198 research outputs found
Comment on "Are periodic solar wind number density structures formed in the solar corona?" by N. M. Viall et al., 2009, Geophys. Res. Lett., 36, L23102, doi:10.1029/2009GL041191
Location of formation of periodic solar wind number density structures is
discussed. Observation of proton and alpha anticorrelation in these structures
[Viall et al., 2009] indicates that taking into account that bulk velocity of
aplha-particles is higher than that of proton the place of formation for these
structures should be located at distance less 0.002 AU from place of
observation.Comment: 6 pages, submitted in GR
Australian forested wetlands under climate change:Collapse or proliferation?
Climatically driven perturbations (e.g. intense drought, fire, sea surface temperature rise) can bring ecosystems that are already stressed by long-term climate change and other anthropogenic impacts to a point of collapse. Recent reviews of the responses of Australian ecosystems to climate change and associated stressors have suggested widespread ecosystem collapse is occurring across multiple biomes. Two commonly cited case studies concern forested wetland ecosystems: mangrove forest dieback in northern Australia (2015-16) and riverine forest dieback in the south-east of the continent (2002-09). We present an alternative interpretation that emphasises the dominant signal of climate change effects, rather than the interdecadal signal of climate variability that drives wetland forest dynamics. For both the south-east Australian riverine forests and mangroves of northern Australia, aerial extent remains greater after dieback than in the early 1990s. We interpret dieback and defoliation in both systems as a dry phase response and provide evidence of a current and near-future climate change trajectory of increased areal extent and cover (i.e. tree colonisation and range infilling). In both case studies, climate change-driven increases in tree cover and extent are occurring at the expense of wetland grasslands and the important ecosystem functions they support
Quasi‐trapped ion and electron populations at Mercury
Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94682/1/grl28663.pd
Autonomous vehicle interactions in the urban street environment: A research agenda
© ICE Publishing 2018. All rights reserved. The Venturer project is trialling an autonomous vehicle (AV) in the context of use on urban roads. This paper summarises a literature review undertaken to assist in developing a research agenda for the trialling. The first contribution of the paper is a framework of four use scenarios for AVs as follows: (1) fully segregated AV network, (2) motorway or expressway network, (3) typical urban network, (4) shared space. The paper then focuses on a review of the social interactions in the street environment and discusses issues concerning human behaviour in relation to autonomy. The second contribution of the paper is a set of research questions for AV trialling in relation to other road users, including, pedestrians and cyclists, which have emerged from the literature review.
Solar parameters for modeling interplanetary background
The goal of the Fully Online Datacenter of Ultraviolet Emissions (FONDUE)
Working Team of the International Space Science Institute in Bern, Switzerland,
was to establish a common calibration of various UV and EUV heliospheric
observations, both spectroscopic and photometric. Realization of this goal
required an up-to-date model of spatial distribution of neutral interstellar
hydrogen in the heliosphere, and to that end, a credible model of the radiation
pressure and ionization processes was needed. This chapter describes the solar
factors shaping the distribution of neutral interstellar H in the heliosphere.
Presented are the solar Lyman-alpha flux and the solar Lyman-alpha resonant
radiation pressure force acting on neutral H atoms in the heliosphere, solar
EUV radiation and the photoionization of heliospheric hydrogen, and their
evolution in time and the still hypothetical variation with heliolatitude.
Further, solar wind and its evolution with solar activity is presented in the
context of the charge exchange ionization of heliospheric hydrogen, and in the
context of dynamic pressure variations. Also the electron ionization and its
variation with time, heliolatitude, and solar distance is presented. After a
review of all of those topics, we present an interim model of solar wind and
the other solar factors based on up-to-date in situ and remote sensing
observations of solar wind. Results of this effort will further be utilised to
improve on the model of solar wind evolution, which will be an invaluable asset
in all heliospheric measurements, including, among others, the observations of
Energetic Neutral Atoms by the Interstellar Boundary Explorer (IBEX).Comment: Chapter 2 in the planned "Cross-Calibration of Past and Present Far
UV Spectra of Solar System Objects and the Heliosphere", ISSI Scientific
Report No 12, ed. R.M. Bonnet, E. Quemerais, M. Snow, Springe
Communication and marketing as tools to cultivate the public's health: a proposed "people and places" framework
<p>Abstract</p> <p>Background</p> <p>Communication and marketing are rapidly becoming recognized as core functions, or core competencies, in the field of public health. Although these disciplines have fostered considerable academic inquiry, a coherent sense of precisely how these disciplines can inform the practice of public health has been slower to emerge.</p> <p>Discussion</p> <p>In this article we propose a framework – based on contemporary ecological models of health – to explain how communication and marketing can be used to advance public health objectives. The framework identifies the attributes of people (as individuals, as social networks, and as communities or populations) and places that influence health behaviors and health. Communication, i.e., the provision of information, can be used in a variety of ways to foster beneficial change among both people (e.g., activating social support for smoking cessation among peers) and places (e.g., convincing city officials to ban smoking in public venues). Similarly, marketing, i.e., the development, distribution and promotion of products and services, can be used to foster beneficial change among both people (e.g., by making nicotine replacement therapy more accessible and affordable) and places (e.g., by providing city officials with model anti-tobacco legislation that can be adapted for use in their jurisdiction).</p> <p>Summary</p> <p>Public health agencies that use their communication and marketing resources effectively to support people in making healthful decisions and to foster health-promoting environments have considerable opportunity to advance the public's health, even within the constraints of their current resource base.</p
Adolescent media use and its association to wellbeing in a Canadian national sample
Our objective is to describe associations between media usage and multiple wellbeing indicators in a nationally representative sample of Canadian youth (CSTADS 2012–13) enrolled in grades 7 to 12 (N = 41,057). Youth reported media usage (television/movie viewing, videogame playing, and surfing the internet), wellbeing (academic achievement, school connectedness, self-esteem, physical activity, intake of fruits and vegetables, and bullying), and psychological (drug use, drinking, and smoking) and sociodemographic confounds (ethnicity, grade, province, gender). Videogame playing was negatively associated with academic achievement, b = −0.07 (99% CI, −0.08–05), physical activity, b = −3.09, (99% CI, −3.63–2.56), school connectedness, b = −0.03 (99% CI, −0.04–0.02), self-esteem, b = −0.13 (99% CI, −0.16–0.09), and the consumption of fruits and vegetables b = −0.07 (99% CI, −0.11–0.03). Internet usage was negatively related to self-esteem, b = −0.25 (99% CI, −0.28–0.21), school connectedness, b = −0.03 (99% CI, −0.03–0.02), academic achievement, b = −0.02 (99% CI, −0.03–0.002) and physical activity b = −1.42 (99% CI, −1.92–0.91). Finally, television exposure was linked with less fruits and vegetable consumption, b = −0.09 (99% CI, −0.12–0.06), academic achievement b = −0.05 (99% CI, −0.07–0.04), school connectedness b = −0.02 (99% CI, −0.03–0.01), self-esteem b = −0.06 (99% CI, −0.11–0.003), and physical activity b = −1.09 (99% CI, −1.64–0.54). Internet, television/movies, and videogame time also increased the odds of bullying others by 9%, OR = 1.09 (99% CI, 1.04–1.14) 8%, OR = 1.08 (99% CI, 1.01–1.16) and 7%, OR = 1.07 (99% CI, 1.01–1.14) respectively. Overall effect sizes were small yet may represent significant impairment for heavy media users. Keywords: Media usage, Academic achievement, School connectedness, Physical activity, Self-esteem, Bullying, Fruits and vegetables, Wellbeing, Yout
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