Investigar con estudio de caso la dirección escolar. Un libro escrito por Rosa Vázquez Recio : Reseña de: Rosa Vázquez Recio (2011). Investigar la dirección escolar con estudio de caso: relato de una experiencia. Archidona: Aljibe, 128 pp.

Reseña sobre el libro Investigar con estudio de caso la dirección escolar escrito por Rosa Vázquez Recio, doctora y profesora titular de Didáctica y Organización escolar de la Universidad de Cádiz, sobre la realización de un estudio de caso acerca de la dirección escolar. La autora comparte sus temores y progresos, los dilemas y aciertos durante la realización de este estudio de caso a pie de escuela. Conocer su experiencia a través de este libro puede ayudar a quienes se inician en la tarea de la realización de estudios de caso o investigación sobre la dirección escolar así como a investigadores e investigadoras en general.

Diana Bellesi, El jardín. Rosario, Bajo la luna nueva, 1994, 2da. Ed., 128 páginas

Fil: Mallol, Anahí Diana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Mössbauer characterisation of sediments from ODP Sites 128-798 and 128-799

57Fe Mössbauer spectra for 26 sediment and 6 carbonate concretion samples from Sites 798 and 799 were recorded at 293 K. Most spectra were deconvolved to two quadrupole doublets without magnetic hyperfine structure. Typical Mössbauer parameters were: isomer shift (I.S.) = 0.34 mm/s and quadrupole splitting (Q.S.) = 0.64 mm/s for the paramagnetic Fe3+ component (partly, pyrite); I.S. = 1.13 mm/s and Q.S. = 2.64 mm/s for the high-spin Fe2+ component derived from iron-bearing aluminosilicates. A few spectra included other high-spin Fe2+ components ascribed to iron-bearing carbonate minerals (e.g., ferroan magnesite), according to the Mössbauer parameters for Fe2+ in the carbonate concretions. We present the distribution of iron among different chemical forms as a function of depth. These data might indicate changes of depositional and diagenetic conditions.

Diana Bellesi, El jardín. Rosario, Bajo la luna nueva, 1994, 2da. Ed., 128 páginas

Fil: Mallol, Anahí Diana. Universidad Nacional de La Plata. Facultad de Humanidades y Ciencias de la Educación; Argentina.

Investigar con estudio de caso la dirección escolar. Un libro escrito por Rosa Vázquez Recio : Reseña de: Rosa Vázquez Recio (2011). Investigar la dirección escolar con estudio de caso: relato de una experiencia. Archidona: Aljibe, 128 pp.

Reseña sobre el libro Investigar con estudio de caso la dirección escolar escrito por Rosa Vázquez Recio, doctora y profesora titular de Didáctica y Organización escolar de la Universidad de Cádiz, sobre la realización de un estudio de caso acerca de la dirección escolar. La autora comparte sus temores y progresos, los dilemas y aciertos durante la realización de este estudio de caso a pie de escuela. Conocer su experiencia a través de este libro puede ayudar a quienes se inician en la tarea de la realización de estudios de caso o investigación sobre la dirección escolar así como a investigadores e investigadoras en general.

Investigar con estudio de caso la dirección escolar. Un libro escrito por Rosa Vázquez Recio : Reseña de: Rosa Vázquez Recio (2011). Investigar la dirección escolar con estudio de caso: relato de una experiencia. Archidona: Aljibe, 128 pp.

Reseña sobre el libro Investigar con estudio de caso la dirección escolar escrito por Rosa Vázquez Recio, doctora y profesora titular de Didáctica y Organización escolar de la Universidad de Cádiz, sobre la realización de un estudio de caso acerca de la dirección escolar. La autora comparte sus temores y progresos, los dilemas y aciertos durante la realización de este estudio de caso a pie de escuela. Conocer su experiencia a través de este libro puede ayudar a quienes se inician en la tarea de la realización de estudios de caso o investigación sobre la dirección escolar así como a investigadores e investigadoras en general.

Geochemistry of ODP Sites 128-798 and 128-799 sediments

Nineteen trace elements, including seven rare earth elements (REE's), and 10 major and minor elements in 76 sediment samples from Sites 798 (Oki Ridge) and 799 (Yamato Trough) were determined by means of instrumental neutron activation analysis and X-ray fluorescence spectrometry. Most REE patterns (chondrite-normalized) of the sediments from both sites were nearly identical to the patterns of terrigenous materials. The cerium anomaly (slightly positive) frequently appeared in REE patterns of the sediments (200-750 mbsf) from Site 799. Cerium may be selectively incorporated into the sediments with hydrogenous manganese precipitation. However, the degree of the anomaly was not well correlated with manganese content, suggesting that cerium may behave as a trivalent REE (like the other REE's) during diagenesis while manganese is transported in the sediment column accompanied by reduction to a lower oxidation state. The Th/Sc ratio of the sediments from Sites 798 and 799 tended to decrease with penetration depth. Such a depth profile may indicate a decrease in basic volcanism activities from the Pliocene (Site 798) and Miocene (Site 799). The La/Yb ratio and degree of europium anomaly also varied with depth, which may imply that two or more components with different REE patterns were supplied throughout sedimentation at sites in the Japan Sea.

Geochemistry of ODP Leg 127 igneous rocks

Legs 127 and 128 of the Ocean Drilling Program cored basement samples from two sites in the Yamato Basin (Sites 794 and 797) and one site in the Japan Basin (Site 795) of the Japan Sea. These samples represent sills and lava flows erupted or shallowly intruded in a marine environment during backarc extension and spreading in the middle Miocene. In this paper, we describe the geochemical characteristics of these igneous units using 52 new instrumental neutron activation analyses (INAA), 8 new X-ray fluorescence (XRF) analyses, and previous shipboard XRF analyses. The sills intruded into soft sediment at Sites 794 and 797 were subject to extensive hydrothermal activity, estimated at <230° C under subgreenschist facies conditions, which heavily to totally altered the fine-grained unit margins and moderately to heavily altered the coarse-grained unit interiors. Diagenesis further altered the composition of these igneous bodies and lava flows at Sites 794, 795, and 797, most intensely at unit margins. Our study of two well-sampled units shows that Mg, Ca, Sr, and the large-ion lithophile elements (LILE) mobilized during alteration, and that the concentrations of Y, Yb, and Lu decreased and Ce increased in the most severely altered samples. Nevertheless, our study shows that the rare-earth elements (REE) were relatively immobile in the majority of the samples, even where secondary mixed-layer clays comprised the great majority of the rock. Fresher Yamato Basin samples are compositionally heterogenous tholeiitic basalts and dolerites. At Site 794 in the north-central portion of the basin, Units 1 to 5 (upper basement) comprise mildly light rare-earth element (LREE) enriched basalts and dolerites (chondrite-normalized La/Sm of 1.4-1.8), while the stratigraphically lower Units 6 to 9 are less enriched dolerites with (La/Sm)N of 0.7-1.3. All Site 794 samples lack Nb and Ta depletions and LILE enrichments, lacking a strong subduction-related incompatible element geochemical signature. At Site 797 in the western margin of the basin, two stratigraphically-definable unit groups also occur. The upper nine units are incompatible-element depleted tholeiitic sills and flows with strong depletions of Nb and Ta relative to normal mid-ocean ridge basalt (N-MORB). The lower twelve sills represent LREE-enriched tholeiites (normalized La/Sm ranges from 1.1 to 1.8), with distinctly higher LILE and high field-strength element (HFSE) contents. At Site 795 at the northern margin of the Japan Sea, three eruptive units consist of basaltic andesite to calc-alkaline basalt (normalized La/Sm of 1.1 to 1.5) containing moderate depletions of the HFSE relative to N-MORB. The LILE-depleted nature of these samples precludes their origin in a continental arc, indicating that they more likely erupted within a rifting oceanic arc system. The heterogenous nature of the Japan Sea rocks indicate that they were derived at each site from multiple parental magmas generated from a compositionally heterogenous mantle source. Their chemistry is intermediate in character between arc basalts, MORB, and intraplate basalts, and implies little involvement of continental crust at any point in their genesis. Their flat chondrite-normalized, medium-to-heavy rare earth patterns indicate that the primary magmas which produced them last equilibrated with and segregated from spinel lherzolite at shallow depths (<30 kbar). In strong contrast to their isotopic compositional arrays, subduction-related geochemical signatures are usually poorly defined. No basin-wide temporal or geographic systematics of rock chemistry may be confidently detailed; instead, the data show both intimate (site-specific) and widespread backarc mantle heterogeneity over a narrow (2 Ma or so) range in time, with mantle heterogeneity most closely resembling a "plum-pudding" model.