Biology Commons^™

Effects Of Leaf Excision And Sample Storage Methods On Spectral Reflectance By Foliage Of Giant Reed, Arundo Donax, Kenneth R. Summy, Jonathan Lieman, Yuridia Patricia Gandy, Adarsh Mamachen, Ashish Mamachen, John A. Goolsby, Patricia J. Moran

School of Integrative Biological & Chemical Sciences (Formerly Dept. of Biology)

Research was conducted to evaluate the effects of leaf excision and sample storage methods on spectral reflectance by foliage of giant reed, Arundo donax, an invasive weed which has caused extensive damage in many areas of the Rio Grande Basin in Texas and Mexico. Within 24 hours of excision, A. donax leaves exposed to ambient laboratory conditions (room temperature under natural lighting conditions) exhibited two trends indicative of physiological stress: 1) small but significant increases in reflectance of blue and red wavelengths (400-500 nm and 600-700 nm, respectively) and 2) a substantial reduction in reflectance of near-infrared (NIR) wavelengths (700-1,100 …

Two Mechanosensitive Channel Homologs Influence Division Ring Placement In Arabidopsis Chloroplasts, Margaret E. Wilson, Gregory S. Jensen, Elizabeth S. Haswell

Biology Faculty Research

Chloroplasts must divide repeatedly to maintain their population during plant growth and development. A number of proteins required for chloroplast division have been identified, and the functional relationships between them are beginning to be elucidated. In both chloroplasts and bacteria, the future site of division is specified by placement of the Filamentous temperature sensitive Z (FtsZ) ring, and the Min system serves to restrict FtsZ ring formation to mid-chloroplast or mid-cell. How the Min system is regulated in response to environmental and developmental factors is largely unstudied. Here, we investigated the role in chloroplast division played by two Arabidopsis thaliana …

Natural Variation In Life History And Aging Phenotypes Is Associated With Mitochondrial Dna Deletion Frequency In Caenorhabditis Briggsae, Suzanne Estes, Anna Luella Coleman-Hulbert, Kiley Ann Hicks, Gene De Haan, Sarah R. Martha, Jeremiah B. Knapp, Samson William Smith, Kevin C. Stein, Dee R. Denver

Biology Faculty Publications and Presentations

Background: Mutations that impair mitochondrial functioning are associated with a variety of metabolic and age-related disorders. A barrier to rigorous tests of the role of mitochondrial dysfunction in aging processes has been the lack of model systems with relevant, naturally occurring mitochondrial genetic variation. Toward the goal of developing such a model system, we studied natural variation in life history, metabolic, and aging phenotypes as it relates to levels of a naturally-occurring heteroplasmic mitochondrial ND5 deletion recently discovered to segregate among wild populations of the soil nematode, Caenorhabditis briggsae. The normal product of ND5 is a central component of the …

Escherichia Coli Fpg Glycosylase Is Nonrendundant And Required For The Rapid Global Repair Of Oxidized Purine And Pyrimidine Damage In Vivo, Brandy J. Schalow, Charmain T. Courcelle, Justin Courcelle

Biology Faculty Publications and Presentations

Endonuclease (Endo) III and formamidopyrimidine-N-glycosylase (Fpg) are two of the predominant DNA glycosylases in Escherichia coli that remove oxidative base damage. In cell extracts and purified form, Endo III is generally more active toward oxidized pyrimidines, while Fpg is more active towards oxidized purines. However, the substrate specificities of these enzymes partially overlap in vitro. Less is known about the relative contribution of these enzymes in restoring the genomic template following oxidative damage. In this study, we examined how efficiently Endo III and Fpg repair their oxidative substrates in vivo following treatment with hydrogen peroxide. We found …

The Analgesic Effect Of The Ethanolic Extract Of Matricaria Aurea, Esam Qnais

Turkish Journal of Biology

The analgesic effect of the ethanolic whole plant extract of Matricaria aurea L. (Asteraceae) was studied in rats using the cold water tail flick assay and in mice using the tail immersion, tail clip, acetic-acid-induced writhing, and formalin pain tests. The results showed dose-dependent and significant (P < 0.001) increases in pain threshold at 60 min post-treatment with doses of 100, 200, and 300 mg/kg of the extract in tail flick, tail immersion, and tail clip tests. The effects of the extract were significantly (P < 0.001) lower than those produced by morphine (10 mg/kg) in the same tests. The extract (100, 200, and 300 mg/kg) exhibited a dose-dependent inhibition of writhing and also showed a significant (P < 0.001) inhibition in both phases of the formalin pain test, but with a less intense effect in the first phase. The results indicate that the analgesic effect of M. aurea ethanolic extract is both centrally and peripherally mediated.

The Interaction Between Renin-Angiotensin System And Sympathetic Nervous System In The Peripheral Vasculature Of Normal Sprague-Dawley Rats, Mohammed H. Abdulla, Munavvar A. Sattar, Nor A. Abdullah, Kolla Rl. Anand Swarup, Abdul Hye Khan, Edward J. Johns

Turkish Journal of Biology

To evaluate possible interactions between the renin-angiotensin system (RAS) and the sympathetic nervous system (SNS) in the systemic circulation upon the intravenous administration of angiotensin II and a set of adrenergic agonists in normal Sprague-Dawley (SD) rats. Rats were treated with carvedilol, a non-selective \beta- and selective \alpha_1-adrenoceptor blocker, in a dose of (5 mg/kg) orally for 7 days, and on day 8, the animals were pentobarbitone-anaesthetized and prepared for systemic hemodynamic study. Dose-response relationships in terms of elevation in the magnitude of the mean arterial blood pressure in response to intravenous injection of noradrenaline (NA), phenylephrine (PE), methoxamine (ME), …

Comparison Of The Anticoagulant Response Of A Novel Fluorogenic Anti-Fxa Assay Wth Two Commercial Anti-Fxa Chromogenic Assays, Leanne F. Harris, Aoife O'Brien, Vanessa Castro-Lopez, James S. O'Donnell, Anthony J. Killard

Articles

Introduction: Fast and accurate monitoring is crucial in the successful regulation of coagulation therapy. For the treatment of venous thromboembolism, both unfractionated heparin (UFH) and low molecular weight heparins (LMWH) are commonly administered. The chromogenic anti-factor Xa (FXa) assay is currently considered the ‘gold standard’ assay for monitoring LMWH. However different commercial chromogenic methods often differ when tested with the same samples. Fluorogenic anti-FXa assays have the potential to offer greater benefits over chromogenic assays in terms of greater specificity, sensitivity and they are not so influenced by sample opacity or turbidity. Materials and Methods: Commercial plasmas were spiked with …

Phytosociology, History And Diversity In Farmer-Managed Landscapes On The Tonle Sap Floodplain, Cambodia, Andrew S. Roberts

Dissertations, Theses, and Capstone Projects

Driven by the annual flood pulse of the Tonle Sap Lake, the Tonle Sap floodplain in central Cambodia is a landscape characterized by dynamism, both ecological and social. Annual floods and rainfall vary in timing, duration and intensity from year to year. Patterns of burning, grazing, and agricultural expansion and contraction all leave their imprint on the landscape. While in the social domain, the region is likewise as complex. The genocidal, Maoist regime of Pol Pot darkened the 1970s. However, this was both preceded by, and followed by, years of civil war and social unrest. In recent years, Cambodia has …

Influenza A And Flavivirus Manipulation Of Cell Death, Jeffrey E. Mclean

Dissertations, Theses, and Capstone Projects

Viruses employ a variety of strategies to manipulate cell fate and maximize their replication potential during infection. Interacting specifically with cell death pathways allows viruses direct control over the cellular decision to survive or die during infection.

Influenza A virus, of the family Orthomyxoviridae, encodes proteins that interact with the cell at several points along the apoptosis pathway to induce apoptosis. We demonstrate that caspase activation through pro-apoptotic Bax, a downstream target of Bcl-2, is a critical determinant of the nature of cell death induced by Influenza A infection. Influenza A virus cannot establish an apoptotic response without functional Bax, …

Myth4 And Ferm Have Overlapping And Distinct Roles In The Function Of Myo1, A Class Xiv Myosin In Tetrahymena Thermophila, Michael Gotesman

Dissertations, Theses, and Capstone Projects

MyTH4 and FERM are conserved tail domains in myosin classes VII, X, XII, XIV, XV and in MyoG. Myo1, a class XIV myosin in Tetrahymena thermophila, contains MyTH4 and FERM. Previous studies have shown that Myo1 localizes to phagosomes, the cytoskeleton, and the macronucleus, and that phagosome trafficking and division of the macronucleus are affected in a MYO1 knockout. To investigate the roles for MyTH4 and FERM in the function of Myo1, GFP-tagged MyTH4, FERM, and truncated FERM were separately overexpressed in Tetrahymena. Actin antibody coprecipitated tubulin, GFP-MyTH4, and GFP-FERM. GFP-MyTH4 and GFP-FERM cosedimented with either exogenous microtubules or exogenous …

Genome-Wide Detection Of Novel Regulatory Rnas In E. Coli, Rahul Raghavan, Eduardo Groisman, Howard Ochman

Biology Faculty Publications and Presentations

The intergenic regions in bacterial genomes can contain regulatory leader sequences and small RNAs (sRNAs), which both serve to modulate gene expression. Computational analyses have predicted the presence of hundreds of these noncoding regulatory RNAs in Escherichia coli; however, only about 80 have been experimentally validated. By applying a deep-sequencing approach, we detected and quantified the vast majority of the previously validated regulatory elements and identified 10 new sRNAs and nine new regulatory leader sequences in the intergenic regions of E. coli. Half of the newly discovered sRNAs displayed enhanced stability in the presence of the RNA-binding protein …

Average Adult Size In Female Lizards, Eric Charnov, Robin Warne

Biology Faculty & Staff Publications

No abstract provided.

Body Size Is The History Of Life: Growth Confronting Landscapes Of Death, Eric Charnov

Biology Faculty & Staff Publications

No abstract provided.

Human Hunting Mortality Threshold Rules For Extinction In Mammals (And Fish), Eric Charnov, Wenyun Zuo

Biology Faculty & Staff Publications

No abstract provided.