Global ETD Search
Search theses and dissertations gathered from participating repositories worldwide. Every result links back to the library that holds it. No account is needed.
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Showing 1 to 20 of 93 for “"snails"”.
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Comparative Bioavailability of Dietary and Dissolved Cadmium to Freshwater Aquatic Snails
… systems was investigated by exposing freshwater snails to dietary or dissolved sources of cadmium. Snails were exposed to control, contaminated food only, contaminated water only, and contaminated food and water treatments. During the 15-day exposure, samples were taken to determine Cd …
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Multi-omic analysis of contaminated sediments from Contrecoeur, QC on Planorbid snails
… and increased water temperature on Planorbid snails’ survival, growth, reproductive output, metabolomic profile, and proteomic profile. A two-week in-situ exposure was performed on Helisoma trivolvis, and a 28-d laboratory exposure of Planorbella pilsbryi to the same sediments was completed. …
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Effects of Atrazine and Metolachlor on Snails, Tadpoles, and Their Trematode Parasites
… first intermediate host, Planorbella trivolvis snails, were exposed to a low concentration (10 ppb: 15 ppb) and high concentration (85 ppb: 100 ppb) mixture of atrazine and metolachlor, respectively. There was a significant decline in parasite survivorship in the high concentration treatment at …
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Size-Selective Predation By Ringed Crayfish (Orconectes Neglectus) On Native And Invasive Snails
… the United States, where it coexists with native snails and their crayfish consumers. This study examined the relative susceptibility of C. chinensis and two native snails (Elimia potosiensis and Physella gyrina) to predation by the ringed crayfish (Orconectes neglectus). I conducted field surveys …
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Isolating Confounding Abiotic and Biotic Effects on the Phenotype on Physa Acuta Snails
… of habitat-specific polymorphism in Physa acuta snails collected from three streams and their corresponding downstream reservoir. In lotic systems shells were rotund with larger apertures, while those from lentic systems were more elongate with smaller apertures. In a reciprocal transplant lab …
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About snails, Franciscans, homelessness, and the city : a contribution to the culture of "college thinking"
… collages. This collection consists of images of snails, Franciscan architecture, personal memory and allegorical objects. 2. A historic research of the initial state of the Franciscan Movement and St. Francis with respect to their attitude towards buildings. 3. Three case studies of Franciscan …
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Comparative analysis of wild and long term captive bred Partula snails using morphometrics and population data
Partula snails are one genus of the Partulidae family of air breathing, land snails that are endemic to the Pacific Islands. Over 100 partulid species are recognised with over half these species known to have existed and endemic to the Society Islands (within the Pacific islands). It is thought …
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Modern radiocarbon offsets within the land snails Cyclophorus: a tropical karst case study from Northern Vietnam
This thesis forms part of the SUNDASIA project on the archaeology of the UNESCO World Heritage Site Tràng An (Ninh Bình, Northern Vietnam), a tower karst area of high endemism and habitat insularity. Archaeological sites in the region contain abundant shell middens, composed mainly of terrestrial …
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Assessing the use of Viviparus georgianus snails as a means for biomanipulation of cyanobacterial species Microcystis aeruginosa
… system with and without the presence of snails, over an approximate 9-day time period. Our results demonstrated that in a clearwater system, the snails were unable to reduce the amount of chl-a present by ingestion. However, with the addition of silt and clay at varying turbidity levels, …
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Snail grazing effects on the composition and metabolism of benthic diatom communities and subsequent effects on fish growth
Eastern mud snails (Ilyanassa obsoleta) in densities of zero, six or twelve snails were placed in flow-through-laboratory microcosms (765 cm2) and incubated for five weeks. Other tanks were raked daily to a depth of 10 mm. Grazing by low densities of snails significantly increased chlorophyll …
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Gastropods in lower Snake River and three of its tributaries and the effects of competition with the New Zealand mud snails (Potamopyrgus antipodarum)
… to determine the distribution of New Zealand mud snails (Potamopyrgus antipodarum) in the lower Snake River and three tributaries and to determine if this invasive snail is competing with native gastropods. Potamopyrgus antipodarum is a successful invader in much of the Western United States and …
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The Effects of Landfill Leachate on the Behavior, Feeding Rate, and Growth Rate of the Freshwater Prosobranch Snail Elimia Potosiensis
… enclosure experiment at Site NC indicated that snails acclimated within one week and reached a net movement of 60 cm in an upstream direction. Comparison of Site NC and C indicated landfill leachate did not adversely affect snail movement after an initial acclimation period. After two weeks 73% …
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PROTEIN PURIFICATION FROM GASTROPODS
… within the mollusks, commonly known as snails and slugs. Recently, scientific interest is directed on snails as pollution indicators, as destroyers of crops, but also as parasites carriers. Furthermore, some species of snails are considered as an important human food source in countries …
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Thermal Tolerances of an Endemic Hot Spring Snail Physella wrighti Te and Clarke (Mollusca: Physidae)
… had a preferred water temperature by allowing snails to explore a gradient of temperatures, and determined that the snails preferred 23oC. I reared snails in 13oC (cold), 23oC (warm), and 33oC (hot) water to examine if water temperature would affect the snail’s period of greatest activity, …
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Evaluation of the relationships between watershed-scale land use and contaminants in aquatic environments and the use of freshwater snails as indicators of impairment
The use of manure from animal feeding operations (AFOs) as fertilizer on agricultural land may introduce contaminants to aquatic environments that can negatively affect the health of aquatic organisms. This study utilized a landscape-scale regression-based design to assess the effects of AFOs on …
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Characterization of Neuromodulatory and Neurotoxic Marine Natural Products Using Microseparations, NMR and Mass Spectrometry
… are examined including toxins from venomous cone snails. Conotoxins represent a wealth of neuropharmacologically active peptides as well as tools for basic research and a review of cone snails and their toxins is included.
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Interactions Among Invasive Species in Lakes: a Mesocosm Experiment
… (Orconectes rusticus, RC), banded mystery snails (Viviparus georgianus, BMS), and Eurasian water-milfoil (Myriophyllum spicatum, EWM), species that commonly co-occur. All three of these species can be very abundant and two (EWM and RC) are known to be individually damaging. The current …
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Land snail species diversity and composition between different forest disturbance regimes in central and eastern Kentucky Forests
<p>Land snails are cornerstone organisms that contribute to properly functioning ecosystems. However, habitat loss and destruction have led to these organisms being one of the most imperiled groups on the planet. Due to their relatively sedentary nature, land snails can be susceptible to …
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An investigation into Manganese(2+) interferences and retrospective dose assessment of shelled species using EPR spectroscopy
… found that shells of zebra mussels, grove snails, and heath snails were best suited as environmental dosimeters due to their low Mn²⁺ concentrations and Mn²⁺ EPR peaks. Dose-response curves for grove and heath snails were developed by irradiating shells to 2, 3, 5, 7, and 10 Gy. Both …
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