Perfect MV-algebras and their Logic

In this paper, after recounting the basic properties of perfect MV-algebras, we explore the role of such algebras in localization issues. Further, we analyze some logics that are based on Łukasiewicz connectives and are complete with respect to linearly ordered perfect MV-algebras.      

The coevolution theory of the origin of the genetic code

A review of the coevolution theory of the origin of the genetic code is presented. This theory maintains that the origin of the code should be sought in the biosynthetic relationships between amino acids. In particular, some amino acids, the precursors, occupied the structure of the genetic code early on. As the product amino acids developed from these precursors, part or all of the codon domain of the precursor amino acid was ceded to the product amino acids, which resulted in the structuring of the genetic code. This paper therefore reviews the evidence in favour of this theory. The existence of some molecular fossils representing the biosynthetic pathways on which the coevolution theory suggests biosynthetic transformations took place (precursor amino acid → product amino acid) seems to be a strong corroboration of this theory. A generalisation imposed by this theory on the ancestral metabolic state is then discussed and, finally, the main prospects that seem to stem from the coevolution theory are presented.     

具有临界增长的p-双调和方程非平凡解的存在性

本文在有界区域Ω(С)RN中讨论p-双调和方程△(a(x)|△u|p-2△u)=f(x,u)的Dirichlet零边值问题,给出了在一般的临界增长条件下非平凡W2,p O(Ω)解的存在性.     

LocalMV-algebras

In this paper we examine and classify the class of localMV-algebras, pointing out some topological properties of them. Particulary we study theMV-algebras generated by radical: some of these algebras are non-linear generalizations of theMV-algebra C defined by C. C. Chang [4].     

Pre-relaxation Processes in a Radiating Relativistic Sphere

The influence of processes occurring before the system relaxes into diffusion, on the evolution of a radiating sphere, is exhibited in a specific example. The luminosity profiles, and consequently the general evolution of the object, are shown to be quite sensitive to the value of relaxation time.     

First direct measurement of the total cross-section of 12C(α,γ)16O

The total cross-section of ¹²C(α,γ)¹⁶O was measured for the first time by a direct and ungated detection of the ¹⁶O recoils. This measurement in inverse kinematics using the recoil mass separator ERNA in combination with a windowless He gas target allowed to collect data with high precision in the energy range E = 1.9 to 4.9 MeV. The data represent new information for the determination of the astrophysical S(E) factor.     

Nonlinear optical beam propagation and solitons in photorefractive media

Conclusions  The last few years have witnessed a great renewal of interest in the photorefractive effect thanks to the realization of the possibility of propagating stable 2D spatial solitons at very low optical powers in PR crystals. This result, besides possessing a great scientific relevance in itself, associated with the first experimental demonstration of a non-diffracting two-dimensional pencil of light, has also an interesting applicative potential thanks to the guidance properties of the waveguide associated with the soliton, which survives in the dark also after the soliton has been turned off. In this paper, we have tried to present a self-contained approach to the theory of self-trapped nonlinear propagation, which is far from being definitive, together with the most important experimental demonstrations obtained in the last few years. The novelty of the field, and the fact that it is still undergoing a rapid growth, has made our task not an easy one and we apologize to the readers for the many inevitable omissions both in the subjects we have chosen to emphasize and in the references. We cannot conclude this review without mentioning self-trapping of planar optical beams by the use of the PR effect in a semiconductor (InP:Fe) [94, 95], the main advantages over standard PR materials being associated with its sensitivity in the range of the near-infrared wavelengths and faster response time.     

High-performance liquid chromatographic-mass spectrometric assay of busulfan in serum and cerebrospinal fluid.

A liquid chromatographic-mass spectrometric method has been developed to determine busulfan concentrations in the cerebrospinal fluid and serum of some children undergoing bone marrow autotransplantation. After two liquid-liquid extraction steps with dichloromethane on a biological matrix, the separation of busulfan was carried out by isocratic reversed-phase chromatography. The mass spectrometric system was operated in electron-impact mode. Principal ions at m/z 175, 111 and 79 were observed for busulfan, but only m/z 175 was chosen for the quantification of the analyte. The retention time of busulfan was 2.5 min. The detection limit of 100 ng/ml allowed the determination of cerebrospinal fluid and serum busulfan concentrations during the four days of high-dose (1 mg/kg) treatment prior to autotransplantation in five child patients.