Thermal counterflow of superfluid $^4$He is investigated experimentally, by employing the particle tracking velocimetry technique. A flat heater, located at the bottom of a vertical channel of square cross-section, is used to generate this unique type of thermally driven flow. Micronic solid particles, made in situ, probe this quantum flow and their time-dependent positions are collected by a digital camera, in a plane perpendicular to the heat source, away from the channel walls. The experiments are performed at relatively large heating powers, resulting in fluid velocities exceeding $10\ \textrm {mm}\,\textrm {s}^{-1}$, to ensure the existence of sufficiently dense tangles of quantized vortices. Within the investigated parameter range, we observe that the particles intermittently switch between two distinct motion regimes, along their trajectories, that is, a single particle can experience both regimes while travelling upward. The regimes can be loosely associated with fast particles, which are moving away from the heat source along almost straight tracks, and to slow particles, whose erratic upward motion can be said to be significantly influenced by quantized vortices. We propose a separation scheme to study the properties of these regimes and of the corresponding transients between them. We find that particles in both regimes display non-classical, broad distributions of velocity, which indicate the relevance of particle–vortex interactions in both cases. At the same time, we observe that the fast particles move along straighter trajectories than the slow ones, suggesting that the strength of particle–vortex interactions in the two regimes is notably different.

Our aim was to determine the effect of risperidone monotherapy treatment on disability and on the quality of life of 318 schizophrenic outpatients who had been previously treated with other neuroleptics. Patients were assessed at baseline 2, 4 and 8 months using the BPRS, CGI, WHO/DDS and SF-36. BPRS scores showed a significant decrease at month 2, both in the total score and in each of the three clusters, negative, positive and depression/anxiety. WHO/DDS scores significantly decreased both in the overall score (from 51.8 to 37.4, P < 0.0001) and in the four dimensions. SF-36 scale scores and summary measures showed a significant improvement after 8 months of risperidone treatment. Risperidone long-term treatment (8 months) has a positive effect on clinical and on psychosocial outcomes. Females, paranoids patients and patients without history of use-abuse of substances showed greater improvements in quality of life.

La composition minéralogique de la phase <2 µm de la croûte d'altération de teinte pâele et de quelques millimétres d'épaisseur, développée sur les faces des prismes basaltiques de Roudadou, près d'Aurillac, Cantal, a été étudiée par plusieurs techniques: RX, analyse thermique différentielle, thermogravimétrie, spectroscopie infra-rouge entre 600 et 200 cm−1, mesure des surfaces totales. Cette phase fine est constituée d'une fraction non cristalline relativement réduite et surtout de minéraux argileux cristallisés, parmi lesquels l'imogolite est largement dominante (50%), accompagnée de l'halloysite (30%). Parfois une smectite compléte ce cortège argileux. A notre connaissance, l'imogolite n'avait jamais été identifiée parmi les produits d'altération superficielle des roches volcaniques du Massif Central.

Fresh and weathered pyrochlore from the Lueshe carbonatite complex (in the northeast of the Democratic Republic of Congo) was studied by Fourier transfom infrared (FTIR) spectroscopy and by a combination of FTIR spectroscopy and thermal analysis. The former was carried out in the spectral range 400–4000 cm−1. The spectra for fresh and weathered pyrochlores were very different. For the weathered pyrochlore, two bands were identified as OH vibration modes, one broad band with a maximum at 3413 cm−1 and another finer band at 1630 cm−1. The fresh pyrochlore does not show OH absorption bands. The presence of OH confirms the hydrated state of the weathered pyrochlore suggested by previous microanalytical work. The combination of FTIR spectroscopy and thermal analysis allows ‘real-time’ observation of gas emanations and solid-state transformations taking place during heating up to 800°C. For fresh pyrochlore, no solid transformation was detected, except a CO2 emanation from 242–576°C. For the weathered pyrochlore a dehydration was observed between 234–565°C followed by an exothermic peak in Differential Scanning Calorimetric (DSC) curve at 604°C. This exothermic peak corresponds to the formation of a Nb oxide phase. At higher temperatures the weathered pyrochlore is partly decomposed, forming a dehydrated pyrochlore and a Nb oxide phase. The combination of FTIR and thermal analysis has provided useful information on both fresh and weathered pyrochlore transformations which has clarified our understanding of the water control of the structural stability of pyrochlore minerals.

The catastrophic lahars triggered by the 13 November 1985 eruption of the ice-clad Nevado del Ruiz volcano, Colombia, demonstrate that the interaction of hot pyroclasts with snow and ice can release 30–50 millionm3 of meltwater in 30–90 minutes. The 1985 eruption caused a 16% loss in area and a 9% loss in volume of snow, firn and ice. Turbulent pyroclastic density currents mechanically mixed with snow and produced meltwater at a rate of 0.5–1.6mms–1. Laboratory experiments suggest that turbulent, fluidized pyroclastic density currents exert mechanical and thermal scour, thereby efficiently transferring heat from hot pyroclasts to snow. Ice cap loss at Nevado del Ruiz continued between 1985 and 2000, representing a ∽52% decline in area and a ∽30% fall in volume. Ice 60–190m thick caps the east and southeast summit plateau, whereas an ice field < 30m thick and devoid of snow is retreating on the north, northeast and west edges. This asymmetrical distribution of ice reflects combined long-term effects of the 1985 eruption and of the post-1985 ice cap retreat. Should volcanic activity resume, steep-sided glaciers can fail and pyroclastic flows and surges can sweep the snowpack and generate mixed avalanches and lahars. Although the potential source of meltwater has decreased since 1985, extensive debris at the ice cap margins can be incorporated to future lahars.

The shallow-marine Carmel Formation (Middle Jurassic) in central Utah hosts low-diversity trace fossil assemblages, including Arenicolites, Chondrites, Gyrochorte, Lockeia, Planolites, Protovirgularia, Rosselia, Scalarituba, Skolithos, Taenidium, and Teichichnus. Non specialized ichnotaxa with a remarkably small burrow size dominate the assemblages. The amount of bioturbation is lower than expected in comparison with modern shallow-marine carbonate environments. These ichnological features also are significantly different from those of other Jurassic shallow-marine carbonates. The trace fossils represent an environmentally stressed benthic community in a marginal marine, restricted setting, with salinities above normal marine and with depletion of oxygen in pore waters.

“ CALLIOPE " est une base de données sous forme de cédérom destinée à la formation de la dosimétrie interne. Cet outil est une aide pour l'interprétation des mesures de surveillance des travailleurs ou du poste de travail réalisées en routine ou après incident. Il contient des informations issues des sept principales Publications de la CIPR sur la dosimétrie interne et permet l'accès aux données nucléaires du logiciel NUCLEIDE. Cet utilitaire facilite la mise en application des réglementations extraites de la Directive européenne 96/29 dans le respect des nouvelles limites. Il est une aide à la validation par l'utilisateur des démarches et des estimations des doses consécutives à l'exposition interne.

Nuestro propósito era determinar el efecto del tratamiento de risperidona en monoterapia sobre la discapacidad y sobre la calidad de vida de 318 pacientes esquizofrénicos ambulatorios que habían sido tratados antes con otros neurolépticos. Los pacientes fueron evaluados en la línea de base y a los dos, cuatro y ocho meses utilizando la BPRS, la CGI, la WHO/DDS y la SF-36. Las puntuaciones de la BPRS mostraron una disminución significativa en el segundo mes, tanto en la puntuación total como en cada uno de los tres grupos negativo, positivo y de depresión/ansiedad. Las puntuaciones de la WHO/DDS disminuyeron significativamente tanto en la puntuación global (de 51,8 a 37,4, P < 0,0001) como en las cuatro dimensiones. Las puntuaciones de la escala SF-36 y las medidas de resumen mostraron una mejoría significativa después de ocho meses de tratamiento de risperidona. El tratamiento a largo plazo (ocho meses) de risperidona tiene un efecto positivo sobre la evolución clínica y psicosocial. Las mujeres, los pacientes paranoides y los pacientes sin historia de uso-abuso de sustancias mostraron mejorías mayores en la calidad de vida.

Interactions between uranium and target cells: Example of UO4 particle transformation within alveolar macrophages. Interactions between uranium and target cells: examples of UO4 particle transformation within alveolar macrophages. 
The understanding of the mechanisms involved in the in vivo dissolution of inhaled particles is necessary to improve the model for determining the parameters. With that perspective, the intracellular transformation of UO4 particles has been investigated. Indeed, very few is known about this compound encountered in the nuclear fuel cycle. After instillation of UO4 particles in rats, alveolar macrophages and lung tissues have been observed. The particles break up very quickly in ultrafine particles and in some cases, this mechanism is accompanied by the formation of uranyl phosphate needles. This phenomenon takes place at very early stage, i.e., within the first 24 hours after the instillation. Particles phagocytised by macrophages in vitro have been observed after inclusion of the cells directly on the culture dish. These observations have confirmed the corrosive action exerted by the macrophages on the UO4 particles.

Se examinó la influencia de un trasplante medular adrenal en el espacio subaracnoideo lumbar sobre la indefensión aprendida, un modelo animal de depresión. Se encontró que las ratas trasplantadas eran menos susceptibles de sufrir indefensión de choques inescapables después de la administración que los animales con un falso trasplante. El efecto se atribuyó a la liberación de péptidos opioides por células cromafines, pues Io invirtió la naloxona. La viabilidad del tejido trasplantado se verificó por microscopio electrónico.

Type IIa diamonds present photoconductive properties as well in X-ray detection range, as in near UV, visible, IR light range, in spite of the large bandgap of the material. Experimental results in these four fields, time measurements in picosecond and subpicosecond ranges are presented.