bluuebunny/crossref_metadata_2025 huggingface dataset:
Observed solar radio burst effects on GPS/Wide Area Augmentation System carrier‐to‐noise ratio
Authors: Cerruti Alessandro P. , Kintner Paul M. , Gary Dale E. , Lanzerotti Louis J. , de Paula Eurico R. , Vo Hien B.
Published: October 2006

The first direct observations of Global Positioning System (GPS) L1 (1.57542 GHz) carrier‐to‐noise ratio degradation due to a solar radio burst are presented for an event that occurred on 7 September 2005. Concurrent carrier‐to‐noise ratio data from GPS satellites are available from receivers at Arecibo Observatory, Puerto Rico; San Juan, Puerto Rico; and also from Anderson, South Carolina, United States. The right‐hand circularly polarized (RHCP) signals from this solar radio burst caused a corresponding decrease in the carrier‐to‐noise ratio of about 2.3 dB across all visible satellites. The maximum solar radio burst power associated with this event was 8700 solar flux units (1 SFU = 10−22 W/m2/Hz) RHCP at 1600 MHz. Direct observations of GPS semicodeless L2 carrier‐to‐noise ratio degradation from receivers in Brazil are also presented for a solar radio burst that occurred on 28 October 2003. The maximum degradation at GPS L1 was about 3.0 dB, and a degradation of 10.0 dB was observed on the semicodeless L2 signal. Scaling to historic solar radio burst records suggests that GPS L1 receivers could fail to produce a navigation solution and that semicodeless L1/L2 receivers will fail.
Regulatory effect of sulphatides on BKCachannels
Authors: Chi S , Qi Z
Published: October 2006

Background and purpose:

Sulphatides are sulphated glycosphingolipids expressed on the surface of many cell types, particularly neurones. Changes in sulphatide species or content have been associated with epilepsy and Alzheimer's disease. As the large conductance, calcium sensitive K+channel (BKCa) are modulated by membrane lipids, the aim of the study was to explore possible effects of sulphatides on BKCachannels.

Experimental approach:

Using patch‐clamp techniques, we studied effects of exogenous sulphatides on BKCachannels expressed in Chinese hamster ovary cells.

Key results:

Sulphatides reversibly increased the whole‐cell current and the single channel open probability of BKCachannels dose‐dependently. The EC50value on the channel at +10 mV was 1.6 μM and the Hill coefficient was 2.5. In inside‐out patches, sulphatides increased the single channel open probability from both intra‐ and extra‐cellular faces of the membrane, but more effectively with external application. Furthermore, activation of the channels by sulphatides was independent of intracellular Ca2+concentration. Sulphatides also shifted the activation curve of the channels to less positive membrane potentials. Mutant BKCachannels lacking a 59 aminoacid region important for amphipath activation (STREX) were less activated by the sulphatides.

Conclusions and Implications:

Sulphatides are novel activators of BKCachannels, independent of intracellular Ca2+or other signalling molecules but partly dependent on the STREX sequence of the channel protein. As changes of sulphatide content are associated with neuronal dysfunction, as in epilepsy and Alzheimer's disease, our results imply that these effects of sulphatides may play important pathophysiological roles in regulation of BKCachannels.

British Journal of Pharmacology(2006)149, 1031–1038. doi:10.1038/sj.bjp.0706947
Hard x-ray diagnostic for lower hybrid experiments on Alcator C-Mod
Authors: Liptac J. , Parker R. , Tang V. , Peysson Y. , Decker J.
Published: October 2006

Alcator C-Mod’s lower hybrid current drive (LHCD) system allows the exploration of advanced tokamak (AT) regimes at densities relevant to ITER and fusion reactors. The location of the LHCD is critical to AT performance and may be inferred by measuring the nonthermal bremsstrahlung emission in the hard x-ray (HXR) region. A pinhole camera using an array of 32 CdZnTe detectors is used to image energies in the 20–200keV range. Detectors and pulse processing electronics are integrated into a compact and modular package making extensive use of printed circuit board and surface mount technology. The system also makes use of fast digitization and software signal processing techniques. An ambient environment of neutrons, gammas, and high rf power requires careful shielding. Shielding is studied using the neutron and photon transport code MCNP. The design of the diagnostic is presented along with background measurements in lieu of LHCD fast electrons. Background measurements are then compared to advanced modeling results to predict the power threshold for meaningful HXR data for a H-mode target plasma.
Mechanics of prestressed polydimethylsiloxane-carbon nanotube composite
Authors: Paul J. , Sindhu S. , Nurmawati M. H. , Valiyaveettil S.
Published: October 2006

The influence of the presence of static stress on the dynamic mechanical properties of polydimethylsiloxane-carbon nanotube composite is evaluated. Significant enhancement in the dynamic stiffness is observed, which can be attributed to the combined effect of nanotube nucleated strain induced crystallization, modulation in the waviness of the nanotube entanglements, and the enhanced interfacial adhesion due to the prevailing hydrostatic pressure. The study provides a platform for understanding the behavior of carbon nanotube composites in the stressed state and thereby to consider the prestressing process as an ideal option for enhancing the mechanical properties.
Synthesis of Carboxylic Acid and Ester Mid-Functionalized Polymers using RAFT Polymerization and ATRP
Authors: Malic Nino , Evans Richard A.
Published: October 2006

Polymers with a single central point of carboxylic acid functionality were prepared by living radical polymerization methods, RAFT and ATRP. A convenient water-based synthesis of a Y-branched ATRP initiator from 3,5-dihydroxybenzoic acid and 2-bromopropionyl bromide, from which the Y-branched RAFT agent is then subsequently derived, is described. Polymerization occurred uniformly from both of the RAFT groups to give chains of equal length as shown by hydrolysis. ATRP polymerization based on an ester derivative of 3,5-bis(2-bromopropionyloxy)benzoic acid as initiator was well controlled, whereas the free carboxylic acid gave inconsistent performance. The ability to couple functional molecules to the middle of polymers would provide better protection or interaction of the functional molecule with the polymer than conventional end attachment. This would find applications such as in drug delivery where more efficient protection would allow the use of lower molecular weight polymers.
Locational Patterns and Dynamics of Industrial Activity in the Modern Metropolis
Authors: Scott Allen J.
Published: October 2006

This paper attempts to review and re-structure a mass of published ideas on the geography of industrial activity in the modern metropolis. The argument proceeds in a series of stages. First, some basic locational factors in the city are examined. Second, a critical discussion of the literature on economies of agglomeration and scale in cities is undertaken. Third, a brief description of manufacturing activity in nineteenth-century cities is provided by way of motivating and orientating the succeeding discussion. Fourth, the phenomenon of industrial decentralisation in twentieth-century cities is described. Fifth, an attempt is made to construct a composite theory of intra-metropolitan industrial location on the basis of the historical process of the substitution of capital for labour in capitalist commodity production. Sixth, a schematic re-statement of the theory is presented, and its implications for the spatial-cum-organisational evolution of modern industry are elucidated. Seventh, some of the main policy issues raised by the continued loss of industry from the cores of large metropolitan areas are briefly treated.
Inflation, New Homeowners and Downgrading in the 1970s
Authors: Rudel Thomas K. , Neaigus Alan
Published: October 2006

This paper uses data from four successive Annual Housing Surveys, 1974 to 1977, to assess the degree to which households moving from rented to owner occupied housing responded to housing price inflation by purchasing smaller, more delapidated units in less choice locations. The data indicate that, while the size of the structures acquired by new homeowners declined, the quality of these structures and the surrounding neighborhoods did not change. Regression analyses suggest that the prospective homeowners' deteriorating economic position had a significant effect on the size of the homes which they purchased.
Marital Status and Occupational Structures in the Ile-de-France Region
Authors: Fagnani Jeanne
Published: October 2006

A comparison of socio-occupational structures of married, single, widowed and divorced women, between 21 and 50 years of age, living in the Ile-de-France region is developed. The latter hold more frequently privileged jobs but the sharpest contrasts are observed between married women and single heads of household (most of them live alone). They work more often in liberal professions and top-level and middle-level management. Moreover, the rate of celibacy among working women according to socio-occupational categories moves in an opposite direction from that of working men: the rate is higher in the higher occupational groups. An analysis of the spatial distribution of residence of married and single women in relation to the distribution of female jobs leads to a paradoxical situation. From the point of view of proximity and access to jobs, single women are favoured in relation to married women. Commuting constraints more frequently weigh heavily on them than on those less taken up with domestic and family activities.
Factors of Urbanisation in the Nineteenth Century Developed Countries
Authors: Bairoch Paul , Goertz Gary
Published: October 2006

This paper describes the situation from the beginning of the industrial revolution when levels of urbanisation were dependent on geography and the historical situation and when the general level of urbanisation was low, through the nineteenth century in which agricultural productivity and industrialisation determined the levels of urbanisation. This period represents a dramatic increase in the levels of urbanisation during which the present urban structures were put into place. A comparative econometric study, finds that economic growth pushed urbanisation, with industrialisation being the most important factor for Europe and agricultural productivity being quite important for the European settled countries. Other important factors are found to be, trade, total population, topography, and form of industrialisation. Railroad networks more or less extensive than normal were not found to be influential.
The Impact of Non-Domestic Property Taxes on Employment: A Comment
Authors: Damania D.
Published: October 2006

This paper attempts to assess the existing empirical work on the impact of non-domestic property taxes (or business rates), on the regional distribution of employment in England and Wales. It is argued that these statistical investigations are based on theoretically misspecified and econometrically deficient models. Consequently, conflicting results are obtained, and these studies do little to dispel doubts about the effects of property taxation. In particular, it is suggested that the econometric tests employed are statistically unreliable, and the conclusions implied by some of these models are shown to be both theoretically untenable and implausible.
Urban-Rural Variations in the Structure of Manufacturing Production
Authors: Blackley Paul R.
Published: October 2006

This paper demonstrates that recent attempts to explain manufacturing shifts to nonmetropolitan areas can be synthesised into a capital vintage model of production. The result is a set of systematic differences between urban and rural production methods which are consistent with the locational implications of the manufacturing process cycle theory. The model is supported by the first comprehensive estimation of separate production functions for SMSAs and nonmetropolitan areas. Using Census data for the US from 1977, only SMSAs are shown to possess the significant agglomeration economies needed for product development and process innovation. Cost-competitive nonmetropolitan areas show much greater variation in input proportions due to spatial factor price differentials.
Moving Up and Moving Out: Confusing Ends and Means About Ghetto Dispersal
Authors: Hughes Mark Alan
Published: October 2006

Assimilation is a pervasive ethos of American life. It is central to the nation's self-understanding and it is fundamental to much of American social theory and policy. See Gordon (1964), Glazer and Moynihan (1978), and Lieberson (1980). The disproportionate poverty and isolation of blacks has raised doubts about the receptive capacity of American society and has fostered a debate about the policy response required by the problem. In this paper, I argue that the assimilation model is relevant and useful to an analysis of urban black poverty. From the model, I derive a series of hypotheses that engage a long-running empirical debate over the relation between the segregated ghetto and economic opportunity. This analysis explores the relation between moving up (in socioeconomic status) and moving out (of the central-city ghetto). I argue that the call for ghetto dispersal as a means of breaking the 'underclass' stems from an incomplete understanding of ethnic group mobility within US society as well as of the pervasive tangle of limited opportunities facing blacks throughout the metropolitan region.
The Nature of Canadian Condominium Submarkets and Their Effect on the Evolving Urban Spatial Structure
Authors: Skaburskis Andrejs
Published: October 2006

The increase in the higher density homeownership options made possible by the introduction of the condominium tenure option can affect the environmental quality of inner-city neighbourhoods and increase the efficiency of the urban and regional spatial structure. The growth of the condominium sector contributes to social welfare by easing the household's transition through the life cycle-related changes in housing needs, by helping young households gain homeownership tenure while improving their housing condition, and by encouraging older households to adjust their space consumption and free their larger houses for family occupancy. The results developed by this empirical study show the Canadian condominium sector to be composed of two submarkets: one is formed by younger families who use their condominium purchase as a step to buying a single family house; the other submarket is formed by older households leaving single family houses to be free of maintenance chores and to gain physical security.
Quantifying the Decision to Become a First-Time Home Buyer
Authors: Cooperstein Richard L.
Published: October 2006

Becoming a first-time homebuyer is quantified in two stages using household data. A renter demand curve is estimated to calculate the consumer surplus gain from moving into housing consumption equilibrium. Probit is used to estimate the probability of becoming a first-time homebuyer. The model suggests that overcoming the transactions cost of buying, and the gain from housing consumption equilibrium are important to the decision.

Renting is explained by current housing demand through income and family size. Buying for the first time is explained by factors which reduce transactions costs, such as assets, marital status, and education. Disequilibrium in rental housing consumption is also important. The results further suggest that permanent income is not important to the decision.
The Ending of Mortgage Rationing and its Effects on the Housing Market: A Simulation Study
Authors: Meen Geoffrey P.
Published: October 2006

The UK mortgage market has undergone important structural changes in recent years. A consequence has been that households are no longer generally subject to mortgage rationing. In this paper we examine some of the results of this change for the housing market. We first construct a simple theoretical model of the housing and mortgage markets and show, as an illustration of the effect of exogenous changes in general, how mortgage tax relief abolition would have different results under alternative regimes. We then quantify these results using a fully estimated model.
Bangkok : A Profile of an Efficiently Performing Housing Market
Authors: Dowall David E.
Published: October 2006

This paper reports on a study of the Bangkok land and housing market. The study is based on extensive surveys of projects, developers, households, and the interpretation of aerial photographic information. The results of the study indicate that Bangkok's land and housing markets are operating very efficiently, with the formal private sector providing 27 per cent of the total housing stock increase between 1974 and 1984. The region's supply of developable land with roadway access increased by over 20 per cent between 1974 and 1984. As a result, land values have not increased substantially in real terms and overall housing affordability improved between 1982 and 1986. The Bangkok study is important for housing policy makers because it provides a profile of a well-performing land and housing market.
The Mexican Landlord: Rental Housing in Guadalajara and Puebla
Authors: Gilbert Alan , Varley Ann
Published: October 2006

In Mexican cities, somewhere between one-third and one-half of all households rent or share accommodation. Over the years, even though rental housing has been in relative decline, the absolute numbers of tenant households have been increasing. Recently, because home ownership has become increasingly expensive, the Mexican state has been anxious to expand the stock of rental housing. However, its policies do not seem to be directed towards the majority of landlords, in part, at least, because the nature of the landlordism is not well understood. This paper examines the main features of landlords and landlordism in two major cities of Mexico, Guadalajara and Puebla. Based on surveys with tenants and landlords, it examines how landlords obtained their property, why they began to rent it, their socio-economic characteristics, their perceptions of the business of renting, and the mechanics of setting rent levels and selecting tenants.
City Marketing, Image Reconstruction and Urban Regeneration
Authors: Paddison Ronan
Published: October 2006

Reflecting the new urban entrepreneuralism, city marketing is more than the mere promotion of place, being used in some cities to rebuild and redefine their image, allied to which has been a strategy of targeting specific types of activity which both reflect and bolster the image. Examining the experience of Glasgow, this paper focuses on the implications raised by the use of such marketing techniques, showing that they have social and political implications which practice tends to overlook.
Social Welfare Policy in the Context of Economic Restructuring: Lessons from the West Virginia Workers' Compensation Programme
Authors: Spieler Emily A.
Published: October 2006

Costs of social programmes resulting from obligations incurred during periods of economic expansion persist into periods of decline and restructuring. Underfunding of these programmes during periods of economic expansion may result in the transfer of costs to new industrial enterprises. This may lead, in turn, to increased political attacks on these programmes. This paper describes the experience of one such programme, the West Virginia Workers' Compensation Fund, which provides monetary and health benefits to injured workers. This West Virginia programme is currently under economic and political threat due to the combination of declining industry and past underfunding. The paper concludes that more attention must be given in the future by those concerned with general economic development policy to adequacy of funding of social programmes. Future research regarding the interrelationship betwen funding for social programmes and economic development policy is warranted.
Contrasts in Ownership and Development: Local versus Global in 'Silicon Glen'
Authors: Turok Ivan
Published: October 2006

This paper examines the recent development of the electronics industry in Scotland and explores the particular role of ownership. The scale of electronics growth has been striking in some respects, but its nature and quality have been less beneficial from the point of view of the local economy. Most growth has come from foreign-owned firms, but their overall impacts in terms of value added, employment and local linkages have been less than expected considering the volume of sales achieved. Indigenous UK firms add more value, have higher-level functions and offer a wider range of jobs, but have struggled to invest and expand. The paper also considers the relationship between the two groups: the patent inequality of this means that local ownership does not confer local economic control.
Metropolitan Government and City-Suburban Cleavages: Differences between Old and Young Metropolitan Areas
Authors: van der Veer Jeroen
Published: October 2006

This paper deals with disparities between city and suburbs in the US and the Netherlands. As a result of suburbanisation, US metropolitan areas are characterised by disparities between poor central cities on the one hand and rich urban fringes on the other. These disparities are particularly apparent in old metropolitan areas, while young metropolitan areas show smaller differences between city and suburbs. In the Dutch case, despite redistributive national policies, disparities between city and fringe still exist. Repeating the US experience, city-suburban disparities seem to be deeper in old than in young metropolitan areas, as will be demonstrated by the contrasting cases of the old Amsterdam metropolitan area and the young Eindhoven metropolitan area.
The Role of Housing Policy in the Transformation Process of Central-East European Cities
Authors: Pichler-Milanovich Natasha
Published: October 2006

This paper is concerned with a process of housing privatisation and urban revitalisation in the transformation of central-east European cities. Today central-east Europe is approaching the political and economic system that prevails in western Europe. Reforms require the extensive privatisation of firms as well as land and housing. The housing privatisation process includes changing the ownership and management of the housing stock, and a new system of housing finance. These processes will influence new housing construction and the modernisation and rehabilitation of the existing housing stock. The change in housing policy and the increasing polarisation within society may result in transformation of the social and physical structure of the city. Larger and, especially, capital cities in central-east Europe are the most attractive locations for business investments and property development, but consequences can be highly selective. Despite dominant or privileged positions in national and, increasingly, international economies, cities could face certain problems in the future with social polarisation, residential segregation, decentralisation of economic activities and rising unemployment. Therefore, the question is: will housing privatisation in central-east European cities lead to better chances for rehabilitation or just the opposite? Housing privatisation in central-east European cities will have an impact on gentrification and the rehabilitation of older housing areas in inner cities, within the context of political and economic restructuring, urban planning policies and the dynamics of the real estate market. All these factors will determine the future of housing and urban development. The availability of funds will be one of the main questions for the future rehabilitation process in central-east European cities. Another important factor will be the degree to which urban governments become proactive. An innovative housing and urban policy and, a policy and technical 'know-how' assistance from western Europe might well be a success.
Amsterdamned: The Rise of Unemployment in Amsterdam in the 1980s
Authors: Kloosterman Robert C.
Published: October 2006

At the end of the 1980s, almost a quarter of the labour force in Amsterdam was without a job. This was about twice the Dutch national average. In the 1970s and the early 1980s, the unemployment rates of Amsterdam and the Netherlands as a whole, differed only slightly. Among the unemployed in Amsterdam, the proportion of members of the minority population rose considerably. Remarkably enough, the strong divergence manifested itself at a time when employment in Amsterdam began to increase for the first time in almost 20 years. This paper tries to find explanations for this urban paradox by using the mismatch approach. This approach turns out to be insufficient to explain the Amsterdam unemployment problem.
Pulmonary Fibrosis and Ferruginous Bodies Associated with Exposure to Synthetic Fibers
Authors: Ghio Andrew J. , Funkhouser William , Pugh Christopher B. , Winters Scot , Stonehuerner Jacqueline G. , Mahar Annabelle M. , Roggli Victor L.
Published: October 2006

Exposure to synthetic fibers with employment in textile mills can be associated with an elevated risk of interstitial lung disease (ILD). A mechanism of injury has not been determined. ILD can follow exposures to inorganic fibers (e.g., asbestos) which are associated with a mobilization of iron and catalysis of an oxidative stress. We describe 2 patients with ILD associated with exposure to synthetic textile fibers who demonstrated carbon-based ferruginous bodies suggesting an in vivo accumulation of iron by synthetic fibers after deposition in the lung. These iron-laden bodies varied from perfectly linear fibers to almost particulate matter. Linear structures were irregularly interrupted by deposition of iron-abundant material. The capacity of these synthetic fibers to complex iron and generate an oxidative stress is confirmed in vitro.
Desensitization Contributes to the Synaptic Response of Gain-of-Function Mutants of the Muscle Nicotinic Receptor
Authors: Elenes Sergio , Ni Ying , Cymes Gisela D. , Grosman Claudio
Published: October 2006

Although the muscle nicotinic receptor (AChR) desensitizes almost completely in the steady presence of high concentrations of acetylcholine (ACh), it is well established that AChRs do not accumulate in desensitized states under normal physiological conditions of neurotransmitter release and clearance. Quantitative considerations in the framework of plausible kinetic schemes, however, lead us to predict that mutations that speed up channel opening, slow down channel closure, and/or slow down the dissociation of neurotransmitter (i.e., gain-of-function mutations) increase the extent to which AChRs desensitize upon ACh removal. In this paper, we confirm this prediction by applying high-frequency trains of brief (∼1 ms) ACh pulses to outside-out membrane patches expressing either lab-engineered or naturally occurring (disease-causing) gain-of-function mutants. Entry into desensitization was evident in our experiments as a frequency-dependent depression in the peak value of succesive macroscopic current responses, in a manner that is remarkably consistent with the theoretical expectation. We conclude that the comparatively small depression of the macroscopic currents observed upon repetitive stimulation of the wild-type AChR is due, not to desensitization being exceedingly slow but, rather, to the particular balance between gating, entry into desensitization, and ACh dissociation rate constants. Disruption of this fine balance by, for example, mutations can lead to enhanced desensitization even if the kinetics of entry into, and recovery from, desensitization themselves are not affected. It follows that accounting for the (usually overlooked) desensitization phenomenon is essential for the correct interpretation of mutagenesis-driven structure–function relationships and for the understanding of pathological synaptic transmission at the vertebrate neuromuscular junction.
Accounting for Voter Heterogeneity within and across Districts with a Factor-Analytic Voter-Choice Model
Authors: Kamakura Wagner A. , Mazzon José Afonso
Published: October 2006

In this study, we propose a model of individual voter behavior that can be applied to aggregate data at the district (or precinct) levels while accounting for differences in political preferences across districts and across voters within each district. Our model produces a mapping of the competing candidates and electoral districts on a latent “issues” space that describes how political preferences in each district deviate from the average voter and how each candidate caters to average voter preferences within each district. We formulate our model as a random-coefficients nested logit model in which the voter first evaluates the candidates to decide whether or not to cast his or her vote, and then chooses the candidate who provides him or her with the highest value. Because we allow the random coefficient to vary not only across districts but also across unobservable voters within each district, the model avoids the Independence of Irrelevant Alternatives Assumption both across districts and within each district, thereby accounting for the cannibalization of votes among similar candidates within and across voting districts. We illustrate our proposed model by calibrating it to the actual voting data from the first stage of a two-stage state governor election in the Brazilian state of Santa Catarina, and then using the estimates to predict the final outcome of the second stage.
The evolutionary emergence of pandemic influenza
Authors: Day Troy , André Jean-Baptiste , Park Andrew
Published: October 2006

Pandemic influenza remains a serious public health threat and the processes involved in the evolutionary emergence of pandemic influenza strains remain incompletely understood. Here, we develop a stochastic model for the evolutionary emergence of pandemic influenza, and use it to address three main questions. (i) What is the minimum annual number of avian influenza virus infections required in humans to explain the historical rate of pandemic emergence? (ii) Are such avian influenza infections in humans more likely to give rise to pandemic strains if they are driven by repeated cross-species introductions, or by low-level transmission of avian influenza viruses between humans? (iii) What are the most effective interventions for reducing the probability that an influenza strain with pandemic potential will evolve? Our results suggest that if evolutionary emergence of past pandemics has occurred primarily through viral reassortment in humans, then thousands of avian influenza virus infections in humans must have occurred each year for the past 250 years. Analyses also show that if there is epidemiologically significant variation among avian influenza virus genotypes, then avian virus outbreaks stemming from repeated cross-species transmission events result in a greater likelihood of a pandemic strain evolving than those caused by low-level transmission between humans. Finally, public health interventions aimed at reducing the duration of avian virus infections in humans give the greatest reduction in the probability that a pandemic strain will evolve.
Importance of pollinators in changing landscapes for world crops
Authors: Klein Alexandra-Maria , Vaissière Bernard E , Cane James H , Steffan-Dewenter Ingolf , Cunningham Saul A , Kremen Claire , Tscharntke Teja
Published: October 2006

The extent of our reliance on animal pollination for world crop production for human food has not previously been evaluated and the previous estimates for countries or continents have seldom used primary data. In this review, we expand the previous estimates using novel primary data from 200 countries and found that fruit, vegetable or seed production from 87 of the leading global food crops is dependent upon animal pollination, while 28 crops do not rely upon animal pollination. However, global production volumes give a contrasting perspective, since 60% of global production comes from crops that do not depend on animal pollination, 35% from crops that depend on pollinators, and 5% are unevaluated. Using all crops traded on the world market and setting aside crops that are solely passively self-pollinated, wind-pollinated or parthenocarpic, we then evaluated the level of dependence on animal-mediated pollination for crops that are directly consumed by humans. We found that pollinators are essential for 13 crops, production is highly pollinator dependent for 30, moderately for 27, slightly for 21, unimportant for 7, and is of unknown significance for the remaining 9. We further evaluated whether local and landscape-wide management for natural pollination services could help to sustain crop diversity and production. Case studies for nine crops on four continents revealed that agricultural intensification jeopardizes wild bee communities and their stabilizing effect on pollination services at the landscape scale.
Down-regulation of radioresistance by LexA2 in Deinococcus radiodurans
Authors: Satoh Katsuya , Ohba Hirofumi , Sghaier Haïtham , Narumi Issay
Published: October 2006

The extremely radioresistant bacterium Deinococcus radiodurans contains two LexA homologues (LexA1 and LexA2) that are possible transcriptional regulators associated with the DNA damage response. In this study, resequencing revealed that there was an additional cytosine nucleotide (nucleotide position 612) in the D. radiodurans lexA2 gene. Purified LexA2 possessed proteolytic activity that could be stimulated by RecA. In an effort to gain an insight into the role of LexA2 in the radiation response mechanism, recA, lexA1 and lexA2 disruptant strains were generated and investigated. The intracellular level of RecA increased in lexA1 and lexA2 disruptant strains following γ-irradiation as in the wild-type strain. These results indicated that the two LexA homologues did not possess functional overlap regarding the induction of RecA. The lexA2 disruptant strains exhibited a much higher resistance to γ-rays than the wild-type strain. Furthermore, a luciferase assay showed that pprA promoter activation was enhanced in the lexA2 disruptant strain following γ-irradiation. The pprA gene encoding the novel radiation-inducible protein PprA plays a critical role in the radioresistance of D. radiodurans. The increase in radioresistance of the lexA2 disruptant strain is explained in part by the enhancement of pprA promoter activation.
Diversity of the genus Lactobacillus revealed by comparative genomics of five species
Authors: Canchaya Carlos , Claesson Marcus J. , Fitzgerald Gerald F. , van Sinderen Douwe , O'Toole Paul W.
Published: October 2006

The genus Lactobacillus contains over 80 recognized species, and is characterized by a high level of diversity, reflected in its complex phylogeny. The authors' recent determination of the genome sequence of Lactobacillus salivarius means that five complete genomes of Lactobacillus species are available for comparative genomics: L. salivarius, L. plantarum, L. acidophilus, L. johnsonii and L. sakei. This paper now shows that there is no extensive synteny of the genome sequences of these five lactobacilli. Phylogeny based on whole-genome alignments suggested that L. salivarius was closer to L. plantarum than to L. sakei, which was closest to Enterococcus faecalis, in contrast to 16S rRNA gene relatedness. A total of 593 orthologues common to all five species were identified. Species relatedness based on this protein set was largely concordant with genome synteny-based relatedness. A Lactobacillus supertree, combining individual phylogenetic trees from each of 354 core proteins, had four main branches, comprising L. salivarius–L. plantarum; L. sakei; E. faecalis; and L. acidophilus–L. johnsonii. The extreme divergence of the Lactobacillus genomes analysed supports the recognition of new subgeneric divisions.
Cell-associated α-amylases of butyrate-producing Firmicute bacteria from the human colon
Authors: Ramsay Alan G. , Scott Karen P. , Martin Jenny C. , Rincon Marco T. , Flint Harry J.
Published: October 2006

Selected butyrate-producing bacteria from the human colon that are related toRoseburiaspp. andButyrivibrio fibrisolvensshowed a good ability to utilize a variety of starches for growth when compared with the Gram-negative amylolytic anaerobeBacteroides thetaiotaomicron. A major cell-associated amylase of high molecular mass (140–210 kDa) was detected in each strain by SDS-PAGE zymogram analysis, and genes corresponding to these enzymes were analysed for two representative strains. Amy13B fromBut. fibrisolvens16/4 is a multi-domain enzyme of 144.6 kDa that includes a family 13 glycoside hydrolase domain, and duplicated family 26 carbohydrate-binding modules. Amy13A (182.4 kDa), fromRoseburia inulinivoransA2-194, also includes a family 13 domain, which is preceded by two repeat units of ∼116 aa rich in aromatic residues, an isoamylase N-terminal domain, a pullulanase-associated domain, and an additional unidentified domain. Both Amy13A and Amy13B have N-terminal signal peptides and C-terminal cell-wall sorting signals, including a modified LPXTG motif similar to that involved in interactions with the cell surface in other Gram-positive bacteria, a hydrophobic transmembrane segment, and a basic C terminus. The overexpressed family 13 domains showed an absolute requirement for Mg2+or Ca2+for activity, and functioned as 1,4-α-glucanohydrolases (α-amylases; EC 3.2.1.1). These major starch-degrading enzymes thus appear to be anchored to the cell wall in this important group of human gut bacteria.
An attack of the plant parasite Cuscuta reflexa induces the expression of attAGP, an attachment protein of the host tomato
Authors: Albert Markus , Belastegui‐Macadam Xana , Kaldenhoff Ralf
Published: October 2006

Dodder or Cuscutaceae are holoparasitic plants subsisting on other dicotyledonous plants. The infection process is initiated by adherence of Cuscuta prehaustoria to the host surface, followed by penetration attempts by hyphae. In the case of a successful infection, these organs connect the parasite's vascular tissue to that of the host. Here we show that contact of Cuscuta reflexa prehaustoria to tomato induces the expression of a new arabinogalactan protein (AGP), attAGP, in the tomato precisely at the site of dodder attack. We show that attAGP is a plasma membrane‐bound cell wall‐localized protein. Using the RNAi technique and attAGP‐targeted virus‐induced gene silencing, we observed a correlation between attAGP expression level and force of attachment of the parasite to host tomatoes. If the expression level of attAGP was reduced, the C. reflexa attachment capability was significantly reduced, too. We conclude that C. reflexa infection induced a signal in the host leading to expression of tomato attAGP, which promotes the parasite's adherence.
Building trust and shared knowledge in communities of e‐learning practice: collaborative leadership in the JISC eLISA and CAMEL lifelong learning projects
Authors: Jameson Jill , Ferrell Gill , Kelly Jacquie , Walker Simon , Ryan Malcolm
Published: October 2006

Trust and collective learning are useful features that are enabled by effective collaborative leadership of e‐learning projects across higher and further education (HE/FE) institutions promoting lifelong learning. These features contribute effectively to the development of design for learning in communities of e‐learning practice. For this, reflexivity, good leadership and the capacity to engage in innovation is crucial to team performance. This paper outlines a serendipitously useful combination of innovative models of collaboration emerging from two 2005–06 UK e‐learning pilots: the Joint Information Systems Committee (JISC) e‐Learning Independent Study Award (eLISA) and JISC infoNet Collaborative Approaches to the Management of e‐Learning (CAMEL) projects. The JISC‐funded eLISA Distributed e‐Learning (DeL) project set up a collaborative partnership among teachers to try out LAMS and Moodle using study skills in e‐learning. Simultaneously, the JISC infoNet CAMEL project developed a model of collaborative approaches to e‐learning leadership and management across four UK HE/FE institutions. This paper proposes two new theoretical collaborative team leadership and operational models for e‐learning projects, including indices of trust, reflexivity and shared procedural knowledge, recommending that these models are further developed in future communities of e‐learning practice in institutions promoting lifelong learning.
On Fodor’s Analogy: Why Psychology is Like Philosophy of Science After All
Authors: MURPHY DOMINIC
Published: October 2006

Abstract: Jerry Fodor has argued that a modular mind must include central systems responsible for updating beliefs, and has defended this position by appealing to shared properties of belief fixation and scientific confirmation. Peter Carruthers and Stephen Pinker have attacked this analogy between science and ordinary inference. I examine their arguments and show that they fail. This does not show that Fodor’s more general position is correct.
Are the Folk Agent‐Causationists?
Authors: TURNER JASON , NAHMIAS EDDY
Published: October 2006

Abstract:  Experimental examination of how the folk conceptualize certain philosophically loaded notions can provide information useful for philosophical theorizing. In this paper, we explore issues raised in Shaun Nichols’ (2004) studies involving people’s conception of free will, focusing on his claim that this conception fits best with the philosophical theory of agent‐causation. We argue that his data do not support this conclusion, highlighting along the way certain considerations that ought to be taken into account when probing the folk conception of free will.
Compatible measurements of volumetric soil water content using a neutron probe and Diviner 2000 after field calibration
Authors: Burgess P. J. , Reinhard B. R. , Pasturel P.
Published: October 2006

Field calibrations for a neutron probe and a capacitance sensor (Diviner 2000) for measuring the soil water content of a shrinking–swelling clay soil were substantially different from commonly used default values. Using our field calibrations, the two instruments estimated similar changes in the cumulative water content of a soil profile (0–1 m depth) over one growing season.
Skull ontogeny: developmental patterns of fishes conserved across major tetrapod clades
Authors: Schoch Rainer R.
Published: October 2006

SUMMARYIn vertebrates, the ontogeny of the bony skull forms a particularly complex part of embryonic development. Although this area used to be restricted to neontology, recent discoveries of fossil ontogenies provide an additional source of data. One of the most detailed ossification sequences is known from Permo‐Carboniferous amphibians, the branchiosaurids. These temnospondyls form a near‐perfect link between the piscine osteichthyans and the various clades of extant tetrapods, retaining a full complement of dermal bones in the skull. For the first time, the broader evolutionary significance of these event sequences is analyzed, focusing on the identification of sequence heterochronies. A set of 120 event pairs was analyzed by event pair cracking, which helped identify active movers. A cladistic analysis of the event pair data was also carried out, highlighting some shared patterns between widely divergent clades of tetrapods. The analyses revealed an unexpected degree of similarity between the widely divergent taxa. Most interesting is the apparently modular composition of the cranial sequence: five clusters of bones were discovered in each of which the elements form in the same time window: (1) jaw bones, (2) marginal palatal elements, (3) circumorbital bones, (4) skull roof elements, and (5) neurocranial ossifications. In the studied taxa, these “modules” have in most cases been shifted fore and back on the trajectory relative to theAmiasequence, but did not disintegrate. Such “modules” might indicate a high degree of evolutionary limitation (constraint).
Effects of developmental and functional interactions on mouse cranial variability through late ontogeny
Authors: Willmore Katherine Elizabeth , Leamy Larry , Hallgrímsson Benedikt
Published: October 2006

SUMMARYThe mammalian skull performs a variety of functions and its growth and development mirrors this complexity. Cranial growth and development have been actively studied for many years. Despite this interest, the variation in the patterns and processes of skull growth has attracted little attention. An important and unanswered question is the extent to which patterns of cranial covariation and variation are dynamically reworked throughout postnatal growth. To address this question, we examine patterns of variability in random‐bred mouse skulls aged 35, 90, and 150 days. Using a battery of both Procrustes coordinate and Euclidean distance‐based methods, we measure mean shape, canalization, developmental stability, and morphological integration in these skulls. We predict that the patterns of variability are dynamic, particularly between the youngest and the two oldest age groups due to the influence of functional effects such as postweaning mastication. We also hypothesize that patterns of variability are structured by the same functional and developmental factors that have been shown to influence cranial growth in primates. Our results indicate that contrary to our predictions, patterns of canalization, developmental stability, and morphological integration are stabilized before 35 days. The mean shape, however, changed significantly with growth. We found that only the facial region showed significant integration as predicted by the functional matrix model used in other studies of integration. These results indicate that phenotypic integration in these mice does not closely match those found for primate species, suggesting that comparisons between species should be made with care.
Ethnicity, Culture, and Child Maltreatment
Authors: Elliott Katherine , Urquiza Anthony
Published: October 2006

Increasingly, child maltreatment research has begun to address ethnicity and culture in both empirical studies and theoretical articles. Despite the expansion of these efforts, cross‐cultural research in child maltreatment has raised more questions than it has answered; and it has highlighted the elusiveness of culture‐specific constructs to scientific study. Research to date has been hampered by several challenges including the failure to disentangle ethnicity and culture. In this article, we provide a review of research in this area and offer a critique and recommendations for enhancing the study of the role of culture and ethnicity in child maltreatment.
Promises and Possibilities: The Application of Research in the Area of Child Maltreatment to Policies and Practices
Authors: Toth Sheree L. , Cicchetti Dante
Published: October 2006

In this closing commentary, we discuss the policy implications of research concerning child maltreatment. We describe the links between the topics reviewed in this special issue and interventions for child victims as well as the state of research concerning consequences of maltreatment more broadly. We further discuss the implications of current research for policy and practice. We close by describing important directions not only for future research, but also for interventions to reduce adverse effects of maltreatment on children. Throughout our commentary, we highlight limitations in the application of empirical findings to actual child victims and we offer concrete suggestions for ways of improving this applicability.