Rural Investment and the Cost of Income Uncertainty

This paper studies optimal investment decision in agriculture under diminishing income expectations. The goal is to study the cost of income uncertainty and its implications to the efficiency of investment subsidies. Investment decision is modelled as a Markov decision process, extended to account for risk. Applying a stochastic programming approach, the cost of imperfect information is evaluated as the difference between the profitability of investment under stable income and under uncertain income. Computational experiments demonstrate that the cost of imperfect information can be high, deteriorating the efficiency of investment subsidies. Also, examples suggest that the optimal timing of the investment can be sensitive to risk.

Fluorescence measurements show stronger cold inhibition of photosynthetic light reactions in Scots pine compared to Norway spruce as well as during spring compared to autumn

We studied the photosynthetic activity of Scots pine (Pinus sylvestris L.) and Norway spruce (Picea abies [L.] Karst) in relation to air temperature changes from March 2013 to February 2014. We measured the chlorophyll fluorescence of approximately 50 trees of each species growing in southern Finland. Fluorescence was measured 13 times per week. We began by measuring shoots present in late winter (i.e., March 2013) before including new shoots once they started to elongate in spring. By July, when the spring shoots had achieved similar fluorescence levels to the older ones, we proceeded to measure the new shoots only.We analysed the data by fitting a sigmoidal model containing four parameters to link sliding averages of temperature and fluorescence. A parameter defining the temperature range over which predicted fluorescence increased most rapidly was the most informative with in describing temperature dependence of fluorescence.The model generated similar fluorescence patterns for both species, but differences were observed for critical temperature and needle age. Down regulation of the light reaction was stronger in spring than in autumn. Pine showed more conservative control of the photosynthetic light reactions, which were activated later in spring and more readily attenuated in autumn. Under the assumption of a close correlation of fluorescence and photosynthesis, spruce should therefore benefit more than pine from the increased photosynthetic potential during warmer springs, but be more likely to suffer frost damage with a sudden cooling following a warm period. The winter of 20132014 was unusually mild and similar to future conditions predicted by global warming models. During the mild winter, the activity of photosynthetic light reactions of both conifers, especially spruce, remained high. Because light levels during winter are too low for photosynthesis, this activity may translate to a net carbon loss due to respiration

Phosphorus in manure and sewage sludge more recyclable than in soluble inorganic fertilizer

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Effect of Mn and Mg dopants on vacancy defect formation in ammonothermal GaN

We have applied positron annihilation spectroscopy to study the formation of Ga vacancy related defects in Mg and Mn doped bulk GaN crystals grown by the ammonothermal method. We show that Mn doping has little or no effect on the formation of Ga vacancies, while Mg doping strongly suppresses their formation, in spite of both dopants leading to highly resistive material. We suggest the differences are primarily due to the hydrogen-dopant interactions. Further investigations are called for to draw a detailed picture of the atomic scale phe-nomena in the synthesis of ammonothermal GaN.Peer reviewe

BABEL3&3a : Crustal-Scale Structures of the Precambrian Svecofennian Accretionary Orogen in the Fennoscandian Shield

obs typo in the title: The title will be changed to FIRE3&3A: Crustal-Scale Structures of the Precambrian Svecofennian Accretionary Orogen in the Fennoscandian Shield. in the second printed version.Peer reviewe

Born too young and likely to die : Should this continue?

Peer reviewe