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

Seasonal variations of the digestive tract of the Eurasian beaver castor fiber.

Forage availability for wild rodents varies with season. In turn, the composition of food can affect morphometric parameters of the digestive tract. This study was performed in Eurasian beavers (Castor fiber) whose population was close to extinction in most Eurasian countries, but has now increased. Due to the previous low number of studies, information about the effect of forage availability on the digestive tract morphology has previously been lacking. This study was performed using beavers captured from the natural environment during three seasons of different forage availability: winter, summer and autumn. It was found that the diet of the beaver varied during the year; in winter it was dominated by woody material consisting of willow shoots, whereas in summer the diet was primarily herbs, grass and leaves. Season also affected the mass of digested contents of the digestive tract. The digestive content increased in the caecum and colon in winter and autumn, when poor-quality food dominated the beaver's diet. The results indicated that the digestive tract parameters of beavers varied based on the composition of available forage

Differential increase in prevalence estimates of inadequate sleep among black and white Americans

BACKGROUND: The National Health Interview Survey (NHIS) was used to ascertain whether increases in inadequate sleep differentially affected black and white Americans. We tested the hypothesis that prevalence estimates of inadequate sleep were consistently greater among blacks, and that temporal changes have affected these two strata differentially. METHODS: NHIS is an ongoing cross-sectional study of non-institutionalized US adults (≥18 years) providing socio-demographic, health risk, and medical factors. Sleep duration was coded as very short sleep [VSS] (<5 h), short sleep [SS] (5–6 h), or long sleep [LS] (>8 h), referenced to 7–8 h sleepers. Analyses adjusted for NHIS’ complex sampling design using SAS-callable SUDAAN. RESULTS: Among whites, the prevalence of VSS increased by 53 % (1.5 % to 2.3 %) from 1977 to 2009 and the prevalence of SS increased by 32 % (19.3 % to 25.4 %); prevalence of LS decreased by 30 % (11.2 % to 7.8 %). Among blacks, the prevalence of VSS increased by 21 % (3.3 % to 4.0 %) and the prevalence of SS increased by 37 % (24.6 % to 33.7 %); prevalence of LS decreased by 42 % (16.1 % to 9.4 %). Adjusted multinomial regression analysis showed that odds of reporting inadequate sleep for whites were: VSS (OR = 1.40, 95 % CI = 1.13-1.74, p < 0.001), SS (OR = 1.34, 95 % CI = 1.25-1.44, p < 0.001), and LS (OR = 0.94, 95 % CI = 0.85-1.05, NS). For blacks, estimates were: VSS (OR = 0.83, 95 % CI = 0.60-1.40, NS), SS (OR = 1.21, 95 % CI = 1.05-1.50, p < 0.001), and LS (OR = 0.84, 95 % CI = 0.64-1.08, NS). CONCLUSIONS: Blacks and whites are characteristically different regarding the prevalence of inadequate sleep over the years. Temporal changes in estimates of inadequate sleep seem dependent upon individuals’ race/ethnicity

Confirmation of the hosts involved in the life cycle of an acanthocephalan parasite of Anguilla anguilla (L.) from Lake Piediluco and its effect on the reproductive potential of its amphipod intermediate host

A total of 37 European eels, Anguilla anguilla, collected from Lake Piediluco, Central Italy, and measuring 35 to 75.5 cm in total length (mean&plusmn;1 SD, 56.41&plusmn;10.89 cm) were examined, and their acanthocephalan infections assessed. Thirty-two (86.49%) eels were infected with Acanthocephalus rhinensis (mean&plusmn;1 SD, 67.38&plusmn;65.16; range, 1-350), a species that, purportedly, can be discriminated on the basis of a characteristic band of orange-brown pigmentation encircling the anterior end of the trunk. This feature, however, was not seen on any of the A. rhinensis specimens that were removed, either attached to the gut wall or free within the gut lumen, from infected eels. Approximately 40% of the eels were coinfected with the dracunculid swimbladder nematode Anguillicoloides crassus, while a single eel was also coinfected with eight specimens of a second acanthocephalan, Dentitruncus truttae. From the stomachs of two eels, 109 intact and partially digested specimens of amphipod Echinogammarus tibaldii (Pinkster &amp; Stock 1970) were recovered, 16 (14.6%) of these were infected with one to two cystacanths of A. rhinensis per host. From a sample of 850 E. tibaldii taken from the peripheral lakeside vegetation, 102 (12%; sex ratio, 1:1) gammarids were infected with one to two A. rhinensis cystacanths. Unparasitised ovigerous female E. tibaldii specimens had significantly higher numbers of eggs in their brood pouches compared with their infected counterparts (t-test, P less than&nbsp; .01)