bluuebunny/crossref_metadata_2025 huggingface dataset:
Examination of the flow near the
leading edge of attached cavitation.
Part 2. Incipient breakdown of two-dimensional
and axisymmetric cavities
Authors: LEGER A. TASSIN , BERNAL L. P. , CECCIO S. L.
Published: July 2002

Local and global three-dimensionality of cavity interfaces near
detachment was examined.
Cavities forming on hydrophilic test objects at higher Reynolds numbers

(Re>105) exhibited a local flow structure in
the cavity interface called ‘divots’.
Divots resulted from a local breakdown of the two-dimensional laminar boundary

separation. Divots did not form on hydrophobic test objects. Instead, at
higher
Reynolds numbers (Re>105), the cavity at
detachment was composed of a series of
wedge shaped structures. Flows with strong adverse pressure gradients upstream
of
cavity detachment exhibited only local three-dimensionality near one cavity
detachment.
Flows with weak adverse pressure gradients upstream of cavity detachment
were
more susceptible to breakdown into global three-dimensionality. This was
the case for
cavitation on the hydrofoils. Holographic particle imaging velocimetry
(HPIV) was
used to examine the spanwise and streamwise variation of the flow upstream
of the
cavity detachment. Three-dimensionality of the cavity detachment was associated
with
strong variations of the flow upstream of the cavity in the direction perpendicular
to
the mean flow direction.
Mechanics of nonlinear short-wave generation
by a moored near-surface buoy
Authors: ZHU Q. , LIU Y. , TJAVARAS A. A. , TRIANTAFYLLOU M. S. , YUE D. K. P.
Published: July 2002

We consider the nonlinear interaction problem of surface waves
with a tethered
near-surface buoy. Our objective is to investigate mechanisms for nonlinear
short
surface wave generation in this complete coupled wave–buoy–cable
dynamical system.
We develop an effective numerical simulation capability coupling an efficient
and
high-resolution high-order spectral method for the nonlinear wave–buoy
interaction
problem with a robust implicit finite-difference method for the cable–buoy
dynamics.
The numerical scheme accounts for nonlinear wave–wave and wave–body
interactions
up to an arbitrary high order in the wave steepness and is able to treat
extreme motions
of the cable including conditions of negative cable tension. Systematic
simulations
show that beyond a small threshold value of the incident wave amplitude,
the buoy
performs chaotic motions, characterized by the snapping of the cable. The
root
cause of the chaotic response is the interplay between the snapping of
the cable
and the generation of surface waves, which provides a source of strong
(radiation)
damping. As a result of this interaction, the chaotic buoy motion switches
between
two competing modes of snapping response: one with larger average peak
amplitude
and lower characteristic frequency, and the other with smaller amplitude
and higher
frequency. The generated high-harmonic/short surface waves are greatly
amplified
once the chaotic motion sets in. Analyses of the radiated wave spectra
show significant
energy at higher frequencies which is orders of magnitude larger than can
be expected
from nonlinear generation under regular motion.
Nonlinear radiated and diffracted waves due to
the motions of a submerged circular cylinder
Authors: LIU YUMING , ZHU QIANG , YUE DICK K. P.
Published: July 2002

We study the high-harmonic surface wave associated with nonlinear
diffraction and
radiation of gravity waves by a near-surface circular cylinder. Based on
nonlinear
potential-flow theory, we show analytically, using a boundary-integral
equation
method, that: (a) for a circular motion of the cylinder, the leading-order
outgoing
radiated waves at any harmonic are generated only in one direction; (b)
for a cylinder
free to respond to regular incident waves, the total leading-order scattered
waves at
any harmonic are two orders smaller upstream of the body. These theoretical
results
are substantially confirmed by direct time-domain simulations of the problem.
The focusing of surface waves by internal waves
Authors: DONATO A. N. , PEREGRINE D. H. , STOCKER J. R.
Published: July 2002

The surface current generated by internal waves in the ocean affects
surface gravity
waves. The propagation of short surface waves is studied using both simple
ray
theory for linear waves and a fully nonlinear numerical potential solver.
Attention
is directed to the case of short waves with initially uniform wavenumber,
as may be
generated by a strong gust of wind. In general, some of the waves are focused
by the
surface current and in these regions the waves steepen and may break. Comparisons

are made between ray theory and the more accurate solutions. For ray theory,
the
occurrence of focusing is examined in some detail and exact analytic solutions
are
found for rays on currents with linear and quadratic spatial variation
– only the latter
giving focusing for our initial conditions. With regard to interpretation
of remote
sensing of the sea surface, we find that enhanced wave steepness is not
necessarily
associated with a particular phase of the internal wave, and simplistic
interpretations
may sometimes be misleading.
An experimental study of recirculating flow
through fluid–sediment interfaces
Authors: KHALILI A. , BASU A. J. , PIETRZYK U. , RAFFEL M.
Published: July 2002

We report here visualizations and quantitative measurements of
scalar transport,
under the influence of rotation, through permeable sediments with an overlying
fluid
layer. The experimental set-up considered here is a stationary cylinder
containing a
fluid-saturated porous medium up to its midheight, with supernatant water
on top.
A rotating lid generates, in the upper fluid region, a flow that partially
percolates
into the porous layer below. The velocity field in the fluid layer is obtained
using
particle image velocimetry (PIV). Further, dye transport from the sediment
is studied
using two different techniques. The first one is positron emission tomography
(PET),
a non-invasive method which allowed us to ‘see’ through the
opaque solid matrix, and
to obtain full three-dimensional pictures of dye transport through the
sediment. The
second one is digital photographic visualization from outside, and subsequent
image
processing in order to obtain the near-wall dye-washout depth. The experimental
data
suggest that the temporal evolution of washout depth for different sediments
follows
near-logarithmic behaviour. This finding is of importance for the a
priori estimation
of the transport of fluid and other solute substances in sandy aquatic sediments.
Planetary waves in a stratified ocean of variable
depth. Part 2. Continuously stratified ocean
Authors: BOBROVICH A. V. , REZNIK G. M.
Published: July 2002

Linear Rossby waves in a continuously stratified ocean over a corrugated rough-bottomed topography are investigated by asymptotic methods. The main results are
obtained for the case of constant buoyancy frequency. In this case there exist three
types of modes: a topographic mode, a barotropic mode, and a countable set of
baroclinic modes. The properties of these modes depend on the type of mode, the
relative height δ of the bottom bumps, the wave scale
L, the topography scale Lb and
the Rossby scale Li. For small δ
the barotropic and baroclinic modes are transformed
into the ‘usual’ Rossby modes in an ocean of constant depth and the topographic
mode degenerates. With increasing δ the frequencies of the barotropic and topographic
modes increase monotonically and these modes become close to a purely topographic
mode for sufficiently large δ. As for the baroclinic modes, their frequencies do not
exceed O(βL) for any δ. For large δ the
so-called ‘displacement’ effect occurs when
the mode velocity becomes small in a near-bottom layer and the baroclinic mode does
not ‘feel’ the actual rough bottom relief. At the same time, for some special values
of the parameters a sort of resonance arises under which the large- and small-scale
components of the baroclinic mode intensify strongly near the bottom.

As in the two-layer model, a so-called ‘screening’ effect takes place here. It implies
that for Lb<Li
the small-scale component of the mode is confined to a near-bottom
boundary layer (Lb/Li)H
thick, whereas in the region above the layer the scale L of
motion is always larger than or of the order of Li.
The vortices of homogeneous geostrophic turbulence
Authors: McWILLIAMS JAMES C. , WEISS JEFFREY B. , YAVNEH IRAD
Published: July 2002

A coherent-vortex analysis is made of a computational solution for the free decay of
homogeneous, Charney-isotropic geostrophic turbulence at large Reynolds number.
The method of analysis is a vortex detection and measurement algorithm that we call
a vortex census. The census demonstrates how, through non-conservative interactions
among closely approaching vortices, the vortex population evolves towards fewer,
larger, sparser, and more weakly deformed vortices. After emergence from random
initial conditions and a further period of population adjustment, there is a period of
approximately self-similar temporal evolution in the vortex statistics. This behaviour
is consistent with a mean-vortex scaling theory based on the conservation of energy,
vortex extremum, and vortex aspect ratio. This period terminates as the population
approaches a late-time non-turbulent end-state vortex configuration. The end state
develops out of merger and alignment interactions among like-sign vortices, and even
during the scaling regime, local clusters of nearly aligned vortices are common.
Experimental study of collisional granular flows down an inclined plane
Authors: AZANZA EMMANUEL , CHEVOIR FRANÇOIS , MOUCHERONT PASCAL
Published: July 2002

The collisional flow of a slightly inelastic granular material down a rough inclined
plane is usually described by kinetic theories. We present an experimental study
aimed at analysing the assumptions and the quantitative predictions of such theories.
A two-dimensional channel coupled to a model granular material and image analysis
allow detailed and complete measurement of the kinematics and structure of the
flows. We determine the range of inclination and particle flux for which the flow is
stationary and uniform. The characteristic profiles of solid fraction, mean velocity and
granular temperature are systematically measured. Both the true collisional and the
dilute kinetic regimes are examined. We show that a quasi-hydrodynamic description
of these regimes seems relevant, and that the pressure and the viscosity terms are in
good qualitative agreement with the prediction of the kinetic theory. The profiles are
well described by the kinetic theory near the top of the flow, at low solid fraction.
Conversely there are large discrepancies near the rough plane, where the material is
structured in layers.
Do longshore bars shelter the shore?
Authors: YU JIE , MEI CHIANG C.
Published: July 2002

In most past theories on Bragg reflection of waves by a finite patch of rigid bars,
only outgoing waves are allowed on the transmission side, simulating the effect of an
idealized shoreline where all the incident wave energy is consumed by breaking. In
these theories the amplitudes of both the incident and reflected waves are found to
decrease monotonically over the bar patch in the shoreward direction. This result has
motivated the idea of artificially constructing bars to protect a beach from incident
waves. However, some numerical calculations have suggested that this tendency does
not always hold when there is some reflection from the shore. We show here that with
finite reflection by the shoreline the spatial distribution of wave energy over the patch
can indeed be reversed, indicating that the mechanism can increase the hazards to
the beach. The phase relation between the bars and the shoreline reflection is found
to be the key to this qualitative change of wave response.
Structure, diffusion and rheology of Brownian
suspensions by Stokesian Dynamics simulation
Authors: FOSS DAVID R. , BRADY JOHN F.
Published: July 2002

The non-equilibrium behaviour of concentrated colloidal dispersions is studied using
Stokesian Dynamics, a molecular-dynamics-like simulation technique for analysing
suspensions of particles immersed in a Newtonian fluid. The simulations are of a
monodisperse suspension of Brownian hard spheres in simple shear flow as a function
of the Péclet number, Pe, which measures the relative importance of hydrodynamic
and Brownian forces, over a range of volume fraction
0.316 [les ] ϕ [les ] 0.49. For Pe < 10,
Brownian motion dominates the behaviour, the suspension remains well-dispersed,
and the viscosity shear thins. The first normal stress difference is positive and the
second negative. At higher Pe, hydrodynamics dominate resulting in an increase in the
long-time self-diffusivity and the viscosity. The first normal stress difference changes
sign when hydrodynamics dominate. Simulation results are shown to agree well with
both theory and experiment.
Presupposition-cancellation and metalinguistic
negation: a reply to Carston
Authors: BURTON-ROBERTS NOEL
Published: July 2002

This is a response to Carston's critique of my account of presupposition-cancellation.
While accepting her demonstration that (contra ‘On Horn's dilemma’)
presupposition-cancellation does not involve a linguistically encoded contradiction, I
show that this is nevertheless consistent with the account of presupposition proposed
in Burton-Roberts 1993/7. In fact, Carston's and my accounts of presupposition-cancellation both treat it as involving a pragmatically derived contradiction. I also
reconsider the nature of so-called ‘metalinguistic negation’, arguing against Carston
that there is a special use of negation (!MN) which involves a use-mention mix and
a pragmatically derived contradiction, and is non-truth-functional. I show that,
although !MN is echoic, not all echoic negations are examples of !MN.
Linear and nonlinear resonant interaction of sound waves in dissipative layers
Authors: BALLAI I. , ERDÉLYI R. , GOOSSENS M.
Published: July 2002

The theory of resonant nonlinear magnetohydrodynamic (MHD) waves
in dissipative steady plasmas developed by Ballai and Erdélyi is used to study the
effect of steady flows on nonlinear resonant heating of MHD waves in (a) linear, (b)
weakly and (c) strongly nonlinear approximations. Nonlinear connection formulae
for slow MHD waves are derived. This nonlinear theory of driven MHD waves is
then used to study the interaction of sound waves with one-dimensional isotropic
steady plasmas. We find that a steady equilibrium flow can significantly influence
the efficiency of resonant absorption in the considered limits. In the case of strong
nonlinearity, the efficiency of the resonant coupling is found to be proportional to
the counterpart obtained in linear theory. The factor of proportion is approximately
of the order of unity, justifying the commonly applied linear approximations.
Analysis of rippled shock-wave propagation and
ablation-front stability by theory and
hydrodynamic simulation
Authors: MATSUI N. , MIMA K. , HONDA M. , NISHIGUCHI A.
Published: July 2002

The hydrodynamic start-up problem is one of the most crucial issues
in laser-driven symmetrical implosion. The target-surface roughness and initial
imprint
by nonuniform laser irradiation result in Rayleigh–Taylor instability
in the
acceleration and deceleration phase. To estimate the tolerance of the target-surface roughness, the temporal behaviour of corrugated ablation surface
and rippled shock-wave propagation are investigated using a perturbation analysis
of the fluid equation, which is solved under the boundary model of a fire-polished ablation surface. The results show good agreement with two-
dimensional hydrodynamic simulation and experimental results [T. Endo
et al.,
Phys. Rev. Lett.74, 3608 (1995)].
Polychaetes from the Atlantic seamounts of the southern Azores: biogeographical distribution and reproductive patterns
Authors: Gillet Patrick , Dauvin Jean-Claude
Published: July 2002

A study of the polychaetes living on isolated seamounts was undertaken to give data on marine biogeography and the dispersal of marine invertebrates. The data from the Meteor and Josephine seamounts came from Hartmann-Schröder and Rosenfeldt's work in the 1980s. Data from Hyeres came from Bellan's work in the 1960s, and data from the Atlantis and Hyeres seamounts were obtained during the Seamount 2 French expedition on board the ‘Suroît’ in 1993. Thirty-five sites from 280 to 2205 m were sampled: 16 on Atlantis (13 with polychaetes), and 19 on Hyeres (16 with polychaetes). In all 84 polychaete taxa from four seamounts were studied: Atlantis, 36; Hyeres, 33; Josephine, 34; and Meteor 50, but data analysis was based on the following number of taxa: Atlantis, 31; Hyeres, 29; Josephine, 34, and Meteor 48. Two groups of sites were identified by cluster analysis: I, Atlantis and Hyeres; and II, Josephine and Meteor. Only seven species were present at all sites. Nine families were present only in group I and six other families only in group II. Hesionidae (three species) occurred in group I, conversely Syllidae (16 species) were sampled only in group II. Some of the species were cosmopolitan (31%), 49% had a large distribution in the Atlantic, 11% were lusitano–mauretanian species, and only 6% were endemic; 51% of the species have direct development against 46% of the species which had a planktotrophic development and 3% a lecithotrophic development. Results of the biogeographical distribution and reproductive patterns of the polychaetes collected on these four sites were compared.
Distribution and damage to the by-catch assemblages of the northern Irish Sea scallop dredge fisheries
Authors: Veale L.O. , Hill A.S. , Hawkins S.J. , Brand A.R.
Published: July 2002

The major by-catch species retained during twice yearly dredge surveys of great scallop, Pecten maximus, and queen scallop, Aequipecten opercularis, (both Mollusca: Pectinidae) populations on 13 fishing grounds in the northern Irish Sea, over a period of five years, were identified and enumerated. Additionally, the damage sustained by the by-catch was assessed and related to a range of physical parameters recorded during the survey. A number of species captured in the spring-toothed dredges exhibited differences in abundance and damage sustained between years, and also between the start and end of the closed season for great scallop fishing (1 June–31 October). The by-catch assemblage varied geographically, dependent upon the underlying community structure, as well as putative factors including gear efficiency and substratum type. Two clear assemblage types were identified by multivariate analysis, one to the south-west of the Isle of Man, the other covering fishing grounds to the north, east and south of the island. There is a hierarchy of species sensitivity to damage in great and queen scallop dredges, probably related to morphological and behavioural characteristics. This selective mortality of a fraction of the community may have long-term implications at the ecosystem level. The degree of damage sustained by many species is related to both the volume of stones retained in the dredge, and the total volume of the catch (dredge fullness). If these were reduced, the overall magnitude of incidental by-catch mortality would be lower.
Morphological characteristics of young, maternal care behaviour and microhabitat use by caprellid amphipods
Authors: Aoki Masakazu
Published: July 2002

Microhabitat use by nine species of caprellid amphipods in the genus Caprella inhabiting a Japanese Sargassum bed could be divided into three major categories. Differences in the patterns of use were closely related to the nature of the mother–young association and morphological characteristics of young. Pattern A was shown by three species Caprella danilevskii, C. okadai and C. subinermis that produced large first instar young (>1.6 mm in body length, BL) with no maternal care, and directly use Sargassum thalli as habitat substrata throughout their lives. Two different patterns of microhabitat use occur in the six other species, which produce small first instar young (<1.3 mm BL) and have trouble using Sargassum thalli as their primary habitat. Pattern B comprised of C. decipiens, C. monoceros and C. scaura in which females care for their young until they become large enough to disperse onto the seaweed thalli. The first instar young of these three maternal care species have specialized pereopods. In Caprella monoceros and C. scaura, which show a ‘cling-to-mother’ type of maternal care, each pereopod has a concaved margin on the propodus and a long dactylus, well adapted for clinging to the mother, and C. decipiens, which show a ‘stay-around-mother’ type of maternal care, have comparatively slender and longer pereopods to hold onto seaweed branches near their mother. Pattern C included C. arimotoi, C. glabra and C. penantis which showed no maternal care and use thin branches of epizoites such as epiphytic hydroids as their primary substrata. It is concluded that caprellids that live on seaweed with thick thalli and branches such as Sargassum patens have different solutions to the problem of where the small first instar young can live: species with larger young emerge directly onto seaweed thalli, but species with smaller young use an epiphytic secondary habitat or depend on maternal care.
Young cuttlefish Sepia officinalis (Mollusca: Sepiidae) in the Morbihan Bay (south Brittany, France): accessory prey of predators
Authors: Blanc A. , Daguzan J.
Published: July 2002

Morbihan Bay, France, is an important spawning area and nursery grounds for young cuttlefish. The eggs and the young cuttlefish are subjected to predatory species of fish. These were identified by analysing the stomach contents of 26 species and two species of cephalopods. Five fish species were found to be predators of young cuttlefish. The Balistes carolinensis feeds on the eggs, and Dicentrarchus labrax, Labrus bergylta, Spondyliosoma cantharus, and Conger conger eat young cuttlefish, from 8 mm (hatching cuttlefish) to 61 mm in mantle length (cuttlefish about 4-months old).
The public health significance of Trichuris trichiura
Authors: STEPHENSON L.S. , HOLLAND C.V. , COOPER E.S.
Published: July 2002

An estimated 1049 million persons harbour T. trichiura, including 114 million preschool-age children and 233 million school-age children. The prevalence of T. trichiura is high and may reach 95% in children in many parts of the world where protein energy malnutrition and anaemias are also prevalent and access to medical care and educational opportunities is often limited. The Trichuris dysentery syndrome (TDS) associated with heavy T. trichiura, which includes chronic dysentery, rectal prolapse, anaemia, poor growth, and clubbing of the fingers constitutes an important public health problem, as do lighter but still heavy infections, even if not strictly TDS, especially in children. The profound growth stunting in TDS can be reversed by repeated treatment for the infection and, initially, oral iron. However findings from Jamaica strongly suggest that the significant developmental and cognitive deficits seen are unlikely to disappear without increasing the positive psychological stimulation in the child's environment. The severe stunting in TDS now appears likely to be a reaction at least in part to a chronic inflammatory response and concomitant decreases in plasma insulin-like growth factor-1 (IGF-1), increases in tumor necrosis factor-α (TNF-α) in the lamina propria of the colonic mucosa and peripheral blood (which likely decrease appetite and intake of all nutrients) and a decrease in collagen synthesis. Improvements in cognitive performance have been found after treatment for relatively heavy infections (without chronic dysentery) in school-going children; it is unclear precisely how much T. trichiura interferes with children's ability to access educational opportunities, but treatment of infections whenever possible is obviously sensible. The blood loss that can occur in T. trichiura infection is likely to contribute to anaemia, particularly if the child also harbours hookworm, malaria and/or has a low intake of dietary iron. Community control is important, particularly for the individuals within a population who harbour heavy worm burdens; this means children, with special attention to girls who will experience increased iron requirements and blood loss due to menstruation, pregnancies, and lactation. Mebendazole and albendazole, both of which are on the WHO Essential Drugs List, are very effective against T. trichiura; multiple doses are needed to attain complete parasitological cure in all cases. However the goal of control programmes in endemic areas is morbidity reduction, which follows when intensity of infection is significantly reduced.
Toxicity of cadmium and zinc to miracidia of Schistosoma mansoni
Authors: MORLEY N.J. , CRANE M. , LEWIS J.W.
Published: July 2002

The specific objectives of this study were to elucidate metal toxicity to hatching, survival and avoidance behaviour of Schistosoma mansoni miracidia. The toxicity of cadmium, zinc, and cadmium/zinc mixtures at concentrations ranging from 10000 to 10μg/l was investigated. Metal mixture toxicity investigation was undertaken with equal concentrations of the metals. The hatching of miracidia from eggs was inhibited by concentrations of 1000–10000μg/l of single metals. Metal mixtures had no effect on egg hatching. Survival of miracidia was reduced by increasing metal concentration except at concentrations of 10μg/l for single metal toxicity where survival was increased above the control. Miracidia demonstrated a rapid avoidance behaviour when briefly exposed to heavy metals. The mechanisms of metal toxicity to miracidia are briefly discussed.
Genetic diversity among Trypanosoma brucei rhodesiense

isolates from Tanzania
Authors: KOMBA E. K. , KIBONA S. N. , AMBWENE A. K. , STEVENS J. R. , GIBSON W. C.
Published: July 2002

We compared 19 stocks of Trypanosoma brucei rhodesiense

collected in 1991 and 1994 from Tanzania with representative

stocks from other foci of Rhodesian sleeping sickness in Zambia, Kenya

and Uganda. Stocks were characterized by

isoenzyme electrophoresis, restriction fragment length polymorphisms in

variant surface glycoprotein genes and random

amplification of polymorphic DNA; the banding patterns obtained were coded
for

numerical analysis. In addition, the

Tanzanian stocks were compared by pulsed field gel electrophoresis.

Overall the Tanzanian stocks formed a homogeneous

group and the predominant genotype isolated in 1991 was still present in

the 1994 sample, although at a reduced level.

The Tanzanian stocks were distinct from representative stocks from other

East African foci. This observation does not

support the proposal that there are northern and southern strains of

T. b. rhodesiense, but is consistent with the view that

T. b. rhodesiense stocks form a mosaic of different genotypes

varying from focus to focus in East Africa.
Protease activity in the larval stage of the parasitoid wasp,
Eulophus pennicornis (Nees) (Hymenoptera: Eulophidae);
effects of protease inhibitors
Authors: DOWN R. E. , FORD L. , MOSSON H. J. , FITCHES E. , GATEHOUSE J. A. , GATEHOUSE A. M. R.
Published: July 2002

Hymenopteran, parasitoid wasps have good potential for use in integrated pest management (IPM); for example, the
gregarious ectoparasitoid, Eulophus pennicornis, has been suggested as a biological control agent for larvae of the tomato
moth (Lacanobia oleracea L.). However, the processes by which such parasitic larvae are able to utilize the nutritional
resource provided by the host have been little studied. Protease activity was present in E. pennicornis larvae, and characterization
of the enzymes responsible for proteolysis was performed using a range of synthetic substrates and specific inhibitors.
Serine protease enzymes was both trypsin- and chymotrypsin-like activities were present. A range of plant-derived serine
protease inhibitors was tested for activity against these enzymes. Certain inhibitors, notably soybean Kunitz inhibitor
(SKTI), inhibited enyzme activity by >80% at <10−5M. When SKTI was fed to L. oleracea larvae in an artificial diet,
the inhibitor was subsequently detected within the larval haemolymph, showing that protease inhibitors in the host diet
can be delivered to a parasitoid via the host haemolymph. If transgenic plants expressing foreign protease inhibitors for
protection against insect pests are to form a component of IPM systems, possible adverse effects, whether direct or indirect,
of transgene expression on parasitoids like E. pennicornis should be considered.
Conflict between co-occurring manipulative parasites?
An experimental study of the joint influence of
two acanthocephalan parasites on the
behaviour of Gammarus pulex
Authors: CEZILLY F. , GREGOIRE A. , BERTIN A.
Published: July 2002

When two parasite species are manipulators and have different definitive hosts, there is a potential for conflict between
them. Selection may then exist for either avoiding hosts infected with conflicting parasites, or for hijacking, i.e.
competitive processes to gain control of the intermediate host. The evidence for both phenomena depends largely on the
study of the relative competitive abilities of parasites within their common intermediate host. We studied the effects of
simultaneous infection by a fish acanthocephalan parasite, Pomphorhynchus laevis, and a bird acanthocephalan parasite,
Polymorphus minutus, on the behaviour of their common intermediate host, the amphipod Gammarus pulex. We compared
the reaction to light and vertical distribution of individuals infected with both parasites to those of individuals harbouring
a single parasite species and uninfected ones under controlled conditions. Compared to uninfected gammarids that were
photophobic and tended to remain at the bottom of the water column, P. laevis-infected gammarids were attracted to light,
whereas P. minutus-infected individuals showed a modified vertical distribution and were swimming closer to the water
surface. The effects of both P. laevis and P. minutus appeared to be dependent only on their presence, not on their intensity.
Depending on the behavioural trait under study, however, the outcome of the antagonism between P. laevis and P. minutus
differed. The vertical distribution of gammarids harbouring both parasites was half-way between those of P. laevis- and
P. minutus-infected individuals, whereas P. laevis was able to induce altered reaction to light even in the presence
of P. minutus. We discuss our results in relation to the occurrence of active avoidance or hijacking between conflicting
manipulative parasites and provide some recommendations for future research.
Anorexia in rats infected with the nematode,
Nippostrongylus brasiliensis: experimental manipulations
Authors: MERCER J. G. , MITCHELL P. I. , MOAR K. M. , BISSETT A. , GEISSLER S. , BRUCE K. , CHAPPELL L. H.
Published: July 2002

Nippostrongylus brasiliensis induces a biphasic anorexia in laboratory rats, the first phase coincident with lung invasion (ca
day 2) and the second when the worms mature in the intestine (ca day 8). Using the anthelminthic, mebendazole (MBZ),
N. brasiliensis infections of the rat were eliminated between the first and second anorexic episodes. This intervention
prevented the expression of the second phase of anorexia. Rats exposed to a second infection with N. brasiliensis, 3 weeks
after the primary infection, exhibited only a first phase anorexic response which was not influenced by MBZ termination
of the primary infection. The lower cumulative food intake and weight gain of all infected rats after 8 days of infection
were accompanied by elevated plasma insulin and, in some individuals, by elevated plasma leptin, compared with
uninfected controls and previously-infected MBZ-treated rats. Messenger RNA levels for neuropeptide Y were higher in
the hypothalamic arcuate nucleus of 8-day infected rats than in recovering MBZ-treated animals. Inoculation of rats with
heat-killed N. brasiliensis larvae failed to induce anorexia and did not alter the severity of biphasic anorexia on subsequent
injection of viable larvae. The first anorexic episode is therefore dependent upon viable migrating larvae. The second
phase of anorexia clearly requires the continuing presence of the parasite beyond the lung phase. Viable migrating larvae
are also required to confer ‘resistance’ to reinfection.
Wittgenstein: Science and Religion
Authors: Harré Rom
Published: July 2002

Extra-philosophical influences were very important in shaping Wittgenstein's philosophical ruminations. The Tractatus-Logico Philosophicus is misunderstood unless it is seen as deriving from the pre-Machian physics of the German tradition, adapted to the problems Russell confronted Wittgenstein with. In like manner, particularly in relation to the discussions of meanings and rules, the philosophy of the Philosophical Investigations is shaped by the role played by a powerful religious sensibility in Wittgenstein's extraordinary and tormented life.
Troubles with Time Travel
Authors: Grey William
Published: July 2002

Talk about time travel is puzzling even if it isn't obviously contradictory. Philosophers however are divided about whether time travel involves empirical paradox or some deeper metaphysical incoherence. It is suggested that time travel requires a Parmenidean four-dimensionalist metaphysical conception of the world in time. The possibility of time travel is addressed (mainly) from within a Parmenidean metaphysical framework, which is accepted by David Lewis in his defence of the coherence of time travel. It is argued that time travel raises formidable difficulties which are not satisfactorily resolved by Lewis's ingenious defence of time travel. Objections to time travel considered include: (1) travel to other times is impossible because there is nowhere (or “nowhen”) to go to; (2) the problem that upon setting out on a journey to the past a time machine will collide with itself; (3) time travel generates a mysterious temporal dualism between experiential time and physical time; (4) travel to the past permits reverse causation, raising the possibility of causal loops and attendant problems arising, for example, from the prospect of empirical contradiction and the possibility of someone being one of their ancestors.
Sex and depression
Authors: BEBBINGTON PAUL E.
Published: July 2002

Sex differences in rates of depressive disorder have not been

convincingly explained, and this reflects

a more general failure of research to provide a comprehensive

aetiological account of depression.

The difference can be used as a probe for evaluating the research

base of integrative models of

depressive disorder (e.g. Akiskal & McKinney, 1975). It is

particularly likely to be illuminating if

the causes of the sex difference do not overlap completely the

causes of depression itself. While there

have been many reviews in the area (Weissman & Klerman, 1977;

Kessler & McRae, 1981; Wolk

& Weissman, 1995; Bebbington, 1996), this point has not been

adequately expressed.

Several lines of investigation are necessary for assessing the

relative importance of social,

psychological and biological influences: the epidemiological study

of macrosocial variables and of

age effects; temperament, personality, and attributional and coping

styles; the experience of

psychosocial adversity; and the possibility of increased susceptibility

to some forms of stress in

women. Both the tendency to affiliation and the requirement for

social support may differ by sex.

The particular strains of the roles available to women may increase

their risk of depression. Possible

genetic explanations of the sex difference are of special relevance

because of their implications for

biological differences. The latter can also be studied directly:

hormonal theories in particular must be evaluated.
Plasma prolactin response to d-fenfluramine is
blunted in bulimic patients with frequent binge episodes
Authors: MONTELEONE P. , BRAMBILLA F. , BORTOLOTTI F. , FERRARO C. , MAJ M.
Published: July 2002

Background. Abnormalities of brain serotonin (5-HT)
transmission have been implicated in the
pathophysiology of bulimia nervosa (BN), but no conclusive data have yet
been provided. The
purpose of this study was to assess 5-HT transmission via the measurement
of the prolactin (PRL)
response to the specific 5-HT releasing agent d-fenfluramine
(d-FEN) in both patients with BN and comparison subjects.

Methods. According to a double-blind placebo-controlled
design, plasma PRL response to d-FEN
was measured in 14 drug-free bulimics and 14 matched healthy controls.
In both patients and
controls, eating-related psychopathology, depressive and obsessive–compulsive

symptoms, and aggressiveness were measured by rating scales.

Results. Baseline plasma levels of PRL and 17β-oestradiol

were significantly reduced in bulimic
patients, whereas basal plasma levels of cortisol did not significantly

differ from healthy controls.
PRL response to d-FEN was not different between patients and
controls as groups, but it was
significantly blunted in bulimics with high frequency bingeing
([ges ]2 binge episodes per day; N=7)
as compared to both those with low frequency bingeing ([les ]1 binge
episode per day; N=7) and
matched controls. A significant negative correlation emerged between the
frequency of binge
episodes and the hormone response to d-FEN. Moreover,
although patients scored higher than
healthy subjects on rating scales assessing depressive and
obsessive–compulsive symptoms and
aggressiveness, no significant correlation was found between these measures
and the PRL response
to d-FEN.

Conclusions. These results support the idea that serotonin

transmission is impaired in bulimic
patients with frequent binge episodes.
Socio-economic factors that predict psychiatric admissions at a local level
Authors: KOPPEL SIÂN , McGUFFIN PETER
Published: July 2002

Background. The aim of the study was to confirm the predictive relationship between socio-economic factors and psychiatric admissions at a fine grain geographical level. The strength of
association was compared with those of other studies that have looked at separate diagnostic
groups.

Method. Psychiatric admissions were from electoral wards of the County of South Glamorgan,
which encompasses the capital city of Wales, Cardiff. Standardized psychiatric admission ratios
(SAR) for different diagnostic groups were calculated for a 5-year period. The ecological association
with deprivation indices and with single variables at the level of electoral ward was examined. Of
a total of 15266 psychiatric admissions, 11296 were analysed.

Results. Psychiatric morbidity, reflected in SAR was inversely related to socio-economic deprivation
for both sexes. This applied to all diagnostic groups except organic disorders. The relationship was
most marked for schizophrenia, delusional disorders and substance abuse, closely followed by
personality disorders, and less for affective and neurotic disorders. Little difference existed between
three composite indices of deprivation (Carstairs, Jarman, Townsend), but the marginally best
predictor was that designed by Jarman. However, low rates of car ownership and high unemployment
were as good at predicting SAR as any of the compound indices.

Conclusion. Socio-economic factors account for almost 50% of the variance in psychiatric
admission rates between electoral wards. The degree of association between psychiatric morbidity
and deprivation varies between diagnostic groups, arguing against a common factor linking
deprivation and psychiatric admissions generally. Frequently updated unemployment figures
provide nearly as useful and more immediate information than 10-yearly Census data used to
calculate the deprivation indices. These figures may be used for needs assessment and targeting
resources at a local level.
Suicide and undetermined death in south east
Scotland. A case–control study using the
psychological autopsy method
Authors: CAVANAGH J. T. O. , OWENS D. G. C. , JOHNSTONE E. C.
Published: July 2002

Background. Mental disorders are major risk factors for suicide. Not all those who suffer from
mental disorders kill themselves. Additional information is required to differentiate higher and
lesser risk patients.

Methods. Retrospective case–control comparison was made of cases of suicide/undetermined
death with living controls using psychological autopsy in South East Scotland. Cases and controls
were matched for age, sex and mental disorder. Informants were those closest to cases and controls.
The subjects were 45 cases of suicide/undetermined death and 40 living controls.

Results. Cases and controls did not differ significantly in severity of mental disorder. The main
factors independently associated with undetermined death or suicide were: a history of deliberate
self-harm (adjusted OR 4·1); physical ill health (adjusted OR 7·8); and engagement by mental health
services (adjusted OR 0·01). Other antecedents associated with increased risk (criminal record,
police involvement, financial problems and failure to vote) and those associated with decreased risk
(contact with a doctor and in-patient care) did not exert effects after controlling for confounding.

Conclusions. Controls were receiving more care of whatever kind. Treatment of mental disorder
co-morbid with physical illness and a history of deliberate self-harm may be especially important.
Factors that separate those with mental disorder at high risk from those at lesser risk relate to care
levels provided, which may be a function of engagement by and with health services. The role of
mental health professionals is beneficial in suicide prevention. The focusing of that role towards
engaging alienated or ‘difficult’ patients should be addressed.
Thought Disorder Index of Finnish adoptees and
communication deviance of their adoptive parents
Authors: WAHLBERG K.-E. , WYNNE L. C. , OJA H. , KESKITALO P. , ANAIS-TANNER H. , KOISTINEN P. , TARVAINEN T. , HAKKO H. , LAHTI I. , MORING J. , NAARALA M. , SORRI A. , TIENARI P.
Published: July 2002

Background. Diverse forms of thought disorder, as measured by the Thought Disorder Index
(TDI), are found in many conditions other than schizophrenia. Certain thought disorder categories
are primarily manifest during psychotic schizophrenic episodes. The present study examined
whether forms of thought disorder qualify as trait indicators of vulnerability to schizophrenia in
persons who are not clinically ill, and whether these features could be linked to genetic or
environmental risk or to genotype–environment interactions. The Finnish Adoptive Study of
Schizophrenia provided an opportunity to disentangle these issues.

Methods. Rorschach records of Finnish adoptees at genetic high risk but without schizophrenia-related clinical diagnoses (N = 56) and control adoptees at low genetic risk (N = 95) were blindly
and reliably scored for the Thought Disorder Index (TDI). Communication deviance (CD), a
measure of the rearing environment, was independently obtained from the adoptive parents.

Results. The differences in total TDI between high-risk and control adoptees were not statistically
significant. However, TDI subscales for Fluid Thinking and Idiosyncratic Verbalization were more
frequent in high-risk adoptees. When Rorschach CD of the adoptive rearing parents was introduced
as a continuous predictor variable, the odds ratio for the Idiosyncratic Verbalization component of
the TDI of the high-risk adoptees was significantly higher than for the control adoptees.

Conclusions. Specific categories of subsyndromal thought disorder appear to qualify as vulnerability
indicators for schizophrenia. Genetic risk and rearing-parent communication patterns significantly
interact as a joint effect that differentiates adopted-away offspring of schizophrenic mothers from
control adopted-away offspring.
EEG frequency and the size of cognitive neuronal assemblies
Authors: von Stein Astrid , Sarnthein Johannes
Published: July 2002

We have performed a set of experiments that correlate EEG spectral parameters with cognitive functions. The tasks (visual perception, supramodal object recognition, short-term memory) were chosen so that the cortical area involved extended over different length scales. The extent of the cognitive neuronal assemblies correlated inversely with the frequency where EEG synchronization was found. This provides a further relation between experiment and the theory put forward in the Nunez target article.
Self-deceivers' intentions and possessions
Authors: Losonsky Michael
Published: July 2002

Although Mele's four sufficient conditions for
self-deception are on track insofar as they avoid the requirement
that self-deception involves contradictory beliefs, they are too weak,
because they are broad enough to include cases of bias or prejudice
that are not typical cases of self-deception. I discuss what
distinguishes self-deception from other forms of bias.
Seeing is not believing
Authors: Csibra Gergely
Published: July 2002

Heyes's proposed study for testing whether chimpanzees
have a theory of mind is (1) too strong because it requires that the
animals apply mental concepts to the interpretation of both their own
experiences and the behaviours of others, and (2) too weak because
dispositional rather than representational understanding of
“seeing” is sufficient to pass it.
No imitation without identification
Authors: de Waal Frans B. M.
Published: July 2002

We cannot solve questions about imitative learning without
knowing what motivates animals to copy others. Imitative capacities
can be expected to be most pronounced in relation to situations and
models of great social significance. Experimental research on nonhuman primates has thus far made little effort to present such situations
and models.
The neuron doctrine is an insult to neurons
Authors: Hameroff Stuart
Published: July 2002

As presently implemented, the neuron doctrine (ND) portrays the
brain's neurons and chemical synapses as fundamental components in
a computer-like switching circuit, supporting a view of brain =
mind = computer. However, close examination reveals individual
neurons to be far more complex than simple switches, with enormous
capacity for intracellular information processing (e.g., in the internal
cytoskeleton). Other poorly appreciated factors (gap junctions, apparent
randomness, dendritic-dendritic processing, possible quantum
computation, the living state) also suggest that the ND grossly
oversimplifies neuronal functions. In the quest to understand
consciousness, the presently implemented ND may throw out the baby
with the bath water.
The contribution of phonological and orthographic processing skills to adult ESL
reading: Evidence from native speakers of Farsi
Authors: NASSAJI HOSSEIN , GEVA ESTHER
Published: July 2002

The present study investigated the role of phonological and orthographic processing skills in
adult second language reading. The subjects were 60 ESL graduate students; all were native
speakers of Farsi. Three types of ESL reading measures were used as criterion variables: reading
comprehension, silent reading rate, and the ability to recognize individual words. Data were
analyzed using correlational and hierarchical multiple regression. Efficiency in phonological and
orthographic processing contributed significantly to individual differences on the reading
measures. In particular, efficiency in orthographic processing contributed to the reading measures
independently of syntactic and semantic measures. The study suggests that it is useful to consider
individual differences in ESL reading with respect to individual differences in lower level
processes – particularly the efficiency with which readers process phonological and
orthographic information.
Multifractal formalism for some parabolic maps
Authors: NAKAISHI KENTARO
Published: July 2002

We study multifractal spectra of a simple class of interval transformations with a neutral fixed point. The analyticity of their spectral curves depends on whether the absolutely continuous invariant measure is infinite or not.