bluuebunny/crossref_metadata_2025_split huggingface dataset:
Multiple positive solutions for singularly perturbed elliptic problems in exterior domains
Authors: Cerami Giovanna , Molle Riccardo 
Published: January 2003

The equation

−ε^2Δu+a_ε(x)u=u^{p−1}

with boundary Dirichlet zero data is considered in an exterior domain

\Omega = \mathbb{R}^{N}\backslash \bar \omega

(

ω

bounded and

N\geqslant 2

). Under the assumption that

a_ε\geqslant a_0>0

concentrates round a point of

Ω

as

ε→0

, that

p>2

and

p<2N/(N−2)

when

N\geqslant 3

, the existence of at least three positive distinct solutions is proved.

Résumé

Dans cet article on étude l’équation

−ε^2Δu+a_ε(x)u=u^{p−1}

dans l’ouvert extérieur

\Omega = \mathbb{R}^{N}\backslash \bar \omega

(

ω

borné et

N\geqslant 2

), avec la condition de Dirichlet

u=0

sur

∂Ω

. En supposant que

a_ε\geqslant a_0>0

se concentre autour d’un point du domaine

Ω

quand

ε→0

, que

p>2

et que

p<2N/(N−2)

quand

N\geqslant 3

, on démontre que le problème possède au moins trois solutions distinctes.
Existence of solutions for the two-dimensional stationary Euler system for ideal fluids with arbitrary force
Authors: Glass Olivier 
Published: January 2003

We generalize a theorem by J.-M. Coron (see [Sur la stabilisation des fluides parfaits incompressibles bidimensionnels, in: Séminaire Équations aux Dérivées Partielles, École Polytechnique, Centre de Mathématiques, 1998–1999, exposé VII]) and prove the existence of steady states of the Euler system for inviscid incompressible fluids with an arbitrary force term, in a plane bounded domain not necessarily simply connected, if one allows the fluid to pass through a prescribed region of the boundary, which satisfies the necessary condition that each connected component of the boundary is met by it.

Résumé
Nous généralisons un théorème de J.-M. Coron (voir [Sur la stabilisation des fluides parfaits incompressibles bidimensionnels, in: Séminaire Équations aux Dérivées Partielles, École Polytechnique, Centre de Mathématiques, 1998–1999, exposé VII]), en prouvant l’existence d’états stationnaires pour le système d’Euler pour les fluides parfaits incompressibles avec un terme de force arbitraire. Ce résultat se place dans un domaine borné du plan non nécessairement simplement connexe, où le fluide peut entrer à travers une partie prescrite du bord, qui satisfait la condition nécessaire, qu’elle en rencontre toutes les composantes connexes.
D1 dopamine receptor regulation of cell cycle in FGF‐ and EGF‐supported primary cultures of embryonic cerebral cortical precursor cells
Authors: Zhang Ling , Lidow Michael S. 
Published: January 2003

AbstractIn the mammalian fetus, proliferation of the majority of cells destined for the cerebral cortex takes place within the transient proliferative zones of the cerebral wall. Recent investigations have demonstrated that cell of these zones express high levels of D1 dopamine receptors (D1Rs). However, the specific roles of these receptors have not been investigated. The present study tests the hypothesis that D1Rs are capable of regulating the cell cycle of cerebral cortical precursor cells. For this purpose, primary cultures of cells of the proliferative zones from the cerebral wall of 14‐day‐old mouse fetuses were generated and maintained in the presence of either fibroblast growth factor‐2 (FGF2) or epidermal growth factor (EGF). These growth factors were chosen as supporting two distinct populations of precursor cells in the fetal cortical proliferative matrix. The involvement of D1Rs in the regulation of proliferative activity was examined by the addition of a range of concentrations of the D1R‐specific agonist, SKF82958, to the culture media. Bromodeoxyuridine incorporation assays demonstrated that exposure to this agonist led to a dose‐dependent reduction of DNA synthesis in both FGF2‐ and EGF‐supported cultures. Flow cytometric cell cycle assays further revealed that this was due to prevention of the transition of cells from the G1 phase to the S phase of the cell cycle. The D1R specificity of the effects of SKF82958 was supported in that they were blocked by the addition of the D1R antagonists, SCH23390 or NNC010756. We also found that D1R stimulation induced stronger suppression of proliferative activity in EGF‐supported than in FGF2‐supported cultures. Our observations suggest that D1Rs are capable of regulating the cell cycle during corticogenesis. Furthermore, they raise a possibility that these receptors may display different efficacies in affecting proliferative activity in FGF2‐supported versus EGF‐supported cerebral cortical precursor cells.
Medium requirements for neuritic outgrowth from goldfish retinal explants and the trophic effect of taurine
Authors: Cubillos S. , Fazzino F. , Lima L. 
Published: January 2003

AbstractThe use of culture media of known composition are necessary for studying the role of trophic molecules. Since most of the in vitro research on regeneration of the optic nerve has been performed in the presence of fetal calf serum, the aim of this study was to obtain a medium in which the neuritic outgrowth from post‐crush goldfish retinal explants could take place without adding fetal calf serum. After the lesion of the optic nerve (10 days), the retina of goldfish was dissected and explants were cultured for 5 and 10 days in the absence or in the presence of fetal calf serum, at which time the neuritic outgrowth was determined. Various concentrations and combinations of glucose, albumin, calcium, HEPES and taurine were used. The highest neuritic outgrowth was observed in the presence of fetal calf serum, in which condition the amino acid taurine increased length and density of neurites. Media supplemented with albumin, calcium or HEPES did not modify the outgrowth of neurites from the explants. However, glucose favored the neuritic outgrowth in a bell‐shaped manner, although fibers were thinner than those observed in the presence of fetal calf serum. Taurine did not stimulate outgrowth of neurites from explants growing in a medium with optimal concentrations of glucose, indicating that elements of the fetal calf serum are determinant for the trophic effect of taurine. The present results contribute to further studies, such as those related to the effect of taurine and of trophic factors derived from the optic tectum, which would be performed in the presence of a medium free of fetal calf serum.
The significance of A‐δ and C fibres for the perception of synthetic heat
Authors: Fruhstorfer Heinrich , Harju Eva‐Liz , Lindblom Ulf F 
Published: January 2003

AbstractSynthetic heat is a perception of strong, but not painful, heat arising when skin is stimulated by an alternating pattern of adjacent cold and warmth. This study examines the contribution of different classes of nerve fibres to this perception. In 40 subjects changes in synthetic heat and thermal perceptions were studied during a 30‐min ischaemic nerve block in one reaction time, and one threshold determination task. Synthetic heat stimuli were described as hot or warm, but not as painful, and were preceded by a transient cold. Reaction times for synthetic heat stimuli did not differ from those for cold stimuli. Thresholds for synthetic heat and thermal stimuli were similar. During A fibre nerve block the perception of synthetic heat lost the cold component whereas the frequency of hot and warm descriptors did not change. The perception of cold stimuli changed, such that pure cold was replaced by dysaesthetic descriptors. Reaction times and thresholds for thermal and synthetic heat stimuli increased equally during the nerve block. It is concluded that the perception of synthetic heat most likely arises from the fusion of signals dependent on unmyelinated low threshold cold and warm receptors. It is not dependent on A‐δ cold fibres, and a contribution of nociceptors is quite unlikely. The possibility of a psychological contribution at the perceptual level is discussed.
Factors influencing the features of postherpetic neuralgia and outcome when treated with tricyclics
Authors: Bowsher David 
Published: January 2003

AbstractThis paper retrospectively reviews features of postherpetic neuralgia (PHN) in up to 279 personal patients in relation to treatment outcome when treated with tricyclic antidepressants (TCAs).Factors affecting characteristics of PHN: (i) Patients with allodynia (89%) and/or burning pain (56%) have a much higher visual analogue pain intensity score than those without; (ii) Acyclovir (ACV) given for acute shingles (HZ) does not reduce the incidence of subsequent PHN, but reduces the pain intensity in PHN patients with allodynia; (iii) ACV given for acute HZ reduces the incidence of burning pain in subsequent PHN, but not of allodynia; (iv) ACV given for acute HZ reduces the incidence of clinically detectable sensory deficit in subsequent PHN.Factors affecting outcome of TCA‐treated PHN: (i) The point in time at which TCA treatment is commenced is by far the most critical factor: started between 3 and 12 months after acute HZ onset, more than two‐thirds obtain pain relief (NNT=1.8); between 13 and 24 months, two‐fifths (41%) (NNT=3.6); and more than two years, one‐third (NNT=8.3). Background and paroxysmal pain disappear earlier and are more susceptible of relief than allodynia. (ii) Twice as many (86%) of PHN patients without allodynia obtain pain relief with TCA treatment than those with (42%); (iii) the use of ACV for acute HZ more than halves the time‐to‐relief of PHN patients by TCAs; (iv) PHN patients with burning pain are significantly less likely to obtain pain relief with TCAs than those without (p<0.0001).
Induction of non‐painful and painful intestinal sensations by hypertonic saline: a new human experimental model
Authors: Drewes Asbjørn M , Babenko Liudmila , Birket‐Smith Lene , Funch‐Jensen Peter , Arendt‐Nielsen Lars 
Published: January 2003

AbstractBackground and aims. To develop a pain model for chemical stimulation of the human gut.Methods. In a double‐blind experimental study 10 subjects with a previously performed sigmoidostomy were randomised to receive injections with either isotonic or hypertonic saline in the colonic mucosa. In the hypertonic experimental arm, 0.1 ml of 0.9%, 2%, 4%, and 6% and 0.2 ml of 2% and 4% saline were given. In the placebo arm, six 0.9% saline injections of the same quantities were given. In a separate experiment 0.8 ml 4% saline was infused into the mucosa by a pump over a period of 2 min. The pain intensity was rated on a 0–10 visual analogue scale with 5 as the pain threshold.Results. The hypertonic saline injections resulted in local as well as referred non‐painful and painful sensations in 9 out of the 10 subjects. The evoked sensations were mostly described as a smarting sensation with an intensity of median 1 (range 0–5.6) for 0.1 ml 2% saline to median 2.9 (range 0–6.2) for 0.2 ml 4% saline. Seven subjects reported referred sensations to the abdominal skin. Continuous infusion of 4% saline resulted in a consistent sensory response in all subjects, with a median intensity of 4.1 (range 2.1–8.1). This sensory intensity was reproducible in 70% in a retest experiment after median 7 weeks. In the placebo arm a total of 70 isotonic saline injections only resulted in inconsistent, short‐lasting non‐painful sensations in three subjects.Conclusion. The model represents a safe method for direct chemical activation of the sensory endings in the human gut. The model may be used for pharmacological screening of analgesics and for basic investigations in patients suffering from gastrointestinal diseases.
Disuse and deconditioning in chronic low back pain: concepts and hypotheses on contributing mechanisms
Authors: Verbunt Jeanine A , Seelen Henk A , Vlaeyen Johan W , van de Heijden Geert J , Heuts Peter H , Pons Kees , Knottnerus J Andre 
Published: January 2003

AbstractFor years enhancement of a patient's level of physical fitness has been an important goal in rehabilitation treatment in chronic low back pain (CLBP), based on the hypothesis that physical deconditioning contributes to the chronicity of low back pain. However, whether this hypothesis in CLBP holds is not clear. In this paper, possible mechanisms that contribute to the development of physical deconditioning in CLBP, such as avoidance behaviour and suppressive behaviour, are discussed. The presence of both deconditioning‐related physiological changes, such as muscle atrophy, changes in metabolism, osteoporosis and obesity as well as deconditioning related functional changes, such as a decrease in cardiovascular capacity, a decrease in muscle strength and impaired motor control in patients with CLBP are discussed. Results of studies on the level of physical activities in daily life (PAL) and the level of physical fitness in patients with CLBP compared to healthy controls were reviewed. In studies on PAL results that were either lower or comparable to healthy subjects were found. The presence of disuse (i.e., a decrease in the level of physical activities in daily life) in patients with CLBP was not confirmed. The inconclusive findings in the papers reviewed may partly be explained by different measurement methods used in research on PAL in chronic pain. The level of physical fitness of CLBP patients also appeared to be lower or comparable to the fitness level of healthy persons. A discriminating factor between fit and unfit patients with back pain may be the fact that fit persons more frequently are still employed, and as such may be involved more in physical activity. Lastly some suggestions are made for further research in the field of disuse and deconditioning in CLBP.
USING EVIDENCE IN THE DEVELOPMENT OF LOCAL HEALTH POLICIES
Authors: Weatherly Helen , Drummond Michael , Smith Dave 
Published: January 2003

Objectives: This paper explores the use of evidence, focusing on economic evidence in particular, in the development of local health policies through an in-depth study of Health Improvement Programmes (HImPs) in England.Methods: A questionnaire was sent to the person responsible for coordinating the development of the HImP in each of the 102 English health authorities. In addition, semi-structured interviews were conducted with 10 HImP leaders, and a random sample of 26 HImP documents was reviewed using a standard pro forma.Results: Of the 102 mail questionnaires sent out, 68 (67%) were returned. It was found that those developing HImPs had multiple objectives, only some of which (e.g., efficiency in healthcare provision) would necessarily require evidence. Where evidence was used, this was a mixture of internal (experiential) and external (empirical) evidence, with the balance (66%) being in favor of the latter. Government reports and guidance from the National Institute for Clinical Excellence (NICE), were the main sources of external evidence, rather than published papers. Key barriers to the use of economic evidence were lack of time and availability and the difficulties in synthesizing information at the local level.Conclusions: Based on responses to our survey, the main ways of increasing the use of evidence in the development of local health policies in England are to produce more evidence-based national guidance and to produce accessible summaries of the available literature for local decision makers.
HTA EDUCATION AND TRAINING IN EUROPE
Authors: Douw Karla , Vondeling Hindrik , Bakketeig Leiv. S. , Gabbay John , Hansen Niels Würgler , Kristensen Finn Børlum 
Published: January 2003

Objective: To identify training programs and educational resources in health technology assessment (HTA) in Europe.Methods: A postal survey among potential informants in European countries and Israel, expanding on surveys among ISTAHC and INAHTA members. Informants were identified either using HTA networks or by means of Internet sources.Results: The combined results of the three surveys show that in the European Union (EU), including Norway and Switzerland, 13 of 17 countries (76%) provide either university level courses or continuing education HTA courses. In the candidate EU countries, 4 of 10 countries (40%) provide HTA courses. In the remainder of countries, only Israel provides HTA courses. Ten different types of courses were identified, mainly applying traditional teaching methods. A substantial number of the courses were first organized in recent years. Many countries in central and eastern Europe expressed the wish to become more involved in HTA.Conclusion: There is a rapid increase in the number and diversity of courses in HTA in Europe. In particular, countries in the EU are well represented. Education and training in HTA is scarce in EU candidate membership countries, and virtually absent in the remainder of countries. In general, HTA as a field is in the process of becoming established and institutionalized both in individual countries and internationally. To stimulate this development in the area of education and training, both bilateral cooperation and an EU-wide coordinated effort are recommended.
Diversity of substance use in eastern Arnhem Land (Australia): patterns and recent changes
Authors: CLOUGH ALAN R. , GUYULA TERRENCE , YUNUPINGU MAYMUNA , BURNS CHRISTOPHER B. 
Published: January 2003

AbstractThe objective of this study was to describe patterns of substance use among remote Aboriginal community populations. The setting was the eastern Arnhem Land (‘Miwatj’) region of the Northern Territory's (NT) ‘To p End’, with a population of 4217 Aboriginal people over 15 years of age using a cross‐sectional description and comparison. Sample 1 (n = 689) from the region used data from health‐worker consensus classification of kava, alcohol, tobacco, petrol and cannabis use. Sample 2 (n = 101) from one community used self‐reported use, age at commencement, duration, amounts consumed and expenditure. In 1999 (sample 1), 46% of males and 18% of females were kava users, alcohol: 53% males, 12% females, tobacco: 68% males, 65% females, and cannabis: 31% males, 8% females. Less than 5% sniffed petrol. In one community in 2000, 39% males and 20% females reported using cannabis during the previous month. In this community between 1999 and 2000, the proportion of current kava users among men declined (77–52%, p = 0.015) with a tendency in women for a decrease in the proportion of tobacco users (87–69%, p = 0.096). The increase in the proportion of cannabis users in men (21–39%, p = 0.068) was not statistically significant. However, in women the increase was significant (0–20%, p = 0.013). Gross expenditure on tobacco and kava were similar in 2000: both greater than cannabis and alcohol. Median years used ranged from 4 years for cannabis and 20 years for tobacco. The data supported anecdotes of a recent rise in cannabis use, especially in women. Kava use declined in men. Tobacco use patterns in women may have been changing. Average per capita consumption of alcohol was low compared with other ‘To p End’ areas. Such varied and dynamic substance use patterns pose challenges for research and policy.
Recent trends in benzodiazepine use by injecting drug users in Victoria and Tasmania
Authors: FRY CRAIG L. , BRUNO RAIMONDO B. 
Published: January 2003

AbstractTo address the lack of data on patterns of benzodiazepine use among injecting drug users (IDU) in Victoria and Tasmania, convenience samples of 152 Melbourne and 100 Hobart IDU were recruited from needle and syringe programme outlets and administered a structured survey on patterns of benzodiazepine use, injection‐related health problems and drug use history. Most respondents had used benzodiazepines during the preceding 6 months, and more than one‐third (Melbourne 36%, 95% CI, 28–44; Hobart 37%, 95% CI, 27–47) had injected benzodiazepines during this period. Diazepam was the preferred benzodiazepine for those using orally, while intravenous benzodiazepine users preferred to inject temazepam. Benzodiazepine injection for Melbourne IDU was related to greater levels of injection‐related health problems. Patterns of benzodiazepine use amongst Melbourne and Hobart IDU are different to that in other Australian jurisdictions, with available data suggesting that prevalence of injection may be increasing. Ongoing monitoring of benzodiazepine injection, together with in‐depth studies of supply characteristics and health impacts in jurisdictions where significant trends are detected is needed. Consideration of regulatory, supply, education and training options for the prevention of benzodiazepine injection is also indicated.
The feasibility and acceptability of introducing brief intervention for alcohol misuse in an urban Aboriginal medical service
Authors: BRADY MAGGIE , SIBTHORPE BEVERLY , BAILIE ROSS , BALL SANDY , SUMNERDODD POLLY 
Published: January 2003

AbstractWe report on the feasibility and perceived acceptability of brief motivational interviewing for hazardous alcohol use in an urban Aboriginal health service. General practitioners (GPs) were trained in brief motivational interviewing, and health workers in other aspects of the intervention. Screening was initially carried out using the AUDIT, but subsequently reduced to two simple questions. Information was obtained through a combination of participant observation by the study team, ongoing ad hoc review and feedback from staff, periodic group meetings, and one‐on‐one interviews with health workers and GPs. The AUDIT was felt to be intrusive and some questions were poorly understood. Brief intervention seemed to be culturally appropriate, but barriers to wider administration included lack of time and the complexity of patients' presenting health problems. As a result of the research there was an increase in general awareness and acceptability of addressing alcohol issues at the health service. This study raises a number of issues that both support and threaten the wide implementation of brief intervention in urban Aboriginal primary care settings.
An extension of Elton’s ℓ₁ⁿ theorem to complex Banach spaces
Authors: Dilworth S. , Patterson Joseph 
Published: January 2003

Let

ε
>
0

\varepsilon > 0

be sufficiently small. Then, for

θ
=
0.225

ε

\theta =0.225\sqrt \varepsilon

, there exists

δ
:=
δ
(
ε
)
>
1

\delta := \delta (\varepsilon )>1

such that if

(

e
i

)

i
=
1

n

(e_i)_{i=1}^n

are vectors in the unit ball of a complex Banach space

X
X

which satisfy
\[

E

‖

∑

i
=
1

n

Z
i

e
i

‖

≥
δ
n

\mathbb {E} \left \| \sum _{i=1}^n Z_i e_i \right \| \geq \delta n

\]
(where

(

Z
i

)

(Z_i)

are independent complex Steinhaus random variables), then there exists a set

B
⊆
{
1
,
…
,
n
}

B \subseteq \{1,\dots ,n\}

, with

|

B

|

≥
θ
n

|B| \geq \theta n

, such that

‖

∑

i
∈
B

z
i

e
i

‖

≥
(
1
−
ε
)

∑

i
∈
B

|

z
i

|

\begin{equation*} \left \|\sum _{i\in B} z_i e_i \right \| \geq (1-\varepsilon ) \sum _{i\in B} |z_i| \end{equation*}

for all

z
i

∈

C

z_i\in \mathbb {C}

(

i
∈
B

i\in B

). The

ε

\sqrt \varepsilon

dependence on

ε
\varepsilon

of the threshold proportion

θ
\theta

is sharp.
An approach to the spectrum structure of Dirac operators by the local-compactness method
Authors: Ikuta Tadashi , Shima Kazuhisa 
Published: January 2003

The purpose of this paper is to investigate the spectra of the Dirac operator

H
=

H
0

+
V
=
−
i
c
α
⋅
∇
+
β
m

c
2

+
V

H=H_0+V=-ic\alpha \cdot \nabla +\beta mc^2+V

. The local compactness of

H
H

is shown under some assumption on

V
V

. This method enables us to prove that if

|

V
(
x
)
−
a
β

|

→
0

|V(x)-a\beta |\to 0

as

|

x

|

→
∞

|x|\to \infty

, then

σ

ess

(
H
)
=
(
−
∞
,
−
m

c
2

−
a
]
∪
[
m

c
2

+
a
,
∞
)

\sigma _{\operatorname {ess}}(H)=(-\infty ,-mc^2-a]\cup [mc^2+a,\infty )

and to give a significant sufficient condition that

H

+

H^{+}

or

H

−

H^{-}

has a purely discrete spectrum.