A subKelvin scanning probe microscope for the electronic spectroscopy of an individual nano-device

We present a combined scanning force and tunneling microscope working in a dilution refrigerator that is optimized for the study of individual electronic nano-devices. This apparatus is equipped with commercial piezo-electric positioners enabling the displacement of a sample below the probe over several hundred microns at very low temperature, without excessive heating. Atomic force microscopy based on a tuning fork resonator probe is used for cryogenic precise alignment of the tip with an individual device. We demonstrate the local tunneling spectroscopy of a hybrid Josephson junction as a function of its current bias

La paternité en contexte migratoire : étude comparative de l’expérience d’engagement paternel et de la construction de l’identité paternelle d’immigrants magrébins de première et de deuxième génération

Pendant la transition à la parentalité, les pères sont confrontés à deux principaux défis, soit le développement de leur identité paternelle et de leur engagement paternel. Pour les pères immigrants, des défis particuliers s’ajoutent en termes de construction de leur identité paternelle, que l’on connaît encore peu. Objectif. Cette comparaison des résultats de deux études qualitatives a pour objectif de décrire l’engagement paternel et le processus de construction de l’identité paternelle de pères originaires du Maghreb. Méthodologie. Les données ont été recueillies lors d’entretiens semi-dirigés auprès de six pères maghrébins de première génération immigrés au Québec et six pères maghrébins de deuxième génération résidant en Belgique. Résultats. Les pères des deux groupes s’impliquent auprès de leur enfant et partagent des facteurs facilitants ou faisant obstacle à la construction de leur identité paternelle. Des recommandations pour la pratique clinique, pour la formation et pour la recherche sont formulées.During the transitional period preceding parenthood, fathers have to face up to two main challenges: the development of their paternal identity, and their commitment to fatherhood. When it comes to immigrant fathers, there are added and specific, though still little known, challenges as regards the construction of their paternal identities. Objective: This comparison of the results of two qualitative studies is intended to describe the paternal commitment and the process of constructing a paternal identity, as experienced by fathers of North-African origin. Methodology: The data was gathered in the course of semi-structured interviews with six first- generation North-African fathers, immigrants to Quebec, and six second-generation North-African fathers resident in Belgium. Results: The fathers from both groups are involved with their children and have in common factors that facilitate or obstruct the construction of their paternal identities. Recommendations are made with regard to clinical practice, training and research

Preliminary Report: A survey of aggressive behaviors in the American coot (Fulica americana) at Ballona Wetlands, California

Understanding interspecific and intraspecific aggression is important for wildlife management and sustainability of populations. The objective of this study was to evaluate whether there is a difference in number of occurrences of interspecific aggression between American coots (Fulica americana) and mallard ducks (Anas platyrhynchos) and intraspecific aggression among American coots in the Ballona wetland habitat of Southern California. Trends in literature describe coots as highly aggressive toward other coots year-round and toward other bird species during the breeding season. Because we conducted observations outside the breeding season, we hypothesized that more instances of intraspecific aggression would be observed. We found a significant difference between the number of occurrences of interspecific and intraspecific aggression based on four behaviors specific for American coots: charging, paired display, splattering, and churning. There were more instances of intraspecific aggressive encounters than interspecific aggressive encounters, which indicate the interacting species at Ballona are not competing for resources and their respective niches may not overlap

Floridoside Extracted from the Red Alga Mastocarpus stellatus Is a Potent Activator of the Classical Complement Pathway

Many biological properties of algae have been found to have useful applications in human health, particularly in the fields of oncology and immunology. Floridoside, extracted from the red alga Mastocarpus stellatus, has a structure similar to the xenoantigen Gal alpha 1–3 Gal. This xenoantigen has been described to induce a high immune response in human xenografts and is mediated by natural anti-gal antibodies that activate the classical complement pathway. Based on this property, we analyzed the potential activities of floridoside on the immune system. We demonstrated that floridoside activates a complement cascade via the classical complement pathway, through the recruitment and activation of natural IgM. This algal molecule could represent an important step in the development of a potent new anticomplementary agent for use in therapeutic complement depletion

Energy transferred to the substrate surface during reactive magnetron sputtering of aluminum in Ar/O2 atmosphere

International audienceA study of the reactive sputtering of aluminum was carried out by coupling energy flux measurements at the substrate location with conventional diagnostics of the gas phase and analyses of the deposited films. The main purpose was to get some insight into the elementary mechanisms involved at the substrate surface during the film growth in the well known metal and oxide regimes and at the transitions from one to another. Measurements were carried out in front of a 10 cmAl target at a power of 400W (i.e. 5 W/cm2) and a total pressure of 0.6 Pa. The flow rate ratio (O2/O2+Ar) was varied in the range 0 to 50 %. Different kinetics and values of energy transfer, denoting different involved mechanisms, were evidenced at metal-oxide (increasing flow rate) and oxide-metal (decreasing flow rate) transitions. The metal-oxide transition was found to be a progressive process, in agreement with optical emission spectroscopy and deposit analysis, characterized by an increase of the energy flux that could be due to the oxidation of the growing metal film. On the contrary, oxide-metal transition is abrupt, and a high energy released at the beginning that could not be attributed to a chemical reaction. The possible effect of O-ions at this step was discussed