bluuebunny/crossref_metadata_2025 huggingface dataset:
Nonlinear dynamics and pattern formation in turbulent wake transition
Authors: HENDERSON RONALD D.
Published: July 2002

Results are reported on direct numerical simulations of transition
from

two-dimensional to three-dimensional states due to secondary instability
in

the wake of a

circular cylinder. These calculations quantify the nonlinear response of

the system to three-dimensional perturbations near threshold for the two
separate

linear instabilities

of the wake: mode A and mode B. The objectives are to classify the nonlinear
form

of the bifurcation to mode A and mode B and to identify the conditions
under which

the wake evolves to periodic, quasi-periodic, or chaotic states with

respect to changes

in spanwise dimension and Reynolds number. The onset of mode A is shown
to occur

through a subcritical bifurcation that causes a

reduction in the primary oscillation

frequency of the wake at saturation. In contrast, the onset of mode B occurs
through

a supercritical bifurcation with no frequency shift

near threshold. Simulations of the

three-dimensional wake for fixed Reynolds number and increasing spanwise

dimension show that large systems evolve to a state of spatiotemporal chaos,

and suggest that three-dimensionality in the wake leads to irregular states

and fast transition to

turbulence at Reynolds numbers just beyond the onset of the secondary instability.
A

key feature of these ‘turbulent’ states is the

competition between self-excited, three-dimensional instability modes

(global modes) in the mode A wavenumber band. These

instability modes produce irregular spatiotemporal patterns and large-scale

‘spot-like’ disturbances in the wake during the breakdown of
the

regular mode A pattern. Simulations at higher Reynolds number show

that long-wavelength interactions modulate

fluctuating forces and cause variations in phase along the span of the
cylinder that

reduce the fluctuating amplitude of lift and drag. Results of both two-dimensional

and three-dimensional simulations are presented for a range of Reynolds
number

from about 10 up to 1000.
Coriolis effect on gravity-driven convection in a
rotating porous layer heated from below
Authors: VADASZ PETER
Published: July 2002

Linear stability and weak nonlinear theories are used to investigate
analytically the
Coriolis effect on three-dimensional gravity-driven convection in a rotating
porous
layer heated from below. Major differences as well as similarities with
the
corresponding problem in pure fluids (non-porous domains) are particularly

highlighted. As such, it is found that, in contrast to the problem in pure
fluids,
overstable convection in porous media is not limited to a particular domain
of Prandtl
number values (in pure fluids the necessary condition is
Pr<1). Moreover, it is also
established that in the porous-media problem the critical wavenumber in
the plane
containing the streamlines for stationary convection is not identical to
the critical
wavenumber associated with convection without rotation, and is therefore
not
independent of rotation, a result which is quite distinct from the corresponding

pure-fluids problem. Nevertheless it is evident that in porous media, just
as in the case of
pure fluids subject to rotation and heated from below, the viscosity at
high rotation
rates has a destabilizing effect on the onset of stationary convection,
i.e. the higher the
viscosity the less stable the fluid. Finite-amplitude results obtained
by using a weak
nonlinear analysis provide differential equations for the amplitude, corresponding
to
both stationary and overstable convection. These amplitude equations permit
one to
identify from the post-transient conditions that the fluid is subject to
a pitchfork
bifurcation in the stationary convection case and to a Hopf bifurcation
associated with
the overstable convection. Heat transfer results were evaluated from the
amplitude
solution and are presented in terms of Nusselt number for both stationary
and
overstable convection. They show that rotation has in general a retarding
effect on
convective heat transfer, except for a narrow region of small values of
the parameter
containing the Prandtl number where rotation enhances the heat transfer
associated
with overstable convection.
Circulation and formation number of laminar vortex rings
Authors: ROSENFELD MOSHE , RAMBOD EDMOND , GHARIB MORTEZA
Published: July 2002

The formation time scale of axisymmetric vortex rings is studied
numerically for
relatively long discharge times. Experimental findings on the existence
and universality
of a formation time scale, referred to as the ‘formation number’,
are confirmed. The
formation number is indicative of the time at which a vortex ring acquires
its
maximal circulation. For vortex rings generated by impulsive motion of
a piston,
the formation number was found to be approximately four, in very good agreement

with experimental results. Numerical extensions of the experimental study
to other
cases, including cases with thick shear layers, show that the scaled circulation
of the
pinched-off vortex is relatively insensitive to the details of the formation
process,
such as the velocity programme, velocity profile, vortex generator geometry
and the
Reynolds number. This finding might also indicate that the properly scaled
circulation
of steady vortex rings varies very little. The formation number does depend
on the
velocity profile. Non-impulsive velocity programmes slightly increase the
formation
number, while non-uniform velocity profiles may decrease it significantly.
In the case
of a parabolic velocity profile of the discharged flow, for example, the
formation
number decreases by a factor as large as four. These findings indicate
that a major
source of the experimentally found small variations in the formation number
is the
different evolution of the velocity profile of the discharged flow.
Shock oscillation in underexpanded screeching jets
Authors: PANDA J.
Published: July 2002

The periodic oscillation of the shock waves in screeching, underexpanded,
supersonic
jets, issuing from a choked, axisymmetric, nozzle at fully expanded Mach
numbers
(Mj) of 1.19 and 1.42, is studied
experimentally and analytically. The experimental part
uses schlieren photography and a new shock detection technique which depends
on a
recently observed phenomenon of laser light scattering by shock waves.
A narrow laser
beam is traversed from point to point in the flow field and the appearance
of the
scattered light is sensed by a photomultiplier tube (PMT). The time-averaged
and
phase-averaged statistics of the PMT data provide significant insight into
the shock
motion. It is found that the shocks move the most in the jet core and the
least in the
shear layer. This is opposite to the intuitive expectation of a larger-amplitude
shock
motion in the shear layer where organized vortices interact with the shock.
The mode
of shock motion is the same as that of the emitted screech tone. The instantaneous

profiles of the first four shocks over an oscillation cycle were constructed
through a
detailed phase averaged measurement. Such data show a splitting of each
shock (except
for the first one) into two weaker ones through a ‘moving staircase-like’
motion.
During a cycle of motion the downstream shock progressively fades away
while a new
shock appears upstream. Spark schlieren photographs demonstrate that a
periodic
convection of large organized vortices over the shock train results in
the above
described behaviour. An analytical formulation is constructed to determine
the
self-excitation of the jet column by the screech sound. The screech waves,
while
propagating over the jet column, add a periodic pressure fluctuation to
the ambient
level, which in turn perturbs the pressure distribution inside the jet.
The oscillation
amplitude of the first shock predicted from this linear analysis shows
reasonable
agreement with the measured data. Additional reasons for shock oscillation,
such as a
periodic perturbation of the shock formation mechanism owing to the passage
of the
organized structures, are also discussed.
Spreading characteristics of compressible jets from nozzles of various geometries
Authors: ZAMAN K. B. M. Q.
Published: July 2002

The spreading characteristics of jets from several asymmetric nozzles,
and a set of
rectangular orifices are compared, covering a jet Mach number range of
0.3–2.0. The
effect of ‘tabs’ for a rectangular and a round nozzle is also
included in the comparison.
Compared to a round jet, the jets from the asymmetric nozzles spread only
slightly
more at subsonic conditions whereas at supersonic conditions, when ‘screech’
occurs,
they spread much more. The dynamics of the azimuthal vortical structures
of the
jet, organized and intensified under the screeching condition, are thought
to be
responsible for the observed effect at supersonic conditions. Curiously,
the jet from a
‘lobed’ nozzle spreads much less at supersonic condition compared
to all other cases;
this is due to the absence of screech with this nozzle. Screech stages
inducing flapping,
rather than varicose or helical, flow oscillation cause a more pronounced
jet spreading.
At subsonic conditions, only a slight increase in jet spreading with the
asymmetric
nozzles contrasts previous observations by others. The present results
show that the
spreading of most asymmetric jets is not much different from that of a
round jet. This
inference is further supported by data from the rectangular orifices. In
fact, jets from
the orifices with small aspect ratio (AR) exhibit virtually no
increase in the spreading.
A noticeable increase commences only when AR is larger than about
10. Thus, ‘shear
layer perimeter stretching’, achieved with a larger AR for
a given cross-sectional area
of the orifice, by itself, proves to be a relatively inefficient mechanism
for increasing
jet spreading. In contrast, the presence of streamwise vortices or ‘natural
excitation’
can cause a significant increase – effects that might explain the
observations in the
previous investigations. Thus far, the biggest increase in jet spreading
is observed with
the tabs. This is true in the subsonic regime, as well as in the supersonic
regime, in
spite of the fact that screech is eliminated by the tabs. The characteristic
spreading of
the tabbed jets is explained by the induced motion of the tab-generated
streamwise
vortex pairs. The tabs, however, incur thrust loss; the flow blockage and
loss in thrust
coefficient, vis-à-vis the spreading increase, are
evaluated for various configurations.
Thermoacoustic heating and cooling
in near-critical fluids in the presence of a
thermal plume
Authors: ZAPPOLI BERNARD , JOUNET ARNAUD , AMIROUDINE SAKIR , MOJTABI ABDELKADER
Published: July 2002

This work brings new insight to the question of heat transfer in near–critical fluids
under Earth gravity conditions. The interplay between buoyant convection and thermoacoustic
heat transfer (piston effect) is investigated in a two-dimensional non-insulated cavity containing a local heat source, to reproduce the conditions used in
recent experiments. The results were obtained by means of a finite-volume numerical
code solving the Navier–Stokes equations written for a low-heat-diffusing near-critical
van der Waals fluid. They show that hydrodynamics greatly affects thermoacoustics
in the vicinity of the upper thermostated wall, leading to a rather singular heat
transfer mechanism. Heat losses through this wall govern a cooling piston effect.
Thus, the thermal plume rising from the heat source triggers a strong enhancement
of the cooling piston effect when it strikes the middle of the top boundary. During
the spreading of the thermal plume, the cooling piston effect drives a rapid thermal
quasi-equilibrium in the bulk fluid since it is further enhanced so as to balance the
heating piston effect generated by the heat source. Then, homogeneous fluid heating
is cancelled and the bulk temperature stops increasing. Moreover, diffusive and convective
heat transfers into the bulk are very weak in such a low-heat-diffusing fluid.
Thus, even though a steady state is not obtained owing to the strong and seemingly
continuous instabilities present in the flow, the bulk temperature is expected to remain
quasi-constant. Comparisons performed with a supercritical fluid at initial conditions
further from the critical point show that this thermalization process is peculiar to
near-critical fluids. Even enhanced by the thermal plume, the cooling piston effect
does not balance the heating piston effect. Thus, overall piston-effect heating lasts
much longer, while convection and diffusion progressively affect the thermal field
much more significantly. Ultimately, a classical two-roll convective-diffusive structure
is obtained in a perfect gas, without thermoacoustic heat transfer playing any role.
Flow field and noise characteristics of a
supersonic impinging jet
Authors: KROTHAPALLI A. , RAJKUPERAN E. , ALVI F. , LOURENCO L.
Published: July 2002

This paper describes the results of a study examining the flow and acoustic
characteristics of an axisymmetric supersonic jet issuing from a sonic and a Mach 1.5
converging–diverging (C–D) nozzle and impinging on a ground plane. Emphasis is
placed on the Mach 1.5 nozzle with the sonic nozzle used mainly for comparison. A
large-diameter circular plate was attached at the nozzle exit to measure the forces
generated on the plate owing to jet impingement. The experimental results described
in this paper include lift loss, particle image velocimetry (PIV) and acoustic
measurements. Suckdown forces as high as 60% of the primary jet thrust were measured
when the ground plane was very close to the jet exit. The PIV measurements were
used to explain the increase in suckdown forces due to high entrainment velocities.
The self-sustained oscillatory frequencies of the impinging jet were predicted using a
feedback loop that uses the measured convection velocities of the large-scale coherent
vortical structures in the jet shear layer. Nearfield acoustic measurements indicate
that the presence of the ground plane increases the overall sound pressure levels
(OASPL) by approximately 8 dB relative to a corresponding free jet. For moderately
underexpanded jets, the influence of the shock cells on the important flow features
was found to be negligible except for close proximity of the ground plane.
Convergence of a cylindrical liquid shell and the
formation of a bore in a rotating fluid
Authors: KEDRINSKII V. K. , NIKULIN V. V.
Published: July 2002

This paper presents the results of experimental studies of a collapsing cylindrical
cavity (the convergence of a liquid shell) in a rotating fluid as well as the formation
and propagation of a jump (bore) at the interface. The basic parameters of the liquid
shell dynamics for a pulsed one-dimensional load are estimated using the equation
of cylindrical cavity pulsation in an unbounded fluid. The theoretical model of a
rotationally symmetric hydraulic jump moving along the free surface of a hollow
vortex is constructed. The jump is simulated by a discontinuous solution of the
equations in the long-wave approximation for tornado-like and hollow vortices. For
comparison with the experimental data, basic theoretical results are obtained for
flows in a hollow vortex with constant circulation and axial velocity varying along
the radius of the rotating liquid shell.
The onset of drag reduction by dilute polymer
additives, and the maximum drag reduction asymptote
Authors: SREENIVASAN KATEPALLI R. , WHITE CHRISTOPHER M.
Published: July 2002

Drag reduction due to dilute addition of high polymers has been known for about
fifty years. In spite of this long history, many aspects of the problem remain poorly
understood. Two of its features for pipe flow are considered here in the context of the
elastic theory of de Gennes: the onset of drag reduction and the so-called maximum
drag reduction (MDR) asymptote. A cautious conclusion is that a version of the
theory agrees qualitatively with existing experiments.
Do Old Habits Die Hard? A Statistical Exploration of the Politicisation of Progresa, Mexico's Latest Federal Poverty-Alleviation Programme, under the Zedillo Administration
Authors: ROCHA MENOCAL ALINA
Published: July 2002

Under his administration (1994–2000), President Ernesto Zedillo replaced Pronasol, the targeted poverty alleviation programme created by his predecessor, with his own programme, Progresa. Pronasol had come under severe attack as a politicised federal welfare programme intended to generate votes for the PRI. In contrast, the Zedillo administration insisted that Progresa was a genuine poverty-alleviation programme devoid of any political agenda. The purpose of this article is to assess whether Zedillo's claim is valid. To do so, I build a statistical model with the aim of identifying the factors that may have influenced the reach of Progresa in 1999, an important year of electoral preparation for the July 2000 elections. The picture that emerges is not entirely clear-cut. On the one hand, poverty indicators played a key role in determining who should benefit from the programme. On the other hand, Progresa also displayed a political edge, revealing that, in certain respects, the executive and the PRI continued to resort to old tricks in an attempt to alter electoral results.
Refounding the African state and local self-governance: the neglected foundation
Authors: Wunsch James S.
Published: July 2002

The political revolution of contemporary Africa has so far largely been
limited to the centre and to re-establishing the same institutional forms and
processes which failed Africa in the 1960s. These regimes are already showing
signs of erosion. This problem can be understood through the theory of
public goods. Key collective or ‘public’ goods problems impede the collective
action necessary for institutional development. Top-down strategies cannot
surmount these problems because they cannot integrate and unify the population
or structure consensual and sustained collective action.

As currently constituted, national levels of government in Africa will be
poor partners with local communities in development, be it of democracy or
of the economy. In many cases, national regimes only exist at all because
minimal contributing sets or political monopolists controlled, were given, or
mobilised the resources to establish constituting rule systems which they used
to sustain their existing relative advantages during the break-up of imperial
systems. As this advantage is usually at the expense of the majority which
lives outside the capitals, resources and policies to improve these areas are
slow in coming. The slow, bottom-up process by which a true public constitution
is built, one which reflects and elaborates generally held values, is
built on existing political relationships, and protects social diversity, has
never been allowed to develop.

Refounding the African state must resolve these problems if it is to succeed.
Ethnically and religiously diverse peoples will rule themselves better under
federal and consociational systems which give local leaders space to lead local
institutional development, authority to play a role in national governance, a
process to develop consensus on central policy and to check the centre when
there is no consensus. This requires a foundation of viable, real, developed
structures of local governance if it is to succeed.
Reforming Dysfunctional Institutions Through Democratisation?

Reflections on Ghana
Authors: SANDBROOK RICHARD , OELBAUM JAY
Published: July 2002

How can Africa's societies reorient and rebuild state

apparatuses where predatory, neo-patrimonial governance has held sway?
This

emerges as a key question if one accepts that dysfunctional institutions,

and not just poor initial conditions, a hostile international environment,

external shocks, or policy errors, have impeded Africa's economic

recovery. Although analysts and organisations place differing weights

on these various causes, few now dissent from the consensus that

political-institutional reforms are a necessary condition for African

development. Yet recognising the need for such change is one thing;

knowing how to bring it about is quite another. Few guidelines exist to

steer this complex and long-term task. Democratisation is now often

cited as one means to foster institutional renewal, and this article draws

on the Ghanaian experience to reflect upon the efficacy of this route.
A moral economy of corruption in Africa?
Authors: de Sardan J. P. Olivier
Published: July 2002

As far as corruption in Africa is both conspicuous and generalised,
it has
to be studied from the viewpoint of the participants. This article starts
with
six general theses on corruption in Africa, which place it within a broader

‘corruption complex’, and emphasise its routine nature, the
stigmatisation
of corruption despite the absence of effective sanctions, its apparent
irreversibility,
the absence of correlation with regime types and its legitimacy to
its perpetrators. Corruption is then shown to be socially embedded in ‘logics’

of negotiation, gift-giving, solidarity, predatory authority and redistributive

accumulation. Any anti-corruption policy must face up to these realities.
Colonial and Contemporary Ideologies of ‘Community Management’: The Case of Tank Irrigation Development in South India
Authors: Mosse David
Published: July 2002

This is an essay in the sociology of knowledge. It aims to demonstrate, firstly, how development institutions construct rural society in terms of organizational imperatives, and secondly, how these ‘constructions’ come to be underpinned by social theory. The focus is on irrigation in south India and colonial and contemporary state policy initiatives to promote local institutions for the community management of decentralized resource systems. The essay presents the social and historical origin of an important and powerful set of contemporary policy ideas. The significance of this lies in the continuing misperception of local institutions of resource management, and in particular the systematic isolation of resource management from its particular social and historical context.
Dipeptidyl peptidase I and III activities of adult
schistosomes
Authors: HOLA-JAMRISKA L. , DALTON J. P. , AASKOV J. , BRINDLEY P. J.
Published: July 2002

Soluble extracts of adult Schistosoma japonicum and S.
mansoni were examined for the presence of proteolytic activities
ascribable to dipeptidyl peptidases (DPPs) at a range of pH from 4 to 11
using synthetic peptidyl substrates diagnostic
of DPPs I, II, III and IV. Activity capable of cleaving the DPP I-specific
substrates H-Gly-Arg-NHMec and H-Gly-Phe-NHMec which exhibited a pH optimum of 5·5 was observed in extracts
of schistosomes. Female schistosomes
exhibited greater DPP I activity than male schistosomes, while female S.
japonicum showed substantially more activity
than female S. mansoni. The specific activities against H-Gly-Arg-NHMec
were 21·5 and 1·9 nmoles NHMec/min/mg
protein for female and male S. japonicum and 8·5 and 1·9
nmoles NHMec/min/mg for female and male S. mansoni. The

biochemical properties of schistosome DPP I were similar to mammalian DPP
I (=cathepsin C) in that schistosome
DPP I was only slowly inhibited by the cysteine protease inhibitor trans-epoxysuccinyl-1-leucylamido
(4-guanidino)-
butane, partly inhibited by the blocked diazomethyl ketones Z-Phe-Ala-CHN2
and Z-Phe-Phe-CHN2, but enhanced by
halide ions. At pH 8·5, activity against the DPP III-specific substrate
H-Arg-Arg-NHMec was evident in schistosome
extracts, and this activity appeared to be due to a zinc metallo-exopeptidase
because it was inhibited by 1,10-phenathroline
and by EDTA. DPP II or DPP IV activity was not detected in the schistosome
extracts.
Potential role for excretory–secretory forms of glutathione-S-transferase (GST) in Fasciola hepatica
Authors: CERVI L. , ROSSI G. , MASIH D. T.
Published: July 2002

The excretory–secretory antigen of Fasciola hepatica (ESA) is involved in the suppressive phenomena of cellular immune
responses in rats. The ESA can depress the proliferative response of spleen mononuclear cells and inhibit nitric oxide
(NO) production by peritoneal cells. In the present study we identified ESA proteins of ca 24 kDa, which shared significant
sequence homology to glutathione-S-transferase (GST) obtained from homogenates of F. hepatica adults, other helminths
and different mammals. When the dimeric form of these proteins ca 48 kDa was cultured with rat spleen cells, a significant
decrease of proliferative response to Con A was detected, starting from 20 μg/ml of ESA protein (P<0·03). We also
observed a significant inhibition of nitrite production by incubation with the dimeric form in normal peritoneal
macrophages (P<0·04). These results indicated that the GST secreted by the parasite could be involved in evasion of
the parasite from the host immune response.
Egg hatching in 3 species of monocotylid monogenean parasites from the shovelnose ray Rhinobatos typus at Heron Island, Australia
Authors: CHISHOLM L. A. , WHITTINGTON I. D.
Published: July 2002

Eggs of Neoheterocotyle rhinobatidis, Troglocephalus rhinobatidis and Merizocotyle icopae (Monogenea: Monocotylidae)
from the shovelnose ray Rhinobatos typus (Rhinobatidae) have a distinct hatching pattern linked to light periodicity. Larvae
of these 3 monogenean species emerge only during daylight when exposed to natural illumination or when incubated in
alternating 12 h periods of light and dark (light on 06.00 h, light off 18.00 h). N. rhinobatidis larvae emerge with a distinct
peak during the first 2 h of light; this peak is not as pronounced in T. rhinobatidis or M. icopae. Eggs of N. rhinobatidis
incubated in a reverse light/dark cycle (light on 18.00 h, light off 06.00 h) hatched only during periods of illumination,
again with a peak during the first 2 h of light. Evidence suggests that the hatching patterns observed in all 3 species
represent true circadian rhythms because eggs incubated in 24 h light or 24 h dark conditions continued to hatch with a
rhythm. Shadows, disturbance and host tissue did not promote hatching in N. rhinobatidis or T. rhinobatidis but there were
indications that host tissue may promote hatching in M. icopae. The hatching patterns observed are discussed with respect
to their adaptive responses to host behaviour and predation pressure.
Causal Closure Principles and Emergentism
Authors: Lowe E. J.
Published: July 2002

Causal closure arguments against interactionist dualism are currently popular amongst physicalists. Such an argument appeals to some principles of the causal closure of the physical, together with certain other premises, to conclude that at least some mental events are identical with physical events. However, it is crucial to the success of any such argument that the physical causal closure principle to which it appeals is neither too strong nor too weak by certain standards. In this paper, it is argued that various forms of naturalistic dualism, of an emergentist character, are consistent with the strongest physical causal closure principles that can plausibly be advocated.
Social support deficits, loneliness and life events as risk
factors for depression in old age. The Gospel Oak Project VI
Authors: PRINCE M. J. , HARWOOD R. H. , BLIZARD R. A. , THOMAS A. , MANN A. H.
Published: July 2002

Background. A companion paper reported a very strong
cross-sectional association between handicap and late-life depression.
Adjusting for handicap weakened associations between sociodemographic
variables and depression. It was unclear whether handicap was a
confounder, or a useful summary variable, mediating the effect of a
range of sociodemographic disadvantages. This paper focusses on the
cross-sectional relationship between depression and demographic
variables, social support, and life events.

Method. A community survey of all residents over the age
of 65 years of an electoral district in London, UK.

Results. There was a moderate association between
SHORT-CARE pervasive depression and the number of life events
experienced over the previous year. Personal illness, bereavement and
theft were the most salient events. There was a stronger, graded,
relationship between the number of social support deficits (SSDs) and
depression. Number of SSDs also related to age, handicap, loneliness
and use of homecare services. Loneliness was itself strongly
associated with depression; odds ratio 12·4
(7·6–20·0).

Conclusions. Problems of collinearity, and the
cross-sectional design of the study limited interpretation of the
exact nature of the relationship between social support, loneliness,
handicap and depression. However, the clustering of these four factors
can be used to define a large part of the elderly population with a
poor quality of life. An important avenue for future research will be
the development and implementation of population intervention
strategies designed to address some or all of these problems among
older people in general.
Cognitive impairment in the euthymic phase of affective disorder
Authors: KESSING LARS VEDEL
Published: July 2002

Background. A review of studies of cognition in the
euthymic phase of unipolar and bipolar
affective disorder reveals diverging results.

Methods. The study was designed as a controlled cohort study,

with the Danish psychiatric case
register of admissions used to identify patients and the Danish
civil register to identify controls.
Patients who were hospitalized between 19 and 25 years ago with
an affective diagnosis and who
at interviews fulfilled criteria for a primary affective unipolar
or bipolar disorder, according to ICD-10, were compared with age- and
gender-matched controls. Interviews and assessment of the
cognitive function were made in the euthymic phase of the disorder.
In all, 118 unipolar patients,
28 bipolar patients and 58 controls were included. Analyses were
adjusted for differences in the level
of education and for subclinical depressive and anxiety symptoms.

Results. Patients with recurrent episodes were significantly

more impaired than patients with a
single episode and more impaired than controls. Also, within patients
the number of prior episodes
seemed to be associated with cognitive outcome. There was no difference
in the severity of the
dysfunction between unipolar and bipolar patients.

Conclusions. Cognitive impairment in out-patients with
unipolar and bipolar disorder appears to
be associated with the number of affective episodes.
The epidemiology of blood-injection-injury phobia
Authors: BIENVENU O. JOSEPH , EATON WILLIAM W.
Published: July 2002

Background. We report the prevalence, clinical characteristics,

frequency of mental health
treatment, demographic correlates, frequency of co-morbid psychiatric conditions,
and general
health ramifications of DSM-IV blood-injection-injury phobia in the general
population.

Method. The Diagnostic Interview Schedule (version III-R),
which
included questions on blood-injection-injury phobia, was administered to
1920 subjects in the
Baltimore ECA Follow-up Study.

Results. The estimated unweighted lifetime prevalence of
blood-injection-injury phobia was 3·5%.
The median age of onset was 5·5 years; 78% had had symptoms within

the last 6 months. Subjects
with blood-injection-injury phobia (cases) had higher lifetime histories

of fainting and seizures than
those without (non-cases). None reported seeking mental health treatment

specifically for phobia.
Prevalences were lower in the elderly and higher in females and persons

with less education. Cases had
significantly higher than expected lifetime prevalences of other
psychiatric conditions, including
marijuana abuse/dependence, major depression, obsessive–compulsive

disorder, panic disorder,
agoraphobia, social phobia and other simple phobia. Cases and
non-cases did not differ with regard
to usual health-care settings, regular care for specific medical
conditions, numbers of out-patient
visits or hospitalizations, or previous general anaesthesia or
live births. However, diabetics with
blood-injection-injury phobia had higher than expected rates of macrovascular
complications.

Conclusion. Blood-injection-injury phobia is common, especially

in females and those with less
education, and it is associated with several co-morbid psychiatric conditions.
No strong, broad
general health ramifications of this phobia are apparent. However,
diabetics with this phobia appear
at particular risk for complications; this deserves further study.
Emotional bias and inhibitory control processes in
mania and depression
Authors: MURPHY F. C. , SAHAKIAN B. J. , RUBINSZTEIN J. S. , MICHAEL A. , ROGERS R. D. , ROBBINS T. W. , PAYKEL E. S.
Published: July 2002

Background. Despite markedly different clinical presentations, few studies have reported differences
in neuropsychological functioning between mania and depression. The disinhibited behaviour
characteristic of mania and evidence that subgenual prefrontal cortex is differentially activated in
mania and depression both suggest that dissociable deficits will emerge on tasks that require
inhibitory control and are subserved by ventromedial prefrontal cortex.

Methods. Manic patients and controls undertook computerized neuropsychological tests of
memory and planning ability. In addition, manic and depressed patients were directly compared
with controls on a novel affective shifting task that requires inhibitory control over different
components of cognitive and emotional processing.

Results. Manic patients were impaired on tests of memory and planning. Importantly, affective
shifting performance of manic patients differed from that of depressed patients. Manic patients were
impaired in their ability to inhibit behavioural responses and focus attention, but depressed patients
were impaired in their ability to shift the focus of attention. Depressed patients exhibited an affective
bias for negative stimuli, and we believe this to be the first demonstration of an affective bias for
positive stimuli in manic patients.

Conclusions. Observed impairments on tests of memory and planning suggest a global pathology
for mania consistent with previous profiles for this disorder and similar to established profiles for
depression. The results on the affective shifting task demonstrate the presence of mood-congruent
bias and dissociable components of inhibitory control in mania and depression. Against a
background of memory and planning impairments in the two groups, these findings are consistent
with a role for the ventromedial prefrontal cortex in mediating mood–cognition relationships.
Responses to depression in unipolar depressed
patients: an investigation of Nolen-Hoeksema's
response styles theory
Authors: KUEHNER CHRISTINE , WEBER IRIS
Published: July 2002

Background. The response styles theory suggests that rumination in response to depressed mood
exacerbates and prolongs depression, while distraction ameliorates and shortens it. Gender
differences in response styles are said to contribute to the observed gender differences in the
prevalence of unipolar depression. While empirical support for the theory has been found from a
variety of non-clinical studies, its generalizability to clinically depressed patient populations remains
unclear.

Methods. A cohort of 52 unipolar depressed in-patients was assessed with the Response Styles
Questionnaire during in-patient stay (T1) and 4 weeks after discharge (T2). The patients were
followed up 4 months after discharge (T3). Clinical assessment included the SCAN-PSE-10.

Results. Moderate and statistically significant retest-stabilities for rumination and distraction were
found, comparable for patients with stable and changing depression status from T1 to T2. A cross-sectional diagnosis of a major depressive episode was associated with rumination, while gender was
not. Post-discharge baseline rumination (T2), adjusted for concurrent depression, predicted follow-up levels of depression (T3), and, in patients who were non-remitted at post-discharge baseline, it
predicted presence of a major depressive episode at follow-up (T3). Results on distraction were
more ambiguous.

Conclusions. Our results suggest that rumination is likely to have a deteriorating impact on the
course of clinical episodes of depression in unipolar depressed patients. Larger longitudinal patient
studies are needed to validate these findings.
The association between childhood feeding problems
and maternal eating disorder: a community study
Authors: WHELAN ELIZABETH , COOPER PETER J.
Published: July 2002

Background. A possible association between childhood feeding problems and maternal eating
disorder has been suggested by a clinic-based self-report questionnaire study. A community study
was conducted, using standardized psychiatric interviews, to investigate the strength and specificity
of this putative association.

Methods. Four-year-old children were screened using a self-report version of the Behaviour
Screening Questionnaire, completed by mothers, and the Pre-School Behaviour Checklist,
completed by teachers. Three groups of children were identified for follow-up: children with feeding
problems (N = 42), children with a non-feeding form of disturbance (i.e. shyness, fearfulness or
behavioural disturbance; N = 79), and a random sample of children with no disturbance (N = 29).
The presence of feeding problems was confirmed by assessment of a filmed family meal, with ratings
made blind to child group and maternal mental state. Maternal current and past affective disorder
and current and past eating disorder were systematically assessed, blind to child status, using the
Anxiety Disorders Interview Schedule and the Eating Disorder Examination respectively.

Results. Compared with the mothers of the two comparison groups of children, the mothers of the
children with feeding problems had no raised rate of any affective disorder, either current or past,
but they did have a markedly raised rate of both current and past DSM-IV eating disorder. The
odds ratio of maternal eating disorder for the children with feeding problems was significantly
raised at 11·1 (CI 1·4–91·8).

Conclusion. There is a strong and specific association between childhood feeding problems and
maternal eating disorder.
The power and omnipotence of voices: subordination
and entrapment by voices and significant others
Authors: BIRCHWOOD M. , MEADEN A. , TROWER P. , GILBERT P. , PLAISTOW J.
Published: July 2002

Background. Cognitive therapy for psychotic symptoms often embraces self-evaluative beliefs (e.g.
self-worth) but whether and how such beliefs are related to delusions remains uncertain. In previous
research we demonstrated that distress arising from voices was linked to beliefs about voices and
not voice content alone. In this study we examine whether the relationship with the voice is a
paradigm of social relationships in general, using a new framework of social cognition, ‘ranking’
theory.

Method. In a sample of 59 voice hearers, measures of power and social rank difference between
voice and voice hearer are taken in addition to parallel measures of power and rank in wider social
relationships.

Results. As predicted, subordination to voices was closely linked to subordination and
marginalization in other social relationships. This was not the result of a mood-linked appraisal.
Distress arising from voices was linked not to voice characteristics but social and interpersonal
cognition.

Conclusion. This study suggests that the power imbalance between the individual and his
persecutor(s) may have origins in an appraisal by the individual of his social rank and sense of group
identification and belonging. The results also raise the possibility that the appraisal of voice
frequency and volume are the result of the appraisal of voices' rank and power. Theoretical and
novel treatment implications are discussed.
Evaluation of treatment and intermediate and long-term outcome of adolescent eating disorders
Authors: STEINHAUSEN H.-C. , SEIDEL R. , WINKLER METZKE C.
Published: July 2002

Background. A cohort of 60 adolescent eating-disordered patients that was consecutively admitted between 1979 and 1988 to a child and adolescent psychiatric university department in Berlin, Germany was followed up at a mean of 5·0 years and for a second time at a mean of 11·5 years.

Methods. Each patient was personally interviewed and findings dealing with eating disorder symptoms and psychosocial functioning were rated on four-point scales. In addition, the duration of both in-patient and out-patient treatment and the Body Mass Index (BMI) were recorded.

Results. Patients were in treatment for a mean of 33% of the initial 5-year follow-up period, but this has dropped to a mean of 17% of the entire 11-year follow-up period. No predictors of treatment duration were found. The mortality rate was 8·3% at the second follow-up. The distribution of abnormal BMIs (<17·5) reflected a trend of improvement with increasing duration of follow-up. In comparison to the 5-year follow-up, fewer patients suffered from symptoms of the full clinical picture of an eating disorder at the 11-year follow-up. Among the surviving patients 80% recovered during the long-term course. There were few specific predictors of three different outcome criteria.

Conclusion. This outcome study of adolescent eating disorders provides further evidence that the long-term course of the disorders in terms of the eating pathology is better than can be expected after a few years. Very little can be said with regard to individual prognosis.
The prevalence of depression in relation to cerebral
atrophy and cognitive performance in 70- and 74-year-old women in Gothenburg. The Women's
Health Study
Authors: PÁLSSON S. , LARSSON L. , TENGELIN E. , WAERN M. , SAMUELSSON S. , HÄLLSTRÖM T. , SKOOG I.
Published: July 2002

Background. Hospital-based studies report that depression in the elderly is associated with brain
atrophy. This notion could not be confirmed in a population study on 85-year-olds. We aimed to
assess depression in relation to brain atrophy and cognition in 70- and 74-year-old women.

Methods. A representative sample of 70- and 74-year-old women (N = 501) was examined with a
psychiatric examination including the Mini-Mental State Examination (MMSE), measuring global
cognitive function, and computerized tomography (CT) of the brain (N = 268). Depression was
diagnosed according to DSM-III-R. Previous depression was diagnosed by history and by
information from previous examinations in this 24-year longitudinal study.

Results. The prevalence of depression was 11·6%, including 8·4% with major depression (MDD).
Among those who were currently mentally healthy, 43·0% had a history of previous depression.
Women with current MDD had lower scores on the MMSE than the mentally healthy women. This
association was only found in women with a lower level of education. Current depressives, previous
depressives and mentally healthy women without a history of depression did not differ on CT with
regard to brain atrophy or white matter lesions. The association between MDD and lower cognitive
performance was independent of the association of cognitive performance with structural brain
changes on CT.

Conclusions. Brain atrophy on CT is not associated with depression in the general population,
despite the fact that individuals with depression have a worse cognitive performance. The finding
that cognitive performance was not decreased in individuals with previous depression suggests that
cognitive dysfunction is a state phenomenon in depression.
Assessing the ability of people with a learning
disability to give informed consent to treatment
Authors: ARSCOTT K. , DAGNAN D. , STENFERT KROESE B.
Published: July 2002

Background. People with a learning disability are increasingly being encouraged to take a more
active role in decisions about their psychological and medical treatment, raising complex questions
concerning their ability to consent. This study investigates the capacity of people with a learning
disability to consent in the context of three treatment vignettes, and the influence of verbal and
memory ability on this capacity.

Methods. Measures of verbal ability, memory ability and ability to consent to treatment (ACQ) were
administered to 40 people with a learning disability. The ACQ consisted of three vignettes depicting
a restraint, psychiatric or surgical intervention. These were followed by questions addressing
people's ability to understand the presenting problem; the nature of the proposed intervention; the
alternatives, risks and benefits; their involvement in the decision-making process; and their ability
to express a clear decision with a rationale for treatment.

Results. Five people (12·5%) could be construed as able to consent to all three vignettes; 26 (65%)
could be construed as able to consent to at least one. The questions that were most difficult to
answer concerned a participants' rights, options and the impact of their choices. Verbal and
memory ability both influenced ability to consent.

Conclusions. This study introduces a measure that may enable clinicians to make more systematic
assessments of people's capacity to consent. A number of issues surrounding the complex area of
consent to treatment are also raised.
Attempted suicide in west London, I. Rates across
ethnic communities
Authors: BHUGRA D. , DESAI M. , BALDWIN D. S.
Published: July 2002

Background. Two previous studies from the United Kingdom have suggested that rates of attempted
suicide in Asian women are higher than in the native population.

Method. Over a 1-year period we identified 434 patients presenting from one catchment area to four
hospitals, after episodes of self-harm. These patients were assessed using the GHQ, CIS-R, and Life
Events Inventory, and by collecting details of the attempt itself.

Results. Asian women had the highest overall rates ; 1·6 times those in White women and 2·5 times
the rate among Asian men. The rates were lowest among older women. Among younger Asian
women (less than 30 years) the rates were 2·5 times those of White women and seven times those
of Asian men. The rates among black groups were lower than expected. Self-poisoning was the
commonest method of self-harm.

Conclusions. Younger Asian women are vulnerable to increased rates of attempted self-harm and
deserve to be studied further.