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Full-Text Articles in Life Sciences

Local Translation And Focal Adhesions Are Dysregulated In Down Syndrome, Ashlyn Gotberg, Nikita Kirkise M.S., Kristy Welshhans Ph.D. Apr 2023

Local Translation And Focal Adhesions Are Dysregulated In Down Syndrome, Ashlyn Gotberg, Nikita Kirkise M.S., Kristy Welshhans Ph.D.

Senior Theses

During cellular migration, fibroblasts sense extracellular cues through membrane complexes at their leading edge and can respond to these cues via local translation. Local translation is the process in which mRNAs are transported to subcellular regions and translated in response to specific cues. There is evidence that local translation may be dysregulated in the neurodevelopmental disorder, Down syndrome, which is caused by the triplication of chromosome 21 and results in genome-wide dysregulation of protein expression. To determine if dysregulated local translation contributes to Down syndrome, we used three sets of primary fibroblasts from individuals with Down syndrome and apparently healthy …


Temperature Effects On Yield Of Ideal Wheat Cultivars, Jeffrey Jiang Apr 2023

Temperature Effects On Yield Of Ideal Wheat Cultivars, Jeffrey Jiang

Senior Theses

North American wheat growing areas show variation in many different factors, one of the most varied and important being temperature. Temperature is well established to correlate with yield. Given data from the Uniform Soft Red Winter Wheat Nursery and independently gathered data from government-owned weather stations, I explored possible correlations between temperature and wheat yield that can be extrapolated to areas that are not covered by the Uniform Soft Red Winter Wheat Nursery database. My analysis did not reveal strong correlations between temperature and growth, and in some cases, the sample size was too small. From this study, it was …


The Classification Of Basket Neural Cells In The Mammalian Neocortex, Sreya Pudi Oct 2021

The Classification Of Basket Neural Cells In The Mammalian Neocortex, Sreya Pudi

Senior Theses

Basket neuronal cells of the mammalian neocortex have been classically categorized into two or more groups. Originally, it was thought that the large and small types are the naturally occurring groups that emerge from reasons that relate to neurobiological function and anatomical position. Later, a study based on anatomical and physiological features of these neurons introduced a third type, the net basket cell which is intermediate in size as compared to the large and small types. In this study, multivariate analysis was used to test the hypothesis that the large and small types are morphologically distinct groups. The results of …


Ahr Expression On Rorc-Expressing Immune Cells Is Essential For I3c-Mediated Protection Against Colitis, Michal C. Williams Jul 2021

Ahr Expression On Rorc-Expressing Immune Cells Is Essential For I3c-Mediated Protection Against Colitis, Michal C. Williams

Senior Theses

Colitis is an inflammatory bowel disorder (IBD) whose etiology is attributed to modification in the luminal microbiota and dysregulation in the immune response. Indole is a signaling molecule which is naturally produced by gut luminal microbiota. Indole-3- carbinol (I3C) is a compound commonly found in vegetables and a ligand for the aryl hydrocarbon receptor (AhR). Previous studies have detected decreased expression and activation on the AhR receptor in colitis patients, thought to possibly alter gut microbiota metabolism, subsequently promoting colitis. 1 AhR, expressed in a variety of immune and epithelial cells, contributes to gut homeostasis by affecting vital mediators such …


Cyclic Fluctuations Of Zooplankton Dynamics In A Tidal Salt-Marsh Basin, Jamaal Jacobs Apr 2021

Cyclic Fluctuations Of Zooplankton Dynamics In A Tidal Salt-Marsh Basin, Jamaal Jacobs

Senior Theses

Zooplankton are pelagic aquatic animals that are limited in their movements by the water currents around them and are major links in aquatic food webs between primary producers and higher trophic levels. Their populations are temporally and spatially variable, as they are sensitive to changes in salinity, temperature, and dissolved oxygen. This is especially true in highly dynamic environments, like estuaries, where environmental conditions are highly variable across seasonal and daily cycles. In order to examine the variability in zooplankton populations across a tidal cycle, we collected zooplankton samples from North Inlet Estuary at 30-minute intervals over a half tidal …


The Effects Of A New Mutation In Lis1 And Its Potential Role In Autism Spectrum Disorder, John A. Slovensky Apr 2020

The Effects Of A New Mutation In Lis1 And Its Potential Role In Autism Spectrum Disorder, John A. Slovensky

Senior Theses

LIS1 is a protein, particularly concentrated in the brain, that is important in regulating the movement and transport capabilities of dynein. Dynein is protein that can move along pathways in the cell, carrying various cellular components and also helping brain cells migrate. These two proteins are crucial during the development of the nervous system, and mutations in them can lead to lissencephaly, a disorder in which the brain does not form properly. This disease causes patients to develop cognitive-motor defects and seizures that can lead to early death. While all previously identified mutations in LIS1 are known to cause lissencephaly, …


The Bioethical Significance Of “The Origin Of Man’S Ethical Behavior” (October 1941, Unpublished) By Ernest Everett Just And Hedwig Anna Schnetzler Just, Theodore Walker Jr. Jan 2020

The Bioethical Significance Of “The Origin Of Man’S Ethical Behavior” (October 1941, Unpublished) By Ernest Everett Just And Hedwig Anna Schnetzler Just, Theodore Walker Jr.

Journal of the South Carolina Academy of Science

Abstract –

E. E. Just (1883-1941) is an acknowledged “pioneer” in cell biology, and he is perhaps the pioneer in study of egg cell fertilization. Here we discover that Just also made pioneering contributions to general biology and evolutionary bioethics.

Within Just’s published contributions to observational cell biology, there are substantial fragments of his theory of ethical behavior, a theory with roots in cell biology. In addition to such previously available fragments, Just’s fully developed theory is now available. This recently discovered unpublished book-length manuscript argues for the biological origins of ethical behavior (evolving from cells to humans, within a …


Individual Movement Rates Are Sufficient To Determine And Maintain Dynamic Spatial Positioning Within Uca Pugilator Herds, Eilea R. Knotts Jun 2016

Individual Movement Rates Are Sufficient To Determine And Maintain Dynamic Spatial Positioning Within Uca Pugilator Herds, Eilea R. Knotts

Theses and Dissertations

Spatial location within aggregations (i.e. periphery, central) is of biological significance to gregarious animals. Because these positions are a potential consequence of consistent individual behavioral differences, or personality, a better understanding of potential mechanisms concerning personality is central to predicting an individuals’ location. To determine the effects of individual personality on the dynamic spatial positioning of Uca pugilator while herding, field data collection and agent-based modeling were employed. Individuals were assayed to establish their personalities and returned to the field for observation as a means of identifying location preference within selfish herds. There was a significant difference between the extreme …


Tp53 And Hras Influence On Hpv16 E7 Expression In Hpv16-Transformed Human Keratinocytes, Nella Christie Delva Jan 2015

Tp53 And Hras Influence On Hpv16 E7 Expression In Hpv16-Transformed Human Keratinocytes, Nella Christie Delva

Theses and Dissertations

Head and Neck Squamous Carcinoma (HNSCC) is one of the most common cancers worldwide. HNSCC affects regions of the upper aerodigestive tract such as the lip, tongue, nasopharynx, oropharynx, larynx, and hypopharynx. About 25% of all HNSCC cases and up to 65% of Oropharyngeal Carcinoma (OPC) cases are positive for HPV DNA. African American patients, especially males, present primarily with HPV-negative HNSCC. HNSCC’s that are HPV-positive tend to be HPV-active at initial presentation: these cancers contain HPV DNA and express HPV RNA. However, recurring HPV-positive cancers of the head and neck are more often inactive: these tumors contain HPV DNA, …


Genetic Stock Identification And Migration In Black Sea Bass (Centropristis Striata) Along The Western Atlantic Coast And Gulf Of Mexico, Justin Francis Lewandowski Jan 2014

Genetic Stock Identification And Migration In Black Sea Bass (Centropristis Striata) Along The Western Atlantic Coast And Gulf Of Mexico, Justin Francis Lewandowski

Theses and Dissertations

The black sea bass, Centropristis striata, is a member of the family Serranidae that is commercially important throughout its range, which extends throughout the western Atlantic (from Cape Cod, Massachusetts to Cape Canaveral, Florida) and Gulf of Mexico (from Mobile Bay, Alabama to Tampa Bay, Florida). There are two known subspecies, C. striata striata in the Atlantic and C. striata melana in the Gulf, and through behavioral and morphological evidence two separate stocks are managed in the Atlantic, north and south of Cape Hatteras, NC. Recent genetic studies on mitochondrial DNA (mtDNA) have supported this. To further investigate the relationships …


Evaluating The Impact Of Fishery-Related Claw Removal On Diet, Consumption Rate, Energetics And Reproduction In The Florida Stone Crab (Menippe Spp.), Jessica Mary Hogan Jan 2013

Evaluating The Impact Of Fishery-Related Claw Removal On Diet, Consumption Rate, Energetics And Reproduction In The Florida Stone Crab (Menippe Spp.), Jessica Mary Hogan

Theses and Dissertations

Many global fisheries are overexploited and working towards the development of sustainable fishing methods. Claw based crab fisheries, such as the Florida stone crab (Menippe mercenaria, M. adina, and hybrids) fishery, use unique fishing techniques that reduce the overall mortality of harvested organisms. For example, the Florida stone crab fishery is regulated by requiring that fisherman only harvest crab claws and requires that fishermen return the live crab to the water following harvesting. This process takes advantage of the ability of crabs to autotomize and regenerate their claws, and enables crabs to re-enter the fishery in subsequent years if they …


Weeds In The Flower Garden: An Exploration Of Plagiarism In Graduate Students’ Research Proposals And Its Connection To Enculturation, Esl, And Contextual Factors, Joanna Gilmore, Denise Strickland, Briana Eileen Timmerman, Michelle Maher, David Feldon Jul 2010

Weeds In The Flower Garden: An Exploration Of Plagiarism In Graduate Students’ Research Proposals And Its Connection To Enculturation, Esl, And Contextual Factors, Joanna Gilmore, Denise Strickland, Briana Eileen Timmerman, Michelle Maher, David Feldon

Faculty Publications

Existing literature provides insight into the nature and extent of plagiarism amongst undergraduate students (e.g., Ellery, 2008; Parameswaran & Devi, 2006; Selwyn, 2008). Plagiarism amongst graduate students is relatively unstudied, however, and the existing data are largely based on self-reports. This study investigated the rates and potential causes of plagiarism amongst graduate students in master’s and doctoral programmes in science, technology, engineering, mathematics, and science or mathematics education by examining actual research proposals written by graduate students. Results indicate that plagiarism is a prevalent issue at each of the three university sites sampled and across all of the investigated disciplines. …


Genomic Organization And Molecular Phylogenies Of The Beta (Β) Keratin Multigene Family In The Chicken (Gallus Gallus) And Zebra Finch (Taeniopygia Guttata): Implications For Feather Evolution, Matthew J. Greenwold, Roger H. Sawyer May 2010

Genomic Organization And Molecular Phylogenies Of The Beta (Β) Keratin Multigene Family In The Chicken (Gallus Gallus) And Zebra Finch (Taeniopygia Guttata): Implications For Feather Evolution, Matthew J. Greenwold, Roger H. Sawyer

Faculty Publications

Background: The epidermal appendages of reptiles and birds are constructed of beta (β) keratins. The molecularphylogeny of these keratins is important to understanding the evolutionary origin of these appendages, especially feathers. Knowing that the crocodilian β-keratin genes are closely related to those of birds, the published genomes ofthe chicken and zebra finch provide an opportunity not only to compare the genomic organization of their β- keratins,but to study their molecular evolution in archosaurians.

Results: The subfamilies (claw, feather, feather-like, and scale) of β-keratin genes are clustered in the same 5' to 3' orderon microchromosome 25 in chicken and zebra finch, …


Development Of A ‘Universal’ Rubric For Assessing Undergraduates’ Scientific Reasoning Skills Using Scientific Writing, Briana Eileen Timmerman, Denise Strickland, Robert L. Johnson, John R. Payne Apr 2010

Development Of A ‘Universal’ Rubric For Assessing Undergraduates’ Scientific Reasoning Skills Using Scientific Writing, Briana Eileen Timmerman, Denise Strickland, Robert L. Johnson, John R. Payne

Faculty Publications

We developed a rubric for measuring students’ ability to reason and write scientifically. The Rubric for Science Writing (Rubric) was tested in a variety of undergraduate biology laboratory courses (total n = 142 laboratory reports) using science graduate students (teaching assistants) as raters. Generalisability analysis indicates that the Rubric provides a reliable measure of students’ abilities (g = 0.85) in these conditions. Comparison of student performance in various biology classes indicated that some scientific skills are more challenging for students to develop than others and identified a number of previously unappreciated gaps in the curriculum. Our findings suggest that use …


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 Mar 2010

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 …


An Intertidal Sea Star Adjusts Thermal Inertia To Avoid Extreme Body Temperatures, Sylvain Pincebourde, Eric Sanford, Brian Helmuth Oct 2009

An Intertidal Sea Star Adjusts Thermal Inertia To Avoid Extreme Body Temperatures, Sylvain Pincebourde, Eric Sanford, Brian Helmuth

Faculty Publications

The body temperature of ectotherms is influenced by the interaction of abiotic conditions, morphology, and behavior. Although organisms living in different thermal habitats may exhibit morphological plasticity or move from unfavorable locations, there are few examples of animals adjusting their thermal properties in response to short-term changes in local conditions. Here, we show that the intertidal sea star Pisaster ochraceus modulates its thermal inertia in response to prior thermal exposure. After exposure to high body temperature at low tide, sea stars increase the amount of colder than-air fluid in their coelomic cavity when submerged during high tide, resulting in a …


Faculty Should Consider Peer Review As A Means Of Improving Students' Scientific Reasoning Skill, Briana Eileen Timmerman, Denise Strickland Mar 2009

Faculty Should Consider Peer Review As A Means Of Improving Students' Scientific Reasoning Skill, Briana Eileen Timmerman, Denise Strickland

Faculty Publications

The following article provides highlights of a larger body of work on the impact of peer review on undergraduate biology students’ scientific reasoning, scientific writing and attitudes. Results suggest that undergraduates, even freshman can be effective peer reviewers and that peer review improves scientific writing, content knowledge, and scientific reasoning skills. Students report peer review to be a beneficial experience both within the course and in terms of helping them to develop as aspiring scientists. Science faculty are therefore encouraged to consider incorporating peer review as a regular part of instruction.


From Cells To Coastlines: How Can We Use Physiology To Forecast The Impacts Of Climate Change?, Brian Helmuth Mar 2009

From Cells To Coastlines: How Can We Use Physiology To Forecast The Impacts Of Climate Change?, Brian Helmuth

Faculty Publications

The interdisciplinary fields of conservation physiology, macrophysiology, and mechanistic ecological forecasting have recently emerged as means of integrating detailed physiological responses to the broader questions of ecological and evolutionary responses to global climate change. Bridging the gap between large-scale records of weather and climate (as measured by remote sensing platforms, buoys and ground-based weather stations) and the physical world as experienced by organisms (niche-level measurements) requires a mechanistic understanding of how ‘environmental signals’ (parameters such as air, surface and water temperature, food availability, water flow) are translated into signals at the scale of the organism or cell (e.g. body temperature, …


Lis1 And Ndel1 Influence The Timing Of Nuclear Envelope Breakdown In Neural Stem Cells, Sachin Hebbar, Mariano T. Mesngon, Aimee M. Guillotte, Bhavim Desai, Ramses Ayala, Deanna S. Smith Sep 2008

Lis1 And Ndel1 Influence The Timing Of Nuclear Envelope Breakdown In Neural Stem Cells, Sachin Hebbar, Mariano T. Mesngon, Aimee M. Guillotte, Bhavim Desai, Ramses Ayala, Deanna S. Smith

Faculty Publications

Lis1 and Ndel1 are essential for animal development. They interact directly with one another and with cytoplasmic dynein. The developing brain is especially sensitive to reduced Lis1 or Ndel1 levels, as both proteins influence spindle orientation, neural cell fate decisions, and neuronal migration. We report here that Lis1 and Ndel1 reduction in a mitotic cell line impairs prophase nuclear envelope (NE) invagination (PNEI). This dyneindependent process facilitates NE breakdown (NEBD) and occurs before the establishment of the bipolar spindle. Ndel1 phosphorylation is important for this function, regulating binding to both Lis1 and dynein. Prophase cells in the ventricular zone (VZ) …


Peer Review In An Undergraduate Biology Curriculum: Effects On Students’ Scientific Reasoning, Writing And Attitudes, Briana Eileen Timmerman Mar 2008

Peer Review In An Undergraduate Biology Curriculum: Effects On Students’ Scientific Reasoning, Writing And Attitudes, Briana Eileen Timmerman

Faculty Publications

Scientific reasoning and writing skills are ubiquitous processes in science and therefore common goals of science curricula, particularly in higher education. Providing the individualized feedback necessary for the development of these skills is often costly in terms of faculty time, particularly in large science courses common at research universities. Past educational research literature suggests that the use of peer review may accelerate students’ scientific reasoning skills without a concurrent demand on faculty time per student. Peer review contains many elements of effective pedagogy such as peer-peer collaboration, repeated practice at evaluation and critical thinking, formative feedback, multiple contrasting examples, and …


Extracellular Stimuli Specifically Regulate Localized Levels Of Individual Neuronal Mrnas, Dianna E. Willis, Erna A. Van Niekerk, Yukio Sasaki, Mariano Mesngon, Tanuja T. Merianda, Gervan G. Williams, Marvin Kendall, Deanna S. Smith, Gary J. Bassell, Jeffery L. Twiss Sep 2007

Extracellular Stimuli Specifically Regulate Localized Levels Of Individual Neuronal Mrnas, Dianna E. Willis, Erna A. Van Niekerk, Yukio Sasaki, Mariano Mesngon, Tanuja T. Merianda, Gervan G. Williams, Marvin Kendall, Deanna S. Smith, Gary J. Bassell, Jeffery L. Twiss

Faculty Publications

Subcellular regulation of protein synthesis requires the correct localization of messenger RNAs (mRNAs) within the cell. In this study, we investigate whether the axonal localization of neuronal mRNAs is regulated by extracellular stimuli. By profiling axonal levels of 50 mRNAs detected in regenerating adult sensory axons, we show that neurotrophins can increase and decrease levels of axonal mRNAs. Neurotrophins (nerve growth factor, brainderived neurotrophic factor, and neurotrophin-3) regulate axonal mRNA levels and use distinct downstream signals to localize individual mRNAs. However, myelin-associated glycoprotein and semaphorin 3A regulate axonal levels of different mRNAs and elicit the opposite effect on axonal mRNA …


Linking Bacterioplankton Community Structures To Environmental State Variables And Phytoplankton Assemblages In Two South Carolina Salt Marsh Estuaries, Wes Johnson, Alan J. Lewitus, Madilyn Fletcher Nov 2006

Linking Bacterioplankton Community Structures To Environmental State Variables And Phytoplankton Assemblages In Two South Carolina Salt Marsh Estuaries, Wes Johnson, Alan J. Lewitus, Madilyn Fletcher

Faculty Publications

Microorganisms are among the most important organisms to the ecology of salt marsh estuaries; however, fundamental questions regarding their distribution, environmental controls, and interactions with phytoplankton remain unanswered. We used denaturing gradient gel electrophoresis (DGGE) of bacterial rRNA genes and high performance liquid chromatography (HPLC) of phytoplankton photopigments to characterize planktonic communities from the Ashepoo, Combahee, and Edisto (ACE) Basin and North Inlet (NI) estuaries on the South Carolina coast, USA. Multivariate comparisons of the planktonic community profiles revealed that the 2 estuaries supported distinct bacterial communities. Furthermore, bacterial communities in both systems were partitioned into separate particle-associated (PA) and …


Ecological Fitting As A Determinant Of The Community Structure Of Platyhelminth Parasites Of Anurans, Daniel R. Brooks, Virginia León-Règagnon, Deborah Mclennan, Derek Zelmer Jul 2006

Ecological Fitting As A Determinant Of The Community Structure Of Platyhelminth Parasites Of Anurans, Daniel R. Brooks, Virginia León-Règagnon, Deborah Mclennan, Derek Zelmer

Faculty Publications

Host–parasite associations are assumed to be ecologically specialized, tightly coevolved systems driven by mutual modification in which host switching is a rare phenomenon. Ecological fitting, however, increases the probability of host switching, creating incongruences between host and parasite phylogenies, when (1) specialization on a particular host resource is a shared characteristic of distantly related parasites, and (2) the resource being tracked by the parasite is widespread among many host species. We investigated the effect of ecological fitting on structuring the platyhelminth communities of anurans from a temperate forest and grassland in the United States and tropical dry and wet forests …


Regulation Of Cytoplasmic Dynein Atpase By Lis1, Mariano T. Mesngon, Cataldo Tarricone, Sachin Hebbar, Aimee Guillotte, E. William Schmitt, Lorene Lanier, Andrea Musacchio, Stephen J. King, Deanna S. Smith Feb 2006

Regulation Of Cytoplasmic Dynein Atpase By Lis1, Mariano T. Mesngon, Cataldo Tarricone, Sachin Hebbar, Aimee Guillotte, E. William Schmitt, Lorene Lanier, Andrea Musacchio, Stephen J. King, Deanna S. Smith

Faculty Publications

Mutations in Lis1 cause classical lissencephaly, a developmental brain abnormality characterized by defects in neuronal positioning.Over the last decade, a clear link has been forged between Lis1 and the microtubule motor cytoplasmic dynein. Substantial evidenceindicates that Lis1 functions in a highly conserved pathway with dynein to regulate neuronal migration and other motile events. Yeasttwo-hybrid studies predict that Lis1 binds directly to dynein heavy chains (Sasaki et al., 2000; Tai et al., 2002), but the mechanistic significance of this interaction is not well understood. We now report that recombinant Lis1 binds to native brain dynein and significantly increases the microtubule-stimulated enzymatic …


Photochemical Transformations Of Riverine Dissolved Organic Matter: Effects On Estuarine Bacterial Metabolism And Nutrient Demand, Erik M. Smith, Ronald Benner Jul 2005

Photochemical Transformations Of Riverine Dissolved Organic Matter: Effects On Estuarine Bacterial Metabolism And Nutrient Demand, Erik M. Smith, Ronald Benner

Faculty Publications

By experimentally simulating the exposure of terrigenous dissolved organic matter (DOM) to sunlight during the mixing of river water and seawater in an estuary (St. Helena Sound, South Carolina), this study examined how photochemical alterations may affect both the magnitude and fate of DOM utilization by estuarine bacteria. In a series of experiments performed with water samples collected from 3 blackwater rivers draining into an estuary of the South Atlantic Bight (USA), exposure to light resulted in significant decreases in dissolved organic carbon (DOC) concentration and DOM absorption at 350 nm relative to dark controls. When these water samples were …


A Patch Hath Smaller Patches: Delineating Ecological Neighborhoods For Parasites, Derek Zelmer, John R. Seed Jul 2004

A Patch Hath Smaller Patches: Delineating Ecological Neighborhoods For Parasites, Derek Zelmer, John R. Seed

Faculty Publications

Use of the host individual as a boundary for parasite populations and communities provides an unambiguous spatial unit that is useful for pattern description, but this framework precludes consideration of the host landscape and within-host population dynamics. Recognizing host individuals as spatially and temporally complex landscapes requires modified concepts of parasite populations and communities. An outline of the currently accepted hierarchies of parasite populations and communities is provided on the basis of ecological neighborhoods that are delineated by discrete habitat patches or functional dynamics (or both), as opposed to host individuals. This parasite-based framework accommodates consideration of both within- and …


Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam May 2004

Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam

Faculty Publications

We tested the application of 5-bromo-2’-deoxyuridine (BrdU), a thymidine analogue that becomes incorporated into DNA during growth, to measure growth rates of individual marine bacteria cells. Immunocytochemical detection of BrdU incorporation into bacterial DNA has the potential for single-cell-based growth measurement. Optimized procedure for immunocytochemistry was applicable to 14 marine heterotrophic bacterial isolates belonging to g-proteobacteria, α-proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group and Gram-positive bacteria. The relationship between cell-specific fluorescence intensity and specific growth rate was linearly correlated among CFB group isolates, which indicated a potential of the method for quantitative measurement. Analysis of the detection limit indicated …


Particle Removal Rates By The Mud Shrimp Upogebia Pugettensis, Its Burrow, And A Commensal Clam: Effects On Estuarine Phytoplankton Abundance, Blaine D. Griffen, Theodore H. Dewitt, Chris Langdon Mar 2004

Particle Removal Rates By The Mud Shrimp Upogebia Pugettensis, Its Burrow, And A Commensal Clam: Effects On Estuarine Phytoplankton Abundance, Blaine D. Griffen, Theodore H. Dewitt, Chris Langdon

Faculty Publications

The burrowing shrimp Upogebia pugettensis is an abundant intertidal invertebrate of Pacific Northwest, USA bays and estuaries where it lives commensally with the bivalve Cryptomya californica. Suspension-feeding activities by the shrimp and by its commensal clam, as well as particle settlement within the burrow, represent 3 different components that could remove phytoplankton from water drawn into shrimp burrows. These 3 components together comprise what we call the ‘U. pugettensis shrimp-burrow complex’. In laboratory experiments, we measured particle removal by each of these components. Our results indicated that U. pugettensis itself is responsible for filtering the majority of phytoplankton removed …


P-Limitation Of Respiration In The Sargasso Sea And Uncoupling Of Bacteria From P-Regeneration In Size-Fractionation Experiments, Ingrid Obernosterer, Nobu Kawasaki, Ronald Benner Jul 2003

P-Limitation Of Respiration In The Sargasso Sea And Uncoupling Of Bacteria From P-Regeneration In Size-Fractionation Experiments, Ingrid Obernosterer, Nobu Kawasaki, Ronald Benner

Faculty Publications

Community respiration rates were measured in unfiltered seawater collected in the upper 75 m of the water column along a transect in the Sargasso Sea and at the Bermuda Atlantic Time-series Study (BATS) station (31° 50’ 00 N; 64° 10’ 00 W) during a cruise in June and July 2001. Community respiration rates in the upper 75 m of the water column averaged 1.1 ± 0.4 μM O2 d-1 and exhibited significant spatial and temporal variability. Concurrent determination of the heterotrophic and autotrophic community revealed no relationship between community respiration and the abundance of any of the major …


Microalgal-Meiofaunal Trophic Relationships In Muddy Intertidal Estuarine Sediments, James L. Pinckney, Kevin R. Carman, S. Elizabeth Lumsden, Sabrina N. Hymel Feb 2003

Microalgal-Meiofaunal Trophic Relationships In Muddy Intertidal Estuarine Sediments, James L. Pinckney, Kevin R. Carman, S. Elizabeth Lumsden, Sabrina N. Hymel

Faculty Publications

The determination of the primary factors controlling carbon (C) transfer rates in situ are a basic requirement for developing a mechanistic view of the processes that regulate benthic microbial community structure and function. In many estuarine ecosystems, the base of the food web is dominated by microalgal production; however, information on the quantitative relationships and process rates of meiofaunal grazers and benthic microalgal (BMA) producers is limited to a few habitats and short temporal scales. The primary objective of this study was to examine the trophic interactions between meiofaunal grazers and BMA producers to determine if grazing is a primary …