INTERACTION OF FAST HYDROGEN IONIC CLUSTERS WITH MATTER

Fast ionic clusters Hn+ interact with matter in a specific way which is observed to deviate strongly from the interaction of atomic ions at the same velocity. We present some results obtained at Lyon about foil and gas interactions of hydrogen clusters (5 ≤ n ≤ 23) at projectile velocities close to the Bohr velocity, i.e. dynamics of the cluster fragmentation, charge state of atomic fragments and absolute dissociation cross sections in gas. We also discuss future experiments specially at higher velocities

Childlessness in France

Even though the average age at first childbirth has been increasing and education and employment options for women have improved immensely in recent decades, in France, unlike in other European countries, these developments have not led to a major increase in childlessness. Birth rates remain high and the share of the population who are childless is among the lowest in western Europe. This article discusses the historical roots as well as the societal conditions, institutional regulations, and political decisions that may explain the low levels of childlessness in France. We also discuss differences in rates of childlessness by education and occupation. Using a large representative survey on family life that was conducted parallel to the French census in 2011, we study the fertility histories of men and women born between the 1920s and late 1970s. We find that while the differences in fertility by level of education seem to have declined, having a higher education is still an obstacle to parenthood for women. For men, having a low educational and occupational status is associated with a greater likelihood of being childless. A large part of the differences in rates of childlessness between social groups can be traced back to the men and women who have never lived in a couple relationship; thus, partnership status can be regarded as a decisive parameter of the extent of childlessness

The Cost of Active Services in Active Reliable Multicast

Associating customized processing to incoming packets, active networking provides a general framework for new protocol deployment and new service implementations. Recently, the use of these active network concepts has been proposed in many research areas including multicast protocols where efficient mechanisms to the reliability problems can be proposed. However, these active services introduce additional processing costs that must be carefully evaluated. This paper presents the preliminary results in measuring, in the context of the DyRAM protocol, the raw processing time required for enabling low-latency multicast communications on the Internet

The Cost of Active Services in Active Reliable Multicast

Associating customized processing to incoming packets, active networking provides a general framework for new protocol deployment and new service implementations. Recently, the use of these active network concepts has been proposed in many research areas including multicast protocols where efficient mechanisms to the reliability problems can be proposed. However, these active services introduce additional processing costs that must be carefully evaluated. This paper presents the preliminary results in measuring, in the context of the DyRAM protocol, the raw processing time required for enabling low-latency multicast communications on the Internet