NMR,optical, and plastic flow experiments in bcc3He —4 He mixture crystals — in pursuit of a vacancy fluid

We describe experiments on the properties of bcc³He —⁴ He solid mixtures on the melting curve between 0.5K and 1.9K. In this paper we focus on effects related to the presence of thermal vacancies. First, we used NMR to image the³He distribution within the solid in equilibrium with the superfluid, as well as its T₁ and t₂. The most surprising result was that above about 1K, vacancy related motion of³He atoms in the solid becomes faster than in the liquid. To check the macroscopic aspects of this motion, we used the vibrating wire technique to look at plastic flow of the bcc solid phase, by moving the wire through the crystal. The temperature dependence of the plastic flow velocity indicates that the vacancy population in the bcc solid behaves like a viscous fluid. The extent to which the vacancy population causes the solid to have liquid like properties is best demonstrated through optical observations of the distillation of³He atoms out of the crystal, which takes place via formation of fluid bubbles within the solid, which then percolate into the liquid, creating a vivid impression of boiling.     

The effect of the ingestion of ethanol on obstruction of the left ventricular outflow tract in hypertrophic cardiomyopathy

BACKGROUND: Ethanol causes vasodilation, which might have an adverse effect, due to increased obstruction of the left ventricular outflow tract, in patients with hypertrophic obstructive cardiomyopathy. We assessed the hemodynamic effects of the ingestion of ethanol, in an amount commonly consumed socially, in patients with hypertrophic cardiomyopathy. METHODS: We performed echocardiography in 36 patients before and several times after the ingestion of either 50 ml of 40 percent ethanol or an isocaloric placebo with the aroma of rum. Each patient received both ethanol and placebo, on different days. The patients, but not the physicians, were blinded to the content of the drink. We measured the sizes of the left atrium and left ventricle, the left-ventricular-wall thickness, blood pressure, heart rate, the degree of systolic anterior motion of the mitral valve, and the pressure gradient across the left ventricular outflow tract. RESULTS: The ingestion of ethanol regulated in a significant drop in the mean (+/- SD) systolic blood pressure (from 130.5 +/- 18.6 to 122.5 +/- 20.3 mm Hg, P<0.001), a significant increase in systolic anterior motion of the mitral valve (from a grade of 2.1 to a grade of 2.5, P<0.001), and a 63 percent increase in the mean gradient across the left ventricular outflow tract (from 38.1 +/- 26.5 to 62.2 +/- 42.4 mm Hg, P<0.001). These changes, which were not associated with symptoms, did not occur after the ingestion of placebo. CONCLUSION: The ingestion of a small amount of ethanol caused an increase in the gradient across the left ventricular outflow tract in patients with hypertrophic obstructive cardiomyopathy, which could have and adverse clinical effect.     

Schizophrenic symptoms, work adjustment, and behavioral family therapy.

Investigated work adjustment among 41 recently exacerbated patients (aged 21–42 yrs) with schizophrenia who were randomly assigned to receive either customary care alone or behavioral family therapy (BFT) and customary care. At baseline, most Ss were unemployed and evidenced poor work adjustment. Negative schizophrenic symptoms were more strongly associated with current work dysfunction than were indices of other psychopathology. At 1 yr, significantly fewer Ss participating in BFT had evidenced psychotic exacerbations. However, vocational adjustment in both groups was still poor, with few benefits of BFT on work functioning noted. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Trapping of two-dimensional electrons in substrate potentials

We report preliminary measurements of high (ripplon-limited) electron mobility on helium films supported by a hydrogen-coated glass substrate. From the smooth dependence of the mobility as a function of helium film thickness we deduce that no polaron transition occurs on films thicker than 500 Å at T>1 K. On poorer quality substrates we observe a rapid drop in the mobility at a substrate-dependent critical film thickness. We interpret these drops as due to localization in variations in the substrate potential.     

Effect of permeabilization on peripheral blood lymphocytes of bovine leukemia virus (BLV)-infected cattle

Cell surface proteins serve as markers for immunophenotypic characterization of lymphocyte subsets by appropriate monoclonal antibodies and fluorescence-activated cell sorter (FACS) analysis. By the same method, internal antigens or those that are only partially expressed on the cell surface can be determined after permeabilization of the cells. Peripheral blood lymphocytes obtained from bovine leukemia virus (BLV)-infected cattle and from BLV-free cattle were permeabilized and several lymphocyte populations were examined. BoCD4, BoCD8 and three CD4 CD8-T-cell subsets retained their original frequencies after permeabilization in both groups of animals. The recognition of the B-B2 lymphocyte molecule was only partially expressed on the cell surface of intact lymphocytes and was further revealed on permeabilization. The frequency of permeabilized, but not intact, cells stained with this mAb was significantly higher for BLV-infected cattle than for BLV-free animals (P = 0.006). Reactivities of an anti-heat shock protein (Hsp) 70 were measured before and after permeabilization of PBLs. Similar increased cell frequencies were obtained for both groups of bovines. These data indicate that flow cytometry studies should be conducted on both permeabilized and intact cells for a better assessment of protein expression on the cell surface, as well as in the cytoplasm.     

Fujisaki–Okamoto hybrid encryption revisited

At Crypto’99, Fujisaki and Okamoto [11] presented a generic transformation from weak secure asymmetric and symmetric schemes into an IND-CCA hybrid encryption scheme in the Random Oracle Model, which has been extensively used in several cryptographic scenarios. The work we present here forms part of the careful revision of the provable security techniques initiated by Shoup in [25] insofar as we find some ambiguities in the proof of this generic conversion, which can lead to false claims. Consequently, the original conversion is modified and the class of asymmetric primitives that can be used is shortened. Furthermore, the concept of easily verifiable primitive is formalized, showing its connection with the gap problems introduced in [18]. Using these ideas, a completely new security proof for the modified transformation is given, which is phrased using currently widely accepted techniques. The reduction thereby obtained turns out to be tight, enhancing the concrete security claimed in the original work for the easily verifiable primitives. For the remaining primitives, the concrete security is improved at the cost of stronger assumptions. Finally, the resistance of the new conversion against reject timing attacks is addressed.     

Optimization of a Priority List Algorithm for 3-D Rendering of Buildings

Architectural scenes usually have some peculiar properties, like parallel surfaces, symmetry, instantiation, easy clustering, etc. These properties can be used by visualization algorithms in order to improve the solution of the hidden surface removal problem. This paper presents some practical implementation policies for the binary space partition algorithm proposed by Fuchs. They take advantage of the characteristics found in architectural scenes. These suggestions help to minimize both the time needed to build the tree and the memory space used. Five optimization techniques are presented and applied to fourteen architectural scenes.     

Predictive value of IGE in the newborn infant

To study the relationship of IgE titles to development of allergy disease in the nursing, it was quantified the levels of this immunoglobulin in blood of the umbilical cord in healthy term eutrofic infants born consecutively in a period of two months. A total of 74 infants were followed for six with monthly appointments. The mean of IgE was 0.08 IU/ml with standard deviation of 0.15. Only two infants developed allergy, this determined a negative predictive value for IgE of 94%. Our outputs agree with that of other authors with respect to high negative predictive value of the low or normal levels of IgE in blood of the umbilical cord and the development of allergy. We concluded that its determination should limit to infants with family antecedent of atopy in order to improve the capacity of prediction of this illness.     

Physically Based Simulation and Rendering of Urban Thermography

Urban thermography is a non-invasive measurement technique commonly used for building diagnosis and energy efficiency evaluation. The physical interpretation of thermal images is a challenging task because they do not necessarily depict the real temperature of the surfaces, but one estimated from the measured incoming radiation. In this sense, the computational rendering of a thermal image can be useful to understand the results captured in a measurement campaign. The computer graphics community has proposed techniques for light rendering that are used for its thermal counterpart. In this work, a physically based simulation methodology based on a combination of the finite element method (FEM) and ray tracing is presented. The proposed methods were tested using a highly detailed urban geometry. Directional emissivity models, glossy reflectivity functions and importance sampling were used to render thermal images. The simulation results were compared with a set of measured thermograms, showing good agreement between them.