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Coming To America: Multiple Origins Of New World Geckos, Tony Gamble, A. M. Bauer, G. R. Colli, E. Greenbaum, T. R. Jackman, Laurie J. Vitt, Andrew M. Simons Feb 2011

Coming To America: Multiple Origins Of New World Geckos, Tony Gamble, A. M. Bauer, G. R. Colli, E. Greenbaum, T. R. Jackman, Laurie J. Vitt, Andrew M. Simons

Biological Sciences Faculty Research and Publications

Geckos in the Western Hemisphere provide an excellent model to study faunal assembly at a continental scale. We generated a time-calibrated phylogeny, including exemplars of all New World gecko genera, to produce a biogeographic scenario for the New World geckos. Patterns of New World gecko origins are consistent with almost every biogeographic scenario utilized by a terrestrial vertebrate with different New World lineages showing evidence of vicariance, dispersal via temporary land bridge, overseas dispersal, or anthropogenic introductions. We also recovered a strong relationship between clade age and species diversity, with older New World lineages having more species than more recently …


Neuronal Control Of Swimming Behavior: Comparison Of Vertebrate And Invertebrate Model Systems, Olivia Mullins, John Hackett, James T. Buchanan, W. Otto Friesen Feb 2011

Neuronal Control Of Swimming Behavior: Comparison Of Vertebrate And Invertebrate Model Systems, Olivia Mullins, John Hackett, James T. Buchanan, W. Otto Friesen

Biological Sciences Faculty Research and Publications

Swimming movements in the leech and lamprey are highly analogous, and lack homology. Thus, similarities in mechanisms must arise from convergent evolution rather than from common ancestry. Despite over 40 years of parallel investigations into this annelid and primitive vertebrate, a close comparison of the approaches and results of this research is lacking. The present review evaluates the neural mechanisms underlying swimming in these two animals and describes the many similarities that provide intriguing examples of convergent evolution. Specifically, we discuss swim initiation, maintenance and termination, isolated nervous system preparations, neural-circuitry, central oscillators, intersegmental coupling, phase lags, cycle periods and …


Mathematical Model Of Chlorella Minutissima Utex2341 Growth And Lipid Production Under Photoheterotrophic Fermentation Conditions, Jinshui Yang, Ehsan Rasa, Prapakorn Tantayotai, Kate M. Scow, Hong Li Yuan, Krassimira R. Hristova Feb 2011

Mathematical Model Of Chlorella Minutissima Utex2341 Growth And Lipid Production Under Photoheterotrophic Fermentation Conditions, Jinshui Yang, Ehsan Rasa, Prapakorn Tantayotai, Kate M. Scow, Hong Li Yuan, Krassimira R. Hristova

Biological Sciences Faculty Research and Publications

To reduce the cost of algal biomass production, mathematical model was developed for the first time to describe microalgae growth, lipid production and glycerin consumption under photoheterotrophic conditions based on logistic, Luedeking–Piret and Luedeking–Piret-like equations. All experiments were conducted in a 2 L batch reactor without considering CO2 effect on algae’s growth and lipid production. Biomass and lipid production increased with glycerin as carbon source and were well described by the logistic and Luedeking–Piret equations respectively. Model predictions were in satisfactory agreement with measured data and the mode of lipid production was growth-associated. Sensitivity analysis was applied to examine …


Long Island Sound And Climate Change: What Is Going To Happen?, Juliana Barrett Jan 2011

Long Island Sound And Climate Change: What Is Going To Happen?, Juliana Barrett

Wrack Lines

Certain plants and animals can be used as "sentinels", to help us monitor the impacts of a changing climate and warming planet on the ecology and biodiversity of Long Island Sound.


Oxygen Limitation And Tissue Metabolic Potential Of The African Fish Barbus Neumayeri: Roles Of Native Habitat And Acclimatization, Bernard Rees Jan 2011

Oxygen Limitation And Tissue Metabolic Potential Of The African Fish Barbus Neumayeri: Roles Of Native Habitat And Acclimatization, Bernard Rees

Biological Sciences Faculty Publications

Oxygen availability in aquatic habitats is a major environmental factor influencing the ecology, behaviour, and physiology of fishes. This study evaluates the contribution of source population and hypoxic acclimatization of the African fish, Barbus neumayeri, in determining growth and tissue metabolic enzyme activities. Individuals were collected from two sites differing dramatically in concentration of dissolved oxygen (DO), Rwembaita Swamp (annual average DO 1.35 mgO2 L-1) and Inlet Stream West (annual average DO 5.58 mgO2 L-1) in Kibale National Park, Uganda, and reciprocally transplanted using a cage experiment in the field, allowing us to …


Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation And Muscle Histology Using The Crayfish: Student Laboratory Exercises, Brittany Baierlein, Alison L. Thurow, Harold L. Atwood, Robin L. Cooper Jan 2011

Membrane Potentials, Synaptic Responses, Neuronal Circuitry, Neuromodulation And Muscle Histology Using The Crayfish: Student Laboratory Exercises, Brittany Baierlein, Alison L. Thurow, Harold L. Atwood, Robin L. Cooper

Biology Faculty Publications

The purpose of this report is to help develop an understanding of the effects caused by ion gradients across a biological membrane. Two aspects that influence a cell's membrane potential and which we address in these experiments are: (1) Ion concentration of K+ on the outside of the membrane, and (2) the permeability of the membrane to specific ions. The crayfish abdominal extensor muscles are in groupings with some being tonic (slow) and others phasic (fast) in their biochemical and physiological phenotypes, as well as in their structure; the motor neurons that innervate these muscles are correspondingly different in …


Physiological Experimentation With The Crayfish Hindgut: A Student Laboratory Exercise, Ann S. Cooper, Bonnie Leksrisawat, Allison B. Gilberts, A. Joffre Mercier, Robin L. Cooper Jan 2011

Physiological Experimentation With The Crayfish Hindgut: A Student Laboratory Exercise, Ann S. Cooper, Bonnie Leksrisawat, Allison B. Gilberts, A. Joffre Mercier, Robin L. Cooper

Biology Faculty Publications

The purpose of the report is to describe dissection techniques for preparing the crayfish hindgut and to demonstrate how to make physiological recordings with a force transducer to monitor the strength of contraction. In addition, we demonstrate how to visually monitor peristaltic activity, which can be used as a bioassay for various peptides, biogenic amines and neurotransmitters. This preparation is amenable to student laboratories in physiology and for demonstrating pharmacological concepts to students. This preparation has been in use for over 100 years, and it still offers much as a model for investigating the generation and regulation of peristaltic rhythms …


110 Years Of Avipoxvirus In The Galapagos Islands, Robert Ricklefs Jan 2011

110 Years Of Avipoxvirus In The Galapagos Islands, Robert Ricklefs

Biology Department Faculty Works

No abstract provided.


110 Years Of Avipoxvirus In The Galapagos Islands, Patricia Parker, Elizabeth Buckles, Heather Farrington, Kenneth Petren, Noah Whiteman, Robert Ricklefs, Jennifer Bollmer, Gustavo Jiménez-Uzcátegui Jan 2011

110 Years Of Avipoxvirus In The Galapagos Islands, Patricia Parker, Elizabeth Buckles, Heather Farrington, Kenneth Petren, Noah Whiteman, Robert Ricklefs, Jennifer Bollmer, Gustavo Jiménez-Uzcátegui

Biology Department Faculty Works

The role of disease in regulating populations is controversial, partly owing to the absence of good disease records in historic wildlife populations. We examined birds collected in the Galapagos Islands between 1891 and 1906 that are currently held at the California Academy of Sciences and the Zoologisches Staatssammlung Muenchen, including 3973 specimens representing species from two well-studied families of endemic passerine birds: finches and mockingbirds. Beginning with samples collected in 1899, we observed cutaneous lesions consistent with Avipoxvirus on 226 (6.3%) specimens. Histopathology and viral genotyping of 59 candidate tissue samples from six islands showed that 21 (35.6%) were positive …


Reduced Mhc And Neutral Variation In The Galápagos Hawk, An Island Endemic, Jennifer Bollmer, Joshua Hull, Holly Ernest, José Sarasola, Patricia Parker Jan 2011

Reduced Mhc And Neutral Variation In The Galápagos Hawk, An Island Endemic, Jennifer Bollmer, Joshua Hull, Holly Ernest, José Sarasola, Patricia Parker

Biology Department Faculty Works

BackgroundGenes at the major histocompatibility complex (MHC) are known for high levels of polymorphism maintained by balancing selection. In small or bottlenecked populations, however, genetic drift may be strong enough to overwhelm the effect of balancing selection, resulting in reduced MHC variability. In this study we investigated MHC evolution in two recently diverged bird species: the endemic Galápagos hawk (Buteo galapagoensis), which occurs in small, isolated island populations, and its widespread mainland relative, the Swainson's hawk (B. swainsoni).ResultsWe amplified at least two MHC class II B gene copies in each species. We recovered only three different sequences from 32 Galápagos …


Casein Α S1 Is Expressed By Human Monocytes And Upregulates The Production Of Gm-Csf Via P38 Mapk, Stefan Vordenbäumen, Achim Braukmann, Klaudia Petermann, Andrea Scharf, Ellen Bleck, Anna Von Mikecz, Joachim Jose, Matthias Schneider Jan 2011

Casein Α S1 Is Expressed By Human Monocytes And Upregulates The Production Of Gm-Csf Via P38 Mapk, Stefan Vordenbäumen, Achim Braukmann, Klaudia Petermann, Andrea Scharf, Ellen Bleck, Anna Von Mikecz, Joachim Jose, Matthias Schneider

Biological Sciences Faculty Research & Creative Works

Caseins are major constituents of mammalian milks that are thought to be exclusively expressed in mammary glands and to function primarily as a protein source, as well as to ameliorate intestinal calcium uptake. In addition, proinflammatory and immunomodulatory properties have been reported for bovine caseins. Our aim was to investigate whether human casein α s1 (CSN1S1) is expressed outside the mammary gland and possesses immunomodulatory functions in humans as well. For this purpose, CSN1S1 mRNA was detected in primary human monocytes and CD4+ and CD8+ T cells, but not in CD19 + B cells. CSN1S1 protein was traceable in supernatants …


Evaluation Of In-Vitro Antibiotic Susceptibility Of Different Morphological Forms Of Borrelia Burgdorferi, Eva Sapi, Navroop Kaur, Samuel Anyanwu, David Luecke, Akshita Datar, Seema Patel, Michael J. Rossi, Raphael B. Stricker Jan 2011

Evaluation Of In-Vitro Antibiotic Susceptibility Of Different Morphological Forms Of Borrelia Burgdorferi, Eva Sapi, Navroop Kaur, Samuel Anyanwu, David Luecke, Akshita Datar, Seema Patel, Michael J. Rossi, Raphael B. Stricker

Biology and Environmental Science Faculty Publications

Background: Lyme disease is a tick-borne illness caused by the spirochete Borrelia burgdorferi. Although antibiotic therapy is usually effective early in the disease, relapse may occur when administration of antibiotics is discontinued. Studies have suggested that resistance and recurrence of Lyme disease might be due to formation of different morphological forms of B. burgdorferi, namely round bodies (cysts) and biofilm-like colonies. Better understanding of the effect of antibiotics on all morphological forms of B. burgdorferi is therefore crucial to provide effective therapy for Lyme disease. Methods: Three morphological forms of B. burgdorferi (spirochetes, round bodies, and biofilmlike colonies) were generated …


Flow In Culverts As A Potential Mechanism Of Stream Fragmentation For Native And Non-Indigenous Crayfish Species, Troy Keller Jan 2011

Flow In Culverts As A Potential Mechanism Of Stream Fragmentation For Native And Non-Indigenous Crayfish Species, Troy Keller

Faculty Bibliography

Habitat fragmentation and nonindigenous species are 2 of the leading causes of species loss globally. Thus, scientific information is needed to assess their interactive effects on the biota of lotic ecosystems. We tested the hypothesis that culverts (i.e., pipes) at road–stream intersections elevate flow velocities and differentially slow upstream locomotion of native relative to nonindigenous crayfishes. We: 1) mapped culvert locations and measured their flow; 2) quantified movement of Orconectes propinquus (native) in culverts with velocities of 2, 31, and 42 cm/s; 3) compared the movement of Orconectes rusticus (nonindigenous), O. propinquus, and Orconectes virilis (native) in a culvert with …


Convergent And Parallel Evolution In Life Habit Of The Scallops (Bivalvia: Pectinidae), Alvin Alejandrino, Louise Puslednik, Jeanne M. Serb Jan 2011

Convergent And Parallel Evolution In Life Habit Of The Scallops (Bivalvia: Pectinidae), Alvin Alejandrino, Louise Puslednik, Jeanne M. Serb

Biology

We employed a phylogenetic framework to identify patterns of life habit evolution in the marine bivalve family Pectinidae. Specifically, we examined the number of independent origins of each life habit and distinguished between convergent and parallel trajectories of life habit evolution using ancestral state estimation. We also investigated whether ancestral character states influence the frequency or type of evolutionary trajectories.


Morphological Convergence Of Shell Shape In Distantly Related Scallop Species (Mollusca: Pectinidae), Alvin Alejandrino, Jeanne M. Serb, Erik Otárola-Castillo, Dean C. Adams Jan 2011

Morphological Convergence Of Shell Shape In Distantly Related Scallop Species (Mollusca: Pectinidae), Alvin Alejandrino, Jeanne M. Serb, Erik Otárola-Castillo, Dean C. Adams

Biology

Morphological convergence is a central concept in evolutionary biology, but convergent patterns remain under-studied in nonvertebrate organisms. Some scallop species exhibit long-distance swimming, a behaviour whose biomechanical requirements probably generate similar selective regimes. We tested the hypothesis that shell shape similarity in long-distance swimming species is a result of convergent evolution. Using landmark-based geometric morphometrics, we quantified shell shape in seven species representing major behavioural habits. All species displayed distinct shell shapes, with the exception of the two long-distance swimmers, whose shells were indistinguishable. These species also displayed reduced morphological variance relative to other taxa. Finally, a phylogenetic simulation revealed …


The Pax Gene Eyegone Facilitates Repression Of Eye Development In Tribolium, Nazanin Zarinkamar, Xiaoyun Yang, Riyue Bao, Frank Friedrich, Rolf Beutel, Markus Friedrich Jan 2011

The Pax Gene Eyegone Facilitates Repression Of Eye Development In Tribolium, Nazanin Zarinkamar, Xiaoyun Yang, Riyue Bao, Frank Friedrich, Rolf Beutel, Markus Friedrich

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

The Pax transcription factor gene eyegone (eyg) participates in many developmental processes in Drosophila, including the Notch signaling activated postembryonic growth of the eye primordium, global development of the adult head and the development of the antenna. In contrast to other Pax genes, the functional conservation of eyg in species other than Drosophila has not yet been explored.

Results

We investigated the role of eyg during the postembryonic development of the red flour beetle Tribolium castaneum. Our results indicate conserved roles in antennal but not in eye development. Besides segmentation defects in the antenna, Tribolium eyg knockdown animals …


Cytogenetic Analysis Of An Exposed-Referent Study: Perchloroethylene-Exposed Dry Cleaners Compared To Unexposed Laundry Workers, James D. Tucker, Karen J. Sorensen, Avima M. Ruder, Lauralynn Mckernan, Christy L. Forrester, Mary Butler Jan 2011

Cytogenetic Analysis Of An Exposed-Referent Study: Perchloroethylene-Exposed Dry Cleaners Compared To Unexposed Laundry Workers, James D. Tucker, Karen J. Sorensen, Avima M. Ruder, Lauralynn Mckernan, Christy L. Forrester, Mary Butler

Wayne State University Associated BioMed Central Scholarship

Abstract

Background

Significant numbers of people are exposed to tetrachloroethylene (perchloroethylene, PCE) every year, including workers in the dry cleaning industry. Adverse health effects have been associated with PCE exposure. However, investigations of possible cumulative cytogenetic damage resulting from PCE exposure are lacking.

Methods

Eighteen dry cleaning workers and 18 laundry workers (unexposed controls) provided a peripheral blood sample for cytogenetic analysis by whole chromosome painting. Pre-shift exhaled air on these same participants was collected and analyzed for PCE levels. The laundry workers were matched to the dry cleaners on race, age, and smoking status. The relationships between levels of …


How Is Encystment Regulated In Giardia Intestinalis, Iryna G. Tsarukyanova Jan 2011

How Is Encystment Regulated In Giardia Intestinalis, Iryna G. Tsarukyanova

ETD Archive

Giardia intestinalis is a protozoan parasite causing one of the most widely spread water-born intestinal infections: named giardiasis. The parasite has two life forms: trophozoite, responsible for the symptoms, and a transmittable cyst. Cysts are protected from the environment by a cyst wall build up from protein and a complex polysaccharide. The initiation and the key for cyst wall biosynthesis is amination of fructose 6-phosphate by glucosamine 6-phosphate deaminase (GNP). Fructose 6-phosphate is also an intermediate in glycolysis, the main energy producing pathway in trophozoites. The alternative energy source is the arginine dihydrolase pathway (ADHP), which is upregulated upon encystment. …


Escape From Competition: Neighbors Reduce Centaurea Stoebe Performance At Home But Not Away, Ragan Callaway, Lauren Waller, Alecu Diaconu, Robert Pal, Alexandra Collins, Heinz Mueller-Schaerer, John Maron Jan 2011

Escape From Competition: Neighbors Reduce Centaurea Stoebe Performance At Home But Not Away, Ragan Callaway, Lauren Waller, Alecu Diaconu, Robert Pal, Alexandra Collins, Heinz Mueller-Schaerer, John Maron

Biological Sciences

The greater abundance of some exotic plants in their nonnative ranges might be explained in part by biogeographic differences in the strength of competition, but these competitive effects have not been experimentally examined in the field. We compared the effects of neighbors on the growth and reproduction of spotted knapweed (Centaurea stoebe) in Europe, where it is native, and in Montana, where it is invasive. There were strong negative competitive effects of neighboring vegetation on C. stoebe growth and reproduction in Europe. In contrast, identical experiments in Montana resulted in insignificant impacts on C. stoebe. Although the mechanisms that produce …


Ampk Directly Inhibits Ndpk Through A Phosphoserine Switch To Maintain Cellular Homeostasis, R. U. Onyenwoke, L. J. Forsberg, L. Liu, Tyisha Williams, O. Alzate, J. E. Brenman Jan 2011

Ampk Directly Inhibits Ndpk Through A Phosphoserine Switch To Maintain Cellular Homeostasis, R. U. Onyenwoke, L. J. Forsberg, L. Liu, Tyisha Williams, O. Alzate, J. E. Brenman

Biology Faculty Research

AMP-activated protein kinase (AMPK) is a key energy sensor that regulates metabolism to maintain cellular energy balance. AMPK activation has also been proposed to mimic benefits of caloric restriction and exercise. Therefore, identifying downstream AMPK targets could elucidate new mechanisms for maintaining cellular energy homeostasis. We identified the phosphotransferase nucleoside diphosphate kinase (NDPK), which maintains pools of nucleotides, as a direct AMPK target through the use of two-dimensional differential in-gel electrophoresis. Furthermore, we mapped the AMPK/NDPK phosphorylation site (serine 120) as a functionally potent enzymatic “off switch” both in vivo and in vitro. Because ATP is usually the most abundant …


Influence Of Season And Sex On Terrapene C. Carolina (Eastern Box Turtle) Movements: An Observation Of A Population In West Virginia, Nathalie Caroline Aall Jan 2011

Influence Of Season And Sex On Terrapene C. Carolina (Eastern Box Turtle) Movements: An Observation Of A Population In West Virginia, Nathalie Caroline Aall

Theses, Dissertations and Capstones

Environmental conditions influence box turtle movements on multiple temporal scales as they navigate their home ranges. This study focuses on the impacts of seasonal shift and sex on straight-line distances traveled, movements along elevations, and home range sizes in the Eastern Box Turtle, Terrapene c. carolina. Radio telemetry was used to track nine T. c. carolina (5 males; 4 females) from May to October 2010 at Beech Fork State Park in Wayne County, West Virginia. Turtles were tracked once a day at two-day intervals. At each turtle location, microhabitat variables recorded were relative humidity, soil and ground surface temperature, canopy …


The Consequence Of Anthropogenic Disturbance On Communication And The Operation Of Sexual Selection In The Eastern Bluebird (Sialia Sialis), Ellen Michale Wisner Jan 2011

The Consequence Of Anthropogenic Disturbance On Communication And The Operation Of Sexual Selection In The Eastern Bluebird (Sialia Sialis), Ellen Michale Wisner

Biology - Dissertations

Signals that are efficiently transmitted and easily detected in their signaling environment are favored by natural selection. Anthropogenic disturbance can rapidly alter the signaling environment, and recent studies have shown that acoustic and visual signals change in response to these altered habitats. Although these studies provide important insight into the effects of urbanization on animal signals and have served as experiments testing the role of the environment in shaping signal design, several key aspects of how signal design can be influenced by environmental changes remain unclear.

Previous studies have focused on signals used between adults, such as those used in …


The Maintenance Of Male Color Polymorphism In Poecilia Parae, Jorge L. Hurtado-Gonzales Jan 2011

The Maintenance Of Male Color Polymorphism In Poecilia Parae, Jorge L. Hurtado-Gonzales

Biology - Dissertations

Genetic color polymorphisms are common in nature, and a major challenge for evolutionary biologists has been to understand how they are maintained despite the effects of directional selection. Recent studies suggest that frequency-dependent selection may explain the persistence of intraspecific variation in color. However, it remains to be determined whether frequency-dependent selection is the most predominant (or perhaps the only) mechanism to maintain such genetically-based polymorphisms. Using a South American fish, Poecilia parae, my dissertation aims to elucidate the relative roles of natural and sexual selection in the maintenance of polymorphisms in natural populations. Poecilia parae males exhibit five distinct, …


Review Of The Interactions Between Catfishes And Freshwater Mollusks In North America, Jeremy S. Tiemann, Stephen E. Mcmurray, M. Christopher Barnhart, G. Thomas Watters Jan 2011

Review Of The Interactions Between Catfishes And Freshwater Mollusks In North America, Jeremy S. Tiemann, Stephen E. Mcmurray, M. Christopher Barnhart, G. Thomas Watters

College of Natural and Applied Sciences

Catfishes are important in freshwater ecosystems not only as consumers, but also as essential partners in symbiotic relationships with other organisms. Freshwater mollusks are among the many organisms that have interactions with catfishes. For example, ictalurids are hosts for larvae of several native freshwater mussel species. The larvae, which attach briefly to gills or fins of fish to complete their development to the free-living juvenile stage, disperse via upstream and downstream movement of host fish. In turn, freshwater mussels serve as a food source for some catfish species while other catfish species may use spent mussel shells for habitat. Ictalurids …


Temperature Increase Effects On Sagebrush Ecosystem Forbs: Exprimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb Jan 2011

Temperature Increase Effects On Sagebrush Ecosystem Forbs: Exprimental Evidence And Range Manager Perspectives, Hilary Louise Whitcomb

Green Canyon Environmental Research Area, Logan Utah

No abstract provided.


Lea Proteins During Water Stress: Not Just For Plants Anymore, Steven C. Hand, Michael A. Menze, Mehmet Toner, Leaf Boswell, Daniel Moore Jan 2011

Lea Proteins During Water Stress: Not Just For Plants Anymore, Steven C. Hand, Michael A. Menze, Mehmet Toner, Leaf Boswell, Daniel Moore

Faculty Research & Creative Activity

Late embryogenesis abundant (LEA) proteins are extremely hydrophilic proteins that were first identified in land plants. Intracellular accumulation is tightly correlated with acquisition of desiccation tolerance, and data support their capacity to stabilize other proteins and membranes during drying, especially in the presence of sugars like trehalose. Exciting reports now show LEA proteins are not restricted to plants; multiple forms are expressed in desiccation-tolerant animals from at least four phyla. We evaluate here the expression, subcellular localization, biochemical properties and potential functions of LEA proteins in animal species during water stress. LEA proteins are intrinsically unstructured in aqueous solution, but …


Lifelines Winter 2011, Southern Adventist University Jan 2011

Lifelines Winter 2011, Southern Adventist University

Lifelines - Biology Department Newsletter

The Winter 2011 issue of Lifelines includes articles on research done by the Ecology class, an alumni feature, the TriBeta National Biological Honor Society, and a pictorial directory of the 2011 biology and allied health graduates.


Chemical Characterization And In Vitro Fermentation Of Brassica Straw Treated With The Aerobic Fungus, Trametes Versicolor, J. E. Ramirez-Bribiesca, Y. Wang, L. Jin, Thomas Canam, J. R. Town, A. Tsang, T. J. Dumonceaux, T. A. Mcallister Jan 2011

Chemical Characterization And In Vitro Fermentation Of Brassica Straw Treated With The Aerobic Fungus, Trametes Versicolor, J. E. Ramirez-Bribiesca, Y. Wang, L. Jin, Thomas Canam, J. R. Town, A. Tsang, T. J. Dumonceaux, T. A. Mcallister

Faculty Research & Creative Activity

Brassica napus straw (BNS) was either not treated or was treated with two strains of Trametes versicolor; 52J (wild type) or m4D (a cellobiose dehydrogenase-deficient mutant) with four treatments. Glucose was provided to encourage growth of the mutant strain. All treatments with T. versicolor decreased (P<0.05) neutral-detergent fibre and increased (P<0.05) protein and the concentration of lignin degradation products in straw. Ergosterol was highest (P<0.05) in straw treated with B-52J, suggesting it generated the most fungal biomass. Insoluble lignin was reduced (P<0.05) in straw treated with B-52J and B-m4D, but not with B-m4Dg. Mannose and xylose concentration were generally higher (P<0.05) in straw treated with fungi, whereas glucose and galactose were lower as compared with C-BNS. The four treatments above were subsequently assessed in rumen in vitro fermentations, along with BNS treated with 5 N NaOH. Concentrations of total volatile fatty acids after 24 and 48h were lower (P<0.05) in incubations that contained BNS treated with T. versicolor as compared with C-BNSor NaOH-treated BNS. Compared with C-BNS, in vitrodry matter disappearance and gas production were increased (P<0.05) by NaOH, but not by treatment with either strain of T. versicolor. Although treatment with T. versicolor did release more lignin degradation products, it did not appear to provide more degradable carbohydrate to in vitro rumen microbial populations, even when a mutant strain with compromised carbohydrate metabolism was utilized. Production of secondary compounds by the aerobic fungi may inhibit rumen microbial fermentation.


Amp-Activated Protein Kinase (Ampk) Activity Is Not Required For Neuronal Development But Regulates Axogenesis During Metabolic Stress, Tyisha Williams, J. Courchet, B. Viollet, J. E. Brenman, F. Polleux Jan 2011

Amp-Activated Protein Kinase (Ampk) Activity Is Not Required For Neuronal Development But Regulates Axogenesis During Metabolic Stress, Tyisha Williams, J. Courchet, B. Viollet, J. E. Brenman, F. Polleux

Biology Faculty Research

Mammalian brain connectivity requires the coordinated production and migration of billions of neurons and the formation of axons and dendrites. The LKB1/Par4 kinase is required for axon formation during cortical development in vivo partially through its ability to activate SAD-A/B kinases. LKB1 is a master kinase phosphorylating and activating at least 11 other serine/threonine kinases including the metabolic sensor AMP-activated protein kinase (AMPK), which defines this branch of the kinome. A recent study using a gene-trap allele of the β1 regulatory subunit of AMPK suggested that AMPK catalytic activity is required for proper brain development including neurogenesis and neuronal survival. …


Hepatitis C Virus-Induced Hepatocellular Carcinoma: Cancer Stem Cell And Gene Therapy, Heba Samir Esmaeil Allam Jan 2011

Hepatitis C Virus-Induced Hepatocellular Carcinoma: Cancer Stem Cell And Gene Therapy, Heba Samir Esmaeil Allam

Electronic Theses and Dissertations

Hepatitis C virus (HCV) is an important human pathogen that causes chronic hepatitis cirrhosis, steatosis and hepatocellular carcinoma (HCC) worldwide. Although current FDA-approved drugs are partially effective in the treatment of HCV, methods for cure and vaccine against the virus are still awaited. My thesis work presented here is focused on finding mechanism (s) of HCV-induced hepatocarcinogenesis and devising novel means to combat the HCV infection.

Herein, we have shown that long-term HCV expression results in the acquisition of cancer stem-like cells (CSCs) traits in liver derived cell lines. These traits include enhanced expression of putative stem cell markers DCAMKL-1, …