Physical Sciences and Mathematics Commons^™

Genomic And Transcriptomic Evidence For Scavenging Of Diverse Organic Compounds By Widespread Deep-Sea Archaea, Meng Li, Brett J. Baker, Karthik Anantharaman, Sunit Jain, John A. Breier, Gregory J. Dick

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Microbial activity is one of the most important processes to mediate the flux of organic carbon from the ocean surface to the seafloor. However, little is known about the microorganisms that underpin this key step of the global carbon cycle in the deep oceans. Here we present genomic and transcriptomic evidence that five ubiquitous archaeal groups actively use proteins, carbohydrates, fatty acids and lipids as sources of carbon and energy at depths ranging from 800 to 4,950 m in hydrothermal vent plumes and pelagic background seawater across three different ocean basins. Genome-enabled metabolic reconstructions and gene expression patterns show that …

Particle Dynamics In The Rising Plume At Piccard Hydrothermal Field, Mid-Cayman Rise, Margaret L. Estapa, John A. Breier, Chris R. German

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Processes active in rising hydrothermal plumes, such as precipitation, particle aggregation, and biological growth, affect particle size distributions and can exert important influences on the biogeochemical impact of submarine venting of iron to the oceans and their sediments. However, observations to date of particle size distribution within these systems are both limited and conflicting. In a novel buoyant hydrothermal plume study at the recently discovered high-temperature (3988C) Piccard Hydrothermal Field, Mid- Cayman Rise, we report optical measurements of particle size distributions (PSDs). We describe the plume PSD in terms of a simple, power-law model commonly used in studies of upper …

Modification Of Traffic-Related Respiratory Response By Asthma Control In A Population Of Car Commuters, Maria C. Mirabelli, Rachel Golan, Roby Greenwald, Amit U. Raysoni, Fernando Holguin, Priya Kewada, Andrea Winquist, W Dana Flanders, Jeremy A. Sarnat

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Background: Effects of traffic-related exposures on respiratory health are well documented, but little information is available about whether asthma control influences individual susceptibility. We analyzed data from the Atlanta Commuter Exposure study to evaluate modification of associations between rush-hour commuting, in- vehicle air pollution, and selected respiratory health outcomes by asthma control status.

Methods: Between 2009 and 2011, 39 adults participated in Atlanta Commuter Exposure, and each conducted two scripted rush-hour highway commutes. In-vehicle particulate components were measured during all commutes. Among adults with asthma, we evaluated asthma control by questionnaire and spirometry. Exhaled nitric oxide, forced expiratory volume in …

Lateral Dispersal And Foraging Behavior Of Entomopathogenic Nematodes In The Absence And Presence Of Mobile And Non-Mobile Hosts, Harit K. Bal, Parwinder Grewal

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Entomopathogenic nematodes have been classified into cruisers (active searchers) and ambushers (sit and wait foragers). However, little is known about their dispersal and foraging behavior at population level in soil. We studied lateral dispersal of the ambush foraging Steinernema carpocapsae (ALL strain) and cruise foraging Heterorhabditis bacteriophora (GPS11 strain) from infected host cadavers in microcosms (0.05 m2) containing Wooster silt-loam soil (Oxyaquic fragiudalf) and vegetation in the presence or absence of non-mobile and mobile hosts. Results showed that the presence of a non-mobile host (Galleria mellonella larva in a wire mesh cage) enhanced H. bacteriophora dispersal for up …

Changes In Spatial Patterns Of Caragana Stenophylla Along A Climatic Drought Gradient On The Inner Mongolian Plateau, Li-Na Xie, Hong-Yu Guo, Christopher A. Gabler, Qing-Fang Li, Cheng-Cang Ma

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Few studies have investigated the influence of water availability on plant population spatial patterns. We studied changes in the spatial patterns of Caragana stenophylla along a climatic drought gradient within the Inner Mongolian Plateau, China. We examined spatial patterns, seed density, “nurse effects” of shrubs on seedlings, transpiration rates and water use efficiency (WUE) of C. stenophylla across semi-arid, arid, and intensively arid zones. Our results showed that patches of C. stenophylla populations shifted from a random to a clumped spatial pattern towards drier environments. Seed density and seedling survival rate of C. stenophylla decreased from the semi-arid zone to …

Microbial Iron Mats At The Mid-Atlantic Ridge And Evidence That Zetaproteobacteria May Be Restricted To Iron-Oxidizing Marine Systems, Jarrod J. Scott, John A. Breier, George W. Luther Iii, David Emerson

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

Chemolithoautotrophic iron-oxidizing bacteria play an essential role in the global iron cycle. Thus far, the majority of marine iron-oxidizing bacteria have been identified as Zetaproteobacteria, a novel class within the phylum Proteobacteria. Marine iron-oxidizing microbial communities have been found associated with volcanically active seamounts, crustal spreading centers, and coastal waters. However, little is known about the presence and diversity of iron-oxidizing communities at hydrothermal systems along the slow crustal spreading center of the Mid-Atlantic Ridge. From October to November 2012, samples were collected from rust-colored mats at three well-known hydrothermal vent systems on the Mid-Atlantic Ridge (Rainbow, Trans-Atlantic Geotraverse, and …

Octocoral Mitochondrial Genomes Provide Insights Into The Phylogenetic History Of Gene Order Rearrangements, Order Reversals, And Cnidarian Phylogenetics, Diego F. Figueroa, Amy R. Baco

School of Earth, Environmental, and Marine Sciences Faculty Publications and Presentations

We use full mitochondrial genomes to test the robustness of the phylogeny of the Octocorallia, to determine the evolutionary pathway for the five known mitochondrial gene rearrangements in octocorals, and to test the suitability of using mitochondrial genomes for higher taxonomic-level phylogenetic reconstructions. Our phylogeny supports three major divisions within the Octocorallia and show that Paragorgiidae is paraphyletic, with Sibogagorgia forming a sister branch to the Coralliidae. Furthermore, Sibogagorgia cauliflora has what is presumed to be the ancestral gene order in octocorals, but the presence of a pair of inverted repeat sequences suggest that this gene order was not conserved …