Immunolocalization of the 38.3 kDa calponin-like protein in stratified muscles of the tail of Schistosoma japonicum cercariae

Calponins are proteins present in vertebrate smooth musculature where they occur in association with thin myofilaments. Calponins are not present in vertebrate or invertebrate striated muscles. The blood fluke Schistosoma japonicum expresses a 38.3-kDa protein that bears substantial homology with vertebrate calponin and occurs entirely within smooth musculature of adults. Calponin-like immunoreactivity has been demonstrated in smooth muscles of many invertebrate phyla. The Schistosoma japonicum calponin has been localised in smooth myofibrils of adults where it is associated with myofilaments and sarcoplasmic reticulum. In this study, the ultrastructural localisation of the protein in muscles of S. japonicum cercariae is described. The protein is present in smooth muscles of the forebody and the stratified muscle of the tail. Within the stratified layer, the protein occurs predominantly in transverse arrays of sarcoplasmic reticulum. The localisation data suggest that the calponin-like protein of S. japonicum is involved in contraction of the stratified tail muscle. Furthermore, the presence of a calponin system in the stratified muscle suggests that this muscle is simply a superior form of muscle, closely related to smooth muscles that use a caldesmin-calponin system in contraction. (C) 2001 Elsevier Science Ireland Ltd. All rights reserved.

Izergin-Korepin model with a boundary

The Izergin-Korepin model on a semi-infinite lattice is diagonalized by using the level-one vertex operators of the twisted quantum affine algebra U-q[((2))(2)]. We give the bosonization of the vacuum state with zero particle content. Excitation states are given by the action of the vertex operators on the vacuum state. We derive the boundary S-matrix. We give an integral expression of the correlation functions of the boundary model, and derive the difference equations which they satisfy. (C) 2001 Elsevier Science B.V. All rights reserved.

Should optional properties be used in conceptual modelling? A theory and three empirical tests

An important feature of some conceptual modelling grammars is the features they provide to allow database designers to show real-world things may or may not possess a particular attribute or relationship. In the entity-relationship model, for example, the fact that a thing may not possess an attribute can be represented by using a special symbol to indicate that the attribute is optional. Similarly, the fact that a thing may or may not be involved in a relationship can be represented by showing the minimum cardinality of the relationship as zero. Whether these practices should be followed, however, is a contentious issue. An alternative approach is to eliminate optional attributes and relationships from conceptual schema diagrams by using subtypes that have only mandatory attributes and relationships. In this paper, we first present a theory that led us to predict that optional attributes and relationships should be used in conceptual schema diagrams only when users of the diagrams require a surface-level understanding of the domain being represented by the diagrams. When users require a deep-level understanding, however, optional attributes and relationships should not be used because they undermine users' abilities to grasp important domain semantics. We describe three experiments which we then undertook to test our predictions. The results of the experiments support our predictions.

Integrable open boundary conditions for the Bariev model of three coupled X Y spin chains

The integrable open-boundary conditions for the Bariev model of three coupled one-dimensional XY spin chains are studied in the framework of the boundary quantum inverse scattering method. Three kinds of diagonal boundary K-matrices leading to nine classes of possible choices of boundary fields are found and the corresponding integrable boundary terms are presented explicitly. The boundary Hamiltonian is solved by using the coordinate Bethe ansatz technique and the Bethe ansatz equations are derived. (C) 2001 Elsevier Science B.V. All rights reserved.

Genomic organization of the CC chemokine MIP-3 alpha/CCL20/LARC/EXODUS/SCYA20, showing gene structure, splice variants, and chromosome localization

We describe the genomic organization of a recently identified CC chemokine, MIP3 alpha /CCL20 (HGMW-approved symbol SCYA20). The MIP-3 alpha /CCL20 gene was cloned and sequenced, revealing a four exon, three intron structure, and was localized by FISK analysis to 2q35-q36. Two distinct cDNAs were identified, encoding two forms of MIP-3 alpha /CCL20, Ala MLP-3 alpha /CCL20 and Ser MIP-3 alpha /CCL20, that differ by one amino acid at the predicted signal peptide cleavage site. Examination of the sequence around the boundary of intron 1 and exon 2 showed that use of alternative splice acceptor sites could give rise to Ata MIP-3 alpha /CCL20 or Ser MIP-3 alpha /CCL20. Both forms of MIP-3cr/CCL20 were chemically synthesized and tested for biological activity. Both flu antigen plus IL-a-activated CD4(+) and CD8(+) T lymphoblasts and cord blood-derived dendritic cells responded to Ser and Ala MIP-3 alpha /CCL20. T lymphocytes exposed only to IL-2 responded inconsistently, while no response was detected in naive T lymphocytes, monocytes, or neutrophils. The biological activity of Ser MIP-3 alpha /CCL20 and Ala MIP-3 alpha /CCL20 and the tissue-specific preference of different splice acceptor sites are not yet known. (C) 2001 Academic Press.

A generalised dynamic model for char particle gasification with structure evolution and peripheral fragmentation

A generalised model for the prediction of single char particle gasification dynamics, accounting for multi-component mass transfer with chemical reaction, heat transfer, as well as structure evolution and peripheral fragmentation is developed in this paper. Maxwell-Stefan analysis is uniquely applied to both micro and macropores within the framework of the dusty-gas model to account for the bidisperse nature of the char, which differs significantly from the conventional models that are based on a single pore type. The peripheral fragmentation and random-pore correlation incorporated into the model enable prediction of structure/reactivity relationships. The occurrence of chemical reaction within the boundary layer reported by Biggs and Agarwal (Chem. Eng. Sci. 52 (1997) 941) has been confirmed through an analysis of CO/CO2 product ratio obtained from model simulations. However, it is also quantitatively observed that the significance of boundary layer reaction reduces notably with the reduction of oxygen concentration in the flue gas, operational pressure and film thickness. Computations have also shown that in the presence of diffusional gradients peripheral fragmentation occurs in the early stages on the surface, after which conversion quickens significantly due to small particle size. Results of the early commencement of peripheral fragmentation at relatively low overall conversion obtained from a large number of simulations agree well with experimental observations reported by Feng and Bhatia (Energy & Fuels 14 (2000) 297). Comprehensive analysis of simulation results is carried out based on well accepted physical principles to rationalise model prediction. (C) 2001 Elsevier Science Ltd. AH rights reserved.

Duck hepatitis B virus expresses a regulatory HBx-like protein from a hidden open reading frame

Duck hepatitis B viruses (DHBV), unlike mammalian hepadnaviruses, are thought to lack X genes, which encode transcription-regulatory proteins believed to contribute to the development of hepatocellular carcinoma. A lack of association of chronic DHBV infection with hepatocellular carcinoma development supports this belief. Here, we demonstrate that DHBV genomes have a hidden open reading frame from which a transcription-regulatory protein, designated DHBx, is expressed both in vitro and in vivo. We show that DHBx enhances neither viral protein expression, intracellular DNA synthesis, nor virion production when assayed in the full-length genome context in LMH cells. However, similar to mammalian hepadnavirus X proteins, DHBx activates cellular and viral promoters via the Raf-mitogen-activated protein kinase signaling pathway and localizes primarily in the cytoplasm. The functional similarities as,well as the weak sequence homologies of DHBx and the X proteins of mammalian hepadnaviruses strongly suggest a common ancestry of ortho- and avihepadnavirus X genes. In addition, our data disclose similar intracellular localization and transcription regulatory functions of the corresponding proteins, raise new questions as to their presumed role in hepatocarcinogenesis, and imply unique opportunities for deciphering of their still-enigmatic in vivo functions.

'Homescapes' and identity reformations in Australian multicultural drama

A consideration of identity formation in contemporary Australian multicultural theatre is offered through a re-assessment of the unsettled (and unsettling) constructions of Australia as 'home' in the work of three playwrights. William Yang's Sadness disrupts a localized perception of home, space, and cultural communities to amalgamate two disparate communities (the queer/homosexual community in Sydney and the Asian-Australian, or 'Austasian' community) into a reconfigured Australian identity. Janis Balodis's The Ghosts Trilogy uses many actors who play across the unsettled lines of history, amid numerous voices, homes, and homelands that indicate the enormity of what 'Australia' comes to signify. Noelle Janaczewska's The History of Water constructs a way of locating the self by means of a metaphoric home as each character establishes herself on a psychic plane rather than choosing the strictly physical locations to which she has access. In their interrogations of home and homeland, these plays challenge assumptions regarding identity, disrupt notions of the ultimate ownership of land/culture by anyone, and problematize the idea of settlement as it is currently articulated in Australia.

Phylogenetic revision of Agapophytinae subf.n. (Diptera : Therevidae) based on molecular and morphological evidence

Agapophytinae subf.n. is a highly diverse lineage of Australasian Therevidae, comprising eight described and two new genera: Agapophytus Guerin-Meneville, Acupalpa Krober, Acraspisa Krober, Belonalys Krober, Bonjeania Irwin & Lyneborg, Parapsilocephala Krober, Acatopygia Krober, Laxotela Winterton & Irwin, Pipinnipons gen.n. and Patanothrix gen.n. A genus-level cladistic analysis of the subfamily was undertaken using sixty-eight adult morphological characters and c. 1000 base pairs of the elongation factor-1 alpha (EF-1 alpha) protein coding gene. The morphological data partition produced three most parsimonious cladograms, whereas the molecular data partition gave a single most parsimonious cladogram, which did not match any of the cladograms found in the morphological analysis. The level of congruence between the data partitions was determined using the partition homogeneity test (HTF) and Wilcoxon signed ranks rest. Despite being significantly incongruent in at least one of the incongruence tests, the partitions were combined in a simultaneous analysis. The combined data yielded a single cladogram that was better supported than that of the individual partitions analysed separately. The relative contributions of the data partitions to support for individual nodes on the combined cladogram were investigated using Partitioned Bremer Support. The level of support for many nodes on the combined cladogram was non-additive and often greater than the sum of support for the respective nodes on individual partitions. This synergistic interaction between incongruent data partitions indicates a common phylogenetic signal in both partitions. It also suggests that criteria for partition combination based solely on incongruence may be misleading. The phylogenetic relationships of the genera are discussed using the combined data. A key to genera of Agapophytinae is presented, with genera diagnosed and figured. Two new genera are described: Patanothrix with a new species (Pat. skevingtoni) and Pat. wilsoni (Mann) transferred from Parapsilocephala, and Pipinnipons with a new species (Pip. kroeberi). Pipinnipons fascipennis (Krober) is transferred from Squamopygin Krober and Pip. imitans (Mann) is transferred from Agapophytus. Agapophytus bicolor (Krober) is transferred from Parapsilocephala. Agapophytus varipennis Mann is synonymised with Aga, queenslandi Krober and Aga. flavicornis Mann is synonymised with Aga. pallidicornis (Krober).

Integrability and exact solution for coupled BCS systems associated with the su(4) Lie algebra

We introduce an integrable model for two coupled BCS systems through a solution of the Yang-Baxter equation associated with the Lie algebra su(4). By employing the algebraic Bethe ansatz, we determine the exact solution for the energy spectrum. An asymptotic analysis is conducted to determine the leading terms in the ground state energy, the gap and some one point correlation functions at zero temperature. (C) 2002 Published by Elsevier Science B.V.

Integrable variant of the one-dimensional Hubbard model

A new integrable model which is a variant of the one-dimensional Hubbard model is proposed. The integrability of the model is verified by presenting the associated quantum R-matrix which satisfies the Yang-Baxter equation. We argue that the new model possesses the SO(4) algebra symmetry, which contains a representation of the eta-pairing SU(2) algebra and a spin SU(2) algebra. Additionally, the algebraic Bethe ansatz is studied by means of the quantum inverse scattering method. The spectrum of the Hamiltonian, eigenvectors, as well as the Bethe ansatz equations, are discussed. (C) 2002 American Institute of Physics.

Simulation of interface states effect on the scanning capacitance microscopy measurement of p-n junctions

A two-dimensional numerical simulation model of interface states in scanning capacitance microscopy (SCM) measurements of p-n junctions is presented-In the model, amphoteric interface states with two transition energies in the Si band gap are represented as fixed charges to account for their behavior in SCM measurements. The interface states are shown to cause a stretch-out-and a parallel shift of the capacitance-voltage characteristics in the depletion. and neutral regions of p-n junctions, respectively. This explains the discrepancy between - the SCM measurement and simulation near p-n junctions, and thus modeling interface states is crucial for SCM dopant profiling of p-n junctions. (C) 2002 American Institute of Physics.

Automatic construction of explicit R matrices for the one-parameter families of irreducible typical highest weight (0(m)vertical bar alpha(n)) representations of U-q[gl(m vertical bar n)]

We detail the automatic construction of R matrices corresponding to (the tensor products of) the (O-m\alpha(n)) families of highest-weight representations of the quantum superalgebras Uq[gl(m\n)]. These representations are irreducible, contain a free complex parameter a, and are 2(mn)-dimensional. Our R matrices are actually (sparse) rank 4 tensors, containing a total of 2(4mn) components, each of which is in general an algebraic expression in the two complex variables q and a. Although the constructions are straightforward, we describe them in full here, to fill a perceived gap in the literature. As the algorithms are generally impracticable for manual calculation, we have implemented the entire process in MATHEMATICA; illustrating our results with U-q [gl(3\1)]. (C) 2002 Published by Elsevier Science B.V.