667 research outputs found
Formal Definitions of Unbounded Evolution and Innovation Reveal Universal Mechanisms for Open-Ended Evolution in Dynamical Systems
Open-ended evolution (OEE) is relevant to a variety of biological, artificial
and technological systems, but has been challenging to reproduce in silico.
Most theoretical efforts focus on key aspects of open-ended evolution as it
appears in biology. We recast the problem as a more general one in dynamical
systems theory, providing simple criteria for open-ended evolution based on two
hallmark features: unbounded evolution and innovation. We define unbounded
evolution as patterns that are non-repeating within the expected Poincare
recurrence time of an equivalent isolated system, and innovation as
trajectories not observed in isolated systems. As a case study, we implement
novel variants of cellular automata (CA) in which the update rules are allowed
to vary with time in three alternative ways. Each is capable of generating
conditions for open-ended evolution, but vary in their ability to do so. We
find that state-dependent dynamics, widely regarded as a hallmark of life,
statistically out-performs other candidate mechanisms, and is the only
mechanism to produce open-ended evolution in a scalable manner, essential to
the notion of ongoing evolution. This analysis suggests a new framework for
unifying mechanisms for generating OEE with features distinctive to life and
its artifacts, with broad applicability to biological and artificial systems.Comment: Main document: 17 pages, Supplement: 21 pages Presented at OEE2: The
Second Workshop on Open-Ended Evolution, 15th International Conference on the
Synthesis and Simulation of Living Systems (ALIFE XV), Canc\'un, Mexico, 4-8
July 2016 (http://www.tim-taylor.com/oee2/
Integrated Information Theory and Isomorphic Feed-Forward Philosophical Zombies
Any theory amenable to scientific inquiry must have testable consequences.
This minimal criterion is uniquely challenging for the study of consciousness,
as we do not know if it is possible to confirm via observation from the outside
whether or not a physical system knows what it feels like to have an inside - a
challenge referred to as the "hard problem" of consciousness. To arrive at a
theory of consciousness, the hard problem has motivated the development of
phenomenological approaches that adopt assumptions of what properties
consciousness has based on first-hand experience and, from these, derive the
physical processes that give rise to these properties. A leading theory
adopting this approach is Integrated Information Theory (IIT), which assumes
our subjective experience is a "unified whole", subsequently yielding a
requirement for physical feedback as a necessary condition for consciousness.
Here, we develop a mathematical framework to assess the validity of this
assumption by testing it in the context of isomorphic physical systems with and
without feedback. The isomorphism allows us to isolate changes in
without affecting the size or functionality of the original system. Indeed, we
show that the only mathematical difference between a "conscious" system with
and an isomorphic "philosophical zombies" with is a
permutation of the binary labels used to internally represent functional
states. This implies is sensitive to functionally arbitrary aspects of a
particular labeling scheme, with no clear justification in terms of
phenomenological differences. In light of this, we argue any quantitative
theory of consciousness, including IIT, should be invariant under isomorphisms
if it is to avoid the existence of isomorphic philosophical zombies and the
epistemological problems they pose.Comment: 13 page
Health Disparities Among Racial and Ethnic Minority Firefighters
ABSTRACT
Background: Racial/ethnic minorities are substantially underrepresented in the fire service and this situation is unique when compared to similarly mentally and physically demanding and hazardous occupations such as the military and law enforcement. There is little systematic research to provide greater clarity about this significant disparity. The purpose of this study is to examine physical and behavioral health issues of racial/ethnic minority firefighters when compared to their white, non-Hispanic counterparts and potentially identify areas for future research that might assist in improving their substantial underrepresentation.
Materials and Methods: We report the results of a secondary analysis of data combining the baseline evaluations of two different firefighter health studies, the Firefighter Injury and Risk Evaluation (FIRE) and Fuel 2 Fight (F2F) studies. Male career firefighters (N=1,404) were from 31 fire departments across the US and its territories. White, non-Hispanic firefighters comprised 72.5% of the sample (n=1,018) and 27.5% classified themselves as a racial/ethnic minority. Firefighters who agreed to participate comprised 94% (F2F) and 97% (FIRE) of those available and all underwent assessments including body composition, fitness, and general/behavioral health, and job satisfaction.
Results: We examined differences in health and job status between minority and non-minority firefighters and between firefighters in minority- (MDCs) and white-dominated communities (WDCs). After adjusting for potential confounds, there were significant main effects for the individual minority status vs. non-minority status on both BMI and BF%, indicating that minority firefighters had significantly higher average BMI (28.8±0.3kg/m2) and BF% (24.7± 0.7%) when compared to their white, non-Hispanic colleagues (27.7±0.2kg/m2and 23.1±0.6% for BMI and BF%, respectively). Minority firefighters also were 59% more likely to be obese (adjusted [A]OR=1.59; 95% CI=1.16-2.18). Firefighters serving in MDCs reported significantly more poor health days (Mean±SE; 3.2±0.2 days) than firefighters serving in WDCs (2.8±0.2 days; p=0.038). In addition, minority firefighters reported significantly more poor health days (3.6±0.4 days) than their non-minority colleagues (2.8±0.2 days; p=0.003), while the interaction indicates that minority firefighters in MDCs reported more poor health days than the other groups (p
Conclusions: Individual and community minority status (i.e., ethnic density effect) were both significantly associated with a number of important health status indicators, with racial/ethnic minority firefighters demonstrating greater risk for unfavorable body composition and more poor physical health days. In addition, minority firefighters in WDCs reported the highest prevalence of lifetime diagnosis of depression by a physician, while minority firefighters in MDCs had the lowest. Many of these health status indicators have recently been studied within the context of experiences with discrimination, demonstrating that racial discrimination is associated with greater risk for obesity, depression, and poor physical and mental health and could be contributing to health disparities and potentially negatively impacting racial/ethnic minority firefighter health, safety, and retention
Clone Swarms: Learning to Predict and Control Multi-Robot Systems by Imitation
In this paper, we propose SwarmNet -- a neural network architecture that can
learn to predict and imitate the behavior of an observed swarm of agents in a
centralized manner. Tested on artificially generated swarm motion data, the
network achieves high levels of prediction accuracy and imitation authenticity.
We compare our model to previous approaches for modelling interaction systems
and show how modifying components of other models gradually approaches the
performance of ours. Finally, we also discuss an extension of SwarmNet that can
deal with nondeterministic, noisy, and uncertain environments, as often found
in robotics applications
When Is a Change Significant? The Update Problem of Apps in Medical and Behavioral Research
Digital applications (apps) are commonly used across the research ecosystem. While apps are frequently updated in the course of clinical and behavioral research, there is limited guidance as to when an app update should trigger action related to human research participant protections and who should be responsible for monitoring and reviewing these updates. We term this the “update problem” and argue that, while it is the principal investigator\u27s duty to track all relevant updates, the level of involvement and re-review by the institutional review board (IRB) of an approved research protocol should vary depending on whether the update may be classified as minor, not minor, or significant. Minor updates require at most annual notification of the IRB, updates that are not minor require prompt notification of the IRB, and significant updates may require full board re-review or another response. We also suggest how these policies might be implemented
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