Lawson criterion for ignition exceeded in an inertial fusion experiment

For more than half a century, researchers around the world have been engaged in attempts to achieve fusion ignition as a proof of principle of various fusion concepts. Following the Lawson criterion, an ignited plasma is one where the fusion heating power is high enough to overcome all the physical processes that cool the fusion plasma, creating a positive thermodynamic feedback loop with rapidly increasing temperature. In inertially confined fusion, ignition is a state where the fusion plasma can begin "burn propagation" into surrounding cold fuel, enabling the possibility of high energy gain. While "scientific breakeven" (i.e., unity target gain) has not yet been achieved (here target gain is 0.72, 1.37 MJ of fusion for 1.92 MJ of laser energy), this Letter reports the first controlled fusion experiment, using laser indirect drive, on the National Ignition Facility to produce capsule gain (here 5.8) and reach ignition by nine different formulations of the Lawson criterion

Formation of Submicrometer pore arrays by electrochemical etching of silicon and nanoimprint lithography

International audienc

Acute moderate hypoxia affects the oxygen desaturation and the performance but not the oxygen uptake response

Protein cages are an interesting class of biomaterials with potential applications in bionanotechnology. Therefore, substantial effort is spent on the development of capsule-forming designer polypeptides with a tailor-made assembly profile. The expanded assembly profile of a triblock copolypeptide consisting of a metal ion chelating hexahistidine-tag, a stimulus-responsive elastin-like polypeptide block, and a pH-responsive morphology-controlling viral capsid protein is presented. The self-assembly of this multi-responsive protein-based block copolymer is triggered by the addition of divalent metal ions. This assembly process yields monodisperse nanocapsules with a 20 nm diameter composed of 60 polypeptides. The well-defined nanoparticles are the result of the emergent properties of all the blocks of the polypeptide. These results demonstrate the feasibility of hexahistidine-tags to function as supramolecular cross-linkers. Furthermore, their potential for the metal ion-mediated encapsulation of hexahistidine-tagged proteins is shown

Weaning is associated with an up-regulation of expression of inflammatory cytokines in the intestine of piglets

International audienc

Effect of stroke rate on performance and physiological demand of outrigger canoeing ergometry

Outrigger canoeists adopt a variety of racing stroke rates without scientific basis. The aim of this study was to compare the effect of self-selected and imposed slow (Hawaiian) and fast (Tahitian) stroke rates on 1000-m outrigger ergometer performance and physiological demand to determine which stroke rate was best for performance. Female outrigger canoeists (n=17) completed 1000-m ergometer time trials using a self-selected, Hawaiian (≤55 strokes · min−1) and Tahitian (≥65 strokes · min−1) stroke rate. Performance time and physiological demand were compared for the overall 1000 m and for each 250-m split across trials. There was no significant difference in performance time between the Hawaiian (mean value 358 s, s=30) and Tahitian (mean value 357 s, s=28) trials with both trials significantly faster than the self-selected trial (mean value 371 s, s=38) (P < 0.05). The Hawaiian trial resulted in significantly lower physiological demand than the Tahitian and self-selected trials. When choosing their stroke rate, female outrigger canoeists perform sub-optimally. The Hawaiian stroke rate resulted in the same performance time as the Tahitian stroke rate but with reduced physiological demand. Outrigger canoe coaches should employ a slower stroke rate of ≤ 55 strokes · min−1 to optimize 1000-m performance and minimize physiological demand that may lead to fatigue across multiple races

Developmental vitamin D deficiency alters brain protein expression in the adult rat: Implications for neuropsychiatric disorders

An increased risk for multiple sclerosis and schizophrenia is observed at increasing latitude and in patients born in winter or spring. To explore a possible link between maternal vitamin D deficiency and these brain disorders, we examined the impact of prenatal hypovitaminosis D on protein expression in the adult rat brain. Vitamin D-deficient female rats were mated with vitamin D normal males. Pregnant females were kept vitamin D-deficient until birth whereupon they were returned to a control diet. At week 10, protein expression in the progeny's prefrontal cortex and hippocampus was compared with control animals using silver staining 2-D gels associated with MS and newly devised data mining software. Developmental vitamin D (DVD) deficiency caused a dysregulation of 36 brain proteins involved in several biological pathways including oxidative phosphorylation, redox balance, cytoskeleton maintenance, calcium homeostasis, chaperoning, PTMs, synaptic plasticity and neurotransmission. A computational analysis of these data revealed that (i) nearly half of the molecules dysregulated in our animal model have also been shown to be misexpressed in either schizophrenia and/or multiple sclerosis and (ii) an impaired synaptic network may be a consequence of mitochondrial dysfunction