9,478 research outputs found
Resource curse or not: A question of appropriability
This paper shows that whether natural resources are good or bad for a country’s development crucially depends on the interaction between institutional setting and the type of resources possessed by the country. Some natural resources are, for economical and technical reasons, more likely to cause problems such as rent-seeking and conflicts than others. This potential problem can, however, be countered by good institutional quality. In contrast to the traditional resource curse hypothesis, we show the impact of natural resources on economic growth to be non-monotonic in institutional quality. Countries rich in minerals are cursed only if they have low quality institutions, while the curse is reversed if institutions are sufficiently good.Natural Resources, Appropriability, Property Rights, Institutions, Economic Growth, Development
Resource curse or not: A question of appropriability
This paper shows that whether natural resources are good or bad for a country's development depends crucially on the interaction between institutional setting and the type of resources that the country possesses. Some natural resources are for economical and technical reasons more likely to cause problems such as rent-seeking and conflicts than others (termed technically appropriable resources). This potential problem can, however, be countered by good institutional quality (rendering these resources less institutionally appropriable). In contrast to the traditional resource curse hypothesis we show that the impact of natural resources on economic growth is non-monotonic in institutional quality. Mineral rich countries are cursed only if they have low quality institutions, while the curse is reversed if institutions are good enough. Using new data we find that this is even more stark for countries rich in diamonds and precious metals
First ice core records of NO3− stable isotopes from Lomonosovfonna, Svalbard
Samples from two ice cores drilled at Lomonosovfonna, Svalbard, covering the period 1957–2009, and 1650–1995, respectively, were analyzed for NO3− concentrations, and NO3− stable isotopes (δ15N and δ18O). Post-1950 δ15N has an average of (−6.9 ± 1.9) ‰, which is lower than the isotopic signal known for Summit, Greenland, but agrees with values observed in recent Svalbard snow and aerosol. Pre-1900 δ15N has an average of (4.2 ± 1.6) ‰ suggesting that natural sources, enriched in the 15 N-isotope, dominated before industrialization. The post-1950 δ18O average of (75.1 ± 4.1) ‰ agrees with data from low and polar latitudes, suggesting similar atmospheric NOy (NOy = NO + NO2 + HNO3) processing pathways. The combination of anthropogenic source δ15N and transport isotope effect was estimated as −29.1 ‰ for the last 60 years. This value is below the usual range of NOx (NOx = NO + NO2) anthropogenic sources which is likely the result of a transport isotope effect of –32 ‰. We suggest that the δ15N recorded at Lomonosovfonna is influenced mainly by fossil fuel combustion, soil emissions and forest fires; the first and second being responsible for the marked decrease in δ15N observed in the post-1950s record with soil emissions being associated to the decreasing trend in δ15N observed up to present time, and the third being responsible for the sharp increase of δ15N around 2000
A Case Study on Artefact-based RE Improvement in Practice
Most requirements engineering (RE) process improvement approaches are
solution-driven and activity-based. They focus on the assessment of the RE of a
company against an external norm of best practices. A consequence is that
practitioners often have to rely on an improvement approach that skips a
profound problem analysis and that results in an RE approach that might be
alien to the organisational needs. In recent years, we have developed an RE
improvement approach (called \emph{ArtREPI}) that guides a holistic RE
improvement against individual goals of a company putting primary attention to
the quality of the artefacts. In this paper, we aim at exploring ArtREPI's
benefits and limitations. We contribute an industrial evaluation of ArtREPI by
relying on a case study research. Our results suggest that ArtREPI is
well-suited for the establishment of an RE that reflects a specific
organisational culture but to some extent at the cost of efficiency resulting
from intensive discussions on a terminology that suits all involved
stakeholders. Our results reveal first benefits and limitations, but we can
also conclude the need of longitudinal and independent investigations for which
we herewith lay the foundation
Sinking and floating rates of natural phytoplankton assemblages in Lake Erken
Sinking rates of the <120 mu m size phytoplankton fraction of water from Lake Erken were determined during the summer 1992 by following the increase of chlorophyll a in the 10 ml-bottom layer in replicate 100 ml settling cylinders. Changes in chlorophyll a concentrations as a function of incubation time allowed two fractions to be separated. Fast sinking rates varied between values of 1.9 m/day when pennate and centric diatoms and coccal cyanobacteria were dominant tin cell concentration) and values of 0.5 m/day when cryptophytes and chrysophytes dominated the <120 mu m size fraction. Slow sinking rates decreased from 0.04 m/day at the beginning of July to 0.02 m/day in late July. Photosynthesis-Irradiance parameters (P-max(B) light saturated photosynthesis and #alpha#(B), light limited photosynthesis) were lower in the fast sinking fraction (P-max(B) = 1.3 - 2.4 mu gC/mu gChl/h and #alpha#(B) = 0.01 - 0.04 mu gC/mu gChl/h/(mu E/m(2)/s) than in the slow or non-sinking one (P-max(B) = 3.9 - 6.4 mu gC/mu gChl/h and #alpha#(B) = 0.03 - 0.08 mu gC/mu gChl/h/(mu E/m(2)/s). P-max(B) and #alpha#B of the planktonic Gloeotrichia echinulata, a colonial broom-forming cyanobacterium, were similar to those found in the fast sinking fraction. Mean floating rates of G. echinulata were around 43 m/d from 15 to 27 July and increased by a factor of two afterwards. G. echinulata colonies migrating upwards from sediments and captured in inverted traps showed a mean floating rate of 104 m/d
Combined endo-β-1,4-xylanase and α-L-arabinofuranosidase increases butyrate concentration during broiler cecal fermentation of maize glucurono-arabinoxylan
Solubilisation of prebiotic arabinoxylooligosaccharides from complex arabinoxylans in e.g. maize by xylanases may be increased by addition of auxiliary debranching enzymes. In this study, the hydrolysis and fermentation of maize fibre was investigated in vitro using a xylanase and an alpha-L-arabinofuranosidase. Combining the enzymes induced a higher (P < .001) xylose solubilisation and higher (P < .05) butyrate production during in vitro fermentation of maize fibre with cecal broiler inoculum compared to applying enzymes separately after 48 h. Subsequently, fibre degradation and fermentation was investigated in ROSS 308 broiler chickens supplemented with the enzyme combination to test the effects on gut morphology and microbiota composition along with performance. However, to address the relevance of combining the enzymes in vivo, further full factorial studies using individual enzymes at lower dosages are needed. Birds were fed a maize/soy based diet with 100 g/kg maize DDGS and 50 g/kg rapeseed meal. Enzymes supplementation increased (P < .001) body weight (+ 5.4%) and improved (P < .001) feed conversion ratio (-5.8%) after 29 days compared to control birds. Non-starch polysaccharide analysis and confocal microscopy of jejunum digesta visualised and confirmed solubilisation of the insoluble maize (glucurono)arabinoxylan. Birds receiving enzyme supplementation had increased (P < .001) duodenum villi length (+120 mu m) and reduced (P < .002) CD3 T-cell infiltration (-22.1%) after 29 days. Cecal butyrate levels were increased (P < .05) compared to controls. Although the microbiota composition was not significantly altered, numerical increases in cecal Ruminococcaceae and Lachnospiraceae genera were observed in birds supplemented with enzymes
Charged particle jet measurements with the ALICE experiment in proton-proton collisions at the LHC
We present preliminary results of measurements of charged particle jet
properties in proton-proton collisions at = 7 TeV using the ALICE
detector. Jets are reconstructed using and SISCone jet
finding algorithms with resolution parameter in the range of transverse
momentum from 20 to 100 GeV/ in the midrapidity region
(\mid\eta\mid\textless 0.5). The uncorrected charged jet spectra obtained
using the three different jet finders show good agreement. The data are
compared to predictions from PYTHIA-Perugia0, PYTHIA-Perugia2011, and PHOJET.
The mean charged particle multiplicity in leading jets increases with
increasing jet and is consistent with model predictions. The radial
distributions of transverse momentum about the jet direction and the
distributions of the average radius containing 80% of the total jet
found in the jet cone ( in this analysis), indicate that high jets are more collimated than low jets.Comment: 6 pages, 6 figures, Conference Proceedings submitted for the 28th
Winter Workshop on Nuclear Dynamics, Puerto Rico, April 7-14, 201
Застосування визначеного інтегралу до розв’язування економічних задач
The aim of the present work was to study the influence of the stress on the electrode potential of the austenitic stainless steel301LN using Scanning Kelvin Probe (SKP). It was found that elastic deformation reversibly ennobles the potential whereas plasticdeformation decreases the potential in both tensile and compressive deformation mode and this decrease is retained even 24 h afterremoval of the load. To interpret the stress effects, different surface preparations were used and the composition and thickness ofthe passive film were determined by GDOES. Slip steps formed due to plastic deformation were observed using AFM. The effect ofplastic strain on the potential is explained by the formation of dislocations, which creates more a defective passive film.QC 20160516</p
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