Index theory for basic Dirac operators on Riemannian foliations

In this paper we prove a formula for the analytic index of a basic Dirac-type operator on a Riemannian foliation, solving a problem that has been open for many years. We also consider more general indices given by twisting the basic Dirac operator by a representation of the orthogonal group. The formula is a sum of integrals over blowups of the strata of the foliation and also involves eta invariants of associated elliptic operators. As a special case, a Gauss-Bonnet formula for the basic Euler characteristic is obtained using two independent proofs.

Generalized descriptive set theory and classification theory

Descriptive set theory is mainly concerned with studying subsets of the space of all countable binary sequences. In this paper we study the generalization where countable is replaced by uncountable. We explore properties of generalized Baire and Cantor spaces, equivalence relations and their Borel reducibility. The study shows that the descriptive set theory looks very different in this generalized setting compared to the classical, countable case. We also draw the connection between the stability theoretic complexity of first-order theories and the descriptive set theoretic complexity of their isomorphism relations. Our results suggest that Borel reducibility on uncountable structures is a model theoretically natural way to compare the complexity of isomorphism relations.

Strong isomorphism reductions in complexity theory

We give the first systematic study of strong isomorphism reductions, a notion of reduction more appropriate than polynomial time reduction when, for example, comparing the computational complexity of the isomorphim problem for different classes of structures. We show that the partial ordering of its degrees is quite rich. We analyze its relationship to a further type of reduction between classes of structures based on purely comparing for every n the number of nonisomorphic structures of cardinality at most n in both classes. Furthermore, in a more general setting we address the question of the existence of a maximal element in the partial ordering of the degrees.

Vintage capital growth theory: three breakthroughs

Vintage capital growth models have been at the heart of growth theory in the 60s. This research line collapsed in the late 60s with the so-called embodiment controversy and the technical sophisitication of the vintage models. This paper analyzes the astonishing revival of this literature in the 90s. In particular, it outlines three methodological breakthroughs explaining this resurgence: a growth accounting revolution, taking advantage of the availability of new time series, an optimal control revolution allowing to safely study vintage capital optimal growth models, and a vintage human capital revolution, along with the rise of economic demography, accounting for the vintage structure of human capital similarly to physical capital age structuring. The related literature is surveyed.

The longitudinal association between social functioning and theory of mind in first episode psychosis

Introduction. There is some cross-sectional evidence that theory of mind ability is associated with social functioning in those with psychosis but the direction of this relationship is unknown. This study investigates the longitudinal association between both theory of mind and psychotic symptoms and social functioning outcome in first-episode psychosis. Methods. Fifty-four people with first-episode psychosis were followed up at 6 and 12 months. Random effects regression models were used to estimate the stability of theory of mind over time and the association between baseline theory of mind and psychotic symptoms and social functioning outcome. Results. Neither baseline theory of mind ability (regression coefficients: Hinting test 1.07 95% CI 0.74, 2.88; Visual Cartoon test 2.91 95% CI 7.32, 1.51) nor baseline symptoms (regression coefficients: positive symptoms 0.04 95% CI 1.24, 1.16; selected negative symptoms 0.15 95% CI 2.63, 2.32) were associated with social functioning outcome. There was evidence that theory of mind ability was stable over time, (regression coefficients: Hinting test 5.92 95% CI 6.66, 8.92; Visual Cartoon test score 0.13 95% CI 0.17, 0.44). Conclusions. Neither baseline theory of mind ability nor psychotic symptoms are associated with social functioning outcome. Further longitudinal work is needed to understand the origin of social functioning deficits in psychosis.

Health services utilization associated with cognitive impairment and dementia in older patients undergoing post-acute rehabilitation.

OBJECTIVE: To investigate the relationship between levels of cognitive impairment and health services utilization in older patients undergoing post-acute rehabilitation. DESIGN: Cross-sectional study. SETTING: Post-acute rehabilitation facility. PARTICIPANTS: Patients (N = 1764) aged 70 years and older admitted over 3 years. MEASUREMENTS: Sociodemographic, medical, and functional data were collected upon admission. Based on discharge diagnoses, patients were classified as cognitively intact, cognitively impaired with no dementia (CIND), and demented. RESULTS: Dementia and CIND were diagnosed in 425 (24.1%) and 301 (17.1%) patients, respectively. Gradients from cognitively intact to cognitively impaired to demented patients were observed in median length of stay (19, 22, and 25 days, P < .001), and institutionalization rates at discharge (4.2%, 7.6%, and 28.8%, P < .001). Among patients discharged home, similar gradients were observed in utilization of home care (68.2%, 79.7%, and 83.3%, P < .001) and day care (3.1%, 7.1%, and 14.3%, P < .001). After adjustment, compared with cognitively intact patients, only those with dementia still had longer stays (+2.7 days) and increased odds of institutionalization (adjOR 6.1, 95% CI 4.0-9.3, P < .001). Among patients discharged home, use of home and day care remained higher in those with dementia (adjOR 1.8, 95% CI 1.2-2.7, P = .005, and adjOR 1.8, 95% CI 1.2-2.7, P = .005, respectively), while CIND patients had higher odds of using home care (adjOR 1.6, 95% CI 1.1-2.4, P = .028). CONCLUSION: Among patients undergoing post-acute rehabilitation, those with dementia had increased use of both institutional and community care, whereas those with CIND had increased use of home care services only. Future studies should investigate specific strategies susceptible to reduce the related burden on health care systems.

Off-label utilization of antipsychotics

Résumé Ce travail s'inscrit dans un programme de recherche centré sur la pharmacovigilance en psychiatrie. Buts de l'étude Les nouveaux antipsychotiques atypiques sont prescrits avec beaucoup de succès, parce qu'ils présentent une sécurité dans leur emploi bien supérieure à celle des antipsychotiques classiques. Cette situation a conduit à une large prescription «off-label» (hors indication admise). Le but de ce travail a été d'étudier la pratique en matière de prescription des psychiatres hospitaliers en ce qui concerne les antipsychotiques en comparant des patients traités pour des psychoses ou d'autres indications officielles aux patients recevant un traitement antipsychotique «off-label». Méthode Dans le cadre d'un programme de pharmacovigilance - pharmacoépidemiologie, tous les médicaments prescrits à 5 jours de référence (entre 1999 et 2001) à l'hôpital psychiatrique universitaire de Lausanne (98 lits) ont été enregistrés, avec des données sur l'âge, le sexe et le diagnostic des patients. Les prescriptions de 202 patients ont été évaluées. Les patients ont été classés dans 3 groupes diagnostiques : (1) patient présentant des troubles psychotiques, (2) patient présentant des épisodes maniaques et des épisodes dépressifs avec des symptômes psychotiques, et (3) patient présentant d'autres troubles. Les groupes (1) et (2) forment une classe de patients recevant un antipsychotique pour une indication officielle, et les prescriptions dans le groupe (3) ont été considérées comme «off-label». Résultats principaux Moins de patients psychotiques ont reçu un antidépresseur (p<0.05) ou des hypnotiques non-benzodiazepine (p<0.001) comparés aux patients des deux autres groupes. Les patients présentant des troubles affectifs recevaient seulement exceptionnellement une combinaison d'un antipsychotique atypique et conventionnel, tandis qu'un nombre inférieur de patients avec des indications « off-label » ont reçu moins .souvent des antipsychotiques atypiques que ceux des deux groupes de comparaison (p<0.05). L'analyse statistique (stepwise logistic regression) a révélé que les patients présentant des troubles psychotiques avaient un risque plus élevé de recevoir un médicament antipsychotique d'une dose moyenne ou élevée, (p<0.001) en comparaison aux deux autres groupes. Conclusion Les nouveaux médicaments antipsychotiques semblent être prescrits avec moins d'hésitation principalement pour des indications admises. Les médecins prescrivent de nouveaux médicaments « off-label » seulement après avoir acquis une certaine expérience dans le domaine des indications approuvées, et ils étaient plus prudents en ce qui concerne la dose en traitant sur la base «off-label». Abstract Objective The new brands of atypical antipsychotics are very successfully prescribed because of their enhanced safety profiles and their larger pharmacological profile in comparison to the conventional antipsychotic. This has led to broad off-label utilisation. The aim of the present survey was to study the prescription practice of hospital psychiatrists with regard to antipsychotic drugs, comparing patients treated for psychoses or other registered indications to patients receiving an off-label antipsychotic treatment. Method As part of a pharmacovigilance/pharmacoepidemiology program, all drugs given on 5 reference days (1999 - 2001) in the 98-bed psychiatric hospital of the University of Lausanne, Switzerland, were recorded along with age, sex and diagnosis. The prescriptions of 202 patients were assessed. Patients were classified in 3 diagnostic groups: (1) patient with psychotic disorders, (2) patients with manic episodes and depressive episodes with psychotic symptoms, and (3) patients with other disorders. Group (1) and (2) formed the class of patients receiving an antipsychotic for a registered indication, and the prescriptions in group (3) were considered as off-label. Main results A lesser number of psychotic patients received antidepressant (p<0.05) and nonbenzodiazepine hypnotics (p<0.001) compared to the patients of the other two groups. The patients with affective disorders received only exceptionally a combination of an atypical and a conventional antipsychotic, whereas a lesser number of patients with off-label indications received less often atypical antipsychotics than those of the two comparison groups (p<0.05). Stepwise logistic regression revealed that patients with psychotic disorder were at higher risk of receiving an antipsychotic medication in medium or high dose (p<0.001), in comparison to the two other groups. Conclusions The new antipsychotic drugs seem to be prescribed with less hesitation mainly for approved indications. Physicians prescribe new drugs on off-label application only after having gained some experience in the field of the approved indications, and were more cautious with regard to dose when treating on an off-label basis.

Recommandations de pratique clinique dans la schizophrénie: de la théorie à la mise en application = Clinical practice guidelines for the treatment of schizophrenia: from theory to practice

Dans le cadre d'une étude rétrospective au sein d'une unité de réhabilitation, nous avons cherché à examiner le degré de respect de recommandations de pratique clinique (RPC) abordant le traitement pharmacologique au long cours de la schizophrénie, par des médecins qui n'en ont qu'une connaissance indirecte. The Expert Consensus Guideline for the treatment of schizophrenia (ECGTS) a été retenu comme référence sur la base d'une comparaison avec cinq autres RPC principales. Sur un collectif de 20 patients, les recommandations de l'ECGTS sont totalement respectées dans 65 % des cas, partiellement respectées dans 10 % et non respectées dans 25 %, démontrant ainsi que la pratique clinique est clairement perfectible (principalement dans le traitement des symptômes psychotiques et dépressifs). Cependant, le respect des RPC ne garantit pas forcément la résolution de tous les problèmes cliniques rencontrés : 12 patients sur 20 présentent des effets secondaires à l'évaluation clinique et pour huit d'entre eux, les recommandations à ce niveau, sont respectées. Notre étude montre cependant que le choix et l'application d'une RPC ne sont pas simples. Les RPC actuelles donnent peu ou pas d'instruments de mesure, ni de critères précis pour évaluer les problèmes cliniques auxquels elles font référence. L'avenir appartient donc à des RPC qui proposent, outre les recommandations cliniques elles-mêmes, les moyens de leur vérification et de leur application sur le terrain.

Temperament in Bach’s Well-tempered clavier: a historical survey and a new evaluation according to dissonance theory

After a historical survey of temperament in Bach’s Well-Tempered Clavier by Johann Sebastian Bach, an analysis of the work has been made by applying a number of historical good temperaments as well as some recent proposals. The results obtained show that the global dissonance for all preludes and fugues in major keys can be minimized using the Kirnberger II temperament. The method of analysis used for this research is based on the mathematical theories of sensory dissonance, which have been developed by authors such as Hermann Ludwig Ferdinand von Helmholtz, Harry Partch, Reinier Plomp, Willem J. M. Levelt and William A. Sethares