Life cycle assessment of the selective catalytic reduction process for power plants

The overall reduction of the environmental impact by the use of selective catalytic reduction (SCR) of nitrogen oxide emissions in power plants was determined by strict application of ISO 14040 and ISO/DIS 14041. Special emphasis was placed on the implementation of the total product life cycle (PLC) of ammonium molybdate as a key input material. The environmental impact was generated by application of the life cycle assessment (LCA) concept of “ecoscarcity” and integrated in the life cycle inventory analysis (LCI) of SCR systems. The LCI was used to generate the life cycle impact assessment (LC1A) by use of different quantitative valuation methods. Under consideration of the overall LCIA results and the environmental protection costs of the SCR variants, the Ecological Effectiveness of the SCR alternatives was determined. The results enable plausible conclusions with regard to the ecological advantages of the use of deNOx catalysts in the SCR used in hard-coal fired power plants.     

Endogenous gibberellins and inhibitors in caryopses of rye

Gibberellins A₈, A₁₆, A₂₄, and abscisic acid were identified by GC-MS of derivatized extracts from immature fruits of Secale cereale. Mature caryopses contained ABA and trans-ABA in a ratio 1:1 as well as 4′-dihydrophaseic acid. During milk ripeness a neutral GA conjugate was detected. Free GA, afforded by enzymatic hydrolysis of the conjugate, was chromatographically identified as GA₁₆     

Conditional Point Estimation in Adaptive Group Sequential Test Designs

It is well known that point estimates in group sequential designs are biased. This also applies to adaptive designs that enable, e.g., data driven reassessments of group sample sizes. For triangular designs, Whitehead (1986) (Biometrika 73 , 573–581) proposed a bias adjusted estimate. But this estimate is not feasible in adaptive designs although it is in group sequential designs. Furthermore, there is a waste of information because it does not use the information at which stage the trial was stopped. We present a modification which does use this information and which is applicable to adaptive designs. The modified estimate achieves an improvement in group sequential designs and shows similar results in adaptive designs.     

Group Sequential Monitoring with Arbitrary Inspection Times

The classical group sequential test procedures that were proposed by Pocock (1977) and O'Brien and Fleming (1979) rest on the assumption of equal sample sizes between the interim analyses. Regarding this it is well known that for most situations there is not a great amount of additional Type I error if monitoring is performed for unequal sample sizes between the stages. In some cases, however, problems can arise resulting in an unacceptable liberal behavior of the test procedure. In this article worst case scenarios in sample size imbalancements between the inspection times are considered. Exact critical values for the Pocock and the O'Brien and Fleming group sequential designs are derived for arbitrary and for varying but bounded sample sizes. The approach represents a reasonable alternative to the flexible method that is based on the Type I error rate spending function. The SAS syntax for performing the calculations is provided. Using these procedures, the inspection times or the sample sizes in the consecutive stages need to be chosen independently of the data observed so far.     

The FTD‐like syndrome causing TREM2 T66M mutation impairs microglia function,brain perfusion,and glucose metabolism

Genetic variants in the triggering receptor expressed on myeloid cells 2 (TREM2) increase the risk for several neurodegenerative diseases including Alzheimer's disease and frontotemporal dementia (FTD). Homozygous TREM2 missense mutations, such as p.T66M, lead to the FTD‐like syndrome, but how they cause pathology is unknown. Using CRISPR/Cas9 genome editing, we generated a knock‐in mouse model for the disease‐associated Trem2 p.T66M mutation. Consistent with a loss‐of‐function mutation, we observe an intracellular accumulation of immature mutant Trem2 and reduced generation of soluble Trem2 similar to patients with the homozygous p.T66M mutation. Trem2 p.T66M knock‐in mice show delayed resolution of inflammation upon in vivo lipopolysaccharide stimulation and cultured macrophages display significantly reduced phagocytic activity. Immunohistochemistry together with in vivo TSPO small animal positron emission tomography (μPET) demonstrates an age‐dependent reduction in microglial activity. Surprisingly, perfusion magnetic resonance imaging and FDG‐μPET imaging reveal a significant reduction in cerebral blood flow and brain glucose metabolism. Thus, we demonstrate that a TREM2 loss‐of‐function mutation causes brain‐wide metabolic alterations pointing toward a possible function of microglia in regulating brain glucose metabolism.     

Genetic impoverishment of the last black grouse (Tetrao tetrix) population in the Netherlands: detectable only with a reference from the past

We have studied a small isolated population of black grouse (Tetrao tetrix) in the Netherlands to examine the impact of isolation and reduction in numbers on genetic diversity. We compared the genetic diversity in the last extant Dutch population with Dutch museum samples and three other black grouse populations (from England, Austria and Norway, respectively) representing isolated and continuous populations. We found significantly lower allelic richness, observed and expected heterozygosities in the present Dutch population compared to the continuous populations (Austria and Norway) and also to the historical Dutch population. However, using a bottleneck test on each population, signs of heterozygosity excess were only found in the likewise isolated English population despite that strong genetic drift was evident in the present Dutch population in comparison to the reference populations, as assessed both in pairwise F(ST)and STRUCTURE analyses. Simulating the effect of a population reduction on the Dutch population from 1948 onwards, using census data and with the Dutch museum samples as a model for the genetic diversity in the initial population, revealed that the loss in number of alleles and observed heterozygosity was according to genetic drift expectations and within the standard error range of the present Dutch population. Thus, the effect of the strong decline in the number of grouse on genetic diversity was only detectable when using a reference from the past. The lack of evidence for a population reduction in the present Dutch population by using the program bottleneck was attributed to a rapidly found new equilibrium as a consequence of a very small effective population size.     

Islands in the ice: colonisation routes for rock ptarmigan to the Svalbard archipelago

The ancestors of rock ptarmigan Lagopus muta originated in the Beringia area well before the disruption of the Beringian land bridge. They spread westwards to Siberia and eastwards to the North American arctic and Greenland. The distribution of rock ptarmigan has been affected by glaciations restricting it to geographically limited refugia. Today the species has a circumpolar distribution in arctic tundra and alpine habitats, with up to 30 subspecies recognised based on morphological characters. We sequenced the mitochondrial control region for 72 individuals and genotyped 69 individuals for 12 microsatellite loci to investigate neutral genetic variation within and among five rock ptarmigan populations, Greenland, Iceland, Scandinavia, Svalbard and Taimyr. Genetic structure among the studied samples was high, overall F_ST estimated from microsatellite loci was 0.18 and only one out of 16 mtDNA haplotypes was found in more than one population. Genetic variation ( h, π, H_e, allelic richness) was slightly lower in the Svalbard population than in other populations, suggesting a low effective population size, possibly due to isolation following colonisation. An unrooted network and a phylogenetic tree showed that the Scandinavian population has diverged from the other populations by at least ten mutational steps, probably due to independent colonisation of Europe and subsequent long-term isolation, and rules out Scandinavia as a source for colonisation of Svalbard. Alignment with partial control region sequences from other studies showed that the haplotype that was central in our network and found on Svalbard and in Taimyr, most likely corresponds to a haplotype found in Siberia, Alaska and the Canadian Arctic, but not in Greenland, Scandinavia and Iceland. This suggests an eastern origin of rock ptarmigan in Svalbard, although this question cannot be settled conclusively.