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Articles 6571 - 6600 of 17812
Full-Text Articles in Entire DC Network
Active Learning For Efficient Soil Monitoring In Large Terrain With Heterogeneous Sensor Network, Hui Chen, Ju Wang
Active Learning For Efficient Soil Monitoring In Large Terrain With Heterogeneous Sensor Network, Hui Chen, Ju Wang
Publications and Research
Soils are a complex ecosystem that provides critical services, such as growing food, supplying antibiotics, filtering wastes, and maintaining biodiversity; hence monitoring soil health and domestication is required for sustainable human development. Low-cost and high-resolution soil monitoring systems are challenging to design and build. Compounded by the sheer size of the monitoring area of interest and the variety of biological, chemical, and physical parameters to monitor, naive approaches to adding or scheduling more sensors will suffer from cost and scalability problems. We investigate a multi-robot sensing system integrated with an active learning-based predictive modeling technique. Taking advantage of advances in …
Prevalence And Plasmid Profiles Of Enterobacteriaceae Isolates Obtained From Individuals With Asymptomatic Bacteriuria In Okada, Edo State, Nigeria, Osarumwense Precious Otote, Maureen Uchechukwu Okwu, Osazee Ekundayo Izevbuwa, Happy Ovuerhi Oferiofe
Prevalence And Plasmid Profiles Of Enterobacteriaceae Isolates Obtained From Individuals With Asymptomatic Bacteriuria In Okada, Edo State, Nigeria, Osarumwense Precious Otote, Maureen Uchechukwu Okwu, Osazee Ekundayo Izevbuwa, Happy Ovuerhi Oferiofe
Makara Journal of Science
Asymptomatic bacteriuria (ASB) is the presence of bacteria in apparently healthy individuals. Although, the prevalence varies widely with age, gender, and the presence or absence of genitourinary abnormalities, the detection of pathogenic bacteria in urine constitutes firm evidence of infection. The objectives of this study were to isolate members of the family Enterobacteriaceae from urine samples of research participants, and to determine the antibacterial susceptibility and plasmid profiles of the isolates. A total of 122 mid-stream urine samples consisting of 72 male and 50 female participants from selected primary and secondary schools were collected. The age of the participants used …
Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman
Rapid Bacterial And Fungal Successional Dynamics In First Year After Chaparral Wildfire, M. Fabiola Pulido-Chavez, James W. J. Randolph, Cassandra A. Zalman, Loralee Larios, Peter M. Homyak, Sydney I. Glassman
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The rise in wildfire frequency and severity across the globe has increased interest in secondary succession. However, despite the role of soil microbial communities in controlling biogeochemical cycling and their role in the regeneration of post-fire vegetation, the lack of measurements immediately post-fire and at high temporal resolution has limited understanding of microbial secondary succession. To fill this knowledge gap, we sampled soils at 17, 25, 34, 67, 95, 131, 187, 286, and 376 days after a southern California wildfire in fire-adapted chaparral shrublands. We assessed bacterial and fungal biomass with qPCR of 16S and 18S and richness and composition …
Geological Soil Formation For Ecological Restoration Of Mining Areas And Its Case Study, Hu Zhenqi, Zhang Zixuan, Sun Huang
Geological Soil Formation For Ecological Restoration Of Mining Areas And Its Case Study, Hu Zhenqi, Zhang Zixuan, Sun Huang
Coal Geology & Exploration
Soil is an important substrate of plant growth, as well as the key for successful ecological restoration of mine. In view of the status of insufficient soil for most of ecological restoration of mine and the reality of a very long process of geological soil formation, the concept and method of geological soil formation for ecological restoration of mine (Mine-GSF for short) were discussed on the basis of description on the principle of natural geological soil formation. Natural geologic soil formation is the process of turning “rock” into “soil” through a long period of macro-geological cycle and biological cycle, including …
Experimental Study On Effect Of Soil Layer Reconstruction And Inoculation On Plant Root Hydraulic Lift In Open-Pit Coal Mine Dump, Bi Yinli, Gao Xuejiang, Ke Zengming, Xiao Li
Experimental Study On Effect Of Soil Layer Reconstruction And Inoculation On Plant Root Hydraulic Lift In Open-Pit Coal Mine Dump, Bi Yinli, Gao Xuejiang, Ke Zengming, Xiao Li
Coal Geology & Exploration
Soil layer reconstruction of open-pit coal mine dump is of great significance for ecological reconstruction. In order to study the effect of inoculation of dark septate endophytes (DSE) on water utilization of corn root system under different reconstructed soil layer models, soil column simulating and culturing test was adopted, with DSE inoculation and control treatment set up under each of the four soil layer types, in a total of 8 groups. The results show that the roots of corn are the longest with the maximum density under the treatment with 20% loess, which are 3.2, 2.4 and 2.8 times that …
Nitrous Oxide Production And Isotopomer Composition By Fungi Isolated From Salt Marsh Sediments, Birch Maxwell Lazo-Murphy, Samantha Larson, Sydney Staines, Heather Bruck, Julianne Mchenry, Annie Bourbonnais, Xuefeng Peng
Nitrous Oxide Production And Isotopomer Composition By Fungi Isolated From Salt Marsh Sediments, Birch Maxwell Lazo-Murphy, Samantha Larson, Sydney Staines, Heather Bruck, Julianne Mchenry, Annie Bourbonnais, Xuefeng Peng
Faculty Publications
The emissions of nitrous oxide (N2O), a potent greenhouse gas and ozone-depleting agent, have been steadily increasing from coastal environments, such as salt marsh sediments, as a result of anthropogenic nutrient loading. Biotic processes, including nitrification and denitrification, are the largest sources of N2O from salt marsh sediments. While it is assumed that the bulk of N2O from salt marsh sediment is produced by nitrification and bacterial denitrification, recent reports suggest fungal denitrification may contribute significantly. In this study, four fungi capable of growth under sulfidic conditions were isolated from salt marsh sediments in …
Relative Importance Of Radar Variables For Nowcasting Heavy Rainfall: A Machine Learning Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos
Relative Importance Of Radar Variables For Nowcasting Heavy Rainfall: A Machine Learning Approach, Yi Victor Wang, Seung Hee Kim, Geunsu Lyu, Choeng-Lyong Lee, Gyuwon Lee, Ki-Hong Min, Menas C. Kafatos
Institute for ECHO Articles and Research
Highly short-term forecasting, or nowcasting, of heavy rainfall due to rapidly evolving mesoscale convective systems (MCSs) is particularly challenging for traditional numerical weather prediction models. To overcome such a challenge, a growing number of studies have shown significant advantages of using machine learning (ML) modeling techniques with remote sensing data, especially weather radar data, for high-resolution rainfall nowcasting. To improve ML model performance, it is essential first and foremost to quantify the importance of radar variables and identify pertinent predictors of rainfall that can also be associated with domain knowledge. In this study, a set of MCS types consisting of …
Application Of Accuracy And Precision Evaluations Based On The Current United States And Indonesian Pharmacopoeias: A Critical Review, Gunawan Indrayanto
Application Of Accuracy And Precision Evaluations Based On The Current United States And Indonesian Pharmacopoeias: A Critical Review, Gunawan Indrayanto
Makara Journal of Science
New methods for the evaluation of accuracy and precision are mentioned in the latest edition of the United States Pharmacopoeia (USP), whereas other validation parameters, that is, selectivity, linearity, range, and robustness, remained relatively unchanged. In obtaining reliable data from any chemical/pharmaceutical analysis, the analytical procedure must be validated or verified in accordance with the latest edition of the pharmacopoeia. Some review articles on the general validation methods have been published by the author. This present review will focus on the implementation and discussion of the accuracy and precision evaluation based on the current USP and Indonesian pharmacopoeia. Some examples …
Chitosan Oligosaccharides As A Nanomaterial Platform: Biological Properties And Applications In The Biomedical And Pharmaceutical Fields, Muhamad Alif Razi
Chitosan Oligosaccharides As A Nanomaterial Platform: Biological Properties And Applications In The Biomedical And Pharmaceutical Fields, Muhamad Alif Razi
Makara Journal of Science
Chitosan oligosaccharides (COS) have been introduced as marine-derived biomaterials with potential health benefits and good water solubility properties. This study presents an overview of the promising nanomaterial platform for biomedical and pharmaceutical applications of COS. The health benefits of COS, primarily their antioxidant and protective effects, anti-inflammatory activity, antidiabetic properties, and cholesterol-lowering effects are discussed. Furthermore, the promising recent articles on specific topics such as drug delivery systems and nanobiomaterials, are highlighted
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Cenozoic Extension Of The Lake Tanganyika Rift, East Africa: Structures, Tectonostratigraphy And Paleoenvironmental Reconstruction, Shaidu Shaban
Dissertations - ALL
Active continental rifts are ideal sites for understanding the break-up of continents, and long-lived rift lake environments are known as important reservoirs for endemic communities and biodiversity. The sedimentary fill of extensional continental rifts within the East Africa Rift System (EARS) records a long history of continental extension and variable tropical climate that is unparalleled in its duration and fidelity. Continental extensional basins are sensitive to variations caused by the interplay between tectonics, sedimentary processes, and climate change. However, to discern the sedimentary fill history and its related tectonostratigraphy, as well as for reconstructing past climate changes, high-fidelity data such …
A Synthesis-Based Approach To The Study Of Fe(Ii) Oxidation In Smectites, Robert Joe Kupper Ii
A Synthesis-Based Approach To The Study Of Fe(Ii) Oxidation In Smectites, Robert Joe Kupper Ii
Arts & Sciences Graduate Student Theses and Dissertations
Smectite clay minerals are present in diverse environments on Earth as a major product of silicate weathering. Although smectites are compositionally varied, they almost always incorporate iron. Iron-bearing smectites are an important component of the biogeochemical iron cycle, serving as a major iron fraction in many soils and altered rocks as well as participating in redox reactions within the surrounding environment. Iron incorporates into smectites in the ferric [Fe(III)] form at the modern, oxygenated surface of Earth but clays forming in anoxic settings instead incorporate ferrous iron [Fe(II)]. Owing to their ubiquity at the surface of the modern Earth, the …
Predicted Episode Of Submarine Groundwater Discharge Onto The South Carolina, Usa, Continental Shelf And Its Effect On Dissolved Oxygen, Wilson S. Moore, Jacob Vincent, James L. Pickney, Alicia M. Wilson
Predicted Episode Of Submarine Groundwater Discharge Onto The South Carolina, Usa, Continental Shelf And Its Effect On Dissolved Oxygen, Wilson S. Moore, Jacob Vincent, James L. Pickney, Alicia M. Wilson
Faculty Publications
Submarine groundwater discharge (SGD) may directly influence the dissolved oxygen (DO) content of coastal bottom waters. Here, we report a predicted episode of enhanced SGD that caused low DO concentrations on the South Carolina continental shelf. The prediction model linked episodes of SGD to upwelling-favorable winds. The data revealed these waters were a factor of 2–6 higher in 226Ra and 228Ra compared to typical bottom water values and were significantly depleted in DO (<130 μM). The tight 228Ra:226Ra correlation of these data was similar to values during a strong hypoxic event off SC in 2012. Water ages from …130>
Silting Dynamics And Metal Contaminants In The Georgetown Inner Harbor, Ezekiel Wil Meyers
Silting Dynamics And Metal Contaminants In The Georgetown Inner Harbor, Ezekiel Wil Meyers
Electronic Theses and Dissertations
The Georgetown inner harbor is an abandoned oxbow-like river loop and a vital historic site with a wealth of traditional businesses and heavy local industry located within Winyah Bay. Since the modification of the Sampit River in 1949, chronic rapid silting has plagued the inner harbor. With these substantial amounts of fine-grained material accumulating inside the inner harbor, business operations along the waterfront, navigational and maritime operations, and contamination within the harbor are of major concern. The goals of this study were to (a) understand the silting dynamics inside the inner harbor, (b) identify heavy metals which might be of …
Extraction, Analysis, And Comparison Of Microplastics In Sc Marsh Substrates, Austin G. Sige
Extraction, Analysis, And Comparison Of Microplastics In Sc Marsh Substrates, Austin G. Sige
Electronic Theses and Dissertations
The global, rapid increase in plastic production is a widespread problem for coastal environments such as marshes that present favorable conditions for plastic retention. This study looked at the microplastic abundance within three previously unstudied South Carolina marshes located in Myrtle Beach, Murrells Inlet, and Waties Island. A comparison between the microplastic types and abundances between locations provided knowledge about the impacts of sediment composition (sand, silt, clay, and organic matter) on microplastic sequestration. This study also produced a novel microplastic extraction methodology for cohesive marsh sediment that used elutriation to effectively break apart aggregates prior to chemical digestion and …
Potential Use Of Pgpr Based Biofertilizer For Improving The Nutrient Availability In Soil And Agronomic Efficiency Of Upland Rice, Rahma Tia Harahap, Diyan Herdiyantoro, Mieke Rochimi Setiawati, Isna Niar Rahmatul Azizah, Tualar Simarmata
Potential Use Of Pgpr Based Biofertilizer For Improving The Nutrient Availability In Soil And Agronomic Efficiency Of Upland Rice, Rahma Tia Harahap, Diyan Herdiyantoro, Mieke Rochimi Setiawati, Isna Niar Rahmatul Azizah, Tualar Simarmata
Jurnal Kultivasi
Present study aimed to perform literature review to investigate the current status and potential use of plant growth promoting rhizobacteria (PGPR) for enhancing the soil plant’s health, plant growth and productivity in sustainable ways. The Systematic Literature Review (SLR) methods was applied according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) on published scientific literature from 2012-2022. Results revealed that genus diversity of PGPR (Bacillus sp., Serratia sp., Streptomyces sp., Pseudomonas sp., and Burkholderia sp.) produce siderophore and phytohormones such as indole-3-acetic acid (IAA), gibberellin (GAs), auxin, and 1-aminocyclopropane-1-carboxylic acid (ACC) deaminase activity, organic acids, biocontrol agent that …
Pfas Mass Balance, Donovan Vitale
Pfas Mass Balance, Donovan Vitale
Honors Theses
First-generation, PFOS-dominant Aqueous Film Forming Foam (AFFF) concentrate of approximately 200 gallons was released to the sewer system from the Kalamazoo/Battle Creek International Airport on March 30, 2021. The AFFF release migrated to the Kalamazoo Water Reclamation Plant (KWRP), raising plant effluent above the Department of Environment, Great Lakes, and Energy (EGLE) PFOS water quality standard for a total of 46 days post-spill, although the influent concentrations exhibited sharp declines after only 7 days. By sampling influent, effluent, and biosolids daily, the only known long duration, high-frequency PFAS data set of an accidental AFFF release was generated. This study has …
Examining The Relationship Between Stomiiform Fish Morphology And Their Ecological Traits, Mikayla L. Twiss
Examining The Relationship Between Stomiiform Fish Morphology And Their Ecological Traits, Mikayla L. Twiss
All HCAS Student Capstones, Theses, and Dissertations
Trait-based ecology characterizes individuals’ functional attributes to better understand and predict their interactions with other species and their environments. Utilizing morphological traits to describe functional groups has helped group species with similar ecological niches that are not necessarily taxonomically related. Within the deep-pelagic fishes, the Order Stomiiformes exhibits high morphological and species diversity, and many species undertake diel vertical migration (DVM). While the morphology and behavior of stomiiform fishes have been extensively studied and described through taxonomic assessments, the connection between their form and function regarding their DVM types, morphotypes, and daytime depth distributions is not well known. Here, three …
Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard
Surficial Geologic Mapping Of The Starkville 7.5-Minute United States Geological Survey Quadrangle 33088d-7 In Oktibbeha County, Mississippi, Jonathan Leard
Theses and Dissertations
The Starkville Quadrangle is a hotspot for geological research. The Late Cretaceous is represented by the Demopolis Formation in the northeast corner of the quadrangle, followed by the Ripley Formation, and the Prairie Bluff Formation. The K-Pg boundary is exposed in the quadrangle, and the remarkable paleontology is of global importance. The Clayton Formation is the first Paleocene unit. Where the Clayton Formation channel sands are in contact with the underlying Prairie Bluff Formation, springs occur. Springs were a rare source of water in the Black Prairie and spurred the settlement of the area over 10,000 years ago. The Paleocene …
Diversifying And Perennializing Plants In Agroecosystems Alters Retention Of New C And N From Crop Residues, Marshall D. Mcdaniel, Jeffrey A. Bird, Jennifer Pett-Ridge, Erika Marin-Spiotta, Tom M. Schmidt, A. Stuart Grandy
Diversifying And Perennializing Plants In Agroecosystems Alters Retention Of New C And N From Crop Residues, Marshall D. Mcdaniel, Jeffrey A. Bird, Jennifer Pett-Ridge, Erika Marin-Spiotta, Tom M. Schmidt, A. Stuart Grandy
Faculty Publications
Managing soils to retain new plant inputs is key to moving toward a sustainable and regenerative agriculture. Management practices, like diversifying and perennializing agroecosystems, may affect the decomposer organisms that regulate how new residue is converted to persistent soil organic matter. Here we tested whether 12 years of diversifying/perennializing plants in agroecosystems through extended rotations or grassland restoration would decrease losses of new plant residue inputs and, thus, increase retention of carbon (C) and nitrogen (N) in soil. We tracked dual-labeled (13C and 15N), isotopically enriched wheat (Triticum aestivum) residue in situ for 2 years as it decomposed in three …
Application Of Organic Fertilizer And Phosphate Solubilizing Bacteria To Increase The Growth And Yield Of Potatoes In Andisol, Agustina Erlinda Marpaung, Bina Karo, Susilawati Barus, Rina Christina Hutabarat, Rasiska Tarigan
Application Of Organic Fertilizer And Phosphate Solubilizing Bacteria To Increase The Growth And Yield Of Potatoes In Andisol, Agustina Erlinda Marpaung, Bina Karo, Susilawati Barus, Rina Christina Hutabarat, Rasiska Tarigan
Jurnal Kultivasi
Andisol has low phosphate (P) nutrient content due to high P fixation by allophane minerals, which affects crop production. The application of organic fertilizers and phosphate solubilizing bacteria can increase the availability of P in the soil in order to increase the production of potato plants. This study aimed to evaluate the effect of different types of organic fertilizer and phosphate solubilizing bacteria (PSB) on potato production. The research was conducted from August to November 2020 in the installation of research and assessment of agricultural technology Berastagi, Karo Regency, with an altitude of ± 1,340 m above sea level and …
Larval Ecology Of Atlantic Bluefin Tuna (Thunnus Thynnus): New Insights From Otolith Microstructure, Biotic, And Abiotic Analyses From The Gulf Of Mexico And Mediterranean Sea, Estrella Malca
All HCAS Student Capstones, Theses, and Dissertations
Atlantic bluefin tuna (ABT), Thunnus thynnus, spawn in the Gulf of Mexico (GoM) and the Mediterranean Sea (MED). Spawning occurs within narrow temporal and environmental parameters. Efforts to characterize growth of ABT in wild conditions revealed a wide range of growth variability during the early life stages. This series of studies examined potential biotic and abiotic influences of larval growth from seven ABT cohorts, and identified several key drivers of growth for this commercially valuable species. A detailed investigation of larval dynamics using otolith microstructure was conducted as follows. First, companion growth curves and stable isotope analysis from the same …
Behaviors For Which Deinonychosaurs Used Their Feet, Alexander King
Behaviors For Which Deinonychosaurs Used Their Feet, Alexander King
Honors Projects
This paper seeks to show for what purpose deinonychosaurs used their feet. Fowler et al., (2011) showed that D. antirrhopus’s feet were closest in function to accipitrids, as they found it was more built for grasping prey than running.
I answered this question by using 2D images of the feet of three modern birds (Buteo jamaicensis, Phasianus colchicus, and Gallus gallus domesticus), one eudromaeosaur (Deinonychus antirrhopus), and one troodontid (Borogovia gracilicrus). I used ImageJ to apply 73 landmarks to each foot, capturing the variation between species in the metatarsals and pedal phalanges. These data were then uploaded to the software …
Sturgeon Chub Distributional Patterns And Habitat Use And Benthic Fish Assemblage Structure In Missouri River Tributaries Of South Dakota, Mitchell R. Magruder
Sturgeon Chub Distributional Patterns And Habitat Use And Benthic Fish Assemblage Structure In Missouri River Tributaries Of South Dakota, Mitchell R. Magruder
School of Natural Resources: Dissertations, Theses, and Student Research
Native species of the Missouri River drainage inhabiting benthic habitats dominate state and federal lists of species at risk. Sicklefin Chub Macrhybopsis meeki and Sturgeon Chub Macrhybopsis gelida are two native Missouri River benthic minnows that are currently under review for federal listing under the Endangered Species Act (ESA) due to extensive population declines and local extirpations within their native range. Substantial alterations to the Missouri River threaten Macrhybopsis spp. and other benthic fishes; however, large, less impacted tributaries in South Dakota may act as refugia for native species. The extent of Sicklefin Chub and Sturgeon Chub populations is largely …
Earlier Snowmelt May Lead To Late Season Declines In Plant Productivity And Carbon Sequestration In Arctic Tundra Ecosystems, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Barbara Bailey, Beniamino Gioli, George Burba, Jordan P. Goodrich, Anna K. Liljedahl, Eugénie S. Euskirchen, Jennifer D. Watts, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Marcin Jackowicz-Korczynski, Albertus J. Dolman, Luca Belelli Marchesini, Roisin Commane, Steven C. Wofsy, Charles E. Miller, David A. Lipson, Josh Hashemi, Kyle A. Arndt, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Xia Song
Earlier Snowmelt May Lead To Late Season Declines In Plant Productivity And Carbon Sequestration In Arctic Tundra Ecosystems, Donatella Zona, Peter M. Lafleur, Koen Hufkens, Barbara Bailey, Beniamino Gioli, George Burba, Jordan P. Goodrich, Anna K. Liljedahl, Eugénie S. Euskirchen, Jennifer D. Watts, Mary Farina, John S. Kimball, Martin Heimann, Mathias Göckede, Martijn Pallandt, Torben R. Christensen, Mikhail Mastepanov, Efrén López-Blanco, Marcin Jackowicz-Korczynski, Albertus J. Dolman, Luca Belelli Marchesini, Roisin Commane, Steven C. Wofsy, Charles E. Miller, David A. Lipson, Josh Hashemi, Kyle A. Arndt, Lars Kutzbach, David Holl, Julia Boike, Christian Wille, Torsten Sachs, Aram Kalhori, Xia Song
Daugherty Water for Food Global Institute: Faculty Publications
Arctic warming is affecting snow cover and soil hydrology, with consequences for carbon sequestration in tundra ecosystems. The scarcity of observations in the Arctic has limited our understanding of the impact of covarying environmental drivers on the carbon balance of tundra ecosystems. In this study, we address some of these uncertainties through a novel record of 119 site-years of summer data from eddy covariance towers representing dominant tundra vegetation types located on continuous permafrost in the Arctic. Here we found that earlier snowmelt was associated with more tundra net CO2 sequestration and higher gross primary productivity (GPP) only in June …
Modeling Of Population Dynamics In Spatially Continuous And Heterogeneous Environments Using Partial Differential Equations, Ryan T. St. Clair
Modeling Of Population Dynamics In Spatially Continuous And Heterogeneous Environments Using Partial Differential Equations, Ryan T. St. Clair
Masters Theses & Specialist Projects
This thesis provides an expansion of existing reaction diffusion population ecology models into patchy landscapes with greater spatial heterogeneity. The Sturm-Loiville eigenvalue problem for a heterogeneous 3 patch landscape is solved implicitly and the population growth rate and migration dynamics on such a landscape are thoroughly discussed. In addition a system of interface equations is found whose greatest solution is the dominant eigenvalue of an N-patch landscape. The results of this model agree well with previously published results and show the mathematical equivalence of two published approaches for incorporating organism behavior at habitat interfaces. Increased modeling capabilities in heterogeneous environments …
Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan
Carbon Cycling And Critical Zone Dynamics In An Urbanized Karst Groundwater System, Amy Hourigan
Masters Theses & Specialist Projects
Increasing atmospheric CO2 concentrations are correlated to rising global temperatures. Investigating the cumulative global carbon cycling processes is important to understand and quantify the global carbon cycle. By investigating basic geochemical parameters, EpCO2, DIC, and δ13CDIC, at four sites along Lost River Cave (LRC), in Bowling Green, Kentucky, concentrations, fluxes and sources of C dissolved in groundwater were determined. Urban karst groundwater systems, compared to more natural karst landscapes, typically exhibit widespread impervious, heat-absorbing surfaces, urban heat island effects, and increased anthropogenic groundwater inputs and localized CO2 emissions. Carbonate hydrogeochemical …
Flood Hazard And Risk Analyses In The Republic Of Panama: A Case Study From The Juan Diaz River Watershed In Panama City, Virgilio De Jesus Quintero
Flood Hazard And Risk Analyses In The Republic Of Panama: A Case Study From The Juan Diaz River Watershed In Panama City, Virgilio De Jesus Quintero
Graduate Theses and Dissertations
Flooding is the natural hazard with most occurrences in Panama. Its frequency and magnitude have increased over the years. This dissertation analyzes Panama’s flood activity in order to better understand flood hazards, the current evolution of Panamanian perceptions of flood risk, and the incorporation of indigenous knowledge used to mitigate flood hazards. The first chapter developed a baseline of past and current flood inventory in Panama, which required the use of flood historical data, thematic cartography, and Geographic Information Science (GIS). This chapter shows Panama has experienced floods in varying degrees. Through the spatial and temporal distribution of floods from …
Investigating The Frictional Properties Of Organic Matter And Pore Structure Of Organic-Rich Shales With Atomic Force Microscopy And Scanning Electron Microscopy, Farnood Sobhbidari
Investigating The Frictional Properties Of Organic Matter And Pore Structure Of Organic-Rich Shales With Atomic Force Microscopy And Scanning Electron Microscopy, Farnood Sobhbidari
Earth & Environmental Sciences Dissertations - Archive
Understanding geomechanical properties of shales, such as stiffness properties and fracture toughness, is important in different areas of petroleum industry-related activities including fracturing efficiency, petroleum flow to the wellbores, and induced seismicity. Nanoscale to microscale experiments on shale samples require a much smaller sample compared to macroscale experiments. This is a major advantage because irregularly-shaped drill cuttings from shales can be used for experimental analyses, such as nanoindentation or atomic force microscopy (AFM). However, a characterization of mechanical properties at the nano- to micro-scale is a relatively new addition to classical geomechanical experiments on shales, and there is still lack …
Antiphased Dust Deposition And Productivity In The Antarctic Zone Over 1.5 Million Years, Michael E. Weber, Ian Bailey, Sidney R. Hemming, Yasmina M. Martos, Brendan T. Reilly, Thomas A. Ronge, Stefanie Brachfeld, Trevor Williams, Maureen Raymo, Simon T. Belt, Lukas Smik, Hendrik Vogel, Victoria L. Peck, Linda Armbrecht, Alix Cage, Fabricio G. Cardillo, Zhiheng Du, Gerson Fauth, Christopher J. Fogwill, Marga Garcia, Marlo Garnsworthy, Anna Glüder, Michelle Guitard, Marcus Gutjahr, Iván Hernández-Almeida, Frida S. Hoem, Ji Hwan Hwang, Mutsumi Iizuka, Yuji Kato, Bridget Kenlee, Suzanne Oconnell, Lara F. Pérez
Antiphased Dust Deposition And Productivity In The Antarctic Zone Over 1.5 Million Years, Michael E. Weber, Ian Bailey, Sidney R. Hemming, Yasmina M. Martos, Brendan T. Reilly, Thomas A. Ronge, Stefanie Brachfeld, Trevor Williams, Maureen Raymo, Simon T. Belt, Lukas Smik, Hendrik Vogel, Victoria L. Peck, Linda Armbrecht, Alix Cage, Fabricio G. Cardillo, Zhiheng Du, Gerson Fauth, Christopher J. Fogwill, Marga Garcia, Marlo Garnsworthy, Anna Glüder, Michelle Guitard, Marcus Gutjahr, Iván Hernández-Almeida, Frida S. Hoem, Ji Hwan Hwang, Mutsumi Iizuka, Yuji Kato, Bridget Kenlee, Suzanne Oconnell, Lara F. Pérez
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The Southern Ocean paleoceanography provides key insights into how iron fertilization and oceanic productivity developed through Pleistocene ice-ages and their role in influencing the carbon cycle. We report a high-resolution record of dust deposition and ocean productivity for the Antarctic Zone, close to the main dust source, Patagonia. Our deep-ocean records cover the last 1.5 Ma, thus doubling that from Antarctic ice-cores. We find a 5 to 15-fold increase in dust deposition during glacials and a 2 to 5-fold increase in biogenic silica deposition, reflecting higher ocean productivity during interglacials. This antiphasing persisted throughout the last 25 glacial cycles. Dust …
Impact Of Eocene-Oligocene Antarctic Glaciation On The Paleoceanography Of The Weddell Sea, Victoria Hojnacki, Allison Lepp, Josie Horowitz Castaldo, Abbey States, Xiaona Li, Sandra Passchier
Impact Of Eocene-Oligocene Antarctic Glaciation On The Paleoceanography Of The Weddell Sea, Victoria Hojnacki, Allison Lepp, Josie Horowitz Castaldo, Abbey States, Xiaona Li, Sandra Passchier
Department of Earth and Environmental Studies Faculty Scholarship and Creative Works
The Eocene-Oligocene Transition (EOT) at ∼34 Ma marked a climatic shift from greenhouse to icehouse conditions, toward long-lasting lower global temperatures and a continental ice sheet in the Antarctic. We report on sedimentological and inorganic geochemical results across the EOT at Ocean Drilling Program (ODP) Site 696 in the Weddell Sea, within the Antarctic limb of the Atlantic circulation. The geochemical composition of detrital, authigenic and biogenic marine sediment components, and sortable silt proxies demonstrate the impact of ice growth on high latitude water masses. Sortable silt grain size and Zr/Rb ratios attest to a period of vigorous circulation at …