• Refine Query
  • Source
  • Publication year
  • to
  • Language
  • 3
  • 1
  • Tagged with
  • 7
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 2
  • 1
  • 1
  • 1
  • 1
  • 1
  • 1
  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
1

Where the Watchers Wait

Peckham, Rachael S. 11 August 2009 (has links)
No description available.
2

One-Dimensional Computer Modeling of Thermal and Water Quality Characteristics of Coldwater Lake, WA

Whitaker, David Kevin 30 April 1993 (has links)
Coldwater Lake is a new lake formed when a massive mudflow down the Toutle River Valley, caused by the eruption of Mount St. Helens on May 18, 1980, blocked the natural outlet of Coldwater Creek. This research utilizes physical, biological and chemical data collected at Coldwater Lake during the sun1mers of 1989 and 1990 to calibrate and verify the one-dimensional computer models CE-THERMRl and CE-QUAL-Rl for Coldwater Lake. CE-THERM-R1 was used to simulate thermal characteristics in Coldwater Lake during the summer stratification periods of 1989 and 1990. The model was calibrated to 1989 data and was verified with 1990 data. The model performed well with respect to typical stratification features such as depth and temperature of the epilimnion, gradient of the thermocline and temperature of the hypolimnion. The 1990 verification simulation indicated a lack of heat in the epilimnion and metalimnion towards the end of the summer. This is thought to be a product of inaccurate cloud cover data. Model simulations predicted vertical eddy diffusion coefficients (Ez) throughout the water column. These were compared to Ez values in the hypolimnion calculated from temperature data collected by Kelly (1991). Model simulated Ez values in the hypolimnion were near molecular diffusion while field calculated values were one to two orders of magnitude greater than molecular diffusion. The model simulation assumed no lake inflow or outflow so the hypolimnion was more stable than the natural system. The amount of photosynthetically available radiation (PAR) to Coldwater Lake was determined from output derived from the model simulation. This will be useful in determining primary productivity within the lake. CE-QUAL-R1 was used to simulate water quality in Coldwater Lake. The model was calibrated using dissolved oxygen (D.O.) data collected in 1989. The model adequately predicted the D.O. profile in the hypolimnion but tended to over predict D.O. concentration in the epilimnion by 1.0- 3.0 mg/1. This may be caused by an under estimation of the vertical diffusion coefficient in the model simulation. Mean phytoplankton concentrations were similar to field data in the surface layer assuming a 1 mg/1 phytoplankton to 10 ug/1 chlorophyll a ratio. However, concentrations at 10 m and 20 m were under predicted. The phytoplankton - chlorophyll a comparison may not be valid for these lower regions because a significant portion of algal cells within this region are non-viable and are found as particulate detritus in various stages of decomposition. Model simulated nutrient concentrations were in good agreement with the field data. N03 concentration in the hypolimnion increased slightly throughout the model simulation due to decay of the assumed initial condition of 2 mg/1 refractory dissolved organic matter which was contributed to the lake during the eruption of Mt. Saint Helens on May 18, 1980. The model simulation predicted that the phytoplankton were nitrogen limited. An analysis of potential changes in water clarity and water temperature due to the addition of fish in the summer of 1989 was made. The 1990 model simulation predicted that the addition of 200 kg/hectare of Rainbow Trout had little change on water temperature and water clarity. Collection of further site specific data such as; cloud cover estimates, primary productivity rates and quantity of dissolved organic matter contributed by the May 18, 1980 eruption of Mt. Saint Helens would be useful in building a reliable water quality model at Coldwater Lake.
3

Utilizing the Public on Public Lands: The Application of Community Science to Monitor and Model Erosion in National Forests

Hansen, Jacob L 01 August 2020 (has links)
Unpaved forest roads are adversely affecting coldwater streams through excessive erosion and the subsequent sedimentation of adjacent waterways. To help identify areas of concern, Trout Unlimited (TU) in the Southern Appalachian region developed a Community Science initiative to gather data on sediment sources and stream-road crossings. Volunteers were recruited and trained to monitor road and trail conditions and collect and submit data using a Survey123 application on their cell phones. Analysis of the contributed data reveals statistical connections between drainage type and both erosion level and stream sedimentation. The contributed data were also included as a calibration for the lite version of the Geomorphic Road Analysis and Inventory Package (GRAIP-Lite), a GIS-based road sediment contribution model. The analysis found statistically significant differences between Basic and Calibrated models at one of two sites, and substantial increases in sediment delivery from the Alternate model at both sites.
4

Limnology of two new lakes, Mount St. Helens, WA

Kelly, Valerie Jean 01 January 1991 (has links)
Coldwater Lake and Castle Lake are two new lakes which were formed in the aftermath of the volcanic eruption of Mount St . Helens, WA in May, 1980. This research describes the limnology of these lakes ten years later, and includes physical, chemical, and biological parameters. The two lakes are compared and contrasted. Previous research on the eruption and its aftermath, as well as earlier studies of the lakes are described.
5

Analyses and Declarations of Omega-3 Fatty Acids in Canned Seafood May Help to Quantify Their Dietary Intake

Singer, Peter, Richter, Volker, Singer, Konrad, Löhlein, Iris 05 May 2023 (has links)
The American Heart Association (AHA) recently confirmed common recommendations of one to two fish dishes per week in order to prevent cardiovascular disease (CVD). Nevertheless, the natural fluctuations of lipids and fatty acids (FA) in processed seafood caught little public attention. Moreover, consumers of unprocessed seafood in general do not know how much omega-3 fatty acids (omega-3 FA) within servings they actually ingest. The few studies published until today considering this aspect have been re-evaluated in today’s context. They included four observational studies with canned fatty coldwater fish (mackerel and herring from the same region, season, producer and research group). Their outcomes were similar to those conducted in the following years using supplements. Cans containing seafood (especially fatty coldwater fish) with declared content of omega-3 FA are ready-to-use products. Human studies have shown a higher bioavailability of omega-3 FA by joint uptake of fat. Canned fatty coldwater fish contain omega-3 FA plus plenty of fat in one and the same foodstuff. That suggests a new dietary paradigm with mixed concepts including several sources with declared content of omega-3 FA for reducing the cardiovascular risk and other acknowledged indications.
6

Using DNA markers to trace pedigrees and population substructure and identify associations between major histocompatibility regions and disease resistance in rainbow trout (Oncorhynchus mykiss)

Johnson, Nathan Allen 28 August 2007 (has links)
Examination of variation at polymorphic microsatellite loci is a widely accepted method for determining parentage and examining genetic diversity within rainbow trout (Oncorhynchus mykiss) breeding programs. Genotyping costs are considerable; therefore, we developed a single-step method of co-amplifying twelve microsatellite loci in two hexaplex reactions. The protocol is explicitly described to ensure reproducible results. I applied the protocol to samples previously analyzed at the National Center for Cool and Coldwater Aquaculture (NCCCWA) with previously reported marker sets for a comparison of results. Each marker within the multiplex system was evaluated for duplication, null alleles, physical linkage, and probability of genotyping errors. Data from four of the 12 markers were excluded from parental analysis based on these criteria. Parental assignments were compared to those of a previous study that used five independently amplified microsatellites. Percentages of progeny assigned to parents were higher using the subset of eight markers from the multiplex system than with five markers used in the previous study (98% vs. 92%). Through multiplexing, use of additional markers improved parental allocation while also improving efficiency by reducing the number of PCR reactions and genotyping runs required. I evaluated the methods further through estimation of F-statistics, pairwise genetic distances, and cluster analysis among brood-years at the NCCCWA facility. These estimates were compared to those from nine independently amplified microsatellites used in a previous study. Fst metrics calculated between brood-years showed similar values of genetic differentiation using both marker sets. Estimates of individual pairwise genetic distances were used for constructing neighbor-joining trees. Both marker-sets yielded trees that showed similar subpopulation structuring and agreed with results from a model-based cluster analysis and available pedigree information. These approaches for detecting population substructure and admixture portions within individuals are particularly useful for new breeding programs where the founders' relatedness is unknown. The 2005 NCCCWA brood-year (75 full-sib families) was challenged with Flavobacterium psychrophilum, the causative agent of bacterial coldwater disease (BCWD). The overall mortality rate was 70%, with large variation among families. Resistance to the disease was assessed by monitoring post-challenge days-to-death. Phenotypic variation and additive genetic variation were estimated using mixed models of survival analysis. The microsatellite markers used were previously isolated from BAC clones that harbor genes of interest and mapped onto the rainbow trout genetic linkage map. A general relationship between UBA gene sequence types and MH-IA-linked microsatellite alleles indicated that microsatellites mapped near or within specific major histocompatibility (MH) loci reliably mark sequence variation at MH genes. The parents and grandparents of the 2005 brood-year families were genotyped with markers linked to the four MH genomic regions (MH-IA, MH-IB, TAP1, and MH-II) to assess linkage disequilibrium (LD) between those genomic regions and resistance to BCWD. Family analysis suggested that MH-IB and MH-II markers are linked to BCWD survivability. Tests for disease association at the population level substantiated the involvement of MH-IB with disease resistance. The impact of MH sequence variation on selective breeding for disease resistance is discussed in the context of aquaculture production. / Master of Science
7

Erfassung und Bewertung von Quellen im Forstrevier Ottomühle zur Erarbeitung von Handlungsempfehlungen für die Renaturierung oder zukünftige Pflege der Quellbereiche und die forstliche Bewirtschaftung im Umfeld

Kunath, Maxi 10 December 2020 (has links)
Ziel der vorliegenden Bachelorarbeit war es, die Grundwasseraustritte im Forstrevier Ottomühle zu erfassen und zu bewerten, um Handlungsempfehlungen für die Renaturierung oder zukünftige Pflege der Quellbereiche und die forstliche Bewirtschaftung im Umfeld erarbeiten zu können. Zwischen März und Juni 2020 konnten insgesamt 19 Quellen im Forstrevier Ottomühle auf Grundlage einer Handlungsanleitung des Bayrischen Landesamtes für Umwelt erfasst und nach ihrer Naturnähe bewertet werden. Die vorgefundenen Beeinträchtigungen waren in absteigender Häufigkeit (Anzahl der betroffenen Quellen): • Nicht standortgerechter Baumbestand (12) • Kronenmaterial oder Schlagabraum (9) • Trittschäden (8) • Aufstau (5) • Kahlschlag (3) • Oberflächen- oder Drainagewassereinleitung (3) • Uferverbau oder Sohlenverbau (3) • Verrohrung (3) • Totalverbau (2) • Umleitung oder Verlegung (2) Auf Basis aktueller Literatur wurde anschließend für jede Quelle eine Handlungsempfehlung erarbeitet. Sie beinhaltet Maßnahmenvorschläge, Renaturierungsempfehlungen sowie Pflege- und Bewirtschaftungshinweise für den Quellbereich und das nähere Umfeld.:1 EINLEITUNG 2 MATERIAL UND METHODEN 2.1 UNTERSUCHUNGSGEBIET 2.2 SYSTEMATIK DER QUELLEN 2.3 DATENAUFNAHME IM FREILAND 2.3.1 Basis-Bogen 2.3.2 Detail-Bogen 2.4 QUELLENBEWERTUNG 2.5 ERARBEITUNG DER HANDLUNGSEMPFEHLUNG 3 ERGEBNISSE 3.1 ALLGEMEINE AUSWERTUNG 3.2 EINZELQUELLEN 3.2.1 „Wegquelle“ (ID 00001) 3.2.2 Zehrborn (ID 00002) 3.2.3 „Sumpfquelle“ (ID00003) 3.2.4 „Eisenquelle“ (ID 00004) 3.2.5 „Flurquelle“ (ID 00005) 3.2.6 Singeborn (ID 00006) 3.2.7 „Turmquelle“ (ID 00007/00008) 3.2.8 „Wildquelle“ (ID 00009) 3.2.9 „Teichquelle“ (ID 00010) 3.2.10 „Kapuzinerquelle“ (ID 00011) 3.2.11 Herkulesquelle (ID 00012) 3.2.12 „Johannisquelle“ (ID 00013) 3.2.13 „Kachequelle“ (ID 00015) 3.2.14 „Fichtenquelle“ (ID 00016) 3.2.15 „Jägerquelle“ (ID 00017) 3.2.16 „Brennnesselquelle“ (ID 00018) 3.2.17 „Fallenquelle“ (ID 00019) 3.2.18 „Dornquelle“ (ID 00020) 3.2.19 „Hainquelle“ (ID 00021) 4 DISKUSSION 5 FAZIT ANHANG / The aim of this bachelor thesis was to register and evaluate the current state of coldwater springs in the forest district „Ottomühle“. The gathered data was used to develop recommendations for action, which include renaturation processes, future maintenance of the springs and forest management in the surrounding areas. From March to June 2020 a total of 19 springs were registered in the district. The collection of needed parameters and the proximate assessment according to a springs natural state followed the instruction manual of the Bavarian State Office for the Environment (Bayrisches Landesamtes für Umwelt). The impairments found were in decreasing frequency (number of affected springs): • Non-natural tree population (12) • Branch material or low-grade timber (9) • Soil damage by trampling or vehicles (8) • Water impoundment (5) • Forest clearance (3) • Waterinput from surface or drainage water (3) • Piping (3) • Obstruction of riverbanks or riverbed sheeting (3) • Complete obstruction (2) • Bypass or relocation (2) The recommendations for further action in relation to impairments are presented in this paper.:1 EINLEITUNG 2 MATERIAL UND METHODEN 2.1 UNTERSUCHUNGSGEBIET 2.2 SYSTEMATIK DER QUELLEN 2.3 DATENAUFNAHME IM FREILAND 2.3.1 Basis-Bogen 2.3.2 Detail-Bogen 2.4 QUELLENBEWERTUNG 2.5 ERARBEITUNG DER HANDLUNGSEMPFEHLUNG 3 ERGEBNISSE 3.1 ALLGEMEINE AUSWERTUNG 3.2 EINZELQUELLEN 3.2.1 „Wegquelle“ (ID 00001) 3.2.2 Zehrborn (ID 00002) 3.2.3 „Sumpfquelle“ (ID00003) 3.2.4 „Eisenquelle“ (ID 00004) 3.2.5 „Flurquelle“ (ID 00005) 3.2.6 Singeborn (ID 00006) 3.2.7 „Turmquelle“ (ID 00007/00008) 3.2.8 „Wildquelle“ (ID 00009) 3.2.9 „Teichquelle“ (ID 00010) 3.2.10 „Kapuzinerquelle“ (ID 00011) 3.2.11 Herkulesquelle (ID 00012) 3.2.12 „Johannisquelle“ (ID 00013) 3.2.13 „Kachequelle“ (ID 00015) 3.2.14 „Fichtenquelle“ (ID 00016) 3.2.15 „Jägerquelle“ (ID 00017) 3.2.16 „Brennnesselquelle“ (ID 00018) 3.2.17 „Fallenquelle“ (ID 00019) 3.2.18 „Dornquelle“ (ID 00020) 3.2.19 „Hainquelle“ (ID 00021) 4 DISKUSSION 5 FAZIT ANHANG

Page generated in 0.059 seconds