bluuebunny/crossref_metadata_2025_split huggingface dataset:
Embryonic versus blastogenetic development in the compound ascidian Botryllus schlosseri: Insights from Pitx expression patterns
Authors: Tiozzo Stefano , Christiaen Lionel , Deyts Carole , Manni Lucia , Joly Jean‐Stéphane , Burighel Paolo 
Published: December 2004

AbstractThe colonial ascidians reproduce either sexually or asexually, having evolved a rich variety of modes of propagative development. During embryogenesis, the fertilized egg develops into a swimming tadpole larva that subsequently metamorphoses into a sessile oozooid. Clonal individuals (blastozooids), resembling oozooids, are formed from few bud‐forming multipotent somatic cells, following a wide range of ways that seem to characterize each family of this class. Here, we compare these two developmental processes in the compound ascidian species Botryllus schlosseri to determine whether similar gene activities are used during embryogenesis/metamorphosis and recruited in the asexual development. We analyzed expression of Pitx, a Paired‐related homeobox gene. Pitx genes are key developmental genes in vertebrates, and their expression is reported to be conserved in chordate stomodea and in the establishment of left/right asymmetries. Here, we report full‐length cDNA cloning of a B. schlosseri Pitx ortholog (Bs‐Pitx) and expression analysis during both embryo/metamorphosis and blastogenesis. During organogenesis of both developmental sequences, Bs‐Pitx was detected in identical domains: the stomodeum/neural complex and asymmetrically in the left digestive system. In striking contrast, expression patterns at early stages differ deeply. These observations provide the first evidence for a key developmental gene being deployed in essentially similar ways in two different developmental sequences that eventually give rise to similar zooids. Developmental Dynamics 232:468–478, 2005. © 2004 Wiley‐Liss, Inc.
Executive functions in children with dyslexia
Authors: Reiter Astrid , Tucha Oliver , Lange Klaus W. 
Published: December 2004

AbstractThere is little data available concerning the executive functions of children with dyslexia. The small number of existing studies in this field focus on single aspects of these functions such as working memory. The aim of the present study was therefore to assess a variety of aspects of executive functioning in children with dyslexia. Forty‐two children with dyslexia and 42 non‐dyslexic children were examined using a neuropsychological test battery. The test battery consisted of standardised tests examining the assessment of working memory, concept formation, inhibition, flexibility, problem solving and fluency functions. Comparison between the test performance of non‐dyslexic children and children with dyslexia revealed obvious difficulties of children with dyslexia in tests measuring working memory. Inhibition of inappropriate reactions was impaired in children with dyslexia in more demanding tests, but not in simple ones. Furthermore, children with dyslexia displayed impairments of both verbal and figural fluency functions. While in comparison to non‐dyslexic children no disturbances of concept formation were observed, problem solving seemed to be partially impaired. The present findings suggest that children with dyslexia demonstrate impairments in a variety of executive functions. This should be considered in the development of new concepts in the treatment of dyslexia. Copyright © 2004 John Wiley & Sons, Ltd.
Late Quaternary landscape history and geoarchaeology of two drainages on Black Mesa, northeastern Arizona, USA
Authors: Karlstrom Eric T. 
Published: December 2004

AbstractTwo approximately 5‐ to 6‐km drainage segments on Black Mesa preserve unusually complete sequences of late Quaternary alluvium and soils. Radiocarbon‐ and tree‐ring‐dated alluvial and soil stratigraphy suggests entrenched paleoarroyos were beginning to aggrade at about >24,260, 11,070, 9660, 8800, 7060, 3500, 2140, and 1870 14C yr B.P. Using the quantity of sediment removal from post‐A.D. 1900 arroyos as analogue, at least 77–200% of total valley alluvium has been removed and replaced by younger sediments during an estimated 11 late Pleistocene and Holocene erosion epicycles. Given that most (59%) of the 150 recorded prehistoric sites in the two study areas occur on valley floors where only about 3% of surface alluvium predates Lolomai phase Basketmaker II occupation (˜1900–1600 yr B.P.), it may be inferred that pre‐Lolomai phase Basketmaker II sites which may have been located along washes have been removed or buried by fluvial erosion. Identification of five buried hearths in alluvial sections, including White Dog and Lolomai phase Basketmaker II sites (dating about 3500 and 1870 14C yr B.P., respectively) and one possible Early Archaic site, supports this conclusion. © 2005 Wiley Periodicals, Inc.
Using sulfur isotopes to determine the sources of vermillion in ancient burial mounds in Japan
Authors: Minami Takeshi , Imai Akira , Bunno Michiaki , Kawakami Kunihiko , Imazu Setsuo 
Published: December 2004

AbstractThis study represents an attempt to determine the sources of vermillion found in ancient Japanese burial mounds of the 1st–6th centuries A.D., by comparing their ratios of sulfur isotopes with those of cinnabar ore samples collected in Japan and China. Cinnabar ore samples were taken from three mines in central Japan (Niu in Mie, Yamato in Nara, and Sui in Tokushima prefectures), and from Wanshan in China, where mining activity has been recorded back to the 6th century A.D. and earlier. When the ratios of a 34S and 32S were compared with the Canyon Diablo meteorite standard, a high δ34S value of +22.6 ± 3.6‰ was found for the Wanshan mine, as opposed to low values ranging from −7.3 ± 1.9 to −2.1 ± 1.6‰ for the Japanese mines. The ratios of sulfur isotopes in vermillion collected from ancient Japanese burial mounds also divided into two groups. High ratios (+11.1 to +22.8‰) were found in 1st‐ and 2nd‐ century burials in the western regions of northern Kyushu and San'in, suggesting that local, powerful chiefs obtained vermillion through relations with China. Lower ratios (−8.4 to −2.0‰) were found in burials of the 2nd through 6th centuries in central Japan, where the ancient Yamato dynasty emerged as the first unified polity around the end of the 2nd century A.D. We, therefore, conclude that the Yamato dynasty exploited local sources of vermillion, rather than depending solely on China. The present study demonstrates the feasibility of determining sources of vermillion using sulfur isotope ratios, and the relevance of such findings for archaeological research. © 2005 Wiley Periodicals, Inc.
Effect of maternal age on uterine flow impedance
Authors: Pirhonen Jouko , Bergersen Tone Kristin , Abdlenoor Michael , Dubiel Marius , Gudmundsson Saemundur 
Published: December 2004

AbstractPurposeThis study was conducted to determine possible maternal age‐related changes in uterine artery impedance in normal late pregnancy.Patients and MethodsIn a cross‐sectional design study, Doppler velocimetry of the uterine vessels was performed in 884 pregnant women with normal, late, singleton pregnancies. We hypothesized that maternal age is associated with changes in uterine blood flow Doppler parameters. We tested for univariate associations and for an adjusted relationship between these factors using a multivariate model to control for confounders.ResultsWe found a statistically significant, nonlinear relationship between mean uterine artery impedance (pulsatility index) and maternal age, with an increase of the pulsatility index in women above the age of 35. This association continued to be significant even when adjusted for gestational age and parity as confounders.ConclusionsIn normal pregnancy, an increase in uterine artery impedance was noted in women above the age of 35. This finding may be related to the physiologic process of aging and may partly explain why pregnancies in older women are associated with diverse complications more often than those in younger women. © 2004 Wiley Periodicals, Inc. J Clin Ultrasound 33:14–17, 2005
Expression and possible function of fibroblast growth factor 9 (FGF9) and its cognate receptors FGFR2 and FGFR3 in postnatal and adult retina
Authors: Cinaroglu Ayca , Ozmen Yesim , Ozdemir Anil , Ozcan Ferruh , Ergorul Ceren , Cayirlioglu Pelin , Hicks David , Bugra Kuyas 
Published: December 2004

AbstractFibroblast growth factors (FGFs) are important regulators of retinal development and survival. We examined the expression and distribution of FGF9 and its preferred receptors FGFR2IIIc and FGFR3IIIc in this tissue. FGF9 transcripts in whole rat retina were detected by RT‐PCR but were not present in purified cultured Müller glia. Transcripts appeared as 3.2‐kb and 4.0‐kb bands on Northern blots, and Western blotting of whole retina revealed FGF9‐immunoreactive bands at 30 and 55 kDa. FGF9 mRNA demonstrated a biphasic expression profile, elevated at birth and adulthood, but relatively decreased during terminal retinal differentiation (4–14 days postnatal). Antibody labeling broadly reflected these findings: staining in vivo was observed mainly in the inner retina (and outer plexiform layer in adults) whereas FGF9 was not detectable in cultured Müller glia. In adults, FGF9 in situ hybridization also showed a detectable signal in inner retina. FGFR2IIIc and FGFR3IIIc were detected by RT‐PCR, and Western blotting showed both FGFRs existed as multiple forms between ∼100–200 kDa. FGFR2 and FGFR3 antibodies showed prominent labeling in the inner retina, especially in proliferating cultured Müller glia. Exogenous FGF9 elicited a dose‐dependent increase in Müller glial proliferation in vitro. These data suggest a role for FGF9 in retinal differentiation and maturation, possibly representing a neuronally derived factor acting upon glial (and other) cells. © 2004 Wiley‐Liss, Inc.
Morale victories: How leaders can build positive energy
Authors: Klann Gene 
Published: December 2004

AbstractIt's not difficult to recognize an organization or team that has strong morale, pride, and spirit as opposed to one that does not. In the former, productivity and creativity are high and relationships are strong; in the latter, negativism, dissatisfaction, and friction reign. Here's a look at some steps leaders can take to enhance the characteristics that make for a prolific, efficient, cooperative, and loyal team.
Assessment and correction of B1‐induced errors in magnetization transfer ratio measurements
Authors: Ropele Stefan , Filippi Massimo , Valsasina Paola , Korteweg Tijmen , Barkhof Frederik , Tofts Paul S. , Samson Rebecca , Miller David H. , Fazekas Franz 
Published: December 2004

AbstractThe magnetization transfer ratio (MTR) is strongly related to the field strength (B1) of the saturation pulse. B1 variations therefore can result in significant MTR variations and can affect histogram analysis, particularly if data from a large volume of interest are included. A multicenter study was performed to determine the typical range of B1 errors and the corresponding MTR variations in brain tissue of healthy volunteers. Seven subjects were included at each center resulting in a total cohort of 28 subjects. Additionally, numerical simulations were done to study this relationship more generally for pulsed saturation. It could be demonstrated, both theoretically and empirically, that for typical B1 errors there is a linear relationship between B1 error and the corresponding MTR change. In addition, for proton density‐weighted sequences, this relationship seems to be largely independent of the underlying relaxation properties.Mean B1 errors in the entire brain were typically in the range between ‐3% and ‐7%. Due to different coil characteristics, significant MTR differences between different scanners and sites were observed. Using a simple correction scheme that is based on a linear regression analysis between MTR and B1 data it was possible to reduce the intersubject variation by ∼50%. Furthermore, interscanner variation could be reduced such that no significant differences between scanners could be detected. The correction scheme may be useful when investigating MTR as an outcome measure in single or multicenter studies. Magn Reson Med 53:134–140, 2005. © 2004 Wiley‐Liss, Inc.
Interactions between hemodynamic responses to scanner acoustic noise and auditory stimuli in functional magnetic resonance imaging
Authors: Langers Dave R. M. , Van Dijk Pim , Backes Walter H. 
Published: December 2004

AbstractIn functional MRI experiments on the central auditory system, activation caused by acoustic scanner noise is a dominating factor that partially masks the hemodynamic response signals to sound stimuli of interest. In this study, the nonlinear interaction between auditory responses to single scans and those to tone stimuli was investigated. By using irregular acquisition repetition times and quasi‐random stimulus timings, the brain responses to pure tone stimuli were analyzed, as well as their interaction with scanner noise. The tone frequencies were chosen to match either the fundamental frequency of the scanner noise (730 Hz) or a region with little spectral power (4.70 kHz). The hemodynamic responses could be characterized by amplitudes of 1.3% and a time‐to‐peak of 4.0–4.5 sec in the absence of scanner noise. Interaction effects due to a single previous scan typically decreased the response magnitudes to 0.9%. The functional shape of the interaction was analyzed and could be described by a highly separable, dominantly symmetric interaction function that fairly agreed with a low‐order Volterra expansion of a simple nonlinear model. Interactions were stronger and more complex in shape when the spectral content of the tone stimulus and the scanner noise were more similar. Magn Reson Med 53:49–60, 2005. © 2004 Wiley‐Liss, Inc.
Visualization of tensor fields using superquadric glyphs
Authors: Ennis Daniel B. , Kindlman Gordon , Rodriguez Ignacio , Helm Patrick A. , McVeigh Elliot R. 
Published: December 2004

AbstractThe spatially varying tensor fields that arise in magnetic resonance imaging are difficult to visualize due to the multivariate nature of the data. To improve the understanding of myocardial structure and function a family of objects called glyphs, derived from superquadric parametric functions, are used to create informative and intuitive visualizations of the tensor fields. The superquadric glyphs are used to visualize both diffusion and strain tensors obtained in canine myocardium. The eigensystem of each tensor defines the glyph shape and orientation. Superquadric functions provide a continuum of shapes across four distinct eigensystems (λi, sorted eigenvalues), λ1 = λ2 = λ3 (spherical), λ1 < λ2 = λ3 (oblate), λ1 > λ2 = λ3 (prolate), and λ1 > λ2 > λ3 (cuboid). The superquadric glyphs are especially useful for identifying regions of anisotropic structure and function. Diffusion tensor renderings exhibit fiber angle trends and orthotropy (three distinct eigenvalues). Visualization of strain tensors with superquadric glyphs compactly exhibits radial thickening gradients, circumferential and longitudinal shortening, and torsion combined. The orthotropic nature of many biologic tissues and their DTMRI and strain data require visualization strategies that clearly exhibit the anisotropy of the data if it is to be interpreted properly. Superquadric glyphs improve the ability to distinguish fiber orientation and tissue orthotropy compared to ellipsoids. Magn Reson Med 53:169–176, 2005. Published 2004 Wiley‐Liss, Inc.
Evaluation of MRI for in vivo monitoring of retinal damage and detachment in experimental ocular inflammation
Authors: Pop‐Fanea Laura , Vallespin Sonia Nielles , Hutchison James M. S. , Forrester John V. , Seton Hugh C. , Foster Margaret A. , Liversidge Janet 
Published: December 2004

AbstractTwo quantitative methods were developed for investigation of the potential of MRI for in vivo monitoring of retinal damage and detachment in experimental autoimmune uveitis (EAU). Measurements of retinal thickness and detachment area were performed on matched MR and histologic (HIST) images of rat eyes at different stages of EAU. In vivo MR images of rat eyes were acquired at 4.7 T using a figure‐of‐eight surface coil and a spin echo pulse sequence. Ex vivo measurements were performed on HIST images acquired using a digital camera attached to a microscope. MR images mirrored the HIST appearance of inflamed eyes at each stage of disease. Retinal detachments as small as 0.1 mm2 were measured in vivo by MRI and confirmed in the same eye ex vivo by histology. Measurements performed on corresponding MR and HIST images demonstrated a good agreement between the two techniques. The potential of MRI for in vivo visualization and for monitoring changes in the eye during development of EAU was demonstrated in this study. Magn Reson Med 53:61–68, 2005. © 2004 Wiley‐Liss, Inc.
Artifact and noise suppression in GRAPPA imaging using improved k‐space coil calibration and variable density sampling
Authors: Park Jaeseok , Zhang Qiang , Jellus Vladimir , Simonetti Orlando , Li Debiao 
Published: December 2004

AbstractA parallel imaging technique, GRAPPA (GeneRalized Auto‐calibrating Partially Parallel Acquisitions), has been used to improve temporal or spatial resolution. Coil calibration in GRAPPA is performed in central k‐space by fitting a target signal using its adjacent signals. Missing signals in outer k‐space are reconstructed. However, coil calibration operates with signals that exhibit large amplitude variation while reconstruction is performed using signals with small amplitude variation. Different signal variations in coil calibration and reconstruction may result in residual image artifact and noise. The purpose of this work was to improve GRAPPA coil calibration and variable density (VD) sampling for suppressing residual artifact and noise. The proposed coil calibration was performed in local k‐space along both the phase and frequency encoding directions. Outer k‐space was acquired with two different reduction factors. Phantom data were reconstructed by both the conventional GRAPPA and the improved technique for comparison at an acceleration of two. Under the same acceleration, optimal sampling and calibration parameters were determined. An in vivo image was reconstructed in the same way using the predetermined optimal parameters. The performance of GRAPPA was improved by the localized coil calibration and VD sampling scheme. Magn Reson Med 53:186–193, 2005. © 2004 Wiley‐Liss, Inc.
Pulsed star labeling of arterial regions (PULSAR): A robust regional perfusion technique for high field imaging
Authors: Golay Xavier , Petersen Esben T. , Hui Francis 
Published: December 2004

AbstractRegional perfusion imaging (RPI) has recently been introduced as a potentially powerful technique to map the perfusion territories of patients with vascular diseases in a fully noninvasive manner. However, this technique suffers from the problems of the transfer insensitive labeling technique upon which it is based. In particular, RPI is very sensitive to magnetic field inhomogeneities, and therefore the definition of the labeled bolus can deteriorate at field strength higher than 1.5 T. Furthermore, the slab‐selective triple‐pulse postsaturation sequence used originally will also be impaired due to the same problem, rendering RPI unusable at higher field. In this work, an adiabatic‐based signal targeting with alternating radiofrequency pulses sequence is proposed as a labeling scheme to solve the problems related to variations in local magnetic field, together with an improved four‐pulse water suppression enhanced through T1 effects technique as a presaturation scheme. Magn Reson Med 53:15–21, 2005. © 2004 Wiley‐Liss, Inc.
Exercise tolerance and daily life in McArdle's disease
Authors: Ollivier Karen , Hogrel Jean‐Yves , Gomez‐Merino Danielle , Romero Norma B. , Laforêt Pascal , Eymard Bruno , Portero Pierre 
Published: December 2004

AbstractMcArdle's disease is a common disorder of muscle metabolism and is due to myophosphorylase deficiency. The major complaint of patients with this disease is effort intolerance. Although the clinical features of affected patients are well known, their daily lifestyle is not well documented. The main objective of this work was to assess their mean daily energy expenditure (DEE) and compare it with control subjects. Thirty patients and 87 control subjects completed a questionnaire. A 3‐day self‐record of daily physical activities was used to estimate the mean DEE for patients and control subjects. A separate section of the questionnaire was used to assess patients' clinical features and daily lifestyle. The DEE of patients (44.1 ± 6.9 kcal/kg) was not significantly different from control subjects (44.5 ± 5.6 kcal/kg). Half of the patients with McArdle's disease performed a daily physical leisure activity as sport, sometimes at a high level (17%). Despite large individual variation, physical abilities and patients' symptoms were negatively correlated. Physical leisure activity significantly decreased the sensation of muscle pain (P< 0.03). These findings show that patients with McArdle's disease do not have a strictly sedentary lifestyle. Moreover, physical exercise appears to have positive effects on the main clinical features, such as effort intolerance. Thus, regular, moderate physical activity may be beneficial in McArdle's disease. Muscle Nerve, 2005
Numerical Investigation of Shock Wave Interference Heating in Chemical Nonequilibrium
Authors: Reinartz Birgit U. , van Keuk Jörn , Ballmann Josef 
Published: December 2004

AbstractA Navier‐Stokes solver is extended by a nonequlibrium gas model to investigate heat transfer rates in hypersonic flow. The nonequlibrium model is shortly discussed and results for a type IV interaction on a cylinder are presented and compared to experimental measurements. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)
Zur gasdynamischen Auslegung eines Stosswellenkanals
Authors: Schemperg Katrin , Mundt Christian 
Published: December 2004

AbstractEin Stosswellenkanal wird zur experimentellen Simulation von Hochenthalpieströmungen, wie sie beispielsweise beim Wiedereintritt von Raumflugkörpern in eine Atmosphäre auftreten, verwendet. Bei gleichzeitigem Betrieb eines Plasmabrenners (der u. a. der Modellaufheizung dient) kann zusätzlich die Interaktion eines Hochenthalpiestrahles mit einer Hyperschallströmung untersucht werden. Hierbei sind ins besondere Untersuchungen der aerothermodynamischen Phänomene der Hochgeschwindigkeits‐ bzw. Hochenthalpieströmung von Interesse. Die gasdynamische Auslegung des Stosswellenkanals umfasst die adiabatische Treibergaskompression durch einen mit Druckgas angetriebenen Kolben, der durch das komprimierte Treibergas bis zum Ende des Treiberrohres zum Stillstand kommen muss. Gleichzeitig bricht eine am Rohrende angebrachte Stahlmembran und eine Stosswelle läuft in das Stossrohr, bis sie am Rohrende reflektiert wird. Hier bildet sich nun eine ortsfeste Region hohen Druckes und hoher Temperatur aus. Eine zweite Membran bricht, und das Gas expandiert durch eine Düse. Um für einen möglichst langen Zeitraum das Ausströmen der Hochenthalpieströmung zu gewährleisten, muss die Stossreflexion im sog. tailored interface mode erfolgen, das heisst, die ursprünglichen Gaszustandsgrössen werden so gewählt, dass der reflektierte Stoss die nachfolgende Kontaktfläche zum Stillstand bringt. (© 2004 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)