Silencing of tumor suppressor genes (TSGs), by DNA methylation, is well known in adult cancers. However, based on the “stem cell” theory of tumorigenesis, the early epigenetic events arising in malignant precursors remain unknown. A recent report1 demonstrates that, while pluripotent embryonic stem cells lack DNA methylation and possess a “bivalent” pattern of activating and repressive histone marks in numerous TSGs, analogous multipotent malignant cells derived from germ cell tumors (embryonic carcinoma cells) gain additional silencing modifications to those same genes. (...) These results suggest a possible mechanism by which aberrant differentiation, mediated by histone and DNA methylation, instigates tumor progression. BioEssays 29:842–845, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Graphical AbstractScience and technology consortia provide a viable solution for the recent unsustainable academic growth in biomedical research.

The failure of conventional quantum theory to recognize time as an observable and to admit time operators is addressed. Instead of focusing on the existence of a time operator for a given Hamiltonian, we emphasize the role of the Hamiltonian as the generator of translations in time to construct time states. Taken together, these states constitute what we call a timeline. Such timelines are adequate for the representation of any physical state, and appear to exist even for the semi-bounded and (...) discrete Hamiltonian systems ruled out by Pauli’s theorem. However, the step from a timeline to a valid time operator requires additional assumptions that are not always met. Still, this approach illuminates the issues surrounding the construction of time operators, and establishes timelines as legitimate alternatives to the familiar coordinate and momentum bases of standard quantum theory. (shrink)

Extinction deeply colors the way we think about conservation and the role of humans in nature. It is easy to overlook how recently, in fact, it has entered our consciousness. Only in the last two centuries has science sought to critically study life's origins, development, and diversification. Only in the last several generations have we identified and calibrated life's five major extinction events and speculated on their causes and effects. And only in recent decades have we come to appreciate the (...) still‐unfolding fate of life's diversity under the increasing influence of humanity. The story of extinction has continually changed as this monumental process of interdisciplinary synthesis and imagination has unfolded. Geology, paleontology, taxonomy, biogeography, and evolutionary biology have allowed us to comprehend the deep temporal and broad spatial dynamics of the extinction story. Archaeology, cultural anthropology, and environmental and economic history have illuminated the role of humans in altering the trajectory of species, landscapes, and ecosystems over the millennia. Ecology, genetics, population biology, and conservation biology have revealed the more recent patterns in life's vulnerability and resilience. As a phenomenon, extinction is as old as life itself. As a story shaping our consciousness, values, and intentions, it is still new. And it is uncomfortable. (shrink)

This paper addresses the issue of whether robots could substitute for human care, given the challenges in aged care induced by the demographic change. The use of robots to provide emotional care has raised ethical concerns, e.g., that people may be deceived and deprived of dignity. In this paper it is argued that these concerns might be mitigated and that it may be sufficient for robots to take part in caring when they behave *as if* they care.

Die Autoren sind katholische Priester und stellen das christliche Menschenbild und die Ethik der Gesundheitssorge in den Mittelpunkt. Herausgearbeitet wird die ihrer Ansicht nach besondere ethische Verantwortung der Pflegekräfte in ihren Beziehungen zu Patienten, Angehörigen und Ärzten bei Fragen der Lebens- und Sterbehilfe.

The focus of this review is on positive emotional granularity. Emotional granularity is the level of specificity that characterizes verbal representations of an affective experience. Although there has been research on negative emotional granularity, relatively less attention has been given to the study of positive emotional granularity. Positive emotions are theorized to motivate an individual to “broaden and build” one’s scope of cognition, attention, and behavior. Distinct positive emotion concepts may provide individuals with more informational value than that provided by (...) global mood. Indeed, individuals who are higher in positive emotional granularity report being better at coping with stressful experiences. In this review, we discuss growing research on positive emotional granularity and well-being. Issues of measurement, interventions, and considerations for future lines of research are discussed. (shrink)