The effect of high optical power on modern fibre at 1.5 μm

Here we study the impact of high optical power, within the C-band, on the reliability of modern single mode fibre. Our experiments show that modern fibre demonstrates >10 dB higher power handling performance beyond what has previously been reported

Gestion clinique et réhabilitation du patient souffrant de schizophrénie et réfractaire au traitement : fondements conceptuels et résultats (première partie)

Malgré les percées importantes en psychopharmacologie dans le traitement des personnes souffrant de schizophrénie, plusieurs patients demeurent trop handicapés pour obtenir leur congé des établissements psychiatriques publics. Cet article décrit le développement d’un partenariat entre les secteurs public et privé qui a mené à la création d’un programme spécialisé et intensif de réhabilitation behaviorale, dans les hôpitaux publics, à l’intention des patients souffrant de schizophrénie, et considérés réfractaires aux traitements. Les éléments essentiels de ce programme et ses fondements philosophiques y sont décrits. Des données sur les résultats sont discutées afin de souligner le fait que lorsque des traitements basés sur des données probantes sont dispensés à cette population, les résultats peuvent être positifs dans la plupart des cas. Et le nombre de patients « réfractaires aux traitements » devient moindre lorsque son estimation n’est pas seulement basée sur la réponse aux médicaments.Despite advances in psychopharmacology for people with schizophrenia, many patients remain too disabled to be discharged from public psychiatric facilities. This paper decribes the development of a public-private partnership which led to the creation of a specialized, intensive behavioral rehabilitation program for schizophrenia patients who were considered to be treatment-refractory at public hospitals. The essential elements of this treatment program are described, along with the philosophical bases of its treatment. Outcome data are discussed to emphasize the point that when evidence-based treatment is implemented with this population, outcomes can be positive in most cases, and therefore, the number of « treatment-refractory » patients is actually less than is estimated based on response to medication alone.A pesar de los avances importantes de la psicofarmacología en el tratamiento de las personas con esquizofrenia, muchos pacientes siguen estando demasiado discapacitados para obtener sus incapacidades en los establecimientos psiquiátricos públicos. Este artículo describe el desarrollo de una asociación entre el sector público y privado, que ha conducido a la creación de un programa especializado e intensivo de rehabilitación conductista, en los hospitales públicos, para los pacientes que sufren de esquizofrenia y que son considerados como refractarios a los tratamientos. Los elementos esenciales de este programa y sus fundamentos filosóficos son descritos en este artículo. También se discuten los datos de los resultados con el fin de subrayar el hecho de que cuando los tratamientos basados en los datos probantes son presentados a esta población, los resultados pueden ser positivos en la mayoría de los casos y el número de pacientes “refractarios a los tratamientos” disminuye cuando su estimación no se basa sólo en su respuesta a los medicamentos.Apesar das descobertas importantes em psicofarmacologia no tratamento de pessoas que sofrem de esquizofrenia, vários pacientes continuam debilitados demais para obter sua alta dos estabelecimentos psiquiátricos públicos. Este artigo descreve o desenvolvimento de uma parceria entre os setores público e privado que levou à criação de um programa especializado e intensivo de reabilitação behaviorista, nos hospitais públicos, para pacientes que sofrem de esquizofrenia, considerados refratários aos tratamentos. Os elementos essenciais deste programa e seus fundamentos filosóficos são descritos no artigo. São discutidos dados sobre os resultados para ressaltar o fato de que, quando tratamentos baseados nos dados probatórios são dispensados a esta população, os resultados podem ser positivos na maior parte dos casos. O número de pacientes “refratários aos tratamentos” diminui quando sua estimativa não é somente baseada na resposta aos medicamentos

Extragalactic Constraints on the Initial Mass Function

The local stellar mass density is observed to be significantly lower than the value obtained from integrating the cosmic star formation history (SFH), assuming that all the stars formed with a Salpeter initial mass function (IMF). Even other favoured IMFs, more successful in reconciling the observed $z=0$ stellar mass density with that inferred from the SFH, have difficulties in reproducing the stellar mass density observed at higher redshift. In this study we investigate to what extent this discrepancy can be alleviated for any universal power-law IMF. We find that an IMF with a high-mass slope shallower (2.15) than the Salpeter slope (2.35) reconciles the observed stellar mass density with the cosmic star formation history, but only at low redshifts. At higher redshifts $z>0.5$ we find that observed stellar mass densities are systematically lower than predicted from the cosmic star formation history, for any universal power-law IMF.Comment: 6 pages, 5 figures, accepted to MNRA

Prevalence of true vein graft aneurysms: Implications for aneurysm pathogenesis

AbstractBackground: Circumstantial evidence suggests that arterial aneurysms have a different cause than atherosclerosis and may form part of a generalized dilating diathesis. The aim of this study was to compare the rates of spontaneous aneurysm formation in vein grafts performed either for popliteal aneurysms or for occlusive disease. The hypothesis was that if arterial aneurysms form a part of a systemic process, then the rates of vein graft aneurysms should be higher for patients with popliteal aneurysms than for patients with lower limb ischemia caused by atherosclerosis. Methods: Infrainguinal vein grafting procedures performed from 1990 to 1995 were entered into a prospective audit and graft surveillance program. Aneurysmal change was defined as a focal increase in the graft diameter of 1.5 cm or greater, excluding false aneurysms and dilatations after graft angioplasty. Results: During the study period, 221 grafting procedures were performed in 200 patients with occlusive disease and 24 grafting procedures were performed in 21 patients with popliteal aneurysms. Graft surveillance revealed spontaneous aneurysm formation in 10 of the 24 bypass grafts (42%) for popliteal aneurysms but in only 4 of the 221 grafting procedures (2%) that were performed for chronic lower limb ischemia. Conclusion:This study provides further evidence that aneurysmal disease is a systemic process, and this finding has clinical implications for the treatment of popliteal aneurysms. (J Vasc Surg 1999;29:403-8.

On the 3D structure of the mass, metallicity, and SFR space for SF galaxies

We demonstrate that the space formed by the star-formation rate (SFR), gas-phase metallicity (Z), and stellar mass (M), can be reduced to a plane, as first proposed by Lara-Lopez et al. We study three different approaches to find the best representation of this 3D space, using a principal component analysis, a regression fit, and binning of the data. The PCA shows that this 3D space can be adequately represented in only 2 dimensions, i.e., a plane. We find that the plane that minimises the chi^2 for all variables, and hence provides the best representation of the data, corresponds to a regression fit to the stellar mass as a function of SFR and $Z$, M=f(Z,SFR). We find that the distribution resulting from the median values in bins for our data gives the highest chi^2. We also show that the empirical calibrations to the oxygen abundance used to derive the Fundamental Metallicity Relation (Nagao et al.) have important limitations, which contribute to the apparent inconsistencies. The main problem is that these empirical calibrations do not consider the ionization degree of the gas. Furthermore, the use of the N2 index to estimate oxygen abundances cannot be applied for ~8.8 because of the saturation of the [NII]6584 line in the high-metallicity regime. Finally we provide an update of the Fundamental Plane derived by Lara-Lopez et al.Comment: ApJ, accepted. 15 pages, 13 figure