Efficient FPGA implementation of a STBC-OFDM combiner for an IEEE 802.16 software radio receiver

In this paper, an efficient FPGA implementation of a 4×4 Space-Time Block Coding (STBC) combiner for MIMO-OFDM software radio receivers is considered. The proposed combiner is based on a low-complexity algorithm which reduces the interference due to the Quasi-Orthogonality of the STBC decoding. In the literature, feedback techniques have been proposed to solve this problem. However, the algorithm introduced in this paper has been conceived in order to avoid the transmission feedback, by estimating the interference factors and removing them. The proposed algorithm exhibits a low computational complexity and complies with the requirements of HW feasibility, considering the execution time/area occupation trade-off.     

Asymptomatic respiratory tract microsporidiosis due to Encephalitozoon hellem in three patients with AIDS

Patients with massive breasts may also suffer from concurrent obesity and preexisting cardiac and respiratory problems, thus presenting significant anesthetic and surgical risk. A modified new technique, evaluated by means of three cases, is described. Preliminary findings show a rapid surgical operating time, little blood loss, acceptable aesthetic appearance, and high patient satisfaction.     

Isolation and identification of Encephalitozoon hellem from an Italian AIDS patient with disseminated microsporidiosis

Microsporidia are primitive mitochondria-lacking spore-forming eukaryotic protozoa that infect a wide variety of animals and also humans. Of the five genera (Encephalitozoon, Enterocytozoon, Septata, Nosema and Pleistophora) that cause infections in humans, Enterocytozoon bieneusi, Septata intestinalis, and Encephalitozoon hellem are being increasingly identified in patients with acquired immunodeficiency syndrome (AIDS). E. bieneusi causes gastrointestinal disease, S. intestinalis causes gastrointestinal and disseminated disease, and E. hellem causes ocular as well as disseminated disease. We have established in continuous culture a strain of microsporidia isolated from the urine and throat washings of an Italian AIDS patient and identified it as Encephalitozoon hellem, based on its ultrastructural morphology, antigenic pattern, and polymerase chain reaction-amplified small subunit ribosomal RNA. We believe that this is the first time that a strain of microsporidia has been isolated from the throat washings of a patient with microsporidiosis.     

Methyl acrylate polymers as suitable materials for the conservation of stone: performance improvements through atom transfer radical polymerization

Acrylic polymers are a suitable category of materials for application in building stone conservation mainly due to their peculiarities (i.e., easy to apply, low cost, good adhesive and cohesive properties, and high solubility in many organic solvents). The performances of polyacrylates have been improved through atom transfer radical polymerization (ATRP). Polymers were obtained with low polydispersity, controlled molecular weight, and showing better stability to UV irradiation than products obtained by radical polymerization. New poly(methyl acrylate-co-perfluoropolyethers) were also prepared via ATRP, using a perfluoropolyether derivative as initiator, showing the possibility of synthesizing copolymers between acrylates and perfluoropolyethers in common solvents. Protective efficiency of poly(methyl acrylate-co-perfluoropolyether) was close to that of commercially available products.     

Contribution to the study of metal contacts on semiconductor real surfaces

The forward characteristics of Au-n type epitaxial Si contacts, measured at different temperatures, are interpreted in terms of a nonsilicon layer between metal and semiconductor, with a contribution of surface states. The proposed model is verified by correlating the I/V characteristics, with the potential barrier height at null bias.     

A finite element approximation of a variational inequality related to hydraulics

In this paper we study the convergence of a finite element approximation for a variational inequality related to hydraulics and we prove, for both linear and quadratic elements, error bounds in terms of the mesh size and a theorem of convergence of the domains This work is based in part on the graduation thesis of G. Sacchi discussed in october 1974 at University of Pavia.     

Study on protein content of rabbit reticulocyte ribosomal subunits: correlation with functional activity

The correlation between chemical composition (protein content) of native and derived ribosomal subunits and their activity in a cell-free system, programmed with haemoglobin messenger RNA, has been investigated. On the basis of isodensity sedimentation of formaldehyde fixed particles in CsC1 and of two-dimensional gel electrophoresis of ribosomal proteins, it appears that the native ribosomal subparticles contain a large protein complement than the derived subparticles and, correspondingly, they are less dependent on an external supply of initiation factors for haemoglobin synthesis in vitro.