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Institute
We present the data of the 2nd research expedition of the European Dry Grassland Group (EDGG), which was conducted in 2010 in Central Podolia, Ukraine. The aim was to collect plot data to compare Ukrainian dry grasslands with those of other parts of Europe in terms of syntaxonomy and biodiversity. We sampled 21 nested-plot series (0.0001–100 m2) and 184 normal plots (10 m2) covering the full variety of dry grassland types occurring in the study region. For all plots, we recorded species composi-tion of terrestrial vascular plants, bryophytes and lichens, while for the 226 10-m2 plots we estimated and measured percentage cover of all species, structural, topographic, soil and landuse parameters. The 10-m² plots were used for phytosociological classification based on iteratively refined TWINSPAN classification as well as for DCA ordination. Differences between the derived vegetation types with respect to environmental conditions and species richness were assessed with ANOVAs. We assigned our plots to nine association-level units but refrained from placing them into formal associations with two exceptions. In the study area, dry grasslands of the Festuco-Brometea were far more common than those of the Koelerio-Corynephoretea. Among the Festuco-Brometea, xeric Festucetalia valesiacae grasslands were more frequent and represented by the Festucion valesiacae (2 associations, including the Allio taurici-Dichanthietum ischaemi ass. nova) and the Stipion lessingianae (1) compared to the Brachypodietalia pinnati with the Agrostio vinealis-Avenulion schellianae (3). The Koelerio-Corynephoretea were represented by three associations, each from a different order and alliance: basiphilous outcrops (Alysso alyssoidis-Sedetalia: Alysso alyssoidis-Sedion?), acidophilous outcrops (Sedo-Scleranthetalia: Veronico dillenii-Sedion albi?) and mesoxeric sandy grasslands (Trifolio arvensis-Festucetalia ovinae: Agrostion vinealis). We discuss the issue of the mesoxeric order Galietalia veri placed within the Molinio-Arrhenatheretea by Ukrainian authors and conclude that the content of that order would probably be better placed in the mesoxeric orders of the Koelerio-Corynephoretea and Festuco-Brometea. Other syntaxonomic questions could not be solved with our geographically limited dataset and await a supraregional analysis, e.g. whether the Ukrainian outcrop communities should be assigned to the same alliances as known from Central Europe or rather represent new vicariant units. The analysis of the biodiversity patterns showed that at a grain size of 10 m2, Podolian Koelerio-Corynephoretea communities were overall richer than Festuco-Brometea communities (46.4 vs. 40.6 species). This difference was due to the Koelerio-Corynephoretea containing twice as many bryophytes and nine times more lichens, while vascular plant species richness did not differ significantly between classes. The orders within the classes showed no real differences in species richness. The richness patterns observed in Podolia were almost the opposite of those usually found in dry grasslands, where Brachypodietalia pinnati are richer than Festucetalia valesiacae, and these richer than stands of the Koelerio-Corynpehoretea – and we do not have a good explanation for these idiosyncrasies. In conclusion, Podolian dry grasslands behave quite unexpectedly regarding biodiversity, and their syntaxonomy is still poorly understood. These knowledge gaps can only be addressed with supranational analyses based on comprehensive datasets.
MTO1-deficient mouse model mirrors the human phenotype showing complex I defect and cardiomyopathy
(2014)
Recently, mutations in the mitochondrial translation optimization factor 1 gene (MTO1) were identified as causative in children with hypertrophic cardiomyopathy, lactic acidosis and respiratory chain defect. Here, we describe an MTO1-deficient mouse model generated by gene trap mutagenesis that mirrors the human phenotype remarkably well. As in patients, the most prominent signs and symptoms were cardiovascular and included bradycardia and cardiomyopathy. In addition, the mutant mice showed a marked worsening of arrhythmias during induction and reversal of anaesthesia. The detailed morphological and biochemical workup of murine hearts indicated that the myocardial damage was due to complex I deficiency and mitochondrial dysfunction. In contrast, neurological examination was largely normal in Mto1-deficient mice. A translational consequence of this mouse model may be to caution against anaesthesia-related cardiac arrhythmias which may be fatal in patients.
Background: Alzheimer's disease is a common debilitating dementia with known heritability, for which 20 late onset susceptibility loci have been identified, but more remain to be discovered. This study sought to identify new susceptibility genes, using an alternative gene-wide analytical approach which tests for patterns of association within genes, in the powerful genome-wide association dataset of the International Genomics of Alzheimer's Project Consortium, comprising over 7 m genotypes from 25,580 Alzheimer's cases and 48,466 controls.
Principal findings: In addition to earlier reported genes, we detected genome-wide significant loci on chromosomes 8 (TP53INP1, p = 1.4×10−6) and 14 (IGHV1-67 p = 7.9×10−8) which indexed novel susceptibility loci.
Significance: The additional genes identified in this study, have an array of functions previously implicated in Alzheimer's disease, including aspects of energy metabolism, protein degradation and the immune system and add further weight to these pathways as potential therapeutic targets in Alzheimer's disease.
Reintroductions of plant species are increasingly popular in conservation practice. Steppe grasslands contain many rare and endangered plant species that are potential objects for such reintroductions. Most reintroduction projects, however, can only target a restricted number of species, which raises the question of how species should be prioritised. Here, we present a method to select priority species for reintroduction based on species' characteristics that are widely used in conservation practice. We first determined the local species pool containing those vascular plant species that occurred both in our target region (Thuringia, Germany) and target habitat (steppe grasslands), yielding 369 species. With the help of an a priori filter that selected currently endangered species with limited distribution, 136 potential target species were determined. These potential target species had experienced stronger decline, had a narrower phytosociological amplitude and were more likely to be species of the Festuco-Brometea class and the Festucetalia valesiacae order than non-target species. Potential target species were then ranked by a points system based on ten conservation-relevant characteristics of the species from the categories "threat and protection status", "distribution and decline", and "habitat affiliation". In the ranking, six steppe grassland plant species (Astragalus exscapus, Bothriochloa ischaemum, Prunella laciniata, Pulsatilla pratensis subsp. nigricans, Scorzonera purpurea, and Seseli hippomarathrum) achieved the highest scores. An additional seven species not specifically characteristic for steppe grasslands also scored highly. A post hoc evaluation of these 13 highest scoring species based on additional conservation criteria left five species (Astragalus exscapus, Linum leonii, Orchis morio, Pulsatilla pratensis subsp. nigricans and Scorzonera purpurea) as species with highest priority for reintroductions and another five species as highly suitable for reintroductions. Associations between the ranking order and different ranking criteria revealed that a species’ threat and rarity in Thuringia and its protection status had the highest representation in the ranking, followed by threat in Germany, regional decline and habitat affiliation. In contrast, international threat and responsibility of Thuringia for its conservation had only low representation in the ranking, probably because these characteristics applied to only a few species. The ranking list gives a selection of species for reintroductions, which combined with additional information based on comprehensive local and floristic knowledge, allows the identification of the species with the highest priority. Our method can be transferred to other regions or habitat types.
Der diesjährige 9. Trockenrasen-Sonderteil von Tuexenia beginnt mit einem Bericht über die aktuellen Aktivitäten der European Dry Grassland Group (EDGG). Zunächst geben wir einen Überblick über die Entwicklung der Mitgliederzahl. Dann berichten wir vom letzten European Dry Grassland Meeting in Zamość (Polen, 2013) und vom letzten European Dry Grassland Field Workshop in Chakassien (Russland, 2013) und informieren über künftige Veranstaltungen der EDGG. Anschließend erläutern wir die Publikationsaktivitäten der EDGG. Im zweiten Teil des Editorials geben wir eine Einführung zu den fünf Artikeln des diesjährigen Trockenrasen-Sonderteils: Zwei davon beschäftigen sich mit der Syntaxonomie von Trockenrasen in Osteuropa: Der eine Artikel präsentiert erstmalig eine nach internationalen Nomenklaturregeln gültige Liste der Trockenrasengesellschaften Serbiens während der andere die Ergebnisse des zweiten EDGG-Field Workshop 2010 nach Podolien (Ukraine) vorstellt. Im dritten Artikel werden kryophytische Steppen in Südsibirien (Russland) analysiert. Der vierte Artikel analysiert in Böhmen (Tschechien) die bestimmenden Kräfte für Artenreichtum und Artenzusammensetzung der Trockenrasen. Der fünfte Artikel befasst sich mit der Auswahl von Wiederansiedlungsarten am Beispiel der Steppenrasen in Thüringen (Deutschland).
Heterogenous subtypes of breast cancer need to be analyzed separately. Pooling of datasets can provide reasonable sample sizes but dataset bias is an important concern. We assembled a combined dataset of 579 Affymetrix microarrays from triple negative breast cancer (TNBC) in Gene Expression Omnibus (GEO) series GSE31519. We developed a method for selecting comparable datasets and to control for the amount of dataset bias of individual probesets.