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Full-Text Articles in Physical Sciences and Mathematics

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr Nov 2008

Leading Firms As Knowledge Gatekeepers In A Networked Environment, Deogratias Harorimana Mr

Dr Deogratias Harorimana

This chapter introduces the role of the knowledge gatekeeper as a mechanism by which knowledge is created and transferred in a networked environment. Knowledge creation and transfer are essential for building a knowledge based economy. The chapter considers obstacles that inhibit this process and argues that leading firms create a shared socio-cultural context that enables the condivision of tacit meanings and codification of knowledge. Leading firms act as gatekeepers of knowledge through the creation of shared virtual platforms. There will be a leading firm that connects several networks of clients and suppliers may not interact directly with one another, but …


Microproteomics: Analysis Of Protein Diversity In Small Samples, Howard B. Gutstein, Jeffrey S. Morris, Suresh P. Annangudi, Jonathan V. Sweedler Feb 2008

Microproteomics: Analysis Of Protein Diversity In Small Samples, Howard B. Gutstein, Jeffrey S. Morris, Suresh P. Annangudi, Jonathan V. Sweedler

Jeffrey S. Morris

Proteomics, the large-scale study of protein expression in organisms, offers the potential to evaluate global changes in protein expression and their post-translational modifications that take place in response to normal or pathological stimuli. One challenge has been the requirement for substantial amounts of tissue in order to perform comprehensive proteomic characterization. In heterogeneous tissues, such as brain, this has limited the application of proteomic methodologies. Efforts to adapt standard methods of tissue sampling, protein extraction, arraying, and identification are reviewed, with an emphasis on those appropriate to smaller samples ranging in size from several microliters down to single cells. The …


Optimal Switching Control For Microbial Fed-Batch Culture, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin Jan 2008

Optimal Switching Control For Microbial Fed-Batch Culture, Chongyang Liu, Zhaohua Gong, Enmin Feng, Hongchao Yin

Chongyang Liu

In fed-batch culture of glycerol bio-dissimilation to 1,3-propanediol (1,3-PD), the aim of adding glycerol is to obtain as much 1,3-PD as possible. Hence, a proper feed strategy is required during the process. In this paper, we present an optimal switching control model based on our proposed controlled switching system. Some properties of the controlled switching system are obtained. Subsequently, we prove the existence of optimal control. In order to deduce the optimality conditions, we transcribe the optimal switching control model into an equivalent one with fixed switching instants and parameters. Finally, the optimality conditions of the equivalent problem are investigated …


Identification Of Intracellular Kinetic Parameters In Continuous Bioconversion Of Glycerol By Klebsiella Pneumoniae, Enmin Feng, Chongyang Liu, Zhaohua Gong, Yaqin Sun Jan 2008

Identification Of Intracellular Kinetic Parameters In Continuous Bioconversion Of Glycerol By Klebsiella Pneumoniae, Enmin Feng, Chongyang Liu, Zhaohua Gong, Yaqin Sun

Chongyang Liu

In this paper, we propose a hybrid nonlinear dynamical system to describe the concentration changes of extracellular and intracellular substances of glycerol bioconversion to 1,3- propanedol (1,3-PD) in microbial continuous cultures. It is proved that the solution to the system exists and is continuous with respect to kinetic parameters. Subsequently, a novel quantitative definition of biological robustness is investigated. We present a performance index based on experiment data of extracellular concentrations and biological robustness. Taking the proposed hybrid nonlinear dynamical system as a constraint, we establish an identification model to determine the most reasonable metabolic pathway and optimal kinetic parameters. …


Climate Change And Freshwater Resources, Noah D. Hall, Bret B. Stuntz, Robert H. Abrams Jan 2008

Climate Change And Freshwater Resources, Noah D. Hall, Bret B. Stuntz, Robert H. Abrams

Noah D Hall

The Earth’s climate is warming. This is the unequivocal conclusion of climate scientists. Despite the complexities of climatology, certain consistent trends emerge with implications for water availability: as the world gets warmer, it will experience increased regional variability in precipitation, with more frequent heavy precipitation events and more susceptibility to drought. These simple facts will have a profound impact on freshwater resources throughout the United States, as the warmer climate will reduce available water supplies and increase water demand. Unfortunately, current water law and policy are not up to the new challenges of climate change and resulting pressures on freshwater …


Stoichiometric Network Analysis And Associated Dimensionless Kinetic Equations. Application To A Model Of The Bray-Liebhafsky Reaction, Zeljko D. Cupic Jan 2008

Stoichiometric Network Analysis And Associated Dimensionless Kinetic Equations. Application To A Model Of The Bray-Liebhafsky Reaction, Zeljko D. Cupic

Zeljko D Cupic

No abstract provided.


When Fairness Bends Rationality: Ernst Fehr Meets John Nash, Alessandro Tavoni Jan 2008

When Fairness Bends Rationality: Ernst Fehr Meets John Nash, Alessandro Tavoni

Alessandro Tavoni

No abstract provided.


Using The Estimated Penetrances To Determine The Range Of The Underlying Genetic Model In Case-Control Design, Mark J. Meyer, Neal Jeffries, Gang Zheng Jan 2008

Using The Estimated Penetrances To Determine The Range Of The Underlying Genetic Model In Case-Control Design, Mark J. Meyer, Neal Jeffries, Gang Zheng

Mark J Meyer

It is well known that the penetrance cannot be estimated using the retrospective case- control samples without making additional assumptions. In the literature the estimation of the penetrance is based on the assumptions that either the disease is rare or the disease prevalence is known. We propose an alternative approach to estimate the penetrance by assuming an underlying genetic model even though it is unknown. With this assumption, we can obtain the point estimates of the penetrances as functions of the genetic model, from which the range of underlying genetic models can be determined. We examine the performance of our …


Climate Change And Carbon Sequestration: Assessing A Liability Regime For Long-Term Storage Of Carbon Dioxide, Alexandra B. Klass, Elizabeth J. Wilson Jan 2008

Climate Change And Carbon Sequestration: Assessing A Liability Regime For Long-Term Storage Of Carbon Dioxide, Alexandra B. Klass, Elizabeth J. Wilson

Alexandra B. Klass

As the nation struggles with how to address climate change, one of the most significant questions is how to reduce increasing levels of carbon dioxide in the atmosphere. One promising technology is carbon capture and sequestration (“CCS”), which consists of capturing carbon dioxide emissions from power plants and industrial sources and sequestering them in deep geologic formations for long periods of time. Areas for potential CO2 sequestration include oil and gas fields, saline aquifers, and coal seams. As Congress and the private sector begin to spend billions of dollars to research and deploy this technology, there has been insufficient attention …


Important, But Odd And Obscure, Reasons To Use The Library, Maxine G. Schmidt Jan 2008

Important, But Odd And Obscure, Reasons To Use The Library, Maxine G. Schmidt

Maxine G Schmidt

No abstract provided.