No description available.

Thesis (Ph. D.)--Columbia University, 1934. / Vita. Bibliography: p. 39.

Universiẗat, Diss., 2002--Heidelberg.

The Kaskaskia River is a large river system situated in central and southwestern Illinois serving as a tributary to the Mississippi River. Within the Lower Kaskaskia River Watershed (LKRW), an active urban-rural gradient currently exists in the Metro East area of St. Louis. Such areas of urbanization are particularly vulnerable to stream degradation. This study focuses on the effects of urbanization on water quality parameters within Silver and Richland Creeks, both of which are tributaries to the LKRW. Forty-three catchments within Silver and Richland Creeks were identified as study catchments. Stream water samples were collected within these catchments every two weeks in the dormant season and monthly in the growing season from January 2008 to August 2009. Stream storm samples were collected and stage was recorded within 4 intensively sampled catchments, which were representative of urban, village and agriculture watersheds. Stream samples were measured and analyzed for total suspended solids (TSS), turbidity, pH, specific conductance, total coliform, bacteria coliforms (as total coliform, fecal coliform (FC), and Escherichia coli (EC)), nutrients (orthophosphate, ammonium-N, nitrate-N, chloride, sulfate), and caffeine. GIS was utilized to identify percent urban land cover (LC) at the whole catchment scale and percent impervious surfaces (IS) at the riparian buffer scale. Whole catchment urban land cover (WCULC) was used to designate land cover categories of urban, village, and agriculture watersheds (>10.5%, >1% to 10.5%, and 0% to 1% WCULC, respectively). IS were identified at the riparian scale through manual digitization and classification of structures (i.e. buildings, houses) and roads (i.e. highways, streets) within 10, 30, and 50 m buffer widths. Correlations of water quality variables to percent whole catchment urban LC were comparable to that of riparian-scale IS (RIS). Whole storm Event Mean Concentrations (EMCs) for nitrate-N, orthophosphate, and sulfate were generally significantly lower in urban watersheds compared to village and agriculture watersheds. Stream water levels of EC, FC, and orthophosphate were relatively high. Levels of FC at both baseflow and stormflow and EC at stormflow far exceeded US EPA and IL EPA Review criteria, respectively. During baseflow, stream orthophosphate and nitrate concentrations within urban watersheds were significantly higher than in village and agricultural watersheds. The significant nutrient and bacteria levels in urban streams may be due to inputs via stormwater runoff, wastewater treatment effluent, and home septic systems. Although hydrometric data showed no significant differences among the intensively sampled catchments, the village watershed had much higher mean and larger maximum stream discharge compared to the urban and agriculture watersheds. Caffeine concentration in streams was not a useful indicator of anthropogenic impacts within the LKRW study area. Results from this study demonstrate that watershed managers can utilize WCULC since it is comparable to RIS. In addition, results further illustrate the need for urban best management practices to reduce water quality impacts, such as storm water management, improved wastewater treatment, and maintaining or developing vegetated riparian buffers.

No description available.

No description available.

No description available.

To determine the limiting factors in nitrate assimilation in maize and barley, the effects of nitrate on 1) steady state levels of nitrate reductase activity (NRA) and nitrate reductase protein (NRP); 2) the uptake, translocation and accumulation of nitrate in the shoots of the seedling plant were examined. Seedlings were grown on Kimpack paper containing l, 5 or 20mM KN0₃ for 7 days at 20°c (barley) or 28°C (maize). At lmM KN0₃ the rate of 3 nitrate uptake and the levels of NRA and NRP were higher in maize than in barley. In contrast., at 5 and 20mlv1 KNo₃, the rate of uptake, the accumulation of nitrate and the NRA were higher in barley than in maize. The results suggest that the synthesis of NR is induced by lower levels of nitrate in maize relative to barley. In addition, nitrate-nitrogen appears to be more efficiently converted to proteins, other than NR, in maize than in barley. At very low levels of nitrate an inactive NR protein was present. in maize. To characterize the inactive NR, maize plants were grown under conditions where high levels of NRA were detected (vermiculite:sand, l:lw/w, containing 10mM KN0₃) and under conditions where NR was present primarily in the inactive form (Kimpack paper:washed sand). Nitrate reductase was purified from primary leaves using Blue Sepharose affinity chromatography. The column was washed with NADH and KN0₃ in each case. The peaks of NR were 3 detected using Dot-immunoblotting, with an antibody prepared against maize leaf NR and by assessing the NRA. Active and inactive NR forms were found both at the NADH-and the KN0₃-wash. In the NADH-wash, the inactive NR as compared to the active form, has very low NADH (complete), FMNH₂, MV and BPB (reductase) activities. Significant levels of cyt-c and FeCN (dehydrogenase) partial activities were detected. Similarly, the inactive NR in the KN0-wash, had 3no NADH (complete), FMNH2 , MV and BPB (reductase) activities. Very low levels of cyt-c and FeCN (dehydrogenase) NR partial activities were detected, compared to the respective activities of the active enzyme in the KNO₃ wash. / Thesis / Master of Science (MSc)

The investigation of microbial nitrate removal pathways in the environment has received growing attention in recent decades. Nitrate loading is a leading cause of eutrophication, and thus contributes to the collapse of multiple ecosystem services and is a cause of concern for public health. This study investigates nitrate removal processes in southernmost Illinois by analyzing DNA from environmental communities derived from sediment cores taken from a variety of land uses with varying flood regimes. Investigative methods include metagenomic analyses using amplicon sequence variants (ASVs) derived from next generation sequencing (NGS) data, PCR, alpha and beta diversity comparisons, and in silico methodologies to determine the presence or absence of genes associated with nitrate removal, the effects of spatial, seasonal, and flood regime variability on community-level taxonomic distributions, and the effect of various environmental conditions on community assemblages existing within the Dogtooth Bend region of Southern Illinois. Some nitrate removal pathways are shown to exist within the study area, spatial variability was more determinative of community assemblages than season or flood regime, and pH is shown to be the primary driving factor of dissimilarities in beta diversity among the representative samples. To understand the full extent of nitrate removal processes in the environment, efforts to improve sampling depth of microbial communities and to further understanding of microbial ecology must occur.

Les nitrates, largement dérivés des activités anthropiques posent un réel problème pour la santé et l'environnement lorsqu'ils se retrouvent dans le milieu naturel, en particulier lorsque la ressource est destinée à la production d'eau potable. Déterminer l'origine de ces nitrates est alors une première étape indispensable pour assurer ensuite une meilleure gestion de ces ressources en eau. C'est dans ce but, qu'une approche multi-traceurs originale a été développée sur la source karstique du Marseillon, située dans le Sud-Ouest de la France et exploitée pour l'eau potable. Une stratégie d'échantillonnage a été menée entre octobre 2010 et janvier 2013 à différentes échelles spatiales (du régional à l'étude du forage) et temporelles (du suivi mensuel au suivi horaire). Les outils hydrodynamiques et géochimiques ont mis en évidence une contribution importante d'une eau pauvre en nitrate à l'alimentation de la source. Les outils isotopiques (?15N-NO3, ?18O-NO3 et ?11B) et microbiologiques ont permis d'identifier une connexion hydraulique entre les eaux de surface et la source du Marseillon, favorisée pendant les épisodes de crues de surface. Les outils de datation ont permis d'estimer une contribution d'environ 80% d'une eau de 1980 et de 20 % d'une eau rechargée au cours de l'année de la mesure (2011) caractérisée par des nitrates d'origine organique et des contaminations fécales humaines et animales. Les résultats obtenus ainsi que la démarche développée dans cette thèse ont permis de dresser les grandes lignes d'un guide méthodologique, accessible aux plus grand nombre d'acteurs de l'eau, pour la détermination de l'origine des nitrates dans les eaux souterraines. / Nitrate is widely derived from anthropogenic activities. When it reaches groundwater bodies, it becomes an environmental issue especially when the resource is used for drinking water supply. The determination of nitrate sources is thus the first step in water restoration and preservation management. An innovative multi-indicators approach has been used in Marseillon karstic spring (Southwest of France) which is considered as a strategic resource for drinking water supply. A spatial and temporal multi-scale sampling plan has been carried out in surface waters and groundwater. Hydrodynamic and geochemical tools helped to highlight an important contribution of deep water origin (i.e.: low nitrate concentration) in spring alimentation. Isotopic (?15N-NO3, ?18O-NO3 and ?11B) and microbiological tools have allowed identifying a hydraulic connection between surface water and the spring. This connection seems to be more important during the river?s flood events. Water dating shows a heterogeneous recharge of Marseillon spring with old water (<1940) mixed with current water characterized by nitrate derived from organic sources and fecal contamination originated from both human and animal wastes. This original multi-tracers approach developed in this thesis improves the knowledge on the nitrate origin determination and can be seen as a methodological guide for drinking water management.