bluuebunny/crossref_metadata_2025_split huggingface dataset:
Sediment transport in a highly regulated fluvial system during two consecutive floods (lower Ebro River, NE Iberian Peninsula)
Authors: Vericat Damia , Batalla Ramon J. 
Published: April 2005

AbstractThe transfer of sediment through a highly regulated large fluvial system (lower Ebro River) was analysed during two consecutive floods by means of sediment sampling. Suspended sediment and bedload transport were measured upstream and downstream of large reservoirs. The dams substantially altered flood timing, particularly the peaks, which were advanced downstream from the dams for flood control purposes. The suspended sediment yield upstream from the dams was 1 700 000 tonnes, which represented nearly 99 per cent of the total solid yield. The mean concentrations were close to 0·5 g l−1. The sediment yield downstream from the dams was an order of magnitude lower (173 000 tonnes), showing a mean concentration of 0·05 g l−1. The dams captured up to 95 per cent of the fine sediment carried in suspension in the river channel, preventing it from reaching the lowermost reaches of the river and the delta plain. Total bedload transport upstream from the dams was estimated to be about 25 000 tonnes, only 1·5 per cent of the total load. The median bedload rate was 100 gms−1. Below the dams, the river carried 178 000 tonnes, around 51 per cent of the total load, at a mean rate of 250 g ms−1. The results of sediment transport upstream and downstream from the large dams illustrate the magnitude of the sediment deficit in the lower Ebro River. The river mobilized a total of 350 000 tonnes in the downstream reaches, which were not replaced by sediment from upstream. Therefore, sediment was necessarily entrained from the riverbed and channel banks, causing a mean incision of 33 mm over the 27 km long study reach, altogether a significant step towards the long‐term degradation of the lower Ebro River. Copyright © 2005 John Wiley & Sons, Ltd.
Effect of rock fragment embedding on the aeolian deposition of dust on stone‐covered surfaces
Authors: Goossens Dirk 
Published: April 2005

AbstractMany stone‐covered surfaces on Earth are subject to aeolian deposition of atmospheric dust. This study investigates how the deposition of dust is affected when rock fragments become gradually more embedded in the ground or, inversely, become more concentrated on the surface. Experiments were executed in an aeolian dust wind tunnel with eight different types of pebbles. The following parameters were measured: dust deposition on the pebbles, dust deposition between and underneath pebbles, total dust deposition (pebbles + inter‐pebble space), and the fraction, of total deposition, of dust caught by the pebbles alone. The absolute amount of dust deposition and the dust deposition density (dust deposition per unit surface) were studied for each parameter. The effects exerted by pebble size, pebble flattening, pebble elongation and wind speed were also investigated. Dust patterns on and around pebbles were also studied via flow visualization.The absolute amount of dust settling on pebbles decreases the more that the pebbles become embedded. Dust deposition density on pebbles, on the other hand, increases with embedding. The more pebbles become embedded in the soil, the more efficient the process of dust deposition on pebbles becomes. Dust deposition between and underneath pebbles increases with pebble embedding. Dust deposition density between and underneath pebbles is maximum at 50 per cent embedding, showing that in this area dust deposition is most efficient when pebbles are halfway embedded. Total deposition slightly decreases the more pebbles become embedded, but total dust deposition density increases with embedding.Aerodynamic flow separation and diverging and converging airflow play an important role in the process of dust deposition on stone‐covered surfaces. The more pebbles protrude above the soil, the more they act as an obstacle and the more they disturb the air and dust flow creating scouring zones, flow separation bubbles and shelter areas for the dust. All these effects diminish as pebbles become more embedded in the soil. However, perturbations in dust patterns remain visible until pebbles have disappeared entirely. Copyright © 2005 John Wiley & Sons, Ltd.
DEM resolution effects on shallow landslide hazard and soil redistribution modelling
Authors: Claessens L. , Heuvelink G. B. M. , Schoorl J. M. , Veldkamp A. 
Published: April 2005

AbstractIn this paper we analyse the effects of digital elevation model (DEM) resolution on the results of a model that simulates spatially explicit relative shallow landslide hazard and soil redistribution patterns and quantities. We analyse distributions of slope, specific catchment area and relative hazard for shallow landsliding for four different DEM resolutions (grid sizes of 10, 25, 50 and 100 m) of a 12 km2 study area in northern New Zealand. The effect of DEM resolution is especially pronounced for the boundary conditions determining a valid hazard calculation. For coarse resolutions, the smoothing effect results in a larger area becoming classified as unconditionally stable or unstable. We apply simple empirical soil redistribution algorithms for scenarios in which all sites with a certain landslide hazard fail and generate debris flow. The lower initial number of failing cells but also the inclusion of slope (limit) in those algorithms becomes apparent with coarser resolutions. For finer resolutions, much larger amounts of soil redistribution are found, which is attributed to the more detailed landscape representation. Looking at spatial patterns of landslide erosion and sedimentation, the size of the area affected by these processes also increases with finer resolutions. In general, landslide erosion occupies larger parts of the area than deposition, although the total amounts of soil material eroded and deposited are the same. Analysis of feedback mechanisms between soil failures over time shows that finer resolutions show higher percentages of the area with an increased or decreased landslide hazard. When the extent of sites with lower and higher hazards are compared, finer grid sizes and higher landslide hazard threshold scenarios tend to increase the total extent of areas becoming more stable relative to the less stable ones. Extreme care should be taken when quantifying landslide basin sediment yield by applying simple soil redistribution formulas to DEMs with different resolutions. Rather, quantities should be interpreted as relative amounts. For studying shallow landsliding over a longer timeframe, the ‘perfect’ DEM resolution may not exist, because no resolution can possibly represent the dimensions of all different slope failures scattered in space and time. We assert that the choice of DEM resolution, possibly restricted by data availability in the first place, should always be adapted to the context of a particular type of analysis. Copyright © 2005 John Wiley & Sons, Ltd.
Cytogenetic alterations in nonmelanoma skin cancer: A review
Authors: Ashton Kevin J. , Carless Melanie A. , Griffiths Lyn R. 
Published: April 2005

AbstractSince the advent of cytogenetic analysis, knowledge about fundamental aspects of cancer biology has increased, allowing the processes of cancer development and progression to be more fully understood and appreciated. Classical cytogenetic analysis of solid tumors had been considered difficult, but new advances in culturing techniques and the addition of new cytogenetic technologies have enabled a more comprehensive analysis of chromosomal aberrations associated with solid tumors. Our purpose in this review is to discuss the cytogenetic findings on a number of nonmelanoma skin cancers, including squamous‐ and basal cell carcinomas, keratoacanthoma, squamous cell carcinoma in situ (Bowen's disease), and solar keratosis. Through classical cytogenetic techniques, as well as fluorescence‐based techniques such as fluorescence in situ hybridization and comparative genomic hybridization, numerous chromosomal alterations have been identified. These aberrations may aid in further defining the stages and classifications of nonmelanoma skin cancer and also may implicate chromosomal regions involved in progression and metastatic potential. This information, along with the development of newer technologies (including laser capture microdissection and comparative genomic hybridization arrays) that allow for more refined analysis, will continue to increase our knowledge about the role of chromosomal events at all stages of cancer development and progression and, more specifically, about how they are associated with nonmelanoma skin cancer. © 2005 Wiley‐Liss, Inc.
Detection of chromosomal imbalances in retinoblastoma by matrix‐based comparative genomic hybridization
Authors: Zielinski Boris , Gratias Sandrine , Toedt Grischa , Mendrzyk Frank , Stange Daniel E. , Radlwimmer Bernhard , Lohmann Dietmar R. , Lichter Peter 
Published: April 2005

AbstractThe genetic hallmark of retinoblastoma is mutation or deletion of the RB1 gene, whereas other genetic alterations that are also required are largely unknown. To screen for genomic imbalances on a genomewide level, we studied a series of 17 primary retinoblastomas by matrix‐based comparative genomic hybridization (matrix‐CGH). The matrix‐CGH chip contained 6,000 immobilized genomic DNA fragments covering the human genome, with an average resolution of about 500 kb. The most frequent imbalances detected were gains on chromosome arms 1q (12 of 17), 6p (10 of 17), 2p (5 of 17), and 19q (4 of 17) and loss on 16q (7 of 17). Candidate regions could be narrowed to small intervals by the identified minimally overlapping regions on 1q22, 1q32.1q32.2, 2p24.1, and 6p21.33–p21.31. Furthermore, two as‐yet‐unknown high‐level amplifications were detected, each in a single patient, on chromosome bands 1p34.2 and 1p33. Thus, this study identified new chromosomal regions and therefore potential candidate genes that may play a role in retinoblastoma. © 2005 Wiley‐Liss, Inc.
Intratumor versus intertumor heterogeneity in gene expression profiles of soft‐tissue sarcomas
Authors: Francis Princy , Fernebro Josefin , Edén Patrik , Laurell Anna , Rydholm Anders , Domanski Henryk A. , Breslin Thomas , Hegardt Cecilia , Borg Åke , Nilbert Mef 
Published: April 2005

AbstractSoft‐tissue sarcomas (STSs) constitute more than 30 histologic entities. In addition, within each entity, tumors are often heterogeneous in macroscopic features, genetic alterations, microscopic appearance, and clinical course. Therefore, there has been concern about whether a single tumor sample can provide a gene expression profile representative of the entire tumor. We used 27‐k cDNA microarray slides to assess the importance of intratumor versus intertumor heterogeneity of the gene expression profiles of 2 morphologically heterogeneous STSs. Multiple pieces of tumor (8 and 10 pieces) were obtained from a myxoid variant of malignant fibrous histiocytoma (MFH) and a leiomyosarcoma (LMS), respectively, and the expression patterns were compared with single tumor samples from 20 MFHs and 16 LMSs. Hierarchical clustering analysis of the expression profiles showed that samples from the same tumor clustered together. The average intratumor distance was considerably shorter than the average intertumor distance in both LMS and MFH. In addition, tumor subclusters that distinguished different macroscopic parts of the tumor could be discerned. We concluded that intratumor variability exists but that accurate gene expression profiling also could be obtained using single samples from a large STS. © 2005 Wiley‐Liss, Inc.
Association testing with Mendel
Authors: Lange Kenneth , Sinsheimer Janet S. , Sobel Eric 
Published: April 2005

AbstractThis report presents an overview of association testing strategies from a user's perspective, with particular attention to the capabilities of the computer program Mendel. Association testing is driven by the nature of the study sample, the nature of the disease trait, and the kind of markers employed. The practicing statistician must also choose whether to conduct parametric or nonparametric tests. Because of the complexities involved, Mendel offers users several analysis options. The different options are tied together by shared input and output conventions and a shared language for defining models. Mendel also features new statistics and theory found in no other genetics software. The most important innovations include: association testing by penetrance estimation, expansion of matched‐pair designs to permutation unit designs, and a rigorous implementation of the measured genotype approach for quantitative trait loci. This report explains how Mendel imputes allele counts and conducts both asymptotic and permutation tests in the measured genotype framework. Genet. Epidemiol. © 2005 Wiley‐Liss, Inc.
Auditing after SOX: Some tips from the front lines
Authors: Smith Gordon 
Published: April 2005

AbstractThe Sarbanes‐Oxley Act (SOX) was the big event of last year. Auditors were scrambling to meet the deadline. It was a monumental effort. But how can we turn SOX to our advantage? The author, an auditing consultant, gives us some tips from the front lines in the ongoing battle to comply with SOX. What key questions should we be asking ourselves? How can we change the SOX process—a necessary but expensive headache— into a valuable business resource? © 2005 Gordon Smith of Canaudit, Inc.
In vitro validation of phase‐contrast flow measurements at 3 T in comparison to 1.5 T: Precision, accuracy, and signal‐to‐noise ratios
Authors: Lotz Joachim , Döker Rolf , Noeske Ralph , Schüttert Meike , Felix Roland , Galanski Michael , Gutberlet Matthias , Meyer Gerd Peter 
Published: April 2005

AbstractPurposeTo evaluate the signal‐to‐noise ratio (SNR), precision, and accuracy of phase‐contrast flow measurements at 3 T with the help of an in vitro model and to compare the results with data from two 1.5‐T scanners.Materials and MethodsUsing an identical setup of a laminar flow model and sequence parameters, measurements were done at one 3‐T and at two 1.5‐T systems. Precision, accuracy, and SNR were obtained for velocity encodings ranging from 55 up to 550 cm−1. SNRs were calculated from the magnitude as well as the flow encoded images.ResultsPrecision and accuracy for the in vitro flow model were similarly high in all scanners with no significant difference. For velocity encodings from 55 cm−1 up to 550 cm−1, the SNR in magnitude as well as phase encoded images of the 3‐T measurements was approximately 2.5 times higher than the SNR obtained from the two 1.5‐T systems.ConclusionEven without optimization for the 3‐T environment, flow measurements show the same high accuracy and precision as is known from clinical 1.5‐T scanners. The superior SNR at 3 T will allow further improvements in temporal and spatial resolution. This will be of interest for small‐size vessels like coronary arteries or for slow diastolic flow patterns. J. Magn. Reson. Imaging 2005;21:604–610. © 2005 Wiley‐Liss, Inc.
Magnetic resonance imaging of the upper abdomen using a free‐breathing T2‐weighted turbo spin echo sequence with navigator triggered prospective acquisition correction
Authors: Klessen Christian , Asbach Patrick , Kroencke Thomas J. , Fischer Thomas , Warmuth Carsten , Stemmer Alto , Hamm Bernd , Taupitz Matthias 
Published: April 2005

AbstractPurposeTo evaluate a free‐breathing navigator triggered T2‐weighted turbo spin‐echo sequence with prospective acquisition correction (T2w‐PACE‐TSE) for MRI of the upper abdomen in comparison to a conventional T2‐weighted TSE (T2w‐CTSE), a single‐shot TSE (T2w‐HASTE), and a T1‐weighted gradient‐echo sequence (T1w‐FLASH).Materials and MethodsA total of 40 consecutive patients were examined at 1.5 T using free‐breathing T2w‐PACE‐TSE, free‐breathing T2w‐CTSE, and breath‐hold T2w‐HASTE and T1w‐FLASH acquisition. Images were evaluated qualitatively by three radiologists regarding motion artifacts, liver‐spleen contrast, depiction of intrahepatic vessels, the pancreas and the adrenal glands, and overall image quality on a four‐point scale. Quantitative analysis of the liver‐spleen contrast was performed.ResultsDepiction and sharpness of intrahepatic vessels were rated significantly better (P < 0.01) using T2w‐PACE‐TSE compared to T2w‐CTSE and T2w‐HASTE sequences. Significantly higher contrast values were measured for T2w‐PACE‐TSE images compared to T2w‐CTSE, T2w‐HASTE, and T1w‐FLASH images (P < 0.01). Mean examination time of the T2w‐PACE‐TSE was 7.91 minutes, acquisition time of the T2w‐CTSE sequence was 4.52 minutes.ConclusionProspective acquisition correction is an efficient method for reducing respiratory movement artifacts in T2w‐TSE imaging of the upper abdomen. Compared to T2w‐CTSE and T2w‐HASTE sequences recognition of anatomical details and contrast can be significantly improved. J. Magn. Reson. Imaging 2005;21:576–582. © 2005 Wiley‐Liss, Inc.
An MRI‐compatible semiautomated vacuum‐assisted breast biopsy system: Initial feasibility study
Authors: Daniel Bruce L. , Freeman Lynetta J. , Pyzoha Jessica M. , McCoy Terry D. , Birdwell Robyn L. , Bouley Donna M. , Movius Brennan , Hibner John A. 
Published: April 2005

AbstractPurposeTo develop an MR‐compatible vacuum‐assisted core needle breast biopsy system.Materials and MethodsA vacuum‐assisted breast biopsy system (Mammotome Hand Held; Ethicon Endo‐Surgery, USA) was modified for freehand MRI‐guided biopsy in an open, interventional 0.5‐T scanner (Signa SP; GE, USA). Probes (11 gauge [G]) were fabricated without significant susceptibility artifact. These mate with an electromechanical hand piece and control system that were modified for use within the MRI scanner. A total of 62 breast lesions were simulated in the mammary tissues of six recently lactating sows by injecting between 0.1 and 1.0 mL of an aqueous gel containing dilute gadopentetate dimeglumine (Gd‐DTPA) that formed a bright mass on T1‐weighted imaging.ResultsMechanical performance was satisfactory. Magnetic susceptibility and radiofrequency (RF) artifacts from the 11‐G probe were negligible. T1‐weighted fast spin echo (FSE) was used to guide biopsy. Up to eight samples were removed per lesion. Overall, 461 samples were obtained in 493 attempts (94%). Sample weights averaged 54 mg (N = 493) compared to 4.6 mg (N = 24) from 14‐G titanium MRI‐compatible needles. On average, 59% of the attempted samples yielded target lesion material.ConclusionPreliminary results demonstrate the feasibility of a vacuum‐assisted breast biopsy system in the MRI environment. Small 0.1‐mL lesions can be biopsied without needle artifacts obscuring the target. J. Magn. Reson. Imaging 2005;21:637–644. © 2005 Wiley‐Liss, Inc.
Whole‐body MR angiography using a novel 32‐receiving‐channel MR system with surface coil technology: First clinical experience
Authors: Fenchel Michael , Requardt Martin , Tomaschko Katrin , Kramer Ulrich , Stauder Norbert I. , Naegele Thomas , Schlemmer Heinz‐Peter , Claussen Claus D. , Miller Stephan 
Published: April 2005

AbstractPurposeTo demonstrate the feasibility of detecting atherosclerotic vascular disease using an innovative magnetic resonance angiography (MRA) protocol in combination with a dedicated whole‐body MR scanner with new surface coil technology.Materials and MethodsA total of 10 volunteers and eight patients with peripheral arterial occlusive disease (PAOD) were examined at 1.5 T. Conventional digital subtraction angiography (DSA) of the symptomatic region was available as a reference standard in all eight patients. Depending on subjects' size, four to five three‐dimensional data sets were acquired using an adapted injection protocol. Images were assessed independently by two readers for vascular pathology. Additionally, signal‐to‐noise ratios (SNRs) and contrast‐to‐noise ratios (CNRs) were measured.ResultsWhole‐body MRA yielded excellent sensitivity and specificity of more than 95% for both readers with high interobserver agreement (k = 0.93). Surface coil signal reception rendered a high SNR (mean 151.28 ± 54.04) and CNR (mean 120.75 ± 46.47). Despite lower SNR and CNR of the cranial and cervical vessels, a two‐step injection protocol exhibited less venous superposition and therefore proved to be superior compared to single‐bolus injection.ConclusionOur approach provides accurate noninvasive high‐resolution imaging of systemic atherosclerotic disease, covering the arterial vasculature from intracranial arteries to distal runoff vessels. The recently introduced MR scanner and coil technology is feasible to significantly increase the performance of whole‐body MRA. J. Magn. Reson. Imaging 2005;21:596–603. © 2005 Wiley‐Liss, Inc.
Comparison of qualitative and quantitative measurements on unenhanced T1‐weighted fat saturation MR images in predicting pancreatic pathology
Authors: Gallix Benoît P. , Bret Patrice M. , Atri Mostafa , Lecesne Robin , Reinhold Caroline 
Published: April 2005

AbstractPurposeTo evaluate the accuracy of signal intensity (SI) analysis on unenhanced fat‐suppressed T1‐weighted MR images in the diagnosis of pancreatic disease and to compare subjective interpretation with different quantitative measurements.Materials and MethodsThe pancreas was evaluated in 159 patients (86 normal and 73 with pancreatic disease) with spoiled gradient echo (GRE) T1‐weighted fat saturation MR images. The relative SI of the pancreas to liver and spleen was quantitatively measured using regions of interest (ROIs) and qualitatively assessed by two independent observers.ResultsThe mean values between a normal and an abnormal pancreas with pancreas–liver ratios of 0.14 ± 0.37 vs. –0.32 ± 0.24, respectively, and pancreas–spleen ratios of 0.89 ± 0.55 vs. 0.02 ± 0.43, respectively, were significantly different (P < 0.001). The pancreas–liver SI ratio was significantly better than the pancreas–spleen ratio throughout the disease group (area under the receiver operating characteristic (ROC) curve ± SD; 0.92 ± 0.02 for pancreas–liver vs. 0.86 ± 0.03 for pancreas–spleen, P < 0.01), and after excluding cases of acute pancreatitis (0.96 ± 0.02 for pancreas–liver vs. 0.89 ± 0.03 for pancreas–spleen, P < 0.01). There was no statistically significant difference between quantitative and qualitative analysis (area under the ROC curve ± SD; 0.93 ± 0.02 vs. 0.93 ± 0.02 for the entire disease group; excluding acute pancreatitis 0.96 ± 0.02 vs 0.97 ± 0.02) for the diagnosis of pancreatic disease when using liver as internal standard. The interobserver concordance was very good (kappa > 0.71). The sensitivity of visual liver comparison was 80% in the entire disease group and 91% after the cases of acute pancreatitis were excluded, while specificity was 93%.ConclusionThe pancreas–liver ratio is the best quantitative means of distinguishing normal from abnormal pancreas. Visual observation by experienced observers (qualitative measurement) was just as accurate as quantitative measurement. Detection of pancreatic pathology can be made with high accuracy by visually comparing the SI of the pancreas with that of the normal liver. J. Magn. Reson. Imaging 2005;21:583–589. © 2005 Wiley‐Liss, Inc.