There is evidence that asexual reproduction has a long-term disadvantage when compared to sexual reproduction. This disadvantage is usually assumed to arise from the more efficient incorporation of advantageous mutations by sexual populations. We consider here the effect on asexual and sexual populations of changes in the fitness of harmful mutations. It is shown that the re-establishment of equilibrium following environmental change is generally faster in sexual populations, and that the mutational load experienced by the sexual population can be significantly (...) less during this period than that experienced by an asexual one. Changes in the fitness of harmful mutations may therefore impose a greater long-term disadvantage on asexual populations than those which are sexual. (shrink)

Progressive supranuclear palsy is a movement disorder with prominent tau neuropathology. Brain diseases with abnormal tau deposits are called tauopathies, the most common of which is Alzheimer's disease. Environmental causes of tauopathies include repetitive head trauma associated with some sports. To identify common genetic variation contributing to risk for tauopathies, we carried out a genome-wide association study of 1,114 individuals with PSP and 3,247 controls followed by a second stage in which we genotyped 1,051 cases and 3,560 controls for the (...) stage 1 SNPs that yielded P ≤ 10-3. We found significant previously unidentified signals associated with PSP risk at STX6, EIF2AK3 and MOBP. We confirmed two independent variants in MAPT affecting risk for PSP, one of which influences MAPT brain expression. The genes implicated encode proteins for vesicle-membrane fusion at the Golgi-endosomal interface, for the endoplasmic reticulum unfolded protein response and for a myelin structural component. © 2011 Nature America, Inc. All rights reserved. (shrink)

OBJECTIVE: To examine the long-term effects of an innovative curriculum on medical house officers' (HOs') knowledge, confidence, and attitudes regarding medical ethics. DESIGN: Long term cohort study. The two-year curriculum, implemented by a single physician ethicist with assistance from other faculty, was fully integrated into the programme. It consisted of monthly sessions: ethics morning report alternating with didactic conferences. The content included topics such as ethics vocabulary and principles, withdrawing life support, informed consent, and justice. Identical content was offered simultaneously (...) at the largest affiliated community hospital. SETTING: A multi-hospital university training programme from July, 1992 to June, 1994. PARTICIPANTS: Thirty-nine HOs responded in 92. Thirty HOs from the same cohort responded in 94 (response rates = 83% v 71%; P = 0.19). RESULTS: The curriculum was well received, with 96% of HOs finding the sessions stimulating. Previously validated scales of knowledge and confidence were administered at baseline and at follow-up. The average knowledge score improved 14% (P < 0.001). Confidence also improved, rising from 3.3 to 3.8 on a 5-point Likert scale (P < 0.001). These findings were independent of age, gender, religion, and prior education. The only attitudinal change was an increase in the proportion of residents who thought that ethics should be a required part of residency training (57% v 80%, P = 0.05). CONCLUSION: This curriculum appears practical, popular, and effective. It should be readily transferable to other institutions. (shrink)

OBJECTIVES: To study the accuracy of reviewing ward notes (chart review) as a measure of the quality of care rendered to patients with "Do Not Resuscitate" (DNR) orders. DESIGN: We reviewed the charts of 19 consecutive, competent inpatients with DNR orders for evidence that the staff addressed a broad range of patient care needs called Concurrent Care Concerns (CCCs), such as withholding treatments other than resuscitation itself, and attention to patient comfort needs. We then interviewed the patient, consultant physician, house (...) officer, and primary nurse and compared the ward notes with the understandings of these staff members. SETTING: The medical service of an urban university medical centre. RESULTS: The average number of documented CCCs addressed per DNR order was 1.1. The ward notes generally agreed with the perceptions of patients, house officers, and nurses (% agreement with notes = 79%, 77%, and 82%; kappa = 0.43, 0.40, 0.50). Consultant physicians' understandings were poorly reflected in the ward notes (% agreement = 59%; kappa = 0.18). They overestimated attention to CCCs compared with the notes (P < 0.0001) and with other observers (P < 0.0001). CONCLUSION: Chart review for attention to CCCs accurately reflects the understandings of patients, house officers, and nurses, but consultant physicians report more attention to CCCs than is recorded in the ward notes or understood by other observers. Better communication regarding end-of-life care plans should be encouraged. (shrink)

This study represents an improvement in the ethics scales inventory published in a 1988 Journal of Business Ethics article. The article presents the distillation and validation process whereby the original 33 item inventory was reduced to eight items. These eight items comprise the following ethical dimensions: a moral equity dimension, a relativism dimension, and a contractualism dimension. The multidimensional ethics scale demonstrates significant predictive ability.

A recently formulated concept of stochastic localizability is shown to be consistent with a concept of stochastic microcausality, which avoids the conclusions of Hegerfeldt's no-go theorem as to the inconsistency of sharp localizability of quantum particles and Einstein causality. The proposed localizability on quantum space-time is shown to lead to strict asymptotic causality. For finite time evolutions, upper bounds on propagation to the exterior of stochastic light cones are derived which show that the resulting probabilities are too small to be (...) actually observable in a realistic context. (shrink)

Although nature of science and nature of scientific inquiry are related to each other, they are differentiated as NOS is being more related to the product of scientific inquiry which is scientific knowledge whereas NOSI is more related to the process of SI. Lederman et al. determined eight NOSI aspects for K-16 context. In this study, a science camp was conducted to teach scientific inquiry and NOSI to 24 6th and 7th graders. The core of the program was guided inquiry (...) in nature. The children working in small groups under guidance of science advisors conducted four guided-inquiries in the nature in morning sessions on nearby plants, animals, water, and soil. NOSI aspects were made explicit during and at the end of each inquiry session. Views about scientific inquiry questionnaire was applied as pre- and post-test. The results of the study showed that children developed in all eight NOSI aspects, but higher developments were observed in “scientific investigations all begin with a question” and “there is no single scientific method,” and “explanations are developed from data and what is already known” aspects. It was concluded that the science camp program was effective in teaching NOSI. (shrink)

We begin with the idea that lines of reasoning are continuous mental processes and develop a notion of continuity in proof. This requires abstracting the notion of a proof as a set of sentences ordered by provability. We can then distinguish between discrete steps of a proof and possibly continuous stages, defining indexing functions to pick these out. Proof stages can be associated with the application of continuously variable rules, connecting continuity in lines of reasoning with continuously variable reasons. Some (...) examples of continuous proofs are provided. We conclude by presenting some fundamental facts about continuous proofs, analogous to continuous structural rules and composition. We take this to be a development on its own, as well as lending support to non-finitistic constructionism. (shrink)

Rufus of Ephesus (fl.c.a.d.100) wrote a large body of works on a variety of medical topics. Generally speaking, the Arabic tradition is particularly important for the reconstruction of much of his œuvre. In the present article, I am going to present four new fragments of Rufus’On Melancholyand a fragment from an otherwise unknown monographOn Preferring Fresh Poppies. These new fragments provide fascinating new insights into Rufus’ approach to recording case histories.