Biology Commons^™

Overexpression Of Patatin-Related Phospholipase Aiiiβ Altered The Content And Composition Of Sphingolipids In Arabidopsis, Xuemin Wang, Maoyin Li, Jennifer. E. Markham

Biology Department Faculty Works

In plants, fatty acids are primarily synthesized in plastids and then transported to the endoplasmic reticulum (ER) for synthesis of most of the complex membrane lipids, including glycerolipids and sphingolipids. The first step of sphingolipid synthesis, which uses a fatty acid and a serine as substrates, is critical for sphingolipid homeostasis; its disruption leads to an altered plant growth. Phospholipase As have been implicated in the trafficking of fatty acids from plastids to the ER. Previously, we found that overexpression of a patatin-related phospholipase, pPLAIIIβ, resulted in a smaller plant size and altered anisotropic cell expansion. Here, we determined the …

Limited Sex-Biased Neural Gene Expression Patterns Across Strains In Zebrafish (Danio Rerio), Ryan Y. Wong, Melissa M. Mcleod, John Godwin

Biology Faculty Publications

Background: Male and female vertebrates typically differ in a range of characteristics, from morphology to physiology to behavior, which are influenced by factors such as the social environment and the internal hormonal and genetic milieu. However, sex differences in gene expression profiles in the brains of vertebrates are only beginning to be understood. Fishes provide a unique complement to studies of sex differences in mammals and birds given that fish show extreme plasticity and lability of sexually dimorphic characters and behaviors during development and even adulthood. Hence, teleost models can give additional insight into sexual differentiation. The goal of …

White Fringetree, Chionanthus Virginicus, As A Novel Larval Host For Emerald Ash Boer, Don Cipollini

Biological Sciences Faculty Publications

Emerald ash borer is an invasive Asian pest of ash species in North America. All North American species of ash tested so far are susceptible to it, but there are no published reports of this insect developing fully in non-ash hosts in the field in North America. I report here evidence that EAB can attack and complete development in white fringetree, Chionanthus virginicus L., a species native to the southeastern U.S. that is also planted ornamentally.

Mechanisms Of Ash Resistance To Emerald Ash Borer: Progress And Gaps, Caterina Villari, Justin G.A. Whitehill, Don Cipollini, Daniel A. Herms, Pierluigi Bonello

Biological Sciences Faculty Publications

The emerald ash borer (EAB) invasion of North America has caused widespread mortality of native ash, and is threatening the native ash resources. As a consequence of its devastating impact, EAB has caught the attention of the scientific community, and several studies have focused on different aspects of the biology and behavior of this pest, including its interaction with host defenses. Here we present a review of the published literature on mechanisms of ash resistance to EAB, the understanding of which, despite starting from a tabula rasa, has achieved significant progress in the last few years.

Mercury And Selenium In Stranded Indo-Pacific Humpback Dolphins And Implications For Their Trophic, Duan Gui, Ri-Qing Yu, Laiguo Chen, Laiguo Chen, Qin Tu, Hui Mo, Yuping Wu

Biology Faculty Publications and Presentations

As top predators in the Pearl River Estuary (PRE) of China, Indo-Pacific humpback dolphins (Sousa chinensis) are bioindicators for examining regional trends of environmental contaminants in the PRE. We examined samples from stranded S. chinensis in the PRE, collected since 2004, to study the distribution and fate of total mercury (THg), methylmercury (MeHg) and selenium (Se) in the major tissues, in individuals at different ages and their prey fishes from the PRE. This study also investigated the potential protective effects of Se against the toxicities of accumulated THg. Dolphin livers contained the highest concentrations of THg (32.34658.98 mg g21 dw) …

A Central Support System Can Facilitate Implementation And Sustainability Of A Classroom-Based Undergraduate Research Experience (Cure) In Genomics, David Lopatto, Charles Hauser, Christopher J. Jones, Don Paetkau, Vidya Chandrasekaran, David Dunbar, Joyce Stamm, Consuelo Alvarez, Daron Barnard, James E. J. Bedard, Additional Author(S)

School of Science Faculty Works

In their 2012 report, the President's Council of Advisors on Science and Technology advocated “replacing standard science laboratory courses with discovery-based research courses”—a challenging proposition that presents practical and pedagogical difficulties. In this paper, we describe our collective experiences working with the Genomics Education Partnership, a nationwide faculty consortium that aims to provide undergraduates with a research experience in genomics through a scheduled course (a classroom-based undergraduate research experience, or CURE). We examine the common barriers encountered in implementing a CURE, program elements of most value to faculty, ways in which a shared core support system can help, and the …

Astrocyte-Specific Regulation Of Hmecp2 Expression In Drosophila, David Hess-Homeier, Chia-Yu Fan, Tarun Gupta, Ann-Shyn Chiang, Sarah J. Certel

Biological Sciences Faculty Publications

Alterations in the expression of Methyl-CpG-binding protein 2 (MeCP2) either by mutations or gene duplication leads to a wide spectrum of neurodevelopmental disorders including Rett Syndrome and MeCP2 duplication disorder. Common features of Rett Syndrome (RTT), MeCP2 duplication disorder, and neuropsychiatric disorders indicate that even moderate changes in MeCP2 protein levels result in functional and structural cell abnormalities. In this study, we investigated two areas of MeCP2 pathophysiology using Drosophila as a model system: the effects of MeCP2 glial gain-of-function activity on circuits controlling sleep behavior, and the cell-type specific regulation of MeCP2 expression. In this study, we first examined …

Un Cuento Satírico En Medio Del Debate Sobre El Darwinismo En México, Miguel A. Fernández Delgado Mafd

Alambique. Revista académica de ciencia ficción y fantasía / Jornal acadêmico de ficção científica e fantasía

Charles Darwin's theory of biological evolution of species was accepted or rejected by Mexican scientists, including Gabino Barreda, representative of Comte's philosophy. It was also included by Justo Sierra in a history book for the Escuela Nacional Preparatoria, a decision which raised a lot of criticism from conservative groups. It is also discussed the implications of social Darwinism in the early Twentieth Century Mexico. The document we offer is a satire published in those years, which resembles the tone of Swift's Gulliver Travels.

Residency Time As An Indicator Of Reproductive Restraint In Male Burying Beetles, Ashlee N. Smith, Mark C. Belk, J. Curtis Creighton

Faculty Publications

The cost of reproduction theory posits that there are trade-offs between current and future reproduction because resources that are allocated to current offspring cannot be used for future reproductive opportunities. Two adaptive reproductive strategies have been hypothesized to offset the costs of reproduction and maximize lifetime fitness. The terminal investment hypothesis predicts that as individuals age they will allocate more resources to current reproduction as a response to decreasing residual reproductive value. The reproductive restraint hypotheses predicts that as individuals age they will allocate fewer resources to current reproduction to increase the chance of surviving for an additional reproductive opportunity. …

Causes And Consequences Of Chinese Privet (Ligustrum Sinense Lour.) Invasion In Hydrologically Altered Forested Wetlands, Meghan Beth Foard

Student Theses and Dissertations

What drives invasive species success? My research consists of four studies aiming to answer this question for Ligustrum sinense. The four projects are: (1) Synthesis of invasion literature within passenger-driver-backseat driver frameworks; (2) hydrochory investigation of water as a dispersal mechanism for invasion; (3) ecohydrology investigation of inundation effects on seed viability of L. sinense; (4) dendrochronology study of the effects of stream channelization and L. sinense invasion on bottomland oak tree growth. Results suggest that L. sinense initially invaded habitats that were hydrologically altered, resulting in drier conditions and a "novel niche." Dispersal via hydrochory allowed L. sinense to …

Collapse Of An Ecological Network In Ancient Egypt, Justin Yeakel, Mathias Pires, Lars Rudolf, Nathaniel Dominy

Dartmouth Scholarship

The dynamics of ecosystem collapse are fundamental to determining how and why biological communities change through time, as well as the potential effects of extinctions on ecosystems. Here, we integrate depictions of mammals from Egyptian antiquity with direct lines of paleontological and archeological evidence to infer local extinctions and community dynamics over a 6,000-y span. The unprecedented temporal resolution of this dataset enables examination of how the tandem effects of human population growth and climate change can disrupt mammalian communities. We show that the extinctions of mammals in Egypt were nonrandom and that destabilizing changes in community composition coincided with …

Allopolyploidy, Diversification, And The Miocene Grassland Expansion, Matt Estep, Michael Mckain, Dilys Diaz, Jinshun Zhong, John Hodge, Trevor Hodkinson, Daniel Layton, Simon Malcomber, Rémy Pasquet, Elizabeth Kellogg

Biology Department Faculty Works

The role of polyploidy, particularly allopolyploidy, in plant diversification is a subject of debate. Whole-genome duplications precede the origins of many major clades (e.g., angiosperms, Brassicaceae, Poaceae), suggesting that polyploidy drives diversification. However, theoretical arguments and empirical studies suggest that polyploid lineages may actually have lower speciation rates and higher extinction rates than diploid lineages. We focus here on the grass tribe Andropogoneae, an economically and ecologically important group of C4 species with a high frequency of polyploids. A phylogeny was constructed for ca. 10% of the species of the clade, based on sequences of four concatenated low-copy nuclear loci. …

Effects Of Extreme Climate Events On Tea (Camellia Sinensis) Functional Quality Validate Indigenous Farmer Knowledge And Sensory Preferences In Tropical China, Selena Ahmed, John Richard Stepp, Colin M. Orians, Timothy S. Griffin, Corene Matyas, Albert Robbat, Sean Cash, Dayuan Xue, Chunlin Long, Uchenna Unachukwu, Sarabeth Buckley, Edward J. Kennelly

Publications and Research

Climate change is impacting agro-ecosystems, crops, and farmer livelihoods in communities worldwide. While it is well understood that more frequent and intense climate events in many areas are resulting in a decline in crop yields, the impact on crop quality is less acknowledged, yet it is critical for food systems that benefit both farmers and consumers through high-quality products. This study examines tea (Camellia sinensis; Theaceae), the world’s most widely consumed beverage after water, as a study system to measure effects of seasonal precipitation variability on crop functional quality and associated farmer knowledge, preferences, and livelihoods. Sampling was conducted in …

Dietary Carbohydrates Influence The Structure And Function Of The Intestinal Alpha-Glucosidases, Mohammad Chegeni

Open Access Dissertations

As the primary products of starch digestion by pancreatic α-amylase, maltooligosaccharides (including maltose) are the main substrates for the α-glucosidases at the intestinal brush border. Here, maltose was shown to induce the formation of a higher molecular weight (HMW) sucrase-isomaltase (SI) species in Caco-2 cells that sorts more quickly to the enterocyte surface to act as a digestive enzyme. As this finding suggested a maltose sensing ability of small intestinal enterocytes, molecular mechanisms associated with the maturation and trafficking of HMW SI were further investigated. A pulse-chase experiment using [ ³⁵S]-methionine revealed a higher rate of early trafficking and …

Lifelines Fall 2014, Southern Adventist University

Lifelines - Biology Department Newsletter

The Fall 2014 issue of Lifelines features articles on the new research facilities in Hickman Science Center, the addition of Dr. David Nelsen to the faculty, and the Southern Union Medical/Dental Retreat.

Maldi-Tof Ms As A Supportive Tool For The Evaluation Of Bacterial Diversity In Soils From Africa And The Americas, Adrian Douglas Allen, Maria Velez-Quinones, Broderick Eribo, Vernon Morris

Department of Biology Faculty Publications

Identification and characterization of viable-culturable bacteria (VCB) associated with soils from Africa and the Americas is significant for environmental and battlefield security. Such analyses are scarce and their evaluation using traditional microbiological methods do not fully elucidate the structure and chemotaxonomic characteristics of the microbial community. In this study, matrix assisted laser desorption time of flight mass spectrometry (MALDI-TOF MS) spectrometry in addition to 16S rRNA sequencing, and diversity indices were employed to characterize VCB and their associated biomarkers. Nineteen genera were identified across all sample locations, but only four (Bacillus, Brevibacillus, Paenibacillus and Terribacillus) confirmed by ClustalW2 as being …

Neonatal Nmda Receptor Blockade Disrupts Spike Timing And Glutamatergic Synapses In Fast Spiking Interneurons In A Nmda Receptor Hypofunction Model Of Schizophrenia, Kevin Jones, Joshua Corbin, Molly Huntsman

Department of Biology Faculty Publications

The dysfunction of parvalbumin-positive, fast-spiking interneurons (FSI) is considered a primary contributor to the pathophysiology of schizophrenia (SZ), but deficits in FSI physiology have not been explicitly characterized. We show for the first time, that a widely-employed model of schizophrenia minimizes first spike latency and increases GluN2B-mediated current in neocortical FSIs. The reduction in FSI first-spike latency coincides with reduced expression of the Kv1.1 potassium channel subunit which provides a biophysical explanation for the abnormal spiking behavior. Similarly, the increase in NMDA current coincides with enhanced expression of the GluN2B NMDA receptor subunit, specifically in FSIs. In this study mice …

The Evolution Of Copulation Frequency And The Mechanisms Of Reproduction In Male Anolis Lizards, Michele A. Johnson, Maria Veronica Lopez, Tara K. Whittle, Bonnie K. Kircher, A K. Dill, Divina Varghese, J. Wade

Biology Faculty Research

The evolution of many morphological structures is associated with the behavioral context of their use, particularly for structures involved in copulation. Yet, few studies have considered evolutionary relationships among the integrated suite of structures associated with male reproduction. In this study, we examined nine species of lizards in the genus Anolis to determine whether larger copulatory morphologies and higher potential for copulatory muscle performance evolved in association with higher copulation rates. In 10–12 adult males of each species, we measured the size of the hemipenes and related muscles, the seminiferous tubules in the testes, and the renal sex segments in …

Acclimation Of Photosynthetic Temperature Optima Of Temperate And Boreal Tree Species In Response To Experimental Forest Warming, Kerrie M. Sendall, Peter B. Reich, Changming Zhao, Hou Jihua, Xia Orong Wei, Artur Stefanski, Karen Rice, Roy L. Rich, Rebecca A. Montgomery

Faculty Research & Creative Activity

Rising temperatures caused by climate change could negatively alter plant ecosystems if temperatures exceed optimal

temperatures for carbon gain. Such changes may threaten temperature-sensitive species, causing local extinctions and

range migrations. This study examined the optimal temperature of net photosynthesis (Topt) of two boreal and four

temperate deciduous tree species grown in the field in northern Minnesota, United States under two contrasting temperature

regimes. We hypothesized that Topt would be higher in temperate than co-occurring boreal species, with

temperate species exhibiting greater plasticity in Topt, resulting in better acclimation to elevated temperatures. The

chamberless experiment, located at two sites in …

Low O2-Induced Atp Release From Erythrocytes Of Humans With Type 2 Diabetes Is Restored By Physiological Ratios Of C-Peptide And Insulin, Jennifer P. Richards, Gina L.C. Yosten, Grant R. Kolar, Cory W. Jones, Alan H. Stephenson, Mary L. Ellsworth, Randy S. Sprague

Biological Sciences Faculty Research & Creative Works

ATP release from erythrocytes in response to reduced oxygen (O2) tension stimulates local vasodilation, enabling these cells to direct perfusion to areas in skeletal muscle in need of O2. Erythrocytes of humans with type 2 diabetes do not release ATP in response to low O2. Both C-peptide and insulin individually inhibit low O2-induced ATP release from healthy human erythrocytes, yet when co administered at physiological concentrations and ratios, no inhibition is seen. Here, we determined: that 1) eryth-rocytes of healthy humans and humans with type 2 diabetes possess a C-peptide receptor (GPR146), 2) the combination of C-peptide and insulin at …

Editorial Overview: Environmental Physiology: Insect Environmental Physiology, Brent J. Sinclair

Biology Publications

No abstract provided.

Sensitivity And Tolerance Of Riparian Arthropod Communities To Altered Water Resources Along A Drying River, Kevin E. Mccluney, John L. Sabo

Biological Sciences Faculty Publications

Rivers around the world are drying with increasing frequency, but little is known about effects on terrestrial animal communities. Previous research along the San Pedro River in southeastern AZ, USA, suggests that changes in the availability of water resources associated with river drying lead to changes in predator abundance, community composition, diversity, and abundance of particular taxa of arthropods, but these observations have not yet been tested manipulatively.

African Philosophy: A Key To African Innovation And Development, George Middendorf

Department of Biology Faculty Publications

This essay demonstrates how African philosophy can be a key to African innovation and development. Its first section illustrates how philosophy as a discipline drives innovation in science and technology. The second part proposes a new discipline linking science, engineering and technology to sustainable, ethical development. The third section proposes an ethics core derived from ancient Egyptian and Ethiopian thought. It addresses the fact that non-African principles and personnel have in some measure directed African development, resulting in unsustainable and sometimes destructive outcomes. The conclusion argues that the primary instrument for African development must be a Pan-African curriculum developed through …

The Peopling Of The African Continent And The Diaspora Into The New World, Michael Campbell, Jibril Hirbo, Jeffrey Peter Townsend, Sarah Tishkoff

Department of Biology Faculty Publications

Africa is the birthplace of anatomically modern humans, and is the geographic origin of human migration across the globe within the last 100,000 years. The history of African populations has consisted of a number of demographic events that have influenced patterns of genetic and phenotypic variation across the continent. With the increasing amount of genomic data and corresponding developments in computational methods, researchers are able to explore long-standing evolutionary questions, expanding our understanding of human history within and outside of Africa. This review will summarize some of the recent findings regarding African demographic history, including the African Diaspora, and will …

A Comparison Of Techniques Measuring Stress In Birds, Deborah A. O'Dell, Michael A. Carlo, Abigail Kimmitt, Ellen Bikowski, Katherine R. Morris, Andrew Dolby

Virginia Journal of Science

Free-living birds are subjected to both external and internal stresses which can affect their health, activity, and reproductive success. To study stress in free living birds, they must be captured in nets and handled by the researcher to take blood samples for commonly used measures of stress, an activity which itself can induce stress and confound results. This study compares the effects of handling time on three different measures of stress: levels of the stress hormone corticosterone (CORT), levels of Heat Shock Protein 60 (HSP 60) and the ratio of heterophils to lymphocytes (H/L ratio) in tufted titmouse (Baeolophus bicolor …

Characterization Of Metal-Reducing Microorganisms In Walker Lake: A Terminal Saline Desert Lake, Memona Khan

Honors College Theses

Metal-reducing microorganisms are increasingly being recognized as an essential component of aquatic microbial ecosystems involved in decomposition of organic matter. Alkaliphilic microbial reduction from alkaline lakes is a little studied field and one particular ecosystem, Walker Lake, presents the opportunity to investigate alkaliphilic metal reducers in their native ecological setting. Walker lake is a terminal, saline, desert lake with pH 9.4, Walker Lake samples of surface and deep sediments and water column samples from 0, 10, 5, 15, 17.5, 19 m depths were cultured by serial dilution in synthetic Walker Lake medium and supplemented separately with Hydrous Ferric Oxide (HFO), …

Spatial Variation In Carbon And Nitrogen In Cultivated Soils In Henan Province, China: Potential Effect On Crop Yield, Xuelin Zhang, Qun Wang, Frank S. Gilliam, Yilun Wang, Feina Cha, Chaohai Li

Biological Sciences Faculty Research

Improved management of soil carbon (C) and nitrogen (N) storage in agro-ecosystems represents an important strategy for ensuring food security and sustainable agricultural development in China. Accurate estimates of the distribution of soil C and N stores and their relationship to crop yield are crucial to developing appropriate cropland management policies. The current study examined the spatial variation of soil organic C (SOC), total soil N (TSN), and associated variables in the surface layer (0–40 cm) of soils from intensive agricultural systems in 19 counties within Henan Province, China, and compared these patterns with crop yield. Mean soil C and …

Developing A Practical Wireless Monitoring Solution For A Size-Constrained, Low-Power, Biomechanical, Sports Telemetry System, Jeffery Ray King

Open Access Theses

As sport-related concussions become more prevalent, the ability to quickly and reliably assess brain injury risk is increasingly essential. Commercially-available systems exist with the goal of assessing the risk of traumatic brain injury in athletes in real-time. These systems utilize a pre-determined acceleration threshold, discarding all captured information below this arbitrary threshold. The use of an event-based model to assess the risk of traumatic brain injury has been shown to be inadequate. Therefore, these systems falsely promote "accurate" real-time communication of risk. Research conducted by the Purdue Neurotrauma Group (PNG) seeks to advance the field by developing a biomechanical sports …

Population Differentiation, Dispersal Limitation, And Local Adaptation In The Gametophytic Fern Vittaria Appalachiana, Sally M. Stevens

Open Access Dissertations

Species' distributions are driven by a variety of abiotic and biotic factors. As these factors become altered by global climate change, species are believed to respond to these projected environmental changes in four different ways. One response is the shifting of the species' geographic range to higher latitudes and elevations, which will be unlikely for those species that have limited dispersal potential. Alternatively, organisms may tolerate the change, which will be unlikely for those organisms that are not phenotypically plastic. A third potential response is to adapt to the new environment via rapid evolution, an unlikely response for those organisms …

Integrative High-Throughput Study Of Arsenic Hyper-Accumulation In Pteris Vittata, Qiong Wu

Open Access Dissertations

Arsenic is a natural contaminant in the soil and ground water, which raises considerable concerns in food safety and human health worldwide. The fernPteris vittata (Chinese brake fern) is the first identified arsenic hyperaccumulator[1]. It and its close relatives have un-paralleled ability to tolerant arsenic and feature unique arsenic metabolisms. The focus of the research presented in this thesis is to elucidate the fundamentals of arsenic tolerance and hyper-accumulation in Pteris vittata through high throughput technology and bioinformatics tools. The transcriptome of the P. vittatagametophyte under arsenate stress was obtained using RNA-Seq technology and Trinity de novo assembly. …