228 research outputs found
Can existing assessment tools be used to track equity in protected area management under Aichi Target 11?
Aichi Target 11 (AT11) includes the commitment of 194 governments to equitably manage protected areas (PAs) by 2020. Here we evaluate whether existing PA Management Effectiveness (PAME) and social and governance assessment tools can be used to determine if AT11 meets equity goals. We find that PAME assessment conditions are insufficiently inclusive of relevant actors and do not satisfactorily allow for a diversity of perspectives to be expressed and accounted for, both of which are essential for equitable PA management. Furthermore, none of the analysed PAME tools fully cover multidimensional equity and thus they are inadequate for assessing progress towards equitable management in PAs. The available social and governance PA assessment tools stipulate more inclusive and participatory conditions within their guidelines, and the IUCN Governance Guidelines comprehensively capture equity dimensions in PA management, but results are not comparable across sites. We conclude that available assessment tools do not provide a reliable way to track equity in PAs at global scale. The IUCN Governance Guidelines could be adjusted to achieve this goal, providing that the information collected is made globally comparable, while ensuring transparency, accountability and room for contestation, including by communities whose livelihoods are directly implicated. Ultimately, developing and deploying globally comparable measures to evaluate equity is problematic, as the process of gathering comparable data inevitably obscures information that is highly relevant to resolving equity issues at local scales. This challenge must be met, however, if nations are to achieve and report on their success at meeting AT11 by 2020. © 2018 Elsevier LtdWe thank Jens Friis Lund from the University of Copenhagen for his great support in the writing of this publication. We also thank the following for their assistance in the data collection and analysis: April Eassom, Lauren Coad, Kathryn Knights, Jonas Geldmann, Murielle Misrachi and Naomi Kingston from UNEP-WCMC, PA Solutions, University of Oxford and University of Copenhagen, Phil Franks, Kate Schreckenberg and Dilys Roe from IIED, Marc Hockings, Fiona Leverington from IUCN WCPA/University of Queensland. N.Z-C. and N.B. acknowledge the funding provided by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 659881 to N.Z-C. and the Danish National Research Foundation for funding for the Centre for Macroecology, Evolution and Climate; grant number DNRF96 . We thank Jens Friis Lund from the University of Copenhagen for his great support in the writing of this publication. We also thank the following for their assistance in the data collection and analysis: April Eassom, Lauren Coad, Kathryn Knights, Jonas Geldmann, Murielle Misrachi and Naomi Kingston from UNEP-WCMC, PA Solutions, University of Oxford and University of Copenhagen, Phil Franks, Kate Schreckenberg and Dilys Roe from IIED, Marc Hockings, Fiona Leverington from IUCN WCPA/University of Queensland. N.Z-C. and N.B. acknowledge the funding provided by the European Union's Horizon 2020 research and innovation programme under the Marie Sklodowska-Curie grant agreement No 659881 to N.Z-C. and the Danish National Research Foundation for funding for the Centre for Macroecology, Evolution and Climate; grant number DNRF96
Calibration of quasi-static aberrations in exoplanet direct-imaging instruments with a Zernike phase-mask sensor. II. Concept validation with ZELDA on VLT/SPHERE
Warm or massive gas giant planets, brown dwarfs, and debris disks around
nearby stars are now routinely observed by dedicated high-contrast imaging
instruments on large, ground-based observatories. These facilities include
extreme adaptive optics (ExAO) and state-of-the-art coronagraphy to achieve
unprecedented sensitivities for exoplanet detection and spectral
characterization. However, differential aberrations between the ExAO sensing
path and the science path represent a critical limitation for the detection of
giant planets with a contrast lower than a few at very small
separations (<0.3\as) from their host star. In our previous work, we proposed a
wavefront sensor based on Zernike phase contrast methods to circumvent this
issue and measure these quasi-static aberrations at a nanometric level. We
present the design, manufacturing and testing of ZELDA, a prototype that was
installed on VLT/SPHERE during its reintegration in Chile. Using the internal
light source of the instrument, we performed measurements in the presence of
Zernike or Fourier modes introduced with the deformable mirror. Our
experimental and simulation results are consistent, confirming the ability of
our sensor to measure small aberrations (<50 nm rms) with nanometric accuracy.
We then corrected the long-lived non-common path aberrations in SPHERE based on
ZELDA measurements. We estimated a contrast gain of 10 in the coronagraphic
image at 0.2\as, reaching the raw contrast limit set by the coronagraph in the
instrument. The simplicity of the design and its phase reconstruction algorithm
makes ZELDA an excellent candidate for the on-line measurements of quasi-static
aberrations during the observations. The implementation of a ZELDA-based
sensing path on the current and future facilities (ELTs, future space missions)
could ease the observation of the cold gaseous or massive rocky planets around
nearby stars.Comment: 13 pages, 12 figures, A&A accepted on June 3rd, 2016. v2 after
language editin
Research Activities for the DORIS Contribution to the Next International Terrestrial Reference Frame
For the preparation of ITRF2008, the IDS processed data from 1993 to 2008, including data from TOPEX/Poseidon, the SPOT satellites and Envisat in the weekly solutions. Since the development of ITRF2008, the IDS has been engaged in a number of efforts to try and improve the reference frame solutions. These efforts include (i) assessing the contribution of the new DORIS satellites, Jason-2 and Cryosat2 (2008-2011), (ii) individually analyzing the DORIS satellite contributions to geocenter and scale, and (iii) improving orbit dynamics (atmospheric loading effects, satellite surface force modeling. . . ). We report on the preliminary results from these research activities, review the status of the IDS combination which is now routinely generated from the contributions of the IDS analysis centers, and discuss the prospects for continued improvement in the DORIS contribution to the next international reference frame
Semi-kinematic mount of the FIREBALL large optics
In the context of the NASA CNES FIREBALL balloon borne experiment, we present the design of a semi-kinematic mount to hold the 1 meter class mirrors of this mission. To maintain these large optics in a reasonable mass and price budgets we choose thin ULE mirrors with a thickness over diameter ratio of 1/16. Such thin mirrors require a multi support mount to reduce self weight deflection. Classical multi support mount used for ground based telescope would not survive the level of shock observed in a balloon experiment either at parachute opening or landing. To firmly maintain these mirrors in several points without noticeably deforming them we investigated the design of a two stages semi-kinematic mount composed of 24 monopods. We present the detailed design of this innovative mirror mount, the finite element modeling with the deduced optical wavefront deformation. During the FIREBALL integration and flight campaign in July 2007 at CSBF, we confirmed the validity of the mechanical concept by obtaining an image quality well within the required specifications. Variants of this approach are potentially applicable to large thin mirrors on ground-based observatories
Higher-precision radial velocity measurements with the SOPHIE spectrograph using octagonal-section fibers
High-precision spectrographs play a key role in exoplanet searches using the
radial velocity technique. But at the accuracy level of 1 m.s-1, required for
super-Earth characterization, stability of fiber-fed spectrograph performance
is crucial considering variable observing conditions such as seeing, guiding
and centering errors and, telescope vignetting. In fiber-fed spectrographs such
as HARPS or SOPHIE, the fiber link scrambling properties are one of the main
issues. Both the stability of the fiber near-field uniformity at the
spectrograph entrance and of the far-field illumination on the echelle grating
(pupil) are critical for high-precision radial velocity measurements due to the
spectrograph geometrical field and aperture aberrations. We conducted tests on
the SOPHIE spectrograph at the 1.93-m OHP telescope to measure the instrument
sensitivity to the fiber link light feeding conditions: star decentering,
telescope vignetting by the dome,and defocussing.
To significantly improve on current precision, we designed a fiber link
modification considering the spectrograph operational constraints. We have
developed a new link which includes a piece of octagonal-section fiber, having
good scrambling properties, lying inside the former circular-section fiber, and
we tested the concept on a bench to characterize near-field and far-field
scrambling properties.
This modification has been implemented in spring 2011 on the SOPHIE
spectrograph fibers and tested for the first time directly on the sky to
demonstrate the gain compared to the previous fiber link. Scientific validation
for exoplanet search and characterization has been conducted by observing
standard stars.Comment: 12 pages, 9 figures, Proceedings of SPIE 201
Membrane Potential Dynamics of CA1 Pyramidal Neurons during Hippocampal Ripples in Awake Mice
Ripples are high-frequency oscillations associated with population bursts in area CA1 of the hippocampus that play a prominent role in theories of memory consolidation. While spiking during ripples has been extensively studied, our understanding of the subthreshold behavior of hippocampal neurons during these events remains incomplete. Here, we combine in vivo whole-cell and multisite extracellular recordings to characterize the membrane potential dynamics of identified CA1 pyramidal neurons during ripples. We find that the subthreshold depolarization during ripples is uncorrelated with the net excitatory input to CA1, while the post-ripple hyperpolarization varies proportionately. This clarifies the circuit mechanism keeping most neurons silent during ripples. On a finer timescale, the phase delay between intracellular and extracellular ripple oscillations varies systematically with membrane potential. Such smoothly varying delays are inconsistent with models of intracellular ripple generation involving perisomatic inhibition alone. Instead, they suggest that ripple-frequency excitation leading inhibition shapes intracellular ripple oscillations
The International DORIS Service (IDS) - Recent Developments in Preparation for ITRF2013
The International DORIS Service (IDS) was created in 2003 under the umbrella of the International Association of Geodesy (IAG) to foster scientific research related to the French DORIS tracking system and to deliver scientific products, mostly related to the International Earth rotation and Reference systems Service (IERS). We first present some general background related to the DORIS system (current and planned satellites, current tracking network and expected evolution) and to the general IDS organization (from Data Centers, Analysis Centers and Combination Center). Then, we discuss some of the steps recently taken to prepare the IDS submission to ITRF2013 (combined weekly time series based on individual solutions from several Analysis Centers). In particular, recent results obtained from the Analysis Centers and the Combination Center show that improvements can still be made when updating physical models of some DORIS satellites, such as Envisat, Cryosat-2 or Jason-2. The DORIS contribution to ITRF2013 should also benefit from the larger number of ground observations collected by the last generation of DGXX receivers (first instrument being onboard Jason-2 satellite). In particular for polar motion, sub-millarcsecond accuracy seems now to be achievable. Weekly station positioning internal consistency also seems to be improved with a larger DORIS constellation
G14A-06- Analysis of the DORIS, GNSS, SLR, VLBI and Gravimetric Time Series at the GGOS Core Sites
Analysis of the time series at the 3-4 multi-technique GGOS sites to analyze and compare the spectral content of the space geodetic and gravity time series. Evaluate the level of agreement between the space geodesy measurements and the physical tie vectors
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