Narratives in exposomics: A reversed heuristic determinism?

Since the completion of the Human Genome Project (HGP), biomedical sciences have moved away from a gene-centred view and towards a multi-factorial one in which environment, broadly speaking, plays a central role in the determination of human health and disease. Environmental exposures have been shown to be highly prevalent in disease causation. They are considered as complementary to genetic factors in the etiology of diseases, hence the introduction of the concept of the "exposome" as encompassing the totality of human environmental exposures, from conception onwards (Wild in Cancer Epidemiol Biomark Prev 14:1847-1850, 2005), and the launch of the Human Exposome Project (HEP) which aims to complement the HGP. At first sight, and seen as complementary to the genome, the exposome could thus appear as contributing to the rise of novel postgenomic deterministic narratives which place the environment at their core. Is this really the case? If so, what sort of determinism is at work in exposomics research? Is it a case of environmental determinism, and if so, in what sense? Or is it a new sort of deterministic view? In this paper, we first show that causal narratives in exposomics are still very similar to gene-centred deterministic narratives. They correspond to a form of Laplacian determinism and, above all, to what Claude Bernard called the "determinism of a phenomenon". Second, we introduce the notion of "reversed heuristic determinism" to characterize the specific deterministic narratives present in exposomics. Indeed, the accepted sorts of external environmental exposures conceived as being at the origins of diseases are determined, methodologically speaking, by their identifiable internal and biological markers. We conclude by highlighting the most relevant implications of the presence of this heuristic determinism in exposomics research.

Differences in Perceived and Experienced Stigma Between Problematic Gamblers and Non-gamblers in a General Population Survey.

We consider a sample of about 700 people, interviewed on the streets, who are sorted into two groups by a self-report, screening questionnaire: namely, non-problematic gamblers/non-gamblers and problematic gamblers. Within each group, we compare both social (perceived) stigma and self-perceived (experienced) stigma, measured by means of other two self-report questionnaires, and we seek for relations between stigma and socio-demographic variables that can help targeting possible interventions to reduce gambling-related stigma. We, then, compare stigma between the two groups of non-(problematic) gamblers and problematic ones, and we also check the hypothesis that higher social stigma is related to higher self-perceived stigma, as well as higher stigma is related to lesser help-seeking. The latter hypothesis is of utmost importance, given that stigma is recognised to be one of the major causes for hindering help-seeking by problematic gamblers. The research is carried out in Italy, one of the first countries in the world for the money spent per capita in gambling activity every year.

Inheritance as Evolved and Evolving Physiological Processes.

In this paper, we adopt a physiological perspective in order to produce an intelligible overview of biological transmission in all its diversity. This allows us to put forward the analysis of transmission mechanisms, with the aim of complementing the usual focus on transmitted factors. We underline the importance of the structural, dynamical, and functional features of transmission mechanisms throughout organisms' life cycles in order to answer to the question of what is passed on across generations, how and why. On this basis, we propose a vision of biological transmission as networks of heterogeneous physiological mechanisms, not restricted to transmission mechanisms stricto sensu. They prove to be themselves suited candidates for evolutionary explanations. They are processes both necessary for evolution to happen and resulting themselves from evolution. This leads us to call for a strategy of endogenization to account for transmission, and more specifically inheritance, as evolved and evolving physiological mechanisms.

Suitable Polymeric Coatings to Avoid Localized Surface Plasmon Resonance Hybridization in Printed Patterns of Photothermally Responsive Gold Nanoinks.

When using gold nanoparticle (AuNP) inks for writing photothermal readable secure information, it is of utmost importance to obtain a sharp and stable shape of the localized surface plasmon resonance (LSPR) absorption bands in the prints. The T increase at a given irradiation wavelength (DTl) is the retrieved information when printed patterns are interrogated with a laser source. As DTl is proportional to the absorbance at the wavelength l, any enlargement or change of the absorbance peak shape in a printed pattern would lead to wrong or unreliable reading. With the aim of preparing AuNP inks suitable for inkjet printing of patterns with stable and reliable photothermal reading, we prepared liquid solutions of spherical AuNP coated with a series of different polymers and with or without additional dispersant. The optical stability of the inks and of the printed patterns were checked by monitoring the shape changes of the sharp LSPR absorption band of AuNP in the visible (lmax 519 nm) along weeks of ageing. AuNP coated with neutral polyethylenglycol thiols (HS-PEG) of mw 2000-20,000 showed a strong tendency to rapidly agglomerate in the dry prints. The close contact between agglomerated AuNP resulted in the loss of the pristine shape of the LSPR band, that flattened and enlarged with the further appearance of a second maximum in the Near IR, due to plasmon hybridization. The tendency to agglomerate was found directly proportional to the PEG mw. Addition of the ethylcellulose (EC) dispersant to inks resulted in an even stronger and faster tendency to LSPR peak shape deformation in the prints due to EC hydrophobicity, that induced AuNP segregation and promoted agglomeration. The introduction of a charge on the AuNP coating revelead to be the correct way to avoid agglomeration and obtain printed patterns with a sharp LSPR absorption band, stable with ageing. While the use of a simple PEG thiol with a terminal negative charge, HS-PEGCOO(-) (mw 3000), was not sufficient, overcoating with the positively charged polyallylamine hydrochloride (PAH) and further overcoating with the negatively charged polystyrene sulfonate (PSS) yielded AuNP@HS-PEGCOO(-)/PAH(+) and AuNP@HS-PEGCOO(-)/PAH(+)/PSS(-), both giving stable prints. With these inks we have shown that it is possible to write photothermally readable secure information. In particular, the generation of reliable three-wavelength photothemal barcodes has been demonstrated.

Mapping Biological Transmission: An Empirical, Dynamical, and Evolutionary Approach.

The current debate over extending inheritance and its evolutionary impact has focused on adding new categories of non-genetic factors to the classical transmission of DNA, and on trying to redefine inheritance. Transmitted factors have been mainly characterized by their directions of transmission (vertical, horizontal, or both) and the way they store variations. In this paper, we leave aside the issue of defining inheritance. We rather try to build an evolutionary conceptual framework that allows for tracing most, if not all forms of transmission and makes sense of their different tempos and modes. We discuss three key distinctions that should in particular be the targets of theoretical and empirical investigation, and try to assess the interplay among them and evolutionary dynamics. We distinguish two channels of transmission (channel 1 and channel 2), two measurements of the temporal dynamics of transmission, respectively across and within generations (durability and residency), and two types of transmitted factors according to their evolutionary relevance (selectively relevant and neutral stable factors). By implementing these three distinctions we can then map different forms of transmission over a continuous space describing the combination of their varying dynamical features. While our aim is not to provide yet another model of inheritance, putting together these distinctions and crossing them, we manage to offer an inclusive conceptual framework of transmission, grounded in empirical observation, and coherent with evolutionary theory. This interestingly opens possibilities for qualitative and quantitative analyses, and is a necessary step, we argue, in order to question the interplay between the dynamics of evolution and the dynamics of multiple forms of transmission.

Epigenetics: A way to bridge the gap between biological fields.

The concept of epigenetics has evolved since Waddington defined it from the late 1930s as the study of the causal mechanisms at work in development. It has become a multi-faceted notion with different meanings, depending on the disciplinary context it is used. In this article, we first analyse the transformations of the concept of epigenetics, from Waddington to contemporary accounts, in order to identify its different meanings and traditions, and to come up with a typology of epigenetics throughout its history. Second, we show on this basis that epigenetics has progressively turned its main focus from biological problems regarding development, toward issues concerning evolution. Yet, both these different epistemological aspects of epigenetics still coexist. Third, we claim that the classical opposition between epigenesis and preformationism as ways of thinking about the developmental process is part of the history of epigenetics and has contributed to its current various meanings. With these objectives in mind, we first show how Waddington introduced the term "epigenetics" in a biological context in order to solve a developmental problem, and we then build on this by presenting Nanney's, Riggs' and Holliday's definitions, which form the basis for the current conception of "molecular epigenetics". Then, we show that the evo-devo research field is where some particular uses of epigenetics have started shifting from developmental issues to evolutionary problems. We also show that epigenetics has progressively focused on the issue of epigenetic inheritance within the Extended Evolutionary Synthesis' framework. Finally, we conclude by presenting a typology of the different conceptions of epigenetics throughout time, and analyse the connections between them. We argue that, since Waddington, epigenetics, as an integrative research area, has been used to bridge the gap between different biological fields.

Monod's conception of chance: its diversity and relevance today.

In his famous book Le hasard et la nécessité (1970), Monod claims that natural evolution is based on the interplay between chance and necessity bringing about adaptive evolutionary change. This article addresses a set of related questions about Monod's conception of chance: what does he mean when he uses the term "chance"? Does he invoke one or many different concepts of chance? What are the implications of his conception about the issue of the deterministic or indeterministic nature of the biological world? Is Monod's view of what chance is relevant in contemporary biology? This paper, structured by these four questions, aims at providing a synthetic study of the way Monod conceptualizes chance, particularly highlighting the metaphysical and epistemological implications of his conception and its value in biology today.