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Photosystem II (PSII) catalyzes the unique reaction of light-dependent water oxidation and subsequent reduction of plastoquinone at the beginning of the photosynthetic electron transport chain. The mature complex consists of at least 20 protein-subunits and over 80 cofactors. Further proteins are required for biogenesis and repair of PSII. Most of these proteins interact specifically with assembly intermediates during defined steps in PSII assembly. This review shall emphasize the function of the two factors Psb27 and Psb28 during the biogenesis and repair of PSII in cyanobacteria and give an impression of their potential biochemical, structural and physiological properties in plants considering the fact that they both have homologues in all oxygenic photosynthetic organisms. We hypothesize that Psb28 may have retained its function in higher plants while the two Psb27 forms bind differently to PSII intermediates depending on PSII core phosphorylation state.
The papers here collected are divided in an English and an Italian section, to facilitate the reader who is confident, or prefers, only one of these languages. In both sections, Critical Theory is addressed in a twofold way: as regards its origins in the so-called School of Frankfurt and as concerns its further and contemporary developments, from an interdisciplinary perspective.
The decay properties of the Pygmy Dipole Resonance (PDR) have been investigated in the semi-magic N=82 nucleus 140Ce using a novel combination of nuclear resonance fluorescence and γ–γ coincidence techniques. Branching ratios for transitions to low-lying excited states are determined in a direct and model-independent way both for individual excited states and for excitation energy intervals. Comparison of the experimental results to microscopic calculations in the quasi-particle phonon model exhibits an excellent agreement, supporting the observation that the Pygmy Dipole Resonance couples to the ground state as well as to low-lying excited states. A 10% mixing of the PDR and the [21+ x PDR] is extracted.
The article aims to sharpen the neo-republican contribution to international political thought by challenging Pettit’s view that only representative states may raise a valid claim to non-domination in their external relations. The argument proceeds in two steps: First I show that, conceptually speaking, the domination of states, whether representative or not, implies dominating the collective people at least in its fundamental, constitutive power. Secondly, the domination of states – and thus of their peoples – cannot be justified normatively in the name of promoting individual non-domination because such a compensatory rationale misconceives the notion of domination in terms of a discrete exercise of power instead of as an ongoing power relation. This speaks in favour of a more inclusive law of peoples than Pettit (just as his liberal counterpart Rawls) envisages: In order to accommodate the claim of collective peoples to non-domination it has to recognize every state as a member of the international order.
Like most jurisdictions, Australia is managing a broad range of invasive alien species. Here, we provide the first holistic quantification of how much invasive species impact Australia’s economy, and how much Australia spends on their management. In the 01–02 financial year (June to July), the combined estimated cost (economic losses and control) of invasive species was $9.8 billion, rising to $13.6 billion in the 11–12 financial year. Approximately $726 million of grants funded through the Commonwealth of Australia (i.e. federal funding) was spent on invasive species management and research between 1996 to 2013. In 01–02, total national expenditure on invasive species was $2.31 billion, rising to $3.77 billion in 11–12. Agriculture accounted for more than 90% of the total cost. For 01–02 and 11–12, these expenditure figures equate to $123 and $197 per person per year respectively, as well as 0.32 and 0.29% of GDP respectively. All values provided here are most likely to be underestimates of the real values due to the significant constraints of the data obtainable. Invasive species are clearly a significant economic burden in Australia. Given the extent of the issue of invasive species globally, there is a clear need for better quantifications of both economic loss and expenditure in more jurisdictions, as well as in Australia.
The growth of freshly formed aerosol particles can be the bottleneck in their survival to cloud condensation nuclei. It is therefore crucial to understand how particles grow in the atmosphere. Insufficient experimental data has impeded a profound understanding of nano-particle growth under atmospheric conditions. Here we study nano-particle growth in the CLOUD (Cosmics Leaving OUtdoors Droplets) chamber, starting from the formation of molecular clusters. We present measured growth rates at sub-3 nm sizes with different atmospherically relevant concentrations of sulphuric acid, water, ammonia and dimethylamine. We find that atmospheric ions and small acid-base clusters, which are not generally accounted for in the measurement of sulphuric acid vapour, can participate in the growth process, leading to enhanced growth rates. The availability of compounds capable of stabilizing sulphuric acid clusters governs the magnitude of these effects and thus the exact growth mechanism. We bring these observations into a coherent framework and discuss their significance in the atmosphere.
DESPITE A RECENT SLIGHT RECOVERY FROM CRISIS LOW LEVELS, STOCK MARKET PARTICIPATION IN GERMANY IS STILL AT ONLY 14% OF ADULT POPULATION. PREVIOUS RESEARCH SHOWED THAT TRADITIONAL PERSONAL ADVICE – DUE TO HIGH COSTS AND MISALIGNED INCENTIVES – CAN HARDLY ALLEVIATE PRIVATE INVESTORS' INVESTMENT MISTAKES, OF WHICH STOCK MARKET NON-PARTICIPATION IS ONE. ROBOADVICE IS A "HOT TOPIC" IN REGULATORY AND INDUSTRY DISCUSSIONS. THE RESULTS OF THIS STUDY SHOW EMPIRICAL EVIDENCE THAT INVITATIONS TO ROBO-ADVICE INCREASE STOCK MARKET PARTICIPATION.
Background: Lectures remain an important teaching method to present and structure knowledge to many students concurrently. Adequate measures are necessary to maintain the quality of the lectures. The aim of this study was to determine the impact on the lecture quality using written structured feedback and to compare the ratings of surgical lectures between students and surgical peers.
Methods: Prospective analysis of two consecutive surgical lecture series for undergraduate students at Goethe-University Medical School was performed before and after evaluation of the lecturers via independent written feedback from trained undergraduate students and surgeons. The 22-item feedback instrument covered three areas of performance: content, visualization, and delivery. Additional suggestions for improvement were provided from
both students and surgical peers who anonymously attended the lectures. The lecturers, experienced surgeons, as well as the student and peer raters were blinded in terms of the aim and content of the study. Their response to the feedback was collected using a web-based 13-item questionnaire. The Kendall’s-W coefficient was computed to calculate inter-rater reliability (IRR). Differences between ratings before and after feedback were analyzed using Student’s t-test for dependent samples. The Kolmogorov-Smirnov-test was used for independent samples.
Results: A total of 22 lectures from a possible 32 given by 13 lecturers were included and analyzed by at least three surgeons and two students. There were significant improvements in overall score as well as in the details of 9 of the 13 items were found. The average inter-rater reliability was 0.71. There were no differences in the ratings as a function of the rater’s level of expertise (peers vs. students). We found that 13/23 lecturers (56.5%) answered the questionnaire, and 92% strongly agreed that the written feedback was useful. 76.9% of the lecturers revised their lecture based on the written feedback requiring on average 112.5 min (range from 20 to 300 min).
Conclusions: Overall, this study indicates that structured written feedback provided by trained peers and students that is subsequently discussed by the lecturers concerned is a highly effective and efficient method to improve aspects of lecturing. We anticipate that structured written feedback by trained students that is discussed by the lecturers concerned will improve lecturing.
Keywords: Lecture, Feedback, Surgery, Peer-feedback, Evaluation, Undergraduate training
The effects of acute physical exercise on memory, peripheral BDNF, and cortisol in young adults
(2016)
In animals, physical activity has been shown to induce functional and structural changes especially in the hippocampus and to improve memory, probably by upregulating the release of neurotrophic factors. In humans, results on the effect of acute exercise on memory are inconsistent so far. Therefore, the aim of the present study was to assess the effects of a single bout of physical exercise on memory consolidation and the underlying neuroendocrinological mechanisms in young adults. Participants encoded a list of German-Polish vocabulary before exercising for 30 minutes with either high intensity or low intensity or before a relaxing phase. Retention of the vocabulary was assessed 20 minutes after the intervention as well as 24 hours later. Serum BDNF and salivary cortisol were measured at baseline, after learning, and after the intervention. The high-intensity exercise group showed an increase in BDNF and cortisol after exercising compared to baseline. Exercise after learning did not enhance the absolute number of recalled words. Participants of the high-intensity exercise group, however, forgot less vocabulary than the relaxing group 24 hours after learning. There was no robust relationship between memory scores and the increase in BDNF and cortisol, respectively, suggesting that further parameters have to be taken into account to explain the effects of exercise on memory in humans.
Within the family of NADPH oxidases, NOX4 is unique as it is predominantly localized in the endoplasmic reticulum, has constitutive activity, and generates hydrogen peroxide (H2O2). We hypothesize that these features are consequences of a so far unidentified NOX4-interacting protein. Two-dimensional blue native (BN) electrophorese combined with SDS-PAGE yielded NOX4 to reside in macromolecular complexes. Interacting proteins were screened by quantitative SILAC (stable isotope labeling of amino acids in cell culture) co-immunoprecipitation (Co-IP) in HEK293 cells stably overexpressing NOX4. By this technique, several interacting proteins were identified with calnexin showing the most robust interaction. Calnexin also resided in NOX4-containing complexes as demonstrated by complexome profiling from BN-PAGE. The calnexin NOX4 interaction could be confirmed by reverse Co-IP and proximity ligation assay, whereas NOX1, NOX2, or NOX5 did not interact with calnexin. Calnexin deficiency as studied in mouse embryonic fibroblasts from calnexin(-/-)mice or in response to calnexin shRNA reduced cellular NOX4 protein expression and reactive oxygen species formation. Our results suggest that endogenous NOX4 forms macromolecular complexes with calnexin, which are needed for the proper maturation, processing, and function of NOX4 in the endoplasmic reticulum.
The Fire Modeling Intercomparison Project (FireMIP), phase 1: experimental and analytical protocols
(2016)
The important role of fire in regulating vegetation community composition and contributions to emissions of greenhouse gases and aerosols make it a critical component of dynamic global vegetation models and Earth system models. Over two decades of development, a wide variety of model structures and mechanisms have been designed and incorporated into global fire models, which have been linked to different vegetation models. However, there has not yet been a systematic examination of how these different strategies contribute to model performance. Here we describe the structure of the first phase of the Fire Model Intercomparison Project (FireMIP), which for the first time seeks to systematically compare a number of models. By combining a standardized set of input data and model experiments with a rigorous comparison of model outputs to each other and to observations, we will improve the understanding of what drives vegetation fire, how it can best be simulated, and what new or improved observational data could allow better constraints on model behavior. Here we introduce the fire models used in the first phase of FireMIP, the simulation protocols applied, and the benchmarking system used to evaluate the models. The works published in this journal are distributed under the Creative Commons Attribution 3.0 License. This license does not affect the Crown copy-right work, which is re-usable under the Open Government Licence (OGL). The Creative Commons Attribution 3.0 License and the OGL are interoperable and do not conflict with, reduce, or limit each other.
Background: The systematic analysis of a large number of comparable plant trait data can support investigations into phylogenetics and ecological adaptation, with broad applications in evolutionary biology, agriculture, conservation, and the functioning of ecosystems. Floras, i.e., books collecting the information on all known plant species found within a region, are a potentially rich source of such plant trait data. Floras describe plant traits with a focus on morphology and other traits relevant for species identification in addition to other characteristics of plant species, such as ecological affinities, distribution, economic value, health applications, traditional uses, and so on. However, a key limitation in systematically analyzing information in Floras is the lack of a standardized vocabulary for the described traits as well as the difficulties in extracting structured information from free text.
Results: We have developed the Flora Phenotype Ontology (FLOPO), an ontology for describing traits of plant species found in Floras. We used the Plant Ontology (PO) and the Phenotype And Trait Ontology (PATO) to extract entity-quality relationships from digitized taxon descriptions in Floras, and used a formal ontological approach based on phenotype description patterns and automated reasoning to generate the FLOPO. The resulting ontology consists of 25,407 classes and is based on the PO and PATO. The classified ontology closely follows the structure of Plant Ontology in that the primary axis of classification is the observed plant anatomical structure, and more specific traits are then classified based on parthood and subclass relations between anatomical structures as well as subclass relations between phenotypic qualities.
Conclusions: The FLOPO is primarily intended as a framework based on which plant traits can be integrated computationally across all species and higher taxa of flowering plants. Importantly, it is not intended to replace established vocabularies or ontologies, but rather serve as an overarching framework based on which different application- and domain-specific ontologies, thesauri and vocabularies of phenotypes observed in flowering plants can be integrated.
The German postgraduate degree program in ecotoxicology (SETAC GLB and GDCh) : a success story
(2016)
This article gives a comprehensive overview on the strategy, the development and the progress of the German postgraduate degree program in ecotoxicology (SETAC GLB and GDCh). The program soon prompted positive results: more than 10 years now the courses had an average enrolment rate of 90 %, and employment-seeking graduates from the first courses mostly succeeded in quickly finding employment relevant to their training. With over 450 students enrolled to date, the degree program contributes significantly to the field of Environmental Chemistry and Ecotoxicology.
The essay, originally written in German as an introduction to a volume of collected papers, shows the influence of the Historical School of Law on legal, historical and social sciences in Germany throughout the 19th and even 20th centuries – a time span running contrary to the dominate view that sees the end of the School in the middle of the 19th century. In my view the School constitutes not only a method for developing norms of private law out of the historical materials of Roman and German-Germanic laws, but is based on a wider conception of culture, law and history that is also connected to the political positions of that time. In Savigny’s founding pamphlet, "The vocation of our time ...", two major theoretical topics for this long-lasting influence can be found: The Romantic one, which views law as a part of culture and parallel to language and custom, based on the "spirit of the people", and, on the other side, the rationality of the European tradition of Roman law, which was developed and administered by jurists. These two basic points, in part standing in contradiction to one another, form a fertile tension that provides an impulse to the intellectual discussions and new movements in jurisprudence and history analysed in the text. Realism, founded in the connection of both sciences to political and social life, builds a kind of "basso continuo" and acts as a counterbalance to the former two. And it is in this context that the works of Jacob Grimm, Puchta and Beseler, Heinrich Brunner, Georg von Below and others are analysed, in particular the works of Otto von Gierke and Max Weber. Finally, evidence is furnished that a new image of the medieval period, and its impact on law, as a centre of Western identity was outlined in the 20th century by authors like Ernst Kantorowicz, Fritz Kern, Otto Brunner and, last but not least, by Harold J. Berman (walking in the footsteps of Eugen Rosenstock- Huessy), all of whom were situated in different ways within the tradition of the broader, cultural-based Romantic view.
The concept of freedom as non-domination that is associated with neo-republican theory provides a guiding ideal in the global, not just the domestic arena, and does so even on the assumption that there will continue to be many distinct states. It argues for a world in which states do not dominate members of their own people and, considered as a corporate body, no people is dominated by other agencies: not by other states and not, for example, by any international agency or multi-national corporation. This ideal is not only attractive in the abstract, it also supports a concrete range of sensible, if often radical international policies.
Epigenetic marks critically control gene expression and thus the cellular activity state. The functions of many epigenetic modifiers in the vascular system have not yet been studied. We screened for histone modifiers in endothelial cells and observed a fairly high expression of the histone plant homeodomain finger protein 8 (PHF8). Given its high expression, we hypothesize that this histone demethylase is important for endothelial cell function. Overexpression of PHF8 catalyzed the removal of methyl-groups from histone 3 lysine 9 (H3K9) and H4K20, whereas knockdown of the enzyme increased H3K9 methylation. Knockdown of PHF8 by RNAi also attenuated endothelial proliferation and survival. As a functional readout endothelial migration and tube formation was studied. PHF8 siRNA attenuated the capacity for migration and developing of capillary-like structures. Given the impact of PHF8 on cell cycle genes, endothelial E2F transcription factors were screened, which led to the identification of the gene repressor E2F4 to be controlled by PHF8. Importantly, PHF8 maintains E2F4 but not E2F1 expression in endothelial cells. Consistently, chromatin immunoprecipitation revealed that PHF8 reduces the H3K9me2 level at the E2F4 transcriptional start site, demonstrating a direct function of PHF8 in endothelial E2F4 gene regulation. Conclusion: PHF8 by controlling E2F4 expression maintains endothelial function.
The Hydrogen Dependent Carbon dioxide Reductase (HDCR) from Acetobacterium woodii presents a promising solution to the issue of H2 storage by reversibly coupling H2 oxidation to CO2 reduction. We here report on the electrocatalytic properties of the hydrogenase (Hase) module in the intact complex, including (an)aerobic oxidation, CO inhibition and the first systematic analysis of the catalytic bias (CB) of a Hase. CB depends on pH, regardless of the H2 concentration, despite a higher affinity for H2 than other FeFe-Hases. Remarkably, CO inhibition is fully reversible under all oxidation states of the active site, making HDCR the first "syngas-friendly" FeFe-Hase.
Ambrosia artemisiifolia is an invasive annual herb infamous for the high allergenicity of its pollen, which is related to increasing medical costs. Additionally, it can cause serious yield losses as agricultural weed. Common ragweed seeds accumulate in the soil and can remain therein viable for decades, which poses a problem for the sustainable management of these populations. A long term management should thus target a reduction of the soil seed bank. We observed the influence of four different mowing regimes on the ragweed soil seed bank at six roadside populations in eastern Austria. The mowing regimes were based on methods from common roadside management practice and specifically adapted to reduce seed production. After three years of application, the soil seed bank was indeed reduced by 45 to 80 percent through three of the four mowing regimes tested. Therefore, we suggest that the best mowing regime for the most effective reduction of the size of the soil seed bank is the one consisting of one cut just after the beginning of female flowering (around the 3rd week of August in Eastern Central Europe), followed by a second cut 2–3 weeks later.
Bilberry (Vaccinium myrtillus L.) is a dwarf shrub with high ecological relevance as habitat and as a food source for many animals in mountain forests of central Europe. This species benefits from conifer forests and declines with an increase of broadleaved tree species in the canopy. The ongoing large-scale conversion from conifer to broadleaved forests may significantly alter the ground vegetation, especially the dominance of a key species such as bilberry. We used morphological indicators to investigate the vitality of bilberry. The first objective was to determine whether the vitality of bilberry is negatively impacted by increasing the proportion of beech (Fagus sylvatica L.) in Norway spruce (Picea abies Karst.) forests. The vitality of bilberry was measured by its cover, height, biomass, shoot length and basal diameter. The second objective was to determine whether these changes in bilberry vitality were related to light, canopy cover, soil pH, organic layer mass and tree species. The data was collected from three study areas in the southern and central Black Forest. The bedrock consisted of gneiss and granite whereas the stands were either: pure beech, a mixture of beech and spruce or pure spruce. The stands were located adjacent to each other. On all three areas a higher vitality of bilberry was observed under spruce compared to beech. Mixed effect models show that the occurrence of spruce is the most important variable explaining the increase in bilberry biomass. Light had a small positive effect, whereas soil properties had negligible effects and were site specific. These results are a strong indication of the negative influence that beech has on bilberry in conifer dominated forests. This has to be taken into consideration when developing silvicultural approaches and should be a consideration when making plans for the preservation of habitat for species like capercaillie (Tetrao urogallus L.). This is even more important today because the recent trend in central European forestry is to increase the proportion of beech.
One hallmark of MLL-r leukemia is the highly specific gene expression signature indicative for commonly deregulated target genes. An usual read-out for this transcriptional deregulation is the HOXA gene cluster, where upregulated HOXA genes are detected in MLL-r AML and ALL patients. In case of t(4;11) leukemia, this simple picture becomes challenged, because these patients separate into HOXAhi- and HOXAlo-patients. HOXAlo-patients showed a reduced HOXA gene transcription, but instead overexpressed the homeobox gene IRX1. This transcriptional pattern was associated with a higher relapse rate and worse outcome. Here, we demonstrate that IRX1 binds to the MLL-AF4 complex at target gene promotors and counteract its promotor activating function. In addition, IRX1 induces transcription of HOXB4 and EGR family members. HOXB4 is usually a downstream target of c-KIT, WNT and TPO signaling pathways and necessary for maintaining and expanding in hematopoietic stem cells. EGR proteins control a p21-dependent quiescence program for hematopoietic stem cells. Both IRX1-dependend actions may help t(4;11) leukemia cells to establish a stem cell compartment. We also demonstrate that HDACi administration is functionally interfering with IRX1 and MLL-AF4, a finding which could help to improve new treatment options for t(4;11) patients.