Spiders spin multiple types of silks that are renowned for their superb mechanical properties. Flagelliform silk, used in the capture spiral of an orb‐web, is one of the few silks characterized by both cDNA and genomic DNA data. This fibroin is composed of repeating ensembles of three types of amino acid sequence motifs. The predominant subrepeat, GPGGX, likely forms a β‐turn, and tandem arrays of these turns are thought to create β‐spirals. These spring‐like helices may be critical for the exceptional (...) ability of capture silk to stretch and recoil. Each ensemble of motifs was found to correspond to a different exon within the flagelliform gene. The pattern of sequence similarity among exons indicates intragenic concerted evolution. Surprisingly, the introns between the iterated exons are also homogenized with each other. This unusual molecular architecture in the flagelliform silk gene has implications for the evolution and maintenance of spider silk proteins. BioEssays 23:750–756, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Are acids natural kinds? Or are they merely relevant kinds? Although acidity has been one of the oldest and most important concepts in chemistry, surprisingly little ink has been spilled on the natural kind question. I approach the question from the perspective of microstructural essentialism. After explaining why both Brønsted acids and Lewis acids are considered functional kinds, I address the challenges of multiple realization and multiple determination. Contra Manafu and Hendry, I argue that the stereotypical (...) properties of acids are not multiply realized. Instead, given the equivalence between the proton-donating and electron-accepting mechanisms of Brønsted and Lewis, respectively, I show that acidity as a property type can be identified with a unique microstructural property, namely the presence of a LUMO or other low energy empty orbital. In doing so, I defend the view that the Lewis theory encompasses Brønsted–Lowry, and that all Brønsted acids are also Lewis acids. Contra Hacking and Chang, I thus maintain that the different concepts of acidity do not crosscut, and that the hierarchy requirement is met. Finally, by characterizing natural kinds as powerful objects and by adopting a dispositional view of functions, I illustrate how the microessentialist can make sense of the latent and relational character of most acids. In sum, I contend that acids are genuine natural kinds, even for the microstructural essentialist. (shrink)

For a period of several years the philosopher of science Hasok Chang has promoted various inter-related views including pluralism, pragmatism, and an associated view of natural kinds. He has also argued for what he calls the persistence of everyday terms in the scientific view. Chang claims that terms like phlogiston were never truly abandoned but became transformed into different concepts that remain useful. On the other hand, Chang argues that some scientific terms such as acidity have suffered a form of (...) “rupture”, especially in the case of the modern Lewis definition of acids. Chang also complains that the degree of acidity of a Lewis acid cannot be measured using a pH meter and seems to regard this as a serious problem. The present paper examines some of these views, especially what Chang claims to be a rupture in the definition of acidity. It is suggested that there has been no such rupture but a genuine generalization, on moving from the Brønsted-Lowry theory to the Lewis theory of acidity. It will be shown how the quantification and measurement of Lewis acidity can easily be realized through the use of equilibrium theory and the use of stability constants. (shrink)

Among the many acid-base concepts, the theory of Usanovich is one of the least known despite the most general scope including almost all chemical reaction types and even redox chemistry. Published 1939 in a Soviet journal in Russian language, it gained little immediate attention, and was later criticized mainly as being too broad in scope. Although several articles recently remembered Usanovich and his acid–base theory, one major inconsistency again was overseen: the electron is put in a row along with anions. (...) Chemical history probably correctly puts this concept aside, also because it added little explanation capabilities beyond the elaborated considerations of the simultaneously published acid–base theory of Gilbert N. Lewis which was later refined by Pearson (hard and soft acids and bases, “HSAB”). A modified version of the core of Usanovich' concept is finally discussed. It combines the classic protic and aprotic acid–base concepts on the foundations of Lewis’ and Pearsons ideas. (shrink)

An Example of Teaching of Chemistry Before and After Mendeleev’s 1869 Periodic Table of Elements is presented. Prior to Mendeleev’s publication in 1869, only 63 elements were known. The ensuing discovery of the electron and the correspondence of the number of electrons to equivalent weight and atomic number is of singular importance to the impact of the Periodic Table of Elements and the way modern chemistry is taught. Without the identity of the electron and its alliance to atomic number, modern (...) teaching of chemistry would be very different. Without it concepts of electronic configuration, oxidation and reduction, polarization, intermolecular interactions, types of bonding, Lewis acid/base definition, etc. would disappear in our vernacular. Thus, we trace the origin of the electron. (shrink)

Now in a thoroughly revised and expanded third edition, this authoritative Handbook reviews current knowledge about all aspects of emotion and its role in human ...

In lieu of an abstract, here is a brief excerpt of the content:The Three Pillars of Catholic EducationArchbishop Salvatore CordileoneIntroductionOn February 13, 1999, then-Cardinal Joseph Ratzinger visited St. Patrick's Seminary and University in Menlo Park, California. He gave a lecture entitled, "Faith and Culture." Pope St. John Paul II had only back in September of the previous year published his momentous encyclical Fides et Ratio. Purposely placing his own remarks under the umbrella of that encyclical, Cardinal Ratzinger used the opportunity (...) at St. Patrick's Seminary to discuss the growing relativism which was even at that time eroding our culture.He began his lecture by using an example from C. S. Lewis's great work The Screwtape Letters. The future Pope remarked:This book consists of fictional letters from a senior devil who is giving advice on how best to proceed to one beginning in the work of leading men astray. The younger devil has expressed concern to his superior that especially intelligent people, in particular, might read the books of wisdom of the ancients and might thus come upon the track of the truth. Screwtape calms him by pointing out that the "Historical point of View," with which the intellectuals of the Western world have fortunately been inculcated by the devils, means in fact that "when a learned man is presented with any statement in an ancient author, the one question he never asks is whether it [End Page 7] is true. He asks who influenced the ancient writer, and how far the statement is consistent with what he said in other books, and what phase in the writer's development, or in the general history of thought, it illustrates, and how it affected other writers," and so on.1The startling truth is that now, almost twenty-five years later, what Cardinal Ratzinger articulated back in 1999 has only crystallized. In almost every area of our culture, the notion of truth has receded due to the acidic encroachment of relativism. As a culture we have given up on any hope of finding truth and instead consigned reality to something that is determined by the individual. We see the extent to which this relativism has taken hold of our culture in the now-famous words of Supreme Court Justice Anthony Kennedy: "At the heart of liberty is the right to define one's own concept of existence, of meaning, of the universe, and of the mystery of human life."2 In this breathtaking statement, Justice Kennedy seemingly makes irrelevant the entire history of Western civilization. The irony, of course, is that it is precisely the course of Western philosophy and thought which has steered the culture in such a direction that it could produce a Supreme Court justice who would articulate such a bewildering statement. For we do not, nor can we, exist in a philosophical vacuum. And such is the great irony of this moment that we occupy—it is on the ash heap of Western civilization that relativists stand attacking the very history which brought them to be there in the first place.Given this sad reality, we can see Cardinal Ratzinger's criticism from 1999 as a clarion call, and as prophetic in describing what has transpired in the decades since. The complete dominance of relativism in all its forms demands that we return to the primacy of truth. But it is not only unfettered relativism that necessitates this return to truth. The return to the splendor of truth becomes all the more important for us as Christians. As the First Letter of St. Peter makes clear, the Christian is to purify his soul by obedience to the truth (1 Pet1:22). And in the Gospel of St. John, we are told that Christ is the true Light who enlightens all, and who gives the power to become children of God to those who receive him (John 1:9–11).In this vein, I would like to present what I believe is the strength of Catholic education and the need to restore a truly Catholic vision. To this end, I believe Cardinal Ratzinger was correct in his forecast of the repercussions of bracketing out truth from our culture. While the broader repercussions of... (shrink)

In “Non-Rigid Forms” I characterized possibilities as indefinite forms, in contrast to the definite forms (eternal objects) of actualities. This did not do justice to the atemporality of eternal objects. Indefinite forms ought to be construed as dense clusters of eternal objects. By progressive definition God specifies relevant possibilities to the occasion, which determines one to become actual.

It is easy to dispose of the historical aspect of this question. When Aristotle affirmed that the family is more natural than the State, in the sense of original rather than final or necessary, and taught his contemporaries to regard the State as the result of a gradual development through the family and the tribe, he adopted a viewpoint which would probably find universal endorsement to-day. Only a particularly perverse writer would endeavour to revive the controversy as to whether or (...) not the institution of the State began with explicit resolutions concluded at a specific date. No doubt there are plentiful instances of the establishment of particular States through some agreement or contract on the part of its members. The case of the Pilgrim Fathers is often cited as a classical example. But this does not give us an original contract. We should seek one in vain. (shrink)

It is a platitude that when we reason, we often take things for granted, sometimes even justifiably so. The chemist might reason from the fact that a substance turns litmus paper red to that substance being an acid. In so doing, they take for granted, reasonably enough, that this test for acidity is valid. We ordinarily reason from things looking a certain way to their being that way. We take for granted, reasonably enough, that things are as they look Although (...) it is a platitude that we often take things for granted when we reason—whether justifiably or not—one might think that we do not have to. In fact, it is a natural expectation that were we not pressed by time, lack of energy or focus, we could always in principle make explicit in the form of premises every single presupposition we make in the course of our reasoning. In other words, it is natural to expect it to be true that presuppositionless reasoning is possible. In this essay, I argue that it is false: presuppositionless reasoning is impossible. Indeed, I think this is one of the lessons of a long-standing paradox about inference and reasoning known as Lewis Carroll’s (1985) regress of the premises. Many philosophers agree that Carroll’s regress teaches us something foundational about reasoning. I part ways about what it is that it teaches us. What it teaches us is that the structure of reasoning is constitutively presuppositional. (shrink)

SummaryKekulé first suggested a hexagonal structure for benzene in 1865. For over a half-century after, chemists struggled to reconcile proposed structures for benzene and other aromatic compounds with their resistance to chemical transformation and tendency to maintain the type during reaction. The combined structural and reactivity features of these compounds were eventually covered by the term ‘aromaticity’. Kekulé, Bamberger and Thiele had each proposed a criterion for aromaticity; all were either empirically contradicted or incapable of evaluation. In the 1930s, two (...) rival quantum mechanical methods succeeded in establishing a physical basis for aromaticity. Using valence bond theory, Pauling attributed benzene's stability to its being a resonance hybrid of several Lewis structures. Calculating resonance energies was challenging but manipulating Lewis structures was not; that procedure provided qualitative insights into aromatic structure and reactivity. Resonance theory appealed especially to organic chemists and eclipsed Hückel's contemporaneous molecular orbital approach, which remained relatively inaccessible. In the 1950s, however, simple rules derived from Hückel's mathematics, combined with proton NMR data, provided seemingly universal criteria for aromaticity. In the event, post-1950 discoveries of non-organic, three-dimensional compounds such as ferrocene and the fullerenes that exhibit aromatic properties led chemists to doubt the utility and universality of ‘aromaticity’ as a concept. A recent consensus maintains that aromaticity is a multi-variable phenomenon that cannot be reduced to a strict definition, a property it shares with other core chemical concepts such as ‘acidity’ and ‘reactivity’. (shrink)

Taking an analytic and historical approach, this work develops and defends Althusserian critical theory. This theory, it is argued, produces knowledge of how a particular class of people, in a particular time, in a particular place, is dominated, oppressed, or exploited. Moreover, without relying on a general notion of human emancipation, concrete critical theory can suggest political means for the alleviation of these conditions. Because it puts Althusser’s ideas in dialogue with contemporary social science and philosophy, the book as a (...) whole makes contributions to Althusser studies, to Anglo-American political philosophy, and to current debates in the philosophy of the social sciences. (shrink)

With a mass digitisation programme underway and the addition of non-print legal deposit and web archive collections, the National Library of Scotland is now both producing and collecting data at an unprecedented rate, with over 5PB of storage in the Library’s data centres. As well as the opportunities to support large scale analysis of the collections, this also presents new challenges around data management, storage, rights, formats, skills and access. Furthermore, by assuming the role of both creators and collectors, libraries (...) face broader questions about the concepts of ‘collections' and ‘heritage', and the ethical implications of collecting practices. While the ‘collections as data’ movement has encouraged cultural heritage organisations to present collections in machine-readable formats, new services, processes and tools also need to be established to enable these emerging forms of research, and new modes of working need to be established to take into account an increasing need for transparency around the creation and presentation of digital collections. This commentary explores the National Library of Scotland's new digital scholarship service, the implications of this new activity and the obstacles that libraries encounter when navigating a world of Big Data. (shrink)

In this paper, I discuss the concept of ‘shared meaning’, and the relationship between a shared understanding of signs within an animal social group and the Umwelten of individuals within the group. I explore the concept of the ‘Total Umwelt’, as described by Tønnesen, (2003), and use examples from the traditional ethology literature to demonstrate how semiotic principles can not only be applied, but underpin the observations made in animal social biology. Traditionally, neo-Darwinian theories of evolution concentrate on ‘fitness’ or (...) an organism’s capacity to survive and reproduce in its own environmental niche. However, this process also relies on underlying signs and sign processes, which are often over-looked in traditional ethology and behavioural ecology. Biosemiotics, however, places the emphasis on sign process, with signs and signals comprising a semiosphere. Significantly, whilst the semiosphere is formulated as physical phenomena, specifically energetic and material signs which can be detected and transmitted as signals from one individual to another, it is the Umwelten of living organisms which give those signals meaning. Further, two or more Umwelten can merge, giving rise to a ‘Total Umwelt’, which facilitates shared meaning of signs between two or more individuals. Across and within generations, this gives rise to cultural interpretation of signs within populations. I argue this is the fundamental basis for emergent group properties in social species, or indeed in solitary living species where individuals interact to mate, defend territories or resources, or in raising altricial young. I therefore discuss a fusion of traditional behavioural ecology- based theory with semiotics, to examine the phenomenon of ‘shared meaning’ in animal social groups. (shrink)

This article is a historical narrative and philosophical evaluation of nicolai hartmann's articles and book "grundzuege einer metaphysik der erkenntnis" (1925) in which he gradually distanced himself from kant and from marburg neo-Kantianism.