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Bias In Population Growth Rate Estimation: Sparse Data, Partial Life Cycle Analysis And Jensen's Inequality, Jason S. Grear, Bret D. Elderd Oct 2008

Bias In Population Growth Rate Estimation: Sparse Data, Partial Life Cycle Analysis And Jensen's Inequality, Jason S. Grear, Bret D. Elderd

Faculty Publications

Demographic matrix models have become an integral part of population viability analysis for threatened and endangered species, but their use is often limited by data availability. A common solution to this problem is to assume constant annual rates within a multi-year stage. Partial life cycle analysis (PLC), which incorporates only juvenile and adult stages, is a noteworthy example of this approach because it has been described in the literature as a reliable approximation of age-structured populations. However, we predict from Jensen's Inequality that the required lumping of age classes leads to over- or underestimation of population fitness when survival rates …

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Mathematics Library News 4, Aaron Lercher Oct 2008

Mathematics Library News 4, Aaron Lercher

Faculty Publications

No abstract provided.

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The Effects Of Packaging Film And Storage Temperature On The Internal Package Atmosphere And Fermentation Enzyme Activity Of Sweet Potato Slices, Elif Erturk, David H. Picha Oct 2008

The Effects Of Packaging Film And Storage Temperature On The Internal Package Atmosphere And Fermentation Enzyme Activity Of Sweet Potato Slices, Elif Erturk, David H. Picha

Faculty Publications

Fresh-cut sweet potato slices were packaged in low- (PD900), medium- (PD961) and high-permeability (PD941) film bags, and were stored at 2 or 8C for 14 days. Changes in O 2, CO 2, ethanol and acetaldehyde concentrations in the headspace were monitored over 14 days. The activities of fermentation enzymes and the concentration of fermentation volatiles were measured from tissue extracts on days 0, 7 and 14. Storage at 8C was an excessively high temperature for fresh-cut sweet potatoes to maintain aerobic respiration for 14 days. Low-permeability film bags resulted in anaerobiosis at 2 and 8C. Medium-permeability film bags were able …

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Combustion Byproducts And Their Health Effects: Summary Of The 10 Th International Congress, Barry Dellinger, Antonio D'Alessio, Andrea D'Anna, Anna Ciajolo, Brian Gullett, Heather Henry, Mel Keener, Jo Ann Lighty, Slawomir Lomnicki, Donald Lucas, Günter Oberdörster, Demetrio Pitea, William Suk, Adel Sarofim, Kirk R. Smith, Tobias Stoeger, Paige Tolbert, Ron Wyzga, Ralf Zimmermann Oct 2008

Combustion Byproducts And Their Health Effects: Summary Of The 10 Th International Congress, Barry Dellinger, Antonio D'Alessio, Andrea D'Anna, Anna Ciajolo, Brian Gullett, Heather Henry, Mel Keener, Jo Ann Lighty, Slawomir Lomnicki, Donald Lucas, Günter Oberdörster, Demetrio Pitea, William Suk, Adel Sarofim, Kirk R. Smith, Tobias Stoeger, Paige Tolbert, Ron Wyzga, Ralf Zimmermann

Faculty Publications

The 10th International Congress on Combustion Byproducts and their Health Effects was held in Ischia, Italy, from June 17-20, 2007. It is sponsored by the US NIEHS, NSF, Coalition for Responsible Waste Incineration (CRWI), and Electric Power Research Institute (EPRI). The congress focused on: the origin, characterization, and health impacts of combustion-generated fine and ultrafine particles; emissions of mercury and dioxins, and the development/application of novel analytical/diagnostic tools. The consensus of the discussion was that particle-associated organics, metals, and persistent free radicals (PFRs) produced by combustion sources are the likely source of the observed health impacts of airborne PM rather …

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Hydrologic Response To Extreme Warm And Cold Summers In The Mcmurdo Dry Valleys, East Antarctica, Peter T. Doran, Christopher P. Mckay, Andrew G. Fountain, Thomas Nylen, Diane M. Mcknight, Chris Jaros, John E. Barrett Oct 2008

Hydrologic Response To Extreme Warm And Cold Summers In The Mcmurdo Dry Valleys, East Antarctica, Peter T. Doran, Christopher P. Mckay, Andrew G. Fountain, Thomas Nylen, Diane M. Mcknight, Chris Jaros, John E. Barrett

Faculty Publications

The meteorological characteristics and hydrological response of an extreme warm, and cold summer in the McMurdo Dry Valleys are compared. The driver behind the warmer summer conditions was the occurrence of down-valley winds, which were not present during the colder summer. Occurrence of the summer down-valley winds coincided with lower than typical mean sea level pressure in the Ross Sea region. There was no significant difference in the amount of solar radiation received during the two summers. Compared to the cold summer, glaciological and hydrological response to the warm summer in Taylor Valley included significant glacier mass loss, and 3- …

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Newly Discovered Sister Lineage Sheds Light On Early Ant Evolution, Christian Rabeling, Jeremy M. Brown, Manfred Verhaagh Sep 2008

Newly Discovered Sister Lineage Sheds Light On Early Ant Evolution, Christian Rabeling, Jeremy M. Brown, Manfred Verhaagh

Faculty Publications

Ants are the world's most conspicuous and important eusocial insects and their diversity, abundance, and extreme behavioral specializations make them a model system for several disciplines within the biological sciences. Here, we report the discovery of a new ant that appears to represent the sister lineage to all extant ants (Hymenoptera: Formicidae). The phylogenetic position of this cryptic predator from the soils of the Amazon rainforest was inferred from several nuclear genes, sequenced from a single leg. Martialis heureka (gen. et sp. nov.) also constitutes the sole representative of a new, morphologically distinct subfamily of ants, the Martialinae (subfam. nov.). …

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Faculty Senate Resolution 08-12, Louisiana State University And Agricultural & Mechanical College Sep 2008

Faculty Senate Resolution 08-12, Louisiana State University And Agricultural & Mechanical College

LSU Faculty Senate Publications

Faculty Senate Resolution proposing a LSU policy statement on comprehensive whistleblower protection, and establishing a university ethics office at LSU, adopted on September 10, 2008.

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Determining The Impact Of Crawfish Imports On U.S. Domestic Prices, P. Lynn Kennedy, Young Jae Lee Sep 2008

Determining The Impact Of Crawfish Imports On U.S. Domestic Prices, P. Lynn Kennedy, Young Jae Lee

Faculty Publications

The study identifies the linkage between imports and the domestic price of crawfish. The results show a simultaneous increase in imports and domestic prices of crawfish while showing a negative relationship between domestic landings and price. Each model shows that there is a seasonality effect on the domestic price of crawfish. The study also shows that increases in the domestic supplies of shrimp, tilapia, and clams generated increases in the domestic crawfish price, while increases in imported and domestic supplies of beef and imported supplies of pork decreased the domestic crawfish price.

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Diffusion Models For Animals In Complex Landscapes: Incorporating Heterogeneity Among Substrates, Individuals And Edge Behaviours, John D. Reeve, James T. Cronin, Kyle J. Haynes Sep 2008

Diffusion Models For Animals In Complex Landscapes: Incorporating Heterogeneity Among Substrates, Individuals And Edge Behaviours, John D. Reeve, James T. Cronin, Kyle J. Haynes

Faculty Publications

1. Animals move commonly through a variety of landscape elements and edges in search of food, mates and other resources. We developed a diffusion model for the movement of an insect herbivore, the planthopper Prokelisia crocea, that inhabits a landscape composed of patches of its host plant, prairie cordgrass Spartina pectinata, embedded in a matrix of mudflat or smooth brome Bromus inermis. 2. We used mark-release-resight experiments to quantify planthopper movements within cordgrass-brome and cordgrass-mudflat arenas. A diffusion model was then fitted that included varying diffusion rates for cordgrass and matrix, edge behaviour in the form of a biased random …

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Four-Dimensional Computed Tomography-Based Treatment Planning For Intensity-Modulated Radiation Therapy And Proton Therapy For Distal Esophageal Cancer, Xiaodong Zhang, Kuai Le Zhao, Thomas M. Guerrero, Sean E. Mcguire, Brian Yaremko, Ritsuko Komaki, James D. Cox, Zhouguang Hui, Yupeng Li, Wayne D. Newhauser, Radhe Mohan, Zhongxing Liao Sep 2008

Four-Dimensional Computed Tomography-Based Treatment Planning For Intensity-Modulated Radiation Therapy And Proton Therapy For Distal Esophageal Cancer, Xiaodong Zhang, Kuai Le Zhao, Thomas M. Guerrero, Sean E. Mcguire, Brian Yaremko, Ritsuko Komaki, James D. Cox, Zhouguang Hui, Yupeng Li, Wayne D. Newhauser, Radhe Mohan, Zhongxing Liao

Faculty Publications

Purpose: To compare three-dimensional (3D) and four-dimensional (4D) computed tomography (CT)-based treatment plans for proton therapy or intensity-modulated radiation therapy (IMRT) for esophageal cancer in terms of doses to the lung, heart, and spinal cord and variations in target coverage and normal tissue sparing. Methods and Materials: The IMRT and proton plans for 15 patients with distal esophageal cancer were designed from the 3D average CT scans and then recalculated on 10 4D CT data sets. Dosimetric data were compared for tumor coverage and normal tissue sparing. Results: Compared with IMRT, median lung volumes exposed to 5, 10, and 20 …

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Inchoate Cd8+ T Cell Responses In Neonatal Mice Permit Influenza-Induced Persistent Pulmonary Dysfunction, Dahui You, Michael Ripple, Shrilatha Balakrishna, Dana Troxclair, Dane Sandquist, Liren Ding, Terry A. Ahlert, Stephania A. Cormier Sep 2008

Inchoate Cd8+ T Cell Responses In Neonatal Mice Permit Influenza-Induced Persistent Pulmonary Dysfunction, Dahui You, Michael Ripple, Shrilatha Balakrishna, Dana Troxclair, Dane Sandquist, Liren Ding, Terry A. Ahlert, Stephania A. Cormier

Faculty Publications

Influenza infection remains a significant cause of pulmonary morbidity and mortality worldwide, with the highest hospitalization and mortality rates occurring in infants and elder adults. The mechanisms inducing this considerable morbidity and mortality are largely unknown. To address this question, we established a neonatal mouse model of influenza infection to test the hypothesis that the immaturity of the neonatal immune system is responsible for the severe pulmonary disease observed in infants. Seven-day-old mice were infected with influenza A virus (H1N1) and allowed to mature. As adults, these mice showed enhanced airway hyperreactivity, chronic pulmonary inflammation, and diffuse emphysematous-type lesions in …

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Wtse, An Avre-Family Type Iii Effector Protein Of Pantoea Stewartii Subsp. Stewartii, Causes Cell Death In Non-Host Plants, Jong Hyun Ham, Doris Majerczak, Sophie Ewert, Mysore Venkatarau Sreerekha, David Mackey, David Coplin Sep 2008

Wtse, An Avre-Family Type Iii Effector Protein Of Pantoea Stewartii Subsp. Stewartii, Causes Cell Death In Non-Host Plants, Jong Hyun Ham, Doris Majerczak, Sophie Ewert, Mysore Venkatarau Sreerekha, David Mackey, David Coplin

Faculty Publications

Pantoea stewartii subsp. stewartii (Pnss) causes Stewart's bacterial wilt of sweet corn and leaf blight of maize. The pathogenicity of Pnss depends on synthesis of extracellular polysaccharide and an Hrp type III secretion system. WtsE, a type III secreted effector protein, is essential for the virulence of Pnss on corn. It belongs to the AvrE family of effectors, which includes DspA/E from Erwinia amylovora and AvrE1 from Pseudomonas syringae. Previously, WtsE was shown to cause disease-associated cell death in its host plant, sweet corn. Here, we examine the biological activity of WtsE in several non-host plants. WtsE induced cell death …

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Identification Of Repeat Structure In Large Genomes Using Repeat Probability Clouds, Wanjun Gu, Todd A. Castoe, Dale J. Hedges, Mark A. Batzer, David D. Pollock Sep 2008

Identification Of Repeat Structure In Large Genomes Using Repeat Probability Clouds, Wanjun Gu, Todd A. Castoe, Dale J. Hedges, Mark A. Batzer, David D. Pollock

Faculty Publications

The identification of repeat structure in eukaryotic genomes can be time-consuming and difficult because of the large amount of information (∼3 × 109 bp) that needs to be processed and compared. We introduce a new approach based on exact word counts to evaluate, de novo, the repeat structure present within large eukaryotic genomes. This approach avoids sequence alignment and similarity search, two of the most time-consuming components of traditional methods for repeat identification. Algorithms were implemented to efficiently calculate exact counts for any length oligonucleotide in large genomes. Based on these oligonucleotide counts, oligonucleotide excess probability clouds, or "P-clouds," were …

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Diagnoses For Leiognathus Lacepède 1802, Equula Cuvier 1815, Equulites Fowler 1904, Eubleekeria Fowler 1904, And A New Ponyfish Genus (Teleostei: Leiognathidae), Prosanta Chakrabarty, John S. Sparks Aug 2008

Diagnoses For Leiognathus Lacepède 1802, Equula Cuvier 1815, Equulites Fowler 1904, Eubleekeria Fowler 1904, And A New Ponyfish Genus (Teleostei: Leiognathidae), Prosanta Chakrabarty, John S. Sparks

Faculty Publications

Recent phylogenetic work on ponyfishes has delimited and revealed the interrelationships of major leiognathid clades. To begin to recognize a monophyletic taxonomy for Leiognathidae we diagnose, delimit, and describe a number of ponyfish genera to reflect our current knowledge of their phylogenetic history. Equula Cuvier, 1815, is resurrected from synonymy with Leiognathus Lacepède, 1802, and comprises E. fasciata and E longispinis. Members of Equula, the sister group to all other members of Leiognathidae, are large-bodied ponyfishes characterized by conspicuous round yellow blotches on the flank. The genus Leiognathus Lacepède, 1802, the sister group to the remaining members of Leiognathidae less …

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Assessment Of The Accuracy Of An Mcnpx-Based Monte Carlo Simulation Model For Predicting Three-Dimensional Absorbed Dose Distributions, U. Titt, N. Sahoo, X. Ding, Y. Zheng, W. D. Newhauser, X. R. Zhu, J. C. Polf, M. T. Gillin, R. Mohan Aug 2008

Assessment Of The Accuracy Of An Mcnpx-Based Monte Carlo Simulation Model For Predicting Three-Dimensional Absorbed Dose Distributions, U. Titt, N. Sahoo, X. Ding, Y. Zheng, W. D. Newhauser, X. R. Zhu, J. C. Polf, M. T. Gillin, R. Mohan

Faculty Publications

In recent years, the Monte Carlo method has been used in a large number of research studies in radiation therapy. For applications such as treatment planning, it is essential to validate the dosimetric accuracy of the Monte Carlo simulations in heterogeneous media. The AAPM Report no 105 addresses issues concerning clinical implementation of Monte Carlo based treatment planning for photon and electron beams, however for proton-therapy planning, such guidance is not yet available. Here we present the results of our validation of the Monte Carlo model of the double scattering system used at our Proton Therapy Center in Houston. In …

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Neuropoietin Attenuates Adipogenesis And Induces Insulin Resistance In Adipocytes, Ursula A. White, William C. Stewart, Randall L. Mynatt, Jacqueline M. Stephens Aug 2008

Neuropoietin Attenuates Adipogenesis And Induces Insulin Resistance In Adipocytes, Ursula A. White, William C. Stewart, Randall L. Mynatt, Jacqueline M. Stephens

Faculty Publications

Recent findings have implicated gp130 receptor ligands, particularly ciliary neurotrophic factor (CNTF), as potential antiobesity therapeutics. Neuropoietin (NP) is a recently discovered cytokine in the gp130 family that shares functional and structural features with CNTF and signals via the CNTF receptor tripartite complex comprised of CNTFRα, LIF receptor, and gp130. NP plays a role in the development of the nervous system, but the effects of NP on adipocytes have not been previously examined. Because CNTF exerts anti-obesogenic effects in adipocytes and NP shares the same receptor complex, we investigated the effects of NP on adipocyte development and insulin action. Using …

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Genome-Wide Transposon Tagging Reveals Location-Dependent Effects On Transcription And Chromatin Organization In Arabidopsis, Faye M. Rosin, Naohide Watanabe, Jean Luc Cacas, Naohiro Kato, Juana M. Arroyo, Yuda Fang, Bruce May, Matthew Vaughn, Joseph Simorowski, Umamaheswari Ramu, Richard W. Mccombie, David L. Spector, Robert A. Martienssen, Eric Lam Aug 2008

Genome-Wide Transposon Tagging Reveals Location-Dependent Effects On Transcription And Chromatin Organization In Arabidopsis, Faye M. Rosin, Naohide Watanabe, Jean Luc Cacas, Naohiro Kato, Juana M. Arroyo, Yuda Fang, Bruce May, Matthew Vaughn, Joseph Simorowski, Umamaheswari Ramu, Richard W. Mccombie, David L. Spector, Robert A. Martienssen, Eric Lam

Faculty Publications

The interphase nucleus exists as a highly dynamic system, the physical properties of which have functional importance in gene regulation. Not only can gene expression be influenced by the local sequence context, but also by the architecture of the nucleus in three-dimensions (3D), and by the interactions between these levels via chromatin modifications. A challenging task is to resolve the complex interplay between sequence- and genome structure-based control mechanisms. Here, we created a collection of 277 Arabidopsis lines that allow the visual tracking of individual loci in living plants while comparing gene expression potential at these locations, via an identical …

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Estimating Species Trees Using Multiple-Allele Dna Sequence Data, Liang Liu, Dennis K. Pearl, Robb T. Brumfield, Scott V. Edwards Aug 2008

Estimating Species Trees Using Multiple-Allele Dna Sequence Data, Liang Liu, Dennis K. Pearl, Robb T. Brumfield, Scott V. Edwards

Faculty Publications

Several techniques, such as concatenation and consensus methods, are available for combining data from multiple loci to produce a single statement of phylogenetic relationships. However, when multiple alleles are sampled from individual species, it becomes more challenging to estimate relationships at the level of species, either because concatenation becomes inappropriate due to conflicts among individual gene trees, or because the species from which multiple alleles have been sampled may not form monophyletic groups in the estimated tree. We propose a Bayesian hierarchical model to reconstruct species trees from multiple-allele, multilocus sequence data, building on a recently proposed method for estimating …

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An Update Of The Field Guide To Louisiana Soil Classification (Bulletin #889), David C. Weindorf Aug 2008

An Update Of The Field Guide To Louisiana Soil Classification (Bulletin #889), David C. Weindorf

LSU AgCenter Bulletins

This field guide represents an update of work by Amacher et al. (1989), the original idea of which started with Dr. Bob Miller. The guide provides researchers and others interested in soils with a concise key to the classification of soils throughout Louisiana along with information on geology, climate, vegetation, etc.

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Telomeres And Race: What Can We Learn About Human Biology From Health Differentials?, Jay S. Kaufman, Richard S. Cooper Aug 2008

Telomeres And Race: What Can We Learn About Human Biology From Health Differentials?, Jay S. Kaufman, Richard S. Cooper

Faculty Publications

The advent of molecular technology that can be applied across large population samples has added - rather than reduced - complexity in the analysis of the intertwined effects of social history and heritable factors on health outcomes. The report by Hunt et al. in this issue of Aging Cell provides an example of the promises and dilemmas associated with this increased complexity. © 2008 The Authors Journal compilation © Blackwell Publishing Ltd/The Anatomical Society of Great Britain and Ireland 2008.

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Determining The Accepability Of Menus And Recipes That Meet The 2005 Dietary Guidelines For Americans By Low Socioeconomic Status Individuals In South Louisiana Using Focus Group Discussions, Anna L. Mullenix Aug 2008

Determining The Accepability Of Menus And Recipes That Meet The 2005 Dietary Guidelines For Americans By Low Socioeconomic Status Individuals In South Louisiana Using Focus Group Discussions, Anna L. Mullenix

Honors Capstones

No abstract provided.

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Viability And Fertilizing Capacity Of Cryopreserved Sperm From Three North American Acipenseriform Species: A Retrospective Study, Á Horváth, W. R. Wayman, J. C. Dean, B. Urbányi, T. R. Tiersch, S. D. Mims, D. Johnson, J. A. Jenkins Aug 2008

Viability And Fertilizing Capacity Of Cryopreserved Sperm From Three North American Acipenseriform Species: A Retrospective Study, Á Horváth, W. R. Wayman, J. C. Dean, B. Urbányi, T. R. Tiersch, S. D. Mims, D. Johnson, J. A. Jenkins

Faculty Publications

Populations of sturgeon across the globe are threatened due to unregulated harvest and habitat loss, and the status varies among species across North America. Ready access to viable and functional sperm would contribute to recovery programmes for these species. In this study, we examined the motility, viability (cell membrane integrity) of cryopreserved sperm from three North American acipenseriform species and fertilizing capacity. Milt samples were collected from captive shortnose sturgeon (Acipenser brevirostrum), wild paddlefish (Polyodon spathula) and pallid sturgeon (Scaphirhynchus albus) and cryopreserved using combinations of Modified Tsvetkova's (MT) extender, Original Tsvetkova's extender, and modified Hanks' balanced salt solution, along …

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Prevalence And Infection Load Dynamics Of Rickettsia Felis In Actively Feeding Cat Fleas, Kathryn E. Reif, Rhett W. Stout, Gretchen C. Henry, Lane D. Foil, Kevin R. Macaluso Jul 2008

Prevalence And Infection Load Dynamics Of Rickettsia Felis In Actively Feeding Cat Fleas, Kathryn E. Reif, Rhett W. Stout, Gretchen C. Henry, Lane D. Foil, Kevin R. Macaluso

Faculty Publications

Background: Rickettsia felis is a flea-associated rickettsial pathogen recurrently identified in both colonized and wild-caught cat fleas, Ctenocephalides felis. We hypothesized that within colonized fleas, the intimate relationship between R. felis and C. felis allows for the coordination of rickettsial replication and metabolically active periods during flea bloodmeal acquisition and oogenesis. Methodology/Principal Findings: a quantitative real-time PCR assay was developed to quantify R. felis in actively feeding R. felis-infected fleas. In three separate trials, fleas were allowed to feed on cats, and a mean of 3.9 × 106 R. felis 17-kDa gene copies was detected for each flea. A distinct …

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Q-Dock: Low-Resolution Flexible Ligand Docking With Pocket-Specific Threading Restraints, Michal Brylinski, Jeffrey Skolnick Jul 2008

Q-Dock: Low-Resolution Flexible Ligand Docking With Pocket-Specific Threading Restraints, Michal Brylinski, Jeffrey Skolnick

Faculty Publications

The rapidly growing number of theoretically predicted protein structures requires robust methods that can utilize low-quality receptor structures as targets for ligand docking. Typically, docking accuracy falls off dramatically when apo or modeled receptors are used in docking experiments. Low-resolution ligand docking techniques have been developed to deal with structural inaccuracies in predicted receptor models. In this spirit, we describe the development and optimization of a knowledge-based potential implemented in Q-Dock, a low-resolution flexible ligand docking approach. Self-docking experiments using crystal structures reveals satisfactory accuracy, comparable with all-atom docking. All-atom models reconstructed from Q-Dock's low-resolution models can be further refined …

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Size And Heterozygosity Influence Partner Selection In The Formosan Subterranean Termite, Claudia Husseneder, Dawn M. Simms Jul 2008

Size And Heterozygosity Influence Partner Selection In The Formosan Subterranean Termite, Claudia Husseneder, Dawn M. Simms

Faculty Publications

In monogamous species that exhibit extensive biparental investment, such as termites, both sexes are predicted to be selective when choosing a mate. Size-related traits are expected to be important in partner selection because the fat reserves of the colony founders sustain the incipient colony. Partner relatedness and heterozygosity determine the degree of inbreeding and genetic diversity within the colony and may thus also influence partner selection. To test these predictions, we investigated whether phenotypic and genetic traits influence mate choice and/or competitive advantage during pair formation of Formosan subterranean termites, Coptotermes formosanus (Isoptera: Rhinotermitidae). Pair formation in termites normally occurs …

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Replication Of The Wellcome Trust Genome-Wide Association Study Of Essential Hypertension: The Family Blood Pressure Program, Georg B. Ehret, Alanna C. Morrison, Ashley A. O'Connor, Megan L. Grove, Lisa Baird, Karen Schwander, Alan Weder, Richard S. Cooper, D. C. Rao, Steven C. Hunt, Eric Boerwinkle, Aravinda Chakravarti Jul 2008

Replication Of The Wellcome Trust Genome-Wide Association Study Of Essential Hypertension: The Family Blood Pressure Program, Georg B. Ehret, Alanna C. Morrison, Ashley A. O'Connor, Megan L. Grove, Lisa Baird, Karen Schwander, Alan Weder, Richard S. Cooper, D. C. Rao, Steven C. Hunt, Eric Boerwinkle, Aravinda Chakravarti

Faculty Publications

Essential hypertension is a principal cardiovascular risk factor whose origin remains unknown. Classical genetic studies have shown that blood pressure is at least partially heritable, opening a window to understanding the pathophysiology of essential hypertension in the human using modern genetic tools. The Wellcome Trust Case Control Consortium has recently published the results of screening the genomes of 2000 essential hypertension cases and 3000 controls using 500000 genome-wide single nucleotide polymorphisms (SNPs). None of the variants proved to be genome-wide significant after correction for multiple tests but the most significantly associated SNPs (P<10-5) constitute a priority list that warrant follow-up in other studies. We describe here replication studies of the top six SNPs in subjects from the US National Heart, Lung, and Blood Institute funded Family Blood Pressure Program comprising 11433 individuals recruited by hypertensive families. The results suggest that only one of the six SNPs might be associated with essential hypertension in Americans of European origin. This SNP shows a significant but opposite effect in Americans of Hispanic origin and no association in African Americans. The significance of the opposing effect estimates is unclear. No replication could be shown for hypertension status, but there are differences in study design. This attempted replication highlights that essential hypertension studies will require more comprehensive and larger genetic screens.

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Leaf Area Index Simulation In Soybean Grown Under Near-Optimal Conditions, T. D. Setiyono, A. Weiss, J. E. Specht, K. G. Cassman, A. Dobermann Jul 2008

Leaf Area Index Simulation In Soybean Grown Under Near-Optimal Conditions, T. D. Setiyono, A. Weiss, J. E. Specht, K. G. Cassman, A. Dobermann

Faculty Publications

Different approaches have been used to simulate leaf area index (LAI) in soybean (Glycine max L. Merr). Many of these approaches require genotype-specific calibration procedures. Studies modeling LAI dynamics under optimal growth conditions with yields close to the yield potential of soybean have remained scarce. A sink-driven approach was developed and evaluated for LAI simulation in soybean under near-optimal environments. The rate of change in expanding leaf area was simulated using the first derivative of a logistic function accounting for plant population density, air temperature, and water deficit. The rate of change in senescing leaf area was also simulated using …

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Highly Efficient Circulating Tumor Cell Isolation From Whole Blood And Label-Free Enumeration Using Polymer-Based Microfluidics With An Integrated Conductivity Sensor, André A. Adams, Paul I. Okagbare, Juan Feng, Matuesz L. Hupert, Don Patterson, Jost Götten, Robin L. Mccarley, Dimitris Nikitopoulos, Michael C. Murphy, Steven A. Soper Jul 2008

Highly Efficient Circulating Tumor Cell Isolation From Whole Blood And Label-Free Enumeration Using Polymer-Based Microfluidics With An Integrated Conductivity Sensor, André A. Adams, Paul I. Okagbare, Juan Feng, Matuesz L. Hupert, Don Patterson, Jost Götten, Robin L. Mccarley, Dimitris Nikitopoulos, Michael C. Murphy, Steven A. Soper

Faculty Publications

A novel microfluidic device that can selectively and specifically isolate exceedingly small numbers of circulating tumor cells (CTCs) through a monoclonal antibody (mAB) mediated process by sampling large input volumes (≥1 mL) of whole blood directly in short time periods (<37 >min) was demonstrated. The CTCs were concentrated into small volumes (190 nL), and the number of cells captured was read without labeling using an integrated conductivity sensor following release from the capture surface. The microfluidic device contained a series (51) of high-aspect ratio microchannels (35 μm width x 150 μm depth) that were replicated in poly(methyl methacrylate), PMMA, from …

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Latitudinal Variation In Leaf And Tree Traits Of The Mangrove Avicennia Germinans (Avicenniaceae) In The Central Region Of The Gulf Of Mexico, Rodrigo Méndez-Alonzo, Jorge López-Portillo, Victor H. Rivera-Monroy Jul 2008

Latitudinal Variation In Leaf And Tree Traits Of The Mangrove Avicennia Germinans (Avicenniaceae) In The Central Region Of The Gulf Of Mexico, Rodrigo Méndez-Alonzo, Jorge López-Portillo, Victor H. Rivera-Monroy

Faculty Publications

The variation in leaf mass per area, leaf nutrients (% carbon, nitrogen and phosphorus), and the allometric relation between tree height and diameter of the black mangrove, Avicennia germinans, were explored in nine mangrove forests in similar environments along a 50 latitudinal gradient in the central region of the Gulf of Mexico, as indicated by a southward increase in temperature and precipitation. There was no correlation between leaf nitrogen or phosphorus content and latitude. Leaf mass per area and leaf carbon content were positively correlated with latitude and negatively correlated with temperature and annual rainfall, whereas asymptotic tree height and …

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Weak Competition Among Tropical Tree Seedlings: Implications For Species Coexistence, C. E.Timothy Paine, Kyle E. Harms, Stefan A. Schnitzer, Walter P. Carson Jul 2008

Weak Competition Among Tropical Tree Seedlings: Implications For Species Coexistence, C. E.Timothy Paine, Kyle E. Harms, Stefan A. Schnitzer, Walter P. Carson

Faculty Publications

The intensity of competition among forest tree seedlings is poorly understood, but has important ramifications for their recruitment and for the maintenance of species diversity. Intense competition among seedlings could allow competitively dominant species to exclude subordinate species. Alternatively, the low density and small stature of forest tree seedlings could preclude intense interseedling competition. In this case, other processes, such as size-asymmetric competition with adults, interactions with consumers, or neutral dynamics would prevail as those structuring the forest understory. We tested the intensity of, and potential for, intraspecific competition among tree seedlings of three species (Brosimum alicastrum, Matisia cordata, and …

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