Digital Commons Network^™

Modulation Of L-Type Calcium Current By Gaba-B Receptor Activation In The Neonatal Rat Hippocampus, Jennifer Grace Bray

Dissertations (1934 -)

During the early postnatal period, the inhibitory neurotransmitter γ-aminobutyric acid (GABA) facilitates current through voltage-dependent L-type calcium channels by activating metabotropic GABA_B receptors in the rat hippocampus. In the present study, the effects of the GABA_B receptor agonist baclofen on L-type currents were tested using whole-cell voltage clamp recording on neurons isolated from the superior region of hippocampi obtained from pups of various ages to determine the exact time course of L-type current facilitation. The facilitation of L-type current by GABA_B receptors is more prominent during the second week of development.

One developmental process that L-type current …

Neuroscience's New Techniques For Evaluating Future Dangerousness: Are We Returning To Lombroso's Biological Criminality, J. W. Looney

University of Arkansas at Little Rock Law Review

No abstract provided.

The University Of Texas At Tyler Magazine (Spring 2010, University Of Texas At Tyler

UT Tyler Magazine

Articles in this edition of UT Tyler Magazine include: President's Letter; Around Campus: Education Professor Takes Holocaust Study Tour in Israel, University Receives $1.4 Million to Begin UTeach Program, Psychology Professors Collaborate with Alzheimer's Research Team, Student Organization Assists East Texas Crisis Center, 3 Students Chosen for Community Service Trip to Costa Rica, Nursing School Partners with Nonprofits at Longview Clinic, University Represented at Budapest Science Forum, Sign Up for PatriotALERT Emergency Notifications; Making a Difference in Business Decisions, Dr. Marilyn Young Promotes Success Through Management Development; Soaring to New Corporate Heights, UT Tyler Graduate Has Something to 'Quack' About; …

Legal, Moral And Biological Implications Of Poaching And Illegal Animal Trafficking On An International Scale, Meghan A. Pastor

Pell Scholars and Senior Theses

Poaching and animal trafficking is a global issue in the areas of biology, morality and politics. This paper will discuss the different areas of impact as well as consider options for the prevention and alleviation of this issue.

The Effect Of Individual Or Group Guidelines On The Calibration Accuracy Of High School Biology Students, Camilla C. Walck

Teaching & Learning Theses & Dissertations

The effect of individual or group guidelines on the calibration accuracy of high school biology students was investigated. The study was conducted with 102 International Baccalaureate Middle Years Program biology students in a public school setting. The study was carried out over three testing occasions. Students worked in group or individual settings with and without calibration guidelines. Four intact classes were randomly assigned to one of four conditions: groups calibrating without guidelines; groups calibrating with guidelines; individuals calibrating without guidelines; individuals calibrating with guidelines. The students participated in the calibration activities one block before they actually took each of the …

Part I: Evaluation Of Student Assessment Of Learning Gains (Salg)In Two Different Biology 100 Classes Part 2: What Biology Concepts Are Important In General Education?: Analysis Of Seventeen Core Concepts, Jessica Marie Rosenvall Howelle

Theses and Dissertations

The purpose of this two-part study is to examine how to improve introductory level non-majors biology courses to improve student attitude and learning gains in the sciences. The first part of this study examines the collective effect of three different pedagogies (service learning, concept mapping and guest lectures) on student attitude and learning gains in a freshman, non-majors biology course. Two classes, one with the three pedagogies, and one without, were compared. Data were collected from two classes in Fall 2008 (one treatment and one control) and two similar classes replicated in Fall 2009. Learning and attitude gains were measured …

Organismal Climatology: Analyzing Environmental Variability At Scales Relevant To Physiological Stress, Brian Helmuth, Bernardo R. Broitman, Lauren Yamane, Sarah E. Gilman, Katharine Mach, K. A.S. Mislan, Mark W. Denny

Faculty Publications

Predicting when, where and with what magnitude climate change is likely to affect the fitness, abundance and distribution of organisms and the functioning of ecosystems has emerged as a high priority for scientists and resource managers. However, even in cases where we have detailed knowledge of current species’ range boundaries, we often do not understand what, if any, aspects of weather and climate act to set these limits. This shortcoming significantly curtails our capacity to predict potential future range shifts in response to climate change, especially since the factors that set range boundaries under those novel conditions may be different …

Why Some Stems Are Red: Cauline Anthocyanins Shield Photosystem Ii Against High Light Stress, Dana A. Dudle

Biology Faculty publications

Red-stemmed plants are extremely common, yet the functions of cauline anthocyanins are largely unknown. The possibility that photoabatement by anthocyanins in the periderm reduces the propensity for photoinhibition in cortical chlorenchyma was tested for Cornus stolonifera. Anthocyanins were induced in green stems exposed to full sunlight. PSII quantum yields (Ф_PSII) and photochemical quenching coefficients were depressed less in red than in green stems, both under a light ramp and after prolonged exposures to saturating white light. These differences were primarily attributable to the attenuation of PAR, especially green/yellow light, by anthocyanins. However, the red internodes also …

The Effects Of Seasonality And Land Use On Microbe Populations In Three Ecological Areas, Rachel E. Hutchins

McNair Scholars Research Journal

The Huron River watershed is comprised of three primary land uses: agricultural, natural, and urban. Land usage affects the biological and chemical conditions within the watershed, therefore affecting water quality. Recent studies have provided evidence that water quality can be assessed by examining the composition of the microbial communities found in biofilms. In this study we analyzed and compared samples collected from a natural site and urban site over the course of three seasons; fall (August), winter (December), and spring (April). Microbial diversity was determined by isolating, amplifying, and genotyping the 16S rRNA gene. The results show that microbial community …

Incomplete Spring Turnover In Small Deep Lakes In Se Michigan, Lisa Denys

McNair Scholars Research Journal

While temperate lakes are commonly thought to turnover twice annually, in the fall and the spring, there are several factors that can reduce the probability of turnover. Whether or not a lake turns over has important implications for nutrient dynamics and food webs. In this study, we investigated several small deep lakes in SE Michigan to determine whether spring turnover had occurred. One factor affected by lake turnover is the distribution of oxygen in the lake. Lakes receive oxygen from the atmosphere at their surface and from small plant-like organisms called phytoplankton within the body of the lake. Photosynthesizing phytoplankton …

The Synergistic Effects Of Probiotic Microorganisms On The Microbial Production Of Butyrate In Vitro, Khadija A. Abbas

McNair Scholars Research Journal

Butyrate producing microbiota perform a number of activities important in supporting the normal function of the human gastrointestinal tract. The goal of this study was to determine the synergistic effects of lactate- and butyrate-producing bacteria on butyrate production in vitro co-culture. PCR was used to detect the genes butyrate kinase and butyryl-CoA transferase that contribute to butyrate production, in a panel of representative gut microbiota. Preliminary data suggested that two Clostridium sp. (ASF 500 and ASF 502) and one Eubacterium sp. (ASF492) possessed at least one of these genes for butyrate production. Co-culture experiments mixing a lactate-producer with a butyrate-producer …

Does Rac Gtpase Play A Role In Epha4 Signaling In Xenopus Embroys?, Ashley Durand

McNair Scholars Research Journal

In embryonic development, many cells migrate in order to correctly form new structures. One way that guidance of this migration occurs is via a repulsion mechanism involving the Eph family of receptors. Signaling through these receptors activates the repulsive mechanism that limits which tissues can interact with each other. The repulsion mechanism is not well understood, but involves the reorganization of the actin cytoskeleton and a loss of cell-cell adhesion. Activation of the EphA4 signaling pathway in Xenopus laevis embryos has been shown to cause the repulsion mechanism. the Rho family of GTPases consisting of Cdc42, Rho, and Rac, has …

A Search For Genetic Modifiers Responsible For Congenital Heart Disease Variability In The Presence Of Nkx2-5 Haploinsufficiency, Julia Brandeis Winston Honold

All Theses and Dissertations (ETDs)

While a clear heritable risk has been observed for congenital heart disease, there is considerable variation in penetrance and presentation likely due to multiple genetic and environmental risk factors. To identify causative factors and interactions responsible for variability in heart development, greater than 4,200 hearts from Nkx2-5 heterozygous knockout mice have been collected and examined. Nkx2-5+/- mice in the inbred strain background C57Bl/6 frequently have atrial and ventricular septal defects. The incidences are substantially reduced in the Nkx2-5+/- progeny of first-generation: F1) outcrosses to the strains FVB/N or A/J. Defects recur in the second generation: F2) of the F1xF1 intercross …

Spotted Ash Looper, Abraxas Pantaria (L.) (Lepidoptera: Geometridae), A New Ash Pest In Turkey, Hi̇kmet Özbek, Önder Çalmaşur

Turkish Journal of Zoology

Abraxas pantaria (L.) (Lepidoptera: Geometridae), the spotted ash looper (Light Magpie), is recognized as a new pest of common ash, Fraxinus excelsior (L.) in the eastern part of Turkey. Description of different developmental stages of A. pantaria is given. Its development, biology, damage, and parasitoids were studied in the field (Aras Valley, Karakurt, Sarıkamış, Kars Province) and partly in the laboratory during 2004-2006. In the field adults started to appear at the end of June and were seen until the middle of August. The eggs were laid mostly on the lower sides of leaves adjacent to the midrib in single …

Lifelines Winter 2010, Southern Adventist University

Lifelines - Biology Department Newsletter

The Winter 2010 issue of Lifelines features articles on research done in the Southern Connections class, the retirement of Dr. David Ekkens, the death of Dr. Richard Seidel, the Allied Health Club's service projects, and a pictorial directory of the 2010 biology and allied health graduates.

Full Issue: Volume 4, Number 1

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Post-­Fire Alterations In Mechanical Strength Of Leaves In Heteromeles Arbutifolia, Andrew Hair, Madeline Dilascia, Nick Novella, Taylor Wurdeman

Featured Research

Wildfires in the Santa Monica mountains in Southern California burn down a decent percentage of the local vegetation. However, some plants like Heteromeles Arbutifolia, are considered to be resprouters because they return a mere two years after being burnt down. It is hypothesized that the artificially browsed resprout leaves will have a lower tensile strength than both the young and adult leaves because they use a lower amount of carbohydrates per unit-leaf-area. Data showed that although there was a slight different between the young leaves and the adult leaves of the Heteromeles, there was no statistically significant difference between the …

A Comparison Of The Tensile Strength Of Leaves In Encelia Californica In Canyon And Beach Species, Anna Chowaniec, Annie Lee, Hayley Springs

Featured Research

Our research is concerned with the further exploration of leaf biomechanics, a relatively unexamined field. The purpose of this experiment was to find a correlation between environmental stress factors and tensile strength of leaves of Encelia californica. We hypothesized the beach species would have a higher tensile strength than canyon species. After evaluating data collected from both Pepperdine’s Presidents Canyon and Malibu beach we found that while the canyon species could withstand a higher maximum load of force, there was no difference between the canyon and the beach species with leaf area taken into account. Using Young’s Modulus, we …

Mathematical Biology At An Undergraduate Liberal Arts College, Stephen C. Adolph, Lisette G. De Pillis

All HMC Faculty Publications and Research

Since 2002 we have offered an undergraduate major in Mathematical Biology at Harvey Mudd College. The major was developed and is administered jointly by the mathematics and biology faculty. In this paper we describe the major, courses, and faculty and student research and discuss some of the challenges and opportunities we have experienced.

Full Issue: Volume 3, Number 1

The Science Journal of the Lander College of Arts and Sciences

No abstract provided.

Ground Arthropod Community Survey In Grassland, Shrubland, And Woodland At The Sevilleta National Wildlife Refuge, New Mexico (1992-2004), David Lightfoot

Sevilleta LTER Program Data

This data set contains records for the numbers of selected groups of ground-dwelling arthropod species and individuals collected from pitfall traps at 4 sites on the Sevilleta NWR, including creotostebush shrubland, both black and blue grama grasslands, and a pinyon/juniper woodland. Data collections begin in May of 1989, and are represented by subsequent sample collections every 2 months. One site (Goat Draw/Cerro Montosa) was discontinued in 2001, and a new site (Blue Grama) was initiated . Only three sites, creosotebush, black grama, and blue grama were continued between 2001-2004.

Effect Of Long-Term Nitrogen Fertilization On Mycorrhizal Fungi Associated With A Dominant Grass In A Chihuahuan Desert Grassland At The Sevilleta National Wildlife Refuge, New Mexico (2005), Andrea Porras-Alfaro, Robert Sinsabaugh, Don Natvig

Sevilleta LTER Program Data

We studied the diversity of arbuscular mycorrhizal fungi (AMF) in a semiarid grassland and the effect of long-term nitrogen (N) fertilization on this fungal community. Root samples of Bouteloua gracilis were collected at the Sevilleta National Wildlife Refuge (New Mexico, USA) from control and N-amended plots that have been fertilized since 1995. Small subunit rDNA was amplified using AMF specific primers NS31 and AM1. The diversity of AMF was low in comparison with other ecosystems, only seven operational taxonomic units (OTU) were found in B. gracilis and all belong to the genus Glomus. The dominant OTU was closely related to …

Ocotillo Plant Demography Study At The Sevilleta National Wildlife Refuge, New Mexico, 2003, Joanna Redfern, William Pockman, Tim Lowrey

Sevilleta LTER Program Data

In order to better understand the life history of Ocotillo, a re-sampling of Ocotillo plants originally marked and studied in 1991 was done in the southeast corner of the Sevilleta National Wildlife Refuge. All plants measured in 1991 were re-censused and re-tagged with new numbers. Measurements of plant height and branch number were repeated along with measurements pertaining to overall plant size.

Die Stellungnahme Der Europäischen Gruppe Für Ethik Der Naturwissenschaften Und Der Neuen Technologien (Ege) Zum Thema „Ethik Der Synthetischen Biologie, Hille Haker

Theology: Faculty Publications and Other Works

No abstract provided.

Effect Of Fertilizer On Leaf Tensile Strength In Salvia Leucophylla, Tawny Lindahl, John Buie, Eiichiro Uemura

Featured Research

This experiment sought to establish a connection between short term growth in Salvia leucophylla found in Southern California and nutrient availability in the soil. It was hypothesized that adding artificially produced nutrient mix Miracle Grow would increase the strength of the leaves in the herb after one week of addition. Newer leaves were tested in the Instron device for tensile strength after one week, and after data analysis, it was concluded that there was no difference in tensile strength of leaves treated with fertilizer compared with leaves without fertilizer.

Differences In Hydraulic Conductance (Kh) As A Function Of Leaf Area (Ks Leaf) And Xylem Size (Ks Xylem) In Encelia Californica And Venegasia Carpesioides, Tony Audin, Andrew Dudley, Janel Gonzalez

Featured Research

Southern California and the Santa Monica Mountains experience a climate similar to that of the Mediterranean basin. This means hot, dry summers, mild, wet winters, and large amounts of plant diversity. A major issue that can affect these regions is water availability and processing. To demonstrate this, hydraulic conductance (Kh) was measured as a function of leaf area (KS Leaf) and xylem size (KS Xylem). Two vascular plants were used for this study, Encelia californica and Venegasia carpesioides. This is because they are similar morphologically but are different genus and species. It was hypothesized that the larger plant (V. carpesioides) …

The Affect Of Temperature On The Fluorescence Of Heteromeles Arbutifolia (Hollywood) In The Santa Monica Mountains, Patrick Y. Chisum, Adam S. Graham, Arthur C. Sanders

Featured Research

Presented here is a comparison of the predawn fluorescence of adult Heteromeles arbutifolia growing on the Pepperdine Seaver campus next to the lacrosse field, and adult Heteromeles growing in Tapia canyon. The analysis of the leaf temperature measured by an IR thermometer showed an average of 9.32°C drop when measuring plants in Tapia canyon compared to those growing on the warmer Pepperdine campus. The air temperature measured by the Kestrel and IR thermometer showed Tapia canyon being an average of 7.27°C colder than predawn measurements on Pepperdine campus. Finally, the fluorescence of the plants in both locations was measured using …

Effect Of Petiole-­To-­Branchlet Angle On Tensile Stress And Tensile Strength In Heteromeles Arbutifolia, Matt W. Andrus, Anthony P. Lisankis, Valen C. Anderson

Featured Research

Heteromeles arbutifolia an important chaparral species of southern California, Is a food source for mule deer (Odocoileus hemionus). This predation has become more pronounced as the climate shifts to hotter, drier, and longer summers. Other species that the deer normally feed on cannot survive these harsh conditions, while Heteromeles arbutifolia is able to persevere (Letourneau, 2004). We decided that there must be mechanisms involved in the petiole of leafs to keep them from being pulled off by deer and strong winds. Our group hypothesized that as the angle between the petiole and branchlet increased, the tensile strength of the petiole …

Comparing Leaf Properties Of Inland And Coastal Malosma Laurina In The Santa Monica Mountains, Rosemary Busch Conn, Lauren Parker, Brittany Sawrey

Featured Research

Our group chose Malosma laurina, commonly known as Laurel Sumac, to observe and test. We hypothesized that there would be difference in photosynthetic trade-offs and capabilities between coastal and inland populations, specifically with respect to leaves. This was based on the low freezing tolerance in Malosma laurina (Pratt et al. 2005), and hypothesized that based on this stress, resources would be allocated differently in inland leaves than in coastal leaves. This hypothesis was tested using the indices of Normalized Difference Vegetation Index (NDVI), the Photochemical Reflectance Index (PRI), the ratio of green to red reflectance, and Leaf Specific Area …

Tensile Strength Of Malosma Laurina Leaves In Wet And Dry Conditions, T. Candelore, N. Despenza, L. Garrison, L. Hinther

Featured Research

Pepperdine University is one located in one of the most diverse places of the world. It is located in the Mediterranean which occupies less than 5% of the earth's landmass and is only found in five areas which includes California. On the campus there are several canyons. One of the canyons is called Winter Canyon. The canyon contained a plant called Malosma laurina which is located in a riparian environment and a chaparral environment. The plant grows in both areas however, our hypothesis was that the dry plants' leaves would demonstrate more plasticity. The soil humidity was also measured to …