35,490 research outputs found
Normative agent reasoning in dynamic societies
Several innovative software applications such as those
required by ambient intelligence, the semantic grid, e-commerce and e-marketing, can be viewed as open societies
of heterogeneous and self-interested agents in which social order is achieved through norms. For agents to participate
in these kinds of societies, it is enough that they are able to represent and fulfill norms, and to recognise the authority of certain agents. However, to voluntarily be part of a society or to voluntarily leave it, other
characteristics of agents are needed. To find these characteristics we observe that on the one hand, autonomous
agents have their own goals and, sometimes, they act on behalf of others whose goals must be satisfied. On the other, we observe that by being members, agents must comply
with some norms that can be in clear conflict with their goals. Consequently, agents must evaluate the positive
or negative effects of norms on their goals before making a decision concerning their social behaviour. Providing
a model of autonomous agents that undertake this kind of norm reasoning is the aim of this paper
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Modeling of the general circulation with the LMD-AOPP-IAA GCM: Update on model design and comparison with observations
The LMD-AOPP GCM is developed conjointly by LMD in Paris and AOPP in Oxford, with the collaboration of
IAA in Granada for the physical processes specific to the upper atmosphere. The collaboration between the
two teams is based on the use of two different dynamical core (gridpoint at LMD, spectral at AOPP), which
allow us to estimate the likely uncertainty arising from certain types of modeling errors. Similarly, we use
different schemes to compute tracer transport, etc. The work has benefited from support from ESA (since 1995)
and CNES (since 2000). Within that context, the GCMs are used to produce a Martian climate 'database' which
is used by more than 30 teams around the world for mission design and scientific studies (see Bingham et al.,
this issue and Lewis et al., 1999). The baseline version of the GCM is described in detail in Forget et al. (1999). Here we describe the recent improvement and design changes since this publication. Compared to this previous version, the new GCM covers a wider range of altitude, from 0 to 120km in the vertical, it uses improved topography and thermal inertia surface
maps from Mars Global Surveyor (MGS), and includes a new 'dust scenario' to describe the distribution of airborne dust in the atmosphere
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The Mars Climate Database
The Mars Climate Database (MCD) [1] is a database of statistics describing the climate and environment of the Martian atmosphere. It was constructed directly on the basis of output from mulitannual integrations of two general circulation models (GCMs)developed by Laboratoire de Météorologie Dynamique du CNRS, France, the University of Oxford, UK, and Instituto de Astrofisica de Andalucia, Spain, with support from the European Space Agency (ESA) and Centre National d–Etudes Spatiales (CNES). A description of the MCD is given along with a comparison between spacecraft observations of Mars and results predicted at similar locations and times in the MCD.
The MCD can be used as a tool for mission planning and has been applied to prepare for several missions in Europe and the USA. It also provides information for mission design specialists on the mean state and variability of the Martian environment from the surface to above 120km. The GCMs on which the database is founded, include a set of physical parameterizations (radiative transfer in the visible and thermal infrared ranges, turbulent mixing, condensation-sublimation of CO2, thermal conduction in
the soil and representation of gravity waves) and two
different codes for the representation of large scale
dynamics: a spectral code for the AOPP version and
a grid-point code for the LMD version. The GCMs correctly reproduce the main meteorological features of Mars, as observed by the Mariner 9 and Viking orbiters, the Viking landers, and Mars Global Surveyor (MGS). As well as the standard statistical measures for mission design studies, the MCD includes a novel representation of large-scale variability, using empirical eigenfunctions derived from an
analysis of the full simulations, and small-scale variability based on parameterizations of processes such
as gravity wave propagation. The database allows the user to choose from 5 dust storm scenarios including a best guess, default scenario, deduced from recent MGS observations, an upper boundary for an atmosphere without dust storms, as observed by Viking the landers, and a clear, cold, lower boundary scenario, as observed by Phobos 2 and from Earth. The full version of the MCD is available on CDROM (for UNIX systems and PCs) and is also
accessible through an interactive WWW interface at
http://www-mars.lmd.jussieu.fr/
Perceptions of Fishermen Households on the Long-Term Impact of Coastal Resources Management in Panguil Bay
Coastal resources management (CRM) has flourished as a management approach for attaining a more sustainable form of economic development in the coastal areas of the Philippines. Its proliferation, coupled with the reasonably long time it has been in implementation, now calls for an evaluation of its long-term impact as a management and development approach. In this study, the long-term impact of CRM is evaluated not from the perspectives of technical people but based on the perception of its intended primary beneficiaries--the fishermen households. It does so not by looking into a specific CRM program or project but by observing the succession of CRM activities conducted in a single coastal area--Panguil Bay, Mindanao--over many years. The objectives were to ascertain if CRM works, identify its major constraints if it does not, and recommend future courses of actions to address the constraints.coastal resources management, long-term impact indicators, ladder diagram, Panguil Bay
Perceptions of Fishermen Households on the Long-Term Impact of Coastal Resources Management in Panguil Bay
Coastal resources management (CRM) has flourished as a management approach for attaining a more sustainable form of economic development in the coastal areas of the Philippines. Its proliferation, coupled with the reasonably long time it has been in implementation, now calls for an evaluation of its long-term impact as a management and development approach. In this study, the long-term impact of CRM is evaluated not from the perspectives of technical people but based on the perception of its intended primary beneficiaries--the fishermen households. It does so not by looking into a specific CRM program or project but by observing the succession of CRM activities conducted in a single coastal area--Panguil Bay, Mindanao--over many years. The objectives were to ascertain if CRM works, identify its major constraints if it does not, and recommend future courses of actions to address the constraints.coastal resources management, long-term impact indicators, ladder diagram, Panguil Bay
Distribution of red clump stars does not support the X-shaped Galactic bulge
CONTEXT. Claims of an X-shaped Galactic bulge were based on the assumption of
red clump stars as standard candles in some lines of sight crossing the
off-plane bulge. However, some doubts have been cast on whether the two peaks
in star counts along the line of sight really represent a double peak in the
density distribution, or whether there is something wrong with the assumption
of a unique constant absolute magnitude for all of these stars.
AIMS. With the advent of Gaia-DR2 parallaxes in combination with
near-infrared VISTA-VVV data, we are able to check which of the hypotheses is
correct.
METHODS. We calculated the median absolute magnitude corresponding to
both peaks of putative red clumps in seven lines of sight with the lowest
extinction in the interesting coordinates' range.
RESULTS. The difference between the absolute magnitude of the bright and the
faint peak is . The selected stars in both peaks cannot
be represented by the same red clump giants with constant .
CONCLUSIONS. The hypothesis that the bulge contains an X-shape is based on
the assumption that the faint and bright peaks of the density distribution
towards the bulge are dominated by standard red clump stars. However, we show
that both the faint and bright peaks cannot be dominated by standard red clump
stars simultaneously.Comment: 5 pages, accepted to be published in A&
Cancer treatment associated cardiac toxicities
Cardiovascular disease remains the leading cause of mortality and morbidity in men and women both in the US and worldwide. With increased access to healthcare, it is predicted that life expectancies in developed countries will continue to rise and thus, lead to an increase in both cardiovascular disease and cancer. Similarly, improved survival rates in cancer patients have led to an increased awareness of the presence and potential worsening of cardiovascular disease in these patients. Cardiovascular complications due to side effects from cancer therapy or from cancer progression can be a common occurrence. Although recent advances in cancer therapeutics have led to improved survival rates and quality of life, the increase in life expectancy may be counteracted by the increased morbidity and mortality from progressive cardiac pathology. Examples of such complications include local invasion or distant metastatic spread, which can lead to superior vena cava syndrome, cardiac tamponade, or hyperviscosity syndromes. In addition, many chemo and radiation therapies can be directly toxic to the cardiovascular system. This review aims to discuss the potential cardiac toxicities of the most commonly used chemotherapeutics along with some strategies to manage these complex patients
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