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2010

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Variation In Nutrient Resorption By Desert Shrubs, Rebecca E. Drenovsky, Jeremy J. James, James H. Richards Nov 2010

Variation In Nutrient Resorption By Desert Shrubs, Rebecca E. Drenovsky, Jeremy J. James, James H. Richards

Biology

Plant nutrient resorption prior to leaf senescence is an important nutrient conservation mechanism for aridland plant species. However, little is known regarding the phylogenetic and environmental factors influencing this trait. Our objective was to compare nitrogen (N) and phosphorous (P) resorption in a suite of species in the Asteraceae and Chenopodiaceae and assess the impact of soil salinity on nitrogen resorption. Although asters and chenopods did not differ in N resorption proficiency, chenopods were more proficient than asters at resorbing P. Plant responses to salinity gradients were species-specific and likely related to different salt-tolerances of the species. During the three …


Notes, James Smith Allen Nov 2010

Notes, James Smith Allen

A Privileged Past

For more information about the sources used to write "A Privileged Past," the notes offer the reader the opportunity to explore the author's verifiable claims in more detail.


Piper Spp. Scent As An Indicator Of Larvicidal Activity, November 2010, Erica Jansen Nov 2010

Piper Spp. Scent As An Indicator Of Larvicidal Activity, November 2010, Erica Jansen

Monteverde Institute: Tropical Ecology and Conservation

Cebus capucinus monkeys search for licorice-scented Pipers to use as an insect repellent (Brown 1996). Bioassays measuring mosquito larvicidal activity of six Piper plants were completed in Monteverde, Costa Rica to see if scent is a reliable cue. Overall, there was no relationship between strength of scent and larvicidal activity (Linear Regression F=0.064, P<0.05). The species in the study that exhibited the highest larvicidal activity was Piper auritum, a species that contains the essential oil safrole and has a strong licorice odor. Piper auritum and Piper marginatum (the only species C. capucinus is reported to use) both had a licorice-like scent and together had significantly higher larvicidal activity than the four species tested that lacked the licorice-like scent (Independent Samples T-test t=2.74, DF=15, P<0.05). Altogether these data show that the quality of Piper scent can indicate insect repellent ability but strength cannot. Thus, it makes sense that C. capucinus use scent cues to find effective plant repellents as specific scents can indicate larvicidal essential oils.


Our Health Matters: Promoting The Health Of Sexual Minority Women In The New Media Landscape, Brenda Kane Nov 2010

Our Health Matters: Promoting The Health Of Sexual Minority Women In The New Media Landscape, Brenda Kane

Electronic Theses and Dissertations

The shifts occurring in the mediascape and the field of public health offer new opportunities for promoting the health and wellness of sexual minority women. As a population that has historically been underserved by the healthcare system, sexual minority women face multiple barriers to achieving positive health outcomes. They are often less likely to access preventive healthcare services and more likely to engage in risky behaviors that are detrimental to health than heterosexual women. Despite the significant health disparities among sexual minority women, studying this population has not been a priority in health research and there is little research-based evidence …


Scholarworks Statistics - November 2010, Scholarworks Nov 2010

Scholarworks Statistics - November 2010, Scholarworks

ScholarWorks Reports

For the month of November 2010, ScholarWorks recorded a total of 12,727 full-text downloads.


Hidden Consequences Of Living In A Wormy World: Nematode-Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart Nov 2010

Hidden Consequences Of Living In A Wormy World: Nematode-Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart

Biological Sciences Faculty Publications

Most hosts are infected with multiple parasites, and responses of the immune system to co occurring parasites may influence disease spread. Helminth infection can bias the host immune response toward a T-helper type 2 Th2) over a type 1 Th1) response, impairing the host's ability to control concurrent intracellular microparasite infections and potentially modifying disease dynamics. In humans, immune-mediated interactions between helminths and microparasites can alter host susceptibility to diseases such as HIV, tuberculosis TB), and malaria. However, the extent to which similar processes operate in natural animal populations and influence disease spread remains unknown. We used cross-sectional, experimental, and …


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 …


Hidden Consequences Of Living In A Wormy World: Nematode‐Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart, Albano Beja-Pereira, Anna E. Jolles Nov 2010

Hidden Consequences Of Living In A Wormy World: Nematode‐Induced Immune Suppression Facilitates Tuberculosis Invasion In African Buffalo, Vanessa O. Ezenwa, Rampal S. Etienne, Gordon Luikart, Albano Beja-Pereira, Anna E. Jolles

Biological Sciences Faculty Publications

Most hosts are infected with multiple parasites, and responses of the immune system to co-occurring parasites may influence disease spread. Helminth infection can bias the host immune response toward a T-helper type 2 (Th2) over a type 1 (Th1) response, impairing the host’s ability to control concurrent intracellular microparasite infections and potentially modifying disease dynamics. In humans, immune-mediated interactions between helminths and microparasites can alter host susceptibility to diseases such as HIV, tuberculosis (TB), and malaria. However, the extent to which similar processes operate in natural animal populations and influence disease spread remains unknown.We used cross-sectional, experimental, and genetic studies …


Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, Jon C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig Nov 2010

Chloroquine Susceptibility And Reversibility In A Plasmodium Falciparum Genetic Cross, Jigar J. Patel, Drew Thacker, Jon C. Tan, Perri Pleeter, Lisa Checkley, Joseph M. Gonzales, Bingbing Deng, Paul D. Roepe, Roland A. Cooper, Michael T. Ferdig

Collected Faculty Scholarship

Mutations in the Plasmodium falciparum chloroquine (CQ) resistance transporter (PfCRT), are major determinants of verapamil (VP)-reversible CQ resistance (CQR). In the presence of mutant PfCRT, additional genes contribute to the wide range of CQ susceptibilities observed. It is not known if these genes influence mechanisms of chemosensitization by CQR reversal agents. Using quantitative trait locus (QTL) mapping of progeny clones from the HB3 × Dd2 cross, we show that the P. falciparum multidrug resistance gene 1 (pfmdr1) interacts with the Southeast Asiaderived mutant pfcrt haplotype to modulate CQR levels. A novel chromosome 7 locus is predicted to contribute with the …


The Tablet Pc: Cool Toy Or Useful Tool?, Sara D. Miller Nov 2010

The Tablet Pc: Cool Toy Or Useful Tool?, Sara D. Miller

LOEX Conference Proceedings 2008

The tablet PC, or convertible laptop computer, is a relatively new technology - the potential of which is still being tested in the field of education and in libraries. This presentation will provide a brief overview of available tablets, evaluate some of their current uses in libraries and education, and demonstrate how a tablet PC is currently being used during information literacy sessions at Michigan State University. Participants will discuss the tablet’s potential uses in information literacy and will walk away with ideas, information, and best practices for incorporating this new technology into library instruction.


Spr Bulletin, Spring 2010, Uno Office Of Research And Creative Activity Nov 2010

Spr Bulletin, Spring 2010, Uno Office Of Research And Creative Activity

Sponsored Programs Bulletins

This bulletin features Recent Grant Recipients and SPR Welcomes Dr. Scott Snyder as the new Associate Vice Chancellor for Research and Creative Activity!


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.


From The Offshore World Of International Finance To Your Backyard: Structuring Series Llcs For Diverse Business Purposes, James D. Blake Nov 2010

From The Offshore World Of International Finance To Your Backyard: Structuring Series Llcs For Diverse Business Purposes, James D. Blake

DePaul Business & Commercial Law Journal

No abstract provided.


Office Of Research And Economic Development Annual Report 2009-2010 Nov 2010

Office Of Research And Economic Development Annual Report 2009-2010

Office of Research and Economic Development: Publications

Planting Seeds for the Future 1
New Institute Focuses on Water for Food 2
Probing the Evapotranspiration Equation 3
Yield Potential Key to Food Security 4
Water-smart Sensors Going Underground 6
Lakes Showing Signs of Warming Climate 7
Informed Choices–Assessing Green Features 9
Powering Roadways with Solar and Wind 10
Improving Sustainable Energy Technologies 11
Biosensor Work Aims for Simple HIV Test 12
Developing Stronger Nanomagnets 14
Peering into Ultra-fast Molecular World 15
Getting the Skinny on Dietary Fat 17
Novel Approach Targets Tuberculosis 18
Pathways to Homelessness for Women 19
Bison Books–50 Years of Great Reading 21
Historian Weaving …


Caribbean Corals In Crisis: Record Thermal Stress, Bleaching, And Mortality In 2005, C. Mark Eakin, Jessica A. Morgan, Scott F. Heron, Tyler B. Smith, Gang Liu, Lorenzo Alvarez-Filip, Bart J. Baca, Erich Bartels, Carolina Bastidas, Claude Bouchon, Marilyn Brandt, Andrew W. Bruckner, Lucy Bunkley-Williams, Andrew Cameron, Billy D. Causey, Mark Chiappone, Tyler R. L. Christensen, M. James C. Crabbe, Owen Day, Elena De La Guardia, Guillermo Diaz-Pulido, Daniel Diresta, Diego L. Gil-Agudelo, David S. Gilliam, Robert N. Ginsburg, Shannon Gore, Hector M. Guzman, James C. Hendee, Edwin A. Hernandez-Delgado, Ellen Husain, Christopher F. G. Jeffrey, Ross J. Jones, Eric Jordan-Dahlgren, Les S. Kaufman, David I. Kline, Philip A. Kramer, Judith C. Lang, Diego Lirman, Jennie Mallela, Carrie Manfrino, Jean-Philippe Marechal, Ken Marks, Jennifer Mihaly, W. Jeff Miller, Erich M. Mueller, Erinn M. Muller, Carlos A. Orozco Toro, Hazel A. Oxenford, Daniel Ponce-Taylor, Norman Quinn, Kim B. Ritchie, Sebastian Rodriguez, Alberto Rodriguez Ramirez, Sandra Romano, Jameal F. Samhouri, Juan A. Sanchez, George P. Schmahl, Burton V. Shank, William J. Skirving, Sascha C. C. Steiner, Estrella Villamizar, Sheila M. Walsh, Cory Walter, Ernesto Weil, Ernest H. Williams, Kimberly Woody Roberson, Yusri Yusuf Nov 2010

Caribbean Corals In Crisis: Record Thermal Stress, Bleaching, And Mortality In 2005, C. Mark Eakin, Jessica A. Morgan, Scott F. Heron, Tyler B. Smith, Gang Liu, Lorenzo Alvarez-Filip, Bart J. Baca, Erich Bartels, Carolina Bastidas, Claude Bouchon, Marilyn Brandt, Andrew W. Bruckner, Lucy Bunkley-Williams, Andrew Cameron, Billy D. Causey, Mark Chiappone, Tyler R. L. Christensen, M. James C. Crabbe, Owen Day, Elena De La Guardia, Guillermo Diaz-Pulido, Daniel Diresta, Diego L. Gil-Agudelo, David S. Gilliam, Robert N. Ginsburg, Shannon Gore, Hector M. Guzman, James C. Hendee, Edwin A. Hernandez-Delgado, Ellen Husain, Christopher F. G. Jeffrey, Ross J. Jones, Eric Jordan-Dahlgren, Les S. Kaufman, David I. Kline, Philip A. Kramer, Judith C. Lang, Diego Lirman, Jennie Mallela, Carrie Manfrino, Jean-Philippe Marechal, Ken Marks, Jennifer Mihaly, W. Jeff Miller, Erich M. Mueller, Erinn M. Muller, Carlos A. Orozco Toro, Hazel A. Oxenford, Daniel Ponce-Taylor, Norman Quinn, Kim B. Ritchie, Sebastian Rodriguez, Alberto Rodriguez Ramirez, Sandra Romano, Jameal F. Samhouri, Juan A. Sanchez, George P. Schmahl, Burton V. Shank, William J. Skirving, Sascha C. C. Steiner, Estrella Villamizar, Sheila M. Walsh, Cory Walter, Ernesto Weil, Ernest H. Williams, Kimberly Woody Roberson, Yusri Yusuf

Marine & Environmental Sciences Faculty Articles

Background: The rising temperature of the world’s oceans has become a major threat to coral reefs globally as the severity and frequency of mass coral bleaching and mortality events increase. In 2005, high ocean temperatures in the tropical Atlantic and Caribbean resulted in the most severe bleaching event ever recorded in the basin.

Methodology/Principal Findings: Satellite-based tools provided warnings for coral reef managers and scientists, guiding both the timing and location of researchers’ field observations as anomalously warm conditions developed and spread across the greater Caribbean region from June to October 2005. Field surveys of bleaching and mortality exceeded prior …


Electronic Properties Of N(5)-Ethyl Flavinium Ion, Vincent Sichula, Pavel Kucheryavy, Renat Khatmullin, Ying Hu, Ekaterina Mirzakulova, Shubham Vyas, Samuel F. Manzer, Christopher M. Hadad, Ksenija D. Glusac Nov 2010

Electronic Properties Of N(5)-Ethyl Flavinium Ion, Vincent Sichula, Pavel Kucheryavy, Renat Khatmullin, Ying Hu, Ekaterina Mirzakulova, Shubham Vyas, Samuel F. Manzer, Christopher M. Hadad, Ksenija D. Glusac

Chemistry Faculty Publications

We investigated the electronic properties of N(5)-ethyl flavinium perchlorate (Et-Fl(+)) and compared them to those of its parent compound, 3-methyllumiflavin (Fl). Absorption and fluorescence spectra of Fl and Et-Fl(+) exhibit similar spectral features, but the absorption energy of Et-Fl(+) is substantially lower than that of Fl. We calculated the absorption signatures of Fl and Et-Fl(+) using time-dependent density functional theory (TD-DFT) methods and found that the main absorption bands of Fl and Et-Fl(+) are (pi,pi*) transitions for the S(1) and S(3) excited states. Furthermore, calculations predict that the S(2) state has (n,pi*) character. Using cyclic voltammetry and a simplistic consideration …


Photoinduced Charge Separation In Platinum Acetylide Oligomers, Chen Liao, James E. Yarnell, Ksenija D. Glusac, Kirk S. Schanze Nov 2010

Photoinduced Charge Separation In Platinum Acetylide Oligomers, Chen Liao, James E. Yarnell, Ksenija D. Glusac, Kirk S. Schanze

Chemistry Faculty Publications

The series of three donor-spacer-acceptor complexes, DPAF-Ptn-NDI, has been synthesized and characterized using time-resolved absorption spectroscopy In these complexes, the donor is a (diphenylamino)-2,7-fluorenylene (DPAF) unit, the acceptor is a naphthalene diimide (NDI), and the spacers are a series of platinum acetylides of varying lengths, [-Pt(PBu(3))(2)C C-Ph-C C-](n) (where Bu = n-butyl Ph = 1,4-phenylene and n = 1 2, and 3) Electrochemistry indicates that the DPAF-Ptn-NDI system has a charge transfer state at ca 1 5 eV above the ground state that is based on one electron transfer from the DPAF donor to the NDI acceptor Transient absorption spectroscopy …


Nanomanufacturing And Analysis Of Novel Integrated Continuous Nanofibers, John E. Hannappel Nov 2010

Nanomanufacturing And Analysis Of Novel Integrated Continuous Nanofibers, John E. Hannappel

Department of Engineering Mechanics: Dissertations, Theses, and Student Research

Complex nanostructured materials have great potential for applications in many areas of nanotechnology. This potential is being unlocked by precise control of their nanoscale architecture and properties. Most current methods of creating these nanostructures are expensive and difficult to control, with the majority of techniques resulting in non-continuous nanostructures and nanoparticles. Electrospinning is an economic nanomanufacturing method resulting in continuous nanofibers. The method consists of spinning fiber-forming liquids in high electric fields. In this work, a modified electrospinning process was analyzed. The process utilized two concentric liquids that resulted in integrated continuous hollow or composite nanofibers. A new adjustable co-axial …


Sotl Chronicles [Volume 2, Number 1], Georgia Southern University Nov 2010

Sotl Chronicles [Volume 2, Number 1], Georgia Southern University

Faculty Center: News & Publications

No abstract provided.


The Role Of Caspases In Alzheimer's Disease; Potential Novel Therapeutic Opportunities, Troy T. Rohn Nov 2010

The Role Of Caspases In Alzheimer's Disease; Potential Novel Therapeutic Opportunities, Troy T. Rohn

Biology Faculty Publications and Presentations

Although apoptosis plays a critical role in molding the CNS into its final appearance and function, inappropriate activation of this pathway in the aging brain may contribute to neurodegeneration. In Alzheimer’s disease (AD), an overwhelming body of evidence supports the activation of apoptosis in general, and caspases specifically as an early event that may not only contribute to neurodegeneration but also promote the underlying pathology associated with this disease. Therefore, caspase inhibitors may provide an effective strategy for treating AD. However, despite the compelling evidence indicating a role for caspases in disease progression, chronic treatment with caspase inhibitors in animal …


The Utah Statesman, November 1, 2010, Utah State University Nov 2010

The Utah Statesman, November 1, 2010, Utah State University

The Utah Statesman

Weekly student newspaper of Utah State University in Logan.


Development And Evaluation Of Methods For Surveying Fish Populations In Nearshore Waters, Philip Smith, Ian Burrett, David Bailey, Francis Neat, David Donnan, Katherine Dunlop, James Thorburn, Rosanna Milligan, Steve Bastiman, Jane Dodd Nov 2010

Development And Evaluation Of Methods For Surveying Fish Populations In Nearshore Waters, Philip Smith, Ian Burrett, David Bailey, Francis Neat, David Donnan, Katherine Dunlop, James Thorburn, Rosanna Milligan, Steve Bastiman, Jane Dodd

Marine & Environmental Sciences Faculty Reports

  1. Nearshore areas provide critical habitat for a range of fish species targeted by commercial and recreational fisheries, both of which make an important contribution to local economies in rural areas. However, established trawl survey methods are not suited to many nearshore areas, owing to shallow depths, obstructions on the sea bed or vulnerable habitats, so there is a lack of information on fish abundance in these areas.
  2. The aim of the present project was to develop and test survey methods applicable to Scottish inshore waters, focussing on baited underwater cameras, fish traps, systematic rod-and-line surveys and observations of fish bycatch …


3d Oceanographic Data Compression Using 3d-Odetlap, You Li, Tsz-Yam Lau, Christopher S. Stuetzle, Peter Fox, W. Randolph Franklin Nov 2010

3d Oceanographic Data Compression Using 3d-Odetlap, You Li, Tsz-Yam Lau, Christopher S. Stuetzle, Peter Fox, W. Randolph Franklin

Computer and Data Science Faculty Publications

This paper describes a 3D environmental data compression technique for oceanographic datasets. With proper point selection, our method approximates uncompressed marine data using an over-determined system of linear equations based on, but essentially different from, the Laplacian partial differential equation. Then this approximation is refined via an error metric. These two steps work alternatively until a predefined satisfying approximation is found. Using several different datasets and metrics, we demonstrate that our method has an excellent compression ratio. To further evaluate our method, we compare it with 3D-SPIHT. 3D-ODETLAP averages 20% better compression than 3D-SPIHT on our eight test datasets, from …


The Effect Of Enrollment In Middle School Challenge Courses On Advanced Placement Exams In Social Studies And Science, Katherine Glaude-Bolte Nov 2010

The Effect Of Enrollment In Middle School Challenge Courses On Advanced Placement Exams In Social Studies And Science, Katherine Glaude-Bolte

Dissertations

Educators seek to guide students through appropriate programs and courses that prepare them for future success, in more advanced coursework and in other challenges of life. Some middle schools offer Challenge, or honors, courses for students who have demonstrated high ability. High schools often offer Advanced Placement (AP) courses, which are taught at the college level. This study examined the correlation between enrollment in middle school Challenge courses and subsequent AP exam category scores in social studies and science in a suburban school district. The independent variables were the number of years of enrollment in middle school social studies or …


Intracranial Cavernous Angiomas, Syed Faraz Kazim, Atta-Ul-Aleem Bhatti, Ather Enam Nov 2010

Intracranial Cavernous Angiomas, Syed Faraz Kazim, Atta-Ul-Aleem Bhatti, Ather Enam

Section of Neurosurgery

Objective: To describe the clinical presentation, diagnosis, and management of patients presenting with intracranial cavernous angiomas (CAs) at a tertiary care hospital in Pakistan.
Study Design: Case series. Place and Duration of Study: Section of Neurosurgery, The Aga Khan University Hospital (AKUH), Karachi, from January 1990 to September 2008.
Methodology: A retrospective case note review of all patients diagnosed with intracranial CAs at AKUH during the study period. The studied variables included patient demographics, clinical presentation, family history of intracranial CAs or other space occupying lesions, modality of diagnosis, management, and outcome. Results were described as frequency percentages.
Results: During …


Autonomous Underwater Vehicles As Tools For Deep-Submergence Archaeology, Christopher N. Roman, Ian Roderick Mather Nov 2010

Autonomous Underwater Vehicles As Tools For Deep-Submergence Archaeology, Christopher N. Roman, Ian Roderick Mather

Graduate School of Oceanography Faculty Publications

Marine archaeology beyond the capabilities of scuba divers is a technologically enabled field. The tool suite includes ship-based systems such as towed side-scan sonars and remotely operated vehicles, and more recently free-swimming autonomous underwater vehicles (AUVs). Each of these platforms has various imaging and mapping capabilities appropriate for specific scales and tasks. Broadly speaking, AUVs are becoming effective tools for locating, identifying, and surveying archaeological sites. This paper discusses the role of AUVs in this suite of tools, outlines some specific design criteria necessary to maximize their utility in the field, and presents directions for future developments. Results are presented …


Leaf Area, Worker Size, And Number Of Hitchhiking Minima In Atta Cephalotes, November 2010, Daniel Shimek Nov 2010

Leaf Area, Worker Size, And Number Of Hitchhiking Minima In Atta Cephalotes, November 2010, Daniel Shimek

Monteverde Institute: Tropical Ecology and Conservation

Several species of leaf-cutter ants, including Atta cephalotes, exhibit an interesting behavior of hitchhiking minima. Minima are the smallest of the polymorphic castes of leaf-cutter ants and the function and origin of this hitchhiking behavior is not completely understood. There are several hypotheses for this behavior, and the most popular include defense against parasites and cleaning the leaf fragment of contaminants. Studies have investigated some patterns of hitchhiking behavior including different frequencies during day and night and distance from colony. This study examined the relationship between head width, leaf area and the number of hitchhiking minima in A. cephalotes. Ants …


Differences In Atta Cephalotes Foraging Rate And Amount Of Substrate Harvested Following The Introduction Of An Antifungal Agent, November 2010, Benjamin Hedin Nov 2010

Differences In Atta Cephalotes Foraging Rate And Amount Of Substrate Harvested Following The Introduction Of An Antifungal Agent, November 2010, Benjamin Hedin

Monteverde Institute: Tropical Ecology and Conservation

Optimal foraging theory dictates animals will behave in the most energetic favorable fashion, maximizing energy gained while minimizing energy lost. However, exceptions do exist, such as mating behaviors and predator avoidance. I show that oat flakes contaminated with antifungal powder, simulating secondary compounds, are selected less and at a lower rate by a colony of Atta cephalotes. This demonstrates the ability of the colony to recognize and discriminate against the contaminant to protect their symbiotic fungus. It also suggests that leafcutters, to an extent, can detect the amount or toxicity of the secondary compound. The willingness of the ants to …


Host Genes Associated With Hiv-1 Replication In Lymphatic Tissue, Anthony J. Smith, Qingsheng Li, Stephen W. Wietgrefe, Timothy W. Schacker, Cavan S. Reilly, Ashley T. Haase Nov 2010

Host Genes Associated With Hiv-1 Replication In Lymphatic Tissue, Anthony J. Smith, Qingsheng Li, Stephen W. Wietgrefe, Timothy W. Schacker, Cavan S. Reilly, Ashley T. Haase

Qingsheng Li Publications

Much effort has been spent recently in identifying host factors required for HIV-1 to effectively replicate in cultured human cells. However, much less is known about the genetic factors in vivo that impact viral replication in lymphatic tissue, the primary anatomical site of virus-host interactions where the bulk of viral replication and pathogenesis occur. In order to identify genetic determinants in lymphatic tissue that critically affect HIV-1 replication, we used microarrays to transcriptionally profile and identify host genes expressed in inguinal lymph nodes that were associated determinants of viral load. Strikingly, ~95% of the transcripts (558) in this data set …