INTERACTION BETWEEN WATER AND PLANTS: RICH DYNAMICS IN A SIMPLE MODEL

An ordinary differential equation model describing interaction of water and plants in ecosystem is proposed. Despite its simple looking, it is shown that the model possesses surprisingly rich dynamics including multiple stable equilibria, backward bifurcation of positive equilibria, supercritical or subcritical Hopf bifurcations, bubble loop of limit cycles, homoclinic bifurcation and Bogdanov-Takens bifurcation. We classify bifurcation diagrams of the system using the rain-fall rate as bifurcation parameter. In the transition from global stability of bare-soil state for low rain-fall to the global stability of high vegetation state for high rain-fall rate, oscillatory states or multiple equilibrium states can occur, which can be viewed as a new indicator of catastrophic environmental shift

Estimating uncertainties in integrated reservoir studies

To make sound investment decisions, decision makers need accurate estimates of the uncertainties present in forecasts of reservoir performance. In this work I propose a method, the integrated mismatch method, that incorporates the misfit in the history match into the estimation of uncertainty in the prediction. I applied the integrated mismatch method, which overcomes some deficiencies of existing methods, to uncertainty estimation in two reservoir studies and compared results to estimations from existing methods. The integrated mismatch method tends to generate smaller ranges of uncertainty than many existing methods. When starting from nonoptimal reservoir models, in some cases the integrated mismatch method is able to bracket the true reserves value while other methods fail to bracket it. The results show that even starting from a nonoptimal reservoir model, but as long as the experimental designs encompass the true case parameters, the integrated mismatch method brackets the true reserves value. If the experimental designs do not encompass all the true case parameters, but the true reserves value is covered by the experiments, the integrated mismatch method may still bracket the true case. This applies if there is a strong correlation between mismatch and closeness to the true reserves value. The integrated mismatch method does not need a large number of simulation runs for the uncertainty analysis, while some other methods need hundreds of runs

Integrativna ekspresija gena za glukoamilazu u soju pivskoga kvasca Saccharomyces pastorianus

The recombinant brewer’s yeast Saccharomyces pastorianus strain was constructed byintroducing the ilv2:GLA fragment released from pMGI6, carrying glucoamylase gene (GLA) and using the yeast α-acetolactate synthase gene (ILV2) as the recombination sequence. The strain was able to utilise starch as the sole carbon source, its glucoamylase activity was 6.3 U/mL and its α-acetolactate synthase activity was lowered by 33.3 %. The introduced GLA gene was integrated at the recipient genomic ILV2 gene, one copy of ILV2 gene was disrupted and the other copy remained intact. Primary wort fermentation test confirmed that the diacetyl and residual sugar concentration in the wort fermented by the recombinant strain were reduced by 65.6 and 34.2 % respectively, compared to that of the recipient strain. Under industrial operating conditions, the maturation time of beer fermented by the recombinant strain was reduced from 7 to 4 days, there were no significant differences in the appearance and mouthfeel, and the beer satisfied the high quality demands. That is why the strain could be used in beer production safely.Uvođenjem ilv2:GLA isječka iz pMGI6, kao nosioca gena za glukoamilazu (GLA) i uporabom rekombinacijske sekvencije gena za α-acetolaktat sintazu (ILV2), konstruiran je rekombinantni soj pivskoga kvasca Saccharomyces pastorianus. Utvrđeno je da soj može koristiti škrob kao jedini izvor ugljika, da aktivnost glukoamilaze iznosi 6,3 U/mL, a da je aktivnost α-acetolaktat sintaze smanjena za 33,3 %. Uvedeni gen GLA, integriran u gen primatelja ILV2, raskinuo je jednu kopiju gena ILV2, dok je druga kopija ostala nepromijenjena. Prvi test fermentacije sladovine potvrdio je da je fermentacijom s pomoću rekombinantnog soja koncentracija diacetila smanjena za 65,6 %, a koncentracija ostatka šećera za 34,2 % u usporedbi sa sojem primatelja. U industrijskim uvjetima zrenje piva fermentiranog s pomoću rekombinantnog soja smanjeno je sa 7 na 4 dana, pri čemu nema značajne razlike u izgledu i okusu, te je ono zadovoljilo visoke zahtjeve. Stoga se ovaj soj može sigurno upotrijebiti u proizvodnji piva

Integrativna ekspresija gena za glukoamilazu u soju pivskoga kvasca Saccharomyces pastorianus

The recombinant brewer’s yeast Saccharomyces pastorianus strain was constructed byintroducing the ilv2:GLA fragment released from pMGI6, carrying glucoamylase gene (GLA) and using the yeast α-acetolactate synthase gene (ILV2) as the recombination sequence. The strain was able to utilise starch as the sole carbon source, its glucoamylase activity was 6.3 U/mL and its α-acetolactate synthase activity was lowered by 33.3 %. The introduced GLA gene was integrated at the recipient genomic ILV2 gene, one copy of ILV2 gene was disrupted and the other copy remained intact. Primary wort fermentation test confirmed that the diacetyl and residual sugar concentration in the wort fermented by the recombinant strain were reduced by 65.6 and 34.2 % respectively, compared to that of the recipient strain. Under industrial operating conditions, the maturation time of beer fermented by the recombinant strain was reduced from 7 to 4 days, there were no significant differences in the appearance and mouthfeel, and the beer satisfied the high quality demands. That is why the strain could be used in beer production safely.Uvođenjem ilv2:GLA isječka iz pMGI6, kao nosioca gena za glukoamilazu (GLA) i uporabom rekombinacijske sekvencije gena za α-acetolaktat sintazu (ILV2), konstruiran je rekombinantni soj pivskoga kvasca Saccharomyces pastorianus. Utvrđeno je da soj može koristiti škrob kao jedini izvor ugljika, da aktivnost glukoamilaze iznosi 6,3 U/mL, a da je aktivnost α-acetolaktat sintaze smanjena za 33,3 %. Uvedeni gen GLA, integriran u gen primatelja ILV2, raskinuo je jednu kopiju gena ILV2, dok je druga kopija ostala nepromijenjena. Prvi test fermentacije sladovine potvrdio je da je fermentacijom s pomoću rekombinantnog soja koncentracija diacetila smanjena za 65,6 %, a koncentracija ostatka šećera za 34,2 % u usporedbi sa sojem primatelja. U industrijskim uvjetima zrenje piva fermentiranog s pomoću rekombinantnog soja smanjeno je sa 7 na 4 dana, pri čemu nema značajne razlike u izgledu i okusu, te je ono zadovoljilo visoke zahtjeve. Stoga se ovaj soj može sigurno upotrijebiti u proizvodnji piva

Semantic Role Labeling as Dependency Parsing: Exploring Latent Tree Structures Inside Arguments

Semantic role labeling (SRL) is a fundamental yet challenging task in the NLP community. Recent works of SRL mainly fall into two lines: 1) BIO-based; 2) span-based. Despite ubiquity, they share some intrinsic drawbacks of not considering internal argument structures, potentially hindering the model's expressiveness. The key challenge is arguments are flat structures, and there are no determined subtree realizations for words inside arguments. To remedy this, in this paper, we propose to regard flat argument spans as latent subtrees, accordingly reducing SRL to a tree parsing task. In particular, we equip our formulation with a novel span-constrained TreeCRF to make tree structures span-aware and further extend it to the second-order case. We conduct extensive experiments on CoNLL05 and CoNLL12 benchmarks. Results reveal that our methods perform favorably better than all previous syntax-agnostic works, achieving new state-of-the-art under both end-to-end and w/ gold predicates settings.Comment: COLING 202

Effect of Diffusion and Cross-Diffusion in a Predator-Prey Model with a Transmissible Disease in the Predator Species

We study a Lotka-Volterra type predator-prey model with a transmissible disease in the predator population. We concentrate on the effect of diffusion and cross-diffusion on the emergence of stationary patterns. We first show that both self-diffusion and cross-diffusion can not cause Turing instability from the disease-free equilibria. Then we find that the endemic equilibrium remains linearly stable for the reaction diffusion system without cross-diffusion, while it becomes linearly unstable when cross-diffusion also plays a role in the reaction-diffusion system; hence, the instability is driven solely from the effect of cross-diffusion. Furthermore, we derive some results for the existence and nonexistence of nonconstant stationary solutions when the diffusion rate of a certain species is small or large