Exocomets from a Solar System Perspective

Exocomets are small bodies releasing gas and dust which orbit stars other than the Sun. Their existence was first inferred from the detection of variable absorption features in stellar spectra in the late 1980s using spectroscopy. More recently, they have been detected through photometric transits from space, and through far-IR/mm gas emission within debris disks. As (exo)comets are considered to contain the most pristine material accessible in stellar systems, they hold the potential to give us information about early stage formation and evolution conditions of extra solar systems. In the solar system, comets carry the physical and chemical memory of the protoplanetary disk environment where they formed, providing relevant information on processes in the primordial solar nebula. The aim of this paper is to compare essential compositional properties between solar system comets and exocomets to allow for the development of new observational methods and techniques. The paper aims to highlight commonalities and to discuss differences which may aid the communication between the involved research communities and perhaps also avoid misconceptions. The compositional properties of solar system comets and exocomets are summarized before providing an observational comparison between them. Exocomets likely vary in their composition depending on their formation environment like solar system comets do, and since exocomets are not resolved spatially, they pose a challenge when comparing them to high fidelity observations of solar system comets. Observations of gas around main sequence stars, spectroscopic observations of “polluted” white dwarf atmospheres and spectroscopic observations of transiting exocomets suggest that exocomets may show compositional similarities with solar system comets. The recent interstellar visitor 2I/Borisov showed gas, dust and nuclear properties similar to that of solar system comets. This raises the tantalising prospect that observations of interstellar comets may help bridge the fields of exocomet and solar system comets

Breast cancer incidence in food- vs non-food-producing areas in Norway: possible beneficial effects of World War II

It has been suggested that World War II influenced breast cancer risk among Norwegian women by affecting adolescent growth. Diet changed substantially during the war, and the reduction in energy intake was assumed to be larger in non-food- producing than in food-producing municipalities. In the present study, we have looked at the influence of residential history in areas with and without food production on the incidence of breast cancer in a population-based cohort study consisting of 597 906 women aged between 30 and 64 years. The study included 7311 cases of breast cancer, diagnosed between 1964 and 1992. The risk estimates were calculated using a Poisson regression model. The results suggest that residential history may influence the risk of breast cancer, where the suggested advantageous effect of World War II seems to be larger in non-food-producing than in food-producing areas. Breast cancer incidence was observed to decline for the post-war cohorts, which is discussed in relation to diet

Nursing during World War II: Finnmark County, Northern Norway

INTRODUCTION: This study is part the project “Nursing in Borderland – Finnmark 1939–1950” within nursing history that sheds light on nursing and health care during World War II in Finnmark County, Northern Norway. The study focuses on challenges in nursing care that arose during the war because of war activities in the Barents area. This article focuses on challenges caused by shortage of supplies. The aim of the project is to widen the understanding of development within health care and living conditions in the area. STUDY DESIGN: This is a historical study using narratives, government documents and literature. METHODS: Interviews with nurses and persons active in health care during World War II constitute the main data of the research. Thematic issues that arise from interviews are analysed. Primary and secondary written sources are used in analysing the topics. Because of war activities, deportation and burning of the county, archives were partly destroyed. Central archives can contribute with annual reports, whereas local archives are fragmentary. There are a number of reports written soon after the War, as well as a number of biographical books of newer date. RESULTS: Challenges caused by war, which appear in the interviews, are: 1) shortage of supplies, 2) increased workload, 3) multicultural society, 4) ethical dilemmas, 5) deportation of the population. In this paper, focus is on challenges caused by shortage of supplies. CONCLUSIONS: Both institutions, personnel and patients were marked by the war. This has to be taken in consideration in health care today