Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

191,641 Full-Text Articles 233,850 Authors 37,582,314 Downloads 397 Institutions

All Articles in Life Sciences

Faceted Search

191,641 full-text articles. Page 4759 of 4777.

Stream Invertebrate Responses To A Catastrophic Decline In Consumer Diversity, J. Checo Colón-Gaud, Matt R. Whiles, Karen R. Lips, Catherine M. Pringle, Susan Kilham, Roberto Brenes, Scot D. Peterson 2010 Georgia Southern University

Stream Invertebrate Responses To A Catastrophic Decline In Consumer Diversity, J. Checo Colón-Gaud, Matt R. Whiles, Karen R. Lips, Catherine M. Pringle, Susan Kilham, Roberto Brenes, Scot D. Peterson

Biology Faculty Publications

Tadpoles are often abundant and diverse consumers in headwater streams in the Neotropics. However, their populations are declining catastrophically in many regions, in part because of a chytrid fungal pathogen. These declines are occurring along a moving disease front in Central America and offer the rare opportunity to quantify the consequences of a sudden, dramatic decline in consumer diversity in a natural system. As part of the Tropical Amphibian Declines in Streams (TADS) project, we examined stream macroinvertebrate assemblage structure and production for 2 y in 4 stream reaches at 2 sites in Panama. One site initially had healthy amphibians ...


Are Health Care Professionals Addressing The Psychological Aspect Of Athletic Injury? A Survey Of Injured Athletes, Hayley C. Russell 2010 Wilfrid Laurier University

Are Health Care Professionals Addressing The Psychological Aspect Of Athletic Injury? A Survey Of Injured Athletes, Hayley C. Russell

Theses and Dissertations (Comprehensive)

Millions of athletic injuries occur annually. Athletic injures involve not only physical distress but psychological distress as well. Nevertheless, injured athletes rarely see a mental health care professional. It has been suggested that health care professionals, such as physicians, physiotherapists, and athletic therapists, are well positioned to address the psychological aspect of injury. Health care professionals report that they sometimes address the psychological aspect of injury with the athletes they treat. There is limited research, however, on what injured athletes perceive to be the role of health care professionals in addressing the psychological aspect of injuries. Therefore the purpose of ...


How Does Background And Training Affect Dance Pedagogy In Higher Education?, Meredith Erin Sims 2010 University of Kentucky

How Does Background And Training Affect Dance Pedagogy In Higher Education?, Meredith Erin Sims

University of Kentucky Master's Theses

Dance faculty in higher education have various backgrounds and training ranging from professional dance careers to doctoral degrees in dance. This study sought to examine the ways background and training impact faculty members‟ pedagogical approach to a dance technique class in a higher education dance department. This study examined the pedagogical knowledge, content knowledge, and pedagogical content knowledge of participants through qualitative methods including interviews, observations, and document analysis. Six major themes emerged from the data: desire to teach, teaching focus, challenging students, planning and preparation, instructional methods, and assessment strategies.


Distribution Of Eastern Hemlock, Tsuga Canadensis, In Eastern Kentucky And The Susceptibility To Invasion By The Hemlock Woolly Adelgid, Adelges Tsugae, Joshua Taylor Clark 2010 University of Kentucky

Distribution Of Eastern Hemlock, Tsuga Canadensis, In Eastern Kentucky And The Susceptibility To Invasion By The Hemlock Woolly Adelgid, Adelges Tsugae, Joshua Taylor Clark

University of Kentucky Master's Theses

The hemlock woolly adelgid, an invasive non-native insect, is threatening eastern hemlock in Kentucky. This study examined three techniques to map the distribution of eastern hemlock using decision trees, remote sensing, and species distribution modeling. Accuracy assessments showed that eastern hemlock was best modeled using a decision tree without incorporating satellite radiance. Using the distribution from the optimal model, risk maps for susceptibility to hemlock woolly adelgid infestation were created using two species distribution models. Environmental variables related to dispersal were used to build the models and their contributions to the models assessed. The models showed similar spatial distributions of ...


Creating An Interactive And Dichotomous Key To The World Subfamilies Of Braconidae, Kacie Jo Johansen 2010 University of Kentucky

Creating An Interactive And Dichotomous Key To The World Subfamilies Of Braconidae, Kacie Jo Johansen

University of Kentucky Master's Theses

Members of Braconidae (Hymenoptera: Ichneumonoidea) are mostly parasitoids of other holometabolous insects. It is a large family with a little over 18,000 described species and many more to be described. Subfamily classification in this group has been unstable and resolution of phylogenetic history at the subfamily level has been problematic. Since 1993, no new keys to the subfamilies of Braconidae have been produced. Many taxonomic and phylogenetic changes have taken place since then, including a recent phylogeny proposing 47 subfamilies and representing the most robust and resolved analysis to date. A pressing need for new keys to the world ...


Spiny Amaranth Control And Aminopyralid Persistence In Kentucky Pastures, Meghan Elizabeth Edwards 2010 University of Kentucky

Spiny Amaranth Control And Aminopyralid Persistence In Kentucky Pastures, Meghan Elizabeth Edwards

University of Kentucky Master's Theses

Spiny amaranth is a problematic weed of heavily grazed pastures in Kentucky and surrounding states. The first objective was to evaluate spiny amaranth control when herbicides are applied before and after emergence. Spiny amaranth seed collected in 2008 were seeded in rows in the fall (November) and the following spring (March) in fields located near Lexington and Princeton, KY. Treatments consisted of five application dates and five herbicides plus an untreated control arranged in a split-split plot design. The following parameters were measured: fresh weight, plant height and percent visual control. At both locations pendimethalin applied in November, March and ...


Target Eccentricity Effects For Defensive Responses, Taegyong Kwon 2010 Louisiana State University and Agricultural and Mechanical College

Target Eccentricity Effects For Defensive Responses, Taegyong Kwon

LSU Doctoral Dissertations

Defensive actions involving goal-directed responses to visual stimuli presented in different parts of the viewing field commonly include movements either toward (TOWARD) or away from (AWAY) the actual stimulus. One can categorize the type of defensive movements by outcome or the level of stimulus-response (S-R) compatibility, where a congruent response corresponds to a response in the TOWARD condition and an incongruent response corresponds to a response in the AWAY condition. In an effort to better understand defensive responses, which have received less attention in the literature than offensive movements regardless of their importance in combative situations, we studied the responses ...


Exercise-Induced Alterations In Melanocortin Receptor Expression And Inflammation, Tara Michelle Henagan 2010 Louisiana State University and Agricultural and Mechanical College

Exercise-Induced Alterations In Melanocortin Receptor Expression And Inflammation, Tara Michelle Henagan

LSU Doctoral Dissertations

Inflammatory cytokines play a significant role in the pathogenesis of obesity-related diseases and have been implicated as integral factors in both early and late phases of atherosclerosis. Lifestyle modifications such as increasing physical activity and making dietary changes to induce weight loss are part of the primary prescription for the treatment of metabolic syndrome. Additionally, physical activity has been implicated as a potentially effective regimen for the control of inflammation, yet little is known about the anti-inflammatory mechanistic alterations induced by physical activity.

Exercise training causes acute changes in inflammation immediately post exercise, evidenced by upregulation of inflammatory cytokines and ...


In Vivo Oxidative Stress In Alzheimer Disease Brain And A Mouse Model Thereof: Effects Of Lipid Asymmetry And The Single Methionine Residue Of Amyloid-Β Peptide, Miranda Lu Bader Lange 2010 University of Kentucky

In Vivo Oxidative Stress In Alzheimer Disease Brain And A Mouse Model Thereof: Effects Of Lipid Asymmetry And The Single Methionine Residue Of Amyloid-Β Peptide, Miranda Lu Bader Lange

University of Kentucky Doctoral Dissertations

Studies presented in this dissertation were conducted to gain more insight into the role of phospholipid asymmetry and amyloid-β (Aβ)-induced oxidative stress in brain of subjects with amnestic mild cognitive impairment (aMCI) and Alzheimer disease (AD). AD is a largely sporadic, age-associated neurodegenerative disorder clinically characterized by the vast, progressive loss of memory and cognition commonly in populations over the age of ~65 years, with the exception of those with familial AD, which develop AD symptoms as early as ~30 years-old. Neuropathologically, both AD and FAD can be characterized by synapse and neuronal cell loss in conjunction with accumulation ...


Improvement Of New Oil Crops For Kentucky, Watchareewan Jamboonsri 2010 University of Kentucky

Improvement Of New Oil Crops For Kentucky, Watchareewan Jamboonsri

University of Kentucky Doctoral Dissertations

Three oil crops, chia (Salvia hispanica L.), flax (Linum usitatissimum L.), and castor (Ricinus communis L.), were studied because of their nutritional and industrial values. Chia and flax are rich in an ω3 fatty acid, α-linolenic acid, and castor is a very high oil producer and high in a hydroxy fatty acid. Ethyl methanesulfonate (EMS) and gamma rays were employed to mutagenize chia seeds to produce early flowering mutants. The M1 population was grown and induced to flower by short-day photoperiods. The M2 population was planted in the field in Lexington, KY in 2008. Early flowering plants were ...


Explorations In Homeoviscous Adaptation And Mass Spectral Analysis Of Membrane Lipids, Michael Douglas Timmons 2010 University of Kentucky

Explorations In Homeoviscous Adaptation And Mass Spectral Analysis Of Membrane Lipids, Michael Douglas Timmons

University of Kentucky Doctoral Dissertations

The focus of this dissertation is centered on the mass spectral analysis of lipids and changes occurring in keeping with the concept of homeoviscous adaptation [1]. Homeoviscous adaptation is the process of modification of membrane lipids in response to environmental stimuli [1]. Dissertation investigations applied this concept to prokaryotic and eukaryotic organisms, and expanded the perception of environmental factors from exogenous organic solvents to intracellular environment.

The field of lipidomics deals with the analysis of phospholipid and fatty acid components of membranes the changes that occur due to environmental stimuli and their biological significance [2-6]. The high sensitivity of mass ...


Impact Of High-Input Production Practices On Soybean Yield, Daniel L. Jordan 2010 University of Kentucky

Impact Of High-Input Production Practices On Soybean Yield, Daniel L. Jordan

University of Kentucky Master's Theses

High-input management practices are often heavily marketed to producers to increase soybean [Glycine max (L) Merr.] yield in already high-yielding environments. Field research was conducted in three locations within 6 states (Arkansas, Iowa, Kentucky, Louisiana, Michigan, and Minnesota) in 2009 to determine the effect of seed treatment, inoculant, foliar fungicide, additional soil fertility beyond state recommendations, foliar fertilizer, increased population over state recommendations, and narrow row spacing on yield. The high-input system (combination of the management practices) yielded higher than standard-input system (University recommended management practices) in only 8 of the 18 locations. Narrow rows, in both the high and ...


Shelter Availability, Occupancy, And Residency In Size-Asymmetric Contests Between Rusty Crayfish, Orconectes Rusticus, Nathan M. Klar 2010 University of Kentucky

Shelter Availability, Occupancy, And Residency In Size-Asymmetric Contests Between Rusty Crayfish, Orconectes Rusticus, Nathan M. Klar

University of Kentucky Master's Theses

Contest outcomes are usually determined by differences in resource holding potential, the social histories of the combatants, and perceptions of resource value. One understudied aspect of gaining an advantage is the residency effect. Prior occupancy of a particular place can affect the knowledge and motivation of the resident. There could be a tactical advantage in knowing the terrain or an increased willingness to fight to maintain control of a familiar area. In this study we evaluated the importance of shelter residency effects relative to size differences between rusty crayfish (Orconectes rusticus) as potential competitors for access to shelter. The intensity ...


Phylloplanins: Novel Antifungal Proteins On Plant Leaf Surfaces, Ryan William Shepherd 2010 University of Kentucky

Phylloplanins: Novel Antifungal Proteins On Plant Leaf Surfaces, Ryan William Shepherd

University of Kentucky Doctoral Dissertations

Secreted surface proteins are an innate immune defense component employed by animals to inhibit invading microbes. Surface proteins have not been documented in plants, even though the aerial leaf surface, or phylloplane, is a major site of pathogen ingress. We have discovered novel proteins, termed phylloplanins, which accumulate on leaf surfaces of Nicotiana tabacum, and we have isolated the gene Phylloplanin that is unique in gene databases. Natural and E. coli-expressed phylloplanins inhibit spore germination and limit leaf infection by the oomycete pathogen Peronospora tabacina.

We investigated the site of phylloplanin biosynthesis using biochemical techniques. These techniques included radiolabeling ...


Soil Water And Crop Growth Processes In A Farmer's Field, Susmitha Surendran Nambuthiri 2010 University of Kentucky

Soil Water And Crop Growth Processes In A Farmer's Field, Susmitha Surendran Nambuthiri

University of Kentucky Doctoral Dissertations

The study was aimed to provide information on local biomass development during crop growth using ground based optical sensors and to incorporate the local crop status to a crop growth simulation model to improve understanding on inherent variability of crop field. The experiment was conducted in a farmer’s field located near Princeton in Caldwell County, Western Kentucky. Data collection on soil, crop and weather variables was carried out in the farm from 2006 December to 2008 October. During this period corn (Zea mays L.) and winter wheat (Triticum sp) were grown in the field. A 450 m long representative ...


Polychlorinated Biphenyl-Induced Endothelial Cell Dysfunction And Its Modulation By Dietary Lipids, Zuzana Majkova 2010 University of Kentucky

Polychlorinated Biphenyl-Induced Endothelial Cell Dysfunction And Its Modulation By Dietary Lipids, Zuzana Majkova

University of Kentucky Doctoral Dissertations

Cardiovascular diseases are the number one cause of death in Western societies. Endothelial dysfunction is an early event in the pathology of atherosclerosis, which is an underlying cause in the majority of cardiovascular events. Exposure to persistent environmental pollutants, such as polychlorinated biphenyls (PCBs), is a risk factor for the development of atherosclerosis.

First, we tested a hypothesis that coplanar PCBs, dioxin-like chemicals with affinity for aryl hydrocarbon receptor (AhR), can stimulate up-regulation of monocyte chemoattractant protein-1 (MCP-1), an endothelium-derived chemokine that attracts monocytes into sub-endothelial space in early stages of atherosclerosis. Coplanar PCBs 77 and 126 increased expression of ...


Modeling Water Use In Nursery Crops, Amy Fulcher 2010 University of Kentucky

Modeling Water Use In Nursery Crops, Amy Fulcher

University of Kentucky Doctoral Dissertations

Water use is an important topic in the global agriculture community and is a critical input in nursery crop production. Several plants in the genus Cornus are important nursery crops. Not only are they economically relevant, they are found in grafted and seedling forms and parents and their hybrid are readily available in the trade, facilitating an assessment of water requirements. Anecdotal information suggests that Cornus taxa have differing stress tolerance and water use requirements. Research was conducted to characterize and model water use among Cornus taxa. Scanning electron microscopy and anatomy‐based micromorphological studies as well as transpiration chamber ...


Biochemical Characterization Of Human Mismatch Recognition Proteins Mutsα And Mutsβ, Lei Tian 2010 University of Kentucky

Biochemical Characterization Of Human Mismatch Recognition Proteins Mutsα And Mutsβ, Lei Tian

University of Kentucky Doctoral Dissertations

The integrity of an organism's genome depends on the fidelity of DNA replication and the efficiency of DNA repair. The DNA mismatch repair (MMR) system, which is highly conserved from prokaryotes to eukaryotes, plays an important role in maintaining genome stability by correcting base-base mismatches and insertion/deletion (ID) mispairs generated during DNA replication and other DNA transactions. Mismatch recognition is a critical step in MMR. Two mismatch recognition proteins, MutSα (MSH2-MSH6 heterodimer) and MutSβ (MSH2-MSH3 heterodimer), have been identified in eukaryotic cells. MutSα and MutSβ have partially overlapping functions, with MutSα recognizing primarily base-base mismatches and 1-2 nt ...


Characterization Of Soil Carbon Stabilization In Long-Term Row-Cropped Agro-Ecosystems, Soraya Patricia Alvarado-Ochoa 2010 University of Kentucky

Characterization Of Soil Carbon Stabilization In Long-Term Row-Cropped Agro-Ecosystems, Soraya Patricia Alvarado-Ochoa

University of Kentucky Doctoral Dissertations

Soil organic matter (SOM) is a dynamic soil property, sensitive and responsive to many factors. The possibility of increasing soil carbon (C) sequestration by changing land use and management practices has been of great interest recently due to concerns with global changes in the atmospheric carbon dioxide (CO2) balance. Nonetheless, as a result of the complex dynamics of SOM, there is still the need for SOM characterization procedures capable of monitoring SOM stabilization, taking into account all the factors involved.

This study characterized SOM stabilization as affected by management practices in three long-term field experiments, considering physical, chemical and ...


Dissecting The Biosyntheses Of Gilvocarcins And Ravidomycins, Madan Kumar Kharel 2010 University of Kentucky

Dissecting The Biosyntheses Of Gilvocarcins And Ravidomycins, Madan Kumar Kharel

University of Kentucky Doctoral Dissertations

Gilvocarcin V (GV) and ravidomycin (RMV) exhibit excellent antitumor activities in the presence of near-UV light at low concentration maintaining a low in vivo cytotoxicity. Although, the exact molecular mechanism for in vivo actions of these antibiotics has yet to be determined, a [2+2] cycloaddition reaction of the vinyl side chain with DNA thymidine residues in addition to the inhibition of topoisomerase II and DNAhistone H3 cross-linking are reported for the GV’s mechanism of action. Such activities have made these molecules interesting candidates for the biosynthetic investigation to generate analogues with improved activity/solubility. Previous biosynthetic studies have ...


Digital Commons powered by bepress