Editorial

No abstract

Holistically Evaluating Agent Based Social System Models

The philosophical perspectives on model evaluation can be broadly classified into reductionist/logical positivist and relativist/holistic. In this paper, we outline some of our past efforts in, and challenges faced during, evaluating models of social systems with cognitively detailed agents. Owing to richness in the model, we argue that the holistic approach and consequent continuous improvement are essential to evaluating complex social system models such as these. A social system built primarily of cognitively detailed agents can provide multiple levels of correspondence, both at observable and abstract aggregated levels. Such a system can also pose several challenges, including large feature spaces, issues in information elicitation with database, experts and news feeds, counterfactuals, fragmented theoretical base, and limited funding for validation. We subscribe to the view that no model can faithfully represent reality, but detailed, descriptive models are useful in learning about the system and bringing about a qualitative jump in understanding of the system it attempts to model – provided they are properly validated. Our own approach to model evaluation is to consider the entire life cycle and assess the validity under two broad dimensions of (1) internally focused validity/quality achieved through structural, methodological, and ontological evaluations; and (2) external validity consisting of micro validity, macro validity, and qualitative, causal and narrative validity. In this paper, we also elaborate on selected validation techniques that we have employed in the past. We recommend a triangulation of multiple validation techniques, including methodological soundness, qualitative validation techniques, such as face validation by experts and narrative validation, and formal validation tests, including correspondence testing

Reduction Reactions of Electrolyte Salts for Lithium Ion Batteries: LiPF6, LiBF4, LiDFOB, LiBOB, and LiTFSI

The reduction products of common lithium salts for lithium ion battery electrolytes, LiPF6, LiBF4, lithium bisoxalato borate (LiBOB), lithium difluorooxalato borate (LiDFOB), and lithium trifluorosulfonylimide (LiTFSI), have been investigated. The solution phase reduction of different lithium salts via reaction with the one electron reducing agent, lithium naphthalenide, results in near quantitative reactions. Analysis of the solution phase and head space gasses suggests that all of the reduction products are precipitated as insoluble solids. The solids obtained through reduction were analyzed with solution NMR, IR-ATR and XPS. All fluorine containing salts generate LiF upon reduction while all oxalate containing salts generate lithium oxalate. In addition, depending upon the salt other species including, LixPFyOz, LixBFy, oligomeric borates, and lithium bis[N-(trifluoromethylsulfonylimino)] trifluoromethanesulfonate are observed

Modeling the Personality & Cognition of Leaders

This paper summarizes efforts at adapting a personality profiling framework to model behavior and choices of political and military leaders. This is part of a larger project to create a role-playing, decision-making game to allow you to play out scenarios of interest against other leaders. In this modeling exercise we implement the Hermann leader personality profile tool to create historic leaders (Saladin, Richard I, etc.). We then attempt to validate the leader agents against scenarios of the 3rd Crusade

High frequency occurrence of single cotyledonary embryo morphotype and repetitive somatic embryogenesis in ‘Thompson Seedless’ crossed with seven grapevine male parents

Direct somatic embryogenesis was observed in zygotic embryos rescued from intra- and inter-specific crosses between ‘Thompson Seedless’ and seven male parents of grapevine when the embryos were cultured on Woody Plant Medium (WPM) supplemented with benzyladenine (1 μM). Repetitive somatic embryogenesis occurred on the same medium, which also supported a high percentage of embryo maturation, germination and plantlet development. The cultures retained embryogenic potential for more than two years. We observed a high frequency occurrence of monocotyledonous embryo morphotype and other morphological variations in somatic embryos of all the crosses. The percentage of embryos having mono-, di-, tri-, multiple and abnormal cotyledons varied among the crosses. The overall percentage of monocot embryos was 35.50 %, as against 38.64 % of dicot embryos, while the germination rates for mono- and dicot- embryos were 24.44 % and 24.15 %, respectively. Shoot development was poor in tri- and multiple-cotyledonary embryos, while there was no shoot formation in abnormal embryos. We assume that the relatively high occurrence of single cotyledonary morphotype may be due to the repetitive exposure of embryogenic tissues to a medium containing benzyladenine

Validating Agent Based Social Systems Models

Validating social systems is not a trivial task. The paper outlines some of our past efforts in validating models of social systems with cognitively detailed agents. It also presents some of the challenges faced by us. A social system built primarily of cognitively detailed agents can provide multiple levels of correspondence, both at observable and abstract aggregated levels. Such a system can also pose several challenges including large feature spaces, issues in information elicitation with database, experts and news feeds, counterfactuals, fragmented theoretical base, and limited funding for validation. Our own approach to validity assessment is to consider the entire life cycle and assess the validity under four broad dimensions of methodological validity, internal validity, external validity and qualitative, causal and narrative validity. In the past, we have employed a triangulation of multiple validation techniques, including face validation as well as formal validation tests including correspondence testing

Profiling is Politically \u27Correct\u27: Agent-Based Modeling of Ethno-Political Conflict

A holy grail for military, diplomatic, and intelligence analysis is a valid set of software agent models that act as the desired ethno-political factions so that one can test the effects that may arise from alternative courses of action in different lands. This article enumerates the challenges of such a testbed and describes best-of-breed leader and follower profiling models implemented to improve the realism and validity of the agent. Realistic, \u27descriptive\u27 agents are contrasted to rational actor theory in terms of the different equilibria one would expect to emerge in conflict games. These predictions are examined in two real world cases (Iraq and SE Asia) where the agent models are subjected to validity tests and a policy experiment is then run. We conclude by arguing that substantial effort on game realism, best-of-breed social science models, and agent validation efforts is essential if analytic experiments are to effectively explore conflicts and alternative ways to influence outcomes. Such efforts are likely to improve behavioral game theory as well

ANTI FUNGAL COMPOUNDS FROM MARINE STREPTOMYCES

Objective: To identify antifungal compounds from marine Streptomyces.Methods: Strptomyces were isolated from marine soil sample by the spread plate method. From the active strain crude compounds were extracted by the solvent extraction method. Crude compounds were purified by TLC method. Then the identification of compounds done by GC-MS analysis.Results: One of the active strain was identified as Streptomyces rubralavendulae strain SU1 (HQ234765). The antifungal compounds were shown resistant to Candida albicans. The antifungal compounds were identified by GC-MS as 2-Isopropyl-5-methyl-1-heptanol and Eicosane.Conclusion: These results could support the suggestion of Streptomyces as an alternative of the host for medicinal activity for treating fungal infections.Â