2,155 research outputs found
The impact of support for imports on food security in Indonesia
This study on the impact of import support on food security was conducted in eight developing countries -including Indonesia- that were facing food insecurity and were recipients of subsidized exports and food aid. In Indonesia, the analysis of import flows in comparison with overall production and consumption data led to the selection of the three import substitute commodities, soybean, sugar and milk, that were the focus of this study. The objective of the study was to provide an analysis of the national impact of export support measures on food security, by taking into account their impact on the producers and consumers of the three commodities.IMPORTS, EXPORTS, FOOD, ECURITY, SOYBEANS, SUGAR, MILK, FOOD AID, Agricultural and Food Policy, Crop Production/Industries, Food Security and Poverty, International Relations/Trade, Production Economics,
Searching for thermal signatures of persistent currents in normal metal rings
We introduce a calorimetric approach to probe persistent currents in normal
metal rings. The heat capacity of a large ensemble of silver rings is measured
by nanocalorimetry under a varying magnetic field at different temperatures (60
mK, 100 mK and 150 mK). Periodic oscillations versus magnetic field are
detected in the phase signal of the temperature oscillations, though not in the
amplitude (both of them directly linked to the heat capacity). The period of
these oscillations (, with the magnetic flux quantum)
and their evolution with temperature are in agreement with theoretical
predictions. In contrast, the amplitude of the corresponding heat capacity
oscillations (several ) is two orders of magnitude larger than
predicted by theory
New obstructions to symplectic embeddings
In this paper we establish new restrictions on symplectic embeddings of
certain convex domains into symplectic vector spaces. These restrictions are
stronger than those implied by the Ekeland-Hofer capacities. By refining an
embedding technique due to Guth, we also show that they are sharp.Comment: 80 pages, 3 figures, v2: improved exposition and minor corrections,
v3: Final version, expanded and improved exposition and minor corrections.
The final publication is available at link.springer.co
On invariants of almost symplectic connections
We study the irreducible decomposition under Sp(2n, R) of the space of
torsion tensors of almost symplectic connections. Then a description of all
symplectic quadratic invariants of torsion-like tensors is given. When applied
to a manifold M with an almost symplectic structure, these instruments give
preliminary insight for finding a preferred linear almost symplectic connection
on M . We rediscover Ph. Tondeur's Theorem on almost symplectic connections.
Properties of torsion of the vectorial kind are deduced
Laboratory and field measurements of enantiomeric monoterpene emissions as a function of chemotype, light and temperature
Plants emit significant amounts of monoterpenes into the
earth's atmosphere, where they react rapidly to form a multitude of gas phase
species and particles. Many monoterpenes exist in mirror-image forms or
enantiomers. In this study the enantiomeric monoterpene profile for several
representative plants (<i>Quercus ilex L., Rosmarinus officinalis L.</i>,
and <i>Pinus halepensis Mill.</i>) was investigated as a function of
chemotype, light and temperature both in the laboratory and in the field.
Analysis of enantiomeric monoterpenes from 19 <i>Quercus ilex</i>
individuals from Southern France and Spain revealed four regiospecific
chemotypes (genetically fixed emission patterns). In agreement with previous
work, only <i>Quercus ilex</i> emissions increased strongly with light.
However, for all three plant species no consistent enantiomeric variation was
observed as a function of light, and the enantiomeric ratio of α-pinene was found to vary by less than 20% from 100 and
1000 μmol m<sup>−2</sup> s<sup>−1</sup> PAR (photosynthetically active
radiation). The rate of monoterpene emission increased with temperature from
all three plant species, but little variation in the enantiomeric
distribution of α-pinene was observed with temperature. There was
more enantiomeric variability between individuals of the same species than
could be induced by either light or temperature. Field measurements of
α-pinene enantiomer mixing ratios in the air, taken at a
<i>Quercus ilex</i> forest in Southern France, and several other previously
reported field enantiomeric ratio diel cycle profiles are compared. All show
smoothly varying diel cycles (some positive and some negative) even over
changing wind directions. This is surprising in comparison with variations of
enantiomeric emission patterns shown by individuals of the same species
Processing oblique aerial photographs in Flanders: the Havik Project at the Ghent University. A contribution to archaeological resource management
A contribution to archaeological resource management. Ghent University has organised an archaeological aerial survey of both provinces of East- and West-Flanders since the beginning of the 1980s. As a result of these activities, some 50,000 photographs have been captured. They reveal thousands of archaeological structures, from the Neolithic through to the most recent periods. Since 1997, financial support has been received from the Flemish Community aimed at the realisation of a GIS based database (Access 97 relational database - Arcview 3.1) and the digitalisation of some 50% of the photographs. As a result, it was possible to locate all 50,000 images and connect them with geographical information offered by the support centre GIS Flanders. It is expected in the near future that this information will be available for SMR-purposes and archaeological heritage management. There are also several scientific outputs: one of them is the study of Bronze Age barrows
Exact Algorithms for Maximum Independent Set
We show that the maximum independent set problem (MIS) on an -vertex graph
can be solved in time and polynomial space, which even is
faster than Robson's -time exponential-space algorithm
published in 1986. We also obtain improved algorithms for MIS in graphs with
maximum degree 6 and 7, which run in time of and
, respectively. Our algorithms are obtained by using fast
algorithms for MIS in low-degree graphs in a hierarchical way and making a
careful analyses on the structure of bounded-degree graphs
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