This paper proposes a model of network interactions in the interbank market. Our innovation is to model systemic risk in the interbank network as the propagation of incentives or strategic behavior rather than the propagation of losses after default. Transmission in our model is not based on default. Instead, we explain bank profitability based on competition incentives and the outcome of a strategic game. As competitors' lending decisions change, banks adjust their own decisions as a result: generating a “transmission” of shocks through the system. We provide a unique equilibrium characterization of a static model, and embed this model into a full dynamic model of network formation. We also determine the key bank, which is the bank that is crucial for the stability of the financial network.

One of the most important concerns in assisted reproduction (ART), and in particular ICSI, is the quality of sperm DNA. Oxidative stress is one of the major causes of damage to DNA and attempting to reduce generation of DNA damage related to reactive oxygen species (ROS) through consumption of antioxidants is often tempting. However, current antioxidant treatments, given irrespectively of clinically quantified deficiencies, are poorly efficient, potentially detrimental and over-exposure is risky. Here we discuss new treatments in relation to present day concepts on oxidative stress. This discussion includes stimulation of endogenous anti-ROS defense i.e. glutathione synthesis and recycling of homocysteine, the epicentre of multiple ROS-linked pathologies.

The genome of all cells is protected at all times by mechanisms collectively known as DNA repair activity (DRA). Such activity is particularly important at the beginning of human life, i.e. at fertilization, immediately after and at the very onset of embryonic development. DRA in early development is, by definition, of maternal origin: the transcripts stored during maturation, need to control the integrity of chromatin, at least until the maternal/zygotic transition at the 4- to 8-cell stage in the human embryo. Tolerance towards DNA damage must be low during this critical stage of development. The majority of DNA damage is due to either apoptosis or reactive oxygen species (ROS). Apoptosis, abortive or not, is a common feature in human sperm, especially in oligoasthenospermic patients and FAS ligand has been reported on the surface of human spermatozoa. The susceptibility of human sperm to DNA damage is well documented, particularly the negative effect of ROS (Kodama et al., 1997; Lopes et al., 1998a, b) and DNA modifying agents (Zenzes et al., 1999; Badouard et al., 2007). DNA damage in sperm is one of the major causes of male infertility and is of much concern in relation to the paternal transmission of mutations and cancer (Zenzes, 2000; Aitken et al., 2003; Fernández-Gonzalez, 2008). It is now clear that DNA damaged spermatozoa are able to reach the fertilization site in vivo (Zenzes et al., 1999), fertilize oocytes and generate early embryos both in vivo and in vitro. The effect of ROS on human oocytes is not as easy to study or quantify. It is a common consensus that the maternal genome is relatively well protected while in the maturing follicle; however damage may occur during the long quiescent period before meiotic re-activation (Zenzes et al., 1998). In fact, during the final stages of follicular growth, the oocyte may be susceptible to damage by ROS. With regards to the embryo there is active protection against ROS in the surrounding environment i.e. in follicular and tubal fluid (El Mouatassim et al., 2000; Guerin et al., 2001). DNA repair activity in the zygote is mandatory in order to avoid mutation in the germ line (Derijck et al., 2008). In this review we focus on the expression of mRNAs that regulate DNA repair capacity in the human oocyte and the mechanisms that protect the embryo against de novo damage.

Malondialdehyde (MDA), a product involved in membrane lipid peroxidation, was dosed in the sperm of 163 patients who had consulted the clinic regarding hypofertility. We attempted to determine if there was correlation between MDA content, sperm World Health Organization parameters and DNA fragmentation that results mainly from reactive oxygen species assaults. We found that no correlation could be established; however MDA and sperm decondensation were shown to be significantly linked. The impact of membrane polyunsaturated fatty acids and the role of phospholipid hydroperoxide glutathione peroxidase are discussed.

The recently reported human pregnancies and births after fertilising oocytes with round spermatids recovered from the ejaculate of men with non-obstructive azoospermia have underscored the need for a more accurate evaluation of the nuclear and cytoplasmic maturation status of ejaculated germ cells. In this study we describe our first experience with a method combining the immunocytochemical visualisation of proacrosin with autosomal DNA fluorescence in situ hybridisation (FISH) to assess ejaculated germ cells from patients with a spermiogenesis defect. The proacrosin immunoreactivity, analysed with the use of the monoclonal antibody 4D4, has been detected in cells of round spermatid size presenting a haploid FISH figure as well as in larger cells whose ploidy corresponds to primary and secondary spermatocytes. These observations are in agreement with previously published results obtained, with the use of the same antibody, by immunocytochemical analysis of histological sections of testicular tissue. All the cells of round spermatid size possessing proacrosin immunoreactivity were found to be haploid by FISH. On the other hand, some of the haploid cells of round spermatid size did not possess proacrosin immunoreactivity. The structural pattern of proacrosin immunoreactivity was highly variable both in spermatids and in younger spermatogenic cells. These data show that cell size is the main criterion to be used for the identification of ejaculated round spermatids, whereas the presence of the developing acrosome represents only an auxiliary criterion. The scoring of acrosomal development in ejaculated spermatids may be useful as part of pre-treatment diagnosis before the inclusion of infertile couples in a spermatid conception programme.

On the basis of our clinical experience, we hypothesized that the role of mitral valvar anomalies in the development and recurrence of discrete subaortic stenosis might be underestimated. From January 1994 to October 2000, the anatomy of the mitral valve and its relationship to the other components of the left ventricular outflow tract were studied by echocardiography in a series of 73 consecutive patients referred to our institution for surgical correction of discrete subaortic stenosis. In all patients for whom it was considered advisable, surgical correction of the mitral anomaly was performed, together with resection of the fibro-muscular subaortic stenosis. One or more mitral valvar anomalies were found in 35 patients (48%). They could be grouped into five categories: insertion of a papillary muscle into the aortic leaflet, insertion of a papillary muscle into the ventricular wall, “muscularization” of the subaortic portion of the aortic leaflet, anomalous insertion of the valvar tissue into the ventricular wall, and accessory valvar tissue. In all cases with anomalous mitral valvar anatomy, surgical correction was feasible. It consisted of transection of the anomalous papillary muscle or its attachment, resection of accessory valvar tissue, and/or patch enlargement of the aortic leaflet. The incidence of mitral valvar anomalies associated with subaortic stenosis is probably underestimated. Our data suggest that they should be systematically searched for during the evaluation of all cases of subaortic stenosis. Their surgical correction is generally feasible, and might improve the mid and long term results.

Deux livres importants sur l'industrie de l'entre-deux-guerres viennent d'être publiés. L'un traite des systèmes d'organisation qui se répandent dans l'industrie française, l'autre de la mise en place en URSS d'un « despotisme d'État industriel et moderne » (« modem industrial state despotism » à la fin des années 1920. Les réunir dans une même note critique permet de marquer la différence entre des styles historiographiques, sinon des traditions historiennes, et de confronter des démarches sur des champs très voisins. Les deux livres occupent cependant dans leur champ respectif des situations différentes. Celui d'Aimée Moutet constitue la première grande synthèse consacrée à l'industrie française de l'entre-deux-guerres, alors que celle-ci commence à être touchée par des politiques systématiques de rationalisation. Elle fait de la sorte figure de monographie.

Il faut croire que la question de la technique (ou des techniques) est extraordinairement compliquée et qu'elle peut être l'objet des propos les plus divers. Voici un sociologue, Nicolas Dodier, qui se situe entièrement du côté de ces sciences sociales qui opèrent depuis une vingtaine d'années un tournant analytique, critique et pragmatique, influencé, au moins à l'origine, par les travaux de Michel Callon et Bruno Latour d'un côté, Luc Boltanski et Laurent Thévenot de l'autre. Il s'est intéressé, dans le courant des années 1980, aux questions de sécurité dans le travail, d'ergonomie et de médecine (dont la médecine du travail). Il nous parle de technique, du rapport des hommes avec les machines, et des hommes et des machines en présentant sa réflexion, dès son titre, sous la forme de la plus grande généralité.

Après des «Réflexions sur l'histoire des techniques» et une note liminaire de Lucien Febvre, qu ‘y trouvons-nous ? Trois articles principaux : deux sur des objets, le moulin à eau (c'est le grand article de Marc Bloch, toujours discuté aujourd'hui) et le gouvernail (par Guilleux de la Roërie), le troisième sur un individu, Taylor (par Georges Friedmann). Ils sont suivis de deux notes de Lucien Febvre, l'une énonçant les premières conclusions d'une enquête sur les forges de village en France, l'autre critiquant le premier volume d'A la lumière du marxisme, recueil d'articles sur les sciences et la technique écrits par des scientifiques communistes. Viennent ensuite cinq autres notes, plus courtes, de Charles Parain (recherches du généticien soviétique Vavilov sur l'origine des plantes cultivées), Jules Sion et Marc Bloch (commentaires sur les propositions du commandant Lefebvre des Noëttes), Louis Lacrocq (sur la croisée d'ogives) et Lucien Febvre (sur l'Institut d'Histoire des Sciences et des Techniques nouvellement créé).

Dominique Pestre nous dit que les sciences ne sont pas, comme on le croit le plus souvent, un régime d'énoncés qui se répondent les uns aux autres dans un pur éther, mais d'élégants discours tout autant que de grasses pratiques, d'épaisses relations, de laborieux efforts soumis à la division du travail et de délicats objets très techniques. Il trace de ce fait une histoire des sciences tout autant technique que culturelle et sociale, sinon encore politique.

The following article combines an analysis of production techniques in the French automobile industry between the wars and a rich supply of photographs that visually document the course of innovation in the industry. The text and illustrations show that, though production managers at Citroën, Peugeot, and Renault were aware of the methods of Henry Ford and Frederick W. Taylor, they adapted them to specific situations within the French industry and within their own companies. By looking specifically at the work of Ernest Mattern, who held production responsibilities at both Peugeot and Citroën and observed Renault as well, the essay traces the incremental changes in the organization of automobile manufacturing in France before the Second World War.