bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion planning for multiple non-holonomic robots: a geometric approach
Authors: Xidias Elias K. , Aspragathos Nikos A.
Published: November 2007

In this paper, a geometrical approach is developed to generate simultaneously optimal (or near-optimal) smooth paths for a set of non-holonomic robots, moving only forward in a 2D environment cluttered with static and moving obstacles. The robots environment is represented by a 3D geometric entity called Bump-Surface, which is embedded in a 4D Euclidean space. The multi-motion planning problem (MMPP) is resolved by simultaneously finding the paths for the set of robots represented by monoparametric smoothC2curves onto the Bump-Surface, such that their inverse images onto the initial 2D workspace satisfy the optimization motion-planning criteria and constraints. The MMPP is expressed as an optimization problem, which is solved on the Bump-Surface using a genetic algorithm. The performance of the proposed approach is tested through a considerable number of simulated 2D dynamic environments with car-like robots.
DISPROVING THE COASE THEOREM?
Authors: HALPIN ANDREW
Published: November 2007

Fascination with the Coase Theorem arises over its apparently unassailable counterintuitive conclusion that the imposition of legal liability has no effect on which of two competing uses of land prevails, and also over the general difficulty in tying down an unqualified statement of the theorem. Instead of entering the debate over what exactly the theorem holds, this article suggests that the core of Coase's reasoning is flawed and to the extent that any version of the theorem relies upon this reasoning it can be disproved. The article commences by modelling the nature of the counter-intuitive thrust to the Coase Theorem, which is used to trace the development of Coase's reasoning, and ultimately to expose the flaw it contains. The heart of the article comprises the allegation of an error made by Coase when he transferred his core argument to the context of economic rents. Ancillary observations are made on the relationship between the Coasean analysis of characteristically legal problems and the conditions of general market equilibrium, and the theoretical status of Law-and-Economics.
HARSANYI BEFORE ECONOMICS: AN INTRODUCTION
Authors: FONTAINE PHILIPPE
Published: November 2007

Upon learning that John C. Harsanyi (1920–2000) was awarded the Bank of Sweden Prize in Economic Sciences in Memory of Alfred Nobel, in 1994, for his pioneering work in game theory, few economists probably questioned the appropriateness of that choice. The Budapest-born social scientist had already been recognized as a first-rank contributor to non-cooperative game theory for some time (see, e.g., Gul 1997). However, as many readers of this journal will be aware, Harsanyi first contributed to welfare economics, not game theory. More importantly, he was philosophically minded and accordingly has been “acknowledged as the most influential philosopher in economics” (Güth 1994: 252).1 This is of some significance since, before Harsanyi became acquainted with economics around 1950, his main interest was philosophy and, to a lesser extent, sociology and psychology. Rather than an economist with philosophical leanings, Harsanyi was actually a philosopher turned economist.
Editorial: Connections with Clive
Authors: Trussler Simon
Published: November 2007

I shared some memories of Clive and paid my personal tribute in NTQ 83, the issue that immediately followed his death; so in this brief introduction to our special issue celebrating his life and work I want rather to look at the contributions we have included, and how these connect with Clive's legacy.
Clive Barker: Man of Counterpoint
Authors: Barba Eugenio
Published: November 2007

Point against point, note against note: the counterpoint, in music, is not just simple difference and contrast. It creates dialogue and density. It is distinguishable from harmony because it increases the firmness and the complexity of the composition by continuously keeping a distance. Different melodic lines intertwine and collaborate without melting together, each developing its own difference.
The Shadows and the Rush of Light: Ewan MacColl and Expressionist Drama
Authors: Warden Claire Altree
Published: November 2007

It has generally been assumed that the Expressionist movement had little noticeable impact on British theatre. Claire Altree Warden here suggests that in the plays of Ewan MacColl (and in particular his The Other Animals of 1948) there is a discernible challenge to this assumption. In order to advocate a specific political position, MacColl took the conventions of Expressionism and developed a highly engaged, artistically innovative theatrical aesthetic that could tackle socio-political inequalities and the suppression of the dissident voice. Through linguistic experiment, episodic structure, representational characters, and a focus on the individual mind, the playwright challenges the audience to confront class injustice and hegemonic tyranny. Claire Altree Warden is based at the University of Edinburgh, where she teaches English Literature. She also teaches Critical Theory and Theatre History at Queen Margaret University, Edinburgh, and is currently preparing a new critical study of Ewan MacColl's plays.
Did Clive Barker Write The Hostage?
Authors: Favre June
Published: November 2007

Clive Barker often wrote about Joan Littlewood and his time at Theatre Workshop with a mixture of warmth and bewilderment at her unorthodox methods. While preparing her doctoral thesis, Text and Collaboration: an Examination of the Roles of Joan Littlewood and Theatre Workshop in the Genesis and Production of Brendan Behan's ‘The Hostage’, at the National University of Ireland, Galway, June Favre wrote to Clive praising the article ‘Closing Joan's Book: Some Personal Footnotes’ (NTQ, May 2003). As a result of that first letter, Clive and June began a correspondence – exchanging questions, notes, published and unpublished material, with a final email to June dated 4 March 2005, less than two weeks before his death on 17 March. Clive had accepted the position of external examiner for the thesis with the viva voce to take place 10 May 2005 in Galway – a city Clive had never visited. An email sent on 21 February 2005 informed June that Clive was looking forward to ‘seeing the sun go down on Galway Bay’. His sudden death deprived him of that pleasure. Concluding the ‘Acknowledgments’ of the thesis, June wrote: ‘Above all my heartfelt gratitude for the dozens of emails, letters, and articles Clive Barker shared with me. He promptly supplied information on Joan Littlewood and the productions of Brendan Behan plays from first-hand experience.’ There follow some of the informative and humorous exchanges between Clive and June, who was awarded her doctoral degree later in 2005.
Taking Clive Seriously for a Moment…
Authors: McCaw Dick
Published: November 2007

Dick McCaw was a friend and colleague of Clive Barker's for many years, notably during Clive's chairmanship of the International Workshop Festival, which McCaw created and directed to answer the continuing training and development needs of professionals working in the performing arts. In this article, he assesses the roots from which Barker's Theatre Games derives its continuing influence, and offers a critique of its vulnerabilities, interwoven with personal reflections on his association with its author. He discusses our greater understanding of the workings of the brain since the advent of fMRI imaging, and how this affects Clive's metaphor of the roles of the ‘back’ and ‘front’ brain in controlling and integrating the actor's motivation and movement, relating this to other ways in which Clive's proudly autodidactic methods often reached towards the right solutions through unscientific methodology. He looks also at Clive's use of the teachings of Moshe Feldenkrais, and of his intuitive and successful use of Feldenkrais techniques in regaining momentum following his first stroke. Dick McCaw, whose DVD celebrating Clive's theatre games workshops and their background, Theatre Jazz, was issued by Arts Archives, Exeter, in 2005, is currently teaching at Royal Holloway, University of London.
Peter Pan and Susan: Lost Children from Juliet to Michael Jackson
Authors: Trussler Simon
Published: November 2007

As the two articles following this amplify, whatever one's views of its intrinsic merits, J. M. Barrie's Peter Pan is open to a multiplicity of readings, and (notably since the RSC broke the mould in 1982) of stage interpretations – not to mention its co-option into Walt Disney's cartoon canon. Simon Trussler takes the play for a spin in such unaccustomed company as Romeo and Juliet and the almost contemporaneous ‘tragedy of childhood’ by Frank Wedekind, Spring Awakening, exploring the theme it sustains of betrayed childhoods, surrogate parenting, and changing attitudes towards grown men sleeping with small boys – a magical experience for Barrie, but much less comfortable for the singer Michael Jackson in his ranch called…Neverland. Simon Trussler is Co-Editor of New Theatre Quarterly and presently Professor and Senior Research Fellow at Rose Bruford College. His numerous books on drama and theatre include Shakespearean Concepts (Methuen, 1989), the award-winning Cambridge Illustrated History of British Theatre (1993), The Faber Pocket Guide to Elizabethan and Jacobean Drama (2006), and Will's Will: the Lives and Last Wishes of William Shakespeare (National Archives, 2007).
Peter Pan and the White Imperial Imaginary
Authors: Brewer Mary
Published: November 2007

To consider racial difference in terms of exclusion enables whiteness to retain its relative invisibility. Drawing upon the theoretical insights of critical whiteness studies, Mary Brewer examines J. M. Barrie's Peter Pan, exploring how the amorphous status granted to whiteness in the text lends it cultural authority. She aims to uncover how race and racism structure the play and to find ways of exploiting the gaps in its representation of white identity. These gaps potentially may be exploited in production – that is, made to operate against the grain and yield explicitly oppositional performances that work toward the denaturalization of hegemonic constructions of whiteness, gender, and sexuality. Mary Brewer lectures in the Department of English and Drama at Loughborough University. Her books include Race, Sex, and Gender in Contemporary Women's Theatre (Sussex Academic Press, 1992) and Problems of Exclusions in Feminist Thought: Challenging the Boundaries of Womanhood (Sussex Academic Press, 2002).
Locating Never Land: Peter Pan and Parlour Games
Authors: Varty Anne
Published: November 2007

John Doyle's centennial adaptation and direction of Peter Pan for the Oxford Playhouse in December 2004 provides the starting point for a fresh investigation of the play. As Clive Barker has placed the playing of games as central to the training of actors, so Doyle's setting for this production, which never departs from the Darling nursery, places games at the heart of his interpretation of this play about learning to act an adult part. The adult roles in Doyle's production all display a small element of Peter Pan, as their acting style requires them to step in and out of role, to demonstrate the playfulness of their actions, and so to resist growing up. These observations invite a backward glance at the ideological significance of play for late nineteenth-century thinkers about childhood. An exploration of playground and parlour games that formed a common currency of childhood experience during the late Victorian era is set against the documentary evidence of games which Barrie played with the Llewellyn Davies boys, and these in turn are shown to be not just manifest within Peter Pan itself, but also to afford the play a structural and ideological cohesion. Anne Varty is a Senior Lecturer in the English Department at Royal Holloway, University of London, and her monograph Children and Theatre in Victorian Britain will be published later this year.
Characters, Connections, Constructing an Action: Forty Years of Theatre of the Eighth Day
Authors: Tyszka Juliusz
Published: November 2007

Based in Poznań, Poland, Teatr Ósmego Dnia (Theatre of the Eighth Day) is now recognized not only as one of the most important companies in the history of Polish theatre, but as one of the leading avant-garde ensembles in the world. From its origins in a student theatre group of the late sixties, Theatre of the Eighth Day developed during the early seventies the artistically and socially radical methods of work and of living which have continued to be the hallmark of its work over four decades, but has remained in touch and in tune with the rapid changes in Polish life, first under martial law, and then in the new Poland of the ‘free market’ – towards which the company has sustained an attitude no less critical than to Communist authoritarianism. A number of its productions have accordingly left indelible marks on the sensitivities and even life choices made by two generations of Polish spectators. Juliusz Tyszka is Professor at the Adam Mickiewicz University, Poznań. A contributing editor of NTQ, he has been a close witness of more than thirty years of the work of Theatre of the Eighth Day, and here sets the artistic development of the group in the changing context of Polish life and politics.
Localization of alpha 2 receptors in ocular tissues
Authors: WOLDEMUSSIE ELIZABETH , WIJONO MERCY , POW DAVID
Published: November 2007

Alpha 2 adrenergic agonists are used for controlling intraocular pressure (IOP) in the treatment of glaucoma. They have also been shown to be neuroprotective to retinal cells in a variety of injury models. Despite this significance, the localization of the three known alpha 2 adrenergic receptors has not been unequivocally established. The aim of this study was to determine the location of the three alpha 2 adrenergic receptors in ocular tissues using immunohistochemical techniques. New antibodies were generated and their specificity was determined using Western blotting and preadsorption. In the anterior segment of the eye alpha 2A immunoreactivity was located in the nonpigmented ciliary epithelium, corneal, and conjunctival epithelia. Alpha 2B staining was not apparent in these tissues. Alpha 2C immunostaining was present in the membrane of pigmented ciliary epithelium and corneal and conjunctival epithelial cells. In the rat retina, all three receptor subtypes were present but were differentially localized. Alpha 2A was present in the somata of ganglion cell layer and inner nuclear layer somas, alpha 2B was located in the dendrites and axons of most of the neurons as well as glia, while alpha 2C was present in the somata and inner segment of the photoreceptors. In human and monkey retinas, similar pattern of labeling for alpha 2A and 2B receptors were observed, while alpha 2B was additionally present in the membranes of many cell somata in addition to dendrites and axons. Alpha 2C labeling was much weaker but exhibited similar pattern to that observed in the rat. These data provide additional information on the location of the alpha 2 receptors in the anterior portion of the eye and present new information on their specific location in the retina. This offers insights into possible targets for adrenergic agonists in a therapeutic context.
Bill Staines's Bridges and the Art of Meta-Folk
Authors: MERCER-TAYLOR PETER
Published: November 2007

Folksinger-songwriter Bill Staines came of age at the height of the mid-twentieth-century American folk music revival and has spent the years since then writing and playing music that seems impelled by the conviction that this vanished era's core stylistic premises and clear-eyed optimism remain as alive and available as they were at the revival's peak. Through this exploration of his 1984 album Bridges, I seek to show that Staines accomplishes this fantasy of the revival's continued vitality not, as his commentators frequently suggest, by clinging fast to decades-old stylistic practices but by introducing a dimension of reflexivity into his craft. What comes to matter is not music's political or social meaning but the self-conscious celebration of the idea of music having such a meaning.

The article's first section explores Staines's self-mythologizing enfolding of his own persona into Woody Guthrie's in the Guthrie ballad that opens the album. The second section examines Bridges' poetic weaving of music into narratives of social redemption and personal self-actualization. The third section examines Bridges' many moments of diegetic song, which effectively collapse the worlds of Staines's poetic subjects into that of his immediate audience. The last section explores how melodic choices in the traditional song that closes the album have the effect of bringing many of the songs that precede it directly into the fold of traditional music.
White Masculinity in Barbershop Quartet Singing
Authors: MOOK RICHARD
Published: November 2007

This article explores the cultural work of white masculinity in barbershop quartet singing in two historical contexts: the barbershop revival of the 1920s and 1930s and barbershop's struggle for survival in twenty-first century Philadelphia. It first details how revivalists attempted to re-create Victorian white masculinity by codifying and promoting a barbershop musical style and repertory that fostered closeness between men. By performing their musical style in public, masculine spaces, and admitting only white men to their gatherings, the organizers of the Barbershop Harmony Society opposed a number of contemporary social changes in the United States, including shifting gender roles, a rise in immigration, the economic instability of the Great Depression, and New Deal liberalism. The article then documents how and why barbershoppers in Philadelphia at the turn of the twenty-first century still perform this “close,” neo-Victorian mode of white masculinity. In this new context, barbershop whiteness enabled a group of white men to claim belonging in their racially divided city despite years of migration and displacement caused by deindustrialization and urban decay. In both historical moments, barbershoppers used whiteness to challenge social and economic change and to assert the continued relevance of their musical style.
Quantifying the remote triggering capabilities of large earthquakes using data from the ANZA Seismic Network catalog (southern California)
Authors: Kane Deborah L. , Kilb Debi , Berg Arthur S. , Martynov Vladislav G.
Published: November 2007

Various studies have examined remote earthquake triggering in geothermal areas, but few studies have investigated triggering in nongeothermal areas. We search the ANZA (southern California) network catalog for evidence of remote triggering. Using three statistical tests (binomial, Kolmogorov‐Smirnov, and Wilcoxon rank sum), we determine the significance of the rates and timing of earthquakes in southern California following large teleseismic events. To validate our statistical tests, we identify 20 local main shocks (ML ≥ 3.1) with obvious aftershock sequences and 22 local main shocks (ML ≥ 3.0) that lack obvious aftershock sequences. Our statistical tests quantify the ability of these local main shocks to trigger aftershocks. Assuming that the same triggering characteristic (i.e., a particular seismic wave amplitude, perhaps in a specific frequency band) is evident for both local and remote main shocks, we apply the same tests to 60 remote main shocks (mb ≥ 7.0) and assess the ability of these events to trigger seismicity in southern California. We find no obvious signature of remote triggering. We find minimal differences between the spectral amplitudes and maximum ground velocities of the local triggering and nontriggering earthquakes. Similar analysis of a select few of our remote earthquakes shows that the related ground motion regularly exceeds that of local earthquakes both at low frequencies and in maximum velocity. This evidence weakly suggests that triggering requires larger amplitudes at high frequencies and that a maximum ground velocity alone is not the primary factor in remote triggering. Our results are complex, suggesting that a triggering threshold, if it exists, may depend on several factors.
A new approach to estimation of global air‐sea gas transfer velocity fields using dual‐frequency altimeter backscatter
Authors: Frew Nelson M. , Glover David M. , Bock Erik J. , McCue Scott J.
Published: November 2007

A new approach to estimating air‐sea gas transfer velocities based on normalized backscatter from the dual‐frequency TOPEX and Jason‐1 altimeters is described. The differential scattering of Ku‐band (13.6 GHz) and C‐band (5.3 GHz) microwave pulses is used to isolate the contribution of small‐scale waves to mean square slope and gas transfer. Mean square slope is derived for the nominal wave number range 40–100 rad m−1 by differencing mean square slope estimates computed from the normalized backscatter in each band, using a simple geometric optics model. Model parameters for calculating the differenced mean square slope over this wave number range are optimized using in situ optical slope measurements. An empirical relation between gas transfer velocity and mean square slope, also based on field measurements, is then used to derive gas transfer velocities. Initial results demonstrate that the calculated transfer velocities exhibit magnitudes and a dynamic range which are generally consistent with existing field measurements. The new algorithm is used to construct monthly global maps of gas transfer velocity and to illustrate seasonal transfer velocity variations over a 1‐year period. The measurement precision estimated from >106 duplicate observations of the sea surface by TOPEX and Jason‐1 altimeters orbiting in tandem is better than 10%. The estimated overall uncertainty of the method is ±30%. The long‐term global, area‐weighted, Schmidt number corrected, mean gas transfer velocity is 13.7 ± 4.1 cm h−1. The new approach, based on surface roughness, represents a potential alternative to commonly used parameterizations based on wind speed.
Verifying Southern Hemisphere trends in atmospheric carbon dioxide stable isotopes
Authors: Allison C. E. , Francey R. J.
Published: November 2007

Stable isotopes of carbon dioxide distinguish between oceanic and terrestrial uptake of accumulating atmospheric carbon dioxide. At Cape Grim (41°S, 141°E), two Commonwealth Scientific and Industrial Research Organisation programs provide δ13C and δ18O of CO2 employing different collection, sample pretreatment, and calibration strategies that exemplify calibration problems. A comprehensive reexamination of methods results in δ13C agreement of 0.005 ± 0.004‰ through 14 overlapping years of data and suggests we have described and accounted for the main sources of bias. For δ18O, flask storage effects and early standard assignment problems contribute to larger variation and the comparable differences are 0.024 ± 0.184‰. Cape Grim records are reissued with uncertainties reflecting the histories of each method, as well as selected “best” records for δ13C from 1981, and for δ18O from 1978. The uncertainties reflect the internal consistency against an in‐house reference, of most interest in determining the limits of temporal behavior, and can be combined with a larger fixed uncertainty if a Cape Grim record is used to quantify spatial differences from sites operated by different measurement laboratories. Marked variability on seasonal and interannual timescales is observed in both isotope records. The geographical location and sampling strategy at Cape Grim ensures large‐scale (hemispheric) representativeness on interannual timescales, and we show differences from comparable records maintained by the University of Colorado (using National Oceanic and Atmospheric Administration flasks) and Scripps Institution of Oceanography. The long‐term Southern Hemisphere relationships between δ13C and CO2 are explored for the seasonal and interannual variability in the Cape Grim record. The interannual relationship is characterized by distinct periods of δ13C leveling immediately following increased global CO2 growth rate.
Characterization of the seasonal cycle of south Asian aerosols: A regional‐scale modeling analysis
Authors: Adhikary Bhupesh , Carmichael Gregory R. , Tang Youhua , Leung L. Ruby , Qian Yun , Schauer James J. , Stone Elizabeth A. , Ramanathan Veerabhadran , Ramana Muvva V.
Published: November 2007

The sulfur transport and deposition model (STEM) is used to study the aerosol seasonality, distribution, and composition over south Asia from September 2004 to August 2005. Model predictions of sulfate, black carbon, primary organic carbon, other anthropogenic particulate matter, windblown mineral dusts, and sea salt are compared at two sites in south Asia where yearlong experimental observations are available from the Atmospheric Brown Cloud (ABC) project. The model predictions are able to capture both the magnitude and seasonality of aerosols over Hanimaadhoo Observatory, Maldives. However, the model is not able to explain the seasonality at the Kathmandu Observatory; but the model does capture Kathmandu's observed annual mean concentration. The absence of seasonal brick kiln emissions within Kathmandu valley in the current inventory is a probable reason for this problem. This model study reveals high‐anthropogenic aerosol loading over the Ganges valley even in the monsoonal months, which needs to be corroborated by experimental observations. Modeling results also show a high dust loading over south Asia with a distinct seasonality. Model results of aerosol monthly composition are also presented at five cities in south Asia. Total and fine‐mode monthly aerosol optical depth along with contribution from each aerosol species is presented; the results show that the anthropogenic fraction dominates in the postmonsoon and the early dry season with major contributions from sulfate and absorbing aerosols. Model sensitivity studies of dry deposition velocity and wet scavenging efficiency show that model improvements are needed in the treatment of carbonaceous aerosol dry and wet removal processes. Modeled SO2 conversion rate constrained with sulfate observations at Hanimaadhoo suggests the need to increase model sulfate production rate during the dry season to account for probable sulfate production via heterogeneous pathways.
Nutrient (N, P) loads and yields at multiple scales and subbasin types in the Yukon River basin, Alaska
Authors: Dornblaser Mark M. , Striegl Robert G.
Published: November 2007

Loads and yields of dissolved and particulate nitrogen (N) and phosphorus (P) were measured and modeled at three locations on the Yukon River (YR) and on the Tanana and Porcupine Rivers in Alaska during 2001–2005. Total export of N and P upstream of Yukon Delta averaged 120 Gg N a−1 and 56 Gg P a−1, respectively, with 43.5% of total N (TN) as dissolved organic N, and 98% of total P (TP) as particulate phosphorus. Approximately half of the annual export of TN and TP occurred during spring. Hydrologic yields of TN (5.6–13.3 mmol N m−2 a−1) and TP (0.8–9.0 mmol P m−2 a−1) were least in the Porcupine basin and greatest in the Tanana basin and were proportional to water yield. Comparison of current and historical dissolved organic matter (DOM) export from the basin indicates decreased DON export with respect to total water discharge during summer and autumn in recent decades. Any possible climate‐related change in annual water discharge will result in proportional changes in N and P export.
ENSO and convective activities in Southeast Asia and western Pacific
Authors: Yoshida S. , Morimoto T. , Ushio T. , Kawasaki Z.
Published: November 2007

The remarkable contrasts between El Niño and La Niña in the East/Southeast Asia region and the western Pacific region are reported. One is that the lightning flash rate in the East/Southeast Asia region shows a clear inverse correlation with the Southern Oscillation Index (SOI). The lightning activity increases during the El Niño period and decrease during the La Niña period in this area. The other is that the contrast of the areal distribution of the variation of the flash rate in the western Pacific region. During the El Niño period the moist air from the ocean is warmed over the land, and that makes strong updrafts in high‐pressure systems over the oceanic area. As a result, well‐developed cumulonimbus with frequent lightning activity is observed in the coastal area. During the La Niña period, low‐pressure systems on the land cause the increase of rainfall frequency with less lightning activity.
Solar wind electric field driving of magnetospheric activity: Is it velocity or magnetic field?
Authors: Pulkkinen T. I. , Goodrich C. C. , Lyon J. G.
Published: November 2007

The Lyon‐Fedder‐Mobarry global magnetohydrodynamic simulation code is used to examine a period of steady magnetospheric convection driven by a moderately southward IMF and a steady and quite low solar wind speed. Two other runs were performed to test the effects of increasing solar wind driving: one with 50% increase in the IMF magnitude and one with 50% increase in the solar wind speed. Larger IMF magnitude leads to nightside reconnection closer to the Earth but the steady state of the magnetotail is not changed. On the other hand, higher solar wind speed enhances Earthward mass and Poynting flux transport as well as their variability. The increase in the solar wind EY is the same for both runs, but the EY in the magnetosheath is larger in the run in which the speed is enhanced, which is associated with the higher magnetotail activity in that simulation.
Phase speed spectra and the recent poleward shift of Southern Hemisphere surface westerlies
Authors: Chen Gang , Held Isaac M.
Published: November 2007

The poleward shift of the Southern Hemisphere surface westerlies in recent decades is examined in reanalysis data and in the output of coupled atmosphere‐ocean and uncoupled atmospheric models. The space‐time spectra of the eddy momentum fluxes in the upper troposphere reveal a trend that marks an increase in the eastward phase speed of the tropospheric eddies accompanied by a poleward displacement of the region of wave breaking in the subtropics. A dynamical mechanism is suggested that may help explain the connections among the lower stratospheric wind anomalies, the increased eastward propagation of tropospheric eddies and the poleward shift of the tropospheric circulation.
Quasi‐biennial modulation of the semidiurnal tide in the upper mesosphere above Halley, Antarctica
Authors: Hibbins R. E. , Espy P. J. , Jarvis M. J.
Published: November 2007

We present an analysis of a long‐term archive of horizontal wind data derived from meteor wind observations from a SuperDARN radar at Halley, Antarctica (76°S, 27°W). Systematic differences between the 12‐hour component in the meridional wind and the climatological mean are observed showing evidence of a quasi‐biennial modulation of the high‐latitude semidiurnal tide in the upper mesosphere. The amplitude of the observed tides is enhanced when the equatorial stratospheric quasi‐biennial oscillation above 10 hPa is westerly. This enhancement is greatest in the summertime tidal amplitudes when the zonal wavenumber one (S = 1) non‐migrating component dominates the semidiurnal wind field, and is coincident with an enhancement of the summertime planetary wave activity in the upper mesosphere. These observations strongly support the hypothesis that the S = 1 component of the semidiurnal tide observed at high latitudes is due to a non‐linear interaction between the migrating S = 2 semidiurnal tide and quasi‐stationary S = 1 planetary waves.
Magnetic activity in the polar caps: Relation to sudden changes in the solar wind dynamic pressure
Authors: Troshichev O. A. , Janzhura A. S. , Stauning P.
Published: November 2007

Response of the polar cap (PC) magnetic activity to sudden changes in solar wind dynamic pressure is analyzed with use of the northern and southern polar cap indices for 1998–2002 and corresponding solar wind parameters: geoeffective interplanetary electric field (Em) and the solar wind dynamic pressure (PSW), reduced to the magnetopause. Only sudden pressure pulses starting against the background of steady quiet pressure levels were taken for the analysis. To separate effects produced by Em and PSW, we examined the behavior of the average characteristics PSW, Em, and PC under the different restrictions imposed in turn on (1) electric field Em, (2) magnitude of the pressure PSW after the jump, and (3) rate of the pressure increase (dPSW/dt), the other two quantities being kept invariant in so doing. The following results have been obtained. The electric field Em determines behavior of the PC index, the value of which is directly influenced by the Em increase with a delay time of about 15–30 min. The solar wind pressure growth rate (i.e., jump power dPSW/dt) appears to be the second most important factor for the PC index increase, the pressure gradient dPSW = 1 nPa being approximately equivalent to the action of dEm = 0.33 mV/m, with a delay time shortened up to a few minutes. The growth rate of the pressure gradient seems to be the sole factor for the PC index increase under conditions of the northward interplanetary magnetic field BZ and for the PC index decrease after the dynamic pressure negative jump.
Current deformation in the northern Canadian Cordillera inferred from GPS measurements
Authors: Leonard Lucinda J. , Hyndman Roy D. , Mazzotti Stéphane , Nykolaishen Lisa , Schmidt Michael , Hippchen Sabine
Published: November 2007

Continuous and campaign‐style Global Positioning System (GPS) measurements provide new constraints on the first‐order current deformation pattern of the northern Cordillera of NW Canada and eastern Alaska. The Yakutat block is currently colliding with North America in the corner of the Gulf of Alaska. Our data infer that relative Yakutat–North America motion is accommodated across the eastern boundary by right‐lateral motion (∼40 mm/a), mainly on the Fairweather fault, and minor shortening (∼6 mm/a). To the north, collision is taken up by shortening (∼31 mm/a) mainly on the Chugach–St. Elias fault system, with westward extrusion and possible counterclockwise rotation of the Yakutat block and Alaskan fore arc facilitated by ∼23 mm/a right‐lateral motion that is shared by several faults. The seismicity pattern indicates that plate boundary deformation is far reaching, producing strain throughout eastern Alaska, Yukon, and western Northwest Territories. Our GPS data confirm the transfer of strain from the Yakutat collision zone and enable the extent of plate boundary deformation to be mapped, thereby defining the western edge of “stable” North America. GPS sites in SW Yukon show motion of 3–10 mm/a to the NE, confirming that strain is transferred at least 400 km from the Yakutat collision. Continued transfer north toward the Mackenzie Delta and NE to the Mackenzie Mountains, indicated by current seismicity, is not yet well resolved by the campaign GPS data, which are hampered by coseismic and postseismic effects of the 2002 Mw 7.9 earthquake on the Denali fault in eastern Alaska.
Aerosol single scattering albedo estimated across China from a combination of ground and satellite measurements
Authors: Lee Kwon Ho , Li Zhanqing , Wong Man Sing , Xin Jinyuan , Wang Yuesi , Hao Wei‐Min , Zhao Fengsheng
Published: November 2007

Single scattering albedo (SSA) governs the strength of aerosols in absorbing solar radiation, but few methods are available to directly measure this important quantity. There currently exist many ground‐based measurements of spectral transmittance from which aerosol optical thickness (AOT) are retrieved under clear sky conditions. Reflected radiances at the top of the atmosphere as measured by a spaceborne spectroradiometer are sensitive to both AOT and SSA. On the basis of extensive radiative transfer simulations, it is demonstrated that the combined use of the two measurements allows for the retrieval of SSA at a reasonable accuracy under moderate to heavy aerosol loadings. Retrieval of SSA is most sensitive to AOT and surface reflectance. The accuracy of SSA retrievals increases with aerosol loading. The uncertainties in SSA retrievals are 0.02 ∼ 0.03 for AOT = 1.0 and 0.03 ∼ 0.05 for AOT = 0.5 at 0.47μm. The proposed retrieval method is applied to 1 a worth of Moderate Resolution Imaging Spectroradiometer (MODIS) Level‐1 calibrated reflected radiances matched with surface spectral transmittances acquired at 24 stations of the Chinese Sun Hazemeter Network established under the auspices of the East Asian Study of Tropospheric Aerosols: An International Regional Experiment (EAST‐AIRE). Measurements made under high‐turbidity conditions (AOT > 0.4) were used. All the stations are located in relatively remote and thus spatially representative locations. From the retrieved values, the first gross map of SSA across China is generated. The retrieved SSA values were compared with those retrieved independently from AERONET sites in China. The root‐mean‐square deviation (RMSD) is on the order of 0.03, and the mean difference is ∼0.02. The nationwide means of AOT, Ångström exponent, and SSA (at 0.5μm) in 2005 are 0.69 ± 0.17, 1.06 ± 0.26, and 0.89 ± 0.04, respectively.
Large‐time behavior of macrodispersion in heterogeneous trending aquifers
Authors: Chang Ching‐Min , Yeh Hund‐Der
Published: November 2007

This paper presents a stochastic analysis of the large‐time behavior of macrodispersion in a three‐dimensional heterogeneous aquifer with a linear trend in the mean log hydraulic conductivity. To solve the problem analytically, focus is placed on the particular case where the linear trend is aligned in the direction of mean hydraulic head gradient. A spectral approach based on Fourier‐Stieltjes representations for the perturbed quantities is used to develop closed‐form expressions that describe variability of flow velocity, the second‐order mean flow, and asymptotic macrodispersion. The impact of the mean log hydraulic conductivity gradient on these results is examined. It is found that the asymptotic longitudinal and transverse macrodispersion coefficients decrease with the increasing trend gradient of mean log hydraulic conductivity in the case of finite Peclet numbers. This feature is a consequence of the reduction in variability of flow velocity with the trend gradient.
Src kinase modulates the activation, transport and signalling dynamics of fibroblast growth factor receptors
Authors: Sandilands Emma , Akbarzadeh Shiva , Vecchione Anna , McEwan David G , Frame Margaret C , Heath John K
Published: November 2007

The non‐receptor tyrosine kinase Src is recruited to activated fibroblast growth factor receptor (FGFR) complexes through the adaptor protein factor receptor substrate 2 (FRS2). Here, we show that Src kinase activity has a crucial role in the regulation of FGFR1 signalling dynamics. Following receptor activation by ligand binding, activated Src is colocalized with activated FGFR1 at the plasma membrane. This localization requires both active Src and FGFR1 kinases, which are inter‐dependent. Internalization of activated FGFR1 is associated with release from complexes containing activated Src. Src‐mediated transport and subsequent activation of FGFR1 require both RhoB endosomes and an intact actin cytoskeleton. Chemical and genetic inhibition studies showed strikingly different requirements for Src family kinases in FGFR1‐mediated signalling; activation of the phosphoinositide‐3 kinase–Akt pathway is severely attenuated, whereas activation of the extracellular signal‐regulated kinase pathway is delayed in its initial phase and fails to attenuate.
A conserved Toll‐like receptor is required for Caenorhabditis elegans innate immunity
Authors: Tenor Jennifer L , Aballay Alejandro
Published: November 2007

Pathogen recognition through Toll‐like receptors (TLRs) is crucial in order to mount an appropriate immune response against microorganisms. On the basis of a lack of evidence indicating that Caenorhabditis elegans uses TLRs to elicit an immune response and on the absence of genes encoding Rel‐like transcription factors in its genome, it is believed that TLR‐mediated immunity arose after coelomates split from pseudocoelomates and acoelomates. Here, we show that C. elegans tol‐1(nr2033) mutants are killed by the human pathogen Salmonella enterica, which causes a significant pharyngeal invasion in the absence of TOL‐1‐mediated immunity. We also show that TOL‐1 is required for the correct expression of ABF‐2, which is a defensin‐like molecule expressed in the pharynx, and heat‐shock protein 16.41, which is also expressed in the pharynx and is part of a HSP family of proteins required for C. elegans immunity. The results indicate that TOL‐1 has a direct role in defence response to certain Gram‐negative bacteria and indicate that part of the TLR‐mediated immunity might be evolutionarily conserved.
Immobilization of pigeonpea (Cajanus cajan) urease on DEAE‐cellulose paper strips for urea estimation
Authors: Reddy K. Ravi Charan , Srivastava Punit K. , Dey Prakash M. , Kayastha Arvind M.
Published: November 2007

Pigeonpea (Cajanus cajan) urease was immobilized on 1 cm×1 cm DEAE‐cellulose paper strips. The optimum immobilization (51% activity) was observed at 4 °C, with a protein concentration of 1.0 mg/strip. The apparent optimum pH shifted from 7.3 to 6.8. Immobilized urease showed an optimal stability temperature of 67 °C, compared with 47 °C for the soluble urease. Time‐dependent kinetics of the thermal inactivation of the immobilized urease were examined and found to be monophasic as compared with the soluble enzyme, which was biphasic. The Michaelis constant (Km) for the DEAE‐cellulose‐immobilized urease was found to be 4.75 mM, 1.5 times higher than the soluble enzyme. Immobilized strips stored at 4 °C showed an increased half‐life (t1/2=150 days). There was practically no leaching of the enzyme from the immobilized strips over a period of 2 weeks. These strips were used for estimating the urea content of blood samples; the results obtained matched well with those obtained in a clinical laboratory through an Autoanalyzer® (Zydus Co., Rome, Italy). The easy availability of pigeonpea urease, the ease of its immobilization on DEAE‐cellulose strips and the significantly lower cost of urease described in the present study makes it a suitable product for future applications in diagnostics.
Purification of goat immunoglobulin G by immobilized metal‐ion affinity using cross‐linked alginate beads
Authors: Jain Sulakshana , Gupta Munishwar N.
Published: November 2007

The alginate beads obtained by cross‐linking of the polymer by epichlorohydrin were charged with Cu(II). The copper‐charged beads could be directly used as a immobilized‐metal‐affinity‐chromatographic medium for purification of goat IgG. The best results in the packed‐bed mode were obtained by using beads charged with 95.4 μmol/ml Cu(II). We found that we could recover 97.4% IgG with an 8‐fold purification.
A convenient method for the identification and expression of eukaryotic genes
Authors: Hu Rongliang , Zhang Shoufeng , Xu Qing , Tu Changchun
Published: November 2007

In order to identify whether the product of a genetically modified or newly isolated eukaryotic gene has biological activity, the gene of interest is usually subcloned into a mammalian expression vector and then expressed in anin vitrosystem such as in tissue culture. In the present study an efficientin vivosystem has been developed by employing a mammary‐gland‐specific vector and expressing the targeted protein in the lactating‐goat mammary glands. In this system, the synthesized lumbrokinase cDNA variant (LK‐m) and the tissue‐type plasminogen activator (tPA) cDNA were selected as genes of interest and cloned downstream of the goat β‐casein regulatory sequence. The LK‐m‐ and tPA‐expressing plasmids were prepared to high purity and portions (100–800 μg) injected into lactating‐goat mammary‐gland tissues. High‐level expression of the LK‐m and tPA was detected, by a fibrin–agarose plate assay, as fibrin‐lysis activity. A dynamic study showed that the specific expression starts immediately after injection, generally reaches peak in 6–9 h, persists for 20–24 h at peak and the expression lasts for 4 days with gradual decline in the amounts expressed. The potential use of this system as bioreactor for the production of biological proteins in place of transgenic animals is implicated from this study.
Tissue‐engineered skin substitutes: from in vitro constructs to in vivo applications
Authors: Auger François A. , Berthod François , Moulin Véronique , Pouliot Roxane , Germain Lucie
Published: November 2007

The field of skin tissue engineering is a paradigm for the various efforts towards the reconstruction of other tissues and organ substitutes. As skin replacement, this biotechnological approach has evolved from simple cultured autologous epidermal sheets to more complex bilayered cutaneous substitutes. The various types of such substitutes are herein presented with their intended use. However, two integrative characteristics are analysed more specifically because of their critical role: neovascularization and re‐innervation. Furthermore, the in vitro use of these various skin substitutes has shed light on various physiological and pathological phenomena. Thus, not only the in vivo application of these skin substitutes as grafts, but also their in vitro value as skin models, are presented.
Two mathematical models for the correction of carbohydrate and protein interference in the determination of uronic acids by them‐hydroxydiphenyl method
Authors: Murado Miguel Anxo , Vázquez José Antonio , Montemayor María Ignacia , Cabo Marta López , González María del Pilar
Published: November 2007

The most common method in the routine determination of uronic acids, them‐hydroxydiphenyl reaction, recently adapted to rapid microplate analysis, has as a main inconvenience, in any one of their modalities, interferences due to the frequent presence of proteins and neutral carbohydrates in the samples. Corresponding corrections in the literature are unsatisfactory when applied to complex matrices, and further adaptation to the microplate analysis is not free from additional problems. With particular reference to hyaluronic acid, the interactions between the principal reactants and the interfering materials are studied kinetically under realistic conditions, and simple mathematical models are proposed which satisfactorily describe the experimental results and allow adequate corrections to be made.