Heart rate variability (HRV) is an indicator of the regulation of the heart, see Task Force (Circulation 93(5):1043–1065, 1996). This study compares the regulation of the heart in two cases of healthy subjects within real life situations: Marathon runners and shift workers. After an update on the state of the art on HRV processing, we specify our probabilistic model: We choose modeling heartbeat series by locally stationary Gaussian process (Dahlhaus in Ann Stat 25, 1997). HRV is then processed by the (...) combination of two statistical methods: (1) Continuous wavelet transform for calculating the spectral density energy in the high frequency (HF) and low frequency (LF) bands and (2) Change point analysis to detect changes of heart regulation. Next, we plot the variations of the HF and LF energy in extreme conditions for both populations. This puts in light, that physical activities (rest, moderate sport, marathon race) can be ordered in a logical continuum. This allows to define a new index based on HF and LF energy that is log HF + log LF which appears relevant to measure HR regulation. The results obtained are pertinent but have to be completed by further studies. (shrink)

"Tant de choses nous échappent, non par accident, mais ontologiquement, à savoir compte tenu de leur nature et de la nôtre. II y a des choses dont nous ne pouvons pas être conscients. Nous avons beau vouloir ouvrir notre esprit, il y a des limites à cette ouverture. C'est l'un des traits de notre finitude. La philosophie entretient une prétention à l'universalité. Elle tente de s'ouvrir le plus largement possible à la réalité telle qu'elle est. Ce faisant, elle doit être (...) consciente de ses limites. Si elle s'ouvre, c'est aussi en se fermant. Si elle voit certaines choses, elle est aveugle à d'autres. Ces limites se font sentir avec force quand il s'agit de mettre en parole la vision. Celle-ci doit entrer dans la forme de celle-là, avec un sujet ou un substantif, un verbe ou une action, un prédicat ou un attribut. Une telle mise en forme élimine forcément un chaos, une indétermination ou un flou constitutifs de la réalité. Le défi est alors d'exprimer par la parole ce qui pourtant lui résiste, de manière à ce que continue de poindre et d'insister ce qui résiste". (shrink)

The serological properties of the major histocompatibility (class I) antigens of mammals have raised many questions about the structure and function of these molecules. Over the past four years the cloning of their gene sequences has begun to provide some of the answers to these questions. The structural analyses have demonstrated close similarities between class I genes of man and mouse, established the existence of numerous class I pseudogenes in human and murine genomes, and indicated the importance of gene conversion (...) events in regulating the sequence diversity of this gene family. In addition, the ability to construct new class I genes in vitro and to transfect cultured murine cells with the synthetic sequences is permitting new tests of the functional organization of these genes in relation to their structure. (shrink)

Until quite recently, recombinant DNA technology was not able to deal with DNA molecules larger than 20–40 kb. This is a serious limitation for the study of mammalian, and in particular human genomes whose total length is approx. 3 × 106 kb, since the best resolution of genetic and chromosomal analysis is usually the rough equivalent of 1000–5000 kb. Three recently developed methods promise to bridge this gap: pulsed field gel electrophoresis, which can analyze megabase‐sized DNA fragments; cloning in yeast, (...) which can clone and propagate DNA fragments of several hundred kb; and jumping libraries, which allow ‘jumping’ over large distances along the chromosome. This review presents the current status of these very promising technologies. (shrink)

DNA arrays are now widely used in academia and industry, and expression profiling is recognised as a major tool for basic research as well as for drug development. It is also likely, in the near future, that DNA arrays will be used in clinical laboratories for diagnostic and prognostic purposes. Since several types of arrays are being used, the coherence of results obtained using these diverse platforms becomes an important issue: to what extent can data obtained in different laboratories and (...) with different equipment be combined? Several recent papers address this issue and demonstrate that the expected agreement is not necessarily found. Consistent results can be obtained, but this requires careful identification of the genes assessed by the arrays, and scrupulous adherence to strict experimental procedures. BioEssays 26:1236–1242, 2004. © 2004 Wiley Periodicals, Inc. (shrink)

Cancers rely on multiple, heterogeneous processes at different scales, pertaining to many biomedical fields. Therefore, understanding cancer is necessarily an interdisciplinary task that requires placing specialised experimental and clinical research into a broader conceptual, theoretical, and methodological framework. Without such a framework, oncology will collect piecemeal results, with scant dialogue between the different scientific communities studying cancer. We argue that one important way forward in service of a more successful dialogue is through greater integration of applied sciences (experimental and clinical) (...) with conceptual and theoretical approaches, informed by philosophical methods. By way of illustration, we explore six central themes: (i) the role of mutations in cancer; (ii) the clonal evolution of cancer cells; (iii) the relationship between cancer and multicellularity; (iv) the tumour microenvironment; (v) the immune system; and (vi) stem cells. In each case, we examine open questions in the scientific literature through a philosophical methodology and show the benefit of such a synergy for the scientific and medical understanding of cancer. (shrink)

The objective of this article is to contribute to the epistemological, theoretical, methodological, and pedagogical debates concerning the relationship between research activities, training activities, and work activities. Its main focus is on new forms of engineering, thought of as cooperative and transformative. After situating the issues of the reciprocal triadic relationships between the three poles, the article presents two practical cases of transformative cooperative engineering. The authors then return to their epistemological position, which is socio-constructivist, complex, interactionist, and critical. They (...) sketch out the first elements of an elaborate system of intelligibility (multi-referential and transdisciplinary) aimed at supporting the hypothesis of an engineering process of joint transformation (trades, actors, organizations, training provision). The article also presents the research methodology (training-action-research) developed. A discussion of the issues and conditions of possibility of cooperative and transformative engineering concludes the article. (shrink)

What is truth? This famous question does not express merely the anguish—or the detachment—of the person who, at the moment of choosing, hesitates between deciding for one or the other of the contradictory theses being presented. At a second level, the question no longer concerns merely the content but the very conditions for the decision: in what name, by virtue of what criterion do we say that a given assertion is true while its contrary is false? We could limit ourselves (...) to recognizing in this second phase a particular species of philosophical questioning, which proceeds reflexively from the constituted to the constituent, from the given of the experience to the conditions for the possibility of the experience in general. But in the question about truth, a prejudicial difficulty inevitably arises which is proper to this question and makes it incomparable to any other. How can I be assured of the truth of my assertions about truth without presupposing at the same time a theory for that truth which I am in tact in the process of seeking? In other words, any question about truth moves in a circle since, by demanding a true answer, just like every question it implies that the questioner already knows what is truth at the very moment when he is asking what it is. (shrink)

Two types of variables impact face recognition: estimator variables that cannot be controlled and system variables that are under direct control by the criminal justice system. This article addresses some of the reasons that eyewitnesses are prone to making errors, particularly false identifications. It provides a discussion of the differences between typical facial memory and eyewitness studies and shows that the two areas generally find similar results. It reviews estimator variable effects and focuses on system variables. Traditional facial recognition researchers (...) rarely study system variables but reveal important factors that police and policy makers should consider with regard to eyewitness identification and the courts. It concludes that there is still room for considerable improvement in identification procedures and wants to encourage more system variable research as a means of reducing wrongful convictions. (shrink)

After reviewing the literature on current knowledge about consciousness in humans, we present a state-of-the art discussion on consciousness and related key concepts in animals. Obviously much fewer publications are available on non-human species than on humans, most of them relating to laboratory or wild animal species, and only few to livestock species. Human consciousness is by definition subjective and private. Animal consciousness is usually assessed through behavioural performance. Behaviour involves a wide array of cognitive processes that have to be (...) assessed separately using specific experimental protocols. Accordingly, several processes indicative of the presence of consciousness are discussed: perception and cognition, awareness of the bodily-self, self-related knowledge of the environment (including social environment). When available, specific examples are given in livestock species. Next, we review the existing evidence regarding neuronal correlates of consciousness, and emphasize the difficulty of linking aspects of consciousness to specific neural structures across the phyla because high-level cognitive abilities may have evolved independently along evolution. Several mammalian brain structures (cortex and midbrain) are involved in the manifestations of consciousness, while the equivalent functional structures for birds and fishes would likely be the pallium/tectum and midbrain. Caution is required before excluding consciousness in species not having the same brain structures as the mammalian ones as different neural architectures may mediate comparable processes. Finally, specific neurophysiological mechanisms appear to be strongly linked to the emergence of consciousness, namely neural synchrony and neural feedback. Considering the limited amount of data available and the few animal species studied so far, we conclude that different manifestations of consciousness can be observed in animals but that further refinement is still needed to characterize their level and content in each species. Further research is required to clarify these issues, especially in livestock species. (shrink)

v. 1. Raison et conscience de soi.--v. 2. Raison et histoire.

Although DNA microarrays are now widely used in research settings, they have been slow to penetrate clinical practice in spite of their apparent advantages. This is due to the very different requirements for a clinical test in contrast to a research tool, and to a strict necessity for demonstrated clinical utility. There is a clear differentiation between two types of DNA array tests: “genomic” diagnostics, developed to ascertain the presence or absence of mutations, deletions or duplications, and for which clinical (...) evidence is already established, and tests using expression profiling for prognosis or predictive purposes, in which case the clinical correlate must be proven. Most array diagnostics currently used belong, understandably, to the “genomic” variety. It is to be expected that future improvements in tailored technology, as well as a logical trend towards measuring an ever‐increasing number of parameters, will ensure an important diagnostic role for DNA arrays in the coming decade. BioEssays 29:699–705, 2007. © 2007 Wiley Periodicals, Inc. (shrink)

Fragile X‐linked mental retardation is an enigmatic inheritable syndrome in which severe mental retardation, a cytogenetically detectable fragile site at Xq27.3 (FraX) and a number of dysmorphic features are associated. Genetic analysis shows that the mode of inheritance is more complex than a straightforward X‐linked recessive trait and probably involves a two‐step process for which several models have been proposed. Early attempts ‘at cloning the fragile site’ provided several DNA segments lying in its general vicinity, and large scale DNA mapping (...) methods were extensively applied in an effort to generate maps including this region. These efforts were complemented by more focussed methods such as microdissection; together these approaches have now provided a number of DNA segments within a 5cM interval around FraX, and with the help of these new probes the site is indeed being cloned. Unravelling the nature of the sequence(s) responsible for the mental retardation syndrome will probably take some time, however. (shrink)

The ardent antagonism between two aesthetic parties, figuration and abstraction, which for more than half a century has stamped art history in old Europe, with increasingly overlapping implications for youthful America, Japan and many other places, today tends to reduce itself to being simply the anecdotal imprint of an era: in the final analysis it seems already condemned to disappear in favor of a notion of complementarity and even synthesis.