bluuebunny/crossref_metadata_2025_split huggingface dataset:
Morphological analysis of the Sudd region using land survey and remote sensing data
Authors: Petersen G. , Sutcliffe J. V. , Fohrer N. 
Published: May 2008

AbstractAn analysis of the vast wetland of the Sudd swamps in southern Sudan was designed to assess and describe interdependencies between morphology and hydrology. Findings based on field survey and remote sensing data include an assessment of the effect of ground slopes and morphological features on spill and flooding of the seasonally flooded grasslands. Through bathymetric surveys and analysis of Landsat images, depth profiles and cross‐sectional depth and flow distributions were established. Data from remote sensing, field survey and historical sources were correlated and correction factors established; the SRTM was found to be partly unsuitable for further assessments. Further analysis of remote sensing data was used to investigate the Sudd's inland delta as well as the question of spill into the Bahr el Ghazal basin. Copyright © 2008 John Wiley & Sons, Ltd.
A low‐dimensional physically based model of hydrologic control of shallow landsliding on complex hillslopes
Authors: Talebi Ali , Uijlenhoet Remko , Troch Peter A. 
Published: May 2008

AbstractHillslopes have complex three‐dimensional shapes that are characterized by their plan shape, profile curvature of surface and bedrock, and soil depth. To investigate the stability of complex hillslopes (with different slope curvatures and plan shapes), we combine the hillslope‐storage Boussinesq (HSB) model with the infinite slope stability method. The HSB model is based on the continuity and Darcy equations expressed in terms of storage along the hillslope. Solutions of the HSB equation account explicitly for plan shape by introducing the hillslope width function and for profile curvature through the bedrock slope angle and the hillslope soil depth function. The presented model is composed of three parts: a topography model conceptualizing three‐dimensional soil mantled landscapes, a dynamic hydrology model for shallow subsurface flow and water table depth (HSB model) and an infinite slope stability method based on the Mohr–Coulomb failure law. The resulting hillslope‐storage Boussinesq stability model (HSB‐SM) is able to simulate rain‐induced shallow landsliding on hillslopes with non‐constant bedrock slope and non‐parallel plan shape. We apply the model to nine characteristic hillslope types with three different profile curvatures (concave, straight, convex) and three different plan shapes (convergent, parallel, divergent). In the presented model, the unsaturated storage has been calculated based on the unit head gradient assumption. To relax this assumption and to investigate the effect of neglecting the variations of unsaturated storage on the assessment of slope stability in the transient case, we also combine a coupled model of saturated and unsaturated storage and the infinite slope stability method. The results show that the variations of the unsaturated zone storage do not play a critical role in hillslope stability. Therefore, it can be concluded that the presented dynamic slope stability model (HSB‐SM) can be used safely for slope stability analysis on complex hillslopes. Our results show that after a certain period of rainfall the convergent hillslopes with concave and straight profiles become unstable more quickly than others, whilst divergent convex hillslopes remain stable (even after intense rainfall). In addition, the relation between subsurface flow and hillslope stability has been investigated. Our analyses show that the minimum safety factor (FS) occurs when the rate of subsurface flow is a maximum. In fact, by increasing the subsurface flow, stability decreases for all hillslope shapes. Copyright © 2008 John Wiley & Sons, Ltd.
Consequences of short‐term changes in coastal processes: a case study
Authors: Phillips M. R. 
Published: May 2008

AbstractIn 1997–98, unique critical beach erosion led to structural failure along the Penarth, South Wales, UK coastline and anthropogenic activities, such as the construction of the Cardiff Bay Barrage and offshore marine aggregate dredging, were suggested as causes. The time‐frame of significant erosion was between 1995 and 1997 and forcing agents (extreme sea level and wind direction) and shoreline indicators (mean beach level and MHW) were analysed in order to assess change. Water level analysis showed that although there was no significant difference between actual and predicted mean sea levels, extreme sea levels at that time were significantly higher (t = 3·305; d.f. = 8; p < 0·05). Three wind direction analyses (annual mean, mean annual maximum gust and mean annual maximum gust ≥28 kn) between 1995 and 1997 also showed significant differences (p < 0·05). All comprised more easterly components which meant they approached the beach from the sea. Furthermore, gusts ≥28 kn from the northeast quadrant, that is, 0° to 90° true, were significantly more frequent during these years (t = 3·674; d.f. = 8; p < 0·01). Justification of statistical significances was established and there was supporting evidence of unusual meteorological conditions at that time. Relationships showed correlation between forcing agents (extreme sea level and wind direction) and shoreline indicators (mean beach level and Mean High Water). Furthermore, regression analysis showed winds from the northeast quadrant resulted in steeper longshore gradients, as a consequence of beach material loss. Therefore, it was concluded that the critical erosion of Penarth beach between 1995 and 1997 was caused by increased wave attack from the northeast and southeast quadrants, generated by unique significant changes in wind direction and extreme sea levels. Copyright © 2008 John Wiley & Sons, Ltd.
Bank erosion and channel width change in a tropical catchment
Authors: Bartley Rebecca , Keen Rex J. , Hawdon Aaron A. , Hairsine Peter B. , Disher Mark G. , Kinsey‐Henderson A. E. 
Published: May 2008

AbstractCatchment sediment budget models are used to predict the location and rates of bank erosion in tropical catchments draining to the Great Barrier Reef lagoon, yet the reliability of these predictions has not been tested due to a lack of measured bank erosion data. This paper presents the results of a 3 year field study examining bank erosion and channel change on the Daintree River, Australia. Three different methods were employed: (1) erosion pins were used to assess the influence of riparian vegetation on bank erosion, (2) bench‐marked cross‐sections were used to evaluate annual changes in channel width and (3) historical aerial photos were used to place the short term data into a longer temporal perspective of channel change (1972–2000). The erosion pin data suggest that the mean erosion rate of banks with riparian vegetation is 6·5 times (or 85%) lower than that of banks without riparian vegetation. The changes measured from cross‐section surveys suggest that channel width has increased by an average of 0·74 (±0·47) m a−1 over the study period (or ∼0·8% yr−1). The aerial photo results suggest that over the last 30 years the Daintree River has undergone channel contraction of the order of 0·25 m a−1. The cross‐section data were compared against modelled SedNet bank erosion rates, and it was found that the model underestimated bank erosion and was unable to represent the variable erosion and accretion processes that were observed in the field data. The reach averaged bank erosion rates were improved by the inclusion of locally derived bed slope and discharge estimates; however, the results suggest that it will be difficult for catchment scale sediment budget models to ever accurately predict the location and rate of bank erosion due to the variation in bank erosion rates in both space and time. Copyright © 2008 John Wiley & Sons, Ltd.
The potential of digital filtering of generic topographic data for geomorphological research
Authors: Milledge D. G. , Lane S. N. , Warburton J. 
Published: May 2008

AbstractHigh resolution terrain models generated from widely available Interferometric Synthetic Aperture Radar (IfSAR) and digital photogrammetry are an exciting resource for geomorphological research. However, these data contain error, necessitating pre‐processing to improve their quality. We evaluate the ability of digital filters to improve topographic representation, using: (1) a Gaussian noise removal filter; (2) the proprietary filters commonly applied to these datasets; and (3) a terrain sensitive filter, similar to those applied to laser altimetry data. Topographic representation is assessed in terms of both absolute accuracy measured with reference to independent check data and derived geomorphological variables (slope, upslope contributing area, topographic index and landslide failure probability) from a steepland catchment in northern England. Results suggest that proprietary filters often degrade or fail to improve precision. A combination of terrain sensitive and Gaussian filters performs best for both IfSAR and digital photogrammetry datasets, improving the precision of photogrammetry digital elevation models (DEMs) by more than 50 per cent relative to the unfiltered data. High‐frequency noise and high‐magnitude gross errors corrupt geomorphological variables derived from unfiltered photogrammetry DEMs. However, a terrain sensitive filter effectively removes gross errors and noise is minimized using a Gaussian filter. These improvements propagate through derived variables in a landslide prediction model, to reduce the area of predicted instability by up to 29 per cent of the study area. Interferometric Synthetic Aperture Radar is susceptible to removal of topographic detail by oversmoothing and its errors are less sensitive to filtering (maximum improvement in precision of 5 per cent relative to the raw data). Copyright © 2008 John Wiley and Sons, Ltd.
Avulsion regimes in southeast Texas rivers
Authors: Phillips Jonathan D. 
Published: May 2008

AbstractAvulsions – relatively sudden changes in course, or establishment of new anabranches – are an important process in alluvial rivers. Their key role in floodplain construction and alluvial architecture, and the general conditions favouring avulsions, are well known. However, avulsion processes and evolution, and the factors controlling avulsion regimes, are poorly understood. In the southeast Texas coastal plain, where avulsions are common features of the river valleys, avulsions were studied on the lower Brazos, Navasota, Trinity, Neches and Sabine rivers using a combination of aerial imagery, digital elevation models and field surveys. Avulsions have important influences on the surface morphology and contemporary processes in all five rivers. Features associated with avulsions are active and distinct throughout the study area, and all the rivers have experienced geologically (if not historically) recent avulsions. However, no two of the study rivers have the same contemporary avulsion regime. First‐order differences in avulsion style are controlled by the stage of valley filling, and within the three rivers characterized by an unfilled incised valley, antecedent morphology associated with late Quaternary and Holocene coastal and fluvial‐deltaic processes accounts for the major differences. In the Navasota (27 avulsions in 185 km) and Neches (21 in 340 km) rivers, subchannels associated with avulsions exist in all stages of development from active to infilled, and some have occurred in recent decades. The other rivers have fewer avulsions, but both the Sabine and Trinity have experienced historic channel shifts. Only the Brazos River has experienced no avulsions within the past c. 300 years. Results show that even within a region of similar environmental controls and geological history local variations in inherited morphology can result in different avulsion regimes. Copyright © 2008 John Wiley & Sons, Ltd.
A comparison of predictive methods in modelling the distribution of periglacial landforms in Finnish Lapland
Authors: Marmion Mathieu , Hjort Jan , Thuiller Wilfried , Luoto Miska 
Published: May 2008

AbstractThis study compares the predictive accuracy of eight state‐of‐the‐art modelling techniques for 12 landforms types in a cold environment. The methods used are Random Forest (RF), Artificial Neural Networks (ANN), Generalized Boosting Methods (GBM), Generalized Linear Models (GLM), Generalized Additive Models (GAM), Multivariate Adaptive Regression Splines (MARS), Classification Tree Analysis (CTA) and Mixture Discriminant Analysis (MDA). The spatial distributions of 12 periglacial landforms types were recorded in sub‐Arctic landscape of northern Finland in 2032 grid squares at a resolution of 25 ha. First, three topographic variables were implemented into the eight modelling techniques (simple model), and then six other variables were added (three soil and three vegetation variables; complex model) to reflect the environmental conditions of each grid square. The predictive accuracy was measured by two methods: the area under the curve (AUC) of a receiver operating characteristic (ROC) plot, and the Kappa index (κ), based on spatially independent model evaluation data. The mean AUC values of the simple models varied between 0·709 and 0·796, whereas the AUC values of the complex model ranged from 0·725 to 0·825. For both simple and complex models GAM, GLM, ANN and GBM provided the highest predictive performances based on both AUC and κ values. The results encourage further applications of the novel modelling methods in geomorphology. Copyright © 2008 John Wiley & Sons, Ltd.
Seasonal waves on glaciers
Authors: Hewitt I. J. , Fowler A. C. 
Published: May 2008

AbstractSeasonal waves accompanying annual changes in the sliding velocity of ice travel down glacier at speeds much faster than the ice itself. A simple explanation for these waves in terms of the passage of a pressure wave through the subglacial drainage system is given. Drainage by both distributed and localized systems is explored, with the sliding velocity governed by a dependence on the effective pressure. Waves are caused by drainage through a slow distributed system, but may be damped if this is well connected to an efficient channelized system. A possible connection between these waves and high velocity spring events is discussed. Copyright © 2008 John Wiley & Sons, Ltd.
Elevated oxidative stress and DNA damage and repair levels in urinary bladder carcinomas associated with schistosomiasis
Authors: Salim Elsayed I. , Morimura Keiichirou , Menesi Ahmed , El‐Lity Mohammed , Fukushima Shoji , Wanibuchi Hideki 
Published: May 2008

AbstractTo cast light on mechanisms underlying development of urothelial carcinomas (UCs) of the urinary bladder associated with Schistosomiasis, we immunohistochemically analyzed the relationship between oxidative stress markers, DNA single strand breaks (ssDNA) which could also measure the levels of base damage and apoptosis in DNA, and expression of DNA repair genes with levels of nitric oxide synthases in bladder carcinomas of Egyptian patients with or without Schistosoma hematobium infection. Marked elevation of 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG) levels was found in squamous cell carcinomas and UCs associated with Schistosomiasis when compared with non‐Schistosomal carcinomas. This was accompanied by strong over expression of the DNA‐repair genes, 8‐oxoguanine‐DNA‐glycosylase and apurinic/apyrimidinic endonuclease, as well as increased formation levels of ssDNA. Expression levels of inducible nitric oxide synthase (iNOS) which is known to be indirectly related to oxidative stress was higher in Schistosomal than in the non‐Schistosomal carcinomas. However, expression of endothelial nitric oxide synthase was slightly stronger in non‐Schistosomal than in the Schistosomal carcinomas. In conclusion, these findings suggest a strong correlation between Schistosoma haematobium infection and increased levels of oxidative stress accompanied by a continuous DNA damage and repair in UCs, all directly correlating with elevated iNOS. © 2008 Wiley‐Liss, Inc.
All cause mortality and incidence of cancer in workers in bauxite mines and alumina refineries
Authors: Fritschi Lin , Hoving Jan Lucas , Sim Malcolm R. , Del Monaco Anthony , MacFarlane Ewan , McKenzie Dean , Benke Geza , de Klerk Nicholas 
Published: May 2008

AbstractBauxite is a reddish clay that is refined to produce alumina, which is then reduced to aluminium. There have been studies examining the health of workers in aluminium smelters, but not workers in bauxite mining and alumina refining. A cohort of employees of 1 large aluminium company since 1983 was assembled (n = 6,485, 5,828 men). Deaths and incident cancers to 2002 were ascertained by linkage to national and state cancer and death registries. SIRs and SMRs were calculated compared to national rates standardizing for calendar year, sex and 5‐year age group. The mortality from all causes (SMR 0.68, 95% CI: 0.60–0.77), and from circulatory and respiratory diseases, all cancers combined and injury in the male cohort were lower than in the Australian male population and were similar across work groups and with duration of employment. The only significant increased mortality risk was from pleural mesothelioma. The incidence of all cancers combined was similar to the Australian rate. The cohort had a lower risk of incident lymphohaematopoietic cancer (SIR 0.50, 95% CI: 0.31–0.88) and a higher risk of melanoma (SIR 1.30, 95% CI: 1.00–1.69) although no dose‐responses were seen. There was also an increased risk of mesothelioma (SIR 3.49, 95% CI: 1.82–6.71), which was associated with exposures outside the aluminium industry. This study is the first to examine cancer and mortality amongst workers in bauxite mines and alumina refineries and found little evidence for increased cancer incidence or mortality in these workers. © 2008 Wiley‐Liss, Inc.
Contributions of the mother–infant relationship to dissociative, borderline, and conduct symptoms in young adulthood
Authors: Lyons‐Ruth Karlen 
Published: May 2008

AbstractRecent high‐risk longitudinal studies have documented a unique contribution of the quality of the early mother–child relationship to diverse forms of psychopathology in young adulthood, even with family economic status, later traumatic experiences, and some genetic factors controlled. In addition, measures of attachment‐related deviations in caregiver–infant interaction predict more than measures of infant attachment behavior alone. This article reviews those findings in the context of cross‐disciplinary thinking on the importance of shared subjectivities in human evolution and development and in the context of recent studies beginning to map the intersection between processes of interaction and the development of the child's propensities to share mental states with others.
Tethering a laminin peptide to a crosslinked collagen scaffold for biofunctionality
Authors: Damodaran Gopinath , Collighan Russell , Griffin Martin , Pandit Abhay 
Published: May 2008

AbstractCell adhesion peptide regulates various cellular functions like proliferation, attachment, and spreading. The cellular response to laminin peptide (PPFLMLLKGSTR), a motif of laminin‐5 α3 chain, tethered to type I collagen, crosslinked using microbial transglutaminase (mTGase) was investigated. mTGase is an enzyme that initiates crosslinking by reacting with the glutamine and lysine residues on the collagen fibers stabilizing the molecular structure. In this study that tethering of the laminin peptide in a mTGase crosslinked collagen scaffold enhanced cell proliferation and attachment. Laminin peptide tethered crosslinked scaffold showed unaltered cell morphology of 3T3 fibroblasts when compared with collagen and crosslinked scaffold. The triple helical structure of collagen remained unaltered by the addition of laminin peptide. In addition a dose‐dependent affinity of the laminin peptide towards collagen was seen. The degree of crosslinking was measured by amino acid analysis, differential scanning calorimeter and fourier transform infrared spectroscopy. Increased crosslinking was observed in mTGase crosslinked group. mTGase crosslinking showed higher shrinkage temperature. There was alteration in the fibrillar architecture due to the crosslinking activity of mTGase. Hence, the use of enzyme‐mediated linking shows promise in tethering cell adhesive peptides through biodegradable scaffolds. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
Structural characterization and cell response evaluation of electrospun PCL membranes: Micrometric versus submicrometric fibers
Authors: Del Gaudio Costantino , Bianco Alessandra , Folin Marcella , Baiguera Silvia , Grigioni Mauro 
Published: May 2008

AbstractElectrospinning is a valuable technique to fabricate fibrous scaffolds for tissue engineering. The typical nonwoven architecture allows cell adhesion and proliferation, and supports diffusion of nutrients and waste products. Poly(ε‐caprolactone) (PCL) electrospun membranes were produced starting from 14% w/v solutions in (a) mixture 1:1 tetrahydrofuran and N,N‐dimethylformamide and (b) chloroform. Matrices made up of randomly arranged uniform fibers free of beads were obtained. The average fiber diameters were (a) 0.8 ± 0.2 μm and (b) 3.6 ± 0.8 μm. PCL matrices showed the following tensile mechanical properties: tensile modulus (a) 5.0 ± 0.7 MPa (b) 6.4 ± 0.2 MPa, yield stress (a) 0.55 ± 0.06 MPa (b) 0.43 ± 0.02 MPa, and ultimate tensile stress (a) 1.7 ± 0.2 MPa and (b) 0.8 ± 0.1 MPa. The ultimate strain ranged between 300% and 400%. Cytotoxicity of electrospun membranes was continuously evaluated by means of electric cell–substrate impedance sensing technique using human umbilical vein endothelial cells (HUVEC). PCL matrices resulted free of toxic amounts of contaminants and/or process by‐products. In vitro studies performed by culturing HUVEC on micrometric and submicrometric fibrous mats showed that both structures supported cell adhesion and spreading. However, cells cultured on the micrometric network showed higher vitality and improved interaction with the polymeric fibers, suggesting an increased ability to promote cell colonization. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009
In vivo study on hydroxyapatite scaffolds with trabecular architecture for bone repair
Authors: Appleford Mark R. , Oh Sunho , Oh Namsik , Ong Joo L. 
Published: May 2008

AbstractThe objective of this research was to investigate the bone formation and angio‐conductive potential of hydroxyapatite (HA) scaffolds closely matched to trabecular bone in a canine segmental defect after 3 and 12 weeks post implantation. Histomorphometric comparisons were made between naturally forming trabecular bone (control) and defects implanted with scaffolds fabricated with micro‐size (M‐HA) and nano‐size HA (N‐HA) ceramic surfaces. Scaffold architecture was similar to trabecular bone formed in control defects at 3 weeks. No significant differences were identified between the two HA scaffolds; however, significant bone in‐growth was observed by 12 weeks with 43.9 ± 4.1% and 50.4 ± 8.8% of the cross‐sectional area filled with mineralized bone in M‐HA and N‐HA scaffolds, respectively. Partially organized, lamellar collagen fibrils were identified by birefringence under cross‐polarized light at both 3 and 12 weeks post implantation. Substantial blood vessel infiltration was identified in the scaffolds and compared with the distribution and diameter of vessels in the surrounding cortical bone. Vessels were less numerous but significantly larger than native cortical Haversian and Volkmann canals reflecting the scaffold architecture where open spaces allowed interconnected channels of bone to form. This study demonstrated the potential of trabecular bone modeled, highly porous and interconnected, HA scaffolds for regenerative orthopedics. © 2008 Wiley Periodicals, Inc. J Biomed Mater Res, 2009