A simple and versatile Sol-Gel method for the synthesis of functional nanocrystalline oxides

MxOy nanometric powders (Nb2O5, In2O3, and ZrO2) have been efficiently synthesized at low temperatures with the use of simple precursors and with no acid or base catalysis or stabilizing agents. The powders have been characterized by Thermogravimetry/Differential Thermal Analysis, X-ray diffraction, and scanning electron microscopy. The oxides obtained have well-defined crystalline structures, exhibit homogeneity, and crystallite sizes ranging from 9 to 16 nm in diameter.     

Simulation of the biomechanical behavior of the skin in virtual surgical applications by finite element method

The objective of this study was to develop a software application that is able to support plastic surgeons interested in applying simulations and soft tissue modeling during presurgical planning activities. By using our user-friendly interface and force-displacement graphs, users can analyze scalp skin behaviors when subjected to stress. Users can 1) determine the dynamic of a general point of scalp skin after the application of a specific force, 2) predict the force needed for displacement of a point, and 3) study the deformation of all the points of the entire scalp based on the force applied. Results showed how users are able to manipulate and analyze mechanical behaviors on a mechanical model rather than on a pure geometric qualitative physiological model. The entire application was developed on a Silicon Graphics workstation.     

On the angular-spectrum representation of multipole wave fields

The closed-form expression of the angular spectrum of multipole fields, both scalar and vectorial, of any order and degree, evaluated across a plane orthogonal to an arbitrary (fixed) direction, is provided. Such a result has been obtained by starting from the Weyl representation of multipole fields and using suitable transformation rules. Moreover, as far as the vectorial case is concerned, knowledge of the (vectorial) transverse angular spectrum allows one to gain some insight into the polarization structure of the multipole fields evaluated across a typical plane. Such information could be useful, for instance, in those problems dealing with the interaction between planar partially reflecting surfaces and waves.     

Intracellular calcium and protein tyrosine phosphorylation during the release of bovine sperm adhering to the fallopian tube epithelium in vitro

In mammals, sperm adhesion to the epithelial cells lining the oviductal isthmus plays a key role in the maintenance of motility and in the selection of superior quality subpopulations. In the bovine species, heparin and other sulfated glycoconjugates powerfully induce the synchronous release of sperm adhering to tubal epithelium in vitro and may represent the signal which triggers release at ovulation in vivo. Sperm detachment may be due either to surface remodeling or to hyperactivation brought about by capacitation. In this paper, the dynamics of intracellular free Ca2+concentration ([Ca2+]i) and protein tyrosine phosphorylation in sperm during and after heparin-induced release from in vitro cultured oviductal monolayers were assessed to determine whether this event is due to capacitation. Moreover, Ca2+-ionophore A23187, thapsigargin, thimerosal and caffeine were used to determine whether [Ca2+]i increase and/or hyperactivation can induce sperm release. Results showed that: 1. heparin-released sperm have significantly higher [Ca2+]i than adhering sperm; 2. heparin induces a [Ca2+]i elevation in the sperm head followed by detachment from the monolayers; 3. external Ca2+is not required for heparin-induced release; 4. [Ca2+]i increase and/or hyperactivation are unable to release sperm; and 5. heparin-released sperm have an increased level of tyrosine phosphorylated proteins compared with adhering sperm. In conclusion, although heparin is considered a long-lasting capacitation agent, it quickly modulates the capacitation of bovine sperm adhering to the fallopian epithelium, probably leading to surface remodeling and therefore to the release of sperm selected and stored within the oviduct through adhesion.     

Coherent-mode decomposition of partially polarized,partially coherent sources

It is shown that any partially polarized, partially coherent source can be expressed in terms of a suitable superposition of transverse coherent modes with orthogonal polarization states. Such modes are determined through the solution of a system of two coupled integral equations. An example, for which the modal decomposition is obtained in closed form in terms of fully linearly polarized Hermite Gaussian modes, is given.     

Incremental adaptive equalizers using ternary +1, 0, −1 tap coefficients and/or delta modulation input encoding

In this paper a new approach to fractionally-spaced adaptive equalization is presented, which uses for the input and/’or the impulse response of the filter a delta modulation — type incremental encoding with a substantially reduced number of bits (binary + 1, ? 1 or ternary + 1, 0, ? 1 representation). When the oversampling factor is of the order of few tens, performance of these equalizers is comparable to that of the corresponding non-incremental equalizers with oversampling factor of few units. This approach to adaptive equalization appears promising for implementation simplicity in both filtering and control algorithms.     

Local orthogonal bases II: Window design

In the first part of this work we presented a technique to find a local orthogonal basis for a given vector space. The concept of a local orthogonal basis can be seen as an extension of the one-dimensional local cosine basis used, for example, in audio processing. Here the problem of window design is discussed, with a particular emphasis on the two-dimensional case, both in continuous and discrete time.     

A modified look-up table for implicit disambiguation of Marching Cubes

A new triangulation scheme for the Marching Cubes algorithm is proposed. The scheme allows the extraction of continuous isosurfaces from volumetric data without the need to use disamgiguation techniques.     

Effectiveness and limits of magnetic resonance techniques in the identification of different coordination pathways of the Mn(II) in the presence of biomacromolecules

Summary Magnetic resonance techniques yield important information on different coordination behaviour of Mn(II) in the presence of biomacromolecules. A preliminary study on model systems is necessary to have a deeper insight on dynamics and structural aspects.The EPR technique is not able to identify a binding interaction between Trp and manganous ion when the metal is bonded to the Imidazole. Proton shift NMR studies on the Mn(II)-5ATP-Imid complex evidenziate a ternary system formation and a stacking interaction between the imidazole-ring and the nucleotide purine-moiety.An EPR and NMR combined analysis on the Mn(II)-5ATP-Trp system points out a stacking interaction and the simultaneous presence of a covalent binding between the metal ion and the biomolecules. The role of the metal ion to favour this coordination is suggested.Presented at the 22nd Microsymposium, Characterization of Structure and Dynamics of Macromolecular Systems by NMR Methods, Prague, July 20–23, 1981     

Enterprise modeling and Data Warehousing in Telecom Italia

We present a methodology for Data Warehouse design and its application within the Telecom Italia information system. The methodology is based on a conceptual representation of the Enterprise, which is exploited both in the integration phase of the Warehouse information sources and during the knowledge discovery activity on the information stored in the Warehouse. The application of the methodology in the Telecom Italia framework has been supported by prototype software tools both for conceptual modeling and for data integration and reconciliation.