On the trail of Leonardo

A night course taken almost 25 years ago sparked an interest in Leonardo da Vinci that has become a passion for a London, Ont., neurosurgeon. Dr. Rolando Del Maestro now boasts one of the largest collections of da Vinci artifacts in North America.     

Léonard de Vinci (1452–1519): andrologue avant la lettre

Leonardo da Vinci devoted 41 years of his lifetime to anatomy and anatomical drawing and opened new horizons in these two disciplines. He is therefore justly considered to be the father of modern anatomy. Considering the great number of his anatomical drawings dealing with the male urogenital tract and its function, Leonardo da Vinci can also be considered to be the father of andrology.     

Spectacular Bodies: The Art and Science of the Human Body from Leonardo to Now

Spectacular Bodies: The Art and Science of the Human Body from Leonardo to Now. Martin Kemp and Marina Wallace. Berkeley: University of California Press, 2000. 232 pp.     

Plant development: introducing trehalose metabolism

Trehalose metabolism, a short side-branch of primary carbon metabolism that is controlled by a surprisingly large gene family, is emerging as an important new regulatory pathway in plants. Two recent studies by Namiko Satoh-Nagasawa et al. and Leonardo Gomez et al. have highlighted its novel and possibly pivotal role in coordinating carbon supply with plant growth and development.     

Valéry et l’automatisme psychologique

While the name of Paul Valery is usually associated with that of Leonardo da Vinci or the character, Monsieur Teste, most people are unaware of Valery’s posthumous work, which he considered the most significant of his writings: Cahiers/Notebooks, a voluminous and dense work, in its dimensions (around 30,000 pages) as well as in what it discloses about the daily ponderings of a man who considered himself — in spite of himself — a philosopher. It is a multifaceted work, touching on all fields of thought: history, politics, and the sciences, in all their diversity, from mathematics to physics, and biology to the theory of evolution. Neither philosophy, nor theology, nor linguistics is left in the dark. But he clearly expressed a preference for psychology and, more specifically, the question of mental function: What is it to think? How does the mind link ideas? What is abstraction? What role do feelings play? What is the relationship between the mind and the machine? Must we concede the existence of the unconscious mind. These are some of the questions we address in elucidating the concept of automatism through what makes it work as well as its failings.     

Exotics at Home: Anthropologies, Others, American Modernity

Exotics at Home: Anthropologies, Others, American Modernity. Micaela di Leonardo. Chicago: University of Chicago Press, 1998. 445 pp.     

The Gender/Sexuality Reader: Culture, History, Political Economy

The Gender/Sexuality Reader: Culture, History, Political Economy. Roger N. Lancaster and Micaela di Leonardo. eds. New York; Routledge, 1997. 574 pp.     

Meeting review: a summary of the Label-Free Summit

‘All our knowledge has its origins in our perceptions.’ Leonardo da Vinci

Scientific progress is often enabled by the development of new tools and technologies that have given us new ways of perceiving the world. In the early days of our science, optical microscopy gave us the ability to observe cells for the first time and opened the new world of cell biology. More recently, advances in cloning and labeling technologies have permitted us to study the interactions of individual proteins. Now, label-free detection technology provides another promising advance – the means to generically study signal transduction in living cells through the dynamic mass redistribution (DMR) of intracellular contents. On October 6–7, 2008 a group of researchers gathered in Corning, NY to share recent advances in the field of label-free detection. Attendees came from nearby Ithaca, NY and as far away as Tokyo, Japan, representing a diverse set of institutions engaged in drug discovery research. Topics ranged from seven transmembrane receptor (7TMR) signaling, to high throughput screening and profiling, and to new applications such as ion channels and viral infection assays. Overall, the Label-Free Summit has given us additional perspective on the potential of this promising technology.     

Approval of the first biosimilar antibodies in Europe

In a defining moment for the European Medicines Agency (EMA) and the biopharmaceutical industry, on June 27, 2013 EMA’s Committee for Medicinal Products for Human Use adopted a positive opinion for two biosimilar infliximab products (Celltrion’s Remsima® and Hospira’s Inflectra®), and recommended that they be approved for marketing in the European Union (EU). The European Commission’s decision on an application is typically issued 67 d after an opinion is provided; thus, decisions are expected in early September 2013. If approved, the products will comprise the first biosimilar antibody made available to patients in a highly regulated market, although launch may be delayed due to an extension of the reference product’s (Remicade®) patent in the EU.     

Fleck and the social constitution of scientific objectivity

Ludwik Fleck’s theory of thought-styles has been hailed as a pioneer of constructivist science studies and sociology of scientific knowledge. But this consensus ignores an important feature of Fleck’s epistemology. At the core of his account is the ideal of ‘objective truth, clarity, and accuracy’. I begin with Fleck’s account of modern natural science, locating the ideal of scientific objectivity within his general social epistemology. I then draw on Fleck’s view of scientific objectivity to improve upon reflexive accounts of the origin and development of the theory of thought-styles, and reply to objections that Fleck’s epistemological stance is self-undermining or inconsistent. Explicating the role of scientific objectivity in Fleck’s epistemology reveals his view to be an internally consistent alternative to recent social accounts of scientific objectivity by Harding, Daston and Galison. I use these contrasts to indicate the strengths and weaknesses of Fleck’s innovative social epistemology, and propose modifications to address the latter. The result is a renewed version of Fleck’s social epistemology, which reconciles commitment to scientific objectivity with integrated sociology, history and philosophy of science.     

The Doctrine of Constructive Presence and the Arctic Sunrise Award (2015): The Emergence of the “Scheme Theory”

Abstract

The doctrine of constructive presence allows a coastal state to pursue and arrest a vessel on the high seas, even though that vessel may have never entered the state’s jurisdiction. This is because the vessel’s presence can be “constructed” inside the state’s jurisdiction when a connection can be found with other craft, suspected of having committed an illegal act there. This article explores the impact of the Tribunal’s decision in the Arctic Sunrise case (2015) on constructive presence. It shows that the necessary link between the vessels is now found when there exists evidence of participation in an illegal scheme.     

A pluralist challenge to “integrative medicine”: Feyerabend and Popper on the cognitive value of alternative medicine

This paper is a critique of ‘integrative medicine’ as an ideal of medical progress on the grounds that it fails to realise the cognitive value of alternative medicine. After a brief account of the cognitive value of alternative medicine, I outline the form of ‘integrative medicine’ defended by the late Stephen Straus, former director of the US National Centre for Complementary and Alternative Medicine. Straus’ account is then considered in the light of Zuzana Parusnikova’s recent criticism of ‘integrative medicine’ and her distinction between ‘cognitive’ and ‘opportunistic’ engagement with alternative medicine. Parusnikova warns that the medical establishment is guilty of ‘dogmatism’ and proposes that one can usefully invoke Karl Popper’s ‘critical rationalism’ as an antidote. Using the example of Straus, I argue that an appeal to Popper is insufficient, on the grounds that ‘integrative medicine’ can class as a form of cognitively-productive, critical engagement. I suggest that Parusnikova’s appeal to Popper should be augmented with Paul Feyerabend’s emphasis upon the role of ‘radical alternatives’ in maximising criticism. ‘Integrative medicine’ fails to maximise criticism because it ‘translates’ alternative medicine into the theories and terminology of allopathic medicine and so erodes its capacity to provide cognitively-valuable ‘radical alternatives’. These claims are then illustrated with a discussion of ‘traditional’ and ‘medical’ acupuncture. I conclude that ‘integrative medicine’ fails to exploit the cognitive value of alternative medicine and so should be rejected as an ideal of medical progress.     

Minireview: On the homology of the protocoel in Cephalochordata and 'lower' Deuterostomia

Hypotheses regarding the homology of the protocoel in planktonic deuterostome larvae and mesodermal structures in ontogenetic stages of cephalochordates are evaluated. The prevalent ‘classical’ hypothesis describes the protocoel as being homologous with the diverticula of Hatschek, which, on the left side, develop into the preoral pit, subsequently into Hatschek’s pit and groove (in part). This hypothesis is based mainly on the position of Hatschek’s diverticula anterior to the rest of the mesoderm during their enterocoelic origin. It is shown here that during development the mesodermal segment that develops into Hatschek’s nephridium is the most anterior one prior to formation of Hatschek’s diverticula, and this segment assumes an anteriormost position after differentiation of Hatschek’s diverticula. Additional similarities between this segment and protocoels are: (i) presence of endomesodermal cells with podocytic extensions, (ii) excretory function, (iii) relatively early ontogenetic origin, (iv) probable lack of association with nervous structures, (v) probable ectodermal origin of a portion of the canal, and (vi) position relative to the mouth opening. Therefore, homology between the protocoel and the segment that becomes Hatschek’s nephridium is proposed. It is concluded that a glandular structure homologous to the diverticula of Hatschek and anterior to the protocoel/Hatschek’s nephridium is a synapomorphy of notochordates or chordates.     

The specificity of medical facts: the case of diabetology

The fact that Ludwik Fleck drew his inspiration from medicine has been largely overlooked, with the exception of a few scholars. Although Fleck considered his ideas applicable to all sciences, he always insisted on the specificity of medicine. To illustrate the usefulness of Fleck’s concepts for the history of medicine, three main ideas developed by Fleck are applied to the historical study of diabetes mellitus (DM): first, that different and often divergent pictures of disease coexist within a given culture; second, that scientific ideas circulate between ‘esoteric’ and ‘exoteric’ circles; and third, that scientific concepts are often incommensurable. The author also suggests that Fleck’s epistemology, like other scholars’, is loaded with ethical and political consequences. However, the link between an ‘open’ epistemology and political or ethical questions is more explicit in Georges Canguilhem’s pioneering work on the normal and the pathological (1943). Indeed, Canguilhem and Fleck’s conceptions of disease have much in common, so that we can use Canguilhem’s work to bring out the hidden ethical and political issues in Fleck’s work.     

Development of cyclic peptide derivatives from the N-terminal region of LANA for targeting the nucleosome acidic patch

Kaposi’s sarcoma-associated herpesvirus (KSHV) is known to be a carcinogenic agent that causes AIDS-associated Kaposi’s sarcoma (KS). When KSHV infects host’s cells, one of the virus’s proteins, latency-associated nuclear antigen 1 (LANA), binds to the host’s nucleosomes to retain episomes and create latency circumstances. Although the infectious mechanism of KSHV is partly elucidated, the development of drug candidates for targeting KS is ongoing. In this study, we developed cyclic peptides corresponding to an N-terminal LANA sequence that disrupt the LANA–nucleosome interaction. The cyclic peptides showed a different secondary structure compared to their corresponding linear peptide derivatives, which suggests that our cyclization strategy imitates the N-terminal LANA binding conformation on nucleosomes.     

Aristotle on the Mechanism of Inheritance

In this paper I address an important question in Aristotle’s biology, What are the causal mechanisms behind the transmission of biological form? Aristotle’s answer to this question, I argue, is found in Generation of Animals Book 4 in connection with his investigation into the phenomenon of inheritance. There we are told that an organism’s reproductive material contains a set of “movements'' which are derived from the various “potentials'' of its nature (the internal principle of change that initiates and controls development). These “movements,'' I suggest, function as specialized vehicles for communicating the parts of the parent’s heritable form during the act of reproduction. After exploring the details of this mechanism, I then take up Aristotle’s theory of inheritance proper. At the heart of the theory are three general principles (or ‘laws’) that govern the interactions between the maternal and paternal movements, the outcome of which determines the pattern of inheritance for the offspring. Although this paper is primarily aimed at providing a detailed analysis of Aristotle’s account of inheritance, the results of that analysis have implications for other areas of Aristotle’s biology. One of the most interesting of these is the question of whether Aristotle’s biology is anti-evolutionary (as traditionally assumed) or whether (as I argue) it leaves room for a theory of evolution by natural selection, even if Aristotle himself never took that step.     

Options for histological study of the structure and ultrastructure of human urinary bladder epithelium

The urothelium lines all urinary passages, with exception of the distal portions of the urethra. For the first time the structure of the human bladder was described by Leonardo Da Vinci in 15^th century, however, the exact ultrastructure and function of the bladder’s epithelium have not been fully understood. The aim of our study was to investigate the structure of normal human urinary bladder epithelium with methods of classical histology, transmission electron microscopy (TEM) and scanning electron microscopy (SEM). We obtained biopsies from non-tumor areas from the human urinary bladder of tumor-bearing patients during transurethral resections of these tumours in general or spinal anaesthesia. Totally we investigated biopsies from 20 patients, 16 males and 4 females. The mean age of this group of patients was averaged 66.5 years. The urothelium is comprised of three cell types including polyhedral basal cells, piriform intermediate cells, and superficial umbrella cells. In human urinary bladder epithelium we found a direct connection between intermediate cells and the basement membrane. These thin cytoplasmic projections are detectable not only on slides for light microscopy (semi-thin sections), but also in transmission electron-micrographs. In semi-thin sections we found also direct connections between superficial umbrella cells and basement membrane. These connections we were not able to verify via transmission electron-microscopy. Nevertheless our results show that the human urinary bladder urothelium is a special type of pseudostratified epithelium and each cell has a thin cytoplasmic projection with a direct contact with basement membrane.     

The Ecological Role of the Vaquita, Phocoena sinus, in the Ecosystem of the Northern Gulf of California

From an ecosystem management perspective, analysis of the functional roles of species is a challenge. It is valuable to determine which species are irreplaceable within a given community based on their contribution to the system’s organization. This study relates the emergent functional and structural indices of biological groups estimated from a trophic model of the Northern Gulf of California to identify the roles of these groups in the ecosystem context, with a particular focus on the role of the vaquita, an endemic porpoise in critically endangered status. The simulation of removing each group allowed the analysis of the removal’s functional effect on the ecosystem’s global attributes and organization (based on Ulanowicz’s ascendency concept). Groups from lower trophic levels (TL) were more related to complexity indicators, suggesting their contribution to the organization and structure of energy flows in the food web. Groups from intermediate TL had higher values of structural indexes, indicating their function in the control of flows throughout the network. The vaquita along with other marine mammals, aquatic birds, and some species of fish with a high TL contribute in a similar way to the order (for example, ascendency/capacity-of-development ratio) of the system, showing a relatively high value of ascendency (contribution of the group to the organization inherent to the ecosystem) and the change in ecosystem ascendency when they were removed. The vaquita, like marine and coastal birds, plays a small role in the ecosystem. But like them, it does contribute substantially to ecosystem organization. This study thus provides information potentially useful for management in understanding the species’ role and in reducing uncertainty in decision-making.