289 research outputs found
Landing the blame : the influence of EU Member States on quota setting
Fisheries in European Union (EU) waters have been managed under the Common Fisheries Policy since 1983. The main regulatory tool in EU fisheries management is the use of Total Allowable Catches (TACs). In principle, TACs are set according to biological scientific advice provided by the International Council for the Exploration of the Sea (ICES) which recommends catch limits with the objective of maximising catches in a sustainable manner. The objective of this paper is to compare TACs set by the EU and its Member States between 2001 and 2015 with those recommended by ICES in their annual scientific advice in order to (a) investigate the level of compliance with scientific advice by the European Council and, (b) consider whether particular Member States have received more TACs above advice than others. For the time-series analysed, the European Council set TACs above scientific advice by an average of 20% per year, with around 7 out of every 10 TACs exceeding advice. Of all Member States, Denmark and the United Kingdom received the highest TACs in volume above scientific advice. Relative to the size of their TAC however, Spain and Portugal exceeded advice by the greatest percentage. Greater transparency is required to determine what takes place during the closed door negotiations and to improve the fishery sustainability credentials of the EU and its Member States
Multi-wavelength modeling of the spatially resolved debris disk of HD 107146
(abridged) We aim to constrain the location, composition, and dynamical state
of planetesimal populations and dust around the young, sun-like (G2V) star HD
107146}. We consider coronagraphic observations obtained with the Advanced
Camera for Surveys (HST/ACS) onboard the HST in broad V and broad I filters, a
resolved 1.3mm map obtained with the Combined Array for Research in
Millimeter-Wave Astronomy (CARMA), Spitzer/IRS low resolution spectra, and the
spectral energy distribution (SED) of the object at wavelengths ranging from
3.5micron to 3.1mm. We complement these data with new coronagraphic high
resolution observations of the debris disk using the Near Infrared Camera and
Multi-Object Spectrometer (HST/NICMOS) aboard the HST in the F110W filter. The
SED and images of the disk in scattered light as well as in thermal reemission
are combined in our modeling using a parameterized model for the disk density
distribution and optical properties of the dust. A detailed analytical model of
the debris disk around HD 107146 is presented that allows us to reproduce the
almost entire set of spatially resolved and unresolved multi-wavelength
observations. Considering the variety of complementary observational data, we
are able to break the degeneracies produced by modeling SED data alone. We find
the disk to be an extended ring with a peak surface density at 131AU.
Furthermore, we find evidence for an additional, inner disk probably composed
of small grains released at the inner edge of the outer disk and moving inwards
due to Poynting-Robertson drag. A birth ring scenario (i.e., a more or less
broad ring of planetesimals creating the dust disk trough collisions) is found
to be the most likely explanation of the ringlike shape of the disk.Comment: 15 pages, 9 figures, accepted for publication in A&
Common knowledge that help is needed increases helping behavior in children
Although there is considerable evidence that at least some helping behavior is motivated by genuine concern for others’ well-being, sometimes we also help solely out of a sense of obligation to the persons in need. Our sense of obligation to help may be particularly strong when there is common knowledge between the helper and the helpee that the helpee needs help. To test whether children’s helping behavior is affected by having common knowledge with the recipient about the recipient’s need, 6-year-olds faced a dilemma: They could either collect stickers or help an experimenter. Children were more likely to help when they and the experimenter had common knowledge about the experimenter’s plight (because they heard it together) than when they each had private knowledge about it (because they heard it individually). These results suggest that already in young children common knowledge can heighten the sense of obligation to help others in need.PostprintPeer reviewe
Shear behavior of DFDP-1 borehole samples from the Alpine Fault, New Zealand, under a wide range of experimental conditions
The Alpine Fault is a major plate-boundary fault zone that poses a major seismic hazard in southern New Zealand. The initial stage of the Deep Fault Drilling Project has provided sample material from the major lithological constituents of the Alpine Fault from two pilot boreholes. We use laboratory shearing experiments to show that the friction coefficient µ of fault-related rocks and their precursors varies between 0.38 and 0.80 depending on the lithology, presence of pore fluid, effective normal stress, and temperature. Under conditions appropriate for several kilometers depth on the Alpine Fault (100 MPa, 160 °C, fluid-saturated), a gouge sample located very near to the principal slip zone exhibits µ = 0.67, which is high compared with other major fault zones targeted by scientific drilling, and suggests the capacity for large shear stresses at depth. A consistent observation is that every major lithological unit tested exhibits positive and negative values of friction velocity dependence. Critical nucleation patch lengths estimated using representative values of the friction velocity-dependent parameter a−b and the critical slip distance D c , combined with previously documented elastic properties of the wall rock, may be as low as ~3 m. This small value, consistent with a seismic moment M o = ~4 × 1010 for an M w = ~1 earthquake, suggests that events of this size or larger are expected to occur as ordinary earthquakes and that slow or transient slip events are unlikely in the approximate depth range of 3–7 km
Time of Harvest and Wine Quality of Esprit Wine Grapes
Currently there is little to no information regarding when to harvest many of the coldhardy hybrid grape cultivars. There are contrasting opinions of the quality of the wine made from some of these cultivars, which may in part be due to a difference in timing of harvest. Many of the cold hardy cultivars contain Vitis labrusca in their parentage that can lead to differing levels of ‘foxy’ flavors depending on when the fruit is harvested. Wineries may prefer different levels of the typical V. labrusca flavors in their wines. Many of the cold-hardy cultivars also tend to have high titratable acidity (TA) and harvest is delayed to lower the TA. It is unknown what impact a later harvest has on other parameters of fruit quality. The objective of this study was to evaluate the quality attributes of the wine made from the grape cultivar Esprit harvested earlier and later than the traditional harvest date
The dust, planetesimals and planets of HD 38529
HD 38529 is a post-main sequence G8III/IV star (3.5 Gyr old) with a planetary
system consisting of at least two planets having Msin(i) of 0.8 MJup and 12.2
MJup, semimajor axes of 0.13 AU and 3.74 AU, and eccentricities of 0.25 and
0.35, respectively. Spitzer observations show that HD 38529 has an excess
emission above the stellar photosphere, with a signal-to-noise ratio (S/N) at
70 micron of 4.7, a small excess at 33 micron (S/N=2.6) and no excess <30
micron. We discuss the distribution of the potential dust-producing
planetesimals from the study of the dynamical perturbations of the two known
planets, considering in particular the effect of secular resonances. We
identify three dynamically stable niches at 0.4-0.8 AU, 20-50 AU and beyond 60
AU. We model the spectral energy distribution of HD 38529 to find out which of
these niches show signs of harboring dust-producing plantesimals. The secular
analysis, together with the SED modeling resuls, suggest that the planetesimals
responsible for most of the dust emission are likely located within 20-50 AU, a
configuration that resembles that of the Jovian planets + Kuiper Belt in our
Solar System. Finally, we place upper limits (8E-6 lunar masses of 10 micron
particles) to the amount of dust that could be located in the dynamically
stable region that exists between the two planets (0.25--0.75 AU).Comment: 23 pages, including 1 table and 5 figures. Accepted for publication
in Ap
Are Debris Disks and Massive Planets Correlated?
Using data from the Spitzer Space Telescope Legacy Science Program
``Formation and Evolution of Planetary Systems'' (FEPS), we have searched for
debris disks around 9 FGK stars (2-10 Gyr), known from radial velocity (RV)
studies to have one or more massive planets. Only one of the sources, HD 38529,
has excess emission above the stellar photosphere; at 70 micron the
signal-to-noise ratio in the excess is 4.7 while at wavelengths < 30 micron
there is no evidence of excess. The remaining sources show no excesses at any
Spitzer wavelengths. Applying survival tests to the FEPS sample and the results
for the FGK survey published in Bryden et al. (2006), we do not find a
significant correlation between the frequency and properties of debris disks
and the presence of close-in planets. We discuss possible reasons for the lack
of a correlation.Comment: 24 pages, 3 figures. Accepted to Astrophysical Journa
Inner edges of planetesimal belts: collisionally eroded or truncated?
The radial structure of debris discs can encode important information about
their dynamical and collisional history. In this paper we present a 3-phase
analytical model to analyse the collisional evolution of solids in debris
discs, focusing on their joint radial and temporal dependence. Consistent with
previous models, we find that as the largest planetesimals reach collisional
equilibrium in the inner regions, the surface density of dust and solids
becomes proportional to within a certain critical radius. We
present simple equations to estimate the critical radius and surface density of
dust as a function of the maximum planetesimal size and initial surface density
in solids (and vice versa). We apply this model to ALMA observations of 7 wide
debris discs. We use both parametric and non-parametric modelling to test if
their inner edges are shallow and consistent with collisional evolution. We
find that 4 out of 7 have inner edges consistent with collisional evolution.
Three of these would require small maximum planetesimal sizes below 10 km, with
HR 8799's disc potentially lacking solids larger than a few centimeters. The
remaining systems have inner edges that are much sharper, which requires
maximum planetesimal sizes km. Their sharp inner edges suggest they
could have been truncated by planets, which JWST could detect. In the context
of our model, we find that the 7 discs require surface densities below a
Minimum Mass Solar Nebula, avoiding the so-called disc mass problem. Finally,
during the modelling of HD 107146 we discover that its wide gap is split into
two narrower ones, which could be due to two low-mass planets formed within the
disc.Comment: Accepted for publication in MNRAS, 21 pages, 11 figure
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