Life Sciences Commons^™

Histone Modifications Influence Mediator Interactions With Chromatin, Xuefeng Zhu, Yongqiang Zhang, Gudrun Bjornsdottir, Zhongle Liu, Amy Quan, Michael Costanzo, Marcela Davila Lopez, Jakub Orzechowski Westholm, Hans Ronne, Charles Boone, Claes M. Gustafsson, Lawrence C. Myers

Dartmouth Scholarship

The Mediator complex transmits activation signals from DNA bound transcription factors to the core transcription machinery. Genome wide localization studies have demonstrated that Mediator occupancy not only correlates with high levels of transcription, but that the complex also is present at transcriptionally silenced locations. We provide evidence that Mediator localization is guided by an interaction with histone tails, and that this interaction is regulated by their post-translational modifications. A quantitative, high-density genetic interaction map revealed links between Mediator components and factors affecting chromatin structure, especially histone deacetylases. Peptide binding assays demonstrated that pure wild-type Mediator forms stable complexes with the …

Mathematical Modeling And Dynamical Analysis Of The Operation Of The Hypothalamus - Pituitary - Thyroid (Hpt) Axis In Autoimmune (Hashimoto's) Thyroiditis, Balamurugan Pandiyan

Dissertations (1934 -)

This thesis is a mathematical modeling study of the operation of the negative feedback control through the hypothalamus-pituitary- thyroid (HPT) axis in autoimmune (Hashimoto's) thyroiditis. Negative feedback control through the HPT axis is a mechanism in which the high levels of thyroid hormone; free thyroxine (FT4) in the blood inhibits the secretion of the pituitary hormone, thyroid stimulating hormone (TSH) into the blood. Similarly, the low levels of free thyroxine (FT4) sensed by the pituitary gland and then it secretes thyroid stimulating hormone (TSH) into the blood. Autoimmune (Hashimoto's) thyroiditis is a disease in which the immune system turns against …

Transcriptional Analysis Of Schistosoma Mansoni Treated With Sub-Lethal Doses Of The Anthelmintic Drug Praziquantel, Jarrett Hines-Kay

Biology ETDs

Schistosoma mansoni is one of the most common etiological agents responsible for the disease schistosomiasis. More than 200 million people suffer from this disease making it the most severe tropical disease after malaria in terms of morbidity. Praziquantel (PZQ) is the treatment of choice for schistosomiasis and has been used almost exclusively to treat the disease since the 1970s. However, while the drug is lethal for sexually mature schistosomes, it is ineffective against juveniles. Thus, while morbidity can be eased, a cure is difficult to achieve. As a result there is an urgent need to develop a new generation of …

Yeast Bax Inhibitor, Bxi1p, Is An Er-Localized Protein That Links The Unfolded Protein Response And Programmed Cell Death In Saccharomyces Cerevisiae, Nicanor Austriaco, James Cebulski, Joshua Malouin, Nathan Pinches, Vincent Cascio

Biology Faculty Publications

Bax inhibitor-1 (BI-1) is an anti-apoptotic gene whose expression is upregulated in a wide range of human cancers. Studies in both mammalian and plant cells suggest that the BI-1 protein resides in the endoplasmic reticulum and is involved in the unfolded protein response (UPR) that is triggered by ER stress. It is thought to act via a mechanism involving altered calcium dynamics. In this paper, we provide evidence that the Saccharomyces cerevisiae protein encoded by the open reading frame, YNL305C, is a bona fide homolog for BI-1. First, we confirm that yeast cells from two different strain backgrounds lacking YNL305C, …

Eugenics And Modern Biology: Critiques Of Eugenics, 1910-1945, Garland E. Allen

Biology Faculty Research

Eugenics in most western countries in the first four decades of the twentieth century was based on the idea that genes control most human phenotypic traits, everything from physical features such as polydactyly and eye color to physiological conditions such as the A-B-O blood groups to mental and personality traits such as “feeblemindedness”, alcoholism and pauperism. It assessing the development of the eugenics movement – its rise and decline between 1900 and 1950 – it is important to recognize that its naïve assumptions and often flawed methodologies were openly criticized at the time by scientists and non-scientists alike. This paper …

Comparative Analysis Of Hepatic And Pulmonary Immune Mediators During Postnatal Development, Michelle Mack

Seton Hall University Dissertations and Theses (ETDs)

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Mind Perception: Real But Not Artificial Faces Sustain Neural Activity Beyond The N170/Vpp, Thalia Wheatley, Anna Weinberg, Christine Looser, Tim Moran, Greg Hajcak

Dartmouth Scholarship

Faces are visual objects that hold special significance as the icons of other minds. Previous researchers using event-related potentials (ERPs) have found that faces are uniquely associated with an increased N170/vertex positive potential (VPP) and a more sustained frontal positivity. Here, we examined the processing of faces as objects vs. faces as cues to minds by contrasting images of faces possessing minds (human faces), faces lacking minds (doll faces), and non-face objects (i.e., clocks). Although both doll and human faces were associated with an increased N170/VPP from 175–200 ms following stimulus onset, only human faces were associated with a sustained …

Library Impact Statement For Bps 555 Protein Molecular Modeling, Michael Vocino

Library Impact Statements

Library Impact Statement for BPS 555 Protein Molecular Modeling. No new resources were required to support this course.

A Synthesis Of Plant Invasion Effects On Biodiversity Across Spatial Scales, Kristin I. Powell, Jonathan M. Chase, Tiffany M. Knight

Biology Faculty Research

PREMISE OF THE STUDY:

Invasive plant species are typically thought to pose a large threat to native biodiversity, and local-scale studies typically confirm this view. However, plant invaders rarely cause regional extirpations or global extinctions, causing some to suggest that invasive species' influence on native biodiversity may not be so dire. We aim to synthesize the seemingly conflicting literature in plant invasion biology by evaluating the effects of invasive plant species across spatial scales.

METHODS:

We first conducted a meta-analysis on the effects of invasive plants on the species richness of invaded communities across a range of spatial extents. We …

Lifelines Winter 2011, Southern Adventist University

Lifelines - Biology Department Newsletter

The Winter 2011 issue of Lifelines includes articles on research done by the Ecology class, an alumni feature, the TriBeta National Biological Honor Society, and a pictorial directory of the 2011 biology and allied health graduates.

Is There A Relationship Between Water Potential And The Mechanical Strength Of Salix Lasiolepis?, William Cohen, Gina Fitzgerald, Joseph Liao

Featured Research



Quantitatively Measuring In Situ Flows Using A Self-Contained Underwater Velocimetry Apparatus (Scuva), Kakani Katija, Sean Colin, John H. Costello, John O. Dabiri

Arts & Sciences Faculty Publications

The ability to directly measure velocity fields in a fluid environment is necessary to provide empirical data for studies in fields as diverse as oceanography, ecology, biology, and fluid mechanics. Field measurements introduce practical challenges such as environmental conditions, animal availability, and the need for field-compatible measurement techniques. To avoid these challenges, scientists typically use controlled laboratory environments to study animal-fluid interactions. However, it is reasonable to question whether one can extrapolate natural behavior (i.e., that which occurs in the field) from laboratory measurements. Therefore, in situ quantitative flow measurements are needed to accurately describe animal swimming in their natural …

Hands-On Labs (Hol): Using Technology And Web-Based Resources To Transform A Traditional Lab-Based Biology Course Into A Distance Learning (Dl) Hybrid Course, Across Schools At Pace University., Erica Kipp

Cornerstone 3 Reports : Interdisciplinary Informatics

No abstract provided.

Full Issue: Volume 4, Number 2

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Stress-Induced Proteolysis Of Fkbp10: Mutational Analysis And Functional Implications, Lindsey A. Murphy

Featured Research

Cellular signaling is a complex system of communication that regulates cell function through a variety of molecular messengers. When cell survival is threatened by changes in environment or by malfunction of internal regulatory pathways, signals are initiated to restore homeostasis. Deficient protein processing within the endoplasmic reticulum (ER) causes an accumulation of misfolded proteins and stress signaling. The resulting stress signaling includes both adaptive signals (unfolded protein response) and in cases of severe ER stress apoptotic signals induced via the mitochondria. FKBP10 is a key ER luminal peptidy-prolyl isomerase (rotamase) that mediates protein folding. The production of chaperone proteins and …

Effects Of 2, 4-D On Zea Maize Physiology, Caitlin Thompson, Lori Patrick, Acacia Osbourne, Katrina Brock

Featured Research

Growth rate, fluorescence and stomatal conductance, in zea was examined to determine the effects of artificial auxin, 2-4-d, on common crop plants. We measured florescence, growth rate, and stomatal conductance. Low concentrations of 2,4-D increased light-adapted fluorescence, anthocyanin levels and height of zea maize. A high concentration of 2,4-D increased anthocyanin levels, but also caused decreased fluorescence and height and spindliness to occur. It appears 2,4-D is only beneficial to monocot crop plants in low quantities. We cannot accurately comment on the accuracy of our data, however, due to several potential sources of error.

Effects Of Soil Moisture On Photosynthesis And Fluorescence In Heteromeles Arbutifolia, Ali Alyami, Colin Byrne, Katherine Currie

Featured Research

Some plants have evolved to increase their chances of survival by being drought-adapted. Among those plant species is Heteromeles arbutifolia, native to California. Logically, the fact that Heteromeles arbutifolia tolerates the low supply of water makes this plant more likely to be within environments where the level of sun exposure is high. Thus, we hypothesized that lowering soil moisture will cause an increase in xylem pressure, causing an increase in photo-protection and florescence, and a decrease in photosynthetic rate. This has not been tested before on a native chaparral plant such as Heteromeles arbutifolia. The experiment was held …

The Effect Of Nitrogen Soil Concentration On Leaf Fluorescence In Zea Mays, Ashton Garbutt, Daniel Rossie, Anup Solsi

Featured Research

Macronutrients in the soil are essential to the growth and development of a plant. One of the most important nutrients to a plants growth is nitrogen. Nitrogen has been directly correlated to photosynthetic output in various studies and this relationship is the subject of this experiment. Since nitrogen has an effect on photosynthetic rate, there should be a correlation between nitrogen and fluorescence – a form of energy dissipation. This study attempted to show that nitrogen concentration in the soil is inversely proportional to fluorescence of the plant because the more nitrogen in the soil, the more energy should be …

The Effect Of Proximity To A Highway On The Health Of Malosma Laurina Leaves, Jessica Bermea, Haley Clayton, Jack Klobas

Featured Research

Due to an increase in air pollutants, heavy metal contaminates, and other adverse ecological conditions that plants near a road endure, it was hypothesized that plant species situated near a road would have a detectable decrease in photosynthetic performance when compared to plants away from the road. This investigation evaluated the in vivo photosynthetic status of two Malasma Laurina pairs with differing microhabitats, adjacent to the Pacific Coast Highway and 100 meters away from a Pacific Coast Highway. Maximum quantum yield and stomatal conductance measurements were recorded for each group. On average, the maximum quantum yield was greater on plants …

The Effect Of Hydration Status On Tensile Strength Of The Leaves Of Elymus Glaucus, Chelsie Corbett, Uri Hong, Scott Davis

Featured Research

Tensile strength and water potential are both factors that are essential to the life and survival of a plant. Tensile strength is a measure of the amount of force that a plant can undergo before tissue damage and breakage occur. The primary objective of this study was to examine the correlation between tensile strength and leaf hydration status, or water potential. The water potential of leaves of a monocot grass native to North America, Elymus Glaucus, commonly known as blue wildrye, was measured using the Scholander-Hammel Pressure Chamber. The tensile strength of hydrated and of dehydrated leaves was measured …

The Effects Of Agitation Upon Plant Anatomy In Phaseolus Vulgaris, Craig Sutter, Nicholas Huron

Featured Research

The earthquake that struck Japan’s coast a month ago gained national attention for the damage caused by the tsunami that was caused by the earthquake. Japan’s coast is subject to multiple earthquakes each year with tremors and aftershocks following. The quakes are bound to have an effect on the growth and development of Camellia sinensis, the tea plant, which is one of the most important exports of Japan. Due to the time restraints of this project, C. sinensis were not tested, instead two week old Phaseolus vulgaris were used to show the effects of constant agitation which might mimic …

Effects Of Dehydration Stress On The Dark Adapted Fluorescence (Fv/Fm) Of Giant Bladder Kelp (Macrocystis Pyrifera), J. Avery Powell, Leah Smith

Featured Research

The unique semi-diurnal tide system of Southern California suspends beach wrack along the beaches for approximately six hour periods before being washed back into the ocean. It has been noted in prior research that beach wrack is an essential part of Southern California's costal ecology but not much research has been done to learn about the viability of beach wrack as it dehydrates on the beach. To better understand the viability of wrack as it travels through these hydration changes, this study tested the effect of dehydration and rehydration on the fronds of Macrocystis pyrifera as they have been partially …

Exploring The Open-Close Mechanism Of Dimorphotheca Aurantiaca: Day Versus Night And Cold Versus Hot Temperatures, Tommy Chung, Kathleen Aguilar, Sunny Kim

Featured Research

In the spring of every year on Pepperdine University’s campus, patches of hills are covered with the South African native flower Dimorphotheca aurantiaca or more commonly known as the African Daisy. An observation of the opening and closing mechanism of the flower triggered an important question: does the flower change its shape based on temperature or the presence of light? At night, the African Daisy closes and then opens up again in the daytime. Because temperature has such strong effects on different species of ectodermic animals and temperature-sensitive plants, we hypothesized that the change in temperature initiates the flower’s morphological …

Passing Pains: Revenge, Retaliation, And Redirected Aggression In A New Light, Lixing Sun

Biology Faculty Scholarship

A review of David P. Barash and Judith Eve Lipton, Payback: Why We Retaliate, Redirect Aggression, and Take Revenge, Oxford University Press: New York, 2011, 209 pp., US$24.95, ISBN 019539514X (hardcover).

Full Issue: Volume 5, Number 1, Fall 2011

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

The Characterization Of Genes Involved In Response To The Phenol Derivative And Xenoestrogen Bisphenol-A In Saccharomyces Cerevisiae, Sasha N. Farina

CMC Senior Theses

Bisphenol A is an estrogenic compound that is found in polycarbonate plastics and epoxy resins; humans are continuously exposed to the compound and it is believed to possess the same carcinogenic effects as estrogen (Iso, 2006). In this study, I used Saccharomyces cerevisiae as a model organism to identify mechanisms by which BPA acts based on the genomic profiling of kinase genes from a Mat-α haploid deletion library. Kinases regulate many other proteins, so the identification of a single mutant could identify an entire affected pathway of genes. I conducted a systematic screen of these mutants using the phenotype of …

Expression And Characterization Of The Bacterial Mechanosensitive Channel Mscs In Xenopus Laevis Oocytes., Elizabeth S. Haswell, Grigory Maksaev

Biology Faculty Research

We have successfully expressed and characterized mechanosensitive channel of small conductance (MscS) from Escherichia coli in oocytes of the African clawed frog, Xenopus laevis. MscS expressed in oocytes has the same single-channel conductance and voltage dependence as the channel in its native environment. Two hallmarks of MscS activity, the presence of conducting substates at high potentials and reversible adaptation to a sustained stimulus, are also exhibited by oocyte-expressed MscS. In addition to its ease of use, the oocyte system allows the user to work with relatively large patches, which could be an advantage for the visualization of membrane deformation. …

Myosin Vi Regulates Actin Structure Specialization Through Conserved Cargo-Binding Domain Sites, Mamiko Isaji, Marta Lenartowska, Tatsuhiko Noguchi, Deborah J. Frank, Kathryn G. Miller

Biology Faculty Research

Actin structures are often stable, remaining unchanged in organization for the lifetime of a differentiated cell. Little is known about stable actin structure formation, organization, or maintenance. During Drosophila spermatid individualization, long-lived actin cones mediate cellular remodeling. Myosin VI is necessary for building the dense meshwork at the cones' fronts. We test several ideas for myosin VI's mechanism of action using domain deletions or site-specific mutations of myosin VI. The head (motor) and globular tail (cargo-binding) domains were both needed for localization at the cone front and dense meshwork formation. Several conserved partner-binding sites in the globular tail previously identified …

On The Utility Of Population Models For Invasive Plant Management: Response To Evans And Davis, Eleanor A. Pardini, John M. Drake, Tiffany M. Knight

Biology Faculty Research

No abstract provided.

Will The Use Of Less Fecund Cultivars Reduce The Invasiveness Of Perennial Plants?, Tiffany M. Knight, Kayri Havens, Pati Vitt

Biology Faculty Research

Many invasive species were originally introduced for horticultural purposes, and several continue to be profitable for the green (nursery, horticulture, and landscape) industry. Recently, some plant suppliers have marketed less fecund cultivars of several invasive species, including glossy buckthorn (Frangula alnus), burning bush (Euonymus alatus), and Japanese barberry (Berberis thunbergii), as “safe” alternatives to invasive relatives. We use published matrix population models to simulate the effect of reducing fecundity on the population growth rates of invasive species. We show that large changes in fecundity result in relatively small changes to the population growth rates of long-lived species, which suggests that …