A diagram that places two planets in orbit around the sun was inserted into the textual space of a Timaeus manuscript of the late 11th century as well as three more in the 12th century. The diagram derives from a Carolingian tradition of study of Martianus Capella’s astronomy and shows his continued authority into the twelfth century. By way of Capella and through similarly-inspired commentaries on Macrobius’ Commentary on the Dream of Scipio, the idea of circumsolar motion for Mercury and (...) Venus became a well-known and authoritative theme for William of Conches and other scholars in the eleventh and twelfth centuries wo interpreted Plato in terms of current scientific knowledge. (shrink)

No one before Platter and Kepler proposed retinal reception of an inverted visual image. The dominant tradition in visual theory, especially that of Alhazen and his Western followers, subordinated the intra-ocular geometry of visual rays to the requirement for an upright image and to preconceptions about the precise nature of the visual spirit and its part in vision. Henry of Langenstein and an anonymous glossator in the late Middle Ages proposed alternatives to Alhazen, including the suggestion of double inversion of (...) the image. Leonardo da Vinci was aware of both Alhazen's theory and Henry's contradiction, but perhaps not of the anonymous hypothesis of double inversion. Leonardo's visual ‘theory’ has more the character of a critique than of a theoretical alternative, and he did not transcend the medieval concept of visual spirit. (shrink)

The brain and body need to adapt constantly to changing social and physical environments. A key mechanism for this adaptation is the ‘stress response’, which is necessary and not negative in and of itself. The term ‘stress’, however, is ambiguous and has acquired negative connotations. We argue that the concept of allostasis can be used instead to describe the mechanisms employed to achieve stability of homeostatic systems through active intervention (adaptive plasticity). In the context of allostasis, resilience denotes the ability (...) of an organism to respond to stressors in the environment by means of the appropriate engagement and efficient termination of allostatic responses. In this review, we discuss the neurobiological and organismal factors that modulate resilience, such as growth factors, chaperone molecules and circadian rhythms, and highlight its consequences for cognition and behavior. (shrink)

Mass literacy, mass communication, and the Internet have all increased the amount of information available. But false knowledge still abounds. Taking cues from Sir Thomas Browne, the English Renaissance skeptic, this title examines a host of contemporary errors in thinking and offers a powerful explanation of why they occur.

The Many-Worlds Interpretation is a theory in physics which proposes that, rather than quantum-level events being resolved randomly as according to the Copenhagen Interpretation, the universe constantly divides into different versions or worlds. All physically possible worlds occur, though some outcomes are more likely than others, and therefore all possible histories exist. This paper explores some implications of this for history, especially concerning causation. Unlike counterfactuals, which concern different starting conditions, MWI concerns different outcomes of the same starting conditions. It (...) is argued that analysis of causation needs to take into account the divergence of outcomes and the possibility that we inhabit a less probable world. Another implication of MWI is convergent history: for any given world there will be similar worlds which are the result of different pasts which are, however, more or less probable. MWI can assist in thinking about historical causation and indicates the importance of probabilistic causation. (shrink)

Background: Nurses, social workers, and medical residents are ethically mandated to engage in policy advocacy to promote the health and well-being of patients and increase access to care. Yet, no instrument exists to measure their level of engagement in policy advocacy. Research objective: To describe the development and validation of the Policy Advocacy Engagement Scale, designed to measure frontline healthcare professionals’ engagement in policy advocacy with respect to a broad range of issues, including patients’ ethical rights, quality of care, culturally (...) competent care, preventive care, affordability/accessibility of care, mental healthcare, and community-based care. Research design: Cross-sectional data were gathered to estimate the content and construct validity, internal consistency, and test–retest reliability of the Policy Advocacy Engagement Scale. Participants and context: In all, 97 nurses, 94 social workers, and 104 medical residents were recruited from eight acute-care hospitals in Los Angeles County. Ethical considerations: Informed consent was obtained via Qualtrics and covered purposes, risks and benefits; voluntary participation; confidentiality; and compensation. Institutional Review Board approval was obtained from the University of Southern California and all hospitals. Findings: Results supported the validity of the concept and the instrument. In confirmatory factor analysis, seven items loaded onto one component with indices indicating adequate model fit. A Pearson correlation coefficient of.36 supported the scale’s test–retest stability. Cronbach’s α of.93 indicated strong internal consistency. Discussion: The Policy Advocacy Engagement Scale demonstrated satisfactory psychometric properties in this initial test. Findings should be considered within the context of the study’s limitations, which include a low response rate and limited geographic scope. Conclusion: The Policy Advocacy Engagement Scale appears to be the first validated scale to measure frontline healthcare professionals’ engagement in policy advocacy. With it, researchers can analyze variations in professionals’ levels of policy advocacy engagement, understand what factors are associated with it, and remedy barriers that might exist to their provision of it. (shrink)

Analysis of the mechanisms underlying sex determination and sex differentiation in Drosophila has provided evidence for a complex but comprehensible regulatory hierarchy governing these developmental decisions. It is suggested here that the pattern of sexual differentiation and dosage compensation characteristic of the male is a default regulatory state. Recent results have provided, in addition, some surprising and intriguing conclusions: (1) that several of the critical controlling genes produce more transcripts than was predicted from the genetic analyses; (2) that setting of (...) the alternative sex‐specific states of the doublesex (dsx) locus involves differential transcript processing; and (3) that some aspects of sexual differentation require the prolonged action of certain elements of the regulatory hierarchy. These findings are discussed in connection with the current model of sex determination in Drosophila. (shrink)

Characterizing the genetic structure of populations is of importance to evolutionary biology, to human disease gene mapping, and to forensic science. Sewall Wright introduced a set of F-statistics to describe population structure in 1951, and he emphasized that these quantities were ratios of variances. Responding to uncertainty over the best way to estimate F-statistics, Weir and Cockerham published a method-of-moments set of estimators in 1984. This paper continues to be widely cited, with over 7,000 citations to date. Some background to (...) the publishing history of the Weir and Cockerham paper is given here, along with subsequent developments and a discussion of current uses of Wright's F-statistics. (shrink)

This research project investigated the extent to which nurses engage in two important kinds of ethical behaviours: ethical activism (where they try to make hospitals more receptive to nurses’ participation in ethics deliberations) and ethical assertiveness (where they participate in ethics deliberations even when not formally invited). This research probed not only the extent to which nurses engage in these ethical behaviours but also whether this is influenced by professional, training and organizational factors. A random sample of 165 nurses from (...) three major hospitals in Los Angeles provided the data. Regression analyses indicate that both ethical activism and ethical assertiveness are strongly influenced by nurses’ perceptions of the receptivity of hospitals to their inclusion in ethics deliberations. In addition, nurses’ education in ethics is a significant predictor of ethical activism. The findings have important implications for the content of nurses’ ethics training as well as for expanding the boundaries of nurses’ participation in ethics deliberations. The authors define ethics deliberations as specific meetings of a number of people to discuss an ethical issue, such as one regarding the care of a patient. (shrink)

Kids in the Middle: The Micro-Politics of Special Education takes the reader on a fascinating journey through special education in the past, present, and future. On this journey, the micro-politics of special education are seen through the eyes and experiences of children with disabilities, their parents and advocates, adult educators, and school administrators. Supplementing these perspectives to develop an understanding of special education that goes beyond its administrative and political aspects, such as the Individuals with Disabilities Education Act , are (...) scholars with expertise in special education law, administration, severe and profound disabilities, ethics, finance, teaching, and disability rights. Together, these voices explain the micro-political issues that affect how children with disabilities are educated. Kids in the Middle promotes a new model of special education to help transform special education. Instead of perpetuating a system grounded in the concepts of promises, privilege, and power, this book considers how to build a system based on caring, compassion, and the common good, a system that will elevate the status of special education children who are lost in the middle. (shrink)

The brain is an ever‐changing organ that encodes memories and directs behavior. Neuroanatomical studies have revealed structural plasticity of neural architecture, and advances in gene expression technology and epigenetics have demonstrated new mechanisms underlying the brain's dynamic nature. Stressful experiences challenge the plasticity of the brain, and prolonged exposure to environmental stress redefines the normative transcriptional profile of both neurons and glia, and can lead to the onset of mental illness. A more thorough understanding of normal and abnormal gene expression (...) is needed to define the diseased brain and improve current treatments for psychiatric disorders. The efforts to describe gene expression networks have been bolstered by microarray and RNA‐sequencing technologies. The heterogeneity of neural cell populations and their unique microenvironments, coupled with broad ranging interconnectivity, makes resolving this complexity exceedingly challenging and requires the combined efforts of single cell and systems level expression profiling to identify targets for therapeutic intervention. (shrink)