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Nitric Oxide Is Involved In Growth Regulation And Re-Orientation Of Pollen Tubes, Ana Margarida Prado, D. M. Porterfield, José A. Feijó Jun 2004

Nitric Oxide Is Involved In Growth Regulation And Re-Orientation Of Pollen Tubes, Ana Margarida Prado, D. M. Porterfield, José A. Feijó

Biological Sciences Faculty Research & Creative Works

Nitric oxide (NO) controls diverse functions in many cells and organs of animals. It is also produced in plants and has a variety of effects, but little is known about their underlying mechanisms. in the present study, we have discovered a role for NO in the regulation of pollen tube growth, a fast tip-growing cellular system. Pollen tubes must be precisely oriented inside the anatomically complex female ovary in order to deliver sperm. We hypothesized that NO could play a role in this guidance and tested this hypothesis by challenging the growth of pollen tubes with an external NO point …


Allometry Of Kinematics And Energetics In Carpenter Bees (Xylocopa Varipuncta) Hovering In Variable-Density Gases, Stephen P. Roberts, Jon F. Harrison, Robert Dudley Feb 2004

Allometry Of Kinematics And Energetics In Carpenter Bees (Xylocopa Varipuncta) Hovering In Variable-Density Gases, Stephen P. Roberts, Jon F. Harrison, Robert Dudley

Biological Sciences Faculty Research & Creative Works

We Assessed the Energetic and Aerodynamic Limits of Hovering Flight in the Carpenter Bee Xylocopa Varipuncta. using Normoxic, Variable-Density Mixtures of O2, N2 and He, We Were Able to Elicit Maximal Hovering Performance and Aerodynamic Failure in the Majority of Bees Sampled. Bees Were Not Isometric Regarding Thorax Mass and Wing Area, Both of Which Were Disproportionately Lower in Heavier Individuals. the Minimal Gas Density Necessary for Hovering (MGD) Increased with Body Mass and Decreased with Relative Thoracic Muscle Mass. Only the Four Bees in Our Sample with the Highest Body Mass-Specific Thorax Masses Were Able to Hover in Pure …


Identifying Character Non-Independence In Phylogenetic Data Using Data Mining Techniques, Jennifer Leopold, Anne M. Maglia, M. Thakur, B. Patel, Fikret ErçAl Jan 2004

Identifying Character Non-Independence In Phylogenetic Data Using Data Mining Techniques, Jennifer Leopold, Anne M. Maglia, M. Thakur, B. Patel, Fikret ErçAl

Computer Science Faculty Research & Creative Works

Undiscovered relationships in a data set may confound analyses, particularly those that assume data independence. Such problems occur when characters used for phylogenetic analyses are not independent of one another. A main assumption of phylogenetic inference methods such as maximum likelihood and parsimony is that each character serves as an independent hypothesis of evolution. When this assumption is violated, the resulting phylogeny may not reflect true evolutionary history. Therefore, it is imperative that character non-independence be identified prior to phylogenetic analyses. To identify dependencies between phylogenetic characters, we applied three data mining techniques: 1) Bayesian networks, 2) decision tree induction, …


Lead Tolerant Bacteria Could Be The Future Of Bioremediation, Kendra Waltermire Jan 2004

Lead Tolerant Bacteria Could Be The Future Of Bioremediation, Kendra Waltermire

Opportunities for Undergraduate Research Experience Program (OURE)

The contamination of soil, sediment, and water by toxic metals is a major problem worldwide, both environmentally, and economically. Microorganisms that are resistant to lead are rare in nature. Lead is toxic to most microorganisms and only a few have developed mechanisms to survive in this toxic environment In this study, bacteria found in soil and water with high concentrations of soluble lead are isolated and characterized. I grew and isolated bacteria that are resistant to the lead found in the solid medium. A gram stain was used to characteristically determine the bacteria that were isolated. Four isolated bacteria were …


An Intelligent Dissolved Oxygen Microsensor System With Electrochemically Actuated Fluidics, Chang-Soo Kim, Jongwon Park, Xinbo He Jan 2004

An Intelligent Dissolved Oxygen Microsensor System With Electrochemically Actuated Fluidics, Chang-Soo Kim, Jongwon Park, Xinbo He

Electrical and Computer Engineering Faculty Research & Creative Works

A new dissolved oxygen monitoring microsystem is proposed to achieve in situ intelligent self-calibration by using an electrochemically actuated fluidic system. The electrochemical actuation, based on water electrolysis, plays two critical roles in the proposed microsystem. First, the electrochemically generated gases serve as the calibrants for the in situ 2-point calibration/diagnosis procedure of the microsensor in a chip. Secondly, the electrochemical generation and collapse of gas bubbles provide the driving force of the bidirectional fluidic manipulation for sampling and dispensing of the sample solution. A microsystem including a dissolved oxygen microprobe, electrochemical actuators, and a fluidic structure are prepared by …


Manipulation Of Microenvironment With A Built-In Electrochemical Actuator In Proximity Of A Dissolved Oxygen Microsensor, Chang-Soo Kim, J. O. Fiering, C. W. Scarantino, H. Troy Nagle, Chae-Hyang Lee, Stefan Ufer Jan 2004

Manipulation Of Microenvironment With A Built-In Electrochemical Actuator In Proximity Of A Dissolved Oxygen Microsensor, Chang-Soo Kim, J. O. Fiering, C. W. Scarantino, H. Troy Nagle, Chae-Hyang Lee, Stefan Ufer

Electrical and Computer Engineering Faculty Research & Creative Works

Biochemical sensors for continuous monitoring require dependable periodic self diagnosis with acceptable simplicity to check its functionality during operation. An in-situ self-diagnostic technique for a dissolved oxygen microsensor is proposed in an effort to devise an intelligent microsensor system with an integrated electrochemical actuation electrode. With a built-in platinum microelectrode that surrounds the microsensor, two kinds of microenvironments, called the oxygen-saturated or oxygen-depleted phases, can be created by water electrolysis, depending on the polarity. The functionality of the microsensor can be checked during these microenvironment phases. The polarographic oxygen microsensor is fabricated on a flexible polyimide substrate (Kapton) and the …


A Method For Enhancing The Snapshot Performance In San Volume Manager, Chang-Soo Kim, Dong-Jae Kang, Young-Ho Kim, Hag-Young Kim, Myoung-Jun Kim, Yu-Hyeon Bak Jan 2004

A Method For Enhancing The Snapshot Performance In San Volume Manager, Chang-Soo Kim, Dong-Jae Kang, Young-Ho Kim, Hag-Young Kim, Myoung-Jun Kim, Yu-Hyeon Bak

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.