The Art of Randomness teaches readers to harness the power of randomness (and Python code) to solve real-world problems in programming, science, and art through hands-on experiments-from simulating evolution to encrypting messages to making machine-learning algorithms. Each chapter describes how randomness plays into the given topic area, then proceeds to demonstrate its problem-solving role with hands-on experiments to work through using Python code.

In 1898 men and women from all over the world converged on Alaska. Gold had been discovered. In the Yukon Territory, all winter long eager gold seekers struggled over the mountain passes connecting Canada with the United States. A small group of photographers chronicled this epic, creating images of men and women laboring through blinding snowstorms over the windswept, ice-covered mountains. One of that group was a young Swedish immigrant by the name of P. E. Larson. Frozen in Silver documents (...) how this man used the recent medium of photography to earn a living as a merchant and tradesman. From the relative tranquility of a Minnesota photographic studio, he moved westward. And, like thousands of others, he made his way to the Klondike Gold Rush, although with camera in hand. In addition to preserving the rich photographic record of the Great Stampede to the Klondike, Larson recorded contemporary Western life and culture, including that of the hard rock mining community of Goldfield, Nevada. Frozen in Silver is a riveting story of one man's trek through a time and place that have been captured on film and now in print. (shrink)

We extend prior research of deceitful behavior by studying the reactions of those who are targets of deception and how a specific attribute of communication media, cue multiplicity , influences such reactions. We report on a laboratory experiment involving dyads asked to engage in a stock share purchase exercise. We find that when a broker is perceived to act deceitfully by the buyer, the buyer reacts with negative affect (anger) which provokes subsequent acts of revenge against the broker. Importantly, we (...) find that media with higher cue multiplicity attenuate buyer anger as well as lessen the propensity for the buyer to seek retaliatory acts of revenge. We further find that moral anger mediates the effect of buyers’ perceived deception on revenge. (shrink)

We show that early vision can use monocular cues to rapidly complete partially-occluded objects. Visual search for easily detected fragments becomes difficult when the completed shape is similar to others in the display; conversely, search for fragments that are difficult to detect becomes easy when the completed shape is distinctive. Results indicate that completion occurs via the occlusion-triggered removal of occlusion edges and linking of associated regions. We fail to find evidence for a visible filling-in of contours or surfaces, but (...) do find evidence for a "functional" filling-in that prevents the constituent fragments from being rapidly accessed. As such, it is only the completed structures—and not the fragments themselves—that serve as the basis for rapid recognition. (shrink)

Diane Vaughan’s analysis of the causes of the Challenger accident suggests ways to apply science and technology studies to the teaching of engineering ethics. By sensitizing future engineers to the ongoing construction of risk during mundane engineering practice, we can better prepare them to address issues of public health, safety, and welfare before they require heroic intervention. Understanding the importance of precedents, incremental change, and fallible engineering judgment in engineering design may help them anticipate potential threats to public safety arising (...) from routine aspects of workplace culture. We suggest modifications of both detailed case studies on engineering disasters and hypothetical, ethical dilemmas employed in engineering ethics classes. Investigating the sociotechnical aspects of engineering practice can improve the initial recognition of ethical problems in real-world settings and provide an understanding of the role of workplace organization and culture in facilitating or impeding remedial action. (shrink)

Experiments are presented showing that visual search for Mueller-Lyer (ML) stimuli is based on complete configurations, rather than component segments. Segments easily detected in isolation were difficult to detect when embedded in a configuration, indicating preemption by low-level groups. This preemption—which caused stimulus components to become inaccessible to rapid search—was an all-or-nothing effect, and so could serve as a powerful test of grouping. It is shown that these effects are unlikely to be due to blurring by simple spatial filters at (...) early visual levels. It is proposed instead that they are due to more sophisticated processes that rapidly bind contour fragments into spatially-extended assemblies. These results support the view that rapid visual search cannot access the primitives formed at the earliest stages of visual processing; rather, it can access only higher-level, more ecologically-relevant structures. (shrink)

Analyzed F. Galton's data on the sensory, psychomotor, and physical attributes of 1,639 females and 4,849 males. The reliability of the measures, developmental trends in mean scores, correlations of the measures with age, correlations among measures, occupational differences in scores, and sibling correlations are described. Developmental trends during later childhood, adolescence, and early maturity are compared to those described in contemporary developmental psychological literature.

Background: SNOMED CT is a large terminology system designed to represent all aspects of healthcare. Its current form and content result from decades of bottom-up evolution. Due to SNOMED CT’s formal descriptions, it can be considered an ontology. The Basic Formal Ontology (BFO) is a foundational ontology that proposes a small set of disjoint, hierarchically ordered classes, supported by relations and axioms. In contrast, as a typical top-down endeavor, BFO was designed as a foundational framework for domain ontologies in the (...) natural sciences and related disciplines. Whereas it is mostly assumed that domain ontologies should be created as extensions of foundational ontologies, a post-hoc harmonization of consolidated domain ontologies in use, such as SNOMED CT, is known to be challenging. Methods: We explored the feasibility of harmonizing SNOMED CT with BFO, with a focus on the SNOMED CT Clinical Finding hierarchy. With more than 100,000 classes, it accounts for about one third of SNOMED CT’s content. In particular, we represented typical SNOMED CT finding/disorder concepts using description logics under BFO. Three representational patterns were created and the logical entailments analyzed. Results: Under a first scrutiny, the clinical intuition that diseases, disorders, signs and symptoms form a homogeneous ontological upper-level class appeared incompatible with BFO’s upper-level distinction into continuants and occurrents. The Clinical finding class seemed to be an umbrella for all kinds of entities of clinical interest, such as material entities, processes, states, dispositions, and qualities. This suggests the conclusion that Clinical finding would not be a suitable upper-level class from an BFO perspective. On closer inspection of the taxonomic links within this hierarchy and the implicit meaning derived thereof, it became clear that Clinical finding classes do not characterize the entity (e.g. a fracture, allergy, tumor, pain, hemorrhage, seizure, fever) in a literal sense but rather the condition of a patient having that fracture, allergy, pain etc. This gives sense to the current characteristic of the Clinical Finding hierarchy, in which complex classes are modeled as subclasses of their constituents. Most of these taxonomic links are inferred, as the consequence of the ‘role group’ design pattern, which is ubiquitous in SNOMED CT and has often been subject of controversy regarding its semantics. Conclusion: Our analyses resulted in the proposal of (i) equating SNOMED CT’s ‘role group’ property with the reflexive and transitive BFO relation ‘has occurrent part’; and (ii) reinterpreting Clinical Findings as Clinical Occurrents, i.e. temporally extended entities in an organism, having one or more occurrents as temporal parts that occur in continuants. This re-interpretation was corroborated by a manual analysis of classes under Clinical Finding, as well as the identification of similar modeling patterns in other ontologies. As a result, SNOMED CT does not require any content redesign to establish compatibility with BFO, apart from this re-interpretation, and a suggested re-labeling. Regarding the feasibility of harmonizing terminologies with principled foundational ontologies post-hoc, our results provide support to the assumption that this does not necessarily require major redesign efforts, but rather a careful analysis of the implicit assumptions of terminology curators and users. (shrink)

Cracks in the one‐gene, one‐band paradigm for polytene chromosome organization are widening. At the same time evidence is accumulating suggesting that decondensed regions of the chromosomes (puffs, diffuse bands, interbands and possibly vacuoles within some bands) are generally associated with gene transcription. A model, now on the ascendancy, is based on the proposal that the band‐interband pattern is primarily a reflection of local transcriptional state, rather than the distribution of genic and non‐genic material.

It has generally been assumed that rapid visual search is based on simple features and that spatial relations between features are irrelevant for this task. Seven experiments involving search for line drawings contradict this assumption; a major determinant of search is the presence of line junctions. Arrow- and Y-junctions were detected rapidly in isolation and when they were embedded in drawings of rectangular polyhedra. Search for T-junctions was considerably slower. Drawings containing T-junctions often gave rise to very slow search even (...) when distinguishing arrow- or Y-junctions were present. This sensitivity to line relations suggests that preattentive processes can extract 3-dimensional orientation from line drawings. A computational model is outlined for how this may be accomplished in early human vision. (shrink)

Since 1991, the Patient Self-Determination Act (PSDA) has required all health care institutions that receive Federal funds to inform patients upon admission of their rights to make decisions about medical care and to execute advance directives. Implementation of the PSDA presents a special challenge for state mental hospitals. The relevance and possible negative therapeutic impact of discussing end of life decisions at the time of an acute psychiatric admission has recently been raised in the literature. Other ethical dilemmas arising from (...) the interplay between mental illness and informed consent for medical treatment, particularly for older patients committed to state mental hospitals, have been highlighted by the PSDA. In this article we discuss some of the issues raised by implementation of the PSDA in this setting. (shrink)