Laland and colleagues have sought to challenge the proximate–ultimate distinction claiming that it imposes a unidirectional model of causation, is limited in its capacity to account for complex biological phenomena, and hinders progress in biology. In this article the core of their argument is critically analyzed. It is claimed that contrary to their claims Laland et al. rely upon the proximate–ultimate distinction to make their points and that their alternative conception of reciprocal causation refers to phenomena that were already accounted (...) for by standard theory. (shrink)

Nucleation and motion of kink pairs on partial dislocations are examined by elasticity theory for materials with a high Peierls stress. Two approaches are used: one considers the change in average stacking-fault energy due to alloying elements and the other considers the change in local SFE due to a nearby solute atom. Both approaches highlight the role of SFE on kink nucleation, propagation and annihilation and both furnish strain rate as a function of stress, temperature and SFE. Model predictions are (...) compared with yield stress data for two systems: firstly, an intermetallic, MoSi 2 , which softens for alloying elements that decrease the SFE and hardens for Re additions that increase the SFE; secondly, a ceramic oxide, MgO-Al 2 O 3 spinel, which softens with increasing addition of excess alumina and at the same time exhibits a decrease in SFE. The average SFE approach agrees qualitatively with the data while quantitative agreement is obtained with the local SFE approach. The possibility is considered that the model applies to other materials, such as TiAl, HfV 2 and Fe 3 Al, which show softening with certain alloying additions. One requirement is that the dislocations are dissociated more than a few atomic distances; otherwise kink nucleation occurs on the perfect dislocation . Hence the model does not apply to materials such as bcc metals which only have a core dissociation. Normal hardening effects of solutes from size and modulus misfits are additive with any softening effects from a decrease in SFE and so may mask the latter, as occurs for W additions to MoSi 2. (shrink)

Background: Priority setting is necessary in current healthcare services. Discussion of fair process has highlighted the value of developing reasons for allocation decisions on the basis of experience gained from real cases.Aim: To identify the reasons that those with experience of real decision-making concerning resource allocation think relevant in deciding on the priority of a new but expensive drug treatment.Methods: Semistructured interviews with members of committees with responsibility for making resource allocation decisions at a local level in the British National (...) Health Service, analysed using modified grounded theory.Results: 22 interviews were carried out. 14 reasons were identified. Four reasons were almost universally considered most important: cost effectiveness; clinical effectiveness; equality and gross cost. No one reason was considered dominant. Some considerations, such as political directives and fear of litigation, were thought by many participants to distort decision-making. There was a substantial lack of agreement over the relevance of some reasons, such as the absence of alternative treatment for the condition.Conclusions: There is a clear consensus on the importance and role of a limited number of reasons in allocation decisions among participants. A focus on the process of decision-making, however, does not obviate the need for those involved in the process to engage with problematical ethical issues, nor for the importance of further ethical analysis. (shrink)

Using covariant derivatives and the operator definitions of quantum mechanics, gauge invariant Proca and Lehnert equations are derived and the Lorenz condition is eliminated in U(1) invariant electrodynamics. It is shown that the structure of the gauge invariant Lehnert equation is the same in an O(3) invariant theory of electrodynamics.

In a series of five experiments, we demonstrate that moral judgments and folk intuitions are often predictably fragmented. Drawing on the domains of ethics and action theory, we illustrate ways in which judgment tends to be associated with stable individual differences such as personality traits and reflective cognitive styles. We argue that these individual differences pose several unique challenges as well as provide opportunities for further theoretical development in the emerging field of experimental philosophy. Implications are briefly discussed.

In contemporary discussion of the philosophy of religion, or for that matter of any branch of philosophy, the names of Whitehead and Wittgenstein are not often linked. Whitehead's later work is, for the most part, treated as a rather specialized interest, an attractively under-cultivated field for the enterprising thesis-writer perhaps, but well away from the main centres of current philosophical activity. And what he has to say about specifically religious or theological issues 1 becomes simply one ramification of an ingenious (...) but somewhat eccentric system. Nonetheless, there is at least this much justification for considering it in relation to the much more influential and widely discussed views of Wittgenstein. Whitehead has some original things to say about God, Wittgenstein some original reasons for thinking that Whitehead's brand of originality is here radically misplaced. And the possibility or otherwise of such theological originality is an issue of very considerable importance for the philosophy of religion. (shrink)

What is a natural kind? As we shall see, the concept of a natural kind has a long history. Many of the interesting doctrines can be detected in Aristotle, were revived by Locke and Leibniz, and have again become fashionable in recent years. Equally there has been agreement about certain paradigm examples: the kinds oak, stickleback and gold are natural kinds, and the kinds table, nation and banknote are not. Sadly agreement does not extend much further. It is impossible to (...) discover a single consistent doctrine in the literature, and different discussions focus on different doctrines without writers or readers being aware of the fact. In this paper I shall attempt to find a defensible distinction between natural and non-natural kinds. (shrink)

To what extent does the fact that a philosopher, in order to communicate, is constrained to use the same language and the same concepts as other members of his society, inhibit him from developing genuinely original modes of thought? Section I of this paper outlines arguments for the view that any attempt at radical originality, of the kinds traditionally expected of philosophy, must involve misuse of these shared concepts. Section II, however, on the basis of an examination of what it (...) is for different members of a society to use the same concepts, argues that so doing does not rule out important differences over instantiations and logical interrelations. It then attempts to show that this latitude for difference is adequate to allow for certain kinds of philosophical originality, for example, that shown in the Whiteheadian philosophy of organism. (shrink)

Background: Discussing treatment risks has become increasingly important in medical communication. Still, despite regulations, physicians must decide how much and what kind of information to present. Objective: To investigate patients’ preference for information about a small risk of a complication of colonoscopy, and whether medical and personal factors contribute to such preference. To propose a disclosure policy related to our results. Design: Vignettes study. Setting: Department of Gastroenterology, Academic Medical Centre, the Netherlands. Patients: 810 consecutive colonoscopy patients. Intervention: A home-sent (...) questionnaire containing three vignettes. Vignettes varied in the indication for colonoscopy, complication severity and level of risk. Patients were invited to indicate their wish to be informed and the importance of such information. In addition, sociodemograhic, illness-related and psychological characteristics were assessed. Main outcome measurements: Wish to be informed and importance of information. Results: Of 810 questionnaires, 68% were returned. Patients generally wished to be informed about low-risk complications, regardless of the indication for colonoscopy or the severity of the complication. The level of risk did matter, though (OR = 2.48, SE = 0.28, p = 0.001). The information was considered less important if done for population screening purposes or diagnosis of colon cancer, if the complication was less severe (bleeding) and if the risk was smaller (0.01% and 0.1%). Patients’ information preference was also related to age, mood and coping style. Limitations: Difficulty of vignettes. Conclusions: Patients generally wish to be informed about all possible risks. However, this might become uninformative. A stepwise approach is suggested. (shrink)

Graph polynomials are graph parameters invariant under graph isomorphisms which take values in a polynomial ring with a fixed finite number of indeterminates. We study graph polynomials from a model theoretic point of view. In this paper we distinguish between the graph theoretic (semantic) and the algebraic (syntactic) meaning of graph polynomials. Graph polynomials appear in the literature either as generating functions, as generalized chromatic polynomials, or as polynomials derived via determinants of adjacency or Laplacian matrices. We show that these (...) forms are mutually incomparable, and propose a unified framework based on definability in Second Order Logic. We show that this comprises virtually all examples of graph polynomials with a fixed finite set of indeterminates. Finally we show that the location of zeros and stability of graph polynomials is not a semantic property. The paper emphasizes a model theoretic view. It gives a unified exposition of classical results in algebraic combinatorics together with new and some of our previously obtained results scattered in the graph theoretic literature. (shrink)