BackgroundEvidence-based public health gives public health practitioners the tools they need to make choices based on the best and most current evidence. An evidence-based public health training course developed in 1997 by the Prevention Research Center in St. Louis has been taught by a transdisciplinary team multiple times with positive results. In order to scale up evidence-based practices, a train-the-trainer initiative was launched in 2010.MethodsThis study examines the outcomes achieved among participants of courses led by trained state-level faculty. Participants from trainee-led courses in four states (Indiana, Colorado, Nebraska, and Kansas) over three years were asked to complete an online survey. Attempts were made to contact 317 past participants. One-hundred forty-four (50.9 %) reachable participants were included in analysis. Outcomes measured include frequency of use of materials, resources, and other skills or tools from the course; reasons for not using the materials and resources; and benefits from attending the course. Survey responses were tabulated and compared using Chi-square tests.ResultsAmong the most commonly reported benefits, 88 % of respondents agreed that they acquired knowledge about a new subject, 85 % saw applications for the knowledge to their work, and 78 % agreed the course also improved abilities to make scientifically informed decisions at work. The most commonly reported reasons for not using course content as much as intended included not having enough time to implement evidence-based approaches (42 %); other staff/peers lack training (34 %); and not enough funding for continued training (34 %). The study findings suggest that utilization of course materials and teachings remains relatively high across practitioner groups, whether they were taught by the original trainers or by state-based trainers.ConclusionsThe findings of this study suggest that train-the-trainer is an effective method for broadly disseminating evidence-based public health principles. Train-the-trainer is less costly than the traditional method and allows for courses to be tailored to local issues, thus making it a viable approach to dissemination and scale up of new public health practices.Electronic supplementary materialThe online version of this article (doi:10.1186/s12913-015-1224-2) contains supplementary material, which is available to authorized users.

This study focuses on meteor smoke particle (MSP) induced effects on the D region ion chemistry. Hereby, MSPs, represented with an 11 bin size distribution, have been included as an active component into the Sodankyä Ion and Neutral Chemistry model. By doing that, we model the diurnal variation of the negatively and positively charged MSPs as well as ions and the electron density under quiet ionospheric conditions. Two distinct points in time are studied in more detail, i.e., one for sunlit conditions (Solar zenith angle is 72°) and one for dark conditions (Solar zenith angle is 103°). We find nightly decrease of free electrons and negative ions, the positive ion density is enhanced at altitudes above 80 km and reduced below. During sunlit conditions the electron density is enhanced between 60 and 70 km altitude, while there is a reduction in negative and positive ions densities. In general, the MSP influence on the ion chemistry is caused by changes in the electron density. On the one hand, these changes occur due to nightly electron scavenging by MSPs resulting in a reduced electron‐ion recombination. As a consequence positive ion density increase, especially water cluster ions are highly affected. On the other hand, the electron density is slightly increased during daytime by a MSP‐related production due to solar radiation. Thus, more electrons attach to neutrals and short‐lived negative ions increase in number density. The direct attachment of ions to MSPs is a minor process, but important for long living ions.

Abstract. This work investigates the influence of meteoric smoke particles (MSP) on the charge balance in the D-region ionosphere. Both experimental in situ measurements and a one-dimensional ionospheric model reveal a clear impact of MSP on the ionospheric composition of the D-region. The study reviews rocket-borne in situ measurements of electron and positive ion density, which show a distinct deficit of electrons in comparison to positive ions between 80 and 95 km. This deficit can be explained by the ambient negatively charged MSP measured simultaneously with a Faraday cup. The influence of MSP on the D-region charge balance is addressed with a simplified ionospheric model with only six components, i.e. electrons, positive and negative ions and neutral and charged MSP (both signs). The scheme includes reactions of plasma captured by MSP and MSP photo reactions as well as the standard ionospheric processes, e.g. ionion recombination. The model shows that the capture of plasma constituents by MSP is an important process leading to scavenging of electrons. Since Faraday cup measurements are biased towards heavy MSP because of aerodynamical filtering, we have applied an estimate of this filter on the modelled MSP densities. By doing that, we find good qualitative agreement between the experimental data and our model results. In addition, the model study reveals an increase of positive ions in the presence of MSP. That is primarily caused by the reduced dissociative recombination with electrons which have been removed from the gas phase by the MSP.

The ECOMA (Existence of Charge state Of meteoric smoke particles in the Middle Atmosphere) sounding rocket campaign was conducted during the Geminid meteor shower in December 2010 in order to explore whether there is a change of the properties of meteoric smoke particles due to the stream. In parallel to the rocket flights, three radars monitored the Geminid activity located at the launch site in Northern Norway and in Northern Germany to gain information about the meteor flux into the atmosphere. The results presented here are based on specular meteor radar observations measuring the radiant position, the velocity and the meteor flux into the atmosphere during the Geminids. Further, the MAARSY (Middle Atmosphere Alomar Radar System) radar was operated to conduct meteor head echo experiments. The interferometric capabilities of MAARSY permit measuring the meteor trajectories within the radar beam and to determine the source radiant and geocentric meteor velocity, as well as to compute the meteor orbit