bluuebunny/crossref_metadata_2025 huggingface dataset:
An analytic description of converging shock waves
Authors: CHISNELL R. F.
Published: July 2002

The similarity solution describing the motion of converging

spherical and cylindrical

shocks is governed by a set of three ordinary differential

equations. Previous descriptions of the shock motion have been

based on numerical solutions of these differential

equations. In the present paper a study of the singular points of the

differential equations leads to an analytic description of the flow

and a determination of the similarity

exponent which is in excellent agreement with the earlier numerical

values. Limiting

values of the ratio of specific heats are considered. It is shown that

as the ratio tends

to unity the shock becomes ‘freely propagating’ and the

first terms in a power series

for the similarity exponent are obtained. Large values of the ratio

of specific heats

are briefly considered and provide a further check on the analytic

description of this

paper. Finally in the Appendix the condition for the pressure to

have a maximum

is clarified and the location of the maximum provides further

strong evidence of the

high accuracy of the analytic approach of this paper.
Reflection of gravity waves by a steep beach with a porous bed
Authors: BODY GILES L. , EHRENMARK ULF T.
Published: July 2002

Solutions are determined for normally incident non-breaking linear
gravity waves in a
perfect fluid over a porous plane bed of arbitrary slope α both with
and without bed
friction. For simplicity, computations are restricted to α=π/2m,

m∈N. Modifications
to wave height transformations due to percolation and to friction are determined
for
a variety of slopes and coefficients. The effect on the reflection coefficient

Rf is also
studied and excellent qualitative agreement is found with recent work on
damping
and reflection by permeable structures. In particular, for a choice of
parameters, the
Rf response is determined in closed form.
Steady flow in a helically symmetric pipe
Authors: ZABIELSKI L. , MESTEL A. J.
Published: July 2002

Fully developed flow in an infinite helically coiled pipe is studied,
motivated by
physiological applications. Most of the bends in the mammalian arterial
system curve
in a genuinely three-dimensional way, so that the arterial centreline has
not only
curvature but torsion and can be modelled by a helix. Flow in a helically
symmetric
pipe generalizes related problems in axisymmetry (Dean flow) and two-dimensionality,

but the geometry ensures that even irrotational flow has a cross-pipe component.
Fully
developed helical flows driven by a steady pressure gradient are studied
analytically
and numerically. Varying the radius and pitch of the helical pipe, the
effects of
curvature and torsion on the flow are investigated.
Two-dimensional solidification and melting in potential flows
Authors: CUMMINGS LINDA M. , HOHLOV YURI E. , HOWISON SAM D. , KORNEV KONSTANTIN
Published: July 2002

The problem of solidification or melting under the action of a
forced hydrodynamic
flow is considered. In the appropriate parameter régime, the problem
admits a formulation
in terms of analytic functions. It is shown that a crystal with a parabolic
tip
propagates without change of shape at a steady velocity. Some novel explicit
solutions
are presented.
Propagation of solitary waves through significantly curved shallow
water channels
Authors: SHI AIMIN , TENG MICHELLE H. , WU THEODORE Y.
Published: July 2002

Propagation of solitary waves in curved shallow water channels
of constant depth
and width is investigated by carrying out numerical simulations based on
the
generalized weakly nonlinear and weakly dispersive Boussinesq model. The
objective is to
investigate the effects of channel width and bending sharpness on the transmission

and reflection of long waves propagating through significantly curved channels.
Our
numerical results show that, when travelling through narrow channel bends
including
both smooth and sharp-cornered 90°-bends, a solitary wave is transmitted
almost
completely with little reflection and scattering. For wide channel bends,
we find that,
if the bend is rounded and smooth, a solitary wave is still fully transmitted
with little
backward reflection, but the transmitted wave will no longer preserve the
shape of
the original solitary wave but will disintegrate into several smaller waves.
For solitary
waves travelling through wide sharp-cornered 90°-bends, wave reflection
is seen to
be very significant, and the wider the channel bend, the stronger the reflected
wave
amplitude. Our numerical results for waves in sharp-cornered 90°-bends
revealed a
similarity relationship which indicates that the ratios of the transmitted
and reflected
wave amplitude, excess mass and energy to the original wave amplitude,
mass and
energy all depend on one single dimensionless parameter, namely the ratio
of the
channel width b to the effective wavelength λe.

Quantitative results for predicting wave transmission and reflection based
on
b/λe are presented.
Axisymmetric propagating vortices in
the flow between a stationary and a rotating disk
enclosed by a cylinder
Authors: GAUTHIER G. , GONDRET P. , RABAUD M.
Published: July 2002

The destabilization of the stationary basic flow occurring between two disks enclosed
by a cylinder is studied experimentally when the radius of the disks is large compared
to the spacing. In the explored range of the cell aspect ratio, when one disk only
is rotating, circular vortices propagating to the centre are observed above a critical
angular velocity. These structures occur naturally but can also be forced by small
modulations of the angular velocity of the disk. For each rotation rate the dispersion
relation of the instability is experimentally reconstructed from visualizations and it
is shown that this dispersion relation can be scaled by the boundary layer thickness
measured over the disk at rest. The bifurcation is found to be of supercritical nature.
The effect of the forcing amplitude is in favour of a linear convective nature of this
instability of the non-parallel inward flow existing above the stationary disk. The
most unstable temporal frequency is found to be about four times the frequency
of the rotating disk. The evolution of the threshold of this primary instability is
described for different aspect ratios of the cell. Finally, two sets of experiments made
under transient conditions are presented: one in order to investigate further a possible
convective/absolute transition for the instability, and the other to compare with the
impulsive spin-down-to-rest experiments of Savas (1983).
SIR JAMES LIGHTHILL
Authors: Crighton D. G.
Published: July 2002

James Lighthill died on 17 July 1998, at the end of a ten-hour swim round the
Channel Island of Sark. He had earlier, at age 49, been the first person ever to do
this, and he was carrying out the swim for the seventh time when the exertion revealed
a mitral valve weakness which had never been diagnosed, and which led to his sudden
death in the water. The swim was one of many long ‘adventure swims’ which Lighthill
liked to take, all characterized by strong tidal currents and often heavy seas. And
Lighthill took much pleasure through exercising his comprehensive understanding of
fluid mechanics first in preparing for them through study of local conditions and then
in adapting his performance when, as often, he found that in practice the currents
were not as charted and, in fact, often more treacherous.

Many obituary notices have already appeared in the national press in the UK and
USA, and now in the newsletters and journals of learned societies; and extensive
conspectuses of Lighthill's contributions to fluid mechanics and applied mathematics,
and to science generally and to the administration of science, will be published in
Annual Review of Fluid Mechanics (2000), and in Biographical Memoirs of Fellows of
the Royal Society (2000). The reader will learn, from those accounts, of the unique
range and depth of Lighthill's contributions; and virtually all readers should expect
to be surprised and impressed to read of facets of Lighthill's work of which they were
previously totally unaware.
Flow structure produced by
the interaction and merger of a pair of
co-rotating wing-tip vortices
Authors: DEVENPORT WILLIAM J. , VOGEL CHRISTINE M. , ZSOLDOS JEFFERY S.
Published: July 2002

Experiments have been performed to study the co-rotating wing-tip vortex pair
produced by a pair of rectangular wings in a split-wing configuration. Detailed
measurements made in cross-sections upstream and downstream of merger reveal,
for the first time, the complex turbulence structure of this flow. The vortices spiral
around each other and merge some 20 chordlengths downstream of the wings. As
merger is approached the vortices lose their axisymmetry – their cores develop lopsided
tangential velocity fields and the mean vorticity field is convected into filaments. The
cores also become part of a single turbulence structure dominated by a braid of high
turbulence levels that links them together. The braid, which quite closely resembles
the structure formed between adjacent spanwise eddies of transitional mixing layers,
grows in intensity with downstream distance and extends into the vortex cores. Unlike
a single tip vortex, the unmerged cores appear turbulent.

The merging of the vortices wraps the cores and the flow structure that surrounds
them into a large turbulent region with an intricate double spiral structure. This
structure then relaxes to a closely axisymmetric state. The merged core appears
stable and develops a structure similar to the laminar core of a vortex shed from
a single wing. However, the turbulent region formed around the vortex core during
the merger process is much larger and more axisymmetric than that found around a
single wing-tip vortex.
Directional solidification of a binary alloy into a
cellular convective flow: localized morphologies
Authors: CHEN Y.-J. , DAVIS S. H.
Published: July 2002

A steady, two-dimensional cellular convection modifies the morphological instability
of a binary alloy that undergoes directional solidification. When the convection
wavelength is far longer than that of the morphological cells, the behaviour of the
moving front is described by a slow, spatial–temporal dynamics obtained through
a multiple-scale analysis. The resulting system has a parametric-excitation structure
in space, with complex parameters characterizing the interactions between flow,
solute diffusion, and rejection. The convection in general stabilizes two-dimensional
disturbances, but destabilizes three-dimensional disturbances. When the flow is weak,
the morphological instability is incommensurate with the flow wavelength, but as the
flow gets stronger, the instability becomes quantized and forced to fit into the flow
box. At large flow strength the instability is localized, confined in narrow envelopes. In
this case the solutions are discrete eigenstates in an unbounded space. Their stability
boundaries and asymptotics are obtained by a WKB analysis. The weakly nonlinear
interaction is delivered through the Lyapunov–Schmidt method.
Turbulent heat and momentum transport on a rotating disk
Authors: ELKINS CHRISTOPHER J. , EATON JOHN K.
Published: July 2002

Measurements in the turbulent momentum and thermal boundary layers on a rotating
disk with a uniform heat flux surface are described for Reynolds numbers up to 106.
Measurements include mean velocities and temperatures, all six Reynolds stresses,
turbulent temperature fluctuations, and three turbulent heat fluxes. The mean velocity
profiles have no wake region, but the mean temperature profiles do. The turbulent
temperature fluctuations have a large peak in the outer layer, and there is a third
turbulent heat flux in the cross-flow direction. Correlation coefficients and structure
parameters are not constant across the boundary layer as they are in two-dimensional
boundary layers (2DBLs), and their values are lower. The turbulent Prandtl number
agrees with 2DBL values in the lower part of the outer region but is reduced from the
2DBL values higher in the boundary layer. In the outer region of the boundary layer,
the transport processes differ significantly from what is observed in two-dimensional
turbulent boundary layers: ejections dominate the transport of momentum while both
ejections and sweeps contribute to the transport of the passive scalar.
Formalizing formality: an analysis of register variation in Sinhala
Authors: PAOLILLO JOHN C.
Published: July 2002

Variation in language on the basis of formality (register variation) is often neglected
both in grammatical descriptions and in sociolinguistic analyses. I demonstrate here
that in Sinhala, and perhaps in other diglossic languages, register variation in syntax
cannot be ignored. In a Head-Driven Phrase Structure Grammar (HPSG) analysis
based on a corpus of naturally occurring Sinhala texts, I propose an analysis of
register variation in which the syntax of all observed registers is accounted for within
a single grammar. I further explain how the approach to register variation developed
here can be extended to other types of sociolinguistic variation.
Parameters and the periphery: reflections on Syntactic nuts
Authors: DEAN FODOR JANET
Published: July 2002

Peter W. Culicover, Syntactic nuts: hard cases, syntactic theory, and language acquisition. Oxford: Oxford University Press, 1999. Pp. viii + 244.
Crossover: a unified view
Authors: KEMPSON RUTH , GABBAY DOV
Published: July 2002

This paper informally outlines a Labelled Deductive System for
on-line language
processing. Interpretation of a string is modelled as a composite lexically
driven
process of type deduction over labelled premises forming locally discrete
databases,
with rules of database inference then dictating their mode of combination.
The
particular LDS methodology is illustrated by a unified account of the interaction
of
wh-dependency and anaphora resolution, the so-called
‘cross-over’ phenomenon,
currently acknowledged to resist a unified explanation. The shift of perspective
this
analysis requires is that interpretation is defined as a proof structure
for labelled
deduction, and assignment of such structure to a string is a dynamic left-right
process
in which linearity considerations are ineliminable.
Inherent vs. derived clisis: evidence from Czech proclitics
Authors: FRIED MIRJAM
Published: July 2002

I investigate a diverse set of Czech words of unclear prosodic status. The analysis
reveals that while it is possible to make a clear distinction between proclitics and
nonclitics, certain nonclitics are disposed to occasional clitic-like behavior. I propose
to capture this fact by distinguishing between inherent clisis vs. derived clisis, the
latter being sensitive to certain semantic, pragmatic, and prosodic conditions. This
approach allows us to address the striking similarities in certain behaviors between
clitics and nonclitics without ignoring their equally important differences.
Local perceptions of indigenous land tenure systems: views of
peasants, women and dignitaries in a rural province of Burkina Faso
Authors: Sawadogo Jean-Pierre , Stamm Volker
Published: July 2002

This article is based on the observation that the large debate on the nature
and consequences of so-called indigenous land tenure systems does not
sufficiently take into account the perceptions and interpretations of peasants
themselves. Consequently, its aims are to provide people with a voice and to
analyse their assessment of different forms of access to land, of the modifications
undergone in recent times, and their adjustments to this change. The
results of this qualitative approach are compared with some statistical information
gathered by the authors in the study region – three villages in
central Burkina Faso – as well as country-wide. As a result, one may conclude
that peasants in this area do not feel insecure about their land tenure
situation, and this assessment of their own position is confirmed by empirical
data.
Redesigning African civil service reforms
Authors: Olowu Bamidele
Published: July 2002

Since the late 1980s, many African countries have been reforming
their civil
services as a part of the process of state redesign. Unfortunately, these
reforms
have not been very successful because of faulty diagnosis and prognosis.
They
have failed to tackle the major problems confronting African civil services.

These include serious human resource management issues of leadership,
merit pay and related governance reforms, the appropriate strategy for

mobilising resources for civil service reform (CSR) and for implementing

such reforms. These issues must be adequately addressed before African

countries can make significant progress in CSR and in development.
Spectral representation of the isotropic Coulomb collisional operator
Authors: KHABIBRAKHMANOV I. K. , SUMMERS D.
Published: July 2002

A spectral representation for the isotropic part of the Coulomb
collisional operator is given. The particle distribution function is expanded
in a series of generalized Laguerre polynomials, and the Coulomb collisional
operator is expressed in
terms of the spectral amplitudes. When the spectral representation is applied
to
the Fokker–Planck equation, a system of coupled ordinary
differential equations
for the spectral amplitudes is obtained. The spectral coefficients related
to the
Coulomb operator are defined through recurrence relations, which we reduce
to
simplified form. This makes possible accurate and efficient analytical
and
numerical evaluations of the interaction matrices. The results presented
can be used in
analytical investigations of the properties of the Coulomb collisional
operator as
well as in numerical calculations for plasmas far from thermal equilibrium.
The
method can also be generalized to include angular dependencies for non-isotropic
particle distributions.
Order and chaos in ETG-driven drift–dissipative
waves with sheared flows
Authors: MIRZA ARSHAD M. , RAFIQ TARIQ , QAMAR ANISA , MURTAZA G. , SHUKLA P. K. , FARIA R. T.
Published: July 2002

We derive a system of nonlinear equations that govern the dynamics
of low-frequency short-wavelength electromagnetic waves in the presence of
equilibrium density, temperature, magnetic field and velocity gradients. In the
linear limit, a local dispersion relation is obtained and analyzed.
New ηe-driven
electromagnetic drift modes and instabilities are shown to exist. In the
nonlinear case, the temporal behaviour of a nonlinear dissipative system can be
written in the form of Lorenz- and Stenflo-type equations that admit chaotic
trajectories. On the other hand, the stationary solutions of the nonlinear system
can be represented in the form of dipolar and vortex-chain solutions.
Fast mixing mechanism of two vortex–current filaments
Authors: YATSUYANAGI YUICHI , HATORI TADATSUGU , KATO TOMOKAZU
Published: July 2002

We demonstrate fast mixing of vortex–current filaments by means of
numerical simulations of collision (strong interaction) between two straight filaments.
The two filaments mutually approach, collide, and are rapidly tangled with
each other. In fact, the instantaneous Lyapunov exponent shows that the dynamics
becomes chaotic. Then there appear many small regions where the two filaments
overlap. We consider each overlapping region to be equivalent to the traditional
resistive diffusion region. We assume that the overall ‘reconnection rate’ of the two
filaments is proportional to the product of the traditional (non-chaotic) resistive
reconnection rate and the normalized overlapping volume. The overlapping volume
rapidly increases on the time scale of ideal MHD. When many overlapping regions
are produced, the overall reconnection probability, i.e. the sum of the probabilities
of reconnection in every overlapping region, should be increased compared with that
of the single overlapping region. Thus the overall reconnection rate becomes sufficiently
large, although the basic reconnection process in each overlapping region is
resistive and slow. We conclude that the fast mixing due to chaos may enhance the
conventional resistive reconnection. We call this process ‘chaotic reconnection’.
Serpuloidea (Annelida: Polychaeta) from Milos, an island in the Aegean Sea with submarine hydrothermalism
Authors: Bianchi C. Nike , Morri Carla
Published: July 2002

Serpuloidea were collected by diving within 45 m depth, by indirect sampling in deeper waters (50 and 81 m), and among the fouling settled on oceanographic instruments at various depths (10, 50, 80 and 83 m depth). A total of 33 species or subspecific taxa was found: 25 Serpulidae and eight Spirorbidae. All the species collected are already known for the western Mediterranean and have Atlantic–Mediterranean or worldwide distribution. Several of these, however, may be species-complexes hiding species with restricted geographic ranges. No Lessepsian migrants were found. The number of species found at vent sites was significantly higher than that found at non-vent sites, although no vent-obligate species were recognized. Hydrothermal vents might influence serpuloidean richness through four main mechanisms: (i) increasing food sources to these filter-feeders, due to the chemiosynthetic production by vent microbiota; (ii) enhancing the development of biogenic carbonate mounds, which provide habitats for encrusting and cryptic species; (iii) inducing advective mechanisms that concentrate larval stages in the vicinity of vents and thus favouring recruitment; (iv) creating, through the periodic emission of toxic fluids, a regime of `intermediate disturbance' that allows a larger number of species to coexist.
Age estimation and annulus-formation in dorsal spines of juvenile bluefin tuna, Thunnus thynnus, from the Mediterranean Sea
Authors: Megalofonou P. , de Metrio G.
Published: July 2002

The first dorsal fin spines were used to estimate the age of juvenile bluefin tuna, Thunnus thynnus, from the Mediterranean Sea. Observations on the type of growth zones occurring on the outside margin of each spine section by month and marginal increment analysis indicated that only one translucent zone is formed per year between February and April, when lower sea surface temperatures are observed. Age estimations were based on counts of translucent zones on the spine sections and mean size at estimated age was calculated for the first three years of life.
The missing links: larval and post-larval development of the ascoglossan opisthobranch Elysia viridis
Authors: Trowbridge Cynthia D.
Published: July 2002

The stenophagous ascoglossan (=sacoglossan) opisthobranch Elysia viridis has long been a model organism for the study of endosymbiosis or kleptoplasty as well as one of the few herbivores to consume the introduced green macroalga Codium fragile on European shores. Larval and post-larval dynamics of the ascoglossan were investigated. Planktotrophic larvae of E. viridis grew at 5–10 μm d−1 (shell length) at 15°C on a unicellular algal diet (the cryptophyte Rhodomonas baltica); larvae became competent one month post-hatching. Effective feeding and chloroplast acquisition typically started within 2–3 d of metamorphosis. Slugs grew about 8 mm in the first month of post-larval life. During this period, juveniles held in the light did not grow faster or survive better than conspecifics held in the dark; thus, functional kleptoplasty did not occur during first three weeks of benthic life. While larval growth rates and the nature of metamorphic cues are consistent with those of many other opisthobranch species with planktotrophic larvae, measures of post-larval growth—particularly as it pertains to kleptoplasty—is a new contribution to opisthobranch biology.
Physico-chemical structure of the benthic environment of a Galician ría (Ría de Ares-Betanzos, north-west Spain)
Authors: Sánchez-Mata A. , Glémarec M. , Mora J.
Published: July 2002

In a preliminary study of the marine benthos of Ría de Ares-Betanzos, 50 stations covering the quadrant delineated by the coordinates 43°26′42″N–43°20′42″N and 08°18′54″W–08°10′12″W were sampled and sediment samples analysed for particle-size composition, sand, silt and clay content, degree of sorting, median diameter and grain-size diversity of sediments. Organic and inorganic content, total carbon and nitrogen, carbonates, organic carbon/total nitrogen ratio and bathymetric data were also collected. On a smaller scale a few stations were sampled for sediment redox potential and pH measurement. The salinity, temperature and oxygen content of the overlying water was also assessed.

Cluster analysis and Principal Component Analysis methods were used to describe seabed heterogeneity and the pattern of sediment distribution within the ría, and to relate the environmental variables to each sediment type. Sediments were predominantly fine to very fine sands, and exhibited a direct depth-related gradient, i.e. with the finer grades, higher organic carbon and silt and clay occurring at the shallower areas of Pontedeume, Ares and Redes inlets and Ría de Betanzos sector where terrigenous input was important. Carbonate, organic carbon and organic matter maxima occurred in the central sector of the ría where most mollusc recruitment takes place: revealing the chiefly bioclastic origin of sediments. Taking into account the geological and hydrographic processes, explanations for the formation of the sedimentary bottoms in Ría de Ares-Betanzos are provided.
Diversity of metazoan parasites of the introduced oyster species Crassostrea gigas in the Exe Estuary
Authors: Aguirre-Macedo M.L. , Kennedy C.R.
Published: July 2002

Temporal patterns in metazoan parasite community diversity of Crassostrea gigas, (Lamellibranchia: Ostreidae) were studied in the Exe Estuary at monthly intervals over one year and in relation to host age-classes. A total of four metazoan species was found to parasitize C. gigas in the Exe Estuary: the turbellarian Paravortex sp., cercaria Lepocreadiidae, metacercariae of Renicola roscovita and the copepod Mytilicola intestinalis. Only R. roscovita and M. intestinalis were present in all months throughout the year and in all host age-classes. Analysis of the metazoan parasite community at individual host level revealed little variation in community structure with respect to season or host age, as only a slight increase in diversity values was observed during the summer months. However, community diversity does vary from year to year, as shown by comparison between host age group samples in three consecutive years. None of the parasites are specialist to oysters but all appear to be widespread and abundant parasite of other lamellibranch species.
Development time of harpacticoid copepods: some empirical models and implications
Authors: Santos P.J.P. , Castel J. , Souza-Santos L.P.
Published: July 2002

Some meiobenthic harpacticoid copepod species cannot be successfully cultured, therefore empirical models were developed to estimate their development times, using literature data, but taking into consideration several empirical rules previously formulated to model the development of planktonic copepods. The present models demonstrated the overwhelming influence of rearing temperature on egg development time, and of body length on total development time and indicate a capacity to adapt development rates to environmental temperature.
A single maturity classification key for five common Mediterranean chaetognath species
Authors: Kehayias G. , Koutsikopoulos C. , Fragopoulu N. , Lykakis J.
Published: July 2002

A single maturity classification key applied to five common chaetognath species of the eastern Mediterranean is presented. The efficiency of the key was tested using biometrical data: body length (BL), ovary length (OL) and seminal vesicle width (SVW). For each species the key proved easy to use and efficient in the distinction of the maturity stages providing a satisfactory size separation between them.
Specific growth rates of protozooplankton in the marginal ice zone of the central Barents Sea during spring
Authors: Winding Hansen Benni , Jensen Frank
Published: July 2002

Protozooplankton growth was measured by incubation in a walk-in cooling room at 5°C of filtered seawater from six stations on a south–north transect from open water through drift ice and into fast ice in the central Barents Sea (72°30′N–76°32′N). Eight species of naked ciliates, two species of tintinnids, seven species of athecate dinoflagellates and nine species of thecate dinoflagellates grew in the 24 and 48 h bottle incubations. Maximum potential mean specific growth rates of 0.84, 0.59, 0.39 and 0.39 d−1, respectively, indicated a hierarchy in growth rates determined by taxonomic differences where growth of naked ciliates > tintinnids > athecate dinoflagellates > thecate dinoflagellates. The mean±SD in situ temperature (4 to −1.8°C) corrected growth rates (Q10=2.8) for the six stations (0.74±0.31, 0.74±0.16, 0.25±0.16, 0.23±0.27 d−1) also suggested a higher growth for ciliates in comparison to dinoflagellates. Additionally, it revealed that the naked ciliates responded to the increased food availability, whereas this was not the case for all other groups of protozooplankton.
Rhythmic dimension in the echolocation click trains of sperm whales: a possible function of identification and communication
Authors: André Michel , Kamminga Cees
Published: July 2002

Fourier spectral analysis was used to highlight a rhythmic dimension of the click repetition pattern of the sperm whale (Physeter macrocephalus). Analysis of numerous series of regular clicks only showed occasionally the previously described codas used for communication. Out of a sample recording of vocalizing sperm whales, an apparent cacophony, belonging to a year-round resident group foraging a few miles off the coast of Gran Canaria, the individual click sequences of four animals have been unravelled by cross-correlating their time wave shapes.

The Fourier spectrum, which yields the harmonic aspects of each isolated click sequence, shows a deterministic structure that appears as a strong modulating frequency. This shows that click production is not a random process and possibly characterizes, in fact, a signature of the animal. Here we introduce a new concept: this rhythmic modulation represents the acoustic signature of each individual sperm whale, which we have called RIME (rhythmic identity measurement). The RIME would allow a whale to distinguish its own echo time pattern from the background of other click trains during echolocation. The RIME appears to represent a new concept in communication strategies and might also be present in other-social-odontocete repertoires.
Population structure and growth of the squid Illex illecebrosus (Cephalopoda: Ommastrephidae) off Nova Scotia, north-west Atlantic
Authors: Arkhipkin A.I. , Fetisov A.A.
Published: July 2002

Population structure of the short-finned squid Illex illecebrosus (Ommastrephidae) was studied on the Nova Scotian shelf between July–September 1984. It was characterized by a prevalence of winter-hatched squid in summer–early autumn, their short (three months of the summer) occurrence on the shelf, and a predominance of females in sex ratios during the feeding period. Ages of squid were estimated by statolith increment counts and ranged from 128 to 201 d. Growth in length was described by linear model with daily growth rates of 0.99 mm/d−1. Adding the length-at-age data from juveniles caught in 1979 to the 1984 data set enabled to construct an ontogenetic growth curve for the winter-hatched squid which was best approximated by the Gompertz growth function.
Deep-sea hydrothermal vent communities of the Logatchev area (14°45′N, Mid-Atlantic Ridge): diverse biotopes and high biomass
Authors: Gebruk A.V. , Chevaldonné P. , Shank T. , Lutz R.A. , Vrijenhoek R.C.
Published: July 2002

Results from recent biological studies (including three Alvin dives in July 1997) of the southernmost deep-sea hydrothermal area known on the Mid-Atlantic Ridge (MAR), the Logatchev hydrothermal area, are described. The Logatchev area includes three vent fields, each with a different geological setting corresponding to: (1) a large sulphide mound with ‘smoking craters’; (2) an active chimney complex (known as ‘Irina-2’); and (3) a diffuse flow through soft sediment (‘Anya's Garden’). Hydrothermal communities found at these fields differ considerably: Anya's Garden is dominated by vesicomyid clams, Ectenagena sp. aff. kaikoi, Irina-2 by mytilid mussels, Bathymodiolus sp. aff. puteoserpentis, with swarms of shrimps and other rich associated fauna, whereas on the main mound the fauna as a whole is less abundant and less diverse. This is the first record of a living clam population on the MAR. Other bivalves found on the clam field included thyasirids, Thyasira (Parathyasira) spp., not reported previously from deep-sea hot vent communities. The biomass on the mussel bed at Irina-2 exceeds 70 kg m−2 (wet weight with shells) and is the highest known on the MAR. The large shrimp population at Irina-2 includes swarms of Rimicaris exoculata. A diverse shrimp fauna (including a new species Alvinocaris sp. aff. muricola) on the mussel bed is dominated by Mirocaris keldyshi. Overall the Logatchev area is dominated by mussels which may be attributable to the presence of both methane-oxidizing (dominant type) and sulphur-oxidizing bacterial symbionts in their gills. The diversity of vent organisms and biotopes at Logatchev appears to be the highest on the MAR.
A mass stranding of the asteroid Asterias rubens on the Isle of Man
Authors: Thorpe J.P. , Spencer E.L.
Published: July 2002

Over the period 1—4 April 1999 a large number of dead asteroids were washed ashore at the northern end of the Isle of Man. The area is commonly used for public recreation and the stranding prompted numerous alarmed telephone calls to various bodies. Initially, disease or pollution were suspected, but a more detailed examination of the circumstances indicated that the mass stranding was probably a result of tides and weather conditions. The stranding occurred on the east coast of the Isle of Man from about 100 m to the south of the Point of Ayre, which is the northernmost point of the Isle of Man, and extended southwards for ≈600 m. This is a highly exposed shore with a strong tidal flow, subtidally it is shallow, with coarse gravel and exposed bedrock, and extensive mussel (Mytilus edulis) beds, which may be expected to attract large numbers of predatory starfish.
The Rise of Sunni Militancy in Pakistan: The Changing Role of Islamism and the Ulama in Society and Politics
Authors: Nasr S. V. R.
Published: July 2002

The past two decades have witnessed a notable escalation in sectarian violence in Pakistan. Since 1979 doctrinal disputes between Sunnis (who constitute the majority of Pakistan's population) and Twelver Shi‘is (who number between 15% and 25% of the population, and are to be distinguished from Islami‘ili, Khoja and Bohri Shi‘is) has given place to full-fledged sectarian conflict. Militant Sunni and Shi‘i organizations have carried out assassinations and bombing campaigns that have killed political rivals as well as children and the innocent at prayer in mosques. In the first seven months of 1997 alone—the year when sectarian conflict reached its apogee—one hundred people died in such attacks in Punjab. The violence escalated further when in the first ten days of August 1997 (immediately preceding the celebration of the fiftieth anniversary of the country's independence) another seventy people were killed in incidents of sectarian violence.
Colonial Prisons and Anti-colonial Resistance in French Indochina: The Thai Nguyen Rebellion, 1917
Authors: Zinoman Peter
Published: July 2002

Between the pacification of Tonkin in the late 1880s and the Nghe-Tinh Soviet Movement of 1930–31, the Thai Nguyen Rebellion was
the largest and most destructive anti-colonial uprising to occur in
French Indochina. On August 31, 1917, an eclectic band of political
prisoners, common criminals and mutinous prison guards seized the
Thai Nguyen Penitentiary, the largest penal institution in northern
Tonkin. From their base within the penitentiary, the rebels stormed
the provincial arsenal and captured a large cache of weapons which
they used to take control of the town. Anticipating a counterattack,
the rebels fortified the perimeter of the town, executed French officials and Vietnamese collaborators and issued a proclamation calling
for a general uprising against the colonial state. Although colonial
forces retook the town following five days of intense fighting, mopping-up campaigns in the surrounding countryside stretched on for
six months and led to hundreds of casualties on both sides.
Orality, Literacy and Memorization: Priestly Education in Contemporary South India
Authors: FULLER C. J.
Published: July 2002

For the debate on orality, literacy and memorization, India provides some
striking evidence. In his comparative analysis
of ‘oral aspects of scripture’, Graham gives the Hindu tradition
a special place, for the ‘ancient Vedic tradition
represents the paradigmatic instance of scripture as spoken, recited word’ (Graham 1987:68). The Vedas,
the oldest texts of Hinduism, have been transmitted orally for three thousand years
or more, despite the very early implementation of writing, and it is the Vedas as recited from memory by
Brahmans that are alone authoritative. A corollary of the spoken word's
primacy is that in teaching the Vedas and other texts, although ‘written texts have been
used’, ‘a text without a teacher to teach it directly and orally to a pupil is only so many useless leaves or pages’ (ibid.: 74).
History as Self-Representation: The Recasting of a Political Tradition in Late Eighteenth-Century Eastern India
Authors: Chatterjee Kumkum
Published: July 2002

If power is mediated by knowledge, then the early decades of British colonial rule in India were indeed, as Ghulam Hussain Khan Tabatabai, the intellectual and historian par excellence of those times wrote, a time of ‘half-knowledge’.The decades between 1757 and 1772 witnessed the implantation of this colonial regime in Eastern India through the transformation of the English East India Company from a mercantilist trading corporation into the paradoxical status of ‘merchant-sovereign and the sovereign merchant’ at the same time. The role of sovereign thrust upon the officials of the company the far from easy task of administering this society in ways that were most conducive to the extraction of the largest possible surplus from it for its new masters.
Long-term dynamics of infectiousness within the infective-stage pool
of

the entomopathogenic nematode Steinernema feltiae

(Site 76 strain) Filipjev
Authors: BOHAN D. A. , HOMINICK W. M.
Published: July 2002

Infection experiments were conducted to assess the proportion of

Steinernema feltiae (Site 76 strain) Filipjev infective

juveniles which penetrated into the test host Galleria mellonella

L. over an 8-week period. Using a combined ANOVA and

infection model approach, the analyses showed that the proportion of

infective juveniles which penetrated into the test

hosts changed significantly over time. This change was found to be

consistent with a fluctuation in the size of a non-infectious population

structure within the infective juvenile pool.

These fluctuations in the magnitude of the infectious

structure would dynamically alter the number of juveniles available

for infection in hosts and so impose the observed

change in the proportion of juveniles penetrating into hosts, over the

8-week time-course. The empirical and ecological

implications of such a dynamically limited pattern of infection and

possible future research into the mechanisms

responsible for the non-infectious population structure are discussed.
Neutral lipids and the assessment of infectivity in entomopathogenic
nematodes: observations on four Steinernema species
Authors: PATEL M. N. , STOLINSKI M. , WRIGHT D. J.
Published: July 2002

An 8-point visual index was developed for Oil Red O staining of
neutral
lipids in infective juveniles (IJs) of Steinernema
carpocapsae (All), S. riobravis (Biosys 355), S. feltiae
(UK76) and S. glaseri
(NC). The visual index was found to be a
reliable and rapid method for determining the relative neutral lipid content
of individual IJs and was validated quantitatively by gas chromatography.
The
relationship between neutral lipid utilization and infectivity of IJs stored
in
distilled water at 25°C was also investigated and the first quantitative
results on neutral lipid utilization in entomopathogenic
nematodes are reported. Neutral lipid contents of freshly harvested IJs
of
S. carpocapsae, S. riobravis, S. feltiae and
S.
glaseri were 31, 31, 24 and 26% dry wt, respectively. Steinernema
carpocapsae showed a sigmoidal pattern for neutral lipid
utilization while S. riobravis used neutral lipids at an almost
constant
rate. Survivorship of these two species ranged
between 120 and 135 days, whereas S. feltiae and S. glaseri
lived >450 days
and had a slower rate of lipid utilization
during a 260 day storage period. Oil Red O staining showed that individual
IJs in each population utilized lipids at different
rates, even though they had the same initial lipid index. The infectivity
of S. riobravis, S. feltiae and S. glaseri declined
with lipid utilization. In contrast, S. carpocapsae maintained
a high
level of infectivity even at relatively low lipid levels.
Therefore, neutral lipid content was found to be a suitable indicator of
infectivity for S. riobravis, S. feltiae and S. glaseri
but not for S. carpocapsae.
Malaria toxins: effects on murine spleen and bone marrow
cell proliferation and cytokine production in vitro
Authors: BORDMANN G. , FAVRE N. , RUDIN W.
Published: July 2002

The ability of deproteinated malaria exoantigens from Plasmodium
falciparum (Pf-MT) and P. berghei ANKA (PbA-MT)
to activate murine haematopoietic cells was analysed in vitro.
Malaria toxins (MT) of both plasmodium species induced
cell proliferation and the production of IFN-γ in overnight and
long-term (5 days) spleen and bone marrow cultures and
a reduction of the number of TNF-α spot forming cells (SFC).
When added to cells of malaria-experienced animals, MT
decreased the number of IL-4 SPC and increased the number of IL-5 SPC.
However,
the same proliferative and IFN-γ induction properties as in
naive cells were observed. Simultaneous addition of IL-2 and PbA-MT to
spleen
cells inhibited
the proliferation but increased the IFN-γ production usually induced
by
IL-2. Flow cytometric analysis revealed that the
addition of MT triggered an expansion of CD3+ and GR1+
cell populations. Our results suggest that malaria toxins of
different species can induce an immediate and strong proliferation and
a
TH1-type cytokine release by murine cells,
independently of previous in vivo priming.
Cross-reactions between Eimeria falciformis and Eimeria

pragensis in mice induced by trickle infections
Authors: SHEHU K. , NOWELL F.
Published: July 2002

We describe a laboratory model using Eimeria falciformis
and E. pragensis to investigate some of the interactions in double-species
infections of Eimeria. Mice were given trickle infections by oral
inoculation of 100 sporulated oocysts of one species
at 3 or 4 day intervals throughout the experiments and, once immunity had
developed, as indicated by cessation of oocyst
production, the animals were challenged with a single inoculation of the
other species. A trickle infection of E. falciformis
gave a significant enhancement of oocyst output from E. pragensis
infection as compared with animals that had not received
E. falciformis. Histological examination of the mice infected
with E. pragensis showed significantly more asexual parasites

and a significantly higher female/male ratio in the mice that had received
trickle E. falciformis infections than in those that
had not. There was no evidence to suggest that extra asexual generations
were occurring in these mice. In the converse
experimental protocol, trickle E. pragensis infections had no
significant effect on a single E. falciformis infection. We discuss

the possible mechanisms for the interactions and also how these interactions
may influence multiple species infections in animals in their natural habitats.
Predatory behaviour of trapping fungi against srf mutants
of Caenorhabditis elegans and different plant and animal
parasitic nematodes
Authors: DE GIVES P. MENDOZA , DAVIES K. G. , CLARK S. J. , BEHNKE J. M.
Published: July 2002

The initial infection process of nematode-trapping fungi is based on an interaction between the trapping structure of the
fungus and the surface of the nematode cuticle. A bioassay was designed to investigate the predatory response of several
isolates of nematode-trapping fungi against 3 mutants of Caenorhabditis elegans (AT6, AT10 and CL261), which have
been reported to differ in the reaction of their cuticle to antibodies and lectins. The bioassay was also applied to infective
larvae of animal (Haemonchus contortus, Teladorsagia (Ostertagia) circumcincta and Trichostrongylus axei) and plant
(Meloidogyne spp.) parasitic nematodes. Differences in trapping ability were most marked in the first 24 h, and were density
dependent. Although the isolate of Arthrobotrys responded very rapidly in the first 24 h, Duddingtonia flagrans was
generally the most effective isolate and Monacrosporium responded relatively poorly throughout all experiments. All the
fungi tested trapped the srf mutants of C. elegans more efficiently than the wild type, and there were differences between
the different srf mutants of C. elegans. Differences in trapping ability were also observed between different isolates of D.
flagrans; similarly, differences in trapping behaviour were observed not only amongst the different species of plant-parasitic nematodes, but also between the sheathed and exsheathed larvae of the animal-parasitic nematodes.
A 32 kDa surface antigen of Theileria parva:
characterization and immunization studies
Authors: SKILTON R. A. , MUSOKE A. J. , WELLS C. W. , YAGI Y. , NENE V. , SPOONER P. R. , GACHANJA J. , OSASO J. , BISHOP R. P. , MORZARIA S. P.
Published: July 2002

Previous studies using monoclonal antibody (mAb) 4C9 specific for a 32 kDa antigen (p32) of Theileria parva demonstrated
expression of the antigen on the surface of the sporozoite, making it a potential antigen for sporozoite neutralization. A
full-length cDNA encoding the major merozoite/piroplasm surface antigen (mMPSA) of T. parva was cloned and
expressed in bacteria. The expressed product reacted strongly with mAb 4C9, demonstrating identity between the p32
and mMPSA of T. parva. Using immunoblot analysis and immunoelectron microscopy with mAb 4C9 it was shown that
the mMPSA is a major antigen of the merozoite and piroplasm at the cell surface, while lower levels of antigen are expressed
in the sporozoite and schizont stages. Upregulation of the mMPSA occurs at merogony and can be induced by culturing
schizont-infected lymphocytes at 42 °C. Recombinant mMPSA of T. parva induced high titres of specific antibodies in
cattle but failed to confer protection against a T. parva sporozoite stabilate challenge. The pre-challenge sera also failed
to neutralize infectivity of sporozoites in an in vitro assay. Possible reasons for the lack of parasite neutralization in vivo
and in vitro are discussed.
Davidson on Intentionality and Externalism
Authors: Hacker P.M.S.
Published: July 2002

Davidson has attempted to integrate externalism into his account of meaning and understanding. He contends that what words mean is fixed in part by the circumstances in which they were learnt, in which the basic connection between words and things is established. This connection is allegedly established by causal interaction between people and the world. Words and sentences derive their meanings from the objects and circumstances in which they were learnt, which ‘anchor’ language to the world.

Against this it is argued that there is no ‘semantic connection’ between words and things, that words derive their meanings from explanations of meaning, which are rules for their use, and that the manner of concept acquisition is irrelevant to determination of meaning, understanding and speaker's meaning.