Wider Applicability (wider + applicability)

Distribution by Scientific Domains

Selected Abstracts

High resolution quantification of gully erosion in upland peatlands at the landscape scale

Martin Evans
Abstract The upland peatlands of the UK are severely eroded, with large areas affected by gully erosion. The peatlands are important areas of carbon storage and provide a range of other ecosystem services including water supply and biodiversity all of which are negatively impacted by erosion of the upland surface. The magnitude of the gully erosion, and consequent adjustment of the peatland morphology, is such that in degraded peatlands the extent and magnitude of erosion is a major control on peatland function. Accurate mapping of gully form is therefore a necessary precondition to the understanding and management of these systems. This paper develops an approach to extracting gully maps from high resolution digital elevation models (DEMs). Gully maps of the Bleaklow Plateau in northern England were derived from a 2,m LiDAR DEM by combining areas of low difference from mean elevation and high positive plan curvature. Gully depth was modelled by interpolating between gully edges. Testing of the gully mapping and depth modelling against aerial photography, manual interpretation of the DEM and ground survey revealed that gully plan form is well represented and gully width and depth are modelled with tolerances close to the horizontal and vertical resolution of the LiDAR imagery. Estimates of gully width and depth were less reliable for gullies with total width of less than four pixels. The approach allows for the first time the derivation of accurate estimates of gully extent and magnitude over large areas and provides the basis for modelling a range of processes controlled by gullying. The approach has wider applicability to mapping gully erosion in a wide range of environments. Copyright 2010 John Wiley & Sons, Ltd. [source]

Geomorphic constraints on the active tectonics of southern Taiwan

Lucy A. Ramsey
SUMMARY Taiwan is a region of rapid active tectonics, yet the study of the tectonic processes that shape the interior of the island is difficult due to the high rates of erosion and dense vegetation. We use digital topography to look for indications of active deformation preserved in the local geomorphology. In particular, anomalies in the regional pattern of drainage are used to infer zones of enhanced tectonic activity. The apparent anticlockwise rotation of major river systems in plan view indicates the presence of a diffuse zone of left-lateral shear running down the southeastern side of Taiwan. Asymmetries in the catchments of individual drainage basins show the influence of varying rates of uplift across southern Taiwan, with the most rapid uplift close to Taitung at the indentation point of the Luzon arc with the Chinese continental margin. Our interpretations, though based predominantly on remote-sensing observations, are consistent with the available field evidence. This study demonstrates the usefulness of drainage basins as tectonic markers in the quantification of regional strain and uplift, which may have wider applicability in other deforming parts of the world. [source]

Quantification of immunohistochemistry,issues concerning methods, utility and semiquantitative assessment I

R A Walker
Immunohistochemistry is no longer a technique used only for research but is employed increasingly for diagnosis and for the assessment of therapeutic biomarkers. The latter, in particular, often require a semiquantitative evaluation of the extent of their presence. There are many factors that can affect this that relate to the method: fixation of tissue, duration and type of antigen retrieval, antibody specificity, antibody dilution and detection systems. Other complexities relate to assessment. Different scoring systems are used for either the same or different antigens. Cut-off levels for assessing whether a tissue is ,positive' or ,negative' can vary for the same antigen. Whilst there are quality assurance schemes for the methodology that have improved standards of staining, there are no similar schemes that relate to interpretation, although errors here can create as many problems. There have been improvements in automated analysis but availability is limited and it is still predominantly a research tool. In order for quantification of immunohistochemistry to be a reliable and reputable tool, there must be easy to use, reproducible, standardized protocols for assessment which are international. Improvements in automated analysis with wider applicability could lead to standardization. [source]

Effects of topography on the spatial distribution of evapotranspiration over a complex terrain using two-source energy balance model with ASTER data

H. K. Kafle
Abstract Spatial distribution of evapotranspiration (ET) over a complex terrain is estimated using a new approach of the conventional two-source energy balance (TSEB) model by considering the effect of topography (difference in slope and aspect). We name this approach topography considered two-source energy balance (T2SEB) model. The novelty of this model is the estimation of incoming shortwave solar radiation considering slope, aspect, altitude, latitude, longitude, and the day of calculation in the TSEB model, so that the new model should have wider applicability than existing models over topographically complex areas. In this study, high spatial resolution Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER) data and meteorological data are used. ET over a complex terrain of Nagoya, Japan, on three different dates, 4 November 2005, 25 May 2004 and 30 October 2003, is estimated using both TSEB and T2SEB models. To validate both models, estimated results are compared with ground observation data at the flux tower site. Moreover, estimated results from TSEB and T2SEB models are compared in five different locations of different topography within the study area. Variation of net radiation absorbed by the surface (Rn) with topographical variables is also studied with the help of scatter plots. Estimated results for all three dates agreed within 75 W m,2 with calculated values from both models at the flux tower site. TSEB underestimated/overestimated ET in sunlit/shaded areas in hilly areas. The T2SEB model estimated ET in hilly areas better than the TSEB model. Copyright 2009 John Wiley & Sons, Ltd. [source]

The generalized spectral kurtosis estimator

G. M. Nita
ABSTRACT Due to its conceptual simplicity and its proven effectiveness in real-time detection and removal of radio frequency interference (RFI) from radio astronomy data, the spectral kurtosis (SK) estimator is likely to become a standard tool of a new generation of radio telescopes. However, the SK estimator in its original form must be developed from instantaneous power spectral density estimates, and hence cannot be employed as an RFI excision tool downstream of the data pipeline in existing instruments where any time averaging is performed. In this Letter, we develop a generalized estimator with wider applicability for both instantaneous and averaged spectral data, which extends its practical use to a much larger pool of radio instruments. [source]

Predicting the low energy landscape of nanoscale silica using interatomic potentials

S. T. BromleyArticle first published online: 18 APR 200
Abstract The energies of 52 of the lowest lying structural isomers of the (SiO2)12 nanocluster are accurately calculated via energy minimisations employing density functional theory (DFT) and also with two silica interatomic potentials (IPs). Of the tested IPs, one was specifically parameterised with respect to small silica nanoclusters, and the other was biased to accurately recover bulk silica properties, although having been applied numerous times to silica nanosystems. The predicted energetic ordering of the nanocluster isomers resulting from the IP optimisations are compared with respect to their deviance from benchmark nanocluster energies from DFT calculations. Although both IPs predict the DFT ground state isomer to be a very low energy cluster and thus are of use in global optimisation studies, large fluctuations in the IP energies of other low lying isomers (relative to the respective DFT energies) shed doubt on their wider applicability to nanoscale silica systems. ( 2006 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) [source]

Macromolecular crystal data phased by negative-stained electron-microscopy reconstructions

Stefano Trapani
The combination of transmission electron microscopy with X-ray diffraction data is usually limited to relatively large particles. Here, the approach is continued one step further by utilizing negative staining, a technique that is of wider applicability than cryo-electron microscopy, to produce models of medium-size proteins suitable for molecular replacement. The technique was used to solve the crystal structure of the dodecameric type II dehydroquinase enzyme from Candida albicans (,190,kDa) and that of the orthologous Streptomyces coelicolor protein. [source]

Cancer and the blood,brain barrier: ,Trojan horses' for courses?

M Mazza
The blood,brain barrier (BBB) limits the bioavailability of most bioactive molecules and drugs in the CNS, leaving clinicians with only a few options for pharmacotherapy. In this issue Regina et al. demonstrate that a ,Trojan horse' drug conjugate, acting as a substrate of a physiological BBB receptor that facilitates transcytosis, significantly improves drug transport into the CNS. Specifically, the low-density lipoprotein receptor-related protein (LRP) is used to carry a conjugate of paclitaxel and Angiopep-2, an aprotinin-derived peptide, across the BBB. Interestingly, in its conjugated form paclitaxel circumvents the efflux pumps at the BBB but still retains its activity against microtubules. Importantly, the authors were able to demonstrate improved therapeutic efficacy of this approach in orthotopic models of primary and metastatic brain cancer. This proof-of-principle study thus represents a milestone for drug delivery across the BBB but also a starting point for studies exploring wider applicability and potential limitations of the approach. British Journal of Pharmacology (2008) 155, 149,151; doi:fn1; published online 30 June 2008 [source]