On the origin of the canyon diablo no. 2 and no. 3 meteorites

Measurements of helium-3, neon-21, and argon-38 in Canyon Diablo meteorites indicated origin of Canyon Diablo-

Rare gas evidence for two paired meteorite falls

Mass spectroscopic analysis of rare gas contents of two paired meteorite fall

A formulation and analysis of combat games

Combat is formulated as a dynamical encounter between two opponents, each of whom has offensive capabilities and objectives. With each opponent is associated a target in the event space in which he endeavors to terminate the combat, thereby winning. If the combat terminates in both target sets simultaneously or in neither, a joint capture or a draw, respectively, is said to occur. Resolution of the encounter is formulated as a combat game; namely, as a pair of competing event-constrained differential games. If exactly one of the players can win, the optimal strategies are determined from a resulting constrained zero-sum differential game. Otherwise the optimal strategies are computed from a resulting non-zero-sum game. Since optimal combat strategies frequencies may not exist, approximate of delta-combat games are also formulated leading to approximate or delta-optimal strategies. To illustrate combat games, an example, called the turret game, is considered. This game may be thought of as a highly simplified model of air combat, yet it is sufficiently complex to exhibit a rich variety of combat behavior, much of which is not found in pursuit-evasion games

Ages of Ca-rich achondrites

Ages of calcium-rich achondrites determined by study of 27 eucrites and shergottite

Biology of bone sarcomas and new therapeutic developments

Bone sarcomas are tumours belonging to the family of mesenchymal tumours and constitute a highly heterogeneous tumour group. The three main bone sarcomas are osteosarcoma, Ewing sarcoma and chondrosarcoma each subdivided in diverse histological entities. They are clinically characterised by a relatively high morbidity and mortality, especially in children and adolescents. Although these tumours are histologically, molecularly and genetically heterogeneous, they share a common involvement of the local microenvironment in their pathogenesis. This review gives a brief overview of their specificities and summarises the main therapeutic advances in the field of bone sarcoma

A formulation and analysis of combat games

Combat which is formulated as a dynamical encounter between two opponents, each of whom has offensive capabilities and objectives is outlined. A target set is associated with each opponent in the event space in which he endeavors to terminate the combat, thereby winning. If the combat terminates in both target sets simultaneously, or in neither, a joint capture or a draw, respectively, occurs. Resolution of the encounter is formulated as a combat game; as a pair of competing event constrained differential games. If exactly one of the players can win, the optimal strategies are determined from a resulting constrained zero sum differential game. Otherwise the optimal strategies are computed from a resulting nonzero sum game. Since optimal combat strategies may frequently not exist, approximate or delta combat games are also formulated leading to approximate or delta optimal strategies. The turret game is used to illustrate combat games. This game is sufficiently complex to exhibit a rich variety of combat behavior, much of which is not found in pursuit evasion games

HIV/AIDS, income loss and economic survival in Botswana.

In countries facing severe HIV/AIDS epidemics, the overwhelming majority of those who are infected and affected by HIV are already living in poverty. Further income loss can threaten the ability to meet basic needs such as food, education and access to healthcare. Due to this, understanding the impact of HIV infection and caregiving on household income is essential to improving the health and welfare of HIV-affected individuals and families. This qualitative study examines how HIV infection and HIV caregiving affect household income in a population located within Botswana, a country with high HIV prevalence. We find that extended unpaid leave from work or job loss are common consequences and are associated with failure to meet basic needs in the short and long-term. We make recommendations for policy and programme support, including workplace adaptations and public sector support for meeting health and basic needs of HIV-affected families

Extended family caring for children orphaned by AIDS: balancing essential work and caregiving in a high HIV prevalence nations.

While over 90 per cent of the 15 million children who have been orphaned by HIV/AIDS are cared for by family members, there is little information about whether adults can meet orphans' essential caregiving needs while working to economically survive. Using a survey we conducted in Botswana of 1033 working adults, we analyse the experience of adults who are caring for orphans. Over one-third of working adults were caring for orphans and many with few financial resources: 82% were living on household incomes below US$10 purchasing power parity adjusted per person per day. Because of their caregiving responsibilities, they were less able to supplement income with overtime, weekend, evening, or night work. At the same time caregiving responsibilities meant orphan caregivers spent fewer hours caring for their own children and other family members. Nearly half of orphan caregivers had difficulties meeting their children's needs, and nearly 75% weren't able to meet with children's teachers. Pay loss at work compounded the problems: One-quarter of orphan caregivers reported having to take unpaid leave to meet sick childcare needs and nearly half reported being absent from work for children's routine health care. This paper makes clear that if families are to provide adequate care for orphans while economically surviving there needs to be increases in social supports and improvements in working conditions