1,774 research outputs found
Nieuwe landgoederen; hoe passen ze in het landschap? : een beslisboom ter ondersteuning van het afwegingsproces
Nieuwe landgoederen kunnen een impuls betekenen voor het landschap en de leefbaarheid. Veel gemeenten zijn echter huiverig met het verlenen van een aanlegvergunning omdat ze niet goed weten hoe nieuwe landgoederen in het landschap ingepast moeten worden. In dit artikel wordt een beslisboom gepresenteerd die gemeenten en vergunningaanvragers hierbij kan helpen
On the central structure of M15
We present a detailed comparison between the latest observational data on the
kinematical structure of the core of M15, obtained with the Hubble STIS and
WFPC2 instruments, and the results of dynamical simulations carried out using
the special-purpose GRAPE-6 computer. The observations imply the presence of a
significant amount of dark matter in the cluster core. In our dynamical
simulations, neutron stars and/or massive white dwarfs concentrate to the
center through mass segregation, resulting in a sharp increase in toward
the center. While consistent with the presence of a central black hole, the
Hubble data can also be explained by this central concentration of stellar-mass
compact objects. The latter interpretation is more conservative, since such
remnants result naturally from stellar evolution, although runaway merging
leading to the formation of a black hole may also occur for some range of
initial conditions. We conclude that no central massive object is required to
explain the observational data, although we cannot conclusively exclude such an
object at the level of solar masses. Our findings are unchanged
when we reduce the assumed neutron-star retention fraction in our simulations
from 100% to 0%.Comment: 12 pages, 4 figures. Accepted for publication in ApJ
The Nobel Prize as a Reward Mechanism in the Genomics Era: Anonymous Researchers, Visible Managers and the Ethics of Excellence
The Human Genome Project (HGP) is regarded by many as one of the major scientific achievements in recent science history, a large-scale endeavour that is changing the way in which biomedical research is done and expected, moreover, to yield considerable benefit for society. Thus, since the completion of the human genome sequencing effort, a debate has emerged over the question whether this effort merits to be awarded a Nobel Prize and if so, who should be the one(s) to receive it, as (according to current procedures) no more than three individuals can be selected. In this article, the HGP is taken as a case study to consider the ethical question to what extent it is still possible, in an era of big science, of large-scale consortia and global team work, to acknowledge and reward individual contributions to important breakthroughs in biomedical fields. Is it still viable to single out individuals for their decisive contributions in order to reward them in a fair and convincing way? Whereas the concept of the Nobel prize as such seems to reflect an archetypical view of scientists as solitary researchers who, at a certain point in their careers, make their one decisive discovery, this vision has proven to be problematic from the very outset. Already during the first decade of the Nobel era, Ivan Pavlov was denied the Prize several times before finally receiving it, on the basis of the argument that he had been active as a research manager (a designer and supervisor of research projects) rather than as a researcher himself. The question then is whether, in the case of the HGP, a research effort that involved the contributions of hundreds or even thousands of researchers worldwide, it is still possible to âindividualiseâ the Prize? The âHGP Nobel Prize problemâ is regarded as an exemplary issue in current research ethics, highlighting a number of quandaries and trends involved in contemporary life science research practices more broadly
Simultaneous Spectrophotometric Calibration of Wavelength and Absorbance in an Interlaboratory Survey Using Holmium Oxide (HO2O3) in Perchloric Acid as Reference, Compared with p-Nitrophenol and Cobaltous Sulphate Solutions (1978-1984)
Peer Reviewe
Modest-2: A Summary
This is a summary paper of MODEST-2, a workshop held at the Astronomical
Institute ``Anton Pannekoek'' in Amsterdam, 16-17 December 2002. MODEST is a
loose collaboration of people interested in MOdelling DEnse STellar systems,
particularly those interested in modelling these systems using all the
available physics (stellar dynamics, stellar evolution, hydrodynamics and the
interplay between the three) by defining interfaces between different codes. In
this paper, we summarize 1) the main advances in this endeavour since MODEST-1;
2) the main science goals which can be and should be addressed by these types
of simulations; and 3) the most pressing theoretical and modelling advances
that we identified.Comment: Accepted by New Astronom
Evolution of Neutron-Star, Carbon-Oxygen White-Dwarf Binaries
At least one, but more likely two or more, eccentric neutron-star,
carbon-oxygen white-dwarf binaries with an unrecycled pulsar have been
observed. According to the standard scenario for evolving neutron stars which
are recycled in common envelope evolution we expect to observe \gsim 50 such
circular neutron star-carbon oxygen white dwarf binaries, since their formation
rate is roughly equal to that of the eccentric binaries and the time over which
they can be observed is two orders of magnitude longer, as we shall outline. We
observe at most one or two such circular binaries and from that we conclude
that the standard scenario must be revised. Introducing hypercritical accretion
into common envelope evolution removes the discrepancy by converting the
neutron star into a black hole which does not emit radio waves, and therefore
would not be observed.Comment: 25 pages, 1 figure, accepted in Ap
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