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Dissolved Carbon Transport And Processing In North America's Largest Swamp River Entering The Northern Gulf Of Mexico, Emily M. Delduco, Y. Jun Xu Jan 2019

Dissolved Carbon Transport And Processing In North America's Largest Swamp River Entering The Northern Gulf Of Mexico, Emily M. Delduco, Y. Jun Xu

Faculty Publications

Transport and transformation of riverine dissolved carbon is an important component of global carbon cycling. The Atchafalaya River (AR) flows 189 kilometers through the largest bottomland swamp in North America and discharges ~25% of the flow of the Mississippi River into the Gulf of Mexico annually, providing a unique opportunity to study the floodplain/wetland impacts on dissolved carbon. The aim of this study is to determine how dissolved organic carbon (DOC) and dissolved inorganic carbon (DIC) in the AR change spatially and seasonally, and to elucidate which processes control the carbon cycling in this intricate swamp-river system. From May 2015 …

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The 30-Year Dynamic Of The Softwood Sawtimber Stumpage Market In Louisiana: Insights From Quarterly Data From 1988 To 2017, Fan Zhang, Sun Joseph Chang Jan 2019

The 30-Year Dynamic Of The Softwood Sawtimber Stumpage Market In Louisiana: Insights From Quarterly Data From 1988 To 2017, Fan Zhang, Sun Joseph Chang

Faculty Publications

Based on a 30-year quarterly data set, this paper examines the dynamics of the softwood sawtimber stumpage market in Louisiana, United States, from 1988 to 2017. Cointegration analysis and the vector error correction model were used to examine the demand and supply of softwood sawtimber stumpage products in Louisiana. Competition among different stumpage products, seasonality patterns in the market, and the impact of some exogenous events were also investigated. The results showed that the demand for softwood sawtimber products is inelastic to its own price, whereas the supply is elastic. Strong seasonality patterns were detected for both stumpage price and …

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Nest And Brood Site Selection Of Eastern Wild Turkeys, Jeremy D. Wood, Bradley S. Cohen, L. Mike Conner, Bret A. Collier, Michael J. Chamberlain Jan 2019

Nest And Brood Site Selection Of Eastern Wild Turkeys, Jeremy D. Wood, Bradley S. Cohen, L. Mike Conner, Bret A. Collier, Michael J. Chamberlain

Faculty Publications

Management of longleaf pine (Pinus palustris) forests relies on frequent prescribed fire to maintain desirable plant communities. Prescribed fire is often applied while female wild turkeys (Meleagris gallopavo) are reproductively active and may immediately affect habitat availability and demographic outcomes. We identified covariates affecting selection of areas used by nesting and brooding females and determined if these covariates influenced nest and brood survival in a longleaf pine ecosystem. We captured 63 female wild turkeys and measured vegetation and landscape characteristics surrounding nests, brood roosts, and daytime use sites. We used conditional logistic regression to determine which vegetation and landscape-scale characteristics …

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The Role Of Talker Familiarity In Auditory Distraction, Brittan A. Barker, Emily M. Elliott Jan 2019

The Role Of Talker Familiarity In Auditory Distraction, Brittan A. Barker, Emily M. Elliott

Faculty Publications

The current research employed a classic irrelevant sound effect paradigm and investigated the talker-specific content of the irrelevant speech. Specifically, we aimed to determine if the participants' familiarity with the irrelevant speech's talker affected the magnitude of the irrelevant sound effect. Experiment 1 was an exploration of talker familiarity established in a natural listening environment (i.e., a university classroom) in which we manipulated the participants' relationships with the talker. In Experiment 2, we manipulated the participants' familiarity with the talker via 4 days of controlled exposure to the target talker's audio recordings. For both Experiments 1 and 2, a robust …

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Diet Of Lesser Scaup Wintering On Lake Pontchartrain, Louisiana, Clay M. Stroud, Claire E. Caputo, Michael A. Poirrier, Kevin M. Ringelman Jan 2019

Diet Of Lesser Scaup Wintering On Lake Pontchartrain, Louisiana, Clay M. Stroud, Claire E. Caputo, Michael A. Poirrier, Kevin M. Ringelman

Faculty Publications

The lesser scaup Aythya affinis has been a species of conservation concern since continental breeding populations began declining in the 1980s. The causes of this decline are likely multifaceted, but cross-seasonal effects are believed to play a prominent role: females unable to acquire sufficient nutrient reserves during winter and spring migration have poor survival and breeding success. Understanding scaup diet composition and prey selection can help managers not only diagnose mechanisms underlying wintering scaup distributions, but may also help direct management actions to increase forage availability and quality. We evaluated the diet of 60 scaup collected from a major wintering …

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Voice Teacher Certification And Research: Relationships And Trends, Rockford Sansom Jan 2019

Voice Teacher Certification And Research: Relationships And Trends, Rockford Sansom

Faculty Publications

No abstract provided.

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Planting Rate And Nitrogen Fertility Affect Runoff Losses During Hybrid Bermudagrass Establishment, Lance Rice, Jeffrey Beasley, Lewis Gaston, Kayla Sanders, Gregg Munshaw Jan 2019

Planting Rate And Nitrogen Fertility Affect Runoff Losses During Hybrid Bermudagrass Establishment, Lance Rice, Jeffrey Beasley, Lewis Gaston, Kayla Sanders, Gregg Munshaw

Faculty Publications

Core Ideas The high sprig planting rate resulted in faster bermudagrass establishment. The high and low N fertilizer rates resulted in similar bermudagrass establishment. Runoff, sediment, and nutrient losses decreased over time as groundcover increased. High sprigging and low N fertilization rates reduce nutrient losses during establishment. Bermudagrass is grown on athletic fields, home lawns, and right-of-ways because of its quality, excellent wear tolerance, and vigorous growth. Sprigging followed by high N application rates is used for large acreage sites to accelerate bermudagrass establishment. However, low plant density, high soil moisture, and frequent fertilizer applications during establishment present conditions prone …

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Effect Of Macroporosity On Pedotransfer Function Estimates At The Field Scale, Xi Zhang, Junfeng Zhu, Ole Wendroth, Christopher Matocha, Dwayne Edwards Jan 2019

Effect Of Macroporosity On Pedotransfer Function Estimates At The Field Scale, Xi Zhang, Junfeng Zhu, Ole Wendroth, Christopher Matocha, Dwayne Edwards

Faculty Publications

Saturated hydraulic conductivity (Ks) is one of the crucial hydraulic properties for assessing water and solute transport in soils. However, direct measurement of Ks is time consuming and arduous. Alternatively, pedotransfer functions (PTFs) have been developed to estimate Ks indirectly through more easily measurable soil properties that are part of regional, national, or international databases. These PTFs are usually based on datasets collected from large regions. However, their validity for a specific site remains unclear. The objectives of this study were to evaluate the performance of established PTFs in estimating Ks in a specific field and improve PTFs to arrive …

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Calibrating A Taper Model For Oriental Spruce In Turkey, Ramazan Özçelik, Quang V. Cao, Hakkı Yavuz Jan 2019

Calibrating A Taper Model For Oriental Spruce In Turkey, Ramazan Özçelik, Quang V. Cao, Hakkı Yavuz

Faculty Publications

In this study, Max and Burkhart (1976)’s segmented taper model was used to describe stem profile and predict stem volume of oriental spruce in Turkey. Thirty procedures were evaluated, which include five fitting methods and six adjustment strategies. The fitting methods resulted in parameters that were optimized for (1) taper, (2) cumulative volume, (3) taper and cumulative volume, (4) taper and total volume, and (5) taper, cumulative volume, and total volume. The adjustment strategies are (1) unadjusted, and adjusted to match (2) DBH, (3) predicted total volume, (4) DBH and predicted total volume, (5) a combined estimator, and (6) DBH …

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A Method To Derive A Tree Survival Model From Any Existing Stand Survival Model, Quang V. Cao Jan 2019

A Method To Derive A Tree Survival Model From Any Existing Stand Survival Model, Quang V. Cao

Faculty Publications

This study addresses a situation in which a forest manager has been using a whole-stand model that seems to predict well for their stands and now wants to derive an individual-tree model from it to form an integrated system that can perform well at both stand and tree levels. A simple method was developed to derive tree survival models from three existing stand-level survival models. The derived tree survival models were based on the difference between the diameter of a given tree and the diameter at which tree and stand survival probabilities are equal. For stand survival prediction, each stand …

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Sweetpotato Cultivar Trials On Hawai‘I Island, Susan C. Miyasaka, Marisa Wall, Don Labonte, Alton Arakaki Jan 2019

Sweetpotato Cultivar Trials On Hawai‘I Island, Susan C. Miyasaka, Marisa Wall, Don Labonte, Alton Arakaki

Faculty Publications

Twelve sweetpotato (Ipomoea batatas var. batatas) accessions/cultivars/ landraces (entries) were evaluated for yield, resistance to pests, and quality in five field trials planted at Pepe‘ekeo, Hawai‘i Island, and replicated over time with blocks planted on May and Oct. 2014, Feb. and July 2015, and Jan. 2016. Plots were harvested at 4.5 to 6 months after planting. In the first two field trials, local entries planted were ‘Okinawan’, ‘Mokuau’, and ‘Kona B’, as well as PI 531094, ‘Beauregard’, PI 573309, PI 573330, ‘Darby’, ‘Pelican Processor’, and ‘Picadito’. Yields of ‘Mokuau’ and ‘Kona B’ were low and were replaced in the latter …

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What We Know About Team Dynamics For Long-Distance Space Missions: A Systematic Review Of Analog Research, Suzanne T. Bell, Shanique G. Brown, Tyree Mitchell Jan 2019

What We Know About Team Dynamics For Long-Distance Space Missions: A Systematic Review Of Analog Research, Suzanne T. Bell, Shanique G. Brown, Tyree Mitchell

Faculty Publications

Background: To anticipate the dynamics of future long-distance space exploration mission (LDSEM) teams, research is conducted in analog environments (e.g., Antarctic expeditions, space chamber simulations), or environments that share key contextual features of LDSEM such as isolation and confinement. We conducted a systematic review of research conducted on teams in LDSEM-analog environments to identify which factors have been examined with quantitative research, and to summarize what the studies reveal about team dynamics in LDSEM-analog environments. Methods: We used a comprehensive search strategy to identify research on teams that lived and worked together. Data on team dynamics were extracted where possible, …

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Review Of The World Doesn't Require You, Michael F. Russo Jan 2019

Review Of The World Doesn't Require You, Michael F. Russo

Faculty Publications

No abstract provided.

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Review Of The Promise Of Elsewhere, Michael F. Russo Jan 2019

Review Of The Promise Of Elsewhere, Michael F. Russo

Faculty Publications

No abstract provided.

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Co2 Electrochemical Reduction At Thiolate-Modified Bulk Au Electrodes, Yuxin Fang, Xun Cheng, John C. Flake, Ye Xu Jan 2019

Co2 Electrochemical Reduction At Thiolate-Modified Bulk Au Electrodes, Yuxin Fang, Xun Cheng, John C. Flake, Ye Xu

Faculty Publications

Electrochemical reduction provides an opportunity to convert atmospheric CO2 to fuels or chemicals using renewable energy. In this work, we demonstrate unexpected influence on the catalytic activity and selectivity of the electrochemical CO2 reduction reaction (CO2RR) through the functionalization of Au with thiols. 2-Phenylethanethiol modified Au electrodes (2-PET-Au) show up to a 2-fold enhancement in both Faradaic efficiency and current density for CO evolution, between -0.6 and -0.9 V vs. the reversible hydrogen electrode. Functionalization with 2-mercaptopropionic acid, which has a readily ionized carboxylate group, leads to hydrogen evolution with up to 100% Faradaic efficiency at the expense of CO …

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Ictv Virus Taxonomy Profile: Endornaviridae, Rodrigo A. Valverde, Mahmoud E. Khalifa, Ryo Okada, Toshiyuki Fukuhara, Sead Sabanadzovic Jan 2019

Ictv Virus Taxonomy Profile: Endornaviridae, Rodrigo A. Valverde, Mahmoud E. Khalifa, Ryo Okada, Toshiyuki Fukuhara, Sead Sabanadzovic

Faculty Publications

The family Endornaviridae includes viruses with linear, single-stranded, positive-sense RNA genomes that range from 9.7 to 17.6 kb and have been reported infecting plants, fungi and oomycetes. The family consists of two genera, Alphaendornavirus and Betaendornavirus, into which viruses are classified based on their genome size, host and presence of unique domains. Alphaendornavirus includes species whose members infect plants, fungi and oomycetes, while the genus Betaendornavirus includes species whose members infect ascomycete fungi. This is a summary of the ICTV Report on the family Endornaviridae, which is available at www.ictv.global/report/endornaviridae.

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Progesterone Alters The Bovine Uterine Fluid Lipidome During The Period Of Elongation, Constantine A. Simintiras, José M. Sánchez, Michael Mcdonald, Pat Lonergan Jan 2019

Progesterone Alters The Bovine Uterine Fluid Lipidome During The Period Of Elongation, Constantine A. Simintiras, José M. Sánchez, Michael Mcdonald, Pat Lonergan

Faculty Publications

Successful bovine pregnancy establishment hinges on conceptus elongation, a key reproductive phenomenon coinciding with the period during which most pregnancies fail. Elongation is yet to be recapitulated in vitro, whereas in vivo it is directly driven by uterine secretions and indirectly influenced by prior circulating progesterone levels. To better understand the microenvironment evolved to facilitate this fundamental developmental event, uterine fluid was recovered on Days 12–14 of the oestrous cycle – the window of conceptus elongation initiation – from cycling heifers supplemented, or not, with progesterone. Subsequent lipidomic profiling of uterine luminal fluid by advanced high-throughput metabolomics revealed the consistent …

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Aspects Of Embryo-Maternal Communication In Establishment Of Pregnancy In Cattle, José M. Sánchez, Constantine A. Simintiras, Patrick Lonergan Jan 2019

Aspects Of Embryo-Maternal Communication In Establishment Of Pregnancy In Cattle, José M. Sánchez, Constantine A. Simintiras, Patrick Lonergan

Faculty Publications

Establishment of pregnancy in mammals requires reciprocal molecular communication between the conceptus and endometrium that modifies the endometrial transcriptome and uterine luminal milieu to support pregnancy. Due to the small size of the early embryo and elongating conceptus relative to the volume of the uterine lumen, collection of endometrium adjacent to the developing conceptus is difficult following conventional uterine flushing methods in cattle. Use of endometrial explants in culture can overcome this challenge and reveal information about the dialogue between the developing embryo and the uterus. The aim of this short review is to summarize some of our recent findings …

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Attachment Strength And On-Farm Die-Off Rate Of Escherichia Coli On Watermelon Surfaces, Vijay Singh Chhetri, Kathryn Fontenot, Ronald Strahan, Veerachandra K. Yemmireddy, Cameron Cason, Karuna Kharel, Achyut Adhikari Jan 2019

Attachment Strength And On-Farm Die-Off Rate Of Escherichia Coli On Watermelon Surfaces, Vijay Singh Chhetri, Kathryn Fontenot, Ronald Strahan, Veerachandra K. Yemmireddy, Cameron Cason, Karuna Kharel, Achyut Adhikari

Faculty Publications

Pre-harvest contamination of produce has been a major food safety focus. Insight into the behavior of enteric pathogens on produce in pre-harvest conditions will aid in developing pre-harvest and post-harvest risk management strategies. In this study, the attachment strength (S R ) and die-off rate of E. coli on the surface of watermelon fruits and the efficacy of aqueous chlorine treatment against strongly attached E. coli population were investigated. Watermelon seedlings were transplanted into eighteen plots. Prior to harvesting, a cocktail of generic E. coli (ATCC 23716, 25922 and 11775) was inoculated on the surface of the watermelon fruits (n …

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Inhibition Of Selected Pathogens Inoculated On The Surface Of Catfish Fillets By High Molecular Weight Chitosan Coating, Baris Karsli, Emre Caglak, Dapeng Li, Nancy K. Rubio, Marlene Janes, Witoon Prinyawiwatkul Jan 2019

Inhibition Of Selected Pathogens Inoculated On The Surface Of Catfish Fillets By High Molecular Weight Chitosan Coating, Baris Karsli, Emre Caglak, Dapeng Li, Nancy K. Rubio, Marlene Janes, Witoon Prinyawiwatkul

Faculty Publications

Antibacterial activity of high molecular weight water-soluble (HMWWS) chitosan (800 kDa) was investigated against four Gram-negative (Escherichia coli, Salmonella typhimurium, Vibrio cholerae and Vibrio parahaemolyticus) and two Gram-positive (Staphylococcus aureus and Listeria monocytogenes) bacteria. Catfish fillets were surface-inoculated with these food-borne pathogens and coated with chitosan dissolved in aspartic acid (AS) or acetic acid (AC) solution at different concentrations (1% or 3%). Samples were stored at 4 °C for 8 days, except for those inoculated with Vibrio species (10 °C for 6 days). Overall, the most effective coating treatment was the 3% HMWWS chitosan in AS solution (800AS3%). Compared with …

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An Actin-Depolymerizing Factor From The Halophyte Smooth Cordgrass, Spartina Alterniflora (Saadf2), Is Superior To Its Rice Homolog (Osadf2) In Conferring Drought And Salt Tolerance When Constitutively Overexpressed In Rice, Sonali Sengupta, Venkata Mangu, Luis Sanchez, Renesh Bedre, Rohit Joshi, Kanniah Rajasekaran, Niranjan Baisakh Jan 2019

An Actin-Depolymerizing Factor From The Halophyte Smooth Cordgrass, Spartina Alterniflora (Saadf2), Is Superior To Its Rice Homolog (Osadf2) In Conferring Drought And Salt Tolerance When Constitutively Overexpressed In Rice, Sonali Sengupta, Venkata Mangu, Luis Sanchez, Renesh Bedre, Rohit Joshi, Kanniah Rajasekaran, Niranjan Baisakh

Faculty Publications

Actin-depolymerizing factors (ADFs) maintain the cellular actin network dynamics by regulating severing and disassembly of actin filaments in response to environmental cues. An ADF isolated from a monocot halophyte, Spartina alterniflora (SaADF2), imparted significantly higher level of drought and salinity tolerance when expressed in rice than its rice homologue OsADF2. SaADF2 differs from OsADF2 by a few amino acid residues, including a substitution in the regulatory phosphorylation site serine-6, which accounted for its weak interaction with OsCDPK6 (calcium-dependent protein kinase), thus resulting in an increased efficacy of SaADF2 and enhanced cellular actin dynamics. SaADF2 overexpression preserved the actin filament organization …

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Food-Burying Behavior In Red Imported Fire Ants (Hymenoptera: Formicidae), Wenquan Qin, Xuan Chen, Linda M. Hooper-Bùi, Jiacheng Cai, Lei Wang, Zhaohui Sun, Xiujun Wen, Cai Wang Jan 2019

Food-Burying Behavior In Red Imported Fire Ants (Hymenoptera: Formicidae), Wenquan Qin, Xuan Chen, Linda M. Hooper-Bùi, Jiacheng Cai, Lei Wang, Zhaohui Sun, Xiujun Wen, Cai Wang

Faculty Publications

The food-burying behavior has been reported in many mammals and birds, but was rarely observed in invertebrates. The red imported fire ants, Solenopsis invicta Buren, is an invasive pest in many areas of the world that usually performing food-burying during the foraging processes. However, the impacted factors and measureable patterns of this behavior is largely unknown. In the present study, food-burying vs food-transport behaviors of Solenopsis invicta were observed under laboratory and field conditions. When starved (no food was provided for 37 days) in the laboratory, food (sausage) was consumed by large numbers of ants, and few burying behaviors were …

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Topographic Control On The Post-Lgm Grounding Zone Locations Of The West Antarctic Ice Sheet In The Whales Deep Basin, Eastern Ross Sea, M. Danielson, P. J. Bart Jan 2019

Topographic Control On The Post-Lgm Grounding Zone Locations Of The West Antarctic Ice Sheet In The Whales Deep Basin, Eastern Ross Sea, M. Danielson, P. J. Bart

Faculty Publications

After the Last Glacial Maximum (LGM), the Antarctic Ice Sheet retreated several hundred kilometers from the outer continental shelf. An overall backstepping stratal pattern of grounding zone wedges (GZWs) indicates that the post-LGM retreat occurred in a step-wise fashion. Each GZW records a prior interval of ice-stream sedimentation during which the location of paleo-grounding zone (i.e., the former seaward limit of flowing ice grounded to the seafloor) was relatively stationary. Here we investigate whether the locations of post-LGM grounding-zone stillstands in the Whales Deep Basin (WDB) of the eastern Ross Sea were controlled by the antecedent topography. The Bindschadler Ice …

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Radon Transforms Over Lower-Dimensional Horospheres In Real Hyperbolic Space, William O. Bray, Boris Rubin Jan 2019

Radon Transforms Over Lower-Dimensional Horospheres In Real Hyperbolic Space, William O. Bray, Boris Rubin

Faculty Publications

We study horospherical Radon transforms that integrate functions on the n-dimensional real hyperbolic space over horospheres of arbitrary fixed dimension 1 ≤ d ≤ n-1. Exact existence conditions and new explicit inversion formulas are obtained for these transforms acting on smooth functions and functions belonging to Lp. The case d = n 1 agrees with the well-known Gelfand-Graev transform.

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Comparative Functional And Phylogenomic Analyses Of Host Association In The Remoras (Echeneidae), A Family Of Hitchhiking Fishes, C. P. Kenaley, A. Stote, W. B. Ludt, P. Chakrabarty Jan 2019

Comparative Functional And Phylogenomic Analyses Of Host Association In The Remoras (Echeneidae), A Family Of Hitchhiking Fishes, C. P. Kenaley, A. Stote, W. B. Ludt, P. Chakrabarty

Faculty Publications

The family Echeneidae consists of eight species of marine fishes that hitchhike by adhering to a wide variety of vertebrate hosts via a sucking disc. While several studies have focused on the interrelationships of the echeneids and the adhesion performance of a single species, no clear phylogenetic hypothesis has emerged and the morphological basis of adhesion remains largely unknown. We first set out to resolve the interrelationships of the Echeneidae by taking a phylogenomic approach using ultraconserved elements. Then, within this framework, we characterized disc morphology through μ-CT analysis, evaluated host specificity through an analysis of host phylogenetic distance, and …

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Behavioral Health Risk And Resilience Among International Students In The United States: A Study Of Sociodemographic Differences, Youn Kyoung Kim, Arati Maleku, Catherine Lemieu, Xi Du, Zibei Chen Jan 2019

Behavioral Health Risk And Resilience Among International Students In The United States: A Study Of Sociodemographic Differences, Youn Kyoung Kim, Arati Maleku, Catherine Lemieu, Xi Du, Zibei Chen

Faculty Publications

Using a resilience framework, the current cross-sectional study examined indicators of behavioral health risk and resilience among U.S. international students (N=322) across key sociodemographic characteristics. A multimethod approach was used to collect data with both an online platform and paper-based survey instrument. Results showed that higher levels of acculturative stress were reported by older students, females, undergraduates, students who lived with their families, and those who had resided in the US longer than 2 years. Findings underscore the importance of culturally relevant screening and prevention strategies that target resilience and other protective factors to reduce health risk and encourage well-being …

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Characterization Of The Genomically Encoded Fosfomycin Resistance Enzyme From: Mycobacterium Abscessus, Skye Travis, Madeline R. Shay, Shino Manabe, Nathaniel C. Gilbert, Patrick A. Frantom, Matthew K. Thompson Jan 2019

Characterization Of The Genomically Encoded Fosfomycin Resistance Enzyme From: Mycobacterium Abscessus, Skye Travis, Madeline R. Shay, Shino Manabe, Nathaniel C. Gilbert, Patrick A. Frantom, Matthew K. Thompson

Faculty Publications

Mycobacterium abscessus belongs to a group of rapidly growing mycobacteria (RGM) and accounts for approximately 65-80% of lung disease caused by RGM. It is highly pathogenic and is considered the prominent Mycobacterium involved in pulmonary infection in patients with cystic fibrosis and chronic pulmonary disease (CPD). FosM is a putative 134 amino acid fosfomycin resistance enzyme from M. abscessus subsp. bolletii that shares approximately 30-55% sequence identity with other vicinal oxygen chelate (VOC) fosfomycin resistance enzymes and represents the first of its type found in any Mycobacterium species. Genes encoding VOC fosfomycin resistance enzymes have been found in both Gram-positive …

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Inferring The Mammal Tree: Species-Level Sets Of Phylogenies For Questions In Ecology, Evolution, And Conservation, Nathan S. Upham, Jacob A. Esselstyn, Walter Jetz Jan 2019

Inferring The Mammal Tree: Species-Level Sets Of Phylogenies For Questions In Ecology, Evolution, And Conservation, Nathan S. Upham, Jacob A. Esselstyn, Walter Jetz

Faculty Publications

Big, time-scaled phylogenies are fundamental to connecting evolutionary processes to modern biodiversity patterns. Yet inferring reliable phylogenetic trees for thousands of species involves numerous trade-offs that have limited their utility to comparative biologists. To establish a robust evolutionary timescale for all approximately 6,000 living species of mammals, we developed credible sets of trees that capture root-to-tip uncertainty in topology and divergence times. Our “backbone-and-patch” approach to tree building applies a newly assembled 31-gene supermatrix to two levels of Bayesian inference: (1) backbone relationships and ages among major lineages, using fossil node or tip dating, and (2) species-level “patch” phylogenies with …

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Domain Decomposition For Quasi-Periodic Scattering By Layered Media Via Robust Boundary-Integral Equations At All Frequencies, Carlos Pérez-Arancibia, Stephen P. Shipman, Catalin Turc, Stephanos Venakides Jan 2019

Domain Decomposition For Quasi-Periodic Scattering By Layered Media Via Robust Boundary-Integral Equations At All Frequencies, Carlos Pérez-Arancibia, Stephen P. Shipman, Catalin Turc, Stephanos Venakides

Faculty Publications

We develop a non-overlapping domain decomposition method (DDM) for scalar wave scattering by periodic layered media. Our approach relies on robust boundary-integral equation formulations of Robin-to-Robin (RtR) maps throughout the frequency spectrum, including cutoff (or Wood) frequencies. We overcome the obstacle of non-convergent quasi-periodic Green functions at these frequencies by incorporating newly introduced shifted Green functions. Using the latter in the definition of quasi-periodic boundary-integral operators leads to rigorously stable computations of RtR operators. We develop Nyström discretizations of the RtR maps that rely on trigonometric interpolation, singularity resolution, and fast convergent windowed quasi-periodic Green functions. We solve the tridiagonal …

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Removing Mercury From Aqueous Solution Using Sulfurized Biochar And Associated Mechanisms, Jong Hwan Park, Jim J. Wang, Baoyue Zhou, Joseph E.R. Mikhael, Ronald D. Delaune Jan 2019

Removing Mercury From Aqueous Solution Using Sulfurized Biochar And Associated Mechanisms, Jong Hwan Park, Jim J. Wang, Baoyue Zhou, Joseph E.R. Mikhael, Ronald D. Delaune

Faculty Publications

Biochar has been used to remove heavy metals from aqueous solutions. In this study, a sulfurized wood biochar (SWB) by direct impregnation with elemental sulfur was produced and evaluated along with pristine wood biochar (WB) for adsorption characteristics and mechanism of mercury. Mercury adsorption by WB and SWB was well described by Langmuir model and pseudo second order model and the maximum adsorption capacities of WB and SWB were 57.8 and 107.5 mg g−1, respectively. Intraparticle diffusion model showed that mercury adsorption was fast due to boundary layer and slow adsorption due to diffusion into biochar pores. Although, mercury adsorption …

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