bluuebunny/crossref_metadata_2025_split huggingface dataset:
Evolution of OTP‐Independent larval skeleton patterning in the direct‐developing sea urchin, Heliocidaris erythrogramma
Authors: ZHOU NA , WILSON KEEN A. , ANDREWS MARY E. , KAUFFMAN JEFFERY S. , RAFF RUDOLF A. 
Published: December 2003

AbstractHeliocidaris erythrogramma is a direct‐developing sea urchin that has evolved a modified ontogeny, a reduced larval skeleton, and accelerated development of the adult skeleton. The Orthopedia gene (Otp) encodes a homeodomain transcription factor crucial in patterning the larval skeleton of indirect‐developing sea urchins. We compare the role of Otp in larvae of the indirect‐developing sea urchin Heliocidaris tuberculata and its direct‐developing congener H. erythrogramma. Otp is a single‐copy gene with an identical protein sequence in these species. Expression of Otp is initiated by the late gastrula, initially in two cells of the oral ectoderm in H. tuberculata. These cells are restricted to oral ectoderm and exhibit left‐right symmetry. There are about 266 copies of Otp mRNA per Otp‐ expressing cell in H. tuberculata. We tested OTP function in H. tuberculata and H. erythrogramma embryos by microinjection of Otp mRNA. Mis‐expression of Otp mRNA in H. tuberculata radialized the embryos and caused defects during larval skeletogenesis. Mis‐expression of Otp mRNA in H. erythrogramma embryos did not affect skeleton formation. This is consistent with the observation by in situ hybridization of no concentration of Otp transcript in any particular cells or region of the H. erythrogramma larva, and measurement of a level of less than one copy of endogenous Otp mRNA per cell in H. erythrogramma. OTP plays an important role in patterning the larval skeleton of H. tuberculata, but this role apparently has been lost in the evolution of the H. erythrogramma larva, and replaced by a new patterning mechanism. J. Exp. Zool. (Mol. Dev. Evol.) 300B:58–71, 2003. © 2003 Wiley‐Liss, Inc.
Semi‐transitive graphs
Authors: Wilson Steve 
Published: December 2003

AbstractIn this paper, we first consider graphs allowing symmetry groups which act transitively on edges but not on darts (directed edges). We see that there are two ways in which this can happen and we introduce the terms bi‐transitive and semi‐transitive to describe them. We examine the elementary implications of each condition and consider families of examples; primary among these are the semi‐transitive spider‐graphs PS(k,N;r) and MPS(k,N;r). We show how a product operation can be used to produce larger graphs of each type from smaller ones. We introduce the alternet of a directed graph. This links the two conditions, for each alternet of a semi‐transitive graph (if it has more than one) is a bi‐transitive graph. We show how the alternets can be used to understand the structure of a semi‐transitive graph, and that the action of the group on the set of alternets can be an interesting structure in its own right. We use alternets to define the attachment number of the graph, and the important special cases of tightly attached and loosely attached graphs. In the case of tightly attached graphs, we show an addressing scheme to describe the graph with coordinates. Finally, we use the addressing scheme to complete the classification of tightly attached semi‐transitive graphs of degree 4 begun by Marus̆ic̆ and Praeger. This classification shows that nearly all such graphs are spider‐graphs. © 2003 Wiley Periodicals, Inc. J Graph Theory 45: 1–27, 2004
Elucidation of the fragmentation pathways of azaspiracids, using electrospray ionisation, hydrogen/deuterium exchange, and multiple‐stage mass spectrometry
Authors: Díaz Sierra Mónica , Furey Ambrose , Hamilton Brett , Lehane Mary , James Kevin J. 
Published: December 2003

AbstractCollision‐induced dissociation (CID) mass spectra were generated for azaspiracids using electrospray ionisation (ESI), and hydrogen/deuterium (H/D) exchange was used to ascertain the number and type of replaceable hydrogens in the three predominant azaspiracid toxins. H/D exchange was conveniently achieved using deuterated solvents for liquid chromatography (LC). Using ion‐trap mass spectrometry, multiple‐stage CID experiments (MSn) on the protonated and fully exchanged ions were performed to decipher characteristic fragmentation pathways. The precursor and product ions from azaspiracids lost up to five water molecules from different regions during MSn experiments and it was possible to distinguish between the water losses from different molecular regions. These studies confirmed that the first water‐loss ion in the spectra of azaspiracids resulted from dehydration at the vicinal diol at C20–C21. Five MS dissociation pathways were identified that resulted from fragmentation of the carbon skeleton of azaspiracids producing nitrogen‐containing ions. Two pathways, involving cleavage of the E‐ring and C27–C28, gave ions that were found in all azaspiracids. Three pathways, A‐ring, C‐ring and C19–C20 cleavages, were useful for distinguishing between azaspiracid analogues. The same product ions from backbone fragmentation were also observed using hybrid quadrupole time‐of‐flight mass spectrometry (QqTOFMS). The fragmentation of the A‐ring was the most facile and was exploited in the development of LC/MSn methods for the analysis of azaspiracids. Copyright © 2003 John Wiley & Sons, Ltd.
Alterations in primary afferent input to substantia gelatinosa of adult rat spinal cord after neonatal capsaicin treatment
Authors: Yang Kun , Furue Hidemasa , Fujita Tsugumi , Kumamoto Eiichi , Yoshimura Megumu 
Published: December 2003

AbstractPrimary afferent fibers are divided into three main subgroups: Aβ‐, Aδ‐, and C‐fibers. Morphological studies have demonstrated that neonatal capsaicin treatment (NCT) depletes C‐fiber inputs in the spinal dorsal horn; the electrophysiological features of the NCT‐induced changes, however, remain unclear. This issue was addressed by performing whole‐cell voltage‐clamp recordings from substantia gelatinosa (SG) neurons in dorsal root‐attached spinal cord slices. When estimated from excitatory postsynaptic currents (EPSCs) evoked by stimulating primary afferent fibers, 24 (49%) of 49 neurons examined exhibited C‐fiber EPSCs that were either monosynaptic (n = 15) or polysynaptic (n = 9) in origin; only two of the neurons had Aβ‐fiber responses. In NCT rats, however, SG neurons exhibiting C‐fiber‐mediated EPSCs decreased to 7% (3 of 41 neurons tested), whereas Aβ‐fiber EPSCs were observed in 21 (51%) of the neurons, and 14 (67%) of them exhibited monosynaptic ones. There was no change in the cell proportion having Aδ‐fiber innervation after NCT. Our electrophysiological data suggest that NCT diminishes primary afferent C‐fiber inputs while enhancing Aβ‐fiber direct innervation in the SG in adulthood. © 2003 Wiley‐Liss, Inc.
Distribution of polysialylated neural cell adhesion molecule in rat septal nuclei and septohippocampal pathway: Transient increase of polysialylated interneurons in the subtriangular septal zone during memory consolidation
Authors: Foley Andrew G. , Rønn Lars C.B. , Murphy Keith J. , Regan Ciaran M. 
Published: December 2003

AbstractDuring memory consolidation neuroplastic events in the mediotemporal corticohippocampal pathway are accompanied by transient increases in the frequency of neurons expressing polysialylated neural cell adhesion molecule (NCAM PSA), a posttranslational modification associated with morphofunctional change. As a bidirectional pathway between the hippocampus and the septal nuclei also influences memory processing, we have determined the distribution of NCAM PSA within this system before and after learning in the adult Wistar rat. The most intense NCAM PSA immunoreactivity was observed in the medial and triangular septal nuclei, regions that regulate hippocampal theta rhythm during memory consolidation. Within the fimbria, NCAM PSA was expressed only in a subpopulation of fibres, most likely cholinergic projections from the medial septum to the hippocampus. Grey level analysis or direct cell counting revealed no learning‐specific change in NCAM PSA expression in these septal subregions after avoidance conditioning or spatial training. A population of discrete polysialylated neurons in the subtriangular septal zone, however, exhibited a transient twofold frequency increase at 12 hr after training in either task. Immunohistochemical analysis revealed these cells to be gamma–aminobutyric acid (GABAergic) interneurons co‐expressing vasoactive intestinal peptide. The unique location of these interneurons is proposed to provide a natural plexus by which bidirectional communication between the septum and hippocampus may be modified during memory consolidation. © 2003 Wiley‐Liss, Inc.
Mechanism of preventive action of Viburnum dilatatum Thunb (gamazumi) crude extract on oxidative damage in rats subjected to stress
Authors: Iwai Kunihisa , Onodera Akio , Matsue Hajime 
Published: December 2003

AbstractThe fruit of Viburnum dilatatum Thunb (gamazumi) has been shown to prevent oxidative injury induced by water immersion restraint stress (WIRS) in rats. In this study the effect of gamazumi crude extract (GCE) on antioxidant enzymatic activities in the plasma, liver and stomach of rats with WIRS was investigated to elucidate the mechanism of prevention of oxidative injury. Ulcer formation and lipid peroxidation were inhibited in rats supplied GCE for 2 weeks in comparison with rats supplied water. Although the activities of plasma, hepatic and gastric antioxidant enzymes in rats given water were decreased by WIRS, only slight changes were observed in rats given GCE. There was no difference in enzymatic activities between the water and GCE groups not subjected to WIRS. Furthermore, ferrous ascorbate‐induced oxidation in hepatic homogenate from rats given GCE was inhibited. These results suggest that ingestion of GCE does not induce antioxidant enzymes and that the absorbed antioxidant components of GCE have a direct effect on oxidative injury in the body. Copyright © 2003 Society of Chemical Industry
The evolution of lung cancer screening
Authors: Wilkinson Neal W. , Loewen Gregory M. , Klippenstein Donald L. , Litwin Alan M. , Anderson Timothy M. 
Published: December 2003

AbstractIn the 1970s, four trials failed to demonstrate any mortality reduction using a combination of chest X‐ray (CXR) and/or sputum cytology. The recent early lung cancer action project (ELCAP) demonstrated that modern screening is capable of detecting Stage I lung cancers. Bronchial epithelial changes leading up to cancers are now being understood to include histologic changes and genetic alterations. Emerging molecular markers detected in sputum and serum show promise in the future of lung cancer screening. J. Surg. Oncol. 2003;84:234–238. © 2003 Wiley‐Liss, Inc.
Tumor markers and colorectal cancer: Utility in management
Authors: Crawford Nigel P.S. , Colliver Daniel W. , Galandiuk Susan 
Published: December 2003

AbstractColorectal cancer (CRC) is a leading cause of morbidity and mortality. Although genetic testing can screen for rare hereditary CRC syndromes, there is no ideal means of screening for sporadic forms of CRC. This review will focus on markers that are currently used in the management of sporadic CRC and their limitations, as well as possible future clinical applications. J. Surg. Oncol. 2003;84:239–248. © 2003 Wiley‐Liss, Inc.
Similarity between the soil seed bank and the standing vegetation in the Strandveld Succulent Karoo, South Africa
Authors: de Villiers A. J. , Van Rooyen M. W. , Theron G. K. 
Published: December 2003

AbstractThe similarity in species composition and abundance between the soil seed bank and its associated vegetation was studied in six vegetation units of the Strandveld Succulent Karoo, South Africa. A total of 103 taxa were recorded in the vegetation, of which 34 taxa were also present in the seed bank. Five taxa were unique to the soil seed bank. In general, the taxa most abundant in the vegetation were also recorded in the seed bank and vice versa. Mean seed bank density varied between different plant types. Perennial taxa were most abundant in the vegetation, while annual taxa were most abundant in the seed bank. Annual taxa (excluding grasses) yielded the highest similarity between vegetation and seed bank (67ċ9 per cent), while that of perennial (excluding grasses) and grass taxa were 34ċ2 per cent and 40ċ0 per cent respectively. An overall similarity of 47ċ0 per cent between the seed bank and its associated vegetation was obtained for this part of the Strandveld Succulent Karoo. The seed bank of the study site will be a good source of future annual vegetation, but not of perennial vegetation. Topsoil replacement, sowing and transplanting of selected species will be essential for the success of post‐mining revegetation efforts following complete destruction of the existing vegetation. Annual species may be recruited from the soil stored seed bank, while many perennial species will have to be reintroduced by means of sowing and/or transplanting. Copyright © 2003 John Wiley & Sons, Ltd.
Tensile Properties of Extruded Zein Sheets and Extrusion Blown Films
Authors: Wang Ying , Padua Graciela W. 
Published: December 2003

AbstractZein‐based plastic sheets and films were formed by extrusion through a slit‐die or blowing head. Zein was plasticized with oleic acid and formed into a wet moldable mass (resin) to feed the extruders. Both single‐ and twin‐screw extruded sheets showed higher elongation at break, lower tensile strength, and lower Young's Modulus than non‐extruded samples. Stress‐strain plots for extruded samples showed evidence of plastic behavior. Observed necking of samples under tensile stress was also taken as evidence of plastic behavior. Small differences in tensile strength and elongation at break between single‐ and twin‐screw extruded samples were attributed to the effect of small voids observed by SEM in single‐screw extruded samples. Blown film extrusion was affected by feed moisture content and barrel temperatures. Optimal moisture content was determined at 14–15% while temperature at the three extruder zones was maintained at 20–25, 20–25, and 35 °C, respectively. Temperature at the blowing head was 45 °C. Film samples blown after either single‐ or twin‐screw extrusion showed similar tensile properties to those of slit die extruded samples.Blown extrusion of zein film with single‐screw extruder.magnified imageBlown extrusion of zein film with single‐screw extruder.
Transcrystallinity in Surface Modified Aramid Fiber Reinforced Nylon 66 Composites
Authors: Feldman Alexander , Gonzalez M. Fernanda , Marom Gad 
Published: December 2003

AbstractAramid (kevlar‐49) fibers were surface treated by two different methods to induce roughness and then used to produce unidirectional nylon 66 based composites. The transcrystallinity generated around the treated fibers was characterized by SEM and polarized light microscopy and compared with the regular transcrystalline layers produced by pristine aramid under the same processing conditions. The treated fibers generated a double transcrystalline layer, the inner layer being thinner and more compact than the regular nylon 66 transcrystallinity. In addition, mechanical testing of the composites showed the longitudinal Young's modulus of the treated fiber composites to be significantly higher than the control in a wide range of fiber volume fractions.Polarized light microscopy picture of double transcrystallinity in Br/NH3 treated aramid fiber reinforced nylon 66.magnified imagePolarized light microscopy picture of double transcrystallinity in Br/NH3 treated aramid fiber reinforced nylon 66.
Exploring the antecedents and consumer behavior consequences of the trait of superstition
Authors: Mowen John C. , Carlson Brad 
Published: December 2003

AbstractIn two exploratory studies, a hierarchical model of personality was employed to investigate a number of possible trait antecedents and consumer‐behavior–related consequences of superstition. One of the interesting findings was that the antecedents of superstition include a lower need for learning among older adults, higher levels of sports interest, a belief in fate, and a decreased belief in heaven and hell. In addition, the results suggested that the consequences of superstition might include beliefs in astrology, magic, psychokinesis, and the existence of fictitious creatures (e.g., the Loch Ness monster). Evidence suggesting a negative association between superstitious beliefs and attitudes concerning the genetic engineering of food products was also obtained. © 2003 Wiley Periodicals, Inc.
Consumer adoption of the Internet: The case of apparel shopping
Authors: Yoh Eunah , Damhorst Mary Lynn , Sapp Stephen , Laczniak Russ 
Published: December 2003

AbstractThe theory of reasoned action and components of a theory of innovation adoption were integrated into a model of consumer adoption of the Internet for apparel shopping. The hypothesized model included psychological factors (beliefs and attitude), social factors (social support and social acceptance), and prior experience to explain intention to purchase apparel via the Internet. A questionnaire was mailed to a random national sample of households. All hypothesized variables were significant. Prior experience with the Internet had the strongest influence on intention to purchase apparel through the Internet. © 2003 Wiley Periodicals, Inc.
A random evolution related to a Fisher–Wright–Moran model with mutation, recombination and drift
Authors: Bobrowski Adam , Kimmel Marek 
Published: December 2003

AbstractThe paper deals with a model of the genetic process of recombination, one of the basis mechanisms of generating genetic variability. Mathematically, the model can be represented by the so‐called random evolution of Griego and Hersch, in which a random switching process selects from among several possible modes of operation of a dynamical system. The model, introduced by Polanska and Kimmel, involves mutations in the form of a time‐continuous Markov chain and genetic drift. We demonstrate asymptotic properties of the model under different demographic scenarios for the population in which the process evolves. Copyright © 2003 John Wiley & Sons, Ltd.
Toxicogenomic difference between diethylstilbestrol and 17β‐estradiol in mouse testicular gene expression by neonatal exposure
Authors: Adachi Tetsuya , Koh Kyu‐Bom , Tainaka Hitoshi , Matsuno Yoshiharu , Ono Yushin , Sakurai Kenichi , Fukata Hideki , Iguchi Taisen , Komiyama Masatoshi , Mori Chisato 
Published: December 2003

AbstractIn this study, we investigated the effects of neonatal exposure to exogenous estrogen (diethylstilbestrol: DES, 17β‐estradiol: E2) on testicular gene expressions. Male C57BL/6J mice, 1 day after birth, were subcutaneously injected with DES or E2 (3 μg/mouse/day) for 5 days, and then they were raised for 8 weeks. In morphological observation of 8‐week‐old mice testes, spermatozoa were absent from many seminiferous tubules in DES‐treated mice testes, but there was no change in E2‐treated mice testes. Analysis of in‐house cDNA microarray (mouse cDNA 889 genes) revealed that 17 genes were altered in DES‐treated mice testes at 8 weeks of age, compared to each control. Real‐time reverse transcription‐polymerase chain reaction (real‐time RT‐PCR) analysis of these genes revealed that some genes, which were changed in E2‐treated testis, were the same as in DES‐treated testis, whereas in other cases there was a difference between DES‐treated and E2‐treated testis. The present results suggest that each exogenous estrogenic compound has both a common gene expression change pattern and its own testicular gene expression change pattern. Mol. Reprod. Dev. 67: 19–25, 2004. © 2004 Wiley‐Liss, Inc.
Cryopreservation of Xenopus transgenic lines
Authors: Buchholz Daniel R. , Fu Liezhen , Shi Yun‐Bo 
Published: December 2003

AbstractXenopus laevis has been widely used for molecular, cellular, and developmental studies. With the development of the sperm‐mediated transgenic method, it is now possible to study gene function during vertebrate development by using this popular model. On the other hand, like other animal species, it is labor intensive, and the maintenance of transgenic lines is expensive. In this article, we investigated the possibility of using sperm‐cryopreservation as a means to preserve transgenic frog lines. We demonstrated that cryopreserved sperms are viable but not fertile under our in vitro fertilization (IVF) conditions. However, by microinjecting cryopreserved sperm nuclei, we successfully regenerated a transgenic line carrying a double promoter transgene construct, where the marker gene encoding the green fluorescent protein (GFP) is driven by the γ‐crystallin gene promoter and a gene of interest, encoding a fusion protein of GFP with the matrix metalloproteinase stromelysin‐3 (ST3‐GFP), is driven by a heat shock‐inducible promoter. We demonstrated the functional transmission of the ST3‐GFP transgene by analyzing the phenotype of the F1 animals after heat‐shock to induce its expression. Our method thus provides an inexpensive means to preserve transgenic frog lines and a convenient way for distribution of transgenic lines. Furthermore, the ease with which to microinject nuclei compared to the technically demanding transgenesis procedure with variable outcome should facilitate more laboratories to use transgenic Xenopus laevis for functional studies in vivo. Mol. Reprod. Dev. 67: 65–69, 2004. © 2004 Wiley‐Liss, Inc.
Comparison of bulk enucleation methods for porcine oocytes
Authors: Savard Christian , Novak Susan , Saint‐Cyr Antoine , Moreau Marc , Pothier Francois , Sirard Marc‐André 
Published: December 2003

AbstractCloning of mammalian oocytes requires that the recipient oocyte is enucleated to remove all genetic material associated with the chromosomes. The procedure currently used in most species requires careful micromanipulation of oocytes treated with cytochalasin B to prevent structural damage. Although functional, this procedure requires time and limits the number of oocytes available for cloning, and our ability to understand the mechanisms of nuclear reprogramming. Therefore, this study aimed at evaluating different procedures to enucleate large pools of oocytes in a time‐efficient manner. Two different approaches were tested. The first approach involved centrifugation of zona‐free oocytes through a percoll gradient to separate the portion containing the chromatin from the cytoplasmic portion. The second used etoposide to prevent chromatin segregation at first metaphase and resulting in the expulsion of all chromosomes in the polar body. Using the chemical approach an average enucleation rate of 39.4 ± 7.5% was obtained, while the centrifugation approach resulted in an average enucleation rate of 66.9 ± 6. In terms of time efficiency, the control manipulation method takes 0.11 min and the centrifugation took an average of 0.52 min per oocyte. The MPF activity at the end of procedure was estimated through the measurement of H1 activity and as expected, the etoposide‐cycloheximide treated oocytes had lower H1 activity which was restored by further incubation in the maturation medium for 5 hr while the centrifugation gave a nonsignificant intermediary result. In conclusion, the results presented suggest that both the chemical and the mechanical methods are usable alternatives to micromanipulation of oocytes to generate a large number of chromosome free cytoplasm for biochemical analysis. Mol. Reprod. Dev. 67: 70–76, 2004. © 2004 Wiley‐Liss, Inc.