bluuebunny/crossref_metadata_2025 huggingface dataset:
Numerical study of convection in the horizontal

Bridgman configuration under the action of a

constant magnetic field. Part 2. Three-dimensional flow
Authors: BEN HADID HAMDA , HENRY DANIEL
Published: July 2002

The effects of a constant magnetic field on electrically

conducting liquid-metal flows

in a parallelepiped cavity are investigated using a spectral numerical

method involving direct numerical solution of the Navier–Stokes and

Ohm equations for three-dimensional flows. Three horizontal Bridgman

configurations are studied: buoyancy-driven convection in a confined cavity

and in a cavity where the top boundary is

a stress-free surface and thirdly, thermocapillary-driven flow in a cavity

where the

upper boundary is subjected to effects of surface tension. The results

of varying the Hartmann number (Ha) are described for a cavity

with Ax = L/H = 4 and

Ay = W/H = 1, where L is the length,

W is the width and H is the height of the

cavity. In general, an increase in the strength of the applied magnetic

field leads to

several fundamental changes in the properties of thermal convection. The

convective circulation progressively loses its intensity and when

Ha reaches a certain critical

value, which is found to depend on the direction (longitudinal or vertical)
of

the

applied magnetic field, decrease of the flow intensity takes on an

asymptotic form with important changes in the structure of the flow

circulation. The flow structure may be separated into three regions:

the core flow, Hartmann layers which develop in the

immediate vicinity of the rigid horizontal boundaries or at the

endwalls, and parallel

layers appearing in the vicinity of the sidewalls. The behaviour of

the maxima of velocity and of the overall flow circulation is found

to depend on both the boundary conditions used and the direction of

the applied magnetic field. Furthermore, the interaction of the

electric current density with the applied magnetic field

which leads to the structural reorganization described above can

also create more subtle flow modifications, such as flow inversions

which are observed mainly in the central region of the cavity.
Small-amplitude oscillatory forcing on two-layer plane channel flow
Authors: COWARD ADRIAN V. , RENARDY YURIKO Y.
Published: July 2002

The effect of oscillatory forcing as a dynamic stabilization or

destabilization mechanism

for two-layer plane Couette–Poiseuille flow at low Reynolds number
is

studied using

numerical and asymptotic methods. The flow is driven by the relative planar
motion

of the upper boundary and a pressure gradient in the streamwise direction.
Both

driving forces are composed of a steady part and small-amplitude time-periodic

fluctuations. An asymptotic expansion for the growth rates for small amplitudes
is

developed and the correction terms are quadratic in the amplitudes. The
modulations

to the steady flow can have either a stabilizing or destabilizing influence

depending upon the conditions of flow. Complete stabilization is possible
for

certain flows which

are otherwise unstable owing to the viscosity stratification across the
interface.

The combined pressure and velocity fluctuations can have an opposite effect
on

the flow stability to that induced by the separate time-periodic forcing

mechanisms.
Unsteady heat or mass transport from a

suspended particle at low Péclet numbers
Authors: POZRIKIDIS C.
Published: July 2002

Unsteady heat or mass transport from a particle with an arbitrary
shape

suspended in

a fluid of infinite expanse is considered in the limit of small Péclet

numbers where

diffusion is dominant. In a frame of reference in which the particle appears
to be

stationary, the velocity of the fluid is uniform or varies in a linear
manner

with respect

to the spatial coordinates, with an arbitrary time dependence. The temperature
or

concentration of a species at the surface of the particle is held at a
certain

constant value, whereas that at infinity is held at another constant value.

Two particular problems are considered, both to leading order with respect
to the

Péclet number: (a)

the rate of transport from a particle that is introduced suddenly into
a

steady flow near

the steady state; and (b) the average rate of transport from a

particle that is suspended

in a time-periodic flow. The theory uses the method of matched

asymptotic expansions

and employs the Green's function of the convection–diffusion
equation

for a generally

unsteady uniform or linear flow. The Green's function is derived in
closed

form by first

performing a transformation to a Lagrangian framework. In the first problem
of

transient transport, it is found that the functional form of the rate of

transport near

the steady state is affected strongly by the structure of the incident
flow:

the decay in

uniform or elongational flow is exponential, whereas the decay in simple

shear flow is

algebraic. In the second problem of transport in a periodic flow, it is

found that the

value of a properly defined frequency parameter has a strong influence
on the mean

rate of transport, for all types of flow. The oscillation induces

convective mixing and

thereby reduces the mean rate of transport by a substantial factor. The

ability of the

theory to describe another situation of heat or mass transport considered

by Pedley is also discussed.
Transverse velocity increments in turbulent flow
using the RELIEF technique
Authors: NOULLEZ A. , WALLACE G. , LEMPERT W. , MILES R. B. , FRISCH U.
Published: July 2002

Non-intrusive measurements of the streamwise velocity in turbulent round
jets in
air are performed by recording short-time displacements and distorsions of very
thin tagging lines written spanwise into the flow. The lines are written by
Raman-exciting oxygen molecules and are interrogated by laser-induced electronic
fluorescence
(relief). This gives access to the spatial structure of transverse velocity
increments
without recourse to the Taylor hypothesis. The resolution is around
25 μm, less than
twice the Kolmogorov scale η for the experiments performed (with
Rλ≈360–600).

The technique is validated by comparison with results obtained from other
techniques for longitudinal or transverse structure functions up to order 8.
The agreement
is consistent with the estimated errors – a few percent on exponents determined
by extended-self-similarity – and indicates significant departures from
Kolmogorov (1941) scaling.

Probability distribution functions of transverse velocity increments
Δu over separations down to 1:8η are reported for the first time.
Violent events, with Δu comparable
to the r.m.s. turbulent velocity fluctuation, are found to take place
with statistically
significant probabilities. The shapes of the corresponding lines suggest
the effect of intense slender vortex filaments.
Buoyancy-driven coalescence of slightly deformable drops
Authors: ROTHER MICHAEL A. , ZINCHENKO ALEXANDER Z. , DAVIS ROBERT H.
Published: July 2002

The simultaneous effect of small deformation and short-range

van der Waals attraction on the coalescence efficiency of two different-sized

slowly sedimenting drops is

considered. For spherical drops, it has been shown previously that the
tangential

mobility of drop surfaces makes collision possible even without van der
Waals

attraction; on the other hand, even a small amount of deformation precludes

drops from

coming into contact unless van der Waals attraction is accounted for. In
the present

work, the conditions are delineated when these two small-scale factors,
acting in

opposite directions, have a considerable combined effect on the coalescence

efficiency.

The problem is solved by matched asymptotic expansions valid for small
capillary

numbers (Ca). The outer solution, for two spherical drops moving
in

apparent contact without van der Waals attraction, determines the

contact force as a function of

time. This force is used as the driving force for the inner solution of
the relevant

integro-differential thin-film equations (coupling the flow in

the small-gap region to

that inside the drops) to determine whether coalescence occurs during the
apparent

contact motion. The initial gap profile for the inner solution

is provided by matching

with the outer trajectory for spherical drops approaching contact.

The analysis shows that, for Ca[Lt ]1, the near-contact

deformation is mainly

axisymmetric, greatly simplifying the inner solution; nevertheless, determination
of

the critical horizontal offsets leading to coalescence and the

parametric analysis are

computationally very intensive. To facilitate these tasks, a substantially

new, highly efficient, and absolutely stable numerical method for solving
stiff

thin-film equations is

developed. Unlike for spherical drops, when the upstream intersection

area is a circle,

the existence of a second coalescence zone for deformable drops is found
over much

of the parameter space. Results are mapped out for a range of four dimensionless

parameters (capillary number, size and drop-to-medium viscosity ratios,
dimensionless

Hamaker parameter). As a physical application, predicted coalescence efficiencies
are

shown for a system of ethyl salicylate drops in diethylene glycol.

The present solution extends the range of drop sizes where the coalescence

efficiencies are known theoretically and can be used in drop population
dynamics.

Comparison with full three-dimensional boundary-integral calculations for
deformable

drops without van der Waals attraction is also made to demonstrate that,
when

the drop-to-medium viscosity ratio is of the order of unity, the present
asymptotic

approach is valid in a wide range of small and moderately small capillary
numbers.
A complete Crocco integral for two-dimensional

laminar boundary layer flow over an adiabatic

wall for Prandtl numbers near unity
Authors: VAN OUDHEUSDEN B. W.
Published: July 2002

The so-called Crocco integral establishes a relation between the

velocity and temperature distributions in steady boundary layer flow. It

corresponds to an exact solution

of the flow equations in the case of unity Prandtl number and an adiabatic
wall,

where it reduces to the condition that the total enthalpy remains constant
throughout

the boundary layer, irrespective of pressure gradient and compressibility.
The effect

of Prandtl number is usually incorporated by assuming a constant recovery
factor

across the entire boundary layer. Strictly, however, this modification
is in

conflict with

the conservation-of-energy principle. In search of a more complete expression
for the

Crocco integral the present study applies an asymptotic solution approach
to the

energy equation in constant-property flow. The analysis of self-similar

boundary layer

solutions results in a formulation of the Crocco integral which correctly

incorporates

the effect of Prandtl number to first order, and that is complete in the
sense that

it satisfies the energy conservation requirement. Furthermore, the result
is found to

be applicable not only to self-similar boundary layers, but also

to provide a solution

to the laminar flow equations in general as well. The effect of varying
properties is

considered with regard to the extension of the expression to more

general flow conditions. In addition to the asymptotic expression for

the Crocco integral, asymptotic

solutions are also obtained for the recovery factor for various classes
of flows.
Stationary travelling cross-flow mode
interactions on a rotating disk
Authors: CORKE T. C. , KNASIAK K. F.
Published: July 2002

This work involves the study of the development of
Type 1 stationary and travelling
cross-flow modes in the three-dimensional boundary layer over
a rotating disk. In
order to control the characteristics of the stationary modes,
we utilized organized
patterns of roughness which were applied to the disk surface.
These consisted of ink
dots which were equally spaced in the azimuthal direction at
a fixed radius in order
to enhance particular azimuthal wavenumbers. Logarithmic
spiral patterns of dots
were also used to enhance azimuthal wave angles. Velocity
fluctuation time series
were decomposed into the components corresponding to the
stationary and travelling
modes using the instantaneous disk position as a reference.
Their development was
documented through the linear and nonlinear stages leading to
turbulence. The
linear stage agreed well with linear stability predictions for
both modes. In the
nonlinear stage we documented a triad coupling between
pairs of travelling modes
and a stationary mode. The strongest of these was a
difference interaction which
led to the growth of a low-azimuthal-number, stationary
mode. This mode had
the largest amplitude and appeared to dominate transition.
In retrospect, we can
observe the signs of this mechanism in past flow
visualization (Kobayashi, Kohama
& Takamadate 1980), and it can account for the
‘jagged’ front normally associated
with cross-flow-dominated transition on swept wings.
Thermocapillary and oscillatory-shear instabilities in a layer of
liquid with a
deformable surface
Authors: OR A. C. , KELLY R. E.
Published: July 2002

The thermocapillary and shear-induced instabilities of a thin heated
layer of liquid
bounded from the top by a deformable free surface and at the bottom by
a horizontally
oscillating plate are studied for both Earth-bound and microgravity conditions.

Finite-wavelength thermocapillary convection can be stabilized very significantly
by
the oscillatory shear, whereas shear-induced instabilities are greatly
stabilized if the
Marangoni number is negative. For long-wavelength thermocapillary convection,
oscillatory
shear can stabilize or destabilize the basic state, depending primarily
on the
imposed forcing frequency. With microgravity, significant stabilization
of the dominant
long-wavelength convection can be achieved by carefully selecting the imposed
frequency.
Stability of plane Couette flow of a granular material
Authors: ALAM MEHEBOOB , NOTT PRABHU R.
Published: July 2002

This paper presents a linear stability analysis of plane Couette
flow of a granular
material using a kinetic-theory-based model for the rheology of the medium.
The stability analysis, restricted to two-dimensional disturbances, is carried
out for three illustrative sets of grain and wall properties which correspond to the
walls being perfectly adiabatic, and sources and sinks of fluctuational energy. When
the walls are not adiabatic and the Couette gap H is sufficiently large, the
base state of steady fully developed flow consists of a slowly deforming ‘plug’ layer where the bulk density is close to that of maximum packing and a rapidly shearing layer where the bulk density is considerably lower. The plug is adjacent to the wall when the latter acts as a sink of energy and is centred at the symmetry axis when it acts as a source of energy. For each set of properties, stability is determined for a range of H and the mean solids fraction [barvee ]. For a given value of [barvee ], the flow is stable if H is sufficiently small; as H increases it is susceptible to instabilities in the
form of cross-stream layering waves with no variation in the flow direction, and stationary and travelling waves with variation in the flow and gradient directions. The layering instability prevails over a substantial range of H and [barvee ] for all sets of wall properties. However, it grows far slower than the strong stationary and travelling wave instabilities which become active at larger H. When the walls act as energy sinks, the strong travelling wave instability is absent altogether, and instead there are relatively slow growing long-wave instabilities. For the case of adiabatic walls there is another stationary instability for dilute flows when the grain collisions are quasi-elastic; these modes become stable when grain collisions are perfectly elastic or very inelastic. Instability of all modes is driven by the inelasticity of grain collisions.
Hydrodynamic equations for rapid flows of
smooth inelastic spheres, to Burnett order
Authors: SELA N. , GOLDHIRSCH I.
Published: July 2002

The Chapman–Enskog expansion is generalized in
order to derive constitutive relations
for flows of inelastically colliding spheres in three dimensions –
to Burnett
order. To this end, the pertinent (nonlinear) Boltzmann equation is perturbatively

solved by performing a (double) expansion in the Knudsen number and the
degree
of inelasticity. One of the results is that the normal stress differences

and the ‘temperature
anisotropy’, characterizing granular fluids, are Burnett effects.
The constitutive
relations derived in this work differ, both qualitatively and quantitatively,
from those
obtained in previous studies. In particular, the Navier–Stokes (order)
terms have a
different dependence on the degree of inelasticity and the number density
than in
previously derived constitutive relations; for instance, the expression
for the heat
flux contains a term which is proportional to ε∇ log n,

where ε is a measure of the
degree of inelasticity and n denotes the number density. This
contribution to the
heat flux is of zeroth order in the density; a similar term, i.e.
one that is proportional to ε∇n, has been
previously obtained by using the Enskog correction but
this term is O(n) and it vanishes in the
Boltzmann limit. These discrepancies are
resolved by an analysis of the Chapman–Enskog and Grad expansions,
pertaining
to granular flows, which reveals that the quasi-microscopic rate of decay
of the temperature,
which has not been taken into account heretofore, provides an important

scale that affects the constitutive relations. Some (minor) quantitative
differences
between our results and previous ones exist as well. These are due to the
fact that
we take into account an isotropic correction to the leading Maxwellian
distribution,
which has not been considered before, and also because we consider the
full
dependence of the corrections to the Maxwellian distribution on the (fluctuating)
speed.
The effect of solute concentration on hindered
gradient diffusion in polymeric gels
Authors: BUCK KRISTAN K. S. , DUNGAN STEPHANIE R. , PHILLIPS RONALD J.
Published: July 2002

The effect of solute concentration on hindered diffusion of sphere-like colloidal solutes
in stiff polymer hydrogels is examined theoretically and experimentally. In the
theoretical development, it is shown that the presence of the gel fibres enhances the
effect of concentration on the thermodynamic driving force for gradient diffusion,
while simultaneously reducing the effect of concentration on the hydrodynamic drag.
The result is that gradient diffusion depends more strongly on solute concentration
in gels than it does in pure solution, by an amount that depends on the partition
coefficient and hydraulic permeability of the gel–solute system. Quantitative calculations
are made to determine the concentration-dependent diffusivity correct to first
order in solute concentration. In order to compare the theoretical predictions with
experimental data, rates of diffusion have been measured for nonionic micelles and
globular proteins in solution and agarose hydrogels at two gel concentrations. The
measurements were performed by using holographic interferometry, through which
one monitors changes in refractive index as gradient diffusion takes place within a
transparent gel. If the solutes are modelled as spheres with short-range repulsive
interactions, then the experimentally measured concentration dependence of the diffusivities
of both the protein and micelles is in good agreement with the theoretical
predictions.
A reappraisal of democracy in civil
society: evidence from rural Senegal
Authors: Patterson Amy S.
Published: July 2002

Civil society is the space of uncoerced human association and relational

networks formed for the sake of family, faith, interests and ideology.

Supporters of civil society have argued that this conglomeration of
networks and organisations has helped to fuel democratic aspirations
and channel democratic demands in Africa. Proponents maintain that
civil society serves as a counter to the actions of the predatory African

state, which seeks to limit individual freedoms and to encroach on
societal resources. By questioning the actions of state officials and by

challenging state policies, civil society organisations can cause the state

to be more accountable and transparent, and can facilitate a positive
deconcentration of political power. A plural, vibrant civil society
encourages political liberalisation and the development of a democratic

and legitimate state. It is because the organisations of civil society

promote democratic values among their members that they are able to
challenge repressive state actions and facilitate democratic development.

Since their members trust each other and feel that they have
a say in group activities, democratic organisations are more unified and

effective at achieving their political objectives.

This article challenges these assumptions about civil society through

an examination of rural Senegalese organisations. I argue that groups
in civil society rarely teach their members democratic values because
most associations do not practice legitimate, inclusive and accountable

decision making. More often than not, social hierarchies and power
relations that define how individuals of different genders and classes
are
to interact in the public realm limit democracy. As a result, civil society

groups often become ineffective and disorganised, and cannot achieve
their political, economic or social goals. The inefficiency and
undemocratic nature of civil society have larger implications for
democratic transitions in Africa.
Instabilities in localized non-uniform charged dust streams in cold plasmas
Authors: ČADEŽ VLADIMIR M. , VERHEEST FRANK
Published: July 2002

Surface eigenmodes in a dusty plasma, where the dust is confined to
a particular region, modelled as a uniform slab with non-uniform smooth
boundary layers, are discussed. Inside this region, electron depletion occurs,
while outside it, the plasma is just a normal uncontaminated plasma. In
addition, the dust component can flow with respect to the background plasma,
as a first approximation to cometary tails, where there is a notable difference
between the fast flowing solar wind and the slow moving dust tail, viewed in
the comet frame. The equilibrium densities and flow are non-uniform and the
description involves a space-dependent dielectric function, which indicates
the possibility of singular points, where eigenmodes resonate with local plasma
oscillations. Surface eigenmodes on the slab are obtained analytically in the
limit of long wavelengths, and these give rise to two distinct frequency
domains, both having three different wave solutions. One of these refers
to plasma surface waves, unaffected by the dust flow. The other two lead to
convective surface modes, which become unstable for large flow speeds, akin
to Buneman-type instabilities. A detailed study is made of the resonant
processes in the boundary layers, including damping and growth rates.
Spatial absorption of a magnetosonic wave in a dusty magnetized plasma
Authors: de JULI M. C. , SCHNEIDER R. S.
Published: July 2002

The dielectric tensor for a multicomponent magnetized dusty
plasma, including the effect of capture of plasma electrons and ions by the dust
particles, is rewritten in order to provide expressions more suitable for
applications. We use this tensor to study the spatial absorption of a
magnetosonic wave, including effects up to second order in the Larmor radius.
We analyse the absorption of the wave due to the presence of dust particles with
variable charge and the modification of this absorption due to finite-Larmor-radius effects.
Evolution of nonlinear magnetosonic waves propagating obliquely to an external magnetic field in a collisionless plasma
Authors: CHAKRABORTY DEBALINA , DAS K. P.
Published: July 2002

It is shown that the asymptotic evolution of finite-amplitude
magnetosonic waves propagating obliquely to an external uniform magnetic
field in a warm homogeneous plasma is governed by a Kadomtsev–Petviashvili
equation having an extra dispersive term. The dispersion is provided by finite-Larmor-radius
(FLR) effects in the momentum equation and by the Hall-current and
electron-pressure corrections in the generalized Ohm's law. A
double-layer-type solution of the equation is obtained, and the equation is
shown to reduce to a KdV–Burgers equation under certain assumptions.
Response to ‘Comment on “Boundary
conditions for surface waves propagating along
the interface of plasma flow and free space” ’
Authors: LEE HEE J. , CHO SANG-HOON
Published: July 2002

Shoucri (1999) has commented on our paper (Lee and Cho 1997) in
view of his
relativistic calculation, and has stated that the boundary condition and
the
dispersion relation obtained there are incorrect. In this response, we
reaffirm
that all the results contained in Lee and Cho (1997) are correct in so
far as one
uses the nonrelativistic equation of motion. In particular, the boundary

condition that we used (equation (57) in Lee and Cho 1997) is valid in
both the
nonrelativistic and the relativistic theory, and is equivalent to equation
(11) of
Shoucri (1999). Shoucri's hasty conclusion that our boundary condition
(57) is
incorrect appears to be due to his neglect of the fact that a boundary
condition
can be put into different forms depending upon problems under consideration.

One way to derive a boundary condition for the surface-wave problem
with
a sharp boundary is to assume an inhomogeneous plasma having a varying

density N(x) (in the notation of Lee and Cho 1997),
integrate the inhomogeneous
wave equation or the Maxwell equations across the infinitesimal transition

layer, and specialize N(x) as a step function, as was
done in Lee (1995).
Starting from the Maxwell equations on p. 418 of Lee and Cho (1997) and

calculating the currents relativistically, we find that the following three

boundary conditions are equivalent, and any one of them is acceptable:

(i) equation (57) in Lee and Cho (1997);

(ii) equation (11) in Shoucri (1999);

(iii) formula here

(in the notation of Lee and Cho (1997), with γ as the relativistic factor).
Restoration of deleted and assimilated consonant sequences in conversational French speech: effects of preceding and following context
Authors: Duez Danielle
Published: July 2002

The present study was designed to test the effects of preceding and following context on the restoration of deleted and assimilated consonant sequences in conversational French speech. Consonant restoration was found to be enhanced by lexical information and by the different sources of information contained in the breath group. The fundamental contribution of breath-group information suggests that the breath group, which is a production unit in conversational speech, might be a perception unit. Interestingly, the results also appear to be in line with Lindblom's claim (1990, 1996) that speakers adapt their utterances to the listeners' needs and maintain sufficient contrast for promoting correct lexical access.
Daily variability in height-related settlement-pattern in an intertidal barnacle
Authors: Noda Takashi , Fukushima Kotaro , Mori Tsukasa , Ban Shuhei
Published: July 2002

To examine the effects of submergence time, free-space availability, and larval supply on height-related differences in settlement density of Semibalanus cariosus, we monitored the daily settlement density in plots where all benthos were removed daily and in natural-community plots, which were left undisturbed, at two sites with different tidal heights: the centre and the upper limit of S. cariosus zone, during one settlement season. Settlement density was higher at the low-tidal site, where settler mortality was low, than at the mid-tidal site, where settler mortality was high. The between-site differences in settlement was determined by larval preference for height and not immersion time. The settlement preference for height was masked on days with high larval supply, since suitable settlement sites in lower height were saturated by settlers.
Geographical, seasonal occurrence and incidental fishing captures of basking shark Cetorhinus maximus (Chondricthyes: Cetorhinidae)
Authors: Valeiras Julio , López Alfredo , García Manuel
Published: July 2002

This is the first report on the presence of basking sharks Cetorhinus maximus in Galician waters (north-west Iberian Peninsula) from sightings, strandings and incidental catches by fishing gear. Morphometric, biological, geographic and temporal data on 19 basking sharks recorded from 1988 to 1998 are presented. Average total length is 401·4 cm. Male:female ratio is 0·6. Seventy per cent of records are from incidental fishing catches in bottom gill nets. Approximately 74% of sharks were recorded during February, March and April, which may suggest that the species occurs seasonally in this area.
Influence of trematode infections on in situ growth rates of Littorina littorea
Authors: Mouritsen Kim N. , Gorbushin A. , Jensen K. Thomas
Published: July 2002

The influence of various species of digenean trematodes on the in situ growth rate of Littorina littorea (Gastropoda: Prosobranchia) from different habitats was investigated. The main results showed: (1) that infections either reduced or had no significant effect on growth in comparison with uninfected snails; (2) that the same type of infection could have a differential effect on growth depending on the habitat/population from which the snails originated. These findings are consistent with the life history hypothesis expecting no or a stunting effect of trematode infections on the growth of longer-lived snails, but do also emphasize that growth rates following trematode invasion can be significantly modified by environmental conditions, such as, food availability.
Prodissoconch morphology of the relict marine paleoheterodont Neotrigonia margaritacea (Mollusca: Bivalvia) indicates a non-planktotrophic prejuvenile ontogeny
Authors: O'Foighil Diarmaid , Graf Daniel L.
Published: July 2002

Trigonioids represent the most plausible marine outgroup for freshwater palaeoheterodonts, yet details of their early ontogeny are scant. We utilized museum specimens and scanning electron microscopy to characterize the prodissoconch structure of the ‘living fossil’ Neotrigonia margaritacea. This species produces a large inflated prejuvenile shell (mean length ±SD=664±16.9 μm, N=8) that lacks both an umbone and a prodissoconch II. It is concluded that N. margaritacea does not rely on planktotrophy to fuel its prejuvenile ontogeny.
The size range of suspended particles trapped and ingested by the filter-feeding lancelet Branchiostoma floridae (Cephalochordata: Acrania)
Authors: Ruppert Edward E. , Nash Troy R. , Smith Allison J.
Published: July 2002

Lancelets of the genus Branchiostoma (amphioxus) are widespread and locally abundant filter-feeding animals in shallow coastal waters of the south-eastern US (up to 5000 ind/m2) and in temperate and tropical seas worldwide (up to 9000 ind/m2). Lancelets are consumed by bottom-dwelling fish and humans. As part of a larger project to aquaculture lancelets, an experiment was conducted to determine the range of diameters of suspended particles filtered and ingested by the Florida lancelet, Branchiostoma floridae (Chordata: Cephalochordata). After a period of starvation, animals were exposed to a suspension of tracer particles of seven different diameters (range 90–0.062 μm) and the protein, ferritin (0.012 μm) and their faeces were examined subsequently for the presence or absence of tracer. Particles ranging from 90–0.062 μm, but not ferritin, were filtered and ingested. Many of the 90 μm diameter particles, however, were excluded from entering the body by the oral cirri. Under experimental conditions, B. floridae filters and ingests particles in the range of ∼100–0.062 μm (microplankton to colloidal particles). This result suggests that the lancelet diet, like that of appendicularians, includes microbial as well as phytoplankton production.
Occurrence of Maritrema arenaria (Digenea: Microphallidae) in the acorn barnacle, Balanus perforatus (Cirripedia: Balanidae) from south-west Wales
Authors: Sari A. , Malek M.
Published: July 2002

This is the first record of the digenean parasite (Maritrema arenaria) in the acorn barnacle (Balanus perforatus). The seasonal variations in the abundance and prevalence of infection as well as variation of these with tidal level and barnacle scutum lengths are discussed.
The Way of Efficiency: Ueno Yoichi and Scientific Management in Twentieth-Century Japan
Authors: TSUTSUI WILLIAM M.
Published: July 2002

The profound influence of American management thought on Japanese industrial practice has generally been considered
a postwar phenomenon. Stressing the contributions of Deming, Drucker and other American experts, both popular
wisdom and scholarly opinion have embraced the notion that ‘the managerial revolution that occurred in Japan after
World War II was made in the United States’. Prewar Japanese management, however, has seldom been figured in
terms of American inspiration. Historians have commonly conceived prewar Japanese practice as somehow impervious
to American theories and techniques, emphasizing instead the importance of indigenous patterns of familialism,
German influences, or a capital-labor dynamic largely detached from external stimuli. Thus, in industrial
management—as in so many facets of modern Japanese history—the prewar narrative and the postwar narrative have remained
separate and unreconciled. Despite recent interest in establishing a fuller genealogy of Japanese management, the
question of how American models could thrive in postwar Japan without a prewar legacy of integration has yet to be
answered or even seriously addressed.
Alterations in cytochrome-c oxidase expression between
praziquantel-resistant and susceptible strains of Schistosoma mansoni
Authors: PEREIRA C. , FALLON P. G. , CORNETTE J. , CAPRON A. , DOENHOFF M. J. , PIERCE R. J.
Published: July 2002

The genetic differences between praziquantel-resistant (R) and
susceptible (S)
strains of Schistosoma mansoni (Fallon &
Doenhoff, 1994) were explored using RAPD and by cloning differentially

expressed mRNAs by subtractive PCR. No
differences between the 2 strains were detectable by RAPD using 41 different

primers indicating that no major genomic
rearrangements were present. Subtractive PCR generated a number of fragments,

1 of which was shown to correspond
to an over-expressed mRNA in the R strain and to encode a fragment of the

subunit 1 of cytochrome-c oxidase (SCOX1).
In the absence of a complete sequence for this gene, we used EST sequences

to compile a consensus sequence for the
904 bp at the 3′ end that enabled us to choose primers for semi-quantitative

RT–PCR. This technique showed that SCOX1
was indeed over-expressed about 5 to 10-fold in the R strain whereas the
genes
encoding the 28 kDa glutathione S-transferase, glutathione peroxidase,

NADH dehydrogenase subunit 5 and the ATP-binding cassette family protein

SMDR2 were not. In contrast, cytochrome-c oxidase enzyme
activity was 4-fold lower in the R strain than in the S strain.
Dynamics of natural infections of Rhabdias cf. hylae

(Nematoda) in Bufo marinus (Amphibia) in Australia
Authors: BARTON D. P.
Published: July 2002

Infrapopulation dynamics of the nematode Rhabdias cf.
hylae within naturally-infected Bufo marinus in north
Queensland,
Australia, were detailed. Over 80% of 580 toads were infected with Rh.
cf. hylae with a mean intensity of 16·1. Distribution
of Rh. cf. hylae within the toad population was aggregated,
with an increase in the variance-to-mean ratio with increasing
toad size. Intensity of infection and length of nematode were both correlated
with length of toad in the smaller size classes.
Length of nematode was not related to intensity of infection at any time.
Mean intensity of infection rose significantly in
small toads following initial infection after metamorphosis. Over the same
period, average length of nematode did not
increase implying constant re-infection of the toads. Larger toads were
not reinfected to the same extent, and the number
of uninfected toads in the larger size class increased which indicated
a natural loss of infections. Changes in parameters
of Rh. cf. hylae infection within B. marinus
were attributed to seasonal rainfall and its subsequent effect on the behaviour
of the toad.
Making Sense of Retributivism
Authors: Corlett J. Angelo
Published: July 2002

This paper explicates and challenges John Rawl's argument concerning a rule-utilitarian theory of punishment. In so doing, it argues in favour of a retributivist theory of punishment, one that seeks to justify, not only particular forms of punishment, but the institution of punishment itself. Some crucial objections to retributivism are then considered: one regarding the adverse effects of punishment on the innocent, another concerning proportional punishment, a third pertaining to vengeance and retribution, a Marxian concern with retributive punishment, and a concern with the concept of desert. Each objection is deflected in order to ward-off what seem to be the most serious criticisms of a retributivist view of punishment and to clarify the depth of the retributivist position.
Obsessive–compulsive disorder and separation anxiety co-morbidity in early onset panic disorder
Authors: GOODWIN R. , LIPSITZ J. D. , CHAPMAN T. F. , MANNUZZA S. , FYER A. J.
Published: July 2002

Background. This study was undertaken to examine the relationship between anxiety co-morbidity and age of onset of panic disorder.

Methods. Age of onset of panic disorder and co-morbid anxiety disorders were assessed among 201 panic disorder probands with childhood separation anxiety disorder, obsessive–compulsive disorder, obsessive–compulsive symptoms, social phobia and specific phobia as part of a clinician-administered lifetime diagnostic interview. A generalized linear model was used to test the association between each anxiety co-morbidity and age of panic disorder onset while simultaneously controlling for the potential confounding effects of sociodemographic characteristics and other psychiatric co-morbidity.

Results. Earlier onset of panic disorder was found in patients with co-morbid obsessive–compulsive disorder, obsessive–compulsive symptoms and separation anxiety disorder, but not simple phobia or social phobia. Patients with both childhood separation anxiety disorder and obsessive–compulsive disorder had an even earlier panic onset than those with either childhood separation anxiety disorder or obsessive–compulsive disorder.

Conclusions. The association between anxiety co-morbidity and earlier onset of panic disorder is specific to obsessive–compulsive disorder and childhood separation anxiety disorder.
Psychosocial sequelae of the 1989 Newcastle
earthquake: III. Role of vulnerability factors in post-disaster morbidity
Authors: CARR V. J. , LEWIN T. J. , KENARDY J. A. , WEBSTER R. A. , HAZELL P. L. , CARTER G. L. , WILLIAMSON M.
Published: July 2002

Background. This paper examines the contributions of dispositional and non-dispositional
factors to post-disaster psychological morbidity. Data reported are from the 845 participants in
the longitudinal component of the Quake Impact Study.

Methods. The phase 1 survey was used to construct dimensional indices of threat and disruption
exposure. Subsequently, a range of dispositional characteristics were measured, including
neuroticism, personal hopefulness and defence style. The main morbidity measures were the General
Health Questionnaire (GHQ-12) and Impact of Event Scale (IES).

Results. Dispositional characteristics were the best predictors of psychological morbidity
throughout the 2 years post-disaster, contributing substantially more to the variance in morbidity
(12–39%) than did initial exposure (5–12%), but the extent of their contribution was greater for
general (GHQ-12) than for post-traumatic (IES) morbidity. Among the non-dispositional
factors, avoidance coping contributed equally to general and post-traumatic morbidity
(pr = 0·24). Life events since the earthquake (pr = 0·18), poor social
relationships (pr =−0·25) and
ongoing earthquake-related disruptions (pr = 0·22) also contributed to general morbidity, while
only the latter contributed significantly to post-traumatic morbidity (pr = 0·15).

Conclusions. Medium-term post-earthquake morbidity appears to be a function of multiple
factors whose contributions vary depending on the type of morbidity experienced and include
trait vulnerability, the nature and degree of initial exposure, avoidance coping and the nature
and severity of subsequent events.
How distinct is ‘distinct quality’ of mood?
Authors: PARKER G. , ROUSSOS J. , EYERS K. , WILHELM K. , MITCHELL P. , HADZI-PAVLOVIC D.
Published: July 2002

Background. The DSM-IV criteria for melancholia
include the clinical feature ‘distinct quality’, defined
as a mood state differing from that experienced in bereavement. Both
propositions – its specificity to melancholia and its definition
– remain problematical.

Methods. We examine both propositions by analysing an
adjective checklist completed by melancholic and non-melancholic
depressed subjects, as well as by a bereaved sample. The checklist was
refined by a principal components analysis to four scales – one
assessing a general ‘mood’ severity or dysphoric
dimension, and the other three assessing dimensions of
‘fatigue’, ‘numbness’ and
‘guilt’.

Results. If the concept of ‘distinct quality’
has validity, we would require specificity of the refined qualitative
constructs to melancholic depression. The ‘numbness’
component met that requirement, but only to a degree. While bereaved
subjects did differ from those with melancholic depression on a number
of our refined qualitative mood domains, such differences appeared
more related to lower levels of depression in the bereaved sample.

Conclusions. We argue for deleting the ‘distinct
quality’ criterion from diagnostic checklists of melancholia
until its definition has been improved, its utility demonstrated and
its specificity to any depressive subtype established as having
clinical significance.
Types of social support as predictors of psychiatric
morbidity in a cohort of British Civil Servants (Whitehall II Study)
Authors: STANSFELD S. A. , FUHRER R. , SHIPLEY M. J.
Published: July 2002

Background. Few studies have examined prospectively
both the direct and buffering effects of types
of social support and social networks on mental health. This
paper reports longitudinal associations
between types of social support and psychiatric morbidity from the Whitehall
II study.

Methods. Social support was measured by the Close Persons Questionnaire

and psychiatric morbidity by the General Health Questionnaire at baseline

(1985–1988) and at first follow-up (1989)
in 7697 male and female London-based civil servants aged
35–55 years at baseline. The cohort was
followed up and baseline measures were used to predict psychiatric disorder
measured by the
General Health Questionnaire at second follow-up (1991–1993).

Results. Longitudinal analyses showed that low confiding/emotional

support in men and high
negative aspects of close relationships in men and women were associated
with greater risk of
psychiatric morbidity even after adjustment for baseline General
Health Questionnaire score. There
was no evidence of a buffering effect among men or women who experienced
life events or chronic
stressors. Controlling for a personality measure of hostility
did not affect the observed relations.

Conclusions. The present findings illustrate that different
types of support are risk factors for
psychological distress and that they operate in different ways
for men and women. Direct effects of
emotional support are predictive of good mental health in men and negative
aspects of close
relations predict poor mental health in both men and women. Emotional support
is predictive of
good mental health in women whereas, confiding alone is not.
Antidepressant agents: from tricyclics to serotonin uptake inhibitors
Authors: GARATTINI S. , BARBUI C. , SARACENO B.
Published: July 2002

Background. The number of antidepressant drugs
available in the market has grown rapidly in the
last few years. The present paper underlines some of the pre-clinical
and clinical problems that call
close attention from the regulatory authorities when approving new drugs.

Methods. We present here a review of the literature.

Results. A wide heterogeneity in the action of the various

antidepressants precludes any single
theory about the pathogenesis and therapy of depression. Antidepressant

activity, in fact, may be
achieved by acting on a number of different monoaminergic mechanisms. The
variety in the
neurochemical effects of antidepressants is not reflected in clinical
trials, which tend to stereotypy.
In many cases clinical trials aim at demonstrating equivalence rather
than differences in efficacy.
Regulatory authorities should, therefore, pay attention in accepting
the equivalence of effects of a
new drug in relation to a reference one: most clinical trials of new
antidepressant drugs do not have
the power to detect clinically relevant differences.

Conclusions. Unconventional new pre-clinical tests are
needed to generate antidepressants with a
different mechanism of action. Clinical studies are needed to promote objective
comparative
evaluation of the cost, benefits and toxic effects of new antidepressants.
Non-melancholic depression: the contribution of
personality, anxiety and life events to subclassification
Authors: PARKER G. , HADZI-PAVLOVIC D. , ROUSSOS J. , WILHELM K. , MITCHELL P. , AUSTIN M.-P. , HICKIE I. , GLADSTONE G. , EYERS K.
Published: July 2002

Background. We sought to develop a clinically useful
subtyping system for the non-melancholic
depressive disorders, and here we assess one weighted to central aetiological
factors.

Methods. We studied 185 patients meeting DSM-III-R
and/or clinical criteria for non-melancholic
depression. Data were obtained by self-report, interview of patients and
from corroborative
witnesses. We developed a set of variables for class definition,
assessing: (i) ‘P’, disordered
personality as a vulnerability factor; (ii) ‘A’,
meeting criteria for a lifetime anxiety disorder or
positive on probe questions about trait anxiety characteristics,
so assessing anxiety as a vulnerability
factor; and (iii) ‘L’, psychiatrist and
consensually-rated life event stress prior to depression onset.

Results. A latent class analysis generated a four-class
solution for the P–A–L variables. Life event
stressors had similar item probabilities across all four classes,
and did not influence the four-class
‘P–A’ solution when deleted from the analysis,
suggesting that life event stress may act more as a
general provoking agent, rather than constituting any distinct
‘reactive’ or ‘situational’ depression
class. Three classes generated clinically meaningful groupings,
reflecting varying contributions of
anxiety and disordered personality functioning, and with evidence of
differential outcome over the following 12 months.

Conclusions: We suggest that a refined aetiologically-weighted

model may assist definition of the
non-melancholic depressive disorders, and provide the logic for exploring

the comparative utility of
differing treatments to identified vulnerability-based classes.
How rational is rational theology?
A reply to Mikael Stenmark
Authors: BRÜMMER VINCENT
Published: July 2002

In this response to Stenmark's critique of my views on rational
theology,
I concentrate on his distinction between the epistemic and the practical
goals of
religion and between descriptive and normative rational theology. With
regard to
the first distinction, I grant that truth claims play an essential role
in religious belief
and that it is indeed the task of philosophy of religion to decide on the
meaning and
rationality of such claims. I argue, however, that since such claims are
internally
related to the practical context of religious belief, their meaning and
rationality
cannot be determined apart from this context as is done in the kind of
rational
theology which Stenmark calls ‘scientific’.
With regard to the second distinction, I
reject Stenmark's view that philosophy of religion has a descriptive
task with
reference to religion, and hence also his claim that I have put forward
a false
description of ‘the religious language game’.