was found to be varying from 9.13 to 9.33 mg/g for different sizes of sorbent. The uptake of cadmium(II) is a function of pH of the solution and increases with the increasing pH. Increasing ionic strength and the presence of soluble complexing agents such as ethylene diamine tetraacetic acid (EDTA) decrease the sorption of cadmium (II). The presence of other diavalent cations like calcium and magnesium impedes the uptake of cadmium (II). The presence of chloride ion has no significant effect on cadmium (II) removal. The spent biosorbent can effectively be regenerated with acid and can then be reused.

Correlation between interfacial free energy and albumin adsorption in poly(acrylonitrile–acrylamide–acrylic acid) hydrogels

Abstract: An investigation on the influence of chemical compositions and surface properties (e.g., surface free energy in air and hydrogel–water interfacial energy) on the adsorption of bovine serum albumin (BSA) at pH 7.4 on to a series of poly(acrylonitrile–acrylamide–acrylic acid) hydrogels was carried out. The interfacial energetics were determined from the contact angle data for air–gel and octane–gel in the water environment and the specific adsorption of BSA was determined with UV–VIS spectroscopy. It is shown that the higher contents of amide and acid groups in hydrogel bulk lead to the greater polar component of surface energy in air and the greater BSA adsorption in aqueous solutions. The BSA adsorption decreases with water amount in gels at lower amide/acid contents and increases at higher contents. The results imply that the interfacial interactions between the protein and the reorganized hydrogel interface in exposure with water, as well as the penetration of protein into pores of swollen gels, influence the BSA adsorption. © 1996 John Wiley & Sons, Inc.

Chemical and Biological Influence of Hazardous Substances and Obstacle Organisms to Aquatic Environment and Their Control. Risk Assessment of Genotoxic Substances Related to Human Diet in the Water Environment.

Abstract: Genotoxic activities have been detected in the river water. The umu test, which can detect DNA damage, was carried out with blue rayon extracts of various water samples from the river systems and treatment plants. HPLC fractionations followed by MS or UV analysis were applied to the extracts to identify the genotoxic substances. Trp-P-2 (3-amino-1-methyl-5H-pyrido[4,3-b]indole), which is one of mutagenic and carcinogenic heterocyclic amines, was detected in concentration from 1 μg·l-1 to 1 ng·l-1. These results show that carcinogenic substances related to humans' daily diet remain after usual biological treatment. To evaluate the level of Trp-P-2, the added risks were calculated by use of the doseresponse relationships obtained in a carcinogenic animal experiment with mice. The values at assumed exposures of 2l per day of samples from the night soil treatment plant over an average life span of 70 years for 70kg person were in excess of 10-6. Because of the possibility of the reuse of wastewater, the need for the investigation on the safety of the secondary effluent from the treatment plants was suggested.

The European water environment in a period of transformation

Abstract: Issues in European and international water management the water resource - economic characteristics, industrial structure and management instruments for water quality management modelling the synthesis between water management and economics England and Wales - an historical perspective France - public responsibility - private execution water management in the transformation to the market - opportunities for Hungary unified German water management - political and economic reunification and the integration of water policy transboundary water management in Europe - conflict and co-operation on the Danube.

Phosphorylation-induced torsion-angle strain in the active center of HPr, detected by NMR and restrained molecular dynamics refinement.

Abstract: The structure of the phosphorylated form of the histidine-containing phosphocarrier protein HPr from Escherichia coli has been solved by NMR and compared with that of unphosphorylated HPr. The structural changes that occur upon phosphorylation of His 15, monitored by changes in NOE patterns, 3JNHH,,-coupling constants, and chemical shifts, are limited to the region around the phosphorylation site. The His15 backbone torsion angles become strained upon phosphorylation. The release of this strain during the phosphoryl-transfer to Enzyme I1 facilitates the transport of carbohydrates across the membrane. From an X-ray study of Streptococcus faeculis HPr (Jia Z, Vandonselaar M, Quail JW, Delbaere LTJ, 1993, Nature 361:94-97), it was proposed that the observed torsion-angle strain at residue 16 in unphosphorylated S. fuecalis HPr has a role to play in the protein's phosphocarrier function. The model predicts that this strain is released upon phosphorylation. Our observations on E. coli HPr in solution, which shows strain only after phosphorylation, and the fact that all other HPrs studied thus far in their unphosphorylated forms show no strain either, led us to investigate the possibility that the crystal environment causes the strain in S. faecalis HPr. A 1-ns molecular dynamics simulation of S. faecalis HPr, under conditions that mimic the crystal environment, confirms the observations from the X-ray study, including the torsion-angle strain at residue 16. The strain disappeared, however, when S. faecalis HPr was simulated in a water environment, resulting in an active site configuration virtually the same as that observed in all other unphosphorylated HPrs. This indicates that the torsion-angle strain at Ala 16 in S. faecalis HPr is a result of crystal contacts or conditions and does not play a role in the phosphorylationdephosphorylation cycle.

Dissoluble fishing sinker

Abstract: An annular fishing sinker is formed of environmentally compatible materials to dissolve in variable predetermined times in a water environment The sinker is formed of sand in a matrix of gelatin, particulated cellulosic material that swells in water and unbleached wheat flour with enough water to form a moldable plastic mixture that upon drying is coherent and configurationally sustaining The components may be varied in relative quantity to provide sinkers that dissolve in from less than one minute to more than twenty minutes The sinker is attached to a fishing line by tying in such fashion that a knot will not be left in a supporting line when the sinker dissolves A process is disclosed for forming the sinker by molding with subsequent drying

Chemical and Biological Influence of Hazardous Substances and Obstacle Organisms to Aquatic Environment and Their Control. Toxicity Assessment of the Samples from Water Environment Using Cultured Mammalian Cells.

Abstract: To evaluate the toxicity other than mutagenicity or carcinogenicity present in the water environment, in vitro cytotoxicity tests using cultured mammalian cells were utilized. Cytotoxicity was estimated based on the changes in viable cell numbers of primary rat cerebellar cells, rat pheochromocytoma cell PC12h, and normal rat kidney epithelial cell NRK-52E. Evaluation of these in vitro systems was performed by testing reference chemicals proposed by MEIC (Multicenter Evaluation of In Vitro Cytotoxicity), an international program for the validation of in vitro cytotoxicity tests.When cells in culture were exposed to landfill leachate for 48 hours, viable cell numbers decreased dose dependently. However, fractions prepared by condensation and extraction from the leachates showed much less effects on the viable cell numbers. Their individual cytotoxicity did not account for that of unfractionated leachate, suggesting that component(s) with higher cytotoxicity may not be successfully recovered during the condensation and extraction process.Among the silica-gel column fractions of acetone-extracts of sediment samples, fractions eluted with acetone showed the highest cytotoxicity.These results indicate that the cytotoxicity of water samples like landfill leachates or of their extracts can be detected with the present assay system but toxic components may not be recovered quantitatively during the condensation and extraction process.

Comparison of two force fields in MD‐simulations of α‐helical structures in keratins

Abstract: Molecular dynamic (MD) simulations based on two different force fields, CVFF and CFF91, were carried out in order to check their feasibility for the structural investigation of the wool intermediate filament (IF) monomeric unit. Selecting an ideal α-helix as start conformation, all MD-simulations with CVFF in vaccum show the α-helix to be unstable. Independently of the amino acid sequence of the α-helix, a new helical structure with a larger diameter arises during the MD-simulation, due to a shift of the intrahelical hydrogen bonds. However in simulations with surrounding water the α-helix remains stable throughout the simulations with the CVFF force field. In contrast to this, MD-simulations in vaccume based on the CFF91 force field are able to determine different stabilities for the α-helical start conformation of various IF-segments, that agree well with secondary structure predictions. The simulation results obtained with CFF91 in vacuum can like wise be verified using an explicit water environment. We found that higher partial charges attributed to the atoms of the amide groups that form the intrahelical hydrogen bonds are the reason for the superiority of the CFF91 force field.

Optical measurement of the MSX local H2O density

Abstract: The krypton radiometer (KR) is one of a suite of instruments that monitor the gaseous and particulate contamination environments of the midcourse space experiment (MSX) spacecraft. The krypton radiometer measures the local water density in a volume of space approximately 50 cm from the spacecraft near its +X/+Y/+Z corner. The instrument comprises an array of krypton VUV lines source lamps that dissociate water and a near UV radiometer that detects the chemiluminescence from the OH dissociation products. Ground calibrations indicate that the instrument has sufficient sensitivity to detect water densities as low as 1.5 multiplied by 107 molecules cm-3. Water is the primary outgassing species during the early part of a spaceflight. Water deposition is also a particular concern to cryogenic sensors, such as the spatial infrared imaging telescope III (SPIRIT III) on this spacecraft. As the mission progresses, we will correlate the KR measurements of the water density with measurements by the neutral mass spectrometer, total pressure sensor and cryogenic quartz crystal microbalance. Using the MSX external contamination model we will create a complete description of the MSX water environment including outgassing, return flux and deposition, and effects.© (1996) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.