bluuebunny/crossref_metadata_2025_split huggingface dataset:
Uniqueness and stability of regional blow-up in a porous-medium equation
Authors: Cortázar Carmen , del Pino Manuel , Elgueta Manuel 
Published: November 2002

We study the blow-up phenomenon for the porous-medium equation in

\mathbf R^N

,

N⩾1

,

u_{t} = \Delta u^{m} + u^{m},

m>1

, for nonnegative, compactly supported initial data. A solution

u(x,t)

to this problem blows-up at a finite time

\bar T > 0

. Our main result asserts that there is a finite number of points

x_1,…,x_k∈\mathbf R^N

, with

\left|x_{i} - x_{j}\right| \geq 2R^*

for

i≠j

, such that

\lim \limits_{t\rightarrow \bar T}\left(\bar T - t\right)^{\frac{1}{m - 1}}u\left(t,x\right) = \sum \limits_{j = 1}^{k}w_{*}\left(\left|x - x_{j}\right|\right).

Here

w_{*}\left(\left|x\right|\right)

is the unique nontrivial, nonnegative compactly supported, radially symmetric solution of the equation

\Delta w^{m} + w^{m} - \frac{1}{m - 1}w = 0

in

\mathbf R^N

and

R^∗

is the radius of its support. Moreover

u(x,t)

remains uniformly bounded up to its blow-up time on compact subsets of

\mathbf {R}^{N}\backslash \bigcup _{j = 1}^{k}\bar B(x_{j},R^*)

. The question becomes reduced to that of proving that the

ω

-limit set in the problem

v_{t} = \Delta v^{m} + v^{m} - \frac{1}{m - 1}v

consists of a single point when its initial condition is nonnegative and compactly supported.

Résumé

Nous étudions le phénomène d’explosion pour l’équation des milieux poreux dans

\mathbf R^N

,

N⩾1

,

u_{t} = \Delta u^{m} + u^{m},

m>1

, pour une donnée initiale positive ou nulle, à support compact. Une solution

u(x,t)

de ce problème explose en temps fini

\bar T > 0

. Notre principal résultat établit qu’il existe un nombre fini de points

x_1,…,x_k∈\mathbf R^N

, with

\left|x_{i} - x_{j}\right| \geq 2R^*

avec

i≠j

, tels que

\lim \limits_{t\rightarrow \bar T}\left(\bar T - t\right)^{\frac{1}{m - 1}}u\left(t,x\right) = \sum \limits_{j = 1}^{k}w_{*}\left(\left|x - x_{j}\right|\right).

Ici

w_∗(|x|)

est l’unique solution non triviale, positive ou nulle, à support compact et à symétrie radiale de l’équation

\Delta w^{m} + w^{m} - \frac{1}{m - 1}w = 0

dans

\mathbf R^N

et

R^∗

est le rayon de son support. De plus,

u(x,t)

reste uniformément bornée jusqu’à son temps d’explosion sur des sous-ensembles compacts

\mathbf {R}^{N}\backslash \bigcup _{j = 1}^{k}\bar B\left(x_{j},R^*\right)

. La question est ramenée à la démonstration que l’ensemble

ω

-limite du problème

v_{t} = \Delta v^{m} + v^{m} - \frac{1}{m - 1}v

est constitué d’un seul point quand sa donnée initiale est positive ou nulle et à support compact.
Attractors of the reaction-diffusion systems with rapidly oscillating coefficients and their homogenization
Authors: Efendiev M. , Zelik S. 
Published: November 2002

The following reaction-diffusion system in spatially non-homogeneous almost-periodic media is considered in a bounded domain

\Omega \subset \mathbb{R}^{3}

:

\partial _{t}u = A_{ɛ}u - f\left(u\right) + g, \qquad u\mid_{\partial \Omega } = 0. \tag{1}

Here

u=(u^1,…,u^k)

is an unknown vector-valued function,

f

is a given nonlinear interaction function and the second order elliptic operator

A_ε

has the following structure:

(A_{ɛ}u)^l = \sum \limits_{i,j = 1}^{3}\partial_{x_i}(a_{ij}^{l}(ɛ^{ - 1}x)\partial _{x_j}u^{l}(x)), \qquad ɛ \ll 1,\ l = 1,2,3,

where

a_{ij}^l(y)

are given almost-periodic functions. We prove that, under natural assumptions on the nonlinear term

f(u)

, the longtime behavior of solutions of (1) can be described in terms of the global attractor

\mathcal{A}^{ɛ}

of the associated dynamical system and that the attractors

\mathcal{A}^{ɛ}

,

0<ε<ε_0⪡1

, converge to the attractor

\mathcal{A}^{0}

of the homogenized problem (1) as

ε→0

. Moreover, in the particular case of periodic media, we give explicit estimates for the distance between the non-homogenized

\mathcal{A}^{ɛ}

and the homogenized

\mathcal{A}^{0}

attractors in terms of the parameter

ε

.

Résumé

Nous considérons le systéme de réaction-diffusion suivant dans un milieu non homogéne presque périodique en espace dans un domaine borné

\Omega \subset \mathbb{R}^{3}

:

\partial _{t}u = A_{ɛ}u - f\left(u\right) + g, \qquad u\mid_{\partial \Omega } = 0. \tag{1}

Ici,

u=(u^1,…,u^k)

est une fonction vectorielle inconnue,

f

est une fonction d’interaction nonlinéaire donnée et l’opérateur elliptique du second ordre

A_ε

a la structure suivante :

(A_{ɛ}u)^l = \sum \limits_{i,j = 1}^{3}\partial_{x_i}(a_{ij}^{l}(ɛ^{ - 1}x)\partial _{x_j}u^{l}(x)), \qquad ɛ \ll 1,\ l = 1,2,3,

oú les

a_{ij}^l(y)

sont des fonctions presque périodiques données. Nous prouvons que, sous des hypothéses naturelles sur le term nonlinéaire

f(u)

, le comportement asymptotique des solutions de (1) peut etre décrit par l’attracteur global

\mathcal{A}^{ɛ}

du systéme dynamique associé et que les attracteurs

\mathcal{A}^{ɛ}

,

0<ε<ε_0⪡1

, convergent vers l’attracteur

\mathcal{A}^{0}

du probléme homogénéisé de (1) lorsque

ε→0

. De pluis, dans le cas particulier d’un milieu périodique, nous donnons des estimations explicites de la distance entre les attracteur non homogénéisés

\mathcal{A}^{ɛ}

et l’attracteur homogénéisé

\mathcal{A}^{0}

en fonction du paramétre

ε

.
Short-term safety profile of zolpidem: objective measures of cognitive effects
Authors: DeClerk AC , Bisserbe JC 
Published: November 2002

AbstractThe potential effects of zolpidem, a non-benzodiazepine hypnotic, on cognitive and psychomotor functions have been explored in more than 30 placebo controlled studies, and in many cases in comparison with benzodiazepine reference hypnotics (ie flunitrazepam, nitrazepam, triazolam). Daytime impact of drug administration on alertness has been studied with the Multiple Sleep Latency Test, and no significant clinical impairment has been found after zolpidem 5 to 10 mg, unlike benzodiazepines. Evaluation of the effects of zolpidem on attention and psychomotor skills (critical flicker fusion threshold, substitution or copying tests, choice reaction times or driving tests, etc) indicate that zolpidem at recommended doses (5 mg in elderly and 10 mg in adults) is unlikely to produce significant detrimental residual effects on daytime vigilance, concentration and coordination performances on the morning after intake. In accordance with its pharmacokinetic and pharmacodynamic properties, the effects on zolpidem on memory functions were limited to the first hours after administration and no significant difference was observed between zolpidem (5–10 mg) and placebo 6 hours after administration; longer memory impairment was observed with flunitrazepam or triazolam. Various groups of subjects were included in these studies, both young adults and elderly subjects, healthy volunteers and insomniac patients, and duration of treatment varied between one single dose and 28 days of repeated intake. In conclusion, experimental evidence demonstrates a satisfactory safety profile of zolpidem (5–10 mg) on daytime cognitive functions as compared to other hypnotics.
Public health impact and treatment of insomnia
Authors: Dement WC , Pelayo R 
Published: November 2002

SummaryA growing number of people are concerned about their sleep in the United States. There are an estimated 40 million US citizens with chronic sleep disorders. The cost to society of sleep disorders has been estimated at greater than $90 billion US dollars. Despite this enormous cost to society, there remains a pervasive lack of attention provided to medical management of this problem. This is compounded by inadequate funding of sleep disorders research. There are treatments available to improve insomnia. These include different behavioral and pharmacologic regimes that can be used separately or in combination. Successful treatment requires thorough knowledge of the differential diagnosis of insomnia. The greatest public health challenge in the management of insomnia is how to develop effective educational programs that will allow the general public to improve their sleep. This will require greater cooperation from primary care providers and the government. Sleep disorders are the most important public health problem not being addressed in the United States.
The socio-economics of insomnia: the materials and the methods
Authors: Stoller MK 
Published: November 2002

SummaryInsomnia affects about one-third of the population, and is associated with increased morbidity and mortality, reduced production and higher rates of accidents. This suggests that insomnia may burden society with significant cost. However, a precise economic analysis of insomnia is a challenge. Insomnia is part of a very complex interplay of physical and psychological illness, functioning both as a cause and as a consequence. In this paper, some of the methodological issues related to an economic analysis of insomnia are discussed. Data is presented using an economic analysis as an organizer, thus illustrating what conclusions can be drawn, and where further research is needed.
Self-mutilating behaviour of psychiatric inpatients
Authors: Nijman H.L.I. , Dautzenberg M. , Merckelbach H.L.G.J. , Jung P. , Wessel I. , à Campo J. 
Published: November 2002

SummaryIn the present study two broad hypotheses about the origins of self-mutilation in psychiatric patients were evaluated. The first hypothesis states that self-mutilation originates from child abuse and experiences of neglect and is connected to dissociation in later life. The second hypothesis views self-mutilation as the consequence of impulse control problems. To test these two hypotheses, data concerning traumatic childhood experiences and dissociative symptoms (hypothesis 1), as well as data concerning aggressiveness, obsessive-compulsiveness and sensation seeking (hypothesis 2) were collected in a sample of 54 psychiatric inpatients. Twenty-four out of 54 patients (44%) reported having engaged in self-mutilation. Mean age of onset of this behaviour was 23 years. Self-report measures of self-mutilators were more in line with the first than with the second hypothesis. That is, patients who engaged in self-mutilation reported more traumatic childhood experiences and dissociative symptoms than did control patients. The two groups did not differ in terms of aggressiveness, obsessive-compulsiveness, and sensation seeking. In line with earlier studies, the current results indicate that self-mutilating behaviour is linked to a history of abuse and neglect.
Decreased frontal activation in schizophrenics during stimulation with the Continuous Performance Test - a functional magnetic resonance imaging study
Authors: Volz H.-P. , Gaser C. , Häger F. , Rzanny R. , Pönisch J. , Mentzel H.-J. , Kaiser W.A. , Sauer H. 
Published: November 2002

SummaryThe Continuous Performance Test (CPT) has become an essential constituent of the neuropsychological investigation of schizophrenia. Also, a vast number of brain imaging studies, mostly PET investigations, have employed the CPT as a cognitive challenge and established a relative hypofrontality in schizophrenics compared to controls. The aim of the present investigation was to clarify whether this predescribed hypofrontality could also be verified using functional magnetic resonance imaging (fMRI). 20 healthy volunteers and 14 schizophrenics on stable neuroleptic medication were included. Imaging was performed using the CPT-double-T-version and a clinical 1.5 T MRI-scanner with a single slice technique and a T2*-weighted gradient-echo-sequence. The schizophrenics exhibited a decreased activation in the right mesial prefrontal cortex, the right cingulate and the left thalamus compared to controls. These results obtained by fMRI are discussed in relation to published findings using PET.
Anxiolytic and hypnotic use in 376 psychiatric inpatients
Authors: Hardy P. , Payan C. , Bisserbe J.C. , Lepine J.P. ,   GERMED Neuropsychotropics Group
Published: November 2002

SummaryThis objectives of this study were three-fold: retrospectively evaluate anxiolytic/hypnotic consumption by psychiatric inpatients, identify the risk factors of prolonged intakes, and prospectively measure the impact of hospitalisation on the use of those drugs. Three hundred and seventy-six patients hospitalised in 11 psychiatric departments in the Paris region were studied using a structured interview for the anxiolytic/hypnotic treatments, DSM-III-R criteria, GHQ-12, HAD, Spiegel's questionnaire, COVI's anxiety scale and the CGI. Eighty-five per cent of the patients had taken one anxiolytic/hypnotic or more in the 3 months preceding hospitalisation. Hospitalisation induced little change in anxiolytic/hypnotic use: dosage frequency increased from 77% to 84% between the week preceding hospitalisation and that preceding discharge; 26% of consumers were taking at least two anxiolytics or two hypnotics in the first period vs. 23% in the second. The absence of withdrawal during hospitalisation was related to the high age and a diagnosis of depression rather than schizophrenia, to the existence of continuous intake over the 3 months preceding hospitalisation and to higher drug doses during the 7 days preceding hospitalisation. Prescription of treatment at the end of hospitalisation in previously non-user subjects was related to a higher HAD anxiety score at discharge.
Polypharmacy in psychiatric treatment. Patterns of psychotropic drug use in Austrian psychiatric clinics
Authors: Rittmannsberger H. , Meise U. , Schauflinger K. , Horvath E. , Donat H. , Hinterhuber H. 
Published: November 2002

SummaryThere are great variations in the way psychotropic drugs are prescribed. Most experts are in favour of psychopharmacological monotherapy, but little is known about the extent to which it is actually practised. A survey of the psychopharmacological medication of all patients under treatment was carried out in three Austrian psychiatric clinics of various types on two separate days. A psychiatric university clinic, the psychiatric department of a general hospital and a regional mental hospital were selected for the survey.It was established that only 8% to 22% of the patients underwent psycho-pharmacological monotherapy and that the patients received 2.2 to 3.3 psychotropics on average. Five to 22% of the patients received five or more psychotropic agents. The results are presented in more detail in relation to the diagnoses of schizophrenia and depression.The rare occurence of monotherapy might be due to unsound treatment regimens in some instances, but much more to a general trend in psychiatry fostering polydrug use.
A double-blind comparison of sertraline and fluoxetine in the treatment of major depressive episode in outpatients
Authors: Sechter D. , Troy S. , Paternetti S. , Boyer P. 
Published: November 2002

SummaryDepression is associated with considerable morbidity and mortality. As depressive disorders carry a high risk of relapse, treatment strategies include the use of a 6-month continuation period after resolution of the acute episode. Tolerability is of major importance when determining compliance and outcome during long-term therapy. Due to the superior tolerability profile of the selective serotonin reuptake inhibitors (SSRIs) over the older tricyclic antidepressants (TCAs), the former may be more suitable for extended therapy. Comparative studies have not shown differences between the SSRIs in terms of efficacy, but side-effect profiles may vary. A multicenter, double-blind, comparative study of sertraline and fluoxetine was carried out in outpatients fulfilling DSM-III-R criteria for major depressive disorder. Patients were randomised to receive sertraline (50—150 mg, n = 118) or fluoxetine (20—60 mg, n = 120) for 24 weeks. Assessments for depression (HAM-D, HAD, CGI-I, CGI-S), anxiety (Covi), sleep (Leeds Sleep Evaluation scale) and quality of life (SIP) were made at study entry and at weeks 2, 4, 8, 12, 18 and 24. All adverse events were recorded to allow evaluation of tolerability. In total, 88 patients in the sertraline group completed the study compared with 79 in the fluoxetine group. Side effects were responsible for the premature treatment withdrawal of seven (6%) sertraline patients and 12 (10%) fluoxetine patients. Two-hundred and thirty-four patients were included in an ITT analysis up to last visit (116 sertraline, 118 fluoxetine). At study endpoint, both treatments produced a significant improvement over baseline on all efficacy variables (P < 0.001). Although the magnitude of global changes in depression, anxiety, and quality of life was larger with sertraline than fluoxetine, none of the between-group differences reached statistical significance. However, significant differences in favour of sertraline were observed for individual HAM-D items including item 4 (insomnia onset) (P = 0.04), item 9 (agitation) (P = 0.02), and item 13 (general somatic symptoms) (P = 0.008). In addition, sertraline was associated with significantly superior performance on the Leeds Sleep Evaluation scale and on SIP items relating to sleep and rest, emotional behaviour and ambulation. Both sertraline and fluoxetine were well tolerated with no significant differences between treatments.
Abnormality in saccadic eye movement in dementia
Authors: Schewe H.J. , Uebelhack R. , Vohs K. 
Published: November 2002

SummaryIn a small (n = 15) clinically heterogeneous group of patients with dementia of the Alzheimer-type or vascular dementia, abnormally high frequency of saccadic intrusions during fixation was significantly correlated to the Mini-Mental-State-Examination (MMSE) scores. In addition, the latency of saccades and hypometric saccades also correlated significantly to MMSE-scores. The results point to the possible use of saccadic eye movement as a physiological marker of cognitive performance.
Panic disorder and memory: does panic disorder result from memory dysfunction?
Authors: Berksun O.E. 
Published: November 2002

SummaryIt is proposed that patients with panic disorder have a defect in fear-relevant episodic memory, and their panic attacks arise from automaticity in recollecting fear-relevant emotional-autonomic cluster. The cluster as a component of fear appears to have been dissociated from cognitive structure (episodic or informative memory trace) or from ‘information structure’.A special method was created for testing this hypothesis where 30 panic disorder patients, 12 healthy controls, and 32 patients with other psychiatric diagnoses were asked to recall and describe a fearful experience. None of the patients in the panic disorder group could recall any fearful event or episode in their past. All but one subject among healthy controls and all the subjects in the non-panic group could recall one or more fearful event or episode. Possible theoretical implications of these results are discussed in the context of some classical concepts.
Psychiatrists meet on the web: the chance for a virtual congress. Results and experiences from the First International Internet Congress on Psychiatry 1997
Authors: Batra A. , Bartels M. , Aicher L. , Hefler T. , Buchkremer G. 
Published: November 2002

SummaryFrom December 1–31, 1997, the Department of Psychiatry and Psychotherapy in co-operation with the Department of Information Technology, University of Tübingen, Germany, organised the first virtual congress on psychiatry in the Internet. The congress was aimed at facilitating exchange of results of psychiatric studies and ideas and at stimulating discussion among interested colleagues. Almost 100 participants from 17 countries on four continents took part in this event. Sixteen contributions were presented and discussed. The problems and opportunities of this medium in the organisation and running of congresses are presented and discussed. The experience gained in this congress suggests that the Internet will find increasing use as a medium for medical congresses within the next few years.
The association between psychological factors and oro‐facial pain: a community‐based study
Authors: Macfarlane Tatiana V , Kincey John , Worthington Helen V 
Published: November 2002

OBJECTIVE To examine the hypothesis that psychological factors of psychological distress, maladaptive response to illness and perception of happiness in childhood, are associated with self‐reported oro‐facial pain (OFP).METHOD A cross‐sectional population‐based study was conducted in South‐East Cheshire, UK. The adjusted participation rate was 74%, and 2504 adults aged 18–65 years participated in the study.RESULTS A report of not having had a happy childhood was associated with risk of 1.6 (95% CI 1.4–2.0) of reporting OFP. An increased propensity to report symptoms associated with OFP was seen for those individuals with higher levels of psychological distress measured using the general health questionnaire (GHQ) with the risk of 2.7 (95% CI 2.3–3.2) in the highest category. All components of the illness behaviour questionnaire (IBQ) were associated with presence of OFP. There was a linear increase in risk (test for trend,P<0.01) associated with the report of OFP for general hypochondriasis, disease conviction, affective inhibition, affective disturbance, and irritability. However there was a significant decrease in risk with a high score for perception of illness (0.6; 95% CI 0.6–0.7) and denial (0.6; 95% CI 0.5–0.7). None of the factors showed significant change in estimates when adjusted for age and gender.CONCLUSIONS This large cross‐sectional community‐based study showed significant association for all of the factors considered. The obtained data raise interesting questions of cause and effect for which further, longitudinal studies are required to establish temporal relationship between these factors and the onset, cause, and treatment of OFP.
A Messy Derivation of the Categorical Imperative
Authors: Kupperman Joel J. 
Published: November 2002

Here are two widespread responses to Kant's categorical imperative. On one hand, one might note the absence of detailed rational derivation. On the other hand, even someone who maintains some skepticism is likely to have a sense that (nevertheless) there is something to Kant's central ideas.The recommended solution is analysis of elements of the categorical imperative. Their appeal turns out to have different sources. One aspect of the first formulation rests on the logic of normative utterances. But others can be justified only in terms of their contributions to desirable functionings of a moral order.
Poles and Jews in the Second World War: the Revisions of Jan T. Gross
Authors: Connelly John 
Published: November 2002

Jan T. Gross, Neighbors: The Destruction of the Jewish Community in Jedwabne, Poland (Princeton: Princeton University Press, 2001), 261 pp., ISBN 0-691-08667-2.Marek Jan Chodakiewicz, Żydzi i Polacy 1918–1955: Współistnienie – zagłada – komunizm (Warsaw: Biblioteka Frondy, 2000), 731 pp., ISBN 8-391-25418-6.Leo Cooper, In the Shadow of the Polish Eagle: The Poles, the Holocaust, and Beyond (Houndmills and New York: Palgrave, 2000), 255 pp., ISBN 0-333-75265-1.Martin Dean, Collaboration in the Holocaust: Crimes of the Local Police in Belorussia and Ukraine, 1941–44 (New York: St. Martin's Press, 1999), ISBN 0-312-22056-1.Yitzhak Arad, Israel Gutman, and Abraham Margaliot, eds., Documents on the Holocaust: Selected Sources on the Destruction of the Jews of Germany and Austria, Poland, and the Soviet Union, 8th edn (Lincoln: University of Nebraska Press and Jerusalem: Yad Vashem, 1999), 508 pp., ISBN 0-803-21050-7.
Before UNESCO and the WHO
Authors: Ghebali Victor-Yves 
Published: November 2002

Jean-Jacques Renoliet, L'UNESCO oubliée. La Société des Nations et la coopération intellectuelle (1919–1946), foreword by René Girault (Paris: Publications de la Sorbonne, 1999), 352 pp., FF180, ISBN 2-6384-7701-1.Christel Taillibert, L'Institut international du cinématographe international éducatif. Regards sur le rôle du cinéma éducatif dans la politique internationale du fascisme italien (Paris: L'Harmattan, 1999), 401 pp., FF180, ISBN 2-85944-384-3.Marta Aleksandra Balińska, Une vie pour l'humanitaire. Ludwik Rajchmann, 1881–1965, foreword by Bronislaw Geremek, L'Espace de l'histoire (Paris: La Découverte, 1995), 399 pp., FF165, ISBN 2-7071-2485-0.