Estimation of the total uncertainty of sky-radiance measurements in field experimental conditions: implications for the aerosol single-scattering albedo

We compare the spectral sky radiance measured by three ground-based optical radiometers during the second Aerosol Characterization Experiment (ACE-2) to estimate the total uncertainty of the radiance in field experimental conditions. The propagation of this uncertainty on the column-integrated aerosol single-scattering albedo omega0 at 868 nm is investigated. The radiance measurements are affected by a systematic gain uncertainty of less than 2% in the visible spectral region and within 6% in the near-IR region. Correcting the measured radiance by a systematic uncertainty reduces the dispersion of the omega0 from 0.07 to 0.03. Besides, the total relative uncertainty of the radiance measurements in field experimental conditions is within 4% at any wavelength. The corresponding uncertainty delta omega0 is 4% for an aerosol optical thickness of 0.2.     

BMP regulates vegetal pole induction centres in early xenopus development

BACKGROUND: Bone morphogenetic protein (BMP) plays an important role in mesoderm patterning in Xenopus. The ectopic expression of BMP-4 protein hyperventralizes embryos, whereas embryos expressing a BMP-2/4 dominant-negative receptor (DNR) are hyperdorsalized. Mesoderm is initially induced in the marginal zone by cells in the underlying vegetal pole. While much is known about BMP's expression and role in patterning the marginal zone, little is known about its early role in regulating vegetal mesoderm induction centre formation. RESULTS: The role of BMP in regulating formation of vegetal mesoderm inducing centres during early Xenopus development was examined. Ectopic BMP-4 expression in vegetal pole cells inhibited dorsal mesoderm induction but increased ventral mesoderm induction when recombined with animal cap ectoderm in Nieuwkoop explants. 32-cell embryos injected with BMP-4 RNA in the most vegetal blastomere tier were not hyperdorsalized by LiCl treatment. The ectopic expression of Smad or Mix.1 proteins in the vegetal pole also inhibited dorsal mesoderm induction in explants and embryos. Expression of the BMP 2/4 DNR in the vegetal pole increased dorsal mesoderm induction and inhibited ventral mesoderm induction in explants and embryos. CONCLUSIONS: These results support a role for BMP signalling in regulating ventral vegetal and dorsal vegetal mesoderm induction centre formation during early Xenopus development.     

Circumferential pharyngolaryngectomy with total esophagectomy for locally advanced carcinomas

In 1996, 20 of 21 patients with mucosal leishmaniasis, treated in 1994 with aminosidine sulfate, 16mg/kg/day salt, by intramuscular injection for 20 days, were clinically evaluated. One patient died due to disease not related to mucosal leishmaniasis. Seven of 14 patients (66.7% N = 21) who achieved complete remission three months after treatment remained clinically cured 24 months later and seven relapsed in the same period (50% N = 14). Sorological follow-up showed poor correlation with the results of clinical examination.     

On Barenblatt's problem

The problem of flow in media with double porosity (e.g. fissured rocks) is considered by utilizing the author's concept of “multiporosity” and employing the apparatus of continuum theory of mixtures. Relevant results obtained by Barenblatt et al. within the Russian literature are shown to be contained in the present theory.     

Inverted-annular film boiling heat transfer from vertical surfaces

A theoretical model is developed which allows a consistent treatment of the wall heat flux in an inverted-annular film boiling regime. The model is based on an analytical solution of the energy conservation equations in the vapor and liquid regions downstream of the quench front. A constant vapor film thickness is assumed, which depends on the fluid equilibrium quality at the quench front. Good agreement is obtained in comparing the model with quasi-steady state experimental results.     

Investigations of the deposition of lead-bearing aerosols on the surfaces of vegetation

SEM and X-ray microprobe analysis were combined with clean lab technology atomic absorption spectroscopy to observe the deposition of aerosols on undisturbed pine needle surfaces, to obtain physical and chemical information from the observed particles and to chemically remove these particles for analysis. Comparisons were made among sites with traffic densities of 100, 1000, 10000 cars per day. Correlations were made with periods of heavy rainfall. The results show that the particle size distribution, shape and surface chemistry are possibly characteristic of automotive exhausts, that both the chemical washing procedure and rainfall efficiently remove most particles from the surface, including those bearing lead, and that the rate of deposition is constant between rainfalls and partly a function of traffic density. Deposition rates of 0.3 ng Pb cm^?2 day^?1 were observed at 100 cars per day, 2–3 ng Pb cm^?2 day^?1 for 1000 and 10000 cars per day.     

Electrodeposition of ZnO nanowires with controlled dimensions for photovoltaic applications: Role of buffer layer

The role of a ZnO buffer layer on the electrodeposition of ZnO nanowire arrays was analyzed. ZnO buffer layers were deposited on conducting glass substrates by spray pyrolysis and electrodeposition. The electrodeposited ZnO buffer layer resulted in a collection of open-packed small grains (∼ 20 nm), while the sprayed layers were comprised of close-packed grains with size in the range of 15-100 nm. The ZnO nanowire arrays electrodeposited on ZnO buffer layers exhibited increased nanowire density (by factors of 6× and 3×, for electrodeposited and sprayed buffer layers, respectively) compared to arrays deposited directly on naked substrates, demonstrating that ZnO nanocrystalline layers can be used to increase nucleation sites for nanowire growth. On the other hand, nanowire diameters were tailored from 45 to 160 nm as a function of the size of the grains in the buffer layer. The influence of crystallographic orientation of the buffer layer was also analyzed.     

An Object Oriented Architectural Library for the Design and Implementation of Network Protocols

The society of telecommunication and computer networks encompasses a wide variety of organizations, forums and industry companies that specify, standardize, evaluate, implement and deploy network infrastructures. These infrastructures are well defined and deployed in order to offer high quality end-user services and meet the need for interconnectivity, expandability and upgradeability. What users see and experience is the tip of the iceberg. Great amount of time and money is spent in specification, standardization, design, debugging, testing (both conformance and stress) and finally evaluating network components or subsystems before the deployment takes place. The framework, proposed in the current paper and implemented in open source software library, provides an object oriented methodology for the implementation of network protocols and the software realization of network components. The method is formed in respect to: (a) operating system architecture (b) network architecture and (c) Object Oriented (OO) methodology.     

A method for minimising of low frequency and unwrapping artefacts from interferometric calculations

On 7 September 1999 a magnitude M_W = 5.9 earthquake occurred in the Athens area of Greece producing a subsidence of 6–7 cm detected by radar interferometry. This study introduces a processing technique, which produces a clear deformation pattern of the earthquake, mostly released from artefacts due to orbital effects, unwrapping cycle slipping errors and atmospherics disturbances. A set of 17 ERS‐1 and ERS‐2 SAR images acquired between December 1997 and January 2001 has been used. The contribution of each artefact to the interferograms was calculated, both in the frequency and spatial domains.