bluuebunny/crossref_metadata_2025 huggingface dataset:
Motion of three point vortices in a periodic parallelogram
Authors: STREMLER MARK A. , AREF HASSAN
Published: July 2002

The motion of three interacting point vortices with zero net circulation in a periodic
parallelogram defines an integrable dynamical system. A method for solving this
system is presented. The relative motion of two of the vortices can be ‘mapped’ onto
a problem of advection of a passive particle in ‘phase space’ by a certain set of
stationary point vortices, which also has zero net circulation. The advection problem
in phase space can be written in Hamiltonian form, and particle trajectories are given
by level curves of the Hamiltonian. The motion of individual vortices in the original
three-vortex problem then requires one additional quadrature. A complicated structure
of the solution space emerges with a large number of qualitatively different regimes
of motion. Bifurcations of the streamline pattern in phase space, which occur as the
impulse of the original vortex system is changed, are traced. Representative cases are
analysed in detail, and a general procedure is indicated for all cases. Although the
problem is integrable, the trajectories of the vortices can be surprisingly complicated.
The results are compared qualitatively to vortex paths found in large-scale numerical
simulations of two-dimensional turbulence.
On the breakup of an air bubble injected into
a fully developed turbulent flow. Part 2.
Size PDF of the resulting daughter bubbles
Authors: MARTÍNEZ-BAZÁN C. , MONTAÑÉS J. L. , LASHERAS J. C.
Published: July 2002

Based on energy principles, we propose a statistical model to describe the bubble size
probability density function of the daughter bubbles resulting from the shattering of
a mother bubble of size D0 immersed in a fully developed turbulent water flow. The
model shows that the bubble size p.d.f. depends not only on D0, but also on the value
of the dissipation rate of turbulent kinetic energy of the underlying turbulence of the
water, ε. The phenomenological model is simple, yet it predicts detailed experimental
measurements of the transient bubble size p.d.f.s performed over a range of bubble sizes and
dissipation rates ε in a very consistent manner. The agreement between the model and the
experiments is particularly good for low and moderate bubble turbulent Weber numbers,
Wet =
ρΔu2(D0)D0/σ
where the assumption of the binary
breakup is shown to be consistent with the experimental observations. At larger
values of Wet, it was found that the most probable number of daughter bubbles
increases and the assumption of tertiary breakup is shown to lead to a better fit of
the experimental measurements.
Scattering of an eddy advected by a current
towards a topographic obstacle
Authors: STERN MELVIN E.
Published: July 2002

Contour dynamics is used to compute the two-dimensional (f-plane) motion of an
initially circularly symmetric barotropic eddy with piecewise-uniform vorticity as it
is advected around a circular obstacle by a uniform upstream current. For grazing
incidence of this ‘shielded’ eddy (compensating positive and negative vorticity) the
main effect of the vortex images (inside the obstacle) is to change the speed of those
particles in the outer portion of the eddy that are closest to the obstacle; a lesser
velocity is induced on the oppositely signed vortices near the eddy centre. The result
is a systematic separation of the centroids of the ± vortices in the eddy, and the eddy
emerges far downstream with an invariant dipole moment (m = 1 azimuthal mode).
This causes the eddy to move with a constant velocity V normal to the uniform
basic flow. The ratio of the numerically computed V to the accompanying far-field
dipole moment agrees with a previous analytical theory for a completely isolated eddy
subjected to a small-amplitude m = 1 initial disturbance. The scattering effect might
be realizable in a rotating homogeneous fluid by translating a cylinder relative to an
otherwise stationary eddy. Application to a density-stratified model is suggested.
Analysis and modelling of turbulent flow in an axially rotating pipe
Authors: SPEZIALE C. G. , YOUNIS B. A. , BERGER S. A.
Published: July 2002

The analysis and modelling of the structure of turbulent flow in a circular pipe
subjected to an axial rotation is presented. Particular attention is paid to determining
the terms in various turbulence closures that generate the two main physical features
that characterize this flow: a rotationally dependent axial mean velocity and a
rotationally dependent mean azimuthal or swirl velocity relative to the rotating
pipe. It is shown that the first feature is well represented by two-dimensional explicit
algebraic stress models but is irreproducible by traditional two-equation models. On
the other hand, three-dimensional frame-dependent models are needed to predict the
presence of a mean swirl velocity. The latter is argued to be a secondary effect which
arises from a cubic nonlinearity in standard algebraic models with conventional near-wall treatments. Second-order closures are shown to give a more complete description
of this flow and can describe both of these features fairly well. In this regard, quadratic
pressure–strain models perform the best overall when extensive comparisons are made
with the results of physical and numerical experiments. The physical significance of
this problem and the implications for future research in turbulence are discussed in
detail.
A reply to Pitcher
Authors: Cramer Christopher , Pontara Nicola
Published: July 2002

Pitcher's rejoinder to our paper (Cramer & Pontara 1998), is a useful
contribution to the policy and analytical debate on poverty and rural
relations in Mozambique. Some of her points are well taken, in
particular her careful attention to empirical imprecision in much of the
literature. Indeed, she points out that we used a figure for how much
land the government had conceded to private owners that turns out to
be mistaken. We accept this useful clarification graciously, though
slightly less graciously would point out that Pitcher earlier cited the
same (erroneous) figure herself.

Overall, her complaint about our paper seems to boil down to the
following: that we are incomplete in our coverage of the literature; that
we fail to notice that the government may say it favours smallholders
but is in fact leaving them high and dry by allocating resources to large-scale commercial investors; and that we present an exclusive choice
between the land and the labour market as the solution to poverty in
Mozambique. On the first point, our coverage was indeed less than
complete, though the implications of this are not as Pitcher implies. On
the second, we think the picture is more complex than she suggests, and
if our paper did not make this adequately clear we shall try to make it
more so here. On the third part of her complaint, Pitcher is plainly
wrong: in fact, the most interesting thing about her comment on our
paper is that she appears entirely to have missed the point that we were
making and does not engage with our core argument at all. She is at
pains to agree with our discussion of the socioeconomic differentiation
that has a long-term and more recent history in rural Mozambique,
and to present the lives of the poor as highly insecure. Nonetheless, she
makes little effort to consider the implications of this beyond making
the fairly obvious point that people hang onto their land when they can
and pursue multiple and ‘redundant’ (whatever this is supposed to
mean) strategies.
Properties of high-pressure discharge plasmas
Authors: UHM HAN S. , CHOI EUN H. , CHO GUANGSUP , KO JAE J.
Published: July 2002

Plasma properties during and immediately after electrical breakdown
in a high-pressure gas are investigated. A simple scaling law of electrical
discharge at high pressure is obtained. Introducing the normalized net
ionization rate ξ, the electron temperature at breakdown is described uniquely
in terms of the ionization properties of the gas, the second ionization coefficient
γ at the cathode, and the parameter pd, where p is the gas pressure and d is the
system dimension. The electron attachment process plays a decisive role in the
breakdown phenomenon for a high-pressure gas, whereas it is not important in
low-pressure discharges. An analytical expression for the high-pressure plasma
density is obtained by making use of the electron rate equation. A simple
analytical expression for plasma generation in a high-pressure gas provides
important scaling laws in the d.c. electrical discharge system, where the
electron attachment process is negligible. It is found that the logarithm of the
electron density at breakdown is proportional to the discharge time τb, and is
inversely proportional to the pulse risetime and the gap distance d between the
two electrodes. The plasma density at breakdown is also an increasing function
of the gas ionization energy εi.
Influence of carbon dioxide on the radial
temperature distribution in an argon arc
Authors: MAOUHOUB E.
Published: July 2002

The temperature profiles in wall-stabilized atmospheric-pressure arcs
in pure argon and in argon–carbon dioxide mixtures have been obtained at
currents of 5–40 A and for molar percentages of CO2 ranging from 0.9% to 25%
using spectroscopic techniques. With the addition of CO2 to a pure-Ar arc, we
show the formation of a core of higher temperatures with a larger gradient of
the radial temperature distribution at the arc centre. These investigations show
that the addition of even a few percent of CO2 to Ar has a marked effect both
upon extinction of the arc according to current values and upon the temperature
profiles. Few measurements have been done in Ar–CO2 mixtures in a wall-stabilized arc.
Relics, oaths and politics in thirteenth-century Siam
Authors: Wyatt David K.
Published: July 2002

Recent efforts have re-dated the Wat Bang Sanuk inscription to 1219, long before the Ram Khamhaeng inscription of 1292. Attempts to assess the implications force a re-thinking of Thai rebellion against Angkor by linking rebellion to religious thought, including especially the discovery and public show of relics of the Buddha.
Clonal diversity and rockpool size in the marine ostracod, Callistocythere badia
Authors: Hull Susan L. , Rollinson Daniel
Published: July 2002

Samples containing the marine ostracod Callistocythere badia were collected from upper shore rockpools on Filey Brigg, north-east England in order to examine the life cycle and genetic structure of the species. Reproduction occurred during spring/summer after which the adults died; juveniles over-wintered as A-1 instars. No males were ever found during the study. Analysis at three polymorphic loci (Gpi, Pgm and Mpi), showed significant deviations from Hardy–Weinberg equilibrium, and significant linkage equilibrium at and between all loci. The genetic data and absence of males confirm that Callistocythere is an asexual species. There was a significant positive relationship between the number of clones found within a pool and rockpool size, but not with algal habitat heterogeneity.
A revision of the family Stauroteuthidae (Octopoda: Cirrata) with redescriptions of Stauroteuthis syrtensis and S. gilchristi
Authors: Collins Martin A. , Henriques Camila
Published: July 2002

The cirrate octopod family Stauroteuthidae is revised on the basis of new material collected from the North and South Atlantic and a thorough examination of relevant type material. The family is characterized by the presence of a secondary web, U-shaped shell vestige, reduced mantle aperture and with long cirri, not reaching the arm tips. The radula is absent. The family contains a single genus with two valid species, Stauroteuthis syrtensis and S. gilchristi, which are redescribed based on the holotypes and new material. Chunioteuthis ebersbachii is a junior synonym of S. syrtensis and C. gilchristi is placed in the genus Stauroteuthis. The genus Chunioteuthis is no longer valid. The form and arrangement of suckers distinguish the two species of Stauroteuthis. Stauroteuthis syrtensis is broadly distributed in the North Atlantic at depths of 700—4000 m with peak abundance at 1500—2500 m. Stauroteuthis gilchristi is known only from the type locality off Cape Town (2604 m) and from new material captured off South Georgia (1000 m).
Morphological and biochemical evidence that Perinereis cultrifera (Polychaeta: Nereididae) is a complex of species
Authors: Scaps Patrick , Rouabah Abdelkader , Leprêtre Alain
Published: July 2002

Paragnath variation was examined in two populations of the epitokous form of the polychaete Perinereis cultrifera from the English Channel and the Algerian Mediterranean coast. Populations differ from each other in the mean number of paragnaths in groups I, II, III, V and VII–VIII, in the number of teeth per half jaw and in the morphology of paragnaths in the posterior belt. Individuals of the two populations studied share no common alleles at five loci involved in electrophoretic comparison. The general protein band patterns reveal 13 markers that discriminate between the Perinereis individuals. Congruence of all the reported results agree with the assignment that P. cultrifera is a complex of species, probably more than two.
Egg size and fecundity in females of the subfamilies Todaropsinae and Todarodinae (Cephalopoda: Ommastrephidae)
Authors: Laptikhovsky V.V. , Nigmatullin C.M.
Published: July 2002

Size of ripe eggs and potential fecundity are described in the squid of the subfamilies Todaropsinae and Todarodinae (Oegopsida: Ommastrephidae)—Todaropsis eblanae from West Africa, Todarodes angolensis from Namibia, Todarodes sagittatus from north-west Africa and the Mediterranean Sea, Todarodes sp. from the south-east Pacific, Nototodarus hawaiiensis from the south-east Pacific and West Indian Ocean and Martialia hyadesi from the south-west Atlantic. Females of both subfamilies are characterized by a wide range of ripe egg size (0.7–2.4 mm) and low and medium values of potential fecundity (20,000–2,500,000).
A comparison of vegetated and unvegetated soft-sediment macrobenthic communities in the River Yealm, south-western Britain
Authors: Turner S.J. , Kendall M.A.
Published: July 2002

Macrofaunal community structure was examined in a shallow sublittoral sea grass bed (Zostera marina L.) and adjacent unvegetated sediment in the River Yealm, Devon, south-west Britain, on a single sampling occasion in August 1995. The presence of Zostera had a significant influence on macrobenthic community structure in the River Yealm. Samples from inside the sea grass bed were characterized by significantly higher numbers of individuals and species, as well as by greater species richness and high faunal dominance (i.e. low evenness) compared with the unvegetated samples. High faunal dominance within the sea grass bed was attributable to the large numbers of a few species (e.g. the polychaetes juvenile capitellids, Spio filicornis, Exogone hebes, Nereis pelagica and the tanaidacean Apseudes talpa), while increased species richness was a result of a large number of additional rare (1–2 individuals) species. The greatest number of individuals was found in samples with the highest sea grass biomass. Multivariate ordination revealed a distinct separation of macrofauna communities from vegetated and unvegetated sites. Significance testing with ANOSIM shows that there were significant differences in community structure between vegetated and unvegetated habitats.
Temporal variation in lipid, protein and carbohydrate content in the Red Sea soft coral Heteroxenia fuscescens
Authors: Ben-David-Zaslow R. , Benayahu Y.
Published: July 2002

Heteroxenia fuscescens is a common zooxanthellate soft coral on the shallow reefs of the Gulf of Eilat, northern Red Sea. Its main nutritional sources are the uptake of dissolved organic material (DOM) and carbon fixation by its symbiotic algae (zooxanthellae). Recent studies have indicated that although colonies of H. fuscescens release planulae all year round, their fecundity was subject to seasonal changes. In this study the monthly per cent of ash, lipid, protein and carbohydrate in the coral tissue over a three year period was determined. It was found that the tissues of colonies of H. fuscescens contained a monthly per cent mean of 8.8±4 ash (without sclerites), 11±3.5 lipid, 19.2±6.4 protein, and 0.6±0.01 carbohydrate (N=36). This study is the first to present such values based on long term investigation of the biochemical profile of a coral, thus enabling an examination of temporal variability in biochemical composition among seasons and successive years. The results indicated seasonal fluctuations in lipid and protein content, while variation in the biochemical composition among years was expressed only in the protein content. The mean energetic content of H. fuscescens was relatively high at 23.3±1.2 kJ g−1 dry weight (DW). A significant difference in the energetic content of H. fuscescens was found among seasons. It is suggested that the increase in nutrient levels following the annual mixing event at the Gulf of Eilat and the raised light levels led to high energetic content during summer, which may reflect the increase in the number of embryos and developing planulae in H. fuscescens colonies. Furthermore, it is suggested that in the Gulf of Eilat seasonal fluctuations in the abiotic features of the water may have an impact on the biochemical composition and energetic content of the studied species.
Intertidal ostracod (Crustacea: Ostracoda) abundance and assemblage structure within and between four shores in north-east England
Authors: Hull Susan L.
Published: July 2002

Triplicate samples of rockpool algae were collected at each of three tidal elevations (upper, mid and low) from four shores on the north-east coast of England. Two moderately exposed (Ravenscar, the exposed shore at Filey Brigg), and two moderately sheltered (Selwicks Bay, the sheltered shore at Filey Brigg) shores were sampled during one week of spring tides during June 1996. A total of 6866 individual ostracods comprising of 26 ostracod species were recovered from the algal samples. Some species showed significant differences in abundance with tidal elevation across the four shores, e.g. Hirschmannia viridis was significantly more abundant in the upper shore pools. Other species, e.g. Heterocythereisalbomaculata, showed no significant difference in abundance either with tidal elevation or between shores. Significant differences in abundance occurred between shores at a given tidal height in some species, e.g. Semicytherura nigrescens was absent from Selwicks Bay but abundant on the remaining shores. Other species had markedly disjunct distributions, e.g. Callistocythere badia only occurred in the exposed upper shore pools at Filey Brigg. Ostracods were significantly less abundant in the low shore pools. Cluster analysis showed that low shore samples had a high degree of similarity between the four shores whereas the upper and mid-shore samples clustered primarily to shore. A two-way ANOSIM indicated that there was a significant difference in assemblage similarity between the four shores and also between the different tidal elevations.
Rhythms of activity and foraging in the intertidal insect Anurida maritima: coping with the tide
Authors: McMeechan Fiona K. , Manica Andrea , Foster William A.
Published: July 2002

The intertidal insect Anurida maritima (Apterygota: Collembola) has a circatidal rhythm of locomotory activity on the soil surface which was observed during both the day and the night. The main function of this activity was foraging for food. When a superabundant food supply was provided on the upper shore, this completely repressed the usual migration to the lower shore. There was a clear rhythm in feeding activity which was highest shortly after the sea uncovered the insects' shelters and declined rapidly during the intertidal period. The circatidal rhythm of locomotory activity persisted in the laboratory in constant light for seven days (15 cycles). A free-running rhythm underlying the degree of aggregation was also detected.
ERWÄHLUNG UND VERGELTUNG. ZUR OPTIONALEN STRUKTUR RABBINISCHER SOTERIOLOGIE
Authors: AVEMARIE FRIEDRICH
Published: July 2002

Zur Beschreibung rabbinischer ‘Soteriologie’ haben sich in der Forschung zwei konträre Modelle etabliert: Dem einen zufolge entscheiden die Werke eines Menschen über seine Teilhabe an der kommenden Welt; dem anderen zufolge entscheidet seine Zugehörigkeit zum erwählten Volk. Beide Denkmuster sind in Talmud und Midrasch reichlich belegt. Herkömmliche Hierarchisierungen, die das eine Muster dem anderen starr über- oder unterordnen, sind jedoch unangemessen. Vielmehr bringt die rabbinische Tradition Erwählung und Vergeltung in stets wechselnden Proportionen zum Ausgleich, was bis zur scheinbaren Verabsolutierung des einen und Ignorierung des anderen der beiden Prinzipien reichen kann. Rabbinische Soteriologie ist in diesem Sinne ‘optional’ strukturiert.
The structure of parasite component communities in brackish water fishes of the northeastern Baltic Sea
Authors: VALTONEN E. T. , PULKKINEN K. , POULIN R. , JULKUNEN M.
Published: July 2002

We used nestedness analysis to seek non-random patterns in the structure of component communities of metazoan parasites collected from 31 sympatric fish species from the northeastern Bothnian Bay, the most oligohaline area of the Baltic Sea. Only 8 marine parasite species were found among the 63 species recorded, although some marine fish species reproduce in the bay and others occasionally visit the area. Marine parasite species can utilize both freshwater and marine fish species as intermediate or final hosts, and marine fish can harbour freshwater parasite species. This exchange of parasite species between marine and freshwater fish has probably resulted from ecological factors acting over short time scales rather than from evolutionary processes acting over longer time; the key factor probably being the immediate presence of suitable intermediate and definitive hosts. Marine fish were expected to harbour species-poor parasite communities consisting mainly of generalists acquired from the sympatric freshwater fish species, which would result in a nested pattern among the different component communities. However, an anti-nested pattern was found in the component communities of metazoan parasites of fishes from the Bothnian Bay. A likely explanation for the observed pattern is that there are specialist parasite species, the majority of which are cestodes, in some of the freshwater fish species which otherwise have depauperate parasite communities.
Onchocerca ochengi: morphological identification of the L3

in wild Simulium damnosum s.l., verified by DNA probes
Authors: WAHL G. , SCHIBEL J. M.
Published: July 2002

In order to assess the prevalence of the cattle filaria Onchocerca
ochengi
in onchocerciasis vectors (Simulium damnosum s.l.)
in North Cameroon, we searched for a means to morphologically identify
its
developing larvae, which closely resemble
those of O. volvulus. To this end microfilariae of the 2 Onchocerca

species were isolated from slaughter cattle in Ngaoundéré

and injected into neonate Simulium species. Whereas the early

developmental stages (sausage stage, L2 and pre-infective
larva) were indistinguishable, the infective larvae (L3) of O. ochengi

were longer (median: 740 μm), more slender (diameter
= 19·3 μm = 2·6% of body length) and had a relatively

shorter tail (4·9% of body length) than those of O. volvulus

(680 μm, 20·5 μm, 3·0% and 5·8% respectively).
The
tail of O. ochengi L3 was thick and rounded, whereas it was slightly

tapering in O. volvulus L3. O. ochengi L3 produced by

feeding flies on infected cattle in a different area in North Cameroon

(Sora Mboum) showed the same features as intrathoracically produced
O. ochengi L3 from Ngaoundéré, but were even
longer (785 μm). On the basis of the differences in length, relative

diameter, length of the tail and shape of the tail, a simple
key for the separation of O. volvulus and O. ochengi
L3
was elaborated, and 248 L3 found in wild S. damnosum s.l. were

separated into ‘O. ochengi’ (160 L3) and
‘O. volvulus’ (88 L3) following this key. Sequential

dot blot hybridization of each
of the 248 larvae with a DNA probe which reacts with O. ochengi

and O. volvulus but not with other Onchocerca species

(pOo5/1) and with an O. volvulus-specific DNA probe (pOv12)

revealed that the morphological identification had been
correct in 86–91% of the cases. Only a small proportion (6–9%)
of
the dot blots did not react with either probe. Since
this proportion was equal in experiments using experimentally produced
L3
and in experiments using wild L3, the non-hybridization was certainly due

to a loss of L3 during washing of the filters and not due to the presence
of other unknown
L3 species resembling O. volvulus and O. ochengi. Our

study shows that in Cameroon it is possible to identify O. volvulus

and O. ochengi infective larvae during routine fly dissections
by morphology alone.
The metalloprotease inhibitor 1,10-phenanthroline affects
Schistosoma mansoni motor activity, egg laying and viability
Authors: DAY T. A. , CHEN G.-Z.
Published: July 2002

The Zn2+-chelating metalloprotease inhibitor 1,10-phenanthroline

(phenanthroline, 5–150 μM) elicited dose-dependent
contraction of the longitudinal and circular (transverse) musculature of
adult
male schistosomes. At the same concentrations, phenanthroline did not cause

contraction of dispersed individual muscle fibres. The phenanthroline-induced

contractions were reduced by the inclusion of 100 or 300 μM
Zn2+
in the extracellular medium. Phenanthroline
(0·5–150 μM) also inhibited the egg production
of
adult worm pairs in vitro, with a 98% reduction at 50
μM.
When worm
pairs were exposed to phenanthroline, the males detached from the dish

and released the females, resulting in unpaired
worms. At the higher concentrations (50 and 150 μM), the worms

were killed in vitro. Worm burdens were reduced by
over 50% in infected mice injected with phenanthroline (20 mg/kg/day

for 4 days), but twice the dose resulted in only
a 25% reduction. Phenanthroline injections also induced an hepatic shift

and an unpairing of adult worms in infected
mice, and the female worms appeared degenerate and lacked gut pigmentation.

Mice fed a diet containing 0·3%
phenanthroline received significant protection from infection when challenged

with schistosome cercaria, where
phenanthroline-fed mice had 94% fewer adult worms than control mice. The

broad range of phenanthroline effects on
schistosomes suggests broad and important functions for metalloproteases
in these worms.
Chloroquine increases Plasmodium falciparum
gametocytogenesis in vitro
Authors: BUCKLING A. , RANFORD-CARTWRIGHT L. C. , MILES A. , READ A. F.
Published: July 2002

Malaria parasites are capable of modulating the diversion of resources
from asexual growth to the production of stages
infective to mosquitoes (gametocytes). Increased rates of gametocytogenesis
appear to be a general response to stress, both
naturally encountered and novel. We have previously reported earlier and
greater gametocytogenesis in response to
subcurative antimalarial chemotherapy in the rodent malaria, Plasmodium
chabaudi, in vivo. Using an immunofluorescent
assay to detect parasites that had invaded red blood cell monolayers, we
demonstrate a 5-fold increase in gametocytogenesis
in the human malaria, P. falciparum, in vitro, in response
to treatment with the antimalarial drug chloroquine. In all clones
used, gametocytogenesis increased with increasing inhibition of asexual
growth by chloroquine. Furthermore, there were
clone differences in the relationship between stress and gametocyte production,
implying the response was genetically
variable. This was not, however, associated with chloroquine resistance.
The epidemiological significance of these results
is discussed.
Antibody response of carp, Cyprinus carpio to the cestode,
Bothriocephalus acheilognathi
Authors: NIE P. , HOOLE D.
Published: July 2002

The humoral antibody response and the number of pronephric antibody-secreting cells were examined in naturally
Bothriocephalus acheilognathi-infected carp. Cyprinus carpio, and in those injected intraperitoneally with an extract of the
cestode. In the extract-injected fish, specific antibody was detected 3 weeks after a second injection given 2 weeks after
the primary injection, and antibody levels persisted for more than 200 days. A third injection also enhanced the antibody
level in the extract-injected carp. The numbers of antibody-secreting cells were significantly higher in carp injected 3
times with the extract than in the control. In naturally-infected fish, the serum antibody levels and the number of
pronephric antibody-secreting cells were higher in infected fish than in uninfected individuals although this difference was
not statistically significant. The relevance of these results to immune protection against infection is discussed.
Detection of parasites in food
Authors: GAMBLE H. R. , MURRELL K. D.
Published: July 2002

The importance of foodborne parasitic zoonoses remains high in many regions of the world. Although control efforts have
been exerted for quite some time, overall progress has not been satisfactory, even in many well developed countries. An
important drawback in control programmes for parasites such as Trichinella, Toxoplasma and Taenia has been the absence
of rapid, accurate and sensitive diagnostic tests for these meatborne parasites. However, the rapid advances in the molecular
biology of these organisms has yielded concomitant gains in precision of detection. This review highlights these advances
and their impact or potential application to the control of foodborne parasites.
Immune responses during the acute stages of infection
with the intestinal trematode Echinostoma caproni
Authors: BRUNET L. R. , JOSEPH S. , DUNNE D. W. , FRIED B.
Published: July 2002

This study investigated the nature of the immune response of C57BL/6 mice infected with the trematode Echinostoma
caproni. To determine the preferential development of either a Th1 or Th2 cytokine pattern during early stages of infection,
cytokine production by spleen and mesenteric lymph node (MLN) cells during the first 3 weeks of infection was followed.
Whereas spleen cells failed to respond to antigen stimulation, MLN cells produced IFN-γ and to a lesser extent IL-4.
IL-5 levels were elevated throughout the period studied. The humoral response was consistent with a Th1 cytokine pattern
as antigen-specific IgG2a antibodies were preferentially developed. We investigated whether IFN-γ is critical for
establishment of E. caproni infection. Worm burden in infected mice treated with a single injection of anti-IFN-γ mAb
was significantly reduced compared to that of animals treated with a control antibody.
Ruth Anna Putnam and the Fact-Value Distinction
Authors: Smart J. J. C.
Published: July 2002

This article is a defence of the Fact-Value distinction against considerations brought up by Ruth Anna Putnam in three articles in Philosophy, especially her ‘Perceiving Facts and Values’ January 1998. I defend metaphysical realism about facts and anti-realism about values against Putnam' intermediate position about both and I relate the matter to the logic of imperatives. The motivations of scientists or historians to select fields of investigation are irrelevant to the objectivity of their hypotheses, and so is the goodness or badness of the social consequences of their work though these may affect their motivations.
The Cardiff Depression Study: a sib-pair study of dysfunctional attitudes in depressed probands and healthy control subjects
Authors: FARMER A. , HARRIS T. , REDMAN K. , MAHMOOD A. , SADLER S. , McGUFFIN P.
Published: July 2002

Background. Current cognitive theories propose that depression develops as a result of the interaction between dysfunctional cognitive schemata and environmental stressors. There is also consistent evidence of a substantial genetic contribution to depression. This study examines the familiality and stability of dysfunctional attitudes and attempts to distinguish whether they reflect trait vulnerability to depression or the state of being depressed.

Method. The 24-item Dysfunctional Attitude Scale (DAS-24) was completed by 108 depressed probands and their nearest-aged siblings and 105 healthy control probands and their nearest-age siblings, at the time of a semi-structured clinical interview and 10–12 months later. Subjects also completed self-report measures of depressed mood on both occasions.

Results. Measures of clinical depression were significantly correlated with DAS scores. At retest, DAS scores remained elevated despite improvement in mood, giving support for earlier findings, that dysfunctional attitudes remain active following recovery.

The dependency subscale (DAS-D) of the DAS showed modest familiality, although there were no significant differences for DAS-D scores between the two groups of siblings. In a multiple regression analysis, current mood-state was the overwhelming predictor of DAS scores. However for DAS-D, gender as well as current mood influenced scores on this subscale.

Conclusion. Although there was modest evidence for temporal stability and familiality for some DAS-24 subscale scores, dysfunctional attitudes were predominantly influenced by current low mood, and therefore reflect the state of being depressed rather than a familial vulnerability trait underpinning depression.
Long-term outcome of social phobia treated by exposure
Authors: FAVA G. A. , GRANDI S. , RAFANELLI C. , RUINI C. , CONTI S. , BELLUARDO P.
Published: July 2002

Background. There is very little information on long-term follow-up of social phobia.

Methods. A consecutive series of 70 patients satisfying the DSM-IV criteria for social phobia was treated in an out-patient clinic with behavioural methods based on exposure homework. Forty-five patients were judged to be remitted after eight individual sessions of psychotherapy. A 2 to 12 year (median = 6 years) follow-up was performed. Survival analysis was selected to characterize the clinical course of patients. Assessments were performed before treatment, at the end of therapy, after 1 year, and subsequently on a yearly basis, and utilized selected items of Paykel's Clinical Interview for Depression.

Results. Six of the 45 patients (13%) had a relapse of social phobia at some time during follow-up. The estimated cumulative percentage of patients remaining in remission was 98 after 2 years, 85 after 5 years and 85 after 10 years. Such probabilities increased in the absence of a personality disorder, of residual social phobic avoidance after exposure, and of concurrent use of benzodiazepines.

Conclusions. The findings suggest that, even though one patient out of three is unable to complete treatment or does not benefit sufficiently from it, exposure treatment can provide lasting effects to the majority of patients with social phobia. Disappearance of residual, subclinical social phobic avoidance appears to be the target of treatment.
Social support and psychiatric sickness absence: a
prospective study of British civil servants
Authors: STANSFELD S. A. , RAEL G. S. , HEAD J. , SHIPLEY M. , MARMOT M.
Published: July 2002

Background. Studies on the direct and buffering effects of social support have not examined
psychiatric sickness absence and few studies have considered support both at home and at work.
This study addresses prospectively the effects of chronic stressors and social supports, at home
and at work, on psychiatric sickness absence rates.

Methods. Sociodemographic factors, health and social support were measured at baseline, and
short and long spells of sickness absence were measured prospectively over a 5-year period. The
participants were a subsample of 4202 male and female civil servants, aged 35–55 years at baseline,
from an occupational cohort, the Whitehall II Study, who completed detailed social support
questions.

Results. Support from colleagues and supervisors at work is related to lower risk of short spells
of psychiatric sickness absence, particularly for those also receiving high levels of negative
aspects of close relationships from their closest person outside work. Negative aspects of close
relationships from the closest person increase the risk of taking long spells of psychiatric
sickness absence in men. High levels of material problems increase the risk of short spells of
sickness absence.

Conclusions. Negative aspects of close relationships may have an aetiological role in
non-psychotic psychiatric disorder. Social support at work appears to protect against short spells of
psychiatric sickness absence. This potentially implies that levels of short spells of absence might
be reduced by increasing support at work. Conversely, emotional support at home may
influence absence-related behaviour and encourage a person to take absence at a time of
illness.
Effects of fluoxetine versus bright light in the
treatment of seasonal affective disorder
Authors: RUHRMANN S. , KASPER S. , HAWELLEK B. , MARTINEZ B. , HÖFLICH G. , NICKELSEN T. , MÖLLER H.-J.
Published: July 2002

Background. Disturbances of serotonergic neurotransmission

appear to be particularly important
for the pathophysiology of winter depression. This study investigated whether
fluoxetine has
antidepressant effects comparable to bright light in the treatment of
seasonal affective disorder (winter type).

Method. A randomized, parallel design was used with rater and

patients blind to treatment
conditions. One week of placebo (phase I) was followed by 5 weeks of treatment
(phase II) with
fluoxetine (20 mg per day) and a placebo light condition versus

bright light (3000 lux, 2 h per day)
and a placebo drug. There were 40 patients (20 in each treatment condition)

suffering from seasonal
affective disorder (SAD) according to DSM-III-R who had a total score on
the Hamilton
Depression Scale of at least 16.

Results. Forty patients entered phase II and 35 completed
it (one drop-out in the fluoxetine group
and four in the bright light group). Fourteen (70%) of the patients
treated with bright light and 13
(65%) of those treated with fluoxetine were responders (NS). The
remission rate in the bright light
group tended to be superior (bright light 50%, fluoxetine 25%;
P=0·10). Light therapy improved
HDRS scores significantly faster, while fluoxetine had a faster
effect on atypical symptoms. Light
treatment in the morning produced a significantly faster onset of
improvement, but at the end of
treatment the time of light application seemed not to be crucial.

Conclusion. Both treatments produced a good antidepressant
effect
and were well tolerated.
An apparently better response to bright light requires confirmation in
a larger sample.
Mari C. Jones, Language obsolescence and revitalization:
Linguistic change in two sociolinguistically contrasting Welsh
communities. (Oxford studies in language contact.) Oxford: Clarendon;
New York: Oxford University Press, 1998. Pp. x, 452.
Authors: Trosset Carol
Published: July 2002

Jones's book should fascinate two audiences:
those concerned with the current state of the Welsh language,
and those with a more general interest in the phenomenon
of language obsolescence. Her presentation is both clearly
readable and meticulous in its detail. The work centers
on case studies of two sociologically similar but linguistically
different communities, Rhymney and Rhosllannerchrugog,
situated in different regions of Wales. These studies investigate,
in parallel fashion, the varied retention both of Welsh
and of its relevant local dialect across the generations.
Jones demonstrates greater linguistic retention in the
community where Welsh still plays a significant role in
everyday social interactions (Rhosllannerchrugog), but
her data also illustrate a strong trend in both communities
toward the greater use of historically inappropriate forms
by younger speakers. Both studies also reveal a recent
loss of dialect-specific features, to the point where many
schoolchildren in both towns fail even to recognize the
local dialect as belonging to their own community. Jones's
generational analysis is quite revealing, particularly
because the current set of generations have experienced
quite different social contexts with respect to the state
of the language and its use in official settings.
Measuring liability for schizophrenia using optimized antisaccade stimulus parameters
Authors: McDowell Jennifer E. , Myles‐Worsley Marina , Coon Hilary , Byerley William , Clementz Brett A.
Published: July 2002

The ability to identify unaffected gene carriers within families may be crucial to the success of schizophrenia genetics studies. Data collected from three family samples (N= 365) demonstrated that poor antisaccade performance is an exceptionally promising indicator of liability for schizophrenia. A particular antisaccade task version provides large separations (5–6 sigma) between proband and normal groups. Poor antisaccade performance alone correctly identified 70% of patients in California, Utah, and Micronesia schizophrenia samples. Twenty‐five to 50% of these patients' nonpsychotic first‐degree relatives also had poor antisaccade performance, yielding risk ratios around 20:1 for simplex and 50:1 for multiplex schizophrenia families. Poor antisaccade performance is associated with dorsolateral prefrontal cortex pathology, suggesting that dysfunction of this circuitry also may predispose individuals to developing this disease.
Social play is more than a Pavlovian romp
Authors: Bekoff Marc , Allen Colin
Published: July 2002

Some aspects of play may be explained by Pavlovian learning processes, but others are not so easily handled. Especially when there is a chance that specific actions can be misinterpreted; animals alter their behavior to reduce the likelihood that this will occur. The flexibility and fine-tuning of play make it an ideal candidate for comparative and evolutionary cognitive studies.
Eating their cake and having it too: Or, how women maximize reproductive success by simultaneous mating and dating
Authors: Broude Gwen J.
Published: July 2002

Data support the claim from the target article that women, both cross-culturally and historically, have employed a variety of mating strategies, marrying but also engaging in short-term unions. But those strategies appear to be practiced simultaneously and not conditionally as Gangestad & Simpson propose, a finding consistent with assumed constraints on the potential reproductive success of females.
I doubt evolutionary explanations
Authors: Mazur Allan
Published: July 2002

No doubt all our behavior is the result of evolution, but I express skepticism about the validity of detailed arguments that purport to explain in detail how or why this occurred historically.
Koch's postulates confirm cholinergic modulation of REM sleep
Authors: Lydic Ralph , Baghdoyan Helen A.
Published: July 2002

Robert Koch (1843–1910) discovered the causal agents for tuberculosis, cholera, and anthrax. The 1905 Nobel Prize acknowledged Koch's criteria for identifying the causal agent of an infectious disease. These criteria remain useful and the data reviewed below show that the cholinergic contributions to REM sleep control are confirmed by Koch's postulates.

[Hobson et al.]
Neurotransmitter mechanisms of dreaming: Implication of modulatory systems based on dream intensity
Authors: Perry E. K. , Piggott M. A.
Published: July 2002

Based on increasing dream intensity and alterations in neurophysiological activity from waking, through NREM to REM sleep, dreaming appears to correlate with sustained midbrain dopaminergic and basal forebrain cholinergic, in conjunction with decreasing brainstem 5-HT and noradrenergic neuronal activities. This, model, with features in common with the modulatory transmitter models of Hobson et al. and Solms, is consistent with some clinical observations on drug induced alterations in dreaming and transmitter correlates of delusions.

[Hobson et al.; Solms]
Two conceptions of access-consciousness
Authors: Browne Derek
Published: July 2002

Block's (1995) cognitive conception of consciousness
might be introduced in the service of two different projects. In one,
the explanatory gap between science and folklore remains. In the
other, a reductive claim is advanced, but the intuitive idea of
consciousness is abandoned.
What working memory is for
Authors: Logie Robert H.
Published: July 2002

Glenberg focuses on conceptualizations that change from
moment to moment, yet he dismisses the concept of working memory
(sect. 4.3), which offers an account of temporary storage and on-line
cognition. This commentary questions whether Glenberg's account
adequately caters for observations of consistent data patterns in
temporary storage of verbal and visuospatial information in healthy
adults and in brain-damaged patients with deficits in temporary
retention.
Biology versus computation in the study of consciousness
Authors: Block Ned
Published: July 2002

The distinction between phenomenal (P) and access (A)
consciousness arises from the battle between biological and
computational approaches to the mind. If P = A, the
computationalists are right; but if not, the biological nature
of P yields its scientific nature.
Is memory like understanding?
Authors: Musen Gail
Published: July 2002

There are three major weaknesses with Glenberg's
theory. The first is that his theory makes assumptions about internal
representations that cannot be adequately tested. The second is that
he tries to accommodate data from three disparate domains: mental
models, linguistics, and memory. The third is that he makes light of
advances in cognitive neuroscience.
Relational problems are not fully solved by a temporal sequence of statistical learning episodes
Authors: Vinter A. , Perruchet P.
Published: July 2002

Clark & Thornton's conception finds an echo in
implicit learning research, which shows that subjects may perform
adaptively in complex structured situations through the use of simple
statistical learning mechanisms. However, the authors fail to draw a
distinction between, on the one hand, subjects' representations which
emerge from type-1 learning mechanisms, and, on the other, their
knowledge of the genuine abstract “recoding function”
which defines a type-2 problem.
On the psychological reality of parallel relational architectures: Whose knowledge system is it anyway?
Authors: Chalmers Margaret , McGonigle Brendan
Published: July 2002

We argue that Halford et al.'s characterisation of
relational complexity offers an unadaptive principle in terms of
cognitive economy, that its relation with the empirical evidence is
highly selective, and that the task behaviours used in support of a
multivector processing space are better described by linear serial
processes which do not require n-dimensional mappings for their
emergence.
Dennett versus Gibson
Authors: Byrne Alex
Published: July 2002

Pessoa et al. misinterpret some of Dennett's discussion
of filling-in. Their argument against the representational conception
of vision and for a Gibsonian alternative is also flawed.
Chunks, bindings, STAR, and Holographic Reduced Representations
Authors: Plate Tony A.
Published: July 2002

Much of Halford et al.'s discussion of vector models
for representing relations concerns the perceived inadequacies of
alternative methods with respect to chunking, binding, systematicity,
and resource requirements. Vector-based models for storing relations
are in their infancy, however, and the relative merits of different
schemes are not so clearly in favor of their STAR scheme as Halford
et al. portray.
Historical increases in expert performance suggest large possibilities for improvement of performance without implicating innate capacities
Authors: Lehmann Andreas C.
Published: July 2002

Innate talents supposedly limit an individual's highest
attainable level of performance and the rate of skill acquisition.
However, Howe et al. have not reviewed evidence that the level of
expert performance has increased dramatically over the last few
centuries. Those increases demonstrate that the highest levels of
performance may be less constrained by innate capacities than is
commonly believed.