Background: Although convolutional neural networks (CNNs) achieve high diagnostic accuracy for detecting Alzheimer’s disease (AD) dementia based on magnetic resonance imaging (MRI) scans, they are not yet applied in clinical routine. One important reason for this is a lack of model comprehensibility. Recently developed visualization methods for deriving CNN relevance maps may help to fill this gap as they allow the visualization of key input image features that drive the decision of the model. We investigated whether models with higher accuracy (...) also rely more on discriminative brain regions predefined by prior knowledge. Methods: We trained a CNN for the detection of AD in N = 663 T1-weighted MRI scans of patients with dementia and amnestic mild cognitive impairment (MCI) and verified the accuracy of the models via cross-validation and in three independent samples including in total N = 1655 cases. We evaluated the association of relevance scores and hippocampus volume to validate the clinical utility of this approach. To improve model comprehensibility, we implemented an interactive visualization of 3D CNN relevance maps, thereby allowing intuitive model inspection. Results: Across the three independent datasets, group separation showed high accuracy for AD dementia versus controls (AUC ≥ 0.91) and moderate accuracy for amnestic MCI versus controls (AUC ≈ 0.74). Relevance maps indicated that hippocampal atrophy was considered the most informative factor for AD detection, with additional contributions from atrophy in other cortical and subcortical regions. Relevance scores within the hippocampus were highly correlated with hippocampal volumes (Pearson’s r ≈ −0.86, p < 0.001). Conclusion: The relevance maps highlighted atrophy in regions that we had hypothesized a priori. This strengthens the comprehensibility of the CNN models, which were trained in a purely data-driven manner based on the scans and diagnosis labels. The high hippocampus relevance scores as well as the high performance achieved in independent samples support the validity of the CNN models in the detection of AD-related MRI abnormalities. The presented data-driven and hypothesis-free CNN modeling approach might provide a useful tool to automatically derive discriminative features for complex diagnostic tasks where clear clinical criteria are still missing, for instance for the differential diagnosis between various types of dementia. (shrink)

Frank A. Lewis presents a close study of book Zeta of Aristotle's Metaphysics, one of his most dense and controversial texts, commonly understood to contain his deepest thoughts on the definition of substance and related metaphysical issues. Lewis argues that Aristotle returns to the causal view of primary substance from his Posterior Analytics.

The American Journal of Bioethics, Volume 11, Issue 12, Page 59-61, December 2011.

Replying to Theaetetus’ suggestion that knowledge is true opinion at Tht. 200e, Socrates remarks that ‘a whole profession’ testifies against this definition. The orator practises the art of persuasion, not to teach people, but make them believe whatever he wants. If a robbery has taken place, for example, he cannot in a short time teach adequately the truth about what happened to people who were not on the scene.

The topic of homonymy, especially the variety of homonymy that has gone under the title, “focal meaning,” is of fundamental importance to large portions of Aristotle’s work-not to mention its central place in the ongoing controversies between Aristotle and Plato. It is quite astonishing, therefore, that the topic should have gone so long without a book-length treatment. And it is all the more gratifying that the new book on homonymy by Christopher Shields should be so comprehensive, and of such uniformly (...) high quality.’ Everyone who cares about Aristotle will be in his debt. Shields’s book falls into two parts. In the first, he is concerned to lay out the basic structure of Aristotle’s views about homonymy; in the second part, we are led through the various applications of the idea, to the analysis of friendship, for example, the homonymy of the body, the account of goodness and, not least, the homonymy of being. Shields’s book brings out well how the topic of homonymy weaves in and out of the fabric of Aristotle’s thinking in a variety of areas. I will resist the temptation to follow Shields through these various subject-matters, and instead take up essentially two topics. First, (I), the basic outline of Aristotle’s notion of homonymy, more or less independently of its different applications (here, I follow Shields’s example in the first half of his book). Thereafter, I discuss a single application: the homonymy of being (this is the subject of Shields’s last and longest chapter). Here, I will be interested (II) in how homonymy relates to the theory of the categories; and (III) in the application of homonymy to the analysis of substance in the Metaphysics. (shrink)

Neither Johnston's nor Wright's account of response-dependence offers a complete picture of response-dependence, as they do not apply to all concepts that are intrinsically related to our mental responses. In order to (begin to) remedy this situation, a new conception of response-dependence is introduced that I call "acceptance-dependence". This account applies to concepts such as goal, constitutional, and money, the first two of which have mistakenly been taken to be response-dependent in another sense. Whereas on Johnston's and Wright's accounts response-dependent (...) concepts depend on counterfactual responses of individuals, acceptance-dependent concepts depend on the actual responses of groups of people. This implies that concepts of the latter kind are less objective than concepts of the former kind. (shrink)

This article seeks to broaden the debate on the recruitment of REC lay members by arguing that the recruitment of good members requires that there is initially a need to heighten awareness among potential candidates of the nature of the lay contribution. The article offers a recruiting process model of: awareness; advocacy; characterization; recruitment, and training, and focuses on the first three steps in that process. The current position is that there is sparse awareness and advocacy of the role of (...) the lay member at a time of rapid change, both in the ‘research ethics service’ and the lay contribution thereto. Thus it is seen as imperative that positive steps are taken to change this position, filling a lacuna that appears to exist. Given that the candidate pool can become larger and have a fuller understanding of the ‘research ethics service’, better recruitment and hence better-trained members should result. As a way forward, practical ways and means to do this are suggested, providing topics that will engender a wider debate and perhaps as an outcome, some new initiative. (shrink)

The ethics of managing obstetric patients in medical disasters poses ethical challenges that are unique in comparison to other disaster patients, because the medical needs of two patients—the pregnant patient and the fetal patient—must be considered. We provide an ethical framework for doing so. We base the framework on the justice-based prevention of exploitation of populations of patients, both obstetric and non-obstetric, in medical disasters. We use the concept of exploitation to identify a spectrum from ethically acceptable, to ethically challenging, (...) to ethically unacceptable, management of obstetric patients in medical disasters. We also address the ethics of the care of obstetric and neonatal patients when the resources of a hospital are completely overwhelmed in a large-scale medical disaster. (shrink)

ABSTARCT When people go shopping, they enter a building. But the shop cannot be identified with the building, because it would remain the same shop if it moved to another building or if it became an e-store. Daniel Korman [2019] uses these two observations to argue that establishments are immaterial objects. However, all that follows is that establishments are not buildings. I argue that establishments are organisations or corporate agents that are constituted by people. This entails that they are material (...) objects. Korman’s observations can be accommodated in terms of the further observation that corporate agents can but need not own or rent buildings. (shrink)

Secular change in sex ratios is examined in relation to experience in the family. Two theoretical perspectives are outlined: Guttentag and Secord’s (1983) adaptation of social exchange theory, and sexual selection theory. Because of large-scale change in number of births and typical age differentials between men and women at marriage, low sex ratios at couple formation ages existed in the U.S. between 1965 and the early 1980s. The currently high sex ratios, however, will persist until the end of the century. (...) High sex ratios appear to be associated with lower divorce rates, male commitment to careers that promise economic rewards, male willingness to engage in child care, higher fertility, and higher rates of sexual violence. Sexual selection theory calls attention to intrasexual competition in the numerically larger sex. (shrink)

What in Aristotle corresponds, in whole or (more likely) in part, to our contemporary notion of predication? This paper sketches counterparts in Aristotle's text to our theories of expression and of truth, and on this basis inquires into his treatment of sentences assigning an individual to its kinds. In some recent accounts, the Metaphysics offers a fresh look at such sentences in terms of matter and form, in contrast to the simpler theory on offer in the Categories . I argue (...) that the Metaphysics initiates no change in this regard over the Categories . The point that form is (metaphysically) predicated of matter is a contribution, not to the account of statement predication, but to the analysis of compound material substances. Otherwise put, in our terms Aristotelian form is not - in particular, is not also - a propositional function, but a function from matter to compound material substances. (shrink)

This book takes up the central themes of Aristotle's metaphysical theory and the various transformations they undergo prior to their full expression in the Metaphysics. Aristotle's metaphysics is bedevilled by classic puzzles involving such notions as form, predication, universal, and substance, which result from his attempt to adapt the various requirements on primary substance developed in his earlier works so that they fit the very different metaphysical picture in his later work. Professor Lewis argues that Aristotle is himself aware of (...) most if not all of these difficulties and in the Metaphysics works hard to ensure the coherence of his theory. He presents Aristotle's views as a formal theory complete with axioms, definitions, and theorems. (shrink)

This study clearly reveals that the benefits ascribed to strategic planning typically are achieved through a variety of means. A formal process that seeks to plan in a comprehensive, linear fashion is likely to be too complicated, politically divisive, expensive and inflexible, and to ignore how decisions are made in a complex, highly decentralised university. While many approaches to planning are used, universities must ensure they provide periodically opportunities for university staff—freed from daily responsibilities—to consider strategic concerns. Accurate and relevant (...) information must be available to all who make and carry out decisions. Planning should be viewed as a learning process rather than a document producing exercise. Extensive communication among university staff and faculty is needed to ensure informed debate and substantial acceptance of decisions—otherwise they are unlikely to be implemented. Perhaps most important is not the process employed but the decision-maker's breadth of perspective and sophistication. No process will overcome lack of competent leadership. The importance of daily decision-making in various councils and committees on issues such as cost containment and budgetary priorities is underestimated in the literature on planning.Critics have doubted whether universities' structures and processes permit them, or their leaders have the resolve, to confront the emerging issues. However, in many respects, the universities' decentralised, multiple decision-making practices may suit them well. They face the same challenging societal changes as other sectors of society. Their staff include some of the most capable individuals in the United States, and in the past they have been highly adaptable during periods of profound social change.Universities do not appear to be less aware of the need to adapt, nor more constrained in adapting to new conditions, than other sectors of society. In fact, university research and scholarship will be highly important in pointing the way for the whole of society to meet this era's challenges. If pessimistic predictions about current trends turn out to be accurate, universities no doubt will adapt at least as well as other kinds of institutions. The travails of business in this environment are daily news! There will be occasional casualties among the universities, as frequently occurs during major social transitions, but institutions that have grown in importance for over 1,000 years, will doubtless emerge from this period perhaps somewhat changed but still performing their historic social functions. (shrink)

Programmed cell death (PCD) is a process aimed at the removal of redundant, misplaced, or damaged cells and it is essential to the development and maintenance of multicellular organisms. In contrast to the relatively well‐described cell death pathway in animals, often referred to as apoptosis, mechanisms and regulation of plant PCD are still ill‐defined. Several morphological and biochemical similarities between apoptosis and plant PCD have been described, including DNA laddering, caspase‐like proteolytic activity, and cytochrome c release from mitochondria. Reactive oxygen (...) species (ROS) have emerged as important signals in the activation of plant PCD. In addition, several plant hormones may exert their respective effects on plant PCD through the regulation of ROS accumulation. The possible plant PCD regulators discussed in this review are integrated in a model that combines plant‐specific regulators with mechanisms functionally conserved between animals and plants. BioEssays 25:47–57, 2003. © 2002 Wiley Periodicals, Inc. (shrink)

In this paper, we study the lattice of r.e. subspaces of a recursively presented vector space V ∞ with regard to the various complexity-theoretic speed-up properties such as speedable, effectively speedable, levelable, and effectively levelable introduced by Blum and Marques. In particular, we study the interplay between an r.e. basis A for a subspace V of V ∞ and V with regard to these properties. We show for example that if A or V is speedable , then V is levelable (...) . We also show that if A is an r.e. subset of a recursive basis for V ∞ , then A is levelable iff V is speedable while it is not the case that A is levelable iff V is speedable. We also provide several contrasts between the lattice of r.e. subspaces and the lattice of r.e. sets with respect to these speed-up properties. For example, every maximal set is levelable but we show that there exist supermaximal spaces which are nonspeedable in all possible r.e. degrees as well as supermaximal spaces which are levelable in all r.e. degrees which contain levelable sets. (shrink)

Leading scholars in the field of health economics evaluate the role of incentives in health and health-care decision making from the perspectives of both supply and demand.