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Food System Transformation: Integrating a Political-Economy and Social-Ecological Approach to Regime Shifts.
Sustainably achieving the goal of global food security is one of the greatest challenges of the 21st century. The current food system is failing to meet the needs of people, and at the same time, is having far-reaching impacts on the environment and undermining human well-being in other important ways. It is increasingly apparent that a deep transformation in the way we produce and consume food is needed in order to ensure a more just and sustainable future. This paper uses the concept of regime shifts to understand key drivers and innovations underlying past disruptions in the food system and to explore how they may help us think about desirable future changes and how we might leverage them. We combine two perspectives on regime shifts-one derived from natural sciences and the other from social sciences-to propose an interpretation of food regimes that draws on innovation theory. We use this conceptualization to discuss three examples of innovations that we argue helped enable critical regime shifts in the global food system in the past: the Haber-Bosch process of nitrogen fixation, the rise of the supermarket, and the call for more transparency in the food system to reconnect consumers with their food. This paper concludes with an exploration of why this combination of conceptual understandings is important across the Global North/ Global South divide, and proposes a new sustainability regime where transformative change is spearheaded by a variety of social-ecological innovations
[The Impact of Nuclear Star Formation on Gas Inflow to AGN
Our adaptive optics observations of nearby AGN at spatial resolutions as
small as 0.085arcsec show strong evidence for recent, but no longer active,
nuclear star formation. We begin by describing observations that highlight two
contrasting methods by which gas can flow into the central tens of parsecs. Gas
accumulation in this region will inevitably lead to a starburst, and we discuss
the evidence for such events. We then turn to the impact of stellar evolution
on the further inflow of gas by combining a phenomenological approach with
analytical modelling and hydrodynamic simulations. These complementary
perspectives paint a picture in which all the processes are ultimately
regulated by the mass accretion rate into the central hundred parsecs, and the
ensuing starburst that occurs there. The resulting supernovae delay accretion
by generating a starburst wind, which leaves behind a clumpy interstellar
medium. This provides an ideal environment for slower stellar outflows to
accrete inwards and form a dense turbulent disk on scales of a few parsecs.
Such a scenario may resolve the discrepancy between the larger scale structure
seen with adaptive optics and the small scale structure seen with VLTI.Comment: to appear in: Co-Evolution of Central Black Holes and Galaxies; 7
page
WASP-14 b: Transit Timing analysis of 19 light curves
Although WASP-14 b is one of the most massive and densest exoplanets on a
tight and eccentric orbit, it has never been a target of photometric follow-up
monitoring or dedicated observing campaigns. We report on new photometric
transit observations of WASP-14 b obtained within the framework of "Transit
Timing Variations @ Young Exoplanet Transit Initiative" (TTV@YETI). We
collected 19 light-curves of 13 individual transit events using six telescopes
located in five observatories distributed in Europe and Asia. From light curve
modelling, we determined the planetary, stellar, and geometrical properties of
the system and found them in agreement with the values from the discovery
paper. A test of the robustness of the transit times revealed that in case of a
non-reproducible transit shape the uncertainties may be underestimated even
with a wavelet-based error estimation methods. For the timing analysis we
included two publicly available transit times from 2007 and 2009. The long
observation period of seven years (2007-2013) allowed us to refine the transit
ephemeris. We derived an orbital period 1.2 s longer and 10 times more precise
than the one given in the discovery paper. We found no significant periodic
signal in the timing-residuals and, hence, no evidence for TTV in the system.Comment: 12 pages, 10 figures, 7 table
Sphere rolling on the surface of a cone
We analyse the motion of a sphere that rolls without slipping on a conical
surface having its axis in the direction of the constant gravitational field of
the Earth. This nonholonomic system admits a solution in terms of quadratures.
We exhibit that the only circular of the system orbit is stable and furthermore
show that all its solutions can be found using an analogy with central force
problems. We also discuss the case of motion with no gravitational field, that
is, of motion on a freely falling cone.Comment: 12 pages, 2 figures, to be published in Eur J Phy
A Planetary Mass Companion to the K0 Giant HD 17092
We report the discovery of a substellar-mass companion to the K0-giant HD
17092 with the Hobby-Eberly Telescope. In the absence of any correlation of the
observed 360-day periodicity with the standard indicators of stellar activity,
the observed radial velocity variations are most plausibly explained in terms
of a Keplerian motion of a planetary-mass body around the star. With the
estimated stellar mass of 2.3Msun, the minimum mass of the planet is 4.6MJ. The
planet's orbit is characterized by a mild eccentricity of e=0.17 and a
semi-major axis of 1.3 AU. This is the tenth published detection of a planetary
companion around a red giant star. Such discoveries add to our understanding of
planet formation around intermediate-mass stars and they provide dynamical
information on the evolution of planetary systems around post-main sequence
stars.Comment: 13 pages, 3 figures, 2 tables. Submitted to Ap
Implementation and evaluation of the VA DPP clinical demonstration: protocol for a multi-site non-randomized hybrid effectiveness-implementation type III trial.
BackgroundThe Diabetes Prevention Program (DPP) study showed that lifestyle intervention resulted in a 58% reduction in incidence of type 2 diabetes among individuals with prediabetes. Additional large randomized controlled trials have confirmed these results, and long-term follow-up has shown sustained benefit 10-20 years after the interventions ended. Diabetes is a common and costly disease, especially among Veterans, and despite strong evidence supporting the feasibility of type 2 diabetes prevention, the DPP has not been widely implemented. The first aim of this study will evaluate implementation of the Veterans Affairs (VA) DPP in three VA medical centers. The second aim will assess weight and hemoglobin A1c (A1c) outcomes, and the third aim will determine the cost-effectiveness and budget impact of implementation of the VA DPP from a health system perspective.Methods/designThis partnered multi-site non-randomized systematic assignment study will use a highly pragmatic hybrid effectiveness-implementation type III mixed methods study design. The implementation and administration of the VA DPP will be funded by clinical operations while the evaluation of the VA DPP will be funded by research grants. Seven hundred twenty eligible Veterans will be systematically assigned to the VA DPP clinical demonstration or the usual care VA MOVE!® weight management program. A multi-phase formative evaluation of the VA DPP implementation will be conducted. A theoretical program change model will be used to guide the implementation process and assess applicability and feasibility of the DPP for VA. The Consolidated Framework for Implementation Research (CFIR) will be used to guide qualitative data collection, analysis, and interpretation of barriers and facilitators to implementation. The RE-AIM framework will be used to assess Reach, Effectiveness, Adoption, Implementation, and Maintenance of the VA DPP. Twelve-month weight and A1c change will be evaluated for the VA DPP compared to the VA MOVE!ProgramMediation analyses will be conducted to identify whether program design differences impact outcomes.DiscussionFindings from this pragmatic evaluation will be highly applicable to practitioners who are tasked with implementing the DPP in clinical settings. In addition, findings will determine the effectiveness and cost-effectiveness of the VA DPP in the Veteran population
Non integrability of a self-gravitating Riemann liquid ellipsoid
We prove that the motion of a triaxial Riemann ellipsoid of homogeneous
liquid without angular momentum does not possess an additional first integral
which is meromorphic in position, impulsions, and the elliptic functions which
appear in the potential, and thus is not integrable. We prove moreover that
this system is not integrable even on a fixed energy level hypersurface.Comment: 14 pages, 8 reference
New transit observations for HAT-P-30 b, HAT-P-37 b, TrES-5 b, WASP-28 b, WASP-36 b, and WASP-39 b
We present new transit light curves for planets in six extrasolar planetary
systems. They were acquired with 0.4-2.2 m telescopes located in west Asia,
Europe, and South America. When combined with literature data, they allowed us
to redetermine system parameters in a homogeneous way. Our results for
individual systems are in agreement with values reported in previous studies.
We refined transit ephemerides and reduced uncertainties of orbital periods by
a factor between 2 and 7. No sign of any variations in transit times was
detected for the planets studied.Comment: Submitted to Acta Astronomic
Towards the Rosetta Stone of planet formation
Transiting exoplanets (TEPs) observed just about 10 Myrs after formation of
their host systems may serve as the Rosetta Stone for planet formation
theories. They would give strong constraints on several aspects of planet
formation, e.g. time-scales (planet formation would then be possible within 10
Myrs), the radius of the planet could indicate whether planets form by
gravitational collapse (being larger when young) or accretion growth (being
smaller when young). We present a survey, the main goal of which is to find and
then characterise TEPs in very young open clusters.Comment: Poster contribution to Detection and Dynamics of Transiting
Exoplanets (Haute Provence Observatory Colloquium, 23-27 August 2010
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