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Phyllodictyon Robustum (Setchell Et Gardner) Comb. Nov. (Siphonocladales, Chlorophyta), A Morphologically Variable Species From The Tropical Pacific Coast Of America, Frederik Leliaert, Brian Wysor, Heroen Verbruggen, Caroline Vlaeminck, Olivier De Clerck

Arts & Sciences Faculty Publications

The systematic positions of Cladophoropsis robusta and Willeella mexicana, both occurring along the tropical Pacific coast of America, have long been uncertain. Willeella mexicana has been generally accepted as a synonym of C. robusta, which is currently placed in the genus Struveopsis. Reinvestigation of type material and recently collected specimens from Mexico and Panama, including culture observations, along with a molecular phylogenetic analysis inferred from rDNA ITS1-5.8S-ITS2 sequences, confirm that both taxa belong to the same, morphologically variable species. Thallus architecture ranges from stipitate, Struveopsis-like blades (produced by apical cell divisions and formation of opposite and flabellate branches) to Valoniopsis-like …

Microbial Colonization Of Deep-Sea Hydrothermal Vent Chimneys, Antoine Pagé

Dissertations and Theses

Deep-sea hydrothermal vent chimneys harbor some of the most extreme environments supporting life on Earth. In the absence of sunlight, the microbial communities that colonize these deposits are based on energy harvested by chemolithoautotrophs exploiting the chemical disequilibria created as hydrothermal fluids mix with seawater. Although controversial, several models consider deep-sea vent chimneys as likely habitats for primitive ecosystems that developed during the Archean.

The goal of this study was to describe spatial and temporal patterns of microbial colonization in deep-sea vent chimneys emitting high temperature (>300°C) fluids. Microbial community composition and structure were evaluated through analyses of 16S …

Systematic Reviews Of Animal Experiments Demonstrate Poor Contributions To Human Healthcare, Andrew Knight

Experimentation Collection

Widespread reliance on animal models during preclinical research and toxicity testing assumes their reasonable predictivity for human outcomes. However, of 20 published systematic reviews examining human clinical utility located during a comprehensive literature search, animal models demonstrated significant potential to contribute toward clinical interventions in only two cases, one of which was contentious. Included were experiments expected by ethics committees to lead to medical advances, highly-cited experiments published in major journals, and chimpanzee experiments—the species most generally predictive of human outcomes. Seven additional reviews failed to demonstrate utility in reliably predicting human toxicological outcomes such as carcinogenicity and teratogenicity. Results …

Bio-Optics In Integrated Ocean Observing Networks: Potential For Studying Harmful Algal Blooms, Oscar Schofield, J. Bosch, Scott Glenn, Gary Kirkpatrick, John Kerfoot, Steven Lohrenz, Mark A. Moline, Matthew Oliver, Paul Bissett

Biological Sciences

Ships have a difficult time sampling the time and space scales relevant for understanding how the physics and chemistry regulates marine ecosystems (National Research Council 2000, 2003, Figure 3.1); therefore the biology in the oceans is chronically under-sampled. This is a major problem for policy makers and local governments charged with managing coastal resources who are increasingly being asked to develop ‘ecosystem-based management’ plans (US Ocean Commission on Ocean Policy, 2004). Th is is especially true in regions where Harmful Algal Blooms (HABs) are present (Hallegraeff, 1993). Ecosystem-based management requires a quantitative understanding of the processes controlling marine food webs. …

Drinking-Water Arsenic Exposure Modulates Gene Expression In Human Lymphocytes From A U.S. Population, Angeline S. Andrew, David A. Jewell, Rebecca A. Mason, Michael L. Whitfield, Jason H. Moore, Margaret R. Karagas

Dartmouth Scholarship

Background:

Arsenic exposure impairs development and can lead to cancer, cardiovascular disease, and diabetes. The mechanism underlying these effects remains unknown. Primarily because of geologic sources of contamination, drinking-water arsenic levels are above the current recommended maximum contaminant level of 10 μg/L in the northeastern, western, and north central regions of the United States.

Objectives:

We investigated the effects of arsenic exposure, defined by internal biomarkers at levels relevant to the United States and similarly exposed populations, on gene expression.

Methods:

We conducted separate Affymetrix microarray-based genomewide analyses of expression patterns. Peripheral blood lymphocyte samples from 21 controls interviewed (1999–2002) …

Switching Language Switches Mind: Linguistic Effects On Developmental Neural Bases Of ‘Theory Of Mind’, Chiyoko Kobayashi, Gary H. Glover, Elise Temple

Dartmouth Scholarship

Theory of mind (ToM)—our ability to predict behaviors of others in terms of their underlying intentions—has been examined through false-belief (FB) tasks. We studied 12 Japanese early bilingual children (8−12 years of age) and 16 late bilingual adults (18−40 years of age) with FB tasks in Japanese [first language (L1)] and English [second language (L2)], using fMRI. Children recruited more brain regions than adults for processing ToM tasks in both languages. Moreover, children showed an overlap in brain activity between the L1 and L2 ToM conditions in the medial prefrontal cortex (mPFC). Adults did not show such a convergent activity …

Female Mate Choice Is Influenced By Male Sport Participation, Albrecht I. Schulte-Hostedde, Mark A. Eys, Krista Johnson

Kinesiology and Physical Education Faculty Publications

Sexual selection theory argues that females invest more heavily in reproduction than males and thus tend to be choosier in terms of mate choice. Sport may provide a context within which females can gain information about male quality to inform this choice. Males may be able to display attractive traits such as athleticism, strength, and physique to females while participating in sport. We predicted that females would favor males that participated in team sports over individual sports and non-athletes because team sport athletes may be more likely to display qualities such as the ability to work well with others and …

Lignin Degradation In Wood-Feeding Insects, Scott M. Geib, Timothy R. Filley, Patrick G. Hatcher, Kelli Hoover, John E. Carlson, Maria Del Mar Jimenez-Gasco, Akiko Nakagawa-Izumi, Rachel L. Sleighter, Ming Tien

Chemistry & Biochemistry Faculty Publications

The aromatic polymer lignin protects plants from most forms of microbial attack. Despite the fact that a significant fraction of all lignocellulose degraded passes through arthropod guts, the fate of lignin in these systems is not known. Using tetramethylammonium hydroxide thermochemolysis, we show lignin degradation by two insect species, the Asian longhorned beetle (Anoplophora glabripennis) and the Pacific dampwood termite (Zootermopsis angusticollis). In both the beetle and termite, significant levels of propyl side-chain oxidation (depolymerization) and demethylation of ring methoxyl groups is detected; for the termite, ring hydroxylation is also observed. In addition, culture-independent fungal gut …

Examination Of Blueberry Anthocyanins In Prevention Of Age-Related Macular Degeneration Through Retinal Pigment Epithelial Cell Culture Study, Naomi Marie Sundalius

LSU Master's Theses

This research investigated the ability of blueberry anthocyanins to inhibit the uptake of N-retinyl-N-retinylidene ethanolamine (A2E) by retinal pigment epithelial (RPE) cells as quantified by pigment epithelial derived factor (PEDF) levels in RPE cells. The A2E was synthesized and identified by matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS). Freeze dried blueberry powder of 50/50 blend (Tifblue/Rubel) anthocyanins were extracted by acetone and concentrated through chromatography. A RPE cell culture study investigating four treatments using a combination of 100 ìM A2E in DMSO and 100 ìg of blueberry anthocyanins in DMSO was tested. The treatments included: (A) control RPE cells; (B) RPE …

A Novel Ecological Role Of The Firmicutes Identified In Thermophilic Microbial Fuel Cells, Kelly C. Wrighton, Peter Agbo, Falk Warnecke, Karrie A. Weber, Eoin L. Brodie, Todd Z. Desantis, Philip Hugenholtz, Gary L. Andersen, John D. Coates

School of Biological Sciences: Faculty Publications

Significant effort is currently focused on microbial fuel cells (MFCs) as a source of renewable energy. Most studies concentrate on operation at mesophilic temperatures. However, anaerobic digestion studies have reported on the superiority of thermophilic operation and demonstrated a net energy gain in terms of methane yield. As such, our studies focused on MFC operation and microbiology at 55 °C. Over a 100-day operation, these MFCs were stable and achieved a power density of 37mW m^–2 with a coulombic efficiency of 89%. To infer activity and taxonomic identity of dominant members of the electricity-producing community, we performed phylogenetic microarray …

Interactions Between Changing Pco2, N2 Fixation, And Fe Limitation In The Marine Unicellular Cyanobacterium Crocosphaera, Fei-Xue Fu, Margaret R. Mulholland, Nathan S. Garcia, Aaron Beck, Mark E. Warner, Sergio A. Sañudo, David A. Hutchins

OES Faculty Publications

We examined the physiological responses of steady-state iron (Fe)-replete and Fe-limited cultures of the biogeochemically critical marine unicellular diazotrophic cyanobacterium Crocosphaera at glacial (19 Pa; 190 ppm), current (39 Pa; 380 ppm), and projected year 2100 (76 Pa; 750 ppm) CO₂ levels. Rates of N₂ and CO₂ fixation and growth increased in step with increasing partial pressure of CO₂ (pCO₂), but only under Fe- replete conditions. N₂) and carbon fixation rates at 75 Pa CO₂ were 1.4-1.8-fold and 1.2-2.0-fold higher, respectively, relative to those at present day and glacial pCO_{2 …}

A Quantitative Synthesis Of The Medicinal Ethnobotany Of The Malinké Of Mali And The Asháninka Of Peru, With A New Theoretical Framework, Nathaniel Bletter

Publications and Research

Background: Although ethnomedically and taxonomically guided searches for new medicinal plants can improve the percentage of plants found containing active compounds when compared to random sampling, ethnobotany has fulfilled little of its promise in the last few decades to deliver a bounty of new, laboratory-proven medicinal plants and compounds. It is quite difficult to test, isolate, and elucidate the structure and mechanism of compounds from the plethora of new medicinal plant uses described each year with limited laboratory time and resources and the high cost of clinical trials of new drug candidates.

Methods: A new quantitative theoretical framework of mathematical …

Vitamin E (Tocotrienols) And Prostate Cancer: A Proteomics Approach., Christian Mbangha Muenyi

Electronic Theses and Dissertations

Proteomics is the large scale study of proteins in cells or organisms. The purpose of this study was to characterize the proteomic alterations occurring in a prostate cancer (LNCaP) cell line after treatment with delta-tocotrienol (a form of vitamin E not very prevalent from most dietary sources). We found that both gamma- and delta-tocotrienols induced time and concentration dependent growth inhibition and programmed cell dead (apoptosis) in LNCaP cells. Secondly, we used two-dimensional gel electrophoresis (2-DE) to characterize changes in protein expression levels associated with this treatment. Our results show that a specific set of proteins are regulated at both …

An Analysis Of Enzymatic Activity In Truncated And Wild-Type Auxin Conjugate Hydrolases In Medicago Trunculata (Barrel Clover) And Implications In Structural Modeling, Scott Sigethy

Theses, Dissertations and Culminating Projects

Auxins are plant phytohormones that play an important part in plant growth and development. The level of active auxins in plants is regulated by enzymes known as hydrolases that release inactive bound forms of auxins, known as conjugates, as the active free form. We have previously isolated and enzymatically characterized the auxin conjugate hydrolase family from the model legume Medicago truncatula (barrel clover). In the process of cloning the cDNA for the genes MtIAR31, -32, -33, -34, and -36, we also cloned a truncated version of MtIAR33 (AMtIAR33) that apparently expresses an alternative hydrolase protein from a secondary, internal AUG …

Effect Of Calcium Channel Antagonists And Sex On Bone Metabolism In Aged Brown Norway Rats, Brent Kidd

Morehead State Theses and Dissertations

A thesis presented to the faculty of the College of Science & Technology at Morehead State University in partial fulfillment of the requirements for the Degree of Master of Science by Brent Kidd on April 19, 2007.

Interactions Between Phytoplankton And Bacteria In The Uptake Of Organic Compounds, Andrea Michel Rocha

OES Theses and Dissertations

The most common methods for estimating bacterial productivity are [³H]-leucine and [³H]-thymidine incorporation. Uptake of these compounds has been attributed primarily to bacteria; however, because dissolved organic nitrogen may be an important N source for some phytoplankton, the use of these compounds to estimate bacterial productivity needs to be reexamined. In order to ascertain whether phytoplankton could compete with bacteria on relevant timescales and thereby bias bacterial productivity estimates in estuaries, I examined the ability of cultured phytoplankton and size-fractionated natural populations to take up leucine and thymidine in systems seasonally dominated by phytoplankton mixotrophs. In …

Ecology Of Culturable Organisms At Rozel Point, Great Salt Lake, Utah, Emily Sarah Haws

Theses and Dissertations

The study of organisms from extreme environments is an emerging field of research with applications to multiple scientific areas. One of these extreme environments is Great Salt Lake (GSL), whose microbiology has yet to be extensively studied. This dynamic and unique environment offers an excellent opportunity to increase understanding of hypersaline ecology. Cultivation of microorganisms remains an important part of ecology research, as it is essential for understanding microbial physiology. We report here the culturing and characterization of isolates from Rozel Point, located on the northeastern shore of Great Salt Lake. This site was chosen because of the presence of …

Soil Carbon Dynamics During A Long-Term Incubation Study Involving 13C And 14C Measurements, Ronald F. Follett, Eldor A. Paul, Elizabeth G. Pruessner

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Soil organic matter is the earth's largest terrestrial reservoir of carbon (C). Thus, it serves as a major control on atmospheric carbon dioxide (CO₂) levels. To better understand these controls, decreases in soil organic C (SOC), soil microbial biomass (SMB) C, and the role of SMB as a source of mineralizable C were measured during a long-term incubation (853 days) without added substrate. The 2 soils used were a Weld loam (fine montmorillonitic, mesic, Aridic Paleustoll) from near Akron, Colorado, and a Duroc loam (fine silty, mixed mesic Pachic Haplustoll) from near Sidney, Nebraska. The Akron soil was …

The Effects Of Trivalent Arsenicals And Thioredoxin Reductase Inhibitors On Selenium Metabolism In Lung Cell Culture Models, Sarah Ryann Talbot

Electronic Theses and Dissertations

Arsenic exposure, through various routes, is associated with the development of cancer of the skin, lung, liver, kidney, and bladder. Treatment of cells in culture with trivalent arsenicals has been shown to increase reactive oxygen species (ROS). In particular, monomethylarsonous acid (MMAIII), a trivalent metabolite of arsenite, is highly cytotoxic and possibly carcinogenic. Three trivalent arsenicals; arsenite, arsenic trioxide (ATO), and MMAIII, are also known inhibitors of the selenoprotein thioredoxin reductase (TrxR). Selenium, an essential micronutrient in mammals, is needed in the form of selenocysteine for activity of this enzyme and other selenoproteins. TrxR is part of a key component …

Punking Yoga: Reconstructing Post/Neo/Colonial Fashion And Movement, Tara Brabazon

Reconstruction: Studies in Contemporary Culture

The branded clothes worn through sporting and fitness activities confirm that any movement, practice or behaviour that seems transgressive of heteronormative masculinity and femininity is also implicated in neo/colonial incorporations and the casualized workforce that is a characteristic of sports clothing manufacture. In an environment washed by the marketing of opposition, resistance is both difficult to define and apply in cultural studies. This paper invokes 'the problem' of resistance while denying the seamless and simple determinations of positive and negative representations. The focus of study is Yogurt Activewear, a company attacking corporatized yoga wear by creating an anti-brand brand. They …

Hsv-1 Infection Of C3h Central Nervous System Cell Lines, Lauren Kay Van Buren

Browse all Theses and Dissertations

Herpes Simplex Virus Type 1 (HSV-1) can infect the nervous system, resulting in a disease known as herpes encephalitis (HSE). Herpes encephalitis affects thousands of people each year; many cases are fatal or permanently debilitating. Approximately two thousand known cases occur in the United States each year alone (Neuroland online source). Acyclovir has been the drug of choice used to treat herpes encephalitis. Even after the administration of acyclovir, permanent neurological damage and/or death often results. Thousands of individuals would benefit by the discovery of drugs that are more effective at preventing lasting HSE damage and death. Knowledge concerning HSE …

The Effect Of Walnuts Compared To Fatty Fish On Plasma And Erythrocyte Fatty Acid Composition, Lymphocyte Subsets And Inflammatory Mediators, Yu-Lan Ching

Loma Linda University Electronic Theses, Dissertations & Projects

The purpose of this study was to compare the effects of walnuts vs. fatty fish on circulating inflammatory markers, on lymphocyte subsets, on plasma concentrations of eicosanoids precursor polyunsaturated fatty acid and on erythrocyte membrane fatty acid composition. Under controlled metabolic feeding conditions and randomized crossover (3x3 Latin-square) design, 27 subjects alternately consumed a control diet, a walnut diet (1.5 oz (42.5g) /day of walnuts, 6 times/week) or a fish diet (8 oz (226g) /week of salmon) for 4 weeks each. Consumption of the walnut diet (ALA 5.43 g/day) compared to the fish diet (EPA 170 mg/day and DHA 590 …

Prior Experience As A Stimulus Category Confound: An Example Using Facial Expressions Of Emotion, Leah H. Somerville, Paul J. Whalen

Dartmouth Scholarship

Facial expressions of emotion represent a stimulus set widely used to assess a broad range of psychological processes. However, a consideration of systematic differences between expression categories, other than differences relating to characteristics of the expressions themselves, has remained largely unaddressed. By collecting experience rankings in a large sample of undergraduates, we observed that the amount of reported experience individuals have had with different facial expressions of emotion systematically differed between all expression categories. These findings shed light on the potential for identifying confounds inherent to comparing some stimulus categories and, in this case, may aid in the interpretation of …

Mig-5/Dsh Controls Cell Fate Determination And Cell Migration In C. Elegans, Timothy Walston, Chaobo Guo, Rui Proenca, Mingfu Wu, Michael Herman, Jeff Hardin, Edward Hedgecock

School of Biological Sciences: Faculty Publications

Cell fate determination and cell migration are two essential events in the development of an organism. We identify mig-5, a Dishevelled family member, as a gene that regulates several cell fate decisions and cell migrations that are important during C. elegans embryonic and larval development. In offspring from mig-5 mutants, cell migrations are defective during hypodermal morphogenesis, QL neuroblast migration, and the gonad arm migration led by the distal tip cells (DTCs). In addition to abnormal migration, DTC fate is affected, resulting in either an absent or an extra DTC. The cell fates of the anchor cell in hermaphrodites …

Unexpected Diversity And Complexity Of The Guerrero Negro Hypersaline Microbial Mat, Ruth E. Ley, J. Kirk Harris, Joshua Wilcox, John R. Spear, Scott R. Miller, Brad M. Bebout, Julia A. Maresca, Donald A. Bryant, Mithcell L. Sogin, Norman R. Pace

Biological Sciences Faculty Publications

We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements of chemical gradients, to map microbial diversity vertically on a millimeter scale in a hypersaline microbial mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents of the mat, small-subunit rRNA genes were amplified by PCR from community genomic DNA extracted from layers, cloned, and sequenced. Bacteria dominated the mat and displayed unexpected and unprecedented diversity. The majority (1,336) of the 1,586 bacterial 16S rRNA sequences generated were unique, representing 752 species (>= 97% rRNA sequence identity) in 42 of the …

Development Of Self-Assembled Monolayer-Based Cell Culture Platform Towards Fabrication Of A Three-Dimensional Bioreactor, Rajendra Kandoor Aithal

Doctoral Dissertations

The extracellular matrix (ECM) plays an important role in regulating a number of cellular properties and functions like cell differentiation, cell synthesis and degradation, cell viability and proliferation, cell function, and cell aging. Surface modification of planar substrates with self-assembled monolayers (SAMs) is a promising technique to achieve stable ECMs.

In this work, substrates such as silicon (Si), gallium arsenide (GaAs) and indium tin oxide (ITO) substrates were modified with SAMS containing amino (-NH2), methyl (-CH3), thiol (-SH) and carboxylic (-COOH) end groups and characterized using contact angle measurements, surface infrared (IR) spectroscopy and atomic force microscopy (AFM). Different cell …

Tmem27: A Cleaved And Shed Plasma Membrane Protein That Stimulates Pancreatic Beta Cell Proliferation, Pinar Akpinar

Student Theses and Dissertations

The signals and the molecular mechanisms that regulate the replication of terminally differentiated β cells are unclear. In this thesis I report the identification of a gene encoding transmembrane protein 27 (TMEM27) in pancreatic β cells. Expression of Tmem27 is reduced in Tcf1-/- mice, which exhibit defects in proliferation, and is increased in islets of ob/ob, db/db and aP2- Srebp-1c transgenic mice with marked hypertrophy of the endocrine pancreas. Tmem27 is expressed in hormone positive cells at early stages of pancreas development and becomes restricted to pancreatic β cells in the mature pancreas. Biochemical characterization revealed that the Tmem27 exists …

Anaerobic Redox Cycling Of Iron By Freshwater Sediment Microorganisms, Karrie A. Weber, Matilde M. Urrutia, Perry F. Churchill, Ravi K. Kukkadapu, Eric E. Roden

School of Biological Sciences: Faculty Publications

The potential for microbially mediated anaerobic redox cycling of iron (Fe) was examined in a first-generation enrichment culture of freshwater wetland sediment microorganisms. Most probable number enumerations revealed the presence of significant populations of Fe(III)-reducing (approximately 10⁸ cells ml^-1 ) and Fe(II)-oxidizing, nitrate-reducing organisms (approximately 10⁵ cells ml^-1 ) in the freshwater sediment used to inoculate the enrichment cultures. Nitrate reduction commenced immediately following inoculation of acetate-containing (approximately 1 mM) medium with a small quantity (1% v/v) of wetland sediment, and resulted in the transient accumulation of NO₂^– and production of a mixture of …

Temperature Effects On Bradyrhizobium Spp. Growth And Symbiotic Effectiveness With Pigeonpea And Cowpea, Lurline E. Marsh, Raymond Baptiste, Dyremple B. Marsh, David Trinklein, Robert J. Kremer

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Temperature is a limiting factor on legume-Bradyrhizobium symbiosis of subtropical plants in the temperate region. Twelve strains of Bradyrhizobium spp. that nodulate pigeonpea [Cajanus cajan (L.) Millsp], and cowpea [Vigna unguiculata (L.) Walp], were evaluated for tolerance to three temperature regimes (20 °C/10 °C, 30 °C/20 °C, and 38 °C/25 °C day/night temperature) by determining their growth following exposure to the regimes. The five most temperature-tolerant strains were further evaluated for symbiotic effectiveness with pigeonpea and cowpea under controlled temperatures. These strains were USDA 3278, USDA 3362, USDA 3364, USDA 3458, and USDA 3472. Plant heights of …

Interactions Between Formosan Subterranean Termites, Brown Rot Fungus (Gloeophyllum Trabeum) And Some Of The Fungi Present On The Termite Integument And Gut, Poornima Jayasimha

LSU Master's Theses

Although the brown rot fungus, Gloeophyllum trabeum (Pers.:Fr.) Murrill, has been shown to be attractive and beneficial to subterranean termites, including Coptotermes formosanus Shiraki, to date no research has been conducted to determine if the association is mutualistic. We first set out to determine if the fungus could be spread by termites. This would represent an obvious benefit to the fungus. We found that C. formosanus does not spread G. trabeum. Unexpectedly, Formosan subterranean termites were found to suppress the growth of G. trabeum. To further investigate this finding, Formosan subterranean termite workers were released into Petri dishes with wood …