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1	Changes in Scaled-Chrsyophyte Assemblages in Response to Recent Climate Change in Northwestern Ontario FLEAR, Karlee 30 September 2011 (has links) A two-part paleolimnological study was conducted to: i) understand the important factors that are related to the present-day distribution of scaled-chrysophytes; ii) investigate changes in the scaled-chrysophyte assemblages in the Experimental Lakes Area northwestern Ontario, in response to recent climate warming. Scaled-chrysophyte assemblages were analyzed in the modern sediments of 40 ELA lakes to determine their relationship to measured environmental variables. The sediment record from 210Pb dated cores from six ELA lakes were analyzed at a sub-decadal resolution to evaluate if chrysophytes were changing in a consistent fashion and if these changes could be accounted for by measured climatic factors. Ordination analysis of the modern chrysophyte flora was significantly related to pH, lake depth, and the degree of thermal stratification, as well as water temperature. Mallomonas punctifera ‘small’ and Mallomonas acaroides were indicators of warm surface-waters. High-resolution analysis of six ELA lakes revealed pronounced shifts in the chrysophyte assemblages over the last ca. 150 years. The most notable shift in the chrysophyte assemblage was characterized by an overall shift towards higher relative abundances of colonial taxa. In several lakes increases in unicellular warm-water taxa were also observed. Breakpoint Analysis identified significant changes in the chrysophyte assemblages beginning in the late-1800s to mid-1900s in most lakes. An interclass correlation coefficient (ri) was used to assess the temporal coherency of the chrysophyte assemblages over the past ca. 100 years. All lakes displayed a similar directional change which was significantly coherent (p<0.05). A Brien’s Test identified sub-sets of lakes that were temporally coherent and homogenous. The high coherency of two groups, (Group A, grand mean=0.89, p-value=5.3x10-15; Group B, grand mean=0.38, p-value=0.038), suggests the dominance in extrinsic factors in governing the lake responses. The average PCA axis-1 scores of Group A (r-value=0.62, p=0.03) and Group B (r-value=0.60, p=0.038) were significantly correlated to regional mean annual temperature. Collectively, the results of this study suggest that changes observed in the scaled-chrysophyte assemblages in the ELA region are consistent with recent climate warming. / Thesis (Master, Biology) -- Queen's University, 2011-09-29 16:42:06.753 Scaled Chrsyophytes Temporal Coherency Breakpoint Analysis Paleolimnology Climate Change Experimental Lakes Area
2	Sulphur Amino Acid Requirement and Metabolism in the Total Parenteral Nutrition (TPN) Fed Human Neonate Courtney-Martin, Glenda 23 September 2009 (has links) Except for tyrosine, the amino acid requirement of parenterally fed (PN) human neonates has not been derived. Methionine and cysteine are indispensable and dispensable sulphur amino acids respectively. Cysteine is synthesized from methionine. Cysteine is unstable in solution, and is left out or added in very small amounts to amino acid solutions. Methionine is added to compensate for the lack of cysteine, assuming that the neonate will convert methionine to cysteine to meet the body’s metabolic demand. Methionine is hepatotoxic and there is evidence that the neonate has limited ability for its conversion to cysteine. To determine the requirement of the neonate for methionine, PN-fed, stable, post-surgical neonates received graded intakes of methionine. The mean methionine requirement was estimated to be 49 mg.kg-1.day-1, which is 48 to 90% of the methionine content of current commercial amino acid solutions. Because cysteine is the rate limiting substrate for glutathione (GSH) synthesis and current methods of determining amino acid requirement measure requirement for protein synthesis, SAA requirements for maintenance of GSH status was deleniated in healthy adult males and in PN-fed human neonates. GSH kinetics was measured in healthy men receiving the mean methionine requirement and graded intakes of cysteine. GSH synthesis did not change with the addition of cysteine. Additionally, PN-fed post-surgical neonates recieved a methionine-adequate cysteine-free PN followed by cysteine supplemented PN for two 3-day periods and GSH kinetics measured on days 3 and 6. There was no change in GSH synthesis in response to cysteine supplementation. It is concluded that the PN-fed human neonate is capable of synthesizing enough cysteine from methionine not only for protein synthesis but for GSH synthesis. For both healthy men and stable post-surgical neonates, the requirement for GSH synthesis is met at the sulphur amino acid requirement derived using the indicator amino acid technique sulphur amino acids methionine cysteine glutathione neonate methionine requirement parenteral nutrition antioxidant amino acid requirement methionine requirement cysteine metabolism methionine metabolism cystathionine homocysteine urinary sulphate breakpoint analysis 0570
3	Sulphur Amino Acid Requirement and Metabolism in the Total Parenteral Nutrition (TPN) Fed Human Neonate Courtney-Martin, Glenda 23 September 2009 (has links) Except for tyrosine, the amino acid requirement of parenterally fed (PN) human neonates has not been derived. Methionine and cysteine are indispensable and dispensable sulphur amino acids respectively. Cysteine is synthesized from methionine. Cysteine is unstable in solution, and is left out or added in very small amounts to amino acid solutions. Methionine is added to compensate for the lack of cysteine, assuming that the neonate will convert methionine to cysteine to meet the body’s metabolic demand. Methionine is hepatotoxic and there is evidence that the neonate has limited ability for its conversion to cysteine. To determine the requirement of the neonate for methionine, PN-fed, stable, post-surgical neonates received graded intakes of methionine. The mean methionine requirement was estimated to be 49 mg.kg-1.day-1, which is 48 to 90% of the methionine content of current commercial amino acid solutions. Because cysteine is the rate limiting substrate for glutathione (GSH) synthesis and current methods of determining amino acid requirement measure requirement for protein synthesis, SAA requirements for maintenance of GSH status was deleniated in healthy adult males and in PN-fed human neonates. GSH kinetics was measured in healthy men receiving the mean methionine requirement and graded intakes of cysteine. GSH synthesis did not change with the addition of cysteine. Additionally, PN-fed post-surgical neonates recieved a methionine-adequate cysteine-free PN followed by cysteine supplemented PN for two 3-day periods and GSH kinetics measured on days 3 and 6. There was no change in GSH synthesis in response to cysteine supplementation. It is concluded that the PN-fed human neonate is capable of synthesizing enough cysteine from methionine not only for protein synthesis but for GSH synthesis. For both healthy men and stable post-surgical neonates, the requirement for GSH synthesis is met at the sulphur amino acid requirement derived using the indicator amino acid technique sulphur amino acids methionine cysteine glutathione neonate methionine requirement parenteral nutrition antioxidant amino acid requirement methionine requirement cysteine metabolism methionine metabolism cystathionine homocysteine urinary sulphate breakpoint analysis 0570
4	Extraktion von Trends in der Phänologie komplexer Ökosysteme am Beispiel des westafrikanischen Niger Binnendeltas für den Zeitraum 1982‑2006 : Auswertung von NOAA‑AVHRR Zeitreihen Seiler, Ralf 04 July 2016 (has links) (PDF) Die vorliegende Arbeit analysiert die Phänologie photosynthetisch aktiver Vegetation mit Hilfe von NDVI Zeitreihen für einen Zeitraum von 24 Jahren (AVHRR‑GIMMS Daten). Neben einer Datierung des jahreszeitlichen Wechsels zwischen Wachstums-, Reife- und Seneszenzphase wird das Ziel verfolgt, Trends sowohl in phänologischen Ereignissen (Start-of-Season) als auch im NDVI zu identifizieren. Das, in der semi-ariden Sahelregion gelegene, Untersuchungsgebiet weist mit zwei sich teilweise überlagernden Vegetationsperioden eine komplexe Phänologie auf, deren Modellierung durch die sowohl in ihren Zeitpunkten als auch in ihren Ausprägungen hoch variablen Vegetationsabläufe erschwert wird. Vor diesem Hintergrund ist zunächst ein, auf der Fourieranalyse basierender, Ansatz zur flexiblen Glättung der NDVI Zeitreihen entwickelt worden. Um für die Trendanalyse lineare Regressionsverfahren einsetzen zu können, sind die Zeitreihen nach dem Komponentenmodell untergliedert worden (Subtraktion der Saisonfigur). Alternativ kam der saisonale MANN-KENDALL Trendtest zur Anwendung. Die NDVI Zeitreihen wurden ebenfalls auf Änderungen im mehrjährigen Mittelwert (Bruchpunkte) untersucht. Alle Auswertungen sind in einer eigenen Applikation umgesetzt worden. Es konnte gezeigt werden, daß Änderungen im NDVI Niveau eher abrupt als graduell verlaufen. Langfristige Trends weisen nur geringe Anstiege auf. Die Vegetation erholte sich von der Dürre 1984/85 nur im südlichen Teil des Untersuchungsgebietes, im Norden dominieren langfristig negative Trends. Brüche im mean der NDVI Zeitreihen korrelieren mit Brüchen im Abflußverhalten des Niger. Zeitreihenanalyse Fouriertransformation Bruchpunktanalyse monotone Trends AVHRR-GIMMS phänologische Ereignisse Softwareentwicklung java Niger-Binnendelta time series analysis Fouriertransformation breakpoint analysis analysis of monotonic trends AVHRR-GIMMS phenological events software development with java Niger Inland Delta ddc:550 Masina Pflanzen Phänologie Vegetationsperiode Bioklima Zeitreihenanalyse Mali Binnendelta Feuchtgebiet Fernerkundung Java <Programmiersprache> Programmierung Pflanzenökologie Datenanalyse Datenauswertung
5	Extraktion von Trends in der Phänologie komplexer Ökosysteme am Beispiel des westafrikanischen Niger Binnendeltas für den Zeitraum 1982‑2006 : Auswertung von NOAA‑AVHRR Zeitreihen Seiler, Ralf 11 February 2014 (has links) Die vorliegende Arbeit analysiert die Phänologie photosynthetisch aktiver Vegetation mit Hilfe von NDVI Zeitreihen für einen Zeitraum von 24 Jahren (AVHRR‑GIMMS Daten). Neben einer Datierung des jahreszeitlichen Wechsels zwischen Wachstums-, Reife- und Seneszenzphase wird das Ziel verfolgt, Trends sowohl in phänologischen Ereignissen (Start-of-Season) als auch im NDVI zu identifizieren. Das, in der semi-ariden Sahelregion gelegene, Untersuchungsgebiet weist mit zwei sich teilweise überlagernden Vegetationsperioden eine komplexe Phänologie auf, deren Modellierung durch die sowohl in ihren Zeitpunkten als auch in ihren Ausprägungen hoch variablen Vegetationsabläufe erschwert wird. Vor diesem Hintergrund ist zunächst ein, auf der Fourieranalyse basierender, Ansatz zur flexiblen Glättung der NDVI Zeitreihen entwickelt worden. Um für die Trendanalyse lineare Regressionsverfahren einsetzen zu können, sind die Zeitreihen nach dem Komponentenmodell untergliedert worden (Subtraktion der Saisonfigur). Alternativ kam der saisonale MANN-KENDALL Trendtest zur Anwendung. Die NDVI Zeitreihen wurden ebenfalls auf Änderungen im mehrjährigen Mittelwert (Bruchpunkte) untersucht. Alle Auswertungen sind in einer eigenen Applikation umgesetzt worden. Es konnte gezeigt werden, daß Änderungen im NDVI Niveau eher abrupt als graduell verlaufen. Langfristige Trends weisen nur geringe Anstiege auf. Die Vegetation erholte sich von der Dürre 1984/85 nur im südlichen Teil des Untersuchungsgebietes, im Norden dominieren langfristig negative Trends. Brüche im mean der NDVI Zeitreihen korrelieren mit Brüchen im Abflußverhalten des Niger. info:eu-repo/classification/ddc/550 ddc:550

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