A5076567607- Microbial Community Ecology and Physiology
- Genomics and Phylogenetic Studies
- Protist diversity and phylogeny
- Photosynthetic Processes and Mechanisms
- Child and Adolescent Psychosocial and Emotional Development
- Algal biology and biofuel production
- Aquatic Ecosystems and Phytoplankton Dynamics
- Biocrusts and Microbial Ecology
- Evolution and Genetic Dynamics
- Attention Deficit Hyperactivity Disorder
- Early Childhood Education and Development
- Marine and coastal ecosystems
- Diatoms and Algae Research
- Malaria Research and Control
- Metabolomics and Mass Spectrometry Studies
- Reading and Literacy Development
- Gender, Labor, and Family Dynamics
- Child Development and Digital Technology
- Attachment and Relationship Dynamics
- Impact of Technology on Adolescents
- Adolescent Sexual and Reproductive Health
- Cognitive and developmental aspects of mathematical skills
- Child Abuse and Trauma
- Microbial Fuel Cells and Bioremediation
- Geochemistry and Elemental Analysis
University of Montana
2014-2024
Gates (United States)
2024
Gates Foundation
2020
Jewell Plastic Surgery Center
2018
Windsor Clinical Research
2014
Walter Reed Army Institute of Research
2008-2014
University of Windsor
2007-2013
University of Otago
2013
Icahn School of Medicine at Mount Sinai
2005-2007
North Carolina State University
2002-2006
ABSTRACT We applied nucleic acid-based molecular methods, combined with estimates of biomass (ATP), pigments, and microelectrode measurements chemical gradients, to map microbial diversity vertically on a millimeter scale in hypersaline mat from Guerrero Negro, Baja California Sur, Mexico. To identify the constituents mat, small-subunit rRNA genes were amplified by PCR community genomic DNA extracted layers, cloned, sequenced. Bacteria dominated displayed unexpected unprecedented diversity....
An understanding of how communities are organized is a fundamental goal ecology but one which has historically been elusive for microbial systems. We used bar-coded pyrosequencing approach targeting the V3 region bacterial small-subunit rRNA gene to address factors that structure along thermal gradients two alkaline hot springs in Lower Geyser Basin Yellowstone National Park. The filtered data set included total nearly 34,000 sequences from 39 environmental samples. Each was assigned 391...
Chlorophyll d -producing cyanobacteria are a recently described group of phototrophic bacteria that is major focus photosynthesis research, previously known only from marine environments in symbiosis with eukaryotes. We have discovered free-living member this eutrophic hypersaline lake. Phylogenetic analyses indicated these strains closely related to each other but not prochlorophyte also use an alternative form chlorophyll as the light-harvesting pigment. demonstrated acquired fragment...
Abstract Mounting evidence indicates the presence of a near complete biological nitrogen cycle in redox‐stratified oceans during late Archean to early Proterozoic ( c. 2.5–2.0 Ga). It has been suggested that iron (Fe)‐ or vanadium (V)‐dependent nitrogenase rather than molybdenum (Mo)‐dependent form was responsible for dinitrogen fixation this time because were depleted Mo and rich Fe. We evaluated hypothesis by examining phylogenetic relationships proteins are required biosynthesis active...
ABSTRACT The extension of ecological tolerance limits may be an important mechanism by which microorganisms adapt to novel environments, but it come at the evolutionary cost reduced performance under ancestral conditions. We combined a comparative physiological approach with phylogenetic analyses study evolution thermotolerance in hot spring cyanobacteria genus Synechococcus . Among 20 laboratory clones isolated from collections made along Oregon thermal gradient, four different 16S rRNA...
Article AbstractObjectives: Adults with attention-deficit/hyperactivity disorder (ADHD) experience considerable functional impairment. However, the extent to which comorbid Axis II personality disorders contribute their difficulties and whether such comorbidities are associated childhood condition or persistence of ADHD into adulthood remain unclear. Method: This study examined presence in a longitudinal sample 96 adolescents diagnosed when they were 7 through 11 years old, as compared...
Six phototrophic microbial mat communities from different geothermal springs (YNP) were studied using metagenome sequencing and geochemical analyses. The primary goals of this work to determine differences in community composition high-temperature mats distributed across the Yellowstone ecosystem, identify metabolic attributes predominant organisms present these that may correlate with environmental important niche differentiation. Random shotgun sequences six (average~ 53 Mbp/site)...
A longstanding idea in evolutionary physiology is that an enzyme cannot jointly optimize performance at both high and low temperatures due to a trade-off between stability activity. Although stability-activity has been observed for well-characterized examples, such not imposed by any physical chemical constraint. To better understand the pervasiveness of this trade-off, I investigated relationship comparative biochemical studies purified orthologous enzymes identified literature search. The...
Objectives This study examined whether high levels of television viewing are associated with attention problems and hyperactivity in preschool children. Methods Parent teacher ratings inattention, impulsivity, objectively measured activity level, parental estimation early exposure were collected for a sample Separate linear regression analyses conducted parent behavioral assessed level as outcome variables. Results indicated that after controlling demographic factors (i.e., age, sex, SES),...
ABSTRACT We have taken a phylogeographic approach to investigate the demographic and evolutionary processes that shaped geographic patterns of genetic diversity for sample isolates cosmopolitan thermophilic cyanobacterial Mastigocladus laminosus morphotype collected from throughout most its range. Although M. is found in thermal areas world, our observation populations are typically genetically differentiated on local scales suggests existence dispersal barriers, conclusion corroborated by...
ABSTRACT Physiological and molecular phylogenetic approaches were used to investigate variation among 12 cyanobacterial strains in their tolerance of sulfide, an inhibitor oxygenic photosynthesis. Cyanobacteria from sulfidic habitats found be phylogenetically diverse exhibited approximately 50-fold photosystem II performance the presence sulfide. Whereas degree was positively correlated with sulfide levels environment, a strain's phenotype could not predicted its closest relatives. These...
Hypersaline microbial mat communities have recently been shown to be more diverse than once thought. The variability in community composition of hypersaline mats, both terms spatial and temporal dimensions, is still poorly understood. Because this information essential understanding the complex biotic abiotic interactions within these communities, terminal restriction fragment analysis 16S rRNA gene sequencing were used characterize near-surface a Guerrero Negro, Mexico. Core samples...
Photosynthetic microbial mat communities were obtained from marine hypersaline saltern ponds, maintained in a greenhouse facility, and examined for the effects of salinity variations. Because these mats are considered to be useful analogs ancient communities, they offer insights about evolutionary events during >3 billion year time interval wherein co-evolved with Earth's lithosphere atmosphere. Although photosynthetic can highly dynamic exhibit extremely high activity, present study have...
ABSTRACT The importance of sulfate respiration in the microbial mat found low-sulfate thermal outflow Mushroom Spring Yellowstone National Park was evaluated using a combination molecular, microelectrode, and radiotracer studies. Despite very low concentrations, this community shown to sustain highly active sulfur cycle. highest rates were measured close surface late day when photosynthetic oxygen production ceased associated with Thermodesulfovibrio -like population. Reduced activity at...
We investigated the distributions of genetic and phenotypic variation for two Yellowstone National Park populations heterocyst-forming cyanobacterium Mastigocladus (Fischerella) laminosus that exhibit dramatic differences as a result environmental in nitrogen availability. One population develops heterocysts fixes situ response to deficiency combined its environment, whereas other does neither due availability preferred source. Slowly evolving molecular markers, including 16S rRNA gene...
ABSTRACT Laboratory evolution experiments suggest the potential for microbial populations to contribute significant ecological variation ecosystems, yet functional importance of genetic diversity within natural microorganisms is largely unknown. Here, we investigated distribution and phenotypic a population cyanobacterium Mastigocladus laminosus distributed along temperature gradient White Creek, Yellowstone NP. A total 153 laboratory strains were directly isolated from five sites with mean...