bluuebunny/crossref_metadata_2025 huggingface dataset:
Potentials and Green's Functions in Micropolar Fluid Theory
Authors: Ramkissoon H. , Majumdar S. R.
Published: June 2007

The system of coupled differential equations characterizing the slow, steady, incompressible flow of micropolar fluid is examined. Integral representations for the velocity vector and the microrotation vector are obtained by utilizing the fundamental singular solutions corresponding to a concentrated force and a concentrated couple. The very form of these integral representations suggests the introduction of surface potentials of single and double layers. The properties of these potentials are stated in various theorems without detailed proofs since they behave much like the ordinary harmonic potentials. Matrix Green's functions are then constructed with the aid of the fundamental singular solutions. By making use of the integral representations, formal solutions to two types of boundary value problems are generated in terms of integrals which include given body forces, surface data and these matrix Green's functions.
Zur Stabilisierung von Gleichungen der ersten Variation durch Prozeßrechner
Authors: Herz B.
Published: June 2007

Ein lineares, zeitinvariantes, multivariables System werde als Gleichung der ersten Variation eines nicht explizit bekannten nichtlinearen Systems angesehen und durch eine lineare diskrete Regelung, etwa durch einen Prozeßrechner, stabilisiert. Unter für die Anwendungen hinreichend weiten Voraussetzungen hinsichtlich der bei der Linearisierung vernachlässigten Nichtlinearitäten wird gezeigt, daß diese Stabilisierung auch für das nichtlineare System exponentielle und totale Stabilität sicherstellt. Der von H. J. Stetter gegebene Begiff der totalen Stabilität bei diskreten Systemen wird dabei hier so modifiziert, daß vom Prozeßrechner gemachte zustandsabhängige Rundungsfehler mit erfaßt werden. Wegen der als unbekannt angenommenen, vernachlässigten Nichtlinearitäten ergeben sich zwangsläufig Fortsetzbarkeitsfragen, die im Zentrum der Betrachtung stehen.
Zur Verallgemeinerung zweistufiger Differenzenverfahren für nichtlineare hyperbolische Differentialgleichungssysteme
Authors: Stark W. , Wojcieszynski R.
Published: June 2007

Ausgehend von der von Lerat und Peyret entwickelten Klasse zweistufiger Differenzenverfahren zur Lösung hyperbolischer Differentialgleichungssysteme werden Berechnungsverfahren entwickelt, die aus dieser Klasse die problemorientiert‐optimalen Verfahren auswählen. Die Herleitung dieser Bestimmungsgleichungen erfolgt unter Ausnutzung der Theorie der einfachen Wellen und der Charakteristiken hyperbolischer Differentialgleichungssysteme.
Weak Convergence of Approximations of I tǒ Integral Equations
Authors: Platen E.
Published: June 2007

Weak convergence is proved for continuously interpolated approximations of Itǒ integral equations, which were presented in Wagner, Platen [8], under the assumption of existence of the 4th moment of the initial value.
Some Results Concerning Periodic Solutions of Plane Autonomous Differential Systems
Authors: Sandqvist A. , Andersen K. M.
Published: June 2007

In order to obtain results concerning the possible number of closed trajectories to the plane autonomous system ẋ = P(x, y), ẏ = Q(x, y) a related polar differential equation is considered. Some criteria are derived securing this equation to have at most one, respectively at most two 2π‐periodic solutions — thereby giving corresponding results for the number of closed trajectories to the autonomous system. As an illustration the results are applied to investigate a case of bifurcation in a specific example.
A Theoretical Treatment of Lifting Surface Theory of an Elliptic Wing
Authors: Kida T.
Published: June 2007

This paper is concerned with the exact theoretical treatment of the three‐dimensional lifting surface theory as treated in Krienes [9]. The method treated in this paper includes a new technique for the numerical approach, and the singularity of the lift distribution in the neighbourhood of the wing tips is examined in detail. To use the trigonometric series expressions of Lamé polynomial functions makes the numerical calculations easy and makes the accuracy improved. These expressions are available for the study of the singularity of the lift distribution near the wing tips.
Zur Stabilität ebener Schichtenströmungen gegenüber Störungen mit endlich großer Amplitude
Authors: Brechling J.
Published: June 2007

Die Stabilität ebener Kanal‐ und Grenzschichtströmungen gegen periodische Störungen endlicher Amplitude wird numerisch als kombinierte Rand‐ und Eigenwertaufgabe untersucht. Es werden Amplituden der Störbewegung bis zur Größe turbulenter Schwankungsgeschwindigkeit betrachtet.
Periodic Stress Concentration Problems of Plane Orthotropic Elasticity
Authors: Krenk S.
Published: June 2007

Convenient formulae are provided for the stress fields produced by isolated or periodically distributed forces and dislocations in plane orthotropic elasticity. Their application to the solution of boundary value problems and the influence of the elastic constants are discussed. Special attention is given to the problem of an elastic strip containing a periodic array of holes.
The Integration of Nonlinear Stochastic Systems with Applications to the Damage and Ambiguity Identification
Authors: Wedig W.
Published: June 2007

The paper investigates nonlinear stochastic systems with piecewise linear characteristics whose multi‐dimensional distribution densities are piecewise gaussian and therefore exactly calculable taking into account the necessary continuity and normalization conditions. Applying this approach to a cracked bending oscillator a spectral analysis is performed leading to the new phenomenon that the one degree of freedom system possesses two resonances the distance of which is a measure for the damage extension. In case of a vibrator with a piecewise progressive elasticity the spectral analysis is extended to amplitude frequency distributions in order to show the stochastic analogon to the ambiguity of the deterministic Duffing problem.
Einseitiges Knicken eines schweren Stabes
Authors: Vielsack P.
Published: June 2007

Ein schwerer gedrückter Stab auf starrer Unterlage kann neben der trivialen, geraden Lage auch nach oben gebogene Formen besitzen. Gefragt ist nach der kleinsten Druckkraft Für einen nichttrivialen Gleichgewichtszustand. Eine erste Näherung wird mit der Methode der singulären Störungsrechnung hergeleitet.
On the Economization of Stabilized Runge‐Kutta Methods with Applications to Parabolic Initial Value Problems
Authors: Sommeijer B. P. , van der Houwen P. J.
Published: June 2007

A modification of Runge ‐ Kutta methods is analysed which leads for important classes of parabolic differential equations to a considerable reduction of the computational effort. The main characteristic of the modified methods is the replacement of the right hand side function of the differential equation by a “cheaper” function with roughly the same Jacobian matrix. Numerical experiments are reported and the results are compared with the results obtained by the unmodified Runge‐Kutta method and by an ADI method.
On the Incompleteness of the Number of Physical Parameters of a Free Streamline Potential Flow Problem
Authors: van der Zanden J.
Published: June 2007

The two‐dimensional free‐streamline solution of a plate rectangular in the flow of the jet from a nozzle is solved numerically. Earlier theoretical discussions of this problem mentioned only three physical parameters. However, this number must be equal to that of the independent geometrical parameters of the problem, which is four, otherwise the problem is not well posed. So a fourth parameter has been introduced. Numerical integration is preferred, although analytical integration is, in principle, possible. The determination of parameters and streamlines depends on the solution of nonlinear equations with inequality constraints.
Hydrodynamic Inlet Region Flow of Power‐Law Fluids in a Circular Tube
Authors: Gupta R. C.
Published: June 2007

Momentum‐energy‐integral analysis for the laminar flow of power‐low fluids in the inlet region of a circular tube has been improved by incorporating Volkov's refinement of the Karman‐Pohlhausen method. Analytical expressions for the boundary layer development and the inlet region pressure‐distribution have been obtained. Results have been illustrated graphically and compared with some earlier analyses.
Nichtlineare Bewegungsgleichungen großer Mehrkörpersysteme
Authors: Schiehlen W. , Weidenhammer F.
Published: June 2007

Bei der dynamischen Untersuchung nichtlinearer mechanischer Systeme mit vielen Freiheitsgraden stellt bereits die Gewinnung der Bewegungsgleichungen ein wesentliches Problem dar. Es wird gezeigt, daß die Bewegungsgleichungen holonomer Mehrkörpersysteme durch die Anwendung des Jourdainschen Prinzips in einer einfacheren Form dargestellt werden können. Dies führt zu einem besseren mechanischen Verständnis symbolischer Gleichungen und zu kürzeren Rechenzeiten in numerischen Formalismen.
Dynamic Analysis of Cylindrical Shell under Hot Spot
Authors: Shirakawa K.
Published: June 2007

This paper is concerned with the dynamic analysis of a cylindrical shell subjected to a sudden change of temperature field by a hot spot at an initial state. Applying Dirac's delta function to the hot spot, the solutions are presented for the nonstationary equation of heat conduction for shell. The dynamic, thermoelastic cylindrical shell equation retaining all inertia terms are solved by employing Fourier and Laplace transforms. The solutions for a quasistatic problem enable us to discuss the singularities in thermal displacements and stresses. The importance of the dynamic effects in the practical applications is pointed out by showing some numerical examples. Shell equations employed in this study are those of Flügge and Donnell with the addition of thermal effects.
On a Direct Method of Integral Equations for Solving the Biharmonic Dirichlet Problem
Authors: Fuglede B.
Published: June 2007

In recent years an alternative method of integral equations has been used for numerical solution of the Dirichlet problem for the Laplace equation or the biharmonic equation in a bounded plane domain. This method is based simply on Green's third identity, and its main advantage is that is leads directly from the prescribed Dirichlet boundary data to the (physically relevant) Neumann data. It has been conjectured recently by S. Christiansen and P. Hougaard that, for certain values of the outer mapping radius of the domain, the integral equation(s) in question has (have) other solutions than that which stems from the solution to the Dirichlet problem. They proved this for a circular domain and gave numerical indications in another case. In the present paper we prove this and related conjectures in the case of a general domain with smooth boundary. We do not discuss the numerical aspects of the method in question.
Interaction of Elastic Waves with a Griffith Crack Situated in an Infinitely Long Strip
Authors: Srivastava K. N. , Gupta O. P. , Palaiya R. M.
Published: June 2007

The problem is the determination of the distribution of stress in the neighbourhood of a Griffith crack situated in an infinitely long elastic strip. The crack is opened by longitudinal elastic waves, incident normally on the crack. Fourier transforms are used to reduce the problem to a Fredholm integral equation of the second kind. Numerical solution of this equation is used for calculating the values of dynamical stress intensity factor at the edge of the crack. The results are illustrated graphically.
Young Women's Social and Occupational Development and Mental Health in the Aftermath of Child Sexual Abuse
Authors: Schilling Elizabeth A. , Aseltine Robert H. , Gore Susan
Published: June 2007

We examined social role functioning and depressive symptoms of young adults who were abused as children in data from a longitudinal community sample. Sexually abused women and men were more depressed during their senior year of high school, and this difference was more pronounced 2 years later. We then examined a mediational model to determine whether social functioning explained the course of depressive symptoms over this transitional period. Focusing only on young women, for whom the prevalence of abuse was much higher, results indicated that two‐thirds of the effect of abuse on depressive symptoms was explained by experiences and choices in the domains of work, education and intimate relationships. Having less supportive intimate relationships and lower rates of attendance at 4‐year colleges were particularly important. Findings reveal the key role played by early adult interpersonal and occupational development in perpetuating the mental health impact of childhood trauma.
ABCA3‐mediated choline‐phospholipids uptake into intracellular vesicles in A549 cells
Authors: Matsumura Yoshihiro , Sakai Hiromichi , Sasaki Mayumi , Ban Nobuhiro , Inagaki Nobuya
Published: June 2007

ABCA3 is proposed to function as a lung surfactant lipid transporter. Here we report ABCA3‐dependent lipid uptake into intracellular vesicles in lung adenocarcinoma A549 cells. A549 cells stably expressing GFP‐tagged wild‐type ABCA3 (A549/ABCA3WT) had larger LAMP3‐positive vesicles than their parental cells as well as A549 cells expressing a Walker A motif mutant (A549/ABCA3N568D). The choline‐phospholipids level in A549/ABCA3WT was increased 1.25‐fold compared to that in A549 and A549/ABCA3N568D cells, while the cholesterol levels were similar. Sucrose gradient fractionation analysis in A549/ABCA3WT cells revealed that choline‐phospholipids were enriched in low‐density and nile red‐positive vesicles. Electronmicroscopic analysis showed multilamellar vesicles in A549/ABCA3WT cells. These results indicate that ABCA3 mediates ATP‐dependent choline‐phospholipids uptake into intracellular vesicles.
Transcriptome analysis during the process ofin vitrodifferentiation ofLeishmania donovaniusing genomic microarrays
Authors: SRIVIDYA G. , DUNCAN R. , SHARMA P. , RAJU B. V. S. , NAKHASI H. L. , SALOTRA P.
Published: June 2007

Leishmania donovanicauses visceral disease (kala-azar), a major health problem throughout the tropics with 500 000 new cases every year.Leishmaniadifferentiates from the promastigote to the amastigote form to establish infection in a mammalian host. To understand the process of differentiation, we assessed the global variation in gene expression in promastigotes, an intermediate stage of differentiation (PA24) and axenic amastigotes in culture using anL. donovanigenomic microarray with 4224 clones printed in triplicate. During an intermediate stage of differentiation 24 h after shifting the promastigotes into amastigotes (PA24), there were 41 (∼1%) clones with expression ⩾2·0-fold higher than promastigotes, whereas in terminally differentiated amastigotes there were 130 (∼3%) such clones. Of particular interest were certain genes that exhibited a transient increase or decrease in expression at the PA24 stage. Kinases showed a transient increase, and surface molecules, PSA and amino acid permease, were prominent clones among those showing a brief decrease at the PA24 stage. The microarray results have been validated using Northern blots or RT-PCR. In summary, our results provide important clues about the genes involved in the differentiation process ofL. donovanithat may contribute to virulence.
International environmental cooperation in northwest Russia: an assessment of performance
Authors: Tennberg Monica
Published: June 2007

The effectiveness of international environmental cooperation is a theoretical and methodological challenge that has captured the interest of scholars and students of international relations in the recent years. This article is an evaluation of international environmental cooperation in northwest Russia by applying an approach developed in the Institutional Dimensions of Global Environmental Change (IDGEC) research programme of the International Human Dimension Programme (IHDP). The IDGEC approach emphasises the importance of complex diagnostics of institutional environmental arrangements in terms of performance. The approach relates to the effects of international environmental cooperation in terms of sustainability, efficiency, fairness, and robustness. The article focuses on Russian and Nordic experiences of international environmental cooperation, and the assessment of performance has been done by the participants themselves. According to the results of interviews and questionnaires, the cooperation is considered institutionally effective and robust in general. However, views about the environmental effects vary. Some problems exist that are related to sustainability and fairness, but the most critical issue is the lack of domestic environmental capacity in Russia.
Number and distribution of Adélie penguin (Pygoscelis adeliae) breeding sites in the Robinson Group of islands, Mac.Robertson Land coast, east Antarctica
Authors: Low Matthew , Meyer Lisa , Southwell Colin
Published: June 2007

In November 2005, the first comprehensive survey for Adélie penguin (Pygoscelis adeliae) breeding sites in the Robinson Group of islands, situated 25 to 55 km east of Australia's Mawson station (67.602°S, 62.879°E) was conducted. Breeding Adélie penguins were found on 30 of the 149 islands, with the number of nests on each island ranging from fewer than 10 to several thousand. With the exception of those islands in the southeast, nesting Adélie penguins were found throughout the Robinson Group. In this paper, the spatial coordinates and presence/absence of breeding penguins for all 149 islands are reported so that researchers may interpret the results in relation to possible future survey work. All locations reported in this paper are in decimal degrees.
Globalisation and development in a post-nomadic hunter/gatherer Alaskan village: a follow-up assessment
Authors: Dinero Steven C.
Published: June 2007

Using data collected in the Gwich'in Athabascan community of Vashraii K'oo/Arctic Village, an examination of how the village has continued to develop and evolve as a native space since its initial creation in 1908, is presented. Data collected using a household survey in 2006 is compared with data that was collected in a 1999 survey in order to address and measure such issues as: the village residents’ economic standing and subsistence activities; satisfaction with the planning and governance of the village; and residents’ overall attitudes toward the degree to which their village continues to function as an ‘ethnic space’. The previous conclusion (Dinero 2005) was that these villagers have responded relatively well to globalising forces, effectively bridging the native and white worlds in a manner which allows them to live in both, yet to retain a strong sense of their identity and cultural values despite residence in a settled, post-nomadic setting. While this remains the case, one cannot overlook in the present research the sense of loss of past lifeways that has resulted from the changes brought on by new technologies, despite any positive benefits deriving therefrom. Therefore, the conclusion of this paper is the suggestion that the development of this ‘hybridised’ Alaska native is still very much in process, as these people strive to adapt to the new challenges presented by their ever-changing environment.
Assessing the Capacity of Pension Institutions to Build and Sustain Trust: A Multidimensional Conceptual Framework
Authors: HYDE MARK , DIXON JOHN , DROVER GLENN
Published: June 2007

As policy makers have sought to reconfigure the public–private boundaries of their pension systems, trust has become an increasingly salient issue. At stake is the attainment of desired policy outcomes regarding retirement. By what criteria, then, should the capacity of pension institutions to build and sustain trust be assessed? This article emphasises the strategic importance of institutional design in the trust process. Building on Sztompka's seminal analysis of the institutional foundations of trust, and a substantial review of the literature and survey evidence regarding public confidence in pensions, we identify, justify and give indicative operational content to six trust benchmarks. This provides a conceptual foundation for future empirical research on the capacity of pension institutions to build and sustain trust.
Moving on from ‘Anti-Racism’? Understandings of ‘Community Cohesion’ held by Youth Workers
Authors: THOMAS PAUL
Published: June 2007

‘Community Cohesion’, and the apparent lack of it, was rapidly offered as the explanation for the 2001 disturbances across northern England, and has since become a cornerstone of government approaches to race relations policy. This article explores what Community Cohesion means to welfare practitioners in Oldham, one of the affected towns. Academic discussion of Community Cohesion has been largely hostile, focusing on the language and assumptions of the government reports. While highlighting important issues, these debates have been virtually free of empirical evidence on how Community Cohesion is actually being understood and operationalised by welfare practitioners. Drawing on in-depth research with youth workers in Oldham, I argue that the Community Cohesion analysis of the state of race relations is largely accepted, and supported, by those youth workers, and that it has enabled a significant shift in the assumptions and operations of their professional practice. Within this ‘modal shift’ in practice is a moving away from the language and assumptions of ‘anti-racism’, as it has been largely understood and operationalised by youth workers on the ground, towards what I argue can be seen as ‘critical multi-culturalism’.
It's a Family Affair: Low-Income Children's Perspectives on Maternal Work
Authors: RIDGE TESS
Published: June 2007

This article presents new empirical findings from a qualitative, longitudinal study of low-income working family life. It explores the experiences and perceptions of a group of children living in low-income, working, lone-mother households. Their accounts disclose the impact on children's everyday lives of their mothers' move into low-paid employment following a period out of the labour market. Children's accounts show that their mothers' move into work had brought significant economic and social change to their lives. How children experienced their mothers' employment and made sense of changes in family life was mediated by a range of different factors including their age, changes in income and security, changes in family time and family practices, child care, and their perceptions of maternal wellbeing. The findings also reveal that children, as active social agents, were engaged in a complex range of caring and coping strategies that endeavoured to ease some of the pressures that low-income working life could generate in their family lives. The article concludes with a discussion about the implications of the findings for policy, particularly in relation to the quality of social and economic support that lone mothers and their children receive.
Social Policy Digest Online
Authors: Bennett Fran , Jones Ken
Published: June 2007

The Social Policy Digest went online in the summer of 2003. This means that the Digest, which used to be printed as part of the Journal of Social Policy, is now only available via the web.
UrbanDictionary.com
Authors: Damaso John , Cotter Colleen
Published: June 2007

In traditional English lexicography, individual dictionary editors have had ultimate control over the selection, meaning, and illustration of words and extensive collaboration with contributors has been limited. However, Internet technologies that easily permit exchanges between a user and a database have allowed a new type of dictionary online: one that is built by the collaboration of contributing end-users, allowing users who are not trained lexicographers to engage in the actual making of dictionaries. We discuss here a popular online slang dictionary, UrbanDictionary.com (UD), to illustrate how traditional lexicographic principles are joined with Web-only communication technologies to provide a context for collaborative engagement and meaning-making, and to note the many characteristics and functions shared with traditional print dictionaries. Significantly, UD captures what most traditional English dictionaries fall short of: both recording ephemeral everyday spoken language and representing popular views of meaning. By relying on the users of language to select and define words for a dictionary, UD – which defines more than one million words – has in effect influenced both access to and formulation of the lexis.
Seroepidemiology of hepatitis A in voluntary blood donors from Pune, western India (2002 and 2004–2005)
Authors: GADGIL P. S. , FADNIS R. S. , JOSHI M. S. , RAO P. S. , CHITAMBAR S. D.
Published: June 2007

Recently, a changing pattern of hepatitis A epidemiology has been reported in the Indian population indicating a rise in the rate of hepatitis A infection among adults. The study's objective was to assess anti-HAV prevalence in voluntary blood donors from middle and high socioeconomic strata. Serum samples collected from voluntary blood donors from Pune city and its suburbs in the years 2002 and 2004–2005 were tested for anti-HAV IgG antibodies. Serum samples collected during 2004–2005 were examined for anti-HAV IgM antibodies. Positive samples were tested for HAV-RNA. Agewise anti-HAV positivity was significantly low in adults aged 18–25 years (90·4%) compared to those aged >25 years (97·4%) (P<0·01). A decline in anti-HAV prevalence was significant in 2004–2005 compared to that in 2002 (96·5% vs. 92·1%) (P<0·01). Overall, in both adult age groups, the proportion of anti-HAV positivity was remarkably low in the high socioeconomic group (HSG) (88·96%) compared to that of the middle socioeconomic group (MSG) (95·86%) (P<0·01). Anti-HAV IgM positivity was not significant (~1%), however, presence of HAV-RNA in one of the samples indicated the possibility of horizontal transmission of HAV. Increase in seronegativity to HAV in HSG implicates a rise in the susceptible pool and indicates the need for vaccination against hepatitis A.
Semmelweis and the aetiology of puerperal sepsis 160 years on: an historical review
Authors: NOAKES T. D. , BORRESEN J. , HEW-BUTLER T. , LAMBERT M. I. , JORDAAN E.
Published: June 2007

It is generally accepted that Professor Ignaz Semmelweis was the first to identify the mode of transmission of puerperal sepsis. However no appropriate statistical analysis of Semmelweis's data supporting his theory has been reported. Mean annual percent maternal mortality rates for the Allgemeines Krankenhaus and Dublin Maternity Hospitals (1784–1858) were analysed. The introduction of pathological anatomy at the Allgemeines Krankenhaus in 1823 was associated with increased mortality. After 1840 maternal mortality was higher in Clinic 1 which was staffed by male obstetricians and medical students who, unlike the midwives in Clinic 2, attended autopsies. The introduction of chlorine washing of the male clinicians’ hands in Clinic 1 by Semmelweis in 1847 reduced mortality, whereas the cessation of handwashing after Semmelweis left Vienna in 1850 was associated with increased mortality. This statistical analysis supports Semmelweis's hypothesis that ‘the cadaveric particles adhering to the hand had … caused the preponderant mortality in the first Clinic’.
Population-based study of human papillomavirus infection and cervical neoplasia in Athens, Greece
Authors: KROUPIS C. , THOMOPOULOU G. , PAPATHOMAS T. G. , VOURLIDIS N. , LAZARIS A. C.
Published: June 2007

The aim of our study is to describe the prevalence of the different HPV types in women with pre-neoplastic lesions of the cervix in Greece. Cervical scrapes from 841 women were obtained for both cytological evaluation and analysis for the presence of HPV DNA. PCR was performed on specimens from these 841 women. The Pap test results were normal or showed benign cellular changes in 45·8% of the women, atypical squamous cells of undeterminated significance (ASCUS) in 23·2%, low-grade squamous intra-epithelial lesion (LSIL) in 27·9% and high-grade squamous intra-epithelial lesion (HSIL) in 3·1%. HPV DNA was demonstrated in 23·6% of cytologically normal women. We detected HPV in 60% of the total samples. Of these, HPV-16 was the most common HPV DNA detected. Interestingly, HPV-58 was inversely correlated with positive cytological findings. A clear pattern of decreasing prevalence of HPV with age was also observed. Our results indicate that HPV infections, especially those with HPV-16, represent a significant public health concern in Greece.
First-person plural in Prince Edward Island Acadian French: The
fate of the vernacular variant je…ons
Authors: King Ruth , Nadasdi Terry , Butler Gary R.
Published: June 2007

In Atlantic Canada Acadian communities, definite on
is in competition with the traditional vernacular variant
je…ons (e.g., on parle vs. je parlons
“we speak”), with the latter variant stable only in
isolated communities, but losing ground in communities in which there
is substantial contact with external varieties of French. We analyze
the distribution of the two variants in two Prince Edward Island
communities that differ in terms of amount of such contact. The results
of earlier studies of Acadian French are confirmed in that
je…ons usage remains robust in the more isolated
community but is much lower in the less isolated one. However, in the
latter community, the declining variant, while accounting for less than
20% of tokens for the variable, has not faded away. Although it is not
used at all by some speakers, it is actually the variant of choice for
others, and for still other speakers, it has taken on a particular
discourse function, that of indexing narration. Comparison with
variation in the third-person plural, in which a traditional variant is
also in competition with an external variant, shows that the decline of
je…ons is linked to its greater saliency, making it a
prime candidate for social reevaluation.An earlier version of this article was presented at
UKLVC-3, held in July 2001 at the University of York, U.K. We thank
audience members for comments. We also thank Raymond Mougeon, along
with this journal's anonymous referees, for useful comments on an
earlier written version. The research was funded by standard research
grants awarded to King and Nadasdi by the Social Sciences and
Humanities Research Council of Canada.
Managing Stress and Rehabilitation: A View from the Workplace
Authors: Neary David
Published: June 2007

This article examines work-related stress and rehabilitation in the light of the introduction of Stress Management Standards in the UK in 2004. The Management Standards are outlined and the relevant literature on good practice in stress and rehabilitation is reviewed to provide a context for empirical research conducted with human resource practitioners in organisations. This view from the workplace provides insights on the issues faced, especially in the public services, when managing stress and rehabilitation. These include the role played by stress in people's personal life, the limitations of line management and the role of General Practitioners.
Thickness variation of the descending Philippine Sea slab and its relationship to volcanism beneath the Kanto‐Tokai district, central Japan
Authors: Kamiya Shin'ichiro , Kobayashi Yoji
Published: June 2007

We use an iterative nonlinear travel time tomography technique to determine three‐dimensional P‐wave and S‐wave seismic velocity models for the region beneath the Kanto‐Tokai district of central Japan. Salient points of the models are the following: (1) The subducting Philippine Sea slab has thickness variation with a stepwise offset east of the Izu Peninsula. The eastern (beneath the Kanto district) and western (beneath the area north of Izu Peninsula and the Tokai district) regions have respective thicknesses of 60 and 25 km. The slab clearly subducts continuously to a depth of 100 km from the Sagami Trough beneath the Kanto district, although the Tokai slab is indistinct at depths of 50–70 km. (2) The oceanic crust at the top of the descending Philippine Sea slab transforms into eclogite at a depth of about 70 km beneath the Kanto district. (3) Low‐velocity anomalies are associated with present and past volcanism. They are located on the west of a 110‐km depth contour of the Wadati‐Benioff zone, rather than only on the backarc side of the volcanic front. Deflection of the volcanic front might result from the subducting Philippine Sea slab, which shifts the dehydration reaction deeper as it subducts deeper.
Salinity‐induced hydrate dissociation: A mechanism for recent CH4 release on Mars
Authors: Elwood Madden M. E. , Ulrich S. M. , Onstott T. C. , Phelps T. J.
Published: June 2007

Recent observations of CH4 in the Martian atmosphere suggest that CH4 has been added relatively recently. Several mechanisms for recent CH4 release have been proposed including subsurface biological methanogenesis, abiogenic hydrothermal and/or volcanic activity, dissociation of CH4 hydrates, atmospheric photolysis, or addition of organics via bolide impact. This study examines the effects of increasing salinity on gas hydrate stability and compares estimates of the Martian geothermal gradient to CH4 and CO2 hydrate stability fields in the presence of high salinity brines. The results demonstrate that salinity increases alone result in a significant decrease in the predicted hydrate stability zone within the Martian subsurface and may be a driving force in CH4 hydrate destabilization. Active thermal and/or pressure fluctuations are not required in order for CH4 hydrates to be the source of atmospheric CH4.
Superplumes, plates, and mantle magmatism in two‐dimensional numerical models
Authors: Ogawa Masaki
Published: June 2007

Two‐dimensional numerical models are systematically presented for magmatism in a convecting mantle internally heated by incompatible radioactive elements. Plate tectonics is self‐consistently modeled as a part of convection of Newtonian fluid with temperature‐ and stress‐history‐dependent viscosity driven by thermal and compositional buoyancy, while magmatism is modeled as an upward migration of basaltic magma generated by decompression melting. Ridge magmatism actively takes place to chemically differentiate the mantle, and a superplume is well developed in the lowermost mantle as a broad hot region enriched in basaltic component, provided that the lithosphere is mechanically strong enough to inhibit spontaneous initiation of subduction by its own weight and that the internal heating rate is sufficiently high. Hot narrow plumes frequently rise up from the superplume to induce deep magma generation and hot spot magmatism, which in turn frequently induces new plate margins. The frequent plate margin formation keeps the activity of plate tectonics rather steady. The thermal and chemical state of the mantle remains rather steady, too. As the internal heating rate becomes lower, however, the narrow plumes from superplume become sporadic and significantly colder, deep magma generation becomes rare; and new plate margin formation becomes less frequent. As a consequence, the activity of plate tectonics and the thermal and chemical state of the mantle become fluctuating much with time. The mantle structure and plume behavior modeled here match with many observations for those of the Earth from the Archean to the present.
Responses of permafrost to climate change and their environmental significance, Qinghai‐Tibet Plateau
Authors: Cheng Guodong , Wu Tonghua
Published: June 2007

In this paper we summarize recent research in geocryological studies carried out on the Qinghai‐Tibet Plateau that show responses of permafrost to climate change and their environmental implications. Long‐term temperature measurements indicate that the lower altitudinal limit of permafrost has moved up by 25 m in the north during the last 30 years and between 50 and 80 m in the south over the last 20 years. Furthermore, the thickness of the active layer has increased by 0.15 to 0.50 m and ground temperature at a depth of 6 m has risen by about 0.1° to 0.3°C between 1996 and 2001. Recent studies show that freeze‐thaw cycles in the ground intensify the heat exchange between the atmosphere and the ground surface. The greater the moisture content in the soil, the greater is the influence of freeze‐thaw cycling on heat exchange. The water and heat exchange between the atmosphere and the ground surface due to soil freezing and thawing has a significant influence on the climate in eastern Asia. A negative correlation exists between soil moisture and heat balance on the plateau and the amount of summer precipitation in most regions of China. A simple frozen soil parameterization scheme was developed to simulate the interaction between permafrost and climate change. This model, combined with the NCAR Community Climate Model 3.6, is suitable for the simulation of permafrost changes on the plateau. In addition, permafrost degradation is one of the main causes responsible for a dropping groundwater table at the source areas of the Yangtze River and Yellow River, which in turn results in lowering lake water levels, drying swamps and shrinking grasslands.
Regional calibration of catchment models: Potential for ungauged catchments
Authors: Parajka Juraj , Blöschl Günter , Merz Ralf
Published: June 2007

We present a novel iterative regional calibration (IRC) method in which the model parameters of a number of catchments are calibrated simultaneously. The method exploits the spatial correlations of the parameters to condition their a priori distribution for each catchment. We use a sample of 320 catchments in Austria over a period of 22 years to test the method. The results indicate that the IRC method allows us to reliably calibrate the conceptual hydrologic model used here. The novel method reduces the uncertainty of most parameters as compared to local calibration. This is demonstrated by more consistent model parameters in two independent calibration periods and by an analysis of their spatial variability. Jackknife cross validation indicates that the IRC method tends to improve runoff simulation performance for ungauged catchments as compared to traditional regionalization, although the gain is small in absolute terms.
Vertical distribution of scandium in the north central Pacific
Authors: Amakawa Hiroshi , Nomura Miho , Sasaki Kazunori , Oura Yasuji , Ebihara Mitsuru
Published: June 2007

The concentrations of scandium (Sc) in seawater, which have remained unreported since the early 1970s, were determined together with those of yttrium (Y) and lanthanides (Ln) with samples from the north central Pacific Ocean (St. BO‐3). The Sc concentration shows a so‐called nutrient‐like profile: it increases gradually from the surface (about 2 pmol/kg) to the ocean floor (about 20 pmol/kg). That pattern closely resembles those of Y and Ln (correlation coefficient (r) > 0.92). Some light‐to‐middle Ln (Pr–Tb) exhibit a closer correlation with Sc than do Y, La, or heavy Ln (Ho–Lu). In contrast, Y/Sc and Ln/Sc ratios (elemental abundance ratios) indicate that Sc is depleted compared to either Y or Ln in seawater more than in loess, which represents chemical compositions of crustal material. These observations offer a conflicting view of chemical reactivity related Y, Ln, and Sc: r values show that the chemical reactivity of Sc resembles those of Y and Ln, but differences of Y/Sc and Ln/Sc ratios in seawater and in loess suggest that the chemical reactivity of Sc differs from those of Y and Ln. More Sc data for seawater are necessary to clarify the chemical reactivity of Sc in the ocean. We also propose that comparative studies of vertical profiles of Sc and such elements as Fe, Ti, Zr, and Hf showing so‐called nutrient‐like profiles at the same oceanic stations would be helpful and effective for clarifying the behavior of Sc in the ocean.
Cultivation of a novel cold-adapted nitrite oxidizing betaproteobacterium from the Siberian Arctic
Authors: Alawi Mashal , Lipski André , Sanders Tina , Eva-Maria-Pfeiffer  , Spieck Eva
Published: June 2007

Permafrost-affected soils of the Siberian Arctic were investigated with regard to identification of nitrite oxidizing bacteria active at low temperature. Analysis of the fatty acid profiles of enrichment cultures grown at 4°C, 10°C and 17°C revealed a pattern that was different from that of known nitrite oxidizers but was similar to fatty acid profiles of Betaproteobacteria. Electron microscopy of two enrichment cultures grown at 10°C showed prevalent cells with a conspicuous ultrastructure. Sequence analysis of the 16S rRNA genes allocated the organisms to a so far uncultivated cluster of the Betaproteobacteria, with Gallionella ferruginea as next related taxonomically described organism. The results demonstrate that a novel genus of chemolithoautotrophic nitrite oxidizing bacteria is present in polygonal tundra soils and can be enriched at low temperatures up to 17°C. Cloned sequences with high sequence similarities were previously reported from mesophilic habitats like activated sludge and therefore an involvement of this taxon in nitrite oxidation in nonarctic habitats is suggested. The presented culture will provide an opportunity to correlate nitrification with nonidentified environmental clones in moderate habitats and give insights into mechanisms of cold adaptation. We propose provisional classification of the novel nitrite oxidizing bacterium as ‘Candidatus Nitrotoga arctica’.
Long-term monitoring of transplanted human neural stem cells in developmental and pathological contexts with MRI
Authors: Guzman Raphael , Uchida Nobuko , Bliss Tonya M. , He Dongping , Christopherson Karen K. , Stellwagen David , Capela Alexandra , Greve Joan , Malenka Robert C. , Moseley Michael E. , Palmer Theo D. , Steinberg Gary K.
Published: June 2007

Noninvasive monitoring of stem cells, using high-resolution molecular imaging, will be instrumental to improve clinical neural transplantation strategies. We show that labeling of human central nervous system stem cells grown as neurospheres with magnetic nanoparticles does not adversely affect survival, migration, and differentiation or alter neuronal electrophysiological characteristics. Using MRI, we show that human central nervous system stem cells transplanted either to the neonatal, the adult, or the injured rodent brain respond to cues characteristic for the ambient microenvironment resulting in distinct migration patterns. Nanoparticle-labeled human central nervous system stem cells survive long-term and differentiate in a site-specific manner identical to that seen for transplants of unlabeled cells. We also demonstrate the impact of graft location on cell migration and describe magnetic resonance characteristics of graft cell death and subsequent clearance. Knowledge of migration patterns and implementation of noninvasive stem cell tracking might help to improve the design of future clinical neural stem cell transplantation.
Selectivity and proofreading both contribute significantly to the fidelity of RNA polymerase III transcription
Authors: Alic Nazif , Ayoub Nayla , Landrieux Emilie , Favry Emmanuel , Baudouin-Cornu Peggy , Riva Michel , Carles Christophe
Published: June 2007

We examine here the mechanisms ensuring the fidelity of RNA synthesis by RNA polymerase III (Pol III). Misincorporation could only be observed by using variants of Pol III deficient in the intrinsic RNA cleavage activity. Determination of relative rates of the reactions producing correct and erroneous transcripts at a specific position on a tRNA gene, combined with computational methods, demonstrated that Pol III has a highly efficient proofreading activity increasing its transcriptional fidelity by a factor of 10
3
over the error rate determined solely by selectivity (1.8 × 10
−4
). We show that Pol III slows down synthesis past a misincorporation to achieve efficient proofreading. We discuss our findings in the context of transcriptional fidelity studies performed on RNA Pols, proposing that the fidelity of transcription is more crucial for Pol III than Pol II.
Evidence for Coupled Biogenesis of Yeast Gap1 Permease and Sphingolipids: Essential Role in Transport Activity and Normal Control by Ubiquitination
Authors: Lauwers Elsa , Grossmann Guido , André Bruno
Published: June 2007

Current models for plasma membrane organization integrate the emerging concepts that membrane proteins tightly associate with surrounding lipids and that biogenesis of surface proteins and lipids may be coupled. We show here that the yeast general amino acid permease Gap1 synthesized in the absence of sphingolipid (SL) biosynthesis is delivered to the cell surface but undergoes rapid and unregulated down-regulation. Furthermore, the permease produced under these conditions but blocked at the cell surface is inactive, soluble in detergent, and more sensitive to proteases. We also show that SL biogenesis is crucial during Gap1 production and secretion but that it is dispensable once Gap1 has reached the plasma membrane. Moreover, the defects displayed by cell surface Gap1 neosynthesized in the absence of SL biosynthesis are not compensated by subsequent restoration of SL production. Finally, we show that down-regulation of Gap1 caused by lack of SL biogenesis involves the ubiquitination of the protein on lysines normally not accessible to ubiquitination and close to the membrane. We propose that coupled biogenesis of Gap1 and SLs would create an SL microenvironment essential to the normal conformation, function, and control of ubiquitination of the permease.
Characterization of mismatch and high-signal intensity probes associated with Affymetrix genechips
Authors: Wang Yonghong , Miao Ze-Hong , Pommier Yves , Kawasaki Ernest S. , Player Audrey
Published: June 2007

Motivation: For Affymetrix microarray platforms, gene expression is determined by computing the difference in signal intensities between perfect match (PM) and mismatch (MM) probesets. Although the use of PM is not controversial, MM probesets have been associated with variance and ultimately inaccurate gene expression calls. A principal focus of this study was to investigate the nature of the MM signal intensities and demonstrate its contribution to the experimental results.

Results: While most MM intensities were likely associated with random noise, a subset of ∼20% (99 485) of the MM probes displayed relatively high signal intensities to the corresponding PM probes (MM > PM) in a non-random fashion; 13 440 of these probes demonstrated exceptionally high ‘outlier’ intensities. About 15 938 PM probes also demonstrated exceptionally high outlier intensities consistently across all hybridizations. About 92% of the MM > PM probes had either a dThymidine (dT) or a dCytidine (dC) at the 13th position of the probe sequence. MM and PM probes displaying extremely high outlier intensities contained high dC rich nucleotides, and low dA contents at other nucleotides positions along the 25mer probe sequence. Differentially expressed genes generated using Genechip Operating System (GCOS) or modified PM-only methods were also examined. Of those candidate genes identified in the PM-only method, 157 of them were designated by GCOS as absent across all datasets and many others contained probes with MM > PM signal intensities. Our data suggests that MM intensity from PM signal can be a major source of error analysis, leading to fewer potentially biologically important candidate genes.

Contact:  wangyong@mail.nih.gov

Supplementary information: Supplementary data are available at Bioinformatics online.