Neutrino Masses: Shedding Light on Unification and Our Origin

In the first part of the talk, three key ideas proposed in the 1970s, and in particular their combined role in providing an understanding of the neutrino-masses as well as of the baryon-asymmetry of the universe, are expounded. The ideas in question include: (i) The symmetry SU(4)-color, which introduces the right-handed neutrino as an essential member of each family and also provides (rather reliably) the Dirac mass of the tau-neutrino by relating it to the top quark mass; (ii) SUSY grand unification together with the scale of the meeting of the three gauge couplings, which provides the scale for the superheavy Majorana masses of the RH neutrinos; and (iii) the seesaw mechanism, which combines the Dirac and the superheavy Majorana masses of the neutrinos obtained as above to yield naturally light LH neutrinos and in particular the right magnitude for m(nu-tau). In the second part, an attempt is made, based in part on recent works, to show how a set of diverse phenomena including (a) fermion masses, (b) neutrino oscillations, (c) CP and flavor violations, and (d) baryogenesis via leptogenesis can fit together neatly within a single predictive framework based on an effective symmetry group G(224) = SU(2)_L x SU(2)_R x SU(4)-color or SO(10), possessing supersymmetry. CP and flavor violations arising within this framework include enhanced rates (often close to observed limits) for mu -> e + gamma and tau -> mu + gamma and also measurable electric dipole moments of the neutron and the electron. Expectations arising within the same framework for proton decay are summarized at the end. It is stressed that the two notable missing pieces of this framework, which is otherwise so successful, are supersymmetry and proton decay.Comment: An interesting remark by C. N. Yang on his long-held belief in massless neutrinos is added. Some new references on string-derivation of the G(224) symmetry are cited, and some typographical corrections are mad

N-oxygenation of amino compounds: early stages in its application to the biocatalyzed preparation of bioactive compounds

Among the compounds that contain unusual functional groups, nitro is perhaps one of the most interesting due to the valuable properties it confers on pharmaceuticals and explosives. Traditional chemistry has for many years used environmentally unfriendly strategies; in contrast, the biocatalyzed production of this type of products offers a promising alternative. The small family of enzymes formed by N-oxygenases allows the conversion of an amino group to a nitro through the sequential addition of oxygen. These enzymes also make it possible to obtain other less oxidized N-O functions, such as hydroxylamine or nitroso, present in intermediate or final products. The current substrates on which these enzymes are reported to work encompass a few aromatic molecules and sugars. The unique characteristics of N-oxygenases and the great economic value of the products that they could generate, place them in a position of very high scientific and industrial interest. The most important and best studied N-oxygenases will be presented here.Fil: Nóbile, Matías Leonardo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Stricker, Abigail M.. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Marchesano, Lucas. Universidad Nacional de Quilmes. Departamento de Ciencia y Tecnología; ArgentinaFil: Iribarren, Adolfo Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; ArgentinaFil: Lewkowicz, Elizabeth Sandra. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigación en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres". Grupo Vinculado al INGEBI- Laboratorio de Biocatálisis y Biotransformaciones - LBB - UNQUI; Argentin