Cycles in Metabolic Networks

Modeling sophisticated biological systems in a way that makes them more apprehensible, without losing comprehension or robustness, is challenging task. The flux balance analysis FBA) model describes metabolic networks of single-celled organisms with the goal of simulating their steady-state behavior. FBA simulations yield reliable and biologically relevant growth rate values, but do not simulate intra-cellular behavior well. Solutions to the FBA model are often degenerate and non-unique. Ideally, the model should simulate metabolic activity in exactly one way under any given circumstances--the way the real organism\u27s metabolism behaves. The ultimate goal of this project is to better understand the FBA model in order to improve it, so that this ideal may be more achievable. An overview of biological networks, metabolism, and FBA is given to familiarize the reader. Dominance, the amount that a reaction dominates consumption or production of its reactants and products over other reactions, is used to define a partition of the metabolism that groups reactions with similar properties. The term minimal environment is defined to describe a set of metabolic resources that are limiting for a certain growth rate, and an algorithm is developed for finding the minimal environment of a metabolic network. Dominance is found to be an indicator for certain regions of the network that are cyclic, and thus problematic. An algorithm is developed for finding cycles in a graph, which is then applied to the metabolic network. The complexity of this algorithm when applied to E. coli makes it too computationally diffcult to be used, but the algorithm is useful in other respects

An Exploration Using Narrative Analysis of How Employers and College Student Interns View and Explain the Development of the Career Readiness Competency, Leadership

According to the National Association of Colleges and Employers (NACE), career readiness “has been undefined, making it difficult for leaders in higher education, workforce development, and public policy to work together effectively to ensure the career readiness of today’s graduates” (2016, p. 1). Students rate themselves high for each of the career competencies and believe they are ready for the workforce. Employers disagree and state that students need more competency development during college. Exploring the misconceptions and miscommunications about the leadership competency could be a first step in closing the gap for all of the career readiness competencies. By determining what leadership type best aligns with internship experiences from a college student’s perspective and an employer’s perspective could help in developing more productive and intentional learning opportunities. In this study, I compare the transactional leadership, transformational leadership, and servant leadership types as they relate to the internship experience. I find that students frequently describe leadership experiences using language aligning with transactional and transformational leadership, while mentors use language that does not align with any of the leadership types chosen. As Strong et al. (2013) point out in their encouragement for more leadership-oriented research, “faculty would gain a better understanding of their students and may better understand the leadership experience” (p. 182). As next steps, further research should be completed to see if other leadership types better align with the mentor comments

The role of ferric reduction oxidases in plant anti-herbivore defense.

Iron is an essential element required for plants to carry out metabolic functions such as photosynthesis, heme biosynthesis, and chlorophyll biosynthesis. Within Arabidopsis thaliana, eight ferric reduction oxidase (FRO) genes function in iron uptake and homeostasis with tissue specific expression. However, little else is known regarding the biological role of FROs. Recent studies identify the FRO gene family as particularly responsive to the green leaf plant derived volatile (GLV) cis-3-hexenyl acetate (z3HAC). Since z3HAC acts as a wound signal and cues unaffected parts of the plant to prime defenses prior to herbivory, an increase in FRO activity in response to volatile perception may suggest that these metalloreductases play a role in plant anti-herbivore defense. The objective of this study was to measure transcriptional responses of FROs to herbivore oral secretions (OS) and plant-derived volatile cues. Results of this study show FROs differentially increase expression levels in response to herbivory and volatile exposure. Specifically, z3HAC alone induced expression of FRO3, FRO4, and FRO6. In addition, a number of FROs were primed by the combination of z3HAC and Spodoptera exigua OS including FRO4 and FRO7, suggesting iron homeostasis in leaves may be important in plant anti-herbivore defense. Future work needs to identify a mechanism linking FROs and herbivory

Collegial Mentorship

Mentoring is typically thought of as a top-down process, but it can also be based on collegial mentorship. This article describes an example of peer-to-peer mentoring that helped advance research in the field in field of information systems

METAPLEX: AN INTEGRATED ENVIRONMENT FOR ORGANIZATION AND INFORMATION SYSTEMS DEVELOPMENT

This paper presents an integrated environment, called MetaPlex; for organization and information systems development. The kernel of MetaPlex is a knowledge base management system which captures the semantic primitives of a domain at the meta level and uses these primitives to describe target systems. Three levels of abstraction are used in MetaPlex for representing knowledge: the axiomatic, median, and instance levels. The MetaPlex Language Definition System is used to name the object types in the domain of interest and to define the attributes, relations, and descriptions which can be used by these object types. The structural knowledge of the domain in general is thus captured at the median level. Knowledge of the domain captured at the median level is used by the MetaPlex Specification System to define a target system at the instance level. A rule-based inference engine is embedded in the MetaPlex environment as an intelligent assistant to help end users. The expertise of a designer can be codified into a rule set which can assist users in classifying an object, in decomposing a high level system component, or in clustering the detailed components at the lower level. Both topdown and bottom-up approaches for systems development are thus supported. A layered approach has been proposed to manage the dynamics of such a metasystem environment. An enterprise model has been developed to demonstrate the usage of MetaPlex and the integration of organization and information systems modeling. Directions for future research are also discussed

Automation and Robotics For the Space Station: The Influence of the Advanced Technology Advisory Committee

The creation of the Advanced Technology Advisory Committee (ATAC) was mandated by Congress in 1984 for the purpose of identifying specific systems of the Space Station which would advance automation and\u27robotics technologies. The initial ATAC report, released in 1985, proposed goals for automation and robotics applications for the initial and evolutionary space stations , as well as recommendations for implementation strategies of these goals. These recommendations have been accepted as policy by NASA. Since that initial report, ATAC has continued to release semiannual reports on Space Station\u27s progress in automation and robotics, including areas of concern and further recommendations. This paper will review the history of ATAC and its future. Previously ATAC has been an external force to push the use of automation and robotics on the Space Station. ATAC also promotes the development of state-of-the-art technology in automation and robotics , which is crucial due to the lack of off-the-shelf items. Now that we are approaching the final design and development stages of the Station, actual implementation on the initial Station and provisions for future incorporation of automation and robotics on the evolutionary Station are critical. Where ATAC goes from here and what possible impacts it will have, are discussed