bluuebunny/crossref_metadata_2025_split huggingface dataset:
Expression of zebrafish nos2b surrounds oral cavity
Authors: Poon Kar‐Lai , Richardson Michael , Korzh Vladimir 
Published: May 2008

AbstractInducible nitric oxide synthase (NOS2) catalyzes the production of nitric oxide (NO), and is one of the factors establishing innate immunity. In zebrafish, Nos2 is represented by nos2a and nos2b. Here, we report the cloning and expression pattern of the zebrafish nos2b gene, which does not seem to participate in induced immune response. nos2b was mapped to zebrafish linkage group 15. The spatial and temporal expression pattern of nos2b in embryonic zebrafish was analyzed by whole‐mount in situ hybridization. nos2b is expressed constitutively in two primordia located along the ventral midline. The first group of cells contributes to the neurohypophysis. Initially at the level of the ventral hindbrain, the second group of cells migrates closely with the thyroid primordium to its final position at the basihyal by 3 dpf. Thus, the analysis of expression pattern of nos2b reveals complex morphogenetic movements resulting in its expression surrounding the oral cavity. Developmental Dynamics 237:1662–1667, 2008. © 2008 Wiley‐Liss, Inc.
The role of transforming growth factor‐β signalling in the patterning of the proximal processes of the murine dentary
Authors: Anthwal Neal , Chai Yang , Tucker Abigail S. 
Published: May 2008

AbstractThe evolution of the novel mammalian jaw articulation has resulted in an increased complexity of the dentary bone, reflecting the multiple roles it now fulfils as the primary bone of the mandible. Signalling through the Tgf‐β type II receptor is important in the development and patterning of the proximal dentary processes, especially the angular process, and secondary cartilages. We show that expression of Tgf‐β2 is associated with the developing angular process, and that the connective tissue marker Scleraxis is co‐expressed with Tgf‐β2. Scleraxis expression is lost around the angular process of Tgfbr2 conditional knockouts and Tgf‐β signalling can induce Scleraxis expression in explant culture. Induction of secondary cartilages in explant culture can be prevented by inhibition of Tgf‐β signalling. This study suggests that the proper development of the processes and their secondary cartilages relies on both Tgf‐β signalling and mechanical forces working in concert. Developmental Dynamics 237:1604–1613, 2008. © 2008 Wiley‐Liss, Inc.
All‐trans retinoic acid‐induced ectopic limb and caudal structures: Murine strain sensitivities and pathogenesis
Authors: Liao Xiaoyan , Collins Michael D. 
Published: May 2008

AbstractTreatment of pregnant mice at the egg cylinder stage with retinoic acid (RA) has caused ectopic hindlimbs in the offspring. Proposed causes of ectopic hindlimbs include homeotic transformation or multiple axis formation. Two mouse strains were determined to be divergent in susceptibility to this malformation (C57BL/6N, highly sensitive; SWV/Fnn, less sensitive). Ectopic limbs were hindlimbs (expressing Pitx1 and Tbx4 but not Tbx5), yet they also expressed the predominantly forelimb Hoxb8. Ectopic body axis formation was indicated by gene expression for ectopic primitive streaks, notochords, and nodes, as well as inhibition of anterior visceral endoderm and mesodermal migration. The earlier in development that embryos were examined, the higher the rate of ectopic hindlimb development and axis formation. Ectopic axis formation and cell migration inhibition had the same strain susceptibility as the dysmorphogenesis. We propose that all extra hindlimbs were derived from ectopic axis formation, perturbation of which is genetic background dependent. Developmental Dynamics 237:1553–1564, 2008. © 2008 Wiley‐Liss, Inc.
Comparative analysis of proneural gene expression in the embryonic cerebellum
Authors: Zordan Paola , Croci Laura , Hawkes Richard , Consalez G. Giacomo 
Published: May 2008

AbstractThe embryonic cerebellum contains two germinative epithelia: the rhombic lip and the ventricular zone. While the lineage of glutamatergic neurons arising from the rhombic lip has been characterized, plenty remains to be learned about the factors giving rise to the array of ventricular zone‐derived γ‐aminobutyric acid (GABA)ergic neurons. In the present study, we describe the expression of proneural genes Mash1/Ascl1, Ngn1/Neurog1, and Ngn2/Neurog2 in the cerebellar primordium at key stages of Purkinje cell and interneuron development, and compare them with the expression of other genes active in the same context. Our results indicate that Ngn1, Ngn2 and Mash1 are expressed at relevant stages of cerebellar neurogenesis in the prospective cerebellar nuclei and in the ventricular zone, excluding the Math1/Atoh1‐positive rhombic lip. Their expression domains are only partially overlapping, suggesting that they may contribute selectively to ventricular zone regionalization, giving rise to the diversity of cerebellar GABA neurons and, possibly, Purkinje cell subtypes. Developmental Dynamics 237:1726–1735, 2008. © 2008 Wiley‐Liss, Inc.
Peptide hormones as developmental growth and differentiation factors
Authors: Sanders Esmond J. , Harvey Steve 
Published: May 2008

AbstractPeptide hormones, usually considered to be endocrine factors responsible for communication between tissues remotely located from each other, are increasingly being found to be synthesized in developing tissues, where they act locally. Several hormones are now known to be produced in developing tissues that are unrelated to the endocrine gland of origin in the adult. These hormones are synthesized locally, and are active as differentiation and survival factors, before the developing adult endocrine tissue becomes functional. There is increasing evidence for paracrine and/or autocrine actions for these factors during development, thus, placing them among the conventional growth and differentiation factors. We review the evidence for the view that thyroid hormones, growth hormone, prolactin, insulin, and parathyroid hormone‐related protein are developmental growth and differentiation factors. Developmental Dynamics 237:1537–1552, 2008. © 2008 Wiley‐Liss, Inc.
Id2, Id3, and Id4 proteins show dynamic changes in expression during vibrissae follicle development
Authors: Hammond Nigel L. , Jahoda Colin A.B. 
Published: May 2008

AbstractId proteins are involved in the transcriptional control of many fundamental biological processes, including differentiation and lineage commitment. We studied Id2, Id3, and Id4 protein expression during different stages of rat vibrissa follicle development using immunohistochemistry. Id2 was highly expressed in the cytoplasm of specialized cells in the basal epidermis and outer root sheath during early stages of follicle development. These cells were identified as Merkel cells (MCs) by means of double‐immunolabeling with synaptophysin and cytokeratin‐20, and persisted in neonatal follicles. Id3 immunofluorescence was characterized by membrane‐associated expression in basal epithelial cells of follicles early in development. Subsequently follicle epithelial cells switched to have strong nuclear labeling, also a feature of newly forming dermal papilla cells. Id4 expression was primarily associated with innervation of the developing follicle musculature. These observations illustrate dynamic expression patterns of Id2 and Id3 proteins in developing follicles and specifically link Id2 expression to Merkel cell specification. Developmental Dynamics 237:1653–1661, 2008. © 2008 Wiley‐Liss, Inc.
Brd4 associates with mitotic chromosomes throughout early zebrafish embryogenesis
Authors: Toyama Reiko , Rebbert Martha L , Dey Anup , Ozato Keiko , Dawid Igor B. 
Published: May 2008

AbstractBrd4 is a member of the BET (bromodomains and extraterminal) subfamily of bromodomain proteins that includes chromatin‐modifying proteins and transcriptional regulators. Brd4 has a role in cell cycle progression, making it indispensable in mouse embryos and cultured cells. The N‐terminal domain of Brd4 participates in a fusion oncogene. Brd4 associates with acetylated histones in chromatin, and this association persists during mitosis implicating Brd4 in epigenetic memory. Brd4 sequence, particularly the bromodomains and ET domain, is conserved in the zebrafish and Xenopus laevis proteins reported here. Brd4 is expressed and localized on mitotic chromosomes in early zebrafish embryos before and after the midblastula transition (MBT), indicating that the Brd4‐chromosome association is a conserved property that is maintained even before zygotic transcription. The association of Brd4 with acetylated histones may also be conserved in early embryos as we found that histones H3 and H4 are already acetylated during pre‐MBT stages. Developmental Dynamics 237:1636–1644, 2008. Published 2008 Wiley‐Liss, Inc.
The eye organizes neural crest cell migration
Authors: Langenberg Tobias , Kahana Alon , Wszalek Joseph A. , Halloran Mary C. 
Published: May 2008

AbstractIn the anterior vertebrate head, a population of neural crest cells (NCCs) migrates to the periocular mesenchyme and makes critical contributions to the developing eye and orbit. Improper migration and differentiation of these NCCs have been implicated in human diseases such as congenital glaucoma and anterior segment dysgenesis syndromes. The mechanisms by which these cells migrate to their target tissues within and around the eye are not well understood. We present a fate map of zebrafish diencephalic and mesencephalic NCC contributions to the eye and orbit. The fate map closely resembles that in chick and mice, demonstrating evolutionary conservation. To gain insight into the mechanisms of anterior NCC guidance, we used the eyeless mutant chokh/rx3. We show that, in chokh mutants, dorsal anterior NCC migration is severely disorganized. Time‐lapse analysis shows that NCCs have significantly reduced migration rates and directionality in chokh mutants. Developmental Dynamics 237:1645–1652, 2008. © 2008 Wiley‐Liss, Inc.
Differential expression pattern of the four mitochondrial adenine nucleotide transporter ant genes and their roles during the development of Caenorhabditis elegans
Authors: Farina Francesca , Alberti Adriana , Breuil Norman , Bolotin‐Fukuhara Monique , Pinto Moïse , Culetto Emmanuel 
Published: May 2008

AbstractThe adenine nucleotide transporter (ANT) mediates exchange of cytosolic ADP and mitochondrial ATP. Although most species contain more than one ANT family member, it is not known whether their roles in developmental processes are redundant or specific. Here, we show that the Caenorhabditis elegans genome encodes four candidate ant genes (ant‐1.1, ant‐1.2, ant‐1.3, and ant‐1.4). We have investigated their spatiotemporal expression patterns and discovered that, whereas ANT‐1.1 is a ubiquitously expressed mitochondrial protein, the other three ANT proteins show a restricted range of cell type expression. Moreover, only the disruption of ant‐1.1 function, through RNA interference (RNAi), gives a mutant phenotype. Most of the ant‐1.1(RNAi) mutant embryos arrest before the morphogenesis stage. Furthermore, ant‐1.1 is also required postembryonically because RNAi mutants exhibit small size and life‐span extension. Our results suggest that ant‐1.1 is the only ant gene strictly required for embryonic and postembryonic development in C. elegans. Developmental Dynamics 237:1668–1681, 2008. © 2008 Wiley‐Liss, Inc.
WNT signaling affects gene expression in the ventral diencephalon and pituitary gland growth
Authors: Potok Mary Anne , Cha Kelly B. , Hunt Andrea , Brinkmeier Michelle L. , Leitges Michael , Kispert Andreas , Camper Sally A. 
Published: May 2008

AbstractWNT5A deficiency causes pituitary dysmorphology and ectopic melanotrope differentiation. Immunohistochemistry for prohormone convertase 2 (PC2) marks melanotrope cells, which are normally confined to the intermediate lobe of the pituitary gland. Wnt5a mutant mice contain ectopic melanotropes in a region of dysmorphology adjacent to the intermediate lobe. We show a coronal section from an e18.5 Wnt5a mutant pituitary gland stained with a PC2 specific antibody, developed with the chromagen diaminobenzidine, and counterstained with hematoxylin. The image is artistically arranged as a mirror image duplication with the dorsal aspect of the pituitary facing the outer edges and the ventral aspect towards the center plane. See Potok et al., Developmental Dynamics 237:1006–1020, 2008. © 2008 Wiley‐Liss, Inc.
Improvement and validation of a snow saltation model using wind tunnel measurements
Authors: Clifton Andrew , Lehning Michael 
Published: May 2008

AbstractA Lagrangian snow saltation model has been extended for application to a wide variety of snow surfaces. Important factors of the saltation process, namely number of entrained particles, ejection angle and speed, have been parameterized from data in the literature. The model can now be run using simple descriptors of weather and snow conditions, such as wind, ambient pressure and temperature, snow particle sizes and surface density. Sensitivity of the total mass flux to the new parameterizations is small. However, the model refinements also allow concentration and mass flux profiles to be calculated, for comparison with measurements. Sensitivity of the profiles to the new parameterizations is considerable. Model results have then been compared with a complete set of drifting snow data from our cold wind tunnel. Simulation mass flux results agree with wind tunnel data to within the bounds of measurement uncertainty. Simulated particle sizes at 50 mm above the surface are generally larger than seen in the tunnel, probably as the model only describes particles in saltation, while additional smaller particles may be present in the wind tunnel at this height because of suspension. However, the smaller particles carry little mass, and so the impact on the mass flux is low. The use of simple input data, and parameterization of the saltation process, allows the model to be used predictively. This could include applications from avalanche warning to glacier mass balance. Copyright © 2008 John Wiley & Sons, Ltd.
Effect of altered flow regime on bankfull area of the Lower Yellow River, China
Authors: Wu Baosheng , Xia Junqiang , Fu Xudong , Zhang Yuanfeng , Wang Guangqian 
Published: May 2008

AbstractThe adjustment of the bankfull channel area in the Lower Yellow River has been dramatically affected by altered flow regimes caused by human activities. This paper presents a study on the effects of altered discharge and suspended sediment load on the bankfull area at Gaocun, a representative hydrometric station in the Lower Yellow River. The analysis demonstrates the cumulative effect of previous years' flow and sediment conditions on channel adjustment, a phenomenon commonly occurring in geomorphic systems due to the delayed channel response to flow and sediment conditions. A methodology for the prediction of bankfull area was developed based on the general concept that the rate of adjustment is proportional to the difference between the bankfull area and its equilibrium value. The proposed methodology is not only applicable for the prediction of the bankfull area in response to the changes in flow and sediment conditions in the Lower Yellow River, but can also be extended to other studies where the response times have a key role to play in the assessment of channel adjustment to external changes. Copyright © 2008 John Wiley & Sons, Ltd.
Terrestrial photogrammetric techniques applied to the control of a parabolic dune in the Liencres dune system, Cantabria (Spain)
Authors: Arteaga Carlos , Juan de Sanjosé José , Serrano Enrique 
Published: May 2008

AbstractThe spatial–temporal variations of a dune system can be determined by using diverse ‘geomatic’ methodologies: geodesy, global positioning system (GPS) and photogrammetry. In the case of the Liencres dune system, a study will be carried out using the ‘close‐range’ photogrammetry technique and the topography technique (total station and GPS). In order to determine the dynamic of the dune system it is necessary to repeat the process of study after a specific interval of time. For this reason, three dimensional data should be available in two different time periods, between which the displacement of the object of analysis (the front portion of the dune) will be significant enough to evaluate its magnitude. This work analyses the viability of photogrammetry for the determination of the spatial–temporal changes of a coastal parabolic dune. Two factors have been analysed: first, the comparison of the photogrammetric results with the results obtained from topographic methods (total station and GPS), and second, the quantification of the displacement of the dune system. The analysis of the correspondence between the movement of different parts of the dune and the influence of the intensity and direction of the prevailing wind in the area is also desired. The dune advanced 12·15 ± 0·06 m (an average of 8·5 m/yr), and the partial implications for the dynamic of human modified processes on the natural park have been established. Copyright © 2008 John Wiley & Sons, Ltd.
Implications of the saltation–abrasion bedrock incision model for steady‐state river longitudinal profile relief and concavity
Authors: Sklar Leonard S. , Dietrich William E. 
Published: May 2008

AbstractThe saltation–abrasion model predicts rates of river incision into bedrock as an explicit function of sediment supply, grain size, boundary shear stress and rock strength. Here we use this experimentally calibrated model to explore the controls on river longitudinal profile concavity and relief for the simple but illustrative case of steady‐state topography. Over a wide range of rock uplift rates we find a characteristic downstream trend, in which upstream reaches are close to the threshold of sediment motion with large extents of bedrock exposure in the channel bed, while downstream reaches have higher excess shear stresses and lesser extents of bedrock exposure. Profile concavity is most sensitive to spatial gradients in runoff and the rate of downstream sediment fining. Concavity is also sensitive to the supply rate of coarse sediment, which varies with rock uplift rate and with the fraction of the total sediment load in the bedload size class. Variations in rock strength have little influence on profile concavity. Profile relief is most sensitive to grain size and amount of runoff. Rock uplift rate and rock strength influence relief most strongly for high rates of rock uplift. Analysis of potential covariation of grain size with rock uplift rate and rock strength suggests that the influence of these variables on profile form could occur in large part through their influence on grain size. Similarly, covariation between grain size and the fraction of sediment load in the bedload size class provides another indirect avenue for rock uplift and strength to influence profile form. Copyright © 2008 John Wiley & Sons, Ltd.
A geomatics‐based approach for the derivation of the spatial distribution of sediment transport processes in periglacial mountain environments
Authors: Bartsch A. , Gude M. , Gurney S. D. 
Published: May 2008

AbstractWithin this paper modern techniques such as satellite image analysis and tools provided by geographic information systems (GIS) are exploited in order to extend and improve existing techniques for mapping the spatial distribution of sediment transport processes. The processes of interest comprise mass movements such as solifluction, slope wash, dirty avalanches and rock‐ and boulder falls. They differ considerably in nature and therefore different approaches for the derivation of their spatial extent are required. A major challenge is addressing the differences between the comparably coarse resolution of the available satellite data (Landsat TM/ETM+, 30 m × 30 m) and the actual scale of sediment transport in this environment. A three‐stepped approach has been developed which is based on the concept of Geomorphic Process Units (GPUs): parameterization, process area delineation and combination. Parameters include land cover from satellite data and digital elevation model derivatives. Process areas are identified using a hierarchical classification scheme utilizing thresholds and definition of topology. The approach has been developed for the Kärkevagge in Sweden and could be successfully transferred to the Rabotsbekken catchment at Okstindan, Norway using similar input data. Copyright © 2008 John Wiley & Sons, Ltd.
Expressions for outage probability
Authors: Nadarajah Saralees 
Published: May 2008

AbstractThe outage probability for most wireless communications networks can be approximated by$R = {\rm Pr}(X_2 < X_1)$whereX1andX2are independent random variables. Here, a comprehensive collection of formulae is derived forRby assuming the most commonly known models forX1andX2. A discussion is provided of four possible applications to problems in wireless communications. Copyright © 2008 John Wiley & Sons, Ltd.
Evaluation of effect of cognitive intervention programs for the community‐dwelling elderly with subjective memory complaints
Authors: Tsai Athena Yi‐jung , Yang Ming‐Jen , Lan Chun‐Fu , Chen Cheng‐Sheng 
Published: May 2008

AbstractPurposeTo compare the efficacy of cognitive training (CT) and cognitive stimulation (CS) programs for the community elderly with subjective memory complaints (SMC).MethodThe single‐blind non‐randomized controlled study was applied. The numbers of CT and CS participants were 14 and 11. The mean ages of CT and CS participants were 68.71 and 70.36. Memory training and problem solving strategies were applied in the CT group. There were ten 2‐hourly sessions of CT, held twice weekly. CS group met once weekly in a 1.5‐h class for eight classes. Cognitive performance tests of general cognitive performance, verbal memory and executive function were measured before/after the training and at 6 months follow‐up.ResultsIn both training conditions, the general cognitive performance were enhanced. The CT group showed improvement in the verbal memory test. The CS group did not trigger any training effect in the verbal memory test but the executive function. All cognitive progresses remained at follow‐up.ConclusionBoth cognitive training and cognitive stimulation programs showed training effects and remained until 6 months. Copyright © 2008 John Wiley & Sons, Ltd.