bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of spray application of urea fertilizer at stem extension on winter wheat: N recovery and nitrate leaching
Authors: READMAN R. J. , BECKWITH C. P. , KETTLEWELL P. S.
Published: October 2002

A field experiment was carried out at Harper Adams in Shropshire to investigate the effect of supplying the spring N application to winter wheat as different proportions of urea as a solution, rather than as conventional soil-applied solid urea, on N recovery in the above-ground crop, autumn soil mineral N and nitrate leaching over the subsequent winter. A solid ammonium nitrate treatment was also included to represent alternative commercial practice to solid urea. Treatments were repeated on the same plots over the 3 years 1992, 1993 and 1994. N recovery was measured in all 3 years by difference in N uptake between fertilized and unfertilized plots, and in 1993 for selected treatments, N was applied as 15N-labelled fertilizer to determine direct uptake of fertilizer N in the crop and soil. Both urea sprays and solid soil N applications were labelled with 15N. Urea sprays were split over several days to reduce scorch, whereas solid fertilizer was applied as a single dressing. For some urea spray treatments, apparent N recovery in the above-ground crop in 1992 and 1994 was less compared with soil-applied N treatments. These urea spray treatments were applied in the morning rather than the evening, and gaseous losses, most likely by volatilization, are suggested. In 1992 application of a large proportion of N as urea sprays, such that application of some N as urea solution was delayed to around GS 37, was associated with an increase in physiological N use efficiency. In 1993, there was no difference in direct or apparent recovery of fertilizer N in the crop or soil for N applied as ammonium nitrate, solid urea or as urea sprays. Mean nitrate concentration in the drainage water at 1 m was elevated for all N treatments in all years, but only in 1992 did nitrate concentration and leaching loss decrease with increasing proportion of N applied as urea sprays. It may therefore be possible to reduce gaseous losses by application of urea sprays under cool conditions in the evening and exploit the increased physiological N use efficiency for urea sprays applied later, such that total fertilizer N applied and N losses are reduced.
Sugar metabolism in expanding husk leaves of flint corn (Zea mays L.) genotypes differing in husk leaf size
Authors: FUJIKAWA Y. , SAKURAI N. , SENDO S. , OKA T. , YAMANA H. , OFOSU-BUDU K. G. , EL-SHEMY H. , FUJITA K.
Published: October 2002

Relationships between leaf expansion and MeOH-soluble (cytosol) and cell-wall fractions, and their sugar composition prior to silking in flint corn lines were studied. A greater husk leaf area of one genotype, X-15 is mainly due to prolonged and higher rate of expansion. Prior to rapid expansion of husk leaf area, neutral sugars in the cytosol fraction accounted for most of the non-starch carbohydrates (56–62%), while hemicellulose and cellulose fractions accounted for less than 20%. In mature leaf parts, however, sugars in the cytosol fraction decreased but those in hemicellulose and cellulose fractions increased by 30% and 42%, respectively. The predominant sugar in the cytosol fraction was glucose (Glc), while in the hemicellulose fraction xylose (Xyl) and arabinose (Ara) dominated. During rapid expansion of husk leaves, 13C was incorporated at a higher rate into hemicellulose than cellulose, and this process was more active in X-15 than in other genotypes. During an identical period, 13C atom % excess in Xyl increased markedly in the hemicellulose fraction, however it remained low in the cytosol one. The current results suggest that synthesis of Xyl and xylan plays an important role in renewal of hemicellulose, which may be required for expansion.
On the breaking of internal solitary waves
at a ridge
Authors: SVEEN J. KRISTIAN , GUO YAKUN , DAVIES PETER A. , GRUE JOHN
Published: October 2002

An experimental laboratory study has been carried out to investigate the propagation
of an internal solitary wave of depression and its distortion by a bottom ridge in a
two-layer stratified fluid system. Wave profiles, density fields and velocity fields have
been measured at three reference locations, namely upstream, downstream and over
the ridge. Experiments have been performed with wave amplitudes in the range 0.2–
1.9 times the depth of the upper layer, and a ratio between the lower and the upper
layer in the range 3.0–8.5. The ridge slope was varied from 0.1 to 0.33 and the
maximum ridge height was two-thirds of the thicker fluid layer. Over the ridge, the
flow has been classified into: (i) cases when the bottom ridge has little influence on
the propagation and spatial structure of the internal solitary wave, (ii) cases where
the internal solitary wave is significantly distorted by the blocking effect of the ridge
(though no wave breaking occurs), and (iii) cases for which the internal solitary wave
is broken as it encounters and passes over the bottom ridge. A detailed description
of the processes leading to wave breaking is given. Breaking has been found to take
place when the fluid velocity in the lower layer exceeds 0.7 of a local nonlinear
wave speed, defined at the top of the ridge. The breaking condition is also expressed
in terms of the amplitude of the incident wave, the layer thickness ratio and the
relative height of the ridge. The wave breaking can be determined from the input
parameters of the experiment. The transmitted waves have been found to always
consist of a leading pulse (solitary wave) followed by a dispersive wavetrain. The
(solitary) wave amplitude is significantly reduced only when breaking takes place at
the ridge. Internal waves of mode two are generated in cases with strong breaking.
Rayleigh–Bénard instability in a vertical cylinder
with a vertical magnetic field
Authors: HOUCHENS B. C. , WITKOWSKI L. MARTIN , WALKER J. S.
Published: October 2002

This paper presents two linear stability analyses for an electrically conducting liquid
contained in a vertical cylinder with a thermally insulated vertical wall and with
isothermal top and bottom walls. There is a steady uniform vertical magnetic field.
The first linear stability analysis involves a hybrid approach which combines an
analytical solution for the Hartmann layers adjacent to the top and bottom walls
with a numerical solution for the rest of the liquid domain. The second linear stability
analysis involves an asymptotic solution for large values of the Hartmann number.
Numerically accurate predictions of the critical Rayleigh number can be obtained for
Hartmann numbers from zero to infinity with the two solutions presented here and
a previous numerical solution which gives accurate results for small values of the
Hartmann number.
Free-surface turbulent wake behind towed ship
models: experimental measurements, stability
analyses and direct numerical simulations
Authors: SHEN LIAN , ZHANG CHIONG , YUE DICK K. P.
Published: October 2002

We combine experimental, theoretical and numerical efforts to investigate the turbulent wake far behind a surface ship at model scales. Experimental measurements using
digital particle image velocimetry (DPIV) are performed for the wakes of three towed
hulls with beam-to-draught ratios b/d = 1, 2, 6. Based on model speed and beam, the
Reynolds and Froude numbers are O(103) and O(10−2) respectively. Distinct surface
features associated with persistent surface-normal vorticity have been identified, which
are characterized by large-scale meandering structures. Both lateral and longitudinal
scales of the meandering are quantified, with the former found to increase as b/d
decreases and the latter independent of b/d. Based on measurements at multiple horizontal and vertical planes, profiles of the mean flow and fluctuation intensity for each
velocity component are obtained. To understand the turbulence transition mechanism, an Orr–Sommerfeld stability analysis (OS) is formulated for the wake flow with
free-surface boundary conditions, and solved by using a fourth-order finite-difference
scheme. Unstable modes antisymmetric to the wake centre-plane are identified. Consistent with the experimental results, the growth rates of unstable modes increase
substantially as b/d decreases, while the dependence of meandering wavelengths on
b/d is found to be weak. Finally, we perform direct numerical simulation (DNS)
of Navier–Stokes equations for the wake flow. The growth rates of unstable modes
agree well with the predictions by OS analysis. Compared with experiments, DNS
accurately captures the surface-normal vorticity signatures, the meandering features,
as well as statistics of turbulence intensity. We also obtain from DNS a detailed
description of enstrophy, turbulence length scales, and vortex structures for the wake
flow.
On the viscous motion of a small particle in
a rotating cylinder
Authors: COIMBRA CARLOS F. M. , KOBAYASHI MARCELO H.
Published: October 2002

The dynamics of a non-neutrally buoyant particle moving in a rotating cylinder filled
with a Newtonian fluid is examined analytically. The particle is set in motion from the
centre of the cylinder due to the acceleration caused by the presence of a gravitational
field. The problem is formulated in Cartesian coordinates and a relevant fractional
Lagrangian equation is proposed. This equation is solved exactly by recognizing that
the eigenfunctions of the problem are Mittag–Leffler functions. Virtual mass, gravity,
pressure, and steady and history drag effects at low particle Reynolds numbers are
considered and the balance of forces acting on the particle is studied for realistic
cases. The presence of lift forces, both steady and unsteady, is taken into account.
Results are compared to the exact solution of the Maxey–Riley equation for the
same conditions. Substantial differences are found by including lift in the formulation
when departing from the infinitesimal particle Reynolds number limit. For particles
lighter than the fluid, an asymptotically stable equilibrium position is found to be at
a distance from the origin characterized by X ≈ −Vτ/Ω and Y/X ≈ (CS/3π√2) Res1/2,
where Vτ is the terminal velocity of the particle, Ω is the positive angular velocity of the cylinder, Res is the shear Reynolds number a2Ω/v, and CS is a constant lift
coefficient. To the knowledge of the authors this work is the first to solve the particle
Lagrangian equation of motion in its complete form, with or without lift, for a
non-uniform flow using an exact method.
Measurement of particle accelerations in fully
developed turbulence
Authors: VOTH GREG A. , LA PORTA A. , CRAWFORD ALICE M. , ALEXANDER JIM , BODENSCHATZ EBERHARD
Published: October 2002

We use silicon strip detectors (originally developed for the CLEO III high-energy
particle physics experiment) to measure fluid particle trajectories in turbulence with
temporal resolution of up to 70000 frames per second. This high frame rate allows the Kolmogorov time scale of a turbulent water flow to be fully resolved for
140 [ges ] Rλ [ges ] 970. Particle trajectories exhibiting accelerations up to 16000 m s
−2 (40
times the r.m.s. value) are routinely observed. The probability density function of
the acceleration is found to have Reynolds-number-dependent stretched exponential
tails. The moments of the acceleration distribution are calculated. The scaling of the
acceleration component variance with the energy dissipation is found to be consistent
with the results for low-Reynolds-number direct numerical simulations, and with the
K41-based Heisenberg–Yaglom prediction for Rλ [ges ] 500. The acceleration flatness is
found to increase with Reynolds number, and to exceed 60 at Rλ = 970. The coupling
of the acceleration to the large-scale anisotropy is found to be large at low Reynolds
number and to decrease as the Reynolds number increases, but to persist at all
Reynolds numbers measured. The dependence of the acceleration variance on the
size and density of the tracer particles is measured. The autocorrelation function of
an acceleration component is measured, and is found to scale with the Kolmogorov
time τη.
The merger of vertically offset
quasi-geostrophic vortices
Authors: REINAUD J. N. , DRITSCHEL D. G.
Published: October 2002

We examine the critical merging distance between two equal-volume, equal-potential-
vorticity quasi-geostrophic vortices. We focus on how this distance depends on the
vertical offset between the two vortices, each having a unit mean height-to-width
aspect ratio. The vertical direction is special in the quasi-geostrophic model (used to
capture the leading-order dynamical features of stably stratified and rapidly rotating
geophysical flows) since vertical advection is absent. Nevertheless vortex merger may
still occur by horizontal advection.

In this paper, we first investigate the equilibrium states for the two vortices as a
function of their vertical and horizontal separation. We examine their basic properties
together with their linear stability. These findings are next compared to numerical
simulations of the nonlinear evolution of two spheres of potential vorticity. Three
different regimes of interaction are identified, depending on the vertical offset. For
a small offset, the interaction differs little from the case when the two vortices are
horizontally aligned. On the other hand, when the vertical offset is comparable to
the mean vortex radius, strong interaction occurs for greater horizontal gaps than
in the horizontally aligned case, and therefore at significantly greater full separation
distances. This perhaps surprising result is consistent with the linear stability analysis
and appears to be a consequence of the anisotropy of the quasi-geostrophic equations.
Finally, for large vertical offsets, vortex merger results in the formation of a metastable tilted dumbbell vortex.
The effects of a soluble surfactant
on the interfacial dynamics of stationary bubbles
in inclined tubes
Authors: CAVANAGH DANIEL P. , ECKMANN DAVID M.
Published: October 2002

We have experimentally examined the effects of a common soluble surfactant on gas
bubbles in liquid flows in inclined tubes. Air bubbles of known size (λ = 0.8, 1.0, 1.5)
are held stationary under minimum flow conditions in tubes inclined at fixed angles
(ω = 25°, 45°, 65°, 90°). Sodium dodecyl sulphate (SDS) is infused into the bulk flow
at two bulk concentrations (C = 10% or 100% critical micelle concentration (CMC)).
In addition to recording pressure and flow waveforms, we capture video images of
bubbles before and during exposure to the surfactant. Modification of the interfacial
properties by the surfactant results in extremely dynamic bubble behaviour including
interfacial deformation, deformation plus axial translation, and bubble detachment
from the wall plus translation. We measure the corresponding time-dependent pressure
gradient within the tube. The surfactant mediated responses observed are dependent
upon the interrelated effects of C, λ and ω. A high bulk concentration of surfactant
may produce more rapid modification of bubble shape and influence wetting, thus
increasing the potential for bubble detachment. The likelihood that detachment will
occur increases further as bubble volume in increased. In both vertical tubes in which
contact forces are absent and in non-vertical tubes, the infusion of surfactant may
result in axial translation either in the direction of, or opposite to, the direction of
the bulk flow. Critical to the translation and/or detachment of the bubble is the
surfactant-mediated modification of contact line mechanics. Contact line velocities
corresponding to rates of shrinkage of dewetted surface area are extracted from
experimental data. We also explore the potential effects of surfactants on interfacial
remobilization. This investigation demonstrates the potential use of surfactants to
be used for dislodging dewetted gas bubbles by the intentional manipulation of
interfacial properties.
A local nonlinear solution as an approximation
to low-frequency spanwise jitter in
thermoconvective flows
Authors: GRASSIA P. , RICHARDSON D.
Published: October 2002

A shallow fluid-filled cavity with a longitudinal applied temperature gradient is
subjected to spanwise accelerations (g-jitter) representing the space-based microgravity
environment. A simplified slot model is introduced to describe the buoyancy-driven
flow and advected temperature fields produced in the cavity. Numerical solutions
indicate that boundary layer behaviour can manifest itself in the limit of strong
g-jitter (large Rayleigh number Ra). However, boundary layer thicknesses do not
obey the conventional Ra−1/4
scaling that typically arises in free thermal convection
problems. This anomalous scaling results from the three-dimensional complexity of
the flow and advected temperature fields, which are not themselves produced by a
single fixed applied temperature change. Three different regimes are identified at large
Rayleigh number characterized by the shapes of the advected temperature profiles.
These regimes are selected according to the values of the Biot number Bi and an
aspect ratio parameter. Simple models are presented of the boundary layer behaviour
which reproduce, in each regime, the numerically predicted scalings for boundary layer
thickness and advected temperature. These models give a succinct overall picture of
the slot behaviour in the buoyancy-dominated limit.
Spatial distribution of a deep‐sea crinoid Pentametrocrinus tuberculatus in the Izu‐Ogasawara Arc, western Pacific
Authors: Tokeshi M.
Published: October 2002

Spatial distribution of a deep‐sea crinoid Pentametrocrinus tuberculatus was investigated in the Izu‐Ogasawara Arc, western Pacific. Photographic and video recordings coupled with direct visual observations were conducted from the manned submersible Shinkai 2000 between the depths of 1340 and 1840 m on the south‐western slope of the An'ei Seamount (29° 15′N, 138° 37′E). Close to the seabed, temperature, salinity and dissolved oxygen concentration were in the range of 2.2–3.1 °C, 34.38–34.52 and 1.40–2.15 ml l−1, respectively, and the bottom substratum consisted mainly of flat‐surfaced lava rocks covered by thin manganese oxide crusts. Pentametrocrinus tuberculatus individuals were attached to the surface of lava rocks with their five arms extended horizontally and showed no recognizable movement. Incidence of arm loss (which may indicate mechanical damage or predation pressure) was very low. The highest density of P. tuberculatus occurred in an area termed ‘terrace’ where the slope was reduced above a relatively steep hillside. Analysis of nearest neighbour distances showed that P. tuberculatus individuals generally demonstrate regular spacing with either no or partial overlap of their ambits (= circular area defined by the extended arms), due to a combination of aggregative tendency (to form patches) and behavioural spacing among individuals within a patch. The observed pattern of distribution was clearly different from the pattern expected from random occurrence of individuals in space. Thus, on spatial scales of 101 to 103 m, P. tuberculatus showed a contagious or aggregated distribution, while on smaller scales and in areas where crinoids were concentrated they showed a combination of patch formation and regular distribution of individuals.
Biased geographical distribution of mitochondrial DNA that passed the species barrier from mountain hares to brown hares (genusLepus): an effect of genetic incompatibility and mating behaviour?
Authors: Thulin Carl‐Gustaf , Tegelström Håkan
Published: October 2002

Through interspecific hybridization and subsequent backcrossing, genes and genomes may be transferred over the species barrier. In Sweden, the introduced brown hareLepus europaeushybridizes with the native mountain hareL. timidus. To investigate the direction and the extent of transfer of mitochondrial DNA (mtDNA) between the species, the mtDNA haplotypes were screened in 522 brown hares and 149 mountain hares from areas of sympatry and allopatry. A total of 51 brown hares with mountain hare mtDNA, but no mountain hares with brown hare mtDNA were detected. Thus, mtDNA transfer over the species barrier is directed from mountain hares to brown hares. We argue that frequency‐dependent hybridization and/or interspecific male competition mediates this directionality. Further, the percentage of brown hares with transmitted mountain hare mtDNA was lower in areas of former species sympatry (0.6%) compared to areas of current sympatry (15%). Thus, the transferred mtDNA may disappear from brown hare populations if there is no continuous input through hybridization. We suggest that specimens with an alien mtDNA experience a fitness reduction as a result of a functional incompatibility between the cytoplasmic mitochondrial genomes and the cell nucleus.
Extraordinary life spans of naked mole‐rats (Heterocephalus glaber)
Authors: Sherman Paul W. , Jarvis Jennifer U. M.
Published: October 2002

Senescence is the internal physiological deterioration that accompanies advancing age. Evolutionary hypotheses predict that rates of senescence should vary directly with extrinsic mortality and inversely with fecundity. If so, naked mole‐rats (Heterocephalus glaber) should live a long time (senesce slowly) because in nature they inhabit heavily protected burrows, and large, old breeding females make disproportionate reproductive contributions. In addition H. glaber has an exceptionally low metabolic rate, which may reduce oxidative stress. We have maintained naked mole‐rats in captivity since 1974. Here we report that individuals can live a very long time: many are alive after more than 20 years and some are 26 years old (and counting). Although we do not yet know how long naked mole‐rats can live, they already are older than the maximum longevity of all but one of 156 rodent species that have been maintained in captivity from birth to death.
Short‐term movements and habitat use of the marsupial honey possum (Tarsipes rostratus)
Authors: Bradshaw S. D. , Bradshaw F. J.
Published: October 2002

Miniature radio‐transmitters were used to follow movements over a 10‐day period of the 10 g honey possum Tarsipes rostratus, and the areas covered were compared with home‐range estimates calculated from long‐term mark‐and‐recapture records using pitfall traps. The study was carried out in the Scott National Park, in the extreme south‐west of Western Australia, and shows that honey possums may move far greater distances than is apparent from trapping records. The overall mean area used determined by radio‐tracking was significantly larger at 0.54±0.19 ha than the apparent home range of 0.03 0.01 ha determined by trapping. The area used by males was significantly greater than that of females when measured by radio‐telemetry (0.79±0.24 ha vs 0.14±0.08 ha, P= 0.058), but did not differ significantly when estimated from trapping records (0.03±0.01 ha vs 0.01±0.01 ha). These data suggest that honey possums frequent plant assemblages at night where they are vulnerable to pitfall trapping, but that males, particularly, spend the day in other areas that may be as far as 200 m distant.
Seasonal and spatial variation in the diet of the wild rabbit (Oryctolagus cuniculus L.) in Portugal
Authors: Martins H. , Milne J. A. , Rego F.
Published: October 2002

The seasonal and spatial pattern of diet composition of a population of wild rabbits Oryctolagus cuniculus L. occupying a southern Portuguese montado was estimated using the n‐alkane technique. The diet was analysed in terms of components that are relevant to habitat management. The dietary categories considered were gum cistus leaves and flowers, cork oak and holm oak seedlings and acorns, cereals, olive tree regrowth and grass‐forb species. The objectives were to assess the changes in diet across seasons in relation to the reproductive cycle of the rabbits, and to relate these changes to herbaceous biomass availability and to habitat structure, in terms of density of scrub cover and accessibility to arable crops. The results demonstrated that the diet was dominated by grass‐forbs, and cereals when they were available. Browse was an important component of the diet and became more important in a year of low herbaceous biomass availability and in areas dominated by dense scrub. A similar phenomenon was observed in relation to consumption of acorns in winter. Seasonal and spatial variation in diet composition suggested a strategy aimed at maintaining a high quality diet. This was supported by the observed high dry matter digestibility of the diet during most of the year. The relevance of growing arable crops and providing fodder, as a means of increasing the carrying capacity of montados for rabbits and protecting the natural regeneration of trees, is discussed.
Shamanism and Cognitive Evolution (with comments)
Authors: Winkelman Michael
Published: October 2002

Shamanic referents in Upper Palaeolithic cave art indicate its pivotal role in the Middle–Upper Palaeolithic transition. Etic models of shamanism derived from cross-cultural research help articulate the shamanic paradigm in cave art and explicate the role of shamanism in this transition. Shamanism is found cross-culturally in hunter-gatherer societies, constituting an ecological and psychosociobiological adaptation that reflects the ritual and cosmology of early modern humans. Shamanism played a role in cognitive and social evolution through production of analogical thought processes, visual symbolism and group-bonding rituals. Universals of shamanism are derived from innate modules, particularly the hominid ‘mimetic controller’ and music and dance. These induced altered states of consciousness, which produce physiological, cognitive, personal and social integration through integrative brain-processing. Shamanic altered states of consciousness have the cross-modal integration characteristic of the emergent features of Palaeolithic thought and facilitated adaptations to the ecological and social changes of the Upper Palaeolithic. Cross-modular integration of innate modules for inferring mental states (mind), and social relations (self/others), and understanding the natural world (classificatory schemas) produced the fundamental forms of trope (metaphor) that underlay analogical representation. These integrations also explain animism (mental and social modules applied to natural domains); totemism (natural module applied to social domain); and guardian spirit relations (natural module applied to self and mental domains).
Places Apart? Caves and Monuments in Neolithic and Earlier Bronze Age Britain
Authors: Barnatt John , Edmonds Mark
Published: October 2002

The recent growth of landscape perspectives has stimulated fresh approaches to the ways in which prehistoric communities attached significance to what we classify as topography or geology. Using evidence from North Wales and the Derbyshire Peak District, we argue here that the use of caves during the Neolithic and Bronze Age reflects a significant blurring of the distinction that archaeologists often draw between monuments and natural features.
Wren and the development of structural carpentry 1660–1710
Authors: Campbell James W. P.
Published: October 2002

The late seventeenth century saw massive shifts in construction
techniques and practice. This was particularly true in structural
carpentry and owed much to the innovations of a single architect.

Sir Christopher Wren occupies a central place in
English architectural history. Yet he was also a
mathematician and it is reasonable to assume
that he took more than a passing interest in the
structural aspects of his buildings. Starting from the
work of David Yeomans (1992 et al), this article
considers his involvement in one particular craft,
carpentry. By returning to the original documents
and from careful measurement and recording of the
surviving works and other buildings of the time, it
reveals that his office had a far greater influence
than hitherto supposed.
Measure, metre, irony: reuniting pure mathematics with architecture
Authors: Tavernor Robert
Published: October 2002

The human body once provided the fundamental measurements
by which to gauge human creations – but the metric system offers
‘mere number without concrete being’. A synthesis is needed.

Measure: mens (L – mind), mensurare = measuring/measure

Metre: metron (Gk), metrum (L – measuring rod), mètre (Fr) = metre

Irony: eironeia (Gk – simulated ignorance), eiron – dissembler and simulator of power = irony

No civilization has existed without measures, and
each has described measures in a manner specific to
its needs. To exist at all, measures must be practical
and useful, and most have their origins in everyday
experience. At some stage in the development of a
civilized society measures will be refined,
standardized and regulated and represented
physically. To endure and be accepted by hundreds,
thousands, even millions of people – across great
civilizations and around the globe – measures must
reflect and extend the authority of leaders. Measure
is therefore a statement and record of the changing
balance of power and independence. It is an
expression of culture.
(Against) Continental Drift
Authors: Sharif Mohamed
Published: October 2002

Peter Wilson's early interests in
figuration, metaphor and narrative
in architecture are most clearly
illustrated in sites selected for his
unit projects and competition
entries completed while at the
Architectural Association in the
1970s and '80s. Whether outwith or
within cities, Wilson's concerns
revolved primarily around the
orchestration of a collection of
expressive objects, on various
tableaux themselves embodying, a
priori, charged and original
poetics. These preoccupations have
largely extended to and variously
informed the work of
Arkitekturbüro Bolles+Wilson, the
Münster based practice started in
1987 by Wilson and his partner
Julia Bolles.
Spens on Stirling – too loyal
Authors: Muirhead Thomas
Published: October 2002

Until about 1974 , James Stirling's
work subverted and redefined the
Modernist canon. Michael Spens is
deeply sympathetic to Stirling and
brilliantly analyzes some of the
authentic masterpieces from that
time, particularly Olivetti
Haslemere and the St Andrews
residential accommodation (arq
5/4 ,pp 333–353). Accurately, he
identifies the unbuilt St Andrews
Arts Centre (1974) as the point
where things began to change.
After that, influenced by Werner
Kreis, Léon Krier and others (and of
course Colin Rowe), Stirling began
to explore an exciting amalgam of
the abstract and the figurative,
marrying his previously
intransigent Modernism to a
representational Neo-Classical idiom.
More thoughts on St Mary's Island
Authors: Levitt David
Published: October 2002

It is good to see innovations in
housing design being applied to
the private sector; the ultimate test
of any new idea is that someone
should want to invest in it. All too
often in the past any
experimentation in housing design
was mainly confined to the public
sector. Lack of ‘market testing’ was
one of the main reasons why brave
experiments sometimes went
horribly wrong. All through those
years of experimentation, between
say 1955 and 1975, with the
exception of Eric Lyons' Span
housing, architects found fertile
ground in public sector – local
authority – commissions. It is only
now, with loads of government
encouragement, that major
developers are beginning to
sponsor new ideas in design, in
higher density, ‘joined up’ housing.
… mute on areas of design …
Authors: Coyne Richard
Published: October 2002

Terry Knight and George Stiny's
paper on classical and non-classical
computation (arq 5/4, pp 355–372)
reminds us that shape grammars
have been around for 25 years. Both
Knight and Stiny are to be
congratulated on developing and
sustaining the research paradigm
to the quarter century mark.
Computing about shapes has
certainly been influential among
those who think that theories of
design and theories of
computation have something to
offer each other, or may in fact be
the same thing.
… a useful road map …
Authors: Yakeley Megan
Published: October 2002

It is a great pleasure to see in print
this paper by Knight and Stiny (arq
5/4, pp 355–372), who have been
collaborating for many years, Stiny
predominantly as a theoretician,
and Knight as a design teacher.
Despite their close association, they
have rarely published together, and
it was something of a landmark
when they gave a joint keynote
speech, received with great
warmth, to the conference in
Greenwich in January 2000. The
field in which they engage has
grown rapidly, and few can be
better placed to review its
achievements, and establish a basic
taxonomy to classify existing work,
and map areas for further research.
… part of which deserves a closer look
Authors: Chase Scott C.
Published: October 2002

It is refreshing to see yet another
take on shape grammars and their
representations from Knight and
Stiny (arq 5/4, pp 355–372), in
particular, the distinction made
between process and
representation, thus facilitating
further categorization of a variety
of generative design paradigms.
The term ‘shape grammar’ as used
here refers to very specific
representations of shape and
computational processes and is
often misused. A brief web search
turns up many references to shape
grammars. Some are unrelated to
the work described here; others
reference the shape grammarians
but describe paradigms which are
either not grammars or utilize
different representations of shape.
The global-to-basic level shift in infants’ categorical thinking: First evidence from a longitudinal study
Authors: Pauen Sabina
Published: October 2002

This paper investigates whether preverbal children form categories at different levels of abstraction in any specific sequence. In a longitudinal study, 20 infants were each tested twice, at 8 and 12 months of age. Half of the children solved a global-level task (animals-furniture), followed by a basic-level task (either dogs-birds, or chairs-tables) during each session. The other half received the basic-level task only. During familiarisation, all infants freely explored a series of four different exemplars from the same category presented one at a time. Infants saw all objects twice, for a total of eight trials. During the test phase, a new exemplar from the familiar category was presented, followed by a different-category exemplar. At 8 months of age, children discriminated between categories in the global-level task, but failed to do so in the basic-level task. At 12 months of age, infants recognised a category change in the basic-level task, but treated both test items as equally new in the global-level task. These findings support the hypothesis that infants younger than 1 year of age show a global-to-basic-level shift in category formation.
Perceived control and academic performance: A comparison of high- and low-performing children on within-person change patterns
Authors: Musher-Eizenman Dara R. , Nesselroade John R. , Schmitz Bernhard
Published: October 2002

Children with high expectations of control do better in school than their peers with low perceived control. This finding is based largely on cross-sectional research and longitudinal research with long time intervals. Little attention has been paid to short-term, within-child variability in this important construct. Information about intraindividual change in perceived control, behaviour, and performance is critical to determining the processes by which the link between perception and outcome is affected. In this study, short-term variability in children’s perceived control, perception of task demands, and school performance was assessed and the concurrent and lagged relationships among these variables were considered. High-achieving and low-achieving children were compared. Results of dynamic factor models suggested that both the concurrent and lagged relationships among these variables are stronger and better organised for the high-achieving children. Implications for perceived control theory are discussed.
Intra- and intergenerational communication satisfaction as a function of an individual’s age and age stereotypes
Authors: Chen Yiwei , King Brian Edward
Published: October 2002

The present study assessed the positivity of an individual’s age stereotypes and examined the relationship between individuals’ age stereotypes and intra- and intergenerational communication satisfaction. In addition, two alternative hypotheses (i.e., an ingroup/outgroup hypothesis and a developmental hypothesis) were tested for explaining age differences in intra- and intergenerational communication satisfaction. Specifically, 118 young adults and 102 old adults participated in the study and were asked to generate traits about “a typical 20-year-old woman” and “a typical 70-year-old woman”. Participants also imagined a conversation with the targets and filled out a questionnaire measuring intra- and intergenerational communication satisfaction. Participants with a positive age stereotype toward the opposite age group perceived a higher level of intergenerational communication satisfaction and a lower level of dissatisfaction than those who held a neutral or a negative stereotype. In addition, old adults expressed lower levels of communication dissatisfaction than young adults regardless of which age group they interacted with. Results of this study supported the developmental hypothesis.
Nucleolin as Activator of Human Papillomavirus Type 18 Oncogene Transcription in Cervical Cancer
Authors: Grinstein Edgar , Wernet Peter , Snijders Peter J.F. , Rösl Frank , Weinert Inge , Jia Wentao , Kraft Regine , Schewe Christiane , Schwabe Michael , Hauptmann Steffen , Dietel Manfred , Meijer Chris J.L.M. , Royer Hans-Dieter
Published: October 2002

High risk human papillomaviruses (HPVs) are central to the development of cervical cancer and the deregulated expression of high risk HPV oncogenes is a critical event in this process. Here, we find that the cell protein nucleolin binds in a sequence-specific manner to the HPV18 enhancer. The DNA binding activity of nucleolin is primarily S phase specific, much like the transcription of the E6 and E7 oncoproteins of HPV18 in cervical cancer cells. Antisense inactivation of nucleolin blocks E6 and E7 oncogene transcription and selectively decreases HPV18+ cervical cancer cell growth. Furthermore, nucleolin controls the chromatin structure of the HPV18 enhancer. In contrast, HPV16 oncogene transcription and proliferation rates of HPV16+ SiHa cervical cancer cells are independent of nucleolin activity. Moreover, nucleolin expression is altered in HPV18+ precancerous and cancerous tissue from the cervix uteri. Whereas nucleolin was homogeneously distributed in the nuclei of normal epithelial cells, it showed a speckled nuclear phenotype in HPV18+ carcinomas. Thus, the host cell protein nucleolin is directly linked to HPV18-induced cervical carcinogenesis.
Localization of the Adhesion Receptor Glycoprotein Ib-IX-V Complex to Lipid Rafts Is Required for Platelet Adhesion and Activation
Authors: Shrimpton Corie N. , Borthakur Gautam , Larrucea Susana , Cruz Miguel A. , Dong Jing-Fei , López José A.
Published: October 2002

The platelet glycoprotein (GP) Ib-IX-V complex mediates the attachment of platelets to the blood vessel wall by binding von Willebrand factor (VWF), an interaction that also transmits signals for platelet activation and aggregation. Because the complex is extensively palmitoylated, a modification known to target proteins to lipid rafts, we investigated the role of raft localization in GP Ib-IX-V functions. In unstimulated platelets, a minor portion of the complex localized to Triton-insoluble raft fractions; this portion increased three to sixfold with platelet activation by VWF. Raft-associated GP Ib-IX-V was selectively palmitoylated, with GP Ib-IX-V–associated palmitate increasing in the raft fraction on VWF-mediated activation. The raft fraction was also the site of association between GP Ib-IX-V and the Fc receptor FcγRIIA. The importance of this association was demonstrated by the ability of the FcγRIIA antibody IV.3 to inhibit shear-induced platelet aggregation. Disruption of rafts by depleting membrane cholesterol impaired several GP Ib-IX-V–dependent platelet fractions: aggregation to VWF under static conditions and under shear stress, tyrosine phosphorylation, and adhesion to a VWF surface. Partial restoration of membrane cholesterol content partially restored shear-induced platelet aggregation and tyrosine phosphorylation. Thus, localization of the GP Ib-IX-V complex within rafts is crucial for both platelet adhesion and postadhesion signaling.
Prevention of Hepatocellular Carcinoma Development Associated with Chronic Hepatitis by Anti-Fas Ligand Antibody Therapy
Authors: Nakamoto Yasunari , Kaneko Shuichi , Fan Hong , Momoi Takashi , Tsutsui Hiroko , Nakanishi Kenji , Kobayashi Kenichi , Suda Takashi
Published: October 2002

A persistent immune response to hepatitis viruses is a well-recognized risk factor for hepatocellular carcinoma. However, the molecular and cellular basis for the procarcinogenic potential of the immune response is not well defined. Here, using a unique animal model of chronic hepatitis that induces hepatocellular carcinogenesis, we demonstrate that neutralization of the activity of Fas ligand prevented hepatocyte apoptosis, proliferation, liver inflammation, and the eventual development of hepatocellular carcinoma. The results indicate that Fas ligand is involved not only in direct hepatocyte killing but also in the process of inflammation and hepatocellular carcinogenesis in chronic hepatitis. This is the first demonstration that amelioration of chronic inflammation by some treatment actually caused reduction of cancer development.
Resolvins
Authors: Serhan Charles N. , Hong Song , Gronert Karsten , Colgan Sean P. , Devchand Pallavi R. , Mirick Gudrun , Moussignac Rose-Laure
Published: October 2002

Aspirin (ASA) is unique among current therapies because it acetylates cyclooxygenase (COX)-2 enabling the biosynthesis of R-containing precursors of endogenous antiinflammatory mediators. Here, we report that lipidomic analysis of exudates obtained in the resolution phase from mice treated with ASA and docosahexaenoic acid (DHA) (C22:6) produce a novel family of bioactive 17R-hydroxy-containing di- and tri-hydroxy-docosanoids termed resolvins. Murine brain treated with aspirin produced endogenous 17R-hydroxydocosahexaenoic acid as did human microglial cells. Human COX-2 converted DHA to 13-hydroxy-DHA that switched with ASA to 17R-HDHA that also proved a major route in hypoxic endothelial cells. Human neutrophils transformed COX-2-ASA–derived 17R-hydroxy-DHA into two sets of novel di- and trihydroxy products; one initiated via oxygenation at carbon 7 and the other at carbon 4. These compounds inhibited (IC50 ∼50 pM) microglial cell cytokine expression and in vivo dermal inflammation and peritonitis at ng doses, reducing 40–80% leukocytic exudates. These results indicate that exudates, vascular, leukocytes and neural cells treated with aspirin convert DHA to novel 17R-hydroxy series of docosanoids that are potent regulators. These biosynthetic pathways utilize omega-3 DHA and EPA during multicellular events in resolution to produce a family of protective compounds, i.e., resolvins, that enhance proresolution status.
Inactivation of the Osteopontin Gene Enhances Vascular Calcification of Matrix Gla Protein–deficient Mice
Authors: Speer Mei Y. , McKee Marc D. , Guldberg Robert E. , Liaw Lucy , Yang Hsueh-Ying , Tung Elyse , Karsenty Gerard , Giachelli Cecilia M.
Published: October 2002

Osteopontin (OPN) is abundantly expressed in human calcified arteries. To examine the role of OPN in vascular calcification, OPN mutant mice were crossed with matrix Gla protein (MGP) mutant mice. Mice deficient in MGP alone (MGP−/− OPN+/+) showed calcification of their arteries as early as 2 weeks (wk) after birth (0.33 ± 0.01 mmol/g dry weight), and the expression of OPN in the calcified arteries was greatly up-regulated compared with MGP wild-types. OPN accumulated adjacent to the mineral and colocalized to surrounding cells in the calcified media. Cells synthesizing OPN lacked smooth muscle (SM) lineage markers, SM α-actin and SM22α. However, most of them were not macrophages. Importantly, mice deficient in both MGP and OPN had twice as much arterial calcification as MGP−/− OPN+/+ at 2 wk, and over 3 times as much at 4 wk, suggesting an inhibitory effect of OPN in vascular calcification. Moreover, these mice died significantly earlier (4.4 ± 0.2 wk) than MGP−/− OPN+/+ counterparts (6.6 ± 1.0 wk). The cause of death in these animals was found to be vascular rupture followed by hemorrhage, most likely due to enhanced calcification. These studies are the first to demonstrate a role for OPN as an inducible inhibitor of ectopic calcification in vivo.
Constitutive Presentation of a Natural Tissue Autoantigen Exclusively by Dendritic Cells in the Draining Lymph Node
Authors: Scheinecker Clemens , McHugh Rebecca , Shevach Ethan M. , Germain Ronald N.
Published: October 2002

The major histocompatibility complex (MHC)-dependent presentation of processed tissue-specific self-antigens can contribute to either peripheral (extrathymic) tolerance or the differentiation of autoreactive T cells. Here, we have studied the MHC class II molecule presentation of gastric parietal cell (PC)-specific H+/K+-ATPase, which induces a destructive autoimmune gastritis in BALB/c mice lacking CD4+ CD25+ regulatory T cells. Immunofluorescence microscopy showed physical association of CD11c+ dendritic cells (DCs) with PCs in the gastric mucosa. H+/K+-ATPase protein was found within vesicular compartments of a few CD11c+ DCs only in the draining gastric lymph node (LN) and these antigen-containing DCs increased markedly in number with the onset of tissue destruction in autoimmune animals. Both CD8αhi and CD8αlo gastric DCs, but not peripheral or mesenteric DCs, showed evidence of constitutive in vivo processing and presentation of H+/K+-ATPase. These data provide direct support for a widely held model of local tissue antigen uptake and trafficking by DCs in normal animals and demonstrate that DCs in the draining LN can present a tissue-specific self-antigen under noninflammatory conditions without fully deleting autoreactive T cells or inducing active autoimmunity.
COMPLEMENTATION AND EMBEDDINGS OF c0(I) IN BANACH SPACES
Authors: ARGYROS SPIROS A. , CASTILLO JESÚS F. , GRANERO ANTONIO S. , JIMÉNEZ MAR , MORENO JOSÉ P.
Published: October 2002

We investigate in this paper the complementation of copies of $c_0(I)$ in some classes of Banach spaces (in the class of weakly compactly generated (WCG) Banach spaces, in the larger class $\mathcal{V}$ of Banach spaces which are subspaces of some $C(K)$ space with $K$ a Valdivia compact, and in the Banach spaces $C([1, \alpha ])$, where $\alpha$ is an ordinal) and the embedding of $c_0(I)$ in the elements of the class $\mathcal{C}$ of complemented subspaces of $C(K)$ spaces. Two of our results are as follows:

(i) in a Banach space $X \in \mathcal{V}$ every copy of $c_0(I)$ with $\# I < \aleph _{\omega}$ is complemented;

(ii) if $\alpha _0 = \aleph _0$, $\alpha _{n+1} = 2^{\alpha _n}$, $n \geq 0$, and $\alpha = \sup \{\alpha _n : n \geq 0\}$ there exists a WCG Banach space with an uncomplemented copy of $c_0(\alpha )$.

So, under the generalized continuum hypothesis (GCH), $\aleph _{\omega}$ is the greatest cardinal $\tau$ such that every copy of $c_0(I)$ with $\# I < \tau$ is complemented in the class $\mathcal{V}$. If $T : c_0(I) \to C([1,\alpha ])$ is an isomorphism into its image, we prove that:

(i) $c_0(I)$ is complemented, whenever $\| T \| ,\| T^{-1} \| < (3/2)^{\frac 12}$;

(ii) there is a finite partition $\{I_1, \dots , I_k\}$ of $I$ such that each copy $T(c_0(I_k))$ is complemented.

Concerning the class $\mathcal{C}$, we prove that an already known property of $C(K)$ spaces is still true for this class, namely, if $X \in \mathcal{C}$, the following are equivalent:

(i) there is a weakly compact subset $W \subset X$ with ${\rm Dens}(W) = \tau$;

(ii) $c_0(\tau )$ is isomorphically embedded into $X$.

This yields a new characterization of a class of injective Banach spaces.

2000 Mathematical Subject Classification: 46B20, 46B26.