bluuebunny/crossref_metadata_2025 huggingface dataset:
Enhanced electrokinetic remediation of Cd and Pb spiked soil coupled with cation exchange membrane
Authors: Chen Xuejun , Shen Zhemin , Lei Yangming , Ju Bingxin , Wang Wenhua
Published: August 2006

Electrokinetic (EK) remediation is one of the popular and promising in situ remediation techniques for metal-contaminated soils, but the remediation effect is strongly affected by soil type and chemical species of contaminants; moreover, pH is very difficult to control. This paper investigates the species of cadmium (Cd) and lead (Pb) in simulating contaminated soil before and after EK remediation, and the soil is a typical silt loam soil from Shanghai. Heavy metal speciation in the soil sample was analysed through a sequential extraction procedure. Cation-exchange membrane (CEM) and conductive solution were applied to improve the remediation efficiency. Both methods help to keep acid conditions and CEM can prevent anions in the cathodic compartment from penetrating into the soil sample system. The pH of the soil specimen was acidic during the test, and Cd was quickly removed from the soil while Pb was removed more slowly. The average removal efficiencies of Cd and Pb were 68.7 and 38.7%, respectively, after 60 h of remediation.
Lateral positioning at the dorsal midline: Slit and Roundabout receptors guide
Drosophila
heart cell migration
Authors: Santiago-Martínez Edgardo , Soplop Nadine H. , Kramer Sunita G.
Published: August 2006

Heart morphogenesis requires the coordinated regulation of cell movements and cell–cell interactions between distinct populations of cardiac precursor cells. Little is known about the mechanisms that organize cardiac cells into this complex structure. In this study, we analyzed the role of Slit, an extracellular matrix protein and its transmembrane receptors Roundabout (Robo) and Roundabout2 (Robo2) during morphogenesis of the
Drosophila
heart tube, a process analogous to early heart formation in vertebrates. During heart assembly, two types of progenitor cells align into rows and coordinately migrate to the dorsal midline of the embryo, where they merge to assemble a linear heart tube. Here we show that cardiac-specific expression of Slit is required to maintain adhesion between cells within each row during dorsal migration. Moreover, differential Robo expression determines the relative distance each row is positioned from the dorsal midline. The innermost CBs express only Robo, whereas the flanking pericardial cells express both receptors. Removal of
robo2
causes pericardial cells to shift toward the midline, whereas ectopic
robo2
in CBs drives them laterally, resulting in an unfused heart tube. We propose a model in which Slit has a dual role during assembly of the linear heart tube, functioning to regulate both cell positioning and adhesive interactions between migrating cardiac precursor cells.
A picornavirus protein interacts with Ran-GTPase and disrupts nucleocytoplasmic transport
Authors: Porter Frederick W. , Bochkov Yury A. , Albee Alison J. , Wiese Christiane , Palmenberg Ann C.
Published: August 2006

Active nucleocytoplasmic transport of protein and RNA in eukaryotes depends on the Ran-GTPase system to regulate cargo–receptor interactions. Several viruses, including the RNA picornaviruses, encode factors that alter nuclear transport with the aim of suppressing synthesis of antiviral factors and promoting viral replication. Picornaviruses in the cardiovirus genus express a unique 67-aa Leader protein (L), known to alter the subcellular distribution of IFN regulatory proteins targeted to the nucleus. We report here that L binds directly to Ran and blocks nuclear export of new mRNAs. In
Xenopus
egg extracts, recombinant L also inhibits mitotic spindle assembly, a RanGTP function crucial to cell-cycle progression. We propose that L inhibits nucleocytoplasmic transport during infection by disrupting the RanGDP/GTP gradient. This inhibition triggers an efflux of nuclear proteins necessary for viral replication and causes IFN suppression. To our knowledge, L is the first viral picornaviral protein to interact directly with Ran and modulate the Ran-dependent nucleocytoplasmic pathway.
Melanoma growth is reduced in fat-1 transgenic mice: Impact of omega-6/omega-3 essential fatty acids
Authors: Xia Shuhua , Lu Yan , Wang Jingdong , He Chengwei , Hong Song , Serhan Charles N. , Kang Jing X.
Published: August 2006

An important nutritional question as to whether the ratio of omega-6 (n-6) to omega-3 (n-3) fatty acids plays a role in tumorigenesis remains to be clarified in well qualified experimental models. The recently engineered fat-1 mice, which can convert n-6 to n-3 fatty acids and have a balanced ratio of n-6 to n-3 fatty acids in their tissues and organs independent of diet, allow carefully controlled studies to be performed in the absence of potential confounding factors of diet and therefore are a useful model for elucidating the role of n-6/n-3 fatty acid ratio in tumorigenesis. We implanted mouse melanoma B16 cells into transgenic and WT littermates and examined the incidence of tumor formation and tumor growth rate. The results showed a dramatic reduction of melanoma formation and growth in fat-1 transgenic mice. The level of n-3 fatty acids and their metabolite prostaglandin E
3
(PGE
3
) were much higher (but the n-6/n-3 ratio is much lower) in the tumor and surrounding tissues of fat-1 mice than that of WT animals. The phosphatase and tensin homologue deleted on the chromosome 10 (PTEN) gene was significantly up-regulated in the fat-1 mice.
In vitro
experiments showed that addition of the n-3 fatty acid eicosapentaenoic acid or PGE
3
inhibited the growth of B16 cell line and increased the expression of PTEN, which could be partially attenuated by inhibition of PGE
3
production, suggesting that PGE
3
may act as an antitumor mediator. These data demonstrate an anticancer (antimelanoma) effect of n-3 fatty acids through, at least in part, activation of PTEN pathway mediated by PGE
3
.
The HicAB cassette, a putative novel, RNA-targeting toxin-antitoxin system in archaea and bacteria
Authors: Makarova Kira S. , Grishin Nick V. , Koonin Eugene V.
Published: August 2006

Toxin-antitoxin systems (TAS) are abundant, diverse, horizontally mobile gene modules that encode powerful resistance mechanisms in prokaryotes. We use the comparative-genomic approach to predict a new TAS that consists of a two-gene cassette encoding uncharacterized HicA and HicB proteins. Numerous bacterial and archaeal genomes encode from one to eight HicAB modules which appear to be highly prone to horizontal gene transfer. The HicB protein (COG1598/COG4226) has a partially degraded RNAse H fold, whereas HicA (COG1724) contains a double-stranded RNA-binding domain. The stable combination of these two domains suggests a link to RNA metabolism, possibly, via an RNA interference-type mechanism. In most HicB proteins, the RNAse H-like domain is fused to a DNA-binding domain, either of the ribbon-helix-helix or of the helix-turn-helix class; in other TAS, proteins containing these DNA-binding domains function as antitoxins. Thus, the HicAB module is predicted to be a novel TAS whose mechanism involves RNA-binding and, possibly, cleavage.

Contact:  koonin@ncbi.nlm.nih.gov

Supplementary information: Supplementary data are available at Bioinformatics online.
Pituitary tumour transforming gene (PTTG) expression correlates with the proliferative activity and recurrence status of pituitary adenomas: a clinical and immunohistochemical study
Authors: Filippella Mariagiovanna , Galland Françoise , Kujas Michèle , Young Jacques , Faggiano Antongiulio , Lombardi Gaetano , Colao Annamaria , Meduri Geri , Chanson Philippe
Published: August 2006

Background  The pituitary tumour transforming gene (pttg) plays a central role in pituitary tumorigenesis, but PTTG protein expression is poorly documented and its relationship with tumour cell proliferation and the prognosis of pituitary adenomas is unclear.

Aim  The aim of this study was to evaluate the immunohistochemical expression of PTTG and Ki‐67 in 45 human pituitary adenomas according to the tumour histotype, aggressiveness and persistence/recurrence status.

Patients and methods  The tumours comprised 37 macroadenomas and 8 microadenomas. Twenty patients experienced disease persistence or recurrence after transsphenoidal surgery. Disease recurrence was observed in 16 patients, 8–72 months after surgery.

Results  No PTTG or Ki‐67 expression was detected in normal pituitary tissue. In pituitary adenomas, tumour nuclei were positive for PTTG and Ki‐67 in 89 and 98% of samples, respectively, and there was a strong correlation between the expression of the two proteins (P < 0·001). By the ROC curves method, a PTTG score of 3·3% was the best cut‐off for distinguishing between recurrent and nonrecurrent pituitary adenomas (P < 0·05; sensitivity 60%; specificity 76%). A 2·9% cut‐off was obtained for both PTTG (P < 0·01; sensitivity 77%; specificity 71%) and Ki‐67 (P < 0·05; sensitivity 85%; specificity 64%) among patients with more than 1 year of follow‐up. Neither PTTG nor Ki‐67 expression was influenced by the maximal tumour diameter, tumour grade, age, gender or presurgical medical treatment. Both PTTG and Ki‐67 tumour score > 2·9% identified a subgroup of patients with a significantly higher recurrence‐free interval (P < 0·01). By multivariate analysis, a > 2·9% Ki‐67 tumour score was the best predictor of pituitary tumour persistence/recurrence after surgery (χ2 = 8·2, P < 0·01).

Conclusion  PTTG is expressed in approximately 90% of pituitary tumours of different histotypes but with a high variability from one case to another. As expected, PTTG expression parallels that of Ki‐67 and both are correlated to a more aggressive behaviour. However, a 2·9% Ki‐67 cut‐off proved to be the most reliable biological marker for predicting the recurrence potential of these tumours, when an adequate postsurgical follow‐up is considered.
Influence of climate changes on animal communities in space and time: the case of spider assemblages along an alpine glacier foreland
Authors: GOBBI MAURO , FONTANETO DIEGO , DE BERNARDI FIORENZA
Published: August 2006

The impact of global warming in space and time is described for species assemblages of wandering spiders along the alpine glacier foreland of the Forni Valley (Northern Italy). We tested the effect of environmental variables (e.g. elevation, age of glacier retreat, vegetation cover, debris cover) on species richness and on species composition of spiders. Age of glacier retreat was the only significant variable influencing spider species assemblages in the valley. A spatially structured distribution of species and species assemblages along the chronosequence of glacier retreat was evidenced. The threshold abruptly differentiating two groups of species richness and species composition fell between sites deglaciated 100 and 155 years before the analysis. Latitudinal shifts towards the poles in species ranges at the global scale in response to climatic changes are known, and an altitudinal shift in species range should be expected for spiders at the local scale of the Forni Valley. Such a shift is present in spider species assemblages, although not as an expected gradual change in species richness and composition, but with a threshold effect after one century of glacier retreat. We discuss our results in the light of plausible future scenarios due to global warming, the consequence of further glacier retreats onto spiders, and caveats for monitoring studies.
The effect of climate change on partial migration – the blue tit paradox
Authors: NILSSON ANNA L. K. , LINDSTRÖM ÅKE , JONZÉN NICLAS , NILSSON SVEN G. , KARLSSON LENNART
Published: August 2006

Climate change has proven to affect various aspects of the migration of birds. In response to milder winters making the habitat more profitable and increasing the survival of residents, the migratory fraction of partially migratory populations has been predicted to decline. We studied the blue titParus caeruleus, a common partial migrant in southern Sweden. The numbers migrating at Falsterbo, a migratory passage site in SW Sweden, has increased during the last decades, in parallel with increasing winter and annual temperatures. Migration data from Falsterbo were compared with yearly indices of the size of the breeding population as estimated by the Swedish National Bird Monitoring Programme. Over the study period 1975–2004, also the breeding population has increased in size. The proportion of blue tits migrating each year did not change over the study period, or possibly even increased slightly, which is in contrast to how climate change has been predicted to influence populations containing both migratory and resident individuals. The most important factors determining the intensity of blue tit migration in a given year was the size of an important winter food source, the beech mast crop (more migrants at lower crops) and the size of the breeding population (more migrants at higher densities).
Temporal and intrapopulation variation in prey choice of wintering geese determined by stable isotope analysis
Authors: INGER RICHARD , RUXTON GRAEME D. , NEWTON JASON , COLHOUN KENDREW , ROBINSON JAMES A. , JACKSON ANDREW L. , BEARHOP STUART
Published: August 2006

Individual variability in prey preferences can have marked effects on many demographic parameters from individual survival and fecundity to the vital rates of entire populations. A population level response is ultimately determined by individual prey choices; however, the effect of individual dietary choice is often overlooked.

We determined prey choice by individual consumers, light‐bellied Brent geese Branta bernicla, during the overwintering period. Two hundred and eighty‐one individuals were sampled at distinct temporal points over two winters. Stable isotopic ratios of carbon and nitrogen for blood cells and blood plasma, from each sampled individual were measured. Isotopic ratios for potential prey items were also measured.

δ15N and δ13C for blood samples were both significantly different between sample months. Generally we found a decrease in both isotopic ratios during the course of the winter. All potential prey items were also isotopically distinct. Multisource mixing models (isosource) were used to determine the range of possible contribution to the diet of individuals.

During early winter, diet consisted almost exclusively of sea grass Zostera spp. The level of Zostera spp. in the diet dropped until mid‐winter, and was supplemented by the utilization of green algae Ulva lactuca, and Enteromorpha spp., and terrestrial grasses. Terrestrial grass comprised an increasing proportion of the diet in late winter, representing virtually the exclusive food source by April.

By examining intrapopulation variability in resource utilization we highlight a number of ecologically important factors not addressed by previous population level studies.
Genetic variation and population structure of Fusarium oxysporum f.sp. vasinfectum in Australia
Authors: Wang B. , Brubaker C. L. , Tate W. , Woods M. J. , Matheson B. A. , Burdon J. J.
Published: August 2006

Genetic variation among 348 isolates of Fusarium oxysporum f.sp. vasinfectum (Fov) collected from diseased cotton plants in 31 fields in six cotton‐growing regions in New South Wales and Queensland in 2002 and 2004 was analysed using amplified fragment length polymorphisms (AFLPs). Twenty‐eight haplotypes were identified based on 146 polymorphic bands generated with four EcoRI and MseI and four HindIII and MseI primer combinations. The haplotypes separated into two distinct groups (37% similarity), with 21 in group I and seven in group II. The two unique vegetative compatibility groups of Fov known to occur in Australia (VCG 01111 and VCG 01112) were correlated to the two AFLP groups, with both VCG 01111 reference isolates being included in group I and both VCG 01112 reference isolates in group II. Group I was widespread, occurring in all regions sampled and all but one of the fields, while group II was limited to three fields in the Boggabilla region. Group I was further divided into two subgroups. The two haplotypes in subgroup I‐B (I‐20 and I‐21) may represent the emergence of a new form of Fov based on their marked genetic discrimination from the subgroup I‐A haplotypes. No spatial population differentiation was discernible at the national level, as only 3·9% of total genetic variation was attributed to differences among regions (P = 0·4868). When each region was analysed separately, clear differentiation was found in the Boggabilla region, with 86·3% of total genetic variation resulting from differences among fields (P < 0·0001).
Quantitative trait loci for resistance to fusarium head blight and deoxynivalenol accumulation in Wangshuibai wheat under field conditions
Authors: Ma H. X. , Zhang K. M. , Gao L. , Bai G. H. , Chen H. G. , Cai Z. X. , Lu W. Z.
Published: August 2006

Wangshuibai is a Chinese landrace wheat with a high level of resistance to fusarium head blight (FHB) and deoxynivalenol (DON) accumulation. Using an F7 population of recombinant inbred lines (RILs) derived from the cross between Wangshuibai and Annong 8455 for molecular mapping of quantitative trait loci (QTL) for FHB resistance, the proportion of scabbed spikelets (PSS) and DON content were assessed under field conditions. Composite interval mapping revealed that two and three QTL were significantly associated with low PSS and low DON content, respectively, over 2 years. QTL on chromosomes 3B and 2A explained 17 and 11·5%, respectively, of the phenotypic variance for low PSS, whereas QTL on chromosomes 5A, 2A and 3B explained 12·4, 8·5 and 6·2%, respectively, of the phenotypic variance for low DON content. The 3B QTL appeared to be associated mainly with low PSS, and the 5A QTL primarily with low DON content in Wangshuibai. The 2A QTL had minor effects on both low PSS and DON content. Microsatellite and AFLP markers linked to these QTL should be useful for marker‐assisted selection of QTL for low PSS and low DNA content from Wangshuibai.
Characterization of Potato rough dwarf virus and Potato virus P: distinct strains of the same viral species in the genus Carlavirus
Authors: Nisbet C. , Butzonitch I. , Colavita M. , Daniels J. , Martin J. , Burns R. , George E. , Akhond M. A. Y. , Mulholland V. , Jeffries C. J.
Published: August 2006

In an attempt to resolve whether two putative carlaviruses, potato rough dwarf virus (PRDV) and potato virus P (PVP), reported infecting potato in Argentina and Brazil, respectively, are the same virus in the genus Carlavirus, they were characterized using nucleotide sequence analysis, serology and bioassay. For PRDV and PVP, sequences of 2016 and 1492 bp, respectively, were obtained. Similarity searches of coat‐protein amino acid sequences and the presence of the nucleic‐acid‐binding protein exhibiting the characteristic motif C‐X2‐C‐X11‐C‐X4‐C, highly conserved in carlaviruses, showed PRDV and PVP to be members of the genus Carlavirus. Further analysis showed that they were the same virus species since the full coat‐protein sequence, translated from the nucleotide sequence, exceeded the 84% minimum identity required for members of the same species within the genus Carlavirus, at 90·8% identity in an ungapped alignment of 304 amino acids. Moreover, the viruses could not be distinguished using polyclonal antibodies raised to PRDV and PVP in ELISA. They could, however, be distinguished using an anti‐PVP monoclonal antibody, which did not react to PRDV, and by differences in the susceptibility of plant species and potato cultivars to infection and/or symptom expression following mechanical inoculation. Host plants Datura metel, Nicandra physalodes and Nicotiana edwardsonii were reliably infected systemically with PVP, but not with PRDV. Although all potato cultivars tested were infected, there were marked differences between cultivars in the symptoms produced. The cultivars Ditta and King Edward showed symptoms (including stunting and mottle) when infected with PRDV, but not when infected with PVP. Based on the results, it is proposed that PRDV is a strain of PVP within the genus Carlavirus. For detection of the viruses in postentry quarantine, it is recommended that PRDV or PVP polyclonal antibodies are used, together with inoculation to Nicotiana occidentalis N. megalosiphon‐P1. For differentiation of PRDV and PVP, the PVP monoclonal antibody may be used together with inoculation to D. metel and N. physalodes (systemic infection with PVP but not PRDV, determined using ELISA).
Introduction of an intensive case management style of delivery for a new mental health service
Authors: Hangan Catherine
Published: August 2006

ABSTRACT:  Mental health case management emerged in the 1960s in response to the shift in focus from inpatient to community care. Case management per se had been used by other service industries for some time previously, particularly those involved with people with intellectual disability. The term case management describes a range of service approaches and strategies in mental health rather than a single model of care. One method of delivering case management is with an intensive model of care. Intensive case management is differentiated from other forms of case management through factors like a smaller caseload size, team management, outreach emphasis, a decreased brokerage role, and an assertive approach to maintaining contact with clients. Research has demonstrated that case management, in particular, intensive case management, can improve clients’ and families’ experience of mental health services but only when introduced and used for appropriately targeted client populations and suitably resourced. Determining which model of case management best suits the client population and how to introduce it is a major challenge for any mental health service. With a focus on intensive case management, a review of this process is outlined.
The Metacognitive Awareness Listening Questionnaire: Development and Validation
Authors: Vandergrift Larry , Goh Christine C. M. , Mareschal Catherine J. , Tafaghodtari Marzieh H.
Published: August 2006

This article describes the development and validation of a listening questionnaire designed to assess second language (L2) listeners' metacognitive awareness and perceived use of strategies while listening to oral texts. The process of instrument development and validation is described, along with a review of the relevant literature related to metacognition and learners' regulation of listening comprehension strategies. An exploratory factor analysis of the responses of a large sample (N= 966) of language learners and a subsequent confirmatory factor analysis with another large but different sample (N= 512) resulted in a 21‐item instrument with robust psychometric properties. Five distinct factors emerged: problem‐solving, planning and evaluation, mental translation, person knowledge, and directed attention. The reliability and factorial validity of the instrument are presented along with evidence for a statistically significant relationship between student response on the instrument and L2 listening comprehension success. The article concludes with a discussion of the potential uses of the Metacognitive Awareness Listening Questionnaire (MALQ).
On the Mechanics of Economic Convergence
Authors: Steger Thomas M.
Published: August 2006

The speed at which an economy converges to its steady state is investigated by using a general non-scale R&D-based growth model. To accomplish this task, an analytical decomposition formula for the instantaneous rate of convergence is developed. By applying this decomposition to the model under study, the driving forces behind the convergence process are identified. Two convergence mechanisms are distinguished: the accumulation-decumulation mechanism and the resource-reallocation mechanism. The relative importance of the different convergence mechanisms is assessed using numerical techniques. Moreover, it is shown that the specific shock being considered might be crucial for the instantaneous rate of convergence.
Decreased immunocompetence in a severely bottlenecked population of an endemic New Zealand bird
Authors: Hale K. A. , Briskie J. V.
Published: August 2006

Inbreeding resulting from severe population bottlenecks may impair an individual's immune system and render it more susceptible to disease. Although a reduced immune response could threaten the survival of highly endangered species, few studies have assessed the effect of population bottlenecks on immunocompetence. We compared the counts of leucocytes and external, blood and gastrointestinal parasite loads in two populations of the endemic New Zealand robin Petroica australis to assess the immunocompetence of birds in a severely bottlenecked population relative to its more genetically diverse source population. Despite similar parasite loads in both populations, robins in the severely bottlenecked population showed lower counts of both total leucocyte and total lymphocyte numbers. When the immune system was experimentally challenged using the phytohaemagglutinin skin test, robins in the severely bottlenecked population exhibited a significantly lower immune response than the source population, suggesting that birds passing through a severe bottleneck have a compromised immunocompetence. Our results confirm that severe bottlenecks reduce the immune response of birds and highlight the need to avoid severe bottlenecks in the recovery programmes of endangered species.
Conservation implications of a long‐term decline in body condition of the Brothers Island tuatara (Sphenodon guntheri)
Authors: Hoare J. M. , Pledger S. , Keall S. N. , Nelson N. J. , Mitchell N. J. , Daugherty C. H.
Published: August 2006

Understanding the factors that drive the dynamics of remnant populations of long‐lived species presents a unique challenge for conservation management. The long‐lived Brothers Island tuatara Sphenodon guntheri is represented by one natural, self‐sustaining population on 4‐ha North Brother Island, New Zealand, and two small, translocated populations. The North Brother Island population was almost driven to extinction by extreme habitat modification and collecting in the late 19th century. Analysis of a long‐term (1957–2001) dataset, following the population's recovery, reveals a significant decline in tuatara body condition over time, which is more pronounced in females. Declining body condition, coupled with very low reproductive output, may be symptomatic of a density‐dependent response to elevated population size exacerbated by resource limitation. Sex‐specific effects that disadvantage females could compromise this small population, particularly as it exhibits a male‐biased sex ratio. We recommend removal of infrequently used structures and habitat restoration to alleviate intense resource competition. Population‐level manipulation should be considered if future monitoring indicates an increasingly male‐biased sex ratio and continued decline of female body condition.
Market Arbitrage of Cash Dividends and Franking Credits*
Authors: BEGGS DAVID J. , SKEELS CHRISTOPHER L.
Published: August 2006

Since 1986, dividend imputation has influenced the ex‐dividend day behaviour of Australian share prices. This paper explores the effects of dividend imputation on ex‐dividend share price drop‐off from its inception until mid‐2004, with particular attention paid to the differential effects of cash dividends and franking credits. We also explore the effects of the six major legislative amendments to the dividend imputation system that were introduced over the sample period. Only the most recent tax change, which provided full income rebates for unused franking credits, appears to have caused the market to put a statistically significant value on franking credits.
Australian Banking Efficiency and Its Relation to Stock Returns
Authors: KIRKWOOD JOSHUA , NAHM DAEHOON
Published: August 2006

We used Data Envelopment Analysis to evaluate cost efficiency of Australian banks in producing banking services and profit between 1995 and 2002. Empirical results indicate the major banks have improved their efficiency in producing banking services and profit, while the regional banks have experienced little change in the efficiency of producing banking services, and a decline in the efficiency of producing profit. An attempt is made to relate the changes in efficiency to stock returns. Results indicate that for our sample, changes in firm efficiency are reflected in stock returns.
Trust, Inequality and Ethnic Heterogeneity
Authors: LEIGH ANDREW
Published: August 2006

Using a large Australian social survey, combined with precise data on neighbourhood characteristics, I explore the factors that affect trust at a local level (‘localised trust’) and at a national level (‘generalised trust’). Trust is positively associated with the respondent's education, and negatively associated with the amount of time spent commuting. At a neighbourhood level, trust is higher in affluent areas, and lower in ethnically and linguistically heterogeneous communities, with the effect being stronger for linguistic heterogeneity than ethnic heterogeneity. Linguistic heterogeneity reduces localised trust for both natives and immigrants, and reduces generalised trust only for immigrants. Instrumental variables specifications show similar results. In contrast to the USA, there is no apparent relationship between trust and inequality across neighbourhoods in Australia.
The Impact of Federation on Australia's Trade Flows*
Authors: IRWIN DOUGLAS A.
Published: August 2006

In 1901, six Australian states joined together in political and economic union, creating an internal free trade area and adopting a common external tariff. This paper investigates the impact of federation on Australia's internal and international trade flows by studying changes in the ‘border effect’ over this time. This is possible because Australian states reported intra‐Australian trade prior to 1901 and for 8 years after federation. The results indicate that federation itself produced little change in Australia's trade patterns, but that the border effect increased substantially between 1906 and 1909 when the protectionist Lyne Tariff was imposed.
Competing Approaches to Forecasting Elections: Economic Models, Opinion Polling and Prediction Markets*
Authors: LEIGH ANDREW , WOLFERS JUSTIN
Published: August 2006

We review the efficacy of three approaches to forecasting elections: econometric models that project outcomes on the basis of the state of the economy; public opinion polls; and election betting (prediction markets). We assess the efficacy of each in light of the 2004 Australian election. This election is particularly interesting both because of innovations in each forecasting technology, and also because the increased majority achieved by the Coalition surprised most pundits. While the evidence for economic voting has historically been weak for Australia, the 2004 election suggests an increasingly important role for these models. The performance of polls was quite uneven, and predictions both across pollsters, and through time, vary too much to be particularly useful. Betting markets provide an interesting contrast, and a slew of data from various betting agencies suggest a more reasonable degree of volatility, and useful forecasting performance both throughout the election cycle and across individual electorates.
Diversity Training and Intergroup Contact: A Call to Action Research
Authors: Paluck Elizabeth Levy
Published: August 2006

Diversity training is a type of prejudice reduction and social inclusion intervention in need of “action research”—an integration of research and theory with practice (Lewin, 1946). Hundreds of workplaces and schools use some form of diversity training, but most interventions are not grounded in theory and there is little evidence of program impact. A recent study of a school diversity training program illustrates how action research can address theoretical issues using experimental methods and unobtrusive outcome measures. For future research, the literature on intergroup contact (Pettigrew, 1998) can provide theoretical guidance while testing and refining its principles in the application and investigation of diversity training. Action research will benefit diversity training and the broader theoretical and applied project of prejudice reduction and the promotion of social inclusion.
Previewing Policy Sciences: Multiple Lenses and Segmented Visions
Authors: Sinclair Thomas A.P.
Published: August 2006

In setting an agenda for policy sciences, Harold Lasswell argued that the field would be shaped by its contextuality, problem orientation, and methodological diversity. The review of developments in the field in this article shows that scholars have divided into positivist and post‐positivist orientations that employ multiple frameworks and models. I argue that theoretical diversity should be expected and welcomed given the complexity of policy processes and phenomena. The article encourages positivists and post‐positivists alike to allow the problem being studied to drive analysis and to seek ways to integrate different theoretical and methodological approaches.
Simulation and Symbolic Exchange: Jean Baudrillard’s Augmentation of Marx’s Theory of Value
Authors: Koch Andrew M. , Elmore Rick
Published: August 2006

Jean Baudrillard’s concept of “symbolic exchange” represents an important concept in understanding why Marx’s prediction regarding the collapse of capitalism has not been realized. Baudrillard adds to the Marxian concepts of use value and exchange value, suggesting that, in today’s consumer‐oriented society, commodities take on a symbolic value that constitutes their “status” and, therefore, power. In the Western industrial societies that are “networked” into information cultures, the generation of symbolic value results from a constantly changing symbolic environment in which new demands for access to symbolic status are generated. Baudrillard sees the United States as the farthest along on the path to a simulated environment of symbolic exchange. Manufacturing for symbolic exchange is directed toward the production of the fetish: an object that is positioned purely for its symbolic value. By directing production increasingly in the direction of the fetish, as an object to be used in symbolic exchange, capitalism is able to sustain itself even after the material needs of the population are satisfied.
A novel site of synaptic relay for climbing fibre pathways relaying signals from the motor cortex to the cerebellar cortical C1 zone
Authors: Ackerley Rochelle , Pardoe Joanne , Apps Richard
Published: August 2006

The climbing fibre projection from the motor cortex to the cerebellar cortical C1 zone in the posterior lobe of the rat cerebellum was investigated using a combination of physiological, anatomical and neuropharmacological techniques. Electrical stimulation of the ipsilateral fore‐ or hindimbs or somatotopically corresponding parts of the contralateral motor cortex evoked climbing fibre field potentials at the same cerebellar recording sites. Forelimb‐related responses were located in the C1 zone in the paramedian lobule or lobulus simplex and hindlimb‐related responses were located in the C1 zone in the copula pyramidis. Microinjections of anterograde axonal tracer (Fluoro‐Ruby or Fluoro‐Emerald) were made into the fore‐ or hindlimb parts of the motor cortex where stimulation evoked the largest cerebellar responses. After a survival period of 7–10 days, the neuraxis was examined for anterograde labelling. No terminal labelling was ever found in the inferior olive, but labelled terminals were consistently found in a well‐localized site in the dorso‐medial medulla, ventral to the gracile nucleus, termed the matrix region. Pharmacological inactivation of the matrix region (2 mm caudal to the obex) selectively reduced transmission in descending (cerebro‐olivocerebellar) but not ascending (spino‐olivocerebellar) paths targeting fore‐ or hindlimb‐receiving parts of the C1 zone. Transmission in spino‐olivocerebellar paths was either unaffected, or in some cases increased. The identification of a novel pre‐olivary relay in cerebro‐olivocerebellar paths originating from fore‐ and hindlimb motor cortex has implications for the regulation of transmission in climbing fibre pathways during voluntary movements and motor learning.
Spontaneous rhythmic field potentials of isolated mouse hippocampal–subicular–entorhinal cortices in vitro
Authors: Wu C. P. , Huang H. L. , Asl M. Nassiri , He J. W. , Gillis J. , Skinner F. K. , Zhang L.
Published: August 2006

The rodent hippocampal circuit is capable of exhibiting in vitro spontaneous rhythmic field potentials (SRFPs) of 1–4 Hz that originate from the CA3 area and spread to the CA1 area. These SRFPs are largely correlated with GABA‐A IPSPs in pyramidal neurons and repetitive discharges in inhibitory interneurons. As such, their generation is thought to result from cooperative network activities involving both pyramidal neurons and GABAergic interneurons. Considering that the hippocampus, subiculum and entorhinal cortex function as an integrated system crucial for memory and cognition, it is of interest to know whether similar SRFPs occur in hippocampal output structures (that is, the subiculum and entorhinal cortex), and if so, to understand the cellular basis of these subicular and entorhinal SRFPs as well as their temporal relation to hippocampal SRFPs. We explored these issues in the present study using thick hippocampal–subicular–entorhinal cortical slices prepared from adult mice. SRFPs were found to spread from the CA1 area to the subicular and entorhinal cortical areas. Subicular and entorhinal cortical SRFPs were correlated with mixed IPSPs/EPSPs in local pyramidal neurons, and their generation was dependent upon the activities of GABA‐A and AMPA glutamate receptors. In addition, the isolated subicular circuit could elicit SRFPs independent of CA3 inputs. We hypothesize that the SRFPs represent a basal oscillatory activity of the hippocampal–subicular–entorhinal cortices and that the subiculum functions as both a relay and an amplifier, spreading the SRFPs from the hippocampus to the entorhinal cortex.
Regulation of electromotility in the cochlear outer hair cell
Authors: Frolenkov Gregory I.
Published: August 2006

Mechanosensory outer hair cells play an essential role in the amplification of sound‐induced vibrations within the mammalian cochlea due to their ability to contract or elongate following changes of the intracellular potential. This unique property of outer hair cells is known as electromotility. Selective efferent innervation of these cells within the organ of Corti suggests that regulation of outer hair cell electromotility may be the primary function of the efferent control in the cochlea. A number of studies demonstrate that outer hair cell electromotility is indeed modulated by the efferent neurotransmitter, acetylcholine. The effects of acetylcholine on outer hair cells include cell hyperpolarization and a decrease of the axial stiffness, both mediated by intracellular Ca2+. This article reviews these results and considers other potential mechanisms that may regulate electromotility, such as direct modification of the plasma membrane molecular motors, alteration of intracellular pressure, and modification of intracellular chloride concentration.
Differences between the scaling of miniature IPSCs and EPSCs recorded in the dendrites of CA1 mouse pyramidal neurons
Authors: Andrásfalvy Bertalan K. , Mody Istvan
Published: August 2006

Anatomical studies have described inhibitory synaptic contacts on apical dendrites, and an abundant number of GABAergic synapses on the somata and proximal dendrites of CA1 pyramidal cells of the hippocampus. The number of inhibitory contacts decreases dramatically with distance from the soma, but the local electrophysiological characterization of these synapses at their site of origin in the dendrites is missing. We directly recorded dendritic GABA receptor‐mediated inhibitory synaptic events in adult mouse hippocampal CA1 pyramidal neurons and compared them to excitatory synaptic currents recorded at the same sites. Miniature GABAergic events were evoked using localized application of a hyperosmotic solution to the apical dendrites in the vicinity of the dendritic whole‐cell recording pipette. Glutamatergic synaptic events were blocked by kynurenic acid, leaving picrotoxin‐sensitive IPSCs. We measured the amplitude and kinetic properties of mIPSCs at the soma and at three different dendritic locations. The amplitude of mIPSCs recorded at the various sites was similar along the somato‐dendritic axis. The rise‐ and decay‐times of local mIPSCs were also independent of the location of the synapses. The frequency of mIPSCs was 5 Hz at the soma, in contrast to < 0.5 Hz at dendritic sites, which could be increased to 10–20 Hz and 6–10 Hz, respectively, by our hyperosmotic stimulation protocol. Miniature glutamatergic events were evoked with the same protocol after blocking inhibitory synapses by bicucculine. The measured amplitudes increased along the somato‐dendritic axis proportionally with their distance from the soma. The measured kinetic properties were independent of location. Consistent with the idea that IPSCs may have a restricted local effect in the dendrites, our data show a lack of distance‐dependent scaling of miniature inhibitory synaptic events, in contrast to the scaling of excitatory events recorded at the same sites.
Ancillary subunits and stimulation frequency determine the potency of chromanol 293B block of the KCNQ1 potassium channel
Authors: Bett Glenna C. L. , Morales Michael J. , Beahm Derek L. , Duffey Michael E. , Rasmusson Randall L.
Published: August 2006

KCNQ1 (Kv7.1 or KvLQT1) encodes the alpha‐subunit of a voltage‐gated potassium channel found in tissues including heart, brain, epithelia and smooth muscle. Tissue‐specific characteristics of KCNQ1 current are diverse, due to modification by ancillary subunits. In heart, KCNQ1 associates with KCNE1 (MinK), producing a slowly activating voltage‐dependent channel. In epithelia, KCNQ1 co‐assembles with KCNE3 (Mirp2) producing a constitutively open channel. Chromanol 293B is a selective KCNQ1 blocker. We studied drug binding and frequency dependence of 293B on KCNQ1 and ancillary subunits expressed in Xenopus oocytes. Ancillary subunits altered 293B potency up to 100‐fold (IC50 for KCNQ1 = 65.4 ± 1.7 μm; KCNQ1/KCNE1 = 15.1 ± 3.3 μm; KCNQ1/KCNE3 = 0.54 ± 0.18 μm). Block of KCNQ1 and KCNQ1/KCNE3 was time independent, but 293B altered KCNQ1/KCNE1 activation. We therefore studied frequency‐dependent block of KCNQ1/KCNE1. Repetitive rapid stimulation increased KCNQ1/KCNE1 current biphasically, and 293B abolished the slow component. KCNQ1/KCNE3[V72T] activates slowly with a KCNQ1/KCNE1‐like phenotype, but retains the high affinity binding of KCNQ1/KCNE3, demonstrating that subunit‐mediated changes in gating can be dissociated from subunit‐mediated changes in affinity. This study demonstrates the KCNQ1 pharmacology is significantly altered by ancillary subunits. The response of KCNQ1 to specific blockers will therefore be critically dependent on the electrical stimulation pattern of the target organ. Furthermore, the dissociation between gating and overall affinity suggests that mutations in ancillary subunits can potentially strongly alter drug sensitivity without obvious functional changes in gating behaviour, giving rise to unexpected side‐effects such as a predisposition to acquired long QT syndrome.
5‐HT evokes sensory long‐term facilitation of rodent carotid body via activation of NADPH oxidase
Authors: Peng Ying‐Jie , Yuan Guoxiang , Jacono Frank J. , Kumar Ganesh K. , Prabhakar Nanduri R.
Published: August 2006

5‐Hydroxytryptamine (5‐HT) evokes long‐term activation of neuronal activity in the nervous system. Carotid bodies, the sensory organs for detecting arterial oxygen, express 5‐HT. In the present study we examined whether 5‐HT evokes sensory long‐term facilitation (LTF) of the carotid body, and if so by what mechanism(s). Experiments were performed on anaesthetized adult rats and mice. Sensory activity was recorded from carotid bodies ex vivo. Spaced (3 × 15 s of 100 nm at 5 min intervals) but not mass (300 nm, 45 s) application of 5‐HT elicited LTF, whereas both modes of 5‐HT application evoked initial sensory excitation of the carotid bodies in rats. Ketanserin, a 5‐HT2 receptor antagonist prevented sensory LTF but not the initial sensory excitation. Spaced application of 5‐HT activated protein kinase C (PKC) as evidenced by increased phosphorylations of PKC at Thr514 and myristoylated alanine‐rich C kinase substrate (MARCKS) and these effects were abolished by ketanserin as well as bisindolylmaleimide (Bis‐1), an inhibitor of PKC. Bis‐1 prevented 5‐HT‐evoked sensory LTF. 5‐HT increased NADPH oxidase activity and PKC‐dependent phosphorylation of p47phox subunit of the oxidase complex. NADPH oxidase inhibitors (apocynin and diphenyl iodinium), as well as an anti‐oxidant (N‐acetyl cysteine), prevented 5‐HT‐evoked sensory LTF. Mice deficient in gp91phox, the membrane subunit of the NADPH oxidase complex, showed no sensory LTF, although responding to 5‐HT with initial afferent nerve activation, whereas both LTF and initial excitation by 5‐HT were seen in wild‐type mice. These results demonstrate that spaced but not mass application of 5‐HT elicits sensory LTF of the carotid body via activation of 5‐HT2 receptors, which involves a novel signalling mechanism coupled to PKC‐dependent activation of NADPH oxidase.
AMPA type glutamate receptor mediates neurotransmission at turtle vestibular calyx synapse
Authors: Bonsacquet Jérémie , Brugeaud Aurore , Compan Vincent , Desmadryl Gilles , Chabbert Christian
Published: August 2006

Glutamate is thought to be the main neurotransmitter at the synapse between the type I vestibular hair cell and its cognate calyx afferent. The present study was designed to identify the type of glutamate receptors involved in neurotransmission at this unusual synapse. Immunocytochemistry showed that AMPA GluR2, NMDA NR1 and NR2A/B subunits of the glutamate receptors were confined to the synaptic contact. We then examined the electrical activity at calyx terminals using direct electrophysiological recordings from intact dendritic terminals in explanted turtle posterior crista. We found that sodium‐based action potentials support a background discharge that could be modulated by the mechanical stimulation of the hair bundle of the sensory cells. These activities were prevented by blocking both the mechano‐electrical transduction channels and L‐type voltage‐gated Ca2+ channels involved in synaptic transmission. Although pharmacological analysis revealed that NMDA receptors could operate, our results show that AMPA receptors are mainly involved in synaptic neurotransmission. We conclude that although both AMPA and NMDA glutamate receptor subunits are present at the calyx synapse, only AMPA receptors appear to be involved in the synaptic transmission between the type I vestibular hair cell and the calyx afferent.