bluuebunny/crossref_metadata_2025 huggingface dataset:
Single drop impact onto liquid films:

neck distortion, jetting, tiny bubble entrainment,

and crown formation
Authors: WEISS DANIEL A. , YARIN ALEXANDER L.
Published: July 2002

Single drop impact onto liquid films is simulated numerically. Surface tension and

gravity are taken into account, whereas viscosity and compressibility are neglected.

This permits recourse to a boundary-integral method, based on an integral equation

for a scalar velocity potential. Calculations are performed for normal impacts resulting

in axisymmetric flows.

For times that are small compared to the characteristic time of impact

2R/w0 (R being the drop radius,

w0 its initial velocity towards the liquid film), it is found that a

disk-like jet forms at the neck between the drop and the pre-existing liquid film, if the

impact Weber number is high enough. This jet can pinch off a torus-shaped liquid

volume at its tip or reconnect with the pre-existing liquid film, thus entraining a torus-

shaped bubble. In reality, both the torus-shaped bubble and liquid torus will decay

according to Rayleigh's capillary instability, thus breaking the cylindrical symmetry.

This mechanism of bubble entrainment differs from those described in literature.

For times that are comparable to or larger than the characteristic time of impact,

capillary waves on the film, or the well-known crowns, are obtained again according

to whether the impact Weber number is low or high enough.
The influence of a drag-reducing
surfactant on a turbulent velocity field
Authors: WARHOLIC MICHAEL D. , SCHMIDT GAVIN M. , HANRATTY THOMAS J.
Published: July 2002

A two-component laser-Doppler velocimeter, with high spatial and temporal resolution,
was used to study how the introduction of a drag-reducing surfactant to water
changes the fully-developed velocity field in an enclosed rectangular channel.
Measurements were made for four different Reynolds numbers, Re = 13300; 19100; 32000,
and 49100 (based on the bulk viscosity, the half-height of the channel, and the
viscosity of water). For a fixed volumetric flow the pressure drop was reduced by 62 to
76% when compared to a Newtonian flow with an equal wall viscosity. Measurements
were made of the mean streamwise velocity, the root mean square of two components
of the fluctuating velocity, the Reynolds shear stress and the spectral density function
of the fluctuating velocity in the streamwise direction. The Reynolds shear stress is
found to be zero over the whole channel and the spectra of the streamwise velocity
fluctuations show a sharp cutoff at a critical frequency,
fc. The ratio of the cutoff
frequency to the root mean square of the streamwise velocity fluctuations is found
to be approximately equal to 1 mm−1. The observation of a zero Reynolds shear
stress indicates the existence of additional mean shear stresses (or mean transfers of
momentum) that are not seen with a Newtonian fluid. Furthermore, the presence of a random
fluctuating velocity field suggests a production of turbulence by a mechanism other than that
usually found for a fully developed flow. Possible explanations for this behaviour
are presented.
Wave action on currents with vorticity
Authors: WHITE BENJAMIN S.
Published: July 2002

The interaction of waves on deep water with spatially varying currents may be
described by a ray theory, with the wave amplitudes determined by the principle of
conservation of wave action (CWA). However, all previous deep water derivations
of CWA are restricted to the case of an irrotational current. In this paper, both
the ray theory and CWA are derived by a WKB method without the assumption
of irrotationality. Also derived is a new equation for a spatially varying phase shift
which is not predicted by the usual ray theory, and which, in general, displaces the
positions of the wave crests by a distance on the order of a wavelength. This phase
shift, which is caused by variations of the current velocity with depth, vanishes in the
irrotational case, and so is in accord with the irrotational theory.
Temporal subharmonic amplitude and phase
behaviour in a jet shear layer: wavelet analysis
and Hamiltonian formulation
Authors: GORDEYEV S. V. , THOMAS F. O.
Published: July 2002

Fourier and wavelet transformation techniques are utilized in a complementary
manner in order to characterize temporal aspects of the transition of a planar jet
shear layer. The subharmonic is found to exhibit an interesting temporal amplitude
and phase variation that has not been previously reported. This takes the form of intermittent
π-shifts in subharmonic phase between two fixed phase values. These phase
jumps are highly correlated with local minima of the subharmonic amplitude. In contrast,
the fundamental amplitude and phase show no such behaviour. The temporal
phase behaviour of the subharmonic has the effect of intermittently disrupting the
phase lock with the fundamental. A dynamical systems model is developed which is
based on a classic vortex representation of the shear layer. The Hamiltonian formulation
of the problem is shown to provide remarkable agreement with the experimental
results. All the essential aspects of the temporal amplitude and phase behaviour of
the subharmonic are reproduced by the model including amplitude-dependent effects.
The model is also shown to provide a dynamical systems based explanation for
time-averaged amplitude and phase behaviour observed in these as well as earlier experiments.
The results of experiments involving both bimodal forcing at fundamental
and subharmonic frequencies with prescribed initial effective phase angle as well as
experiments involving only fundamental excitation over an amplitude range extending
two orders of magnitude are presented. The temporal subharmonic amplitude
and phase behaviour is observed in bimodal forcing experiments in those regions of
the flow characterized by subharmonic mode suppression and vortex tearing events
(even if the forcing amplitudes are quite large). In addition, temporal subharmonic
amplitude and phase behaviour is the rule in experiments involving low-amplitude
forcing of the fundamental and the natural development of the subharmonic.
Numerical study of internal wave reflection from
sloping boundaries
Authors: JAVAM A. , IMBERGER J. , ARMFIELD S. W.
Published: July 2002

The breaking of internal waves propagating in a stratified fluid of constant buoyancy
frequency on a sloping boundary was investigated numerically. It was found that at
the boundary, nonlinear non-resonant interactions between the incident and reflected
waves produced higher-mode waves. These modes had frequencies greater than the
local buoyancy frequency and so could not radiate from the interaction region. The
energy level of trapped waves increased with time and subsequently led to overturning
of the density field. At the critical frequency, when the reflected wave propagated in
a direction parallel to the slope, wave overturning occurred near the wall, but the
point of overturning moved off the bottom as the propagation angle changed away
from that of the bottom slope as the waves became increasingly supercritical. The
internal wave reflection coefficient generally increased as the effects of nonlinearity
and viscosity decreased, but depended strongly on the forcing frequency and the angle
of the sloping boundary.
The Impact of Foreign Trade on the Mexican Economy:
Terms of Trade and the Rise of Industry 1880–1923
Authors: BEATTY EDWARD
Published: July 2002

This article uses both new and published data on Mexico's foreign trade
to measure terms of trade and to investigate the relationship between trade and
the early growth of domestic industry. This analysis yields five conclusions: (1)
Mexican terms of trade declined, largely due to the dramatic fall in the price of
silver; (2) the growing diversity of Mexican exports significantly cushioned the
short-term impact of silver depreciation; (3) declining terms of trade did not
characterise the entire era, but instead were concentrated in two periods:
1891–97 and 1912–21; (4) although net barter terms of trade declined, Mexico's
capacity to import – measured by the income terms of trade – improved
markedly, and (5) this proved absolutely crucial in financing the concurrent
process of incipient import-substituting industrialisation. In other words, the
Porfiriato witnessed a development process in which trade growth and the spread
of domestic manufacturing were highly complementary. Without the former,
industrialisation would have been severely handicapped.
Brazil's Real Plan
Authors: DA FONSECA MANUEL A. R.
Published: July 2002

One of the main conclusions of this commentary is that the Real
plan
– the stabilisation programme introduced in Brazil in July 1994 which
was quite
successful in bringing inflation down from the extremely high levels that

prevailed before that period – did not attack the main cause of the
country's
inflation, that is, the large financial imbalance in the public sector.
Instead,
inflation was reduced in an indirect way, by freezing government-controlled

prices and wages. In mid-1998, the programme still relies on extremely
high
interest rates and a tight control of the exchange rate. The main weakness
of the
plan is that, with the overvalued currency, trade deficits are accumulating.
Also,
very high interest rates have brought the economy to a halt and caused
a sharp
increase in the government debt.
The ‘Liberal’ Cristero: Ladislao Molina
and the Cristero Rebellion in
Michoacán, 1927–9
Authors: BUTLER MATTHEW
Published: July 2002

This article studies the Mexican cristero rebellion of 1926–9. While
scholars assert that the rebellion was the product of a clash between ‘modern’
liberal and ‘traditional’ Catholic mentalities, it is argued here that Ladislao
Molina was an astute political actor who embraced a liberal ideology in order to
establish a cacicazgo in his home region of Michoacán. When Molina was
threatened by state encroachments and agrarian demands, he, like other members
of the middling rural strata, promoted a Catholic rebellion not because of
religious piety but in order to protect his sphere of influence.
Be going to: an exercise in grounding
Authors: BRISARD FRANK
Published: July 2002

This paper investigates the semantics of be going to, starting from a schematic definition which interprets temporal meanings in terms of referential and epistemological attributes. The analysis is framed within the model of cognitive grammar, taking deictic syntactical constructions as instances of grounding predications and differences between them as triggered by aspects of construal and profiling. On the basis of corpus material from American and British English texts, it is concluded that be going to features a paradoxical but pragmatically plausible interpretation of the future as non-given yet present, with a pending event's being signaled or announced at the time of speaking.
Syntax versus the lexicon: incorporation and compounding in Modern
Greek
Authors: SMIRNIOTOPOULOS JANE C. , JOSEPH BRIAN D.
Published: July 2002

As a contribution to the long-standing controversy in linguistics
concerning the
proper role in the grammar of syntax as opposed to the lexicon and of syntax
as
opposed to morphology, we study here the proposal made by Rivero 1992 that

Modern Greek has a productive syntactic rule of Adverb Incorporation, and
more
generally Argument Incorporation. Based on measures of productivity and
on
idiosyncrasies in meaning that adverb-plus-verb and object-plus-verb combinations

in Greek show, we argue that the phenomena in question are compounds or
affixed
forms that result from the operation of lexical rules. They are thus quintessentially

morphological in nature, rather than syntactic. More generally, we see
this outcome
as an argument against frameworks in which morphology is collapsed into
the
syntactic component and in which morphology is not a separate component
of
grammar.
From ‘warlord’ to ‘democratic’
president: how Charles Taylor
won the 1997 Liberian elections
Authors: Harris David
Published: July 2002

For the best part of seven years, an increasing number of warring factions
fought a vicious civil war for control of the West African state of Liberia.
In August 1996, the fourteenth peace accord led to presidential and
parliamentary elections in July of the following year. Charles Taylor and his
National Patriotic Party (NPP), formed out of the original invasion force,
emerged victorious with a landslide 75 per cent of the vote. Given the international
reputation of Taylor as a brutal warlord whose sole aim had never
wavered from the capture of power in Monrovia, Taylor's across-the-board
victory appears difficult to explain. Having concluded that, despite problems
and allegations, the election did seem more free and fair than not, the article
examines the factors that probably influenced the electorate's choices. The
results of this research show an election heavily dependent on an uncertain
security situation. However, it suggests that, although a former ‘warlord’
has been rewarded, the voting was a reasoned ploy by the electorate to
maximise the possibility of improved living conditions.
Neutrino Landau damping and collective neutrino–plasma processes
Authors: MENDONÇA J. T. , SHUKLA P. K. , BINGHAM R. B. , DAWSON J. M. , SILVA L. O.
Published: July 2002

The collective kinetic interaction of a neutrino distribution with electrostatic
waves propagating in a dense plasma is considered. A Klimontovich-type
kinetic equation for the neutrino gas in a plasma is derived, and the resulting kinetic
description is applied to study the processes of the neutrino Landau damping
and the neutrino-beam–plasma instability.
Magnetohydrodynamic equations for plasmas with finite-Larmor-radius
effects
Authors: POGUTSE IGOR O. , SMOLYAKOV ANDREI I. , HIROSE AKIRA
Published: July 2002

It is shown that the truncation of the infinite hierarchy of fluid
equations obtained
as moments of the Vlasov kinetic equation leads to a system of nonlinear
equations
that describe finite-Larmor-radius effects with good accuracy. Inertial
terms in the
momentum balance, viscosity and heat-flux evolution equations are crucial
for a
uniform description of the plasma response with an arbitrary Larmor radius.
In
the low-frequency ordering, the obtained equations are simplified by an
expansion
in the parameter 1/B, where B is the
equilibrium magnetic field. The results of
the second-order [Oscr ](1/B2) and the
fourth-order [Oscr ](1/B4) closures are compared.
It
is shown that the accuracy of the description improves for higher-order
closures.
The role of collective effects in the kinetics of
a molecular plasma generated by a particle
beam. Application to nitrogen
Authors: PEYRAUD-CUENCA N. , FAUCHER P.
Published: July 2002

A molecular plasma generated by a particle beam generally departs
strongly from
a Maxwellian distribution and exhibits a pronounced depletion of electrons
as soon
as cold electrons cross the first vibrational barrier. We show that this
situation
produces screened Coulomb interactions that enlarge the Coulomb cross-section
in the
neighbourhood of this first vibrational threshold. Including these screened
interactions
through the Balescu–Lenard operator with all excitation transitions
leads
to a modification of the distribution at the first vibrational barrier.
An application
is given to the case of low-pressure nitrogen lasers.
Collisionless magnetic reconnection in the
presence of an external driving flow
Authors: HORIUCHI RITOKU , SATO TETSUYA
Published: July 2002

The dynamical development of collisionless reconnection and the consequent
energy-conversion process in the presence of an external driving flow are investigated
by means of a full particle simulation. Magnetic reconnection develops in
two steps in accordance with the formation of ion and electron current layers. In
the early phase magnetic reconnection is controlled by an ion kinetic effect, while
an electron kinetic effect becomes dominant in the late phase. There exist two
mechanisms associated with the particle kinetic effects, that break the frozen-in
condition of magnetic field and lead to magnetic reconnection in a collisionless
plasma, namely a particle inertia effect and a particle thermal orbit effect. It is
found that the dominant triggering mechanism in the late phase changes from
an electron thermal orbit effect to an electron inertia effect as the longitudinal
magnetic field increases. Electron acceleration and heating take place in the
reconnection area under the influence of the reconnection electric field, while the energy
conversion takes place from electrons to ions through the action of an electrostatic
field excited downstream. As a result, the average ion temperature becomes about
1.5 times the average electron temperature.
Beam instabilities in a magnetized pair plasma
Authors: LYUTIKOV MAXIM
Published: July 2002

Beam instabilities in the strongly magnetized electron–positron plasma
of a pulsar magnetosphere are considered. We analyse the resonance conditions and
estimate the growth rates of the Cherenkov and cyclotron instabilities of the ordinary
(O), extraordinary (X) and Alfvén modes in two limiting regimes: kinetic and
hydrodynamic. The importance of the different instabilities as a source of coherent
pulsar radiation generation is then estimated, taking into account the angular
dependence of the growth rates and the limitations on the length of the coherent
wave–particle interaction imposed by the curvature of the magnetic field lines. We
conclude that in the pulsar magnetosphere, Cherenkov-type instabilities occur in
the hydrodynamic regime, while cyclotron-type instabilities occur in the kinetic
regime. We argue that electromagnetic cyclotron-type instabilities on the X, O and
probably Alfvén waves are more likely to develop in the pulsar magnetosphere.
Cylindrical ion-acoustic waves in a warm multicomponent plasma
Authors: EL-LABANY S. K. , EL-WARRAKI S. A. , MOSLEM W. M.
Published: July 2002

Cylindrical ion-acoustic solitons are investigated in a warm plasma
with negative ions and multiple-temperature electrons through the derivation
of a cylindrical Korteweg–de Vries equation using a reductive perturbation
theory. The results are compared with those for the corresponding planar
solitons.
Which Indonesian Women Marry Youngest, and Why?
Authors: Jones Gavin W.
Published: July 2002

Although the Indonesian Marriage Law of 1974 set a minimum age of marriage for females of 16, among some groups – notably Sundanese in West Java and Madurese in East Java – early marriage remained common well after the Marriage Law was promulgated. Early marriage has since declined but certainly not disappeared among these groups. This paper analyses trends in early marriage and reports on a field study among the Madurese.
The putative impact of exploitation on rocky infratidal macrofaunal assemblages: a multiple-area comparison
Authors: Lasiaka Theresa
Published: July 2002

The putative impact of subsistence foragers along the Transkei coast of South Africa was determined by comparing the community-level attributes of infratidal macrofaunal assemblages in three ‘no-take’ reserves with those at adjacent exploited localities. The objective of this study was to ascertain whether the differences in the assemblages found at exploited and non-exploited localities were consistent along this coast. Two-way ANOVAs indicated that the presence/absence of exploitation had no effect on univariate community measures. Macrofaunal biomass was the only measure which showed significant differences amongst locations and interaction effects. Abundance/biomass comparison curves revealed that all the exploited sites except one showed the configuration typical of moderately disturbed sites and that all the non-exploited sites except one showed the trend typical of undisturbed sites. Two-way crossed ANOSIM tests indicated that treatment and location both had significant effects on these assemblages and that there were also significant differences between each pair of locations. The latter probably reflects regional differences in species composition due to the fact that this coast lies at the junction of two zoogeographic marine provinces. The multidimensional scaling (MDS) ordinations derived from abundance and biomass estimates revealed two major clusters of sites, one representing sites in the southern region and the other sites within the central and northern regions. The non-exploited sites within each region were situated above and to the right of the corresponding exploited sites. Similarity percentage analyses (SIMPER) indicated that the major species contributing to the average dissimilarity between the exploited and non-exploited localities varied regionally. There was, however, a fair amount of consistency in terms of the functional groups highlighted by these analyses. Some of the species adversely affected by exploitation are dependent on primary substrata either for their food supplies or for attachment. Likewise many of the species which appeared to benefit from exploitation were phytal-associated forms.
Population structure and growth of the squid Todarodes sagittatus (Cephalopoda: Ommastrephidae) in north-west African waters
Authors: Arkhipkin Alexander , Laptikhovsky Vladimir , Golub Alexander
Published: July 2002

The population structure of the European flying squid Todarodes sagittatus was studied using data of about 5000 squid caught in waters off the western Sahara between 1969 and 1997. The bulk of the population consisted of winter-spawned squid, which occurred as juveniles of 80–120 mm mantle length (ML) over the slope in spring, and as immature squid of 160–180 mm ML both on the shelf and slope in summer. In autumn, the squid attained 220–280 mm ML, matured, and shifted to the slope, where the spawning was supposed to occur in winter. Age and growth of T. sagittatus was studied using statolith ageing techniques. Assuming daily production of putative growth increments within statoliths, as well as sizes and proportions of immature and maturing females, the lifespan of the west Saharan populations of T. sagittatus lasts ∼1 y. Todarodes sagittatus is a fast growing squid at juvenile and immature ontogenetic phases. Early maturation (at ages 220–230 d in males and 250–260 d in females, respectively) and subsequent decrease of somatic growth rates caused rather small modal sizes of mature squid (250–300 mm ML) compared with those of their northern counterparts (350–420 mm ML). Both hatching dates and seasonality in occurrence of mature females shows that in waters off the western Sahara T. sagittatus spawns throughout the year with a well-pronounced winter peak.
Changes in the lipophilicity of the surfaces of Meloidogyne
incognita and Haemonchus contortus during exposure to
host signals
Authors: LÓPEZ DE MENDOZA M. E. , MODHA J. , ROBERTS M. C. , CURTIS R. , KUSEL J. R.
Published: July 2002

The surfaces of plant and animal parasitic nematodes share certain lipids, which seem to be important in the infection
process. The surfaces of 2 parasitic nematodes, Meloidogyne incognita and Haemonchus contortus, were activated by different
pH buffers to allow the insertion of different fluorescent probes. The lipid analogue PKH26 and the surface charge
indicator, cationized ferritin, were used as probes with these nematodes but labelled only the retaining 2nd-stage moulted
cuticle of H. contortus 3rd-stage larvae (L3). Shedding of the second moult of H. contortus L3 was also visualized with
PKH26 and cationized ferritin. The fluorescent anionic lipid probe 5-N-(octadecanoyl)-aminofluorescein (AF18) was
inserted into the epicuticle layer of M. incognita 2nd-stage juveniles (J2) and H. contortus L3, and also of the second moult
of H. contortus L3. Incubation with tomato root diffusate caused modifications of the M. incognita surface allowing the
insertion of AF18. Fluorescence with AF18 was significantly decreased after treating M. incognita J2 with amiloride, a
potent blocker of hydrogen and sodium (H+/Na+) antiporter. No surface fluidity was observed in M. incognita J2 and H.
contortus L3 pre-treated with alkaline buffer when the lipid analogue AF18 was used in fluorescence recovery after
photobleaching experiments. The significance of these findings to host infection processes is discussed.
Language and Perceptual Experience
Authors: Lyon Gordon
Published: July 2002

This article is a sequel to ‘The Experience of Perceptual
Familiarity’, published in Philosophy in January 1996. There it was argued that the experience of familiarity of appearance consists in awareness of ease of perception. A successful prediction of this hypothesis was that this experience will be absent if the familiar stimulus is perceptually simple. The new paper examines a series of experiments on recognition-memory for colours, often thought to confirm the Sapir-Whorf hypothesis, that language influences fundamental cognitive and perceptual abilities. I argue that the hypothesis of Perceptual Familiarity provides a more plausible, non-Whorfian explanation of the results. Language is not influencing non-linguistic perception here, since, as the hypothesis is able to explain, recognition-memory for colours is itself invariably mediated by language.
Even More Varieties of Retribution
Authors: Walker Nigel
Published: July 2002

Professor Cottingham's article ‘Varieties of Retribution’ in the Philosophical Quarterly, 1979, 29, 238ff. is discussed, and new varieties of retributivism are outlined and criticised, particularly those proposed by Richard Burgh, Michael Moore and Robert Nozick. The ‘Kantian gap’ between moral censure and the obligation to punish is emphasised. Distinctions are drawn between theories which make punishment a duty and those which make it a right, and also between those based on the notion of a rule and those based on the expression of blame.
Reliability of a lifetime history of major depression:
implications for heritability and co-morbidity
Authors: FOLEY D. L. , NEALE M. C. , KENDLER K. S.
Published: July 2002

Background. In unselected samples, the diagnosis of major

depression (MD) is not highly reliable.
It is not known if occasion-specific influences on reliability index
familial risk factors for MD, or
how reliability is associated with risk for co-morbid anxiety disorders.

Methods. An unselected sample of 847 female twin pairs
was interviewed twice, 5 years apart, about
their lifetime history (LTH) of MD, generalized anxiety disorder (GAD)
and panic disorder (PD).
Familial influences on reliability were examined using structural equation
models. Logistic
regression was used to identify clinical features that predict
reliable diagnosis. Co-morbidity was characterized using the continuation
ratio test.

Results. The reliability of a LTH of MD over 5 years
was fair (κ=0·43). There was no evidence for
occasion-specific familial influences on reliability, and heritability

of reliably diagnosed MD was
estimated at 66%. Subjects with unreliably diagnosed MD reported fewer
symptoms and, if
diagnosed with MD only at the first interview, less impairment and
help seeking, or, if diagnosed
with MD only at the second interview, fewer episodes and a longer
illness. A history of co-morbid
GAD or PD is more prevalent among subjects with reliably diagnosed MD.

Conclusions. A diagnosis of MD based on a single
psychiatric interview incorporates a substantial
amount of measurement error but there is no evidence that transient influences
on recall and
diagnosis index familial risk for MD. Quantitative indices of risk for
MD based on multiple
interviews should reflect both the characteristics of MD and the temporal
order of positive
diagnoses.
Is introversion a risk factor for suicidal behaviour in depression?
Authors: ROY ALEC
Published: July 2002

Background. Personality is an important determinant of
suicidal behaviour. However, it has been
studied little in relation to suicidal behaviour in depression.

Methods. Depressed patients who had attempted suicide (N=41)
were compared with depressed
patients who had never attempted suicide (N=56) and normal controls
(N=56) for their scores
on three personality questionnaires.

Results. Introversion was the only personality dimension where
the post hoc test showed a different
pattern between the two groups of depressed patients in their relation
to controls. In particular, only
depressed patients who had attempted suicide had significantly lower introversion
scores than
controls.

Conclusion. The personality dimension of introversion may be
a risk factor for suicidal behaviour
in depression.
Job strain and psychiatric morbidity
Authors: CROPLEY M. , STEPTOE A. , JOEKES K.
Published: July 2002

Background. This study examined the association between job strain and psychiatric morbidity
using interview-based assessments of mental health. We assessed the prevalence of neurotic disorder
in high job strain (high demand, low control) and low job strain (low demand, high control) school
teachers, and compared these rates with data from individuals with similar educational qualifications
from the National Psychiatric Morbidity Survey of Great Britain.

Methods. One hundred and sixty primary and secondary school teachers were selected from a
larger survey on the basis of high or low job strain, and were assessed for psychiatric morbidity
using the Revised Clinical Interview Schedule (CIS-R). The prevalence of neurotic symptoms and
a total psychiatric morbidity score were calculated.

Results. After adjusting for age, gender and occupational grade, the prevalence of psychiatric
morbidity was greater in high job strain than low job strain individuals. The prevalence of severe
anxiety, worry and fatigue symptoms was significantly greater in the high job strain teachers. In
comparison with the British psychiatric morbidity survey, the prevalence of neurotic disorders was
greater in the high job strain, but not in low job strain teachers. Individuals in the low job strain
group were more likely to report severe anxiety, irritability and fatigue in the week prior to
interview, than comparably educated individuals in the national survey.

Conclusion. Job strain is associated with psychiatric morbidity. The high levels of neurotic
psychopathology among teachers is consistent with previous research that has found teaching to be
a highly stressful occupation.
Schizophrenics know more than they can tell:
probabilistic classification learning in schizophrenia
Authors: KÉRI S. , KELEMEN O. , SZEKERES G. , BAGÓCZKY N. , ERDÉLYI R. , ANTAL A. , BENEDEK G. , JANKA Z.
Published: July 2002

Background. Previous studies have demonstrated impaired explicit and preserved implicit memory
functions in schizophrenia. However, it is less clear whether schizophrenics can learn complex
information (e.g. probabilistic stimulus–response associations) with or without access for conscious
recollection. In this study we applied a classification learning task to assess explicit and implicit
processes concurrently.

Methods. Two test procedures were administered to 40 schizophrenic subjects and 20 healthy
volunteers: a probabilistic classification learning (PCL) task to evaluate implicit memory functions;
and a category cue recognition test to investigate the explicit memory system. The PCL task included
feedback guided category learning of geometrical shapes. These shapes were called category cues,
predicting class membership with certain probabilities. The gradual increase of categorization
performance during the feedback learning was a potentially implicit process, whereas the
subsequent recognition of category cues required explicit memory functions.

Results. The schizophrenic patients improved their categorization performance to a similar extent
to the controls, but they failed to recognize the category cues. Memory performances were
independent of the positive and negative symptoms.

Conclusions. Patients with schizophrenia were able to establish representations of complex
categories, but these remained unconscious. This is consistent with earlier reports, suggesting
damaged explicit and spared implicit memory in schizophrenia.
Life events and prodromal symptoms in bulimia nervosa
Authors: RAFFI A. R. , RONDINI M. , GRANDI S. , FAVA G. A.
Published: July 2002

Background. Little is known about the interaction of life events with prodromal symptoms in
bulimia nervosa.

Methods. A semistructured research interview based on Paykel's Interview for Recent Life Events
and on the Clinical Interview for Depression for eliciting prodromal symptoms was administered
to 30 patients with bulimia nervosa and 30 healthy control subjects matched for sociodemographic
variables.

Results. Patients reported significantly more stressful life events than controls. Most of the patients
reported prodromal symptoms. Anorexia, low self-esteem, depressed mood, anhedonia, generalized
anxiety and irritability were the most common prodromal symptoms.

Conclusions. The prodromal phase of bulimia nervosa was found to be characterized by a
combination of prodromal symptoms of affective type and stressful life events. Their joint
occurrence may increase vulnerability to bulimia nervosa.
Antecedents of the risk of recovery from DSM-III-R social phobia
Authors: DeWIT D. J. , OGBORNE A. , OFFORD D. R. , MacDONALD K.
Published: July 2002

Background. This study reports antecedents of recovery from DSM-III-R social phobia.

Methods. Retrospective data were obtained from 1116 individuals age 15 to 64 participating in a
large population health survey in the province of Ontario, Canada.

Results. Approximately 50% of the sample recovered from their illness. Survival analysis revealed
a median length of illness of 25 years with peak periods of risk of recovery occurring between 30
and 45 years duration. Using discrete time multivariate hazard regression analysis, statistically
significant predictors of recovery from social phobia included: childhood social contextual factors
(one or no childhood siblings, a small town childhood place of residence), characteristics of the
disorder (onset past the age of 7, less than three disorder symptoms), an absence of co-morbid
health-related conditions and psychiatric disorders (chronic health problems and major depression),
and the occurrence of co-morbid chronic health problems and major depression prior to the onset
of the disorder.

Conclusions. Our data indicate that social phobia in the general population is a chronic and
unremittent disorder. Determinants of recovery are rooted in distal childhood circumstances,
disorder attributes, and the physical and mental health status of individuals over the life course.
Structure calculation of biological macromolecules from NMR data
Authors: GÜNTERT PETER
Published: July 2002

The relationship between amino acid sequence, three-dimensional structure
and
biological function of proteins is one of the most intensely pursued areas
of
molecular biology and biochemistry. In this context, the three-dimensional

structure has a pivotal role, its knowledge being essential to understand
the
physical, chemical and biological properties of a protein (Branden &
Tooze, 1991;
Creighton, 1993). Until 1984 structural information at atomic resolution
could
only be determined by X-ray diffraction techniques with protein single
crystals
(Drenth, 1994). The introduction of nuclear magnetic resonance (NMR)
spectroscopy (Abragam, 1961) as a technique for protein structure determination

(Wüthrich, 1986) has made it possible to obtain structures with comparable

accuracy also in a solution environment that is much closer to the natural
situation
in a living being than the single crystals required for protein crystallography.
Ali A. Mazrui & Alamin M. Mazrui, The power
of Babel: Language and governance in the African experience.
Chicago: University of Chicago Press; Oxford: James Currey;
Kampala: Fountain Publishers; Nairobi: East African Educational
Publishers; Cape Town: David Philip, 1998. Pp. xii, 228.
Hb $40.00, pb $15.25.
Authors: Myers-Scotton Carol
Published: July 2002

To understand this book, a little background information
helps. I first encountered Ali Mazrui in 1968–70
when I was the first lecturer in linguistics at Makerere
University in Kampala, Uganda; Mazrui, a member of the
political science faculty, was already a famous orator,
acknowledged by all as possessing “a golden tongue.”
Since then, he has gone on to become probably the most
famous African studies professor in the United States; he was
the presenter of the nine-part BBC/PBS television series The
Africans: A triple heritage, and he is the author of many
books and articles on Africa. He has taught at many universities
around the world, and is now director of the Institute
of Global Cultural Studies and Albert Schweitzer Professor
in the Humanities at the State University of New York at
Binghamton. His junior co-author (a relative?), Alamin
M. Mazrui, was trained as a linguist and is an associate
professor of Black studies at Ohio State University. Both
are native speakers of Swahili from Mombasa, Kenya (they
prefer to refer to the language as Kiswahili, with its
noun class prefix, as it would be if one were speaking
the language itself). Kiswahili, of course, is probably
the best-known African language; many people in East Africa
and other areas (e.g. the Democratic Republic of Congo)
speak it as a second language. Furthermore, it is one of
the few indigenous languages with official status in an
African nation; it is the official language of Tanzania,
and the co-official language in Kenya along with English.
However, Kiswahili is spoken natively mainly along the East
African coastline and on the offshore islands (e.g. Zanzibar),
often by persons with a dual Arabic-African heritage similar
to that of the Mazruis.
Fast and frugal heuristics: What about unfriendly environments?
Authors: Shanteau James , Thomas Rickey P.
Published: July 2002

Simple heuristics that make us smart offers an impressive compilation of work that demonstrates fast and frugal (one-reason) heuristics can be simple, adaptive, and accurate. However, many decision environments differ from those explored in the book. We conducted a Monte Carlo simulation that shows one-reason strategies are accurate in “friendly” environments, but less accurate in “unfriendly” environments characterized by negative cue intercorrelations, that is, tradeoffs.
So what's a modeler to do?
Authors: Thelen Esther , Schöner Gregor , Scheier Christian , Smith Linda B.
Published: July 2002

We argue that mentalistic constructs like the “object concept” are not substitutes for process explanations of cognition, and that it is impossible to prove the existence of such constructs with behavioral tasks. We defend the field theory as an appropriate level for modeling embodiment. Finally, we discuss the model's biological plausibility and its extensions to other tasks and other species.
An internal teacher for neural computation
Authors: Floreano Dario
Published: July 2002

Contextual signals might supervise the discovery of coherently
varying information between cortical modules computing different
functions of their receptive field input. This hypothesis is explored
in two sets of computational experiments, one studying the effects on
learning of long-range unidirectional contextual signals mediated by
intervening processors, and the other showing contextually supervised
discovery of a high-order variable in a multilayer network.
Novel peripheral mechanisms of opioid analgesia
Authors: Stein Christoph , Schäfer Michael
Published: July 2002

dickenson briefly mentions that peripheral opioid
receptors somehow become active following inflammation and that
the appearance of endogenous opioid peptides at the injury site may
be related to immune cell proliferation. Recent findings elucidate the
underlying mechanisms in more detail and provide an incentive for the
development of a novel generation of analgesics devoid of typical
central opioid side effects.
Attribution is more likely to be demonstrated in more natural contexts
Authors: Matheson M. D. , Cooper M. , Weeks J. , Thompson R. , Fragaszy D.
Published: July 2002

We propose a naturalistic version of the “guesser–knower”
paradigm in which the experimental subject has an opportunity to
choose which individual to follow to a hidden food source. This design
allows nonhumans to display the attribution of knowledge to another
conspecific, rather than a human, in a naturalistic context (finding
food), and it is readily adapted to different species.
What makes perceptual symbols perceptual?
Authors: Aydede Murat
Published: July 2002

Three major attempts by Barsalou to specify what makes a
perceptual symbol perceptual fail. One way to give such an account is to
use symbols' causal/nomic relation to what they represent, roughly
the way contemporary informational psychosemanticists develop their
theories, but this fails to draw the distinction Barsalou seems to have
in mind.
Why twin studies really don't tell us much about human heritability
Authors: Segalowitz Sidney J.
Published: July 2002

The derivation of heritability from human twin studies involves
serious methodological flaws. Heritability is consistently overestimated
because of biological confounds of twinning, consistent and often gross
underestimation of the environmental variance, and nonadditive genetic
influences that can hugely exaggerate heritability values. Despite this
bad research design, behaviour geneticists continue to publish results
implying that their heritability results are valid.
Analytic regularity of solutions of Livsic's
cohomology equation and some applications to
analytic conjugacy of hyperbolic dynamical systems
Authors: DE LA LLAVE R.
Published: July 2002

We study Livsic's problem of finding $\phi$ satisfying $X\phi=\eta$, where
$\eta$ is a given function and $X$ is a given Anosov vector field. We show
that, if $\phi$ is a continuous solution and $X,\eta$ are analytic, then
$\phi$ is analytic. We use the previous result to show that if two
low-dimensional Anosov systems are topologically conjugate and the Lyapunov
exponents at corresponding periodic points agree, the conjugacy is analytic.
Analogous results hold for diffeomorphisms.
Exponential instability for a class of dispersing billiards
Authors: STOYANOV LATCHEZAR
Published: July 2002

The billiard in the exterior of a finite disjoint union $K$ of strictly convex bodies in ${\mathbb R}^d$ with smooth boundaries is considered. The existence of global constants $0 < \delta < 1$ and $C > 0$ is established such that if two billiard trajectories have $n$ successive reflections from the same convex components of $K$, then the distance between their $j$th reflection points is less than $C(\delta^j + \delta^{n-j})$ for a sequence of integers $j$ with uniform density in $\{1,2,\dots,n\}$. Consequently, the billiard ball map (although not continuous in general) is expansive. As applications, an asymptotic of the number of prime closed billiard trajectories is proved which generalizes a result of Morita [Mor], and it is shown that the topological entropy of the billiard flow does not exceed $\log (s-1)/a$, where $s$ is the number of convex components of $K$ and $a$ is the minimal distance between different convex components of $K$.
High brightness laser–plasma X-ray source at IFAM:
Characterization and applications
Authors: MARZI S. , GIULIETTI A. , GIULIETTI D. , GIZZI L.A. , SALVETTI A.
Published: July 2002

A high brightness laser-plasma X-ray source has
been set-up and is presently available at IFAM. A wide
range of diagnostics has been set up to monitor the properties
of the X-ray radiation and to control the main parameters
including photon energy, flux intensity, and pulse duration.
A beam extractor enables access to the X-ray radiation
at atmospheric pressure. A simple, easy-to-use projection
microscope has been built which is capable of single-shot
micron resolution imaging with digital acquisition. Preliminary
biomedical experiments show that the X-ray doses available
on a single laser shot exposure of our source fully meet
the conditions required for an important class of biological
experiments based on X-ray induced DNA damage providing
an ideal alternative to the long time exposures needed
with X-ray tubes.
Perspectives of laser inertial fusion energy in Japan
Authors: YAMANAKA CHIYOE
Published: July 2002

The inertial confinement fusion (ICF) research has remarkably
developed in the last 10 years, which enables us to scope the
fusion ignition and burn in the near future. Following the recent
progress in the ICF, the perspectives of the inertial fusion energy
(IFE) are presented. International collaboration is highly expected.
Velocity workspace analysis for multiple arm robot systems
Authors: Lee Jihong
Published: July 2002

In this paper, the analysis of manipulability of robotic systems comprised of multiple cooperating arms is considered. Given bounds on the capabilities of joint actuators for each robot, the purpose of this study is to derive the bounds for task velocity achievable by the system. Since bounds on each joint velocity form a polytope in joint-velocity space and the task space velocity is connected with joint velocity through
Jacobian matrices of each robot, the allowable task velocity space, i.e. velocity workspace, for multiple cooperating robot system is also represented as a polytope which is called manipulability polytope throughout this paper. Based on the fact that the boundaries of
the manipulability polytope are mapped from the boundaries of allowable joint-velocity space, slack variables are introduced in order to transform given inequality constraint given on joint velocities into a set of normal linear equalities in which the unknowns of the
equation are composed of the vertices of manipulability polytope, vectors spanning the null space of the Jacobian matrix, and the slack variables. Either redundant or nonredundant cooperating robot systems can be handled with the proposed technique. Several different application examples including simple SCARA-type robots as well as complex articulated robot manipulators are included, and, under the assumption of firm grip, it will be shown that the calculated manipulability polytope for cooperating robot system is actually the intersection of all the manipulability polytopes of every single robot which is hard to be derived through geometrical manipulation.
Experimental evaluation of generalized predictive control applied to a hydraulic
actuator
Authors: Sepehri N. , Wu G.
Published: July 2002

This paper reports the results of an experimental study, which was conducted to evaluate the performance and implementation aspects of a generalized predictive control (GPC) technique to an electro-hydraulic positioning actuator. Poor dynamics and high
nonlinearities form part of the difficulty in the control of hydraulic functions which make the application of adaptive controls an attractive solution. The applicability of GPC to the position control of hydraulic manipulator has been investigated through computer simulations in the literature. However, there is no experimental record of applying this technique to an actual hydraulic system. A suitable plant model is established and recursive U-D factorization technique is adopted for on-line estimation of time-varying plant parameters. Experimental results are obtained from a laboratory electrohydraulic actuator test stand. Various benchmark tests, comprising step and tracking inputs, demonstrate good performance and the promise of the technique. In spite of significant actuator dynamics (control voltage saturation, flow nonlinearity and dry frictional nonlinearity in the hydraulic actuator), successful control tests could be performed repetitively.