Origin of life in a digital microcosm

While all organisms on Earth descend from a common ancestor, there is no consensus on whether the origin of this ancestral self-replicator was a one-off event or whether it was only the final survivor of multiple origins. Here we use the digital evolution system Avida to study the origin of self-replicating computer programs. By using a computational system, we avoid many of the uncertainties inherent in any biochemical system of self-replicators (while running the risk of ignoring a fundamental aspect of biochemistry). We generated the exhaustive set of minimal-genome self-replicators and analyzed the network structure of this fitness landscape. We further examined the evolvability of these self-replicators and found that the evolvability of a self-replicator is dependent on its genomic architecture. We studied the differential ability of replicators to take over the population when competed against each other (akin to a primordial-soup model of biogenesis) and found that the probability of a self-replicator out-competing the others is not uniform. Instead, progenitor (most-recent common ancestor) genotypes are clustered in a small region of the replicator space. Our results demonstrate how computational systems can be used as test systems for hypotheses concerning the origin of life.Comment: 20 pages, 7 figures. To appear in special issue of Philosophical Transactions of the Royal Society A: Re-Conceptualizing the Origins of Life from a Physical Sciences Perspectiv

Satellite refrigeration study. Part II TECHNICAL analysis

Low temperature refrigeration system for satellite mounted infrared sensor coolin

Concept and considerations of a medical device:the active noise cancelling incubator

Background: An increasingly 24/7 connected and urbanised world has created a silent pandemic of noise-induced hearing loss. Ensuring survival to children born (extremely) preterm is crucial. The incubator is a closed medical device, modifying the internal climate, and thus providing an environment for the child, as safe, warm, and comfortable as possible. While sound outside the incubator is managed and has decreased over the years, managing the noise inside the incubator is still a challenge.Method: Using active noise cancelling in an incubator will eliminate unwanted sounds (i.e., from the respirator and heating) inside the incubator, and by adding sophisticated algorithms, normal human speech, neonatal intensive care unit music-based therapeutic interventions, and natural sounds will be sustained for the child in the pod. Applying different methods such as active noise cancelling, motion capture, sonological engineering. and sophisticated machine learning algorithms will be implemented in the development of the incubator. Projected Results: A controlled and active sound environment in and around the incubator can in turn promote the wellbeing, neural development, and speech development of the child and minimise distress caused by unwanted noises. While developing the hardware and software pose individual challenges, it is about the system design and aspects contributing to it. On the one hand, it is crucial to measure the auditory range and frequencies in the incubator, as well as the predictable sounds that will have to be played back into the environment. On the other, there are many technical issues that have to be addressed when it comes to algorithms, datasets, delay, microphone technology, transducers, convergence, tracking, impulse control and noise rejection, noise mitigation stability, detection, polarity, and performance.Conclusion: Solving a complex problem like this, however, requires a de-disciplinary approach, where each discipline will realise its own shortcomings and boundaries, and in turn will allow for innovations and new avenues. Technical developments used for building the active noise cancellation-incubator have the potential to contribute to improved care solutions for patients, both infants and adults. Code available at: 10.3389/fped.2023.1187815.</p

Effectuation as Ineffectual? Applying the 3E Theory-Assessment Framework to a Proposed New Theory of Entrepreneurship

Effectuation is a proposed new theory of entrepreneurship, with insufficient empirical testing and critical analysis. Drawing on a new, comprehensive set of theory-building criteria—sourced from and complementing those of Robert Dubin and others—we provide the first formal assessment of effectuation as a theory. We highlight its strengths and weaknesses, leveraging the former to address the latter in five different directions that would build on the existing work to improve this theory. The assessment exercise also displays the value of our assessment framework in guiding the evaluation and development of other existing and future theories in entrepreneurship and management

Effectuation, Not Being Pragmatic or Process Theorizing, Remains Ineffectual: Responding to the Commentaries

We appreciate the opportunity to respond to the provocative Dialogue pieces of Read, Sarasvathy, Dew, and Wiltbank (2016; henceforth, “RSDW”); Reuber, Fischer, and Coviello (2016; henceforth, “RFC”); Gupta, Chiles, and McMullen (2016; henceforth, “GCM”); and Garud and Gehman (2016; henceforth, “GG”), each of which makes several claims in defense of effectuation, as well as describes several ways forward in entrepreneurship- and process-related theorizing. We respond in a manner consistent with the traditional perspective in management theorizing that “good theory is practical” (Lewin, 1945), where “theory is theory” (Simon, 1967; Van de Ven, 1989) based on our discipline’s collective commitment to knowledge production (Suddaby, 2014). In fact, we respond in the tradition of scientific theory—its building, its critique, and its defense. Leveraging the logic behind that tradition, we thus refute every point contained in RSDW’s, RFC’s, GCM’s, and GG’s commentaries and attempt to build on what is common to all theory while celebrating what is valuable in the diversity of theorizing (i.e., in the ways we produce theory)

Simulation of an Optional Strategy in the Prisoner's Dilemma in Spatial and Non-spatial Environments

This paper presents research comparing the effects of different environments on the outcome of an extended Prisoner's Dilemma, in which agents have the option to abstain from playing the game. We consider three different pure strategies: cooperation, defection and abstinence. We adopt an evolutionary game theoretic approach and consider two different environments: the first which imposes no spatial constraints and the second in which agents are placed on a lattice grid. We analyse the performance of the three strategies as we vary the loner's payoff in both structured and unstructured environments. Furthermore we also present the results of simulations which identify scenarios in which cooperative clusters of agents emerge and persist in both environments.Comment: 12 pages, 8 figures. International Conference on the Simulation of Adaptive Behavio

Two Immigrants with Tuberculosis of the Ear, Nose, and Throat Region with Skull Base and Cranial Nerve Involvement

We report two immigrants with tuberculosis of the skull base and a review of the literature. A Somalian man presented with bilateral otitis media, hearing loss, and facial and abducens palsy. Imaging showed involvement of both mastoid and petrous bones, extending via the skull base to the nasopharynx, suggesting tuberculosis which was confirmed by characteristic histology and positive auramine staining, while Ziehl-Neelsen staining and PCR were negative. A Sudanese man presented with torticollis and deviation of the uvula due to paresis of N. IX and XI. Imaging showed a retropharyngeal abscess and lysis of the clivus. Histology, acid-fast staining, and PCR were negative. Both patients had a positive Quantiferon TB Gold in-tube result and improved rapidly after empiric treatment for tuberculosis. Cultures eventually yielded M. tuberculosis. These unusual cases exemplify the many faces of tuberculosis and the importance to include tuberculosis in the differential diagnosis of unexplained problems