bluuebunny/crossref_metadata_2025 huggingface dataset:
Some Tests of a Model of Intra-Urban Population Mobility: Melbourne, Australia
Authors: Johnston R.J.
Published: October 2006

A review of a number of studies of intra-urban migration suggests that, for a variety of reasons, most moves are only for short distances and are directed away from the city centre. In-migrants from outside the city generally first reside in the central residential areas, where mobility is greatest, and then move towards the suburbs according to the housing requirements of their families. Five hypotheses relating to these processes are tested on recent data for the Melbourne Metropolitan Area, and all are basically confirmed. Some deviations from the anticipated patterns occur because of marked social and economic variations among in-migrants to the city, however, and while the general patterns are as expected, a considerable portion of the total population is not involved in the migration process.
Low Fares and the Urban Transport Problem
Authors: Williams Penelope M.
Published: October 2006

Among suggested remedies for the rush-hour transport problem in large cities, proposals to reduce fares on public transport have received little attention. By surveying car commuters in central London, this study attempts to determine the consequences of adopting low, standard fares. The results suggest that this policy would persuade nearly half of the regular car commuters to transfer to public transport, resulting in a reduction of over one third in the rush-hour private car traffic. Even greater numbers would transfer given improvements in the speed and comfort of public transport. However, despite a small increase in the number of passengers on public transport, this policy would cause substantial losses on public transport operations. The possible savings in congestion, accident and other costs are examined in conjunction with some suggestions on the sources of the necessary subsidies.
Social Class in a New Town: a Comment
Authors: Bolwell L. , Clarke B. , Stoppard D.
Published: October 2006

This note continues discussion on the theme of an article by B. J. Heraud (Urban Studies, Vol. 5, No. i), in relation to recent social changes in Crawley New Town. The comments are based largely on surveys in that area and relate to the impact of Crawley as a sub-regional centre and to the changing social structure of the town.
The Leasehold System: Towards a Balanced Land Tenure for Urban Development
Authors: McDonald Ian J.
Published: October 2006

Historically, building leases have been responsible for some very enlightened estate management and town planning. They have also been abused by less responsible landlords and have caused much hardship among tenants. This article records some of the good and bad achievements of ground landlords and then attempts to analyse which elements of the leasehold relationship are worthy of preservation. Some ways are then suggested in which the balance of rights and obligations and the nature of the tenant's interest might be amended to make leaseholds more acceptable to tenants.
The Allocation of Police Protection By Income Class
Authors: Weicher John C.
Published: October 2006

Almost a decade ago Aaron Director proposed a law of public expenditures: Public expenditures are made for the primary benefit of the middle classes, and financed with taxes which are borne in considerable part by the poor and the rich.... Fire and police activities, for example, are clearly middle-income oriented to the extent that they protect property, and it would be interesting to investigate the extent to which such activities are provided more liberally in middle than in lower income areas of cities.
Accessibility and Supply Constraints in the Urban Housing Market
Authors: Ball M.J. , Kirwan R.M.
Published: October 2006

This paper discusses some of the chief influences on the urban housing market and their significance for economic analysis. It then looks comparatively at the 'trade-off' approach and the sub-markets approach. Results from an empirical study of owner-occupier housing in Bristol are presented. Although spatial clusters of households and housing types clearly emerged, the empirical tests showed that such spatial structures did not produce separate sub-markets with independent price structures. The data also confirmed a general tendency for unit prices to decline with distance from the centre, but the authors question the importance of the 'trade-off' theory's accessibility factor relative to historical features and planning policies.
Housing in a Welfare State
Authors: Nevitt Adela Adam
Published: October 2006

No universally accepted concept of social justice underlies the provision of housing in the United Kingdom. For the last half century this has led to incrementalist housing policies which have not always been consistent with other welfare policies which have been more comprehensively conceived and applied. Using Scotland as an illustrative case, the practical consequences of social welfare policy in general and deprived areas in particular are described, and the absence of adequate protection for the most vulnerable members of society is noted.
A Longitudinal Study of Urban Populations in England and Wales 1951-1971
Authors: Davies E.M.
Published: October 2006

Data drawn mainly from census publications are used to compute trends in population, household, employment and other characteristics for towns of 50,000 and over in England and Wales over the period 1951 to 1971. Component analysis reveals that the predominating factors illustrating the differentiation between towns are socio-economic status and household characteristics, especially overcrowding. Cluster analysis is used to define twelve classes of towns whose characteristics and trends are compared. This classification is shown to relate closely with a socio-economic group index. Both the component interpretations and the classification possess temporal continuity.
City System Behaviour and Corporate Influence: The Headquarters Location of US Industrial Firms, 1955-75
Authors: Stephens John D. , Holly Brian P.
Published: October 2006

Research on the locational patterns of corporate headquarters in the United States shows that corporate control has become less concentrated over the past 25 years. Analysis of the largest 500 industrial corporations reveals a trend toward a more balanced distribution on a regional basis but a greater degree of stability within the rank size hierarchy. The largest cities, regardless of their location, tend to be the steering points in the economic system. Although corporate headquarters have been decentralising to the suburbs, they are able to do so without surrendering their accessibility to specialised contact networks, ancillary business services, and inter-metropolitan transportation networks.
Survival and Success of the Inner City Economy: The Performance of Manufacturing and Services in Islington
Authors: Wellbelove D. , Woods A. , Zafiris N.
Published: October 2006

The paper uses recent data of financial performance drawn from a sample of manufacturing and service firms from the London Borough of Islington to assess the current position of such enterprises in a typical inner city area. Performance is found to be as good as, and in some cases better than, the national average, suggesting a more optimistic picture than might have been expected in view of recent findings of 'inner city decline'.
The Effects of Racial Composition on Neighbourhood Succession
Authors: Vandell Kerry D.
Published: October 2006

This study investigates the extent to which, under segmented housing market conditions, neighbourhood racial composition has a significant influence on the rate of neighbourhood succession. Using Houston and St Louis census tract data, pooled and stratified regression estimates are developed which predict succession as proxied by income changes. Quite strong relationships are found, indicating that nonwhite and racially transitional neighbourhoods tend toward more rapid downward succession than otherwise equivalent white neighbourhoods. Furthermore, this relationship seems to hold over different housing market types and over a wide range of neighbourhood conditions. The source of these differences is also investigated.
New Firm Formation, Employment Change and the Small Firm: The Case of Cleveland County
Authors: Storey D.J.
Published: October 2006

This employment performance of small and new manufacturing firms is examined in the County of Cleveland, an area of North-East England characterised by large establishments in 'heavy' industry. The paper shows that relatively few jobs were created by wholly new manufacturing firms in the area between 1965 and 1976, and that even raising the formation rate to that of the prosperous East Midlands would not have offset job losses through the contraction of large plants. New firm formations in an area are shown to be strongly associated with the proportion of the workforce employed in small establishments.
A Conditional Logit Model of the Role of Local Public Services in Residential Choice
Authors: Friedman Joseph
Published: October 2006

This study develops and estimates an econometric model of choice among residential communities. The econometric method employed is maximum-likelihood estimation of a multinomial logit. This makes it possible to examine the effects of local public services and other community attributes on the residential location decisions by families. The model was estimated for six subsamples differing by household size, income, and age of head of household.

For most of the subsamples that were examined, the conclusion is that local public services and other community characteristics play only minor roles in determining the residential location choice. The major determinant of residential location is the quantity of housing services that the household can obtain in a community.
Estimating Inter-city Differences in the Price of Housing Services: Further Evidence 1
Authors: Gillingham Robert , Greenlees John S.
Published: October 2006

This paper reconsiders an approach to inter-area house price index construction applied by Harvey Rosen in a recent article in Urban Studies. Rosen's cost function-based approach is shown to rely upon certain implicit assumptions regarding consumer preferences and housing production technology. Using FHA home purchase data, we estimate a more general production model and generate alternative inter-area indexes. Based on our results, Rosen's production technology assumptions are rejected. Further, the production-theoretic indexes are shown to differ only negligibly from a fixed-weight index using FHA data. Thus the difference which Rosen finds between the production-theoretic FHA and published BLS indexes does not result from Rosen's recognition of substitution in production, but because of very different data sources and scopes of coverage.
The Risk Business: Developers' Perceptions and Prospects for Housebuilding in the Inner City
Authors: Nicholls D.C. , Turner D.M. , Kirby-Smith R. , Cullen J.D.
Published: October 2006

This article describes and discusses the principal results from a study of residential developers and their role in the housing development process in Nottingham. The research identified land availability as the critical factor inhibiting private housebuilding in the inner area of Nottingham and cast doubts on certain conventional assumptions about the prospects for private residential development in inner cities. The characteristics and perceptions of developers with and without experience of inner city development are compared, and developers' reactions to a series of specific development sites are analysed in relation to both site and developer characteristics.
The Two-income Household: Relative Contribution of Earners To Housing Costs
Authors: Wulff Maryann Griffin
Published: October 2006

One and two income owner-occupant households are compared with regard to their respective homeownership consumption. An analysis of over 200 husband-wife households in Adelaide, South Australia, all of whom had changed residences within the previous 15 months, reveals that the major advantage of two incomes over one income lies in saving for the housing deposit. Neither the purchase price of the house nor the weekly mortgage payments are significantly related to the additional income earned by the wife in the two income household.
Towards An Analytic Framework for Land-Use Planning Policies
Authors: Bracken Ian
Published: October 2006

A vital process in achieving a systematic knowledge of a subject concerns the development and refinement of classifications of the content of that subject. This is equally true whether the subject is readily quantified or not; though, in this latter case, as for example in the study of policies, there will be additional methodological problems to be faced. Moreover, in the urban context, there is only a short history of work on which to draw.

This paper describes current research which is seeking to develop a policy classification framework for strategic land-use policies. Some potential criteria for classification are identified and methodology for developing a typology from documentary evidence is explained. In addition, the work involves a notation for policy classification, by means of which comparative urban policy study can be carried out. The paper concludes with a brief examination of findings which have emerged following the application of the approach to six British Structure Plans, together with a discussion of the potential of the classification concept.
Unemployment Stocks and Flows in the Travel-to-Work Areas of the North-West Region
Authors: Armstrong Harvey , Taylor Jim
Published: October 2006

This paper examines spatial variations in unemployment stocks and flows in the North-West region of Great Britain. It utilises information describing the monthly flow of persons through the unemployment register. Combining the stock data with the flow data, it is possible to infer the mean duration of unemployment so that the relative contribution of the inflow rate and the mean duration of unemployment in determining spatial variations in the unemployment rate can be investigated. Some travel-to-work areas are shown to have a low inflow rate and a high mean duration of unemployment, whereas other areas have the reverse. This suggests the existence of quite different types of unemployment problems in different areas. The policy implications of this finding are discussed.
Components of Locational Change in Multi-Plant Enterprises
Authors: Healey Michael
Published: October 2006

This paper examines the nature, relative importance and spatial patterns of the changes made over a six-year period by a representative sample of 64 small and medium size multiplant enterprises to the number, location, size and products of their plants. The locational changes occurred frequently, plant size changes, closures and acquisitions were the most common. Significant differences were found in the spatial patterns of the components of change. However, these variations occurred at different spatial levels, implying that the processes of locational change varied with the scale of analysis. The employment performance of the enterprises was markedly better than that of their industries, suggesting that an urban and regional policy of encouraging and fostering medium-sized enterprises may be a fruitful one.
The Economics of Population Dispersal Policy
Authors: Plaut Steven E.
Published: October 2006

The issue of population dispersal is one that enjoys cyclical popularity in much of the Western world. Considerable discussion and media space is devoted to the need for public intervention in order to reduce urban congestion, ecological damage, and protect the 'quality of life'.
Market Structure and the Price of Housing Services
Authors: Cronin Francis J.
Published: October 2006

While many aspects of housing markets have been extensively analysed, little empirical work has been undertaken on the supply of housing services. Despite this dearth of information, many researchers have characterised the supply of housing as being competitive. It is the intent of this article, therefore, to open up the discussion of the supply of housing services and to examine the extent of sellers' market concentration over a set of multifamily rental housing submarkets. New data on sellers' concentration are presented. A model to determine the effect of non-competitive firm behaviour on the price of housing services is specified and estimated. Results support the hypothesis that the supply of housing services may not be perfectly competitive.
The Urban-Rural Manufacturing Shift in the European Community
Authors: Keeble David , Owens Peter L. , Thompson Chris
Published: October 2006

The paper documents, for the first time at the European Community scale, a relative shift of manufacturing industry from highly urbanised to rural regions during the 1970s. This shift is evident in terms of GDP, industrial output and manufacturing employment, and has occurred despite an urban region structural bias towards more modern, viable, industries such as electronics, aerospace and vehicles. Moreover, the shift characterises every individual EC country for which data are available. The degree to which the data are consistent with three different explanatory viewpoints, focussing on production cost differences, the impact of constrained locations, and capital restructuring, is also considered.
Citizen Demand for Exposure to Street Crime
Authors: McDonald John F. , Balkin Steven
Published: October 2006

If individuals gain utility from activities which expose them to the risk of being a victim of crime, then a higher risk of victimisation per unit of time exposed to crime should imply a lower quantity of exposure. This hypothesis leads to the distinction between the 'real' crime rate (probability of victimisation per unit of exposure time) and the 'nominal' crime rate (crimes per capita). Empirical evidence is presented which indicates that some dimensions of exposure are negatively related to proxies for the real crime rate.
The publishing imperative: the pervasive influence of publication metrics
Authors: Steele Colin , Butler Linda , Kingsley Danny
Published: October 2006

This article summarizes the effects of the increasing global trend towards measuring research quality and effectiveness through, in particular, publication‐based metrics, and its effects on scholarly communication. Such metrics are increasingly influencing the behaviour patterns of administrators, publishers, librarians, and researchers. Impact and citation measures, which often rely solely on Thomson Scientific data, are examined in the context of university league tables and research assessment exercises. The need to establish alternate metrics, particularly for the social sciences and humanities, is emphasized, as is an holistic approach to scholarly communication agenda.
CrossRef at the crossroads
Authors: Pentz Ed
Published: October 2006

An account is given of the present position of CrossRef and the background to it. Potential new developments of the system beyond those originally envisaged are then described.
The Monomeric Clathrin Assembly Protein, AP180, Regulates Contractile Vacuole Size inDictyostelium discoideum
Authors: Stavrou Irene , O'Halloran Theresa J.
Published: October 2006

AP180, one of many assembly proteins and adaptors for clathrin, stimulates the assembly of clathrin lattices on membranes, but its unique contribution to clathrin function remains elusive. In this study we identified the Dictyostelium discoideum ortholog of the adaptor protein AP180 and characterized a mutant strain carrying a deletion in this gene. Imaging GFP-labeled AP180 showed that it localized to punctae at the plasma membrane, the contractile vacuole, and the cytoplasm and associated with clathrin. AP180 null cells did not display defects characteristic of clathrin mutants and continued to localize clathrin punctae on their plasma membrane and within the cytoplasm. However, like clathrin mutants, AP180 mutants, were osmosensitive. When immersed in water, AP180 null cells formed abnormally large contractile vacuoles. Furthermore, the cycle of expansion and contraction for contractile vacuoles in AP80 null cells was twice as long as that of wild-type cells. Taken together, our results suggest that AP180 plays a unique role as a regulator of contractile vacuole morphology and activity in Dictyostelium.
Rab8-dependent Recycling Promotes Endosomal Cholesterol Removal in Normal and Sphingolipidosis Cells
Authors: Linder Matts D. , Uronen Riikka-Liisa , Hölttä-Vuori Maarit , van der Sluijs Peter , Peränen Johan , Ikonen Elina
Published: October 2006

The mechanisms by which low-density lipoprotein (LDL)-cholesterol exits the endocytic circuits are not well understood. The process is defective in Niemann–Pick type C (NPC) disease in which cholesterol and sphingolipids accumulate in late endosomal compartments. This is accompanied by defective cholesterol esterification in the endoplasmic reticulum and impaired ATP-binding cassette transporter A1 (ABCA1)-dependent cholesterol efflux. We show here that overexpression of the recycling/exocytic Rab GTPase Rab8 rescued the late endosomal cholesterol deposition and sphingolipid mistrafficking in NPC fibroblasts. Rab8 redistributed cholesterol from late endosomes to the cell periphery and stimulated cholesterol efflux to the ABCA1-ligand apolipoprotein A-I (apoA-I) without increasing cholesterol esterification. Depletion of Rab8 from wild-type fibroblasts resulted in cholesterol deposition within late endosomal compartments. This cholesterol accumulation was accompanied by impaired clearance of LDL-cholesterol from endocytic circuits to apoA-I and could not be bypassed by liver X receptor activation. Our findings establish Rab8 as a key component of the regulatory machinery that leads to ABCA1-dependent removal of cholesterol from endocytic circuits.
Cell Surface Collagenolysis Requires Homodimerization of the Membrane-bound Collagenase MT1-MMP
Authors: Itoh Yoshifumi , Ito Noriko , Nagase Hideaki , Evans Richard D. , Bird Sarah A. , Seiki Motoharu
Published: October 2006

Pericellular degradation of interstitial collagens is a crucial event for cells to migrate through the dense connective tissue matrices, where collagens exist as insoluble fibers. A key proteinase that participates in this process is considered to be membrane-type 1 matrix metalloproteinase (MT1-MMP or MMP-14), but little is known about the mechanism by which it cleaves the insoluble collagen. Here we report that homodimerization of MT1-MMP through its hemopexin (Hpx) domain is essential for cleaving type I collagen fibers at the cell surface. When dimerization was blocked by coexpressing either a membrane-bound or a soluble form of the Hpx domain, cell surface collagenolytic activity was inhibited in a dose-dependent manner. When MMP-13, a soluble collagenase active as a monomer in solution, was expressed as a membrane-anchored form on the cell surface, homodimerization was also required to cleave collagen. Our results introduce a new concept in that pericellular collagenolysis is regulated by correct molecular assembly of the membrane-anchored collagenase, thereby governing the directionality of the cell to migrate in tissue.
Computational prediction of novel components of lung transcriptional networks
Authors: Martinez M. Juanita , Smith Andrew D. , Li Bilan , Zhang Michael Q. , Harrod Kevin S.
Published: October 2006

Motivation: Little is known regarding the transcriptional mechanisms involved in forming and maintaining epithelial cell lineages of the mammalian respiratory tract.

Results: Herein, a motif discovery approach was used to identify novel transcriptional regulators in the lung using genes previously found to be regulated by Foxa2 or Wnt signaling pathways. A human–mouse comparison of both novel and known motifs was also performed. Some of the factors and families identified here were previously shown to be involved epithelial cell differentiation (ETS family, HES-1 and MEIS-1), and ciliogenesis (RFX family), but have never been characterized in lung epithelia. Other unidentified over-represented motifs suggest the existence of novel mammalian lung transcription factors. Of the fraction of motifs examined we describe 25 transcription factor family predictions for lung. Fifteen novel factors were shown here to be expressed in mouse lung, and/or human bronchial or distal lung epithelial tissues or lung epithelial cell lineages.

Availability: DME: . MATCOMPARE: . MOTIFCLASS is available from the authors.

Contact:  kharrod@lrri.org

Supplementary information:   and Bioinformatics Online.
Political Economy of Financial Development: Canada and the United States in the Mirror of the Other, 1790–1840
Authors: Sylla Richard
Published: October 2006

A meeting of the Business History Conference in Toronto with “The Political Economy of Enterprise” as its theme provides an opportunity to consider some historical similarities and differences between the climates of enterprise in Canada and the United States. Because much of my recent work has been on financial development in the United States in the early decades, 1790–1840, I shall focus on that period. During that period, finance, enterprise, and economic development in the United States made great strides. Across the border in British North America, progress in all three areas was limited. The contrast sheds some light on the political conditions that favor financial development, flourishing enterprise, and modern economic growth.
Scaling of tree vascular transport systems along gradients of nutrient supply and altitude
Authors: Coomes David A , Jenkins Kerry L , Cole Lydia E.S
Published: October 2006

A recent metabolic scaling theory predicts that plants minimize resistance to hydraulic conduction in the bulk transport network by narrowing the diameter of xylem conduits distally. We hypothesized that trees growing at high altitude or on nutrient-depleted soils would prioritize survival over minimizing hydraulic resistance, and that their vascular systems would be structured differently from those of trees growing under more benign conditions. In fact, conduits were observed to narrow towards the periphery of vascular system within all 45 trees of three species we investigated, and scaling relationships were indistinguishable across a range of environments. Thus, conduit tapering relationships appear to be invariant with respect to environmental conditions.
A multiple-site similarity measure
Authors: Diserud Ola H , Ødegaard Frode
Published: October 2006

Similarity measures are among the most intuitive and common measures for comparing two or more sites, or samples, with respect to their species overlap. A restriction of similarity measures is that they are limited to pairwise comparisons even in a multiple-site study. This work presents a multiple-site similarity measure that makes use of information on species shared by more than two sites and avoids the problem of covariance between pairwise similarities in a multiple-site study. Further, we show that our multiple-site similarity measure is related to
β
-diversity measures such as Whittaker's
β
-diversity. Similarity measures can also be used as descriptors of effective specialization of insects to host species by measuring similarity from host observations. Finally, we show that multiple-site similarity and host specificity are two sides of the same coin.
Variability of the mechanical properties of bone, and its evolutionary consequences
Authors: Currey John D , Pitchford Jonathan W , Baxter Paul D
Published: October 2006

The relative variabilities (coefficient of variation (CV)) of 10 different mechanical properties of compact bone were determined from 2166 measurements. All measures of variability were made on a minimum of four specimens from any bone. Three pre-yield properties had a CV of about 12%. Six post-yield properties had CVs varying from 24 to 46%. Pre-yield properties increase as a function of mineral content, whereas post-yield properties decrease. These differences give insight into mechanical phenomena occurring at different stages during loading. Furthermore, the fact that some properties are more tightly determined than others has implications for the optimum values set by natural selection. This assertion is made more rigorous using a simple mathematical model for the evolutionarily optimal allocation in a trade-off where one property is imprecisely determined. It is argued that in general the optimum will be biased in favour of the more tightly determined properties than would be the case if all properties had the same CV.
Stochastic Stokes' drift with inertia
Authors: Jansons Kalvis M
Published: October 2006

We consider both the effect of particle inertia on stochastic Stokes' drift, and also a related process which could be considered as a crude model of stochastic Stokes' drift driven by an eddy diffusivity. In the latter, the stochastic forcing is a stable Ornstein–Uhlenbeck process rather than Brownian motion. We show that the eddy Stokes' drift velocity has a peak at a non-zero value of the correlation time-scale for particles that have the same (limiting) diffusivity. For both of the models considered, this study shows that not only can stochastic Stokes' drift be used to sort particles with different diffusivities, but also it can be used to sort particles of the same diffusivities, but with different particle masses or correlation time-scales. This effect may be important in particle sorting applications.
Optical tweezers: 20 years on
Authors: McGloin David
Published: October 2006

In 1986, Arthur Ashkin and colleagues published a seminal paper in
Optics Letters
, ‘Observation of a single-beam gradient force optical trap for dielectric particles’ which outlined a technique for trapping micrometre-sized dielectric particles using a focused laser beam, a technology which is now termed optical tweezers. This paper will provide a background in optical manipulation technologies and an overview of the applications of optical tweezers. It contains some recent work on the optical manipulation of aerosols and concludes with a critical discussion of where the future might lead this maturing technology.
Instabilities and constitutive modelling
Authors: Wilson Helen J
Published: October 2006

The plastics industry today sees huge wastage through product defects caused by unstable flows during the manufacturing process. In addition, many production lines are throughput-limited by a flow speed threshold above which the process becomes unstable. Therefore, it is critically important to understand the mechanisms behind these instabilities.

In order to investigate the flow of a molten plastic, the first step is a model of the liquid itself, a relation between its current stress and its flow history called a constitutive relation. These are derived in many ways and tested on several benchmark flows, but rarely is the stability of the model used as a criterion for selection. The relationship between the constitutive model and the stability properties of even simple flows is not yet well understood. We show that in one case a small change to the model, which does not affect the steady flow behaviour, entirely removes a known instability. In another, a change that makes a qualitative difference to the steady flow makes only tiny changes to the stability.

The long-term vision of this research is to exactly quantify what are the important properties of a constitutive relation as far as stability is concerned. If we could understand that, not only could very simple stability experiments be used to choose the best constitutive models for a particular material, but our ability to predict and avoid wasteful industrial instabilities would also be vastly improved.
Linear and nonlinear generalized Fourier transforms
Authors: Pelloni Beatrice
Published: October 2006

This article presents an overview of a transform method for solving linear and integrable nonlinear partial differential equations. This new transform method, proposed by Fokas, yields a generalization and unification of various fundamental mathematical techniques and, in particular, it yields an extension of the Fourier transform method.
Fundamental problems in provable security and cryptography
Authors: Dent Alexander W
Published: October 2006

This paper examines methods for formally proving the security of cryptographic schemes. We show that, despite many years of active research and dozens of significant results, there are fundamental problems which have yet to be solved. We also present a new approach to one of the more controversial aspects of provable security, the random oracle model.
A random walk approach to quantum algorithms
Authors: Kendon Vivien M
Published: October 2006

The development of quantum algorithms based on quantum versions of random walks is placed in the context of the emerging field of quantum computing. Constructing a suitable quantum version of a random walk is not trivial; pure quantum dynamics is deterministic, so randomness only enters during the measurement phase, i.e. when converting the quantum information into classical information. The outcome of a quantum random walk is very different from the corresponding classical random walk owing to the interference between the different possible paths. The upshot is that quantum walkers find themselves further from their starting point than a classical walker on average, and this forms the basis of a quantum speed up, which can be exploited to solve problems faster. Surprisingly, the effect of making the walk slightly less than perfectly quantum can optimize the properties of the quantum walk for algorithmic applications. Looking to the future, even with a small quantum computer available, the development of quantum walk algorithms might proceed more rapidly than it has, especially for solving real problems.
RNPC1, an RNA-binding protein and a target of the p53 family, is required for maintaining the stability of the basal and stress-induced p21 transcript
Authors: Shu Limin , Yan Wensheng , Chen Xinbin
Published: October 2006

p21, a cyclin-dependent kinase inhibitor, is transcriptionally regulated by the p53 family to induce cell cycle arrest. p21 is also regulated post-transcriptionally upon DNA damage in a p53-dependent manner, but the mechanism is uncertain. Here, we found that RNPC1, an RNA-binding protein and a target of the p53 family, is required for maintaining the stability of the basal and stress-induced p21 transcript. Specifically, we showed that RNPC1 is induced by the p53 family and DNA damage in a p53-dependent manner. The RNPC1 gene encodes at least two alternative spliced isoforms, RNPC1a and RNPC1b, both of which contain an intact RNA recognition motif. Interestingly, we found that RNPC1a, but not RNPC1b, induces cell cycle arrest in G1, although both isoforms are expressed in the nucleus and cytoplasm. In addition, we found that while both isoforms directly bind to the 3′ untranslated region in p21 transcript, only RNPC1a is able to stabilize both the basal and stress-induced p21 transcripts. Conversely, RNPC1a knockdown destabilizes p21 transcript. Finally, we found that RNPC1a is required to maintain the stability of p21 transcript induced by p53.
Runx2 inhibits chondrocyte proliferation and hypertrophy through its expression in the perichondrium
Authors: Hinoi Eiichi , Bialek Peter , Chen You-Tzung , Rached Marie-Therese , Groner Yoram , Behringer Richard R. , Ornitz David M. , Karsenty Gerard
Published: October 2006

The perichondrium, a structure made of undifferentiated mesenchymal cells surrounding growth plate cartilage, regulates chondrocyte maturation through poorly understood mechanisms. Analyses of loss- and gain-of-function models show that Twist-1, whose expression in cartilage is restricted to perichondrium, favors chondrocyte maturation in a Runx2-dependent manner. Runx2, in turn, enhances perichondrial expression of Fgf18, a regulator of chondrocyte maturation. Accordingly, compound heterozygous embryos for Runx2 and Fgf18 deletion display the same chondrocyte maturation phenotype as Fgf18-null embryos. This study identifies a transcriptional basis for the inhibition of chondrocyte maturation by perichondrium and reveals that Runx2 fulfills antagonistic functions during chondrogenesis.
Inhibition of STAT3 activity with AG490 decreases the invasion of human pancreatic cancer cells in vitro
Authors: Huang Chen , Cao Jun , Huang Ke J. , Zhang Fang , Jiang Tao , Zhu Lin , Qiu Zheng J.
Published: October 2006

Signal transducer and activator of transcription 3 (STAT3) is a central cytoplasmic transcription factor. Abnormal activation of STAT3 plays a critical role in oncogenesis and has been found frequently in a wide variety of human tumors including pancreatic cancer. In this study, we elucidated the significance of the STAT3 signaling pathway on metastatic potentials of pancreatic cancer. We found that phosphorylated STAT3 (p‐STAT3) protein levels were significantly higher in highly metastatic SW1990 cells compared to the poorly metastatic CaPan‐2 cells, which expressed weak levels of this protein. Furthermore, a Janus kinase (JAK) specific inhibitor, AG490, significantly inhibited the expression of p‐STAT3, and subsequently reduced invasion and adhesion potential of SW1990 cells compared to the cells treated with vehicle only. Finally, inhibition of the STAT3 signaling pathway by AG490 also led to a decrease in matrix metalloproteinase‐2 and vascular endothelial growth factor expression at the protein and mRNA levels. These results demonstrate that activation of the STAT3 signaling pathway plays an important role in the progression of pancreatic cancer and that inhibition of this pathway may be useful for an anti‐invasive therapeutic option in pancreatic cancer. (Cancer Sci 2006; 97: 1417–1423)
Risk factors differ for non‐small‐cell lung cancers with and without EGFR mutation: assessment of smoking and sex by a case‐control study in Japanese
Authors: Matsuo Keitaro , Ito Hidemi , Yatabe Yasushi , Hiraki Akio , Hirose Kaoru , Wakai Kenji , Kosaka Takayuki , Suzuki Takeshi , Tajima Kazuo , Mitsudomi Tetsuya
Published: October 2006

The present study aimed to assess the impact of smoking and sex for the risk of non‐small‐cell lung cancer (NSCLC) with or without epidermal growth factor receptor (EGFR) mutation. We conducted a case‐control study using 152 patients with EGFR‐mutated (EGFRmut) NSCLC, 283 with EGFR‐wild‐type (EGFRwt) NSCLC and 2175 age‐ and sex‐frequency‐matched controls. Smoking was a significant risk factor for EGFRwt NSCLC (odds ratio [OR] for ever‐smokers, 4.05; 95% confidence interval [CI], 2.79–5.88) but not for EGFRmut NSCLC (OR, 0.73; CI, 0.46–1.14). Sex did not affect this association. The association was observed consistently with other smoking‐related parameters including pack‐years. Sex was the sole risk factor for EGFRmut NSCLC (OR for women relative to men, 2.19; CI, 1.41–3.39) and there was no significant interaction between women and smoking. In contrast, sex, smoking and their interaction were significant in EGFRwt NSCLC. The impact of sex on EGFR mutation status was assessed by several indicators of reproductive history among women. Total fertile years showed a significant positive association with EGFRmut NSCLC but not with EGFRwt NSCLC. Other indicators showed similar trends and this result may partly explain the sexual difference in the acquisition of EGFR mutation. In conclusion, our case‐control study clearly demonstrated that the impacts of smoking and sex on the risk of EGFRmut NSCLC are different from those for EGFRwt NSCLC. Further epidemiological evaluation is warranted. (Cancer Sci 2007; 98: 96–101)
Haematological malignancies developing in previously healthy individuals who received haematopoietic growth factors: report from the Research on Adverse Drug Events and Reports (RADAR) project
Authors: Bennett Charles L. , Evens Andrew M. , Andritsos Leslie A. , Balasubramanian Lakshmi , Mai Mark , Fisher Matthew J. , Kuzel Timothy M. , Angelotta Cara , McKoy June M. , Vose Julie M. , Bierman Philip J. , Kuter David J. , Trifilio Steven M. , Devine Steven M. , Tallman Martin S.
Published: October 2006

Pegylated recombinant human megakaryocyte growth and development factor (PEG‐rHuMGDF) and granulocyte colony‐stimulating factor (G‐CSF) promote haematopoietic progenitor cell maturation. We reviewed the findings for healthy volunteers/donors who developed haematological malignancies following PEG‐rHuMGDF or G‐CSF administration. Information was reviewed for three of 538 volunteers who received PEG‐rHuMGDF in clinical trials and two of 200 donors who underwent G‐CSF mobilised stem cell harvesting procedures for sibling stem cell transplants. Mantle cell, diffuse large B‐cell lymphoma and chronic lymphocytic leukaemia were diagnosed 1–5 years after PEG‐rHuMGDF exposure among three volunteers. For one patient, thrombocytopenia due to autoantibodies to PEG‐rHuMGDF developed shortly after PEG‐rHuMGDF administration and persisted until chemotherapy was administered. All three achieved complete remission, although one patient relapsed. Acute myeloid leukaemia was diagnosed 4 and 5 years after G‐CSF mobilisation in two donors who underwent peripheral blood stem cell donation for sibling allogeneic haematopoietic stem cell transplantation. Following intensive chemotherapy, one died from acute leukaemia and the second is in complete remission. Controversy exists over the appropriateness of administering haematopoietic growth factors to healthy individuals. While a causal relationship with haematological malignancies cannot be demonstrated, long‐term follow‐up among healthy individuals who receive haematopoietic growth factors is needed.
Learning from mothers: how myths, policies and practices affect the detection of subtle developmental problems in children
Authors: Williams J.
Published: October 2006

Background Recent research has revealed increasing concerns over the number of children entering school with unidentified developmental problems, even though there are ostensibly comprehensive health services available for mothers and their children in the pre‐school years. Recognizing that early detection and early intervention reduce the likelihood of long‐term health and educational problems, it is important to understand why so many children are not detected with developmental problems in their pre‐school years.

Methods This doctoral study utilized the knowledge and experience of mothers to draw attention to reasons why children with subtle developmental problems are not identified until school age. A qualitative methodology utilized a synthesis of interpretive biography and literary folkloristics as a method of collecting, reading and interpreting personal stories. Three literary theories, arising, respectively, from the tenets of semiotics, neoMarxism and post‐structuralism, were used to critically deconstruct the mothers’ stories.

Results The findings highlight a number of factors that influence the interaction between mothers, health professionals and members of the community, and how these interactions impact on the early detection of children’s developmental problems. The findings illustrate the influence of societal myths on how mothers and health professionals view their roles, and on how they think about and respond to the child’s problem. They also confirm the value placed on professional knowledge and the role it plays in communications between mothers and health professionals. Finally, they draw attention to how competing arguments about diagnosis and labelling delay identification and access to intervention programmes for children.

Conclusion Health professionals working with mothers and young children should be aware of how their values, beliefs and communication styles affect their professional practice, especially when interacting with mothers who raise concerns about their children. State policies that limit access to early intervention programmes should also be reconsidered so that young children are not excluded from assistance.
Abuse of the disabled child: a systematic review of population‐based studies
Authors: Govindshenoy M. , Spencer N.
Published: October 2006

Objective  To ascertain the strength of the association between childhood disability and abuse and neglect.

Methods  Systematic review of population‐based studies published between 1966 and January 2006. Medline, Embase, Cinahl, Cochrane library, National Research Register, Social Sciences database and PsychInfo databases were searched for potentially relevant studies. Inclusion criteria: population‐based cohort, case–control or cross‐sectional studies of children <18 years of age that reported empirical data on the association of abuse with disability. Risk estimates were expressed as odds ratios with 95% confidence intervals (CI) where possible. Meta‐analysis was not undertaken because of heterogeneity of studies.

Results  Four studies met the inclusion criteria. Two were longitudinal studies, one was a retrospective birth cohort and the remaining study was a cross‐sectional survey. Types of disability studied varied widely as did methods used to ascertain abuse and neglect. Two studies accounted for potential confounding. Three studies reported an association between psychological and emotional disabilities and abuse. Two studies reported an association of learning disability with abuse. Only one study examined the association of physical disability (cerebral palsy) with abuse reporting an adjusted odds ratio for all forms of abuse of 1.79 (95% CI 0.96, 3.36) and for physical abuse of 3.00 (95% CI 1.29, 6.78).

Conclusions  The evidence base for an association of disability with abuse and neglect is weak. Psychological and emotional problems, and learning difficulties appear to be associated with abuse but this association might arise because these conditions share a common aetiological pathway with abuse. There is limited evidence that physical disability predisposes to abuse.