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Full-Text Articles in Life Sciences

Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel Dec 2013

Sources Of Variability In Agronomic Weed Seed Predation: Time, Space, Habitat, And Hyperpredation, Sonja K. Birthisel

Electronic Theses and Dissertations

Weed seed predation is an ecosystem service that benefits farmers by decreasing seedbank inputs, thereby reducing weed pressure in subsequent growing seasons. Seed predation can be considerable, but is highly variable. Sources of variability may include time, space, habitat, and trophic interactions such as hyperpredation. Two experiments were conducted to measure the impacts of these sources of variability on weed seed predation rates in Maine mixed vegetable agroecosystems.

Chapter One of this thesis describes a series of landscape-level field experiments conducted to quantify the effects of time, space, and habitat on seed predation rates. Seed assays, with and without vertebrate ...


The Effect Of Wild Blueberry Consumption On The Inflammatory Response, Oxidative Stress And Dna Damage Associated With Exercise, Taylor K. Bloedon Dec 2013

The Effect Of Wild Blueberry Consumption On The Inflammatory Response, Oxidative Stress And Dna Damage Associated With Exercise, Taylor K. Bloedon

Electronic Theses and Dissertations

At all levels of intensity and duration, exercise is known to cause an increase in the generation of reactive oxygen species (ROS). When derivatives of oxygen occur and exist independently with one or more unpaired electrons they are known as “free radicals” (Halliwell and Gutteridge 2007). Since atoms possess electrons that are usually associated in pairs, free radicals have the potential to act negatively in the body. Reactive oxygen species refer to oxygen-centered radicals as well as nonradical but reactive derivatives of oxygen (Halliwell and Gutteridge 2007). When ROS are created in excess, resulting in the disruption of the pro-oxidant ...


Characterization Of Phycoerythrin Physiology In Low-Light Adapted Prochlorococcus Ecotypes, Kathryn H. Roache-Johnson Aug 2013

Characterization Of Phycoerythrin Physiology In Low-Light Adapted Prochlorococcus Ecotypes, Kathryn H. Roache-Johnson

Electronic Theses and Dissertations

The marine cyanobacteria Prochlorococcus and Synechococcus are the most abundant phototrophs in the oceans. They cohabit the oligotrophic ocean and thus have coevolved together, yet they have distinctly different methods for harvesting light. Synechococcus, like other cyanobacteria, possess phycobilisomes with various combinations of phycobiliproteins to capture wavelengths of light not otherwise available to chlorophyll. Prochlorococcus lack phycobilisomes and use divinyl chlorophyll b (Chl b2) as their primary accessory pigment to divinyl chlorophyll a (Chl a2) to capture light energy. In addition to the divinyl chlorophylls, Prochlorococcus has genes associated with the phycobiliprotein phycoerythrin (PE), the role of which is still ...


Production Ecology And Stand Dynamics Of Young Acadian Forest Stands In Response To Silvicultural Intensity And Compositional Objectives, Andrew S. Nelson Aug 2013

Production Ecology And Stand Dynamics Of Young Acadian Forest Stands In Response To Silvicultural Intensity And Compositional Objectives, Andrew S. Nelson

Electronic Theses and Dissertations

Early successional stands are common across the Acadian forests of eastern Canada and the Northeastern US. However, productivity and dynamics of these stands, as well as the underlying mechanisms influencing these processes, under different management scenarios are poorly understood. To address this need, I used a factorial experiment that controlled silvicultural intensity and species composition to quantify the effects of varying treatments on early stand dynamics, and the physiological and morphological factors influencing tree performance . Specifically, I studied: 1) species differences in aboveground allometrics, 2) light capture, light-use efficiency (LUE; growth/light capture), and foliar carbon isotope composition (δ13C) of ...


Productivity Standards For Whole-Tree And Cut-To-Length Harvesting Systems In Maine, Patrick Hiesl May 2013

Productivity Standards For Whole-Tree And Cut-To-Length Harvesting Systems In Maine, Patrick Hiesl

Electronic Theses and Dissertations

The forest industry is a highly cost intensive business and therefore effective management is necessary. Information about productivity and time consumption of harvesting equipment in a variety of stand and site conditions can help operation managers to be efficient. In the state of Maine there have not been any productivity related publications within the past 25 years. Due to this lack of information and the need of information of productivity, especially in small diameter stands, the presented research developed. The focus of this study is on whole-tree harvesting systems including feller-buncher, grapple skidder and stroke delimber, as well as cut-to-length ...


Enabling Sum Frequency Spectroscopy And Fluorescence Correlation Spectroscopy Of Model Cellular Membranes, Sarah M. Sterling May 2013

Enabling Sum Frequency Spectroscopy And Fluorescence Correlation Spectroscopy Of Model Cellular Membranes, Sarah M. Sterling

Electronic Theses and Dissertations

The majority of proteins secreted from cells contain a signal peptide sequence that is required for secretion mediated by the endoplasmic reticulum and Golgi apparatus. However, many proteins lack the essential signal peptide sequence, yet still undergo secretion. Such proteins are known to regulate cell proliferation, differentiation, and migration. Fibroblast growth factor 1 (FGF-1) is one protein which undergoes non-classical protein transport. The role of its interactions with the cellular membrane during non-classical protein transport is not fully understood, although FGF-1 has shown preferential destabilizing effects on artificial membranes composed of acidic phospholipids. In the present work, physiologically relevant model ...


Relations Among Type 2 Diabetes, Arterial Stiffness And Cognitive Functioning, Gregory A. Dore May 2013

Relations Among Type 2 Diabetes, Arterial Stiffness And Cognitive Functioning, Gregory A. Dore

Electronic Theses and Dissertations

Although the associations among diabetes mellitus, cognitive functioning and arterial stiffness have been explored previously, the degree to which arterial stiffness is responsible for the association between diabetes and cognitive function has not been examined. The primary aim of the current investigations is to examine the extent to which arterial stiffness mediates the association between diabetes and cognitive function, as well as the extent to which this indirect effect is modified by age and APOE genotype. The sample included 590 participants (age 23-94, 62% women, 12% African- American) from the seventh wave of the Maine-Syracuse Longitudinal Study. Individuals with history ...