2,388 research outputs found
Phase-lock loop frequency control and the dropout problem
Technique automatically sets the frequency of narrow band phase-lock loops within automatic lock-in-range. It presets a phase-lock loop to a desired center frequency with a closed loop electronic frequency discriminator and holds the phase-lock loop to that center frequency until lock is achieved
Menu engineering to encourage sustainable food choices when dining out: An online trial of priced-based decoys
Menu-based ‘nudges’ hold promise as effective ways to encourage a shift away from ruminant meat and towards more environmentally friendly plant-based options when dining out. One example of a menu-based nudge is including an inferior ‘decoy’ option to existing items on menus. Decoys have been shown to influence decision-making in other domains (e.g. Lichters, Bengart, Sarstedt, & Vogt, 2017), but have yet to be used to promote sustainable food choices. Two online randomized controlled trials tested whether the addition of higher priced ‘decoy’ vegetarian options to menus influenced the number of diners choosing a ‘target’ vegetarian option. Adjusted Generalized Estimating Equations on data from four menu conditions showed no main effect of intervention group in study 1 (decoy absent vs. decoy present; odds ratio (OR) 1.08 (95% Confidence Interval (CI) 0.45 to 2.57). Replicating the trial in study 2 across seven menu conditions and testing a more expensive decoy also showed no main effect of the intervention (decoy absent vs. decoy present; OR 0.68 (95% CI 0.41 to 1.12). Further analyses revealed that our price-based decoy strategy (a £30% price increase) did not significantly influence the numbers who chose the inferior decoy dish, potentially due to the fact that dish choices were purely hypothetical. Further research is now needed to clarify which attributes of a dish (e.g. taste, portion size, signature ingredients etc.) are optimal candidates for use as decoys and testing these in real world choice contexts
Arresting woodland bird decline in Australian agricultural landscapes: potential application of the European agri-environment model
This paper considered the applicability of the European model of land stewardship payments, in particular its support for biodiversity conservation in agricultural landscapes, to an Australian context. More broadly, the research approach described in the paper may also be applied to assessing the suitability of overseas stewardship schemes to the provision of any ecoservice in
Australia, such as carbon sequestration and floodwater regulation
Simulating star formation in molecular cloud cores IV. The role of turbulence and thermodynamics
We perform SPH simulations of the collapse and fragmentation of low-mass
cores having different initial levels of turbulence
(alpha_turb=0.05,0.10,0.25). We use a new treatment of the energy equation
which captures the transport of cooling radiation against opacity due to both
dust and gas (including the effects of dust sublimation, molecules, and H^-
ions). We also perform comparison simulations using a standard barotropic
equation of state. We find that -- when compared with the barotropic equation
of state -- our more realistic treatment of the energy equation results in more
protostellar objects being formed, and a higher proportion of brown dwarfs; the
multiplicity frequency is essentially unchanged, but the multiple systems tend
to have shorter periods (by a factor ~3), higher eccentricities, and higher
mass ratios. The reason for this is that small fragments are able to cool more
effectively with the new treatment, as compared with the barotropic equation of
state. We find that the process of fragmentation is often bimodal. The first
protostar to form is usually, at the end, the most massive, i.e. the primary.
However, frequently a disc-like structure subsequently forms round this
primary, and then, once it has accumulated sufficient mass, quickly fragments
to produce several secondaries. We believe that this delayed fragmentation of a
disc-like structure is likely to be an important source of very low-mass
hydrogen-burning stars and brown dwarfs.Comment: 14 pages, 8 figures. Accepted for publication by A&
Exploring equity in uptake of the NHS Health Check and a nested physical activity intervention trial.
BACKGROUND: Socio-demographic factors characterizing disadvantage may influence uptake of preventative health interventions such as the NHS Health Check and research trials informing their content. METHODS: A cross-sectional study examining socio-demographic characteristics of participants and non-participants to the NHS Health Check and a nested trial of very brief physical activity interventions within this context. Age, gender, Index of Multiple Deprivation (IMD) and ethnicity were extracted from patient records of four General Practices (GP) in England. RESULTS: In multivariate analyses controlling for GP surgery, the odds of participation in the Health Check were higher for older patients (OR 1.05, 95% CI 1.04-1.07) and lower from areas of greater deprivation (IMD Quintiles 4 versus 1, OR 0.37, 95% CI 0.18-0.76, 5 versus 1 OR 0.42, 95% CI 0.20-0.88). Older patients were more likely to participate in the physical activity trial (OR 1.04, 95% CI 1.02-1.06). CONCLUSIONS: Younger patients and those living in areas of greater deprivation may be at risk of non-participation in the NHS Health Check, while younger age also predicted non-participation in a nested research trial. The role that GP-surgery-specific factors play in influencing participation across different socio-demographic groups requires further exploration.The work was undertaken by the Centre for Diet and Activity
Research (CEDAR), a UKCRC Public Health Research Centre
of Excellence. Funding from the British Heart Foundation,
Cancer Research UK, Economic and Social Research Council,
Medical Research Council, the National Institute for Health
Research, and the Wellcome Trust, under the auspices of the
UK Clinical Research Collaboration, is gratefully acknowledged.
This paper presents independent research funded by the
National Institute for Health Research (NIHR) under its
Programme Grants for Applied Research Programme (Grant
Reference Number RP-PG-0608-10079)This is the final published version. It first appeared at http://jpubhealth.oxfordjournals.org/content/early/2015/06/01/pubmed.fdv070.full
AROD geodetic feasibility analysis program Final report
Airborne Range and Orbit Determination as satellite geodetic survey instrumen
SCUBA observations of the Horsehead Nebula - what did the horse swallow?
We present observations taken with SCUBA on the JCMT of the Horsehead Nebula
in Orion (B33), at wavelengths of 450 and 850 \mum. We see bright emission from
that part of the cloud associated with the photon-dominated region (PDR) at the
`top' of the horse's head, which we label B33-SMM1. We characterise the
physical parameters of the extended dust responsible for this emission, and
find that B33-SMM1 contains a more dense core than was previously suspected. We
compare the SCUBA data with data from the Infrared Space Observatory (ISO) and
find that the emission at 6.75-\mum is offset towards the west, indicating that
the mid-infrared emission is tracing the PDR while the submillimetre emission
comes from the molecular cloud core behind the PDR. We calculate the virial
balance of this core and find that it is not gravitationally bound but is being
confined by the external pressure from the HII region IC434, and that it will
either be destroyed by the ionising radiation, or else may undergo triggered
star formation. Furthermore we find evidence for a lozenge-shaped clump in the
`throat' of the horse, which is not seen in emission at shorter wavelengths. We
label this source B33-SMM2 and find that it is brighter at submillimetre
wavelengths than B33-SMM1. SMM2 is seen in absorption in the 6.75-\mum ISO
data, from which we obtain an independent estimate of the column density in
excellent agreement with that calculated from the submillimetre emission. We
calculate the stability of this core against collapse and find that it is in
approximate gravitational virial equilibrium. This is consistent with it being
a pre-existing core in B33, possibly pre-stellar in nature, but that it may
also eventually undergo collapse under the effects of the HII region.Comment: 11 pages, 6 figures, accepted by MNRA
Managing crop tradeoffs: A methodology for comparing the water footprint and nutrient density of crops for food system sustainability
The relationship between human nutrition and the use of available resources to feed the planet's growing population demands greater attention from decision makers at all levels of governance. Indicators with dual environmental sustainability and food and nutrition security goals can encourage and measure progress towards a more sustainable food system. This article proposes a methodology that supports the development of an approach to assess the water footprint of nutrient-dense foods [m3/kg]. It provides a clear explanation of the methodology, and the use of water footprint benchmark data and corresponding United States Department of Agriculture (USDA) nutrient composition data to apply the process. The study analyzed data for 17 grains, roots and tubers, 9 pulses, 10 nuts and seeds, 17 vegetables, and 27 fruits. Of these, fruits and vegetables are 85% of the bottom quartile for water footprint (i.e., highly water efficient) and 100% of the top quartile for nutrient-density (i.e., very nutrient dense). Spinach is a clear winner, with a very high nutrient-density and low water footprint. The article proposes that this approach can help to establish broad typologies to guide decision makers in distinguishing between win-win, win-lose, and lose-lose scenarios of natural resource use and nutrition security. This resource, if considered along with contributing social, environmental, and economic factors (e.g., local tastes, available water resources, soil fertility, local economies) can promote a food system that offers a diverse range of nutrient-dense foods more sustainably
Exploring equity in primary-care-based physical activity interventions using PROGRESS-Plus: a systematic review and evidence synthesis.
BACKGROUND: Little is known about equity effects in primary care based physical activity interventions. This review explored whether differences in intervention effects are evident across indicators of social disadvantage, specified under the acronym PROGRESS-Plus (place of residence, race/ethnicity, occupation, gender, religion, education, social capital, socioeconomic status, plus age, disability and sexual orientation). METHODS: Six bibliographic databases were systematically searched for randomised controlled trials (RCTs) of physical activity interventions conducted in primary care. Harvest plots were used to synthesize findings from RCTs reporting subgroup or interaction analyses examining differences in intervention effects across levels of at least one PROGRESS-Plus factor. RESULTS: The search yielded 9052 articles, from which 173 eligible RCTs were identified. Despite PROGRESS-Plus factors being commonly measured (N = 171 RCTs), differential effect analyses were infrequently reported (N = 24 RCTs). Where reported, results of equity analyses suggest no differences in effect across levels or categories of place of residence (N = 1RCT), race (N = 4 RCTs), education (N = 3 RCTs), socioeconomic status (N = 3 RCTs), age (N = 16 RCTs) or disability (N = 2 RCTs). Mixed findings were observed for gender (N = 22 RCTs), with some interventions showing greater effect in men than women and others vice versa. Three RCTs examined indicators of social capital, with larger post-intervention differences in physical activity levels between trial arms found in those with higher baseline social support for exercise in one trial only. No RCTs examined differential effects by participant occupation, religion or sexual orientation. CONCLUSION: The majority of RCTs of physical activity interventions in primary care record sufficient information on PROGRESS-Plus factors to allow differential effects to be studied. However, very few actually report details of relevant analyses to determine which population subgroups may stand to benefit or be further disadvantaged by intervention efforts.The work was undertaken by the Centre for Diet and Activity Research (CEDAR), a UKCRC Public Health Research Centre of Excellence (RES-590-28-0002). Funding from the British Heart Foundation, Cancer Research UK, Economic and Social Research Council, Medical Research Council, the National Institute for Health Research, and the Wellcome Trust, under the auspices of the UK Clinical Research Collaboration, is gratefully acknowledged. The work was additionally supported by the Medical Research Council [Unit Programme number: MC_UU_12015/7]
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