Open Access. Powered by Scholars. Published by Universities.®

Life Sciences Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1 - 30 of 107

Full-Text Articles in Life Sciences

Sequence Conservation In The C-Terminal Region Of Spider Silk Proteins (Spidroin) From Nephila Clavipes (Tetragnathidae) And Araneus Bicentenarius (Araneidae), Richard D. Beckwitt, Steven Arcidiacono Dec 2012

Sequence Conservation In The C-Terminal Region Of Spider Silk Proteins (Spidroin) From Nephila Clavipes (Tetragnathidae) And Araneus Bicentenarius (Araneidae), Richard D. Beckwitt, Steven Arcidiacono

Richard D Beckwitt

The Polymerase Chain Reaction (PCR) has been used to amplify the portion of the Spidroin 1 gene that codes for the C-terminal part of the silk protein of the spider Nephila clavipes. Along with some substitution mutations of minor consequence, the PCR-derived sequence reveals an additional base missing from the previously published Nephila Spidroin 1 sequence. Comparison of the PCR-derived sequence with the equivalent region of Spidroin 2 indicates that the insertion of this single base results in greatly increased similarity in the resulting amino acid sequences of Spidroin 1 and Spidroin 2 (75% over 97 amino acids). The same …


Dynamic Adaptation Of Liver Mitochondria To Chronic Alcohol Feeding In Mice: Biogenesis, Remodeling, And Functional Alterations, Derick Han, Maria Ybanez, Heather Johnson, Janiece Mcdonald, Lusine Mesropyan, Harsh Sancheti, Gary Martin, Alanna Martin, Atalie Lim, Lily Dara, Enrique Cadenas, Hidekazu Tsukamoto, Niel Kaplowitz Dec 2012

Dynamic Adaptation Of Liver Mitochondria To Chronic Alcohol Feeding In Mice: Biogenesis, Remodeling, And Functional Alterations, Derick Han, Maria Ybanez, Heather Johnson, Janiece Mcdonald, Lusine Mesropyan, Harsh Sancheti, Gary Martin, Alanna Martin, Atalie Lim, Lily Dara, Enrique Cadenas, Hidekazu Tsukamoto, Niel Kaplowitz

Gary Martin

Liver mitochondria undergo dynamic alterations following chronic alcohol feeding to mice. Intragastric alcohol feeding to mice resulted in 1) increased state III respiration (109% compared with control) in isolated liver mitochondria, probably due to increased levels of complexes I, IV, and V being incorporated into the respiratory chain; 2) increased mitochondrial NAD+ and NADH levels (∼2-fold), with no change in the redox status; 3) alteration in mitochondrial morphology, with increased numbers of elongated mitochondria; and 4) enhanced mitochondrial biogenesis in the liver, which corresponded with an up-regulation of PGC-1α (peroxisome proliferator-activated receptor γ coactivator-1α). Oral alcohol feeding to mice, which …


The Role Of Olfactory Cues In The Sequential Radiation Of A Gall-Boring Beetle, Mordellistena Convicta, Bradley Rhodes, Catherine Blair, Mizuki Takahashi, Warren Abrahamson Nov 2012

The Role Of Olfactory Cues In The Sequential Radiation Of A Gall-Boring Beetle, Mordellistena Convicta, Bradley Rhodes, Catherine Blair, Mizuki Takahashi, Warren Abrahamson

Warren G. Abrahamson, II

1. Herbivorous insects often have close associations with specific host plants, and their preferences for mating and ovipositing on a specific host-plant species can reproductively isolate populations, facilitating ecological speciation. Volatile emissions from host plants can play a major role in assisting herbivores to locate their natal host plants and thus facilitate assortative mating and host-specific oviposition. 2. The present study investigated the role of host-plant volatiles in host fidelity and oviposition preference of the gall-boring, inquiline beetle, Mordellistena convicta, using Y-tube olfactometers. Previous studies suggest that the gall-boring beetle is undergoing sequential host-associated divergence by utilizing the resources that …


Ecologists Engaging With Communities And Regional Decision-Makers: Organized Oral Session 14 At The 2011 Esa Annual Meeting In Austin, Texas, Nadine Lymn, George Middendorf Nov 2012

Ecologists Engaging With Communities And Regional Decision-Makers: Organized Oral Session 14 At The 2011 Esa Annual Meeting In Austin, Texas, Nadine Lymn, George Middendorf

George Middendorf

No abstract provided.


Ultraviolet Radiation Influences Perch Selection By A Neotropical Poison-Dart Frog, Lee Kats, Gary M. Bucciarelli, David E. Schlais, Andrew R. Blaustein, Barbara A. Han Nov 2012

Ultraviolet Radiation Influences Perch Selection By A Neotropical Poison-Dart Frog, Lee Kats, Gary M. Bucciarelli, David E. Schlais, Andrew R. Blaustein, Barbara A. Han

Lee Kats

Ambient ultraviolet-B radiation can harm amphibian eggs, larvae and adults. However, some amphibians avoid UV-B radiation when given the opportunity. The strawberry poison dart frog, Oophaga pumilio, is diurnal and males vocalize throughout the day in light gaps under forest canopies that expose them to solar radiation. Previous studies have demonstrated that males calling from high perches are more successful at mating than those at lower perches. We investigated whether frogs at higher perches receive more ultraviolet-B than those calling from lower perches. We also investigated whether frogs on perches receiving relatively low ultraviolet-B levels maintained their positions for longer …


Pre-Settlement History May Obscure The Effect Of Forest Fragmentation On Genetic Variation In Eastern Red-Backed Salamanders, Mark Jordan, Douglas Morris, Scott Gibson Nov 2012

Pre-Settlement History May Obscure The Effect Of Forest Fragmentation On Genetic Variation In Eastern Red-Backed Salamanders, Mark Jordan, Douglas Morris, Scott Gibson

Mark A. Jordan

No abstract provided.


The Effects Of Water And Habitat Quality On Amphibian Assemblages In Two Midwest Watersheds, Abel Castaneda, Mark Jordan Nov 2012

The Effects Of Water And Habitat Quality On Amphibian Assemblages In Two Midwest Watersheds, Abel Castaneda, Mark Jordan

Mark A. Jordan

No abstract provided.


Two Different High Throughput Sequencing Approaches Identify Thousands Of De Novo Genomic Markers For The Genetically Depleted Bornean Elephant., Reeta Sharma, Benoit Goossens, Benoit Goossens, Célia Kun-Rodrigues, Tatiana Teixeira, Nurzhafarina Othman, Nurzhafarina Othman, Jason Q. Boone, Nathaniel K. Jue, Craig Obergfell, Rachel J. O'Neill, Lounès Chikhi, Lounès Chikhi, Lounès Chikhi Nov 2012

Two Different High Throughput Sequencing Approaches Identify Thousands Of De Novo Genomic Markers For The Genetically Depleted Bornean Elephant., Reeta Sharma, Benoit Goossens, Benoit Goossens, Célia Kun-Rodrigues, Tatiana Teixeira, Nurzhafarina Othman, Nurzhafarina Othman, Jason Q. Boone, Nathaniel K. Jue, Craig Obergfell, Rachel J. O'Neill, Lounès Chikhi, Lounès Chikhi, Lounès Chikhi

Nathaniel Jue

High throughput sequencing technologies are being applied to an increasing number of model species with a high-quality reference genome. The application and analyses of whole-genome sequence data in non-model species with no prior genomic information are currently under way. Recent sequencing technologies provide new opportunities for gathering genomic data in natural populations, laying the empirical foundation for future research in the field of conservation and population genomics. Here we present the case study of the Bornean elephant, which is the most endangered subspecies of Asian elephant and exhibits very low genetic diversity. We used two different sequencing platforms, the Roche …


The Doublecortin-Related Gene Zyg-8 Is A Microtubule Organizer In Caenorhabditis Elegans Neurons, Jean Bellanger, Juan Cueva, Renee Baran, Garland Tang, Miriam Goodman, Anne Debant Nov 2012

The Doublecortin-Related Gene Zyg-8 Is A Microtubule Organizer In Caenorhabditis Elegans Neurons, Jean Bellanger, Juan Cueva, Renee Baran, Garland Tang, Miriam Goodman, Anne Debant

Renee Baran

Doublecortin-domain containing (DCDC) genes play key roles in the normal and pathological development of the human brain cortex. The origin of the cellular specialisation and the functional redundancy of these microtubule (MT)-associated proteins (MAPs), especially those of Doublecortin (DCX) and Doublecortin-like kinase (DCLKs) genes, is still unclear. The DCX domain has the ability to control MT architecture and bundling. However, the physiological significance of such properties is not fully understood. To address these issues, we sought post-mitotic roles for zyg-8, the sole representative of the DCX–DCLK subfamily of genes in C. elegans. Previously, zyg-8 has been shown to control anaphase-spindle …


Catalogue Of Type Material In The Entomological Collection Of The University Of La Laguna (Canary Islands). I – Arachnida, Ana Reboleira, Antonio Pérez, Nuria Macías-Hernandez, Heriberto López, S. De La Cruz, Pedro Oromí Oct 2012

Catalogue Of Type Material In The Entomological Collection Of The University Of La Laguna (Canary Islands). I – Arachnida, Ana Reboleira, Antonio Pérez, Nuria Macías-Hernandez, Heriberto López, S. De La Cruz, Pedro Oromí

Ana Sofia P.S. Reboleira

A catalogue of arachnid type specimens of the collection kept at the Department of Animal Biology, University of La Laguna (Spain) is presented. It harbours type material of 104 species belonging to 23 families of arachnids, represented by 21 holotypes and 164 paratypes for 23 species of pseudoscorpions, and 49 holotypes, 218 paratypes and 3 syntypes for 81 species of spiders. This collection is using the criteria and standards of the Global Biodiversity Information Facility (GBIF) for cataloguing and computerization of the specimens. Type specimens were checked with the original descriptions, and relevant additional information from original labels not included …


Lusoblothrus, A New Syarinid Pseudoscorpion Genus (Arachnida) From Portugal, Occupying An Isolated Position Within The Holarctic Fauna, Ana Reboleira, Juan Zaragoza, Fernando Gonçalves, Pedro Oromí Oct 2012

Lusoblothrus, A New Syarinid Pseudoscorpion Genus (Arachnida) From Portugal, Occupying An Isolated Position Within The Holarctic Fauna, Ana Reboleira, Juan Zaragoza, Fernando Gonçalves, Pedro Oromí

Ana Sofia P.S. Reboleira

The new pseudoscorpion genus Lusoblothrus of the family Syarinidae is described from a cave in the Algarve region, southern Portugal, to accommodate L. aenigmaticus sp. nov., whose morphological affinities within the Holarctic syarinid fauna are not clear and resembles the Gondwanan genera. This discovery emphasizes the relevance of the Algarve region as a hotspot for relictual hypogean fauna within the Iberian Peninsula.


A Phycoerythrin-Specific Bilin Lyase-Isomerase Controls Blue-Green Chromatic Acclimation In Marine Synechococcus., Wendy Schluchter Oct 2012

A Phycoerythrin-Specific Bilin Lyase-Isomerase Controls Blue-Green Chromatic Acclimation In Marine Synechococcus., Wendy Schluchter

Wendy M Schluchter

No abstract provided.


Effects Of Canola And Corn Oil Mimetic On Jurkat Cells, Gabriela Ion, Kayla Fazio, Juliana A. Akinsete, W. Elaine Hardman Oct 2012

Effects Of Canola And Corn Oil Mimetic On Jurkat Cells, Gabriela Ion, Kayla Fazio, Juliana A. Akinsete, W. Elaine Hardman

Gabriela Ion

BACKGROUND: The Western diet is high in omega-6 fatty acids and low in omega-3 fatty acids. Canola oil contains a healthier omega 3 to omega 6 ratio than corn oil. Jurkat T leukemia cells were treated with free fatty acids mixtures in ratios mimicking that found in commercially available canola oil (7% α-linolenic, 30% linoleic, 54% oleic) or corn oil (59% linoleic, 24% oleic) to determine the cell survival or cell death and changes in expression levels of inflammatory cytokines and receptors following oil treatment. METHODS: Fatty acid uptake was assessed by gas chromatography. Cell survival and cell death were …


Maternal Consumption Of Canola Oil Suppressed Mammary Gland Tumorigenesis In C3(1) Tag Mice Offspring, Gabriela Ion, Juliana A. Akinsete, W. Elaine Hardman Oct 2012

Maternal Consumption Of Canola Oil Suppressed Mammary Gland Tumorigenesis In C3(1) Tag Mice Offspring, Gabriela Ion, Juliana A. Akinsete, W. Elaine Hardman

Gabriela Ion

Background: Maternal consumption of a diet high in omega 6 polyunsaturated fats (n-6 PUFA) has been shown to increase risk whereas a diet high in omega 3 polyunsaturated fats (n-3 PUFA) from fish oil has been shown to decrease risk for mammary gland cancer in female offspring of rats. The aim of this study was to determine whether increasing n-3 PUFA and reducing n-6 PUFA by using canola oil instead of corn oil in the maternal diet might reduce the risk for breast cancer in female offspring. Methods: Female SV 129 mice were divided into two groups and placed on …


Consumption Of High Ω-3 Fatty Acid Diet Suppressed Prostate Tumorigenesis In C3(1) Tag Mice, Juliana Akinsete, Gabriela Ion, Theodore Witte, W. Hardman Oct 2012

Consumption Of High Ω-3 Fatty Acid Diet Suppressed Prostate Tumorigenesis In C3(1) Tag Mice, Juliana Akinsete, Gabriela Ion, Theodore Witte, W. Hardman

Gabriela Ion

Prostate cancer incidence and mortality are high in the Western world and high ω-6/ω-3 PUFA in the Western diet may be a contributing factor. We investigated whether changing from a diet that approximates ω-6 fat content of the Western diet to a high ω-3 fat diet at adulthood might reduce prostate cancer risk. Female SV 129 mice that had consumed a high ω-6 diet containing corn oil for 2 weeks were bred with homozygous C3(1)Tag transgenic male mice. All male offspring were weaned to the corn oil diet (CO) until postpuberty when half of the male offspring were transferred to …


Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis Oct 2012

Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Zhenxiang Xi, Brad Ruhfel, Hanno Schaefer, André Amorim, M. Sugumaran, Kenneth Wurdack, Peter Endress, Merran Matthews, Peter Stevens, Sarah Mathews, Charles Davis

Brad R. Ruhfel

The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas …


Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Peter F. Stevens, Zhenxiang Xi, Brad R. Ruhfel, Hanno Schaefer, André M. Amorim, M. Sugumaran, Kenneth J. Wurdack, Peter K. Endress, Merran L. Matthews, Sarah Mathews, Charles C. Davis Oct 2012

Phylogenomics And A Posteriori Data Partitioning Resolve The Cretaceous Angiosperm Radiation Malpighiales, Peter F. Stevens, Zhenxiang Xi, Brad R. Ruhfel, Hanno Schaefer, André M. Amorim, M. Sugumaran, Kenneth J. Wurdack, Peter K. Endress, Merran L. Matthews, Sarah Mathews, Charles C. Davis

Peter Stevens

The angiosperm order Malpighiales includes ∼16,000 species and constitutes up to 40% of the understory tree diversity in tropical rain forests. Despite remarkable progress in angiosperm systematics during the last 20 y, relationships within Malpighiales remain poorly resolved, possibly owing to its rapid rise during the mid-Cretaceous. Using phylogenomic approaches, including analyses of 82 plastid genes from 58 species, we identified 12 additional clades in Malpighiales and substantially increased resolution along the backbone. This greatly improved phylogeny revealed a dynamic history of shifts in net diversification rates across Malpighiales, with bursts of diversification noted in the Barbados cherries (Malpighiaceae), cocas …


Euscorpius Sicanus (Scorpiones: Euscorpiidae) From Tunisia: Dna Barcoding Confirms Ancient Disjunctions Across The Mediterranean Sea, Matthew R. Graham, Pavel Stoev, Nesrine Akkari, Gergin Blagoev, Victor Fet Oct 2012

Euscorpius Sicanus (Scorpiones: Euscorpiidae) From Tunisia: Dna Barcoding Confirms Ancient Disjunctions Across The Mediterranean Sea, Matthew R. Graham, Pavel Stoev, Nesrine Akkari, Gergin Blagoev, Victor Fet

Victor Fet

We used a DNA barcoding marker (mitochondrial cox1) to investigate the controversial natural occurrence of Euscorpius sicanus (C.L. Koch) in North Africa. We tested this hypothesis by comparing a sample collected from a mountain in Tunisia to disjunct populations in Sardinia, Malta, and Greece. Using these samples, and a few additional Euscorpius spp. from southern Europe as outgroups, we reconstructed the maternal phylogeny. We then used a molecular clock to place the phylogeny in a temporal context. The Tunisian sample grouped closest to a specimen from Sardinia, with both being more distantly related to E. sicanus from Malta, which is …


Comparison Of Phenolic Compounds And Antioxidant Capacities Of Traditional Sorghum Beers With Other Alcoholic Beverages, Fatouma Abdoul-Latif, Romaric G. Bayili, Louis C. Obame, Mamoudou H. Dicko Prof. Oct 2012

Comparison Of Phenolic Compounds And Antioxidant Capacities Of Traditional Sorghum Beers With Other Alcoholic Beverages, Fatouma Abdoul-Latif, Romaric G. Bayili, Louis C. Obame, Mamoudou H. Dicko Prof.

Pr. Mamoudou H. DICKO, PhD

Thirty samples of sorghum beers “dolo” were selected from traditionally fermented household manufacturers from Burkina Faso. Dolo samples were screened for their total phenolic content, proanthocyanidins and putative antioxidant capacities, and were compared with industrial beers and wines. Total phenols were measured using the Folin-Ciocalteu method. Proanthocyanidins content were determined by the method of HCl-butanol hydrolysis. Antioxidant activities were evaluated both with 2,2-diphenyl-1-picrylhydrazyl (DPPH) assay and by the trolox equivalent antioxidant capacity (TEAC) using 2,2’-azinobis(3-ethyl-benzothiazoline-6-sulfonic acid radical) (ABTS•+). The average contents of total phenols and proanthocyanidins were 506 μg GAE/ml of dolo and 45 μg APE/ml of dolo, respectively. An …


Regulatory Elements Of Xenopus Col2a1 Drive Cartilaginous Gene Expression In Transgenic Frogs, Ryan R. Kerney, Brian K. Hall, James Hanken Oct 2012

Regulatory Elements Of Xenopus Col2a1 Drive Cartilaginous Gene Expression In Transgenic Frogs, Ryan R. Kerney, Brian K. Hall, James Hanken

Ryan Kerney

This study characterizes regulatory elements of collagen 2α1 (col2a1) in Xenopus that enable transgene expression in cartilage-forming chondrocytes. The reporters described in this study drive strong cartilage-specific gene expression, which will be a valuable tool for further investigations of Xenopus skeletal development. While endogenous col2a1 mRNA is expressed in many embryonic tissues, its expression becomes restricted to tadpole and adult chondrocytes. This chondrocyte-specific expression is recapitulated by col2a1 reporter constructs, which were tested through I-SceI meganuclease-mediated transgenesis. These constructs contain a portion of the Xenopus tropicalis col2a1 intron, which aligns to a cartilage-specific intronic enhancer that has been well characterized …


Simple, Compact Source For Low-Temperature Air Plasmas, D. Sheehan, J. Lawson, M. Sosa, Richard Long Oct 2012

Simple, Compact Source For Low-Temperature Air Plasmas, D. Sheehan, J. Lawson, M. Sosa, Richard Long

Richard A. Long

A simple, compact source of low-temperature, spatially and temporally uniform air plasma using a Telsa induction coil driver is described. The low-power ionization discharge plasma is localized (2 cm X 0.5 cm X 0.1 cm) and essentially free of arc channels. A Teflon coated rolling cylindrical electrode and dielectric coated ground plate are essential to the source’s operation and allow flat test samples to be readily exposed to the plasma. The plasma is a copious source of ozone and nitrogen oxides. Its effects on various microbes are discussed.


Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam Oct 2012

Individual Cell Growth Rates Of Marine Bacteria, Measured By Bromodeoxyuridine Incorporation, Koji Hamasaki, Richard A. Long, Farooq Azam

Richard A. Long

We tested the application of 5-bromo-2’-deoxyuridine (BrdU), a thymidine analogue that becomes incorporated into DNA during growth, to measure growth rates of individual marine bacteria cells. Immunocytochemical detection of BrdU incorporation into bacterial DNA has the potential for single-cell-based growth measurement. Optimized procedure for immunocytochemistry was applicable to 14 marine heterotrophic bacterial isolates belonging to g-proteobacteria, α-proteobacteria, Cytophaga-Flavobacterium-Bacteroides (CFB) group and Gram-positive bacteria. The relationship between cell-specific fluorescence intensity and specific growth rate was linearly correlated among CFB group isolates, which indicated a potential of the method for quantitative measurement. Analysis of the detection limit indicated …


Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström Oct 2012

Coupling Between Bacterioplankton Species Composition, Population Dynamics, And Organic Matter Degradation, Jarone Pinhassi, Farooq Azam, Johanna Hemphälä, Richard A. Long, Josefina Martinez, Ulla Li Zweifel, Åke Hagström

Richard A. Long

To study the effect of substrate addition on short term bacterial population dynamics and species composition in seawater mesocosms were maintained with water collected off Scripps Pier (La Jolla, California USA) Protein enrichment (BSA) triggered a dynamic response from the microbial food web, whereas enrichment with starch had no effect. In the protein enriched mesocosm the number of both nucleoid-containing cells and metabolically active cells increased by 3.0 X 105 cells ml-1 from Day 1 to Day 4 In the same time period the density of a set of 31 phylogenetically different bacteria (α- and g-Proteobactena as well as Flexibacter-Cytophaga-Bacteroides) …


Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam Oct 2012

Abundant Protein-Containing Particles In The Sea, Richard A. Long, Farooq Azam

Richard A. Long

The interaction of bacteria with particulate organic matter has implications for organic matter cycling and bacterial ecology in the ocean. Until recently, the focus has been on 'classical' particles visible by unaided eye (marine snow) or light microscopy. Recent discoveries of several new types of abundant particles, from sub-micrometer to sub-marine snow, are changing our ideas of the physical and chemical nature of the particle field with which pelagic bacteria interact. Previous workers have discovered polysaccharide-containing (Alcian Blue stainable) transparent exopolymer particles (TEP) ranging from 3 to 100s of micrometers. Looking for additional components of the sub-marine snow particle field, …


Dispositional Depression And Hostility Are Associated With Inflammatory Markers Of Cardiovascular Disease In African Americans, Michael Lipscomb Sep 2012

Dispositional Depression And Hostility Are Associated With Inflammatory Markers Of Cardiovascular Disease In African Americans, Michael Lipscomb

Michael Lipscomb

Prior research has demonstrated that state depressive symptoms and hostility can modulate inflammatory immune responses and directly contribute to cardiovascular disease (CVD) onset and development. Previous studies have not considered the contribution of dispositional depressive symptoms to the inflammatory process. They have also largely excluded African Americans, despite their disproportionate risk for CVD. The first aim of the study was to examine the impact of state and dispositional depression and hostility on CVD-associated inflammatory biomarkers interleukin-6 (IL-6) and C-reactive protein (CRP) in an African American sample. The second aim was to examine synergistic influences of hostility and state and dispositional …


Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen L. Krijgsveld, G. Henk Visser Sep 2012

Daily Energy Expenditure In Precocial Shorebird Chicks: Smaller Species Perform At Higher Levels, Robert Ricklefs, Karen L. Krijgsveld, G. Henk Visser

Robert Ricklefs

We measured daily energy expenditure (DEE) during the development periods of precocial chicks of five species of Arctic shorebirds spanning a broad range in size, in order to investigate the relationships between DEE, body size, and growth rate. We also quantified the effect of weather conditions on the energy expenditure of chicks to establish the impact of cold arctic weather on their time and energy budgets. We used the doubly labeled water method to measure DEE at ambient temperatures in an outside enclosure on the subarctic tundra at Churchill, Manitoba, Canada. Growth rate was highest in the smallest species, and …


Cryptococcal Genotype Influences Immunologic Response And Human Clinical Outcome After Meningitis, Darin L. Wiesner, Oleksandr Moskalenko, Jennifer M. Corcoran, Tami Mcdonald, Melissa A. Rolfes, David B. Meya, Henry Kajumbula, Andrew Kambugu, Paul R. Bohjanen, Joseph F. Knight, David R. Boulware, Kirsten Nielsen Sep 2012

Cryptococcal Genotype Influences Immunologic Response And Human Clinical Outcome After Meningitis, Darin L. Wiesner, Oleksandr Moskalenko, Jennifer M. Corcoran, Tami Mcdonald, Melissa A. Rolfes, David B. Meya, Henry Kajumbula, Andrew Kambugu, Paul R. Bohjanen, Joseph F. Knight, David R. Boulware, Kirsten Nielsen

Tami McDonald

No abstract provided.


Dental Enamel As A Dietary Indicator In Mammals, Peter Lucas, Paul Constantino, Bernard Wood, Brian Lawn Sep 2012

Dental Enamel As A Dietary Indicator In Mammals, Peter Lucas, Paul Constantino, Bernard Wood, Brian Lawn

Paul J. Constantino

The considerable variation in shape, size, structure and properties of the enamel cap covering mammalian teeth is a topic of great evolutionary interest. No existing theories explain how such variations might be fit for the purpose of breaking food particles down. Borrowing from engineering materials science, we use principles of fracture and deformation of solids to provide a quantitative account ofhowmammalian enamelmay be adapted to diet. Particular attention is paid to mammals that feed on ‘hard objects’ such as seeds and dry fruits, the outer casings of which appear to have evolved structures with properties similar to those of enamel. …


Adaptation To Hard-Object Feeding In Sea Otters And Hominins, Paul Constantino, James Lee, Dylan Morris, Peter Lucas, Adam Hartstone-Rose, Wah-Keat Lee, Nathaniel Dominy, Andrew Cunningham, Mark Wagner, Brian Lawn Sep 2012

Adaptation To Hard-Object Feeding In Sea Otters And Hominins, Paul Constantino, James Lee, Dylan Morris, Peter Lucas, Adam Hartstone-Rose, Wah-Keat Lee, Nathaniel Dominy, Andrew Cunningham, Mark Wagner, Brian Lawn

Paul J. Constantino

The large, bunodont postcanine teeth in living sea otters (Enhydra lutris) have been likened to those of certain fossil hominins, particularly the ’robust’ australopiths (genus Paranthropus). We examine this evolutionary convergence by conducting fracture experiments on extracted molar teeth of sea otters and modern humans (Homo sapiens) to determine how load-bearing capacity relates to tooth morphology and enamel material properties. In situ optical microscopy and x-ray imaging during simulated occlusal loading reveal the nature of the fracture patterns. Explicit fracture relations are used to analyze the data and to extrapolate the results from humans to earlier hominins. It is shown …


Fracture Susceptibility Of Worn Teeth, Amanda Keown, Mark Bush, James Lee, Chris Ford, Paul Constantino, Brian Lawn Sep 2012

Fracture Susceptibility Of Worn Teeth, Amanda Keown, Mark Bush, James Lee, Chris Ford, Paul Constantino, Brian Lawn

Paul J. Constantino

An experimental simulation study is made to determine the effects of occlusal wear on the capacity of teeth to resist fracture. Tests are carried out on model dome structures, using glass shells to represent enamel and epoxy filler to represent dentin. The top of the domes are ground and polished to produce flat surfaces of prescribed depths relative to shell thickness. The worn surfaces are then loaded axially with a hard sphere, or a hard or soft flat indenter, to represent extremes of food contacts. The loads required to drive longitudinal cracks around the side walls of the enamel to …