4,135 research outputs found
Effects of light and soil flooding on the growth and photosynthesis of ramin (Gonystylus bancanus) seedlings in Malaysia
We studied the ecophysiology of ramin (Gonystylus bancanus) seedlings in an experimental set up at the Forest Research Centre in Kuching, Sarawak, Malaysia. Ramin seedlings were grown on flooded and drained peat soil under 100, 76, 46 and 23% sunlight, thus simulating effects of different light conditions (canopy gap size) and drainage that occur in natural ramin populations. Seedling growth was highest in partial sunlight (76%) and reduced with reducing light levels. Aboveground productivity and fine root development were significantly higher in seedlings grown on flooded soil compared with those on drained soil. In contrast, investment in coarse root biomass was significantly higher in seedlings grown on drained soil. It appeared that the aboveground growth benefits in flooded conditions were the result of more advantageous conditions for allocation of carbon to leaves, thus enhancing overall relative growth rates through higher light interception rates despite lower photosynthetic capacity. The results of this experiment suggested that drainage of peat swamp forests would seriously hamper natural regeneration of ramin by limiting the growth of seedlings. It is also suggested that selective logging operations which produce medium-size canopy gaps improve ramin regeneration in hydrologically undisturbed mixed swamp forest
Potential impacts of genetic use restriction technologies (GURTs) on agrobiodiversity and agricultural production systems
Development and application of GURT as an appropriation mechanism may potentially have considerable impact on agriculture, the environment and the food security of rural areas in developing countries. Positive impacts may include increased investments in breeding as a result of increased intellectual property protection. Increased investments may contribute to higher yields and more advanced varieties, and thus to increased food production, a more sustainable production, and better consumer products. Potential negative impacts have been identified as well. These may require further discussion and close attention by regulatory authorities
Spatially encoded light for Large-alphabet Quantum Key Distribution
Most Quantum Key Distribution protocols use a two-dimensional basis such as
HV polarization as first proposed by Bennett and Brassard in 1984. These
protocols are consequently limited to a key generation density of 1 bit per
photon. We increase this key density by encoding information in the transverse
spatial displacement of the used photons. Employing this higher-dimensional
Hilbert space together with modern single-photon-detecting cameras, we
demonstrate a proof-of-principle large-alphabet Quantum Key Distribution
experiment with 1024 symbols and a shared information between sender and
receiver of 7 bit per photon.Comment: 9 pages, 6 figures, Added references, Updated Fig. 1 in the main
text, Updated Fig.1 in supplementary material, Added section Trojan-horse
attacks in supplementary material, title changed, Added paragraphs about
final key rate and overfilling the detector to result sectio
Teaching and learning reflection in MPA programs: towards a strategy
__Abstract__
Reflection is an essential ingredient of academic education in PublicAdministration, both for
an academic and a professional career. Making a distinction between reflectivity and
reflexivity we identify 30 foci of reflection. The main question of the article is how these
forms of reflection can be taught and learned in PA programs, especially in post-experience
PAprograms. To answer this question,westudied de programand interviewed the teaching
staff op the post-experienceMPA program at Erasmus University in Rotterdamto describe
what is actually done in the to teach students reflection competences and to identify success
and limitations of these efforts. We present our findings and describe how we, in consultation
with the teaching staff, developed a number of feasible options for improvement.
We discuss these options and present a strategy to actually get these implemented
- âŚ