bluuebunny/crossref_metadata_2025_split huggingface dataset:
Geophysical investigation of landslides : a review
Authors: Jongmans Denis , Garambois Stéphane 
Published: May 2007

Abstract
In the last two decades, shallow geophysics has considerably evolved with the emergence of 2D spatial imaging, then 3D spatial imaging and now 4D time and space imaging. These techniques allow the study of the spatial and temporal variations of geological structures. This paper aims at presenting a current state-of-the-art on the application of surface geophysical methods to landslide characterization and focuses on recent papers (after 1990) published in peer-reviewed international journals. Until recently, geophysical techniques have been relatively little used for the reconnaissance of landslides for at least two main reasons. The first one is that geophysical methods provide images in terms of physical parameters, which are not directly linked to the geological and mechanical properties required by geologists and engineers. The second reason shown through this study probably comes from a tendency among a part of the geophysicists to overestimate the quality and reliability of the results. This paper gave the opportunity to review recent applications of the main geophysical techniques to landslide characterisation, showing both their interest and their limits. We also emphasized the geophysical image characteristics (resolution, penetration depth), which have to be provided for assessing their reliability, as well as the absolute requirements to combine geophysical methods and to calibrate them with existing geological and geotechnical data. We hope that this paper will contribute to fill the gaps between communities and to strength of using appropriate geophysical methods for landslide investigation.
Hydrogeochemistry in landslide research: a review
Authors: Bogaard Thom , Guglielmi Yves , Marc Vincent , Emblanch Christophe , Bertrand Catherine , Mudry Jacques 
Published: May 2007

Abstract
This review aims to give an overview of the potential hydrogeochemical information can have for landslide research and analyses the use of hydrogeochemical information to unravel the hydrological processes in landslide triggering. Landslides are well known for their data shortage; especially in case the hydrogeology is heterogeneous and difficult to measure. In this article we analyse the impact hydrogeochemical processes has on physical properties of the soil material and rock slopes, i.e. the relation with deformation rate and the relation of pore fluid composition and residual shear strength of soil material. Furthermore, the paper looks at the subsurface information that can be gained, i.e. the geological information of subsurface architecture and the hydrological information on origin of water, flow paths and travel times (using isotope analyses). Hydrochemical information used in both hard and soft rocks enables the display of clusters of water types, which is useful to identify contribution of different aquifers to the landslide area. Moreover, it can demonstrate the existence of lithologies and structures that are not visible with surface based geological investigations. Kinetic-based modelling is shown to be very useful in the interpretation of hydrogeochemical information. Lastly, it is shown that chemical information such as cation exchange properties coming from cored drilling is worthwhile for hydrological interpretations of landslides.
Seismic noise-based methods for soft-rock landslide characterization
Authors: Méric Ombeline , Garambois Stéphane , Malet Jean-Philippe , Cadet Héloïse , Guéguen Philippe , Jongmans Denis 
Published: May 2007

AbstractIn order to better understand the mechanics and dynamic of landslides, it is of primary interest to image correctly their internal structure and their slip surface. Several active geophysical methods are able to provide the geometry of a given landslide, but were rarely applied in 3 dimensions in the past. The main disadvantages of methods like seismic reflection and electrical tomography are that there are heavy to set up and/or to process, and they consequently are expensive and time consuming. Moreover, in the particular case of soft-rock landslides, their respective sensitivity and resolution are not always adequate to locate the potential slip surfaces. Passive methods may represent an interesting alternative particularly for landslides difficult to access, as they require lighter instrumentation and easier processing tools. Among them, the seismic noise based methods have shown increasing applications and developments, in particular for seismic hazard mapping in urban environment. In this paper, we present seismic noise investigations carried out on two different sites, the “Super Sauze” mudslide and the “Saint Guillaume” translational clayey landslide (France), where independent measurements (geotechnical and geophysical tests) were performed earlier. Our investigations were composed of electrical tomography profiles, seismic profiles for surface-wave inversions, H/V measurements, which are fast and easy to perform in the field, in order to image shear wave contrasts (slip surfaces), and seismic noise array method, which is heavier to apply and interpret, but provides (S)-waves velocity profile versus depth. For both sites, landslide bodies are characterized by lower S wave velocity (Vs &lt; 300 m.s−1) and lower resistivity (ρ &lt; 60 Ohm.m) than in the stable part (Vs &gt; 550 m.s−1; ρ &gt; 150 ohm.m). Their thickness vary from a few m to 50 m. Comparison between geophysical investigations and geotechnical data proved the applicability of such passive methods in 3D complex structures, with however some limitations.
Nitrogen and Phosphorus Runoff Losses from Variable and Constant Intensity Rainfall Simulations on Loamy Sand under Conventional and Strip Tillage Systems
Authors: Franklin D. , Truman C. , Potter T. , Bosch D. , Strickland T. , Bednarz C. 
Published: May 2007

AbstractFurther studies on the quality of runoff from tillage and cropping systems in the southeastern USA are needed to refine current risk assessment tools for nutrient contamination. Our objective was to quantify and compare effects of constant (Ic) and variable (Iv) rainfall intensity patterns on inorganic nitrogen (N) and phosphorus (P) losses from a Tifton loamy sand (Plinthic Kandiudult) cropped to cotton (Gossypium hirsutumL.) and managed under conventional (CT) or strip‐till (ST) systems. We simulated rainfall at a constant intensity and a variable intensity pattern (57 mm h−1) and collected runoff continuously at 5‐min intervals for 70 min. For cumulative runoff at 50 min, the Iv pattern lost significantly greater amounts (p< 0.05) of total Kjeldahl N (TKN) and P (TKP) (849 g N ha−1and 266 g P ha−1for Iv; 623 g N ha−1and 192 g P ha−1for Ic) than did the Ic pattern. However, at 70 min, no significant differences in total losses were evident for TKN or TKP from either rainfall intensity pattern. In contrast, total cumulative losses of dissolved reactive P (DRP) and NO3–N were greatest for ST‐Ic, followed by ST‐Iv, CT‐Ic, and CT‐Iv in diminishing order (69 g DRP ha−1and 361 g NO3–N ha−1; 37 g DRP ha−1and 133 g NO3–N ha−1; 3 g DRP ha−1and 58 g NO3–N ha−1; 1 g DRP ha−1and 49 g NO3–N ha−1). Results indicate that constant‐rate rainfall simulations may overestimate the amount of dissolved nutrients lost to the environment in overland flow from cropping systems in loamy sand soils. We also found that CT treatments lost significantly greater amounts of TKN and TKP than ST treatments and in contrast, ST treatments lost significantly greater amounts of DRP and NO3–N than CT treatments. These results indicate that ST systems may be losing more soluble fractions than CT systems, but only a fraction the total N (33%) and total P (11%) lost through overland flow from CT systems.
Assessment of Vegetation Stress Using Reflectance or Fluorescence Measurements
Authors: Campbell P. K. E. , Middleton E. M. , McMurtrey J. E. , Corp L. A. , Chappelle E. W. 
Published: May 2007

AbstractCurrent methods for large‐scale vegetation monitoring rely on multispectral remote sensing, which has serious limitation for the detection of vegetation stress. To contribute to the establishment of a generalized spectral approach for vegetation stress detection, this study compares the ability of high‐spectral‐resolution reflectance (R) and fluorescence (F) foliar measurements to detect vegetation changes associated with common environmental factors affecting plant growth and productivity. To obtain a spectral dataset from a broad range of species and stress conditions, plant material from three experiments was examined, including (i) corn, nitrogen (N) deficiency/excess; (ii) soybean, elevated carbon dioxide, and ozone levels; and (iii) red maple, augmented ultraviolet irradiation. Fluorescence and R spectra (400–800 nm) were measured on the same foliar samples in conjunction with photosynthetic pigments, carbon, and N content. For separation of a wide range of treatment levels, hyperspectral (5–10 nm) R indices were superior compared with F or broadband R indices, with the derivative parameters providing optimal results. For the detection of changes in vegetation physiology, hyperspectral indices can provide a significant improvement over broadband indices. The relationship of treatment levels to R was linear, whereas that to F was curvilinear. Using reflectance measurements, it was not possible to identify the unstressed vegetation condition, which was accomplished in all three experiments using F indices. Large‐scale monitoring of vegetation condition and the detection of vegetation stress could be improved by using hyperspectral R and F information, a possible strategy for future remote sensing missions.
Nitrogen Dynamics among Cropland and Riparian Buffers
Authors: Young Eric O. , Briggs Russell D. 
Published: May 2007

AbstractNitrate (NO3−) leaching to ground water poses water quality concerns in some settings. Riparian buffers have been advocated to reduce excess ground water NO3− concentrations. We characterized inorganic N in soil solution and shallow ground water for 16 paired cropland‐riparian plots from 2003 to 2005. The sites were located at two private dairy farms in Central New York on silt and gravelly silt loam soils (Aeric Endoaqualfs, Fluvaquentic Endoaquepts, Fluvaquentic Eutrudepts, Glossaquic Hapludalfs, and Glossic Hapludalfs). It was hypothesized that cropland N inputs and soil‐landscape variability would jointly affect NO3− leaching and transformations in ground water. Results showed that well and moderately well drained fields had consistently higher ground water NO3− compared to more imperfectly drained fields receiving comparable N inputs. Average 50‐cm depth soil solution NO3− and ground water dissolved oxygen (DO) explained 64% of average cropland ground water NO3− variability. Cropland ground water with an average DO of <3 mg L−1 tended to have <4 mg L−1 of NO3− with a water table depth (WTD) of ≤1 m. Water table depth and DO explained 83% of ground water NO3− variability among buffers. More poorly drained buffers had low ground water NO3− and DO, a shallow WTD, and higher ground water ammonium and soil organic matter. Chloride patterns indicated that dilution was minor in most buffers, suggesting that denitrification losses were important. Soil‐landscape factors strongly influenced NO3− behavior and suggest the importance of accurately characterizing soil variability along cropland‐riparian zones.
Mechanisms Controlling the Leaching Kinetics of Fixated Flue Gas Desulfurization (FGD) Material under Neutral and Acidic Conditions
Authors: Cheng Chin‐Min , Walker Harold W. , Bigham Jerry M. 
Published: May 2007

AbstractA number of agricultural and engineering uses for fixated flue gas desulfurization (FGD) material exist; however, the potential for leaching of hazardous elements has limited widespread application and the processes controlling the leaching of this material are poorly understood. In this study, a flow‐through rotating‐disk system was applied to elucidate the relative importance of bulk diffusion, pore diffusion, and surface chemical reaction in controlling the leaching of fixated FGD material under pH conditions ranging from 2.2 to 6.8. Changing the hydrodynamics in the rotating disk system did not affect the leaching kinetics at both pH 2.2 and 6.8, indicating that bulk diffusion was not the kinetic‐limiting step. Application of the shrinking core model (SCM) to the data suggested a surface reaction‐controlled mechanism, rather than a pore diffusion mechanism. The leaching of fixated FGD material increased with decreasing pH, suggesting it can be described by a combination of an intrinsic hydration reaction and a proton‐promoted dissolution reaction. X‐ray diffraction (XRD) and elemental composition analyses before and after leaching suggests that for most elements a number of solid phases controlled the leaching process.
Sample Drying Effects on Lead Bioaccessibility in Reduced Soil
Authors: Furman Olha , Strawn Daniel G. , McGeehan Steve 
Published: May 2007

AbstractRisk‐assessment tests of contaminated wetland soils often use experimental protocols that artificially oxidize the soils. Oxidation may impact bioavailability of contaminants from the soils, creating erroneous results and leading to improper management and remediation. The goal of this study was to determine if oxygenation of reduced sediments and soils influences Pb bioaccessibility measurements. The study site is located on the Coeur d'Alene River floodplain, downstream from the Silver Valley Mining District in Idaho. A physiologically based extraction test designed to simulate the gastrointestinal tract of waterfowl (W‐PBET) was used to measure relative Pb bioavailability (bioaccessibility) from the soils. The soils were collected from a submerged wetland. One set of samples was allowed to air‐dry, another set was freeze‐dried, and a third set was analyzed wet. The wet soil showed decreased Pb bioaccessibility compared with the air‐ and freeze‐dried soils. The changes in extractability of Fe and Mn on air‐drying were opposite from each other: Fe extractability decreased while Mn increased. The results from this study show that redox changes may have significant impacts on Pb bioavailability, and should be considered when assessing Pb contamination risks in reduced soils.
Dissolved Organic Carbon in Runoff and Tile‐Drain Water under Corn and Forage Fertilized with Hog Manure
Authors: Royer Isabelle , Angers Denis A. , Chantigny Martin H. , Simard Régis R. , Cluis Daniel 
Published: May 2007

AbstractDissolved organic carbon (DOC) export from soils can play a significant role in soil C cycling and in nutrient and pollutant transport. However, information about DOC losses from agricultural soils as influenced by management practices is scarce. We compared the effects of mineral fertilizer (MF) and liquid hog manure (LHM) applications on the concentration and molecular size of DOC released in runoff and tile‐drain water under corn (Zea mays L.) and forage cropping systems. Runoff and tile‐drain water samples were collected during a 2‐mo period (October to December 1998) and DOC concentration was measured. Characterization of DOC was performed by tangential ultrafiltration with nominal cut‐offs at 3 and 100 kDa. Mean concentration of DOC in runoff water (12.7 mg DOC L−1) was higher than in tile‐drain water (6.5 mg DOC L−1). Incorporation of corn residues increased the DOC concentration by 6‐ to 17‐fold in surface runoff, but this effect was short‐lived. In runoff water, the relative size of the DOC molecules increased when corn residues and LHM were applied probably due to partial microbial breakdown of these organic materials and to a faster decomposition or preferential adsorption of the small molecules. The DOC concentration in tile‐drain water was slightly higher under forage (7.5 mg DOC L−1) than under corn (5.4 mg DOC L−1) even though the application rates of LHM were higher in corn plots. We suggest that preferential flow facilitated the migration of DOC to tile drains in forage plots. In conclusion, incorporation of corn residues and LHM increased the concentration of DOC and the relative size of the molecules in surface runoff water, whereas DOC in tile‐drain water was mostly influenced by the cropping system with relatively more DOC and larger molecules under forage than corn.
Changes in Crested Wheatgrass Root Exudation Caused by Flood, Drought, and Nutrient Stress
Authors: Henry Amelia , Doucette William , Norton Jeanette , Bugbee Bruce 
Published: May 2007

AbstractRoot exudates can chelate inorganic soil contaminants, change rhizosphere pH, and may increase degradation of organic contaminants by microbial cometabolism. Root‐zone stress may increase exudation and enhance phytoremediation. We studied the effects of low K+, high NH4+/NO3− ratio, drought, and flooding on the quantity and composition of exudates. Crested wheatgrass (Agropyron cristatum) was grown in Ottawa sand in sealed, flow‐through glass columns under axenic conditions for 70 d. Root exudates were collected and analyzed for total organic carbon (TOC) and organic acid content to compare treatment effects. Plants in the low K+ treatment exuded 60% more TOC per plant per day (p = 0.01) than the unstressed control. Drought stress increased cumulative TOC exuded per gram dry plant by 71% (p = 0.05). The flooded treatment increased TOC exuded per gram dry plant by 45%, although this was not statistically significant based on the two replicate plants in this treatment. Exudation from the high NH4+/NO3− ratio treatment was 10% less than the control. Exudation rates in this study ranged from 8 to 50% of rates in four other published studies. Gas chromatography‐mass spectrometry (GC–MS) analysis indicated that malic acid was the predominant organic acid exuded. Fumaric, malonic, succinic, and oxalic acids were also detected in the exudates of all treatments. These results demonstrate that nutrient and water stress have significant effects on the quantity and composition of root exudates. Cultural manipulations to induce stress may change the quantity of root exudates and thus increase the effectiveness of phytoremediation.
Atrazine Degradation and Residues Distribution in Two Acid Soils from Temperate Humid Zone
Authors: Mahía J. , Díaz‐Raviña M. 
Published: May 2007

AbstractMineralization of atrazine and formation of extractable and non‐extractable “bound” residues were followed under laboratory conditions in two contrasting soils (organic C, texture, and atrazine application history) from northern Spain. The soils, a Humic Cambisol (MP) and a Gleyic Cambisol (G) were incubated with labeled atrazine (ring‐13C atrazine) at field application dose and measurements were made at different time intervals during 3 mo. Fate and behavior of atrazine along the incubation showed different patterns between the two soils, the time taken for degradation of 50% (DT50) being 9 and 44 d for MP and G soils, respectively. In MP soil, with 40 yr of atrazine application and lower organic C and clay content, more than 89% of U‐13C‐atrazine added was mineralized after 12 wk, with most mineralization occurring within the first 2 wk. G soil, with 10 yr of atrazine application, exhibited a more progressive U‐13C‐atrazine mineralization, reaching 54% of initially added atrazine at 12 wk. Hydroxyatrazine and deisopropylatrazine were the metabolites founded in the extractable fraction, demonstrating that both chemical and biological processes are involved in atrazine degradation. Soil G showed during all the incubation times an extractable residues fraction greater than that in MP soil, indicating a high potential risk of soil and water contamination. Rapid microbial degradation through s‐triazine ring cleavage was proposed to be the main decomposition pathway of atrazine for the two soils studied. Bound residues pool also differed notably between soils accounting for 9 and 41% of initially added atrazine, the higher values shown by soil with higher organic matter and clay content (G soil).
Boosted CO2 Photoreduction Performance by CdSe Nanoplatelets via Se Vacancy Engineering
Authors: Luo Huanhuan , Lu Xuanzhao , Cao Yue , Lyu Zhaoyuan , Ding Shichao , Lin Yuehe , Zhou Yang , Zhu Wenlei , Wang Yuanyuan 
Published: February 2025

Abstract2D metal‐chalcogenide nanoplatelets (NPLs) exhibit promising photocatalysis properties due to their ultrathin morphology, high surface‐to‐volume ratio, and enhanced in‐plane electron transport mobility. However, NPLs, especially cadmium chalcogenides, encounter challenges in CO2 photoreduction due to insufficient solar energy utilization and fast recombination of photogenerated charge carriers. Defect engineering offers a potential solution but often encounters difficulties maintaining structural integrity, mechanical stability, and electrical conductivity. Herein, by taking two monolayers (2ML) CdSe NPLs as a model system, selenium (Se) vacancies confined in atomic layers can enhance charge separation and conductivity. A straightforward approach to create Se vacancies in various monolayers CdSe NPLs (2, 4, and 5ML) has been developed, enabling efficient CO2 photoreduction with a 4‐fold increase in CO generation compared to their defect‐free counterparts. Significantly, accounting for higher charge density and efficient carrier transport due to Se vacancies, defective 2ML CdSe NPLs (VSe‐2ML CdSe) exhibit CO evolution performance up to 2557.5 µmol g−¹ h−¹ with no significant decay over 5 h, which is an order of magnitude higher than that of common semiconductor catalysts. This study establishes a practical way to design advanced 2D semiconductor photocatalysts to achieve efficient CO2 photoreduction via defect engineering.
Ictal scalp EEG patterns are shaped by seizure etiology in temporal lobe epilepsy
Authors: Xu Sha , Zhu Qianwen , Zhou Jinqi , Ye Lingqi , Ye Hongyi , Shen Chunhong , Zheng Zhe , Jiang Hongjie , Wang Shan , Ding Yao , Chen Cong , Guo Yi , Wang Zhongjin , Wang Shuang 
Published: February 2025

AbstractObjectiveTo investigate how etiology and seizure localization influence ictal scalp electroencephalographic (EEG) patterns in temporal lobe epilepsy (TLE).MethodsWe retrospectively analyzed ictal EEG features from 504 focal seizures recorded in 189 TLE patients with various etiologies who underwent resective surgery.ResultsFor seizure onset patterns (SOPs), α/β onset was more common in the low‐grade tumor group (38.4%) than in the hippocampal sclerosis (HS) group (14.1%, p < 0.001). The ictal EEG duration was shorter in the tumor group compared to the focal cortical dysplasia (FCD), HS, and non‐specific groups (p < 0.05). Among mesial TLE patients, SOPs varied depending on the etiology. Within both the tumor and non‐specific groups, SOPs and the spreading time to the contralateral hemisphere differed between mesial and neocortical origins. Ictal pattern (87.7%) and ictal theta activity (83.9%) correctly lateralized the seizure in most cases.SignificanceThe ictal scalp pattern in TLE is influenced by both etiology and seizure localization. TLE associated with low‐grade tumors exhibits distinct ictal EEG characteristics. Furthermore, ictal pattern and ictal theta activity are equally effective in lateralizing seizures, regardless of etiology.Plain Language SummaryThis research examined how brain activity during seizures in people with temporal lobe epilepsy can be different based on what caused the epilepsy and where in the brain the seizure starts. We found that seizures caused by brain tumors have unique patterns in the brain's electrical activity. Additionally, we discovered that specific patterns and types of brain waves can help determine which side of the brain the seizure is occurring on, regardless of its cause.