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Articles 10111 - 10140 of 13624

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High Throughput Virus-Induced Gene Silencing Implicates Heat Shock Protein 90 In Plant Disease Resistance, Rui Lu, Isabelle Malcuit, Peter Moffett, Maria T. Ruiz, Jack Peart, Ai Jiuan Wu, John P. Rathjen, Abdelhafid Bendahmane, Louise Day, David C. Baulcombe Nov 2003

High Throughput Virus-Induced Gene Silencing Implicates Heat Shock Protein 90 In Plant Disease Resistance, Rui Lu, Isabelle Malcuit, Peter Moffett, Maria T. Ruiz, Jack Peart, Ai Jiuan Wu, John P. Rathjen, Abdelhafid Bendahmane, Louise Day, David C. Baulcombe

Faculty Publications

Virus-induced gene silencing was used to assess the function of random Nicotiana benthamiana cDNAs in disease resistance. Out of 4992 cDNAs tested from a normalized library, there were 79 that suppressed a hypersensitive response (HR) associated with Pto-mediated resistance against Pseudomonas syringae. However, only six of these clones blocked the Pto-mediated suppression of P. syringae growth. The three clones giving the strongest loss of Pto resistance had inserts corresponding to HSP90 and also caused loss of Rx-mediated resistance against potato virus X and N-mediated tobacco mosaic virus resistance. The role of HSP90 as a cofactor of disease resistance is associated …

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Methods For Estimating Long-Distance Dispersal, Ran Nathan, Gad Perry, James T. Cronin, Allan E. Strand, Michael L. Cain Nov 2003

Methods For Estimating Long-Distance Dispersal, Ran Nathan, Gad Perry, James T. Cronin, Allan E. Strand, Michael L. Cain

Faculty Publications

Long-distance dispersal (LDD) includes events in which propagules arrive, but do not necessarily establish, at a site far removed from their origin. Although important in a variety of ecological contexts, the system-specific nature of LDD makes "far removed" difficult to quantify, partly, but not exclusively, because of inherent uncertainty typically involved with the highly stochastic LDD processes. We critically review the main methods employed in studies of dispersal, in order to facilitate the evaluation of their pertinence to specific aspects of LDD research. Using a novel classification framework, we identify six main methodological groups: biogeographical; Eulerian and Lagrangian movement/redistributional; short-term …

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Identification Of Three Genomic Haplotypes 5′ To The Human Cd1d Gene And Their Distribution In Four Ethnic Groups, Q. Y. Chen, N. Jackson, A. Vargas, S. Chalew, J. Rao, M. Batzer, M. S. Lan, Y. H. Chang, M. Mokhashi, D. Liu Nov 2003

Identification Of Three Genomic Haplotypes 5′ To The Human Cd1d Gene And Their Distribution In Four Ethnic Groups, Q. Y. Chen, N. Jackson, A. Vargas, S. Chalew, J. Rao, M. Batzer, M. S. Lan, Y. H. Chang, M. Mokhashi, D. Liu

Faculty Publications

CD1d presents lipid antigen to a conserved population of natural killer (NK) T cells, which participate in host immune defense, tumor cell rejection and suppression of autoimmunity. The levels of human CD1d expression vary significantly between individuals. To understand such variation, we sequenced the region up to 1.7 kb 5′ upstream of the translation start site and partially through exon 2 in 44 white Americans. We also studied two tagged single nucleotide polymorphisms (SNP) in 112 white Americans, 60 African-Americans, 88 Europeans, and 84 Chinese people from the region. Six SNP present in the region (-836C→T, -773C→T, -764C→G, -713A→T, -365A→G …

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An Analysis Of Single Clutch Paternity In The Burrower Bug Sehirus Cinctus Using Microsatellites, Jeremy M. Brown, Aneil F. Agrawal, Edmund D. Brodie Nov 2003

An Analysis Of Single Clutch Paternity In The Burrower Bug Sehirus Cinctus Using Microsatellites, Jeremy M. Brown, Aneil F. Agrawal, Edmund D. Brodie

Faculty Publications

Recent studies of the burrower bug, Sehirus cinctus, have examined the genetic basis of parental care. An understanding of the burrower bug mating system, and the subsequent pattern of offspring relatedness that this system generates, is critical to further interpret genetic data. To this end, we developed three consistently amplifiable highly polymorphic microsatellite loci and used them to determine genotypic patterns at the level of both the population and the single clutch. We found that all clutches were sired by single males. Further, we find no evidence for inbreeding. We hypothesize that single paternity within a clutch may play an …

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Pelvic Sexual Dimorphism In A Metatherian, Didelphis Virginiana: Implications For Eutherians, Robert G. Tague Nov 2003

Pelvic Sexual Dimorphism In A Metatherian, Didelphis Virginiana: Implications For Eutherians, Robert G. Tague

Faculty Publications

Eutherians give birth to relatively large infants. Females have larger pelves than males, though males typically have larger nonpelvic bones. Pelvic dimorphism is an adaptation for parturition. Metatherian females, who give birth to markedly small infants, should not show pelvic adaptations for parturition and should have smaller pelves than males. Adult females and males of the Virginia opossum, Didelphis virginiana, are compared. Males are significantly larger than females in absolute size for 14 of 16 pelvic and 8 nonpelvic measures. Sexes did not differ significantly for lower iliac length and posterior space of midplane. However, relative lengths for females are …

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Similar Gene Structure Of Two Sox9a Genes And Their Expression Patterns During Gonadal Differentiation In A Teleost Fish, Rice Field Eel (Monopterus Albus), Rongjia Zhou, Li Liu, Yiqing Guo, Hongshi Yu, Hanhua Cheng, Xiao Huang, Terrence R. Tiersch, Philippe Berta Nov 2003

Similar Gene Structure Of Two Sox9a Genes And Their Expression Patterns During Gonadal Differentiation In A Teleost Fish, Rice Field Eel (Monopterus Albus), Rongjia Zhou, Li Liu, Yiqing Guo, Hongshi Yu, Hanhua Cheng, Xiao Huang, Terrence R. Tiersch, Philippe Berta

Faculty Publications

The Sox9 gene encodes a transcription factor that is critical for testis determination and chondrogenesis in vertebrates. Mutations in human SOX9 cause campomelic dysplasia, a dominant skeletal dysmorphology syndrome often associated with male to female sex reversal. Here we show that the Sox9a gene was duplicated during evolution of the rice field eel, Monopterus albus, a freshwater fish which undergoes natural sex reversal from female to male during its life, and has a haploid genome size (0.6-0.8 pg) that is among the smallest of the vertebrates. The duplicated copies of the gene (named Sox9a1 and Sox9a2) fit within the Sox9 …

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Alu Elements And Hominid Phylogenetics, Abdel Halim Salem, David A. Ray, Jinchuan Xing, Pauline A. Callinan, Jeremy S. Myers, Dale J. Hedges, Randall K. Garber, David J. Witherspoon, Lynn B. Jorde, Mark A. Batzer Oct 2003

Alu Elements And Hominid Phylogenetics, Abdel Halim Salem, David A. Ray, Jinchuan Xing, Pauline A. Callinan, Jeremy S. Myers, Dale J. Hedges, Randall K. Garber, David J. Witherspoon, Lynn B. Jorde, Mark A. Batzer

Faculty Publications

Alu elements have inserted in primate genomes throughout the evolution of the order. One particular Alu lineage (Ye) began amplifying relatively early in hominid evolution and continued propagating at a low level as many of its members are found in a variety of hominid genomes. This study represents the first conclusive application of short interspersed elements, which are considered nearly homoplasy-free, to elucidate the phylogeny of hominids. Phylogenetic analysis of Alu Ye5 elements and elements from several other subfamilies reveals high levels of support for monophyly of Hominidae, tribe Hominini and subtribe Hominina. Here we present the strongest evidence reported …

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Comprehensive Analysis Of Alu-Associated Diversity On The Human Sex Chromosomes, Pauline A. Callinan, Dale J. Hedges, Abdel Halim Salem, Jinchuan Xing, Jerilyn A. Walker, Randall K. Garber, W. Scott Watkins, Michael J. Bamshad, Lynn B. Jorde, Mark A. Batzer Oct 2003

Comprehensive Analysis Of Alu-Associated Diversity On The Human Sex Chromosomes, Pauline A. Callinan, Dale J. Hedges, Abdel Halim Salem, Jinchuan Xing, Jerilyn A. Walker, Randall K. Garber, W. Scott Watkins, Michael J. Bamshad, Lynn B. Jorde, Mark A. Batzer

Faculty Publications

A comprehensive analysis of the human sex chromosomes was undertaken to assess Alu-associated human genomic diversity and to identify novel Alu insertion polymorphisms for the study of human evolution. Three hundred forty-five recently integrated Alu elements from eight different Alu subfamilies were identified on the X and Y chromosomes, 225 of which were selected and analyzed by polymerase chain reaction (PCR). From a total of 225 elements analyzed, 16 were found to be polymorphic on the X chromosome and one on the Y chromosome. In line with previous research using other classes of genetic markers, our results indicate reduced Alu-associated …

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Molecular Characterization Of Brucella Abortus Chromosome Ii Recombination, Georgios Tsoktouridis, Christian A. Merz, Simon P. Manning, Renée Giovagnoli-Kurtz, Leanne E. Williams, Cesar V. Mujer, Sue Hagius, Philip Elzer, Rajendra J. Redkar, Guy Patra, Vito G. Delvecchio Oct 2003

Molecular Characterization Of Brucella Abortus Chromosome Ii Recombination, Georgios Tsoktouridis, Christian A. Merz, Simon P. Manning, Renée Giovagnoli-Kurtz, Leanne E. Williams, Cesar V. Mujer, Sue Hagius, Philip Elzer, Rajendra J. Redkar, Guy Patra, Vito G. Delvecchio

Faculty Publications

Large-scale genomic rearrangements including inversions, deletions, and duplications are significant in bacterial evolution. The recently completed Brucella melitensis 16M and Brucella suis 1330 genomes have facilitated the investigation of such events in the Brucella spp. Suppressive subtractive hybridization (SSH) was employed in identifying genomic differences between B. melitensis 16M and Brucella abortus 2308. Analysis of 45 SSH clones revealed several deletions on chromosomes of B. abortus and B. melitensis that encoded proteins of various metabolic pathways. A 640-kb inversion on chromosome II of B. abortus has been reported previously (S. Michaux Charachon, G. Bourg, E. Jumas Bilak, P. Guigue Talet, …

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Louisiana Agriculture Fall, 2003, Lsu Agcenter Oct 2003

Louisiana Agriculture Fall, 2003, Lsu Agcenter

Louisiana Agriculture

No abstract provided.

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Thermodynamics Of The Binding Of Thermus Aquaticus Dna Polymerase To Primed-Template Dna, Kausiki Datta, Vince J. Licata Oct 2003

Thermodynamics Of The Binding Of Thermus Aquaticus Dna Polymerase To Primed-Template Dna, Kausiki Datta, Vince J. Licata

Faculty Publications

DNA binding of the Type 1 DNA polymerase from Thermus aquaticus (Taq polymerase) and its Klentaq large fragment domain have been studied as a function of temperature. Equilibrium binding assays were performed from 5 to 70°C using a fluorescence anisotropy assay and from 10 to 60°C using isothermal titration calorimetry. In contrast to the usual behavior of thermophilic proteins at low temperatures, Taq and Klentaq bind DNA with high affinity at temperatures down to 5°C. The affinity is maximal at 40-50°C. The ΔH and ΔS of binding are highly temperature dependent, and the ΔCp of binding is -0.7 to -0.8 …

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Mitochondrial Mrna Stability And Polyadenylation During Anoxia-Induced Quiescence In The Brine Shrimp Artemia Franciscana, Brian D. Eads, Steven C. Hand Oct 2003

Mitochondrial Mrna Stability And Polyadenylation During Anoxia-Induced Quiescence In The Brine Shrimp Artemia Franciscana, Brian D. Eads, Steven C. Hand

Faculty Publications

Polyadenylation of messenger RNA is known to be an important mechanism for regulating mRNA stability in a variety of systems, including bacteria, chloroplasts and plant mitochondria. By comparison, little is known about the role played by polyadenylation in animal mitochondrial gene expression. We have used embryos of the brine shrimp Artemia franciscana to test hypotheses regarding message stability and polyadenylation under conditions simulating anoxia-induced quiescence. In response to anoxia, these embryos undergo a profound and acute metabolic downregulation, characterized by a steep drop in intracellular pH (pHi) and ATP levels. Using dot blots of total mitochondrial RNA, we show that …

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The Effect Of Density-Dependent Catastrophes On Population Persistence Time, Chris Wilcox, Bret Elderd Oct 2003

The Effect Of Density-Dependent Catastrophes On Population Persistence Time, Chris Wilcox, Bret Elderd

Faculty Publications

1. There has been increasing recognition that catastrophes are an important factor in modelling threatened populations. However, density dependence has generally been omitted from models of threatened populations on the assumption that this omission yields conservative predictions. We explore the significance of including density-dependent catastrophes in models of threatened populations. 2. Using an analytical model, we show that density-dependent catastrophes have a significant effect on population persistence, decreasing mean persistence time at large population sizes and causing a relative increase at intermediate sizes. 3. We illustrate our results with empirical data from a disease outbreak in crabeater seals Lobodon carcinophagus …

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Comparative Thermal Denaturation Of Thermus Aquaticus And Escherichia Coli Type 1 Dna Polymerases, Irene Karantzeni, Carmen Ruiz, Chin Chi Liu, Vince J. Licata Sep 2003

Comparative Thermal Denaturation Of Thermus Aquaticus And Escherichia Coli Type 1 Dna Polymerases, Irene Karantzeni, Carmen Ruiz, Chin Chi Liu, Vince J. Licata

Faculty Publications

Thermal denaturations of the type 1 DNA polymerases from Thermus aquaticus (Taq polymerase) and Escherichia coli (Pol 1) have been examined using differential scanning calorimetry and CD spectroscopy. The full-length proteins are single-polypeptide chains comprising a polymerase domain, a proofreading domain (inactive in Taq) and a 5′ nuclease domain. Removal of the 5′ nuclease domains produces the 'large fragment' domains of Pol 1 and Taq, termed Klenow and Klentaq respectively. Although the high temperature stability of Taq polymerase is well known, its thermal denaturation has never been directly examined previously. Thermal denaturations of both species of polymerase are irreversible, precluding …

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Scientific Collaboratories In Higher Education: Exploring Learning Style Preferences And Perceptions Of Technology, Diane H. Sonnenwald, Bin Li Sep 2003

Scientific Collaboratories In Higher Education: Exploring Learning Style Preferences And Perceptions Of Technology, Diane H. Sonnenwald, Bin Li

Faculty Publications

Scientific collaboratories hold the promise of providing students access to specialized scientific instruments, data and experts, enabling learning opportunities perhaps otherwise not available. However, evaluation of scientific collaboratories in higher education has lagged behind their development. We conducted a repeated-measures study that provided data regarding social interaction learning styles and perceptions of a scientific collaboratory system from 40 university science students working face-to-face and remotely. Students with a strong competitive learning style preference or who worked with a student with a strong competitive learning style reported a slightly more positive perception of the relative advantage, compatibility and complexity of the …

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Salt Modulates The Stability And Lipid Binding Affinity Of The Adipocyte Lipid-Binding Protein, Allyn J. Schoeffler, Carmen R. Ruiz, Allison M. Joubert, Xuemei Yang, Vince J. Licata Aug 2003

Salt Modulates The Stability And Lipid Binding Affinity Of The Adipocyte Lipid-Binding Protein, Allyn J. Schoeffler, Carmen R. Ruiz, Allison M. Joubert, Xuemei Yang, Vince J. Licata

Faculty Publications

Adipocyte lipid-binding protein (ALBP or aP2) is an intracellular fatty acid-binding protein that is found in adipocytes and macrophages and binds a large variety of intracellular lipids with high affinity. Although intracellular lipids are frequently charged, biochemical studies of lipid-binding proteins and their interactions often focus most heavily on the hydrophobic aspects of these proteins and their interactions. In this study, we have characterized the effects of KCl on the stability and lipid binding properties of ALBP. We find that added salt dramatically stabilizes ALBP, increasing its ΔG of unfolding by 3-5 kcal/mol. At 37 °C salt can more than …

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Advances In Satellite Radiometry For The Surveillance Of Surface Temperatures, Ocean Eddies And Upwelling Processes In The Gulf Of Mexico Using Goes-8 Measurements During Summer, Nan Walker, Soe Myint, Adele Babin, Alaric Haag Aug 2003

Advances In Satellite Radiometry For The Surveillance Of Surface Temperatures, Ocean Eddies And Upwelling Processes In The Gulf Of Mexico Using Goes-8 Measurements During Summer, Nan Walker, Soe Myint, Adele Babin, Alaric Haag

Faculty Publications

GOES-8 satellite infrared (IR) measurements have been under-utilized in oceanographic research, although they provide several advantages over measurements from other sensors such as the NOAA AVHRR. Frequent coverage (48 times/day) over large regions, low noise in the mid- IR channel, and sole use of nighttime data have enabled the development of improved techniques for producing "de-clouded" images and calculating accurate SSTs (with RMS errors < 0.5°C), over cloudy and humid regions such as the Gulf of Mexico. Animations of SST composite images reveal movements of the Loop Current, its frontal eddies and coastal upwelling even during summer months. GOES-12 and future GOES imagers for the next decade are missing the 12 μm channel; however, this study demonstrates that the mid-IR channel is even more useful than previously thought.

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Development And Evolution Of The Amniote Integument: Current Landscape And Future Horizon, Cheng Ming Chuong, Dominique G. Homberger Aug 2003

Development And Evolution Of The Amniote Integument: Current Landscape And Future Horizon, Cheng Ming Chuong, Dominique G. Homberger

Faculty Publications

This special issue on the development and evolution of the amniote integument begins with a discussion of the adaptations to terrestrial conditions, the acquisition of water-impermeability by the reptilian integument, and the initial formation of filamentous integumentary appendages that pave the way towards avian flight. Recent feather fossils are reviewed and a definition of feathers is developed. Hierarchical models are proposed for the formation of complex structures, such as feathers. Molecular signals that alter the phenotype of integumentary appendages at different levels of the hierarchy are presented. Tissue interactions and the roles of keratins in evolution are discussed and linked …

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Following The Lines: An Analysis Of Primate Genomic Variation At Human-Specific Line-1 Insertion Sites, Bethaney J. Vincent, Jeremy S. Myers, Huei Jin Ho, Gail E. Kilroy, Jerilyn A. Walker, W. Scott Watkins, Lynn B. Jorde, Mark A. Batzer Aug 2003

Following The Lines: An Analysis Of Primate Genomic Variation At Human-Specific Line-1 Insertion Sites, Bethaney J. Vincent, Jeremy S. Myers, Huei Jin Ho, Gail E. Kilroy, Jerilyn A. Walker, W. Scott Watkins, Lynn B. Jorde, Mark A. Batzer

Faculty Publications

The L1 Ta subfamily of long interspersed elements (LINEs) consists exclusively of human-specific L1 elements. Polymerase chain reaction-based screening in nonhuman primate genomes of the orthologous sites for 249 human L1 Ta elements resulted in the recovery of various types of sequence variants for approximately 12% of these loci. Sequence analysis was employed to capture the nature of the observed variation and to determine the levels of gene conversion and insertion site homoplasy associated with LINE elements. Half of the orthologous loci differed from the predicted sizes due to localized sequence variants that occurred as a result of common mutational …

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Recently Integrated Alu Elements And Human Genomic Diversity, Abdel Halim Salem, Gail E. Kilroy, W. Scott Watkins, Lynn B. Jorde, Mark A. Batzer Aug 2003

Recently Integrated Alu Elements And Human Genomic Diversity, Abdel Halim Salem, Gail E. Kilroy, W. Scott Watkins, Lynn B. Jorde, Mark A. Batzer

Faculty Publications

A comprehensive analysis of two Alu Y lineage subfamilies was undertaken to assess Alu-associated genomic diversity and identify new Alu insertion polymorphisms for the study of human population genetics. Recently integrated Alu elements (283) from the Yg6 and Yi6 subfamilies were analyzed by polymerase chain reaction (PCR), and 25 of the loci analyzed were polymorphic for insertion presence/absence within the genomes of a diverse array of human populations. These newly identified Alu insertion polymorphisms will be useful tools for the study of human genomic diversity. Our screening of the Alu insertion loci also resulted in the recovery of several "young" …

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Surface Salt Bridges Modulate Dna Wrapping By The Type Ii Dna-Binding Protein Tf1, Anne Grove Jul 2003

Surface Salt Bridges Modulate Dna Wrapping By The Type Ii Dna-Binding Protein Tf1, Anne Grove

Faculty Publications

The histone-like protein HU is involved in compaction of the bacterial genome. Up to 37 bp of DNA may be wrapped about some HU homologues in a process that has been proposed to depend on a linked disruption of surface salt bridges that liberates cationic side chains for interaction with the DNA. Despite significant sequence conservation between HU homologues, binding sites from 9 to 37 bp have been reported. TF1, an HU homologue that is encoded by Bacillus subtilis bacteriophage SPO1, has nM affinity for 37 bp preferred sites in DNA with 5-hydroxymethyluracil (hmU) in place of thymine. On the …

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Maxizyme-Mediated Specific Inhibition On Mutant-Type P53 In Vitro, Xin Juan Kong, Yu Hu Song, Ju Sheng Lin, Huan Jun Huang, Nan Xia Wang, Nan Zhi Liu, Bin Li, You Xin Jin Jul 2003

Maxizyme-Mediated Specific Inhibition On Mutant-Type P53 In Vitro, Xin Juan Kong, Yu Hu Song, Ju Sheng Lin, Huan Jun Huang, Nan Xia Wang, Nan Zhi Liu, Bin Li, You Xin Jin

Faculty Publications

Aim: To evaluate the specific inhibition of maxizyme directing against mutant-type p53 gene (mtp53) at codon 249 in exon 7 (AGG→AGT) in vitro. Methods: Two different monomers of anti-mtp53 maxizyme (maxizyme right MzR, maxizyme left MzL) and control mutant maxizyme (G5→A5) were designed by computer and cloned into vector pBSKU6 (pBSKU6MzR, pBSKU6MzL). After being sequenced, the restrictive endonuclease site in pBSKU6MzR was changed by PCR and then U6MzR was inserted into pBSKU6MzL, the recombinant vector was named pU6Mz and pU6asMz (mutant maxizyme). Mtp53 and wild-type p53 (wtp53) gene fragments were cloned into pGEM-T vector under the T7 promoter control. The …

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Global Conformations, Hydrodynamics, And X-Ray Scattering Properties Of Taq And Escherichia Coli Dna Polymerases In Solution, Allison M. Joubert, Angela S. Byrd, Vince J. Licata Jul 2003

Global Conformations, Hydrodynamics, And X-Ray Scattering Properties Of Taq And Escherichia Coli Dna Polymerases In Solution, Allison M. Joubert, Angela S. Byrd, Vince J. Licata

Faculty Publications

Escherichia coli polymerase 1 (Pol 1) and Thermus aquaticus Taq polymerase are homologous Type I DNA polymerases, each comprised of a polymerase domain, a proofreading domain (inactive in Taq), and a 5′ nuclease domain. "Klenow" and "Klentaq" are the large fragments of Pol 1 and Taq and are functional polymerases lacking the 5′ nuclease domain. In the available crystal structures of full-length Taq, the 5′ nuclease domain is positioned in two different orientations: in one structure, it is extended out into solution, whereas in the other, it is folded up against the polymerase domain in a more compact structure. Analytical …

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Stereoselective In Vitro Formation Of C-Type Cytochrome Variants From Hydrogenobacter Thermophilus Containing Only A Single Thioether Bond, Oliver Daltrop, Kevin M. Smith, Stuart J. Ferguson Jul 2003

Stereoselective In Vitro Formation Of C-Type Cytochrome Variants From Hydrogenobacter Thermophilus Containing Only A Single Thioether Bond, Oliver Daltrop, Kevin M. Smith, Stuart J. Ferguson

Faculty Publications

In vitro formation of Hydrogenobacter thermophilus cytochrome c 552 has previously been demonstrated (Daltrop, O., Allen, J. W. A., Willis, A. C., and Ferguson, S. J. (2002) Proc. Natl. Acad. Sci. U. S. A. 99, 7872-7876). Now we report that the single cysteine variants of H. thermophilus c552, which bind heme via a single thioether bond, also form in vitro. Furthermore, reaction of the apocytochromes containing either AXXCH or CXXAH in the binding motif with 2-vinyldeuteroheme and 4-vinyldeuteroheme resulted predominantly in covalent attachment between Cys-11 and the 2-vinyl moiety and Cys-14 and the 4-vinyl functionality. This observation shows that the …

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Global Patterns Of Dissolved N, P And Si In Large Rivers, R. Eugene Turner, Nancy N. Rabalais, D. Justic', Q. Dortch Jul 2003

Global Patterns Of Dissolved N, P And Si In Large Rivers, R. Eugene Turner, Nancy N. Rabalais, D. Justic', Q. Dortch

Faculty Publications

The concentration of dissolved inorganic nitrogen (DIN), dissolved nitrate-N, Total-N (TN), dissolved inorganic phosphate (DIP), total phosphorus (TP), dissolved silicate-Si (DSi) and their ratios in the world's largest rivers are examined using a global data base that includes 37% of the earth's watershed area and half its population. These data were compared to water quality in 42 subbasins of the relatively well-monitored Mississippi River basin (MRB) and of 82 small watersheds of the United States. The average total nitrogen concentration varies over three orders of magnitude among both world river watersheds and the MRB, and is primarily dependent on variations …

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Methacholine-Induced Airway Hyperresponsiveness Is Dependent On GαQ Signaling, Michael T. Borchers, T. Biechele, J. P. Justice, T. Ansay, S. Cormier, V. Mancino, T. M. Wilkie, M. I. Simon, N. A. Lee, J. J. Lee Jul 2003

Methacholine-Induced Airway Hyperresponsiveness Is Dependent On GαQ Signaling, Michael T. Borchers, T. Biechele, J. P. Justice, T. Ansay, S. Cormier, V. Mancino, T. M. Wilkie, M. I. Simon, N. A. Lee, J. J. Lee

Faculty Publications

Airway function in health and disease as well as in response to bronchospastic stimuli (i.e., irritants, allergens, and inflammatory mediators) is controlled, in part, by cholinergic muscarinic receptor regulation of smooth muscle. In particular, the dependence of airway smooth muscle contraction/relaxation on heterotrimeric G protein-coupled receptor signaling suggests that these events underlie the responses regulating airway function. Gαq-containing G proteins are proposed to be a prominent signaling pathway, and the availability of knockout mice deficient of this subunit has allowed for an investigation of its potential role in airway function. Airway responses in Gαq-deficient mice (activities assessed by both tracheal …

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Genetic Variation Among World Populations: Inferences From 100 Alu Insertion Polymorphisms, W. Scott Watkins, Alan R. Rogers, Christopher T. Ostler, Steve Wooding, Michael J. Bamshad, Anna Marie E. Brassington, Marion L. Carroll, Son V. Nguyen, Jerilyn A. Walker, B. V.Ravi Prasad, P. Govinda Reddy, Pradipta K. Das, Mark A. Batzer, Lynn B. Jorde Jul 2003

Genetic Variation Among World Populations: Inferences From 100 Alu Insertion Polymorphisms, W. Scott Watkins, Alan R. Rogers, Christopher T. Ostler, Steve Wooding, Michael J. Bamshad, Anna Marie E. Brassington, Marion L. Carroll, Son V. Nguyen, Jerilyn A. Walker, B. V.Ravi Prasad, P. Govinda Reddy, Pradipta K. Das, Mark A. Batzer, Lynn B. Jorde

Faculty Publications

We examine the distribution and structure of human genetic diversity for 710 individuals representing 31 populations from Africa, East Asia, Europe, and India using 100 Alu insertion polymorphisms from all 22 autosomes. Alu diversity is highest in Africans (0.349) and lowest in Europeans (0.297). Alu insertion frequency is lowest in Africans (0.463) and higher in Indians (0.544), E. Asians (0.557), and Europeans (0.559). Large genetic distances are observed among African populations and between African and non-African populations. The root of a neighbor-joining network is located closest to the African populations. These findings are consistent with an African origin of modern …

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Contributions Of Atmospheric Co And Hydrogen Uptake To Microbial Dynamics On Recent Hawaiian Volcanic Deposits, Gary M. King Jul 2003

Contributions Of Atmospheric Co And Hydrogen Uptake To Microbial Dynamics On Recent Hawaiian Volcanic Deposits, Gary M. King

Faculty Publications

A series of sites were established on Hawaiian volcanic deposits ranging from about 18 to 300 years old. Three sites occurred in areas that supported tropical rain forests; the remaining sites were in areas that supported little or no plant growth. Sites >26 years old consumed atmospheric CO and hydrogen at rates ranging from about 0.2 to 5 mg of CO m-2 day-1 and 0.1 to 4 mg of H2 m-2 day-1, respectively. Respiration, measured as CO2 production, for a subset of the sites ranged from about 40 to > 1,400 mg of CO2 m-2 day-1. CO and H2 accounted for …

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Common And Distinguishing Regulatory And Expression Characteristics Of The Highly Related Korb Proteins Of Streptomycete Plasmids Pij101 And Psb24.2, Matthew J. Ducote, Gregg S. Pettis Jul 2003

Common And Distinguishing Regulatory And Expression Characteristics Of The Highly Related Korb Proteins Of Streptomycete Plasmids Pij101 And Psb24.2, Matthew J. Ducote, Gregg S. Pettis

Faculty Publications

The conjugative plasmid pIJ101 of the spore-forming bacterium Streptomyces lividans contains a regulatory gene, korB, whose product is required to repress potentially lethal expression of the pIJ101 kilB gene. The KorB protein also auto-regulates korB gene expression and may be involved in control of pIJ101 copy number. KorB (pIJ101) is expressed as a 10-kDa protein in S. lividans that is immediately processed to a mature 6-kDa repressor molecule. The conjugative Streptomyces cyanogenus plasmid pSB24.1 is deleted upon entry into S. lividans to form pSB24.2, a nonconjugative derivative that contains a korB gene nearly identical to that of pIJ101. Previous evidence …

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Evidence Of An Association Among Age-Related Changes In Physical, Psychomotor And Autonomic Function, Robert H. Wood, Jan M. Hondzinski, C. Matthew Lee Jul 2003

Evidence Of An Association Among Age-Related Changes In Physical, Psychomotor And Autonomic Function, Robert H. Wood, Jan M. Hondzinski, C. Matthew Lee

Faculty Publications

Background: autonomic modulation of the heart, as measured by heart rate variability, is directly associated with cardiorespiratory fitness and inversely associated with all-cause mortality. The extent to which cardiorespiratory fitness and heart rate variability are related in older adults is difficult to ascertain due to difficulties in assessing physical fitness among older age groups. Objective: to examine heart rate variability and measures of physical function, thereby allowing for the inclusion of a greater cross-section of older adults than can be tested using traditional fitness tests. Methods: 39 older adults (mean age: 73.2±8.1 years; range=60-93 years) underwent evaluation of short-term (5 …

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