Congenital pulmonary lymphangiectasis with chylothorax: a heterogeneous lymphatic vessel abnormality

We describe the generation of a new antipeptide antibody that binds to the centromeric region of human mitotic chromosomes. This antibody was raised against a synthetic peptide corresponding to the 481-493 amino acid sequence of the human CENP-B autoantigen. Immunofluorescence analysis revealed that this anti-CENP-B serum showed an identical pattern to the human CREST anticentromere autoantibody in both mitotic cells and interphase nuclei. Immunoblotting showed that this antibody reacts with the recombinant human CENP-B autoantigen, indicating that it is directed to the 80-kDa centromere polypeptide. We have used this serum to determine, by indirect immunofluorescence, whether CENP-B is conserved in different mammalian species. Surprisingly, the human antipeptide antibody does not react with the centromeric proteins of cultured mouse, hamster, or Indian muntjac cells. Because the CENP-B gene has been cloned in human and mouse, our results suggest that the CENP-B epitope used as an immunogen in this study is not ubiquitous in mammalian cells, and that we have most probably established a monospecific antibody to the human centromere.     

High temperature transport kinetics in heteroepitaxial LaFeO3 thin films

Heteroepitaxial LaFeO₃(1 1 0) thin films with a thickness of 150 nm were grown on LaAlO₃(0 0 1) by reactive sputtering in an inverted cylindrical magnetron geometry. Equilibrium conductivity was measured as a function of partial pressure of oxygen at T=1000 °C, and logσ plotted vs. logP(O₂) showed a minimum in conductivity for P(O₂)=10⁻¹¹ atm and a linear response between 10⁻¹⁰ and 1 atm. This linear response makes thin films of LaFeO₃ a promising material for oxygen sensor applications. We have also measured the time response of the film conductivity upon an abrupt change in the partial pressure of ambient oxygen from 10⁻² to 10⁻³ atm, which was determined at 60 s for T=700 °C and <3.5 s at T=1000 °C.     

Open Wireless Networks on University Campuses

Open wireless networks raise privacy issues and entail increased risk of malicious attacks and illegal downloading activities. Such networks are nonetheless attractive—particularly to universities—because they enhance usability and thus expand access to nonsensitive system resources. At universities, such access brings numerous benefits to students, faculty, and the surrounding community alike. Here, the authors describe the challenges of removing individual user authentication requirements at the perimeter of a university network in which mobile device users access system resources over wireless links to the wired infrastructure. The authors discuss how to mitigate the security and privacy risks entailed in an open network of this sort, and also describe how IT departments can vary the network's degree of openness.     

Non-destructive methods for space charge distribution measurements: what are the differences?

For more than 25 years, various techniques have been introduced for the nondestructive measurement of the space charge distribution in solid dielectrics. All these techniques can be classified into a set of three methods: (i) the thermal method, (ii) the pressure-wave-propagation method and (iii) the electro-acoustic method. Despite their apparent differences they are based on the same physical idea: the perturbation of the equilibrium between electrostatic and elastic forces in the material induces a response, either electrical or mechanical, which can be analyzed. In this paper, we demonstrate that the information on the material contained in the response is identical whatever the method used. As a consequence the differences between methods stand only in the nature of the perturbation and its physical properties.     

Structural studies of pulsed-laser deposited nanocomposite metal-oxide films

Pulsed laser deposition in vacuum has been used to develop metal-oxide nanocomposite films with well controlled structural quality. Results for the copper–aluminium oxide (Cu:Al₂O₃) system are used to illustrate the main morphological and structural features of these films. High resolution transmission electron microscopy (TEM) analysis shows that the films consist of Cu nanocrystals with average dimensions that can be controlled between 2 nm and 10 nm embedded in an amorphous Al₂O₃ matrix. It is observed that the in-plane shape of the nanocrystals evolves from circular to elongated, and the number of nanocrystals per unit area decreases as their size increases. This evolution is explained in terms of nucleation at the substrate surface and coalescence during the later stages of growth. The thermal stability of the films has been studied by in situ TEM annealing and no transformation could be observed up to about 800 °C when partial crystallization of the Al₂O₃ starts.     

A broad chemical and structural characterization of the damaged region of carbon implanted alumina

As candidate materials for future thermonuclear fusion reactors, isolating ceramics will be submitted to high energy gamma and neutron radiation fluxes together with an intense particle flux. Amorphization cannot be tolerated in ceramics for fusion applications, due to the associated volume change and the deterioration of mechanical properties. Therefore, a comprehensive study was carried out to examine the effects of carbon beam irradiation on polycrystalline aluminium oxide (Al₂O₃), a ceramic component of some diagnostic and plasma heating systems. Complementary techniques have allowed a complete chemical and structural surface analysis of the implanted alumina. Implantation with 75 keV, mono-energetic carbon ions at doses of 1 × 10¹⁷ and 5 × 10¹⁷ ions/cm² was performed on polished and thermally treated ceramic discs. The alumina targets were kept below 120 °C. The structural modifications induced during ion irradiation were studied by the GXRD and TEM techniques. Under these conditions, alumina is readily amorphized by carbon ions, the thickness of the ion-beam induced disordered area increasing with the ion dose. Matrix elements and ion implanted profiles were followed as a function of depth by using ToF-SIMS, indicating the maximum concentration of implanted ions to be in the deeper half of the amorphous region. Ion distribution and chemical modifications caused in the Al₂O₃ substrate by carbon irradiation were corroborated with XPS. The amount of oxygen in the vicinity of the implanted alumina surface was reduced, suggesting that this element was selectively sputtered during carbon irradiation. The intensity of those peaks referring to Al–O bonds diminishes, while contributions of reduced aluminium and metal carbides are found at the maximum of the carbon distribution. TEM observations on low temperature thermally annealed specimens indicate partial recovery of the initial crystalline structure.     

Challenges in Securing Networked J2ME Applications

An increasing number of smart phones support Java 2, Micro Edition. Mobile application developers must deal with J2ME's inherent security weaknesses as well as bugs in implementations on real devices. The new Security and Trust Services API for J2ME addresses some of these challenges, although it too has shortcomings     

The yield of cultures of Sitophilus granarius at 25°C and 70 per cent relative humidity with some observations on rates of oviposition and development

Routine cultures of the granary weevil Sitophilus granarius (L.), set up with 160 young weevils on 320 g of wheat for 3 wk and kept at 25°C and 70 per cent r.h. yield on average 3500–4000 adult weevils by the time the culture is 10 wk old. The chief causes of variability in yield appear to be the age and sex ratio of the parents and minor fluctuations of the environment of the breeding room. The system of culturing used appears to be the best possible for although the number of eggs per beetle is increased if fewer are placed on the wheat the culture yield is less and the variability greater.

In two experiments in which 100 adult weevils were put on 100 g samples of wheat for periods of 1 to 4 days and then moved to a fresh sample of wheat, the oviposition rate was at its highest and most constant over the age range 10–30 days, after which it fell steadily. This is therefore the best age range of adults to use for routine culturing. The yield of cultures declined as the adults aged. Increased culture yield accelerated the rate of development of the weevils, probably by raising culture temperature, and hence, variation of yield is likely to influence the stage composition of cultures of a known age. The age of the parents laying the eggs appeared to influence the developmental period of offspring, but this was not established. If there is such an influence it is not consistent.     

Impact of heat load location and strength on air flow pattern with a passive chilled beam system

A passive chilled beam is a source of natural convection, creating a flow of cold air directly into the occupied zone. Experiments were conducted in a mock-up of an office room to study the air velocities in the occupied spaces. In addition, velocity profiles are registered when underneath heat loads exist and the cool and warm air flows interact. Experimental laboratory study revealed that in the case of the underneath heat gains, even no upward plume was generated and the dummy only acted as a flow obstacle, having a significant effect on the velocity profile. Furthermore, in an actual occupied office environment, the thermal plumes and the supply air diffuser mixed effectively the whole air volume. The maximum air velocity measured was still below 0.25 m/s with the extremely high heat gain of 164 W/m². The results demonstrate that analysis methods were the interaction of convection flow and jet are not taken into account could not accurately describe air movement and draught risk in the occupied room space.     

Effect of the target surface temperature on the distribution of nanoparticles formed by ion implantation

Metal-nanoparticle-containing composite layers were synthesized by implantation of 60 keV Ag⁺ ions into a soda-lime silicate glass to a dose of 3×10¹⁶ ion/cm² at an ion beam current density of 3 μA/cm² and a substrate temperature of 35°C. The results of implantation depend on the temperature effects developed in the glass targets of various thicknesses. Data on the silver distribution profile and the nucleation and growth of metal nanoparticles in depth of the implanted layers were obtained from the optical reflection spectra. It is demonstrated that even small variations in the surface temperature of the ion-bombarded glass substrate lead to significant changes in the conditions of nanoparticle formation in the sample.