bluuebunny/crossref_metadata_2025_split huggingface dataset:
Using on‐nadir spectral reflectance to detect soil surface changes induced by simulated rainfall and wind tunnel abrasion
Authors: Chappell Adrian , Zobeck Ted M. , Brunner Gillian 
Published: April 2005

AbstractThe surface susceptibility to erosion (erodibility) is an important component of soil erosion models. Many studies of wind erosion have shown that even relatively small changes in surface conditions can have a considerable effect on the temporal and spatial variability of dust emissions. One of the main difficulties in measuring erodibility is that it is controlled by a number of highly variable soil factors. Collection of these data is often limited in scale because in situ measurements are labour‐intensive and very time‐consuming. To improve wind erosion model predictions over several spatial and temporal scales simultaneously, there is a requirement for a non‐invasive approach that can be used to rapidly assess changes in the compositional and structural nature of a soil surface in time and space. Spectral reflectance of the soil surface appears to meet these desirable requirements and it is controlled by properties that affect the soil erodibility.Three soil surfaces were modified using rainfall simulation and wind tunnel abrasion experiments. Observations of those changes were made and recorded using digital images and on‐nadir spectral reflectance. The results showed clear evidence of the information content in the spectral domain that was otherwise difficult to interpret given the complicated interrelationships between soil composition and structure. Changes detected at the soil surface included the presence of a crust produced by rainsplash, the production of loose erodible material covering a rain crust and the selective erosion of the soil surface. The effect of rainsplash and aeolian abrasion was different for each soil tested and crust abrasion was shown to decrease as rainfall intensity increased. The relative contributions of the eroded material from each soil surface to trapped mixtures of material assisted the erodibility assessment. Ordination analyses within each of two important soil types explained significant amounts of the variation in the reflectance of all wavebands by treatments of the soil and hence changes in the soil surface. The results show that soil surface conditions within a soil type are an underestimated source of variation in the characterization of soil surface erodibility and in the remote sensing of soil. Copyright © 2005 John Wiley & Sons, Ltd.
Identification of androgen‐responsive genes that are alternatively regulated in androgen‐dependent and androgen‐independent rat prostate tumors
Authors: Pfundt Rolph , Smit Frank , Jansen Corine , Aalders Tilly , Straatman Huub , van der Vliet Walter , Isaacs John , van Kessel Ad Geurts , Schalken Jack 
Published: April 2005

AbstractThe vast majority of androgen‐dependent prostate tumors progress toward incurable, androgen‐independent tumors. The identification of androgen‐responsive genes, which are still actively transcribed in the tumors of patients who have undergone androgen ablation, may shed light on the molecular mechanisms underlying this phenomenon. To address this question, we chose the Dunning R3327 rat model system, in which the progression from androgen‐dependent to ‐independent tumors is represented by several transplantable prostate‐derived tumors. Gene expression profiles were analyzed in normal rat prostates and in the prostates of rats 14 days after castration by use of microarrays containing approximately 5,000 oligonucleotides, together representing more than 4,800 known rat genes. These expression profiles were compared with similarly obtained expression profiles of androgen‐dependent and androgen‐independent rat prostate tumors. By doing so, a series of known and novel prostate cancer–associated androgen‐responsive genes was identified. Within this series, we were able to identify several clusters of genes that are differentially regulated in the various prostate tumors. These genes may serve as (i) novel prognostic identifiers and (ii) novel therapeutic targets. © 2005 Wiley‐Liss, Inc.
Functional evidence of decreased tumorigenicity associated with monochromosome transfer of chromosome 14 in esophageal cancer and the mapping of tumor‐suppressive regions to 14q32
Authors: Ko Josephine Mun Yee , Yau Wing Lung , Chan Pui Ling , Lung Hong Lok , Yang Lichun , Lo Paulisally H. Y. , Tang Johnny C. O. , Srivastava Gopesh , Stanbridge Eric J. , Lung Maria Li 
Published: April 2005

AbstractDespite the abundant evidence of high allelic loss of chromosome arm 14q in human cancers, tumor‐suppressor genes mapped to this chromosome have yet to be identified. To narrow the search for candidate genes, we performed monochromosome transfer of chromosome 14 into an esophageal carcinoma cell line, SLMT‐1 S1. Statistically significant suppression of the tumorigenic potential of microcell hybrids containing the transferred chromosome 14 provided functional evidence that tumor‐suppressive regions of chromosome 14 are essential for esophageal cancer. Tumor segregants emerging in nude mice during the tumorigenicity assay were analyzed by detailed PCR‐microsatellite typing to identify critical nonrandomly eliminated regions (CRs). A 680‐kb CR mapped to 14q32.13 and an ∼2.2‐Mb CR mapped to 14q32.33 were delineated. Dual‐color BAC FISH analysis of microcell hybrids and tumor segregants verified the selective loss of the 14q32.13 region. In contrast, similar transfers of an intact chromosome 11 into SLMT‐1 S1 did not significantly suppress tumor formation. These functional complementation studies showing the correlation of tumorigenic potential with critical regions of chromosome 14 validated the importance of the 14q32 region in tumor suppression in esophageal cancer. The present study also paved the path for further identification of novel tumor‐suppressor genes that are relevant to the molecular pathogenesis of esophageal cancer. © 2005 Wiley‐Liss, Inc.
Cultures of rat astrocytes challenged with a steady supply of glutamate: New model to study flux distribution in the glutamate–glutamine cycle
Authors: Fonseca Luís L. , Monteiro Miguel A.R. , Alves Paula M. , Carrondo Manuel J.T. , Santos Helena 
Published: April 2005

AbstractGlutamate metabolism in astrocytes was studied using an experimental setup that simulates the role of neurons (glutamate producers and glutamine consumers) by the addition of glutaminase to the culture medium. Thereby, a steady supply of glutamate was imposed at the expense of glutamine, and the stress intensity was manipulated by changing the glutaminase concentration. Glutamate supply rates in the range 8–23 nmol/min/mg protein were examined for periods of up to 48 h. When the glutamate supply rate exceeded the uptake rate of this amino acid, a transient increase in the extracellular concentration of glutamate was observed. In response to this stress, the fluxes through the glutamate transporter and glutamine synthetase were increased considerably, and the extracellular concentration of glutamate was eventually restored to a low level. The increased levels of glutamine synthetase were demonstrated by immunoblotting analysis. The effect on glutamate metabolism of the transaminase inhibitor, aminooxyacetic acid (AOAA), and of NH4Cl was also investigated. The supply of glutamate caused a concomitant reduction in the levels of phosphocreatine, phosphoethanolamine, and phosphocholine without affecting the ATP pool. Glutamine synthetase was shown to be is a key element in the control of glutamate metabolism in astrocytic cultures. The metabolic fate of glutamate depends greatly on the time of endurance to the challenge: in naive cells, glutamate was primarily metabolized through the transaminase pathway, while in well‐adapted cells glutamate was converted almost exclusively through glutamine synthetase. © 2005 Wiley‐Liss, Inc.
Optic radiation changes after optic neuritis detected by tractography‐based group mapping
Authors: Ciccarelli Olga , Toosy Ahmed T. , Hickman Simon J. , Parker Geoff J.M. , Wheeler‐Kingshott Claudia A.M. , Miller David H. , Thompson Alan J. 
Published: April 2005

AbstractPostmortem data suggest that trans‐synaptic degeneration occurs in the lateral geniculate nucleus after optic nerve injury. This study investigated in vivo the optic radiations in patients affected by optic neuritis using fast marching tractography (FMT), a diffusion magnetic resonance imaging (MRI) fiber tracking method, and group mapping techniques, which allow statistical comparisons between subjects. Seven patients, 1 year after isolated unilateral optic neuritis, and ten age and gender‐matched controls underwent whole‐brain diffusion tensor MR imaging. The FMT algorithm was used to generate voxel‐scale connectivity (VSC) maps in the optic radiations in each subject in native space. Group maps of the left and right optic radiations were created in the patient and control group in a standardized reference frame using statistical parametric mapping (SPM99). The reconstructed optic radiations in the patient group were localized more laterally in the posterior part of the tracts and more inferiorly than in the control group. Patients showed reduced VSC values in both tracts compared with controls. These findings suggest that the group mapping techniques might be used to assess changes in the optic radiations in patients after an episode of optic neuritis. The changes we have observed may be secondary to the optic nerve damage. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Using automated morphometry to detect associations between ERP latency and structural brain MRI in normal adults
Authors: Cardenas Valerie A. , Chao Linda L. , Blumenfeld Rob , Song Enmin , Meyerhoff Dieter J. , Weiner Michael W. , Studholme Colin 
Published: April 2005

AbstractDespite the clinical significance of event‐related potential (ERP) latency abnormalities, little attention has focused on the anatomic substrate of latency variability. Volume conduction models do not identify the anatomy responsible for delayed neural transmission between neural sources. To explore the anatomic substrate of ERP latency variability in normal adults using automated measures derived from magnetic resonance imaging (MRI), ERPs were recorded in the visual three‐stimulus oddball task in 59 healthy participants. Latencies of the P3a and P3b components were measured at the vertex. Measures of local anatomic size in the brain were estimated from structural MRI, using tissue segmentation and deformation morphometry. A general linear model was fitted relating latency to measures of local anatomic size, covarying for intracranial vault volume. Longer P3b latencies were related to contractions in thalamus extending superiorly into the corpus callosum, white matter (WM) anterior to the central sulcus on the left and right, left temporal WM, the right anterior limb of the internal capsule extending into the lenticular nucleus, and larger cerebrospinal fluid volumes. There was no evidence for a relationship between gray matter (GM) volumes and P3b latency. Longer P3a latencies were related to contractions in left temporal WM, and left parietal GM and WM near the interhemispheric fissure. P3b latency variability is related chiefly to WM, thalamus, and lenticular nucleus, whereas P3a latency variability is not related as strongly to anatomy. These results imply that the WM connectivity between generators influences P3b latency more than the generators themselves do. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Anterior cingulate cortex: An fMRI analysis of conflict specificity and functional differentiation
Authors: Milham Michael P. , Banich Marie T. 
Published: April 2005

AbstractIn this event‐related functional magnetic resonance imaging (fMRI) study, we provide evidence that the role of the anterior cingulate cortex (ACC) in cognitive control may not be unitary, as the responses of different ACC subregions vary depending upon the nature of task‐irrelevant information. More specifically, using the color‐word Stroop task (congruent, incongruent, and neutral trial types), we examined the degree to which increases in neural activity within ACC are specific to conditions of conflict, as posited by the conflict monitoring theory (Botvinick et al. [1999]: Rev Neurosci 10:49–57; Carter et al. [1998]: Science 280:747–749). Although incongruent and congruent trials both involve two competing sources of color information (color word and ink color), only incongruent trials involve a direct conflict between task‐relevant and task‐irrelevant information. Although the anterior division of the ACC rostral zone exhibited conflict specific increases in neural activity (i.e., incongruent > congruent = neutral), the posterior division exhibited a more generalized pattern, increasing whenever the task‐irrelevant information was color related, regardless of whether it was conflicting (i.e., incongruent and congruent > neutral). Our data thus suggest a possible functional differentiation within the ACC. As such, it is unlikely that the role of the ACC in cognitive control will be able to be accommodated by a single unifying theory. Hum Brain Mapp, 2005. © 2005 Wiley‐Liss, Inc.
Rheological and recovery properties of poly(ethylene glycol) diacrylate hydrogels and human adipose tissue
Authors: Patel Parul Natvar , Smith Connie Kathleen , Patrick Charles W. 
Published: April 2005

AbstractThe viscosity and elastic and viscous moduli of poly(ethylene glycol) diacrylate (PEGDA) hydrogels and human abdominal adipose tissue are measured as a function of shear rate and frequency. Results indicate that both materials exhibit shear thinning and are viscoelastic in nature. Rheological tests suggest that the hydrogels become firmer as strain and frequency increase. Adipose tissue, however, begins to fail at higher strains and frequencies. This behavior is confirmed by measuring the complex modulus of both materials as a function of strain. Recovery properties are also measured for each material as a function of deformation. Although PEGDA hydrogels are able to recover up to 78% of their original height after 15% deformation, adipose tissue is not able to recover over the range of deformations tested. The frequencies and strains over which the tests are conducted are those physiologically experienced by the human body. The hydrogels are able to withstand this range of forces and, hence, are appropriate for use as a soft tissue filler material. In addition, the hydrogels swell 38.1% ± 0.9% independent of surface area. The complex modulus of hydrogels of varying polymer concentrations is also measured as a function of strain to determine the effects of changing polymer content. These results indicate that as polymer content increases, the hydrogels become firmer due to the higher number of polymer chains and behave more elastically. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 313–319, 2005
Effects of bone morphogenetic protein‐2 and hyaluronic acid on the osseointegration of hydroxyapatite‐coated implants: An experimental study in sheep
Authors: Aebli Nikolaus , Stich Hermann , Schawalder Peter , Theis Jean‐Claude , Krebs Jörg 
Published: April 2005

AbstractResearch efforts aim at enhancing early osseointegration of cementless implants to improve early fixation and, thus, reduce the risk of loosening. The aim of the present study was to investigate whether bone morphogenetic protein (BMP) 2 had a positive effect on the osseointegration of hydroxyapatite‐coated implants. Hydroxyapatite (HA) implants (perforated hollow cylinders and solid rods) were coated with BMP‐2 and hyaluronic acid (HY) as the carrier or with HY alone. Uncoated HA implants served as controls. The osseointegration of the implants was evaluated either by light microscopy or by pullout tests after 1, 2, and 4 weeks of unloaded implantation in the cancellous bone of 24 sheep. The BMP‐2 coating significantly increased bone growth into the implant perforations compared with HA‐coated implants at 2 and 4 weeks. Bone‐implant contact and interface shear strength of BMP‐2 implants were lower than HA implants at 2 weeks. At 4 weeks, there was no significant difference in bone‐implant contact and shear strength between BMP‐2 and HA‐coated implants. The BMP‐2 coating enhanced gap healing but had no positive or even an inhibitory effect (at 2 weeks) on bone‐implant contact and interface shear strength. In the clinical situation, a perfect press‐fit implantation cannot be achieved, and BMP‐2 may be beneficial for enhancing bone growth into gaps around cementless implants. © 2005 Wiley Periodicals, Inc. J Biomed Mater Res 73A: 295–302, 2005
3D‐Epitope‐Explorer (3DEX): Localization of conformational epitopes within three‐dimensional structures of proteins
Authors: Schreiber Andreas , Humbert Michael , Benz Alexander , Dietrich Ursula 
Published: April 2005

AbstractNeutralizing antibodies often recognize conformational, discontinuous epitopes. Linear peptides mimicking such conformational epitopes can be selected from phage display peptide libraries by screening with the respective antibodies. However, it is difficult to localize these “mimotopes” within the three‐dimensional (3D) structures of the target proteins. Knowledge of conformational epitopes of neutralizing antibodies would help to design antigens able to elicit protective immune responses. Therefore, we provide here a software that allows to localize linear peptide sequences within 3D structures of proteins. The 3D‐Epitope‐Explorer (3DEX) software allows to map conformational epitopes in 3D protein structures based on an algorithm that takes into account the physicochemical neighborhood of Cα‐ or Cβ‐atoms of individual amino acids. A given amino acid of a peptide sequence is localized within the protein and the software searches within predefined distances for the amino acids neighboring that amino acid in the peptide. Surface exposure of the amino acids can also be taken into consideration. The procedure is then repeated for the remaining amino acids of the peptide. The introduction of a joker function allows to map peptide mimotopes, which do not necessarily have 100% sequence homology to the protein. Using this software we were able to localize mimotopes selected from phage displayed peptide libraries with polyclonal antibodies from HIV‐positive patient plasma within the 3D structure of gp120, the exterior glycoprotein of HIV‐1. We also analyzed two recently published peptide sequences corresponding to known conformational epitopes to further confirm the integrity of 3DEX. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 879–887, 2005
Quantum chemical modeling of CO oxidation by the active site of molybdenum CO dehydrogenase
Authors: Siegbahn Per E. M. , Shestakov Alexander F. 
Published: April 2005

AbstractThe catalytic mechanism of molybdenum containing CO dehydrogenase has been studied using hybrid DFT methods with quite large chemical models. The recent high‐resolution X‐ray structure, showing the surprising presence of copper linked to molybdenum, was used as a starting point. A pathway was initially found with a low barrier for CO bond formation and CO2 release. However, this pathway did not include the formation of any SCO2 species, which had been suggested by experiments with an n‐butylisocyanide inhibitor. When these SCO2 structures were studied they were found to lead to deep minima, making CO2 release much more difficult. A large effort was spent, including investigations of other spin states, varying the number of protons and electrons, adding water, etc., until a plausible pathway for SC bond cleavage was found. In this pathway a water molecule is inserted in between molybdenum and the SCO2 group. Full catalytic cycles, including electron and proton transfers, are constructed both with and without SC bond formation. When these pathways are extended to two full catalytic cycles it can be understood why the formation of the SC bond actually makes catalysis faster, even though the individual step of CO2 release becomes much more difficult. These results agree well with experimental findings. © 2005 Wiley Periodicals, Inc. J Comput Chem 26: 888–898, 2005
MR findings in a rare case of sclerosing mesenteritis of the mesocolon
Authors: Ghanem Nadir , Pache Gregor , Bley Thorsten , Kotter Elmar , Langer Mathias 
Published: April 2005

AbstractSclerosing mesenteritis is a rare, usually benign disorder of the mesentery. Depending on the predominant tissue component (inflammation, fat, or fibrosis), it is known as mesenteric panniculitis or retractile mesenteritis. We present a rare case of retractile mesenteritis of the mesocolon as a cause of severe abdominal pain. US, CT, and MRI were the imaging modalities used. We emphasize the MR finding of a fibrous capsula in retractile mesenteritis, as this is to our knowledge the first study to describe this entity. This finding may be valuable for establishing a diagnosis of sclerosing mesenteritis, as well as for differentiating this disease from other mesenteric diseases. J. Magn. Reson. Imaging 2005;21:632–636. © 2005 Wiley‐Liss, Inc.
Normal white matter development from infancy to adulthood: Comparing diffusion tensor and high b value diffusion weighted MR images
Authors: Bashat Dafna Ben , Sira Liat Ben , Graif Moshe , Pianka Pazit , Hendler Talma , Cohen Yoram , Assaf Yaniv 
Published: April 2005

AbstractPurposeTo evaluate the sensitivity of high b value diffusion weight magnetic resonance imaging (DWI) in detecting normal white matter maturation, compare it to conventional diffusion tensor imaging (DTI), and to obtain normative quantitative data using this method.Materials and MethodsHigh b value DWI (bmax= 6000 sec/mm2) using q‐space analysis and conventional DTI (b = 1000 sec/mm2) were performed on 36 healthy subjects aged 4 months to 23 years. Fractional‐anisotropy (FA), apparent‐displacement, and apparent‐probability values were measured in all slices and in six regions of interest (ROIs) of large fiber tracks. Values were correlated with each other and with age using regression analysis.ResultsFA, displacement, and probability indices from all slices were highly correlated with each other (r > 0.87,P< 0.0001) and with age (r > 0.82,P< 0.0001). All age‐related changes in the six pre‐determined ROIs were best fitted by mono‐exponential functions. Changes in the splenium extended to a later age when compared with the genu of the corpus‐callosum, while the centrum semi‐ovale demonstrated the latest changes with age.ConclusionsHigh b‐value DWI and DTI showed changes in white matter from infancy through adulthood. However, high b‐value detects a signal that is likely to originate mainly from the intra‐axonal water population, and thus may represent different aspects of development and different sensitivity to pathology. J. Magn. Reson. Imaging 2005;21:503–511. © 2005 Wiley‐Liss, Inc.