This article presents the results of an experiment that completely measures the utility function and probability weighting function for different positive and negative monetary outcomes, using a representative sample of N = 1,935 from the general public. The results confirm earlier findings in the lab, suggesting that utility is less pronounced than what is found in classical measurements where expected utility is assumed. Utility for losses is found to be convex, consistent with diminishing sensitivity, and the obtained loss-aversion coefficient of (...) 1.6 is moderate but in agreement with contemporary evidence. The estimated probability weighting functions have an inverse-S shape and they imply pessimism in both domains. These results show that probability weighting is also an important phenomenon in the general population. Women and lower educated individuals are found to be more risk averse, in agreement with common findings. In contrast to previous studies that ascribed gender differences in risk attitudes solely to differences in the degree utility curvature, however, our results show that this finding is primarily driven by loss aversion and, for women, also by a more pessimistic psychological response toward the probability of obtaining the best possible outcome. (shrink)

A hypothesis on the evolutionary origin of the genetic pathway of sex determination in the nematode Caenorhabditis elegans is presented here. It is suggested that the pathway arose in steps, driven by frequency‐dependent selection for the minority sex at each step, and involving the sequential acquisition of dominant negative, neomorphic genetic switches, each one reversing the action of the previous one. A central implication is that the genetic pathway evolved in reverse order from the final step in the hierarchy up (...) to the first. The possible applicability of the model to the other well‐characterized sex determination pathway, that of Drosophila melanogaster, and to sex determination in mammals, is discussed, along with some potential implications for pathway evolution in general. Finally, the specific molecular and population genetic questions that the model raises are described and some tests are proposed. (shrink)

The phenomenon of ‘canalization’ ‐ the genetic capacity to buffer developmental pathways against mutational or environmental perturbations ‐ was first characterized in the late 1930s and early 1940s. Despite enormous subsequent progress in understanding the nature of the genetic material and the molecular basis of gene expression, there have been few attempts to interpret the classical work on canalization in molecular genetic terms. Some recent findings, however, bear on one form of canalization, ‘genetic canalization’, the stabilization of development against mutational (...) effects. These data indicate that co‐expressed paralogous genes can function as mutual ‘back‐up’ elements in developmental processes. Paralogues, however, are far from the only basis of canalization: other genetic sources can be readily envisaged and some of these are described here. The evolutionary questions about genetic canalization and the mechanistic questions about developmental instability that still need to be addressed are also briefly discussed. (shrink)

C.H. Waddington is today remembered chiefly as a Drosophila developmental geneticist who developed the concepts of “canalization” and “the epigenetic landscape.” In his lifetime, however, he was widely perceived primarily as a critic of Neo-Darwinian evolutionary theory. His criticisms of Neo-Darwinian evolutionary theory were focused on what he saw as unrealistic, “atomistic” models of both gene selection and trait evolution. In particular, he felt that the Neo-Darwinians badly neglected the phenomenon of extensive gene interactions and that the “randomness” of mutational (...) effects, posited in the theory, was a false postulate. This last criticism dealt with the phenomenon known today as “developmental constraints.” Although population genetics itself has evolved considerably from its form at mid-20th century, much of Waddington’s critique, it is argued here, retains cogency. Yet, he did not attempt to develop a full-fledged alternative theory himself. Perhaps most surprisingly, in retrospect, is that he did not try to marry his work on gene interactions in development with his evolutionary interests, to create a theory of “genetic networks” and their evolution. Whether evolutionary genetics today will incorporate “network thinking” as a central element or whether there will be a general retreat to the more atomistic approach offered by genomics, remains an open question. (shrink)

The power of sexual selection to influence the evolution of morphological traits was first proposed more than 130 years ago by Darwin. Though long a controversial idea, it has been documented in recent decades for a host of animal species. Yet few of the established sexually selected features have been explored at the level of their genetic or molecular foundations. In a recent report, Zauner et al.1 describe some of the molecular features associated with one of the best characterized of (...) sexually selected traits, the male‐specific tail “sword” seen in certain species of the fish genus Xiphophorus. Zauner et al. find that the msxC gene, a gene previously implicated in fin development from work in zebrafish, is dramatically and specifically upregulated in the development of the ventral caudal fin rays, which give rise to the sword, in males. The results provide the first molecular insight into the development of this sexually selected trait while prompting new questions about the structure of the entire genetic network that underlies this trait. To fully understand the molecular‐genetic and evolutionary history of this network, however, it will be essential to determine whether sword‐development is a basal or derived trait in Xiphophorus. BioEssays 26:116–119, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Created at the behest of the abbess Uta, it is not only one of the most beautiful of Ottonian manuscripts but also one of the most complex. The collection of liturgical readings is preceded by four full-page frontispieces illustrating the Hand of God, Uta dedicating the codex to the Virgin and Child, a Crucifixion, and Saint Erhard celebrating Mass. Four evangelist portraits accompany the readings from each Gospel. In this groundbreaking study, Adam Cohen provides comprehensive explications of the codex’s (...) renowned illuminations as well as the first thorough investigation of its historical context. Cohen shows that the lavish miniatures, among the most elaborate pictures of the Middle Ages, use figures, ornaments, Latin tituli, and geometric schemata to fashion visual exegeses of great range and complexity. Through consideration of questions of function, patronage, and program, Cohen also demonstrates that the codex commemorates the abbess Uta’s efforts to reform conventual life and education. _The Uta Codex _will be of interest to scholars of medieval art as well as those exploring questions of women, monastic culture, and intellectual life in the Middle Ages. (shrink)

Moral distress has been widely reviewed across many care contexts and among a range of disciplines. Interest in this area has produced a plethora of studies, commentary and critique. An overview of the literature around moral distress reveals a commonality about factors contributing to moral distress, the attendant outcomes of this distress and a core set of interventions recommended to address these. Interventions at both personal and organizational levels have been proposed. The relevance of this overview resides in the implications (...) moral distress has on the nurse and the nursing workforce: particularly in regard to quality of care, diminished workplace satisfaction and physical health of staff and increased problems with staff retention. (shrink)

Are mechanisms for social attention influenced by culture? Evidence that social attention is triggered automatically by bottom-up gaze cues and is uninfluenced by top-down verbal instructions may suggest it operates in the same way everywhere. Yet considerations from evolutionary and cultural psychology suggest that specific aspects of one's cultural background may have consequence for the way mechanisms for social attention develop and operate. In more interdependent cultures, the scope of social attention may be broader, focusing on more individuals and relations (...) between those individuals. We administered a multi-gaze cueing task requiring participants to fixate a foreground face flanked by background faces and measured shifts in attention using eye tracking. For European Americans, gaze cueing did not depend on the direction of background gaze cues, suggesting foreground gaze alone drives automatic attention shifting; for East Asians, cueing patterns differed depending on whether the foreground cue matched or mismatched background cues, suggesting foreground and background gaze information were integrated. These results demonstrate that cultural background influences the social attention system by shifting it into a narrow or broad mode of operation and, importantly, provides evidence challenging the assumption that mechanisms underlying automatic social attention are necessarily rigid and impenetrable to culture. (shrink)

This paper explores the intersection of time and relational economic sociology. Building on Viviana Zelizer’s relational framework, I argue that analyzing the temporal dimensions of exchange provides insight into how social ties gain meaning through economic practices. The paper shows time’s dual role as both an organizing structure bounding action, and a dynamic element that actors leverage to shape transactional contexts. As structure, time offers culturally-available templates like schedules and rhythms that facilitate coordination and signify predictable social meanings befitting particular (...) relational categories. Yet time also constitutes relational work itself; strategic timing, duration, pacing, and sequencing of interactions signal context, manage expectations, and sustain bonds amidst entanglements. Synchronization through temporal agency prevents mismatches between transactions and social contexts that could strain ties. This agency in time ranges from passive adherence to dominant structures to active assertions of power resistance, enabling both domination and defiance across economic contexts. Analyzing shared temporal infrastructure within circuits of commerce further illuminates how actors distinguish those spheres of exchange at various scale from the impersonal market. Ultimately, incorporating temporality strengthens relational economic sociology by identifying a key mechanism through which practices of exchange become relationally meaningful. (shrink)

DNA replication requires the unwinding of the parental duplex, which generates (+) supercoiling ahead of the replication fork. It has been thought that removal of these (+) supercoils was the only method of unlinking the parental strands. Recent evidence implies that supercoils can diffuse across the replication fork, resulting in interwound replicated strands called precatenanes. Topoisomerases can then act both in front of and behind the replication fork. A new study by Sogo et al. [J Mol Biol 1999;286:637–643 (Ref. 1)], (...) using a topological analysis, provides the best evidence that precatenanes exist in negatively supercoiled, partially replicated molecules in vivo. BioEssays 21:805–808, 1999. © 1999 John Wiley & Sons, Inc. (shrink)

This article proposes that cancers can be initiated by retrotransposon (RTN) activation through changes in the transcriptional regulation of nearby genes. I first detail the hypothesis and then discuss the nature of physiological stress(es) in RTN activation; the role of DNA demethylation in the initiation and propagation of new RTN states; the connection between ageing and cancer incidence and the involvement of activated RTNs in the chromosomal aberrations that feature in cancer progression. The hypothesis neither replaces nor invalidates other theories (...) of cancer, in particular the somatic mutation theory, but helps clarify and unify much of the hitherto poorly integrated, complex phenomenology of cancer. (shrink)