1,523 research outputs found
The Dark UNiverse Explorer (DUNE): Proposal to ESA's Cosmic Vision
The Dark UNiverse Explorer (DUNE) is a wide-field space imager whose primary
goal is the study of dark energy and dark matter with unprecedented precision.
For this purpose, DUNE is optimised for the measurement of weak gravitational
lensing but will also provide complementary measurements of baryonic accoustic
oscillations, cluster counts and the Integrated Sachs Wolfe effect. Immediate
auxiliary goals concern the evolution of galaxies, to be studied with
unequalled statistical power, the detailed structure of the Milky Way and
nearby galaxies, and the demographics of Earth-mass planets. DUNE is an
Medium-class mission which makes use of readily available components, heritage
from other missions, and synergy with ground based facilities to minimise cost
and risks. The payload consists of a 1.2m telescope with a combined visible/NIR
field-of-view of 1 deg^2. DUNE will carry out an all-sky survey, ranging from
550 to 1600nm, in one visible and three NIR bands which will form a unique
legacy for astronomy. DUNE will yield major advances in a broad range of fields
in astrophysics including fundamental cosmology, galaxy evolution, and
extrasolar planet search. DUNE was recently selected by ESA as one of the
mission concepts to be studied in its Cosmic Vision programme.Comment: Accepted in Experimental Astronom
Increasing the Reliability of Adaptive Quadrature Using Explicit Interpolants
We present two new adaptive quadrature routines. Both routines differ from
previously published algorithms in many aspects, most significantly in how they
represent the integrand, how they treat non-numerical values of the integrand,
how they deal with improper divergent integrals and how they estimate the
integration error. The main focus of these improvements is to increase the
reliability of the algorithms without significantly impacting their efficiency.
Both algorithms are implemented in Matlab and tested using both the "families"
suggested by Lyness and Kaganove and the battery test used by Gander and
Gautschi and Kahaner. They are shown to be more reliable, albeit in some cases
less efficient, than other commonly-used adaptive integrators.Comment: 32 pages, submitted to ACM Transactions on Mathematical Softwar
First microlensing candidate towards M31 from the Nainital Microlensing Survey
We report our first microlensing candidate NMS-E1 towards M31 from the data
accumulated during the four years of Nainital Microlensing Survey. Cousin R and
I band observations of ~13'x13' field in the direction of M31 have been carried
out since 1998 and data is analysed using the pixel technique proposed by the
AGAPE collaboration. NMS-E1 lies in the disk of M31 at \alpha = 0:43:33.3 and
\delta = +41:06:44, about 15.5 arcmin to the South-East direction of the center
of M31. The degenerate Paczy\'{n}ski fit gives a half intensity duration of ~59
days. The photometric analysis of the candidate shows that it reached R~20.1
mag at the time of maximum brightness and the colour of the source star was
estimated to be (R-I)_0 ~ 1.1 mag. The microlensing candidate is blended by red
variable stars; consequently the light curves do not strictly follow the
characteristic Paczy\'{n}ski shape and achromatic nature. However its long
period monitoring and similar behaviour in R and I bands supports its
microlensing nature.Comment: no changes except typos corrected, to appear in A&
Interleukin-2 and histamine in combination inhibit tumour growth and angiogenesis in malignant glioma
Biotherapy including interleukin-2 (IL-2) treatment seems to be more effective outside the central nervous system when compared to the effects obtained when the same tumour is located intracerebrally. Recently published studies suggest that reduced activity of NK cells in tumour tissue can be increased by histamine. The present study was designed to determine whether IL-2 and histamine, alone or in combination, can induce anti-tumour effects in an orthotopic rat glioma model. One group of rats was treated with histamine alone (4 mg kg–1s.c. as daily injections from day 6 after intracranial tumour implantation), another group with IL-2 alone as a continuous subcutaneous infusion and a third group with both histamine and IL-2. The animals were sacrificed at day 24 after tumour implantation. IL-2 and histamine in combination significantly reduced tumour growth. The microvessel density was significantly reduced, an effect mainly affecting the small vessels. No obvious alteration in the pattern of VEGF mRNA expression was evident and no significant changes in apoptosis were observed. Neither IL-2 nor histamine alone caused any detectable effects on tumour growth. Histamine caused an early and pronounced decline in tumour blood flow compared to normal brain. The results indicate that the novel combination of IL-2 and histamine can be of value in reducing intracerebral tumour growth and, thus, it might be of interest to re-evaluate the therapeutic potential of biotherapy in malignant glioma. © 2000 Cancer Research Campaig
Tau Be or not Tau Be? - A Perspective on Service Compatibility and Substitutability
One of the main open research issues in Service Oriented Computing is to
propose automated techniques to analyse service interfaces. A first problem,
called compatibility, aims at determining whether a set of services (two in
this paper) can be composed together and interact with each other as expected.
Another related problem is to check the substitutability of one service with
another. These problems are especially difficult when behavioural descriptions
(i.e., message calls and their ordering) are taken into account in service
interfaces. Interfaces should capture as faithfully as possible the service
behaviour to make their automated analysis possible while not exhibiting
implementation details. In this position paper, we choose Labelled Transition
Systems to specify the behavioural part of service interfaces. In particular,
we show that internal behaviours (tau transitions) are necessary in these
transition systems in order to detect subtle errors that may occur when
composing a set of services together. We also show that tau transitions should
be handled differently in the compatibility and substitutability problem: the
former problem requires to check if the compatibility is preserved every time a
tau transition is traversed in one interface, whereas the latter requires a
precise analysis of tau branchings in order to make the substitution preserve
the properties (e.g., a compatibility notion) which were ensured before
replacement.Comment: In Proceedings WCSI 2010, arXiv:1010.233
The Anomaly in the Candidate Microlensing Event PA-99-N2
The lightcurve of PA-99-N2, one of the recently announced microlensing
candidates towards M31, shows small deviations from the standard Paczynski
form. We explore a number of possible explanations, including correlations with
the seeing, the parallax effect and a binary lens. We find that the
observations are consistent with an unresolved RGB or AGB star in M31 being
microlensed by a binary lens. We find that the best fit binary lens mass ratio
is about one hundredth, which is one of most extreme values found for a binary
lens so far. If both the source and lens lie in the M31 disk, then the standard
M31 model predicts the probable mass range of the system to be 0.02-3.6 solar
masses (95 % confidence limit). In this scenario, the mass of the secondary
component is therefore likely to be below the hydrogen-burning limit. On the
other hand, if a compact halo object in M31 is lensing a disk or spheroid
source, then the total lens mass is likely to lie between 0.09-32 solar masses,
which is consistent with the primary being a stellar remnant and the secondary
a low mass star or brown dwarf. The optical depth (or alternatively the
differential rate) along the line of sight toward the event indicates that a
halo lens is more likely than a stellar lens provided that dark compact objects
comprise no less than 15 per cent (or 5 per cent) of haloes.Comment: Latex, 23 pages, 9 figures, in press at The Astrophysical Journa
Proinsulin C-peptide elicits disaggregation of insulin resulting in enhanced physiological insulin effects
Using surface plasmon resonance (SPR) and electrospray mass spectrometry (ESI-MS), proinsulin C-peptide was found to influence insulin-insulin interactions. In SPR with chip-bound insulin, C-peptide mixed with analyte insulin increased the binding, while alone C-peptide did not. A control peptide with the same residues in random sequence had little effect. In ESI-MS, C-peptide lowered the presence of insulin hexamer. The data suggest that C-peptide promotes insulin disaggregation. Insulin/insulin oligomer μM dissociation constants were determined. Compatible with these findings, type 1 diabetic patients receiving insulin and C-peptide developed 66% more stimulation of glucose metabolism than when given insulin alone. A role of C-peptide in promoting insulin disaggregation may be important physiologically during exocytosis of pancreatic β-cell secretory granulae and pharmacologically at insulin injection sites. It is compatible with the normal co-release of C-peptide and insulin and may contribute to the beneficial effect of C-peptide and insulin replacement in type 1 diabetics
Nuclear Data for Sustainable Nuclear Energy
Final report of a coordinated action on nuclear data for industrial development in Europe (CANDIDE).
The successful development of advanced nuclear systems for sustainable energy production depends on high-level modelling capabilities for the reliable and cost-effective design and safety assessment of such systems, and for the interpretation of key benchmark experiments needed for performance and safety evaluations. High-quality nuclear data, in particular complete and accurate information about the nuclear reactions taking place in advanced reactors and the fuel cycle, are an essential component of such modelling capabilities.
In the CANDIDE project, nuclear data needs for sustainable nuclear energy production and waste management have been analyzed and categorized, on the basis of preliminary design studies of innovative systems. Meeting those needs will require that the quality of nuclear data files be considerably improved. The CANDIDE project has produced a set of recommendations, or roadmap, for sustainable nuclear data development. In conclusion, a substantial long-term investment in an integrated European nuclear data development program is called for, complemented by some dedicated actions targeting specific issues.JRC.D.5-Neutron physic
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