Scaffolding and bilingual shared reading experiences: Promoting primary school students' learning and development

This paper explores the connections between scaffolding, second language learning and bilingual shared reading experiences. A socio- cultural theory of cognition underpins the investigation, which involved implementing a language and culture awareness program (LCAP) in a year 4 classroom and in the school community. Selected passages from observations are used to analyse the learning of three students, particularly in relation to languages other than English (LOTE). As these three case study students interacted in the classroom, at home and in the community, they co-constructed, appropriated and applied knowledge form one language to another. Through scaffolding, social spaces were constructed, where students learning and development were extended through a variety of activities that involved active participation, such as experimenting with language, asking questions and making suggestions. Extending these opportunities for student learning and development is considered in relation to creating teaching and learning environments that celebrate socio-cultural and linguistic diversity.

Cultural and gender influences on age identification

Age identification plays a significant role in young adults" mass, interpersonal, intergenerational, and intercultural communication. This research examines cultural and gender influences on young people's age identity by measuring the social age identity of male and female young adult members of five cultures varying in individualism/collectivism (Laos, Thailand, Spain, Australia, and the U.S.A.). We found cultural influences on age identity to be both unexpected in nature and modest in effect. American and Laotian respondents had similar and nominally higher levels of age identity than Australian, Thai, and Spanish respondents, with all having a markedly different age identities than those of Japanese respondents as reported by other researchers. No direct effect for gender on age identity emerged, though American females were more age identified than all other respondents. Across cultures, the social identity scale was found to be a reasonably adequate measure of age identity.

Discovery, structure and biological activities of the cyclotides

The cyclotides are a family of small disulfide rich proteins that have a cyclic peptide backbone and a cystine knot formed by three conserved disulfide bonds. The combination of these two structural motifs contributes to the exceptional chemical, thermal and enzymatic stability of the cyclotides, which retain bioactivity after boiling. They were initially discovered based on native medicine or screening studies associated with some of their various activities, which include uterotonic action, anti-HIV activity, neurotensin antagonism, and cytotoxicity. They are present in plants from the Rubiaceae, Violaceae and Cucurbitaccae families and their natural function in plants appears to be in host defense: they have potent activity against certain insect pests and they also have antimicrobial activity. There are currently around 50 published sequences of cyclotides and their rate of discovery has been increasing over recent years. Ultimately the family may comprise thousands of members. This article describes the background to the discovery of the cyclotides, their structural characterization, chemical synthesis, genetic origin, biological activities and potential applications in the pharmaceutical and agricultural industries. Their unique topological features make them interesting from a protein folding perspective. Because of their highly stable peptide framework they might make useful templates in drug design programs, and their insecticidal activity opens the possibility of applications in crop protection.

Synthesis and biological evaluation of nonpeptide mimetics of co-conotoxin GVIA

A benzothiazole-derived compound (4a) designed to mimic the C-alpha-C-beta bond vectors and terminal functionalities of Lys2, TyrI3 and Arg17 in omega-conotoxin GVIA was synthesised, together with analogues (4b-d), which had each side-chain mimic systematically truncated or eliminated. The affinity of these compounds for rat brain N-type and P/Q-type voltage gated calcium channels (VGCCs) was determined. In terms of N-type channel affinity and selectivity, two of these compounds (4a and 4d) were found to be highly promising, first generation mimetics of omega-conotoxin. The fully functionalised mimetic (4a) showed low PM binding affinity to N-type VGCCs (IC50 = 1.9 muM) and greater than 20-fold selectivity for this channel sub-type over P/Q-type VGCCs, whereas the mimetic in which the guanidine-type side chain was truncated back to an amine (4d, IC50 = 4.1 muM) showed a greater than 25-fold selectivity for the N-type channel. (C) 2004 Elsevier Ltd. All rights reserved.

Impact of social group processes and functional diversity on communication in networked organizations

This study examines the role of social group processes in perceptions of effective communication in Australian Cooperative Research Centres (CRCs). Communication professionals in 25 CRCs discussed the barriers and opportunities for communication in their diverse networked organizations. Thematic analysis of the transcripts highlighted the contribution of social group processes to both barriers and opportunities. Communication challenges implicated the social identity of organizational members, many of which were associated with distinct structural aspects of these organizations. Opportunities for communication frequently involved features that implicated social identity, including taking advantage of existing organizational or industry identities, preventing conflicting identities from becoming salient, and promoting a collective CRC identity.

Novel diaroylhydrazine ligands as iron chelators: coordination chemistry and biological activity

The search for orally effective drugs for the treatment of iron overload disorders is an important goal in improving the health of patients suffering diseases such as beta-thalassemia major. Herein, we report the syntheses and characterization of some new members of a series of N-aroyl-N'-picolinoyl hydrazine chelators (the H2IPH analogs). Both 1:1 and 1:2 Fe-III:L complexes were isolated and the crystal structures of Fe(HPPH)Cl-2, Fe(4BBPH)Cl-2, Fe(HAPH)(APH) and Fe(H3BBPH)(3BBPH) were determined (H2PPH=N,N'-bis-picolinoyl hydrazine; H(2)APH=N-4-aminobenzoyl-N'-picolinoyl hydrazine, H(2)3BBPH=N-3-bromobenzoyl-N'-picolinoylhydrazine and H(2)4BBPH=N-(4-bromobenzoyl)-N'-(picolinoyl)hydrazine). In each case, a tridentate N,N,O coordination mode of each chelator with Fe was observed. The Fe-III complexes of these ligands have been synthesized and their structural, spectroscopic and electrochemical characterization are reported. Five of these new chelators, namely H2BPH (N-(benzoyl)-N'-(picolinoyl)hydrazine), H2TPH (N-(2-thienyl)-N'-(picolinoyl)-hydrazine), H2PPH, H(2)3BBPH and H(2)4BBPH, showed high efficacy at mobilizing Fe-59 from cells and inhibiting Fe-59 uptake from the serum Fe transport protein, transferrin (Tf). Indeed, their activity was much greater than that found for the chelator in current clinical use, desferrioxamine (DFO), and similar to that observed for the orally active chelator, pyridoxal isonicotinoyl hydrazone (H2PIH). The ability of the chelators to inhibit Fe-59 uptake could not be accounted for by direct chelation of Fe-59-Tf. The most effective chelators also showed low antiproliferative activity which was similar to or less than that observed with DFO, which is important in terms of their potential use as agents to treat Fe-overload disease.

Novel natriuretic peptides from the venom of the inland taipan (Oxyuranus microlepidotus): isolation, chemical and biological characterisation

Three natriuretic-like peptides (TNP-a, TNP-b, and TNP-c) were isolated from the venom of Oxyuranus microlepidotus (inland taipan) and were also present in the venoms of Oxyuranus scutellatus canni (New Guinea taipan) and Oxyuranus scutellatus scutellatus (coastal taipan). They were isolated by HPLC, characterised by mass spectrometry and Edman analysis, and consist of 35-39 amino acid residues. These molecules differ from ANP/BNP through replacement of invariant residues within the 17-membered ring structure and by inclusion of proline residues in the C-terminal tail. TNP-c was equipotent to ANP in specific GC-A assays or aortic ring assays whereas TNP-a and TNP-b were either inactive (GC-A over-expressing cells and endothelium-denuded aortic rings) or weakly active (endothelium-in tact aortic rings). TNP-a and TNP-b were also unable to competitively inhibit the binding of TNP-c in endothelium-denuded aortae (GC-A) or endothelium-in tact aortae (NPR-C). Thus, these naturally occurring isoforms provide a new platform for further investigation of structure-function relationships of natriuretic peptides. (C) 2004 Elsevier Inc. All rights reserved.

Biological monitoring and Biological Limit Values (BLV): The strategy of the European Union

Occupational standards concerning allowable concentrations of chemical compounds in the ambient air of workplaces have been established in several countries worldwide. With the integration of the European Union (EU), there has been a need of establishing harmonised Occupational Exposure Limits (OEL). The European Commission Directive 95/320/EC of 12 July 1995 has given the tasks to a Scientific Committee for Occupational Exposure Limits (SCOEL) to propose, based on scientific data and where appropriate, occupational limit values which may include the 8-h time-weighted average (TWA), short-term limits/excursion limits (STEL) and Biological Limit Values (BLVs). In 2000, the European Union issued a list of 62 chemical substances with Occupational Exposure Limits. Of these, 25 substances received a skin notation, indicating that toxicologically significant amounts may be taken up via the skin. For such substances, monitoring of concentrations in ambient air may not be sufficient, and biological monitoring strategies appear of potential importance in the medical surveillance of exposed workers. Recent progress has been made with respect to formulation of a strategy related to health-based BLVs. (c) 2005 Elsevier Ireland Ltd. All rights reserved.

Proteins in the saliva of the Ixodida (ticks): Pharmacological features and biological significance

The saliva of ticks (Suborder Ixodida) is critical to their survival as parasites. A tick bite should result in strong responses from the host defence systems (haemostatic, immune and inflammatory) but tick saliva appears to have evolved to counter these responses. We review current knowledge of tick saliva components, with emphasis on those molecules confirmed to be present in the secreted saliva but including some that have only been confirmed to be present in salivary glands. About 50 tick saliva proteins that are well described in the literature are discussed. These saliva components include enzymes, enzyme inhibitors, amine-binding proteins and cytokine homologues that act as anti-haemostatic, anti-inflammatory or immuno-modulatory agents. Sequence comparisons are illustrated. The importance of tick saliva and the significance of the findings to date are also discussed. (C) 2006 Elsevier Ltd. All rights reserved.