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

Biology Commons

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

2010

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 61 - 90 of 1072

Full-Text Articles in Biology

A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves Dec 2010

A Comprehensive Uncertainty Analysis And Method Of Geometric Calibration For A Circular Scanning Airborne Lidar, Michael Oliver Gonsalves

Dissertations

This dissertation describes an automated technique for ascertaining the values of the geometric calibration parameters of an airborne lidar. A least squares approach is employed that adjusts the point cloud to a single planar surface which could be either a narrow airport runway or a dynamic sea surface. Going beyond the customary three boresight angles, the proposed adjustment can determine up to eleven calibration parameters to a precision that renders a negligible contribution to the point cloud’s positional uncertainty.

Presently under development is the Coastal Zone Mapping and Imaging Lidar (CZMIL), which, unlike most contemporary systems that use oscillating mirrors …


Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle Dec 2010

Life History And Habitat Use Of The Juvenile Alabama Shad (Alosa Alabamae) In Northern Gulf Of Mexico Rivers, Paul Fraser Mickle

Dissertations

The Alabama shad, Alosa alabamae, is an anadromous species that is in decline and has seen extirpations from impoundments as well as decreased water quality. Alabama shad live in the Gulf of Mexico and ascend Northern Gulf of Mexico Drainages to reproduce early in the year (January-May). The juveniles spend the majority of the year in these freshwater systems before emigrating out to the Gulf of Mexico as late as December.

This dissertation focuses on the juvenile life stages that occur within the Northern Gulf of Mexico drainages. Spawning conditions of the river, as well as the habitat and diet, …


Geological And Ichthyological Investigations Into Palaeodrainage Hypothesis For The Tennessee River, Andrea Karen Persons Dec 2010

Geological And Ichthyological Investigations Into Palaeodrainage Hypothesis For The Tennessee River, Andrea Karen Persons

Dissertations

The course of the ancestral Tennessee River has been debated in both the geological and biological literature for over 100 years. Several of the proposed courses for the ancestral Tennessee place its course across the state of Mississippi. Geochemical analysis of sedimentary rocks in the Pascagoula River basin supports these hypotheses suggesting that the rocks in the Pascagoula basin were derived from the Highland Rim of Tennessee and northern Alabama, while geochemical analysis of rocks from the Pearl River basin point to deposition from a mixture of sources including the ancestral Mississippi River and perhaps the ancestral Tennessee. To delve …


Toxicogenomics Analysis Of Non-Model Transcriptomes Using Next-Generation Sequencing And Microarray, Arun Rawat Dec 2010

Toxicogenomics Analysis Of Non-Model Transcriptomes Using Next-Generation Sequencing And Microarray, Arun Rawat

Dissertations

With the advent of next generation technologies like Roche/454 Life Sciences that require low cost and less time for sequencing will help in providing a workable draft of non-model species genomes. Availability of high throughput microarray technologies for gene expression profiling provides low-cost tools for investigation of highly-integrated responses to various stimuli. These advancements along with bioinformatics processing have led to an increasing number of non-model species having well-annotated transcriptomes. The project focuses on the life cycle of development, functional annotation, and utilization of genomic tools for the avian wildlife species to determine the molecular impacts of exposure to munitions …


Environmental Influence On Brain, Behavior, And Gene Expression In Drosophila, Xia Wang Dec 2010

Environmental Influence On Brain, Behavior, And Gene Expression In Drosophila, Xia Wang

UNLV Theses, Dissertations, Professional Papers, and Capstones

Brain development and behavior are sensitive to environmental stimuli. To gain an understanding of how and to what extent environmental variations, particularly with regard to thermal stress and sensory input, affect brain development, function, and genomic activity, in this dissertation, three interrelated studies were conducted in Drosophila melanogaster.

The first study examined the effects of ecologically-relevant hyperthermia stress on development of the Drosophila mushroom body (MB), a conserved sensory integration and associative center in the insect brain. A daily hyperthermic episode throughout larval and pupal development was shown to severely disrupt MB anatomy by reducing intrinsic Kenyon cell neuron …


Physiological Implications Of Natural Versus Induced Arousal From Torpor, Jenifer C. Utz Dec 2010

Physiological Implications Of Natural Versus Induced Arousal From Torpor, Jenifer C. Utz

UNLV Theses, Dissertations, Professional Papers, and Capstones

During the hibernation season, animals oscillate between periods of torpor and periods of interbout arousal (IBA). During torpor, body temperature is often near 0° C and metabolism is severely depressed. Oxygen consumption, a proxy for aerobic metabolism, may fall to 1% of active values. Many physiological processes including cardiovascular, respiratory, and cellular functions nearly cease. During the IBA, euthermic body temperature is restored and most systemic and cellular processes function at fully active levels. The transition period between these two physiologically dissimilar states is called arousal.

The rate of rewarming (RRW) during arousal was previously expected to progressively increase until …


Hsp70 And Hsp40 Functionally Interact With Soluble Mutant Huntingtin Oligomers In A Classic Atp-Dependent Reaction Cycle, Gregor P. Lotz, Justin Legleiter, Rebecca Aron, Emily M. Sontag, Shao-Yi Huang, Cheping Ng, Charles G. Glabe, Leslie M. Thompson, Paul J. Muchowski Dec 2010

Hsp70 And Hsp40 Functionally Interact With Soluble Mutant Huntingtin Oligomers In A Classic Atp-Dependent Reaction Cycle, Gregor P. Lotz, Justin Legleiter, Rebecca Aron, Emily M. Sontag, Shao-Yi Huang, Cheping Ng, Charles G. Glabe, Leslie M. Thompson, Paul J. Muchowski

Biological Sciences Faculty Research and Publications

Inclusion bodies of aggregated mutant huntingtin (htt) fragments are a neuropathological hallmark of Huntington disease (HD). The molecular chaperones Hsp70 and Hsp40 colocalize to inclusion bodies and are neuroprotective in HD animal models. How these chaperones suppress mutant htt toxicity is unclear but might involve direct effects on mutant htt misfolding and aggregation. Using size exclusion chromatography and atomic force microscopy, we found that mutant htt fragments assemble into soluble oligomeric species with a broad size distribution, some of which reacted with the conformation-specific antibody A11. Hsp70 associated with A11-reactive oligomers in an Hsp40- and ATP-dependent manner and inhibited their …


The First Hypogean Dipluran From Portugal: Description Of A New Species Of The Genus Litocampa (Diplura: Campodeidae), Ana Reboleira, Alberto Sendra, Fernando Gonçalves, Pedro Oromí Nov 2010

The First Hypogean Dipluran From Portugal: Description Of A New Species Of The Genus Litocampa (Diplura: Campodeidae), Ana Reboleira, Alberto Sendra, Fernando Gonçalves, Pedro Oromí

Ana Sofia P.S. Reboleira

A new species of subterranean Campodeid Dipluran of the genus Litocampa mendesi n. sp. is described. Despite the presence of this genus in Spain, this is the first record in Portugal, and it is also the first Portuguese species of hypogean Diplura. The new species combines unique characters absent in the European and American species of the genus. Litocampa mendesi n. sp. was collected only in one part of a cave of the Jurassic karstic massif of Algarve, the southwesternmost part of the Iberian Peninsula. The morphological features of this species show some adaptations to hypogean life but not a …


Science As A Human Right: Esa And The Aaas Science And Human Rights Coalition, Clifford S. Duke, George Middendorf, Jessica Wyndham Nov 2010

Science As A Human Right: Esa And The Aaas Science And Human Rights Coalition, Clifford S. Duke, George Middendorf, Jessica Wyndham

George Middendorf

No abstract provided.


Excision Dynamics Of Vibrio Pathogenicity Island-2 From Vibrio Cholerae: Role Of A Recombination Directionality Factor Vefa, Salvador Almagro-Moreno, Michael G. Napolitano, E. Fidelma Boyd Nov 2010

Excision Dynamics Of Vibrio Pathogenicity Island-2 From Vibrio Cholerae: Role Of A Recombination Directionality Factor Vefa, Salvador Almagro-Moreno, Michael G. Napolitano, E. Fidelma Boyd

Dartmouth Scholarship

Vibrio Pathogenicity Island-2 (VPI-2) is a 57 kb region present in choleragenic V. cholerae isolates that is required for growth on sialic acid as a sole carbon source. V. cholerae non-O1/O139 pathogenic strains also contain VPI-2, which in addition to sialic acid catabolism genes also encodes a type 3 secretion system in these strains. VPI-2 integrates into chromosome 1 at a tRNA-serine site and encodes an integrase intV2 (VC1758) that belongs to the tyrosine recombinase family. ntV2 is required for VPI-2 excision from chromosome 1, which occurs at very low levels, and formation of a non-replicative circular intermediate.


Molecular Cloning And Characterization Of The Porcine Fto Promoter And Coding Regions.Pdf, Jinming Huang, Yunzhou Yang, Gang Liu, Jibin Zhang, Xinxing Dong, Ying Bai, Meiying Fang Nov 2010

Molecular Cloning And Characterization Of The Porcine Fto Promoter And Coding Regions.Pdf, Jinming Huang, Yunzhou Yang, Gang Liu, Jibin Zhang, Xinxing Dong, Ying Bai, Meiying Fang

Jibin Zhang

The fat mass and obesity associated gene (FTO) has been widely reported to be associated with fat mass or fat deposition in different species. In the present study, we cloned both promoter and codingregions of the gene in pigs with over 5 Kb of sequence for the former region and 1,596 bp for the latter region. Comparative analysis of the promoter region among 20 species including pig revealed four conserved regions that harbor transcriptional factors involved in adipose differentiation. Using a pooled DNA sequencing approach, we discovered 39 single nucleotide polymorphisms (SNPs) in the pig FTO gene and four of them were …


Antimicrobial And Anticancer Activity Of Essential Oils From Guatemalan Medicinal Plants, Andrew B. Miller Nov 2010

Antimicrobial And Anticancer Activity Of Essential Oils From Guatemalan Medicinal Plants, Andrew B. Miller

Theses and Dissertations

Guatemalan medicinal plants were collected and screened for the presence of essential oils using steam distillation. Oil was found in 63 species from 24 families and was tested in tube dilution assays for activity against Escherichia coli, Staphylococcus aureus, Streptococcus mutans, Lactobacillus acidophilus and Candida albicans. Several essential oils were highly active with 20 instances of oils inhibiting the microbes at an MIC of 0.31 µl/ml. Oils were also tested against cancerous and established cell lines using a 15% (v/v) agar-media which was developed to improve essential oil solubility. Assays were performed against three cancer lines: …


Muscle Receptor Organs In The Crayfish Abdomen: A Student Laboratory Exercise In Proprioception, Bonnie Leksrisawat, Ann S. Cooper, Allison B. Gilberts, Robin L. Cooper Nov 2010

Muscle Receptor Organs In The Crayfish Abdomen: A Student Laboratory Exercise In Proprioception, Bonnie Leksrisawat, Ann S. Cooper, Allison B. Gilberts, Robin L. Cooper

Biology Faculty Publications

The primary purpose of this experiment is to demonstrate primary sensory neurons conveying information of joint movements and positions as proprioceptive information for an animal. An additional objective of this experiment is to learn anatomy of the preparation by staining, dissection and viewing of neurons and sensory structures under a dissecting microscope. This is performed by using basic neurophysiological equipment to record the electrical activity from a joint receptor organ and staining techniques. The muscle receptor organ (MRO) system in the crayfish is analogous to the intrafusal muscle spindle in mammals, which aids in serving as a comparative model that …


Evaluation Of Harassment Of Migrating Double-Crested Cormorants To Limit Depredation On Selected Sport Fisheries In Michigan, Brian S. Dorr, Ashley Moerke, Michael Bur, Chuck Bassett, Tony Aderman, Dan Traynor, Russell D. Singleton, Peter H. Butchko, Jimmy D. Taylor Nov 2010

Evaluation Of Harassment Of Migrating Double-Crested Cormorants To Limit Depredation On Selected Sport Fisheries In Michigan, Brian S. Dorr, Ashley Moerke, Michael Bur, Chuck Bassett, Tony Aderman, Dan Traynor, Russell D. Singleton, Peter H. Butchko, Jimmy D. Taylor

Brian S Dorr

No abstract provided.


Physiological Recordings Of High And Low Output Nmjs On The Crayfish Leg Extensor Muscle, Wenhui Wu, Robin L. Cooper Nov 2010

Physiological Recordings Of High And Low Output Nmjs On The Crayfish Leg Extensor Muscle, Wenhui Wu, Robin L. Cooper

Biology Faculty Publications

We explain in detail how to expose and conduct electrophysiological recordings of synaptic responses for high (phasic) and low (tonic) output motor neurons innervating the extensor muscle in the walking leg of a crayfish. Distinct differences are present in the physiology and morphology of the phasic and tonic nerve terminals. The tonic axon contains many more mitochondria, enabling it to take a vital stain more intensely than the phasic axon. The tonic terminals have varicosities, and the phasic terminal is filiform. The tonic terminals are low in synaptic efficacy but show dramatic facilitated responses. In contrast, the phasic terminals are …


Drosophila Vitelline Membrane Assembly: A Critical Role For An Evolutionarily Conserved Cysteine In The “Vm Domain” Of Sv23, T. Wu, Anita L. Manogaran, J. M. Beauchamp, Gail L. Waring Nov 2010

Drosophila Vitelline Membrane Assembly: A Critical Role For An Evolutionarily Conserved Cysteine In The “Vm Domain” Of Sv23, T. Wu, Anita L. Manogaran, J. M. Beauchamp, Gail L. Waring

Biological Sciences Faculty Research and Publications

The vitelline membrane (VM), the oocyte proximal layer of the Drosophila eggshell, contains four major proteins (VMPs) that possess a highly conserved “VM domain” which includes three precisely spaced, evolutionarily conserved, cysteines (CX7CX8C). Focusing on sV23, this study showed that the three cysteines are not functionally equivalent. While substitution mutations at the first (C123S) or third (C140S) cysteines were tolerated, females with a substitution at the second position (C131S) were sterile. Fractionation studies showed that sV23 incorporates into a large disulfide linked network well after its secretion ceases, suggesting that post-depositional mechanisms are in place to …


Impact Of Aging On Morphine Analgesia And Associated Changes In Μ-Opioid Receptor Binding And Expression In The Ventrolateral Periaqueductal Gray, Richard L. Hanberry Iv Nov 2010

Impact Of Aging On Morphine Analgesia And Associated Changes In Μ-Opioid Receptor Binding And Expression In The Ventrolateral Periaqueductal Gray, Richard L. Hanberry Iv

Biology Theses

Chronic pain in the aged is a widespread phenomenon, and morphine is the most commonly used narcotic analgesic for treatment. Despite that fact, there are relatively few published studies examining the impact of advanced age on morphine analgesia. We hypothesized that aged rats would be less sensitive to morphine than adults, and that aged animals would have reduced mu-opioid receptor (MOR) binding and expression in the ventrolateral periaqueductal gray, a brain region responsible for morphine analgesia. Using a model of persistent inflammatory pain, we found that morphine was significantly less effective in aged males compared to adult males, and that …


Investigating The Spectrum Of Biological Activity Of Ring-Substituted Salicylanilides And Carbamoylphenylcarbamates, Jiahui Guo, Aidan Coffey, Et. Al. Nov 2010

Investigating The Spectrum Of Biological Activity Of Ring-Substituted Salicylanilides And Carbamoylphenylcarbamates, Jiahui Guo, Aidan Coffey, Et. Al.

Department of Biological Sciences Publications

In this study, a series of twelve ring-substituted salicylanilides and carbamoylphenylcarbamates were prepared and characterized. The compounds were analyzed using RP-HPLC to determine lipophilicity. They were tested for their activity related to the inhibition of photosynthetic electron transport (PET) in spinach (Spinacia oleracea L.) chloroplasts. Moreover, their site of action in the photosynthetic apparatus was determined. Primary in vitro screening of the synthesized compounds was also performed against mycobacterial, bacterial and fungal strains. Several compounds showed biological activity comparable with or higher than the standards 3-(3,4-dichlorophenyl)-1,1-dimethylurea, isoniazid, penicillin G, ciprofloxacin or fluconazole. The most active compounds showed minimal anti-proliferative activity …


Micrornas Reveal The Interrelationships Of Hagfish, Lampreys, And Gnathostomes And The Nature Of The Ancestral Vertebrate, Alysha M. Heimberg, Richard Cowper-Sal{Middle Dot}Lari, Marie Semon, Philip C. J. Donoghue, Kevin J. Peterson Nov 2010

Micrornas Reveal The Interrelationships Of Hagfish, Lampreys, And Gnathostomes And The Nature Of The Ancestral Vertebrate, Alysha M. Heimberg, Richard Cowper-Sal{Middle Dot}Lari, Marie Semon, Philip C. J. Donoghue, Kevin J. Peterson

Dartmouth Scholarship

Hagfish and lampreys are the only living representatives of the jawless vertebrates (agnathans), and compared with jawed vertebrates (gnathostomes), they provide insight into the embryology, genomics, and body plan of the ancestral vertebrate. However, this insight has been obscured by controversy over their interrelationships. Morphological cladistic analyses have identified lampreys and gnathostomes as closest relatives, whereas molecular phylogenetic studies recover a monophyletic Cyclostomata (hagfish and lampreys as closest relatives). Here, we show through deep sequencing of small RNA libraries, coupled with genomic surveys, that Cyclostomata is monophyletic: hagfish and lampreys share 4 unique microRNA families, 15 unique paralogues of more …


Diatoms As Indicators Of Water-Level Change In Freshwater Lakes, Julie A. Wolin, Jeffrey R. Stone Nov 2010

Diatoms As Indicators Of Water-Level Change In Freshwater Lakes, Julie A. Wolin, Jeffrey R. Stone

Biological, Geological, and Environmental Faculty Publications

Water-level changes result from a variety of geological, biological, and/or climatic processes. Many of these changes occur over long periods; others may be rapid or result from catastrophic events. In aquatic environments, diatoms are highly sensitive indicator organisms and their microfossils, deposited in lake sediments, can be used to infer environmental changes (Smol, 2008). Unambiguous diatom signals can be reconstructed from lakes isolated from marine or brackish waters (e.g. Fritz et al., this volume; Horton & Sawai, this volume). However, in freshwater systems lake-level changes are often recorded as increases in planktonic (free-floating) diatoms – although as discussed below, interpretation …


Arctic Ecosystem Responses To Changes In Water Availability And Warming: Short And Long-Term Responses, Paulo C. Olivas Nov 2010

Arctic Ecosystem Responses To Changes In Water Availability And Warming: Short And Long-Term Responses, Paulo C. Olivas

FIU Electronic Theses and Dissertations

Arctic soils store close to 14% of the global soil carbon. Most of arctic carbon is stored below ground in the permafrost. With climate warming the decomposition of the soil carbon could represent a significant positive feedback to global greenhouse warming. Recent evidence has shown that the temperature of the Arctic is already increasing, and this change is associated mostly with anthropogenic activities. Warmer soils will contribute to permafrost degradation and accelerate organic matter decay and thus increase the flux of carbon dioxide and methane into the atmosphere. Temperature and water availability are also important drivers of ecosystem performance, but …


The Lotus Japonicus Cytokinin Receptor Gene Family And Its Role In Nitrogen-Fixing Symbiosis, Mark A. Held Nov 2010

The Lotus Japonicus Cytokinin Receptor Gene Family And Its Role In Nitrogen-Fixing Symbiosis, Mark A. Held

Electronic Thesis and Dissertation Repository

Nitrogen is the most abundant element in our atmosphere, yet has become increasingly limited in agricultural lands. Legume plants offer a possible solution to this problem due to their innate ability to symbiotically interact with nitrogen-fixing bacteria called rhizobia. In particular, a histidine kinase cytokinin receptor from the model legume Lotus japonicus (LHK1) has been clearly placed at the core of these interactions. Loss-of-function mutants in LHK1 fail to initiate timely cortical cell divisions in response to abundant bacterial infection, and gain-of-function mutations in the same locus cause L. japonicus plants to form spontaneous nodules in the absence of rhizobia, …


Using Critical-Thinking Skills To Substantiate Or Challenge Controversial Claims Endorsing A Myriad Of Weight-Loss Products, Teresa F. Degolier Nov 2010

Using Critical-Thinking Skills To Substantiate Or Challenge Controversial Claims Endorsing A Myriad Of Weight-Loss Products, Teresa F. Degolier

Biological Sciences Faculty Publications

This exercise engages students in critically evaluating weight-loss products and programs. Specific objectives are to investigate, analyze, and substantiate claims made by the weight-loss industry and interpret how these claims may be fraudulent, misleading, or perhaps even truthful.


Maple Syrup: A Sweet Springtime Lesson, Stephen G. Saupe, Sarah Gainey Nov 2010

Maple Syrup: A Sweet Springtime Lesson, Stephen G. Saupe, Sarah Gainey

Biology Faculty Publications

No abstract provided.


Regulation Of Integrin Αiibβ3 Ligand Binding And Signaling By The Metal Ion Binding Sites In The Β I Domain, Joel Raborn Nov 2010

Regulation Of Integrin Αiibβ3 Ligand Binding And Signaling By The Metal Ion Binding Sites In The Β I Domain, Joel Raborn

Honors Theses

No abstract provided.


A Novel Totivirus And Piscine Reovirus (Prv) In Atlantic Salmon (Salmo Salar) With Cardiomyopathy Syndrome (Cms), Torstein Tengs Nov 2010

A Novel Totivirus And Piscine Reovirus (Prv) In Atlantic Salmon (Salmo Salar) With Cardiomyopathy Syndrome (Cms), Torstein Tengs

Dr. Torstein Tengs

BACKGROUNDCardiomyopathy syndrome (CMS) is a severe disease affecting large farmed Atlantic salmon. Mortality often appears without prior clinical signs, typically shortly prior to slaughter. We recently reported the finding and the complete genomic sequence of a novel piscine reovirus (PRV), which is associated with another cardiac disease in Atlantic salmon; heart and skeletal muscle inflammation (HSMI). In the present work we have studied whether PRV or other infectious agents may be involved in the etiology of CMS.RESULTSUsing high throughput sequencing on heart samples from natural outbreaks of CMS and from fish experimentally challenged with material from fish diagnosed with CMS …


Optimising Maternal Sources Of Breastfeeding During The First Six Weeks Of Postpartum, Roslyn Tarrant, Katherine Younger, Margaret Sheridan-Pereira, John M. Kearney Nov 2010

Optimising Maternal Sources Of Breastfeeding During The First Six Weeks Of Postpartum, Roslyn Tarrant, Katherine Younger, Margaret Sheridan-Pereira, John M. Kearney

Conference Papers

No abstract provided.


Non-Native Salmonids Affect Amphibian Occupancy At Multiple Spatial Scales, David S. Pilliod, Blake R. Hossack, Peter F. Bahls, Evelyn L. Bull, Paul Stephen Corn, Grant Hokit, Bryce A. Maxell, James C. Munger, Aimee Wyrick Nov 2010

Non-Native Salmonids Affect Amphibian Occupancy At Multiple Spatial Scales, David S. Pilliod, Blake R. Hossack, Peter F. Bahls, Evelyn L. Bull, Paul Stephen Corn, Grant Hokit, Bryce A. Maxell, James C. Munger, Aimee Wyrick

Biology Faculty Publications and Presentations

Aim The introduction of non-native species into aquatic environments has been linked with local extinctions and altered distributions of native species. We investigated the effect of non-native salmonids on the occupancy of two native amphibians, the long-toed salamander (Ambystoma macrodactylum) and Columbia spotted frog (Rana luteiventris), across three spatial scales: water bodies, small catchments and large catchments.

Location Mountain lakes at ≥ 1500 m elevation were surveyed across the northern Rocky Mountains, USA.

Methods We surveyed 2267 water bodies for amphibian occupancy (based on evidence of reproduction) and fish presence between 1986 and 2002 and modelled …


Discovery And Analysis Of 4h-Pyridopyrimidines, A Class Of Selective Bacterial Protein Synthesis Inhibitors, Wendy Ribble, Walter E. Hill, Urs A. Ochsner, Thale C. Jarvis, Joseph W. Guiles, Nebojsa Janjic, James M. Bullard Nov 2010

Discovery And Analysis Of 4h-Pyridopyrimidines, A Class Of Selective Bacterial Protein Synthesis Inhibitors, Wendy Ribble, Walter E. Hill, Urs A. Ochsner, Thale C. Jarvis, Joseph W. Guiles, Nebojsa Janjic, James M. Bullard

Biological Sciences Faculty Publications

Bacterial protein synthesis is the target for numerous natural and synthetic antibacterial agents. We have developed a poly(U) mRNA-directed aminoacylation/translation protein synthesis system composed of phenyl-tRNA synthetases, ribosomes, and ribosomal factors from Escherichia coli. This system, utilizing purified components, has been used for high-throughput screening of a small-molecule chemical library. We have identified a series of compounds that inhibit protein synthesis with 50% inhibitory concentrations (IC(50)s) ranging from 3 to 14 mu M. This series of compounds all contained the same central scaffold composed of tetrahydropyrido[4,3-d] pyrimidin-4-ol (e.g., 4H-pyridopyrimidine). All analogs contained an ortho pyridine ring attached to the central …


Disappearing Plants: Why They Hide And How They Return, Jennifer R. Gremer, Anna Sala, Elizabeth E. Crone Nov 2010

Disappearing Plants: Why They Hide And How They Return, Jennifer R. Gremer, Anna Sala, Elizabeth E. Crone

Biological Sciences Faculty Publications

Prolonged dormancy is a life-history stage in which mature plants fail to resprout for one or more growing seasons and instead remain alive belowground. Prolonged dormancy is relatively common, but the proximate causes and consequences of this intriguing strategy have remained elusive. In this study we tested whether stored resources are associated with remaining belowground, and investigated the resource costs of remaining belowground during the growing season. We measured stored resources at the beginning and end of the growing season in Astragalus scaphoides, an herbaceous perennial in southwest Montana, USA. At the beginning of the growing season, dormant plants …