409 research outputs found
Soil contamination following an industrial accident : towards efficient investigations and assessment
International audienceWhen an industrial accident occurs, e.g. the explosion or the fire of a chemical facility, soil investigations and subsequent risk mitigation generally need to be decided and performed rapidly. This requires specific organisation and tools: Procedures for an immediate and coordinated intervention of relevant actors: industrials, administrations for industrial facilities, emergency and health, local authorities, environmental consultants and laboratories, NGOs. Models and input data on emission, atmospheric transfer and deposition on soil, for an accidental source; investigation plans and adequate soil quality references, guidelines... But the European Seveso legislation, and its application in France and probably in Europe, is focused on the prevention of immediate impacts on health and constructions; and the Integrated Pollution Prevention and Control (IPPC) legislation deals with the chronic impacts of operating facilities. Thus, post-accidental impacts of industrial accidents are hardly dealt with, the specific organisation and tools are lacking, and when accidents occur, the industrials and administrations concerned are largely unprepared for managing their delayed impacts, first of them on soils
Characterisation of candidate members of (136108) Haumea's family: II. Follow-up observations
From a dynamical analysis of the orbital elements of transneptunian objects
(TNOs), Ragozzine & Brown reported a list of candidate members of the first
collisional family found among this population, associated with (136108) Haumea
(a.k.a. 2003 EL61). We aim to distinguish the true members of the Haumea
collisional family from interlopers. We search for water ice on their surfaces,
which is a common characteristic of the known family members. The properties of
the confirmed family are used to constrain the formation mechanism of Haumea,
its satellites, and its family. Optical and near-infrared photometry is used to
identify water ice. We use in particular the CH4 filter of the Hawk-I
instrument at the European Southern Observatory Very Large Telescope as a short
H-band (Hs), the (J-Hs) colour being a sensitive measure of the water ice
absorption band at 1.6 {\mu}m. Continuing our previous study headed by
Snodgrass, we report colours for 8 candidate family members, including
near-infrared colours for 5. We confirm one object as a genuine member of the
collisional family (2003 UZ117), and reject 5 others. The lack of infrared data
for the two remaining objects prevent any conclusion from being drawn. The
total number of rejected members is therefore 17. The 11 confirmed members
represent only a third of the 36 candidates. The origin of Haumea's family is
likely to be related to an impact event. However, a scenario explaining all the
peculiarities of Haumea itself and its family remains elusive.Comment: 8 pages, 4 figures, accepted for publication in A&
Characterisation of candidate members of (136108) Haumea's family
Ragozzine & Brown [2007] presented a list of candidate members of the first
collisional family to be found among the trans-Neptunian Objects (TNOs), the
one associated with (136108) Haumea (2003 EL61). We aim to identify which of
the candidate members of the Haumea collisional family are true members, by
searching for water ice on their surfaces. We also attempt to test the theory
that the family members are made of almost pure water ice by using optical
light-curves to constrain their densities. We use optical and near-infrared
photometry to identify water ice, in particular using the (J - H_S) colour as a
sensitive measure of the absorption feature at 1.6 micron. We use the CH_4
filter of the new Hawk-I instrument at the VLT as a short H-band (H_S) for this
as it is more sensitive to the water ice feature than the usual H filter. We
report colours for 22 candidate family members, including NIR colours for 15.
We confirm that 2003 SQ317 and 2005 CB79 are family members, bringing the total
number of confirmed family members to 10. We reject 8 candidates as having no
water ice absorption based on our Hawk-I measurements, and 5 more based on
their optical colours. The combination of the large proportion of rejected
candidates and time lost to weather prevent us from putting strong constraints
on the density of the family members based on the light-curves obtained so far;
we can still say that none of the family members (except Haumea) require a
large density to explain their light-curve.Comment: 9 pages, 5 figures, accepted for publication in A&
Land Use Sector Involvement in Mitigation Policies Across Carbon Markets
Different local and international experiences show that the agroforestry sector can be fully included in the global warming mitigation strategies and in the
market mechanisms that may have environmental and socioeconomic benefits. At present, however, the primary sector plays only a minor role in mitigation policies within the UNFCCC and under Kyoto’s Protocol, due to problems and difficulties related to emission/absorption accounting models andmonitoring and standardisation systems. If, on one hand, the progress in science has enabled to overcome accountingrelated problems, on the other, there are no adequate mechanisms to encourage and remunerate the primary sector’s efforts. More specifically, if the primary sector is considered as a source of emissions, it should also be recognised that it has beneficial impacts, notably in economic terms, as carbon sink. Therefore, the definition of clear and internationally shared rules might increase the carbon friendly initiatives and help reduce greenhouse gas emissions. This article is focused on the international experiences that have concerned the primary sector and is intended to supply researchers and policymakers with suggestions and recommendations for implementing local market practices related to carbon credits
Glycogen synthase kinase-3 mediates acetaminophen-induced apoptosis in human hepatoma cells
ABSTRACT The mild analgesic drug acetaminophen (AAP) induces severe hepatic injury when taken at excessive doses. Recent evidence shows that the initial form of damage is through apoptosis, but this fails to go to completion and degenerates into necrosis. The aim of this study was to elucidate the mechanism through which AAP induces apoptosis using human HuH7 hepatoma cells as an in vitro model system to investigate the initial phase of AAP-induced hepatic injury. AAP-induced apoptosis in HuH7 cells as evidenced by chromatin condensation was preceded by the translocation of Bax to mitochondria and the cytoplasmic release of the proapoptotic factors cytochrome c and Smac/DIABLO. A concomitant loss of mitochondrial membrane potential occurred. Activation of the mitochondrial pathway of apoptosis led to the activation of execution caspases-3 and -7. AAP-induced apoptosis and cell death was blocked by inhibitors of caspases but not by inhibitors of calpains, cathepsins, and serine proteases. Apoptosis was unaffected by inhibitors of the mitochondrial permeability transition pore and by inhibitors of Jun NH 2 -terminal kinases, p38 mitogen-activated protein kinase, or mitogen-activated protein kinase kinase 1/2. However, pharmacological inhibition of glycogen synthase kinase-3 (GSK-3) delayed and decreased the extent of AAP-induced apoptosis. In comparison, endoplasmic reticulum stress-induced but not prooxidant-induced apoptosis of HuH7 cells was sensitive to GSK-3 inhibition. It is concluded that AAP-induced apoptosis involves the mitochondrial pathway of apoptosis that is mediated by GSK-3 and most likely initiated through an endoplasmic reticulum stress response. The mild analgesic acetaminophen (paracetamol, AAP) remains the commonest cause of acute liver failure in the United States and other parts of the world as a result of accidental or deliberate overdose Many of the histochemical and biochemical features of the late stages of AAP toxicity, particularly after high doses, support the conclusion that AAP induces hepatocellular necrosi
The TRAPPIST survey of southern transiting planets. I. Thirty eclipses of the ultra-short period planet WASP-43 b
We present twenty-three transit light curves and seven occultation light
curves for the ultra-short period planet WASP-43 b, in addition to eight new
measurements of the radial velocity of the star. Thanks to this extensive data
set, we improve significantly the parameters of the system. Notably, the
largely improved precision on the stellar density (2.41+-0.08 rho_sun) combined
with constraining the age to be younger than a Hubble time allows us to break
the degeneracy of the stellar solution mentioned in the discovery paper. The
resulting stellar mass and size are 0.717+-0.025 M_sun and 0.667+-0.011 R_sun.
Our deduced physical parameters for the planet are 2.034+-0.052 M_jup and
1.036+-0.019 R_jup. Taking into account its level of irradiation, the high
density of the planet favors an old age and a massive core. Our deduced orbital
eccentricity, 0.0035(-0.0025,+0.0060), is consistent with a fully circularized
orbit. We detect the emission of the planet at 2.09 microns at better than
11-sigma, the deduced occultation depth being 1560+-140 ppm. Our detection of
the occultation at 1.19 microns is marginal (790+-320 ppm) and more
observations are needed to confirm it. We place a 3-sigma upper limit of 850
ppm on the depth of the occultation at ~0.9 microns. Together, these results
strongly favor a poor redistribution of the heat to the night-side of the
planet, and marginally favor a model with no day-side temperature inversion.Comment: 14 pages, 6 tables, 11 figures. Accepted for publication in A&
Glycogen synthase kinase-3 mediates acetaminophen-induced apoptosis in human hepatoma cells
Abstract: 232 Introduction: 61
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