Criteria of election of postgraduate courses in graduated students of technological/ humanistic/ artistic professions : Subjective and contextual involvements to arrive at the conclusion of them

El aumento en la cantidad de estudios de posgrado y de sus cursantes derivados de la demanda por mayores credenciales académicas en lo laboral y por la búsqueda personal para especializarse profesionalmente, es un fenómeno observado en Argentina desde mediados de los años 90. Obtener el título final de estos estudios resulta un porcentaje muy inferior en relación al número de sus inscriptos. Tales motivos focalizaron nuestra atención para analizar tanto los criterios de elección del posgrado como las condiciones contextuales y subjetivas para alcanzar la titulación. Este estudio, de tipo cualitativo, investiga en tres carreras de Especialización que se cursan en diferentes Universidades nacionales , los aspectos de su organización y estilo propuesto para cursar y lograr la finalización de los estudios, así como las motivaciones de la elección de cursantes y egresados en tres ramas diferentes: artística, humanística y tecnológica. El conocimiento sobre la lógica de la organización y la particularidad del objeto de estudio de cada carrera permite analizar diferencias y semejanzas entre ellas aportando algunas propuestas para considerar en programas de formación; mientras que los trayectos de cursantes y egresados explican aspectos subjetivos que intervienen en la finalización o no del posgrado.

Geochemistry and mineralogy of garnet grains from ODP Sample 183-1137A-33R-3,50-53

On Elan Bank, a southwestern promontory of the Kerguelen Plateau in the southern Indian Ocean, we cored an interval of conglomerate and minor sandstone within a thick section of Cretaceous flood basalts. Most of the detritus in these sedimentary rocks is volcanic with the exception of a small amount of conspicuous material of probable continental derivation. The anomalous clasts include several pebbles of gneiss (Nicolaysen et al., 2001, doi:10.1130/0091-7613(2001)029<0235:POPGBG>2.0.CO;2) and garnet sand grains. The presence of continental material on the plateau bears significantly on the interpretation of Indian Ocean basalts (Weis et al., 2001, doi:10.1130/0091-7613(2001)029<0147:OOCCII>2.0.CO;2). The purpose of the present study was to determine the composition of the garnets to provide additional constraints on the nature of the source area.

Isotopic composition and lithic grains concentration of sediment core SI90-09

Theories explaining the origin of the abrupt, massive discharges of ice-rafted detritus (IRD) into the glacial North Atlantic (the Heinrich layers (HLs)) generally point to the Laurentide ice sheet as the sole source of these events, until it was found that the IRDs also originated from Icelandic and European ice sheets (Bond and Lotti, 1995, doi:10.1126/science.267.5200.1005; Snoeckx et al., 1999, doi:10.1016/S0025-3227(98)00168-6; Grousset et al., 2000, doi:10.1130/0091-7613(2000)28<123:WTNAHE>2.0.CO;2). This apparent contradiction must be reconciled as it raises fundamental questions about the mechanism(s) of HL origin. We have analyzed two ~12 cm thick HLs in an ultrahigh-resolution mode (1-2 century intervals) in a mid-Atlantic ridge piston core. The d18O record (N. pachyderma left coiling) reveals strong excursions induced by the melting of the icebergs; these excursions are associated with a strong decrease in the amount of planktic foraminafersand with a 3°C cooling of the surface waters. Counts of coarse detrital grains reveal that IRD are deposited according to a typical sequence (1) volcanic glass, (2) quartz and feldspars, (3) detrital carbonate, that implies a chronology in the melting of the differentpan-Atlantic ice sheets. Sr and Nd isotopic composition confirm that in both Heinrich layers H1 and H2, "precursor" IRD came from first Europe/Iceland, followed then by Laurentide-derived IRD. An internal cyclicity can be identified: during H1 and H2, about four to six major, abrupt discharges occurred roughly on a century timescale. The d13C and d15N records reveal that dominant inputs of continent-derived organic matter are associated with IRD within the HLs, hiding the plankton productivity signal.