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Articles 6691 - 6720 of 18682
Full-Text Articles in Entire DC Network
In-Air Hearing Of A Diving Duck: A Comparison Of Psychoacoustic And Auditory Brainstem Response Thresholds, Sara E. Crowell, Alicia M. Wells-Berlin, Ronald E. Therrien, Sally E. Yannuzzi, Catherine E. Carr
In-Air Hearing Of A Diving Duck: A Comparison Of Psychoacoustic And Auditory Brainstem Response Thresholds, Sara E. Crowell, Alicia M. Wells-Berlin, Ronald E. Therrien, Sally E. Yannuzzi, Catherine E. Carr
United States Geological Survey: Staff Publications
Auditory sensitivity was measured in a species of diving duck that is not often kept in captivity, the lesser scaup. Behavioral (psychoacoustics) and electrophysiological [the auditory brainstem response (ABR)] methods were used to measure in-air auditory sensitivity, and the resulting audiograms were compared. Both approaches yielded audiograms with similar U-shapes and regions of greatest sensitivity (2000-3000 Hz). However, ABR thresholds were higher than psychoacoustic thresholds at all frequencies. This difference was least at the highest frequency tested using both methods (5700 Hz) and greatest at 1000 Hz, where the ABR threshold was 26.8 dB higher than the behavioral measure of …
Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove
Amino Acid Specific Stable Nitrogen Isotope Values In Avian Tissues: Insights From Captive American Kestrels And Wild Herring Gulls, C.E. Hebert, B.N. Popp, K.J. Fernie, C. Ka’Apu-Lyons, B.A. Rattner, N. Wallsgrove
United States Geological Survey: Staff Publications
Through laboratory and field studies, the utility of amino acid compound-specific nitrogen isotope analysis (AA-CSIA) in avian studies is investigated. Captive American kestrels (Falco sparverius) were fed an isotopically characterized diet and patterns in δ15N values of amino acids (AAs) were compared to those in their tissues (muscle and red blood cells) and food. Based upon nitrogen isotope discrimination between diet and kestrel tissues, AAs could mostly be categorized as source AAs (retaining baseline δ15N values) and trophic AAs (showing 15N enrichment). Trophic discrimination factors based upon the source (phenylalanine, Phe) and trophic (glutamic acid, Glu) AAs were 4.1 (muscle) …
Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman
Pranked By Audubon: Constantine S. Rafinesque’S Description Of John James Audubon’S Imaginary Kentucky Mammals, Neal Woodman
United States Geological Survey: Staff Publications
The North American naturalist Constantine S. Rafinesque spent much of the year 1818 engaged in a solo journey down the Ohio River Valley to explore parts of what was then the western United States. Along the way, he visited a number of fellow naturalists, and he spent more than a week at the Henderson, Kentucky, home of artist and ornithologist John James Audubon. During the succeeding two years, Rafinesque published descriptions of new species that resulted from his expedition, including eleven species of fishes that eventually proved to have been invented by Audubon as a prank on the credulous naturalist. …
Leveraging Federal Land Plans Into Landscape Conservation, Robert L. Fischman
Leveraging Federal Land Plans Into Landscape Conservation, Robert L. Fischman
Articles by Maurer Faculty
Professor Fischman’s article suggests several ways in which a mandated unit-level (e.g. an individual national forest) plan can better contribute to goals of a larger region (e.g. the Willamette River watershed) and of federal agencies (e.g. mandates to maintain ecological integrity). The scientific literature is largely in agreement that achieving ecological integrity, adaptive management, and climate change resiliency all require large-scale coordination across property boundaries and jurisdictions. The author takes these widely accepted findings as a starting point and shows how public agencies can implement effective practices. The article attempts to integrate traditional regulatory analysis with actual planning practices as …
Potential Benefits And Shortcomings Of Marine Protected Areas For Small Seabirds Revealed Using Miniature Tags, Sara M. Maxwell, Melinda G. Conners, Nicholas B. Sisson, Tiffany M. Dawson
Potential Benefits And Shortcomings Of Marine Protected Areas For Small Seabirds Revealed Using Miniature Tags, Sara M. Maxwell, Melinda G. Conners, Nicholas B. Sisson, Tiffany M. Dawson
Biological Sciences Faculty Publications
Marine protected areas are considered important tools for protecting marine biodiversity, and animal tracking is a key way to determine if boundaries are effectively placed for protection of key marine species, including seabirds. We tracked chick-rearing brown noddies (Anous stolidus) from the Dry Tortugas National Park in Florida USA in 2016 using 1.8 g Nanofix GPS tags (n = 10), making this the first time this species has ever been tracked. We determined movement parameters, such as flight speed, distance traveled and home range, and how birds used a complex of marine protected areas including the Dry Tortugas …
Geospatial Approaches To Support Pelagic Conservation Planning And Adaptive Management, L. M. Wedding, Sara M. Maxwell, D. Hyrenbach, D. C. Dunn, J. J. Roberts, D. Briscoe, E. Hines, P. N. Halpin
Geospatial Approaches To Support Pelagic Conservation Planning And Adaptive Management, L. M. Wedding, Sara M. Maxwell, D. Hyrenbach, D. C. Dunn, J. J. Roberts, D. Briscoe, E. Hines, P. N. Halpin
Biological Sciences Faculty Publications
Place-based management in the open ocean faces unique challenges in delineating boundaries around temporally and spatially dynamic systems that span broad geographic scales and multiple management jurisdictions, especially in the 'high seas'. Geospatial technologies are critical for the successful design of pelagic conservation areas, because they provide information on the spatially and temporally dynamic oceanographic features responsible for driving species distribution and abundance in the open ocean, the movements of protected species, and the spatial patterns of distribution of potential threats. Nevertheless, there are major challenges to implementing these geospatial approaches in the open ocean. This Theme Section seeks to …
A Small-Scale Water Budget Approach And Water Quality Assessment: A Case Study For Calderas Lake, Guatemala, Edrick Ramos
A Small-Scale Water Budget Approach And Water Quality Assessment: A Case Study For Calderas Lake, Guatemala, Edrick Ramos
Dissertations, Master's Theses and Master's Reports
Increases in water demand and urban development in Calderas community over the past decade have led to questions about the hydrology, water quality, quantity and sustainable management of Calderas Lake micro-basin. However, studies on baseline hydrology are limited for rural communities located inside volcanic origin watersheds of Guatemala. The scope of this study was to characterize the hydrology and establish a method to: 1) quantify a water budget, and 2) qualify the water quality of a lacustrine system that supply water for about 17,000 inhabitants on the state limits or rural Guatemala City. Mean annual rainfall and temperature at the …
Success Stories And Emerging Themes In Conservation Physiology, Christine L. Madliger, Steven J. Cooke, Erica J. Crespi, Jennifer L. Funk, Kevin R. Hultine, Kathleen E. Hunt, Jason R. Rohr, Brent J. Sinclair, Cory D. Suski, Craig K. R. Willis, Oliver P. Love
Success Stories And Emerging Themes In Conservation Physiology, Christine L. Madliger, Steven J. Cooke, Erica J. Crespi, Jennifer L. Funk, Kevin R. Hultine, Kathleen E. Hunt, Jason R. Rohr, Brent J. Sinclair, Cory D. Suski, Craig K. R. Willis, Oliver P. Love
Biology, Chemistry, and Environmental Sciences Faculty Articles and Research
The potential benefits of physiology for conservation are well established and include greater specificity of management techniques, determination of cause–effect relationships, increased sensitivity of health and disturbance monitoring and greater capacity for predicting future change. While descriptions of the specific avenues in which conservation and physiology can be integrated are readily available and important to the continuing expansion of the discipline of ‘conservation physiology’, to date there has been no assessment of how the field has specifically contributed to conservation success. However, the goal of conservation physiology is to foster conservation solutions and it is therefore important to assess whether …
Assessment Of Her2-Neu In Breast Cancer Lines Upon Differential Exposures To Xenoestrogens, Abha Aggarwal
Assessment Of Her2-Neu In Breast Cancer Lines Upon Differential Exposures To Xenoestrogens, Abha Aggarwal
Walden Dissertations and Doctoral Studies
Synthetic xenoestrogens have differential estrogenic properties. Research has shown that exposures to xenoestrogens could promote breast cancer by disrupting normal function of the human epidermal growth factor receptor 2 (Her2) gene. Although animal models demonstrated a connection between xenoestrogen exposure and Her2 activity, no study using human cells has systematically examined their carcinogenic potential influencing the Her2 gene expression. Furthermore, breast cancer cells are phenotypically disparate (ER+, Her2+), with some phenotypes (Her2+), leading to more aggressive disease. This study aimed to dosimetrically assess the carcinogenic potential of commonly used xenoestrogens influencing Her2 gene expression, and delineate cellular phenotypes at greater …
Methylmercury Exposure Via Canned Tuna Fish Consumption And Breast Cancer, Jennifer Bodenrader
Methylmercury Exposure Via Canned Tuna Fish Consumption And Breast Cancer, Jennifer Bodenrader
Walden Dissertations and Doctoral Studies
Widespread consumption of canned tuna fish since the 1950s may explain some of the increase in breast cancer prevalence in the United States and Europe. Although canned tuna is the primary source of human exposure to methylmercury, its role as an estrogen activating metalloestrogen has been overlooked in the etiology and incidence of breast cancer. Carcinogenic theory asserts that increased exposure to estrogen elevates the risk of breast cancer. The purpose of this population-based, case control study was to examine the association between canned tuna consumption, total blood mercury, and breast cancer in the NHANES 2003-2006 surveys. A multivariable logistic …
Environmental Leadership: Exploring Environmental Dissonance Involving Natural Resource Consumption And Ecosystem Degradation, Thomas L. Tochterman
Environmental Leadership: Exploring Environmental Dissonance Involving Natural Resource Consumption And Ecosystem Degradation, Thomas L. Tochterman
Walden Dissertations and Doctoral Studies
As the corporate world, communities, and individuals become more globalized and demands on natural resources increase, a new emphasis on environmental leadership including a new pragmatic environmental ethos is needed to meet certain basic human needs of future generations. The research problem addressed in this study was the lack of knowledge concerning how environmental cognitive dissonance influences consumption practices related to inefficient resource utilization and ecosystem degradation. The purpose of this study was to provide an understanding of the breadth and depth of environmental cognitive dissonance among visitors to the Kruger National Park in South Africa. The research questions addressed …
The Bop Energy Challenge And Pro-Poor Responses: Strategic Entry Pathways For Entrepreneurs, Felix Motekah Tang
The Bop Energy Challenge And Pro-Poor Responses: Strategic Entry Pathways For Entrepreneurs, Felix Motekah Tang
Walden Dissertations and Doctoral Studies
Many large multinational energy company leaders lack strategies to successfully enter and thrive in bottom of the pyramid (BOP) markets. The purpose of this single case study was to explore strategies using a purposeful selection of 7 senior managers from a U. S. based global multinational energy leader with experience in BOP markets in the Republic of Cameroon. The BOP concept served as the conceptual framework for the study. Data were collected through semistructured interviews with senior managers, relevant websites, and government publications. Several themes emerged that were narrowed through categorical aggregation to identify strategies. Major themes included BOP readiness …
Water Management Efficiency In The Food And Beverage Industry, Maria Del C Reyes Torres
Water Management Efficiency In The Food And Beverage Industry, Maria Del C Reyes Torres
Walden Dissertations and Doctoral Studies
Water is critical for food production, food security, and health. Water quality management influences freshwater sustainability, land, and energy administration. Global agriculture accounts for more than 70% of all water consumption; the fertilizer, manure, and pesticide overspills are chief sources of water pollution worldwide. On a global scale, food-related waste directly impacts local food production and water resource management. The purpose of this multiple-case study on the food and beverage (FB) industry in the State of Georgia was to identify successful strategies for improving water management efficiency. The concepts of systems thinking, adaptive resource management, and integrated water resource management …
Relocation Based On Slow-Onset Climate-Induced Environmental Change In Keta, Ghana, Abdul-Moomin Ansong Salifu
Relocation Based On Slow-Onset Climate-Induced Environmental Change In Keta, Ghana, Abdul-Moomin Ansong Salifu
Walden Dissertations and Doctoral Studies
Coastal indigenous communities in Keta, Ghana, are experiencing resettlement as a result of slow-onset, climate-induced flooding and erosion. Previous researchers have documented the risk of relocation from rapid-onset events, but little is known about the effectiveness of policies developed in response to slow-onset changes. This phenomenological study investigated the ongoing lived experiences of adult household members in Keta who were relocated by the government. Jun's critical theory provided a constructionist interpretive framework to determine whether Ghana's national policy on climate change resettlement adequately meets Rawls's criteria for distributive social justice. Policy documents and transcriptions of interviews with a purposeful sample …
Adapting Near-Ultraviolet Colorimetry For Long-Term In Situ Monitoring Of Hexavalent Chromium In Groundwater Aquifers, Janine Carter
Adapting Near-Ultraviolet Colorimetry For Long-Term In Situ Monitoring Of Hexavalent Chromium In Groundwater Aquifers, Janine Carter
Graduate Student Theses, Dissertations, & Professional Papers
This paper briefly describes sources of hexavalent chromium [Cr(VI)] and the risk it poses to human health and the environment; current methods used to regulate, monitor, and measure Cr(VI); the basic design of a submersible, direct-reading sensor in development for long-term monitoring of Cr(VI) concentration in natural waters; and the means developed to correct sensor readings for two common analytical interferences, turbidity and pH, that could lead to an incorrect measurement of Cr(VI). The principal purposes of this study are to analyze the current methods used to compensate for sample turbidity, to develop methods to compensate for sample pH, and …
Human Shields And Redistribution Of Prey Species Complicate The Utility Of Protected Areas As Ecological Baselines, Wesley Sarmento
Human Shields And Redistribution Of Prey Species Complicate The Utility Of Protected Areas As Ecological Baselines, Wesley Sarmento
Graduate Student Theses, Dissertations, & Professional Papers
A key goal of protected areas is the conservation of biodiversity, an aim that garners increasing public support through positive experiences. Increasing visitation, however, can come at the cost of reduced ecological integrity. A fundamental conundrum is that if parks are to serve as our most pristine places, then we must understand how our presence alters species interactions. Species redistributing closer to people is of growing management concern both in and out of national parks because of 1) human safety, 2) animal health, and 3) ecological consequences. Across parks drivers of distributional change are often dissimilar, and include movement to …
Impacts Of Recreational Aviation On Wildlife: The Physiological Stress Response In White-Tailed Deer (Odocoileus Virginianus) And Associated User Perceptions, Devin W. Landry
Graduate Student Theses, Dissertations, & Professional Papers
Recreational aviation on public lands may negatively impact wildlife. However, land-use decisions need to balance user need with wildlife impact. We know very little about 1) how back country airstrip use affects local wildlife, or 2) attitudes and perceptions of recreational pilots toward possible management actions. For my Master’s research, I investigated how aircraft activity influenced physiological measures of stress in white-tailed deer, while also modeling how psychometrics such as wildlife attitudes and place attachment predict the willingness of recreational pilots engage in impact-mitigating behaviors. I measured physiological stress through non-invasive sampling of stress hormones in fecal samples (fecal glucocorticoid …
Seasonal Habitat Selection Of The North American Porcupine (Erethizon Dorsatum) In A Coastal Dune Forest, Cara L. Appel
Seasonal Habitat Selection Of The North American Porcupine (Erethizon Dorsatum) In A Coastal Dune Forest, Cara L. Appel
Cal Poly Humboldt theses and projects
Wildlife-habitat relationship studies are important for understanding the factors that determine where species occur in space and time. Habitat selection by generalist species should be studied on fine spatial and temporal scales to avoid masking important differences between seasons, localities, or orders of selection. I conducted the first study of habitat use and general ecology of North American porcupines (Erethizon dorsatum) in a coastal dune environment. Specifically, I assessed changes in body mass, home range size, and habitat selection in relation to the potential for seasonal nutritional and survival bottlenecks as reported elsewhere. Although they are considered generalists, …
Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman
Juvenile Survival And Adult Return As A Function Of Freshwater Rearing Life History For Coho Salmon In The Klamath River Basin, Molly Gorman
Cal Poly Humboldt theses and projects
The Scott and Shasta rivers, Klamath River tributaries, experience spatial disparity in habitat quality in spring and summer as a result of historical and current land-use. Juvenile Coho Salmon (Oncorhynchus kisutch) born in the upper tributary reaches often rear in natal streams before migrating to sea. However, those born in the lower reaches often encounter unsuitable habitat and emigrate during their first spring to seek non-natal rearing habitats. It is assumed that these early outmigrants are population losses. This study evaluated first-summer survival, and contribution to the adult population, of non-natal rearing juveniles in the Klamath River Basin. …
Do Toxicity Modifying Factors Influence Acute Or Chronic Toxicity Of Thulium To Hyalella Azteca?, Alexandria H. Loveridge
Do Toxicity Modifying Factors Influence Acute Or Chronic Toxicity Of Thulium To Hyalella Azteca?, Alexandria H. Loveridge
Theses and Dissertations (Comprehensive)
The industrial demand for rare earth elements (REEs) is growing and as a result, environmental exposure is a concern. Very little is understood about the toxicity of REEs in aquatic environments. The objective of this research is to evaluate the acute and chronic toxicity of Tm and to also understand the toxicity modifying influence of dissolved organic matter (DOM) and cationic competition (Ca2+, Mg2+ and Na+). Furthermore, the aim of this study was to determine linkages between Tm bioaccumulation, growth and survival during chronic exposures. Standard methods (Environment Canada) were followed for both 96h acute and 14d chronic tests, in …
Multi-Criteria Decision Analysis (Mcda) For Agricultural Sustainability Assessment, Byomkesh Talukder
Multi-Criteria Decision Analysis (Mcda) For Agricultural Sustainability Assessment, Byomkesh Talukder
Theses and Dissertations (Comprehensive)
Multi Attribute Utility Theory (MAUT), Preference Ranking Organization Method for Enrichment Evaluations (PROMETHEE) and Elimination methods of Multi-Criteria Decision analysis (MCDA) are tested to assess and compare the sustainability of different agricultural systems. Indicators and composite indicators are derived from data gathered using the agricultural sustainability categories of Productivity, Stability, Efficiency, Durability, Compatibility and Equity (PSEDCE).
Agricultural systems around the world face challenges from current agricultural practices, over-exploitation of natural resources, population growth and climate change. As a result, understanding agricultural sustainability has become a global issue. Assessment is a first step in benchmarking and tracking agricultural sustainability and …
Chemical Removal Of Total Phosphorus From Wastewater To Low Levels And Its Analysis, Farah Ateeq
Chemical Removal Of Total Phosphorus From Wastewater To Low Levels And Its Analysis, Farah Ateeq
Theses and Dissertations (Comprehensive)
Numerous studies have been conducted on the removal of inorganic phosphorus (P) from wastewater, but a push towards lower effluent targets necessitates the additional removal of organic phosphorus as well. This study tested the ability of manganese oxide nanoparticles and iron oxide as potential catalysts for conversion of organic P into more readily removable inorganic forms, as well as the role of iron(III) chloride as coagulant to subsequently allow P to be removed by solids/liquid separation. Removals of 99-101% were obtained for model compounds at pH 5-7, 0.05-0.5 M H2O2, and Fe:P molar ratio of 5:1. …
Screening And Characterization Of Polyhydroxyalkanoates (Phas) From Cyanobacteria Utilizing Organic Carbon, Somchai Tarawat
Screening And Characterization Of Polyhydroxyalkanoates (Phas) From Cyanobacteria Utilizing Organic Carbon, Somchai Tarawat
Chulalongkorn University Theses and Dissertations (Chula ETD)
Polyhydroxyalkanoates (PHAs) are a group of biodegradable plastic. These biopolymers are environmentally friendly because they can be decomposed by microorganisms. PHAs production is also renewable and sustainable. There are many types of PHAs. This thesis aimed to screen for Thailand-isolated cyanobacterial strains that can produce two types of PHAs: the homopolymer poly(3-hydroxybutyrate) (PHB) and the heteropolymer poly(3-hydroxybutyrate-co-3-hydroxyvalerate) (PHBV). Cells were cultured under the heterotrophic condition (nitrogen deprivation with 0.4% w/v acetate supply in the dark). PHB contents in cyanobacteria were determined using high performance liquid chromatography. From 135 strains accounting for 26 genera, 9 strains accumulated PHB at the levels …
Removal Of Endocrine Disrupting Compounds From Water And Wastewater Using Ecofriendly Materials, Alma Lili Loya Posada
Removal Of Endocrine Disrupting Compounds From Water And Wastewater Using Ecofriendly Materials, Alma Lili Loya Posada
Open Access Theses & Dissertations
Endocrine disrupting chemicals (EDCs) are compounds considered pollutants of emerging concern. The United States Environmental Protection Agency (USEPA) defines emerging pollutants as new chemicals without regulatory status and with an impact on the environment and human health that is poorly understood. Bisphenol A (BPA) has been considered an EDC and found to be ubiquitous in the environment because of its presence in a multitude of products including food and beverage packaging, flame retardants, adhesives, building materials, electronic components, and paper coatings Currently, BPA is not regulated by the federal government in the US and waste water treatment plants are not …
Spatiotemporal Variability Of Plant Phenology In Drylands: A Case Study From The Northern Chihuahuan Desert, Naomi Robin Luna
Spatiotemporal Variability Of Plant Phenology In Drylands: A Case Study From The Northern Chihuahuan Desert, Naomi Robin Luna
Open Access Theses & Dissertations
With global change, which includes climate change, there is a sense of urgency to understand how shifts in climate will affect ecosystems. Although several studies have improved understanding of how and why some ecosystems respond, most studies have not explored simultaneous responses of different land cover types throughout a given region. Dryland ecosystems, such as the Chihuahuan Desert, appear to respond to climate variability and currently make up about 40% of global land surface area. It is expected that drylands will expand to cover 60% of land surface area on earth by mid-century making this ecosystem more critical to global …
Study Of No2 Photolysis Rate Coefficients For The Paso Del Norte Region, Pema Wangchuk
Study Of No2 Photolysis Rate Coefficients For The Paso Del Norte Region, Pema Wangchuk
Open Access Theses & Dissertations
The photolysis of nitrogen dioxide is one of the most influential chemical processes in the formation of photochemical air pollution. In this study, we compared simulated and measured nitrogen dioxide photolysis rate coefficients (J_(NO_2 )) for the Paso Del Norte (PdN) region. The Tropospheric Ultraviolet-Visible (TUV) radiation transfer model was used to calculate J_(NO_2 ) values. The measurements of hemi-spherically integrated, spectrally resolved solar photon flux between the wavelengths 400 and 700 nm were used to obtain the photolysis rate coefficients for ã??NOã??_2. Results are presented for a selected episode on July, 2015. The work investigated the use of measured …
Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana
Computational Modeling Of A 60kw Oxy-Methane Direct Power Extraction Combustor, Omar Daniel Vidana
Open Access Theses & Dissertations
ANSYS Fluent was used to optimize components of a direct power extraction combustor. This includes the fuel injector, nozzle, and cooling units. Changes in the injector's inlet location impacted pressure and velocity distribution. An angle of 115 degrees with respect to the x-axis was found to increase distribution efficiency. Temperature and velocity data from the combustor and nozzle were calculated using NASA CEA and Fluent. Magnitudes of temperature and velocity for CEA and Fluent matched within 9% and 4%, respectively. For the cooling system it is expected that cavitation will not occur since the saturation temperature of water is not …
Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan
Effects Of Temperature, Irradiance And Pco2 On The Growth And Nitrogen Utilization Of Prorocentrum Donghaiense, Zhangxi Hu, Margaret R. Mulholland, Ning Xu, Shunshan Duan
OES Faculty Publications
Environmental factors such as temp erature, irradiance, and nitrogen (N) supply affect the growth of Prorocentrum donghaiense, but the interactive effects of these physical factors and the effects of atmospheric CO2 (pCO2) on growth and N uptake have not been examined. We compared growth kinetics of P. donghaiense grown on 4 different N substrates (nitrate [NO3 -], ammonium [NH4 +], urea, and glutamic acid [glu]) with respect to temperature, irradiance, and pCO2. Temperature (15 to 30°C) had a positive effect on growth (max. growth rates: 0.17 to 0.65 d …
Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl
Vegetation Influences Microbial Community Structure And Methane Emissions In Southeastern Louisiana Wetlands, Anthony Jason Rietl
LSU Doctoral Dissertations
Methane has a warming potential 28 times that of carbon dioxide and has been increasing in the Earth’s atmosphere since 1750. An understanding of the dynamics of methane emissions from natural sources is becoming increasingly important as we may need to mitigate emissions from these sources in the future to help reduce the effects of climate change. Wetlands are the single largest natural source of methane; however, little attention has been given to how plant species, biota, and interactions between above and belowground communities and microbial communities may affect methane emissions. First, microbial community structure and function was assessed for …
Effects Of Landscape Fragmentation On Land Loss, Weijia Cheng
Effects Of Landscape Fragmentation On Land Loss, Weijia Cheng
LSU Master's Theses
Coastal Louisiana, the seventh largest delta on earth, is one of the most vulnerable coastal areas in the United States of America (USA) because of its land loss problem. Coastal land loss is usually caused by many complicated factors. With the rapid increase in human activities, more studies on land loss have focused on the anthropogenic elements, but less on the pattern of the landscape. It is expected that the type of spatial arrangement, such as high degree of fragmentation, would affect the degree of land erosion. A quantitative evaluation of coastal landscape fragmentation and its influences on land loss …