bluuebunny/crossref_metadata_2025 huggingface dataset:
On‐line automatic SPE‐CE coupling for the determination of biological markers in urine
Authors: Ruiz‐Jiménez José , Mata‐Granados José M. , Luque de Castro Maria Dolores
Published: February 2007

Automatic SPE has been coupled on‐line to CE by a transfer tube and the replenishment system of the CE instrument. The approach allows the target analytes (viz. creatinine, creatine, xanthine, hypoxanthine, uric acid, p‐aminohippuric acid and ascorbic acid in urine samples) to be removed from the sample matrix, cleaned up, preconcentrated and injected into the capillary. The detection limits range between 0.14 and 4.50 μg/mL, the quantification limits between 0.45 and 15.0 μg/mL, and linear dynamic ranges – which include the reference healthy human values – from the quantification limits to 1332 μg/mL. The precision, expressed as RSD, ranges between 0.38 and 2.22% for repeatability and between 1.79 and 7.61% for within‐laboratory reproducibility. The errors, expressed as RSD for all compounds, range between 0.20 and 6.90%. The time for automatic SPE and that necessary for the individual separation–detection of the target analytes are 13 and 12 min, respectively; the analysis frequency is 5 h−1. The accuracy of the method and potential matrix effects were studied by using spiked samples and recoveries between 96.00 and 103.07 % were obtained. The proposed method was applied to samples from healthy young students.
Assignment of human plasma polypeptides on a nondenaturing 2‐D gel using MALDI‐MS and PMF and comparisons with the results of intact protein mapping
Authors: Manabe Takashi , Jin Ya , Tani Osamu
Published: February 2007

Human plasma proteins were separated by 2‐DE under nondenaturing conditions followed by the assignment of the CBB‐stained spots using MALDI‐MS and PMF, aiming to correlate the information of intact proteins with that of constituent polypeptides. A microgel system was employed to facilitate the analysis. Totally 157 spots on a nondenaturing micro‐2‐DE gel were numbered, the spots were excised, the proteins in the gel pieces were subjected to in‐gel digestion with trypsin followed by polypeptide analysis using MALDI‐MS and PMF. Two PMF algorithms, MASCOT (with Swiss‐Prot database) and ProFound (with NCBInr database) were employed. A total of 153 spots out of the 157 provided significant match (p <0.05) with polypeptides in databases. Eighty spots were assigned to contain multiple (2–4) polypeptides, suggesting (i) noncovalent interaction between proteins/polypeptides, (ii) disulfide bonding of polypeptides, or (iii) overlapping of the protein locations on the gel. The results of polypeptide assignment coincided very well with the results of protein mapping previously reported, in which 33 plasma proteins were identified using blotting‐immunochemical staining (Manabe, T., Takahashi, Y., Higuchi, N., Okuyama, T., Electrophoresis 1985, 6, 462–467). Further, 19 polypeptides in 25 spots were newly assigned. These results demonstrate that the techniques of MALDI‐MS and PMF can be applied for analysis of proteins separated on nondenaturing 2‐DE gels, providing information on their polypeptide structure. The integrated information on proteins and polypeptides would help the comprehensive understanding on the functions of complex protein systems.
Competition between cis, trans and Cyclopropane Fatty Acid Formation and its Impact on Membrane Fluidity
Authors: Loffhagen N. , Härtig C. , Geyer W. , Voyevoda M. , Harms H.
Published: February 2007

The impact of cis, trans and cyclopropane fatty acids on membrane fluidity was investigated using batch‐grown Pseudomonas putida P8 and Comamonas testosteroni ATCC 17454. A major difference observed between the two investigated strains is the absence of the ability to synthesize trans‐unsaturated fatty acids in Comamonas. When grown exponentially at 30 °C, a shift to 35 °C increased the trans/cis ratios of the fatty acids of P. putida P8 from 0 to 0.81 and 0 to 1.07, in lipid extracts and cell hydrolyzates, respectively. After prolonged growth followed by nutrient deprivation for 48 h, both at 30 °C, trans fatty acids were absent, but the cyclo/cis ratios rose from 0.1 to 1.55 in lipid extracts, and from 0.1 to 1.54 in cell hydrolyzates. C. testosteroni ATCC 17454 contained no cyclo fatty acids when harvested in the exponential phase after 6 h, whereas after 72 h cultivation, the cyclo/cis ratios rose to 0.49 and 0.47, in lipid extracts and cell hydrolyzates, respectively. Trans fatty acids were never observed in this strain. Increased cyclo/cis and trans/cis ratios correlated with decreased fluidity measured by the fluorescence anisotropy of 1,6‐diphenyl‐1,3,5‐hexatriene (DPH) intercalated in the bilayers of liposomes and by Fourier Transform Infrared (FTIR) spectroscopy of lipids prepared from the cells. The specific effect of cyclopropane fatty acids on membrane fluidity was much smaller than that of trans fatty acids. FTIR‐measurements of intact cells of P. putida P8 confirmed the high potency of trans fatty acids to decrease the fluidity. In cells with induced cyclopropane fatty acid synthesis, the membranes remained more fluidized, indicating the lower importance of these fatty acids for homeoviscosis.
Erosion and natural revegetation associated with surface land drains in upland peatlands
Authors: Holden Joseph , Gascoign Michelle , Bosanko Nick R.
Published: February 2007

Open cut drains are the most frequently used drainage technique in peatlands and are common throughout the world. Land drains increase the drainage density and promote enhanced coupling of hillslope sediment sources with streams. They may be major sources of fine sediment to peatland stream systems but data on drain sediment production in peatlands are rare. Many drains are now being dammed by humans, yet some revegetate naturally. This paper presents a survey of the erosion and natural revegetation of peat drains related to variables such as slope, drainage area and shading. The paper also provides measured comparison of sediment flux from open drains, drains that have been blocked by peat dams, undisturbed subcatchments, and the catchment outlet. Natural infilling of drains was often found to occur on gentle slopes <4°. Drains on slopes <2° were rarely eroded, while drains on slopes >4° were rarely infilled. Nick‐point retreat at the confluence of drains was often observed. Revegetation of drains was uncommon where drains have been cut or incised into the underlying mineral substrate. Where the drain floor was peat‐based, revegetation was much more common. Revegetation of drain floors was affected by overhanging vegetation, which provided shading. Drain floors with less than 60% shading tended to have a greater vegetation cover than drains with 60–90% shading. However, drains that were almost totally shaded (>90%) had the greatest floor vegetation. The intact drains were found to be major sources of suspended sediment within the survey catchments, with 18·3% of the sediment originating from the unblocked drains which drained 7·3% of the area. The winter quarter of the year was more important than other seasons for producing suspended sediment, even though precipitation totals were not greatest during this period. Drains which had been dammed at intervals along their length using peat blocks had very low sediment yields. Even poorly dammed drains, where water could still flow along the full course of the drain, had 54 times less suspended sediment production than unblocked drains. Copyright © 2007 John Wiley & Sons, Ltd.
Some fine‐grained sedimentation phenomena in caves
Authors: Bull Peter A.
Published: February 2007

Fine‐grained sedimentation in caves often occurs by the parallel accretion of laminations upon the underlying bedforms. These laminations show remarkable persistence in unit thickness and grain size in a down‐passage direction. A translatory flow mechanism ofdeposition is postulated which results in the rhythmic pulsing of sediment‐laden water into subterranean lakes in response to variations in surface climate. The sediments are pulsed into standing water via multiple inputs, often resulting in coarser sediment being deposited on steeper slopes than on more gentle slopes. The final extension of this sediment input is the complete filling of the cave passage to the roof. The problem of sediment stability on steep slopes remains an unanswered anomaly.
Computer simulation of nearshore bar formation
Authors: Davidson‐Arnott Robin G. D.
Published: February 2007

A computer simulation model, developed from a conceptual model of sediment transport patterns associated with nearshore bars, is presented. The model simulates wave shoaling, breaking and reformation along a profile normal to the shore from deep water to the beach and determines rates and directions of sediment transport under wave orbital currents and rip cell circulation. The model successfully generates a barred profile from an initial planar profile and under most conditions achieves a state of dynamic equilibrium with sediment circulating across the bars. Input values for wave height, wave period, offshore slope and tidal range were varied in turn in order to determine their individual effect on the shape of the equilibrium profile formed. Breaker type—spilling or plunging—is incorporated in the model and also appears to be a significant factor in determining the shape of the equilibrium profile.
Field measurements of soil creep
Authors: Finlayson Brian
Published: February 2007

An instrument has been designed to measure soil creep optically with a minimum of site disturbance. The instrument is sufficiently sensitive to detect movement in the soil over periods as short as one month. The results of measurements over a nine month period indicate that movement in the soil occurs in seemingly random directions and that large total movement does not necessarily imply a similarly large downslope movement. It is suggested that measurements of the type reported here are necessary for a satisfactory examination of the process involved in soil creep but that measurements over very long time periods are required for estimates of the rate of downslope transport.
The effect of surface texture on the determination of the surface hardness of rock using the schmidt hammer
Authors: Williams R. B. G. , Robinson D. A.
Published: February 2007

The Schmidt hammer is employed by geomorphologists as a convenient field instrument for measuring the hardness of rock surfaces. Field trials indicate that the readings obtained are a function of not only the hardness of the surfaces but also their texture. Smooth planar surfaces give much higher readings than rough or irregular surfaces. This makes interpretation of the results particularly difficult when the hammer is used to measure the hardness of natural rock surfaces that have been roughened by weathering.
The effect of forestry drainage operations on upland sediment yields: The results of a storm‐based study
Authors: Burt T. P. , Donohoe M. A. , Vann A. R.
Published: February 2007

The effects of pre‐afforestation open ditching on the sediment yield of an upland catchment in the Southern Pennines, England are described. Marked increases in the production of suspended sediment following ploughing caused major pollution of a local reservoir. Sediment supply prior to ditching was limited and easily exhausted, but afterwards remained plentiful, allowing sustained erosion during periods of storm runoff. Large volumes of sediment were carried into the reservoir during the winter of 1980–81. More recently, exhaustion of supplies of loose material in the ditches and revegetation have led to a lower rate of sediment output.
The use of gypsum spheres for identifying water flow routes in soils
Authors: Crabtree R. W. , Trudgill S. T.
Published: February 2007

Gypsum (plaster of paris) has been cast into spheres and placed in soils; weight loss has been used to identify relative water flow routes. Theoretical considerations and laboratory experimentation show that solutional weight loss of the material used increases with increasing water flow, but is independent of pH above pH 4. Results for gypsum sphere weight loss are presented for soils where moisture conditions have been measured independently using tensiometers. The data suggest that the weight loss method provides a viable time‐integrated demonstration of relative water flow routes.
Relationships among dissolved organic matter, iron, and discharge in a moorland stream
Authors: Grieve Ian C.
Published: February 2007

Dissolved organic matter (DOM) and iron in a moorland stream were determined at 8‐hour intervals over a 6‐month period to examine relationships with streamflow. Regression of both solutes on discharge were positive and explained 50–70 per cent of the variance in the solute data, but better predictions were obtained in both cases when a covariate reflecting temporal variation in the relationships was introduced (explained variance 80–90 per cent). Variations in the regression of Fe on DOM were also identified, indicating differences in the complexing power of DOM for Fe and possible variations in the chemical composition of the DOM.
Long term remeasurements of micro‐erosion meter rates, Aldabra Atoll, Indian Ocean
Authors: Viles H. A. , Trudgill S. T.
Published: February 2007

Micro‐erosion meter sites, installed on Aldabra Atoll, Indian Ocean in 1969 to measure erosion rates in coastal and subaerial sites, were remeasured in 1971 and again in 1982. The orders of magnitude of calculated erosion rates are comparable but the precise figures and patterns differ. For subaerial sites the short term (1969–71) range of 0·11–0·58 mm a−1 compares with a long term (1971–82) range of 0·06–0·75 mm a−1; for coastal sites short term ranges of 0·002–7·5 mm a−1 compare with long term rates of 0·09–2·7 mm a−1. Interpretation and extrapolation of short term data should only be made with caution.
Rock block monitoring of rapid salt weathering in southern Tunisia
Authors: Goudie A. S. , Watson A.
Published: February 2007

Rectangular blocks of York Stone and of concrete placed on a sodium chloride sabkha in southern Tunisia for six years suffered very severe breakdown, thereby indicating the power of salt weathering as a process in sabkha environments.
Some observations on suspended sediment dynamics in Storbregrova, Jotunheimen
Authors: Richards Keith
Published: February 2007

Observations are reported of the dynamics of suspended sediment transport in the meltstream of Storbreen in the Jotunheimen. Fine sediment is transferred from the subglacial to the proglacial environment during low flow (meltdominated) periods, and then removed from the catchment during high flow (rainfall‐controlled) events. Both diurnal and storm period sediment load‐discharge relationships involve clockwise hysteresis, but separate multivariate rating curves define variations of load with streamflow according to (1) the relative importance of meltwater and rainfall runoff, and (2) changes in the sediment source areas contributing to the stream at different times. Particle size variations in the suspended sediment also reflect varying source area influences.
On Playfair's law of accordant junctions
Authors: Kennedy Barbara A.
Published: February 2007

Geomorphologists since Playfair have apparently accepted that fluvial confluences will be morphologically accordant in distinction to the hanging junctions of glaciated troughs, a view reinforced by Gilbert's ‘Law of Declivities’. The issue has been largely ignored despite field instances of discordant fluvial junctions and widespread engineering practice which favours discordant confluences in non‐erodible materials.

Six categories of fluvial junctions are defined: accordant, hanging (discordant), barred, impeded, disrupted and disturbed. The study focuses principally on the first two classes and defines discordance purely morphologically in terms of relative depth of incision of the confluent thalwegs. Likely controls of accordance/discordance are identified as flow magnitudes, synchroneity of flow régimes, channel boundary materials and debris calibre.

Field investigations in Malawi, France, West Malaysia and New Zealand in small (< 100 km2) basins on a variety of rock types are described. Barred junctions are relatively rare, but complex in character. A high proportion of confluences are distinctly discordant and there is a general continuum from accordant cases. Tectonic control is improbable and the principal cause identified is the degree of difference in channel‐forming discharges, estimated by stream magnitude and channel area. Some evidence for lithologic control is also apparent. It appears that many confluences behave as if the tributary junction is non‐erodible and not in the fashion predicted by the Law of Declivities. It is argued that the observed relation is a necessary result of the general down‐stream changes in hydraulic geometry.

Limited comparison with glacial trough confluences reveals a difference in degree, but not in nature, although the relationship between discordance and channel size is affected by cross‐section geometry. A 10‐fold difference in the cross‐sectional areas of channels meeting at a junction produces, on average, a 2·4‐fold difference in mean channel depths for fluvial cases and a 4‐fold difference for glacial troughs.

The role of varying flow regimes seems to require attention. Nevertheless, it is maintained that ‘Playfair's Law’ is a misleading description of the morphology of fluvial junctions, which behaves fundamentally in the same fashion as glacial troughs.
Simulation of pebble abrasion on coastal benches by transgressive waves
Authors: Bigelow Gordon E.
Published: February 2007

Tumbler simulations of abrasion processes affecting rocks on basaltic marine benches have clarified the effects of mass and volume of rock fragments on their rate of wear. Several experiments indicate that rate of basalt wear increases with mass in the interval 1 g to 8 g, but is not related to volume of fragments abraded in seawater.

Relatively small quantities of rock flour suspended in the immersant seawater substantially reduced the rate of basalt wear. Basalt and calcareous beachrock responded differently in systems with both rock types tumbling together.

Examination of the cuttings from these low‐energy encounters suggests that abrasion on elevated benches along exposed seacoasts reduces virtually all clastic material to particles of silt size or smaller, producing essentially no sand.
A simulation model of blowout development
Authors: Jungerius P. D.
Published: February 2007

Blowouts are the main feature of wind erosion in the dunes along the Dutch coast. A number of characteristics, such as their growth against the prevailing wind and the spontaneous stabilization when certain dimensions are reached, are believed to be caused by a prominent quality of the southwest wind, viz. its gustiness. This hypothesis is tested in a two‐dimensional computer model which simulates the effect of wind gusts on a sandy surface along the main axis of the blowout. A number of constraints based on field observations are built into the model. The results closely resemble the longitudinal section of the blowout.
Flow resistance in concentrated overland flow on rough slope surfaces
Authors: Roels J. M.
Published: February 2007

Field experiments have been done on simulated flows over different rough pre‐rill and rill bed surfaces. The purpose of the experiments was to evaluate the hydraulic roughness properties of these bed surfaces. Conventional equations describing the relation of the resistance coefficient to the Reynolds number for flow in closed conduits or open channels can also be applied to shallow flows provided the boundary values of the Reynolds number, which discriminate between the various flow regimes, are adapted. When the Reynolds number is less than 100 the flow regime is laminar. Above this figure the flow is either transitional or turbulent, depending on the roughness of the bed surface. The degree of turbulence can be deduced from a morphological description of the pre‐rill and rill bed surface roughness.
The output of sediments and solutes from forested and cultivated clayey drainage basins in Luxembourg
Authors: Imeson A. C. , Vis M.
Published: February 2007

The output of material from 11 small drainage basins in the Keuper region of central Luxembourg is considered. Attention is given to differences between forested and cultivated basins. Whilst the output of suspended solids from the cultivated Mosergriecht catchment may be as much as five times higher than from the forested Keiwelsbaach, the solute load is only 50 per cent and the runoff 20 per cent higher. Relationships between dispersed clay in suspension and the water chemistry observed for the forested drainage basins are not present in the cultivated catchments. Water having a milky appearance and containing dispersed clay is of more frequent occurrence in forested basins where subsurface runoff occurs in macropores and cracks in the undisturbed soil.
A scanning electron microscope study of bedrock microfractures in granites under high arctic conditions
Authors: Watts Stephen H.
Published: February 2007

Surface specimens obtained from highly‐weathered upland plateau outcrops at three localities in high Arctic Canada have been studied using the scanning electron microscope. Observations are given on factors influencing bedrock surface microfracturing processes. Evidence for the concentration of both salts and organic material in surface cracks which could enhance microfracturing is presented. The importance of lithological parameters including: mineralogy, texture, and structures present in influencing the actual processes of disintegration is reiterated. Under cold, dry high Arctic conditions the combined and apparently inseparable affects of frost action, salt crystallization, and organic activity may have contributed to microfracturing largely responsible for widely scattered examples of highly weathered bedrock terrain.
The role of algae in the stabilization of coastal dune blowouts
Authors: Van Ancker J. A. M. Den , Jungerius P. D. , Mur L. R.
Published: February 2007

A number of mechanisms prevent blowouts in the dunes along the Dutch‐coast from growing beyond a certain length. Plants play an important role in the stabilization process. Algae are the first plants to colonize the blowouts. Their filaments are surrounded by mucilaginous sheaths which adhere to the sand grains and increase the resistance of the sand to entrainment by wind. This suggests that artificially induced algal growths might be used in cheap, and ecologically justifiable, stabilization measures.
The granulometrical characteristics of a slowly‐moving dust cloud
Authors: Goossens Dirk
Published: February 2007

A torn‐up road offered the opportunity to sample a dust cloud continuously at different heights during a time interval of 51 hours. In particular the granulometrical characteristics of the dust caught were investigated. It appears that if the air layer in the vicinity of a dust cloud is not too turbulent, the cloud will be clearly granulometrically stratified. The coarse material moves chiefly at the bottom of the cloud, whereas the fine material will occur both at the bottom and at the top. The experiment also shows that the higher the dust in the cloud, the worse it is sorted. Above a critical height, however, the degree of sorting increases again.

The variation of the mean dust diameter d50, as a function of the height z, can be expressed in a simple semi‐logarithmic equation. The variation of the dust quantity G, as a function of the height z, can also be expressed in a semi‐logarithmic form but the correlation is higher when a power equation is used. The ratio of fine silt to coarse silt seems to vary parabolically with height.

One can only speak of an optimal transport height in the case of particles > 16 μm. For finer particles, the turbulence of a normal air stream is usually high enough to carry the particles anywhere in the dust cloud, so that one can no longer speak of an optimal transport height.

The granulometrical border between aeolian transport in saltation and aeolian transport in suspension lies, according to the results of the experiment, at a diameter of about 63 μm.
The micro‐erosion meter: Use and limitations
Authors: Spate A. P. , Jennings J. N. , Smith D. I. , Greenaway M. A.
Published: February 2007

Detection of anomalies in measurements of low rates of limestone surface lowering with a traversing micro‐erosion meter (MEM) led to temperature‐controlled laboratory and field investigations of some sources of error in the method. Regressions for the correction of temperature change in the instrument and in the stud‐rock interface were obtained. Probe erosion tests permitted a correction to be devised and also provided information whereby a measure of operational irregularity was adopted. Corrections and error terms were applied to field measurements from two southern New South Wales karsts and a collection of Australian limestone slabs exposed at one site.

Examination of these results and of published MEM rates from other parts of the world validated the MEM method. Marine platforms are lowered at such gross rates that these error sources may be neglected there. However limestone lowering in terrestrial environments cannot be assumed to proceed at rates which permit this and recommendations are made about procedures to ensure that investigations are prosecuted within the limitations of the method.
Lithologic control of bedrock meander dimensions in the appalachian valley and ridge province: A comment
Authors: Abrahams Athol D.
Published: February 2007

Braun's finding that the wavelength of bedrock meanders decreases as rock hardness increases is reconciled with Hack's and Tinkler's finding that meander wavelength is greater in bedrock than alluvial channels. In populations of alluvial or bedrock channels, bank resistance controls meander wavelength via its influence on channel shape and is negatively correlated with meander wavelength. In contrast, in mixed populations of alluvial and bedrock channels, bank resistance controls meander wavelength through its effect on the recurrence interval of the channel‐forming discharge and channel size and is positively correlated with meander wavelength.
Hydrostatic‐system palsas at Toolik lake, Alaska: Field observations and simulation
Authors: Outcalt S. I. , Nelson F. E. , Hinkel K. M. , Martin G. D.
Published: February 2007

Stratigraphic and chemical data from the ice core of an ‘anthropogenic palsa’ at Toolik Lake, Alaska, indicate that the mound formed as a consequence of hydrostatic pressure developed in an isolated hydrologic system within the active layer. Survey data for five palsas over a three‐year period suggest that growth was essentially complete at the time of the initial survey; a net decrease of summit elevation is apparent in all five mounds, but complete degradation of the palsas would require several decades at observed rates.

Because accurate field measurements of thermal and hydrologic evolution in such features are extremely difficult, simulation of the environmental conditions and events involved in palsa growth is an important supplement to field observation. Both analytic and finite‐element models yield results that are in substantial agreement with inferences drawn from observational data.
Rock moisture content in the field and the laboratory and its relationship to mechanical weathering studies
Authors: Hall Kevin
Published: February 2007

Rock moisture content is a major control of mechanical weathering, particularly freeze‐thaw, and yet almost no data exist from field situations. This study presents moisture content values for rocks, taken from a variety of positions and conditions, in the maritime Antarctic. Additional information regarding the amount of water the rock could take up, as observed from laboratory experiments, is also presented. The results show that the approaches used in simulation experiments, particularly that of soaking a rock for 24 hours, may produce exaggerated results. It was found that the saturation coefficient (S‐value) was a good indicator of frost susceptibility (based on water content) but that the derivation of that value may underestimate the potential of some rocks. The distribution of moisture within rocks is seen as an important, but unkown, factor. The results of these field moisture contents suggest that for simulations of freeze‐thaw or hydration to be meaningful then they should have rock water contents based on field observations.
Comparison of the results of quantitative and non‐quantitative tracer tests for determination of Karst conduit networks: An example from the Traligill Basin, Scotland
Authors: Smart P. L. , Atkinson T. C. , Laidlaw I. M. S. , Newson M. D. , Trudgill S. T.
Published: February 2007

The relative advantages of fluorescent dyes and Lycopodium spores as tracers are discussed. The major advantage of fluorescent dyes is that they may be detected quantitatively. Thus, in combination with discharge measurements, a dye mass balance can be prepared for tracer tests in karst conduits, which permits elucidation of the underground network. The advantages of this procedure are illustrated by comparison of the networks derived from non‐quantitative (Lycopodium and dye) and quantitative (fluorescent dye) tracer methods in the Traligill Basin, Scotland. These tests also suggest that Lycopodium does not give a true indication of travel time, due to sedimentation underground. This could also cause contamination problems in later tests. For non‐quantitative tracer tests, sensitive methods are necessary if incorrect inferences on conduit networks are to be avoided. In general, however, quantitative tests give much less ambiguous results, and are therefore to be preferred.
The influence of weathering on the geotechnical properties and slope angles of mudstone in the Mineoka earth‐slide area, Japan
Authors: Matsukura Yukinori , Mizuno Keiji
Published: February 2007

Three active earth‐slide slopes of Tertiary mudstone were investigated: Slope 1 has an angle of 17 −4°, Slope 2 of 12.9°, and Slope 3 of 11.6°. Infinite slope analysis indicated that the instability of these three slopes can be well explained by using the residual strength parameters of earth‐slide soils near the sliding surface in conjunction with the highest ground water table. The residual angle of shearing resistance, ø'r, plays an important role in the determination of slope angle because it differs greatly among slopes. Mineralogical studies and X‐ray diffraction analyses were performed for the clay minerals included in the slope material. The results showed that illite and chlorite were found in Slope 1, and also in Slopes 2 and 3 together with interstratified illite/montmorillonite and montmorillonite. The degree of weathering is progressive in order of Slopes 1, 2 and 3. The alteration of clay minerals by weathering causes the reduction in ø'r ‐values, i.e., 19.4° in Slope 1 (steep, less weathered) and 12.1‐9.2° in Slopes 2 and 3 (gentle, much more weathered). This result indicates that the degree of weathering has a great influence on the value of ø'r, which in turn determines the slope angle.
Controls of concentration and loadings of major ions in a stream draining intermediate igneous rocks
Authors: Grieve Ian C.
Published: February 2007

Some 300 measurements under a wide range of flow conditions were used to construct regression models to predict concentrations of six major ions in a moorland stream draining intermediate‐basic lavas in Scotland. Ca, Mg, and HCO3 were very closely related to discharge in log‐log regressions (r2 > 90 percent). Na and Cl required inclusion of seasonal functions for best prediction (r2 = 76 per cent in both cases). K concentrations were predicted from discharge, direction of stage change, and a seasonal function. Annual losses of Ca, Mg, and HCO3 were 252, 36, and 871 kg ha −1, substantially larger than those for upland catchments on acid rocks. Losses of K, Na, and Cl were of a similar order to other upland sites.
Channel erosion along the Carmel river, Monterey county, California
Authors: Kondolf G. Mathias , Curry Robert R.
Published: February 2007

Historic maps, photographs, and channel cross‐sections show that the channel of the Carmel River underwent massive bank erosion, channel migration, and aggradation in a major flood in 1911, then narrowed and incised by 1939. The channel was stable until 1978 and 1980, when bank erosion affected some reaches but not others. The narrowing and incision were in response to a lack of major floods after 1914 and construction in 1921 of a dam that cut off sediment supply from the most actively eroding half of the basin. Localized erosion in 1978 and 1980 occurred during low magnitude events along reaches whose bank strength had been reduced by devegetation. These events illustrate that the stability of a fluvial system can be disrupted either by application of a large erosive force in a high magnitude event (the 1911 flood) or in a low magnitude event, by reducing the resistance to erosion (bank devegetation).

The Carmel River is a potentially unstable system. Its discharge and slope characteristics place it near the threshold between meandering and braided. On the Lower Carmel, the presence of bank vegetation can make the difference between a narrow, stable meandering channel and a wide shifting channel with braided reaches.
Rainfall, runoff and erosion on bare arable soils in east Shropshire, England
Authors: Fullen Michael A. , Reed Alan Harrison
Published: February 2007

The magnitude, frequency, and duration of erosive rainfall on bare arable soils is investigated within an area of sandy soils in east Shropshire. Rainfall parameters are compared with runoff and erosion from ten 25 m2 runoff plots, maintained in a bare condition on slopes of varying steepness.

On rain‐drop compacted (capped) soils measured erosion rates of ≦ 42.7t ha−1 occur during individual storms. Erosion rates increase markedly with slope and on slopes > ˜ 13° are largely attributable to rill erosion.

Prolonged duration, low intensity events cause relatively little erosion; most is accomplished by short duration, high intensity (> 10 mm h−1) convective rainstorms. Comparison of measured erosion‐producing events and long‐term rainfall records indicate that potentially erosive storms are quite frequent, and are most likely to cause erosion in late spring/early summer.
Determination of dissolved organic matter in streamwater using visible spectrophotometry: A reply
Authors: Grieve Ian
Published: February 2007

A reply to Finlayson (1986) suggesting that the priority should be for more widespread measurement of dissolved organic matter, without the need for special equipment. The use of chemical oxygen demand is also clarified.
Valley asymmetry: Evidence for periglacial activity in the central North Sea
Authors: Long David , Stoker Martyn S.
Published: February 2007

Present‐day open valleys with distinct asymmetric profiles have been studied from the central North Sea. The bulk of the valleys exhibit steep north‐facing and shallow south‐facing slopes. This asymmetry is ascribed to preferential slumping of the south‐facing slope under periglacial climatic conditions. Exceptions to the regional asymmetric trend are probably the result of more localized factors such as fluvial and microclimatic processes and the effects of local geology. The recognition of this type of within‐valley asymmetry associated with slumping in buried valleys within the Quaternary sequence may be indicative of former periglacial activity.
Some observations on the chemical weathering of the Dartmoor granite
Authors: Williams Andrew G. , Ternan Les , Kent Martin
Published: February 2007

The majority of geomorphological papers about Dartmoor have been essentially speculative, particularly when discussing weathering processes and the evolution of the Dartmoor landscape. In contrast, this article presents a synthesis of several experimental investigations aimed at studying the chemical weathering of Dartmoor granite through the systematic analysis of soil and water samples. This involved the computation of a geochemical budget to determine the amount of erosion in the catchment, as well as more detailed mineralogical investigations within a soil profile.

The annual output of solutes due to weathering was 116 kg ha−1 a−1 of which the majority was silica (93 kg ha−1 a−1). From an examination of the soil mineralogy, it was calculated that these solutes were derived from the dissolution of approximately 200 kg ha−1 a−1 plagioclase, 90 kg ha−1 a−1 biotite, and 40 kg ha−1 a−1 orthoclase. As well as the weathering of granite, there was also the production of kaolinite (150 kg ha−1 a−1) and gibbsite (0.02 kg ha−1 a−1). Analysis of the soil water chemistry confirmed that kaolinite was the stable mineral phase in the regolith, although in areas where interflow was the dominant mode of water movement, the solute composition was in equilibrium with both kaolinite and gibbsite. Examination of the clay mineralogy confirmed these results.

The microtexture of quartz grains was examined by the scanning electron microscope as another means of investigating the hydrochemical environment in the soil. Silica was found precipitated on all the grains examined but the maximum amount occurred in the Bs horizon. This evidence showed that, firstly, the dissolution of aluminosilicate minerals is greater than that calculated by the chemical budget and, secondly, that models of granite weathering must take localized weathering in the soil profile into account.

The final part of the paper highlights the limitations of calculating denudation rates for an entire catchment and stresses the need to consider weathering as a highly localized phenomenon, particularly where there are high volumes of interflow at hill crest sites. Observations on granite decomposition in the future should be quantitative in approach and be related to the local site conditions.
Observations of bedload movement, bar development and sediment supply in the braided Ohau river
Authors: Davoren A. , Mosley M. P.
Published: February 2007

Relative bedload transport rate and hydraulic parameters were measured on two occasions in a reach of the braided, gravel‐bedded Ohau River. Each reach contained a deep, fast‐flowing chute leading to an area of diverging, shallow flow which contained a middle bar. The measurements are self‐consistent, and indicate that, where flow is concentrated in a deep chute, shear stress is high, but where flow diverges, depth, slope and shear stress decrease. In the first survey, the bed was scoured in the chute and sediment transport rates were high, but where flow diverged sediment transport rate decreased. It appears that deposition leads to bar growth, bar growth in turn reduces slope and depth, deposition is encouraged, and the bar continues to grow vertically, laterally and upstream. In the second survey no sediment transport was observed, despite hydraulic conditions very similar to the first survey. The absence of sediment transport is attributed to the cessation of sediment supply to the river channel.
Some observations concerning the morphology and sedimentology of a protalus rampart, Okstindan, Norway
Authors: Harris Charles
Published: February 2007

A protaius rampart up to 4.75 m high and consisting largely of angular clasts up to boulder size is described. Bulk samples contained up to 35 per cent fines by weight, compared with up to 68 per cent fines in adjacent till. Although the rampart material was clast dominated, fines filled much of the void space, in contrast with most other protalus ramparts described in the literature.
Comparison of taxon calibrations, modern analogue techniques, and forest‐stand simulation models for the quantitative reconstruction of past vegetation: A critique
Authors: Solomon Allen M.
Published: February 2007

Taxon calibrations based on eastern North America or on the southeastern United States alone suggest a different forest composition from that based on Wisconsin/Michigan, which is argued as preferable. Questions are raised about how well comparison with modern analogues distinguishes forest characteristics. The simulation model used by Delcourt and Delcourt is thought to be inappropriate, partly because it is constrained by faulty climatic data. Models are seen as complementary to other techniques rather than as an alternative methodology.
An erosion criterion for gravel‐bed rivers
Authors: Naden Pamela
Published: February 2007

A theoretically‐based erosion criterion is developed for gravel‐bed rivers which incorporates the effect of both grain geometry and turbulent velocity fluctuations. It is derived from a balance of instantaneous drag, lift, and gravity forces operating on individual grains and is calculated for spherical grains arranged in three distinct geometries. To accommodate the temporal variation in bed shear stress, the model includes a stochastic element based on the characteristics of turbulence derived from the flume evidence of McQuivey (1973a, b). In terms of the Shields parameter, results show reasonable agreement with the range of observations quoted from the field and with the experimental data of Fenton and Abbott (1977). Finally, the argument is generalized to cover applications in the wider context of field conditions including a range of grain sizes and flow conditions.
Palaeoflood hydrology of the Salt river, Arizona
Authors: And John Partridge , Baker Victor R.
Published: February 2007

Geomorphic evidence along bedrock‐confined reaches of the Salt River in east‐central Arizona provides a record of the river's largest flood events. Fine‐grained flood slackwater deposits accumulated at channel margin irregularities several metres above the low‐flow channel. Discharges associated with flow events responsible for the deposits were estimated by computer flow modelling. These estimates document flood magnitudes in excess of gauged historic streamflows. Relative and radiocarbon dating suggest that a flood record in excess of 600 y is preserved in the slackwater sequences. A prominent flood scar cut into grussy hillslope soils allows the extension of the prehistoric flood record to several thousand years.

A maximum discharge estimate of 4600 m3s−1 affixed to the flood scar represents the largest flood event in the record, and is given a minimum recurrence interval of 1000–2000 y. The 1952 flood is the largest historic flow event experienced along the study reach and is estimated at 2900 m3s−1. Two palaeoflood events preserved in the slackwater stratigraphy exceed the 1952 event, and are given recurrence intervals of 300 and 600 y. The latter flood event had an estimated discharge of 3200 m3s−1. It is apparent that discharge estimates affixed to these infrequent, large‐magnitude flood events approach a maximum with decreased probabilities (large recurrence intervals). This suggests that a physical limit on discharge may exist within the Salt River drainage basin and is perhaps directly related to drainage basin size.
River channel adjustments downstream from channelization works in England and Wales
Authors: Brookes Andrew
Published: February 2007

Relatively little attention has been given to river channel adjustments that occur downstream from channelization works. This study is concerned with the nature of channel adjustments downstream from a total of 46 channelization works located in low and high energy environments in England and Wales. Channel changes are identified principally by the method of field survey and by reconstructing the original positions of eroded beds and banks. Use is also made of maps, aerial photographs, and engineering drawings of different dates and the technique of space‐for‐time substitution is applied.

Enlargement of channel cross‐sections through erosion had occurred downstream from a variety of types, sizes, and dates of channelization works. The maximum increase of channel size was 153 per cent. Out of a total of 14 sites with enlarged channel cross‐sections, seven had undergone a change of width only, at a further three width increased rather than depth, and at the remaining four sites depth increases were dominant. These sites all have relatively high stream powers.

Factors causing spatial variation of erosion included tree roots locally binding bank sediments and the occurrence of bends. Planform change had taken place at only one site. A further three high stream power sites had downstream reaches incised into bedrock and therefore did not exhibit adjustment.

Channel enlargement is explained in terms of increased flood flows downstream from channelization works causing higher stream velocities, which in turn cause erosion, thereby increasing channel width and/or depth. Examination of flow records for 35 stations revealed flood events which would formerly have spread overbank but are now confined by the channelization works and are therefore likely to alter downstream flows. At sites with downstream change it is proposed that the energy of increased flows was sufficient to exceed a threshold required for erosion of perimeter sediments. By contrast the absence of change at a majority of sites in low energy lowland areas could be a reflection of both the incompetence of increased flows to erode and resistance provided by perimeter sediments. Sites with erosion features appear not to have yet attained new equilibrium conditions.
Genesis of marine terrace soils, Barbados, West Indies: Evidence from mineralogy and geochemistry
Authors: Muhs Daniel R. , Crittenden Russell C. , Rosholt John N. , Bush Charles A. , Stewart Kathleen C.
Published: February 2007

Well‐developed, clay‐rich soils dominated by interstratified kaolinite‐smectite are found on the uplifted coral reef terraces on the island of Barbados. The reef limestone is unlikely to have been the soil parent material however, because it is 98 per cent CaCO3 and geomorphic evidence argues against the 20 m of reef solution required to produce the soils by this process. The mineralogy of the sand, silt, and clay fractions of the soils, and trace element geochemistry, suggest that aeolian materials carried on the trade winds from Africa, volcanic ash from the island of St. Vincent, and quartz from Tertiary bedrock on the island itself are the parent materials for the soils.
A comparison of channel erosion in small urban and rural catchments, Armidale, New South Wales
Authors: Neller R. J.
Published: February 2007

Five years after the cessation of housing construction in a small urban catchment in Armidale, New South Wales, the stability of the channel bed and banks was investigated with the use of erosion pins. After eighteen months of monitoring, the rate of channel bank erosion was found to be 3.6 times greater than that of a nearby rural channel and the rate of knickpoint retreat was 2.4 times greater. There was, however, no evidence to suggest that the urban channel was inherently unstable, but that the increased rate of erosion was the product of changed runoff conditions associated with urban development. Both channels are considered to be in a state of equilibrium.
The freeze‐thaw weathering regime at a section of the Niagara escarpment on the Bruce Peninsula, Southern Ontario, Canada
Authors: Fahey Barry D. , Lefebure Todd H.
Published: February 2007

The bedrock freeze‐thaw and moisture regimes at an actively eroding site on the Niagara Escarpment, Bruce Peninsula, southern Ontario, were monitored between December 1983 and April 1984, and the results compared with amounts of debris collected in an adjacent rock trap.

Frost wedging in pre‐existing rock fissures is the primary mechanism responsible for the observed rockfall events; hydration effects are negligible. Debris production was more closely related to the duration of the freezing leg of the freeze‐thaw cycle than to intensity or to cycle frequency. Release also coincided with periods of high pore saturation (> 60 per cent) and the seepage of water from cracks and fissures.

Fewer freeze‐thaw cycles were recorded in the air than at 1 and 3.5 cm in the bedrock. The number of cycles that could be declared geomorphologically effective according to established temperature criteria was normally less than half the total number of freeze‐thaw cycles recorded in both air and bedrock. Under the current temperature regime at the field site, few effective cycles are capable of penetrating more than 5 cm into the free face.