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

DNA alteration and programmed cell death during ageing of sunflower seed

Sunflower (Helianthus annuus L.) seed viability is affected by moisture content (MC) during ageing and is related to accumulation of hydrogen peroxide and changes in energy metabolism. The aim of the present work was to investigate the effect of ageing on DNA alteration events by RAPD (random amplification of polymorphic DNA) analysis and to determine whether loss of seed viability might correspond to a controlled programmed cell death (PCD). Ageing of sunflower seeds was carried out at 35 °C for 7 d at different MCs. The higher the MC, the lower was the seed viability. RAPD analysis showed that DNA alterations occurred during ageing especially in seeds containing a high MC. In addition, PCD, as revealed by DNA fragmentation and TUNEL (terminal deoxynucleotide transferase-mediated dUTP nick-end labelling) assay, was detected in aged seeds at MCs which resulted in ∼50% seed viability. At the cellular level, TUNEL assay and propidium iodide staining showed that cell death concerns all the cells of the embryonic axis. The quantification of the adenylate pool highlights mitochondrial dysfunction in aged seeds containing a high MC. The involvement of oxidative burst, mitochondria dysfunction, and PCD in seed loss of viability is proposed

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

Sleep architecture when sleeping at an unusual circadian time and associations with insulin sensitivity

Circadian misalignment affects total sleep time, but it may also affect sleep architecture. The objectives of this study were to examine intra-individual effects of circadian misalignment on sleep architecture and inter-individual relationships between sleep stages, cortisol levels and insulin sensitivity. Thirteen subjects (7 men, 6 women, age: 24.3+/-2.5 y; BMI: 23.6+/-1.7 kg/m(2)) stayed in a time blinded respiration chamber during three light-entrained circadian cycles (3x21h and 3x27h) resulting in a phase advance and a phase delay. Sleep was polysomnographically recorded. Blood and salivary samples were collected to determine glucose, insulin and cortisol concentrations. Intra-individually, a phase advance decreased rapid eye movement (REM) sleep and slow-wave sleep (SWS), increased time awake, decreased sleep and REM sleep latency compared to the 24h cycle. A phase delay increased REM sleep, decreased stage 2 sleep, increased time awake, decreased sleep and REM sleep latency compared to the 24h cycle. Moreover, circadian misalignment changed REM sleep distribution with a relatively shorter REM sleep during the second part of the night. Inter-individually, REM sleep was inversely associated with cortisol levels and HOMA-IR index. Circadian misalignment, both a phase advance and a phase delay, significantly changed sleep architecture and resulted in a shift in rem sleep. Inter-individually, shorter REM sleep during the second part of the night was associated with dysregulation of the HPA-axis and reduced insulin sensitivity. Trial Registration: International Clinical Trials Registry Platform NTR2926 http://apps.who.int/trialsearch