bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evaluation of sample fractionation using micro‐scale liquid‐phase isoelectric focusing on mass spectrometric identification and quantitation of proteins in a SILAC experiment
Authors: Thorsell Annika , Portelius Erik , Blennow Kaj , Westman‐Brinkmalm Ann 
Published: February 2007

AbstractMass spectrometric methods based on stable isotopes have shown great promise for identification and quantitation of complex mixtures. Stable isotope labelling by amino acids in cell culture (SILAC) is a straightforward and accurate procedure for quantitation of proteins from cell lines, that are cultured in media containing the natural amino acid or its isotopically labelled analogue, giving rise to either ‘light’ or ‘heavy’ proteins. The two cell populations are pooled and treated as a single sample, which allows the use of various protein purification methods without introducing errors into the quantitative analysis. The quantitation of the proteins is based on the intensities of the light and heavy peptides. The increased number of peptides in a quantitative experiment arising from peptide pairs implies that prefractionation is critical prior to liquid chromatography/mass spectrometric (LC/MS) analysis to minimise signal suppression effects and errors in measurements of the intensity ratios. In this study, the effect of a prefractionation step on identification and quantitation of proteins in a SILAC experiment was evaluated. We show that micro‐scale liquid‐phase isoelectric focusing in the Micro Rotofor separates proteins into well‐defined fractions and reduces the sample complexity. Furthermore, the fractionation enhanced the number of identified proteins and improved their quantitation. Copyright © 2007 John Wiley & Sons, Ltd.
The environmental impacts of the tucuri dam on the middle and lower tocantins river basin, Brazil
Authors: Barrow C. J. 
Published: February 2007

AbstractAn attempt is made to appraise the present and likely future environmental impacts of the Tucuruí Dam upon the mid and lower Araguaia‐Tocantins Basin (Brazilian Amazonia). Information has been obtained by literature review and from field visits made by the author in 1981, 1983, and 1985. The problems of impoundment‐related environmental impact assessment in tropical developing countries are also discussed.Tucuruí is the world's fourth largest hydroelectric project and is the first large dam to be completed in an Amazonian rainforest environment. It is also the first of a number of large dams which Brazil plans to construct in the Araguaia‐Tocantins Basin and on other tributaries of the Amazon. The appraisal of problems associated with Tucuruí Dam should help planners minimize difficulties with future Amazonian hydroprojects.Like many developing country environmental impact assessments, that carried out at Tucuruí was begun after the construction site had been selected and construction had begun. Tucuruí impact studies have tended to concentrate on the environmental and socioeconomic impacts generated in the vicinity of the dam and reservoir; downstream impacts have received less attention but are already apparent. Major impacts identified include reservoir siltation, disruption of fisheries and agriculture (especially floodland cultivation) downstream, and human disease problems.
Changes in benthic sediment in the thomson river, Southeastern Australia, during construction of the thomson dam
Authors: Davey G. W. , Doeg T. J. , Blyth J. D. 
Published: February 2007

AbstractThe particle‐composition (0.15 to >64 mm) of the stream‐bed was monitored by Surber sampling at sites above and below the site of the Thomson Dam during the two years of most active construction. Levels of particles between 0.5−2 mm were highest 9.5 km below the dam site, and increased throughout the study. Levels of these grades at sites above and well below the dam site were variable, but showed no consistent trends. Material greater than 2 mm showed no substantial variation either over time or between sites spanning approximately 70 km of river length and 250 m of elevation.Artificial substratum samplers were used to estimate the rate of sediment input (0‐2 mm) between sampling dates. Sediment input was clearly highest 1 km and 9.5 km below the dam site. Input was seasonal, with maxima in winter and spring of each year. Size classes 1‐2 mm and <0.063 mm contributed over 60 per cent of the total deposited sediment. Over the second year of the study, high levels of sediment <0.063 mm were deposited at a site 33 km below the dam site, indicating the progressive movement of material down the river.Some fine sediment was found to penetrate unconsolidated bed material to depths down to 60 cm. It is suggested that such material, resulting from land disturbance, is capable of filling interstitial spaces in the stream‐bed, and that major disturbance of the bed may be necessary to dislodge it.
Thermal characteristics of two regulated rivers in mid‐wales, U.K.
Authors: Cowx I. G. , Young W. O. , Booth J. P. 
Published: February 2007

AbstractData for three rivers in the upper Severn catchment are examined to assess the influence of regulation strategies on the thermal characteristics. Seasonal and diel temperature variations are markedly influence by the release discharge and the depth of withdrawal from the reservoir. The downstream influence of river regulation is confined to a relatively short reach (ca. 30 km) below the dams. Nevertheless, the control of water temperature during hot, dry summers could benefit salmon populations.
Classification and succession of former channels of the french upper rhone alluvial plain using mollusca
Authors: Richardot‐Coulet M. , Castella E. , Castella C. 
Published: February 2007

AbstractThis paper deals with the results of an extensive sampling of eight former channels of the Rhǒne and eight of its tributary, the Ain River, France, designed to assess the value of molluscs as ‚describers’︁ of ecosystem dynamics.The sampling was stratified on the distribution of aquatic macrophytes. The distribution of molluscs species is shown to provide information on the rate of eutrophication, the groundwater supply and the succession of the abandonned river channels toward semi‐aquatic and terrestrial conditions. Molluscs, together with other macroinvertebrates, not only describe the present stage of these ecosystems but also provide some predictive information on their successional pattern for assistance in the management of the alluvial plain.
Stream regulation in Argentina, including the superior Paraná and Paraguay rivers
Authors: Bonetto Argentino A. , Castello Hugo P. , Wais Irene R. 
Published: February 2007

AbstractArgentine water resources are located in three hydrologically contrasting regions: the so‐called Del Plata basin, the Arid Central Andean area, and Patagonia. About 150 dams and impounding reservoirs that exceed a capacity of 150 × 103 m3, have been built. Most limnological studies of regulated rivers have been conducted recently. In the Del Plata basin, Argentine dams are scarce, although many have been built or are projected upstream, mainly in Brazil. The ecological problems of the reservoirs are related to decomposition of inundated terrestrial vegetation; algae blooms, dissolved oxygen depletion phenomena, eutrophication, impaired fish migrations, overproduction of water hyacinth Eichhornia spp., and schistosomiasis. The importance of examining the influence of the projected middle Paraná dams on downstream sediment regimes, especially as it affects the delta, is emphasized. In the Arid or Central Andean region, the main development of the Grande‐Tercero rivers includes dams, reservoirs, and the operation of a nuclear power plant. One of the most important effects will be a slight increase in the water temperature of the Rio Tercero reservoir as a consequence of water use in the cooling system of the nuclear power plant. In the Patagonian region, the main dams are those built and projected for the Colorado and Negro basins. In the Negro basin studies are being carried out mainly in the Ramos Mexia Reservoir, on different aspects of zooplankton and phytoplankton, benthos, and fishes. Commercial fishing is not permitted and fishing is based mainly on the introduced salmonids which show symptoms of undernourishment because of a lack of forage fishes. Indigenous fishes have been decimated by the introduced salmonids.Although studies have been conducted in several areas, much work remains to be done in relation to the environmental effects of dams on streams in Argentina. Results from ecological studies are still insufficient to solve the multiple problems associated with them, such as climatic influences, retention of suspended solids, deforestation, schistosomiasis and other aquatic diseases, pollution, eutrophication, fish‐ways and fish migrations, accumulations of the water‐hyacinth, salt and nutrient regimes, and siltation. Even partial solutions to these problems will require an ensemble of urgent measures to assure the maximum benefits with minor risks and ecological costs.
Ecological considerations in the development and application of instream flow‐habitat models
Authors: Orth Donald J. 
Published: February 2007

AbstractMethodologies for recommending instream flows for protecting lotic ecosystems are evolving amid constructive criticism. During this period of change it is important that all concerned parties are aware of the ecological factors that control stream ecosystems and fish populations. Ecological factors relating to stream ecology, population dynamics, energetics, predation, and competition are reviewed to explain why indices of microhabitat availability are not expected to be consistent predictors of fish population density. Implications of these concepts for development and application of instream flow‐habitat models for recommending instream flow regimes are discussed. Current ecological theory and empirical studies support the hypothesis that microhabitat availability may limit fish populations but not continuously. Therefore, assessments must consider the limiting habitat events as well as temperature and water quality constraints. Also, invertebrates and non‐game fishes must be considered in instream flow assessments because of their importance in stream ecosystems.
Hydraulic effects of aquatic weeds in U.K. rivers
Authors: Watson David 
Published: February 2007

AbstractThe effects of large aquatic plants (aquatic macrophytes) have been given limited attention in literature dealing with open channel flow. This is despite a large number of river channels in the U.K. being affected by profuse growths of these plants. This paper contributes to three major areas in relation to aquatic macrophytes and river channels.First, a literature review examines four areas of vegetated channel research. Early work on vegetated channels concentrated upon grass‐lined farm drainage channels in the U.S.A. This was complemented by flume studies of predominantly artificial vegetative roughness elements. The review discusses research into large aquatic plants in stream channels, and the discussion draws together a number of disparate areas of research into vegetated channels including theoretical considerations.Secondly, the paper discusses results obtained from laboratory flume experiments, using real plants, and field monitoring on the River Ebble, Wiltshire, U.K. The relationship between discharge and Manning's roughness coefficient (n) is examined. Field monitoring results are presented as generalizations in the relationship between Manning's n when the monitoring sites were vegetated and unvegetated. The relationship between plant cover in the channel and Manning's n is also examined. Two measurements of plant cover are employed: the percentage cross‐sectional area of channel vegetated, and biomass per unit area. The field data for Manning's n and discharge are then discussed in detail in a case study of one site on the River Ebble.Finally, the results obtained from field monitoring are compared to previous research. In the light of these comparisons and detailed examination of the field and flume data, a conceptual model of the effects of aquatic plant growth on channel roughness, mean flow depth, and flow stage is represented. Using this model, an estimate can be made of the likely effect of changing plant cover and discharge on flow stage in an open channel.
The importance for birds of the riparian woodlands within the alluvial corridor of the river garonne, S.W. France
Authors: Decamps H. , Joachim J. , Lauga J. 
Published: February 2007

AbstractCommunities of nesting birds were studied in four distinct biotopes within the alluvial corridor of the River Garonne: 50 terrace woodlands, 17 riparian woodlands, one poplar plantation, and one slope woodland. A total of 400 stations were investigated, consisting of eight distinct classes of forest size for the terrace woodlands and four for the riparian woodlands. The distribution of 64 species of birds, observed by means of 20 minute listening point surveys, was related to three main factors: forest size, site wetness, and the wooded space marginality (forests, woods, copses, hedges, trees).Indices of mean richness and of mean abundance show that the riparian woodlands were the richest and the most densely populated. The surface area of woodlands has a strong effect on the structure of the bird community on terraces but less in the riparian environment.Multivariate analysis contrasted the species from the open islands within closed environments with the species from the closed islands within an open environment. The effect upon the nesting bird communities of the fragmentation of the original forest within the alluvial corridor of the River Garonne is demonstrated by a grouping of two characteristics: the connectivity of the riparian woodlands and the insularity of the terrace woodlands. The conservation of a continuous ribbon of riparian woodlands is shown to be an important condition for maintaining a rich community of nesting birds.
Water development and associated hydrologic changes in the Platte river, Nebraska, U.S.A
Authors: Hadley R. F. , Karlinger M. R. , Burns A. W. , Eschner T. R. 
Published: February 2007

AbstractMajor changes in hydrologic regime and morphology of channels of the Platte River and its major tributaries, the South Platte River and North Platte River in Colorado, Wyoming, and Nebraska have occurred since about 1860, when the water resources of the basin began to be developed for agriculture, municipal, and industrial uses. The extent of this water development, which continues to increase with growth in population and land use, has affected the timing of streamflow and transport of fluvial sediment in the Platte River through diversions, reservoir storage, and increased use of groundwater. Changes in flow regime, such as increase in low‐flow magnitudes and abatement of peak‐flow magnitudes, have made the riverine environment conducive to vegetative growth while reducing channel scour. These factors, in turn, contribute to morphologic changes of decreased channel width and channel area and increased island formation. This paper will focus on these trends over the last several decades in the study area on the Platte River in Nebraska.
Aquatic weed problems in a hydroelectric river: The R. Otra, Norway
Authors: Rørslett Bjørn 
Published: February 2007

AbstractExcessive abundance of submerged macrophytes is a less well‐known but highly undesirable effect resulting from hydropower development. An example is the acidic River Otra, which is an extensively exploited hydroelectric river located in a region of infertile soils in southern Norway. The operating schemes annually generate some 4·1 TWh of hydropower. Many stretches of the River Otra support massive infestations of a submerged phenotype of Juncus bulbosus L. Evidence from a multidisciplinary study demonstrates that proliferation of J. bulbosus is achieved under an altered flow regime typical of Norwegian hydrorivers. The main features are augmented winter flows, concomitant lack of ice‐cover, and intermediate ranges and frequencies of water‐level fluctuation. These hydrological conditions prevail in tailwaters and intermediate‐type hydrolakes on the Otra. By contrast with the Otra River, an adjacent water‐course, the acidified Tovdal River, supported only scattered J. bulbosus in its upper, non‐regulated sections, whereas a hydrolake on the lower Tovdal River had locally abundant growth of J. bulbosus. Acidification per se is an unlikely determinant of profuse growth for this species: non‐natural habitats created by hydropower operation provide vacant space for an opportunistic species such as J. bulbosus.
Deforestation of large reservoir basins
Authors: Paiva Melquíades Pinto 
Published: February 2007

AbstractThis paper deals with the possible alternatives regarding deforestation of large reservoir basins, concluding in favour of the convenience of adopting zoned deforestation, in accordance with the uses for which they are planned. At the same time, a methodology is developed to estimate the quantity of vegetal biomass to be removed from flooding basins of such reservoirs before closing the respective barrages. To this end, recommendations are made regarding plans for the filling phase which must be elaborated together with the plans of deforestation, so that mutual adjustments are allowed, attaining maximum reductions in costs and duration of clearing services. Finally, it is recommended that the occurrence of trunks emerging from the water should be reduced to a minimum in order to avoid the development of floating acquatic macrophytes.
Channel response to grade‐control structures on Muddy Creek, Mississippi
Authors: Harvey Michael D. , Watson Chester C. 
Published: February 2007

AbstractGrade‐control structures are commonly employed to prevent bed degradation and concomitant bank instability of channelized reaches of rivers. A study of a 20 km reach of a coastal plains stream was conducted in 1985 to determine the effects of 12 rock‐lined grade‐control structures that were installed between 1977 and 1983 prior to channel excavation. An Allowable Tractive Stress Method (TR.25) was used to determine the placement of grade‐control structures, and the gradients between them, for a trapezoidal‐shaped channel designed to convey the 1 year recurrence interval peak flow. The design was successful in preventing bed degradation and bank erosion over the period of observation. However, unpredicted channel responses have occurred. Aggradation is apparent between control structures, and a two‐stage compound channel has formed as a consequence of berm development, especially in the lower, older subreach. In the lower subreach, the vegetated berms have constricted the cross‐sectional area at the design discharge (99 m3 s−1), and as a result, water‐surface slope, shear stress, and unit‐stream power have incresed. Bed material has become coarser and better sorted, which has increased shear intensity values. These unexpected changes are attributed to the lack of adequate consideration of the requirement for balance between sediment supply and transport in the TR.25 procedure; seven tributaries contribute sediment to the main channel of the study reach. It appears that the increased energy is utilized in bedload transport rather than channel erosion. This study demonstrates that the TR.25 method is too conservative if significant amounts of sediment are being supplied to the design channel. In such cases, adjustments in channel morphology will increase the energy to accommodate bedload transport.
Suspended solids transport in the regulated River Blithe, Staffordshire, U.K.
Authors: Gilvear David. J. 
Published: February 2007

AbstractSuspended solids concentrations and turbidity were monitored on the regulated River Blithe at two sites downstream of the reservoir for a period of 18 months. Changes in the suspended solids loads transported and the nature of the material in suspension are related to dam overspill and tributary flood events. A hysteretic relationship between suspended solids concentrations and discharge is characteristic of both sites, sediment supply being limited within the regulated river. Downstream of the dam, rapid bank erosion occurred on meander bends but the suspended solids loads transported by the regulated river relate more to the resuspension and transport of tributary injected sediments and scouring of a dense periphyton. Close to the dam, fine biogenic matter dominated the seston, which scanning electron microscopy revealed to contain algal fragments and inorganic diatom frustules, but downstream, tributary‐derived minerogenic particles were dominant.
Historical aspects of irrigation agriculture and river regulation in the Murraay‐Darling Basin, Australia
Authors: Davidson B. R. 
Published: February 2007

AbstractRiver regulation in Australia is a feature of the last on hundred years. Irrigation farms were established along the River Murray in the 1880's and on the Murrumbidgee in the first quarter of the twentieth century. These demonstrated that such labour‐intensive types of farming were unprofitable in Australia. The additional profits obtained by irrigation farmers were not sufficient to pay for the reservoirs and distributary works required and these had to be paid for by the State. Water was sold to farmers at a price which was only sufficient to maintain the projects.Political pressure led to a further increase in the consturction of reservoirs and the area irrigated in the Murray‐Darling basin expanded from 0·6 million hectaers in 1945 to 1·6 million hectares in 1979. As irrigation practices improved, farm profits increased, but the price of water continued to be based on the cost of maintaining the projects. This led to increased profits being built into the price of irrigated land. Low water prices encouraged farmers to over‐irrigate and aggravated the problem of rising water tables and salination.It is argued herein, that the efficiency of water usage in irrigation could be improved by transferring the existing water rights from the state of irrigators, and making them transferable from one irrigator to another or from irrigators to other users at prices negotiated in a free market. Such a system would ensure that water was put to its optimum use, reducing wastage and minimizing detrimental effects of over‐use. The water price established in such a market could be used to calculate whether the marginal returns from irrigation and other uses were high enough to justify the construction of new projects.
A flood alleviation of the Kakehashi Basin, Japan
Authors: Nakagawa Takeo 
Published: February 2007

AbstractA flood alleviation scheme is proposed for the Kakehashi basin, Japan. The scheme consists of one diversion channel, four retarding basins and one dam. The region between the diversion channel and the Kakehashi river is protected from floods. The measures proposed make it possible to achieve flood alleviation whilst minimising changes of the Kakehashi river, and impacts on historical environments and cultural properties. It is emphasized that preservation of the sinuous channel of the Kakehashi river must play a key role in future management because of the physical, biological and aesthetic advantages when compared with a straight stream channel.