bluuebunny/crossref_metadata_2025 huggingface dataset:
Soldiers Cap Group iron‐formations, Mt Isa Inlier, Australia, as windows into the hydrothermal evolution of a base‐metal‐bearing Proterozoic rift basin
Authors: Hatton O. J. , Davidson G. J.
Published: March 2004

The Proterozoic Soldiers Cap Group, a product of two major magmatic rift phases separated by clastic sediment deposition, hosts mineralised (e.g. Pegmont Broken Hill‐type deposit) and barren iron oxide‐rich units at three main stratigraphic levels. Evaluation of detailed geological and geochemical features was carried out for one lens of an apatite–garnet‐rich, laterally extensive (1.9 km) example, the Weatherly Creek iron‐formation, and it was placed in the context of reconnaissance studies of other similar units in the area. Chemical similarities with iron‐formations associated with Broken Hill‐type Pb–Zn deposit iron‐formations are demonstrated here. Concordant contact relationships, mineralogy, geochemical patterns and pre‐deformational alteration all indicate that the Soldiers Cap Group iron‐formations are mainly hydrothermal chemical sediments. Chondrite normalised REE patterns display positive Eu and negative Ce anomalisms, consistent with components of both high‐temperature, reduced, hydrothermal fluid (≥250°C) and cool oxidised seawater. Major element data suggest a largely mafic provenance for montmorillonitic clays and other detritus during chemical sedimentation, consistent with westward erosion of Cover Sequence 2 volcanic rocks, rather than local mafic sources. Ni enrichment is most consistent with hydrogenous uptake by Mn‐oxides or carbonates. Temperatures inferred from REE data indicate that although they are not strongly enriched, base metals such as Pb and Zn are likely to have been transported and deposited prior to or following iron‐formation deposition. Most chemical sedimentation pre‐dated emplacement of the major mafic igneous sill complexes present in the upper part of the basin. Heating of deep basinal brines in a regional‐scale aquifer by deep‐seated mafic magma chambers is inferred to have driven development of hydrothermal fluids. Three major episodes of extension exhausted this aquifer, but were succeeded by a final climactic extensional phase, which produced widespread voluminous mafic volcanism. The lateral extent of the iron‐formations requires a depositional setting such as a sea‐floor metalliferous sediment blanket or series of brine pools, with iron‐formation deposition likely confined to much smaller fault‐fed areas surrounded by Fe–Mn–P‐anomalous sediments. These relationships indicate that in such settings, major sulfide deposits and their associated chemical sediment marker horizons need not overlie major igneous sequences. Rather, the timing of expulsion of hydrothermal fluid reflects the interplay between deep‐seated heating, extension and magmatism.
IUPAC-NIST Solubility Data Series. 79. Alkali and Alkaline Earth Metal Pseudohalides
Authors: Hála Jiri
Published: March 2004

This volume presents solubility data of azides, cyanides, cyanates, and thiocyanates of alkali metals, alkaline earth metals, and ammonium. Covered are binary and ternary systems in all solvents. No solubility data have been found for some of the compounds of alkali metals, alkaline metals, and ammonium. These include beryllium and magnesium azides, lithium, rubidium cesium, ammonium, and alkaline earth cyanates and cyanides, and beryllium thiocyanate. Likewise, no solubility data seem to exist for selenocyanates of the mentioned metals and ammonium. The literature has been covered up to the middle of 2001, and there was a great effort to have the literature survey as complete as possible. The few documents which remained unavailable to the editor, and could not be included in the volume, are listed in the Appendix. For some compounds it was not possible to show the Chemical Abstracts registry numbers since these have not been assigned. For this reason, the registry number index is incomplete.
Correlation for the Second Virial Coefficient of Water
Authors: Harvey Allan H. , Lemmon Eric W.
Published: March 2004

A new correlation has been developed to represent the second virial coefficient of water (H2O) as a function of temperature. The formulation was fitted to experimental data, both for the second virial coefficient itself and for a quantity related to its first temperature derivative, at temperatures between approximately 310 and 1170 K. The high-temperature extrapolation behavior was guided by results calculated from a high-quality intermolecular pair potential. The new correlation agrees well with the experimental data deemed to be reliable, and at high temperatures is a significant improvement over the best previous formulation.
Structure and Vibrations of Lanthanide Trihalides: An Assessment of Experimental and Theoretical Data
Authors: Kovács Attila , Konings Rudy J. M.
Published: March 2004

In the present paper an assessment of experimental and theoretical data on the structure and molecular vibrations of all the LnX3 lanthanide trihalides (X=F,Cl,Br,I) is presented. Our review includes 114 references to recent advanced studies. These data facilitated the confirmation of previously suggested trends in the molecular properties of the title compounds and a reliable estimation of the data of less-studied LnX3 molecules. On the basis of the collected data, a comparative analysis of the experimental and computational results has been performed. This served to assess the capabilities of recent theoretical methods for the above molecular properties.
Revised and Updated Thermochemical Properties of the Gases Mercapto (HS), Disulfur Monoxide (S2O), Thiazyl (NS), and Thioxophosphino (PS)
Authors: Lodders Katharina
Published: March 2004

Computations were done to correct erroneous data tables given in the 4th edition of the NIST-JANAF Thermochemical Tables. Updated enthalpies of formation were included to compute the thermochemical tables for four ideal gases: mercapto (HS), disulfur monoxide (S2O), thiazyl (NS), and thioxophosphino (PS).
NIST Recommended Rest Frequencies for Observed Interstellar Molecular Microwave Transitions—2002 Revision
Authors: Lovas Frank J.
Published: March 2004

Critically evaluated transition frequencies for the molecular transitions detected in interstellar and circumstellar clouds are presented. The tabulated transitions are recommended for reference in future astronomical observations in the microwave and millimeter wavelength regions. The transition frequencies have been selected through a critical examination and analysis of the laboratory spectral data obtained from the literature. The information tabulated includes the species identity, transition frequency, uncertainty, and quantum state labels. For convenience, representative line antenna temperatures are listed for a typical astronomical source for each transition, and the references are cited for the laboratory and astronomical literature that have been employed.
Molecular systematics of the Acmena alliance (Myrtaceae): phylogenetic analyses and evolutionary implications with reference to Australian taxa
Authors: Harrington M. G. , Gadek P. A.
Published: March 2004

The existence within Australia of several Acmena alliance taxa with morphological features inconsistent with current generic boundaries has meant that phylogenetic assessment of relationships has proved difficult. Sequences of nrDNA from the ITS and ETS regions were obtained for 66 Australian taxa, including representatives from both subfamilies and five genera. The ingroup taxa included 54 Australian endemics and 13 species with distributions that also range outside continental Australia. Parsimony analysis and Bayesian inference of posterior possibilities from the combined molecular datasets do not correlate with the species associations implied by the current taxonomic circumscription of genera: Acmena, Acmenosperma, Anetholea, Syzygium and Waterhousea. The molecular phylogeny recognises five supported lineages within the Acmena alliance, and several novel species associations. The recognition of five species groups indicates a need for a reappraisal of all currently recognised morphological groups within the alliance.
Morphological and genetic variation in the Senecio pinnatifolius complex: are variants worthy of taxonomic recognition?
Authors: Radford I. J. , Cousens R. D. , Michael P. W.
Published: March 2004

The current taxonomy of the Senecio pinnatifolius complex (formerly Australian S. lautus) is inadequate in describing intra-specific variation. We present several putative taxa as alternatives to current subspecies, based on variants observed during both herbarium surveys and field studies. We sought to establish whether these taxa were objectively justified in terms of morphology and genetic relationships. This was done in three ways. First, a morphometric study of plants grown under standard conditions was undertaken. Second, isozymes were analysed to establish genetic relationships within the complex. Third, achene morphology was examined by scanning electron microscopy. Variants from central Queensland (BRIGALOW V.) and the deserts of central and Western Australia (DESERT V.) were clearly separated from all other variants based on the number of involucral bracts. This differentiation into two major groups may warrant subspecific recognition. Although variation within each of the proposed subspecies was continuous, separation of variants was possible based on statistical survey. This is consistent with their formal recognition as varieties. Further work is required to determine correct nomenclature of proposed subspecies and varieties, and to fully elucidate variation and provenance in inland forms.
From species to supertrees: Popperian corroboration and some current controversies in systematics
Authors: Faith Dan P.
Published: March 2004

Popper's ideas of falsification and corroboration have been used over a long period to justify cladistic parsimony to the exclusion of other methods for phylogenetic inference. This has been based on a restrictive interpretation that takes observed data as Popperian evidence, and sees Popperian background knowledge as restricted to 'descent with modification'. An alternative, 'inclusive', interpretation, developed over the past decade, does not focus on corroboration as an automatic by-product of supposed non-falsification, but instead focuses on the useful fact that the evidence (e) for an hypothesis provides Popperian corroboration only when it is improbable in the absence of that hypothesis. This perspective highlights key errors in cladistic arguments, including a critical failure to ever assess corroboration through examination of improbability of evidence and a failure to view background knowledge as playing a role in casting doubts about supposed positive evidence. The pitfalls of Popperian justification of phylogenetic methods are not limited to cladistics. Justifications of likelihood methods unfortunately have repeated these key errors of cladistic philosophy, including the failure to satisfy the Popperian corroboration requirement that tests of hypotheses be 'genuine', as indicated by assessment of improbability of evidence given only background knowledge. Criticisms of the inclusive perspective are recognised as incorrect, based on the realisation that evidence e can relate to the hypothesis, that background knowledge can reflect chance, that corroboration does permit tail probabilities, and that corroboration in the inclusive framework is linked to tests as attempted refutations and so remains compatible with falsification. On the positive side, the inclusive approach opens the door to growth of knowledge through assessment of evidence, with no philosophical restriction on the forms of evidence in phylogenetic inference. Whatever the evidence put forward, corroboration can be claimed if attempts to explain away that evidence fail, so providing an indication of the improbability of the evidence without the hypothesis. Further, the repeated use of a form of evidence may reveal its pitfalls—the kinds of occasions when it does not provide corroboration—so providing lessons that guide the future search for effective evidence in different contexts. This theme of resisting the a priori justification of one form of evidence, and focusing sceptically on many different kinds of evidence, is critical in the two other systematics contexts. First, a unified species concept only makes sense if there is a way to sort through the pluralism that remains at the level of evidence for species hypotheses. Second, for building the tree of life (TOL) we must combine various pieces of evidence from separate studies in a meaningful way to evaluate TOL hypotheses. In both cases, Popperian corroboration provides the necessary framework for judging how our evidence bears on our hypotheses.
Phylogenetic positions of Actites megalocarpa and Sonchus hydrophilus (Sonchinae: Asteraceae) based on ITS and chloroplast non-coding DNA sequences
Authors: Kim Seung-Chul , Lu Christina T. , Lepschi Brendan J.
Published: March 2004

Phylogenetic positions of the Australian endemic taxa Actites megalocarpa and Sonchus hydrophilus within the subtribe Sonchinae were determined on the basis of ITS sequences of nuclear rDNA and the psbA–trnH(GUG) intergenic spacer of chloroplast DNA. Both ITS and cpDNA phylogenies suggest that the monotypic genus Actites is not closely related to the members of Sonchus section Asperi, as previously suggested. Rather, this study indicates that it is more closely related to the members of Sonchus sections Maritimi (S.�maritimus) and Arvenses (S. arvensis). It also suggests that S. maritimus from section Maritimi is one of the closest relatives of Actites in Australia, although an alternative origin from section Arvenses is possible. Actites and Embergeria, once treated as congeneric taxa, appear to have originated independently in Australia and New Zealand, respectively. Sonchus hydrophilus is closely related to the S. asper complex, S. oleraceus and S. kirkii. This study suggests that S. kirkii may be involved in the origin of S. hydrophilus in Australia.
A Pioneer's Perspective on the Spatial Mismatch Literature
Authors: Kain John F.
Published: March 2004

This paper was originally prepared as the keynote address for a 12 April 2003 Research Symposium "Understanding Isolation and Change in Urban Neighborhoods", sponsored by the Federal Reserve Bank of Chicago. The conference sponsors provided the paper's title and in that way suggested the central theme. As often happens, however, considerable license was taken in interpreting and implementing the brief. For example, the phrase 'spatial mismatch' is used in two ways. First, the paper examines the origins of the spatial mismatch concept that was the central focus of the author's 1964 and 1968 papers. These papers were concerned with the effects of housing market segregation/discrimination on the employment and earnings of Black Chicago and Detroit residents. The spatial mismatch concept was then broadened to include a number of other, perhaps more important, ways in which serious restrictions on the residential choices of Chicago and Detroit Black residents affected their welfare. These included the effects of housing market discrimination on housing prices, home-ownership and educational opportunities. Reflecting the two-way linkages between the author's research on racial discrimination and involvement in on-going policy debates and civil rights litigation, the discussion of these issues was imbedded in something of a personal history of his involvement in these areas in the 30 years following the publication of the original spatial mismatch papers. The paper ends with a discussion of the author's research during the past 10 years into what may be the most serious example of spatial mismatch and its negative impacts on Black welfare—the continued concentration of Black children in low-achieving inner-city schools and the impact of these patterns on the achievement of individual Black children. This research, which is based on data for Texas public schools, provides substantial evidence that continued Black segregation and the resulting concentration of Black children in low-achieving schools accounts for a large part of the Black-White achievement gap.
Understanding Risk: The Planning Officers' Perspective
Authors: Snary Christopher
Published: March 2004

There is agreement in the risk perception literature that community concerns about the environmental risks posed by locally unwanted land uses are linked to a wide range of psycho-sociological factors, such as the involuntary nature of the risk and the trustworthiness of the regulatory authority. This paper argues that land-use planning officers need to have an understanding of these wider factors in order to award public anxieties an appropriate weight. It tests this contention by examining planning officers' understandings of public concern about the environmental risks posed by waste-to-energy incinerators. Recommendations are made as to how public concern can be accurately and transparently assessed in terms of a full range of psycho-sociological factors.
Capacity-building, Representation and Intracommunity Conflict
Authors: Shirlow Peter , Murtagh Brendan
Published: March 2004

This paper explores the nature of community capacity-building in the context of local development. It challenges some of the simplistic constructions of community as a distinctive stakeholder with a shared set of values and clear identity. Even in apparently homogeneous place-based communities such as in the Catholic Ardoyne area of North Belfast there are important differences in the way in which local people interact with the organised voluntary sector. The paper concludes by highlighting the need to reach deeper into the concerns of local people, rather than the priorities of statutory funders, as a basis for service provision and local planning.
Regional Economic Disparities and Decentralisation
Authors: Canaleta Carlos Gil , Pascual Arzoz Pedro , Rapun Garate Manuel
Published: March 2004

The study of the influence of decentralisation on economic growth has received some attention in recent years, but very few studies deal with its impact on regional inequalities. This paper analyses the impact of both fiscal and political decentralisation on regional inequalities using alternative measures for a sample of 17 OECD countries. In order to check for other possible influences, the study also includes measures of public-sector size and the type of party in government. The final section studies the relevance of fiscal decentralisation in the regional convergence process observed by several authors during the past two decades. The research reveals a strong negative correlation between decentralisation, especially fiscal decentralisation, and regional inequalities, and also a positive influence of decentralisation on regional convergence.
Decomposing Canada's Growing Housing Affordability Problem: Do City Differences Matter?
Authors: Skaburskis Andrejs
Published: March 2004

This article examines the role of eight factors that affect the prevalence and incidence of housing affordability problems: geography, demography, migration/immigration/ ethnicity, income recipients, income source, employment and education. It develops bivariate probit models that use the 1991 and 1996 Canadian census public use microdata to predict the joint probability that a household spends more than half of its income on housing and that its income is below the poverty line. The conclusions show that city and regional differences are negligible after the effects of the factors common to all the cities have been accounted for. Changing employment levels and sources of household income are the most important factors explaining the prevalence and growth of housing poverty. While single parents have the highest incidence, the growth of the problem is mostly in the young non-family households. Migration, immigration and ethnicity play a role that is independent of the other factors. Education has almost no effect. The changes are in the underlying structures and in the variable profiles that differ remarkably across the factors. There were minor adjustments in the demographic and occupational profiles that would tend to reduce the problem but these are unlikely to stem its growth in the foreseeable future.
Reconfiguring Agency and Responsibility in the Governance of Social Housing in Scotland
Authors: Flint John
Published: March 2004

The construction of identities for subjects as self-regulating agents characterises processes of governance in advanced liberal democracies. Such identities implicate subjects within moral bonds of responsibility and agency to prescribed ethics of normalised consumption and duties to community. Within this 'ethopolitics' of social housing in the UK, the conduct of tenants and practitioners is framed within a conceptual triangle of consumerism, communitarianism and managerialism. This paper examines specific technologies used by Scottish social housing agencies to construct identities of agency, self-regulation and responsibility amongst their tenants. It identifies the rationales, processes and implications of these techniques for tenants and practitioners and suggests that emergent ambiguities in the reconfiguration of governing identities reflect conflicting conceptualisations about the role for social housing.
From Industrial District to 'Urban Village'? Manufacturing, Money and Consumption in Birmingham's Jewellery Quarter
Authors: Pollard Jane S.
Published: March 2004

Cities now occupy a central role in economic regeneration. Literature on such regeneration has focused on the supply side, neo-liberal leanings of projects, the centrality of cultural production and consumption, and the undemocratic, exclusionary geographies being produced through such regeneration schemes. This paper explores how urban regeneration strategies, premised on promoting cultural production and consumption, are being experienced by one of Birmingham's oldest manufacturing communities-its jewellers in the city's historic Jewellery Quarter. The aim is to investigate how this repackaging of the Jewellery Quarter, moulded by Birmingham's broader urban regeneration strategies, is affecting the material and social networks that constitute jewellery manufacturing. The repackaging of the Jewellery Quarter highlights some of the contrasting, and contradictory, conceptions of economic development competing for space in the West Midlands. The paper argues that the greater stress being given to the aestheticisation of the Quarter may ultimately undermine the economic (and social) bases of the Quarter's jewellery manufacturing networks.
Fiscal Externality, Rent Sharing and Equalisation Transfers in Japan
Authors: Ogawa Hikaru
Published: March 2004

This article describes a quantitative analysis of Japanese equalisation transfers based on the fiscal externality models of Hartwick, Boadway and Flatters. In particular, it examines whether the actual level of equalisation transfers matches the theoretically optimal level from the efficiency point of view. Although the purpose of interregional fiscal transfer is not necessarily in the pursuit of an efficient allocation of resources, equalisation transfer surely affects it. It is often said in Japan that the equalisation transfer may distort efficiency too much and that it is one of the causes of serious fiscal conflict between the metropolitan area and local (rural) prefectures. The quantitative results show that the actual amount of transfers from resource-rich to resource-poor prefectures was below the optimal level in the 1980s. However, the resource-poor prefectures have received an excessive transfer after 1990. Specifically, the direction of the optimal transfer might change in the second half of the 1990s. The estimates for 1997 show that, at most, 1445 billion yen net should be transferred to relatively high-tax and resource-rich prefectures.
Hong Kong as a Global City? Social Distance and Spatial Differentiation
Authors: Forrest Ray , La Grange Adrienne , Yip Ngai-ming
Published: March 2004

This paper draws on on-going work on Hong Kong's socio-spatial structure to explore the extent to which it fits the dominant image of the global city. While there is a considerable literature on Hong Kong's changing social structure, there is relatively little on the spatial dimensions of social difference and division. The paper situates the available commentaries and analyses of Hong Kong's income, class and employment structure within the global cities debates. It then analyses census data at the tertiary planning unit level (TPU) to explore the spatial dimensions of social distance in Hong Kong. The conclusion focuses on the distinctive mediations which have shaped the socio-spatial structure of the territory. The integrative role of public housing is argued to be of particular importance in this context.
Research as a form of work: expertise, community and methodological objectivity
Authors: Hodkinson Phil
Published: March 2004

Recent years have witnessed the rapid rise of a new educational research orthodoxy in the UK and the USA. Central to that orthodoxy are the assumptions that method can ensure objectivity in research, and that more objective ‘safe’ research to inform practice is needed. But educational research is a field made up of overlapping communities of practice. This field has rules, but they are largely unwritten, and modify and change as part of a contingent tradition. Within the field, knowledge formation develops through the making of embodied judgements, which can only ever be partly rational, and are related to developing researcher identities. The new research orthodoxy entails deliberate attempts to restrict and modify practices in this field. This is unlikely to completely succeed, but centralised sources of funding for educational research make many researchers vulnerable. In resisting these tendencies, it is helpful to view research as contributing to better understanding, in ways that owe more to the quality of interpretations of the data than to the objective purity of any methods used.
Learning landscapes
Authors: Noyes Andrew
Published: March 2004

This article explores the metaphor of learning landscapes, a tool developed in order to map children's experiences of, and attitudes to, learning (mathematics) before and after the transfer from primary to secondary school. Firstly, the continuing problems surrounding school transfer and why a re‐examination of this is required are considered. Secondly, as background to the metaphor, the sociocultural influences which impinge on educational processes are discussed. Following that, the core of the article develops the metaphor, seeking to demonstrate its pertinence to the study of children's schooling, the learning of mathematics and school transfer. The article also questions the potential of some of the current educational reforms to deliver sustained improvement.
Pupils' views on inclusion: moderate learning difficulties and bullying in mainstream and special schools
Authors: Norwich Brahm , Kelly Narcie
Published: March 2004

This study examined the views of 101 boys and girls aged 10–11 and 13–14 with statements of special educational needs for moderate learning difficulties. Questions centred on their experiences of school, teaching and learning in mainstream and special schools. The study is set in the context of the international move towards more inclusion of children with disabilities into mainstream schools and the greater importance attached to the child's voice in decision‐making in education. Most children expressed positive evaluations of their schools and the teaching they received, while a significant minority expressed mixed views. A significant proportion in the mainstream preferred learning support in withdrawal settings. While the majority in both settings preferred their current school, a significant minority in special school preferred to be in a mainstream setting. A notable emergent theme from the study was the high incidence of ‘bullying’ that was experienced. Though experienced in both settings, those in special schools experienced far more ‘bullying’ by children from other mainstream schools and from peers and outsiders in their neighbourhood. These findings are discussed in terms of the tensions or dilemmas about difference that were experienced and their implications for the move towards greater inclusion.
Predicting reading performance during the first and the second year of primary school
Authors: Lerkkanen Marja‐kristiina , Rasku‐puttonen Helena , Aunola Kaisa , Nurmi Jari‐erik
Published: March 2004

The aim of this longitudinal study was to investigate the developmental antecedents of reading performance and its subcomponents from the beginning of the first year to the end of the second year of primary school. One‐hundred‐and‐fourteen seven‐year‐old Finnish‐speaking children were tested on reading‐related skills during their first week of school using a test battery designed for school entrants. Following this they were examined six times on word reading and reading comprehension skills. The results showed that the reading‐related variables predicting reading performance varied according to the phase of reading development. Moreover, partially different antecedents predicted word reading and reading comprehension. Word reading was associated with letter knowledge and listening comprehension, whereas initial word reading skill and listening comprehension were highly associated with the development of reading comprehension. The results support the development of reading instructional methods that take into account these differences in the components of reading performance and their development.
Teachers' assessment of students' research skills
Authors: Stokking Karel , Schaaf Mariekevander , Jaspers Jos , Erkens Gijsbert
Published: March 2004

Today, teachers are expected to develop complex skills, such as research skills, in their students while implementing new views on learning and teaching and using authentic assessment strategies. About these new assessment strategies there is much debate and teachers are vulnerable in using them. We studied upper secondary education natural and social science teachers' practices using two surveys and two rounds of expert panel judgement on teacher‐submitted assessment‐related material and information. Our study shows that there are grounds for concern regarding the clarity of teachers' assessment criteria, the consistency between teachers' goals, assignments, and criteria, and the validity and acceptability of teachers' assessment practices. The extent to which it is justifiable to judge teachers' assessment practice by professional quality criteria is discussed, and suggestions are given as to the main quality criteria for formative and summative assessment and as to ways in which teachers could improve their assessment practices.
Grouping practices in the primary school: what influences change?
Authors: Hallam Susan , Ireson Judith , Davies Jane
Published: March 2004

During the 1990s, there was considerable emphasis on promoting particular kinds of pupil grouping as a means of raising educational standards. This survey of 2000 primary schools explored the extent to which schools had changed their grouping practices in response to this, the nature of the changes made and the reasons for those changes. Forty‐eight per cent of responding schools reported that they had made no change. Twenty‐two per cent reported changes because of the literacy hour, two per cent because of the numeracy hour, seven per cent because of a combination of these and twenty‐one per cent for other reasons. Important influences on decisions about the types of grouping adopted were related to pupil learning and differentiation, teaching, the implementation of the National Literacy Strategy, practical issues and school self‐evaluation.
Effective teaching in the context of a grade 12 high‐stakes external examination in New South Wales, Australia
Authors: Ayres Paul , Sawyer Wayne , Dinham Steve
Published: March 2004

This study identified effective teachers of high‐achieving Grade 12 students in New South Wales, Australia. Nineteen teachers, across a variety of curriculum areas, were observed teaching and then interviewed. A further six teachers were interviewed only. Despite the high‐stakes end‐of‐schooling examination, generating interest in and understanding of the subject was their paramount concern. A key common factor was an emphasis on having students apply knowledge, rather than being ‘spoon‐fed’ information. Although many aspects of the lessons were channelled through the teachers, frequent opportunities existed for independent learning. Classrooms were relaxed environments, but highly focused. Teachers attributed their success to four major factors: their relationships with students, their classroom practices, the students themselves and faculty cooperation. No evidence was found that the high‐stakes examination inhibited best‐practice teaching.
The resources and strategies that 10–11‐year‐old boys use to construct masculinities in the school setting
Authors: Swain Jon
Published: March 2004

The data in this article come from an ethnographic exploration into the construction of masculinities in three junior schools in the UK between 1998 and 1999. The author argues that the construction and performance of masculinity is inextricably linked to the acquisition of status within the school peer group, and he delineates the specific series of resources and strategies that the boys draw on and use in each setting to achieve this. The different meanings and practices at each school, and the different array of resources available, means that there is a different set of options and/or opportunities within each school setting to do boy, and the author classifies these as being either open (possible), restricted (more difficult), or closed (almost impossible). The principal and most esteemed resource used by the boys was physicality and athleticism, and the author highlights the link between masculinity and the body.
Classroom research or w(h)ither development: gender, complexity and diversity in the UK, the USA and Australia
Authors: Rhedding‐jones Jeanette
Published: March 2004

Starting school—young children learning cultures L. Brooker

Embracing identities in early childhood education: diversity and possibilities S. Grieshaber & G. Cannella, G. (Eds)

Caring classrooms/intelligent schools: the social emotional education of young children J. Cohen (Ed.)
Keratins modulate colonocyte electrolyte transport via protein mistargeting
Authors: Toivola Diana M. , Krishnan Selvi , Binder Henry J. , Singh Satish K. , Omary M. Bishr
Published: March 2004

The function of intestinal keratins is unknown, although keratin 8 (K8)–null mice develop colitis, hyperplasia, diarrhea, and mistarget jejunal apical markers. We quantified the diarrhea in K8-null stool and examined its physiologic basis. Isolated crypt-units from K8-null and wild-type mice have similar viability. K8-null distal colon has normal tight junction permeability and paracellular transport but shows decreased short circuit current and net Na absorption associated with net Cl secretion, blunted intracellular Cl/HCO3-dependent pH regulation, hyperproliferation and enlarged goblet cells, partial loss of the membrane-proximal markers H,K-ATPase-β and F-actin, increased and redistributed basolateral anion exchanger AE1/2 protein, and redistributed Na-transporter ENaC-γ. Diarrhea and protein mistargeting are observed 1–2 d after birth while hyperproliferation/inflammation occurs later. The AE1/2 changes and altered intracellular pH regulation likely account, at least in part, for the ion transport defects and hyperproliferation. Therefore, colonic keratins have a novel function in regulating electrolyte transport, likely by targeting ion transporters to their cellular compartments.
Myosin V
Authors: Krementsov Dimitry N. , Krementsova Elena B. , Trybus Kathleen M.
Published: March 2004

Calcium activates the ATPase activity of tissue-purified myosin V, but not that of shorter expressed constructs. Here, we resolve this discrepancy by comparing an expressed full-length myosin V (dFull) to three shorter constructs. Only dFull has low ATPase activity in EGTA, and significantly higher activity in calcium. Based on hydrodynamic data and electron microscopic images, the inhibited state is due to a compact conformation that is possible only with the whole molecule. The paradoxical finding that dFull moved actin in EGTA suggests that binding of the molecule to the substratum turns it on, perhaps mimicking cargo activation. Calcium slows, but does not stop the rate of actin movement if excess calmodulin (CaM) is present. Without excess CaM, calcium binding to the high affinity sites dissociates CaM and stops motility. We propose that a folded-to-extended conformational change that is controlled by calcium and CaM, and probably by cargo binding itself, regulates myosin V's ability to transport cargo in the cell.
The cohesion protein ORD is required for homologue bias during meiotic recombination
Authors: Webber Hayley A. , Howard Louisa , Bickel Sharon E.
Published: March 2004

During meiosis, sister chromatid cohesion is required for normal levels of homologous recombination, although how cohesion regulates exchange is not understood. Null mutations in orientation disruptor (ord) ablate arm and centromeric cohesion during Drosophila meiosis and severely reduce homologous crossovers in mutant oocytes. We show that ORD protein localizes along oocyte chromosomes during the stages in which recombination occurs. Although synaptonemal complex (SC) components initially associate with synapsed homologues in ord mutants, their localization is severely disrupted during pachytene progression, and normal tripartite SC is not visible by electron microscopy. In ord germaria, meiotic double strand breaks appear and disappear with frequency and timing indistinguishable from wild type. However, Ring chromosome recovery is dramatically reduced in ord oocytes compared with wild type, which is consistent with the model that defects in meiotic cohesion remove the constraints that normally limit recombination between sisters. We conclude that ORD activity suppresses sister chromatid exchange and stimulates inter-homologue crossovers, thereby promoting homologue bias during meiotic recombination in Drosophila.
PEX3 functions as a PEX19 docking factor in the import of class I peroxisomal membrane proteins
Authors: Fang Yi , Morrell James C. , Jones Jacob M. , Gould Stephen J.
Published: March 2004

PEX19 is a chaperone and import receptor for newly synthesized, class I peroxisomal membrane proteins (PMPs). PEX19 binds these PMPs in the cytoplasm and delivers them to the peroxisome for subsequent insertion into the peroxisome membrane, indicating that there may be a PEX19 docking factor in the peroxisome membrane. Here we show that PEX3 is required for PEX19 to dock at peroxisomes, interacts specifically with the docking domain of PEX19, and is required for recruitment of the PEX19 docking domain to peroxisomes. PEX3 is also sufficient to dock PEX19 at heterologous organelles and binds PEX19 via a conserved motif that is essential for this docking activity and for PEX3 function in general. Not surprisingly, transient inhibition of PEX3 abrogates class I PMP import but has no effect on class II PMP import or peroxisomal matrix protein import. Taken together, these results suggest that PEX3 plays a selective, essential, and direct role in PMP import as a docking factor for PEX19.
Misfolding diverts CFTR from recycling to degradation
Authors: Sharma Manu , Pampinella Francesca , Nemes Csilla , Benharouga Mohamed , So Jeffrey , Du Kai , Bache Kristi G. , Papsin Blake , Zerangue Noa , Stenmark Harald , Lukacs Gergely L.
Published: March 2004

To investigate the degradation mechanism of misfolded membrane proteins from the cell surface, we used mutant cystic fibrosis transmembrane conductance regulators (CFTRs) exhibiting conformational defects in post-Golgi compartments. Here, we show that the folding state of CFTR determines the post-endocytic trafficking of the channel. Although native CFTR recycled from early endosomes back to the cell surface, misfolding prevented recycling and facilitated lysosomal targeting by promoting the ubiquitination of the channel. Rescuing the folding defect or down-regulating the E1 ubiquitin (Ub)-activating enzyme stabilized the mutant CFTR without interfering with its internalization. These observations with the preferential association of mutant CFTRs with Hrs, STAM-2, TSG101, hVps25, and hVps32, components of the Ub-dependent endosomal sorting machinery, establish a functional link between Ub modification and lysosomal degradation of misfolded CFTR from the cell surface. Our data provide evidence for a novel cellular mechanism of CF pathogenesis and suggest a paradigm for the quality control of plasma membrane proteins involving the coordinated function of ubiquitination and the Ub-dependent endosomal sorting machinery.
CD152 (CTLA-4) Determines the Unequal Resistance of Th1 and Th2 Cells against Activation-induced Cell Death by a Mechanism Requiring PI3 Kinase Function
Authors: Pandiyan Pushpa , Gärtner Dagmar , Soezeri Osman , Radbruch Andreas , Schulze-Osthoff Klaus , Brunner-Weinzierl Monika C.
Published: March 2004

Survival of antigen-experienced T cells is essential for the generation of adaptive immune responses. Here, we show that the genetic and antibody-mediated inactivation of CD152 (cytotoxic T lymphocyte antigen 4) in T helper (Th) effector cells reduced the frequency of nonapoptotic cells in a completely Fas/Fas ligand (FasL)–dependent manner. CD152 cross-linking together with stimulation of CD3 and CD28 on activated Th2 cells prevented activation-induced cell death (AICD) as a result of reduced Fas and FasL expression. Apoptosis protection conferred by CD152 correlated with the up-regulation of Bcl-2 and was mediated by phosphatidylinositol 3 kinase, which prevented FasL expression through the inhibitory phosphorylation of Forkhead transcription factor FKHRL1. We show that signals induced by CD152 act directly on activated T lymphocytes and, due to its differential surface expression on activated Th1 and Th2 cells, induce resistance to AICD mainly in Th2 cells.
Btk Is Required for an Efficient Response to Erythropoietin and for SCF-controlled Protection against TRAIL in Erythroid Progenitors
Authors: Schmidt Uwe , van den Akker Emile , Parren-van Amelsvoort Martine , Litos Gabi , de Bruijn Marella , Gutiérrez Laura , Hendriks Rudi W. , Ellmeier Wilfried , Löwenberg Bob , Beug Hartmut , von Lindern Marieke
Published: March 2004

Regulation of survival, expansion, and differentiation of erythroid progenitors requires the well-controlled activity of signaling pathways induced by erythropoietin (Epo) and stem cell factor (SCF). In addition to qualitative regulation of signaling pathways, quantitative control may be essential to control appropriate cell numbers in peripheral blood. We demonstrate that Bruton's tyrosine kinase (Btk) is able to associate with the Epo receptor (EpoR) and Jak2, and is a substrate of Jak2. Deficiency of Btk results in reduced and delayed phosphorylation of the EpoR, Jak2, and downstream signaling molecules such as Stat5 and PLCγ1 as well as in decreased responsiveness to Epo. As a result, expansion of erythroid progenitors lacking Btk is impaired at limiting concentrations of Epo and SCF. In addition, we show that SCF induces Btk to interact with TNF-related apoptosis-inducing ligand (TRAIL)–receptor 1 and that lack of Btk results in increased sensitivity to TRAIL-induced apoptosis. Together, our results indicate that Btk is a novel, quantitative regulator of Epo/SCF-dependent expansion and survival in erythropoiesis.
Combined TLR and CD40 Triggering Induces Potent CD8+ T Cell Expansion with Variable Dependence on Type I IFN
Authors: Ahonen Cory L. , Doxsee Christie L. , McGurran Sean M. , Riter Tony R. , Wade William F. , Barth Richard J. , Vasilakos John P. , Noelle Randolph J. , Kedl Ross M.
Published: March 2004

Toll-like receptors are important in the activation of innate immunity, and CD40 is a molecule critical for many T and B cell responses. Whereas agonists for either pathway have been used as vaccine adjuvants, we show that a combination of Toll-like receptor (TLR)7 and CD40 agonists synergize to stimulate CD8+ T cell responses 10–20-fold greater than the use of either agonist alone. Antigen-specific CD8+ T cells elicited from combination CD40/TLR7 treatment demonstrated both lytic activities and interferon (IFN)γ production and an enhanced secondary response to antigenic challenge. Agonists for TLRs 2/6, 3, 4, and 9 also synergized with CD40 stimulation, demonstrating that synergy with the CD40 pathway is a property of TLR-derived stimuli in general. The CD8+ T cell expansion induced by CD40/TLR7 triggering was independent of CD4+ T cells, IFNγ, and IL-12 but dependent on B7-mediated costimulation and surprisingly on type I IFN. These studies provide the rational basis for the use of TLR and CD40 agonists together as essential adjuvants to optimize vaccines designed to elicit protective or therapeutic immunity.
Lysophosphatidic Acid Induces Neointima Formation Through PPARγ Activation
Authors: Zhang Chunxiang , Baker Daniel L. , Yasuda Satoshi , Makarova Natalia , Balazs Louisa , Johnson Leonard R. , Marathe Gopal K. , McIntyre Thomas M. , Xu Yong , Prestwich Glenn D. , Byun Hoe-Sup , Bittman Robert , Tigyi Gabor
Published: March 2004

Neointimal lesions are characterized by accumulation of cells within the arterial wall and are a prelude to atherosclerotic disease. Here we report that a brief exposure to either alkyl ether analogs of the growth factor–like phospholipid lysophosphatidic acid (LPA), products generated during the oxidative modification of low density lipoprotein, or to unsaturated acyl forms of LPA induce progressive formation of neointima in vivo in a rat carotid artery model. This effect is completely inhibited by the peroxisome proliferator-activated receptor (PPAR)γ antagonist GW9662 and mimicked by PPARγ agonists Rosiglitazone and 1-O-hexadecyl-2-azeleoyl-phosphatidylcholine. In contrast, stearoyl-oxovaleryl phosphatidylcholine, a PPARα agonist and polypeptide epidermal growth factor, platelet-derived growth factor, and vascular endothelial growth factor failed to elicit neointima. The structure-activity relationship for neointima induction by LPA analogs in vivo is identical to that of PPARγ activation in vitro and disparate from that of LPA G protein–coupled receptor activation. Neointima-inducing LPA analogs up-regulated the CD36 scavenger receptor in vitro and in vivo and elicited dedifferentiation of cultured vascular smooth muscle cells that was prevented by GW9662. These results suggest that selected LPA analogs are important novel endogenous PPARγ ligands capable of mediating vascular remodeling and that activation of the nuclear transcription factor PPARγ is both necessary and sufficient for neointima formation by components of oxidized low density lipoprotein.