Enantiomeric Composition of Monoterpene Hydrocarbons in Some Conifers and Receptor Neuron Discrimination of α-Pinene and Limonene Enantiomers in the Pine Weevil, Hylobius abietis

The enantiomeric composition of seven monoterpene hydrocarbons in headspace volatiles of spruce sawdust and seedlings (Picea abies), pine seedlings (Pinus sylvestris), and branches of juniper (Juniperus communis) was determined by gas chromatographic separation on a -Cyclodextrin column. For the six monoterpenes, -pinene, camphene, -pinene, sabinene, limonene, and -phellandrene, both enantiomers were present, whereas for 3-carene only the (+)-configuration was found. The amount of each enantiomer varied considerably both in relation to total amount of all of them, and for the six pairs also in relation to the opposite enantiomer. One olfactory receptor neuron in the pine weevil (Hylobius abietis) showed a strong response to -pinene when stimulated with all four headspace materials via a GC equipped with a DB-WAX column. The same neuron was subsequently tested with repeated stimulations via the GC effluent containing the (+)- or (–)-enantiomer. A marked better response to (+)- than to (–)--pinene was elicited. Another olfactory receptor neuron that responded strongly to limonene when stimulated with the spruce volatiles was tested for enantiomers of limonene. This neuron responded more strongly to (–)- than to (+)-limonene, when stimulated alternately with each of the limonene enantiomers. Discrimination between enantiomers by plant olfactory receptor neurons suggests that the enantiomeric ratios of volatile compounds may be important in host location by the pine weevil.     

Modular analysis and modelling of risk scenarios with dependencies

The risk analysis of critical infrastructures such as the electric power supply or telecommunications is complicated by the fact that such infrastructures are mutually dependent. We propose a modular approach to the modelling and analysis of risk scenarios with dependencies. Our approach may be used to deduce the risk level of an overall system from previous risk analyses of its constituent systems. A custom made assumption-guarantee style is put forward as a means to describe risk scenarios with external dependencies. We also define a set of deduction rules facilitating various kinds of reasoning, including the analysis of mutual dependencies between risk scenarios expressed in the assumption-guarantee style.     

The significance of the North Atlantic Oscillation (NAO) for sea-salt episodes and acidification-related effects in Norwegian rivers

Acidification of Norwegian surface waters, as indicated by elevated concentrations of sulfate and a corresponding reduction in acid neutralizing capacity and pH, is a result of emission and subsequent deposition of sulfur and nitrogen compounds. Episodic sea-salt deposition during severe weather conditions may increase the effects of acidification by mobilizing more toxic aluminum during such episodes. Changes in climatic conditions may increase the frequency and strength of storms along the coast thus interacting with acidification effects on chemistry and biota. We found that the North Atlantic Oscillation (NAO) is linked to sea-salt deposition and sea-salt induced water chemistry effects in five rivers. Particularly, toxic levels of aluminum in all rivers were significantly correlated with higher NAO index values. Further, temporal trends were studied by comparing tendencies for selected statistical indices (i.e. frequency distributions) with time. The selected indices exhibited strong correlations between the NAO index, sea-salt deposition and river data such as chloride, pH and inorganic monomeric aluminum, pointing at the influence of North Atlantic climate variability on water chemistry and water toxicity. The potentially toxic effects of sea-salt deposition in rivers seem to be reduced as the acidification is reduced. This suggests that sea-salt episodes have to increase in strength in order to give the same potential negative biological effects in the future, if acid deposition is further reduced. More extreme winter precipitation events have been predicted in the northwest of Europe as a result of climate change. If this change will be associated with more severe sea-salt episodes is yet unknown.     

Relating computer systems to sequence diagrams: the impact of underspecification and inherent nondeterminism

Having a sequence diagram specification and a computer system, we need to answer the question: Is the system compliant with the sequence diagram specification in the desired way? We present a procedure for answering this question for sequence diagrams with underspecification and inherent nondeterminism. The procedure is independent of any concrete technology, and relies only on the execution traces that may be produced by the system. If all traces are known, the procedure results in either “compliant” or “not compliant”. If only a subset of the traces is known, the conclusion may also be “likely compliant” or “likely not compliant”.     

Allyl Isothiocyanate Inhibits Actin-Dependent Intracellular Transport in Arabidopsis thaliana

Volatile allyl isothiocyanate (AITC) derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP)-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER), vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system.     

A GPU‐accelerated nodal discontinuous Galerkin method with high‐order absorbing boundary conditions and corner/edge compatibility

Discontinuous Galerkin finite element schemes exhibit attractive features for accurate large‐scale wave‐propagation simulations on modern parallel architectures. For many applications, these schemes must be coupled with nonreflective boundary treatments to limit the size of the computational domain without losing accuracy or computational efficiency, which remains a challenging task. In this paper, we present a combination of a nodal discontinuous Galerkin method with high‐order absorbing boundary conditions for cuboidal computational domains. Compatibility conditions are derived for high‐order absorbing boundary conditions intersecting at the edges and the corners of a cuboidal domain. We propose a GPU implementation of the computational procedure, which results in a multidimensional solver with equations to be solved on 0D, 1D, 2D, and 3D spatial regions. Numerical results demonstrate both the accuracy and the computational efficiency of our approach.     

Bovine claw and limb disorders at claw trimming related to milk yield

As part of a cross-sectional study of Norwegian Red Cattle, associations of lameness, lesions at the tarsus, claw shapes, claw lesions, and claw trimming with milk yield were examined. Fifty-five tie-stall herds and 57 free-stall herds were sampled by computerized systematic selection, and 2,665 cows were trimmed and limb and claw disorders recorded. After exclusions, 2,599 cows were included in this study. Monthly recordings of milk were extracted from the Norwegian Dairy Herd Recording System. Most claw lesions were mild (score 1). The prevalence of moderate and severe lesions (score 2 and 3) did not exceed 5% for any of the lesions. Associations with test-day milk yield were identified using regression analyses (Proc Mixed) with repeated measurements within lactation and herd as random effect. Lactation curves were fit to visualize differences in changes in milk yield throughout the lactation. Milk yield was generally higher in cows with lesions at the tarsus, heel-horn erosions, and hemorrhages of the white line and the sole than in cows without these lesions, whereas cows with dermatitis yielded less than cows without dermatitis. Cows in lactation 1 with corkscrewed claws had reduced milk yield, whereas cows in lactations 2 and above had increased milk yield compared with cows without corkscrewed claws in respective lactations. Cows in lactation 1 yielded 0.47 ± 0.15 kg and cows in later lactations yielded 0.51 ± 0.15 kg more milk on test days after claw trimming than they did before when adjusted for days in milk. In this study, where most disorders were mild, the most evident results were higher milk yield in cows with lesions at the tarsus, heel-horn erosions, and hemorrhages of the white line and the sole than in cows without these lesions. Cows yielded more milk after claw trimming than they did before trimming.     

Operator dependency of arterial input function in dynamic contrast-enhanced MRI

Objective

To investigate the effect of inter-operator variability in arterial input function (AIF) definition on kinetic parameter estimates (KPEs) from dynamic contrast-enhanced (DCE) MRI in patients with high-grade gliomas.

Methods

The study included 118 DCE series from 23 patients. AIFs were measured by three domain experts (DEs), and a population AIF (pop-AIF) was constructed from the measured AIFs. The DE-AIFs, pop-AIF and AUC-normalized DE-AIFs were used for pharmacokinetic analysis with the extended Tofts model. AIF-dependence of KPEs was assessed by intraclass correlation coefficient (ICC) analysis, and the impact on relative longitudinal change in K^trans was assessed by Fleiss’ kappa (κ).

Results

There was a moderate to substantial agreement (ICC 0.51–0.76) between KPEs when using DE-AIFs, while AUC-normalized AIFs yielded ICC 0.77–0.95 for K^trans, k_ep and v_e and ICC 0.70 for v_p. Inclusion of the pop-AIF did not reduce agreement. Agreement in relative longitudinal change in K^trans was moderate (κ = 0.591) using DE-AIFs, while AUC-normalized AIFs gave substantial (κ = 0.809) agreement.

Discussion

AUC-normalized AIFs can reduce the variation in kinetic parameter results originating from operator input. The pop-AIF presented in this work may be applied in absence of a satisfactory measurement.