Digital Commons Network^™

Emergence Of Bimodal Cell Population Responses From The Interplay Between Analog Single-Cell Signaling And Protein Expression Noise., Marc R Birtwistle, Jens Rauch, Anatoly Kiyatkin, Edita Aksamitiene, Maciej Dobrzyński, Jan B. Hoek, Walter Kolch, Babatunde A Ogunnaike, Boris N Kholodenko

Department of Pathology, Anatomy, and Cell Biology Faculty Papers

BACKGROUND: Cell-to-cell variability in protein expression can be large, and its propagation through signaling networks affects biological outcomes. Here, we apply deterministic and probabilistic models and biochemical measurements to study how network topologies and cell-to-cell protein abundance variations interact to shape signaling responses.

RESULTS: We observe bimodal distributions of extracellular signal-regulated kinase (ERK) responses to epidermal growth factor (EGF) stimulation, which are generally thought to indicate bistable or ultrasensitive signaling behavior in single cells. Surprisingly, we find that a simple MAPK/ERK-cascade model with negative feedback that displays graded, analog ERK responses at a single cell level can explain the experimentally …

Measurement Of The Differential Cross Section Dσ/Dt In Elastic Pp- Scattering At √S = 1.96 Tev, David Hedin

Faculty Articles, Papers, and Other Scholarship

We present a measurement of the elastic differential cross section dσ( pp-→ pp-)/dt as a function of the four-momentum-transfer squared t. The data sample corresponds to an integrated luminosity of ≈ 31 nb-1 collected with the D0 detector using dedicated Tevatron pp- Collider operating conditions at √s = 1.96 TeV and covers the range 0.26 < │t │ < 1:2 GeV2. For │t│< 0.6 GeV2, dσ/dt is described by an exponential function of the form Ae-b│t│with a slope parameter b = 16.86 ± 0.10(stat) ± 0.20(syst) GeV-2. A change in slope is observed at │t│≈ 0.6 GeV2, followed by a more gradual │t│ dependence with increasing values of │t│.

Combination Of The Top Quark Mass Measurements From The Tevatron Collider, David Hedin

Faculty Articles, Papers, and Other Scholarship

The top quark is the heaviest known elementary particle, with a mass about 40 times larger than the mass of its isospin partner, the bottom quark. It decays almost 100% of the time to a W boson and a bottom quark. Using top-antitop pairs at the Tevatron proton-antiproton collider, the CDF and D0 Collaborations have measured the top quark’s mass in different final states for integrated luminosities of up to 5.8 fb-1. This paper reports on a combination of these measurements that results in a more precise value of the mass than any individual decay channel can provide. It describes …

The Spatial-Temporal Dynamics Of China’S Changing Urban Hierarchy (1950–2005), Xuwei Chen, Richard Greene

Faculty Articles, Papers, and Other Scholarship

This paper examines the dynamic spatial and temporal patterns of China’s urban hierarchy from 1950 to 2005. We limit the study to mainland China’s 137 urban agglomerations of 750,000 or more population as of 2005. The paper improves upon a classic approach to measuring shifting ranks within an urban hierarchy by applying advanced spatial analysis techniques. We use a Getis-Ord G∗ i , a space-timeMoran scatter plot, and dynamic LISA paths to examine the regional difference and change for these urban agglomerations. Our study revealed a north-south divide in the changing urban hierarchy of China after 1990. The analysis demonstrated …

Glacial Deposits, Vol. 40, 2011-2012, Department Of Geography-Geology

Glacial Deposits

Newsletter of the Department of Geography-Geology

Variations In Pore Water Salinities Above And Below Allochthonous Salt Sheets In The Deepwater Gulf Of Mexico: Implications For Mechanisms Of Solute Transport, Miles Alexander Mccammon

LSU Master's Theses

Spatial variations in salinity of pore waters in marine sediments provide useful information on processes and rates of subseafloor fluid flow and solute transport, particularly if there are evaporites in the section. Pore water salinities were determined for 18 drill holes which penetrated allochthonous salt bodies in 12 widely-scattered protraction blocks on the Louisiana offshore continental shelf and slope. Salinities were calculated from Log ASCII Standard-Logging While Drilling (LAS-LWD) logs using the Revil et al. (1998) dual-conductivity technique. The sites represent a wide range of field settings. Water depths range from 30 to 1990 m, depths to the top of …

Improving Middle School Math Achievement Using A Web-Based Program And Extended Written Tasks, Sarah Claire Dyer

LSU Master's Theses

This thesis outlines a dual-intensity approach using a web-based program, MyMathLab, for procedural fluency and, in parallel, extended written tasks for helping students improve their reasoning skills, to learn to use multiple representations, and securing mathematical knowledge. The new Common Core State Standards have increased expectations and achievement goals at all grade levels, the required changes being most significant at earlier grade levels (in elementary and middle schools). It is my assertion that a combined approach, one that encompasses both procedure-oriented practice for fluency and extended written tasks designed to stretch thinking and reasoning is needed to meet these goals.

A Seismic Attribute Study To Assess Well Productivity In The Ninilchik Field, Cook Inlet Basin, Alaska, Andrew Sampson

LSU Master's Theses

Coal bed methane which has formed in the Tertiary Kenai Group strata has been produced from the Ninilchik field of Cook Inlet, Alaska since 2001. Ninilchik field is located on the eastern margin of the central Cook Inlet along the Kenai Peninsula. Cook Inlet is a forearc basin and is characterized by northeast trending anticlines with upwards of 10,000 feet of Late Oligocene and younger, non-marine sediments. Highly variable well production within the Oligocene to Miocene Tyonek formation of the Kenai Group has been a source of uncertainty. A series of seismic attributes visualized in Schlumberger's Petrel® software were studied …

Biomass And Mass Balance Isotope Content Of Mussel Seep Populations, Philip Martin Riekenberg

LSU Master's Theses

Cold seep mussels, Bathymodiolus childressi, are common cold seep constituents that form large populations at upper continental slope (500-1000 m) cold seep sites in the Northern Gulf of Mexico. These mussels utilize methane present through symbiotic relationships with methanotrophic bacteria. This study uses a coupled isotope technique to determine the relative incorporation of respiratory carbon in the shell as a measure of the availability of methane between different seep sites. This method indicates a higher abundance of methane at the Brine Pool site than at the Bush Hill site which appears significantly more resource limited and that changes in methane …

Implications Of Geothermal History On Microbial Gas Generation And Coalbed Methane Production In The Ninilchik Field, Cook Inlet Basin, Alaska, Eric M. Hart

LSU Master's Theses

Coalbed methane (CBM) production operations atop the Ninilchik anticline of Cook Inlet, Alaska pose intriguing questions regarding the nature of biogenic gas generation in a thermally complex forearc basin setting. This thermal complexity stems, in part, from its up to 30,000 ft thick Tertiary section, comprised of braided stream alluvium and expansive, interbedded coal deposits. Rapid accumulation of cold, glacial strata is documented as being capable of regionally suppressing the elevated heat flux values expected within a forearc basin. In addition, beds with high organic content, such as the coal layers, act as natural insulators from basinal heat flux and …

Simulations Of The Primary Cement Placement In Annular Geometries During Well Completion Using Computational Fluid Dynamics (Cfd), Muhammad Zulqarnain

LSU Master's Theses

Effective zonal isolation during primary cementing is only possible when drilling mud in the annulus is completely displaced with cement, while the spacers aid in this process. During the displacement process the rheological properties of fluids used and the operating conditions control the motion of different fluids interfaces; desired stable interfacial displacement leads to piston like motion. Computational Fluid Dynamics (CFD) tool with the Volume-of-Fluid (VOF) has been validated against experimental and used to conduct numerical experiments in a virtual well model consisting of 50 ft vertical section of 8.765" x 12.5" annulus having initially mud and this mud is …

Consensusability Of Discrete-Time Multi-Agent Systems, Abhishek Pandey

LSU Master's Theses

The study of multi-agent systems (MAS) focuses on systems in which many intelligent agents interact within an environment. The agents are considered to be autonomous entities. MAS can be used to solve problems that are difficult or impossible for an individual agent to solve. The main feature which is achieved when developing MAS, if they work, is flexibility, since MAS can be added to, modified and reconstructed, without the need for detailed rewriting of the application. MAS can manifest self-organization as well as self-steering related complex behaviors even when the individual strategies of all their agents are simple. The goal …

Paley-Wiener Theorem For Line Bundles Over Compact Symmetric Spaces, Vivian Mankau Ho

LSU Doctoral Dissertations

We generalize a Paley-Wiener theorem to homogeneous line bundles $L_\chi$ on a compact symmetric space U/K with $\chi$ a nontrivial character of K. The Fourier coefficients of a $\chi$-bi-coinvariant function f on U are defined by integration of f against the elementary spherical functions of type $\chi$ on U, depending on a spectral parameter $\mu$, which in turn parametrizes the $\chi$-spherical representations $\pi$ of U. The Paley-Wiener theorem characterizes f with sufficiently small support in terms of holomorphic extendability and exponential growth of their $\chi$-spherical Fourier transforms. We generalize Opdam's estimate for the hypergeometric functions in a bigger domain with …

Palynostratigraphy Of The Umir Formation, Middle Magdalena Valley Basin (Mmvb) Colombia, Carlos Enrique Santos

LSU Master's Theses

The Late Cretaceous Umir Formation in Middle Magdalena Valley Basin (MMVB) was recently acknowledged as a new target. However, there is little known about the regional distribution of the Umir Formation since it is affected by structural complexity and a major regional unconformity. To improve biosteering of the Umir Formation and reduce exploratory risks, a detailed biostratigraphic analysis of the Umir Formation in the MMVB is presented. Eighty samples from four cores drilled in the Central Eastern MMVB were analyzed for palynological content. These cores represent 976.6 meters of the Middle to Upper Umir Formation. The sediment yielded a good …

Pmi 5011 Regulates The Ubiquitin Proteasome System In Skeletal Muscle, Heather Christianne Kirk-Ballard

LSU Doctoral Dissertations

Insulin resistance in type 2 diabetes is associated with impaired glucose and protein metabolism in skeletal muscle. The impaired insulin signaling in skeletal muscle affects muscle mass by tilting the balance between skeletal muscle protein synthesis and degradation toward degradation, a process that is primarily regulated by the ubiquitin-proteasome system. Studies have shown that an extensively characterized ethanol extract of Artemisia dracunculus L (Russian Tarragon), termed PMI 5011, enhances insulin signaling in human primary skeletal muscle cells and in a rodent model of insulin resistance. The aim of this project is to determine if the effect of PMI 5011 on …

A Study Of Turnaround Efforts In High-Poverty Schools: Characteristics Of High Reliability Organizations That Determine Why Some Efforts Succeed And Others Fail, Angela Renee Lee

LSU Doctoral Dissertations

The inception of No Child Left Behind (NCLB) has focused national attention on improving the academic achievement of all students. In response to this federal legislation, educators, policymakers and others have sought remedies to turnaround chronically low-performing schools. The academic achievement outcomes of implementing such strategies have been mixed. Some schools have experienced clear, unambiguous growth. Others have remained stagnant. Others have regressed. Because of these mixed results, the research was designed to ascertain the factors that determine what makes these strategies succeed or fail. The researcher took a qualitative approach, the multiple case study design. Using the characteristics of …

Chemical Crystallography At The Interface Of Physics, Chemistry, And In Engineering: Structure Determination Of Highly Correlated Extended Solids, Main Group Compounds, Coordination Complexes, And Bioceramics, Gregory Todd Mccandless

LSU Doctoral Dissertations

Multi-disciplinary research is essential to address the major challenges in science, engineering, and medicine. For these three areas, crystallography has played and continues to play a huge role by providing researchers with the means to determine the structure of a compound and relate these to its properties. This dissertation is highly interdisciplinary, focusing on structure determination of complex systems and materials with tailored applications. This work includes the characterization by single crystal and powder X-ray diffraction of intermetallic extended solids, layered metal oxides, inorganic complexes, discrete organic molecules, and bioceramics. These projects range from modeling translational disorder with pseudo-hexagonal symmetry …

The Head And Tail Conjecture For Alternating Knots, Cody Armond

LSU Doctoral Dissertations

The colored Jones polynomial is an invariant of knots and links, which produces a sequence of Laurent polynomials. In this work, we study new power series link invariants, derived from the colored Jones polynomial, called its head and tail. We begin with a brief survey of knot theory and the colored Jones polynomial in particular. In Chapter 3, we use skein theory to prove that for adequate links, the n-th leading coefficient of the N-th colored Jones polynomial stabilizes when viewed as a sequence in N. This property allows us to define the head and tail for adequate links. In …

Some Tracking Problems For Aerospace Models With Input Constraints, Aleksandra Gruszka

LSU Doctoral Dissertations

We study tracking controller design problems for key models of planar vertical takeoff and landing (PVTOL) aircraft and unmanned air vehicles (UAVs). The novelty of our PVTOL work is the global boundedness of our controllers in the decoupled coordinates, the positive uniform lower bound on the thrust controller, the applicability of our work to cases where the velocity measurements may not be available, the uniform global asymptotic stability and uniform local exponential stability of our closed loop tracking dynamics, the generality of our class of trackable reference trajectories, and the input-to-state stability of the controller performance under actuator errors of …

Monitoring The Molecular Weight Of Poly(Lactic Acid) During Fiber Spinning And Coloration, Ashley Nicole Jacobs

LSU Master's Theses

One fiber that is being researched as a possible alternative to the petroleum based polyester fibers currently being used is polylactic acid (PLA). Being aware of the low heat resistance and degradation of PLA during processing is a concern for practical production and the performance of the polymer. Disperse dyed PLA film and solution dyed PLA film, along with un-dyed film and the original PLA pellets have been investigated to determine molecular weight. Infrared analysis has been conducted to examine the compounds found in the PLA samples at different steps in the polymer processing. Un-dyed PLA samples have been subjected …

High-Throughput Sperm Cryopreservation Of Aquatic Species, E Hu

LSU Doctoral Dissertations

The goal of this dissertation was to integrate multiple disciplines for application of high-throughput sperm cryopreservation to aquatic species. The blue catfish Ictalurus furcatus was selected for research due to its role in production of hybrid catfish with eggs from channel catfish Ictalurus punctatus. A high-throughput cryopreservation pathway was developed by systematically evaluating each process factor and using automated processing systems. Large quantities of cryopreserved sperm produced from this protocol were evaluated in commercial-scale hatcheries in cooperation with aquaculture producers. To develop production for commercial requirements, quality characteristics of materials and products were identified and recorded during processing and analyzed …

Modeling The Spatial And Temporal Dynamics Of Coastal Marsh Birds, Bradley A. Pickens

LSU Doctoral Dissertations

Wetland birds are likely to be influenced by habitat at multiple spatial scales, yet few studies have investigated bird responses at both broad and fine scales. Northern Gulf Coast marshes are dynamic ecosystems, and they provide an ideal place to examine habitat across spatial and temporal scales. My research focused on the secretive marsh bird guild (i.e. bitterns, rails, gallinules, grebes) with an emphasis on the king rail (Rallus elegans), a species of high conservation concern. My objectives were to investigate the wetland bird-environment relationship across scales, and to model annual changes in bird distribution. Study sites were in the …

Optimal Actuation In Active Vibration Control Using Pole-Placement, Carla Ann Guzzardo

LSU Doctoral Dissertations

The purpose of this study was to find and demonstrate a method of optimal actuation in a mechanical system to control its vibration response. The overall aim is to develop an active vibration control method with a minimum control effort, allowing the smallest actuators and lowest control input. Mechanical systems were approximated by discrete masses connected with springs and dampers. Both numerical and analytical methods were used to determine the optimum force selection vector, or input vector, to accomplish the pole placement, finding the optimal location of actuators and their relative gain so that the control effort is minimized. The …

Studies On A Dirhodium Tetraphosphine Hydroformylation Catalyst, Darina Polakova

LSU Doctoral Dissertations

The dirhodium tetraphosphine catalyst [Rh2(nbd)2(rac-et,ph-P4)](BF4)2 was investigated in acetone and water/acetone in order to explain better hydroformylation results in the latter solvent. In-situ NMR spectroscopy showed slower degradation in water/acetone. Less tendency to form penta/hexacarbonyl complexes in water/acetone was shown by 31P{1H} NMR and FT-IR. A pH decrease and hydroformylation studies in presence of a base indicated formation of a monocationic monohydride species. A new reaction mechanism was suggested that takes into account the observed differences from the acetone solvent system. The presence of water enabled production of hydride species when the dirhodium catalyst was exposed to CO gas. We …

Deductive Formal Verification Of Embedded Systems, Zheng Lu

LSU Doctoral Dissertations

We combine static analysis techniques with model-based deductive verification using SMT solvers to provide a framework that, given an analysis aspect of the source code, automatically generates an analyzer capable of inferring information about that aspect.

The analyzer is generated by translating the collecting semantics of a program to a formula in first order logic over multiple underlying theories. We import the semantics of the API invocations as first order logic assertions. These assertions constitute the models used by the analyzer. Logical specification of the desired program behavior is incorporated as a first order logic formula. An SMT-LIB solver treats …

Pah Concentrations Found Within Gulf Menhaden (Brevoortia Patronus) Populations Located Off Of The South/Southeast Coast Of Louisiana, Gregory Michael Olson

LSU Master's Theses

In April 2010, large quantities of crude oil were released into the Gulf of Mexico (GoM) raising questions about the possible contamination of marine organisms with constituents of concern known as Polycyclic Aromatic Hydrocarbons (PAHs). In order to determine the impact of the Deepwater Horizon (DWH) crude oil spill, Gulf menhaden (Brevoortia patronus) were harvested from two coastal regions of Louisiana. Tissue analysis to determine total PAH concentration was conducted using an adapted matrix solid phase dispersion (MSPD) method; a Soxhlet extraction process was used to determine fish oil to mass ratios for “small” (fork length < 16 cm) and “large” (fork length > 16 cm) menhaden. Menhaden …

The Use Of Discrete Computer Simulation Modeling To Estimate The Direct And Diffusion Effects Of Leadership Development Intervention On The Return On Investment, Brett Wayne Richard

LSU Doctoral Dissertations

Organizational leaders seek monetary returns on their investments (ROI). Thus, making decisions to invest in human capital, such as in leadership development interventions, are often difficult due to the lack of research demonstrating monetary returns on development investment (RODI). Further, little research has been conducted on the diffusion effects of leadership development intervention, or returns on leadership diffusion (ROLD). This research expands on previous research conducted by Avolio, Avey & Quinsenberry (2010), which was the first attempt to estimate RODI using utility analysis. This study is unique in that it uses computer simulation modeling along with current research data to …

Potential Health Effects Of Formaldehyde Exposure, Kaylee J. Redmann

Undergraduate Theses and Senior Projects

No abstract provided.

Measuring City Commitment To Climate Change Mitigation, Kelsey Wefer Clinton

LSU Master's Theses

An increasing number of cities are focusing on sustainability and climate change mitigation by joining groups such the International Council for Local Environmental Initiatives (ICLEI). ICLEI uses a five-step milestone process to help cities achieve their mitigation goals. These milestones include conducting a greenhouse gas inventory, setting reduction targets, creating a Climate Action Plan, and implementing and monitoring that plan. Prior studies have examined factors that may influence a city’s decision to join ICLEI, but few have looked at how committed the cities are to sustainability and to ICLEI itself after joining the organization. The purpose of this study is …

Magnetic Compensation In The Bimetallic Oxalates And The Cerium Volume Collapse, Peter Leo Reis

LSU Doctoral Dissertations

In this thesis the author reports his collaborative efforts on two distinct areas of research that has been conducted. The first part of the thesis pertains to the author and his collaborators research on a particular class of organic magnets called the bimetallic oxalates. The main theme of this research was to predict magnetic compensation (magnetization reversal) in unsynthesized bimetallic oxalate structures, motivated by experiments which showed that Fe(II)Fe(III) exhibited magnetic compensation. In addition it was known that a large amount of anisotropy was present in the bimetallic oxalate structure which resulted from the intermediate oxalate molecules between the transition …