bluuebunny/crossref_metadata_2025 huggingface dataset:
The expression and functional significance of the serotonin2Creceptor in murine contact allergy
Authors: El‐Nour Husameldin , Lundeberg Lena , Boman Anders , Abramowski Dorothee , Holst Mikael , Nordlind Klas
Published: June 2007

Abstract: Serotonin (5‐hydroxytryptamine, 5‐HT) was proposed to modulate murine contact allergy by binding to 5‐HT1A/2Areceptors (R). We examined the expression of 5‐HT2CR in the skin of mice with contact allergy, as well as the effects of an agonist and antagonist of this receptor on the elicitation phase of this type of allergy. Immunohistochemistry revealed the presence of 5‐HT2CR on epidermal dendritic cells, and in the inflamed skin the cells expressing this antigen were increased in number (P < 0.01) and exhibited longer dendrites than in the control tissue. Furthermore, the majority of these cells also stained positively for I‐A, a specific marker for Langerhans cells (LCs). Treatment of the skin of sensitized mice in vivo with RO60‐0175 (0.5 and 1.0 mg/kg, once daily for 3 days prior to the challenge with antigen), an agonist for 5‐HT2CR, enhanced the degree of contact eczema (P < 0.05 andP < 0.01 for the two doses respectively), as indicated by ear thickness. This enhancement could be prevented (P < 0.001) by the 5‐HT2CR antagonist SB 242084 at 3 mg/kg. Addition of 5 × 10−5 mol/l RO60‐0175 to murine XS52 cells, which resembles LCs, potentiated their secretion of interleukin (IL)‐1β(P < 0.05); whereas 10−10 mol/l attenuated this secretion (P < 0.05). Under the same conditions, the level of IL‐1βmRNA in these cells (as assessed by RT‐PCR) was unaltered suggesting that this agonist may exert its effect on IL‐1βsecretion at the post‐transcriptional or even at the secretory level. In conclusion, our findings indicate that the 5‐HT2CR is involved in modulating contact allergy in mice.
RNAi‐mediated inhibition of COL1A1 and COL3A1 in human skin fibroblasts
Authors: Wang Qiong , Peng Zhenhui , Xiao Shengxiang , Geng Songmei , Yuan Jingyi , Li Zhengxiao
Published: June 2007

Abstract:  Types I and III collagens are the major collagens comprising skin connective tissue. Defects in these collagens lead to diseases of dermal connective tissue and fibre hyperplasia. RNA interference (RNAi) provides a powerful tool to inhibit specific gene expression. In this study, we generated small interfering RNAs (siRNA) expression cassettes (SECs) by polymerase chain reaction (PCR) as a method to quickly screen the efficacy of siRNAs. We then cloned the most efficient SECs into vectors, using a rapid and novel method intrinsic to the design of the SEC, and transfected human skin fibroblasts (HSF) to generate stable lines. We show that the transfection of SECs into HSFs resulted in specific and effective repression of COL1A1 and COL3A1 expression (5.00% and 6.48% of control levels) provided a rapid method for testing candidate siRNA sequences. We report the use of vector‐based RNAi to establish stable HSF cell lines with persistent knockdown over at least 30 days (25.21% and 22.12% of control levels). These stably modified HSF cell lines may be used for the study of other types of collagen or proteins of the extracellular matrix (ECM).
Involvement of protein kinase C in melatonin’s oncostatic effect in C6 glioma cells
Authors: Martín Vanesa , Herrera Federico , García‐Santos Guillermo , Antolín Isaac , Rodriguez‐Blanco Jezabel , Medina María , Rodriguez Carmen
Published: June 2007

Abstract:  Classical anticancer therapies often are ineffective in patients with malignant glioma who have a survival of <1 year. Our previous studies showed a potent inhibitory effect of melatonin on glioma cell proliferation. This effect seems to be mediated by the well‐known antioxidant properties of this molecule and the negative regulation of some intracellular effectors, such as the kinase Akt or the transcription factor nuclear factor (NF)‐κB. Finally, protein kinase C (PKC) also seems to be implicated in this effect although the intracellular pathways involved have not been elucidated. In this study, we analyzed the role of PKC in the regulation by melatonin of intracellular effectors leading to inhibition of cell proliferation. Activation of PKC by incubation with triphorbol ester acetate (TPA) blocks the inhibitory effect of melatonin on Akt and NF‐κB activity. Moreover, incubation with melatonin induces a decrease in p21 expression in these cells that is partially blocked by co‐incubation with TPA. Taken together, these results suggest that melatonin’s oncostatic effect on glioma cells is mediated, at least in part, by the inhibition of PKC activity which, in turn, results in Akt and NF‐κB activity inhibition and modulation of cell cycle‐related gene expression.
Extra‐esophageal manifestations of gastroesophageal reflux
Authors: Farrokhi F , Vaezi MF
Published: June 2007

Gastroesophageal reflux disease (GERD) is a common medical condition affecting approximately 35–40% of the adult population in the western world. The role of GERD in causing extra‐esophageal symptoms including laryngitis, asthma, cough, chest pain, and dental erosions is increasingly recognized with renewed interest among gastroenterologists and other specialists. Direct injury by mucosal contact, and vagally mediated reflex from distal esophageal acid exposure are the two possible mechanisms by which reflux‐related extra‐esophageal tissue injuries may occur. Several investigational techniques may be used to diagnose gastroesophageal reflux; however, because of the poor sensitivity of endoscopy and pH monitoring, and the poor specificity of laryngoscopy, empiric therapy with proton‐pump inhibitors (PPI) is now considered the initial diagnostic step in patients suspected of having GERD‐related symptoms. In those who improve with such therapy, it is likely that GERD may be the cause of the extra‐esophageal presentation. In those who are unresponsive to such therapy, other diagnostic testing such as impedance/pH monitoring may be reasonable in order to exclude continued acid or weakly acid reflux. However, PPI‐unresponsive patients usually have causes other than GERD for the extra‐esophageal symptoms and signs.
Natural Aesthetics and Grace: the Reality of the World and the Reality of God
Authors: Gilbert Robert J. C.
Published: June 2007

Scientific disciplines seek a truthful description of how things are. One way to think of the way that science does this is to say that science seeks to show how things fit together. In doing this the scientist implicitly makes use of aesthetic and ideal categories, such that aesthetic relationships of things to each other in thought somehow stand for the actual relationships (involving energy, charge, mass and the like). This relationship of ideal thought in the medium of human language to the reality of the world is remarkable. Why is it that we can know anything truthful about the world on the basis of the way we talk to each other? Why is there anything instead of nothing? Scientific practice suggests ways in which these are the same question. It may be that the createdness of the world underlies all truthful human discourses, whether artistic or scientific, mechanical or philosophical.
Inhibitor‐mediated stabilization of the conformational structure of a histone deacetylase‐like amidohydrolase
Authors: Kern Stefanie , Riester Daniel , Hildmann Christian , Schwienhorst Andreas , Meyer‐Almes Franz‐Josef
Published: June 2007

Histone deacetylases are major regulators of eukaryotic gene expression. Not unexpectedly, histone deacetylases are among the most promising targets in cancer therapy. However, despite huge efforts in histone deacetylase inhibitor design, very little is known about the impact of histone deacetylase inhibitors on enzyme stability. In this study, the conformational stability of a well‐established histone deacetylase homolog with high structural similarity (histone deacetylase‐like amidohydrolase from Bordetella/Alcaligenes species FB188) was investigated using denaturation titrations and stopped‐flow kinetics. Based on the results of these complementary approaches, we conclude that the interconversion of native histone deacetylase‐like amidohydrolase into its denatured form involves several intermediates possessing different enzyme activities and conformational structures. The refolding kinetics has shown to be strongly dependent on Zn2+ and to a lesser extent on K+, which underlines their importance not only for catalytic function but also for maintaining the correct conformational structure of the enzyme. Two main unfolding processes of histone deacetylase‐like amidohydrolase were differentiated. The unfolding occurring at submolar concentrations of the denaturant guanidine hydrochloride was not affected by inhibitor binding, whereas the unfolding at higher concentrations of guanidine hydrochloride was strongly affected. It was shown that the known inhibitors suberoylanilide hydroxamic acid and cyclopentylpropionyl hydroxamate are capable of stabilizing the conformational structure of histone deacetylase‐like amidrohydrolase. Judging from the free energies of unfolding, the protein stability was increased by 9.4 and 5.4 kJ·mol−1 upon binding of suberoylanilide hydroxamic acid and cyclopentylpropionyl hydroxamate, respectively.
Overview of the U.S. Department of Energy (DOE) High‐Temperature Superconductivity Program for Large‐Scale Applications
Authors: Haught Debbie , Daley Jim , Bakke Paul , Marchionini Brian
Published: June 2007

High‐temperature superconducting (HTS) power equipment has the potential to become a key 21st century technology for improving the capacity, efficiency, and reliability of the electric delivery system. For example, higher‐capacity HTS power lines could provide a new approach to building transmission and distribution systems that will reduce the footprint and allow additional capacity to be placed in service within existing rights‐of‐way. The U.S. Department of Energy has supported HTS research and development for almost 20 years. Two of its recent cable projects have been commissioned and are now powering over the equivalent of more than 61,000 homes.
YBaCuO and REBaCuO HTS for Applications
Authors: Freyhardt Herbert C.
Published: June 2007

The discovery of electrical conductors that carry loss‐less currents at liquid nitrogen temperatures and above, high‐temperature superconductors (HTS), inspired the imaginations of scientists and engineers in an unprecedented way. It culminated in a broad search for an understanding of their basic phenomena and properties, but also for new classes of the HTS. The availability of these materials created novel ideas of their use for effective and economical generation, transport, and use of electric energy. YBaCuO and related REBaCuO HTS compounds still belong to the most attractive workhorses. This contribution intends to illustrate the efforts to manufacture from these HTS bulk monoliths, wires, tapes, or conductors, which would be needed for novel components and devices for electrical and power engineering, devices that offer not only an effective use of energy but also broad environmental benefits and, furthermore, help to safe resources. The research and developments discussed are mainly focused on efforts in Europe.
Advancing YBCO‐Coated Conductors for Use on Air Platforms
Authors: Barnes Paul N.
Published: June 2007

With progress of the YBCO‐coated conductor to longer lengths, application of the conductor is nearing. An overview of a couple of current U.S. Air Force application programs is presented. A discussion is then made of where research and development of the YBCO‐coated conductor should progress and examples in the U.S. Air Force program. These areas include magnetic flux pinning in YBCO thin films, reduction of the ac losses experienced in the YBCO conductor, and stability and quench issues when implementing the YBCO‐coated conductor.
Quality Control and Thermal Shock Damage Characterization of High‐Temperature Ceramics by Ultrasonic Pulse Velocity Testing
Authors: Boccaccini Dino N. , Romagnoli Marello , Veronesi Paolo , Cannio Maria , Leonelli Christina , Pellacani Gian , Husovic Tatjana Volkov , Boccaccini Aldo R.
Published: June 2007

Ultrasonic pulse velocity testing was carried out to perform nondestructive quality control of refractory plates used as substrates in fast firing of porcelain whiteware. Two cordierite‐mullite refractory compositions characterized by different microstructure morphologies and crack propagation behavior were investigated after a number of industrial thermal cycles. Ultrasonic velocity measurements were used to determine the presence of internal voids/cracks in the samples, originating from the manufacturing procedure. A brief discussion about the correlation between microstructure, crack propagation behavior, and thermal shock resistance is presented. Empirical models were developed to predict the service life of refractory plates from measured values of ultrasonic velocities on as‐received samples.
Black Ceramic Thermal Control Coating Prepared by Microarc Oxidation
Authors: Wu Xiaohong , Qin Wei , Cui Bo , Jiang Zhaohua , Lu Weiqiang
Published: June 2007

The black thermal control coating was produced by in situ growth on an aluminum alloy by a relatively new method: microarc oxidation (MAO). In this article, the black MAO thermal control coating that had a high solar absorptance and a high infrared emittance was produced in a 0.1 mol/L NaAlO2 electrolyte system. The optical properties and phase composition of the coating across the surface to the substrate–coating interface were studied by a spectrophotometer and X‐ray diffraction. Experimental results show that the MAO coating can reach a solar absorptance value >0.90 and an infrared emittance value >0.77.
Residual Strength Prediction of SiC/SiC Composite Exposed to Service Environments with Factor Analysis Method
Authors: Wu Shoujun , Cheng Laifei , Zhang Litong , Xu Yongdong
Published: June 2007

The residual strength prediction of thermal structural materials exposed to different service environments can be conducted using a factor analysis method. As an example, the residual flexural strengths of a 3D silicon carbide (SiC)/SiC composite exposed to vacuum, Ar–O2, and Ar–O2–H2O atmospheres, respectively, were predicted in the present study. The residual strength of the composite was expressed as a function of environmental factors. By analyzing the partial changes of strength of the composite from individual environmental factors, the residual strength of the composite exposed to service environments can be calculated according to the sum of the partial changes of strength. This factor analysis method was useful to illustrate trends of residual flexural strength of 3D SiC/SiC exposed to service environments.
Conserving What and for Whom? Why Conservation Should Help Meet Basic Human Needs in the Tropics
Authors: Kaimowitz David , Sheil Douglas
Published: June 2007

For hundreds of millions of people, biodiversity is about eating, staying healthy, and finding shelter. Meeting these people's basic needs should receive greater priority in the conservation agenda. Wild and semi‐wild plants and animals contribute significantly to nutrition, health care, income, and culture in developing countries, and the poorest and most vulnerable people often rely on those resources most. Depleting those resources or making them inaccessible can impoverish these people even further. ‘Pro‐poor conservation’—that is, conservation that aims to support poor people—explicitly seeks to address basic human needs. Such an emphasis has many potential synergies with more conventional conservation goals. Nonetheless, pro‐poor conservation requires a distinct attitude to gauging conservation outcomes and a different approach to conservation science. Biologists can make a vital contribution.
Expressional and Biochemical Characterization of Rice Disease Resistance Gene Xa3/Xa26 Family
Authors: Xu Songjie , Cao Yinglong , Li Xianghua , Wang Shiping
Published: June 2007

The rice (Oryza sativa L.) Xa3/Xa26 gene, conferring race‐specific resistance to bacterial blight disease and encoding a leucine‐rich repeat (LRR) receptor kinase‐like protein, belongs to a multigene family consisting of tandem clustered homologous genes, colocalizing with several uncharacterized genes for resistance to bacterial blight or fungal blast. To provide more information on the expressional and biochemical characteristics of the Xa3/Xa26 family, we analyzed the family members. Four Xa3/Xa26 family members in the indica rice variety Teqing, which carries a bacterial blight resistance gene with a chromosomal location tightly linked to Xa3/Xa26, and five Xa3/Xa26 family members in the japonica rice variety Nipponbare, which carries at least one uncharacterized blast resistance gene, were constitutively expressed in leaf tissue. The result suggests that some of the family members may be candidates of these uncharacterized resistance genes. At least five putative N‐glycosylation sites in the LRR domain of XA3/XA26 protein are not glycosylated. The XA3/XA26 and its family members MRKa and MRKc all possess the consensus sequences of paired cysteines, which putatively function in dimerization of the receptor proteins for signal transduction, immediately before the first LRR and immediately after the last LRR. However, no homo‐dimer between the XA3/XA26 molecules or hetero‐dimer between XA3/XA26 and MRKa or MRKc were formed, indicating that XA3/XA26 protein might function either as a monomer or a hetero‐dimer formed with other protein outside of the XA3/XA26 family. These results provide valuable information for further extensive investigation into this multiple protein family.
Development of Oryza rufipogon and O. sativa Introgression Lines and Assessment for Yield‐related Quantitative Trait Loci
Authors: Tan Lubin , Liu Fengxia , Xue Wei , Wang Guijuan , Ye Sheng , Zhu Zuofeng , Fu Yongcai , Wang Xiangkun , Sun Chuanqing
Published: June 2007

Introgression lines population was effectively used in mapping quantitative trait loci (QTLs), identifying favorable genes, discovering hidden genetic variation, evaluating the action or interaction of QTLs in multiple conditions and providing the favorable experimental materials for plant breeding and genetic research. In this study, an advanced backcross and consecutive selfing strategy was used to develop introgression lines (ILs), which derived from an accession of Oryza rufipogon Griff. collected from Yuanjiang County, Yunnan Province of China, as the donor, and an elite indica cultivar Teqing (O. sativa L.), as the recipient. Introgression segments from O. rufipogon were screened using 179 polymorphic simple sequence repeats (SSR) markers in the genome of each IL. Introgressed segments carried by the introgression lines population contained 120 ILs covering the whole O. rufipogon genome. The mean number of homozygous O. rufipogon segments per introgression line was about 3.88. The average length of introgressed segments was approximate 25.5 cM, and about 20.8% of these segments had sizes less than 10 cM. The genome of each IL harbored the chromosomal fragments of O. rufipogon ranging from 0.54% to 23.7%, with an overall average of 5.79%. At each locus, the ratio of substitution of O. rufipogon alleles had a range of 1.67‐9.33, with an average of 5.50. A wide range of alterations in morphological and yield‐related traits were also found in the introgression lines population. Using single‐point analysis, a total of 37 putative QTLs for yield and yield components were detected at two sites with 7%‐20% explaining the phenotypic variance. Nineteen QTLs (51.4%) were detected at both sites, and the alleles from O. rufipogon at fifteen loci (40.5%) improved the yield and yield components in the Teging background. These O. rufipogon ‐O. sativa introgression lines will serve as genetic materials for identifying and using favorable genes from common wild rice.
Genome‐wide Analysis of Kelch Repeat‐containing F‐box Family
Authors: Sun Yujin , Zhou Xiaofan , Ma Hong
Published: June 2007

The ubiquitin‐dependent protein degradation pathway plays diverse roles in eukaryotes. Previous studies indicate that both F‐box and Kelch motifs are common in a variety of organisms. F‐box proteins are subunits of E3 ubiquitin ligase complexes called SCFs (SKP1, Cullin1, F‐box protein, and Rbx1); they have an N‐terminal F‐box motif that binds to SKP1 (S‐phase kinase associated protein), and often have C‐terminal protein‐protein interaction domains, which specify the protein substrates for degradation via the ubiquitin pathway. One of the most frequently found protein interaction domains in F‐box proteins is the Kelch repeat domain. Although both the F‐box and Kelch repeats are ancient motifs, Kelch repeats‐containing F‐box proteins (KFB) have only been reported for human and Arabidopsis previously. The recent sequencing of the rice genome and other plant genomes provides an opportunity to examine the possible evolution history of KFB. We carried out extensive BLAST searches to identify putative KFBs in selected organisms, and analyzed their relationships phylogenetically. We also carried out the analysis of both gene duplication and gene expression of the KFBs in rice and Arabidopsis. Our study indicates that the origin of KFBs occurs before the divergence of animals and plants, and plant KFBs underwent rapid gene duplications.
Micro RNAs and Short‐interfering RNAs in Plants
Authors: Sunkar Ramanjulu , Zhu Jian‐Kang
Published: June 2007

Gene silencing can occur either at the transcriptional level or post‐transcriptional level or both. Many instances of sequence‐specific silencing requires small RNAs that can be divided into two major classes: microRNAs (miRNAs) and short‐interfering RNAs (siRNAs). miRNAs function in post‐transcriptional gene silencing by guiding mRNA degradation or translational repression. Endogenous siRNAs are more diverse in plants than in animals and can direct post‐transcriptional gene silencing through mRNA degradation or transcriptional gene silencing by triggering DNA methylation and histone modifications. This review discusses recent advances in the field of small RNA‐guided gene silencing in plants including rice.
A Microarray Based Genomic Hybridization Method for Identification of New Genes in Plants: Case Analyses of Arabidopsis and Oryza
Authors: Fan Chuanzhu , Vibranovski Maria D. , Chen Ying , Long Manyuan
Published: June 2007

To systematically estimate the gene duplication events in closely related species, we have to use comparative genomic approaches, either through genomic sequence comparison or comparative genomic hybridization (CGH). Given the scarcity of complete genomic sequences of plant species, in the present study we adopted an array based CGH to investigate gene duplications in the genus Arabidopsis. Fragment genomic DNA from four species, namely Arabidopsis thaliana, A. lyrata subsp. lyrata, A. lyrata subsp. petraea, and A. halleri, was hybridized to Affymetrix (Santa Clara, CA, USA) tiling arrays that are designed from the genomic sequences of A. thaliana. Pairwise comparisons of signal intensity were made to infer the potential duplicated candidates along each phylo‐genetic branch. Ninety‐four potential candidates of gene duplication along the genus were identified. Among them, the majority (69 of 94) were A. thaliana lineage specific. This result indicates that the array based CGH approach may be used to identify candidates of duplication in other plant genera containing closely related species, such as Oryza, particularly for the AA genome species. We compared the degree of gene duplication through retrotransposon between O. sativa and A. thaliana and found a strikingly higher number of chimera retroposed genes in rice. The higher rate of gene duplication through retroposition and other mechanisms may indicate that the grass species is able to adapt to more diverse environments.
Evolutionary Genomics of Weedy Rice in the USA
Authors: Olsen Kenneth M. , Caicedo Ana L. , Jia Yulin
Published: June 2007

Red rice is an interfertile, weedy form of cultivated rice (Oryza sativa L.) that competes aggressively with the crop in the southern US, reducing yields and contaminating harvests. No wild Oryza species occur in North America and the weed has been proposed to have evolved through multiple mechanisms, including “de‐domestication” of US crop cultivars, accidental introduction of Asian weeds, and hybridization between US crops and Asian wild/weedy Oryza strains. The phenotype of US red rice ranges from “crop mimics”, which share some domestication traits with the crop, to strains closely resembling Asian wild Oryza species. Assessments of genetic diversity have indicated that many weed strains are closely related to Asian taxa (including indica and aus rice varieties, which have never been cultivated in the US, and the Asian crop progenitor O. rufipogon), whereas others show genetic similarity to the tropical japonica varieties cultivated in the southern US. Herein, we review what is known about the evolutionary origins and genetic diversity of US red rice and describe an ongoing research project to further characterize the evolutionary genomics of this aggressive weed.
Molecular Population Genetics of Rice Domestication
Authors: Tang Tian , Shi Suhua
Published: June 2007

Domestication is a selection process that genetically modifies species to meet human needs. A most intriguing feature of domestication is the extreme phenotypic diversification among breeds. What could be the ultimate source of such genetic variations? Another notable outcome of artificial selection is the reduction in the fitness of domesticated species when they live in the wild without human assistance. The complete sequences of the two subspecies of rice cultivars provide an opportunity to address these questions. Between the two subspecies, we found much higher rates of non‐synonymous (N) than synonymous (S) substitutions and the N/S ratios are higher between cultivars than between wild species. Most interestingly, substitutions of highly dissimilar amino acids that are deleterious and uncommon between natural species are disproportionately common between the two subspecies of rice. We suggest strong selection in the absence of effective recombination may be the driving force, which we called the domestication‐associated Hill‐Robertson effect. These hitchhiking mutations may contribute to some fitness reduction in cultivars. Comparisons of the two genomes also reveal the existence of highly divergent regions in the genomes. Haplotypes in these regions often form highly polymorphic linkage blocks that are much older than speciation between wild species. Genes from such regions could contribute to the differences between indica and japonica and are likely to be involved in the diversifying selection under domestication. Their existence suggests that the amount of genetic variation within the single progenitor species Oryza rufipogon may be insufficient to account for the variation among rice cultivars, which may come from a more inclusive gene pool comprising most of the A‐genome wild species. Genes from the highly polymorphic regions also provide strong support for the independent domestication of the two subspecies. The genomic variation in rice has revealing implications for studying the genetic basis of indica‐japonica differentiation under rice domestication and subsequent improvement.
Identification of Chromosomes from Multiple Rice Genomes Using a Universal Molecular Cytogenetic Marker System
Authors: Tang Xiaomin , Bao Weidong , Zhang Wenli , Cheng Zhukuan
Published: June 2007

To develop reliable techniques for chromosome identification is critical for cytogenetic research, especially for genomes with a large number and smaller‐sized chromosomes. An efficient approach using bacterial artificial chromosome (BAC) clones as molecular cytological markers has been developed for many organisms. Herein, we present a set of chromosomal arm‐specific molecular cytological markers derived from the gene‐enriched regions of the sequenced rice genome. All these markers are able to generate very strong signals on the pachytene chromosomes of Oryza sativa L. (AA genome) when used as fluorescence in situ hybridization (FISH) probes. We further probed those markers to the pachytene chromosomes of O. punctata (BB genome) and O. officinalis (CC genome) and also got very strong signals on the relevant pachytene chromosomes. The signal position of each marker on the related chromosomes from the three different rice genomes was pretty much stable, which enabled us to identify different chromosomes among various rice genomes. We also constructed the karyotype for both O. punctata and O. officinalis with the BB and CC genomes, respectively, by analysis of 10 pachytene cells anchored by these chromosomal arm‐specific markers.
Genome‐Wide Comparative Analysis and Expression Pattern of TCP Gene Families in Arabidopsis thaliana and Oryza sativa
Authors: Yao Xuan , Ma Hong , Wang Jian , Zhang Dabing
Published: June 2007

Several TCP genes have been reported to play important roles in plant development; the TCP homologs encode a plant‐specific family of putative transcription factors. To understand the evolutionary relationship of TCP genes of Arabidopsis thaliana and Oryza sativa L. (hereafter called rice), we have identified 23 and 22 TCP genes in the Arabidopsis and rice genomes, respectively. Using phylogenetic analysis, we grouped these TCP genes into three classes. In addition, the motifs outside the TCP domain further support the evolutionary relationships among these genes. The genome distribution of the TCP genes strongly supports the hypothesis that genome‐wide and tandem duplication contributed to the expansion of the TCP gene family. The expression pattern of the TCP genes was analyzed further, providing useful clues about the function of these genes.
The Puzzle of Rice Domestication
Authors: Sang Tao , Ge Song
Published: June 2007

The origin of cultivated rice has puzzled plant biologists for decades. This is due, at least in part, to the complex evolutionary dynamics in rice cultivars and wild progenitors, particularly rapid adaptive differentiation and continuous gene flow within and between cultivated and wild rice. The long‐standing controversy over single versus multiple and annual versus perennial origins of cultivated rice has been brought into shaper focus with the rapid accumulation of genetic and phylogenetic data. Molecular phylogenetic analyses revealed ancient genomic differentiation between rice cultivars, suggesting that they were domesticated from divergent wild populations. However, the recently cloned domestication gene sh4, responsible for the reduction of grain shattering from wild to cultivated rice, seems to have originated only once. Herein, we propose two models to reconcile apparently conflicting evidence regarding rice domestication. The snow‐balling model considers a single origin of cultivated rice. In this model, a core of critical domestication alleles was fixed in the founding cultivar and then acted to increase the genetic diversity of cultivars through hybridization with wild populations. The combination model considers multiple origins of cultivated rice. In this model, initial cultivars were domesticated from divergent wild populations and fixed different sets of domestication alleles. Subsequent crosses among these semi‐domesticated cultivars resulted in the fixation of a similar set of critical domestication alleles in the contemporary cultivars. In both models, introgression has played an important role in rice domestication. Recent and future introgression of beneficial genes from the wild gene pool through conventional and molecular breeding programs can be viewed as the continuation of domestication.
Identification, Expression and Functional Analysis of a Receptor‐like Cytoplasmic Kinase, OsRLCK1, in Rice
Authors: Kong Zhaosheng , Xu Wenying , Li Qun , Xue Yongbiao
Published: June 2007

Pollination involves a series of complex cellular interactions and signal transduction events. Numerous reports have suggested a central role for protein kinases in pollen germination and pollen tube growth and a large number of receptor‐like kinases have been detected exclusively in pollen in higher plants. However, few are well characterized, especially for the receptor‐like cytoplasmic kinases. Here we report a receptor‐like kinase gene, OsRLCK1, which belongs to the receptor‐like cytoplasmic kinase VIII subfamily. Real‐time quantitative polymerase chain reaction analysis and whole mount RNA in situ hybridization showed that OsRLCK1 is a pollen‐specific gene and expressed only in the mature pollen. When expressed in the onion epidermal cells, the OsRLCK1‐GFP fusion protein was diffused throughout the cell, indicating its cytoplasmic and nuclear localization. The Maltose Binding Protein‐OsRLCK1 recombinant protein was found to be capable of autophosphorylation on threonine residue, showing that it encodes a functional kinase. These results suggest that OsRLCK1 is likely to play a role in a signaling pathway associated with pollen performance during pollination in rice.
Super Hybrid Rice Breeding in China: Achievements and Prospects
Authors: Cheng Shi‐Hua , Cao Li‐Yong , Zhuang Jie‐Yun , Chen Shen‐Guang , Zhan Xiao‐Deng , Fan Ye‐Yang , Zhu De‐Feng , Min Shao‐Kai
Published: June 2007

Hybrid rice has contributed greatly to the self‐sufficiency of food supply in China. To meet the future demand for rice production, a national program on super rice breeding was established in China in 1996. The corresponding targets, breeding strategies and most significant advances are reviewed in this paper. New plant type models have been modified to adjust to various rice growing regions. In recognition of the importance of applying parents with intermediate subspecies differentiation in increasing F1 yield, medium type parental lines were selected from populations derived from inter‐subspecies crosses with the assistance of DNA markers for subspecies differentiation. Results also indicate that a substantial increase of biomass is the basis for further enhancement of the grain yield potential, and amelioration of leaf characteristics is helpful in increasing the photosynthetic rate. Thirty‐four super hybrid rice varieties have been released commercially, growing in a total area of 13.5 million hm2 and producing 6.7 thousand million kg more rice in 1998‐2005. Although remarkable progress has been made in super hybrid rice breeding in China, selections on the root system and integration of more biotechnological tools remain a great challenge.
Hypervelocity stars and the environment of Sgr A*
Authors: Sesana Alberto , Haardt Francesco , Madau Piero
Published: June 2007

Hypervelocity stars (HVSs) are a natural consequence of the presence of a massive nuclear black hole (Sgr A*) in the Galactic Centre. Here we use the Brown et al. sample of unbound and bound HVSs together with numerical simulations of the propagation of HVSs in the Milky Way halo to constrain three plausible ejection mechanisms: (i) the scattering of stars bound to Sgr A* by an in-spiralling intermediate-mass black hole (IMBH); (ii) the disruption of stellar binaries in the tidal field of Sgr A*; and (iii) the two-body scattering of stars off a cluster of stellar-mass black holes orbiting Sgr A*. We compare the predicted radial and velocity distributions of HVSs with the limited-statistics data set currently available, and show that the IMBH model appears to produce a spectrum of ejection velocities that is too flat. Future astrometric and deep wide-field surveys of HVSs should shed unambiguous light on the stellar ejection mechanism and probe the Milky Way potential on scales as large as 200 kpc.
Barriers to Understanding Racial Differences in Intelligence: Commentary on Hunt and Carlson (2007)
Authors: Brody Nathan
Published: June 2007

Hunt and Carlson (2007) , (this issue) present sensible guidelines for the conduct of research on group differences in intelligence. In this response, I want to indicate why I believe that their call for more research is not likely, in the near term, to lead to a clarification of the reasons for racial differences in performance on tests of intelligence. There are three barriers to progress in this field that I will consider. First, there are gaps in knowledge that render the interpretation of research problematic (see Brody, 2003 , for a discussion of the indeterminate nature of research alleged to support a genetic basis for racial differences in intelligence). Second, structural inequalities in social arrangements may lead to problematic outcomes for many studies of racial differences in intelligence. Third, conceptual confusions derived from the consideration of race as a category and not as a continuum render group comparisons suspect.
Mechanisms of hypotonic inhibition of the sodium, proton exchanger type 1 (NHE1) in a biliary epithelial cell line (Mz‐Cha‐1)
Authors: Elsing C. , Gosch I. , Hennings J. C. , Hübner C. A. , Herrmann T.
Published: June 2007

Aim:  To elucidate the cellular events that results in inhibition of Na+, H+ exchanger type 1 (NHE1) by hypotonicity.

Methods:  Intracellular pH (pHi) was measured in biliary epithelial cells, with the pH‐sensitive fluorochrome 2′,7′‐bis‐(carboxyethyl)‐5(6)‐carboxyfluorescein (BCECF) using a spectrophotometer. Regulatory volume decrease (RVD) was analysed from confocal images. Changes in NHE1 membrane content were visualized by confocal laser scanning microscopy after transfection of Mz‐Cha‐1 cells with a NHE1–cMyc fusion protein.

Results:  In Mz‐Cha‐1 cells hypotonicity (−80 mmol L−1 NaCl) inhibited endogenous Na+, H+ exchange. Tyrosine and serine kinase inhibitors were incapable to prevent inhibition. As several signalling pathways influence Na+, H+ exchange, we tested the effect of the Ca++, Calmodulin, protein kinase C or the cAMP, protein kinase A system on inhibition of Na+, H+ exchange by hypotonic challenge, but neither system was involved. In contrast, cytoskeleton did influence the effect of hypotonicity. Inhibition of microtubule polymerization by colchicine prevented inhibition of NHE1, and also restored Na+, H+ exchange kinetics. Specific inhibition of Src kinases with PP2, attenuated pHi recovery rate from 1.93 ± 0.16 pH units min−1 (normotonic environment) to 1.02 ± 0.50 pH units min−1 (hypotonic environment). Membrane staining of NHE1–cMyc fusion protein was maintained after hypotonic exposure in colchicine pre‐treated cells as was RVD. Microfilament inhibition by cytochalasin preserved NHE1 activity. Inhibition of phosphatidylinositol‐3′‐kinase was unable to restore Na+, H+ exchange activity.

Conclusion:  We conclude that regulation of Na+, H+ exchange during RVD is mediated by cytoskeletal elements. This receptor independent pathway is regulated by Src.
Physiology and pathology of collagen receptors
Authors: Popova S. N. , Lundgren‐Åkerlund E. , Wiig H. , Gullberg D.
Published: June 2007

Just before the transition from pre‐genomic to the post‐genomic era, the two latest members of the mammalian integrin family were identified. These integrins, which were named α10β1 and α11β1, are both collagen receptors and are related. Rather than being twins, they can be regarded as close cousins. They both belong to the subfamily of integrins that contain an I‐domain in the α subunit. This domain is also the part that endows these integrins with the capacity to bind the GFOGER sequence in collagens. In the current review, we summarize and update the current knowledge about the in vitro and in vivo functions of these integrins.
Magnetic resonance imaging findings of neuroaxonal dystrophy in a papillon puppy
Authors: Tamura S. , Tamura Y. , Uchida K.
Published: June 2007

A 3·5‐month‐old papillon puppy was brought to our clinic with chief complaints of progressive quadriparesis, ataxia and head tremor. Lesions in the cerebellum, brainstem and spinal cord were suspected on the basis of a neurological examination. No abnormality was found in a clinicopathological examination or on magnetic resonance imaging. On the basis of these results differential diagnoses including an inflammatory disease, a degenerative condition or a storage disorder were considered. Subsequently, the signs progressed and glossoplegia and dysphagia developed at six months of age. At a second magnetic resonance imaging, severe atrophy of the entire brain was found. After these examinations, the puppy was euthanased and histopathologically diagnosed with neuroaxonal dystrophy. Because magnetic resonance imaging detected abnormal features that were characteristic of neuroaxonal dystrophy in this case, we speculate that magnetic resonance imaging can assist in the pre‐mortem diagnosis of this disease.
Comparison of recovery times and complication rates between a modified slanted slot and the standard ventral slot for the treatment of cervical disc disease in 20 dogs
Authors: McCartney W.
Published: June 2007

Objectives: To compare the recovery times and complication rates between the standard ventral slot and the modified slanted ventral slot for the treatment of cervical disc disease in dogs with the same neurological grade.

Methods: A retrospective analysis of an equal number of cervical disc cases for each procedure was carried out specifically to determine the recovery times and complication rates. To allow for meaningful comparison only dogs that had the same neurological grade were selected. Outcomes were determined by time to recover and the resolution of symptoms and complications were graded in terms of severity.

Results: The standard ventral slot cases had a higher complication rate than the modified slanted slot cases with one case dying in the postoperative period. However, the modified slanted slot cases on average had a marginally slower recovery time than standard ventral slot cases.

Clinical Significance: Ventral decompression using the modified slanted slot instead of the standard ventral slot will allow for spinal decompression with potentially less destabilisation, and incur a similar incidence of complications and rate of recovery.
Fluid Inclusion, Rare‐Earth Element and Stable Isotope Study of Carbonate Minerals from the Pongkor Epithermal Gold–Silver Deposit, West Java, Indonesia
Authors: Warmada I Wayan , Lehmann Bernd , Simandjuntak Marolop , Hemes Herian Sudarman
Published: June 2007

The Pongkor gold–silver deposit is the largest low‐sulfidation epithermal precious metal deposit in Indonesia, and is of Pliocene age. The deposit consists of nine major subparallel quartz–adularia–carbonate veins with very low sulfide content. Vein infill records five paragenetic sequences, dominated by calcite in the early stage and quartz in the later stage of the hydrothermal evolution. Fluid inclusions in hydrothermal calcite and quartz of all stages indicate a temperature ranging from 180 to 220°C and a meteoric water origin (very low salinity close to 0 wt% NaCl equivalent). Carbon isotope data on calcite display a narrow range from −6.5 to −3.0‰δ13C. The oxygen isotope values have a wider range of +4.6 to +10.1‰δ18O. The broadly positive correlation of the δ13C versus δ18O plot suggests that the carbon species, which equilibrated during the formation of calcite, is dominated by H2CO3 not far from equilibrium with HCO3−. The abundance of rare earth and yttrium (REY) in carbonate samples is very low (>REY mostly <2 ppm). However, there is always a positive Eu anomaly, which indicates a deeper fluid reservoir at >250°C.
Chemical Composition of Rock‐Forming Minerals in Copper–Gold‐Bearing Tonalite Porphyries at the Batu Hijau Deposit, Sumbawa Island, Indonesia: Implications for Crystallization Conditions and Fluorine–Chlorine Fugacity
Authors: Idrus Arifudin , Kolb Jochen , Meyer F. Michael
Published: June 2007

Copper–gold mineralization at the world‐class Batu Hijau porphyry deposit, Sumbawa Island, Indonesia, is closely related to the emplacement of multiple stages of tonalite porphyries. Petrographic examination indicates that at least two texturally distinct types of tonalite porphyries are currently recognized in the deposit, which are designated as “intermediate tonalite” and “young tonalite”. They are mineralogically identical, consisting of phenocrysts of plagioclase, hornblende, quartz, biotite and magnetite ± ilmenite, which are set in a medium‐coarse grained groundmass of plagioclase and quartz. The chemical composition of the rock‐forming minerals, including plagioclase, hornblende, biotite, magnetite and ilmenite in the tonalite porphyries was systematically analyzed by electron microprobe. The chemical data of these minerals were used to constrain the crystallization conditions and fluorine–chlorine fugacity of the corresponding tonalitic magma during its emplacement and crystallization. The crystallization conditions, including temperature (T), pressure (P) and oxygen fugacity (fO2), were calculated by applying the hornblende–plagioclase and magnetite–ilmenite thermometers and the Al‐in‐hornblende barometer. The thermobarometric data indicate that the tonalite porphyries were emplaced at 764 ± 22°C and 1.5 ± 0.3 × 105 kPa. If the pressure is assumed to be lithostatic, it is interpreted that the rim of hornblende and plagioclase phenocrysts crystallized at depths of approximately 5.5 km. As estimated from magnetite–ilmenite thermometry, the subsolidus conditions of the tonalite intrusion occurred at temperatures of 540–590°C and log fO2 ranging from −20 to −15 (between Ni‐NiO and hematite–magnetite buffers). This occurred at relatively high fO2 (oxidizing) condition. The fluorine–chlorine fugacity in the magma during crystallization was determined on the basis of the chemical composition of magmatic biotite. The calculation indicates that the fluorine–chlorine fugacity, represented by log (fH2O)/(fHF) and (fH2O)/(fHCl) in the corresponding tonalitic magma range from 4.31 to 4.63 and 3.62 to 3.79, respectively. The chlorine fugacity (HCl) to water (H2O) is relatively higher than the fluorine fugacity (HF to water), reflecting a high activity of chlorine in the tonalitic magma during crystallization. The relatively higher activity of chlorine (rather than fluorine) may indicate the significant role of chloride complexes (CuCl2− and AuCl2−) in transporting and precipitating copper and gold at the Batu Hijau deposit.
Behavior of Major and Trace Elements during Ore Deposition: Example from the Low‐Sulfidation Pantingan Gold System, Mount Mariveles, Bataan, Philippines
Authors: Payot Betchaida D. , Tamayo Rodolfo A. , Maglambayan Victor B. , Dimalanta Carla B. , Yumul Graciano P. , Suzuki Shigeyuki , Zhou Mei‐Fu
Published: June 2007

The evaluation of the relatively fresh host rock and altered rock samples associated with the Pantingan Gold System exposed in Mount Mariveles, Bataan yield several notable observations that are useful in pinpointing potential gold pathfinder elements. Geochemical and petrologic analysis showed that the altered rocks can be subdivided into rocks that underwent propylitic alteration (group 1), argillized rocks with silica contents similar to those of the fresh host rocks (group 2), argillized but not strongly silicified rocks (group 3) and argillized and strongly silicified rocks (group 4). Selected element ratio patterns in the altered rocks and gold concentrations in gold‐bearing quartz veins vary between the rock groups. Moreover, mass balance calculation also reflected the geochemical observations pertaining to the gains and losses of SiO2, Fe2O3+ MgO, CaO + Na2O and K2O, which are believed to be chemical reactions (i.e. breakdown of plagioclase, silica inundation or leaching, sulfide and calcite formation) caused by the influx of hydrothermal fluids.