Homeostatic Property Cluster (HPC) theory suggests that species and other biological taxa consist of organisms that share certain similarities. HPC theory acknowledges the existence of Darwinian variation within biological taxa. The claim is that “homeostatic mechanisms” acting on the members of such taxa nonetheless ensure a significant cluster of similarities. The HPC theorist’s focus on individual similarities is inadequate to account for stable polymorphism within taxa, and fails properly to capture their historical nature. A better approach is to treat (...) distributions of traits in species populations as irreducible facts, explained in terms of selection pressures, genealogy, and other evolutionary factors. We call this view Population Structure Theory (PST). PST accommodates the view, implicit in biological systematics, that species are identified by reference to particular historical populations. (shrink)

It has been known for six years that the restriction of Girard's polymorphic system $\text{\bfseries\upshape F}$ to atomic universal instantiations interprets the full fragment of the intuitionistic propositional calculus. We firstly observe that Tait's method of “convertibility” applies quite naturally to the proof of strong normalization of the restricted Girard system. We then show that each $\beta$-reduction step of the full intuitionistic propositional calculus translates into one or more $\beta\eta$-reduction steps in the restricted Girard system. As a consequence, we obtain (...) a novel and perspicuous proof of the strong normalization property for the full intuitionistic propositional calculus. It is noticed that this novel proof bestows a crucial role to $\eta$-conversions. (shrink)

This paper provides a framework, based on Peircean pragmatism and a supplemental metaphysical principle, for reconciling realism and antirealism. Peircean polymorphism, the resultant position defended in the paper, is a realist position, accepting that there is a world that exists and has characteristics of its own, independently of our experience of it. The position denies, however, what I call the uniqueness assumption about truth -- that it is possible for one, unique representational approach to adequately represent reality. While Peirce (...) does not explicitly address the uniqueness assumption, his account is sufficiently ambiguous on this point to have been understood as a uniqueness account. The supplemental metaphysical principle introduced here, that reality is polymorphic, serves to fortify Peirce's pragmatism against uniqueness. Briefly, the paper outlines some implications of accepting the fortified Peircean position, including greater explanatory power and more compelling motivation for continued scientific inquiry. (shrink)

The investigations on higher-order type theories and on the related notion of parametric polymorphism constitute the technical counterpart of the old foundational problem of the circularity of second and higher-order logic. However, the epistemological significance of such investigations has not received much attention in the contemporary foundational debate.We discuss Girard’s normalization proof for second order type theory or System F and compare it with two faulty consistency arguments: the one given by Frege for the logical system of the Grundgesetze (...) and the one given by Martin-Löf for the intuitionistic type theory with a type of all types.The comparison suggests that the question of the circularity of second order logic cannot be reduced to Russell’s and Poincaré’s 1906 “vicious circle” diagnosis. Rather, it reveals a bunch of mathematical and logical ideas hidden behind the hazardous idea of impredicative quantification, constituting a vast domain for foundational research. (shrink)

Genome-wide association studies of human complex traits have provided us with new estimates of heritability. These estimates foreground the question of genetic causation. After having presen...

Transparent intensional logic (TIL) is a well-explored type-theoretical framework for semantics of natural language. However, its treatment of polymorphic functions, which are essential for the analysis of various natural language phenomena, is still underdeveloped. In this paper, we address this issue and propose an extension of TIL that introduces polymorphism via type variables ranging over types and generalized variables ranging over constructions and types. Furthermore, we offer an analysis of sentences involving non-specific notional attitudes of the general form ‘_A_ (...) considers (believes, desires, wants, seeks,...) something’. (shrink)

After the birth of thermodynamics’ second principle—outlined in Carnot's Réflexions sur la puissance motrice du feu —several studies provided new arguments in the field. Mainly, they concerned the thermodynamics’ first principle—including energy conceptualisation—, the analytical aspects of the heat propagation, the statistical aspects of the mechanical theory of heat. In other words, the second half of nineteenth century was marked by an intense interdisciplinary research activity between physics and chemistry: new disciplines applied to the heat developed in the form of (...) analytical, mechanical and statistical theories. Inside all these theories, entropy—the brand-new function that Clausius coined in his Mechanical theory of heat—started to play a central epistemic role. In the present paper, we analyse some steps of the historical process of conceptualisation of such function from 1850 to 1902. Particularly, we retrace the historical–foundational path that—starting from Clausius’ Second Law—lead Boltzmann and Gibbs to their distinguished formulations of statistical entropy. As usual, our research has been unrolled through the analyses of primary sources and by leaning on critical readings of the secondary literature. As for the methodological approach, text analysis of historical documents constituted our privileged modus operandi. This paper is the expression of a collaborative historical research program focused on the thermodynamic foundations of physics–chemistry relationship; early results have already been published by the same authors upon the concepts of reversibility––and––thermal equilibrium. (shrink)

Lonergan's account of human consciousness as polymorphic self-presence differs significantly from both the variety of contemporary reductionistic accounts and phenomenological treatments still influenced strongly by Cartesian suppositions and/or Kantian restrictions. It is argued that Lonergan's account grounds not only a critical meta-philosophy, but also provides a heuristic structure for a nuanced genetic account of philosophic differences. In this regard, Lonergan's account is claimed to be an adequate grounding for a thorough contemporary response to the Hegelian requirement that philosophers account not (...) only for their own views but for the existence of contrary and differing philosophic convictions. (shrink)

Acetyltransferase enzymes expressed in hepatic and extrahepatic tissues are products of an acetyltransferase gene locus. Acetylation capacity is regulated by simple autosomal Mendelian inheritance of two codominant alleles at this locus. Human slow acetylators are predisposed to bladder cancer from arylamine chemicals. The role of the bladder in arylamine metabolism and of bladder acetyltransferases in the etiology of bladder cancer is not fully understood, but the acetylator genotype‐dependent expression of arylamine N‐acetyltransferase and N‐hydroxyarylamine O‐acetyltransferase in bladder cytosol may contribute towards (...) the genetic predisposition of human slow acetylators to arylamine‐induced bladder cancer. (shrink)

In this paper, I examine the writings of African American philosopher Leonard Harris as an author who has been read primarily for his contributions to the study of Africana philosophy, U.S. pragmatism, and moral philosophy. Despite contributions to bioethics and reflections on systemic racism within the context of institutional medical settings, Harris’s work has yet to be read in terms of its relevance for disability critique. This paper demonstrates how Harris’s writings may be read as contributing to the field of (...) philosophy of disability by arguing that his concept of “necro-being” helps reveal the mutually reinforcing relationships between race, disability, gender, and class. To carry this out, I consider core themes from his work such as metaphilosophy, health, and autonomy to show the relevance of his writings for philosophy of disability, and, in a parallel manner, the importance of disability critique for expanding his accounts of oppression and racism. (shrink)

This paper addresses the question, which sex ratio will evolve in a population that is subject to mutation and drift. The problem is analyzed using a simulation model as well as analytical methods. A detailed simulation model for the evolution of a population's allele distribution shows that for the sex ratio game a wide spectrum of different population states may evolve from on the one hand a monomorphic state with one predominant allele and with all other alleles suppressed by the (...) forces of selection, to on the other hand a polymorphism determined by recurrent mutations. Which of these states will evolve depends on the population size, the mating system and the rate of mutations. For the sex ratio game the evolutionarily stable strategy (ESS), as defined by evolutionary game theory, can only predict the population sex ratio but not the underlying stable population state. A comparison of different approaches to the problem shows that false predictions of the stable population states might result from two simplifying assumptions that are fairly common in evolutionary biology:a) it is assumed that mutations are rare events and there is never more than one mutant gene present in a population at any one time; b) a deterministic relationship is assumed between the fitness assigned to an individual's strategy and the individual's contribution to the gene pool of future generations. (shrink)

Health policy is increasingly confronted with the demand for financing genetic testing on inherited susceptibility to disease. Tests on polymorphism/snp associated with multicausal and chronic conditions are already offered in private commercial institutions or in academic hospitals. The increasing pressure on public health services to offer SNP testing leads to first methodological approaches for a generally valid regulatory framework applicable for inclusion or refusal of genetic tests into the public health services. Systematic search in Medline, Embase and the Web (...) for methodological papers or guidelines for the assessment of polymorphism-screening. Since genetic testing has not only clinical and economic effects on health care, but also primarily ethical consequences by profiling our understanding of “health” and “disease”, this paper gives an overview of relevant aspects and background information to consider in the assessment of genetic tests. Although 2–3 million SNPs are identified and the journals are full of reported “significant” associations between disease and mutation, only a few can be replicated unequivocally. The ACCE -framework was developed by the Center of Disease Control for the assessment of genetic testing. This standardised appraisal approach proposes collecting and evaluating: Prevalence, genotype-/phenotype-relation. Clinical presentation: natural history; the different expressions of disease. Performance of the genetic test. Implications for therapy and prevention. Conclusion for clinical applications of risk-profiling of health on their susceptibility to disease and/or for clarification of disease for therapy planning. Since genetic testing is urging its way into the health care system, the actual danger is, that population screening starts before valid evidence from big prospective studies have been carried out and delivered proofs of direct causal associations. Before diffusing into the health care system we are suggesting to take a cautious and standardised approach. (shrink)

We show that Martin Hyland's effective topos can be exhibited as the homotopy category of a path category EFF. Path categories are categories of fibrant objects in the sense of Brown satisfying two additional properties and as such provide a context in which one can interpret many notions from homotopy theory and Homotopy Type Theory. Within the path category EFF one can identify a class of discrete fibrations which is closed under push forward along arbitrary fibrations (in other words, this (...) class is polymorphic or closed under impredicative quantification) and satisfies propositional resizing. This class does not have a univalent representation, but if one restricts to those discrete fibrations whose fibres are propositions in the sense of Homotopy Type Theory, then it does. This means that, modulo the usual coherence problems, it can be seen as a model of the Calculus of Constructions with a univalent type of propositions. We will also build a more complicated path category in which the class of discrete fibrations whose fibres are sets in the sense of Homotopy Type Theory has a univalent representation, which means that this will be a model of the Calculus of Constructions with a univalent type of sets. (shrink)

Most studies examining gene-environment effects on self-regulation focus on outcomes early childhood or adulthood. However, only a few studies investigate longitudinal effects during middle childhood and adolescence and compare two domains of early caregiving. In a longitudinal follow-up with a sample of N = 87, we studied the effects of differences in the DRD4 tandem repeat polymorphisms and two domains of early maternal caregiving quality on children’s personality development using Block’s California Child Q-Set at age six and age 12 and (...) on problem behavior at ages six and seven. Early maternal regulation quality predicted later ego-resiliency and aggressiveness. In addition, significant gene-environment interactions revealed that children with the 7+ DRD4 tandem repeat polymorphism and poor maternal regulation quality in infancy showed lower scores in ego-resiliency and higher scores in ego-undercontrol and CCQ aggressiveness. In contrast, children who had experienced effective maternal regulation in infancy showed a comparable level in personality traits and problem behavior as the DRD4 7- group independent of the levels of maternal regulatory behavior. Similarly, longitudinal caregiving × DRD4 interactions were found for behavior problems in middle childhood, especially for oppositional-aggression, inattentive-hyperactivity, and social competence. Early caregiving effects were only found for maternal regulation quality, but not for maternal responsiveness. Effective early maternal regulation in infancy can moderate the negative effect of DRD4 7+ on children’s self-regulation in middle childhood and adolescence. However, maternal responsiveness has no comparable effects. It seems relevant to consider several dimensions of early caregiving and to also measure the environment in more detail in gene-environment studies. (shrink)

Nucleotide diversity of the human Y chromosome is much lower than that in the rest of the genome. A new hypothesis postulates that this invariance may result from mutations in maternally inherited mitochondrial DNA (mtDNA), leading to impaired reproduction among males and lowered male effective population size. If correct, we should expect to see low levels of polymorphism in the male‐specific Y chromosome of many organisms but not necessarily in the female‐specific W chromosome in organisms with female heterogamety. However, (...) recent observations from birds suggest that the avian W chromosome is very low in nucleotide diversity. This indicates that mtDNA mutations cannot broadly explain the evolution of the sex‐limited chromosome. Other work has suggested that sexual selection at loci involved in sex determination or secondary sexual characteristics might reduce levels of genetic variability on Y through hitch‐hiking effects. Although the W chromosome does not seen to play a dominant role for sex determination in birds, it cannot be excluded that selective sweeps arising from natural or sexual selection contribute to the low levels of genetic variability seen on this chromosome. BioEssays 25:163–167, 2003. © 2003 Wiley Periodicals, Inc. (shrink)

I present and defend a novel version of the homeostatic property cluster account of natural kinds. The core of the proposal is a development of the notion of co-occurrence, central to the HPC account, along information-theoretic lines. The resulting theory retains all the appealing features of the original formulation, while increasing its explanatory power, and formal perspicuity. I showcase the theory by applying it to the problem of reconciling the thesis that biological species are natural kinds with the fact that (...) many such species are polymorphic. (shrink)

: This article analyzes German debates on the microbiology of infectious diseases from 1865 to 1875 and asks how and when organic pollution in tissues became noteworthy for aetiology and pathogenesis. It was with Ernst Hallier's pleomorphistic microbiology that the organic character of alien material in tissues came to be regarded as important for pathology. The process that followed saw both vigorous biological critique and a number of medical applications of Hallier's work. Around 1874 contemporaries reached the conclusion that pleomorphous (...) vegetation was most likely of little importance if not accidental in relation to the aetiology of infectious diseases whereas the idea of monomorphous micro-organisms facilitated a causal explanation. It was only then that notions such a pure cultures, bacterial specificity, etc. favored by Ferdinand Julius Cohn and his school became popular in medical circles. (shrink)

Studies associating interactions of 5-HTTLPR and life adversities with depression have yielded equivocal results. Studying endophenotypes may constitute a more powerful approach. In the current study, it was assessed whether interactions of 5-HTTLPR with childhood emotional abuse (CEA) and recent negative life events (RNLE) affect possible cognitive endophenotypes of depression, namely, attention-allocation bias and the ability to recognise others' mind states in 215 young adults of North-West European descent. The ability to classify others' negative mind states was found to be (...) increased with increasing RNLE in carriers of low-expressing Serotonin Transporter Linked Polymorphic Region (5-HTTLPR) alleles. Carriers of two low-expressing alleles also preferentially oriented attention towards negative information. Gene-environment interactions were not observed for attention allocation bias. No effects involving CEA were observed. These results suggest that low-expressing 5-HTTLPR alleles may confer increased risk for depression through enhanced recognition of negative facial expressions following RNLE. (shrink)

I‐J has been regarded as a polymorphic genetic marker controlled by a locus in the major histocompatibility complex (MHC) which is expressed only on functional T cells. However, this antigenic determinant has been found not to be directly encoded by the MHC gene per se but is somatically generated according to the MHC of the cellular environment during ontogeny. This explains the apparent linkage of I‐J to MHC, despite the failure to find the structural gene for I‐J within the MHC. (...) The I‐J paradox provides an instance of a polymorphism that does not follow the standard genetics of Mendelian structural genes. (shrink)

Genericity is the idea that the same program can work at many different data types. Longo, Milstead and Soloviev proposed to capture the inability of generic programs to probe the structure of their instances by the following equational principle: if two generic programs, viewed as terms of type , are equal at any given instance A[T], then they are equal at all instances. They proved that this rule is admissible in a certain extension of System F, but finding a semantically (...) motivated model satisfying this principle remained an open problem.In the present paper, we construct a categorical model of polymorphism, based on game semantics, which contains a large collection of generic types. This model builds on two novel constructions:•A direct interpretation of variable types as games, with a natural notion of substitution of games. This allows moves in games A[T] to be decomposed into the generic part from A, and the part pertaining to the instance T. This leads to a simple and natural notion of generic strategy.•A “relative polymorphic product” which expresses quantification over the type variable Xi in the variable type A with respect to a “universe” which is explicitly given as an additional parameter B. We then solve a recursive equation involving this relative product to obtain a universe in a suitably “absolute” sense.Full Completeness for ML types is proved for this model. (shrink)

Soma‐to‐germline feedback is forbidden under the neo‐Darwinian paradigm. Nevertheless, there is a growing realization it occurs frequently in immunoglobulin (Ig) variable (V) region genes. This is a surprising development. It arises from a most unlikely source in light of the exposure of co‐author EJS to the haplotype data of RL Dawkins and others on the polymorphism of the Major Histocompatibility Complex, which is generally assumed to be the most polymorphic region in the genome (spanning ∼4 Mb). The comparison between (...) the magnitude of MHC polymorphism with estimates for the human heavy chain immunoglobulin V locus (spanning ∼1 Mb), suggests IGHV could be many orders of magnitude more polymorphic than the MHC. This conclusion needs airing in the literature as it implies generational churn and soma‐to‐germline gene feedback. Pedigree‐based experimental strategies to resolve the IGHV issue are outlined. (shrink)

The serotonin transporter plays an important role in regulating serotonergic transmission via removal of serotonin from synaptic clefts. Alterations in 5-HTT expression and subsequent 5-HT transmission have been found to be associated with changes in behaviour, such as fearfulness or activity, in humans and other vertebrates. In humans, alterations in 5-HTT expression have been suggested to be able to lead to better learning performance, with more fearful persons being better at learning. Similar effects of the variation in the 5-HTT on (...) fearfulness have been found in chickens, and in this study, we investigated effects on learning. Therefore, we tested 52 adult laying hens, differing in their functional 5-HTT genotype in an operant learning paradigm in three different phases and in a tonic immobility test for fearfulness. We found that the 5-HTT polymorphism affects the initial learning performance of laying hens, with homogeneous wild-type hens being the slowest learners, and the most fearful birds. W/W hens, showed significantly more choices to solve the initial learning task and had the highest latencies in a tonic immobility test, indicating the highest fearfulness. Our results provide interesting first insights into the role of 5-HTT in chickens and its sensitive interaction with the environment. We further suggest that the 5-HTT gene can be an interesting target gene for future breeding strategies as well as for further experimental studies. (shrink)