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Full-Text Articles in Life Sciences

Examining The Development Of Handedness In Rhesus Monkey And Human Infants Using Behavioral And Kinematic Measures, Eliza Lynn Nelson Sep 2010

Examining The Development Of Handedness In Rhesus Monkey And Human Infants Using Behavioral And Kinematic Measures, Eliza Lynn Nelson

Open Access Dissertations

Handedness is a widely studied behavioral asymmetry that is commonly measured as a preference for using one hand over the other. Right hand preference in humans occurs at a ratio of 9:1, whereas left hand preference in rhesus monkeys has been estimated at 2:1. Despite differences in the direction and degree of hand preference, this dissertation investigated whether primates share common underlying factors for the development of handedness. Previous work in human infants has identified a predictive relationship between rightward supine head orientation and later right hand preference. Experiment 1 examined the relationship between neonatal head orientation and ...


Muscle Weakness In Persons With Multiple Sclerosis, Linda Haiwon Chung Sep 2010

Muscle Weakness In Persons With Multiple Sclerosis, Linda Haiwon Chung

Open Access Dissertations

Skeletal muscle weakness is a problem for people living with Multiple Sclerosis (MS). Alterations in the central nervous system may be the primary source of muscle weakness because of the pathophysiology of MS. However, changes in peripheral mediators of force production may also contribute to muscle weakness in persons with MS. The main objective of the dissertation was to systematically identify key neural (motor unit discharge rates, spasticity) and muscular (muscle size, contractile function) mechanisms of force production that may explain lower isometric strength and dynamic power in persons with MS compared with age-matched controls. The knee extensor muscles of ...


Role Of Sulfate-Reducing Bacteria In The Attenuation Of Acid Mine Drainage Through Sulfate And Iron Reduction, Caryl Ann Becerra Sep 2010

Role Of Sulfate-Reducing Bacteria In The Attenuation Of Acid Mine Drainage Through Sulfate And Iron Reduction, Caryl Ann Becerra

Open Access Dissertations

Acid mine drainage (AMD) is an acidic, iron-rich leachate that causes the dissolution of metals. It constitutes a worldwide problem of environmental contamination detrimental to aquatic life and water quality. AMD, however, is naturally attenuated at Davis Mine in Rowe, Massachusetts. We hypothesize that sulfate-reducing bacteria (SRB) are attenuating AMD. To elucidate the mechanisms by which SRB attenuate AMD, three research projects were conducted using a suite of molecular and geochemical techniques. First we established biological influence on the attenuation of AMD by comparing the microbial community and geochemical trends of microcosms of two contrasting areas within the site: AMD ...


Reproduction In The Wild: The Effect Of Individual Life History Strategies On Population Dynamics And Persistence, Jason Asa Coombs Sep 2010

Reproduction In The Wild: The Effect Of Individual Life History Strategies On Population Dynamics And Persistence, Jason Asa Coombs

Open Access Dissertations

For a sexually reproducing species, the two major decisions facing all individuals are when and with whom to reproduce. When scaled to the population level, the outcome from all individual decisions determines reproductive variance, and age-class contribution to population growth rate. Both of these attributes determine a population‟s effective size (Ne), which is directly correlated with its fitness, persistence probability, and adaptability. The questions of when and with whom to reproduce, and their subsequent effects on Ne and age-at-maturity were assessed for wild brook trout (Salvelinus fontinalis) populations. Mating pairs were significantly size-assortative, with individual length accounting for 37 ...


Conservation While Under Invasion: Insights From A Rare Hemiparasitic Plant, Swamp Lousewort (Pedicularis Lanceolata Michx.), Sydne Record Sep 2010

Conservation While Under Invasion: Insights From A Rare Hemiparasitic Plant, Swamp Lousewort (Pedicularis Lanceolata Michx.), Sydne Record

Open Access Dissertations

with non-native invasive species is considered a major threat to many rare native species. As such, invasives removals are a common management strategy. Rare native species that interact uniquely with other organisms in their community (e.g., hemiparasitic plants) may be adversely affected by removing invasives. A management plan for a regionally rare hemiparasitic plant in Massachusetts, Pedicularis lanceolata Michx., identified invasives as a threat, but more quantitative evidence is needed to determine how P. lanceolata‟s persistence is influenced by its co-occurrence with native or invasive hosts. This research asks how P. lanceolata is affected by growth with native ...


Growth Of Atlantic Salmon (Salmo Salar) In Freshwater, Douglas Bradlee Sigourney Sep 2010

Growth Of Atlantic Salmon (Salmo Salar) In Freshwater, Douglas Bradlee Sigourney

Open Access Dissertations

Growth plays a key role in regulating ecological and population dynamics. Life history characteristics such as age at maturity, fecundity and age and size at migration are tightly linked to growth rate. In addition, size can often determine survival and individual breeding success. To fully understand the process of growth it is important to understand the mechanisms that drive growth rates. In Atlantic salmon, growth is critical in determining life history pathways. Models to estimate growth could be useful in the broader context of predicting population dynamics. In this dissertation I investigate the growth process in juvenile Atlantic salmon (Salmo ...


Plantar Fasciitis: Biomechanics, Atrophy And Muscle Energetics, Ryan Chang May 2010

Plantar Fasciitis: Biomechanics, Atrophy And Muscle Energetics, Ryan Chang

Open Access Dissertations

Purpose: The purpose of this dissertation was to determine the effects of chronic plantar fasciitis on intrinsic foot structures with respect to biomechanics, muscle atrophy and muscle energetics. This was accomplished in three parts. Methods: In Part I, a three-dimensional motion capture system with a synchronized force platform quantified multi-segment foot model kinematics and ground reaction forces associated with walking. Healthy individuals were compared to individuals with chronic plantar fasciitis feet. Typical kinematic variables, measures of coupling, phase and variability were examined in rearfoot, forefoot and hallux segments. In Part II, foot and leg magnetic resonance images were taken in ...


From Mouse Mammary Tumor Model To New Therapeutic Method ---Mammary Tumor Development In Balb/C-Trp53+/- Mice And Magnetic Nanoparticle Induced Heating For Cancer Treatment, Haoheng Yan May 2010

From Mouse Mammary Tumor Model To New Therapeutic Method ---Mammary Tumor Development In Balb/C-Trp53+/- Mice And Magnetic Nanoparticle Induced Heating For Cancer Treatment, Haoheng Yan

Open Access Dissertations

PATHWAYS CONTRIBUTING TO DEVELOPMENT OF SPONTANEOUS MAMMARY TUMORS IN BALB/c-Trp53+/- MICE Mutation and loss of p53 function are common features among human breast cancers. We use BALB/c-Trp53+/- mice as a model to examine the sequence of events leading to mammary tumors. Mammary epithelium proliferation rates were similar in both BALB/c-Trp53+/- mice and wild type controls. Among the 28 mammary tumors collected from BALB/c-Trp53+/- mice, loss of heterozygosity for Trp53 was detected in more than 90% of invasive mammary tumors. Transplantation of Trp53+/- ductal hyperplasias indicated an association between loss of the wild type allele of Trp53 ...


Notch 1 Mediated Inhibition Of Nur77-Induced Apoptosis: Implications For T-Cell Leukemia, Jonathan George Rud May 2010

Notch 1 Mediated Inhibition Of Nur77-Induced Apoptosis: Implications For T-Cell Leukemia, Jonathan George Rud

Open Access Dissertations

It is widely accepted that activating mutations of genes encoding the Notch family of transmembrane receptors, specifically Notch1, are associated with oncogenic transformation. Previous data from our lab has shown that an active form of Notch1 (NICD) provides protection against apoptosis in D011.10 T cells; and that this effect may be attributed to NICD binding the pro-apoptotic protein Nur77. Nur77 is an immediate early gene that is upregulated during both negative selection of thymocytes and activation-induced apoptosis in D011.10 T cells. Nur77 upregulation is tightly regulated and requires MEF2D, NFAT, and the transcriptional co-activator, p300, to effectively respond ...


Fire Regime Dynamics Following The Mid-Holocene Hemlock Decline In Eastern North America, Kennedy Helm Clark May 2010

Fire Regime Dynamics Following The Mid-Holocene Hemlock Decline In Eastern North America, Kennedy Helm Clark

Open Access Dissertations

Approximately 5,000 years ago, eastern hemlock (Tsuga canadensis) experienced a sudden, rapid, range-wide decline most probably due to pest, disease, or climate change. An aphid-like defoliating insect, the hemlock woolly adelgid (Adelges tsugae), recently (1950’s) introduced to eastern North America has been spreading across the eastern United States. The adelgid attacks all size and age classes of hemlocks causing up to 95% mortality in affected stands. The potential for another range-wide hemlock decline has raised a number of concerns including the increased threat of wildfire. Altered fuel loadings in modern adelgid-affected stands and the effects of presumably similar ...


Identifying Critical Fish Habitat And Long-Term Trends In Fish Abundances In The Hudson River Estuary, Megan Patricia O'Connor May 2010

Identifying Critical Fish Habitat And Long-Term Trends In Fish Abundances In The Hudson River Estuary, Megan Patricia O'Connor

Open Access Dissertations

The Hudson River estuary (HRE) is a well monitored aquatic resource and much secondary data exist for this system. We developed two objectives based on accessible HRE aquatic data. The first objective was to determine if changes in HRE fish community over the time period (1974 to 2005) years are correlated to local and regional climate. We addressed this objective by employing a multivariate statistical approach. We confirmed that the HRE fish community structure has changed over the time period (1974 to 2005). These changes are correlated with local hydrology (freshwater flow and water temperature) and regional climate (Atlantic Multidecadal ...


Analyses Of Arabidopsis Yellow Stripe-Like (Ysl) Family Of Metal Transporters, Heng-Hsuan Chu Feb 2010

Analyses Of Arabidopsis Yellow Stripe-Like (Ysl) Family Of Metal Transporters, Heng-Hsuan Chu

Open Access Dissertations

Iron is one of the most important micronutrients used by living organisms. Iron is frequently a limiting nutrient for plant growth, and plants are a major source of iron for human nutrition. The most prominent symptom of iron deficiency in plants is interveinal chlorosis, or yellowing between the veins, which appears first in the youngest leaves. Iron deficiency anemia (IDA) is the number one human nutritional deficiency worldwide. In order to solve the problem of iron deficiency, it is desirable to breed plants that have increased iron in those parts that are consumed by humans. To do this, we must ...


The Role Of Runx1 N-Terminal Splice Isoforms In Hematopoietic Development, Emmett E. Hedblom Feb 2010

The Role Of Runx1 N-Terminal Splice Isoforms In Hematopoietic Development, Emmett E. Hedblom

Open Access Dissertations

Runx1/AML1 transcription factor expression in hematopoietic cell lineages is differentially regulated via usage of two distinct promoters. The 5' UTR and a 19 amino acid encoding sequence transcribed from the distal promoter is inserted via alternative splicing into the 5' end of the mRNA transcript, replacing the 5' UTR and a 5 amino acid encoding sequence usually transcribed from the proximal promoter. Expression of proximal Runx1 in 32Dcl.3 cells delays G-CSF induced neutrophil terminal differentiation by increasing viability compared to distal Runx1. We utilized Runx1 Nterminal deletion and point mutants of three evolutionarily conserved residues to describe dual ...


Vulnerability Of Logfin Inshore Squid (Loligo Pealeii) To Predation: The Influence Of Relative Prey Size And Behavior, Michelle Dana Staudinger Feb 2010

Vulnerability Of Logfin Inshore Squid (Loligo Pealeii) To Predation: The Influence Of Relative Prey Size And Behavior, Michelle Dana Staudinger

Open Access Dissertations

Cephalopods provide forage to a wide range of predators in marine food-webs. Despite their ecological importance, a basic understanding of the mechanisms controlling predation risk and demand is lacking. This is true of one of the most common species of squid found in the northwest Atlantic, the longfin inshore squid (Loligo pealeii). In this dissertation, I address this shortcoming by investigating the role that size and behavior play in influencing squid’s vulnerability to predation. I used long-term food habits, population survey, and commercial landings data, to quantify size-based patterns of predation respective to 25 species of predators. Additionally, I ...


Functional Consequences Of Acute Temperature Stress In The Western Fence Lizard, Sceloporus Occidentalis, David Michael Mcmillan Feb 2010

Functional Consequences Of Acute Temperature Stress In The Western Fence Lizard, Sceloporus Occidentalis, David Michael Mcmillan

Open Access Dissertations

Understanding the effects of natural variation in environmental temperature on organisms and how those organisms evolve to live in different thermal environments is a central tenet of evolutionary physiology. Phenotypic differences among populations are the result of local adaptation, innate genetic differences between populations, and phenotypic plasticity, differential responses to the environment. Although not mutually exclusive, distinguishing between these paradigms can help illuminate species boundaries resulting from thermal limitations in physiology. For my dissertation, I examined geographic variation in measures of thermal physiology of the western fence lizard, Sceloporus occidentalis to understand the relative role of adaptation and acclimation in ...


New Insights In The Tssk Family: Studies In The Activity And Function Of The Testis Specific Serine Kinases, Julian Sosnik Feb 2010

New Insights In The Tssk Family: Studies In The Activity And Function Of The Testis Specific Serine Kinases, Julian Sosnik

Open Access Dissertations

The Testis Specific Serine Kinase (Tssk) family of proteins is a large group of kinases that present high level of conservation within paralogs, as well as within species. In addition, in all reported cases as well as in the analysis of expressed sequence tags available in databases, this family of proteins presents a very strict pattern of either testicular or male-gonadal expression. This high level of conservation prompted the postulate that these kinases ought to be important for either testicular function or fertilization. In this work we attempt a biochemical characterization of one family member (Tssk6) in the mouse. We ...


Beyond Cell Adhesion: Exploring The Role Of Cadherin-11 Extracellular Processing By Adam Metalloproteases In Cranial Neural Crest Migration, Catherine D. Mccusker Feb 2010

Beyond Cell Adhesion: Exploring The Role Of Cadherin-11 Extracellular Processing By Adam Metalloproteases In Cranial Neural Crest Migration, Catherine D. Mccusker

Open Access Dissertations

The migration of the cranial neural crest is an essential part of cranio-facial development in every vertebrate embryo. The cranial neural crest (CNC) is a transient population of cells that forms the lateral border of the anterior neural plate. In the tailbud stage Xenopus embryo, the neural crest cells delaminate from the neural tube, and undergo a large-scale migration from the dorsal to ventral region of the embryo. The CNC travels along distinct pathways, and populates specific regions of the embryos face. Once the CNC ceases migrating, it differentiates into a variety of tissues that are essential for cranio-facial structure ...


"A"-Kids: Activity Kcal Intervention Daily Study. Effects Of 100-Kcal Daily Energy Expenditure On Total Moderate-To-Vigorous Physical Activity In 3rd Grade Children, Cheryl A. Howe Feb 2010

"A"-Kids: Activity Kcal Intervention Daily Study. Effects Of 100-Kcal Daily Energy Expenditure On Total Moderate-To-Vigorous Physical Activity In 3rd Grade Children, Cheryl A. Howe

Open Access Dissertations

A selection of common children’s games were measured in a laboratory-based study to be enjoyable and to elicit sufficient physical activity energy expenditure (PAEE) in 3rd grade children to combat the purported chronic energy surplus of childhood obesity (~100 kcal.day-1). PAEE during the games was similar for boys and girls, yet overweight children expended greater PAEE relative to body weight than healthy weight children. During a subsequent simulated recess program, the enjoyment declined over the 10-session program with no significant decline in PAEE. Using the enjoyable games of known energy cost in a structured recess program for 9 ...


Evaluation Of Disturbance Factors And Their Effect On Breeding Common Loons At Lake Umbagog National Wildlife Refuge, New Hampshire And Maine, Kyle P. Mccarthy Feb 2010

Evaluation Of Disturbance Factors And Their Effect On Breeding Common Loons At Lake Umbagog National Wildlife Refuge, New Hampshire And Maine, Kyle P. Mccarthy

Open Access Dissertations

Virtually any person exposed to American movies or television has likely heard the call of a common loon (Gavia immer). Its use as a sound prop has become ubiquitous in any scene related to the outdoors or the wilderness, even if the area filmed is in no way related to true loon habitat. The reason behind this is that the common loon and its haunting cries have come to symbolize the great outdoors. The sound of their call is meant to make the audience feel like the scene they are watching is in a remote area, far from the trappings ...