Achievement of Target Gain Larger than Unity in an Inertial Fusion Experiment.

On December 5, 2022, an indirect drive fusion implosion on the National Ignition Facility (NIF) achieved a target gain G_{target} of 1.5. This is the first laboratory demonstration of exceeding "scientific breakeven" (or G_{target}>1) where 2.05 MJ of 351 nm laser light produced 3.1 MJ of total fusion yield, a result which significantly exceeds the Lawson criterion for fusion ignition as reported in a previous NIF implosion [H. Abu-Shawareb et al. (Indirect Drive ICF Collaboration), Phys. Rev. Lett. 129, 075001 (2022)PRLTAO0031-900710.1103/PhysRevLett.129.075001]. This achievement is the culmination of more than five decades of research and gives proof that laboratory fusion, based on fundamental physics principles, is possible. This Letter reports on the target, laser, design, and experimental advancements that led to this result.

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.

Atom probe tomography investigation of assisted precipitation of secondary hardening carbides in a medium carbon martensitic steels.

A medium carbon martensitic steel containing nanometer scale secondary hardening carbides and intermetallic particles is investigated by field ion microscopy and atom probe tomography. The interaction between the concomitant precipitations of both types of particles is investigated. It is shown that the presence of the intermetallic phase affects the nucleation mechanism and the spatial distribution of the secondary hardening carbides, which shifts from heterogeneous on dislocations to heterogeneous on the intermetallic particles.

The morphology of secondary-hardening carbides in a martensitic steel at the peak hardness by 3DFIM.

The morphology and composition of secondary-hardening M(2)C carbides in a complex steel under non-isothermal tempering condition has been investigated with three-dimensional field ion microscopy and atom-probe tomography. The technical set-up and the condition of investigations have been developed. We will reveal for the first time, a virtually non-biased image of the so-called secondary-hardening microstructure, consisting in a very fine dispersion of nanometer-sized needles, idiomorphs and blocky carbides. Needles precipitate with a large number density at the maximum hardness peak. We have found out that this mixture of shape could be explained by the onset of coarsening, but the role of local factors have been evidenced: variation of composition among the carbides and even local strain effects due to the precipitation of a second phase can play a role in changing the growth conditions.

[Breastfeeding: pledging allegiance to ourselves]. / L'allaitement maternel: prime de fidélité à nous-mêmes.

Since prehistoric times, how babies should be fed has been a constant for our species, which is one of the more than 4,600 varieties of milk-producing creatures collectively known as mammals. Each mammal produces its own unique milk, and thus feeding a baby something other than breast milk will always be a deviation from the biological norm for our species. Indeed, breast milk is the only truly universal food uniting all 6 billion of us, irrespective of geography and culture. While in extreme cases it may be necessary to feed a baby a breast-milk substitute, this is not without considerable risk. In any case, it should remain the exception. Paediatricians and other professionals responsible for health services are particularly well placed to provide the leadership to sustain or, if necessary, to re-establish, a 'breastfeeding culture'. The WHO/UNICEF Baby-friendly Hospital Initiative offers a useful framework for doing just this. In only eight short years, more than 16,000 hospitals in 171 countries have begun implementing the Initiative. It is hoped that hospitals in France will soon join this worldwide alliance.

Ten steps to successful breastfeeding: a summary of the rationale and scientific evidence.

Ample evidence is available on the impact of health care practices and hospital routines and procedures on breastfeeding. Good practices enhance successful initiation and establishment of breastfeeding and contribute to increased duration, just as inappropriate practices, and failure to support and encourage mothers, have the opposite effect. In 1991 the World Health Organization (WHO) and the United Nations Children's Fund (UNICEF) jointly launched the Baby-Friendly Hospital Initiative, which aims to give every baby the best start in life by ensuring a health care environment where breastfeeding is the norm. The initiative is based on the principles summarized in a joint statement issued by the two organizations in 1989 on the role of maternity services in protecting, promoting, and supporting breastfeeding. To become truly baby-friendly, hospitals and maternity wards around the world are giving practical effect to the principles described in the joint WHO/UNICEF statement that have been synthesized into Ten Steps To Successful Breastfeeding. This summary of the rationale and scientific basis for the Ten Steps is presented in the light of cumulative experience demonstrating the crucial importance of these principles for the successful initiation and establishment of breastfeeding.

The worldwide magnitude of protein-energy malnutrition: an overview from the WHO Global Database on Child Growth.

Using the WHO Global Database on Child Growth, which covers 87% of the total population of under-5-year-olds in developing countries, we describe the worldwide distribution of protein-energy malnutrition, based on nationally representative cross-sectional data gathered between 1980 and 1992 in 79 developing countries in Africa, Asia, Latin America, and Oceania. The findings confirm that more than a third of the world's children are affected. For all the indicators (wasting, stunting, and underweight) the most favourable situation--low or moderate prevalences--occurs in Latin America; in Asia most countries have high or very high prevalences; and in Africa a combination of both these circumstances is found. A total 80% of the children affected live in Asia--mainly in southern Asia--15% in Africa, and 5% in Latin America. Approximately, 43% of children (230 million) in developing countries are stunted. Efforts to accelerate significantly economic development will be unsuccessful until optimal child growth and development are ensured for the majority.

Infant feeding. The physiological basis.

A mother's nutritional status during pregnancy has important implications for both her own health and her ability to produce and breast-feed a healthy infant. Knowledge about adequate maternal nutrition during pregnancy is incomplete, however, and there is still considerable debate about the level of extra energy needed by a pregnant woman. A woman's usual nutritional requirements increase during pregnancy to meet her needs and those of the growing fetus. Additional energy is needed because of increased basal metabolism, the greater cost of physical activity, and the normal accumulation of fat as the energy reserve. The protein, vitamin and mineral requirements of the mother also increase during pregnancy, but the precise amounts for the last two are still a matter for discussion. A woman's weight increments during pregnancy vary between privileged and underprivileged communities. In addition to calcium, phosphorus and iron, a mother provides considerable amounts of protein and fat for fetal growth. Placental metabolism and placental blood flow, which are interrelated, are the most critical factors for fetal development.The nutritional requirements of healthy newborns vary widely according to their weight, gestational age, rate of growth, as well as environmental factors. However, recommendations for some components may be derived from the average composition of early human milk and the amounts consumed by healthy, mature newborns who are following a normal postpartum clinical course. The water requirements of infants are related to their caloric consumption, activity, rate of growth, and the ambient temperature. A postnatal weight loss of 5-8% of body weight is usual during the first few days of life in mature newborn infants; in contrast, infants who experienced intrauterine malnutrition lose little or no weight at all.The dynamic process of mother-newborn interaction from the first hours of life is intimately related to successful early breast-feeding. If this process is delayed, however, it may take longer and may be more difficult to achieve. Close mother-infant contact immediately after birth also helps infants to adapt to their new unsterile environment. Because drugs can interfere with bonding and breast-feeding, such substances should be given only when necessary and their effects should be evaluated. In general, young infants, especially newborns, have very irregular feeding intervals. It is advisable for numerous reasons to feed them whenever they indicate a need.