Collisions Between Gravity-Dominated Bodies: 1. Outcome Regimes and Scaling Laws

Collisions are the core agent of planet formation. In this work, we derive an analytic description of the dynamical outcome for any collision between gravity-dominated bodies. We conduct high-resolution simulations of collisions between planetesimals; the results are used to isolate the effects of different impact parameters on collision outcome. During growth from planetesimals to planets, collision outcomes span multiple regimes: cratering, merging, disruption, super-catastrophic disruption, and hit-and-run events. We derive equations (scaling laws) to demarcate the transition between collision regimes and to describe the size and velocity distributions of the post-collision bodies. The scaling laws are used to calculate maps of collision outcomes as a function of mass ratio, impact angle, and impact velocity, and we discuss the implications of the probability of each collision regime during planet formation. The analytic collision model presented in this work will significantly improve the physics of collisions in numerical simulations of planet formation and collisional evolution. (abstract abridged)Comment: Version 3, accepted to ApJ in Nov. 2011 published online Dec. 2011. Abstract abridge

Shock wave propagation in porous ice

We present data on shock wave propagation in porous ice under conditions applicable to the outer solar system. The equation of state of porous ice under low temperature and low pressure conditions agrees well with measurements under terrestrial conditions implying that data on terrestrial snow may be applicable to the outer solar system. We also observe rarefaction waves from small regions of increased porosity and calculate release wave velocities

Home and community based parenting support programmes and interventions: report of Workpackage 2 of the DataPrev project

The last decade has witnessed an increasing interest in the promotion of mental health and wellbeing because of its importance for health and social functioning at the individual level and for the social and economic wellbeing of societies. Recent research from a range of disciplines has highlighted the importance of the quality of the parent-child relationships and parenting on children‟s emotional and social development, and on adult mental health and wellbeing. Intervention studies involving children of all age groups have shown that if parenting can be influenced for the better outcomes can be changed. The DataPrev project was funded by the 6th Framework of the European Community Research Programme under Policy-Orientated Research with the aim of establishing a database of evidence-based programmes in Europe that promote mental health and wellbeing and prevent mental illness throughout the life course. This is the report of the Workpackage 2 describing the international evidence base on programmes to support parenting, including home and community based programmes

Erosive Hit-and-Run Impact Events: Debris Unbound

Erosive collisions among planetary embryos in the inner solar system can lead to multiple remnant bodies, varied in mass, composition and residual velocity. Some of the smaller, unbound debris may become available to seed the main asteroid belt. The makeup of these collisionally produced bodies is different from the canonical chondritic composition, in terms of rock/iron ratio and may contain further shock-processed material. Having some of the material in the asteroid belt owe its origin from collisions of larger planetary bodies may help in explaining some of the diversity and oddities in composition of different asteroid groups.Comment: 7 pages, 3 figure

The Politics of Zoroastrian Philanthropy and the Case of Qasr-e Firuzeh

In Iran and India religious philanthropy has been a feature of Zoroastrian piety as well as providing the means by which both communities have prospered throughout their respective histories. In Iran an elaborate structure for the regulation of charitable donations was already in place during the Sasanian period and laid the foundation for the laws governing pious foundations, awqāf, after the Islamic conquest. The increased interaction between Iranian Zoroastrians and Parsis from the mid-nineteenth century onwards led to the expansion of the Tehran Zoroastrian community and the rise of a wealthy merchant class which in turn enabled philanthropic activity to flourish. This development will be discussed here with reference to a particular vaqf, that of the first ārāmgāh or Zoroastrian cemetery to be established in Tehran in the early twentieth century. The case of Qasr-e Firuzeh spans three successive governments in Iran and gives an insight into the management of a charitable endowment within different political contexts

Informational Interfaces: A case study of the impact of discovery systems on biodiversity research and search at the Natural History Museum, London, UK

The Natural History Museum is one of the world’s leading research institutions for biological diversity research with collections comprising some 8 million specimens representing a vast wealth of data. It also holds one of the foremost collections of biodiversity-related literature in its Library and Archives, with over one million items catalogued, ranging from artworks and historical manuscripts to born-digital material such as journal articles. This study investigates the impact of discovery systems on search and research at the Natural History Museum with the objectives: to determine exact attitudes to searching for biodiversity information resources using the Library and Archives discovery system and the Data Portal; to explore how biodiversity information is discovered and used through the discovery system; to examine the impact of discovery systems on search and research; and to document the transition toward a digital, networked and aggregated discovery system approach to managing biodiversity information. To date, this is the first case study of the implementation of a discovery system in a natural history museum library with a focus on biodiversity research