Efficient loading of a He* magneto-optic trap using a liquid He cooled source

We report loading large numbers (up to 3×10⁹) of metastable triplet helium atoms into a magneto-optical trap using an atomic beam derived from a liquid He (LHe) cooled dc discharge source. Moreover, we compare the effect of liquidN₂ cooling to LHe cooling the source and demonstrate that LHe cooling offers a significant increase in performance

The Evolution of Dispersal in Random Environments and The Principle of Partial Control

McNamara and Dall (2011) identified novel relationships between the abundance of a species in different environments, the temporal properties of environmental change, and selection for or against dispersal. Here, the mathematics underlying these relationships in their two-environment model are investigated for arbitrary numbers of environments. The effect they described is quantified as the fitness-abundance covariance. The phase in the life cycle where the population is censused is crucial for the implications of the fitness-abundance covariance. These relationships are shown to connect to the population genetics literature on the Reduction Principle for the evolution of genetic systems and migration. Conditions that produce selection for increased unconditional dispersal are found to be new instances of departures from reduction described by the "Principle of Partial Control" proposed for the evolution of modifier genes. According to this principle, variation that only partially controls the processes that transform the transmitted information of organisms may be selected to increase these processes. Mathematical methods of Karlin, Friedland, and Elsner, Johnson, and Neumann, are central in generalizing the analysis. Analysis of the adaptive landscape of the model shows that the evolution of conditional dispersal is very sensitive to the spectrum of genetic variation the population is capable of producing, and suggests that empirical study of particular species will require an evaluation of its variational properties.Comment: Dedicated to the memory of Professor Michael Neumann, one of whose many elegant theorems provides for a result presented here. 28 pages, 1 table, 1 figur

Beyond “#endpjparalysis”, tackling sedentary behaviour in health care

Reducing sedentary behaviour after hospitalization starts with reducing sedentary behaviour whilst in hospital. Although we have eradicated immobilisation as a therapeutic tool due to its potent detrimental effects, it is still in systemic use within health care systems and hospitals. Evidence shows that when in hospital, patients spend most of their time sedentary. In this editorial, we explore the determinants of, and a system-based approach to, reducing sedentary behaviour in health care

Checklist of the Invertebrate Animals Reported from the Region of Port Aransas, Texas

This checklist is of preliminary form with the hope that this will be a beginning for a more complete annotated list of the fauna and flora of this region. In many cases this list is quite obviously incomplete, however further work on the taxonomy of the biota of this region will gradually fill the incomplete gaps, and the resulting list should then prove quite useful to field investigators in this area.Marine Scienc