Paleolimnological comparison of the Laurentian Great Lakes based on diatoms

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/110008/1/lno19933861311.pd

Biogenic silica and phosphorus accumulation in sediments as indices of eutrophication in the Laurentian Great Lakes

Biogenic silica (BSi), total phosphorus (TP), and biologically available phosphorus (AVP) were measured in short cores from Lake Michigan, Lake Erie, and Lake Ontario. Peaks in BSi concentration and peaks in BSi:TP or BSi:AVP ratios provided stratigraphic signals of water column silica (Si) depletion as a response of increased diatom production to P enrichment and decreased diatom production resulting from silica depletion. By contrast the stratigraphic record of P accumulation provided very weak signals of the historical nutrient enrichment in the water column. These results indicate that system P recycling has a higher rate constant than Si recycling and, as a consequence, that relatively small levels of P enrichment can increase diatom production and sedimentation eventually causing Si depletion and Si-limited diatom production in the water mass.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/42873/1/10750_2004_Article_BF00026648.pd

Variations in Melosira islandica valve morphology in Lake Ontario sediments related to eutrophication and silica depletion

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109796/1/lno19853020414.pd

La Gestión por Procesos y Resultados en la DGR de Misiones

Conocer y ordenar la “Gestión por Resultados” del Organismo, identificando sus modelos: Organizacional, de Procesos, Comunicacional, Flujo de Trabajo y Datos. Introducir el nuevo modelo de gestión en un Portal, transitando etapas de fortalecimiento y mejora en la prestación de Servicios a la Comunidad (Cadena de Valor Público), modelando sus Procesos en el paradigma BPM (Business Process Modeling), construidos y ejecutados en entornos web/móvil: unificados, sencillos y amigables. El usuario interno o externo, hace uso efectivo de las nTIC, minimizando la brecha digital al ser asistido por Tutores, para conformar una verdadera Sociedad del Conocimiento. Las autoridades cuentan con Información para: Control de Gestión, mejora e innovación permanente, toma de decisiones, automatización y proactividad (BP-Roules, reglas gestionadas por Usuarios). Se vuelca la Gestión mediante Procesos Catalogados, conformando “Modelos de Negocios”, identificando buenas prácticas, generando Base de Conocimientos a ser replicada en organizaciones similares, a bajo costo y en pocos meses. Los catálogos permiten ordenar toda la Oferta del Organismo, simplificando navegar y ejecutar tareas bajo diferentes perfiles de Usuarios (menú personalizado). Un único sistema integral e integrado en el Estado, remplazando sistemas y sitios: obsoletos, costosos, desconectados y desactualizados. Utilizando Software e Intercambio de Conocimiento Libre, junto a estándares globales.Sociedad Argentina de Informática e Investigación Operativ

SL para la Gestión por Procesos y Resultados en la DGR de Misiones

Conocer y ordenar la “Gestión por Resultados” del Organismo, identificando sus modelos: Organizacional, de Procesos, Comunicacional, Flujo de Trabajo y Datos. Introducir el nuevo modelo de gestión en un Portal, transitando etapas de fortalecimiento y mejora en la prestación de Servicios a la Comunidad(Cadena de Valor Público), modelando sus Procesos en el paradigma BPM(Business Process Modeling), construidos y ejecutados en entornos web/móvil: unificados, sencillos y amigables. El usuario interno o externo, hace uso efectivo de las nTIC, minimizando la brecha digital al ser asistido por Tutores, para conformar un verdadera Sociedad del Conocimiento. Las autoridades cuentan con Información para: Control de Gestión, mejora e innovación permanente, toma de decisiones, automatización y proactividad(BP-Roules, reglas gestionadas por Usuarios). Se vuelca la Gestión mediante Procesos Catalogados, conformando “Modelos de Negocios”, identificando buenas prácticas, generando Base de Conocimientos a ser replicada en organizaciones similares, a bajo costo y en pocos meses. Los catálogos permiten ordenar toda la Oferta del Organismo, simplificando navegar y ejecutar tareas bajo diferentes perfiles de Usuarios (menú personalizado). Un único sistema integral e integrado en el Estado, remplazando sistemas y sitios: obsoletos, costosos, desconectados y desactualizados. Utilizando Software e Intercambio de Conocimiento Libre, junto a estándares globales.Sociedad Argentina de Informática e Investigación Operativ

A classification-based solution for recommending process parameters of production processes without quality measures

Algorithms and the Foundations of Software technolog

Siliceous microfossil succession in the recent history of Green Bay, Lake Michigan

Quantitative analysis of siliceous microfossils in a 210 Pb dated core from Green Bay of Lake Michigan shows clear evidence of eutrophication, but a different pattern of population succession than observed in the main deposition basins of the Great Lakes. Sediments deposited prior to extensive European settlement ( ca A.D. 1850) contain high relative abundance of chrysophyte cysts and benthic diatoms. Quantity and composition of microfossils deposited during the pre-settlement period represented in our core is quite uniform, except for the 30–32 cm interval which contains elevated microfossil abundance and particularly high levels of attached benthic species. Total microfossil abundance and the proportion of planktonic diatoms begins to increase ca 1860 and rises very rapidly beginning ca 1915. Maximum abundance occurs in sediments deposited during the 1970's, with a secondary peak in the late 1940's — early 1950's. Increased total abundance is accompanied by increased dominance of taxa tolerant of eutrophic conditions, however indigenous oligotrophic taxa, particularly those which are most abundant during the summer, are not eliminated from the flora, as in the lower Great Lakes. It appears that a combination of silica resupply from high riverine loadings and replacement of indigenous populations by periodic intrusions of Lake Michigan water allow sequential co-existence of species usually exclusively associated with either eutrophic or oligotrophic conditions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43092/1/10933_2004_Article_BF00153737.pd

Quantifying measures to limit wind driven resuspension of sediments for improvement of the ecological quality in some shallow Dutch lakes

Although phosphorus loadings are considered the main pressure for most shallow lakes, wind-driven resuspension can cause additional problems for these aquatic ecosystems. We quantified the potential effectiveness of measures to reduce the contribution of resuspended sediments, resulting from wind action, to the overall light attenuation for three comparable shallow peat lakes with poor ecological status in the Netherlands: Loosdrecht, Nieuwkoop, and Reeuwijk (1.8–2.7 m depth, 1.6–2.5 km fetch). These measures are: 1. wave reducing barriers, 2. water level fluctuations, 3. capping of the sediment with sand, and 4. combinations of above. Critical shear stress of the sediments for resuspension (Vcrit), size distribution, and optical properties of the suspended material were quantified in the field (June 2009) and laboratory. Water quality monitoring data (2002–2009) showed that light attenuation by organic suspended matter in all lakes is high. Spatial modeling of the impact of these measures showed that in Lake Loosdrecht limiting wave action can have significant effects (reductions from 6% exceedance to 2% exceedance of Vcrit), whereas in Lake Nieuwkoop and Lake Reeuwijk this is less effective. The depth distribution and shape of Lake Nieuwkoop and Lake Reeuwijk limit the role of wind-driven resuspension in the total suspended matter concentration. Although the lakes are similar in general appearance (origin, size, and depth range) measures suitable to improve their ecological status differ. This calls for care when defining the programme of measures to improve the ecological status of a specific lake based on experience from other lakes.

Wet and dry deposition of phosphorus into Lake Huron

The deposition rates for wet, dry, and integrated fallout of P to the southern portion of Lake Huron were determined. Samples were analyzed for water-soluble, acid (pH =2) soluble, and insoluble (bound) P. The term ‘available P’ was used to indicate the sum of the water- and acid-soluble fractions of P in each type of input. Of the integrated fallout samples, approximately one-third was present as available P. The deposition rate for dry fallout of available P was determined to be 1.7 ng cm −2 day −1 . The wet deposition rate was estimated to be 2.2 ng cm −2 day −1 for available P. Total fallout of available P, determined from shore-based integrated fallout collectors, was calculated to occur at a rate of 6.5 ng cm −2 day −1 . The difference between the wet-plus-dry deposition and the integrated deposition rates has been ascribed to the contamination of integrated fallout collectors by local sources (roads, agricultural activity, etc.) though attempts were made to minimize this problem. The presence of large quantities of biological material (pollen, algae, insect larvae) accounted for a large fraction of the difference observed, especially in the spring months.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/43894/1/11270_2004_Article_BF00464714.pd