Can we measure ecological sustainability? Landscape pattern as an indicator for naturalness and land use intensity at regional,national and European level

European landscapes have been shaped over the centuries by processes related to human land use, which are reflected in regionally distinct landscape patterns. Since landscape pattern has been linked to biodiversity and other ecological values of the landscapes, this paper explores landscape pattern as a tool for ecological sustainability assessments at the regional (Austrian Cultural Landscapes), national (Austria) and European (European Union + Norway, Switzerland) level with focus on agricultural landscapes. A set of landscape metrics served as a basis to assess naturalness and geometrisation of Austrian and European landscapes as a proxy for their sustainability. To achieve an accurate spatially explicit assessment, we applied a spatial reference framework consisting in units that are homogeneous in biophysical and socio-economic contexts, adapted the regional approach for its application at European level, and developed relative sustainability thresholds for the landscape metrics. The analyses revealed that several landscape metrics, particularly the “Number of Shape Characterising Points” showed a high correlation with the degree of naturalness. The sustainability map of Austria based on an ordinal regression model revealed well-known problem regions of ecological sustainability. At the European level, the relative deviation from the average pattern showed clearly the simplification processes in the landscapes. However, a better spatial resolution of land cover data would add to the refinement of pattern analysis in regions and therefore the assessment of sustainability. We recommend the combination of information of different scales for the formulation and implementation of sustainability policies.     

Cloning and sequencing of a human liver carboxylesterase isoenzyme

A human liver lambda gt11 library was screened with antibodies raised to a purified rat liver carboxylesterase, and several clones were isolated and sequenced. The longest cDNA contained an open reading frame of 507 amino acids that represented 92% of the sequence of a mature carboxylesterase protein. This sequence possessed many structural features that are highly conserved among rabbit and rat liver carboxylesterase proteins, including Ser, His, and Asp residues that comprise the active site, two pairs of Cys residues that may participate in disulfide bond formation, and one Asn-Xxx-Thr site for N-linked carbohydrate addition. When the clone was used to probe human liver genomic DNA that had been digested with various restriction enzymes, many hybridizing bands of differing intensities were observed. The results suggest that the carboxylesterases exist as several isoenzymes in humans, and that they are encoded by multiple genes.     

Nitrogenase activity in composting horse bedding and leaves

To date little or no nitrogen fixation has been found in composting materials. However, some materials have high C:N ratios and thus might be expected to support nitrogen fixation. We examined windrows of composting horse bedding and leaves for nitrogenase activity via acetylene reduction and used carbon monoxide controls to differentiate ethylene evolved by nitrogenase from that evolved by endogenous processes. In both piles temperatures were substantially elevated and partial pressures of oxygen greatly reduced thus indicating vigorous microbial activity. In the horse bedding, there were only low rates of ethylene evolution and little of this was due to nitrogen fixation. In contrast, much higher rates of ethylene evolution were measured in the leaf pile and 94% of this was due to nitrogenase activity. We estimate that the leaf pile fixed approximately 0.062 mg N/g leaves during a 5-week period.     

Professor Dr. Geoffrey Burnstock (1929–2020)

Purinergic Signalling -     

Characterization,Toxicity, and Optimization for the Growth and Production of Bacteriocin-like Substances by Lactobacillus curvatus

Probiotics and Antimicrobial Proteins - This study aimed to characterize, evaluate toxicity and optimize the conditions for the growth and production of bacteriocin-like substances by Lactobacillus...     

Arguments against the significance of the Fenton reaction contributing to signal pathways under in vivo conditions

One of the common explanations for oxidative stress in the physiological milieu is based on the Fenton reaction, i.e. the assumption that radical chain reactions are initiated by metal-catalyzed electron transfer to hydrogen peroxide yielding hydroxyl radicals. On the other hand — especially in the context of so-called “iron switches” — it is postulated that cellular signaling pathways originate from the interaction of reduced iron with hydrogen peroxide.

Using fluorescence detection and EPR for identification of radical intermediates, we determined the rate of iron complexation by physiological buffer together with the reaction rate of concomitant hydroxylations of aromatic compounds under aerobic and anaerobic conditions. With the obtained overall reaction rate of 1,700 M^-1s^-1 for the buffer-dependent reactions and the known rates for Fenton reactions, we derive estimates for the relative reaction probabilities of both processes.

As a consequence we suggest that under in vivo conditions initiation of chain reactions by hydroxyl radicals generated by the Fenton reaction is of minor importance and hence metal-dependent oxidative stress must be rather independent of the so-called “peroxide tone”. Furthermore, it is proposed that — in the low (subtoxic) concentration range — hydroxylated compounds derived from reactions of “non-free” (crypto) OH radicals are better candidates for iron-dependent sensing of redox-states and for explaining the origin of cellular signals than the generation of “free” hydroxyl radicals.     

Pitfalls of using lucigenin in endothelial cells: Implications for NAD(P)H dependent superoxide formation

Since an increased endothelial superoxide formation plays an important role in the pathogenesis of endothelial dysfunction its specific detection is of particular interest. The widely used superoxide probe lucigenin, however, has been reported to induce superoxide under certain conditions, especially in the presence of NADH. This raises questions as to the conclusion of a NAD(P)H oxidase as the major source of endothelial superoxide. Using independent methods, we showed that lucigenin in the presence of NADH leads to the production of substantial amount of superoxide (～ 15-fold of control) in endothelial cell homogenates. On the other hand, these independent methods revealed that endothelial cells without lucigenin still produce superoxide in a NAD(P)H-dependent manner. This was blocked by inhibitors of the neutrophil NADPH oxidase diphenyleniodonium and phenylarsine oxide. Our results demonstrate that a NAD(P)H-dependent oxidase is an important source for endothelial superoxide but the latter, however, cannot be measured reliably by lucigenin.     

Syntheses of 1-[2-(Phosphonomethoxy)Alkyl]Thymine Monophosphates and an Evaluation of their Inhibitory Activity Toward Human Thymidine Phosphorylase

A series of new monophosphates of 1-[2-(phosphonomethoxy)alkyl]thymines, such as PMPTp_, 3-MeO-PMPTp, HPMPTp, and FPMPTp, were synthesized and tested for their ability to inhibit human thymidine phosphorylase. Kinetic measurements of enzyme activity were performed using thymidine and inorganic phosphate as the substrates. The data show that some monophosphates provide a considerable increase of the multisubstrate inhibitory effect. The highest inhibitory potency was found with (R)-FPMPTp 4c (K _i ^dT = 4.09 ± 0.47 μM, K _i(P_i) = 2.13 ± 0.29 μM) and (R) 3-MeO-PMPTp 4d (K _i ^dT = 5.78 ± 0.71 μM, K _i(P_i) = 2.71 ± 0.37 μM).     

Positive Facial Affect – An fMRI Study on the Involvement of Insula and Amygdala

Imitation of facial expressions engages the putative human mirror neuron system as well as the insula and the amygdala as part of the limbic system. The specific function of the latter two regions during emotional actions is still under debate. The current study investigated brain responses during imitation of positive in comparison to non-emotional facial expressions. Differences in brain activation of the amygdala and insula were additionally examined during observation and execution of facial expressions. Participants imitated, executed and observed happy and non-emotional facial expressions, as well as neutral faces. During imitation, higher right hemispheric activation emerged in the happy compared to the non-emotional condition in the right anterior insula and the right amygdala, in addition to the pre-supplementary motor area, middle temporal gyrus and the inferior frontal gyrus. Region-of-interest analyses revealed that the right insula was more strongly recruited by (i) imitation and execution than by observation of facial expressions, that (ii) the insula was significantly stronger activated by happy than by non-emotional facial expressions during observation and imitation and that (iii) the activation differences in the right amygdala between happy and non-emotional facial expressions were increased during imitation and execution, in comparison to sole observation. We suggest that the insula and the amygdala contribute specifically to the happy emotional connotation of the facial expressions depending on the task. The pattern of the insula activity might reflect increased bodily awareness during active execution compared to passive observation and during visual processing of the happy compared to non-emotional facial expressions. The activation specific for the happy facial expression of the amygdala during motor tasks, but not in the observation condition, might reflect increased autonomic activity or feedback from facial muscles to the amygdala.