Effects of trichlorobenzene on natural phytoplankton populations

Natural phytoplankton assemblages from an offshore station in Lake Michigan were exposed to individual isomers of trichlorobenzene (TCB) and incubated in situ for a 24 h period. One set of exposures was initiated with a lake assemblage collected at 0330 h from 30 m and the TCB isomers added at 0400 h. The second exposure experiment was initiated with an assemblage from 30 m collected at 1530 h and the TCB isomers added at 1600 h.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/44445/1/10646_2004_Article_BF00368534.pd

REJUVENATION OF MELOSIRA GRANULATA (BACILLARIOPHYCEAE) RESTING CELLS FROM THE ANOXIC SEDIMENTS OF DOUGLAS LAKE, MICHIGAN. I. LIGHT MIGROSCOPY AND 14 C UPTAKE 1

Resting cells of Melosira granulate (Ehr.) Ralfs were collected from the anoxic sediments of Douglas Lake, Michigan. Sediment containing M. granulata was inoculated into distilled water and incubated in a growth chamber for one week during which observations were made on the cytological differentiation process. Cells classified as “condensed,” i.e. containing a dark brown cytoplasmic mass were identified as resting cells. The differentiation process consisted of a series of gradual cytological changes that included elongation of the cytoplasmic mass and recognition of definable organelles to the point where the cells were non-distinguishable from water column vegetative cells. Differentiating cells accumulated large polyphosphate and lipid granules. However, these granules disappeared just prior to cell division. The complete differentiation or rejuvenation sequence occurred in some cells in less than 24 h. However, not all dormant cells rejuvenated at the same time and it was observed that the lag period for rejuvenation increased with resting cell age (depth of burial in sediments). In the 14 C uptake studies, label was initially observed in condensed state cells. The label gradually progressed to the more differentiated forms. Total carbon uptake during the rejuvenation process was initially lower in the rejuvenating cells, but roughly equal to water column populations after 8 h, indicating a period of high metabolic activity in the rejuvenating cells between 1 and 8 h.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/66031/1/j.1529-8817.1986.tb02510.x.pd

Estim ation of intracellular carbon and silica content of diatoms from natural assemblages using morphometric techniques

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/109990/1/lno19842961170.pd

Polyphosphate body formation and degradation in Plectonema boryanum (cynophyceae)

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24121/1/0000378.pd

Morphometric analysis of phosphate and chromium interactions in Cyclotella meneghiniana

Quantitative electron microscopy was used to evaluate interactive effects of chromium additions and phosphate nutrient status on the diatom Cyclotella meneghiniana. Cells of differing phosphate status were exposed to hexavalent chromium for 7 days and morphological changes in both phosphate alone and phosphate and chromium treatments were observed. Changes in chloroplast relative volume and number/volume were observed in all treatments. Changes in mitochondrial and vacuolar volume and an increase in presumed autophagic activity were apparent in all chromium treatments. An increase in polyphosphate was also found in most chromium treated cells. These morphological modifications are discussed in relation to changes observed with exposure to other heavy metals.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/28696/1/0000516.pd

Accumulation and cellular effects of heavy metals in benthic and planktonic algae

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24541/1/0000821.pd

Paraformaldehyde-glutaraldehyde as a routine phytoplankton fixative

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/23663/1/0000631.pd

Verdeckte Datenerhebungsmassnahmen in der polizeilichen Praxis

Am 26. Januar 2011 hat der rheinland-pfälzische Landtag eine Novelle des Polizei- und Ordnungsbe-hördengesetzes (POG) beschlossen. Ziel des Änderungsgesetzes ist die Schaffung eines modernen und effizienten POG, um die Sicherheit der Bürgerinnen und Bürger weiterhin gewährleisten zu kön-nen. § 100 POG enthält eine erneute Evaluationsverpflichtung, die vorsieht, dass die Landesregierung dem Landtag über die Wirksamkeit bestimmter eingriffsintensiver Maßnahmen berichtet. Hierzu gehören • die Datenerhebung durch den verdeckten Einsatz technischer Mittel in oder aus Wohnungen, • die Datenerhebung durch den Einsatz technischer Mittel zur Überwachung und Aufzeichnung der Telekommunikation, • Auskunft über die Telekommunikation, • Auskunft über Nutzungsdaten, • Datenerhebung durch den Einsatz technischer Mittel in informationstechnischen Systemen, • Funkzellenabfrage, • besondere Formen des Datenabgleichs. Das Institut für Gesetzesfolgenabschätzung und Evaluation wurde vom rheinland-pfälzischen Minis-terium des Innern, für Sport und Infrastruktur mit der Durchführung der Evaluation beauftragt

Effects of chlorinated benzenes on diatom fatty acid composition and quantitative morphology. III. 1,2,3-Trichlorobenzene

Cells of the diatom Cyclotella meneghiniana were exposed in a closed system to 0.245 ppm 1,2,3-trichlorobenzene. Response of the diatom was measured by quantitative ultrastructure and fatty acid percent composition over a 5-day period. During that time, 35 significant morphological and 12 fatty acid percent composition changes occurred. The most pronounced morphological change that occurred was a significant increase in lipid volume. In addition, changes were observed in vacuolar relative volume, suggesting that the tonoplast became more permeable. Fewer significant changes were observed in fatty acid percent composition upon exposure to this isomer. However, there was a consistent increase in oleic acid (C18∶1). The observed changes in morphological and fatty acid percent composition were uniformly distributed with time after the first hour of exposure. Results support the hypothesis that increased lipid stores may alter the timing of response to lipophilic toxicants.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/48071/1/244_2005_Article_BF01225003.pd

Examination of the surface microlayer of lake michigan using scanning electron microscopy

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/24119/1/0000376.pd