bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geostatistical estimations of bathymetric LiDAR errors on rivers
Authors: Bailly Jean‐Stéphane , Le Coarer Yann , Languille Pascal , Stigermark Carl‐Johann , Allouis Tristan 
Published: June 2010

AbstractThe geometry of river channels is a key descriptive element for hydromorphology, hydraulics and hydroecology. Gravel bed rivers usually have a mean water depth of ∼0·5 m. For such shallow waters, the accuracy of bathymetric LiDAR data has to be precisely assessed. Alongside this accuracy investigation, methodological questions arise: How to assess the data quality of elevation LiDAR when comparing reference topographic points on river beds to laser beam footprints of several square metres at different locations? What are the consequences of uncertainties and scaling in accuracy estimations? In this study, we designed a methodology to assess the quality of LiDAR topographical data within rivers using a specific geostatistical method that conducts upscaling as well as interpolation of reference data that takes into account uncertainties. This method uses an anisotropic block kriging from DGPS points on LiDAR footprint areas within a channel‐fitted coordinate system. This assessment focused on a 1·5 km long reach of the Gardon gravel bed river, in the south of France. DGPS points pseudo‐regularly located along the river were acquired at the same time as the LiDAR survey with the HawkEyeII system. LiDAR accuracy results for river bottom elevation show a negative bias for high depth. Added to that bias, a random error with 0·32 m standard deviation was found by considering upscaling and uncertainties in reference data, and a 0·20 m standard deviation was found if they were not considered. Consequently, if LiDAR bias can be corrected, measuring a water depth less than 32 cm, i.e. for 28% of the river area, is unrealistic.However, this experiment shows that LiDAR provides an accurate representation of the riverbed forms. It also provided a useful, continuous, topographic surface from the underwater river bed up to riparian areas. Copyright © 2010 John Wiley and Sons, Ltd.
Examining the physical components of boundary shear stress for water‐worked gravel deposits
Authors: Cooper James R. , Tait Simon J. 
Published: June 2010

AbstractIt is argued in this commentary that, in order to understand better the physical mechanisms that generate boundary shear stress over water‐worked gravel beds, flow velocity data should be re‐evaluated by spatial averaging the Reynolds equations to produce time‐ and space‐averaged (double‐averaged) momentum equations. A series of laboratory experiments were conducted in which the flow velocities were measured using a PIV system over two water‐worked gravel deposits. Combined with detailed data on the bed surface topography and vertical porosity, the physical components of shear stress were obtained. This enabled the various momentum transfer mechanisms present above, within and at the interface of a porous, fluvial deposit, to be quantified. This included the examination of the relevant contributions of temporal and spatial fluctuations in velocity and surface drag to the overall momentum transfer. It is demonstrated that double‐averaging represents a logical framework for assessing the fluid forces responsible for sediment entrainment and for investigating intragravel flow and sediment–water interface exchange mechanisms within the roughness layer in water‐worked gravel deposits. By considering the physical components of shear stress and their relative sizes it was possible to provide a physically based explanation for existing observations of enhanced mobility of gravel–sand mixtures and the transfer of solutes into porous, gravel deposits. This analysis reveals the importance of obtaining co‐located, high quality spatial data on the flow field and bed surface topography in order to gain a physical understanding of the mechanisms which generate boundary shear stress. Copyright © 2010 John Wiley & Sons, Ltd.
Turbulent shear stresses in hydraulic jumps, bores and decelerating surges
Authors: Chanson Hubert 
Published: June 2010

AbstractIn an open channel, a sudden rise in water level induces a positive surge, or bore, that may develop as a hydraulic jump in translation. When the surge propagates against an adverse slope, it decelerates until it becomes a stationary hydraulic jump. Both hydraulic jumps and decelerating surges induce some intense turbulent mixing and have some major impact on the sediment transport in natural systems. Herein, a physical investigation was conducted in a relatively large rectangular channel. Hydraulic jumps and surges were generated by the rapid closure of a gate at the channel downstream end. The turbulent shear stresses were measured with high temporal and spatial resolution (200 Hz sampling rate) in the jump flow. A comparison between the stationary hydraulic jump, hydraulic jump in translation and decelerating surge measurements showed some marked differences in terms of turbulent mixing. The results highlighted some intense mixing beneath the jump front and roller for all configurations. The levels of turbulent stresses were one to two orders of magnitude larger than a critical threshold for sediment motion. The findings provide some insights into the hydraulic jump migration processes in mobile bed channels, and the complex transformation from a moving jump into a stationary jump. Copyright © 2010 John Wiley & Sons, Ltd.
Structural anatomy of the exhumation of high‐pressure rocks: constraints from the Tongbai Collisional Orogen and surrounding units
Authors: Liu X. , Li S.Z. , Suo Y.H. , Liu X.C. , Dai L.M. , Santosh M. 
Published: June 2010

AbstractThe Tongbai Collisional Orogen and associated units, located between the Qinling and Dabie orogens, can be divided into nine lithotectonic units. From north to south, these are the southern tectonic unit of the North China Plate—the Maoji Group, the Erlangping tectonic unit, the Qinling Complex unit, the Guishan and Nanwan slice, the Xiaojiamiao mélange unit, the northern high‐pressure (HP) unit, the Tongbai high‐grade Complex, the southern HP unit and the Suizhou tectonic belt. Based on structural analysis and available geochronological data, five principal episodes of deformation (D1‐D5) are distinguished in this area following the Mesozoic HP metamorphism. The first two episodes of deformation developed in various tectonic units to the south of the Xiaojiamiao mélange unit, and the subsequent episodes of deformation developed in all the units of this area. The D1 deformation is correlated to ca. 255–238 Ma generating regional penetrative foliation and WNW‐trending stretching lineation, and leading to the initial stage of eastward oblique extrusion of the HP rocks. The D2 event is characterized by top‐to‐the‐SSW thrusting which contributed to the further vertical uplift of the HP rocks sometime around 230–215 Ma. The D3 event is defined by WNW‐trending open folds, and must have taken place earlier than Lower Jurassic. The D4 event is characterized by ductile strike‐slip shearing, and during this episode the Tongbai high‐grade Complex was extruded to the east at ca. 131–119 Ma. The D5 event probably took place at ca. 100–80 Ma, and is marked by the NW and NE trending brittle faults which overprint all of the above mentioned structures. The exhumation of the Tongbai HP rocks illustrates the process of gradual extrusion and uplift, controlled by several episodes of deformation. Copyright © 2010 John Wiley & Sons, Ltd.
Modernization of spate irrigated agriculture: A new approach
Authors: Mehari Abraham , Van Steenbergen Frank , Schultz Bart 
Published: June 2010

AbstractSpate irrigation, a floodwater harvesting and management system, has for the past 70 centuries provided a livelihood for about 13 million resource‐poor people in some 20 countries. Despite being the oldest, the system still remains the least studied and the least understood. It is only in the past two decades that the system has been subject to some modernization interventions, much of which focused on improving floodwater diversion efficiency. Effective floodwater diversion measures are necessary, but they must be supplemented with equally effective field water management and soil moisture conservation measures if sustainable improvement of land and water productivity is to be achieved.This paper draws on studies conducted in the past 5 years, particularly in the Republic of Yemen, Pakistan and Eritrea. The studies employed both qualitative and quantitative methods and assessed the modernization package that could result in lasting enhancement of crop productivity in spate irrigated agriculture. The suggested modernization measures include: avoid overstretching the command area; limit the number of irrigation turns to two or an irrigation gift of 1000 mm; avoid field bund heights of more than 1 m; adopt a field‐to‐field water distribution system instead of an individual field water distribution system; opt for water rights and rules that entitle downstream fields to the more frequent small and medium floods thereby ensuring equity in both water quality and quantity; optimize soil water‐holding capacity and infiltration rate through pre‐and‐post irrigation tillage, combined tillage as well as soil mulching. Copyright © 2010 John Wiley & Sons, Ltd.
AN EXPLORATIVE STUDY IN QUALITATIVE REGIME TRANSITIONS
Authors: Marktanner Marcus , Salman Lana , Bekdash Hania 
Published: June 2010

AbstractThis paper discusses countries along the dimensions of democracy vs. autocracy, income equality vs. inequality, and economic rent‐extraction vs. creation and compares them in a regional context. Transitions within those qualitative characteristics are generally scarce. When occurring, they are limited to one aspect only. Transitions towards more democracy, income equality, and productive economic activity are most likely when relative equality is already given. Contrary to the general redistribution hypothesis of democratisation, this suggests that successful democratisation stems from initial income equality; it is not democratisation that leads to more income equality. Rising income inequality is identified as the greatest threat to the sustainability of favorable socioeconomic and political developments. Copyright © 2010 John Wiley & Sons, Ltd.
Fishery as a livelihood strategy in Malawi. Analyzing a small LSMS sub‐sample
Authors: Hatlebakk Magnus 
Published: June 2010

AbstractWe illustrate how a national household survey can be applied to analyse a subject that requires data from a small sub‐sample. Even for small sub‐samples meaningful statistical tests can be conducted. The benefits of applying sub‐samples from larger household surveys are that primary data collection is not needed and there is a large comparison group. The illustrative case is livelihood strategies among fishermen in Malawi. We find that boat‐owners do not diversify more than other households, while crew‐members appear to diversify more as they combine fishery with agriculture. Copyright © 2010 John Wiley & Sons, Ltd.
Exploring the links between HIV/AIDS, social capital and development
Authors: David Antonio C. , Li Carmen A. 
Published: June 2010

AbstractThis paper attempts to quantify the impact of the HIV/AIDS epidemic on social capital with cross‐country data. Using data from the World Values Survey (WVS), the authors estimate reduced‐form regressions of the main determinants of social capital controlling for HIV prevalence, institutional quality, social distance, and economic indicators. The results obtained indicate that HIV prevalence affects social capital negatively. The empirical estimates suggest that a one standard deviation increase in HIV prevalence will lead to a decline of at least 1 per cent in trust, controlling for other determinants of social capital. Moving from a country with a relatively low level of HIV prevalence, such as Estonia, to a country with a relatively high level, such as Uganda, there is a more than 11 per cent point decline in social capital. These results are robust in a number of dimensions and highlight the empirical importance of an additional mechanism through which HIV/AIDS hinders the development process. Copyright © 2010 John Wiley & Sons, Ltd.
Impact of urban warming on earlier spring flowering in Korea
Authors: Jeong Jee‐Hoon , Ho Chang‐Hoi , Linderholm Hans W. , Jeong Su‐Jong , Chen Deliang , Choi Yong‐Sang 
Published: June 2010

AbstractUsing long‐term (1954–2004) observations of four selected species in South Korea: goldenbell (Forsythia koreana), azalea (Rhododendron mucronulatum), cherry (Prunus yedoensis), and peach (Prunus persica), the impact of urban warming on spring flowering was investigated. Trends of early spring temperatures and first‐flowering dates (FFDs) of the four plants were cross‐compared among nine differently urbanized cities. It was clearly observed that urban warming has led to an advance in the timing of first‐flowering of several days to weeks during recent decades, while the intrinsic physiology of plants to sense thermal energy has not been changed. The degree of advancement of the FFD was observed to be roughly proportional to degree of urbanization. Moreover, the sensitivity of the FFD to urban warming was estimated to be higher for the shrub species (−9.07 and −6.64 days °C−1 for goldenbell and azalea, respectively) than the tree species (−2.46 and −2.90 days °C−1 for peach and cherry, respectively). Our results suggest that the impact of urban warming should be considered as an influential factor which drives changes in the regional natural environment, especially in regions of rapid urbanization. Copyright © 2010 Royal Meteorological Society
Studies of 21st‐century precipitation trends over West Africa
Authors: Druyan Leonard M. 
Published: June 2010

AbstractWest Africa includes a semi‐arid zone between the Sahara Desert and the humid Gulf of Guinea coast, approximately between 10°N and 20°N, which is irrigated by summer monsoon rains. This article refers to the region as the Sahel. Rain‐fed agriculture is the primary sustenance for Sahel populations, and severe droughts (in the 1970s and 1980s), therefore, have devastating negative societal impacts. The future frequency of Sahel droughts and the evolution of its hydrological balance are therefore of great interest. The article reviews 10 recent research studies that attempt to discover how climate changes will affect the hydrology of the Sahel throughout the 21st century. All 10 studies rely on atmosphere–ocean global climate model (AOGCM) simulations based on a range of greenhouse gas emissions scenarios. Many of the simulations are contained in the Intergovernmental Panel on Climate Change archives for Assessment Reports #3 and #4. Two of the studies use AOGCM data to drive regional climate models. Seven studies make projections for the first half of the 21st century and eight studies make projections for the second half. Some studies make projections of wetter conditions and some predict more frequent droughts, and each describes the atmospheric processes associated with its prediction. Only one study projects more frequent droughts before 2050, and that is only for continent‐wide degradation in vegetation cover. The challenge to correctly simulate Sahel rainfall decadal trends is particularly daunting because multiple physical mechanisms compete to drive the trend upwards or downwards. A variety of model deficiencies, regarding the simulation of one or more of these physical processes, taints models' climate change projections. Consequently, no consensus emerges regarding the impact of anticipated greenhouse gas forcing on the hydrology of the Sahel in the second half of the 21st century. Copyright © 2010 Royal Meteorological Society
Remote sensing and GIS for identification of suitable sites for soil and water conservation structures
Authors: Pandey A. , Chowdary V. M. , Mal B. C. , Dabral P. P. 
Published: June 2010

AbstractFormulation of a proper watershed management plan requires reliable and up‐to‐date information about various factors such as morphologic (size and shape of the watershed, drainage parameters, topography), soil and their characteristics, land use, and land cover, etc. that affect the behavior of a watershed. Satellite based remote sensing technology and GIS meets both the requirements of reliability and speed and are ideal tools for generating spatial information needs. In this study, a locale‐specific watershed development plan was generated for the case study area of a small agricultural watershed of Karso, Hazaribagh, India using remote sensing and GIS techniques. Indian Remote Sensing Satellite (IRS‐1C), Linear Imaging Self Scanner (LISS‐III) satellite data along with other datasets, e.g. existing maps and field observation data have been utilized for generating a land use/land cover map and to extract information on morphological parameters (bifurcation ratio, elongation ratio, drainage density, ruggedness number, relief ratio, and circulatory ratio) and other thematic maps which are an essential prerequisites for watershed development. Morphological parameters of subwatersheds were derived to understand its usefulness for surface water development. The conceptual framework for plan and site suitability mapping for soil and water conservation structures is developed and subsequently, these parameters were integrated with other thematic information viz., land use/cover, drainage, slope, and soil in the GIS environment to arrive at a decision regarding a suitable site for having soil and water conservation structures (nala bund, check dam, and percolation tank) in its place adopting a holistic approach. Copyright © 2010 John Wiley & Sons, Ltd.
A 3D distinct lattice spring model for elasticity and dynamic failure
Authors: Zhao Gao‐Feng , Fang Jiannong , Zhao Jian 
Published: June 2010

AbstractA 3D distinct lattice spring model (DLSM) is proposed where matter is discretized into individual particles linked by springs. The presented model is different from the conventional lattice spring models where a shear spring is introduced to model the multibody force by evaluating the spring deformation from the local strain rather than the particle displacement. By doing this, the proposed model can represent the diversity of Poisson's ratio without violating the rotational invariance. The local strain of the spring is calculated through a least square method which makes the model possessing meshless properties. Because of this and explicitly representing the microstructure, DLSM is able to model dynamic fracturing problems and can be used to study the microstructure influences. The material parameters inputted in the model is the conventional material parameters, e.g. the elastic modules and the Poisson's ratio. Relationships between microscopic spring parameters and macroscopic material constants are derived based on the Cauchy–Born rules and the hyperelastic theory. Numerical examples are presented to show the abilities and properties of DLSM in modeling elastic and dynamic failure problems. Copyright © 2010 John Wiley & Sons, Ltd.
Changes in the MR relaxation rate R2* induced by respiratory challenges at 3.0 T: a comparison of two quantification methods
Authors: Mürtz Petra , Flacke Sebastian , Müller Andreas , Soehle Martin , Wenningmann Ingobert , Kovacs Attila , Träber Frank , Willinek Winfried A. , Gieseke Jürgen , Schild Hans H. , Remmele Stefanie 
Published: June 2010

AbstractThe consistent determination of changes in the transverse relaxation rate R2* (ΔR2*) is essential for the mapping of the effect of hyperoxic and hypercapnic respiratory challenges, which enables the noninvasive assessment of blood oxygenation changes and vasoreactivity by MRI. The purpose of this study was to compare the performance of two different methods of ΔR2* quantification from dynamic multigradient‐echo data: (A) subtraction of R2* values calculated from monoexponential decay functions; and (B) computation of ΔR2* echo‐wise from signal intensity ratios. A group of healthy volunteers (n = 12) was investigated at 3.0 T, and the brain tissue response to carbogen and CO2–air inhalation was registered using a dynamic multigradient‐echo sequence with high temporal and spatial resolution. Results of the ΔR2* quantification obtained by the two methods were compared with respect to the quality of the voxel‐wise ΔR2* response, the number of responding voxels and the behaviour of the ‘global’ response of all voxels with significant R2* changes. For the two ΔR2* quantification methods, we found no differences in the temporal variation of the voxel‐wise ΔR2* responses or in the detection sensitivity. The maximum change in the ‘global’ response was slightly smaller when ΔR2* was derived from signal intensity ratios. In conclusion, this first methodological comparison shows that both ΔR2* quantifications, from monoexponential approximation as well as from signal intensity ratios, are applicable for the monitoring of R2* changes during respiratory challenges. Copyright © 2010 John Wiley & Sons, Ltd.
Ethical control and cultural change (in cultural dreams begin organizational responsibilities)
Authors: Magala Slawomir 
Published: June 2010

Abstract

Ethical control is based on transparent access to the accounts of responsible behaviour on the part of individual and organizational actors. It is usually linked to the idea of a checkpoint: where celibate rules, no sexual interaction can be allowed. However, organizing and managing climates in professional bureaucracies have always led towards the empowerment of the operatives (regional bishops and local parish priests in the case of the Catholic Church). History of the church is repeated by corporate bureaucracies in the wake of the globalized and individualized multimedia communications, ushering in the era of hyper‐connectivity and traceability of individual behaviour. From industrial camera records at the parking lot or building entrance to the Google analysis of surfing behaviour, all of us generate public confessions and see more private acts subjected to the public ethical clearings. Universities, like hospitals, airlines and armies before them, had to enter the game of cognitive and institutional conscience game with codes of conduct and other digital tablets with 10 or more commandments. What about the gravest capital and collective sins of our societies translated daily into millions of unethical behaviours? Inequalities and injustices usually circle around gender, race, poverty and nature. Charity begins in heart and mind, but requires cultural change and a humanist coefficient in educational and socializing interactions. Stock options of arts and humanities as the prime suppliers of applied ethical procedures in educational settings should/will go up.

Copyright © 2010 John Wiley & Sons, Ltd.