414 research outputs found
Palm oil, power and participation: the political ecology of social impact assessment
The Roundtable on Sustainable Palm Oil (RSPO), as a form of neoliberal environmental governance operating beyond-the-state, seeks to address its democratic deficit and gain legitimacy through deliberative and consultative processes. The RSPO requires companies to conduct participatory Social Impact Assessment (SIA) for both new developments and existing operations in an attempt to identify and address the critical social impacts associated with palm oil production. Using a political ecology framework, and a mixed methods approach, this study explores SIAs as sites of power struggles, to understand the contestations, inequities, and marginalisations that occur in SIA processes. By exploring the nature of SIA as a market-led regime that privileges certain knowledges and politics, and is co-opted and controlled by powerful actors, the paper challenges the notion that SIA can ensure the inclusion of previously marginalised people in decision-making processes. Participation in SIA is found to be, at most, consultative and top-down, and risks the further disempowerment of affected peoples. By viewing SIA as a discrete intervention, without a clear wider political project for social change for local peoples and workers, the RSPO risks “rendering technical” and “marketable” the multifaceted social impacts associated with palm oil production as it simultaneously enacts particular global, neoliberal “participatory” strategies that are applied locally in ways that (re-)produce hegemony and legitimacy
Tachoastrometry: astrometry with radial velocities
Spectra of composite systems (e.g., spectroscopic binaries) contain spatial
information that can be retrieved by measuring the radial velocities (i.e.,
Doppler shifts) of the components in four observations with the slit rotated by
90 degrees in the sky. By using basic concepts of slit spectroscopy we show
that the geometry of composite systems can be reliably retrieved by measuring
only radial velocity differences taken with different slit angles. The spatial
resolution is determined by the precision with which differential radial
velocities can be measured. We use the UVES spectrograph at the VLT to observe
the known spectroscopic binary star HD 188088 (HIP 97944), which has a maximum
expected separation of 23 milli-arcseconds. We measure an astrometric signal in
radial velocity of 276 \ms, which corresponds to a separation between the two
components at the time of the observations of 18 milli-arcseconds. The
stars were aligned east-west. We describe a simple optical device to
simultaneously record pairs of spectra rotated by 180 degrees, thus reducing
systematic effects. We compute and provide the function expressing the shift of
the centroid of a seeing-limited image in the presence of a narrow slit.The
proposed technique is simple to use and our test shows that it is amenable for
deriving astrometry with milli-arcsecond accuracy or better, beyond the
diffraction limit of the telescope. The technique can be further improved by
using simple devices to simultaneously record the spectra with 180 degrees
angles.With tachoastrometry, radial velocities and astrometric positions can be
measured simultaneously for many double line system binaries in an easy way.
The method is not limited to binary stars, but can be applied to any
astrophysical configuration in which spectral lines are generated by separate
(non-rotational symmetric) regions.Comment: Accepted for publication in A&
Selling out for sustainability? Neoliberal governance, agency and professional careers in the sustainable palm oil sector
In response to high-profile activist campaigns raising public awareness of the destructive effects of large-scale oil palm plantations on tropical rainforests, wildlife and local communities, the palm oil sector has put considerable effort and resources into ensuring "sustainable", "deforestation-free" palm oil production (and thereby countering negative publicity) over the last 15 years or so. The corporate sustainability drive – with the palm oil sector significantly leading other tropical commodities – has involved the direct employment of many professionals with backgrounds in conservation, anthropology or activism by the private palm oil sector. Based on long term participant observation as well as interviews with "sustainability professionals" about their career choices, this article shows that there is more nuance, agency and positive change than the existing political ecology literature attributes to the sustainable palm oil drive. It also shows how neoliberal governance structures and individual professional careers and values intersect and mutually reinforce each other. This dual, seemingly paradoxical analysis is informed by and situated in the wider context that the sustainability professionals we interviewed and we ourselves, as academics, share: growing academic precarity, the climate and ecological emergency, and the challenges and questions posed by both
UV camera conceptual designs for TMT Fiber WFOS
This paper discusses refractive, reflective and catadioptric designs for the Thirty Meter Telescope Fiber Wide Field Optical Spectrograph (WFOS) instrument concept. Custom macros were written to evaluate performance at the detector plane with the grating at the pupil as a function of fiber position in the pseudo-slit and wavelength, and a tolerance analysis has been performed for each design based on best engineering practices to assess performance robustness against opto-mechanical errors. The catadioptric camera appears to provide the best compromise in this regard
The ESO Spectroscopic facility
We present the concept of a novel facility dedicated to massively-multiplexed
spectroscopy. The telescope has a very wide field Cassegrain focus optimised
for fibre feeding. With a Field of View (FoV) of 2.5 degrees diameter and a
11.4m pupil, it will be the largest etendue telescope. The large focal plane
can easily host up to 16.000 fibres. In addition, a gravity invariant focus for
the central 10 arc-minutes is available to host a giant integral field unit
(IFU). The 3 lenses corrector includes an ADC, and has good performance in the
360-1300 nm wavelength range. The top level science requirements were developed
by a dedicated ESO working group, and one of the primary cases is high
resolution spectroscopy of GAIA stars and, in general, how our Galaxy formed
and evolves. The facility will therefore be equipped with both, high and low
resolution spectrographs. We stress the importance of developing the telescope
and instrument designs simultaneously. The most relevant R\&D aspect is also
briefly discussed.Comment: 6 pages 4 figures , presented at IAU Symposium 334 "rediscovering our
galaxy
Hydrologie et météorologie de méso-échelle dans HAPEX-Sahel : dispositif de mesures au sol et premiers résultats
Les objectifs généraux du groupe d'étude "Ecologie et Végétation" consistent d'une part à fournir une typologie des différentes formes de végétation et des phytomasses correspondantes sur l'ensemble du degré carré et aux divers niveaux de perception requis par l'expérimentation générale HAPEX-Sahel, d'autre part à fournir le maximum d'information "sol" pour validation des données de la télédétection spatiale. Les diverses démarches méthodologiques, correspondant aux différents aspects abordés, sont exposées et leur pertinence par rapport au plan général d'expérimentation discutée. Sont présentés les résultats préliminaires concernant deux thèmes majeurs : (1) la cartographie à deux échelles (1/50 000 et 1/200 000) respectivement du "Super-Site-Central-West" et du "Degré Carré", donnant la répartition des unités paysagères échantillonnées par HAPEX-Sahel (champs, jachères et brousse tigrée) et (2) une typologie structurale des jachères du Sahel nigérien. (Résumé d'auteur
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The use of the high conservation value (HCV) and high carbon stock (HCS) approaches by palm oil companies assessed on SPOTT
The High Conservation Value (HCV) and High Carbon Stock (HCS) approaches are used to identify and protect important environmental and social values that should be conserved. This briefing note provides an overview of the commitments to the HCV and HCS approaches made by companies, drawing on SPOTT assessment data from October 2015 to November 2017
Détermination des fonctions de HNF4[alpha] dans les cellules épithéliales intestinales
La protéine HNF4[alpha] est un récepteur nucléaire orphelin exprimé dans le foie et tout au long de l'axe gastro-intestinal. De nombreuses études effectuées dans le foie ou des cultures cellulaires ont mis en évidence l'implication de HNF4[alpha] dans des mécanismes de différenciation cellulaire ainsi que dans le contrôle du métabolisme lipidique. Toutefois, le rôle de cette protéine dans les processus de différenciation et dans le contrôle du métabolisme des cellules épithéliales intestinales est encore mal connu. Nous avons donc décidé d'étudier les rôles de la protéine HNF4[alpha] dans l'intestin et de déterminer de nouvelles cibles transcriptionnelles. Méthodes. Des cellules épithéliales intestinales non différenciées IEC-6 ont été infectées avec un vecteur pBabepuro vide ou exprimant l'isoforme HNF4[alpha]1. La morphologie des cellules a été observée par microscopie optique et électronique. L'impact de l'expression de HNF4[alpha]1 dans les cellules IEC-6 a été étudié à l'aide de micropuces à ADN de type Affymetrix. L'expression et l'activité de différents gènes sélectionnés sur les micropuces à ADN ont été testées par RT-PCR, immunobuvardage, essais luciférase et gels par retard de migration. Finalement l'activité métabolique a été testée en mesurant la synthèse et la sécrétion des apolipoprotéines et des lipoprotéines après marquage avec de l'acide oléique marqué au carbone 14 et de la méthionine marquée au soufre 35. Résultats. (1) les cellules qui expriment HNF4[alpha]1 présentent des microvillosités, habituellement observées sur des cellules épithéliales intestinales différenciées, ainsi que des modifications de la forme des cellules. Parallèlement, on peut noter une meilleure organisation des jonctions intercellulaires. (2) On peut observer une augmentation de l'expression de la villine qui est habituellement observée au niveau de la bordure en brosse. (3) On observe une importante modification d'expression des protéines RAR[bêta] et PPAR[bêta] qui sont notamment impliquées dans le contrôle de mécanismes de différenciation. (4) L'analyse des micropuces à ADN met en évidence l'augmentation d'un nombre important de gènes impliqués dans le métabolisme lipidique. Parallèlement, il y a augmentation de la synthèse d'apolipoprotéines et de HDL. (5) Les micropuces à ADN ont permis d'identifier que la protéine prkaa2, une sous-unité catalytique de l'AMPK, est une cible de HNF4[alpha]1. (6) La protéine Cdx2 peut induire l'expression de HNF4[alpha] via son promoteur. Conclusions. HNF4[alpha]1 est impliquée dans les mécanismes de différenciation et de métabolisme intestinaux. Elle permet l'établissement d'un réseau transcriptionnel qui conduit à une modification des interactions intercellulaires, de la morphologie cellulaire ainsi qu'à l'apparition de microvillosités. De plus, HNF4[alpha]1 induit une augmentation de l'expression de nombreux gènes impliqués dans le métabolisme lipidique ainsi qu'à une augmentation de la synthèse lipidique. Parallèlement, nous avons pu montrer que HNF4[alpha]1 contrôlait l'expression de la sous-unité prkaa2 de l'AMPK et que HNF4[alpha]1 et Cdx2 étaient impliquées dans des voies de régulation communes, notamment dans la différenciation intestinale
Instability patterns in ultrathin nematic films: comparison between theory and experiment
Motivated by recent experimental observations [U. Delabre et al, Langmuir 24,
3998, 2008] we reconsider an instability of ultrathin nematic films, spread on
liquid substrates. Within a continuum elastic theory of liquid crystals, in the
harmonic approximation, we find an analytical expressions for the critical
thickness as well as for the critical wavenumber, characterizing the onset of
instability towards the stripe phase. Comparing theoretical predictions with
experimental observations, we establish the utility of surface-like term such
as an azimuthal anchoring.Comment: 6 pages, 3 figures, LaTeX macros EPL draft, accepted for publication
in EP
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