bluuebunny/crossref_metadata_2025_split huggingface dataset:
Nonlinear theory of geostrophic adjustment. Part 1. Rotating shallow-water model
Authors: REZNIK G. M. , ZEITLIN V. , BEN JELLOUL M. 
Published: October 2003

We develop a theory of nonlinear geostrophic adjustment of arbitrary localized (i.e.
finite-energy) disturbances in the framework of the non-dissipative rotating shallow-water
dynamics. The only assumptions made are the well-defined scale of disturbance
and the smallness of the Rossby number Ro. By systematically using the multi-time-scale
perturbation expansions in Rossby number it is shown that the resulting field is
split in a unique way into slow and fast components evolving with characteristic time
scales f−10 and (f0Ro)−1
respectively, where f0 is the Coriolis parameter. The slow
component is not influenced by the fast one and remains close to the geostrophic
balance. The algorithm of its initialization readily follows by construction.The scenario of adjustment depends on the characteristic scale and/or initial relative
elevation of the free surface ΔH/H0, where
ΔH and H0 are typical values of the initial
elevation and the mean depth, respectively. For small relative elevations
(ΔH/H0 = O(Ro))
the evolution of the slow motion is governed by the well-known quasi-geostrophic potential
vorticity equation for times t [les ] (f0Ro)−1.
We find modifications to this equation for longer times
t [les ] (f0Ro2)−1. The fast component consists mainly
of linear inertia–gravity waves rapidly propagating outward from the initial disturbance.For large relative elevations (ΔH/H0 [Gt ] Ro)
the slow field is governed by the frontal geostrophic dynamics equation. The fast component in this case is a spatially
localized packet of inertial oscillations coupled to the slow component of the flow.
Its envelope experiences slow modulation and obeys a Schrödinger-type modulation
equation describing advection and dispersion of the packet. A case of intermediate
elevation is also considered.
Extensions to the theory of selective withdrawal
Authors: WOOD IAN R. 
Published: October 2003

Most reservoirs contain stratified fluid and selective withdrawal is used to obtain
water with the desired properties. We initially deal with a layered density distribution.
The theory for the critical discharge for a single layer and a point sink is reviewed
and extended to cover the case where there is gate discharge (a line sink). The theory
for the case when the upper layer depth is large and the flow is coming from both
layers is reviewed and it is shown that the valve controls the discharge and a virtual
control determines the ratio of the discharge in each layer. This virtual control moves
further from the valve as the total discharge increases. We determine the position
of the virtual control and the criteria for the maximum for two layers when the
upper layer is finite and below a stationary layer. Before this maximum, we show
that when the discharge is increased above the critical discharge for the single layer,
the finite upper layer does not affect the ratio of the flows from each layer until the
virtual control reaches that for the maximum discharge. At this stage, the upper layer
becomes tangential to the dam face and this condition and the smoothness of the
lower interface determine both the total discharge and the ratio of the flow from each
layer. Indeed, at this stage, virtual control and the control of the discharge are at the
same section.In a similar way, with a stationary layer above and below two flowing layers,
we derive the maximum discharge from the two flowing layers. For this case, the
solution is self-similar. This is then extended to a stable stratified continuous density
distribution. The experiments of Gariel (1949) and Lawrence & Imberger (1979)
suggest that the predictions of the theory are within the experimental errors.
Particle pressures generated around bubbles in
gas-fluidized beds
Authors: RAHMAN KHURRAM , CAMPBELL CHARLES S. 
Published: October 2003

The particle pressure is the surface force in a particle/fluid mixture that is exerted
solely by the particle phase. This paper presents measurements of the particle
pressure on the faces of a two-dimensional gas-fluidized bed and gives insight into the
mechanisms by which bubbles generate particle pressure. The particle pressure is
measured by a specially designed ‘particle pressure transducer’. The results show that,
around single bubbles, the most significant particle pressures are generated below
and to the sides of the bubble and that these particle pressures steadily increase and
reach a maximum value at bubble eruption. The dominant mechanism appears to be
defluidization of material in the particle phase that results from the bubble attracting
fluidizing gas away from the surrounding material; the surrounding material is no
longer supported by the gas flow and can only be supported across interparticle
contacts which results in the observed particle pressures. The contribution of particle
motion to particle pressure generation is insignificant.The magnitude of the particle pressure below a single bubble in a gas-fluidized
bed depends on the bubble size and the density of the solid particles, as might be
expected as the amount of gas attracted by the bubble should increase with bubble
size and because the weight of defluidized material depends on the density of the
solid material. A simple scaling of these quantities is suggested that is otherwise
independent of the bed material.In freely bubbling gas-fluidized beds the particle pressures generated behave
differently. Overall they are smaller in magnitude and reach their maximum value soon
after the bubble passes instead of at eruption. In this situation, it appears that the
bubbles interact with one another in such a way that the de uidization effect below a
leading bubble is largely counteracted by refluidizing gas exiting the roof of trailing
bubbles.
The formation of shear and density layers
in stably stratified turbulent flows:
linear processes
Authors: GALMICHE M. , HUNT J. C. R. 
Published: October 2003

The initial evolution of the momentum and buoyancy fluxes in a freely decaying,
stably stratified homogeneous turbulent flow with r.m.s. velocity u′0 and integral
lengthscale l0 is calculated using a weakly inhomogeneous and unsteady form of the
rapid distortion theory (RDT) in order to study the growth of small temporal and
spatial perturbations in the large-scale mean stratification N(z, t) and mean velocity
profile ū(z, t) (here N is the local Brunt–Väisälä frequency and ū is the local velocity
of the horizontal mean flow) when the ratio of buoyancy forces to inertial forces is
large, i.e. Nl0/u′0[Gt ]1. The lengthscale L of the perturbations in the mean profiles of
stratification and shear is assumed to be large compared to l0 and the presence of a
uniform background mean shear can be taken into account in the model provided
that the inertial shear forces are still weaker than the buoyancy forces, i.e. when the
Richardson number Ri = (N/∂zū)2[Gt ]1 at each height.When a mean shear perturbation is introduced initially with no uniform background
mean shear and uniform stratification, the analysis shows that the perturbations in the
mean flow profile grow on a timescale of order N-1. When the mean density profile is
perturbed initially in the absence of a background mean shear, layers with significant
density gradient fluctuations grow on a timescale of order N−10 (where N0 is the order
of magnitude of the initial Brunt–Väisälä frequency) without any associated mean
velocity gradients in the layers. These results are in good agreement with the direct
numerical simulations performed by Galmiche et al. (2002) and are consistent with the
earlier physically based conjectures made by Phillips (1972) and Posmentier (1977).
The model also shows that when there is a background mean shear in combination
with perturbations in the mean stratification, negative shear stresses develop which
cause the mean velocity gradient to grow in the density layers. The linear analysis for
short times indicates that the scale on which the mean perturbations grow fastest is
of order u′0/N0, which is consistent with the experiments of Park et al. (1994).We conclude that linear mechanisms are widely involved in the formation of shear
and density layers in stratified flows as is observed in some laboratory experiments
and geophysical flows, but note that the layers are also significantly influenced by
nonlinear and dissipative processes at large times.
Triclabendazole-resistant Fasciola hepatica: β-tubulin and response to in vitro treatment with triclabendazole
Authors: ROBINSON M. W. , TRUDGETT A. , HOEY E. M. , FAIRWEATHER I. 
Published: October 2003

Resistance in Fasciola hepatica to triclabendazole (‘Fasinex’) has emerged in several countries. Benzimidazole resistance in parasitic nematodes has been linked to a single amino acid substitution (phenylalanine to tyrosine) at position 200 on the β-tubulin molecule. Sequencing of β-tubulin cDNAs from triclabendazole-susceptible and triclabendazole-resistant flukes revealed no amino acid differences between their respective primary amino acid sequences. In order to investigate the mechanism of triclabendazole resistance, triclabendazole-susceptible and triclabendazole-resistant flukes were incubated in vitro with triclabendazole sulphoxide (50 μg/ml). Scanning and transmission electron microscopy revealed extensive damage to the tegument of triclabendazole-susceptible F. hepatica, whereas triclabendazole-resistant flukes showed only localized and relatively minor disruption of the tegument covering the spines. Immunocytochemical studies, using an anti-tubulin antibody, showed that tubulin organization was disrupted in the tegument of triclabendazole-susceptible flukes. No such disruption was evident in triclabendazole-resistant F. hepatica. The significance of these findings is discussed with regard to the mechanism of triclabendazole resistance in F. hepatica.
A Reply to De Anna on the Simple View of Colour
Authors: Edwards Jim 
Published: October 2003

John Campbell proposed a so-called simple view of colours according to which
colours are categorical properties of the surfaces of objects just as they normally appear to
be. I raised an invertion problem for Campbell's view according to which the senses of
colour terms fail to match their references, thus rendering those terms meaningless—or
so I claimed. Gabriele de Anna defended Campbell's view against my example by contesting
two points in particular. Firstly, de Anna claimed that there is no special problem here for
the simple view of colours, a similar invertion story could apply to primary qualities terms
for shapes. Secondly, de Anna purported to give an account of the senses and references of
colour terms in my invertion story which renders the senses and references of those terms
mutually consistent.In this paper I contested both of de Anna's claims. Regarding
the first, I argue that his imagined invertion of apparent shapes is not epistemically stable,
in contrast to the invertion of apparent shapes is not epistemically stable, in contrast to
the invertion of apparent colours. Hence the victims of apparently inverted shapes would be
able to discover the mismatch of senses and refences of their shape terms, in contrast to the
victims of apparent invertions of colours. Regarding the second, I argue that de Anna's
account of the victim's colour terms itself uses and not merely mentions so-called colours
terms. Hence de Anna' account of them is itself meaningless due to a mismatch of sense and
reference. So I conclude that my objection to Campbell's simple view of colours stands.
Financial aspects of development of remediation technologies for contaminants in soils in cold regions
Authors: Williams Peter J. 
Published: October 2003

During the last several decades there has been much financial investment in the cold regions on projects (mining, oil and gas, etc) that can be the source of ground contamination and that require actions to prevent, mitigate, or remedy such effects. Yet contamination in freezing ground and its remediation have been the subject of research largely only in the last 10 years. This is a short time in terms of research and subsequent technology development, particularly as so few scientists are involved. Probably, therefore, many significant advances remain to be made.Normally in the development of new technologies there is a driving financial input from industrial activity; a certain, if small, percentage of expenditures goes towards research and development. In the case of major geotechnical, contaminant-remediation projects in the cold regions, it appears that a substantially smaller percentage of expenditures than might be expected is going into inherently necessary research. The implication is that contamination management is not developing at a rate that would be the most effective and cost-efficient. The reasons for this are examined with regard to international funding of major construction projects in cold regions, and the associated requirements for contaminant management, and political and societal pressures. The potential scientific advances are examined and it is concluded that not only the contaminant management industry (consultants, contractors) but the industries behind cold-regions development and society more generally, would benefit greatly from an understanding of and provision for such advances.
Predicting admission rates to secure forensic psychiatry services
Authors: COID J. , KAHTAN N. , COOK A. , GAULT S. , JARMAN B. 
Published: October 2003

Background. The planning and development of secure forensic psychiatry services for mentally disordered offenders in England and Wales has proceeded independently within different regional areas. However, certain mental disorders, offenders, and offending behaviour are all more prevalent in geographical areas characterized by socio-economic deprivation and social disorganization. Failure to consider these factors has led to inadequate service provision in some areas and inequity in funding. A new model is required to predict admissions to these services as an aid to resource allocation.Method. Actual admissions (N=3155) to high and medium secure psychiatric services for seven of 14 (pre-reorganization) Regional Health Authorities, 1988–94. Expected admissions were calculated for each district using 1991 census data adjusted for under-enumeration. Standardized psychiatric admission ratios were calculated and a range of social, health status, and service provision data were used as explanatory variables in a regression analysis to determine variation between districts.Results. Actual psychiatric admissions varied from 160% above to 62% below expected for age, sex, and marital status, according to patients' catchment area of origin, measured according to deciles of the distribution of underprivileged area scores at ward level. The most powerful explanatory variables included a composite measure of social deprivation, ethnicity and availability of low secure beds at regional level.Conclusion. Admission rates to secure forensic psychiatry services demonstrate a linear correlation with measures of socio-economic deprivation in patients catchment area of origin. A model was developed to predict admissions from District Health Authorities and is recommended for future use in resource allocation. Identification of factors that explain higher admission rates of serious offenders with mental disorder from deprived areas is a priority for future research.
Long-term outcome of anorexia nervosa in a prospective 21-year follow-up study
Authors: LÖWE B. , ZIPFEL S. , BUCHHOLZ C. , DUPONT Y. , REAS D. L. , HERZOG W. 
Published: October 2003

Background. Given our poor understanding of the very long-term course of anorexia nervosa, many questions remain regarding the potential for recovery and relapse. The purpose of the present study was to investigate long-term outcome and prognosis in an anorexic sample 21 years after the initial treatment.Method. A multidimensional and prospective design was used to assess outcome in 84 patients 9 years after a previous follow-up and 21 years after admission. Among the 70 living patients, the follow-up rate was 90%. Causes of death for the deceased patients were obtained through the attending physician. Predictors of a poor outcome at the 21-year follow-up were selected based on the results of a previous 12-year follow-up of these patients.Results. Fifty-one per cent of the patients were found to be fully recovered at follow-up, 21% were partially recovered and 10% still met full diagnostic criteria for anorexia nervosa. Sixteen per cent were deceased, due to causes related to anorexia nervosa. The standardized mortality rate was 9·8. The three groups also showed significant differences in psychosocial outcome. A low body mass index and a greater severity of social and psychological problems were identified as predictors of a poor outcome.Conclusions. Recovery is still possible for anorexic patients after a period of 21 years. On the other hand, patients can relapse, becoming symptomatic again despite previously achieving recovery status. Only a few patients classified as having a poor outcome were found to seek any form of treatment, therefore, it is recommended that these patients should be monitored regularly and offered treatment whenever possible.
Cognitive therapy, nutritional therapy and their combination in the treatment of bulimia nervosa
Authors: HSU L. K. G. , RAND W. , SULLIVAN S. , LIU D. W. , MULLIKEN B. , McDONAGH B. , KAYE W. H. 
Published: October 2003

Background. This study compared the effectiveness of cognitive therapy (CT), nutritional therapy (NT), the combination of cognitive and nutritional therapy (CNT), against a control condition of support group (SG) in the treatment of bulimia nervosa.Methods. One hundred female out-patients who fulfilled DSM-III-R criteria for bulimia nervosa were randomized to the four treatment groups. NT and CT were designed to cover different areas with minimal overlap, and CNT provided all of the features of both of these treatments. The control condition was conducted in a group self-help format. Each of the treatments lasted 14 weeks.Results. All three active treatments as well as SG produced significant decreases in binge/vomit episodes. Intent-to-treat analysis found CNT and CT to be significantly more effective than SG in retaining subjects in treatment and completion of study, as well as in producing greater improvements in dysfunctional attitudes and self-control. CNT was superior to SG in achieving abstinence from bulimic behaviour. NT was superior to SG only in increase of self-control. Logistic regression found that the cognitive component, whether given alone or in conjunction with NT, and higher pre-treatment self-control scores were significant predictors for both completion of study and abstinence.Conclusion. CT (either alone, or in combination with nutritional therapy) remains the treatment of choice for bulimia nervosa. A treatment escalation approach should be tested for the treatment of bulimia with the more intensive and less widely available CT (with or without nutritional counselling) offered after patients have failed the less intensive and more widely available support group treatment.
Mood congruent memory bias induced by tryptophan depletion
Authors: KLAASSEN T. , RIEDEL W. J. , DEUTZ N. E. P. , VAN PRAAG H. M. 
Published: October 2003

Background. Mood congruent memory bias predicts a more superior recall memory of learnt material congruent with the mood state at the time of learning. The present study is the first report of an experimental study in which a biological mood induction was used to test this hypothesis. The influence of acute tryptophan (TRP) depletion, inducing low serotonin neurotransmission and a depression of mood, on memory bias was evaluated in healthy volunteers (16 with and 11 without a family history of major affective disorder).Methods. Twenty-seven subjects received 100 g of an amino acid mixture with and without TRP according to a placebo-controlled, double-blind, balanced, cross-over design. An affective memory test consisting of a 30-word list with words of positive, neutral, and negative affective valence and a mood questionnaire were assessed at 6 and 24 h following treatment administration.Results. TRP depletion impaired delayed recall of neutral and positive words, but not of negative words. There was no interaction of family history and treatment and there was no post hoc association between the influence of TRP-depletion on mood and on affective memory bias.Conclusion. Experimentally induced serotonergic depletion in normal individuals shifts affective memory bias towards negative affective valent verbal stimuli.
The West London Schools Study: the effects of chronic aircraft noise exposure on child health
Authors: HAINES M. M. , STANSFELD S. A. , BRENTNALL S. , HEAD J. , BERRY B. , JIGGINS M. , HYGGE S. 
Published: October 2003

Background. Previous field studies have indicated that children's cognitive performance is impaired by chronic aircraft noise exposure. However, these studies have not been of sufficient size to account adequately for the role of confounding factors. The objective of this study was to test whether cognitive impairments and stress responses (catecholamines, cortisol and perceived stress) are attributable to aircraft noise exposure after adjustment for school and individual level confounding factors and to examine whether children exposed to high levels of social disadvantage are at greater risk of noise effects.Methods. The cognitive performance and health of 451 children aged 8–11 years, attending 10 schools in high aircraft noise areas (16 h outdoor Leq > 63 dBA) was compared with children attending 10 matched control schools exposed to lower levels of aircraft noise (16 h outdoor Leq < 57 dBA).Results. Noise exposure was associated with impaired reading on difficult items and raised annoyance, after adjustment for age, main language spoken and household deprivation. There was no variation in the size of the noise effects in vulnerable subgroups of children. High levels of noise exposure were not associated with impairments in mean reading score, memory and attention or stress responses. Aircraft noise was weakly associated with hyperactivity and psychological morbidity.Conclusions. Chronic noise exposure is associated with raised noise annoyance in children. The cognitive results indicate that chronic aircraft noise exposure does not always lead to generalized cognitive effects but, rather, more selective cognitive impairments on difficult cognitive tests in children.