Solar cycle influence on the interaction of the solar wind with Local Interstellar Cloud

We present results of a new time-dependent kinetic model of the H atom penetration through the solar wind - interstellar medium interaction region. A kinetic 6D (time, two dimensions in space, and three dimensions in velocity-space) equation for interstellar H atoms was solved self-consistently with time-dependent Euler equations for the solar wind and interstellar charged components. We study the response of the interaction region to 11-year solar cycle variations of the solar wind dynamic pressure. It is shown that the termination shock location varies within ±7 AU, the heliopause variation is ~4 AU, and the bow shock variation is negligible. At large heliocentric distances, the solar cycle induces 10-12% fluctuations in the number density of both primary and secondary interstellar H atoms and atoms created in the inner heliosheath. We underline the kinetic behavior of the fluctuations of the H atom populations. Closer to the Sun the fluctuations increase up to 30-35% at 5 AU due to solar cycle variation of the charge exchange rate. Solar cycle variations of interstellar H atoms in the heliospheric interface and within the heliosphere may have major importance for the interpretation of H atom observations inside the heliosphere

On clocks and clouds

Cumulus clouds exhibit a life cycle that consists of (a) the growth phase (increasing size, most notably in the vertical direction); (b) the mature phase (growth ceases; any precipitation that develops is strongest during this period); and (c) the dissipation phase (cloud dissipates because of precipitation and/or entrainment; no more dynamical support). Although radar can track clouds over time and give some sense of the age of a cloud, most aircraft in situ measurements lack temporal context. We use large eddy simulations of trade wind cumulus cloud fields from cases during the Barbados Oceanographic and Meteorological Experiment (BOMEX) and Rain In Cumulus over the Ocean (RICO) campaigns to demonstrate a potential cumulus cloud "clock." We find that the volume-averaged total water mixing ratio rt is a useful cloud clock for the 12 clouds studied. A cloud's initial rt is set by the subcloud mixed-layer mean rt and decreases monotonically from the initial value due primarily to entrainment. The clock is insensitive to aerosol loading, environmental sounding and extrinsic cloud properties such as lifetime and volume. In some cases (more commonly for larger clouds), multiple pulses of buoyancy occur, which complicate the cumulus clock by replenishing rt. The clock is most effectively used to classify clouds by life phase

Systematizing Planning and Formative Phases of HIV Prevention Research: Case Studies from Brazil, Mongolia, and Kazakhstan

Objectives International Community-Based Participatory Research (CBPR) is vulnerable to contextual, political, and interpersonal issues that may hamper researchers’ abilities to develop and sustain partnerships with local communities. This paper responds to a call for systematizing CBPR practices and to the urgent need for frameworks with potential to facilitate partnership building between researchers and communities in both “developed” and “developing” countries. Methods Using three brief case examples, each from a different context, with different partners and varied research questions, we demonstrate how to apply the International Participatory Research Framework (IPRF). Results IPRF consists of triangulated procedures (steps and actions) that can facilitate known participatory outcomes: (1) community-defined research goals, (2) capacity for further research, and (3) policies and programs grounded in research. Conclusions We show how the application of this model is particularly helpful in the planning and formative phases of CBPR. Other partnerships can use this framework in its entirety or aspects thereof, in different contexts. Further evaluation of how this framework can help other international partnerships, studying myriad diseases and conditions, should be a focus of future international CBPR

The growth and dynamics of <i>Ensis directus</i> in the near-shore Dutch coastal zone of the North Sea

Here we present data on the wax and wane of a subtidal Ensis directus population which settled in 2009 off the coast of Egmond (North Holland Coast in The Netherlands). Initial densities decreased from a maximum of 700 m- 2 in early 2010 to about 50 m- 2 in June 2013. In this period the average length increased from ~ 4 cm to ~ 12 cm. In 2011–2012 the population was sampled at 3 to 6 week intervals and near bottom environmental conditions were monitored continuously. Samples of animals that were collected were used to follow the change in gonadal mass, tissue glycogen content, tissue weight and shell length. On the basis of these data well defined seasonal cycles were observed. The data indicate that the maturation of gonadal tissue already starts early in the year, initially at the expense of somatic tissue. Main spawning takes place in May. After spawning net somatic tissue growth starts after compensation of losses due to spawning. Somatic growth precedes shell growth which starts at water temperatures exceeding 12–14 °C. Mortality, growth and production are comparable to those found for populations in close-by intertidal areas. As such there is no indication that this offshore population significantly suffers from nearby beach nourishments along the Dutch Coast

Accelerator system for the PRISM based muon to electron conversion experiment

The next generation of lepton flavor violation experiments need high intensity and high quality muon beams. Production of such beams requires sending a short, high intensity proton pulse to the pion production target, capturing pions and collecting the resulting muons in the large acceptance transport system. The substantial increase of beam quality can be obtained by applying the RF phase rotation on the muon beam in the dedicated FFAG ring, which was proposed for the PRISM project.This allows to reduce the momentum spread of the beam and to purify from the unwanted components like pions or secondary protons. A PRISM Task Force is addressing the accelerator and detector issues that need to be solved in order to realize the PRISM experiment. The parameters of the required proton beam, the principles of the PRISM experiment and the baseline FFAG design are introduced. The spectrum of alternative designs for the PRISM FFAG ring are shown. Progress on ring main systems like injection and RF are presented. The current status of the study and its future directions are discussed.Comment: Studies performed within the PRISM Task Force initiativ