bluuebunny/crossref_metadata_2025_split huggingface dataset:
Experimental and numerical studies of an eastward jet over topography
Authors: TIAN YUDONG , WEEKS ERIC R. , IDE KAYO , URBACH J. S. , BAROUD CHARLES N. , GHIL MICHAEL , SWINNEY HARRY L. 
Published: July 2002

Motivated by the phenomena of blocked and zonal flows in Earth's atmosphere, we
conducted laboratory experiments and numerical simulations to study the dynamics
of an eastward jet flowing over wavenumber-two topography. The laboratory experiments
studied the dynamical behaviour of the flow in a barotropic rotating annulus
as a function of the experimental Rossby and Ekman numbers. Two distinct flow
patterns, resembling blocked and zonal flows in the atmosphere, were observed to
persist for long time intervals.Earlier model studies had suggested that the atmosphere's normally upstream-
propagating Rossby waves can resonantly lock to the underlying topography, and
that this topographic resonance separates zonal from blocked flows. In the annulus,
the zonal flows did indeed have super-resonant mean zonal velocities, while the
blocked flows appear subresonant. Low-frequency variability, periodic or irregular,
was present in the measured time series of azimuthal velocity in the blocked regime,
with dominant periodicities in the range of 6–25 annulus rotations. Oscillations have
also been detected in zonal states, with smaller amplitude and similar frequency.
In addition, over a large region of parameter space the two flow states exhibited
spontaneous, intermittent transitions from the one to the other.We numerically simulated the laboratory flow geometry in a quasi-geostrophic
barotropic model over a similar range of parameters. Both flow regimes, blocked
and zonal, were reproduced in the simulations, with similar spatial and temporal
characteristics, including the low-frequency oscillations associated with the blocked
flow. The blocked and zonal flow patterns are present over wide ranges of forcing,
topographic height, and bottom friction. For a significant portion of parameter space,
both model flows are stable. Depending on the initial state, either the blocked or
the zonal flow is obtained and persists indefinitely, showing the existence of multiple
equilibria.
A solution technique for longitudinal Stokes flow around multiple aligned cylinders
Authors: TOLL S. 
Published: July 2002

This technique solves the two-dimensional Poisson equations in geometries involving
cylindrical objects. The method uses three fundamental solutions, corresponding to
a line force, a line couple and a pressure gradient, on each cylinder. Superposition
of the fundamental solutions due to all the cylinders involved, while approximately
satisfying the no-slip condition on each cylinder, yields a mobility matrix relating the
various forces and motions of all the cylinders. Any specific problem can be solved
by prescribing the motions of the cylinders and solving the matrix. For problems
involving few cylinders or with a sufficient degree of symmetry this can be done
analytically.Once constructed, the general method is applied analytically to a series of specific
problems. The permeability of an eccentric annulus is derived. The result is numerically
indistinguishable from the exact solution to the problem, but unlike the exact solution
the present one is obtained in closed form. The drag on two parallel rods moving
past one another is also derived and compared to the exact solution. In this case
the result is accurate for rod separations down to about 0.2 times the rod diameter.
Finally the drag on a rod moving in a triangular array of identical rods is derived.
Here it is shown that due to screening it is sufficient to include the six nearest
neighbours, regardless of the rod separation. Although the present examples are all
worked out analytically, the matrix can also be solved numerically, in which case any
two-dimensional arrangement of cylindrical objects can be studied.
Transverse velocity increments in turbulent flow
using the RELIEF technique
Authors: NOULLEZ A. , WALLACE G. , LEMPERT W. , MILES R. B. , FRISCH U. 
Published: July 2002

Non-intrusive measurements of the streamwise velocity in turbulent round
jets in
air are performed by recording short-time displacements and distorsions of very
thin tagging lines written spanwise into the flow. The lines are written by
Raman-exciting oxygen molecules and are interrogated by laser-induced electronic
fluorescence
(relief). This gives access to the spatial structure of transverse velocity
increments
without recourse to the Taylor hypothesis. The resolution is around
25 μm, less than
twice the Kolmogorov scale η for the experiments performed (with
Rλ≈360–600).The technique is validated by comparison with results obtained from other
techniques for longitudinal or transverse structure functions up to order 8.
The agreement
is consistent with the estimated errors – a few percent on exponents determined
by extended-self-similarity – and indicates significant departures from
Kolmogorov (1941) scaling.Probability distribution functions of transverse velocity increments
Δu over separations down to 1:8η are reported for the first time.
Violent events, with Δu comparable
to the r.m.s. turbulent velocity fluctuation, are found to take place
with statistically
significant probabilities. The shapes of the corresponding lines suggest
the effect of intense slender vortex filaments.
Buoyancy-driven coalescence of slightly deformable drops
Authors: ROTHER MICHAEL A. , ZINCHENKO ALEXANDER Z. , DAVIS ROBERT H. 
Published: July 2002

The simultaneous effect of small deformation and short-range

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

slowly sedimenting drops is

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

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

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

drops from

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

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

opposite directions, have a considerable combined effect on the coalescence

efficiency.

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

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

apparent contact without van der Waals attraction, determines the

contact force as a function of

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

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

the small-gap region to

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

contact motion. The initial gap profile for the inner solution

is provided by matching

with the outer trajectory for spherical drops approaching contact.The analysis shows that, for Ca[Lt ]1, the near-contact

deformation is mainly

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

the critical horizontal offsets leading to coalescence and the

parametric analysis are

computationally very intensive. To facilitate these tasks, a substantially

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

thin-film equations is

developed. Unlike for spherical drops, when the upstream intersection

area is a circle,

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

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

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

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

shown for a system of ethyl salicylate drops in diethylene glycol.The present solution extends the range of drop sizes where the coalescence

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

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

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

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

approach is valid in a wide range of small and moderately small capillary
numbers.
A reappraisal of democracy in civil
society: evidence from rural Senegal
Authors: Patterson Amy S. 
Published: July 2002

Civil society is the space of uncoerced human association and relational

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

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

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

challenging state policies, civil society organisations can cause the state

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

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

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

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

effective at achieving their political objectives.This article challenges these assumptions about civil society through

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

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

groups often become ineffective and disorganised, and cannot achieve
their political, economic or social goals. The inefficiency and
undemocratic nature of civil society have larger implications for
democratic transitions in Africa.
Response to ‘Comment on “Boundary
conditions for surface waves propagating along
the interface of plasma flow and free space” ’
Authors: LEE HEE J. , CHO SANG-HOON 
Published: July 2002

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

condition that we used (equation (57) in Lee and Cho 1997) is valid in
both the
nonrelativistic and the relativistic theory, and is equivalent to equation
(11) of
Shoucri (1999). Shoucri's hasty conclusion that our boundary condition
(57) is
incorrect appears to be due to his neglect of the fact that a boundary
condition
can be put into different forms depending upon problems under consideration.One way to derive a boundary condition for the surface-wave problem
with
a sharp boundary is to assume an inhomogeneous plasma having a varying

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

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

calculating the currents relativistically, we find that the following three

boundary conditions are equivalent, and any one of them is acceptable:(i) equation (57) in Lee and Cho (1997);(ii) equation (11) in Shoucri (1999);(iii) formula here(in the notation of Lee and Cho (1997), with γ as the relativistic factor).
Obsessive–compulsive disorder and separation anxiety co-morbidity in early onset panic disorder
Authors: GOODWIN R. , LIPSITZ J. D. , CHAPMAN T. F. , MANNUZZA S. , FYER A. J. 
Published: July 2002

Background. This study was undertaken to examine the relationship between anxiety co-morbidity and age of onset of panic disorder.Methods. Age of onset of panic disorder and co-morbid anxiety disorders were assessed among 201 panic disorder probands with childhood separation anxiety disorder, obsessive–compulsive disorder, obsessive–compulsive symptoms, social phobia and specific phobia as part of a clinician-administered lifetime diagnostic interview. A generalized linear model was used to test the association between each anxiety co-morbidity and age of panic disorder onset while simultaneously controlling for the potential confounding effects of sociodemographic characteristics and other psychiatric co-morbidity.Results. Earlier onset of panic disorder was found in patients with co-morbid obsessive–compulsive disorder, obsessive–compulsive symptoms and separation anxiety disorder, but not simple phobia or social phobia. Patients with both childhood separation anxiety disorder and obsessive–compulsive disorder had an even earlier panic onset than those with either childhood separation anxiety disorder or obsessive–compulsive disorder.Conclusions. The association between anxiety co-morbidity and earlier onset of panic disorder is specific to obsessive–compulsive disorder and childhood separation anxiety disorder.
Psychosocial sequelae of the 1989 Newcastle
earthquake: III. Role of vulnerability factors in post-disaster morbidity
Authors: CARR V. J. , LEWIN T. J. , KENARDY J. A. , WEBSTER R. A. , HAZELL P. L. , CARTER G. L. , WILLIAMSON M. 
Published: July 2002

Background. This paper examines the contributions of dispositional and non-dispositional
factors to post-disaster psychological morbidity. Data reported are from the 845 participants in
the longitudinal component of the Quake Impact Study.Methods. The phase 1 survey was used to construct dimensional indices of threat and disruption
exposure. Subsequently, a range of dispositional characteristics were measured, including
neuroticism, personal hopefulness and defence style. The main morbidity measures were the General
Health Questionnaire (GHQ-12) and Impact of Event Scale (IES).Results. Dispositional characteristics were the best predictors of psychological morbidity
throughout the 2 years post-disaster, contributing substantially more to the variance in morbidity
(12–39%) than did initial exposure (5–12%), but the extent of their contribution was greater for
general (GHQ-12) than for post-traumatic (IES) morbidity. Among the non-dispositional
factors, avoidance coping contributed equally to general and post-traumatic morbidity
(pr = 0·24). Life events since the earthquake (pr = 0·18), poor social
relationships (pr =−0·25) and
ongoing earthquake-related disruptions (pr = 0·22) also contributed to general morbidity, while
only the latter contributed significantly to post-traumatic morbidity (pr = 0·15).Conclusions. Medium-term post-earthquake morbidity appears to be a function of multiple
factors whose contributions vary depending on the type of morbidity experienced and include
trait vulnerability, the nature and degree of initial exposure, avoidance coping and the nature
and severity of subsequent events.
How distinct is ‘distinct quality’ of mood?
Authors: PARKER G. , ROUSSOS J. , EYERS K. , WILHELM K. , MITCHELL P. , HADZI-PAVLOVIC D. 
Published: July 2002

Background. The DSM-IV criteria for melancholia
include the clinical feature ‘distinct quality’, defined
as a mood state differing from that experienced in bereavement. Both
propositions – its specificity to melancholia and its definition
– remain problematical.Methods. We examine both propositions by analysing an
adjective checklist completed by melancholic and non-melancholic
depressed subjects, as well as by a bereaved sample. The checklist was
refined by a principal components analysis to four scales – one
assessing a general ‘mood’ severity or dysphoric
dimension, and the other three assessing dimensions of
‘fatigue’, ‘numbness’ and
‘guilt’.Results. If the concept of ‘distinct quality’
has validity, we would require specificity of the refined qualitative
constructs to melancholic depression. The ‘numbness’
component met that requirement, but only to a degree. While bereaved
subjects did differ from those with melancholic depression on a number
of our refined qualitative mood domains, such differences appeared
more related to lower levels of depression in the bereaved sample.Conclusions. We argue for deleting the ‘distinct
quality’ criterion from diagnostic checklists of melancholia
until its definition has been improved, its utility demonstrated and
its specificity to any depressive subtype established as having
clinical significance.
Types of social support as predictors of psychiatric
morbidity in a cohort of British Civil Servants (Whitehall II Study)
Authors: STANSFELD S. A. , FUHRER R. , SHIPLEY M. J. 
Published: July 2002

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

and psychiatric morbidity by the General Health Questionnaire at baseline

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

support in men and high
negative aspects of close relationships in men and women were associated
with greater risk of
psychiatric morbidity even after adjustment for baseline General
Health Questionnaire score. There
was no evidence of a buffering effect among men or women who experienced
life events or chronic
stressors. Controlling for a personality measure of hostility
did not affect the observed relations.Conclusions. The present findings illustrate that different
types of support are risk factors for
psychological distress and that they operate in different ways
for men and women. Direct effects of
emotional support are predictive of good mental health in men and negative
aspects of close
relations predict poor mental health in both men and women. Emotional support
is predictive of
good mental health in women whereas, confiding alone is not.
Antidepressant agents: from tricyclics to serotonin uptake inhibitors
Authors: GARATTINI S. , BARBUI C. , SARACENO B. 
Published: July 2002

Background. The number of antidepressant drugs
available in the market has grown rapidly in the
last few years. The present paper underlines some of the pre-clinical
and clinical problems that call
close attention from the regulatory authorities when approving new drugs.Methods. We present here a review of the literature.Results. A wide heterogeneity in the action of the various

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

activity, in fact, may be
achieved by acting on a number of different monoaminergic mechanisms. The
variety in the
neurochemical effects of antidepressants is not reflected in clinical
trials, which tend to stereotypy.
In many cases clinical trials aim at demonstrating equivalence rather
than differences in efficacy.
Regulatory authorities should, therefore, pay attention in accepting
the equivalence of effects of a
new drug in relation to a reference one: most clinical trials of new
antidepressant drugs do not have
the power to detect clinically relevant differences.Conclusions. Unconventional new pre-clinical tests are
needed to generate antidepressants with a
different mechanism of action. Clinical studies are needed to promote objective
comparative
evaluation of the cost, benefits and toxic effects of new antidepressants.
Non-melancholic depression: the contribution of
personality, anxiety and life events to subclassification
Authors: PARKER G. , HADZI-PAVLOVIC D. , ROUSSOS J. , WILHELM K. , MITCHELL P. , AUSTIN M.-P. , HICKIE I. , GLADSTONE G. , EYERS K. 
Published: July 2002

Background. We sought to develop a clinically useful
subtyping system for the non-melancholic
depressive disorders, and here we assess one weighted to central aetiological
factors.Methods. We studied 185 patients meeting DSM-III-R
and/or clinical criteria for non-melancholic
depression. Data were obtained by self-report, interview of patients and
from corroborative
witnesses. We developed a set of variables for class definition,
assessing: (i) ‘P’, disordered
personality as a vulnerability factor; (ii) ‘A’,
meeting criteria for a lifetime anxiety disorder or
positive on probe questions about trait anxiety characteristics,
so assessing anxiety as a vulnerability
factor; and (iii) ‘L’, psychiatrist and
consensually-rated life event stress prior to depression onset.Results. A latent class analysis generated a four-class
solution for the P–A–L variables. Life event
stressors had similar item probabilities across all four classes,
and did not influence the four-class
‘P–A’ solution when deleted from the analysis,
suggesting that life event stress may act more as a
general provoking agent, rather than constituting any distinct
‘reactive’ or ‘situational’ depression
class. Three classes generated clinically meaningful groupings,
reflecting varying contributions of
anxiety and disordered personality functioning, and with evidence of
differential outcome over the following 12 months.Conclusions: We suggest that a refined aetiologically-weighted

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

the comparative utility of
differing treatments to identified vulnerability-based classes.
Making modernity in the hinterlands: new Maroon musics in the Black Atlantic
Authors: Bilby Kenneth 
Published: July 2002

IntroductionBorn in mortal opposition to the peculiarly modern forms of slavery that helped to usher in a new era of European world domination, the Maroon societies of the Americas have long provided theorists of identity operating in the realm that has come to be known as the Black Atlantic with a potent symbolic currency. Nowhere has this currency acquired higher value than in the Caribbean region, where questions of identity are so fundamentally bound up with histories of plantation slavery.The runaway slave has had a special place in the literature of the anglophone Caribbean; and francophone, hispanophone and Dutch-speaking Caribbean writers have all displayed a similar fascination with the Maroon epic. In more recent times, popular music – a medium that has played a primary role in the constitution of a truly diasporic sense of identity spanning the Black Atlantic – has helped to carry consciousness of a heroic Maroon past across the globe. Both practitioners of Caribbean (or other Afro-American) popular musics and those who write about them continue to reference the Maroons of yore, often tracing the rebellious thrust of much of today's music to these original Black warriors, whose defiant spirit, it is felt, continues to inhabit and motivate the collective memory (Aly 1988, pp. 55–7, 65; Zips 1993, 1994; Leymarie 1994).