Functional role of high-affinity anandamide transport, as revealed by selective inhibition

Anandamide, an endogenous ligand for central cannabinoid receptors, is released from neurons on depolarization and rapidly inactivated. Anandamide inactivation is not completely understood, but it may occur by transport into cells or by enzymatic hydrolysis. The compound N-(4-hydroxyphenyl)arachidonylamide (AM404) was shown to inhibit high-affinity anandamide accumulation in rat neurons and astrocytes in vitro, an indication that this accumulation resulted from carrier-mediated transport. Although AM404 did not activate cannabinoid receptors or inhibit anandamide hydrolysis, it enhanced receptor-mediated anandamide responses in vitro and in vivo. The data indicate that carrier-mediated transport may be essential for termination of the biological effects of anandamide, and may represent a potential drug target.     

Cavitation in Superfluid Helium Possibly Arising from Penning Ionization of Dimers

We have perforated a series of experiments to study cavitation in superfluid helium into which electrons are injected by field-emission from a sharp tip. The injected electrons force open small cavities in the liquid (“electron bubble”). These objects explode at a critical negative pressure P _c, and in previous experiments we have studied the cavitation that resugts from these explosions. In the present experiments we have detected cavitation events that occur before a negative pressure as large as P _c is reached. We suggest that these events may arise from a process in which two neutral helium dimers interact and an electron is injected into the liquid through Penning ionization.     

Magnetic Levitation of liquid helium

We report on the stable levitation of liquid helium drops of up to 2 cm diameter in a magnetic trap at temperatures down to 1.5 K in the earth's gravitational field. The production and properties of a magnetic trap for diamagnetic materials is discussed. The behavior of liquids in such a trap is analyzed, including the deformation of a liquid drop by the trap forces. We frequently observe two drops in the magnetic trap which are held in apparent contact for up to 3 minutes without coalescing. This non-coalescence effect was only seen above the superfluid transition temperature. We explain this effect in terms of the existence of a vapor layer between the drops caused by evaporation of the drops, much like the suspension of a liquid drop above a hot surface known as the Leidenfrost effect.     

Supersolidity and the Thermodynamics of Solid Helium

The specific heat of solid helium in the temperature range below about 1.2 K has been found to contain a term varying as T ⁷, in addition to the usual T ³ contribution always found in a crystalline dielectric solid. It has been proposed by Anderson, Brinkman and Huse, (Science 310, 1164 (2005)) that the existence of this T ⁷ term supports their theory of supersolidity. However, in this paper we show that corrections to the phonon specific heat arising from phonon dispersion are much larger than expected based on simple order of magnitude estimates and, as a consequence, it is very unlikely that the existence of this T ⁷ term can be considered as evidence for supersolidity.      

Directionality from anisotropic phonon production in solid state dark matter detection

We present results from computer simulations of the events immediately following the scattering of a dark matter particle off a nucleus in a crystal detector. Our simulations show that with NaF as the target, the recoil produces solitary waves that decay slowly, resulting in a narrow wake of phonons. The phonon wake allows a determination of direction of the nuclear recoil.     

Neocytoapheresis in the treatment of polycythemia vera

In absence of thrombocytosis, periodic bloodlettings represent the elective therapy of polycythemia vera. In the present study we tested if neocytoapheresis, a method able to remove large quantities of younger, and then bigger red cells could represent an alternative therapeutic choice in these patients. We found that the employment of neocytoapheresis produced a remarkable delay in the time of procedures with a mean interval of 100 +/- 55 days. The mean value of hematocrit before neocytopheresis is resulted statistically different in comparison with the hematocrit after the procedure (p = 0.0001). The reticulocyte count is resulted higher in apheresis product in comparison with the blood control measured before procedure (p = 0.0001). In the same way, the mean corpuscular volume in the collection bags was higher than the volume measured before neocytoapheresis (p = 0.0095). We did not find any variation about the mean values of white blood cells and platelets before and after neocytoapheresis in the patients examined. These preliminary data seem to underline a better withdrawal of big size cells by this technique suggesting the efficacy of neocytoapheresis in the treatment of polycythemia vera.     

The performance of foliage mass and crown radius models in forming the input of a forest reflectance model: A test on forest growth sample plots and Landsat 7 ETM+ images

Several published foliage mass and crown radius regression models were tested on the preparation of the input for the reflectance model of Kuusk and Nilson [Kuusk, A. and Nilson, T. (2000), A directional multispectral forest reflectance model. Remote Sensing of Environment, 72(2):244–252.] for 246 forest growth sample plots in Estonia. In each test, foliage mass and crown radius for trees in the sample plots were predicted with a particular pair of allometric regression models. The forest reflectance model was then run using the estimated foliage mass and crown radius values. Reflectance factors were simulated and compared with the reflectance values obtained from three atmospherically corrected Landsat 7 Enhanced Thematic Mapper (ETM+) scenes. The statistics of linear regression between the simulated and measured reflectance factors were used to assess the performance of foliage and crown radius models. The hypothesis was that the best allometric regression models should provide the best fit in reflectance. The strongest correlation between the simulated and measured reflectance factors was found in the short-wave infrared band (ETM + 5) for all the images. The highest R² = 0.71 was observed in Picea abies dominated stands. No excellent combination of foliage mass and crown radius functions was found, but the ranking based on determination coefficients showed that some linear crown radius models are not applicable to our data. Processing of raster images, reflectance measurement for small sample plots, usage of tree-species-specific fixed parameters (specific leaf area, etc.), and the ignored influence of phenology introduced additional variation into the relationships between simulated and measured reflectance factors. Further studies are needed, but these preliminary results demonstrate that the proposed method could serve as an effective way of testing the performance of foliage mass and canopy cover regressions.