Some hydrophysical and hydrochemical parameters of the upper part of the hydrogen sulfide zone in the Black Sea, September 11-22, 1994

Features of spatial variability of hydrogen sulfide in the northeastern part of the Black Sea are estimated. Some technical aspects of H2S concentration determination in the anoxic zone are discussed: in its upper part at H2S concentration <30 µmol/l, the photometric method is recommended, while for deeper layers the iodometric method should be used. With linearity of vertical distribution of hydrogen sulfide and ammonium taken into account their vertical gradients are estimated as 0.49+/-0.04 µmol/m and 0.19+/-0.06 µmol/m respectively. It is shown that the upper boundary of the H2S layer corresponds to the isopycnal surface with Sigma_t = 16.19+/-0.05 arbitrary units. Special attention is paid to relationship of hydrogen sulfide distribution with hydrophysical features in the region under study, in particular in the coastal zone. It is shown that hydrodynamic conditions control spatial distribution of hydrogen sulfide. On the basis of isopycnal treatment of the H2S field existence of a coastal convergence zone is proved, and peculiarities are recognized of vertical circulation in the main Black Sea gyre and coastal anticyclonic eddies; here hydrogen sulfide serves as a tracer of hydrophysical mixing processes.

La función de la lectura y del bibliotecario en las bibliotecas hospitalarias especializadas en la atención de niños

El presente trabajo estudia la función terapéutica del libro y el rol que cumplen los bibliotecarios y voluntarios que desempeñan tareas en las bibliotecas para pacientes que se especializan en la atención de niños. Las instituciones que se analizaron fueron la biblioteca ambulante del Hospital de Niños "Sor María Ludovica" y la del Hospital Zonal "Noel Sbarra" (Ex Casa Cuna). En ambos lugares se intentó determinar qué actividades relacionadas con la lectura y qué criterios de selección usan los bibliotecarios y voluntarios al momento de realizar las actividades con los libros. Para este trabajo de tipo exploratorio ? descriptivo se aplicaron tres métodos de investigación: la entrevista en profundidad con los responsables de las instituciones, el estudio de caso en los dos hospitales y, por último, la comparación entre las dos instituciones de la ciudad de La Plata, y la Asociación PAANET de la ciudad de Mar del Plata, la cual utiliza el libro y la lectura como una herramienta para mejorar la calidad de vida de niños enfermos de cáncer. Una vez culminadas las entrevistas y realizados los estudios correspondientes, se procedió al análisis de los datos recogidos, los cuales brindan la información relacionada con las actividades y la labor de los profesionales que trabajan en las bibliotecas para pacientes. Finalmente, se realizó la comparación con la Asociación de Mar del Plata, para determinar las diferencias y similitudes entre las instituciones. Este trabajo pretende que se conozca la función del libro y la labor que desarrollan a diario los bibliotecarios y voluntarios de las bibliotecas para pacientes que trabajan para una mejor calidad de vida de los niños hospitalizados

Geochemical provenance analysis of fine-grained sediment of sediment core AND1-1

Bulk chemical fine-grained sediment compositions from southern Victoria Land glacimarine sediments provide significant constraints on the reconstruction of sediment provenance models in the McMurdo Sound during Late Cenozoic time. High-resolution (~ 1 ka) geochemical data were obtained with a non-destructive AVAATECH XRF Core Scanner (XRF-CS) on the 1285 m long ANDRILL McMurdo Ice Shelf Project (MIS) sediment core AND-1B. This data set is complemented by high-precision chemical analyses (XRF and ICP-OES) on discrete samples. Statistical analyses reveal three geochemical facies which are interpreted to represent the following sources for the sediments recovered in the AND-1B core: 1) local McMurdo Volcanic Group (MVG) rocks, 2) Transantarctic Mountain rocks west of Ross Island (W TAM), and 3) Transantarctic Mountain rocks from more southerly areas (S TAM). Data indicate in combination with other sediment facies analyses (McKay et al., 2009, doi:10.1130/B26540.1) and provenance scenarios (Talarico and Sandroni, 2009, doi:10.1016/j.gloplacha.2009.04.007) that diamictites at the drill site are largely dominated by local sources (MVG) and are interpreted to indicate cold polar conditions with dry-based ice. MVG is interpreted to indicate cold polar condition with dry-based ice. A mixture of MVG and W TAM is interpreted to represent polar conditions and the S TAM facies is interpreted to represent open-marine conditions. Down-core variations in geochemical facies in the AND-1B core are interpreted to represent five major paleoclimate phases over the past 14 Ma. Cold polar conditions with major MVG influence occur below 1045 mbsf and above 120 mbsf. A section of warmer climate conditions with extensive peaks of S TAM influence characterizes the rest of the core, which is interrupted by a section from 525 to 855 mbsf of alternating influences of MVG and W TAM.