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

Life Sciences Commons™

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

Biology

Selected Works

2007

Keyword
Publication
File Type

Articles 1 - 30 of 40

Full-Text Articles in Life Sciences

Microarray-Based Method For Detection Of Unknown Genetic Modifications, Torstein Tengs Dec 2007

Microarray-Based Method For Detection Of Unknown Genetic Modifications, Torstein Tengs

Dr. Torstein Tengs

Background

Due to the increased use of genetic modifications in crop improvement, there is a need to develop effective methods for the detection of both known and unknown transgene constructs in plants. We have developed a strategy for detection and characterization of unknown genetic modifications and we present a proof of concept for this method using Arabidopsis thaliana and Oryza sativa (rice). The approach relies on direct hybridization of total genomic DNA to high density microarrays designed to have probes tiled throughout a set of reference sequences.

Results

We show that by using arrays with 25 basepair probes covering both …

Go to article

Non-Standard Sources In A Standardized World: Responsible Practice And Ethics Of Acquiring Turtle Specimens For Scientific Use, Edgar Lehr, Russell Burke, Linda Ford, Steve Mockford, Peter Pritchard, Jose Rosado, Darrell Senneke, Bryan Stuart Nov 2007

Non-Standard Sources In A Standardized World: Responsible Practice And Ethics Of Acquiring Turtle Specimens For Scientific Use, Edgar Lehr, Russell Burke, Linda Ford, Steve Mockford, Peter Pritchard, Jose Rosado, Darrell Senneke, Bryan Stuart

Edgar Lehr

No abstract provided.

Go to article

Cerebrospinal Fluid And Serum Biomarkers Of Cerebral Malaria Mortality In Ghanaian Children, Winston A. Anderson Oct 2007

Cerebrospinal Fluid And Serum Biomarkers Of Cerebral Malaria Mortality In Ghanaian Children, Winston A. Anderson

Winston Anderson

Plasmodium falciparum can cause a diffuse encephalopathy known as cerebral malaria (CM), a major contributor to malaria associated mortality. Despite treatment, mortality due to CM can be as high as 30% while 10% of survivors of the disease may experience short- and long-term neurological complications. The pathogenesis of CM and other forms of severe malaria is multi-factorial and appear to involve cytokine and chemokine homeostasis, inflammation and vascular injury/repair. Identification of prognostic markers that can predict CM severity will enable development of better intervention.
Postmortem serum and cerebrospinal fluid (CSF) samples were obtained within 2-4 hours of death in Ghanaian …

Go to article

Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella Sep 2007

Life History And Courtship Behavior Of Black Perch, Embiotoca Jacksoni (Teleostomi: Embiotocidae), From Southern California, Bridgette Froeschke, Larry Allen, Daniel Pondella

Daniel Pondella

The black perch, Embiotoca jacksoni Agassiz, 1853, is a common reef fish associated with nearshore marine habitats of California, with the majority of the population occurring within the Southern California Bight. Black perch were collected throughout southern California from Santa Barbara to Carlsbad, including Santa Catalina Island, to determine their physical characteristics, growth, sex ratio, periodicity of reproduction, and length of gestation. Courtship observations were conducted using scuba along the King Harbor Breakwater in Redondo Beach, California, from January 2004 to December 2005 to verify periodicity of courting and associated reproductive behaviors. Specimens captured ranged from 75 to 220 mm …

Go to article

Bactericidal Efficacy Of Liposomal Aminoglycosides Against Burkholderia Cenocepacia, Ali Azghani Jul 2007

Bactericidal Efficacy Of Liposomal Aminoglycosides Against Burkholderia Cenocepacia, Ali Azghani

Ali Azghani

Objectives Burkholderia cenocepacia (formally a genotype of Burkholderia cepacia complex called genomovar III) has emerged as a serious opportunistic pathogen in individuals with cystic fibrosis. We developed a liposomal antibiotic formulation composed of 1,2-distearoyl-sn-glycero-3-phosphocholine and cholesterol (molar ratio 2:1) to overcome B. cenocepacia's resistance to commonly used aminoglycosidic antibiotics.
Methods The dehydration-rehydration vesicles technique was used to entrap antibiotics in liposomes. The size of liposome formulations was measured and encapsulation efficiencies were determined by microbiological assays. MICs of free and liposomal antibiotics against the clinical isolates of B. cenocepacia were determined by the standard broth …

Go to article

Structure And Function Of Haemocytes In Two Marine Gastropods, Megathura Crenulata And Aplysia Californica., Gary Martin, Christopher Oates, Heather Tousignant, Heather Crabtree, Rachel Yamakawa Jul 2007

Structure And Function Of Haemocytes In Two Marine Gastropods, Megathura Crenulata And Aplysia Californica., Gary Martin, Christopher Oates, Heather Tousignant, Heather Crabtree, Rachel Yamakawa

Gary Martin

Aplysia californica is an important mollusc for neurobiological research and Megathura crenulata is becoming valuable as the source of keyhole limpet haemocyanin (KLH) which shows promise in treating cancer, allergy and immunosuppression. The culture of these animals provides opportunities to assess their physiological responses to stress and disease. Molluscan haemocytes are known to be involved in a variety of physiological responses, yet the haemocytes of this opisthobranch and vetigastropod have not been characterized. The purpose of this study is to describe the morphology of these cells and summarize their functions based on a suite of assays previously developed on other …

Go to article

Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard Jun 2007

Tailed Forisomes Of Canavalia Gladiata: A New Model To Study Ca2+-Driven Protein Contractility, Winfried Peters, Michael Knoblauch, Stephen Warmann, Reinhard Schnetter, Amy Shen, William Pickard

Winfried S. Peters

Background and Aims Forisomes are Ca2+-dependent contractile protein bodies that form reversible plugs in sieve tubes of faboid legumes. Previous work employed Vicia faba forisomes, a not entirely unproblematic experimental system. The aim of this study was to seek to establish a superior model to study these intriguing actuators.
Methods Existing isolation procedures were modified to study the exceptionally large, tailed forisomes of Canavalia gladiata by differential interference contrast microscopy in vitro. To analyse contraction/expansion kinetics quantitatively, a geometric model was devised which enabled the computation of time-courses of derived parameters such as forisome volume from simple parameters readily determined …

Go to article

Atplai Is An Acyl Hydrolase Involved In Basal Jasmonic Acid Production And Arabidopsis Resistance To Botrytis Cinerea, Xuemin Wang, Wenyu Yang, Shivakumar P. Devaiah, Xiangqing Pan, Giorgis Isaac, Ruth Welti Jun 2007

Atplai Is An Acyl Hydrolase Involved In Basal Jasmonic Acid Production And Arabidopsis Resistance To Botrytis Cinerea, Xuemin Wang, Wenyu Yang, Shivakumar P. Devaiah, Xiangqing Pan, Giorgis Isaac, Ruth Welti

Xuemin (Sam) Wang

Intracellular phospholipase A2 (PLA2) plays an important role in regulating oxylipin biosynthesis in mammals, but the molecular and biochemical nature of intracellular PLA2 is not well understood in plants. Arabidopsis thaliana gene At1g61850 (AtPLAI) encodes a 140-kDa protein that is most similar to mammalian calcium-independent PLA2, and additionally contains leucine-rich repeats and Armadillo repeats. AtPLAI hydrolyzes phospholipids at both the sn-1 and sn-2 positions, but prefers galactolipids to phospholipids as substrates. Profiling of lipid species altered in response to the necrotrophic fungus Botrytis cinerea revealed decreases in the levels of phosphatidylglycerol and digalactosyldiacylglycerol, suggesting that hydrolysis of plastidic polar lipids …

Go to article

Depleted Carbon Monoxide In Fragment C Of The Jupiter-Family Comet 73p/Schwassmann-Wachmann 3, M. A. Disanti, W. M. Anderson, G. L. Villanueva, B. P. Bonev, K. Magee-Sauer, E. L. Gibb, M. J. Mumma May 2007

Depleted Carbon Monoxide In Fragment C Of The Jupiter-Family Comet 73p/Schwassmann-Wachmann 3, M. A. Disanti, W. M. Anderson, G. L. Villanueva, B. P. Bonev, K. Magee-Sauer, E. L. Gibb, M. J. Mumma

Erika Gibb

Carbon monoxide emission was targeted in fragment C of the recently split Jupiter-family comet 73P/Schwassmann-Wachmann 3 during its 2006 apparition, using the Cryogenic Echelle Spectrograph (CSHELL) at the NASA IRTF on Mauna Kea, Hawaii. Simultaneous sounding with H2O near 4.65 μm revealed highly depleted CO, consistent with a mixing ratio of 0.5% ± 0.13%. Along with depleted CH3OH but nearly normal HCN, this may indicate that this comet formed in the inner giant planets' region or, alternatively, that it formed relatively late, after significant clearing of the protosolar nebula.

Go to article

Antioxidants Preserve Macrophage Phagocytosis Of Pseudomonas Aeruginosa During Hyperoxia, Ali Azghani Apr 2007

Antioxidants Preserve Macrophage Phagocytosis Of Pseudomonas Aeruginosa During Hyperoxia, Ali Azghani

Ali Azghani

Pseudomonas. aeruginosa (PA) is a leading cause of nosocomial pneumonia in patients receiving mechanical ventilation with hyperoxia. Exposure to supraphysiological concentrations of reactive oxygen species during hyperoxia may result in macrophage damage that reduces their ability to phagocytose PA. We tested this hypothesis in cultured macrophage-like RAW 264.7 cells and alveolar macrophages from mice exposed to hyperoxia. Exposure to hyperoxia induced a similarly impaired phagocytosis of both the mucoid and the nonmucoid forms of PA in alveolar macrophages and RAW cells. Compromised PA phagocytosis was associated with cytoskeleton disorganization and actin oxidation in hyperoxic macrophages. To test whether moderate concentrations …

Go to article

Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch Apr 2007

Reversible Birefringence Suggests A Role For Molecular Self-Assembly In Forisome Contractility, Winfried Peters, Reinhard Schnetter, Michael Knoblauch

Winfried S. Peters

Forisomes are contractile protein bodies that control the effective diameter of the sieve elements of the faboid legumes by reversible, Ca2+-driven changes of shape. Forisomes consist of fibrils; we inferred from available electron-microscopical data (which necessarily provide images of fixed, non-functional forisomes) that a reversible assembly of ordered fibrillar arrays might be involved in the contractile mechanism. Here we examined functional forisomes isolated from Vicia faba L. by differential interference contrast microscopy and polarisation microscopy. We found them birefringent in the longitudinally expanded but not in the contracted state, showing ‘parallel extinction’ with the direction of vibration of the slow …

Go to article

Using Math In Cell Biology: A Tale Of Two Channel Types, Borbala Mazzag Mar 2007

Using Math In Cell Biology: A Tale Of Two Channel Types, Borbala Mazzag

Borbala Mazzag

No abstract provided.

Go to article

The Carnegie Protein Trap Library: A Versatile Tool For Drosophila Developmental Studies, Anna K. Allen Feb 2007

The Carnegie Protein Trap Library: A Versatile Tool For Drosophila Developmental Studies, Anna K. Allen

Anna Allen

Metazoan physiology depends on intricate patterns of gene expression that remain poorly known. Using transposon mutagenesis in Drosophila, we constructed a library of 7404 protein trap and enhancer trap lines, the Carnegie collection, to facilitate gene expression mapping at single-cell resolution. By sequencing the genomic insertion sites, determining splicing patterns downstream of the enhanced green fluorescent protein (EGFP) exon, and analyzing expression patterns in the ovary and salivary gland, we found that 600-900 different genes are trapped in our collection. A core set of 244 lines trapped different identifiable protein isoforms, while insertions likely to act as GFP-enhancer traps were …

Go to article

Correction: African American Mitochondrial Dnas Often Match Mtdnas Found In Multiple African Ethnic Groups, Bert Ely, Jamie L. Wilson, Fatimah Linda Collier Jackson, Bruce A. Jackson Feb 2007

Correction: African American Mitochondrial Dnas Often Match Mtdnas Found In Multiple African Ethnic Groups, Bert Ely, Jamie L. Wilson, Fatimah Linda Collier Jackson, Bruce A. Jackson

Fatimah Linda Collier Jackson

After the publication of this work [1], we became aware that AFDIL data set used to construct our database of sub-Saharan mtDNA sequences had been mislabelled, and in fact, did not contain Sierra Leone mtDNA sequences. We have obtained the correct Sierra Leone data set from AFDIL, reconstructed the database using the new file, and reanalyzed all of the data. The size of our database was reduced from 3725 to 3717 since the new Sierra Leone data set contained 109 sequences instead of 117 in the
mislabelled data set. The swapping of data sets resulted in a cascade of minor …

Go to article

Esa And Environmental Justice, George Middendorf, Charles Nilon Feb 2007

Esa And Environmental Justice, George Middendorf, Charles Nilon

George Middendorf

No abstract provided.

Go to article

Med19(Rox3) Regulates Intermodule Interactions In The Saccharomyces Cerevisiae Mediator Complex., Shamara Baidoobonso, Benjamin Guidi, Lawrence Myers Feb 2007

Med19(Rox3) Regulates Intermodule Interactions In The Saccharomyces Cerevisiae Mediator Complex., Shamara Baidoobonso, Benjamin Guidi, Lawrence Myers

Shamara M Baidoobonso, PhD

The Saccharomyces cerevisiae Mediator is a 25-subunit complex that facilitates both transcriptional activation and repression. Structural and functional studies have divided Mediator subunits into four distinct modules. The Head, Middle, and Tail modules form the core functional Mediator complex, whereas a fourth, the Cyc-C module, is variably associated with the core. By purifying Mediator from a strain lacking the Med19(Rox3) subunit, we have found that a complex missing only the Med19(Rox3) subunit can be isolated under mild conditions. Additionally, we have established that the entire Middle module is released when the Deltamed19(rox3) Mediator is purified under more stringent conditions. In …

Go to article

Dna Extraction From Resting Eggs Of The Clam Shrimp Eulimnadia Texana (Branchiopoda : Spinicaudata : Limnadiidae), R. Joel Duff, Chiara Benvenuto, Traci L. Branch, Stephen C. Weeks Jan 2007

Dna Extraction From Resting Eggs Of The Clam Shrimp Eulimnadia Texana (Branchiopoda : Spinicaudata : Limnadiidae), R. Joel Duff, Chiara Benvenuto, Traci L. Branch, Stephen C. Weeks

R. Joel Duff

Large branchiopod crustaceans inhabiting ephemeral ponds are well adapted to their highly unpredictable habitat with a life cycle that includes a short-lived adult stage and a long-lived, desiccation-resistant egg stage. One well studied large branchiopod is the clam shrimp Eulimnadia texana, an androdioecious species with populations comprised of males and self-compatible hermaphrodites. Likely due to the harsh environments in which the eggs are found, e.g., dry areas with high heat and high irradiation, extraction of DNA from individual eggs for genetic analyses can be problematic. Here we report a number of modifications that we have tested allowing for increased efficiency …

Go to article

Taxonomy, Life History, And Population Sex Ratios Of North American Dasineura (Diptera: Cecidomyiidae) On Goldenrods (Asteraceae), Warren Abrahamson, N. Dorchin, C.E. Clarkin, E.R. Scott, M.P. Luongo Dec 2006

Taxonomy, Life History, And Population Sex Ratios Of North American Dasineura (Diptera: Cecidomyiidae) On Goldenrods (Asteraceae), Warren Abrahamson, N. Dorchin, C.E. Clarkin, E.R. Scott, M.P. Luongo

Warren G. Abrahamson, II

No abstract provided.

Go to article

Plethodon Albagula (Western Slimy Salamander), Brooding Defense Behavior And Oophagy, Joseph Milanovich Dec 2006

Plethodon Albagula (Western Slimy Salamander), Brooding Defense Behavior And Oophagy, Joseph Milanovich

Joseph Milanovich

No abstract provided.

Go to article

Evolution, Jonathan Eisen Dec 2006

Evolution, Jonathan Eisen

Jonathan A. Eisen Ph.D.

No abstract provided.

Go to article

Hydroperiod And Metamorphosis In The Small-Mouthed Salamander Dec 2006

Hydroperiod And Metamorphosis In The Small-Mouthed Salamander

Travis J. Ryan

Ambystoma texanum (Small-mouthed Salamander) breeds primarily in temporary wetlands, and while natural history studies have suggested a minimum larval period of about 2 mo, it is not clear how hydroperiod (the length of time that a temporary wetland holds water) infl uences populations. I conducted a mesocosm experiment to investigate the effects of hydroperiod on the completion of metamorphosis, as well as age and size at metamorphosis. I used hydroperiods of 50, 75, and 100 d, and a non-drying treatment as a control. Survival to the end of each hydroperiod was consistent among all groups, but no individuals completed metamorphosis …

Go to article

Water Uptake By Older Roots: Evidence From Desert Succulents, Gretchen North, E. Baker Dec 2006

Water Uptake By Older Roots: Evidence From Desert Succulents, Gretchen North, E. Baker

Gretchen North

Desert succulents are renowned for their rapid recovery of shoot function after periods of drought as a result of shoot succulence, root–shoot interactions, and key root properties. Near the base of the shoot, the proximal (generally older) roots appear to play a major role in the rapid uptake and delivery of water, especially after a period of soil drying when the rest of the root system has a lower hydraulic conductance. In all of the cacti, agaves, and yuccas examined to date, hydraulic conductance for the proximal root zone is unexpectedly high. Substantial water uptake by older roots of cacti …

Go to article

Seed Rain During Initial Colonization Of Abandoned Pastures In The Premontane Wet Forest Zone Of Southern Costa Rica, Jerald Dosch, Cj Peterson, Bl Haines Dec 2006

Seed Rain During Initial Colonization Of Abandoned Pastures In The Premontane Wet Forest Zone Of Southern Costa Rica, Jerald Dosch, Cj Peterson, Bl Haines

Jerald Dosch, PhD

No abstract provided.

Go to article

On Dead Birds' Tales: Museum Specimen Feathers As Historical Archives Of Environmental Pollutants, Jerald Dosch Dec 2006

On Dead Birds' Tales: Museum Specimen Feathers As Historical Archives Of Environmental Pollutants, Jerald Dosch

Jerald Dosch, PhD

No abstract provided.

Go to article

Behavioral Avoidance Of Ultraviolet-B Radiation By Two Species Of Neotropical Poison-Dart Frogs, Barbara Han, Lee Kats, Rachel Pommerening, Ryan Ferrer, Marcia Murry-Ewers, Andrew Blaustein Dec 2006

Behavioral Avoidance Of Ultraviolet-B Radiation By Two Species Of Neotropical Poison-Dart Frogs, Barbara Han, Lee Kats, Rachel Pommerening, Ryan Ferrer, Marcia Murry-Ewers, Andrew Blaustein

Lee Kats

Many animals, plants, and microorganisms are harmed by ultraviolet-B radiation. In particular, several members of class amphibia are negatively affected by exposure to ultraviolet-B radiation. Exposure to ultraviolet-B radiation can cause death or various types of sublethal damage in amphibians. One mechanism to lessen the effect of harmful ultraviolet-B radiation is to limit exposure to sunlight behaviorally. Few studies have examined the behavioral sensitivity of adult amphibians to ultraviolet-B radiation. Using both field experiments and field observations, we found that two species of diurnal poison-dart frogs in Costa Rica (Dendrobates pumilio, D. auratus) consistently preferred areas in the field and …

Go to article

Plant And Pollinator Diversity In Northern Arizona, Warren Abrahamson, L.E. Stevens, T.L. Griswold, O. Messenger, T.J. Ayers Dec 2006

Plant And Pollinator Diversity In Northern Arizona, Warren Abrahamson, L.E. Stevens, T.L. Griswold, O. Messenger, T.J. Ayers

Warren G. Abrahamson, II

No abstract provided.

Go to article

Leaf Traits And Leaf Life Spans Of Two Xeric-Adapted Palmettos, Warren Abrahamson Dec 2006

Leaf Traits And Leaf Life Spans Of Two Xeric-Adapted Palmettos, Warren Abrahamson

Warren G. Abrahamson, II

Plants of nutrient-poor, arid environments often have leaf traits that include small size, sclerophylly, long life span, low nutrient concentration, and low photosynthetic rate. Hence, the success of two large-leaved palmettos in peninsular Florida’s seasonally xeric, nutrient-impoverished uplands seems anomalous, given that their leaves are orders of magnitude larger than the leaves of co-occurring species. An examination of leaf traits and leaf life spans across four vegetative associations differing in available light using a 16-yr data set showed that leaves of Serenoa repens and Sabal etonia had low rates of leaf production coupled with long leaf life spans reaching 3.5 …

Go to article

Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath Dec 2006

Legacy Of Land Use In Southern Appalachian Forests: Effects On Terrestrial Salamander Abundance Along Edges And Within Abandoned Logging Roads, R. Semlitsch,, Travis Ryan, M. Chatfield, B. Drehman, K. Hamed, N. Pekarek, M. Spath

Travis J. Ryan

Roads may be one of the most common disturbances in otherwise continuous forested habitat in the southern Appalachian Mountains. Despite their obvious presence on the landscape, there is limited data on the ecological effects along a road edge or the size of the “road-effect zone.” We sampled salamanders at current and abandoned road sites within the Nantahala National Forest, North Carolina (U.S.A.) to determine the road-effect zone for an assemblage of woodland salamanders. Salamander abundance near the road was reduced significantly, and salamanders along the edges were predominantly large individuals. These results indicate that the road-effect zone for these salamanders …

Go to article

Effects Of Resource Availability On Tolerance Of Herbivory: A Review And Assessment Of Three Opposing Models, Warren Abrahamson, M.J. Wise Dec 2006

Effects Of Resource Availability On Tolerance Of Herbivory: A Review And Assessment Of Three Opposing Models, Warren Abrahamson, M.J. Wise

Warren G. Abrahamson, II

No abstract provided.

Go to article

Computational Modeling Of Calcium Dynamics Near Heterogeneous Release Sites, Borbala Mazzag, Zachary Cooper, Michael Greenwood Dec 2006

Computational Modeling Of Calcium Dynamics Near Heterogeneous Release Sites, Borbala Mazzag, Zachary Cooper, Michael Greenwood

Borbala Mazzag

Background: Calcium is known to play an important role in many physiological
processes, such as egg fertilization and heart muscle functions.
Several recent theoretical studies ([4], [1]) investigated calcium dynamics
near so-called release sites – clusters of calcium-regulated channels on
the intracellular calcium stores. Interest in the synchronized openings of
channels within a release site has increased because these openings are
thought to be the building blocks of global calcium events.
Methods: We conduct computational studies of the effect of heterogeneity
in the make-up of the release site on the resulting calcium dynamics.
We introduce heterogeneity into the model of …

Go to article

Next Last