bluuebunny/crossref_metadata_2025 huggingface dataset:
The regulation of M1 muscarinic acetylcholine receptor desensitization by synaptic activity in cultured hippocampal neurons1
Authors: Willets Jonathon M. , Nelson Carl P. , Nahorski Stefan R. , Challiss R. A. John
Published: October 2007

To better understand metabotropic/ionotropic integration in neurons we have examined the regulation of M1 muscarinic acetylcholine (mACh) receptor signalling in mature (> 14 days in vitro), synaptically‐active hippocampal neurons in culture. Using a protocol where neurons are exposed to an EC50 concentration of the muscarinic agonist methacholine (MCh) prior to (R1), and following (R2) a desensitizing pulse of a high concentration of this agonist, we have found that the reduction in M1 mACh receptor responsiveness is decreased in quiescent (+tetrodotoxin) neurons and increased when synaptic activity is enhanced by blocking GABAA receptors with picrotoxin. The picrotoxin‐mediated effect on M1 mACh receptor responsiveness was completely prevented by α‐amino‐3‐hydroxy‐5‐methyl‐4‐isoxazolepropionic acid receptor blockade. Inhibition of endogenous G protein‐coupled receptor kinase 2 by transfection with the non‐Gq/11α‐binding, catalytically‐inactive D110A,K220RG protein‐coupled receptor kinase 2 mutant, decreased the extent of M1 mACh receptor desensitization under all conditions. Pharmacological inhibition of protein kinase C (PKC) activity, or chronic phorbol ester‐induced PKC down‐regulation had no effect on agonist‐mediated receptor desensitization in quiescent or spontaneously synaptically active neurons, but significantly decreased the extent of receptor desensitization in picrotoxin‐treated neurons. MCh stimulated the translocation of diacylglycerol‐ sensitive eGFP‐PKCε, but not Ca2+/diacylglycerol‐sensitive eGFP‐PKCβII in both the absence, and presence of tetrodotoxin. Under these conditions, MCh‐stimulated eGFP‐myristoylated, alanine‐rich C kinase substrate translocation was dependent on PKC activity, but not Ca2+/calmodulin. In contrast, picrotoxin‐driven translocation of myristoylated, alanine‐rich C kinase substrate was accompanied by translocation of PKCβII, but not PKCε, and was dependent on PKC and Ca2+/calmodulin. Taken together these data suggest that the level of synaptic activity may determine the different kinases recruited to regulate M1 mACh receptor desensitization in neurons.
Retinol activates tyrosine hydroxylase acutely by increasing the phosphorylation of serine40 and then serine31 in bovine adrenal chromaffin cells
Authors: Gelain Daniel P. , Moreira Jose C. F. , Bevilaqua Lia R. M. , Dickson Phillip W. , Dunkley Peter R.
Published: October 2007

Tyrosine hydroxylase is the rate‐limiting enzyme in the biosynthesis of the catecholamines. It has been reported that retinol (vitamin A) modulates tyrosine hydroxylase activity by increasing its expression through the activation of the nuclear retinoid receptors. In this study, we observed that retinol also leads to an acute activation of tyrosine hydroxylase in bovine adrenal chromaffin cells and this was shown to occur via two distinct non‐genomic mechanisms. In the first mechanism, retinol induced an influx in extracellular calcium, activation of protein kinase C and serine40 phosphorylation, leading to tyrosine hydroxylase activation within 15 min. This effect then declined over time. The retinol‐induced rise in intracellular calcium then led to a second slower mechanism; this involved an increase in reactive oxygen species, activation of extracellular signal‐regulated kinase 1/2 and serine31 phosphorylation and the maintenance of tyrosine hydroxylase activation for up to 2 h. No effects were observed with retinoic acid. These results show that retinol activates tyrosine hydroxylase via two sequential non‐genomic mechanisms, which have not previously been characterized. These mechanisms are likely to operate in vivo to facilitate the stress response, especially when vitamin supplements are taken or when retinol is used as a therapeutic agent.
Cerebral clearance of human amyloid‐β peptide (1–40) across the blood–brain barrier is reduced by self‐aggregation and formation of low‐density lipoprotein receptor‐related protein‐1 ligand complexes
Authors: Ito Shingo , Ohtsuki Sumio , Kamiie Junichi , Nezu Yasuko , Terasaki Tetsuya
Published: October 2007

Soluble amyloid‐β peptide (Aβ) exists in the form of monomers and oligomers, and as complexes with Aβ‐binding molecules, such as low‐density lipoprotein receptor‐related protein‐1 (LRP‐1) ligands. The present study investigated the effect of self‐aggregation and LRP‐1 ligands on the elimination of human Aβ(1–40) [hAβ(1–40)] from the rat brain across the blood–brain barrier. Incubation of [125I]hAβ(1–40) monomer resulted in time‐dependent and temperature‐dependent dimer formation, and the apparent elimination rate of [125I]hAβ(1–40) dimer was significantly decreased by 92.7% compared with that of [125I]hAβ(1–40) monomer. Pre‐incubation with LRP‐1 ligands, such as activated α2‐macroglobulin (α2M), apolipoprotein E2 (apoE2), apoE3, apoE4, and lactoferrin, reduced the elimination of [125I]hAβ(1–40). By contrast, pre‐administration of the same concentration of these molecules in the rat brain did not significantly inhibit [125I]hAβ(1–40) monomer elimination. Purified [125I]hAβ(1–40)/activated α2M complex and [125I]activated α2M were not significantly eliminated from the rat brain up to 60 min. MEF‐1 cells, which have LRP‐1‐mediated endocytosis, exhibited uptake of [125I]activated α2M, and enhancement of [125I]hAβ(1–40) uptake upon pre‐incubation with apoE, suggesting that [125I]activated α2M and [125I]hAβ(1–40)/apoE complex function as LRP‐1 ligands. These findings indicate that dimerization and LRP‐1‐ligand complex formation prevent the elimination of hAβ(1–40) from the brain across the blood–brain barrier.
Split GFP complementation assay: a novel approach to quantitatively measure aggregation of tau in situ: effects of GSK3β activation and caspase 3 cleavage
Authors: Chun Wanjoo , Waldo Geoffrey S. , Johnson Gail V. W.
Published: October 2007

To quantitatively measure tau aggregation in situ, we established a cell model system using a split green fluorescence protein (GFP) complementation assay. In this assay the more aggregated the protein of interest the lower the GFP fluorescence. Tau microtubule‐binding domain constructs, whose aggregation characteristics have been described previously (Khlistunova et al. 2006), were used to validate the assay. The aggregation‐prone construct exhibited the lowest GFP intensity whereas the aggregation‐resistant construct showed the highest GFP intensity. To examine the role of glycogen synthase kinase 3β (GSK3β) activity and caspase 3 cleavage on tau aggregation, GFP complementation of full length (T4), caspase‐cleaved (T4C3), and pseudophosphorylated at S396/S404 (T4‐2EC) tau was examined in the presence of an active or a kinase‐dead GSK3β. Extensive phosphorylation of T4 by GSK3β resulted in increased GFP intensity. T4C3 showed neither efficient phosphorylation nor a significant GFP intensity change by GSK3β. The GFP intensity of T4‐2EC was significantly reduced by GSK3β accompanying its presence in the sarkosyl‐insoluble fraction, thus demonstrating that T4‐2EC was partitioning into aggregates. This indicates that if the majority of tau is phosphorylated at S396/S404, in combination with increased GSK3β activity, tau aggregation is favored. These data demonstrate that split GFP complementation may be a valuable approach to determine the aggregation process in living cells.
Down‐regulation of cAMP‐dependent protein kinase by over‐activated calpain in Alzheimer disease brain
Authors: Liang Zhihou , Liu Fei , Grundke‐Iqbal Inge , Iqbal Khalid , Gong Cheng‐Xin
Published: October 2007

Impaired cognition and memory may be associated with down‐regulation of cAMP‐response element‐binding protein (CREB) in the brain in patients with Alzheimer disease, but the molecular mechanism leading to the down‐regulation is not understood. In this study, we found a selective reduction in the levels of the regulatory subunits (RIIα and RIIβ) and the catalytic subunit (Cβ) as well as the enzymatic activity of cAMP‐dependent protein kinase (PKA), which is the major positive regulator of CREB. We also observed that PKA subunits were proteolyzed by calpain and the levels of PKA subunits correlated negatively with calpain activation in the human brain. These findings led us to propose that in the brain in patients with Alzheimer disease, over‐activation of calpain because of calcium dysregulation causes increased degradation and thus decreased activity of PKA, which, in turn, contributes to down‐regulation of CREB and impaired cognition and memory.
PERMANENT GENETIC RESOURCES: Identification and characterization of 14 polymorphic microsatellite loci in the argasid tick Ornithodoros coriaceus
Authors: KIRCHOFF VERONICA S. , PEACOCK MARY M. , TEGLAS MIKE B.
Published: October 2007

Fourteen polymorphic microsatellite loci (di, tetra and di‐tetra complexes) were developed for the argasid tick Ornithodoros coriaceus. Polymorphism was assessed for 56 individuals from two populations separated by ~95 km. All loci were polymorphic (X = 7, range 3–17 alleles). All loci were in Hardy–Weinberg equilibrium except for one locus (OrC 8) in a single population (P < 0.00119, after Bonferroni correction for multiple tests).
Characterization of 25 microsatellite loci in bowhead whales (Balaena mysticetus)
Authors: HUEBINGER RYAN M. , PATTON JOHN C. , GEORGE J. CRAIG , SUYDAM ROBERT , LOUIS EDWARD E. , BICKHAM JOHN W.
Published: October 2007

Bowhead whales (Balaena mysticetus) experienced a severe demographic population bottleneck caused by commercial whaling that ceased in 1914. Aboriginal subsistence whale harvests have continued and are managed by the International Whaling Commission. In an effort to provide management advice for bowhead whales, 25 microsatellite loci were isolated from genomic DNA libraries. This panel of markers will be utilized to analyse stock structure hypotheses of current bowhead whale populations.
Sequencing breakthroughs for genomic ecology and evolutionary biology
Authors: HUDSON MATTHEW E.
Published: October 2007

Techniques involving whole‐genome sequencing and whole‐population sequencing (metagenomics) are beginning to revolutionize the study of ecology and evolution. This revolution is furthest advanced in the Bacteria and Archaea, and more sequence data are required for genomic ecology to be fully applied to the majority of eukaryotes. Recently developed next‐generation sequencing technologies provide practical, massively parallel sequencing at lower cost and without the requirement for large, automated facilities, making genome and transcriptome sequencing and resequencing possible for more projects and more species. These sequencing methods include the 454 implementation of pyrosequencing, Solexa/Illumina reversible terminator technologies, polony sequencing and AB SOLiD. All of these methods use nanotechnology to generate hundreds of thousands of small sequence reads at one time. These technologies have the potential to bring the genomics revolution to whole populations, and to organisms such as endangered species or species of ecological and evolutionary interest. A future is now foreseeable where ecologists may resequence entire genomes from wild populations and perform population genetic studies at a genome, rather than gene, level. The new technologies for high throughput sequencing, their limitations and their applicability to evolutionary and environmental studies, are discussed in this review.
Extra‐pair paternity in the SkylarkAlauda arvensis
Authors: HUTCHINSON JOHN M. C. , GRIFFITH SIMON C.
Published: October 2007

We present the first quantitative data on the genetic breeding system of a lark (Alaudidae), the SkylarkAlauda arvensis. Using a set of eight microsatellite loci isolated in a variety of passerine species, we genotyped 171 offspring from 52 broods of Skylark and detected 35 extra‐pair offspring (20%), in 14 different broods (27%). All offspring matched their putative mother, so there was no evidence of intraspecific brood parasitism. Previous non‐genetic studies had suggested that the species was predominantly socially monogamous, with only rare occurrences of social polygyny and polyandry, although some behaviours, such as mate guarding, did suggest the possibility of extra‐pair copulations. The relatively high level of extra‐pair paternity in this species is likely to affect the variation in male reproductive success because extra‐pair paternity was non‐randomly distributed amongst males, with those with shorter wings more likely to be cuckolded.
Population trends of Rooks Corvus frugilegus in Spain and the importance of refuse tips
Authors: OLEA PEDRO P. , BAGLIONE VITTORIO
Published: October 2007

Anthropogenic food from refuse tips can affect population dynamics in birds, especially gulls, but the evidence is mostly circumstantial. We combine analyses of long‐term population data and natural experiments to show a positive effect of refuse tips on the growth of the Spanish breeding population of Rooks Corvus frugilegus. In this isolated population of around 2000 breeding pairs, monitored since 1976, birds in colonies less than 10 km from tips fed largely on refuse, particularly during periods of lowest natural food availability. Three lines of evidence support the hypothesis that the supply of refuse influenced breeding numbers, suggesting that this population is limited by food: 1) between 1976 and 2003, the two population nuclei that had access to tips increased 2.1 and 3.7 times more than that without a tip nearby; 2) annual colony growth between 1996 and 2003 was strongly correlated with the availability of tips when other potentially important variables were taken into account; 3) the number of breeding pairs in refuse‐foraging colonies declined rapidly after the closure of the local tip and recovered only when a supply of refuse was restored. The effect of tips on colony growth was stronger when the availability of natural foraging habitat around the colonies was low, suggesting that anthropogenic food acts as a buffer against shortage of natural food. Artificial food supplementation may be an effective tool to increase the breeding population of target species, especially those facing a reduction of their foraging habitats. The potential effects on bird species of Directive 1999/31/CE, which is enforcing a massive closure of tips in Europe, are discussed.
Division of labour during incubation in a woodpeckerColaptes auratuswith reversed sex roles and facultative polyandry
Authors: WIEBE KAREN L.
Published: October 2007

The contribution of males to incubation has rarely been studied in altricial birds because the pursuit of extra mating opportunities is believed to conflict with incubation. Woodpeckers show reversed sex roles in parental care with males doing most of the nest construction, incubating and brooding of the young while females may be polyandrous. I investigated incubation by each sex at 71 monogamous and four polyandrous nests of the Northern FlickerColaptes auratus, predicting that males would contribute to incubation according to their energy reserves (body condition) whereas females would contribute based on alternate reproductive opportunities. Nest attendance was 99% with males contributing a mean of 66% of the total incubation including nocturnal incubation. The length of daytime bouts averaged about 2 h and did not differ between the sexes. Consistent with predictions of investment strategies, structurally larger males and those in poorer body condition incubated less than smaller males, perhaps because they required more recess time to forage or to conserve energy. Older females contributed less incubation than young females and polyandrous females contributed less incubation at their secondary nests than monogamous females. Incubation period, nest depredation rate and hatching success were not influenced by bout length, number of bouts or relative contribution of the sexes. Hatching success was 86% at nests of both monogamous and polyandrous females because males compensated for reduced female participation. Because incubation of the sexes is compensatory and not additive, incubation pattern did not influence short‐term reproductive success. I conclude that males invest in incubation according to their energy needs, and females may adjust their contributions based on alternate reproductive tactics.
Risk‐taking and survival in the House Sparrow Passer domesticus: are plumage ornaments costly?
Authors: BÓKONY VERONIKA , LIKER ANDRÁS , LENDVAI ÁDÁM Z. , KULCSÁR ANNA
Published: October 2007

An important cost of sexual and social colour signals may be increased conspicuousness of the animals to visual predators. Although such predation costs have repeatedly been proposed for various ornaments of birds, especially for melanised and depigmented signals with low presumed production costs, tests of this hypothesis are rare and inconclusive. In this study we investigated whether individual variation in plumage ornamentation was associated with predator‐related risk‐taking behaviour and short‐term survival in free‐living House Sparrows Passer domesticus. In a large sample of birds we measured three aspects of coloration used in sexual and social signalling: the size of the melanised black throat patch in males, and the area and conspicuousness of the depigmented wing‐bar in both sexes. We measured risk‐taking by manipulating the distance of feeders from shelters, and recorded individually ringed birds feeding close to and far from shelter. Sparrows seemed to perceive the farther feeders as more risky, as indicated by the shorter time spent and smaller groups feeding far from rather than close to shelter. However, the use of the more risky (farther) feeders was not related to any of the colour traits we measured, suggesting that Sparrows do not adjust their risk‐taking behaviour to their ornamentation. Males (the more ornamented sex) did not take less risk than females. Furthermore, we found no evidence that larger throat patches or more ornamented wing‐bars reduced the probability of survival. Our findings were robust and consistent across multiple approaches, even when we controlled for several potential confounding effects. These results do not support the suggestion that melanised and depigmented plumage ornaments have significant predation costs in House Sparrows.
Carotenoid plumage hue and chroma signal different aspects of individual and habitat quality in tits
Authors: FERNS PETER N. , HINSLEY SHELLEY A.
Published: October 2007

We hypothesized that Blue Tits Cyanistes caeruleus and Great Tits Parus major from low quality habitat (small woods) would have less yellow ventral plumage than those from high quality habitat (large woods) because they moult faster and/or their diet contains fewer carotenoids. They moult faster because they moult later in the season and are subject to more rapidly shortening daylengths. We tested this using a database of the plumage coloration (chroma, hue and lightness) of birds breeding in woods of different sizes, by manipulating the speed of moult in captive Blue Tits, and by counting the abundance and size of caterpillars (the major source of dietary carotenoids) in the diet of nestlings. In accordance with our hypothesis, juveniles of both species (which moult about three weeks later than adults) were about 8% less saturated in colour (lower chroma) than adults, but there was no significant difference in chroma between habitats. However, both species did differ significantly in hue between large and small woods. Blue Tits forced to moult faster in captivity, at a rate similar to that caused by a month's delay in the start of moult, had yellow flank feathers that were 32% less saturated in colour than those allowed to moult more slowly. Blue Tit nestlings in large woods consumed 47% more caterpillar flesh (per gram of faecal material voided) than those in small woods, and Great Tit pulli 81% more. When habitat effects were controlled for in ANOVAs, Blue Tits mated assortatively on the basis of flank hue and Great Tits on the basis of flank lightness. Flank colour therefore has the capacity to provide information about the potential quality of both habitats, and individual birds, to potential colonists and sexual partners.
Acoustical and Poromechanical Characterisation of Titanium Scaffolds for Biomedical Applications
Authors: Müllner H. W. , Fritsch A. , Kohlhauser C. , Reihsner R. , Hellmich C. , Godlinski D. , Rota A. , Slesinski R. , Eberhardsteiner J.
Published: October 2007

Abstract:  Biocompatible materials are designed so as to mimic biological materials such as bone as closely as possible. As regards the mechanical aspect of bone replacement materials, a certain stiffness and strength are mandatory to effectively carry the loads imposed on the skeleton. In this paper, porous titanium with different porosities, produced on the basis of metal powder and space holder components, is investigated as bone replacement material. For the determination of mechanical properties, i.e. strength of dense and porous titanium samples, two kinds of experiments were performed – uniaxial and triaxial tests. The triaxial tests were of poromechanical nature, i.e. oil was employed to induce the same pressure both at the lateral surfaces of the cylindrical samples and inside the pores. The stiffness properties were revealed by acoustic (ultrasonic) tests. Different frequencies give access to different stiffness components (stiffness tensor components related to high‐frequency‐induced bulk waves versus Young's moduli related to low‐frequency‐induced bar waves), at different observation scales; namely, the observation scale the dense titanium with around 100 μm characteristic length (characterised through the high frequencies) versus that of the porous material with a few millimetres of characteristic length (characterised through the low frequencies). Finally, the experimental results were used to develop and validate a poro‐micromechanical model for porous titanium, which quantifies material stiffness and strength from its porosity and (in the case of the aforementioned triaxial tests) its pore pressurisation state.
Friction Coefficient Definition in Compression‐fit Couplings Applying the DOE Method
Authors: Croccolo D. , Cuppini R. , Vincenzi N.
Published: October 2007

Abstract:  This work aims at defining a general‐purpose method of calculating the starting friction coefficient μll of the fork‐pin compression fit couplings of motorbike front suspensions. The research was carried out applying the Design of Experiment method and performing some Finite Element analyses compared with the results produced by theoretical equations. The investigated couplings are different because of the material (steel or aluminium) and the coupling surfaces condition. The second purpose of this work is to update, by means of the new defined mathematical models, an innovative software (Fork Design©), realized by the authors in Visual Basic® programming language. This software, useful to design and to verify the fork‐pin compression fit couplings of motorbike front suspensions, can be applied to different geometries and material conditions.
From convergence to contention: United States mass media representations of anthropogenic climate change science
Authors: Boykoff Maxwell T
Published: October 2007

This article focuses on connected factors that contribute to United States (US) media reporting on anthropogenic climate change science. It analyses US newspapers and television news from 1995 to 2006 as well as semi‐structured interviews with climate scientists and environmental journalists. Through analyses of power and scale, the paper brings together issues of framing in journalism to questions of certainty/uncertainty in climate science. The paper examines how and why US media have represented conflict and contentions, despite an emergent consensus view regarding anthropogenic climate science.
Mapping UK pension benefits and the intended purchase of annuities in the aftermath of the 1990s stock market bubble
Authors: Clark Gordon L , Knox‐Hayes Janelle
Published: October 2007

Many people rely upon personal and employer‐sponsored pensions to supplement the basic state pension. As such, the soon‐to‐retire baby‐boom generation will depend on the nature and number of their pension entitlements as well as the performance of global stock markets – a fact of life ignored when market prospects appear on an upwards trajectory but of considerable concern when markets decline. There are increasing concerns about the social and geographical stratification of pension entitlements. Just as importantly, it appears that individual risk attitudes and financial decisionmaking are associated with the social identity of respondents, including their age, gender, marital status and income. Here, we test whether access to supplementary pension benefits is related to socio‐demographic status or region of residence or both. Having determined that social status is the crucial determinant of the number of pension entitlements held by respondents, we test whether the intended purchase of an annuity can be correlated with socio‐demographic status or region of residence or both. Based upon a unique and large data base of 50–64‐year‐olds – people with an immediate and tangible interest in their pension prospects – it is shown that respondents’ region of residence is significant in explaining the variance in individual's pension‐related risk management strategies. Implications are drawn for the map of UK pension benefits and for the existence of regional subcultures of financial decisionmaking.
Reworking hegemony in the urban waterscape
Authors: Loftus Alex , Lumsden Fiona
Published: October 2007

In this paper, we argue that ideology is fought over through lived environments. In making this argument, we build on Antonio Gramsci's writings on hegemony. In particular, we extend the analysis of the terrain over which hegemony operates from civil society to urban environments. Here, we argue that the socio‐natural relations established through everyday activities are crucial to the consolidation (and contestation) of particular worldviews. Overall, we seek to put Gramsci to work in understanding the politics and the possibilities in the informal settlement of Inanda and more generally within post‐apartheid South Africa.
Technology, Productivity and Public Policy*
Authors: Griffith Rachel
Published: October 2007

The poor productivity performance of the UK and the EU when compared with the US has been a major driver of policy reforms over the past decade. This paper considers what the evidence suggests about why we have lagged behind the US, considering among other factors the importance of globalisation and outsourcing, the role for public policy intervention and what the key drivers of growth are likely to be for the future.
Expenditure Reform in Industrialised Countries: A Case‐Study Approach*
Authors: Hauptmeier Sebastian , Heipertz Martin , Schuknecht Ludger
Published: October 2007

This study examines reforms of public expenditure in industrialised countries over the past two decades. We distinguish ambitious and timid reformers and analyse in detail reform experiences in eight case studies of ambitious reform episodes. We find that ambitious reform countries reduce spending on transfers, subsidies and public consumption. Such expenditure retrenchment is also typically part of a comprehensive reform package that includes improvements in fiscal institutions as well as structural and other macroeconomic reforms. The study finds that ambitious expenditure retrenchment and reform coincides with large improvements in fiscal and economic growth indicators.
Joint Taxation and the Labour Supply of Married Women: Evidence from the Canadian Tax Reform of 1988*
Authors: Crossley Thomas F. , Jeon Sung‐Hee
Published: October 2007

The Canadian federal tax reform of 1988 replaced a spousal tax exemption with a non‐refundable tax credit. This reduced the‘jointness’of the tax system: after the reform, secondary earners’effective‘first dollar’marginal tax rates no longer depended on the marginal tax rates of their spouses. In practice, the effective‘first dollar’marginal tax rates faced by women with high‐income husbands were particularly reduced. Using difference‐indifference estimators, we find a significant increase in labour force participation among women married to higher‐income husbands.
When Taxation Changes the Course of the Year: Fiscal‐Year Adjustments and the German Tax Reform of 2000–01*
Authors: Blasch Frank , Weichenrieder Alfons J.
Published: October 2007

This paper examines 157 German listed corporations that had the option of changing their fiscal year to achieve a possible tax reduction in connection with the major tax reform of 2000—01. The tax reduction from a change was larger, the larger the expected profits. However, with costs of changing the fiscal year, not all firms that expect a tax reduction from a change may do so. The paper presents empirical evidence that the propensity to change the fiscal year was significantly related to the amount of expected tax savings. This suggests that the corporate tax reduction — in combination with the special German transitory provisions — induced a deadweight loss: corporations incurred a non‐tax cost to avoid a tax cost.
On the Characterisation and Measurement of the Redistributive Effect of Agricultural Policy
Authors: Allanson Paul
Published: October 2007

The article proposes a coherent framework for the evaluation of the redistributive performance of agricultural policy. An illustrative study shows that the vertical stance of policy in Scotland was progressive in absolute terms, reflecting the chronic dependence of Scottish agriculture on policy transfers. Nevertheless, the overall redistributive effect of policy was to increase absolute inequality in farm incomes because of horizontal inequities in the incidence of transfers, though neither systematic discrimination between farm types nor systematic reranking was the main cause. The targeting of policy transfers could be improved by the use of indicator variables more strongly correlated with pre‐transfer incomes.
Some Consequences of the 1994–1995 Coffee Boom for Growth and Poverty Reduction in Uganda
Authors: Chant Lindsay , McDonald Scott , Verschoor Arjan
Published: October 2007

This paper reports a computable general equilibrium analysis that explores the consequences of the 1994–1995 increase in the international price of coffee for Uganda's economy. Evidence is found for a small effect on both medium‐term growth and poverty reduction. Aid dependence is among the reasons why this effect is not found to be larger. Major beneficiary groups are not primarily the farmers to which the windfall initially accrued, but urban wage earners and the urban self‐employed.
Factors Affecting Farmers’ Participation in Agri‐environmental Measures: A Northern Italian Perspective
Authors: Defrancesco Edi , Gatto Paola , Runge Ford , Trestini Samuele
Published: October 2007

Agri‐environmental measures play an important role in Italian rural areas, as shown by the financial commitment to the Rural Development programmes. However, in contrast with other European Union (EU) countries, policy‐makers still have limited experience on how farmers approach environmental incentive schemes. This paper casts new light on this issue from a northern Italian perspective. The rationale of the farmers’ decision‐making process is explored using two multinomial models. The first explains the probability of non‐participation or participation in one of three specific agri‐environmental measures. The model outcomes show that labour‐intensive farming types and high dependency of household income on farming activity constrain farmers’ participation, whereas previous experience, easy‐to‐implement environmentally friendly farm practices and adequate compensation of extra costs encourage participation. The second model explores the effect of farmers’ attitudes and beliefs on their predispositions towards participation in any of the schemes. The results highlight that, besides income factors, the farm's future in the business, and the relationship with neighbouring farmers and their opinions on environmentally friendly practices all have significant effects on adoption of agri‐environmental measures. The paper concludes by suggesting that farmers’ attitudes and beliefs, as well as the local behavioural influences, have to be taken into account when designing and communicating agri‐environmental measures.
Synthesizing Citizenship in Modern China1
Authors: Culp Robert
Published: October 2007

This article reviews the recent scholarship on citizenship in early twentieth‐century China and presents a conceptual framework for analyzing citizenship, there and elsewhere, as a complex formation of ideas and practices. The article asks why citizenship became so important in late Qing and early Republican China and why Euro‐American scholars have been so attentive to it during the last two decades. It then draws on the rich historical literature to characterize four distinct dimensions of modern Chinese citizenship. In discussing national identity, political participation and civil rights, cultural citizenship, and social membership, the author reflects on possible axes of comparison between Chinese and Euro‐American approaches to citizenship. Finally, the article argues that these four aspects can be viewed as part of a composite whole that identified Chinese citizenship with active participation in concrete tasks to contribute to national welfare.
British Exploration in the Nineteenth Century: A Historiographical Survey
Authors: Kennedy Dane
Published: October 2007

This article examines the historiography on nineteenth‐century British exploration, tracing major themes in the scholarship on the subject. It credits the work of Edward Said, Mary Louise Pratt, and Paul Carter as the main inspiration for the resurgence of academic interest in the history and literature of travel and exploration, though it also indicates that there are important limitations to the approach they pioneered. The article then traces two key themes of recent work on exploration. The first theme concerns the institutional, social, and intellectual forces in Britain that inspired the exploration of other lands and oversaw its operations. The second theme concerns the cultural encounter between explorers and indigenous peoples, which ranged in its effects from the psychic to the political realm.
Connective tissue growth factor increases matrix metalloproteinase‐2 and suppresses tissue inhibitor of matrix metalloproteinase‐2 production by cultured renal interstitial fibroblasts
Authors: Yang Min , Huang Haichang , Li Jingzi , Huang Wen , Wang Haiyan
Published: October 2007

The involvement of gelatinase (matrix metalloproteinase‐2 [MMP‐2] and MMP‐9) in the matrix remodeling and development of tubulointerstitial fibrosis has been studied recently, but relatively little is known about the regulators and the mechanisms controlling the activation and expression of gelatinase in renal fibroblasts. In these studies, the production and underlying signaling pathway for gelatinase by exogenous connective tissue growth factor (CTGF) treatment were investigated. Here, we show that CTGF acts as a potent promoter of the activation and expression of MMP‐2, but not MMP‐9 in normal rat kidney fibroblasts cell line (NRK‐49F). We found that CTGF significantly increased the activity of MMP‐2, as well as MMP‐2 protein in conditioned medium and MMP‐2 mRNA levels in cells. In studies to address the mechanisms involved in the regulation of MMP‐2 activity, we found that the tissue inhibitor of matrix metalloproteinase‐2 (TIMP‐2), the inhibitor of MMP‐2, decreased significantly when cells were treated with CTGF. Further studies showed that extracellular signal‐regulated kinase (ERK) signaling is responsible for most of the CTGF‐induced MMP‐2 expression and TIMP‐2 suppression. When NRK‐49F fibroblasts were incubated with CTGF, activation of ERK1/2 signaling was observed. Suppression of ERK1/2 activation with nontoxic concentrations of PD98059, a specific inhibitor of ERK activation, was associated with a reduction of CTGF‐stimulated MMP‐2 activity and protein expression. In addition, the CTGF‐mediated reduction of TIMP‐2 activity and protein expression was prevented when ERK1/2 activation was inhibited by PD98059. These results provide evidence that CTGF augments activation of MMP‐2 through an effect on MMP‐2 protein expression and TIMP‐2 suppression, and that these effects are dependent on the activation of the ERK1/2 pathway.
Immobilized gradients of epidermal growth factor promote accelerated and directed keratinocyte migration
Authors: Stefonek Tracy Jane , Masters Kristyn S.
Published: October 2007

Acceleration of wound closure results not only in decreased patient suffering and cost of wound treatment, but may also minimize scarring and lead to formation of a more stable closed wound. Cell migration is a critical element in wound healing, and it is believed that the ability to control the migration direction of cells will lead to accelerated closure of wounds. Thus, we have synthesized surfaces that are covalently modified with gradients of epidermal growth factor (EGF), a key molecule in the native wound‐healing process, in order to create a platform that promotes directed cell migration. Standard photo‐patterning techniques used herein enabled precise control over the spatial location of tethered EGF and the fabrication and quantitative characterization of gradient patterns of different types and slopes. Under serum‐free conditions, human epidermal keratinocytes on immobilized EGF gradients preferentially migrated in the direction of higher EGF concentrations, and exhibited unidirectional migration speed and distance that was over five‐fold greater than that observed on control surfaces. Treatment of migrating cells with an inhibitor of the EGF receptor resulted in immediate cessation of migration, thus verifying that the observed migration trends were directly attributable to keratinocyte interactions with immobilized EGF.
Inhibition of keratinocyte migration by lipopolysaccharide
Authors: Loryman Chris , Mansbridge Jonathan
Published: October 2007

A critical process in cutaneous wound healing is reepithelialization by keratinocytes that closes the breach in the epidermis. Chronic wounds fail to reepithelialize despite the presence of activated and proliferative keratinocytes around the wound perimeter. This type of wound is generally colonized to a greater or lesser extent by bacteria. This study examines the possibility that bacterial products might directly inhibit keratinocyte migration. Using conventional scratch assays, we observed a dose‐dependent inhibition of keratinocyte migration by lipopolysaccharide (LPS) derived from either Pseudomonas aeruginosa or Escherichia coli. Although the P. aeruginosa preparation appeared to be slightly more inhibitory, both gave half‐maximal inhibition at 0.5–0.6 ng/mL. Migration of fibroblasts was not inhibited. The result could not be attributed to a cytotoxic effect of the LPS. LPS inhibition of migration was relieved by neutralizing antibodies to toll‐like receptors (TLR), 40% by anti‐TLR2 and 75% by anti‐TLR4. We conclude that keratinocyte migration is inhibited by bacterial products, detected through TLR4 and also through TLR2. Because chronic wounds always show some presence of bacteria, these findings provide a possible explanation for the lack of healing found in ulcers.
A neurokinin‐1 receptor antagonist that reduces intraabdominal adhesion formation increases peritoneal matrix metalloproteinase activity
Authors: Cohen Philip A. , Gower Adam C. , Stucchi Arthur F. , Leeman Susan E. , Becker James M. , Reed Karen L.
Published: October 2007

Adhesions remain a significant complication of abdominal surgery. There is a growing body of evidence suggesting that remodeling of peritoneal extracellular matrix by matrix metalloproteinases (MMPs) is involved in adhesion formation. We have shown that administration of a specific neurokinin‐1 receptor (NK‐1R) antagonist (CJ‐12,255, Pfizer) to rats within 5 hours of surgery reduces intraabdominal adhesion formation. Because substance P (SP), the primary NK‐1R ligand, is known to augment tissue fibrosis, the aim of this study was to determine the effects of NK‐1R antagonist administration on peritoneal MMP expression and activity 24 hours after surgery in a rat adhesion model. Following laparotomy, four ischemic buttons were created on the peritoneum of rats that received either an intraperitoneal NK‐1R antagonist or a vehicle at surgery. Adhesion formation was assessed 7 days later. Peritoneal fluid and tissue were collected at 24 hours to assess total MMP activity, as well as MMP‐2, MMP‐8, and MMP‐9 activity. Specific MMP and tissue inhibitors of MMP mRNAs were measured, and the effects of SP on MMP‐3 expression were determined in Met‐5A cells, a human peritoneal mesothelial cell line. NK‐1R antagonist administration reduced adhesion formation by 47% (p<0.05) at 7 days and significantly increased the total MMP activity in peritoneal fluid at 24 hours. There was an accompanying increase (p<0.05) in MMP‐8 and MMP‐9 mRNA expression and activity in peritoneal tissue and fluid, respectively. MMP‐3 mRNA was also increased in the 24‐hour peritoneal tissue, and exposure of Met‐5A cells to SP reduced MMP‐3 expression and activity. These data support a role for MMPs, specifically MMP‐3, MMP‐8, and MMP‐9, in intraabdominal adhesion formation and suggest that the NK‐1R antagonist may reduce adhesions, in part, by increasing MMP activity in the peritoneum by 24 hours after surgery.
Review: β‐Blockade in Chronic Dialysis Patients
Authors: Furgeson Seth B. , Chonchol Michel
Published: October 2007

Approximately 50% of the mortality in chronic dialysis patients is due to cardiovascular diseases (CVD). Cardiomyopathy, coronary artery disease, and arrhythmia are all common conditions and predispose to sudden death, which accounts for 60% of all cardiac deaths in this population. Despite advances in dialysis therapy, the mortality from CVD remains substantially unchanged, partly due to the lack of evidence‐based strategies for improving the outcome of cardiac diseases in this population. Activation of the sympathetic adrenergic system is well documented in chronic dialysis patients and is likely involved in the pathogenesis of myocardial hypertrophy, coronary artery disease, heart failure, and arrhythmia. Given the proven benefit of β‐blockers in patients with normal kidney function with similar cardiac comorbidities, β‐blockers would seem to be attractive agents to reduce cardiovascular morbidity and mortality in the patient population with advanced chronic kidney disease. However, the value of β‐blockade in patients on chronic dialysis remains unclear. This uncertainty surrounding the efficacy is compounded by the risk of side effects to these patients, such as hypotension, bradycardia, and hyperkalemia. In addition, numerous studies have suggested suboptimal usage of β‐blockers in the dialysis population; this is seen even in high risk patients, such as those with established coronary artery disease. In this review, we will focus on sympathetic nervous system activation in kidney disease and highlight the benefit and risks of β‐blockers usage in the chronic dialysis patient population.
Calcium Balance during Hemodialysis
Authors: McIntyre Christopher W
Published: October 2007

Calcium balance during hemodialysis (HD) is important in determining short‐term cardiovascular function, this influences the hemodynamic tolerability of dialysis. In the longer term, calcium flux during HD is an important determinant of overall calcium balance in a patient and may also influence the development and progression of vascular calcification, with its attendant consequences. This article aims to review the assessment and mechanisms of calcium flux during HD, choice of dialysate calcium concentration, influence of HD modality, and potential consequences of therapy choices (cardiovascular and skeletal) resulting from an inappropriate intradialytic calcium balance.
Ultrasound/Fluoroscopy‐Assisted Placement of Peritoneal Dialysis Catheters
Authors: Maya Ivan D.
Published: October 2007

Peritoneal dialysis (PD) catheters may be inserted blindly, surgically, and either by laparoscopic, peritoneoscopic, or fluoroscopic approach. A modified fluoroscopic technique by adding ultrasound‐assistance was performed in the present study to ensure entry into the abdominal cavity under direct ultrasound visualization. From March 2005 to May 2007, ultrasound‐fluoroscopic guided placement of PD catheters was attempted in 32 end‐stage renal disease (ESRD) patients. Preoperative evaluation was performed on all patients prior to the procedure. After initial dissection of the subcutaneous tissue anterior to the anterior rectus sheath, the needle was inserted into the abdominal cavity under the guidance of ultrasound. The position of the epigastric artery was also examined using ultrasonography to avoid the risk of arterial injury. PD catheters were successfully placed in 31 of the 32 ESRD patients using this technique. In all of these patients, the needle could be seen entering the abdominal cavity using an ultrasound. In one patient the procedure was abandoned because of bowel puncture by the micro‐puncture needle that was inadvertently advanced into a loop of bowel. This patient did not develop acute abdomen nor needed any intervention. One patient died 4 days after placement of the catheter of unrelated causes. One patient was started on acute peritoneal dialysis the same day of catheter placement without any complications. The rest of the patients started peritoneal dialysis within 2–6 weeks of catheter placement. None of the patients had bleeding related to arterial injury as ultrasound was able to visualize the epigastric artery. Our experience shows that ultrasound‐fluoroscopic technique is minimally invasive and allows for accurate assessment of the entry into the abdominal cavity. This technique can avoid the risk of vascular injury altogether.
Increased Risk of Infection Associated with Polyurethane Dialysis Grafts
Authors: Maya Ivan D. , Weatherspoon Janice , Young Carlton J. , Barker Jill , Allon Michael
Published: October 2007

Conventional polytetrafluoroethylene (PTFE) dialysis grafts cannot be cannulated for 2–3 weeks following their creation. Polyurethane grafts, made of a self‐sealing material, can be cannulated within 24 hours of implantation, representing a potential advantage in patients with limited catheter options. However, early cannulation may increase the risk of graft infection. We retrospectively queried a prospective, computerized access database to identify 31 patients receiving a polyurethane graft, and 56 date‐matched controls with a PTFE graft. Survival techniques were used to plot graft survival. Thrombosis‐free graft survival (from creation to first thrombosis or failure) was similar for polyurethane and PTFE grafts (1‐year survival, 28%, vs. 32%, p = 0.98). Cumulative graft survival (from creation to permanent failure) was also similar (1‐year survival 42% vs. 52%, p = 0.40). Finally, the cumulative risk of graft infection was 37.5% for polyurethane thigh grafts, 23% for polyurethane upper extremity grafts, 21% for PTFE thigh grafts, and 5% for PTFE upper extremity grafts (p = 0.06 for polyurethane vs. PTFE grafts). The likelihood of thrombosis and failure is similar for polyurethane and PTFE grafts. However, polyurethane grafts may have a higher risk of infection, particularly when they are placed in the thigh. In patients with an access emergency, implantation of a polyurethane graft incurs a tradeoff between earlier cannulation and a higher risk of infection.