656 research outputs found

    Decentralized Cooperative Planning for Automated Vehicles with Continuous Monte Carlo Tree Search

    Full text link
    Urban traffic scenarios often require a high degree of cooperation between traffic participants to ensure safety and efficiency. Observing the behavior of others, humans infer whether or not others are cooperating. This work aims to extend the capabilities of automated vehicles, enabling them to cooperate implicitly in heterogeneous environments. Continuous actions allow for arbitrary trajectories and hence are applicable to a much wider class of problems than existing cooperative approaches with discrete action spaces. Based on cooperative modeling of other agents, Monte Carlo Tree Search (MCTS) in conjunction with Decoupled-UCT evaluates the action-values of each agent in a cooperative and decentralized way, respecting the interdependence of actions among traffic participants. The extension to continuous action spaces is addressed by incorporating novel MCTS-specific enhancements for efficient search space exploration. The proposed algorithm is evaluated under different scenarios, showing that the algorithm is able to achieve effective cooperative planning and generate solutions egocentric planning fails to identify

    Identification of developmental functions for Arabidopsis thaliana genes by a reverse genetics approach based on analysis of H3K27me3 distribution

    Get PDF
    Polycomb Group (PcG) protein mediated gene repression is essential for normal development in both plants and animals, as demonstrated by severe developmental defects resulting from their loss-of-function. PcG proteins convey repression of target genes by tri-methylation of lysine 27 of histone 3 (H3K27me3). Many H3K27me3 decorated genes encode developmental regulators in Arabidopsis thaliana and developmental functions are particularly overrepresented in tissue specific sub sets of H3K27me3 targets. This study identified 105 genes specifically expressed in the shoot apex and floral organs by transcriptional clustering analysis, which are particularly enriched for shoot developmental functions according to Gene Ontology analysis. As half of the genes in this group were not characterised in detail, these were screened for a role in shoot development by analysing loss-of-function mutants and selected can- didate gene overexpessor plants. Fourteen putative Development related PcG Targets in the Apex (DPAs) were identified. For five DPA putants developmental abnormalities were confirmedly associated with the respective loci. Among them were genes related to flowering time, leaf size and leaf shape regulation. dpa4 loss-of-function plants display enhanced leaf serrations and enlarged petals, while leaf margins of 35S::DPA4 plants are smooth. DPA4 encodes for a putative RAV (Related to ABI3/VP1) transcriptional repressor and is expressed in the lateral organ boundary region and in leaf sinuses. Total leaf area and cell numbers are not altered in dpa4 plants, suggesting that DPA4 regulates leaf margin outgrowth by inhibiting growth towards leaf serrations. DPA4 expression domains widely overlap with those of CUP-SHAPED COTYLEDON 2, known to regulate leaf margin shape. Genome-wide transcriptional profiling in dpa4 apices revealed 77 differentially expressed genes. An overrepresentation of auxin-response elements in the promoters of these otherwise poorly characterised genes indicates a role for DPA4 in auxin- mediated signalling. This is further supported by an auxin-influx carrier mutant-like phenotype observed for 35S::DPA4 plants displaying left-hand twisted rosette leaves. Taken together, the data confirm that DPA4, which was identified as a candidate by this reverse genetics screen, is a newly identified player in the signalling network controlling leaf serrations in Arabidopsis thaliana

    Meeting Summary of the 6th European Workshop on Plant Chromatin 2019 in Cologne, Germany

    Get PDF
    In June 2019, more than a hundred plant researchers met in Cologne, Germany, for the 6th European Workshop on Plant Chromatin (EWPC). This conference brought together a highly dynamic community of researchers with the common aim to understand how chromatin organization controls gene expression, development, and plant responses to the environment. New evidence showing how epigenetic states are set, perpetuated, and inherited were presented, and novel data related to the three-dimensional organization of chromatin within the nucleus were discussed. At the level of the nucleosome, its composition by different histone variants and their specialized histone deposition complexes were addressed as well as the mechanisms involved in histone post-translational modifications and their role in gene expression. The keynote lecture on plant DNA methylation by Julie Law (SALK Institute) and the tribute session to Lars Hennig, honoring the memory of one of the founders of the EWPC who contributed to promote the plant chromatin and epigenetic field in Europe, added a very special note to this gathering. In this perspective article we summarize some of the most outstanding data and advances on plant chromatin research presented at this workshop

    What Fertilizers for Crop Rotation?

    Get PDF
    No one can predict the exact response of a single crop in a given year or at a specific location. Price relationships change, too. What should you do in a cropping sequence? Here are some clues from our long-term research

    Controlled human malaria infection to evaluate the efficacy of the asexual blood-stage malaria vaccine candidate GMZ2- CAF01

    Get PDF
    Malaria is a life-threatening protozoan parasite disease transmitted by mosquitoes, which infected approximately 228 million people worldwide in 2018, of which 405,000 people died. Even with existing control methods, such as mosquito nets and insecticides, as well as various therapies, resistances to these methods are increasing as well. It would, therefore, be desirable if a vaccine against this dis- ease were developed to tackle this problem sustainably. So far, there is only one vaccine that has been positively evaluated by scientists and is being tested in larger implementation studies in Africa, called RTS,S. Nevertheless, the e↵ective- ness of this pre-erythrocytic vaccine is not yet satisfactory, which is why research continues to be carried out on various alternatives. One of these projects is the blood-stage vaccine candidate Recombinant Lactococcus lactis Hybrid GLURP and MSP3 (GMZ2), which was tested in this study. Previous studies in both animals and humans showed that this candidate proved to be well-tolerated and produced a convincing antibody profile. Since these studies used aluminum hydroxide as the adjuvant, a further boost was expected by using the novel Cationic Adjuvant Formulation 01 (CAF01), which could further increase the immunity and, ulti- mately, the e↵ectiveness. GMZ2CAF01 tries to induce the semi-immunity that occurs in people who permanently live in endemic malaria regions, thereby con- trolling the multiplication of the pathogen in the blood. Based on a Controlled Human Malaria Infection (CHMI), this study tried to test the e cacy of the vac- cine candidate GMZ2CAF01, as well as to make a statement about the safety of the methodology of the CHMI. 50 healthy Gabonese male participants with life- long exposure to malaria were randomly placed into five groups: Group A received a rabies vaccine as placebo, Group B received 100 μg GMZ2-Alhydrogel, Group C received 30 μg GMZ2-CAF01, and Group D and E received 100 μg GMZ2-CAF01. All but Group E received subsequent CHMI via direct venous inoculation (DVI) with 3,200 P. falciparum sporozoites (PfSPZ). This methodology was previously developed at the Institute of Tropical Medicine, University of Tu ̈bingen, to guaran- tee a 100% infection with malaria. Subsequently, the subjects were questioned and observed for any adverse event (AE)s of the CHMI, and regular blood tests were carried out to determine parasitemia through microscopy, which was confirmed by means of Polymerase Chain Reaction (PCR). As soon as either a parasitemia of over 1,000 or a lower parasitemia accompanied by malaria symptoms was de- tected, the volunteers were treated with artemether-lumefantrine. The remaining participants were treated with artemether-lumefantrine after day 35 post CHMI. It could be confirmed that CHMI proved to be safe and that there were no serious adverse events (SAE)s that occurred. However, almost all subjects experienced at least one AE, of which Grade 1 headache was the most common AE. There was no significant di↵erence between the groups in terms of both the occurrence of malaria and the time until malaria occurred. In conclusion, it can be said that the GMZ2CAF01 vaccine candidate did not induce the semi-immunity that was desired. However, CHMI proved to be a safe and promising method for studying malaria immunization and therapies

    Leute machen Kleider: Ein Arbeitskampf indonesischer Textilarbeiterinnen zwischen Selbstorganisation und gewerkschaftlicher Organisierung

    Get PDF
    Im Rahmen dieser empirischen Studie wird ein mehrjähriger Arbeitskonflikt von indonesischen Textilarbeiterinnen im Norden Jakartas analysiert. Von der Blockade der Fabrik über die Aneignung dieser bis hin zur selbstverwalteten Produktion werden die unterschiedlichen Perspektiven der beteiligten Akteur*innen herausgearbeitet. Diskutiert wird dies entlang eines feministischen Arbeitskampfbegriffs, der am Fall theoretisch herausgearbeitet wurde. In den Auseinandersetzungen und Aushandlungen darum zeigt sich, welche Widersprüche und Brüche in der Perspektive auf den Arbeitskampf zwischen den gewerkschaftlichen Vorstellungen und den Vorstellungen der Arbeiterinnen im Rahmen ihrer Selbstorganisation hervortreten. Wie sich die unterschiedlichen Strategien und Vorstellungen gegenseitig bedingen, befruchten oder gar widersprechen, ist demnach wichtiger Bestandteil der Analyse und trägt zur Beantwortung der zentralen Forschungsfrage bei: "Wie denken, verhandeln und gestalten die indonesischen Textilarbeiterinnen den Arbeitskampf vor dem Hintergrund ihrer geschlechtsspezifischen sozialen Rollen als Frauen und damit verbundenen Arbeits- und Lebensrealitäten?" Um dies jedoch entlang der Geschlechterverhältnisse zu verstehen, verschiedene Facetten darin zu erkennen und letztlich deuten zu können, bedarf es eines feministisch erweiterten Arbeitskampfbegriffs, da der verkürzte androzentrische Begriff von Arbeitskampf in erster Linie als Auseinandersetzung zwischen Kapital und Arbeit konzipiert ist. Damit werden andere gesellschaftliche Ungleichheitslagen und Herrschaftsverhältnisse oft außer Acht gelassen und die verschiedenen Arbeits- und Lebensrealitäten von Frauen, trans*- oder nicht-binären Personen finden darin kaum Beachtung. In der Diskussion um einen feministischen Arbeitskampfbegriff wird dieser in seine Wortbestandteile "Arbeit" und "Kampf" geteilt. Diese werden dann aus einer feministischen Perspektive diskutiert, bevor der Begriff Arbeitskampf in der Zusammenführung dann konzeptionell neu gefasst wird

    Leute machen Kleider: Ein Arbeitskampf indonesischer Textilarbeiterinnen zwischen Selbstorganisation und gewerkschaftlicher Organisierung

    Get PDF
    This empirical study analyses a labour conflict of Indonesian textile workers in the north of Jakarta that lasted several years. From the blockade of the factory to the appropriation of the factory to self-managed production, the different perspectives of the actors involved are elaborated. This is discussed along the lines of a feminist concept of labour struggle, which was theoretically elaborated in the case

    A Cold Nearby Cloud Inside the Local Bubble

    Get PDF
    The high-latitude Galactic H I cloud toward the extragalactic radio source 3C 225 is characterized by very narrow 21 cm emission and absorption indicative of a very low H I spin temperature of about 20 K. Through high-resolution optical spectroscopy, we report the detection of strong, very narrow Na I absorption corresponding to this cloud toward a number of nearby stars. Assuming that the turbulent H I and Na I motions are similar, we derive a cloud temperature of 20 (+6, -8) K (in complete agreement with the 21 cm results) and a line-of-sight turbulent velocity of 0.37+/-0.08 km/s from a comparison of the H I and Na I absorption linewidths. We also place a firm upper limit of 45 pc on the distance of the cloud, which situates it well inside the Local Bubble in this direction and makes it the nearest-known cold diffuse cloud discovered to date.Comment: 11 pages, 3 figures, accepted for publication in ApJ Letter
    corecore